ata: libata-scsi: fix ata_dsm_trim_pages() kernel-docgrafted

make htmldocs fails with:

  Documentation/driver-api/libata:604: ./drivers/ata/libata-scsi.c:2301:
  ERROR: Unexpected indentation. [docutils]

The Return: section of ata_dsm_trim_pages() ends its first sentence with
a colon and continues with an indented bullet list. reStructuredText
requires a blank line before an indented block, so docutils chokes on
the list.

Simply adding the missing blank line does not work either: Return: is a
kernel-doc "special section", which is terminated by the first blank
line, so the bullet list would end up in the Description section,
detached from the sentence introducing it.

Spell the two bounds out as prose instead, so that the Return: section
stays self-contained. Documentation-only change.

Fixes: e64e6b5dc867 ("ata: libata-scsi: scale DSM TRIM payload by MAX PAGES PER DSM COMMAND")
Reported-by: Thomas Huth <thuth@redhat.com>
Closes: https://lore.kernel.org/linux-ide/b0a0b8e8-cc4f-4c7b-8bc5-fee0712d405a@redhat.com/
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Link: https://lore.kernel.org/r/20260916130031.29990-2-cassel@kernel.org
Signed-off-by: Niklas Cassel <cassel@kernel.org>

36 files changed, 19714 insertions, 0 deletions

diff --git a/drivers/ntb/Kconfig b/drivers/ntb/Kconfig
new file mode 100644
index 000000000..df16c755b
--- /dev/null
+++ b/drivers/ntb/Kconfig
@@ -0,0 +1,40 @@
+# SPDX-License-Identifier: GPL-2.0-only
+menuconfig NTB
+	tristate "Non-Transparent Bridge support"
+	depends on PCI
+	help
+	 The PCI-E Non-transparent bridge hardware is a point-to-point PCI-E bus
+	 connecting 2 systems.  When configured, writes to the device's PCI
+	 mapped memory will be mirrored to a buffer on the remote system.  The
+	 ntb Linux driver uses this point-to-point communication as a method to
+	 transfer data from one system to the other.
+
+	 If unsure, say N.
+
+if NTB
+
+config NTB_MSI
+	bool "MSI Interrupt Support"
+	depends on PCI_MSI
+	help
+	 Support using MSI interrupt forwarding instead of (or in addition to)
+	 hardware doorbells. MSI interrupts typically offer lower latency
+	 than doorbells and more MSI interrupts can be made available to
+	 clients. However this requires an extra memory window and support
+	 in the hardware driver for creating the MSI interrupts.
+
+	 If unsure, say N.
+source "drivers/ntb/hw/Kconfig"
+
+source "drivers/ntb/test/Kconfig"
+
+config NTB_TRANSPORT
+	tristate "NTB Transport Client"
+	help
+	 This is a transport driver that enables connected systems to exchange
+	 messages over the ntb hardware.  The transport exposes a queue pair api
+	 to client drivers.
+
+	 If unsure, say N.
+
+endif # NTB
diff --git a/drivers/ntb/Makefile b/drivers/ntb/Makefile
new file mode 100644
index 000000000..3a6fa181f
--- /dev/null
+++ b/drivers/ntb/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_NTB) += ntb.o hw/ test/
+obj-$(CONFIG_NTB_TRANSPORT) += ntb_transport.o
+
+ntb-y			:= core.o
+ntb-$(CONFIG_NTB_MSI)	+= msi.o
diff --git a/drivers/ntb/core.c b/drivers/ntb/core.c
new file mode 100644
index 000000000..ed6f4adc6
--- /dev/null
+++ b/drivers/ntb/core.c
@@ -0,0 +1,317 @@
+/*
+ * This file is provided under a dual BSD/GPLv2 license.  When using or
+ *   redistributing this file, you may do so under either license.
+ *
+ *   GPL LICENSE SUMMARY
+ *
+ *   Copyright (C) 2015 EMC Corporation. All Rights Reserved.
+ *   Copyright (C) 2016 T-Platforms. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of version 2 of the GNU General Public License as
+ *   published by the Free Software Foundation.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *   General Public License for more details.
+ *
+ *   BSD LICENSE
+ *
+ *   Copyright (C) 2015 EMC Corporation. All Rights Reserved.
+ *   Copyright (C) 2016 T-Platforms. All Rights Reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copy
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * PCIe NTB Linux driver
+ *
+ * Contact Information:
+ * Allen Hubbe <Allen.Hubbe@emc.com>
+ */
+
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#include <linux/ntb.h>
+#include <linux/pci.h>
+
+#define DRIVER_NAME			"ntb"
+#define DRIVER_DESCRIPTION		"PCIe NTB Driver Framework"
+
+#define DRIVER_VERSION			"1.0"
+#define DRIVER_RELDATE			"24 March 2015"
+#define DRIVER_AUTHOR			"Allen Hubbe <Allen.Hubbe@emc.com>"
+
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_VERSION(DRIVER_VERSION);
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESCRIPTION);
+
+static const struct bus_type ntb_bus;
+static void ntb_dev_release(struct device *dev);
+
+int __ntb_register_client(struct ntb_client *client, struct module *mod,
+			  const char *mod_name)
+{
+	if (!client)
+		return -EINVAL;
+	if (!ntb_client_ops_is_valid(&client->ops))
+		return -EINVAL;
+
+	memset(&client->drv, 0, sizeof(client->drv));
+	client->drv.bus = &ntb_bus;
+	client->drv.name = mod_name;
+	client->drv.owner = mod;
+
+	return driver_register(&client->drv);
+}
+EXPORT_SYMBOL(__ntb_register_client);
+
+void ntb_unregister_client(struct ntb_client *client)
+{
+	driver_unregister(&client->drv);
+}
+EXPORT_SYMBOL(ntb_unregister_client);
+
+int ntb_register_device(struct ntb_dev *ntb)
+{
+	int ret;
+
+	if (!ntb)
+		return -EINVAL;
+	if (!ntb->pdev)
+		return -EINVAL;
+	if (!ntb->ops)
+		return -EINVAL;
+	if (!ntb_dev_ops_is_valid(ntb->ops))
+		return -EINVAL;
+
+	init_completion(&ntb->released);
+
+	ntb->dev.bus = &ntb_bus;
+	ntb->dev.parent = &ntb->pdev->dev;
+	ntb->dev.release = ntb_dev_release;
+	dev_set_name(&ntb->dev, "%s", pci_name(ntb->pdev));
+
+	ntb->ctx = NULL;
+	ntb->ctx_ops = NULL;
+	spin_lock_init(&ntb->ctx_lock);
+
+	ret = device_register(&ntb->dev);
+	if (ret)
+		put_device(&ntb->dev);
+
+	return ret;
+}
+EXPORT_SYMBOL(ntb_register_device);
+
+void ntb_unregister_device(struct ntb_dev *ntb)
+{
+	device_unregister(&ntb->dev);
+	wait_for_completion(&ntb->released);
+}
+EXPORT_SYMBOL(ntb_unregister_device);
+
+int ntb_set_ctx(struct ntb_dev *ntb, void *ctx,
+		const struct ntb_ctx_ops *ctx_ops)
+{
+	unsigned long irqflags;
+
+	if (!ntb_ctx_ops_is_valid(ctx_ops))
+		return -EINVAL;
+	if (ntb->ctx_ops)
+		return -EINVAL;
+
+	spin_lock_irqsave(&ntb->ctx_lock, irqflags);
+	{
+		ntb->ctx = ctx;
+		ntb->ctx_ops = ctx_ops;
+	}
+	spin_unlock_irqrestore(&ntb->ctx_lock, irqflags);
+
+	return 0;
+}
+EXPORT_SYMBOL(ntb_set_ctx);
+
+void ntb_clear_ctx(struct ntb_dev *ntb)
+{
+	unsigned long irqflags;
+
+	spin_lock_irqsave(&ntb->ctx_lock, irqflags);
+	{
+		ntb->ctx_ops = NULL;
+		ntb->ctx = NULL;
+	}
+	spin_unlock_irqrestore(&ntb->ctx_lock, irqflags);
+}
+EXPORT_SYMBOL(ntb_clear_ctx);
+
+void ntb_link_event(struct ntb_dev *ntb)
+{
+	unsigned long irqflags;
+
+	spin_lock_irqsave(&ntb->ctx_lock, irqflags);
+	{
+		if (ntb->ctx_ops && ntb->ctx_ops->link_event)
+			ntb->ctx_ops->link_event(ntb->ctx);
+	}
+	spin_unlock_irqrestore(&ntb->ctx_lock, irqflags);
+}
+EXPORT_SYMBOL(ntb_link_event);
+
+void ntb_db_event(struct ntb_dev *ntb, int vector)
+{
+	unsigned long irqflags;
+
+	spin_lock_irqsave(&ntb->ctx_lock, irqflags);
+	{
+		if (ntb->ctx_ops && ntb->ctx_ops->db_event)
+			ntb->ctx_ops->db_event(ntb->ctx, vector);
+	}
+	spin_unlock_irqrestore(&ntb->ctx_lock, irqflags);
+}
+EXPORT_SYMBOL(ntb_db_event);
+
+void ntb_msg_event(struct ntb_dev *ntb)
+{
+	unsigned long irqflags;
+
+	spin_lock_irqsave(&ntb->ctx_lock, irqflags);
+	{
+		if (ntb->ctx_ops && ntb->ctx_ops->msg_event)
+			ntb->ctx_ops->msg_event(ntb->ctx);
+	}
+	spin_unlock_irqrestore(&ntb->ctx_lock, irqflags);
+}
+EXPORT_SYMBOL(ntb_msg_event);
+
+int ntb_default_port_number(struct ntb_dev *ntb)
+{
+	switch (ntb->topo) {
+	case NTB_TOPO_PRI:
+	case NTB_TOPO_B2B_USD:
+		return NTB_PORT_PRI_USD;
+	case NTB_TOPO_SEC:
+	case NTB_TOPO_B2B_DSD:
+		return NTB_PORT_SEC_DSD;
+	default:
+		return 0;
+	}
+}
+EXPORT_SYMBOL(ntb_default_port_number);
+
+int ntb_default_peer_port_count(struct ntb_dev *ntb)
+{
+	return NTB_DEF_PEER_CNT;
+}
+EXPORT_SYMBOL(ntb_default_peer_port_count);
+
+int ntb_default_peer_port_number(struct ntb_dev *ntb, int pidx)
+{
+	if (pidx != NTB_DEF_PEER_IDX)
+		return -EINVAL;
+
+	switch (ntb->topo) {
+	case NTB_TOPO_PRI:
+	case NTB_TOPO_B2B_USD:
+		return NTB_PORT_SEC_DSD;
+	case NTB_TOPO_SEC:
+	case NTB_TOPO_B2B_DSD:
+		return NTB_PORT_PRI_USD;
+	default:
+		return 0;
+	}
+}
+EXPORT_SYMBOL(ntb_default_peer_port_number);
+
+int ntb_default_peer_port_idx(struct ntb_dev *ntb, int port)
+{
+	int peer_port = ntb_default_peer_port_number(ntb, NTB_DEF_PEER_IDX);
+
+	if (peer_port == -EINVAL || port != peer_port)
+		return -EINVAL;
+
+	return 0;
+}
+EXPORT_SYMBOL(ntb_default_peer_port_idx);
+
+static int ntb_probe(struct device *dev)
+{
+	struct ntb_dev *ntb;
+	struct ntb_client *client;
+	int rc;
+
+	get_device(dev);
+	ntb = dev_ntb(dev);
+	client = drv_ntb_client(dev->driver);
+
+	rc = client->ops.probe(client, ntb);
+	if (rc)
+		put_device(dev);
+
+	return rc;
+}
+
+static void ntb_remove(struct device *dev)
+{
+	struct ntb_dev *ntb;
+	struct ntb_client *client;
+
+	if (dev->driver) {
+		ntb = dev_ntb(dev);
+		client = drv_ntb_client(dev->driver);
+
+		client->ops.remove(client, ntb);
+		put_device(dev);
+	}
+}
+
+static void ntb_dev_release(struct device *dev)
+{
+	struct ntb_dev *ntb = dev_ntb(dev);
+
+	complete(&ntb->released);
+}
+
+static const struct bus_type ntb_bus = {
+	.name = "ntb",
+	.probe = ntb_probe,
+	.remove = ntb_remove,
+};
+
+static int __init ntb_driver_init(void)
+{
+	return bus_register(&ntb_bus);
+}
+module_init(ntb_driver_init);
+
+static void __exit ntb_driver_exit(void)
+{
+	bus_unregister(&ntb_bus);
+}
+module_exit(ntb_driver_exit);
diff --git a/drivers/ntb/hw/Kconfig b/drivers/ntb/hw/Kconfig
new file mode 100644
index 000000000..c325be526
--- /dev/null
+++ b/drivers/ntb/hw/Kconfig
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0-only
+source "drivers/ntb/hw/amd/Kconfig"
+source "drivers/ntb/hw/idt/Kconfig"
+source "drivers/ntb/hw/intel/Kconfig"
+source "drivers/ntb/hw/epf/Kconfig"
+source "drivers/ntb/hw/mscc/Kconfig"
diff --git a/drivers/ntb/hw/Makefile b/drivers/ntb/hw/Makefile
new file mode 100644
index 000000000..223ca592b
--- /dev/null
+++ b/drivers/ntb/hw/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_NTB_AMD)	+= amd/
+obj-$(CONFIG_NTB_IDT)	+= idt/
+obj-$(CONFIG_NTB_INTEL)	+= intel/
+obj-$(CONFIG_NTB_EPF)	+= epf/
+obj-$(CONFIG_NTB_SWITCHTEC) += mscc/
diff --git a/drivers/ntb/hw/amd/Kconfig b/drivers/ntb/hw/amd/Kconfig
new file mode 100644
index 000000000..dd9fb9e5c
--- /dev/null
+++ b/drivers/ntb/hw/amd/Kconfig
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config NTB_AMD
+	tristate "AMD Non-Transparent Bridge support"
+	depends on X86_64
+	help
+	 This driver supports AMD NTB on capable Zeppelin hardware.
+
+	 If unsure, say N.
diff --git a/drivers/ntb/hw/amd/Makefile b/drivers/ntb/hw/amd/Makefile
new file mode 100644
index 000000000..7c23b4a7f
--- /dev/null
+++ b/drivers/ntb/hw/amd/Makefile
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_NTB_AMD) += ntb_hw_amd.o
diff --git a/drivers/ntb/hw/amd/ntb_hw_amd.c b/drivers/ntb/hw/amd/ntb_hw_amd.c
new file mode 100644
index 000000000..36bee0d8a
--- /dev/null
+++ b/drivers/ntb/hw/amd/ntb_hw_amd.c
@@ -0,0 +1,1372 @@
+/*
+ * This file is provided under a dual BSD/GPLv2 license.  When using or
+ *   redistributing this file, you may do so under either license.
+ *
+ *   GPL LICENSE SUMMARY
+ *
+ *   Copyright (C) 2016 Advanced Micro Devices, Inc. All Rights Reserved.
+ *   Copyright (C) 2016 T-Platforms. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of version 2 of the GNU General Public License as
+ *   published by the Free Software Foundation.
+ *
+ *   BSD LICENSE
+ *
+ *   Copyright (C) 2016 Advanced Micro Devices, Inc. All Rights Reserved.
+ *   Copyright (C) 2016 T-Platforms. All Rights Reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copy
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of AMD Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * AMD PCIe NTB Linux driver
+ *
+ * Contact Information:
+ * Xiangliang Yu <Xiangliang.Yu@amd.com>
+ */
+
+#include <linux/debugfs.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/acpi.h>
+#include <linux/pci.h>
+#include <linux/random.h>
+#include <linux/slab.h>
+#include <linux/ntb.h>
+
+#include "ntb_hw_amd.h"
+
+#define NTB_NAME	"ntb_hw_amd"
+#define NTB_DESC	"AMD(R) PCI-E Non-Transparent Bridge Driver"
+#define NTB_VER		"1.0"
+
+MODULE_DESCRIPTION(NTB_DESC);
+MODULE_VERSION(NTB_VER);
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_AUTHOR("AMD Inc.");
+
+static const struct file_operations amd_ntb_debugfs_info;
+static struct dentry *debugfs_dir;
+
+static int ndev_mw_to_bar(struct amd_ntb_dev *ndev, int idx)
+{
+	if (idx < 0 || idx > ndev->mw_count)
+		return -EINVAL;
+
+	return ndev->dev_data->mw_idx << idx;
+}
+
+static int amd_ntb_mw_count(struct ntb_dev *ntb, int pidx)
+{
+	if (pidx != NTB_DEF_PEER_IDX)
+		return -EINVAL;
+
+	return ntb_ndev(ntb)->mw_count;
+}
+
+static int amd_ntb_mw_get_align(struct ntb_dev *ntb, int pidx, int idx,
+				resource_size_t *addr_align,
+				resource_size_t *size_align,
+				resource_size_t *size_max)
+{
+	struct amd_ntb_dev *ndev = ntb_ndev(ntb);
+	int bar;
+
+	if (pidx != NTB_DEF_PEER_IDX)
+		return -EINVAL;
+
+	bar = ndev_mw_to_bar(ndev, idx);
+	if (bar < 0)
+		return bar;
+
+	if (addr_align)
+		*addr_align = SZ_4K;
+
+	if (size_align)
+		*size_align = 1;
+
+	if (size_max)
+		*size_max = pci_resource_len(ndev->ntb.pdev, bar);
+
+	return 0;
+}
+
+static int amd_ntb_mw_set_trans(struct ntb_dev *ntb, int pidx, int idx,
+				dma_addr_t addr, resource_size_t size)
+{
+	struct amd_ntb_dev *ndev = ntb_ndev(ntb);
+	unsigned long xlat_reg, limit_reg = 0;
+	resource_size_t mw_size;
+	void __iomem *mmio, *peer_mmio;
+	u64 base_addr, limit, reg_val;
+	int bar;
+
+	if (pidx != NTB_DEF_PEER_IDX)
+		return -EINVAL;
+
+	bar = ndev_mw_to_bar(ndev, idx);
+	if (bar < 0)
+		return bar;
+
+	mw_size = pci_resource_len(ntb->pdev, bar);
+
+	/* make sure the range fits in the usable mw size */
+	if (size > mw_size)
+		return -EINVAL;
+
+	mmio = ndev->self_mmio;
+	peer_mmio = ndev->peer_mmio;
+
+	base_addr = pci_resource_start(ntb->pdev, bar);
+
+	if (bar != 1) {
+		xlat_reg = AMD_BAR23XLAT_OFFSET + ((bar - 2) << 2);
+		limit_reg = AMD_BAR23LMT_OFFSET + ((bar - 2) << 2);
+
+		/* Set the limit if supported */
+		limit = size;
+
+		/* set and verify setting the translation address */
+		write64(addr, peer_mmio + xlat_reg);
+		reg_val = read64(peer_mmio + xlat_reg);
+		if (reg_val != addr) {
+			write64(0, peer_mmio + xlat_reg);
+			return -EIO;
+		}
+
+		/* set and verify setting the limit */
+		write64(limit, peer_mmio + limit_reg);
+		reg_val = read64(peer_mmio + limit_reg);
+		if (reg_val != limit) {
+			write64(base_addr, mmio + limit_reg);
+			write64(0, peer_mmio + xlat_reg);
+			return -EIO;
+		}
+	} else {
+		xlat_reg = AMD_BAR1XLAT_OFFSET;
+		limit_reg = AMD_BAR1LMT_OFFSET;
+
+		/* Set the limit if supported */
+		limit = size;
+
+		/* set and verify setting the translation address */
+		write64(addr, peer_mmio + xlat_reg);
+		reg_val = read64(peer_mmio + xlat_reg);
+		if (reg_val != addr) {
+			write64(0, peer_mmio + xlat_reg);
+			return -EIO;
+		}
+
+		/* set and verify setting the limit */
+		writel(limit, peer_mmio + limit_reg);
+		reg_val = readl(peer_mmio + limit_reg);
+		if (reg_val != limit) {
+			writel(base_addr, mmio + limit_reg);
+			writel(0, peer_mmio + xlat_reg);
+			return -EIO;
+		}
+	}
+
+	return 0;
+}
+
+static int amd_ntb_get_link_status(struct amd_ntb_dev *ndev)
+{
+	struct pci_dev *pdev = ndev->ntb.pdev;
+	struct pci_dev *pci_swds = NULL;
+	struct pci_dev *pci_swus = NULL;
+	u32 stat;
+	int rc;
+
+	if (ndev->ntb.topo == NTB_TOPO_SEC) {
+		if (ndev->dev_data->is_endpoint) {
+			rc = pcie_capability_read_dword(pdev, PCI_EXP_LNKCTL, &stat);
+			if (rc)
+				return rc;
+
+			ndev->lnk_sta = stat;
+			return 0;
+		}
+
+		/* Locate the pointer to Downstream Switch for this device */
+		pci_swds = pci_upstream_bridge(ndev->ntb.pdev);
+		if (pci_swds) {
+			/*
+			 * Locate the pointer to Upstream Switch for
+			 * the Downstream Switch.
+			 */
+			pci_swus = pci_upstream_bridge(pci_swds);
+			if (pci_swus) {
+				rc = pcie_capability_read_dword(pci_swus,
+								PCI_EXP_LNKCTL,
+								&stat);
+				if (rc)
+					return 0;
+			} else {
+				return 0;
+			}
+		} else {
+			return 0;
+		}
+	} else if (ndev->ntb.topo == NTB_TOPO_PRI) {
+		/*
+		 * For NTB primary, we simply read the Link Status and control
+		 * register of the NTB device itself.
+		 */
+		pdev = ndev->ntb.pdev;
+		rc = pcie_capability_read_dword(pdev, PCI_EXP_LNKCTL, &stat);
+		if (rc)
+			return 0;
+	} else {
+		/* Catch all for everything else */
+		return 0;
+	}
+
+	ndev->lnk_sta = stat;
+
+	return 1;
+}
+
+static int amd_link_is_up(struct amd_ntb_dev *ndev)
+{
+	int ret;
+
+	/*
+	 * We consider the link to be up under two conditions:
+	 *
+	 *   - When a link-up event is received. This is indicated by
+	 *     AMD_LINK_UP_EVENT set in peer_sta.
+	 *   - When driver on both sides of the link have been loaded.
+	 *     This is indicated by bit 1 being set in the peer
+	 *     SIDEINFO register.
+	 *
+	 * This function should return 1 when the latter of the above
+	 * two conditions is true.
+	 *
+	 * Now consider the sequence of events - Link-Up event occurs,
+	 * then the peer side driver loads. In this case, we would have
+	 * received LINK_UP event and bit 1 of peer SIDEINFO is also
+	 * set. What happens now if the link goes down? Bit 1 of
+	 * peer SIDEINFO remains set, but LINK_DOWN bit is set in
+	 * peer_sta. So we should return 0 from this function. Not only
+	 * that, we clear bit 1 of peer SIDEINFO to 0, since the peer
+	 * side driver did not even get a chance to clear it before
+	 * the link went down. This can be the case of surprise link
+	 * removal.
+	 *
+	 * LINK_UP event will always occur before the peer side driver
+	 * gets loaded the very first time. So there can be a case when
+	 * the LINK_UP event has occurred, but the peer side driver hasn't
+	 * yet loaded. We return 0 in that case.
+	 *
+	 * There is also a special case when the primary side driver is
+	 * unloaded and then loaded again. Since there is no change in
+	 * the status of NTB secondary in this case, there is no Link-Up
+	 * or Link-Down notification received. We recognize this condition
+	 * with peer_sta being set to 0.
+	 *
+	 * If bit 1 of peer SIDEINFO register is not set, then we
+	 * simply return 0 irrespective of the link up or down status
+	 * set in peer_sta.
+	 */
+	ret = amd_poll_link(ndev);
+	if (ret) {
+		/*
+		 * We need to check the below only for NTB primary. For NTB
+		 * secondary, simply checking the result of PSIDE_INFO
+		 * register will suffice.
+		 */
+		if (ndev->ntb.topo == NTB_TOPO_PRI) {
+			if ((ndev->peer_sta & AMD_LINK_UP_EVENT) ||
+			    (ndev->peer_sta == 0))
+				return ret;
+			else if (ndev->peer_sta & AMD_LINK_DOWN_EVENT) {
+				/* Clear peer sideinfo register */
+				amd_clear_side_info_reg(ndev, true);
+
+				return 0;
+			}
+		} else { /* NTB_TOPO_SEC */
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static u64 amd_ntb_link_is_up(struct ntb_dev *ntb,
+			      enum ntb_speed *speed,
+			      enum ntb_width *width)
+{
+	struct amd_ntb_dev *ndev = ntb_ndev(ntb);
+	int ret = 0;
+
+	if (amd_link_is_up(ndev)) {
+		if (speed)
+			*speed = NTB_LNK_STA_SPEED(ndev->lnk_sta);
+		if (width)
+			*width = NTB_LNK_STA_WIDTH(ndev->lnk_sta);
+
+		dev_dbg(&ntb->pdev->dev, "link is up.\n");
+
+		ret = 1;
+	} else {
+		if (speed)
+			*speed = NTB_SPEED_NONE;
+		if (width)
+			*width = NTB_WIDTH_NONE;
+
+		dev_dbg(&ntb->pdev->dev, "link is down.\n");
+	}
+
+	return ret;
+}
+
+static int amd_ntb_link_enable(struct ntb_dev *ntb,
+			       enum ntb_speed max_speed,
+			       enum ntb_width max_width)
+{
+	struct amd_ntb_dev *ndev = ntb_ndev(ntb);
+	void __iomem *mmio = ndev->self_mmio;
+
+	/* Enable event interrupt */
+	ndev->int_mask &= ~AMD_EVENT_INTMASK;
+	writel(ndev->int_mask, mmio + AMD_INTMASK_OFFSET);
+
+	if (ndev->ntb.topo == NTB_TOPO_SEC)
+		return -EINVAL;
+	dev_dbg(&ntb->pdev->dev, "Enabling Link.\n");
+
+	return 0;
+}
+
+static int amd_ntb_link_disable(struct ntb_dev *ntb)
+{
+	struct amd_ntb_dev *ndev = ntb_ndev(ntb);
+	void __iomem *mmio = ndev->self_mmio;
+
+	/* Disable event interrupt */
+	ndev->int_mask |= AMD_EVENT_INTMASK;
+	writel(ndev->int_mask, mmio + AMD_INTMASK_OFFSET);
+
+	if (ndev->ntb.topo == NTB_TOPO_SEC)
+		return -EINVAL;
+	dev_dbg(&ntb->pdev->dev, "Disabling Link.\n");
+
+	return 0;
+}
+
+static int amd_ntb_peer_mw_count(struct ntb_dev *ntb)
+{
+	/* The same as for inbound MWs */
+	return ntb_ndev(ntb)->mw_count;
+}
+
+static int amd_ntb_peer_mw_get_addr(struct ntb_dev *ntb, int idx,
+				    phys_addr_t *base, resource_size_t *size)
+{
+	struct amd_ntb_dev *ndev = ntb_ndev(ntb);
+	int bar;
+
+	bar = ndev_mw_to_bar(ndev, idx);
+	if (bar < 0)
+		return bar;
+
+	if (base)
+		*base = pci_resource_start(ndev->ntb.pdev, bar);
+
+	if (size)
+		*size = pci_resource_len(ndev->ntb.pdev, bar);
+
+	return 0;
+}
+
+static u64 amd_ntb_db_valid_mask(struct ntb_dev *ntb)
+{
+	return ntb_ndev(ntb)->db_valid_mask;
+}
+
+static int amd_ntb_db_vector_count(struct ntb_dev *ntb)
+{
+	return ntb_ndev(ntb)->db_count;
+}
+
+static u64 amd_ntb_db_vector_mask(struct ntb_dev *ntb, int db_vector)
+{
+	struct amd_ntb_dev *ndev = ntb_ndev(ntb);
+
+	if (db_vector < 0 || db_vector > ndev->db_count)
+		return 0;
+
+	return ntb_ndev(ntb)->db_valid_mask & (1ULL << db_vector);
+}
+
+static u64 amd_ntb_db_read(struct ntb_dev *ntb)
+{
+	struct amd_ntb_dev *ndev = ntb_ndev(ntb);
+	void __iomem *mmio = ndev->self_mmio;
+
+	return (u64)readw(mmio + AMD_DBSTAT_OFFSET);
+}
+
+static int amd_ntb_db_clear(struct ntb_dev *ntb, u64 db_bits)
+{
+	struct amd_ntb_dev *ndev = ntb_ndev(ntb);
+	void __iomem *mmio = ndev->self_mmio;
+
+	writew((u16)db_bits, mmio + AMD_DBSTAT_OFFSET);
+
+	return 0;
+}
+
+static int amd_ntb_db_set_mask(struct ntb_dev *ntb, u64 db_bits)
+{
+	struct amd_ntb_dev *ndev = ntb_ndev(ntb);
+	void __iomem *mmio = ndev->self_mmio;
+	unsigned long flags;
+
+	if (db_bits & ~ndev->db_valid_mask)
+		return -EINVAL;
+
+	spin_lock_irqsave(&ndev->db_mask_lock, flags);
+	ndev->db_mask |= db_bits;
+	writew((u16)ndev->db_mask, mmio + AMD_DBMASK_OFFSET);
+	spin_unlock_irqrestore(&ndev->db_mask_lock, flags);
+
+	return 0;
+}
+
+static int amd_ntb_db_clear_mask(struct ntb_dev *ntb, u64 db_bits)
+{
+	struct amd_ntb_dev *ndev = ntb_ndev(ntb);
+	void __iomem *mmio = ndev->self_mmio;
+	unsigned long flags;
+
+	if (db_bits & ~ndev->db_valid_mask)
+		return -EINVAL;
+
+	spin_lock_irqsave(&ndev->db_mask_lock, flags);
+	ndev->db_mask &= ~db_bits;
+	writew((u16)ndev->db_mask, mmio + AMD_DBMASK_OFFSET);
+	spin_unlock_irqrestore(&ndev->db_mask_lock, flags);
+
+	return 0;
+}
+
+static int amd_ntb_peer_db_set(struct ntb_dev *ntb, u64 db_bits)
+{
+	struct amd_ntb_dev *ndev = ntb_ndev(ntb);
+	void __iomem *mmio = ndev->self_mmio;
+
+	writew((u16)db_bits, mmio + AMD_DBREQ_OFFSET);
+
+	return 0;
+}
+
+static int amd_ntb_spad_count(struct ntb_dev *ntb)
+{
+	return ntb_ndev(ntb)->spad_count;
+}
+
+static u32 amd_ntb_spad_read(struct ntb_dev *ntb, int idx)
+{
+	struct amd_ntb_dev *ndev = ntb_ndev(ntb);
+	void __iomem *mmio = ndev->self_mmio;
+	u32 offset;
+
+	if (idx < 0 || idx >= ndev->spad_count)
+		return 0;
+
+	offset = ndev->self_spad + (idx << 2);
+	return readl(mmio + AMD_SPAD_OFFSET + offset);
+}
+
+static int amd_ntb_spad_write(struct ntb_dev *ntb,
+			      int idx, u32 val)
+{
+	struct amd_ntb_dev *ndev = ntb_ndev(ntb);
+	void __iomem *mmio = ndev->self_mmio;
+	u32 offset;
+
+	if (idx < 0 || idx >= ndev->spad_count)
+		return -EINVAL;
+
+	offset = ndev->self_spad + (idx << 2);
+	writel(val, mmio + AMD_SPAD_OFFSET + offset);
+
+	return 0;
+}
+
+static u32 amd_ntb_peer_spad_read(struct ntb_dev *ntb, int pidx, int sidx)
+{
+	struct amd_ntb_dev *ndev = ntb_ndev(ntb);
+	void __iomem *mmio = ndev->self_mmio;
+	u32 offset;
+
+	if (sidx < 0 || sidx >= ndev->spad_count)
+		return -EINVAL;
+
+	offset = ndev->peer_spad + (sidx << 2);
+	return readl(mmio + AMD_SPAD_OFFSET + offset);
+}
+
+static int amd_ntb_peer_spad_write(struct ntb_dev *ntb, int pidx,
+				   int sidx, u32 val)
+{
+	struct amd_ntb_dev *ndev = ntb_ndev(ntb);
+	void __iomem *mmio = ndev->self_mmio;
+	u32 offset;
+
+	if (sidx < 0 || sidx >= ndev->spad_count)
+		return -EINVAL;
+
+	offset = ndev->peer_spad + (sidx << 2);
+	writel(val, mmio + AMD_SPAD_OFFSET + offset);
+
+	return 0;
+}
+
+static const struct ntb_dev_ops amd_ntb_ops = {
+	.mw_count		= amd_ntb_mw_count,
+	.mw_get_align		= amd_ntb_mw_get_align,
+	.mw_set_trans		= amd_ntb_mw_set_trans,
+	.peer_mw_count		= amd_ntb_peer_mw_count,
+	.peer_mw_get_addr	= amd_ntb_peer_mw_get_addr,
+	.link_is_up		= amd_ntb_link_is_up,
+	.link_enable		= amd_ntb_link_enable,
+	.link_disable		= amd_ntb_link_disable,
+	.db_valid_mask		= amd_ntb_db_valid_mask,
+	.db_vector_count	= amd_ntb_db_vector_count,
+	.db_vector_mask		= amd_ntb_db_vector_mask,
+	.db_read		= amd_ntb_db_read,
+	.db_clear		= amd_ntb_db_clear,
+	.db_set_mask		= amd_ntb_db_set_mask,
+	.db_clear_mask		= amd_ntb_db_clear_mask,
+	.peer_db_set		= amd_ntb_peer_db_set,
+	.spad_count		= amd_ntb_spad_count,
+	.spad_read		= amd_ntb_spad_read,
+	.spad_write		= amd_ntb_spad_write,
+	.peer_spad_read		= amd_ntb_peer_spad_read,
+	.peer_spad_write	= amd_ntb_peer_spad_write,
+};
+
+static void amd_ack_smu(struct amd_ntb_dev *ndev, u32 bit)
+{
+	void __iomem *mmio = ndev->self_mmio;
+	int reg;
+
+	reg = readl(mmio + AMD_SMUACK_OFFSET);
+	reg |= bit;
+	writel(reg, mmio + AMD_SMUACK_OFFSET);
+}
+
+static void amd_handle_event(struct amd_ntb_dev *ndev, int vec)
+{
+	void __iomem *mmio = ndev->self_mmio;
+	struct device *dev = &ndev->ntb.pdev->dev;
+	u32 status;
+
+	status = readl(mmio + AMD_INTSTAT_OFFSET);
+	if (!(status & AMD_EVENT_INTMASK))
+		return;
+
+	dev_dbg(dev, "status = 0x%x and vec = %d\n", status, vec);
+
+	status &= AMD_EVENT_INTMASK;
+	switch (status) {
+	case AMD_PEER_FLUSH_EVENT:
+		ndev->peer_sta |= AMD_PEER_FLUSH_EVENT;
+		dev_info(dev, "Flush is done.\n");
+		break;
+	case AMD_PEER_RESET_EVENT:
+	case AMD_LINK_DOWN_EVENT:
+		ndev->peer_sta |= status;
+		if (status == AMD_LINK_DOWN_EVENT)
+			ndev->peer_sta &= ~AMD_LINK_UP_EVENT;
+
+		amd_ack_smu(ndev, status);
+
+		/* link down first */
+		ntb_link_event(&ndev->ntb);
+		/* polling peer status */
+		schedule_delayed_work(&ndev->hb_timer, AMD_LINK_HB_TIMEOUT);
+
+		break;
+	case AMD_PEER_D3_EVENT:
+	case AMD_PEER_PMETO_EVENT:
+	case AMD_LINK_UP_EVENT:
+		ndev->peer_sta |= status;
+		if (status == AMD_LINK_UP_EVENT)
+			ndev->peer_sta &= ~AMD_LINK_DOWN_EVENT;
+		else if (status == AMD_PEER_D3_EVENT)
+			ndev->peer_sta &= ~AMD_PEER_D0_EVENT;
+
+		amd_ack_smu(ndev, status);
+
+		/* link down */
+		ntb_link_event(&ndev->ntb);
+
+		break;
+	case AMD_PEER_D0_EVENT:
+		mmio = ndev->peer_mmio;
+		status = readl(mmio + AMD_PMESTAT_OFFSET);
+		/* check if this is WAKEUP event */
+		if (status & 0x1)
+			dev_info(dev, "Wakeup is done.\n");
+
+		ndev->peer_sta |= AMD_PEER_D0_EVENT;
+		ndev->peer_sta &= ~AMD_PEER_D3_EVENT;
+		amd_ack_smu(ndev, AMD_PEER_D0_EVENT);
+
+		/* start a timer to poll link status */
+		schedule_delayed_work(&ndev->hb_timer,
+				      AMD_LINK_HB_TIMEOUT);
+		break;
+	default:
+		dev_info(dev, "event status = 0x%x.\n", status);
+		break;
+	}
+
+	/* Clear the interrupt status */
+	writel(status, mmio + AMD_INTSTAT_OFFSET);
+}
+
+static void amd_handle_db_event(struct amd_ntb_dev *ndev, int vec)
+{
+	struct device *dev = &ndev->ntb.pdev->dev;
+	u64 status;
+
+	status = amd_ntb_db_read(&ndev->ntb);
+
+	dev_dbg(dev, "status = 0x%llx and vec = %d\n", status, vec);
+
+	/*
+	 * Since we had reserved highest order bit of DB for signaling peer of
+	 * a special event, this is the only status bit we should be concerned
+	 * here now.
+	 */
+	if (status & BIT(ndev->db_last_bit)) {
+		ntb_db_clear(&ndev->ntb, BIT(ndev->db_last_bit));
+		/* send link down event notification */
+		ntb_link_event(&ndev->ntb);
+
+		/*
+		 * If we are here, that means the peer has signalled a special
+		 * event which notifies that the peer driver has been
+		 * un-loaded for some reason. Since there is a chance that the
+		 * peer will load its driver again sometime, we schedule link
+		 * polling routine.
+		 */
+		schedule_delayed_work(&ndev->hb_timer, AMD_LINK_HB_TIMEOUT);
+	}
+}
+
+static irqreturn_t ndev_interrupt(struct amd_ntb_dev *ndev, int vec)
+{
+	dev_dbg(&ndev->ntb.pdev->dev, "vec %d\n", vec);
+
+	if (vec > (AMD_DB_CNT - 1) || (ndev->msix_vec_count == 1))
+		amd_handle_event(ndev, vec);
+
+	if (vec < AMD_DB_CNT) {
+		amd_handle_db_event(ndev, vec);
+		ntb_db_event(&ndev->ntb, vec);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t ndev_vec_isr(int irq, void *dev)
+{
+	struct amd_ntb_vec *nvec = dev;
+
+	return ndev_interrupt(nvec->ndev, nvec->num);
+}
+
+static irqreturn_t ndev_irq_isr(int irq, void *dev)
+{
+	struct amd_ntb_dev *ndev = dev;
+
+	return ndev_interrupt(ndev, irq - ndev->ntb.pdev->irq);
+}
+
+static int ndev_init_isr(struct amd_ntb_dev *ndev,
+			 int msix_min, int msix_max)
+{
+	struct pci_dev *pdev;
+	int rc, i, msix_count, node;
+
+	pdev = ndev->ntb.pdev;
+
+	node = dev_to_node(&pdev->dev);
+
+	ndev->db_mask = ndev->db_valid_mask;
+
+	/* Try to set up msix irq */
+	ndev->vec = kcalloc_node(msix_max, sizeof(*ndev->vec),
+				 GFP_KERNEL, node);
+	if (!ndev->vec)
+		goto err_msix_vec_alloc;
+
+	ndev->msix = kcalloc_node(msix_max, sizeof(*ndev->msix),
+				  GFP_KERNEL, node);
+	if (!ndev->msix)
+		goto err_msix_alloc;
+
+	for (i = 0; i < msix_max; ++i)
+		ndev->msix[i].entry = i;
+
+	msix_count = pci_enable_msix_range(pdev, ndev->msix,
+					   msix_min, msix_max);
+	if (msix_count < 0)
+		goto err_msix_enable;
+
+	/* NOTE: Disable MSIX if msix count is less than 16 because of
+	 * hardware limitation.
+	 */
+	if (msix_count < msix_min) {
+		pci_disable_msix(pdev);
+		goto err_msix_enable;
+	}
+
+	for (i = 0; i < msix_count; ++i) {
+		ndev->vec[i].ndev = ndev;
+		ndev->vec[i].num = i;
+		rc = request_irq(ndev->msix[i].vector, ndev_vec_isr, 0,
+				 "ndev_vec_isr", &ndev->vec[i]);
+		if (rc)
+			goto err_msix_request;
+	}
+
+	dev_dbg(&pdev->dev, "Using msix interrupts\n");
+	ndev->db_count = msix_min;
+	ndev->msix_vec_count = msix_max;
+	return 0;
+
+err_msix_request:
+	while (i-- > 0)
+		free_irq(ndev->msix[i].vector, &ndev->vec[i]);
+	pci_disable_msix(pdev);
+err_msix_enable:
+	kfree(ndev->msix);
+err_msix_alloc:
+	kfree(ndev->vec);
+err_msix_vec_alloc:
+	ndev->msix = NULL;
+	ndev->vec = NULL;
+
+	/* Try to set up msi irq */
+	rc = pci_enable_msi(pdev);
+	if (rc)
+		goto err_msi_enable;
+
+	rc = request_irq(pdev->irq, ndev_irq_isr, 0,
+			 "ndev_irq_isr", ndev);
+	if (rc)
+		goto err_msi_request;
+
+	dev_dbg(&pdev->dev, "Using msi interrupts\n");
+	ndev->db_count = 1;
+	ndev->msix_vec_count = 1;
+	return 0;
+
+err_msi_request:
+	pci_disable_msi(pdev);
+err_msi_enable:
+
+	/* Try to set up intx irq */
+	pci_intx(pdev, 1);
+
+	rc = request_irq(pdev->irq, ndev_irq_isr, IRQF_SHARED,
+			 "ndev_irq_isr", ndev);
+	if (rc)
+		goto err_intx_request;
+
+	dev_dbg(&pdev->dev, "Using intx interrupts\n");
+	ndev->db_count = 1;
+	ndev->msix_vec_count = 1;
+	return 0;
+
+err_intx_request:
+	return rc;
+}
+
+static void ndev_deinit_isr(struct amd_ntb_dev *ndev)
+{
+	struct pci_dev *pdev;
+	void __iomem *mmio = ndev->self_mmio;
+	int i;
+
+	pdev = ndev->ntb.pdev;
+
+	/* Mask all doorbell interrupts */
+	ndev->db_mask = ndev->db_valid_mask;
+	writel(ndev->db_mask, mmio + AMD_DBMASK_OFFSET);
+
+	if (ndev->msix) {
+		i = ndev->msix_vec_count;
+		while (i--)
+			free_irq(ndev->msix[i].vector, &ndev->vec[i]);
+		pci_disable_msix(pdev);
+		kfree(ndev->msix);
+		kfree(ndev->vec);
+	} else {
+		free_irq(pdev->irq, ndev);
+		if (pci_dev_msi_enabled(pdev))
+			pci_disable_msi(pdev);
+		else
+			pci_intx(pdev, 0);
+	}
+}
+
+static ssize_t ndev_debugfs_read(struct file *filp, char __user *ubuf,
+				 size_t count, loff_t *offp)
+{
+	struct amd_ntb_dev *ndev;
+	void __iomem *mmio;
+	char *buf;
+	size_t buf_size;
+	ssize_t ret, off;
+	union { u64 v64; u32 v32; u16 v16; } u;
+
+	ndev = filp->private_data;
+	mmio = ndev->self_mmio;
+
+	buf_size = min(count, 0x800ul);
+
+	buf = kmalloc(buf_size, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	off = 0;
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "NTB Device Information:\n");
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "Connection Topology -\t%s\n",
+			 ntb_topo_string(ndev->ntb.topo));
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "LNK STA -\t\t%#06x\n", ndev->lnk_sta);
+
+	if (!amd_link_is_up(ndev)) {
+		off += scnprintf(buf + off, buf_size - off,
+				 "Link Status -\t\tDown\n");
+	} else {
+		off += scnprintf(buf + off, buf_size - off,
+				 "Link Status -\t\tUp\n");
+		off += scnprintf(buf + off, buf_size - off,
+				 "Link Speed -\t\tPCI-E Gen %u\n",
+				 NTB_LNK_STA_SPEED(ndev->lnk_sta));
+		off += scnprintf(buf + off, buf_size - off,
+				 "Link Width -\t\tx%u\n",
+				 NTB_LNK_STA_WIDTH(ndev->lnk_sta));
+	}
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "Memory Window Count -\t%u\n", ndev->mw_count);
+	off += scnprintf(buf + off, buf_size - off,
+			 "Scratchpad Count -\t%u\n", ndev->spad_count);
+	off += scnprintf(buf + off, buf_size - off,
+			 "Doorbell Count -\t%u\n", ndev->db_count);
+	off += scnprintf(buf + off, buf_size - off,
+			 "MSIX Vector Count -\t%u\n", ndev->msix_vec_count);
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "Doorbell Valid Mask -\t%#llx\n", ndev->db_valid_mask);
+
+	u.v32 = readl(ndev->self_mmio + AMD_DBMASK_OFFSET);
+	off += scnprintf(buf + off, buf_size - off,
+			 "Doorbell Mask -\t\t\t%#06x\n", u.v32);
+
+	u.v32 = readl(mmio + AMD_DBSTAT_OFFSET);
+	off += scnprintf(buf + off, buf_size - off,
+			 "Doorbell Bell -\t\t\t%#06x\n", u.v32);
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "\nNTB Incoming XLAT:\n");
+
+	u.v64 = read64(mmio + AMD_BAR1XLAT_OFFSET);
+	off += scnprintf(buf + off, buf_size - off,
+			 "XLAT1 -\t\t%#018llx\n", u.v64);
+
+	u.v64 = read64(ndev->self_mmio + AMD_BAR23XLAT_OFFSET);
+	off += scnprintf(buf + off, buf_size - off,
+			 "XLAT23 -\t\t%#018llx\n", u.v64);
+
+	u.v64 = read64(ndev->self_mmio + AMD_BAR45XLAT_OFFSET);
+	off += scnprintf(buf + off, buf_size - off,
+			 "XLAT45 -\t\t%#018llx\n", u.v64);
+
+	u.v32 = readl(mmio + AMD_BAR1LMT_OFFSET);
+	off += scnprintf(buf + off, buf_size - off,
+			 "LMT1 -\t\t\t%#06x\n", u.v32);
+
+	u.v64 = read64(ndev->self_mmio + AMD_BAR23LMT_OFFSET);
+	off += scnprintf(buf + off, buf_size - off,
+			 "LMT23 -\t\t\t%#018llx\n", u.v64);
+
+	u.v64 = read64(ndev->self_mmio + AMD_BAR45LMT_OFFSET);
+	off += scnprintf(buf + off, buf_size - off,
+			 "LMT45 -\t\t\t%#018llx\n", u.v64);
+
+	ret = simple_read_from_buffer(ubuf, count, offp, buf, off);
+	kfree(buf);
+	return ret;
+}
+
+static void ndev_init_debugfs(struct amd_ntb_dev *ndev)
+{
+	if (!debugfs_dir) {
+		ndev->debugfs_dir = NULL;
+		ndev->debugfs_info = NULL;
+	} else {
+		ndev->debugfs_dir =
+			debugfs_create_dir(pci_name(ndev->ntb.pdev),
+					   debugfs_dir);
+		ndev->debugfs_info =
+			debugfs_create_file("info", S_IRUSR,
+					    ndev->debugfs_dir, ndev,
+					    &amd_ntb_debugfs_info);
+	}
+}
+
+static void ndev_deinit_debugfs(struct amd_ntb_dev *ndev)
+{
+	debugfs_remove_recursive(ndev->debugfs_dir);
+}
+
+static inline void ndev_init_struct(struct amd_ntb_dev *ndev,
+				    struct pci_dev *pdev)
+{
+	ndev->ntb.pdev = pdev;
+	ndev->ntb.topo = NTB_TOPO_NONE;
+	ndev->ntb.ops = &amd_ntb_ops;
+	ndev->int_mask = AMD_EVENT_INTMASK;
+	spin_lock_init(&ndev->db_mask_lock);
+}
+
+static int amd_poll_link(struct amd_ntb_dev *ndev)
+{
+	void __iomem *mmio = ndev->peer_mmio;
+	u32 reg;
+
+	reg = readl(mmio + AMD_SIDEINFO_OFFSET);
+	reg &= AMD_SIDE_READY;
+
+	dev_dbg(&ndev->ntb.pdev->dev, "%s: reg_val = 0x%x.\n", __func__, reg);
+
+	ndev->cntl_sta = reg;
+
+	amd_ntb_get_link_status(ndev);
+
+	return ndev->cntl_sta;
+}
+
+static void amd_link_hb(struct work_struct *work)
+{
+	struct amd_ntb_dev *ndev = hb_ndev(work);
+
+	if (amd_poll_link(ndev))
+		ntb_link_event(&ndev->ntb);
+
+	if (!amd_link_is_up(ndev))
+		schedule_delayed_work(&ndev->hb_timer, AMD_LINK_HB_TIMEOUT);
+}
+
+static int amd_init_isr(struct amd_ntb_dev *ndev)
+{
+	return ndev_init_isr(ndev, AMD_DB_CNT, AMD_MSIX_VECTOR_CNT);
+}
+
+static void amd_set_side_info_reg(struct amd_ntb_dev *ndev, bool peer)
+{
+	void __iomem *mmio = NULL;
+	unsigned int reg;
+
+	if (peer)
+		mmio = ndev->peer_mmio;
+	else
+		mmio = ndev->self_mmio;
+
+	reg = readl(mmio + AMD_SIDEINFO_OFFSET);
+	if (!(reg & AMD_SIDE_READY)) {
+		reg |= AMD_SIDE_READY;
+		writel(reg, mmio + AMD_SIDEINFO_OFFSET);
+	}
+}
+
+static void amd_clear_side_info_reg(struct amd_ntb_dev *ndev, bool peer)
+{
+	void __iomem *mmio = NULL;
+	unsigned int reg;
+
+	if (peer)
+		mmio = ndev->peer_mmio;
+	else
+		mmio = ndev->self_mmio;
+
+	reg = readl(mmio + AMD_SIDEINFO_OFFSET);
+	if (reg & AMD_SIDE_READY) {
+		reg &= ~AMD_SIDE_READY;
+		writel(reg, mmio + AMD_SIDEINFO_OFFSET);
+		readl(mmio + AMD_SIDEINFO_OFFSET);
+	}
+}
+
+static void amd_init_side_info(struct amd_ntb_dev *ndev)
+{
+	void __iomem *mmio = ndev->self_mmio;
+	u32 ntb_ctl;
+
+	amd_set_side_info_reg(ndev, false);
+
+	ntb_ctl = readl(mmio + AMD_CNTL_OFFSET);
+	ntb_ctl |= (PMM_REG_CTL | SMM_REG_CTL);
+	writel(ntb_ctl, mmio + AMD_CNTL_OFFSET);
+}
+
+static void amd_deinit_side_info(struct amd_ntb_dev *ndev)
+{
+	void __iomem *mmio = ndev->self_mmio;
+	u32 ntb_ctl;
+
+	amd_clear_side_info_reg(ndev, false);
+
+	ntb_ctl = readl(mmio + AMD_CNTL_OFFSET);
+	ntb_ctl &= ~(PMM_REG_CTL | SMM_REG_CTL);
+	writel(ntb_ctl, mmio + AMD_CNTL_OFFSET);
+}
+
+static int amd_init_ntb(struct amd_ntb_dev *ndev)
+{
+	void __iomem *mmio = ndev->self_mmio;
+
+	ndev->mw_count = ndev->dev_data->mw_count;
+	ndev->spad_count = AMD_SPADS_CNT;
+	ndev->db_count = AMD_DB_CNT;
+
+	switch (ndev->ntb.topo) {
+	case NTB_TOPO_PRI:
+	case NTB_TOPO_SEC:
+		ndev->spad_count >>= 1;
+		if (ndev->ntb.topo == NTB_TOPO_PRI) {
+			ndev->self_spad = 0;
+			ndev->peer_spad = 0x20;
+		} else {
+			ndev->self_spad = 0x20;
+			ndev->peer_spad = 0;
+		}
+
+		INIT_DELAYED_WORK(&ndev->hb_timer, amd_link_hb);
+		schedule_delayed_work(&ndev->hb_timer, AMD_LINK_HB_TIMEOUT);
+
+		break;
+	default:
+		dev_err(&ndev->ntb.pdev->dev,
+			"AMD NTB does not support B2B mode.\n");
+		return -EINVAL;
+	}
+
+	/* Mask event interrupts */
+	writel(ndev->int_mask, mmio + AMD_INTMASK_OFFSET);
+
+	return 0;
+}
+
+static enum ntb_topo amd_get_topo(struct amd_ntb_dev *ndev)
+{
+	void __iomem *mmio = ndev->self_mmio;
+	u32 info;
+
+	info = readl(mmio + AMD_SIDEINFO_OFFSET);
+	if (info & AMD_SIDE_MASK)
+		return NTB_TOPO_SEC;
+	else
+		return NTB_TOPO_PRI;
+}
+
+static int amd_init_dev(struct amd_ntb_dev *ndev)
+{
+	void __iomem *mmio = ndev->self_mmio;
+	struct pci_dev *pdev;
+	int rc = 0;
+
+	pdev = ndev->ntb.pdev;
+
+	ndev->ntb.topo = amd_get_topo(ndev);
+	dev_dbg(&pdev->dev, "AMD NTB topo is %s\n",
+		ntb_topo_string(ndev->ntb.topo));
+
+	rc = amd_init_ntb(ndev);
+	if (rc)
+		return rc;
+
+	rc = amd_init_isr(ndev);
+	if (rc) {
+		dev_err(&pdev->dev, "fail to init isr.\n");
+		return rc;
+	}
+
+	ndev->db_valid_mask = BIT_ULL(ndev->db_count) - 1;
+	/*
+	 * We reserve the highest order bit of the DB register which will
+	 * be used to notify peer when the driver on this side is being
+	 * un-loaded.
+	 */
+	ndev->db_last_bit =
+			find_last_bit((unsigned long *)&ndev->db_valid_mask,
+				      hweight64(ndev->db_valid_mask));
+	writew((u16)~BIT(ndev->db_last_bit), mmio + AMD_DBMASK_OFFSET);
+	/*
+	 * Since now there is one less bit to account for, the DB count
+	 * and DB mask should be adjusted accordingly.
+	 */
+	ndev->db_count -= 1;
+	ndev->db_valid_mask = BIT_ULL(ndev->db_count) - 1;
+
+	/* Enable Link-Up and Link-Down event interrupts */
+	ndev->int_mask &= ~(AMD_LINK_UP_EVENT | AMD_LINK_DOWN_EVENT);
+	writel(ndev->int_mask, mmio + AMD_INTMASK_OFFSET);
+
+	return 0;
+}
+
+static void amd_deinit_dev(struct amd_ntb_dev *ndev)
+{
+	cancel_delayed_work_sync(&ndev->hb_timer);
+
+	ndev_deinit_isr(ndev);
+}
+
+static int amd_ntb_init_pci(struct amd_ntb_dev *ndev,
+			    struct pci_dev *pdev)
+{
+	int rc;
+
+	pci_set_drvdata(pdev, ndev);
+
+	rc = pci_enable_device(pdev);
+	if (rc)
+		goto err_pci_enable;
+
+	rc = pci_request_regions(pdev, NTB_NAME);
+	if (rc)
+		goto err_pci_regions;
+
+	pci_set_master(pdev);
+
+	rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
+	if (rc) {
+		rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
+		if (rc)
+			goto err_dma_mask;
+		dev_warn(&pdev->dev, "Cannot DMA highmem\n");
+	}
+
+	ndev->self_mmio = pci_iomap(pdev, 0, 0);
+	if (!ndev->self_mmio) {
+		rc = -EIO;
+		goto err_dma_mask;
+	}
+	ndev->peer_mmio = ndev->self_mmio + AMD_PEER_OFFSET;
+
+	return 0;
+
+err_dma_mask:
+	pci_release_regions(pdev);
+err_pci_regions:
+	pci_disable_device(pdev);
+err_pci_enable:
+	pci_set_drvdata(pdev, NULL);
+	return rc;
+}
+
+static void amd_ntb_deinit_pci(struct amd_ntb_dev *ndev)
+{
+	struct pci_dev *pdev = ndev->ntb.pdev;
+
+	pci_iounmap(pdev, ndev->self_mmio);
+
+	pci_release_regions(pdev);
+	pci_disable_device(pdev);
+	pci_set_drvdata(pdev, NULL);
+}
+
+static int amd_ntb_pci_probe(struct pci_dev *pdev,
+			     const struct pci_device_id *id)
+{
+	struct amd_ntb_dev *ndev;
+	int rc, node;
+
+	node = dev_to_node(&pdev->dev);
+
+	ndev = kzalloc_node(sizeof(*ndev), GFP_KERNEL, node);
+	if (!ndev) {
+		rc = -ENOMEM;
+		goto err_ndev;
+	}
+
+	ndev->dev_data = (struct ntb_dev_data *)id->driver_data;
+
+	ndev_init_struct(ndev, pdev);
+
+	rc = amd_ntb_init_pci(ndev, pdev);
+	if (rc)
+		goto err_init_pci;
+
+	rc = amd_init_dev(ndev);
+	if (rc)
+		goto err_init_dev;
+
+	/* write side info */
+	amd_init_side_info(ndev);
+
+	amd_poll_link(ndev);
+
+	ndev_init_debugfs(ndev);
+
+	rc = ntb_register_device(&ndev->ntb);
+	if (rc)
+		goto err_register;
+
+	dev_info(&pdev->dev, "NTB device registered.\n");
+
+	return 0;
+
+err_register:
+	ndev_deinit_debugfs(ndev);
+	amd_deinit_dev(ndev);
+err_init_dev:
+	amd_ntb_deinit_pci(ndev);
+err_init_pci:
+	kfree(ndev);
+err_ndev:
+	return rc;
+}
+
+static void amd_ntb_pci_remove(struct pci_dev *pdev)
+{
+	struct amd_ntb_dev *ndev = pci_get_drvdata(pdev);
+
+	/*
+	 * Clear the READY bit in SIDEINFO register before sending DB event
+	 * to the peer. This will make sure that when the peer handles the
+	 * DB event, it correctly reads this bit as being 0.
+	 */
+	amd_deinit_side_info(ndev);
+	ntb_peer_db_set(&ndev->ntb, BIT_ULL(ndev->db_last_bit));
+	ntb_unregister_device(&ndev->ntb);
+	ndev_deinit_debugfs(ndev);
+	amd_deinit_dev(ndev);
+	amd_ntb_deinit_pci(ndev);
+	kfree(ndev);
+}
+
+static void amd_ntb_pci_shutdown(struct pci_dev *pdev)
+{
+	struct amd_ntb_dev *ndev = pci_get_drvdata(pdev);
+
+	/* Send link down notification */
+	ntb_link_event(&ndev->ntb);
+
+	amd_deinit_side_info(ndev);
+	ntb_peer_db_set(&ndev->ntb, BIT_ULL(ndev->db_last_bit));
+	ntb_unregister_device(&ndev->ntb);
+	ndev_deinit_debugfs(ndev);
+	amd_deinit_dev(ndev);
+	amd_ntb_deinit_pci(ndev);
+	kfree(ndev);
+}
+
+static const struct file_operations amd_ntb_debugfs_info = {
+	.owner = THIS_MODULE,
+	.open = simple_open,
+	.read = ndev_debugfs_read,
+};
+
+static const struct ntb_dev_data dev_data[] = {
+	{ /* for device 145b */
+		.mw_count = 3,
+		.mw_idx = 1,
+	},
+	{ /* for device 148b */
+		.mw_count = 2,
+		.mw_idx = 2,
+	},
+	{ /* for device 0x17d7 */
+		.mw_count = 2,
+		.mw_idx = 2,
+		.is_endpoint = true,
+	},
+};
+
+static const struct pci_device_id amd_ntb_pci_tbl[] = {
+	{ PCI_VDEVICE(AMD, 0x145b), .driver_data = (kernel_ulong_t)&dev_data[0] },
+	{ PCI_VDEVICE(AMD, 0x148b), .driver_data = (kernel_ulong_t)&dev_data[1] },
+	{ PCI_VDEVICE(AMD, 0x14c0), .driver_data = (kernel_ulong_t)&dev_data[1] },
+	{ PCI_VDEVICE(AMD, 0x14c3), .driver_data = (kernel_ulong_t)&dev_data[1] },
+	{ PCI_VDEVICE(AMD, 0x155a), .driver_data = (kernel_ulong_t)&dev_data[1] },
+	{ PCI_VDEVICE(AMD, 0x17d4), .driver_data = (kernel_ulong_t)&dev_data[1] },
+	{ PCI_VDEVICE(AMD, 0x17d7), .driver_data = (kernel_ulong_t)&dev_data[2] },
+	{ PCI_VDEVICE(HYGON, 0x145b), .driver_data = (kernel_ulong_t)&dev_data[0] },
+	{ }
+};
+MODULE_DEVICE_TABLE(pci, amd_ntb_pci_tbl);
+
+static struct pci_driver amd_ntb_pci_driver = {
+	.name		= KBUILD_MODNAME,
+	.id_table	= amd_ntb_pci_tbl,
+	.probe		= amd_ntb_pci_probe,
+	.remove		= amd_ntb_pci_remove,
+	.shutdown	= amd_ntb_pci_shutdown,
+};
+
+static int __init amd_ntb_pci_driver_init(void)
+{
+	int ret;
+	pr_info("%s %s\n", NTB_DESC, NTB_VER);
+
+	if (debugfs_initialized())
+		debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
+
+	ret = pci_register_driver(&amd_ntb_pci_driver);
+	if (ret)
+		debugfs_remove_recursive(debugfs_dir);
+
+	return ret;
+}
+module_init(amd_ntb_pci_driver_init);
+
+static void __exit amd_ntb_pci_driver_exit(void)
+{
+	pci_unregister_driver(&amd_ntb_pci_driver);
+	debugfs_remove_recursive(debugfs_dir);
+}
+module_exit(amd_ntb_pci_driver_exit);
diff --git a/drivers/ntb/hw/amd/ntb_hw_amd.h b/drivers/ntb/hw/amd/ntb_hw_amd.h
new file mode 100644
index 000000000..e8c3165fa
--- /dev/null
+++ b/drivers/ntb/hw/amd/ntb_hw_amd.h
@@ -0,0 +1,224 @@
+/*
+ * This file is provided under a dual BSD/GPLv2 license.  When using or
+ *   redistributing this file, you may do so under either license.
+ *
+ *   GPL LICENSE SUMMARY
+ *
+ *   Copyright (C) 2016 Advanced Micro Devices, Inc. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of version 2 of the GNU General Public License as
+ *   published by the Free Software Foundation.
+ *
+ *   BSD LICENSE
+ *
+ *   Copyright (C) 2016 Advanced Micro Devices, Inc. All Rights Reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copy
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of AMD Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * AMD PCIe NTB Linux driver
+ *
+ * Contact Information:
+ * Xiangliang Yu <Xiangliang.Yu@amd.com>
+ */
+
+#ifndef NTB_HW_AMD_H
+#define NTB_HW_AMD_H
+
+#include <linux/ntb.h>
+#include <linux/pci.h>
+
+#define AMD_LINK_HB_TIMEOUT	msecs_to_jiffies(1000)
+#define NTB_LNK_STA_SPEED_MASK	0x000F0000
+#define NTB_LNK_STA_WIDTH_MASK	0x03F00000
+#define NTB_LNK_STA_SPEED(x)	(((x) & NTB_LNK_STA_SPEED_MASK) >> 16)
+#define NTB_LNK_STA_WIDTH(x)	(((x) & NTB_LNK_STA_WIDTH_MASK) >> 20)
+
+#ifndef read64
+#ifdef readq
+#define read64 readq
+#else
+#define read64 _read64
+static inline u64 _read64(void __iomem *mmio)
+{
+	u64 low, high;
+
+	low = readl(mmio);
+	high = readl(mmio + sizeof(u32));
+	return low | (high << 32);
+}
+#endif
+#endif
+
+#ifndef write64
+#ifdef writeq
+#define write64 writeq
+#else
+#define write64 _write64
+static inline void _write64(u64 val, void __iomem *mmio)
+{
+	writel(val, mmio);
+	writel(val >> 32, mmio + sizeof(u32));
+}
+#endif
+#endif
+
+enum {
+	/* AMD NTB Capability */
+	AMD_DB_CNT		= 16,
+	AMD_MSIX_VECTOR_CNT	= 24,
+	AMD_SPADS_CNT		= 16,
+
+	/*  AMD NTB register offset */
+	AMD_CNTL_OFFSET		= 0x200,
+
+	/* NTB control register bits */
+	PMM_REG_CTL		= BIT(21),
+	SMM_REG_CTL		= BIT(20),
+	SMM_REG_ACC_PATH	= BIT(18),
+	PMM_REG_ACC_PATH	= BIT(17),
+	NTB_CLK_EN		= BIT(16),
+
+	AMD_STA_OFFSET		= 0x204,
+	AMD_PGSLV_OFFSET	= 0x208,
+	AMD_SPAD_MUX_OFFSET	= 0x20C,
+	AMD_SPAD_OFFSET		= 0x210,
+	AMD_RSMU_HCID		= 0x250,
+	AMD_RSMU_SIID		= 0x254,
+	AMD_PSION_OFFSET	= 0x300,
+	AMD_SSION_OFFSET	= 0x330,
+	AMD_MMINDEX_OFFSET	= 0x400,
+	AMD_MMDATA_OFFSET	= 0x404,
+	AMD_SIDEINFO_OFFSET	= 0x408,
+
+	AMD_SIDE_MASK		= BIT(0),
+	AMD_SIDE_READY		= BIT(1),
+
+	/* limit register */
+	AMD_ROMBARLMT_OFFSET	= 0x410,
+	AMD_BAR1LMT_OFFSET	= 0x414,
+	AMD_BAR23LMT_OFFSET	= 0x418,
+	AMD_BAR45LMT_OFFSET	= 0x420,
+	/* xlat address */
+	AMD_POMBARXLAT_OFFSET	= 0x428,
+	AMD_BAR1XLAT_OFFSET	= 0x430,
+	AMD_BAR23XLAT_OFFSET	= 0x438,
+	AMD_BAR45XLAT_OFFSET	= 0x440,
+	/* doorbell and interrupt */
+	AMD_DBFM_OFFSET		= 0x450,
+	AMD_DBREQ_OFFSET	= 0x454,
+	AMD_MIRRDBSTAT_OFFSET	= 0x458,
+	AMD_DBMASK_OFFSET	= 0x45C,
+	AMD_DBSTAT_OFFSET	= 0x460,
+	AMD_INTMASK_OFFSET	= 0x470,
+	AMD_INTSTAT_OFFSET	= 0x474,
+
+	/* event type */
+	AMD_PEER_FLUSH_EVENT	= BIT(0),
+	AMD_PEER_RESET_EVENT	= BIT(1),
+	AMD_PEER_D3_EVENT	= BIT(2),
+	AMD_PEER_PMETO_EVENT	= BIT(3),
+	AMD_PEER_D0_EVENT	= BIT(4),
+	AMD_LINK_UP_EVENT	= BIT(5),
+	AMD_LINK_DOWN_EVENT	= BIT(6),
+	AMD_EVENT_INTMASK	= (AMD_PEER_FLUSH_EVENT |
+				AMD_PEER_RESET_EVENT | AMD_PEER_D3_EVENT |
+				AMD_PEER_PMETO_EVENT | AMD_PEER_D0_EVENT |
+				AMD_LINK_UP_EVENT | AMD_LINK_DOWN_EVENT),
+
+	AMD_PMESTAT_OFFSET	= 0x480,
+	AMD_PMSGTRIG_OFFSET	= 0x490,
+	AMD_LTRLATENCY_OFFSET	= 0x494,
+	AMD_FLUSHTRIG_OFFSET	= 0x498,
+
+	/* SMU register*/
+	AMD_SMUACK_OFFSET	= 0x4A0,
+	AMD_SINRST_OFFSET	= 0x4A4,
+	AMD_RSPNUM_OFFSET	= 0x4A8,
+	AMD_SMU_SPADMUTEX	= 0x4B0,
+	AMD_SMU_SPADOFFSET	= 0x4B4,
+
+	AMD_PEER_OFFSET		= 0x400,
+};
+
+struct ntb_dev_data {
+	const unsigned char mw_count;
+	const unsigned int mw_idx;
+	const bool is_endpoint;
+};
+
+struct amd_ntb_dev;
+
+struct amd_ntb_vec {
+	struct amd_ntb_dev	*ndev;
+	int			num;
+};
+
+struct amd_ntb_dev {
+	struct ntb_dev ntb;
+
+	u32 ntb_side;
+	u32 lnk_sta;
+	u32 cntl_sta;
+	u32 peer_sta;
+
+	struct ntb_dev_data *dev_data;
+	unsigned char mw_count;
+	unsigned char spad_count;
+	unsigned char db_count;
+	unsigned char msix_vec_count;
+
+	u64 db_valid_mask;
+	u64 db_mask;
+	u64 db_last_bit;
+	u32 int_mask;
+
+	struct msix_entry *msix;
+	struct amd_ntb_vec *vec;
+
+	/* synchronize rmw access of db_mask and hw reg */
+	spinlock_t db_mask_lock;
+
+	void __iomem *self_mmio;
+	void __iomem *peer_mmio;
+	unsigned int self_spad;
+	unsigned int peer_spad;
+
+	struct delayed_work hb_timer;
+
+	struct dentry *debugfs_dir;
+	struct dentry *debugfs_info;
+};
+
+#define ntb_ndev(__ntb) container_of(__ntb, struct amd_ntb_dev, ntb)
+#define hb_ndev(__work) container_of(__work, struct amd_ntb_dev, hb_timer.work)
+
+static void amd_set_side_info_reg(struct amd_ntb_dev *ndev, bool peer);
+static void amd_clear_side_info_reg(struct amd_ntb_dev *ndev, bool peer);
+static int amd_poll_link(struct amd_ntb_dev *ndev);
+
+#endif
diff --git a/drivers/ntb/hw/epf/Kconfig b/drivers/ntb/hw/epf/Kconfig
new file mode 100644
index 000000000..314485574
--- /dev/null
+++ b/drivers/ntb/hw/epf/Kconfig
@@ -0,0 +1,5 @@
+config NTB_EPF
+	tristate "Generic EPF Non-Transparent Bridge support"
+	help
+	  This driver supports EPF NTB on configurable endpoint.
+	  If unsure, say N.
diff --git a/drivers/ntb/hw/epf/Makefile b/drivers/ntb/hw/epf/Makefile
new file mode 100644
index 000000000..2f560a422
--- /dev/null
+++ b/drivers/ntb/hw/epf/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_NTB_EPF) += ntb_hw_epf.o
diff --git a/drivers/ntb/hw/epf/ntb_hw_epf.c b/drivers/ntb/hw/epf/ntb_hw_epf.c
new file mode 100644
index 000000000..c47607d4f
--- /dev/null
+++ b/drivers/ntb/hw/epf/ntb_hw_epf.c
@@ -0,0 +1,873 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Host side endpoint driver to implement Non-Transparent Bridge functionality
+ *
+ * Copyright (C) 2020 Texas Instruments
+ * Author: Kishon Vijay Abraham I <kishon@ti.com>
+ */
+
+#include <linux/atomic.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/slab.h>
+#include <linux/ntb.h>
+
+#define NTB_EPF_COMMAND		0x0
+#define CMD_CONFIGURE_DOORBELL	1
+#define CMD_TEARDOWN_DOORBELL	2
+#define CMD_CONFIGURE_MW	3
+#define CMD_TEARDOWN_MW		4
+#define CMD_LINK_UP		5
+#define CMD_LINK_DOWN		6
+
+#define NTB_EPF_ARGUMENT	0x4
+#define MSIX_ENABLE		BIT(16)
+
+#define NTB_EPF_CMD_STATUS	0x8
+#define COMMAND_STATUS_OK	1
+#define COMMAND_STATUS_ERROR	2
+
+#define NTB_EPF_LINK_STATUS	0x0A
+#define LINK_STATUS_UP		BIT(0)
+
+#define NTB_EPF_TOPOLOGY	0x0C
+#define NTB_EPF_LOWER_ADDR	0x10
+#define NTB_EPF_UPPER_ADDR	0x14
+#define NTB_EPF_LOWER_SIZE	0x18
+#define NTB_EPF_UPPER_SIZE	0x1C
+#define NTB_EPF_MW_COUNT	0x20
+#define NTB_EPF_MW1_OFFSET	0x24
+#define NTB_EPF_SPAD_OFFSET	0x28
+#define NTB_EPF_SPAD_COUNT	0x2C
+#define NTB_EPF_DB_ENTRY_SIZE	0x30
+#define NTB_EPF_DB_DATA(n)	(0x34 + (n) * 4)
+#define NTB_EPF_DB_OFFSET(n)	(0xB4 + (n) * 4)
+
+/*
+ * Legacy doorbell slot layout when paired with pci-epf-*ntb:
+ *
+ *   slot 0 : reserved for link events
+ *   slot 1 : unused (historical extra offset)
+ *   slot 2 : DB#0
+ *   slot 3 : DB#1
+ *   ...
+ *
+ * Thus, NTB_EPF_MIN_DB_COUNT=3 means that we at least create vectors for
+ * doorbells DB#0 and DB#1.
+ */
+#define NTB_EPF_MIN_DB_COUNT	3
+#define NTB_EPF_MAX_DB_COUNT	31
+
+#define NTB_EPF_COMMAND_TIMEOUT	1000 /* 1 Sec */
+
+enum pci_barno {
+	NO_BAR = -1,
+	BAR_0,
+	BAR_1,
+	BAR_2,
+	BAR_3,
+	BAR_4,
+	BAR_5,
+};
+
+enum epf_ntb_bar {
+	BAR_CONFIG,
+	BAR_PEER_SPAD,
+	BAR_DB,
+	BAR_MW1,
+	BAR_MW2,
+	BAR_MW3,
+	BAR_MW4,
+	NTB_BAR_NUM,
+};
+
+enum epf_irq_slot {
+	EPF_IRQ_LINK = 0,
+	EPF_IRQ_RESERVED_DB, /* Historically skipped slot */
+	EPF_IRQ_DB_START,
+};
+
+#define NTB_EPF_MAX_MW_COUNT	(NTB_BAR_NUM - BAR_MW1)
+
+struct ntb_epf_dev;
+
+struct ntb_epf_irq_ctx {
+	struct ntb_epf_dev *ndev;
+	unsigned int irq_no;
+};
+
+struct ntb_epf_dev {
+	struct ntb_dev ntb;
+	struct device *dev;
+	/* Mutex to protect providing commands to NTB EPF */
+	struct mutex cmd_lock;
+
+	const enum pci_barno *barno_map;
+
+	unsigned int mw_count;
+	unsigned int spad_count;
+	unsigned int db_count;
+
+	void __iomem *ctrl_reg;
+	void __iomem *db_reg;
+	void __iomem *peer_spad_reg;
+
+	unsigned int self_spad;
+	unsigned int peer_spad;
+
+	atomic64_t db_val;
+	u64 db_valid_mask;
+	struct ntb_epf_irq_ctx irq_ctx[NTB_EPF_MAX_DB_COUNT + 1];
+};
+
+#define ntb_ndev(__ntb) container_of(__ntb, struct ntb_epf_dev, ntb)
+
+static int ntb_epf_send_command(struct ntb_epf_dev *ndev, u32 command,
+				u32 argument)
+{
+	ktime_t timeout;
+	bool timedout;
+	int ret = 0;
+	u32 status;
+
+	mutex_lock(&ndev->cmd_lock);
+	writel(argument, ndev->ctrl_reg + NTB_EPF_ARGUMENT);
+	writel(command, ndev->ctrl_reg + NTB_EPF_COMMAND);
+
+	timeout = ktime_add_ms(ktime_get(), NTB_EPF_COMMAND_TIMEOUT);
+	while (1) {
+		timedout = ktime_after(ktime_get(), timeout);
+		status = readw(ndev->ctrl_reg + NTB_EPF_CMD_STATUS);
+
+		if (status == COMMAND_STATUS_ERROR) {
+			ret = -EINVAL;
+			break;
+		}
+
+		if (status == COMMAND_STATUS_OK)
+			break;
+
+		if (WARN_ON(timedout)) {
+			ret = -ETIMEDOUT;
+			break;
+		}
+
+		usleep_range(5, 10);
+	}
+
+	writew(0, ndev->ctrl_reg + NTB_EPF_CMD_STATUS);
+	mutex_unlock(&ndev->cmd_lock);
+
+	return ret;
+}
+
+static int ntb_epf_mw_to_bar(struct ntb_epf_dev *ndev, int idx)
+{
+	struct device *dev = ndev->dev;
+
+	if (idx < 0 || idx > ndev->mw_count) {
+		dev_err(dev, "Unsupported Memory Window index %d\n", idx);
+		return -EINVAL;
+	}
+
+	return ndev->barno_map[BAR_MW1 + idx];
+}
+
+static int ntb_epf_mw_count(struct ntb_dev *ntb, int pidx)
+{
+	struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+	struct device *dev = ndev->dev;
+
+	if (pidx != NTB_DEF_PEER_IDX) {
+		dev_err(dev, "Unsupported Peer ID %d\n", pidx);
+		return -EINVAL;
+	}
+
+	return ndev->mw_count;
+}
+
+static int ntb_epf_mw_get_align(struct ntb_dev *ntb, int pidx, int idx,
+				resource_size_t *addr_align,
+				resource_size_t *size_align,
+				resource_size_t *size_max)
+{
+	struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+	struct device *dev = ndev->dev;
+	int bar;
+
+	if (pidx != NTB_DEF_PEER_IDX) {
+		dev_err(dev, "Unsupported Peer ID %d\n", pidx);
+		return -EINVAL;
+	}
+
+	bar = ntb_epf_mw_to_bar(ndev, idx);
+	if (bar < 0)
+		return bar;
+
+	if (addr_align)
+		*addr_align = SZ_4K;
+
+	if (size_align)
+		*size_align = 1;
+
+	if (size_max)
+		*size_max = pci_resource_len(ndev->ntb.pdev, bar);
+
+	return 0;
+}
+
+static u64 ntb_epf_link_is_up(struct ntb_dev *ntb,
+			      enum ntb_speed *speed,
+			      enum ntb_width *width)
+{
+	struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+	u32 status;
+
+	status = readw(ndev->ctrl_reg + NTB_EPF_LINK_STATUS);
+
+	return status & LINK_STATUS_UP;
+}
+
+static u32 ntb_epf_spad_read(struct ntb_dev *ntb, int idx)
+{
+	struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+	struct device *dev = ndev->dev;
+	u32 offset;
+
+	if (idx < 0 || idx >= ndev->spad_count) {
+		dev_err(dev, "READ: Invalid ScratchPad Index %d\n", idx);
+		return 0;
+	}
+
+	offset = readl(ndev->ctrl_reg + NTB_EPF_SPAD_OFFSET);
+	offset += (idx << 2);
+
+	return readl(ndev->ctrl_reg + offset);
+}
+
+static int ntb_epf_spad_write(struct ntb_dev *ntb,
+			      int idx, u32 val)
+{
+	struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+	struct device *dev = ndev->dev;
+	u32 offset;
+
+	if (idx < 0 || idx >= ndev->spad_count) {
+		dev_err(dev, "WRITE: Invalid ScratchPad Index %d\n", idx);
+		return -EINVAL;
+	}
+
+	offset = readl(ndev->ctrl_reg + NTB_EPF_SPAD_OFFSET);
+	offset += (idx << 2);
+	writel(val, ndev->ctrl_reg + offset);
+
+	return 0;
+}
+
+static u32 ntb_epf_peer_spad_read(struct ntb_dev *ntb, int pidx, int idx)
+{
+	struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+	struct device *dev = ndev->dev;
+	u32 offset;
+
+	if (pidx != NTB_DEF_PEER_IDX) {
+		dev_err(dev, "Unsupported Peer ID %d\n", pidx);
+		return -EINVAL;
+	}
+
+	if (idx < 0 || idx >= ndev->spad_count) {
+		dev_err(dev, "WRITE: Invalid Peer ScratchPad Index %d\n", idx);
+		return -EINVAL;
+	}
+
+	offset = (idx << 2);
+	return readl(ndev->peer_spad_reg + offset);
+}
+
+static int ntb_epf_peer_spad_write(struct ntb_dev *ntb, int pidx,
+				   int idx, u32 val)
+{
+	struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+	struct device *dev = ndev->dev;
+	u32 offset;
+
+	if (pidx != NTB_DEF_PEER_IDX) {
+		dev_err(dev, "Unsupported Peer ID %d\n", pidx);
+		return -EINVAL;
+	}
+
+	if (idx < 0 || idx >= ndev->spad_count) {
+		dev_err(dev, "WRITE: Invalid Peer ScratchPad Index %d\n", idx);
+		return -EINVAL;
+	}
+
+	offset = (idx << 2);
+	writel(val, ndev->peer_spad_reg + offset);
+
+	return 0;
+}
+
+static int ntb_epf_link_enable(struct ntb_dev *ntb,
+			       enum ntb_speed max_speed,
+			       enum ntb_width max_width)
+{
+	struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+	struct device *dev = ndev->dev;
+	int ret;
+
+	ret = ntb_epf_send_command(ndev, CMD_LINK_UP, 0);
+	if (ret) {
+		dev_err(dev, "Fail to enable link\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int ntb_epf_link_disable(struct ntb_dev *ntb)
+{
+	struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+	struct device *dev = ndev->dev;
+	int ret;
+
+	ret = ntb_epf_send_command(ndev, CMD_LINK_DOWN, 0);
+	if (ret) {
+		dev_err(dev, "Fail to disable link\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static irqreturn_t ntb_epf_vec_isr(int irq, void *dev)
+{
+	struct ntb_epf_irq_ctx *ctx = dev;
+	struct ntb_epf_dev *ndev = ctx->ndev;
+	unsigned int db_vector;
+	unsigned int irq_no = ctx->irq_no;
+
+	if (irq_no == EPF_IRQ_LINK) {
+		ntb_link_event(&ndev->ntb);
+	} else if (irq_no == EPF_IRQ_RESERVED_DB) {
+		dev_warn_ratelimited(ndev->dev,
+				     "Unexpected reserved doorbell slot IRQ received\n");
+	} else {
+		db_vector = irq_no - EPF_IRQ_DB_START;
+		if (ndev->db_count < NTB_EPF_MIN_DB_COUNT ||
+		    db_vector >= ndev->db_count - 1) {
+			dev_warn_ratelimited(ndev->dev,
+					     "Unexpected doorbell vector %u (db_count %u)\n",
+					     db_vector, ndev->db_count);
+			return IRQ_HANDLED;
+		}
+
+		atomic64_or(BIT_ULL(db_vector), &ndev->db_val);
+		ntb_db_event(&ndev->ntb, db_vector);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int ntb_epf_init_isr(struct ntb_epf_dev *ndev, int msi_min, int msi_max)
+{
+	struct pci_dev *pdev = ndev->ntb.pdev;
+	struct device *dev = ndev->dev;
+	u32 argument = MSIX_ENABLE;
+	int irq;
+	int ret;
+	int i;
+
+	irq = pci_alloc_irq_vectors(pdev, msi_min, msi_max, PCI_IRQ_MSIX);
+	if (irq < 0) {
+		dev_dbg(dev, "Failed to get MSIX interrupts\n");
+		irq = pci_alloc_irq_vectors(pdev, msi_min, msi_max,
+					    PCI_IRQ_MSI);
+		if (irq < 0) {
+			dev_err(dev, "Failed to get MSI interrupts\n");
+			return irq;
+		}
+		argument &= ~MSIX_ENABLE;
+	}
+
+	ndev->db_count = irq - 1;
+	for (i = 0; i < irq; i++) {
+		ndev->irq_ctx[i].ndev = ndev;
+		ndev->irq_ctx[i].irq_no = i;
+		ret = request_irq(pci_irq_vector(pdev, i), ntb_epf_vec_isr,
+				  0, "ntb_epf", &ndev->irq_ctx[i]);
+		if (ret) {
+			dev_err(dev, "Failed to request irq\n");
+			goto err_free_irq;
+		}
+	}
+
+	ret = ntb_epf_send_command(ndev, CMD_CONFIGURE_DOORBELL,
+				   argument | irq);
+	if (ret) {
+		dev_err(dev, "Failed to configure doorbell\n");
+		goto err_free_irq;
+	}
+
+	return 0;
+
+err_free_irq:
+	while (i--)
+		free_irq(pci_irq_vector(pdev, i), &ndev->irq_ctx[i]);
+	pci_free_irq_vectors(pdev);
+
+	return ret;
+}
+
+static int ntb_epf_peer_mw_count(struct ntb_dev *ntb)
+{
+	return ntb_ndev(ntb)->mw_count;
+}
+
+static int ntb_epf_spad_count(struct ntb_dev *ntb)
+{
+	return ntb_ndev(ntb)->spad_count;
+}
+
+static u64 ntb_epf_db_valid_mask(struct ntb_dev *ntb)
+{
+	return ntb_ndev(ntb)->db_valid_mask;
+}
+
+static int ntb_epf_db_vector_count(struct ntb_dev *ntb)
+{
+	struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+	unsigned int db_count = ndev->db_count;
+
+	/*
+	 * db_count includes an extra skipped slot due to the legacy
+	 * doorbell layout. Expose only the real doorbell vectors.
+	 */
+	if (db_count < NTB_EPF_MIN_DB_COUNT)
+		return 0;
+
+	return db_count - 1;
+}
+
+static u64 ntb_epf_db_vector_mask(struct ntb_dev *ntb, int db_vector)
+{
+	int nr_vec;
+
+	/*
+	 * db_count includes one skipped slot in the legacy layout. Valid
+	 * doorbell vectors are therefore [0 .. (db_count - 2)].
+	 */
+	nr_vec = ntb_epf_db_vector_count(ntb);
+	if (db_vector < 0 || db_vector >= nr_vec)
+		return 0;
+
+	return BIT_ULL(db_vector);
+}
+
+static int ntb_epf_db_set_mask(struct ntb_dev *ntb, u64 db_bits)
+{
+	return 0;
+}
+
+static int ntb_epf_mw_set_trans(struct ntb_dev *ntb, int pidx, int idx,
+				dma_addr_t addr, resource_size_t size)
+{
+	struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+	struct device *dev = ndev->dev;
+	resource_size_t mw_size;
+	int bar;
+
+	if (pidx != NTB_DEF_PEER_IDX) {
+		dev_err(dev, "Unsupported Peer ID %d\n", pidx);
+		return -EINVAL;
+	}
+
+	bar = ntb_epf_mw_to_bar(ndev, idx);
+	if (bar < 0)
+		return bar;
+
+	mw_size = pci_resource_len(ntb->pdev, bar);
+
+	if (size > mw_size) {
+		dev_err(dev, "Size:%pa is greater than the MW size %pa\n",
+			&size, &mw_size);
+		return -EINVAL;
+	}
+
+	writel(lower_32_bits(addr), ndev->ctrl_reg + NTB_EPF_LOWER_ADDR);
+	writel(upper_32_bits(addr), ndev->ctrl_reg + NTB_EPF_UPPER_ADDR);
+	writel(lower_32_bits(size), ndev->ctrl_reg + NTB_EPF_LOWER_SIZE);
+	writel(upper_32_bits(size), ndev->ctrl_reg + NTB_EPF_UPPER_SIZE);
+	ntb_epf_send_command(ndev, CMD_CONFIGURE_MW, idx);
+
+	return 0;
+}
+
+static int ntb_epf_mw_clear_trans(struct ntb_dev *ntb, int pidx, int idx)
+{
+	struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+	struct device *dev = ndev->dev;
+	int ret = 0;
+
+	ntb_epf_send_command(ndev, CMD_TEARDOWN_MW, idx);
+	if (ret)
+		dev_err(dev, "Failed to teardown memory window\n");
+
+	return ret;
+}
+
+static int ntb_epf_peer_mw_get_addr(struct ntb_dev *ntb, int idx,
+				    phys_addr_t *base, resource_size_t *size)
+{
+	struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+	u32 offset = 0;
+	int bar;
+
+	if (idx == 0)
+		offset = readl(ndev->ctrl_reg + NTB_EPF_MW1_OFFSET);
+
+	bar = ntb_epf_mw_to_bar(ndev, idx);
+	if (bar < 0)
+		return bar;
+
+	if (base)
+		*base = pci_resource_start(ndev->ntb.pdev, bar) + offset;
+
+	if (size)
+		*size = pci_resource_len(ndev->ntb.pdev, bar) - offset;
+
+	return 0;
+}
+
+static int ntb_epf_peer_db_set(struct ntb_dev *ntb, u64 db_bits)
+{
+	struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+	/*
+	 * ffs() returns a 1-based bit index (bit 0 -> 1).
+	 *
+	 * With slot 0 reserved for link events, DB#0 would naturally map to
+	 * slot 1. Historically an extra +1 offset was added, so DB#0 maps to
+	 * slot 2 and slot 1 remains unused. Keep this mapping for
+	 * backward-compatibility.
+	 */
+	u32 interrupt_num = ffs(db_bits) + 1;
+	struct device *dev = ndev->dev;
+	u32 db_entry_size;
+	u32 db_offset;
+	u32 db_data;
+
+	if (interrupt_num > ndev->db_count) {
+		dev_err(dev, "DB interrupt %d greater than Max Supported %d\n",
+			interrupt_num, ndev->db_count);
+		return -EINVAL;
+	}
+
+	db_entry_size = readl(ndev->ctrl_reg + NTB_EPF_DB_ENTRY_SIZE);
+
+	db_data = readl(ndev->ctrl_reg + NTB_EPF_DB_DATA(interrupt_num));
+	db_offset = readl(ndev->ctrl_reg + NTB_EPF_DB_OFFSET(interrupt_num));
+	writel(db_data, ndev->db_reg + (db_entry_size * interrupt_num) +
+	       db_offset);
+
+	return 0;
+}
+
+static u64 ntb_epf_db_read(struct ntb_dev *ntb)
+{
+	struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+
+	return atomic64_read(&ndev->db_val);
+}
+
+static int ntb_epf_db_clear_mask(struct ntb_dev *ntb, u64 db_bits)
+{
+	return 0;
+}
+
+static int ntb_epf_db_clear(struct ntb_dev *ntb, u64 db_bits)
+{
+	struct ntb_epf_dev *ndev = ntb_ndev(ntb);
+
+	atomic64_and(~db_bits, &ndev->db_val);
+
+	return 0;
+}
+
+static const struct ntb_dev_ops ntb_epf_ops = {
+	.mw_count		= ntb_epf_mw_count,
+	.spad_count		= ntb_epf_spad_count,
+	.peer_mw_count		= ntb_epf_peer_mw_count,
+	.db_valid_mask		= ntb_epf_db_valid_mask,
+	.db_vector_count	= ntb_epf_db_vector_count,
+	.db_vector_mask		= ntb_epf_db_vector_mask,
+	.db_set_mask		= ntb_epf_db_set_mask,
+	.mw_set_trans		= ntb_epf_mw_set_trans,
+	.mw_clear_trans		= ntb_epf_mw_clear_trans,
+	.peer_mw_get_addr	= ntb_epf_peer_mw_get_addr,
+	.link_enable		= ntb_epf_link_enable,
+	.spad_read		= ntb_epf_spad_read,
+	.spad_write		= ntb_epf_spad_write,
+	.peer_spad_read		= ntb_epf_peer_spad_read,
+	.peer_spad_write	= ntb_epf_peer_spad_write,
+	.peer_db_set		= ntb_epf_peer_db_set,
+	.db_read		= ntb_epf_db_read,
+	.mw_get_align		= ntb_epf_mw_get_align,
+	.link_is_up		= ntb_epf_link_is_up,
+	.db_clear_mask		= ntb_epf_db_clear_mask,
+	.db_clear		= ntb_epf_db_clear,
+	.link_disable		= ntb_epf_link_disable,
+};
+
+static inline void ntb_epf_init_struct(struct ntb_epf_dev *ndev,
+				       struct pci_dev *pdev)
+{
+	ndev->ntb.pdev = pdev;
+	ndev->ntb.topo = NTB_TOPO_NONE;
+	ndev->ntb.ops = &ntb_epf_ops;
+}
+
+static int ntb_epf_init_dev(struct ntb_epf_dev *ndev)
+{
+	struct device *dev = ndev->dev;
+	int ret;
+
+	ndev->mw_count = readl(ndev->ctrl_reg + NTB_EPF_MW_COUNT);
+	if (ndev->mw_count > NTB_EPF_MAX_MW_COUNT) {
+		dev_err(dev, "Unsupported MW count: %u\n", ndev->mw_count);
+		return -EINVAL;
+	}
+
+	/* One Link interrupt and rest doorbell interrupt */
+	ret = ntb_epf_init_isr(ndev, NTB_EPF_MIN_DB_COUNT + 1,
+			       NTB_EPF_MAX_DB_COUNT + 1);
+	if (ret) {
+		dev_err(dev, "Failed to init ISR\n");
+		return ret;
+	}
+
+	/*
+	 * ndev->db_count includes an extra skipped slot due to the legacy
+	 * doorbell layout, hence -1.
+	 */
+	ndev->db_valid_mask = BIT_ULL(ndev->db_count - 1) - 1;
+	ndev->spad_count = readl(ndev->ctrl_reg + NTB_EPF_SPAD_COUNT);
+
+	return 0;
+}
+
+static int ntb_epf_init_pci(struct ntb_epf_dev *ndev,
+			    struct pci_dev *pdev)
+{
+	struct device *dev = ndev->dev;
+	size_t spad_sz, spad_off;
+	int ret;
+
+	pci_set_drvdata(pdev, ndev);
+
+	ret = pci_enable_device(pdev);
+	if (ret) {
+		dev_err(dev, "Cannot enable PCI device\n");
+		goto err_pci_enable;
+	}
+
+	ret = pci_request_regions(pdev, "ntb");
+	if (ret) {
+		dev_err(dev, "Cannot obtain PCI resources\n");
+		goto err_pci_regions;
+	}
+
+	pci_set_master(pdev);
+
+	ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64));
+	if (ret) {
+		ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
+		if (ret) {
+			dev_err(dev, "Cannot set DMA mask\n");
+			goto err_pci_regions;
+		}
+		dev_warn(&pdev->dev, "Cannot DMA highmem\n");
+	}
+
+	ndev->ctrl_reg = pci_iomap(pdev, ndev->barno_map[BAR_CONFIG], 0);
+	if (!ndev->ctrl_reg) {
+		ret = -EIO;
+		goto err_pci_regions;
+	}
+
+	if (ndev->barno_map[BAR_PEER_SPAD] != ndev->barno_map[BAR_CONFIG]) {
+		ndev->peer_spad_reg = pci_iomap(pdev,
+						ndev->barno_map[BAR_PEER_SPAD], 0);
+		if (!ndev->peer_spad_reg) {
+			ret = -EIO;
+			goto err_pci_regions;
+		}
+	} else {
+		spad_sz = 4 * readl(ndev->ctrl_reg + NTB_EPF_SPAD_COUNT);
+		spad_off = readl(ndev->ctrl_reg + NTB_EPF_SPAD_OFFSET);
+		ndev->peer_spad_reg = ndev->ctrl_reg + spad_off  + spad_sz;
+	}
+
+	ndev->db_reg = pci_iomap(pdev, ndev->barno_map[BAR_DB], 0);
+	if (!ndev->db_reg) {
+		ret = -EIO;
+		goto err_pci_regions;
+	}
+
+	return 0;
+
+err_pci_regions:
+	pci_disable_device(pdev);
+
+err_pci_enable:
+	pci_set_drvdata(pdev, NULL);
+
+	return ret;
+}
+
+static void ntb_epf_deinit_pci(struct ntb_epf_dev *ndev)
+{
+	struct pci_dev *pdev = ndev->ntb.pdev;
+
+	pci_iounmap(pdev, ndev->ctrl_reg);
+	if (ndev->barno_map[BAR_PEER_SPAD] != ndev->barno_map[BAR_CONFIG])
+		pci_iounmap(pdev, ndev->peer_spad_reg);
+	pci_iounmap(pdev, ndev->db_reg);
+
+	pci_release_regions(pdev);
+	pci_disable_device(pdev);
+	pci_set_drvdata(pdev, NULL);
+}
+
+static void ntb_epf_cleanup_isr(struct ntb_epf_dev *ndev)
+{
+	struct pci_dev *pdev = ndev->ntb.pdev;
+	int i;
+
+	ntb_epf_send_command(ndev, CMD_TEARDOWN_DOORBELL, ndev->db_count + 1);
+
+	for (i = 0; i < ndev->db_count + 1; i++)
+		free_irq(pci_irq_vector(pdev, i), &ndev->irq_ctx[i]);
+	pci_free_irq_vectors(pdev);
+}
+
+static int ntb_epf_pci_probe(struct pci_dev *pdev,
+			     const struct pci_device_id *id)
+{
+	struct device *dev = &pdev->dev;
+	struct ntb_epf_dev *ndev;
+	int ret;
+
+	if (pci_is_bridge(pdev))
+		return -ENODEV;
+
+	ndev = devm_kzalloc(dev, sizeof(*ndev), GFP_KERNEL);
+	if (!ndev)
+		return -ENOMEM;
+
+	ndev->barno_map = (const enum pci_barno *)id->driver_data;
+	if (!ndev->barno_map)
+		return -EINVAL;
+
+	ndev->dev = dev;
+
+	ntb_epf_init_struct(ndev, pdev);
+	mutex_init(&ndev->cmd_lock);
+
+	ret = ntb_epf_init_pci(ndev, pdev);
+	if (ret) {
+		dev_err(dev, "Failed to init PCI\n");
+		return ret;
+	}
+
+	ret = ntb_epf_init_dev(ndev);
+	if (ret) {
+		dev_err(dev, "Failed to init device\n");
+		goto err_init_dev;
+	}
+
+	ret = ntb_register_device(&ndev->ntb);
+	if (ret) {
+		dev_err(dev, "Failed to register NTB device\n");
+		goto err_register_dev;
+	}
+
+	return 0;
+
+err_register_dev:
+	ntb_epf_cleanup_isr(ndev);
+
+err_init_dev:
+	ntb_epf_deinit_pci(ndev);
+
+	return ret;
+}
+
+static void ntb_epf_pci_remove(struct pci_dev *pdev)
+{
+	struct ntb_epf_dev *ndev = pci_get_drvdata(pdev);
+
+	ntb_unregister_device(&ndev->ntb);
+	ntb_epf_cleanup_isr(ndev);
+	ntb_epf_deinit_pci(ndev);
+}
+
+static const enum pci_barno j721e_map[NTB_BAR_NUM] = {
+	[BAR_CONFIG]	= BAR_0,
+	[BAR_PEER_SPAD]	= BAR_1,
+	[BAR_DB]	= BAR_2,
+	[BAR_MW1]	= BAR_2,
+	[BAR_MW2]	= BAR_3,
+	[BAR_MW3]	= BAR_4,
+	[BAR_MW4]	= BAR_5
+};
+
+static const enum pci_barno mx8_map[NTB_BAR_NUM] = {
+	[BAR_CONFIG]	= BAR_0,
+	[BAR_PEER_SPAD]	= BAR_0,
+	[BAR_DB]	= BAR_2,
+	[BAR_MW1]	= BAR_4,
+	[BAR_MW2]	= BAR_5,
+	[BAR_MW3]	= NO_BAR,
+	[BAR_MW4]	= NO_BAR
+};
+
+static const enum pci_barno rcar_barno[NTB_BAR_NUM] = {
+	[BAR_CONFIG]	= BAR_0,
+	[BAR_PEER_SPAD]	= BAR_0,
+	[BAR_DB]	= BAR_4,
+	[BAR_MW1]	= BAR_2,
+	[BAR_MW2]	= NO_BAR,
+	[BAR_MW3]	= NO_BAR,
+	[BAR_MW4]	= NO_BAR,
+};
+
+static const struct pci_device_id ntb_epf_pci_tbl[] = {
+	{
+		PCI_DEVICE(PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_J721E),
+		.class = PCI_CLASS_MEMORY_RAM << 8, .class_mask = 0xffff00,
+		.driver_data = (kernel_ulong_t)j721e_map,
+	},
+	{
+		PCI_DEVICE(PCI_VENDOR_ID_FREESCALE, 0x0809),
+		.class = PCI_CLASS_MEMORY_RAM << 8, .class_mask = 0xffff00,
+		.driver_data = (kernel_ulong_t)mx8_map,
+	},
+	{
+		PCI_DEVICE(PCI_VENDOR_ID_RENESAS, 0x0030),
+		.class = PCI_CLASS_MEMORY_RAM << 8, .class_mask = 0xffff00,
+		.driver_data = (kernel_ulong_t)rcar_barno,
+	},
+	{ },
+};
+
+static struct pci_driver ntb_epf_pci_driver = {
+	.name		= KBUILD_MODNAME,
+	.id_table	= ntb_epf_pci_tbl,
+	.probe		= ntb_epf_pci_probe,
+	.remove		= ntb_epf_pci_remove,
+};
+module_pci_driver(ntb_epf_pci_driver);
+
+MODULE_DESCRIPTION("PCI ENDPOINT NTB HOST DRIVER");
+MODULE_AUTHOR("Kishon Vijay Abraham I <kishon@ti.com>");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/ntb/hw/idt/Kconfig b/drivers/ntb/hw/idt/Kconfig
new file mode 100644
index 000000000..c79b54c17
--- /dev/null
+++ b/drivers/ntb/hw/idt/Kconfig
@@ -0,0 +1,31 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config NTB_IDT
+	tristate "IDT PCIe-switch Non-Transparent Bridge support"
+	depends on PCI
+	select HWMON
+	help
+	 This driver supports NTB of capable IDT PCIe-switches.
+
+	 Some of the pre-initializations must be made before IDT PCIe-switch
+	 exposes its NT-functions correctly. It should be done by either proper
+	 initialization of EEPROM connected to master SMbus of the switch or
+	 by BIOS using slave-SMBus interface changing corresponding registers
+	 value. Evidently it must be done before PCI bus enumeration is
+	 finished in Linux kernel.
+
+	 First of all partitions must be activated and properly assigned to all
+	 the ports with NT-functions intended to be activated (see SWPARTxCTL
+	 and SWPORTxCTL registers). Then all NT-function BARs must be enabled
+	 with chosen valid aperture. For memory windows related BARs the
+	 aperture settings shall determine the maximum size of memory windows
+	 accepted by a BAR. Note that BAR0 must map PCI configuration space
+	 registers.
+
+	 It's worth to note, that since a part of this driver relies on the
+	 BAR settings of peer NT-functions, the BAR setups can't be done over
+	 kernel PCI fixups. That's why the alternative pre-initialization
+	 techniques like BIOS using SMBus interface or EEPROM should be
+	 utilized.
+
+	 If unsure, say N.
+
diff --git a/drivers/ntb/hw/idt/Makefile b/drivers/ntb/hw/idt/Makefile
new file mode 100644
index 000000000..f75e9d65c
--- /dev/null
+++ b/drivers/ntb/hw/idt/Makefile
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_NTB_IDT) += ntb_hw_idt.o
diff --git a/drivers/ntb/hw/idt/ntb_hw_idt.c b/drivers/ntb/hw/idt/ntb_hw_idt.c
new file mode 100644
index 000000000..f27df8d7f
--- /dev/null
+++ b/drivers/ntb/hw/idt/ntb_hw_idt.c
@@ -0,0 +1,2913 @@
+/*
+ *   This file is provided under a GPLv2 license.  When using or
+ *   redistributing this file, you may do so under that license.
+ *
+ *   GPL LICENSE SUMMARY
+ *
+ *   Copyright (C) 2016-2018 T-Platforms JSC All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or modify it
+ *   under the terms and conditions of the GNU General Public License,
+ *   version 2, as published by the Free Software Foundation.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+ *   Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License along
+ *   with this program; if not, one can be found http://www.gnu.org/licenses/.
+ *
+ *   The full GNU General Public License is included in this distribution in
+ *   the file called "COPYING".
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * IDT PCIe-switch NTB Linux driver
+ *
+ * Contact Information:
+ * Serge Semin <fancer.lancer@gmail.com>, <Sergey.Semin@t-platforms.ru>
+ */
+
+#include <linux/stddef.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/bitops.h>
+#include <linux/sizes.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+#include <linux/mutex.h>
+#include <linux/pci.h>
+#include <linux/aer.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+#include <linux/debugfs.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/ntb.h>
+
+#include "ntb_hw_idt.h"
+
+#define NTB_NAME	"ntb_hw_idt"
+#define NTB_DESC	"IDT PCI-E Non-Transparent Bridge Driver"
+#define NTB_VER		"2.0"
+#define NTB_IRQNAME	"ntb_irq_idt"
+
+MODULE_DESCRIPTION(NTB_DESC);
+MODULE_VERSION(NTB_VER);
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("T-platforms");
+
+/*
+ * NT Endpoint registers table simplifying a loop access to the functionally
+ * related registers
+ */
+static const struct idt_ntb_regs ntdata_tbl = {
+	{ {IDT_NT_BARSETUP0,	IDT_NT_BARLIMIT0,
+	   IDT_NT_BARLTBASE0,	IDT_NT_BARUTBASE0},
+	  {IDT_NT_BARSETUP1,	IDT_NT_BARLIMIT1,
+	   IDT_NT_BARLTBASE1,	IDT_NT_BARUTBASE1},
+	  {IDT_NT_BARSETUP2,	IDT_NT_BARLIMIT2,
+	   IDT_NT_BARLTBASE2,	IDT_NT_BARUTBASE2},
+	  {IDT_NT_BARSETUP3,	IDT_NT_BARLIMIT3,
+	   IDT_NT_BARLTBASE3,	IDT_NT_BARUTBASE3},
+	  {IDT_NT_BARSETUP4,	IDT_NT_BARLIMIT4,
+	   IDT_NT_BARLTBASE4,	IDT_NT_BARUTBASE4},
+	  {IDT_NT_BARSETUP5,	IDT_NT_BARLIMIT5,
+	   IDT_NT_BARLTBASE5,	IDT_NT_BARUTBASE5} },
+	{ {IDT_NT_INMSG0,	IDT_NT_OUTMSG0,	IDT_NT_INMSGSRC0},
+	  {IDT_NT_INMSG1,	IDT_NT_OUTMSG1,	IDT_NT_INMSGSRC1},
+	  {IDT_NT_INMSG2,	IDT_NT_OUTMSG2,	IDT_NT_INMSGSRC2},
+	  {IDT_NT_INMSG3,	IDT_NT_OUTMSG3,	IDT_NT_INMSGSRC3} }
+};
+
+/*
+ * NT Endpoint ports data table with the corresponding pcie command, link
+ * status, control and BAR-related registers
+ */
+static const struct idt_ntb_port portdata_tbl[IDT_MAX_NR_PORTS] = {
+/*0*/	{ IDT_SW_NTP0_PCIECMDSTS,	IDT_SW_NTP0_PCIELCTLSTS,
+	  IDT_SW_NTP0_NTCTL,
+	  IDT_SW_SWPORT0CTL,		IDT_SW_SWPORT0STS,
+	  { {IDT_SW_NTP0_BARSETUP0,	IDT_SW_NTP0_BARLIMIT0,
+	     IDT_SW_NTP0_BARLTBASE0,	IDT_SW_NTP0_BARUTBASE0},
+	    {IDT_SW_NTP0_BARSETUP1,	IDT_SW_NTP0_BARLIMIT1,
+	     IDT_SW_NTP0_BARLTBASE1,	IDT_SW_NTP0_BARUTBASE1},
+	    {IDT_SW_NTP0_BARSETUP2,	IDT_SW_NTP0_BARLIMIT2,
+	     IDT_SW_NTP0_BARLTBASE2,	IDT_SW_NTP0_BARUTBASE2},
+	    {IDT_SW_NTP0_BARSETUP3,	IDT_SW_NTP0_BARLIMIT3,
+	     IDT_SW_NTP0_BARLTBASE3,	IDT_SW_NTP0_BARUTBASE3},
+	    {IDT_SW_NTP0_BARSETUP4,	IDT_SW_NTP0_BARLIMIT4,
+	     IDT_SW_NTP0_BARLTBASE4,	IDT_SW_NTP0_BARUTBASE4},
+	    {IDT_SW_NTP0_BARSETUP5,	IDT_SW_NTP0_BARLIMIT5,
+	     IDT_SW_NTP0_BARLTBASE5,	IDT_SW_NTP0_BARUTBASE5} } },
+/*1*/	{0},
+/*2*/	{ IDT_SW_NTP2_PCIECMDSTS,	IDT_SW_NTP2_PCIELCTLSTS,
+	  IDT_SW_NTP2_NTCTL,
+	  IDT_SW_SWPORT2CTL,		IDT_SW_SWPORT2STS,
+	  { {IDT_SW_NTP2_BARSETUP0,	IDT_SW_NTP2_BARLIMIT0,
+	     IDT_SW_NTP2_BARLTBASE0,	IDT_SW_NTP2_BARUTBASE0},
+	    {IDT_SW_NTP2_BARSETUP1,	IDT_SW_NTP2_BARLIMIT1,
+	     IDT_SW_NTP2_BARLTBASE1,	IDT_SW_NTP2_BARUTBASE1},
+	    {IDT_SW_NTP2_BARSETUP2,	IDT_SW_NTP2_BARLIMIT2,
+	     IDT_SW_NTP2_BARLTBASE2,	IDT_SW_NTP2_BARUTBASE2},
+	    {IDT_SW_NTP2_BARSETUP3,	IDT_SW_NTP2_BARLIMIT3,
+	     IDT_SW_NTP2_BARLTBASE3,	IDT_SW_NTP2_BARUTBASE3},
+	    {IDT_SW_NTP2_BARSETUP4,	IDT_SW_NTP2_BARLIMIT4,
+	     IDT_SW_NTP2_BARLTBASE4,	IDT_SW_NTP2_BARUTBASE4},
+	    {IDT_SW_NTP2_BARSETUP5,	IDT_SW_NTP2_BARLIMIT5,
+	     IDT_SW_NTP2_BARLTBASE5,	IDT_SW_NTP2_BARUTBASE5} } },
+/*3*/	{0},
+/*4*/	{ IDT_SW_NTP4_PCIECMDSTS,	IDT_SW_NTP4_PCIELCTLSTS,
+	  IDT_SW_NTP4_NTCTL,
+	  IDT_SW_SWPORT4CTL,		IDT_SW_SWPORT4STS,
+	  { {IDT_SW_NTP4_BARSETUP0,	IDT_SW_NTP4_BARLIMIT0,
+	     IDT_SW_NTP4_BARLTBASE0,	IDT_SW_NTP4_BARUTBASE0},
+	    {IDT_SW_NTP4_BARSETUP1,	IDT_SW_NTP4_BARLIMIT1,
+	     IDT_SW_NTP4_BARLTBASE1,	IDT_SW_NTP4_BARUTBASE1},
+	    {IDT_SW_NTP4_BARSETUP2,	IDT_SW_NTP4_BARLIMIT2,
+	     IDT_SW_NTP4_BARLTBASE2,	IDT_SW_NTP4_BARUTBASE2},
+	    {IDT_SW_NTP4_BARSETUP3,	IDT_SW_NTP4_BARLIMIT3,
+	     IDT_SW_NTP4_BARLTBASE3,	IDT_SW_NTP4_BARUTBASE3},
+	    {IDT_SW_NTP4_BARSETUP4,	IDT_SW_NTP4_BARLIMIT4,
+	     IDT_SW_NTP4_BARLTBASE4,	IDT_SW_NTP4_BARUTBASE4},
+	    {IDT_SW_NTP4_BARSETUP5,	IDT_SW_NTP4_BARLIMIT5,
+	     IDT_SW_NTP4_BARLTBASE5,	IDT_SW_NTP4_BARUTBASE5} } },
+/*5*/	{0},
+/*6*/	{ IDT_SW_NTP6_PCIECMDSTS,	IDT_SW_NTP6_PCIELCTLSTS,
+	  IDT_SW_NTP6_NTCTL,
+	  IDT_SW_SWPORT6CTL,		IDT_SW_SWPORT6STS,
+	  { {IDT_SW_NTP6_BARSETUP0,	IDT_SW_NTP6_BARLIMIT0,
+	     IDT_SW_NTP6_BARLTBASE0,	IDT_SW_NTP6_BARUTBASE0},
+	    {IDT_SW_NTP6_BARSETUP1,	IDT_SW_NTP6_BARLIMIT1,
+	     IDT_SW_NTP6_BARLTBASE1,	IDT_SW_NTP6_BARUTBASE1},
+	    {IDT_SW_NTP6_BARSETUP2,	IDT_SW_NTP6_BARLIMIT2,
+	     IDT_SW_NTP6_BARLTBASE2,	IDT_SW_NTP6_BARUTBASE2},
+	    {IDT_SW_NTP6_BARSETUP3,	IDT_SW_NTP6_BARLIMIT3,
+	     IDT_SW_NTP6_BARLTBASE3,	IDT_SW_NTP6_BARUTBASE3},
+	    {IDT_SW_NTP6_BARSETUP4,	IDT_SW_NTP6_BARLIMIT4,
+	     IDT_SW_NTP6_BARLTBASE4,	IDT_SW_NTP6_BARUTBASE4},
+	    {IDT_SW_NTP6_BARSETUP5,	IDT_SW_NTP6_BARLIMIT5,
+	     IDT_SW_NTP6_BARLTBASE5,	IDT_SW_NTP6_BARUTBASE5} } },
+/*7*/	{0},
+/*8*/	{ IDT_SW_NTP8_PCIECMDSTS,	IDT_SW_NTP8_PCIELCTLSTS,
+	  IDT_SW_NTP8_NTCTL,
+	  IDT_SW_SWPORT8CTL,		IDT_SW_SWPORT8STS,
+	  { {IDT_SW_NTP8_BARSETUP0,	IDT_SW_NTP8_BARLIMIT0,
+	     IDT_SW_NTP8_BARLTBASE0,	IDT_SW_NTP8_BARUTBASE0},
+	    {IDT_SW_NTP8_BARSETUP1,	IDT_SW_NTP8_BARLIMIT1,
+	     IDT_SW_NTP8_BARLTBASE1,	IDT_SW_NTP8_BARUTBASE1},
+	    {IDT_SW_NTP8_BARSETUP2,	IDT_SW_NTP8_BARLIMIT2,
+	     IDT_SW_NTP8_BARLTBASE2,	IDT_SW_NTP8_BARUTBASE2},
+	    {IDT_SW_NTP8_BARSETUP3,	IDT_SW_NTP8_BARLIMIT3,
+	     IDT_SW_NTP8_BARLTBASE3,	IDT_SW_NTP8_BARUTBASE3},
+	    {IDT_SW_NTP8_BARSETUP4,	IDT_SW_NTP8_BARLIMIT4,
+	     IDT_SW_NTP8_BARLTBASE4,	IDT_SW_NTP8_BARUTBASE4},
+	    {IDT_SW_NTP8_BARSETUP5,	IDT_SW_NTP8_BARLIMIT5,
+	     IDT_SW_NTP8_BARLTBASE5,	IDT_SW_NTP8_BARUTBASE5} } },
+/*9*/	{0},
+/*10*/	{0},
+/*11*/	{0},
+/*12*/	{ IDT_SW_NTP12_PCIECMDSTS,	IDT_SW_NTP12_PCIELCTLSTS,
+	  IDT_SW_NTP12_NTCTL,
+	  IDT_SW_SWPORT12CTL,		IDT_SW_SWPORT12STS,
+	  { {IDT_SW_NTP12_BARSETUP0,	IDT_SW_NTP12_BARLIMIT0,
+	     IDT_SW_NTP12_BARLTBASE0,	IDT_SW_NTP12_BARUTBASE0},
+	    {IDT_SW_NTP12_BARSETUP1,	IDT_SW_NTP12_BARLIMIT1,
+	     IDT_SW_NTP12_BARLTBASE1,	IDT_SW_NTP12_BARUTBASE1},
+	    {IDT_SW_NTP12_BARSETUP2,	IDT_SW_NTP12_BARLIMIT2,
+	     IDT_SW_NTP12_BARLTBASE2,	IDT_SW_NTP12_BARUTBASE2},
+	    {IDT_SW_NTP12_BARSETUP3,	IDT_SW_NTP12_BARLIMIT3,
+	     IDT_SW_NTP12_BARLTBASE3,	IDT_SW_NTP12_BARUTBASE3},
+	    {IDT_SW_NTP12_BARSETUP4,	IDT_SW_NTP12_BARLIMIT4,
+	     IDT_SW_NTP12_BARLTBASE4,	IDT_SW_NTP12_BARUTBASE4},
+	    {IDT_SW_NTP12_BARSETUP5,	IDT_SW_NTP12_BARLIMIT5,
+	     IDT_SW_NTP12_BARLTBASE5,	IDT_SW_NTP12_BARUTBASE5} } },
+/*13*/	{0},
+/*14*/	{0},
+/*15*/	{0},
+/*16*/	{ IDT_SW_NTP16_PCIECMDSTS,	IDT_SW_NTP16_PCIELCTLSTS,
+	  IDT_SW_NTP16_NTCTL,
+	  IDT_SW_SWPORT16CTL,		IDT_SW_SWPORT16STS,
+	  { {IDT_SW_NTP16_BARSETUP0,	IDT_SW_NTP16_BARLIMIT0,
+	     IDT_SW_NTP16_BARLTBASE0,	IDT_SW_NTP16_BARUTBASE0},
+	    {IDT_SW_NTP16_BARSETUP1,	IDT_SW_NTP16_BARLIMIT1,
+	     IDT_SW_NTP16_BARLTBASE1,	IDT_SW_NTP16_BARUTBASE1},
+	    {IDT_SW_NTP16_BARSETUP2,	IDT_SW_NTP16_BARLIMIT2,
+	     IDT_SW_NTP16_BARLTBASE2,	IDT_SW_NTP16_BARUTBASE2},
+	    {IDT_SW_NTP16_BARSETUP3,	IDT_SW_NTP16_BARLIMIT3,
+	     IDT_SW_NTP16_BARLTBASE3,	IDT_SW_NTP16_BARUTBASE3},
+	    {IDT_SW_NTP16_BARSETUP4,	IDT_SW_NTP16_BARLIMIT4,
+	     IDT_SW_NTP16_BARLTBASE4,	IDT_SW_NTP16_BARUTBASE4},
+	    {IDT_SW_NTP16_BARSETUP5,	IDT_SW_NTP16_BARLIMIT5,
+	     IDT_SW_NTP16_BARLTBASE5,	IDT_SW_NTP16_BARUTBASE5} } },
+/*17*/	{0},
+/*18*/	{0},
+/*19*/	{0},
+/*20*/	{ IDT_SW_NTP20_PCIECMDSTS,	IDT_SW_NTP20_PCIELCTLSTS,
+	  IDT_SW_NTP20_NTCTL,
+	  IDT_SW_SWPORT20CTL,		IDT_SW_SWPORT20STS,
+	  { {IDT_SW_NTP20_BARSETUP0,	IDT_SW_NTP20_BARLIMIT0,
+	     IDT_SW_NTP20_BARLTBASE0,	IDT_SW_NTP20_BARUTBASE0},
+	    {IDT_SW_NTP20_BARSETUP1,	IDT_SW_NTP20_BARLIMIT1,
+	     IDT_SW_NTP20_BARLTBASE1,	IDT_SW_NTP20_BARUTBASE1},
+	    {IDT_SW_NTP20_BARSETUP2,	IDT_SW_NTP20_BARLIMIT2,
+	     IDT_SW_NTP20_BARLTBASE2,	IDT_SW_NTP20_BARUTBASE2},
+	    {IDT_SW_NTP20_BARSETUP3,	IDT_SW_NTP20_BARLIMIT3,
+	     IDT_SW_NTP20_BARLTBASE3,	IDT_SW_NTP20_BARUTBASE3},
+	    {IDT_SW_NTP20_BARSETUP4,	IDT_SW_NTP20_BARLIMIT4,
+	     IDT_SW_NTP20_BARLTBASE4,	IDT_SW_NTP20_BARUTBASE4},
+	    {IDT_SW_NTP20_BARSETUP5,	IDT_SW_NTP20_BARLIMIT5,
+	     IDT_SW_NTP20_BARLTBASE5,	IDT_SW_NTP20_BARUTBASE5} } },
+/*21*/	{0},
+/*22*/	{0},
+/*23*/	{0}
+};
+
+/*
+ * IDT PCIe-switch partitions table with the corresponding control, status
+ * and messages control registers
+ */
+static const struct idt_ntb_part partdata_tbl[IDT_MAX_NR_PARTS] = {
+/*0*/	{ IDT_SW_SWPART0CTL,	IDT_SW_SWPART0STS,
+	  {IDT_SW_SWP0MSGCTL0,	IDT_SW_SWP0MSGCTL1,
+	   IDT_SW_SWP0MSGCTL2,	IDT_SW_SWP0MSGCTL3} },
+/*1*/	{ IDT_SW_SWPART1CTL,	IDT_SW_SWPART1STS,
+	  {IDT_SW_SWP1MSGCTL0,	IDT_SW_SWP1MSGCTL1,
+	   IDT_SW_SWP1MSGCTL2,	IDT_SW_SWP1MSGCTL3} },
+/*2*/	{ IDT_SW_SWPART2CTL,	IDT_SW_SWPART2STS,
+	  {IDT_SW_SWP2MSGCTL0,	IDT_SW_SWP2MSGCTL1,
+	   IDT_SW_SWP2MSGCTL2,	IDT_SW_SWP2MSGCTL3} },
+/*3*/	{ IDT_SW_SWPART3CTL,	IDT_SW_SWPART3STS,
+	  {IDT_SW_SWP3MSGCTL0,	IDT_SW_SWP3MSGCTL1,
+	   IDT_SW_SWP3MSGCTL2,	IDT_SW_SWP3MSGCTL3} },
+/*4*/	{ IDT_SW_SWPART4CTL,	IDT_SW_SWPART4STS,
+	  {IDT_SW_SWP4MSGCTL0,	IDT_SW_SWP4MSGCTL1,
+	   IDT_SW_SWP4MSGCTL2,	IDT_SW_SWP4MSGCTL3} },
+/*5*/	{ IDT_SW_SWPART5CTL,	IDT_SW_SWPART5STS,
+	  {IDT_SW_SWP5MSGCTL0,	IDT_SW_SWP5MSGCTL1,
+	   IDT_SW_SWP5MSGCTL2,	IDT_SW_SWP5MSGCTL3} },
+/*6*/	{ IDT_SW_SWPART6CTL,	IDT_SW_SWPART6STS,
+	  {IDT_SW_SWP6MSGCTL0,	IDT_SW_SWP6MSGCTL1,
+	   IDT_SW_SWP6MSGCTL2,	IDT_SW_SWP6MSGCTL3} },
+/*7*/	{ IDT_SW_SWPART7CTL,	IDT_SW_SWPART7STS,
+	  {IDT_SW_SWP7MSGCTL0,	IDT_SW_SWP7MSGCTL1,
+	   IDT_SW_SWP7MSGCTL2,	IDT_SW_SWP7MSGCTL3} }
+};
+
+/*
+ * DebugFS directory to place the driver debug file
+ */
+static struct dentry *dbgfs_topdir;
+
+/*=============================================================================
+ *                1. IDT PCIe-switch registers IO-functions
+ *
+ *    Beside ordinary configuration space registers IDT PCIe-switch expose
+ * global configuration registers, which are used to determine state of other
+ * device ports as well as being notified of some switch-related events.
+ * Additionally all the configuration space registers of all the IDT
+ * PCIe-switch functions are mapped to the Global Address space, so each
+ * function can determine a configuration of any other PCI-function.
+ *    Functions declared in this chapter are created to encapsulate access
+ * to configuration and global registers, so the driver code just need to
+ * provide IDT NTB hardware descriptor and a register address.
+ *=============================================================================
+ */
+
+/*
+ * idt_nt_write() - PCI configuration space registers write method
+ * @ndev:	IDT NTB hardware driver descriptor
+ * @reg:	Register to write data to
+ * @data:	Value to write to the register
+ *
+ * IDT PCIe-switch registers are all Little endian.
+ */
+static void idt_nt_write(struct idt_ntb_dev *ndev,
+			 const unsigned int reg, const u32 data)
+{
+	/*
+	 * It's obvious bug to request a register exceeding the maximum possible
+	 * value as well as to have it unaligned.
+	 */
+	if (WARN_ON(reg > IDT_REG_PCI_MAX || !IS_ALIGNED(reg, IDT_REG_ALIGN)))
+		return;
+
+	/* Just write the value to the specified register */
+	iowrite32(data, ndev->cfgspc + (ptrdiff_t)reg);
+}
+
+/*
+ * idt_nt_read() - PCI configuration space registers read method
+ * @ndev:	IDT NTB hardware driver descriptor
+ * @reg:	Register to write data to
+ *
+ * IDT PCIe-switch Global configuration registers are all Little endian.
+ *
+ * Return: register value
+ */
+static u32 idt_nt_read(struct idt_ntb_dev *ndev, const unsigned int reg)
+{
+	/*
+	 * It's obvious bug to request a register exceeding the maximum possible
+	 * value as well as to have it unaligned.
+	 */
+	if (WARN_ON(reg > IDT_REG_PCI_MAX || !IS_ALIGNED(reg, IDT_REG_ALIGN)))
+		return ~0;
+
+	/* Just read the value from the specified register */
+	return ioread32(ndev->cfgspc + (ptrdiff_t)reg);
+}
+
+/*
+ * idt_sw_write() - Global registers write method
+ * @ndev:	IDT NTB hardware driver descriptor
+ * @reg:	Register to write data to
+ * @data:	Value to write to the register
+ *
+ * IDT PCIe-switch Global configuration registers are all Little endian.
+ */
+static void idt_sw_write(struct idt_ntb_dev *ndev,
+			 const unsigned int reg, const u32 data)
+{
+	unsigned long irqflags;
+
+	/*
+	 * It's obvious bug to request a register exceeding the maximum possible
+	 * value as well as to have it unaligned.
+	 */
+	if (WARN_ON(reg > IDT_REG_SW_MAX || !IS_ALIGNED(reg, IDT_REG_ALIGN)))
+		return;
+
+	/* Lock GASA registers operations */
+	spin_lock_irqsave(&ndev->gasa_lock, irqflags);
+	/* Set the global register address */
+	iowrite32((u32)reg, ndev->cfgspc + (ptrdiff_t)IDT_NT_GASAADDR);
+	/* Put the new value of the register */
+	iowrite32(data, ndev->cfgspc + (ptrdiff_t)IDT_NT_GASADATA);
+	/* Unlock GASA registers operations */
+	spin_unlock_irqrestore(&ndev->gasa_lock, irqflags);
+}
+
+/*
+ * idt_sw_read() - Global registers read method
+ * @ndev:	IDT NTB hardware driver descriptor
+ * @reg:	Register to write data to
+ *
+ * IDT PCIe-switch Global configuration registers are all Little endian.
+ *
+ * Return: register value
+ */
+static u32 idt_sw_read(struct idt_ntb_dev *ndev, const unsigned int reg)
+{
+	unsigned long irqflags;
+	u32 data;
+
+	/*
+	 * It's obvious bug to request a register exceeding the maximum possible
+	 * value as well as to have it unaligned.
+	 */
+	if (WARN_ON(reg > IDT_REG_SW_MAX || !IS_ALIGNED(reg, IDT_REG_ALIGN)))
+		return ~0;
+
+	/* Lock GASA registers operations */
+	spin_lock_irqsave(&ndev->gasa_lock, irqflags);
+	/* Set the global register address */
+	iowrite32((u32)reg, ndev->cfgspc + (ptrdiff_t)IDT_NT_GASAADDR);
+	/* Get the data of the register (read ops acts as MMIO barrier) */
+	data = ioread32(ndev->cfgspc + (ptrdiff_t)IDT_NT_GASADATA);
+	/* Unlock GASA registers operations */
+	spin_unlock_irqrestore(&ndev->gasa_lock, irqflags);
+
+	return data;
+}
+
+/*
+ * idt_reg_set_bits() - set bits of a passed register
+ * @ndev:	IDT NTB hardware driver descriptor
+ * @reg:	Register to change bits of
+ * @reg_lock:	Register access spin lock
+ * @valid_mask:	Mask of valid bits
+ * @set_bits:	Bitmask to set
+ *
+ * Helper method to check whether a passed bitfield is valid and set
+ * corresponding bits of a register.
+ *
+ * WARNING! Make sure the passed register isn't accessed over plane
+ * idt_nt_write() method (read method is ok to be used concurrently).
+ *
+ * Return: zero on success, negative error on invalid bitmask.
+ */
+static inline int idt_reg_set_bits(struct idt_ntb_dev *ndev, unsigned int reg,
+				   spinlock_t *reg_lock,
+				   u64 valid_mask, u64 set_bits)
+{
+	unsigned long irqflags;
+	u32 data;
+
+	if (set_bits & ~(u64)valid_mask)
+		return -EINVAL;
+
+	/* Lock access to the register unless the change is written back */
+	spin_lock_irqsave(reg_lock, irqflags);
+	data = idt_nt_read(ndev, reg) | (u32)set_bits;
+	idt_nt_write(ndev, reg, data);
+	/* Unlock the register */
+	spin_unlock_irqrestore(reg_lock, irqflags);
+
+	return 0;
+}
+
+/*
+ * idt_reg_clear_bits() - clear bits of a passed register
+ * @ndev:	IDT NTB hardware driver descriptor
+ * @reg:	Register to change bits of
+ * @reg_lock:	Register access spin lock
+ * @set_bits:	Bitmask to clear
+ *
+ * Helper method to check whether a passed bitfield is valid and clear
+ * corresponding bits of a register.
+ *
+ * NOTE! Invalid bits are always considered cleared so it's not an error
+ * to clear them over.
+ *
+ * WARNING! Make sure the passed register isn't accessed over plane
+ * idt_nt_write() method (read method is ok to use concurrently).
+ */
+static inline void idt_reg_clear_bits(struct idt_ntb_dev *ndev,
+				     unsigned int reg, spinlock_t *reg_lock,
+				     u64 clear_bits)
+{
+	unsigned long irqflags;
+	u32 data;
+
+	/* Lock access to the register unless the change is written back */
+	spin_lock_irqsave(reg_lock, irqflags);
+	data = idt_nt_read(ndev, reg) & ~(u32)clear_bits;
+	idt_nt_write(ndev, reg, data);
+	/* Unlock the register */
+	spin_unlock_irqrestore(reg_lock, irqflags);
+}
+
+/*===========================================================================
+ *                           2. Ports operations
+ *
+ *    IDT PCIe-switches can have from 3 up to 8 ports with possible
+ * NT-functions enabled. So all the possible ports need to be scanned looking
+ * for NTB activated. NTB API will have enumerated only the ports with NTB.
+ *===========================================================================
+ */
+
+/*
+ * idt_scan_ports() - scan IDT PCIe-switch ports collecting info in the tables
+ * @ndev:	Pointer to the PCI device descriptor
+ *
+ * Return: zero on success, otherwise a negative error number.
+ */
+static int idt_scan_ports(struct idt_ntb_dev *ndev)
+{
+	unsigned char pidx, port, part;
+	u32 data, portsts, partsts;
+
+	/* Retrieve the local port number */
+	data = idt_nt_read(ndev, IDT_NT_PCIELCAP);
+	ndev->port = GET_FIELD(PCIELCAP_PORTNUM, data);
+
+	/* Retrieve the local partition number */
+	portsts = idt_sw_read(ndev, portdata_tbl[ndev->port].sts);
+	ndev->part = GET_FIELD(SWPORTxSTS_SWPART, portsts);
+
+	/* Initialize port/partition -> index tables with invalid values */
+	memset(ndev->port_idx_map, -EINVAL, sizeof(ndev->port_idx_map));
+	memset(ndev->part_idx_map, -EINVAL, sizeof(ndev->part_idx_map));
+
+	/*
+	 * Walk over all the possible ports checking whether any of them has
+	 * NT-function activated
+	 */
+	ndev->peer_cnt = 0;
+	for (pidx = 0; pidx < ndev->swcfg->port_cnt; pidx++) {
+		port = ndev->swcfg->ports[pidx];
+		/* Skip local port */
+		if (port == ndev->port)
+			continue;
+
+		/* Read the port status register to get it partition */
+		portsts = idt_sw_read(ndev, portdata_tbl[port].sts);
+		part = GET_FIELD(SWPORTxSTS_SWPART, portsts);
+
+		/* Retrieve the partition status */
+		partsts = idt_sw_read(ndev, partdata_tbl[part].sts);
+		/* Check if partition state is active and port has NTB */
+		if (IS_FLD_SET(SWPARTxSTS_STATE, partsts, ACT) &&
+		    (IS_FLD_SET(SWPORTxSTS_MODE, portsts, NT) ||
+		     IS_FLD_SET(SWPORTxSTS_MODE, portsts, USNT) ||
+		     IS_FLD_SET(SWPORTxSTS_MODE, portsts, USNTDMA) ||
+		     IS_FLD_SET(SWPORTxSTS_MODE, portsts, NTDMA))) {
+			/* Save the port and partition numbers */
+			ndev->peers[ndev->peer_cnt].port = port;
+			ndev->peers[ndev->peer_cnt].part = part;
+			/* Fill in the port/partition -> index tables */
+			ndev->port_idx_map[port] = ndev->peer_cnt;
+			ndev->part_idx_map[part] = ndev->peer_cnt;
+			ndev->peer_cnt++;
+		}
+	}
+
+	dev_dbg(&ndev->ntb.pdev->dev, "Local port: %hhu, num of peers: %hhu\n",
+		ndev->port, ndev->peer_cnt);
+
+	/* It's useless to have this driver loaded if there is no any peer */
+	if (ndev->peer_cnt == 0) {
+		dev_warn(&ndev->ntb.pdev->dev, "No active peer found\n");
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+/*
+ * idt_ntb_port_number() - get the local port number
+ * @ntb:	NTB device context.
+ *
+ * Return: the local port number
+ */
+static int idt_ntb_port_number(struct ntb_dev *ntb)
+{
+	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+
+	return ndev->port;
+}
+
+/*
+ * idt_ntb_peer_port_count() - get the number of peer ports
+ * @ntb:	NTB device context.
+ *
+ * Return the count of detected peer NT-functions.
+ *
+ * Return: number of peer ports
+ */
+static int idt_ntb_peer_port_count(struct ntb_dev *ntb)
+{
+	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+
+	return ndev->peer_cnt;
+}
+
+/*
+ * idt_ntb_peer_port_number() - get peer port by given index
+ * @ntb:	NTB device context.
+ * @pidx:	Peer port index.
+ *
+ * Return: peer port or negative error
+ */
+static int idt_ntb_peer_port_number(struct ntb_dev *ntb, int pidx)
+{
+	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+
+	if (pidx < 0 || ndev->peer_cnt <= pidx)
+		return -EINVAL;
+
+	/* Return the detected NT-function port number */
+	return ndev->peers[pidx].port;
+}
+
+/*
+ * idt_ntb_peer_port_idx() - get peer port index by given port number
+ * @ntb:	NTB device context.
+ * @port:	Peer port number.
+ *
+ * Internal port -> index table is pre-initialized with -EINVAL values,
+ * so we just need to return it value
+ *
+ * Return: peer NT-function port index or negative error
+ */
+static int idt_ntb_peer_port_idx(struct ntb_dev *ntb, int port)
+{
+	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+
+	if (port < 0 || IDT_MAX_NR_PORTS <= port)
+		return -EINVAL;
+
+	return ndev->port_idx_map[port];
+}
+
+/*===========================================================================
+ *                         3. Link status operations
+ *    There is no any ready-to-use method to have peer ports notified if NTB
+ * link is set up or got down. Instead global signal can be used instead.
+ * In case if any one of ports changes local NTB link state, it sends
+ * global signal and clears corresponding global state bit. Then all the ports
+ * receive a notification of that, so to make client driver being aware of
+ * possible NTB link change.
+ *    Additionally each of active NT-functions is subscribed to PCIe-link
+ * state changes of peer ports.
+ *===========================================================================
+ */
+
+static void idt_ntb_local_link_disable(struct idt_ntb_dev *ndev);
+
+/*
+ * idt_init_link() - Initialize NTB link state notification subsystem
+ * @ndev:	IDT NTB hardware driver descriptor
+ *
+ * Function performs the basic initialization of some global registers
+ * needed to enable IRQ-based notifications of PCIe Link Up/Down and
+ * Global Signal events.
+ * NOTE Since it's not possible to determine when all the NTB peer drivers are
+ * unloaded as well as have those registers accessed concurrently, we must
+ * preinitialize them with the same value and leave it uncleared on local
+ * driver unload.
+ */
+static void idt_init_link(struct idt_ntb_dev *ndev)
+{
+	u32 part_mask, port_mask, se_mask;
+	unsigned char pidx;
+
+	/* Initialize spin locker of Mapping Table access registers */
+	spin_lock_init(&ndev->mtbl_lock);
+
+	/* Walk over all detected peers collecting port and partition masks */
+	port_mask = ~BIT(ndev->port);
+	part_mask = ~BIT(ndev->part);
+	for (pidx = 0; pidx < ndev->peer_cnt; pidx++) {
+		port_mask &= ~BIT(ndev->peers[pidx].port);
+		part_mask &= ~BIT(ndev->peers[pidx].part);
+	}
+
+	/* Clean the Link Up/Down and GLobal Signal status registers */
+	idt_sw_write(ndev, IDT_SW_SELINKUPSTS, (u32)-1);
+	idt_sw_write(ndev, IDT_SW_SELINKDNSTS, (u32)-1);
+	idt_sw_write(ndev, IDT_SW_SEGSIGSTS, (u32)-1);
+
+	/* Unmask NT-activated partitions to receive Global Switch events */
+	idt_sw_write(ndev, IDT_SW_SEPMSK, part_mask);
+
+	/* Enable PCIe Link Up events of NT-activated ports */
+	idt_sw_write(ndev, IDT_SW_SELINKUPMSK, port_mask);
+
+	/* Enable PCIe Link Down events of NT-activated ports */
+	idt_sw_write(ndev, IDT_SW_SELINKDNMSK, port_mask);
+
+	/* Unmask NT-activated partitions to receive Global Signal events */
+	idt_sw_write(ndev, IDT_SW_SEGSIGMSK, part_mask);
+
+	/* Unmask Link Up/Down and Global Switch Events */
+	se_mask = ~(IDT_SEMSK_LINKUP | IDT_SEMSK_LINKDN | IDT_SEMSK_GSIGNAL);
+	idt_sw_write(ndev, IDT_SW_SEMSK, se_mask);
+
+	dev_dbg(&ndev->ntb.pdev->dev, "NTB link status events initialized");
+}
+
+/*
+ * idt_deinit_link() - deinitialize link subsystem
+ * @ndev:	IDT NTB hardware driver descriptor
+ *
+ * Just disable the link back.
+ */
+static void idt_deinit_link(struct idt_ntb_dev *ndev)
+{
+	/* Disable the link */
+	idt_ntb_local_link_disable(ndev);
+
+	dev_dbg(&ndev->ntb.pdev->dev, "NTB link status events deinitialized");
+}
+
+/*
+ * idt_se_isr() - switch events ISR
+ * @ndev:	IDT NTB hardware driver descriptor
+ * @ntint_sts:	NT-function interrupt status
+ *
+ * This driver doesn't support IDT PCIe-switch dynamic reconfigurations,
+ * Failover capability, etc, so switch events are utilized to notify of
+ * PCIe and NTB link events.
+ * The method is called from PCIe ISR bottom-half routine.
+ */
+static void idt_se_isr(struct idt_ntb_dev *ndev, u32 ntint_sts)
+{
+	u32 sests;
+
+	/* Read Switch Events status */
+	sests = idt_sw_read(ndev, IDT_SW_SESTS);
+
+	/* Clean the Link Up/Down and Global Signal status registers */
+	idt_sw_write(ndev, IDT_SW_SELINKUPSTS, (u32)-1);
+	idt_sw_write(ndev, IDT_SW_SELINKDNSTS, (u32)-1);
+	idt_sw_write(ndev, IDT_SW_SEGSIGSTS, (u32)-1);
+
+	/* Clean the corresponding interrupt bit */
+	idt_nt_write(ndev, IDT_NT_NTINTSTS, IDT_NTINTSTS_SEVENT);
+
+	dev_dbg(&ndev->ntb.pdev->dev, "SE IRQ detected %#08x (SESTS %#08x)",
+			  ntint_sts, sests);
+
+	/* Notify the client driver of possible link state change */
+	ntb_link_event(&ndev->ntb);
+}
+
+/*
+ * idt_ntb_local_link_enable() - enable the local NTB link.
+ * @ndev:	IDT NTB hardware driver descriptor
+ *
+ * In order to enable the NTB link we need:
+ * - enable Completion TLPs translation
+ * - initialize mapping table to enable the Request ID translation
+ * - notify peers of NTB link state change
+ */
+static void idt_ntb_local_link_enable(struct idt_ntb_dev *ndev)
+{
+	u32 reqid, mtbldata = 0;
+	unsigned long irqflags;
+
+	/* Enable the ID protection and Completion TLPs translation */
+	idt_nt_write(ndev, IDT_NT_NTCTL, IDT_NTCTL_CPEN);
+
+	/* Retrieve the current Requester ID (Bus:Device:Function) */
+	reqid = idt_nt_read(ndev, IDT_NT_REQIDCAP);
+
+	/*
+	 * Set the corresponding NT Mapping table entry of port partition index
+	 * with the data to perform the Request ID translation
+	 */
+	mtbldata = SET_FIELD(NTMTBLDATA_REQID, 0, reqid) |
+		   SET_FIELD(NTMTBLDATA_PART, 0, ndev->part) |
+		   IDT_NTMTBLDATA_VALID;
+	spin_lock_irqsave(&ndev->mtbl_lock, irqflags);
+	idt_nt_write(ndev, IDT_NT_NTMTBLADDR, ndev->part);
+	idt_nt_write(ndev, IDT_NT_NTMTBLDATA, mtbldata);
+	spin_unlock_irqrestore(&ndev->mtbl_lock, irqflags);
+
+	/* Notify the peers by setting and clearing the global signal bit */
+	idt_nt_write(ndev, IDT_NT_NTGSIGNAL, IDT_NTGSIGNAL_SET);
+	idt_sw_write(ndev, IDT_SW_SEGSIGSTS, (u32)1 << ndev->part);
+}
+
+/*
+ * idt_ntb_local_link_disable() - disable the local NTB link.
+ * @ndev:	IDT NTB hardware driver descriptor
+ *
+ * In order to enable the NTB link we need:
+ * - disable Completion TLPs translation
+ * - clear corresponding mapping table entry
+ * - notify peers of NTB link state change
+ */
+static void idt_ntb_local_link_disable(struct idt_ntb_dev *ndev)
+{
+	unsigned long irqflags;
+
+	/* Disable Completion TLPs translation */
+	idt_nt_write(ndev, IDT_NT_NTCTL, 0);
+
+	/* Clear the corresponding NT Mapping table entry */
+	spin_lock_irqsave(&ndev->mtbl_lock, irqflags);
+	idt_nt_write(ndev, IDT_NT_NTMTBLADDR, ndev->part);
+	idt_nt_write(ndev, IDT_NT_NTMTBLDATA, 0);
+	spin_unlock_irqrestore(&ndev->mtbl_lock, irqflags);
+
+	/* Notify the peers by setting and clearing the global signal bit */
+	idt_nt_write(ndev, IDT_NT_NTGSIGNAL, IDT_NTGSIGNAL_SET);
+	idt_sw_write(ndev, IDT_SW_SEGSIGSTS, (u32)1 << ndev->part);
+}
+
+/*
+ * idt_ntb_local_link_is_up() - test wethter local NTB link is up
+ * @ndev:	IDT NTB hardware driver descriptor
+ *
+ * Local link is up under the following conditions:
+ * - Bus mastering is enabled
+ * - NTCTL has Completion TLPs translation enabled
+ * - Mapping table permits Request TLPs translation
+ * NOTE: We don't need to check PCIe link state since it's obviously
+ * up while we are able to communicate with IDT PCIe-switch
+ *
+ * Return: true if link is up, otherwise false
+ */
+static bool idt_ntb_local_link_is_up(struct idt_ntb_dev *ndev)
+{
+	unsigned long irqflags;
+	u32 data;
+
+	/* Read the local Bus Master Enable status */
+	data = idt_nt_read(ndev, IDT_NT_PCICMDSTS);
+	if (!(data & IDT_PCICMDSTS_BME))
+		return false;
+
+	/* Read the local Completion TLPs translation enable status */
+	data = idt_nt_read(ndev, IDT_NT_NTCTL);
+	if (!(data & IDT_NTCTL_CPEN))
+		return false;
+
+	/* Read Mapping table entry corresponding to the local partition */
+	spin_lock_irqsave(&ndev->mtbl_lock, irqflags);
+	idt_nt_write(ndev, IDT_NT_NTMTBLADDR, ndev->part);
+	data = idt_nt_read(ndev, IDT_NT_NTMTBLDATA);
+	spin_unlock_irqrestore(&ndev->mtbl_lock, irqflags);
+
+	return !!(data & IDT_NTMTBLDATA_VALID);
+}
+
+/*
+ * idt_ntb_peer_link_is_up() - test whether peer NTB link is up
+ * @ndev:	IDT NTB hardware driver descriptor
+ * @pidx:	Peer port index
+ *
+ * Peer link is up under the following conditions:
+ * - PCIe link is up
+ * - Bus mastering is enabled
+ * - NTCTL has Completion TLPs translation enabled
+ * - Mapping table permits Request TLPs translation
+ *
+ * Return: true if link is up, otherwise false
+ */
+static bool idt_ntb_peer_link_is_up(struct idt_ntb_dev *ndev, int pidx)
+{
+	unsigned long irqflags;
+	unsigned char port;
+	u32 data;
+
+	/* Retrieve the device port number */
+	port = ndev->peers[pidx].port;
+
+	/* Check whether PCIe link is up */
+	data = idt_sw_read(ndev, portdata_tbl[port].sts);
+	if (!(data & IDT_SWPORTxSTS_LINKUP))
+		return false;
+
+	/* Check whether bus mastering is enabled on the peer port */
+	data = idt_sw_read(ndev, portdata_tbl[port].pcicmdsts);
+	if (!(data & IDT_PCICMDSTS_BME))
+		return false;
+
+	/* Check if Completion TLPs translation is enabled on the peer port */
+	data = idt_sw_read(ndev, portdata_tbl[port].ntctl);
+	if (!(data & IDT_NTCTL_CPEN))
+		return false;
+
+	/* Read Mapping table entry corresponding to the peer partition */
+	spin_lock_irqsave(&ndev->mtbl_lock, irqflags);
+	idt_nt_write(ndev, IDT_NT_NTMTBLADDR, ndev->peers[pidx].part);
+	data = idt_nt_read(ndev, IDT_NT_NTMTBLDATA);
+	spin_unlock_irqrestore(&ndev->mtbl_lock, irqflags);
+
+	return !!(data & IDT_NTMTBLDATA_VALID);
+}
+
+/*
+ * idt_ntb_link_is_up() - get the current ntb link state (NTB API callback)
+ * @ntb:	NTB device context.
+ * @speed:	OUT - The link speed expressed as PCIe generation number.
+ * @width:	OUT - The link width expressed as the number of PCIe lanes.
+ *
+ * Get the bitfield of NTB link states for all peer ports
+ *
+ * Return: bitfield of indexed ports link state: bit is set/cleared if the
+ *         link is up/down respectively.
+ */
+static u64 idt_ntb_link_is_up(struct ntb_dev *ntb,
+			      enum ntb_speed *speed, enum ntb_width *width)
+{
+	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+	unsigned char pidx;
+	u64 status;
+	u32 data;
+
+	/* Retrieve the local link speed and width */
+	if (speed != NULL || width != NULL) {
+		data = idt_nt_read(ndev, IDT_NT_PCIELCTLSTS);
+		if (speed != NULL)
+			*speed = GET_FIELD(PCIELCTLSTS_CLS, data);
+		if (width != NULL)
+			*width = GET_FIELD(PCIELCTLSTS_NLW, data);
+	}
+
+	/* If local NTB link isn't up then all the links are considered down */
+	if (!idt_ntb_local_link_is_up(ndev))
+		return 0;
+
+	/* Collect all the peer ports link states into the bitfield */
+	status = 0;
+	for (pidx = 0; pidx < ndev->peer_cnt; pidx++) {
+		if (idt_ntb_peer_link_is_up(ndev, pidx))
+			status |= ((u64)1 << pidx);
+	}
+
+	return status;
+}
+
+/*
+ * idt_ntb_link_enable() - enable local port ntb link (NTB API callback)
+ * @ntb:	NTB device context.
+ * @max_speed:	The maximum link speed expressed as PCIe generation number.
+ * @max_width:	The maximum link width expressed as the number of PCIe lanes.
+ *
+ * Enable just local NTB link. PCIe link parameters are ignored.
+ *
+ * Return: always zero.
+ */
+static int idt_ntb_link_enable(struct ntb_dev *ntb, enum ntb_speed speed,
+			       enum ntb_width width)
+{
+	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+
+	/* Just enable the local NTB link */
+	idt_ntb_local_link_enable(ndev);
+
+	dev_dbg(&ndev->ntb.pdev->dev, "Local NTB link enabled");
+
+	return 0;
+}
+
+/*
+ * idt_ntb_link_disable() - disable local port ntb link (NTB API callback)
+ * @ntb:	NTB device context.
+ *
+ * Disable just local NTB link.
+ *
+ * Return: always zero.
+ */
+static int idt_ntb_link_disable(struct ntb_dev *ntb)
+{
+	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+
+	/* Just disable the local NTB link */
+	idt_ntb_local_link_disable(ndev);
+
+	dev_dbg(&ndev->ntb.pdev->dev, "Local NTB link disabled");
+
+	return 0;
+}
+
+/*=============================================================================
+ *                         4. Memory Window operations
+ *
+ *    IDT PCIe-switches have two types of memory windows: MWs with direct
+ * address translation and MWs with LUT based translation. The first type of
+ * MWs is simple map of corresponding BAR address space to a memory space
+ * of specified target port. So it implemets just ont-to-one mapping. Lookup
+ * table in its turn can map one BAR address space to up to 24 different
+ * memory spaces of different ports.
+ *    NT-functions BARs can be turned on to implement either direct or lookup
+ * table based address translations, so:
+ * BAR0 - NT configuration registers space/direct address translation
+ * BAR1 - direct address translation/upper address of BAR0x64
+ * BAR2 - direct address translation/Lookup table with either 12 or 24 entries
+ * BAR3 - direct address translation/upper address of BAR2x64
+ * BAR4 - direct address translation/Lookup table with either 12 or 24 entries
+ * BAR5 - direct address translation/upper address of BAR4x64
+ *    Additionally BAR2 and BAR4 can't have 24-entries LUT enabled at the same
+ * time. Since the BARs setup can be rather complicated this driver implements
+ * a scanning algorithm to have all the possible memory windows configuration
+ * covered.
+ *
+ * NOTE 1 BAR setup must be done before Linux kernel enumerated NT-function
+ * of any port, so this driver would have memory windows configurations fixed.
+ * In this way all initializations must be performed either by platform BIOS
+ * or using EEPROM connected to IDT PCIe-switch master SMBus.
+ *
+ * NOTE 2 This driver expects BAR0 mapping NT-function configuration space.
+ * Easy calculation can give us an upper boundary of 29 possible memory windows
+ * per each NT-function if all the BARs are of 32bit type.
+ *=============================================================================
+ */
+
+/*
+ * idt_get_mw_count() - get memory window count
+ * @mw_type:	Memory window type
+ *
+ * Return: number of memory windows with respect to the BAR type
+ */
+static inline unsigned char idt_get_mw_count(enum idt_mw_type mw_type)
+{
+	switch (mw_type) {
+	case IDT_MW_DIR:
+		return 1;
+	case IDT_MW_LUT12:
+		return 12;
+	case IDT_MW_LUT24:
+		return 24;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+/*
+ * idt_get_mw_name() - get memory window name
+ * @mw_type:	Memory window type
+ *
+ * Return: pointer to a string with name
+ */
+static inline char *idt_get_mw_name(enum idt_mw_type mw_type)
+{
+	switch (mw_type) {
+	case IDT_MW_DIR:
+		return "DIR  ";
+	case IDT_MW_LUT12:
+		return "LUT12";
+	case IDT_MW_LUT24:
+		return "LUT24";
+	default:
+		break;
+	}
+
+	return "unknown";
+}
+
+/*
+ * idt_scan_mws() - scan memory windows of the port
+ * @ndev:	IDT NTB hardware driver descriptor
+ * @port:	Port to get number of memory windows for
+ * @mw_cnt:	Out - number of memory windows
+ *
+ * It walks over BAR setup registers of the specified port and determines
+ * the memory windows parameters if any activated.
+ *
+ * Return: array of memory windows
+ */
+static struct idt_mw_cfg *idt_scan_mws(struct idt_ntb_dev *ndev, int port,
+				       unsigned char *mw_cnt)
+{
+	struct idt_mw_cfg *mws;
+	const struct idt_ntb_bar *bars;
+	enum idt_mw_type mw_type;
+	unsigned char widx, bidx, en_cnt;
+	bool bar_64bit = false;
+	int aprt_size;
+	u32 data;
+
+	mws = devm_kcalloc(&ndev->ntb.pdev->dev, IDT_MAX_NR_MWS,
+			   sizeof(*mws), GFP_KERNEL);
+	if (!mws)
+		return ERR_PTR(-ENOMEM);
+
+	/* Retrieve the array of the BARs registers */
+	bars = portdata_tbl[port].bars;
+
+	/* Scan all the BARs belonging to the port */
+	*mw_cnt = 0;
+	for (bidx = 0; bidx < IDT_BAR_CNT; bidx += 1 + bar_64bit) {
+		/* Read BARSETUP register value */
+		data = idt_sw_read(ndev, bars[bidx].setup);
+
+		/* Skip disabled BARs */
+		if (!(data & IDT_BARSETUP_EN)) {
+			bar_64bit = false;
+			continue;
+		}
+
+		/* Skip next BARSETUP if current one has 64bit addressing */
+		bar_64bit = IS_FLD_SET(BARSETUP_TYPE, data, 64);
+
+		/* Skip configuration space mapping BARs */
+		if (data & IDT_BARSETUP_MODE_CFG)
+			continue;
+
+		/* Retrieve MW type/entries count and aperture size */
+		mw_type = GET_FIELD(BARSETUP_ATRAN, data);
+		en_cnt = idt_get_mw_count(mw_type);
+		aprt_size = (u64)1 << GET_FIELD(BARSETUP_SIZE, data);
+
+		/* Save configurations of all available memory windows */
+		for (widx = 0; widx < en_cnt; widx++, (*mw_cnt)++) {
+			/*
+			 * IDT can expose a limited number of MWs, so it's bug
+			 * to have more than the driver expects
+			 */
+			if (*mw_cnt >= IDT_MAX_NR_MWS)
+				return ERR_PTR(-EINVAL);
+
+			/* Save basic MW info */
+			mws[*mw_cnt].type = mw_type;
+			mws[*mw_cnt].bar = bidx;
+			mws[*mw_cnt].idx = widx;
+			/* It's always DWORD aligned */
+			mws[*mw_cnt].addr_align = IDT_TRANS_ALIGN;
+			/* DIR and LUT approachs differently configure MWs */
+			if (mw_type == IDT_MW_DIR)
+				mws[*mw_cnt].size_max = aprt_size;
+			else if (mw_type == IDT_MW_LUT12)
+				mws[*mw_cnt].size_max = aprt_size / 16;
+			else
+				mws[*mw_cnt].size_max = aprt_size / 32;
+			mws[*mw_cnt].size_align = (mw_type == IDT_MW_DIR) ?
+				IDT_DIR_SIZE_ALIGN : mws[*mw_cnt].size_max;
+		}
+	}
+
+	return mws;
+}
+
+/*
+ * idt_init_mws() - initialize memory windows subsystem
+ * @ndev:	IDT NTB hardware driver descriptor
+ *
+ * Scan BAR setup registers of local and peer ports to determine the
+ * outbound and inbound memory windows parameters
+ *
+ * Return: zero on success, otherwise a negative error number
+ */
+static int idt_init_mws(struct idt_ntb_dev *ndev)
+{
+	struct idt_ntb_peer *peer;
+	unsigned char pidx;
+
+	/* Scan memory windows of the local port */
+	ndev->mws = idt_scan_mws(ndev, ndev->port, &ndev->mw_cnt);
+	if (IS_ERR(ndev->mws)) {
+		dev_err(&ndev->ntb.pdev->dev,
+			"Failed to scan mws of local port %hhu", ndev->port);
+		return PTR_ERR(ndev->mws);
+	}
+
+	/* Scan memory windows of the peer ports */
+	for (pidx = 0; pidx < ndev->peer_cnt; pidx++) {
+		peer = &ndev->peers[pidx];
+		peer->mws = idt_scan_mws(ndev, peer->port, &peer->mw_cnt);
+		if (IS_ERR(peer->mws)) {
+			dev_err(&ndev->ntb.pdev->dev,
+				"Failed to scan mws of port %hhu", peer->port);
+			return PTR_ERR(peer->mws);
+		}
+	}
+
+	/* Initialize spin locker of the LUT registers */
+	spin_lock_init(&ndev->lut_lock);
+
+	dev_dbg(&ndev->ntb.pdev->dev, "Outbound and inbound MWs initialized");
+
+	return 0;
+}
+
+/*
+ * idt_ntb_mw_count() - number of inbound memory windows (NTB API callback)
+ * @ntb:	NTB device context.
+ * @pidx:	Port index of peer device.
+ *
+ * The value is returned for the specified peer, so generally speaking it can
+ * be different for different port depending on the IDT PCIe-switch
+ * initialization.
+ *
+ * Return: the number of memory windows.
+ */
+static int idt_ntb_mw_count(struct ntb_dev *ntb, int pidx)
+{
+	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+
+	if (pidx < 0 || ndev->peer_cnt <= pidx)
+		return -EINVAL;
+
+	return ndev->peers[pidx].mw_cnt;
+}
+
+/*
+ * idt_ntb_mw_get_align() - inbound memory window parameters (NTB API callback)
+ * @ntb:	NTB device context.
+ * @pidx:	Port index of peer device.
+ * @widx:	Memory window index.
+ * @addr_align:	OUT - the base alignment for translating the memory window
+ * @size_align:	OUT - the size alignment for translating the memory window
+ * @size_max:	OUT - the maximum size of the memory window
+ *
+ * The peer memory window parameters have already been determined, so just
+ * return the corresponding values, which mustn't change within session.
+ *
+ * Return: Zero on success, otherwise a negative error number.
+ */
+static int idt_ntb_mw_get_align(struct ntb_dev *ntb, int pidx, int widx,
+				resource_size_t *addr_align,
+				resource_size_t *size_align,
+				resource_size_t *size_max)
+{
+	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+	struct idt_ntb_peer *peer;
+
+	if (pidx < 0 || ndev->peer_cnt <= pidx)
+		return -EINVAL;
+
+	peer = &ndev->peers[pidx];
+
+	if (widx < 0 || peer->mw_cnt <= widx)
+		return -EINVAL;
+
+	if (addr_align != NULL)
+		*addr_align = peer->mws[widx].addr_align;
+
+	if (size_align != NULL)
+		*size_align = peer->mws[widx].size_align;
+
+	if (size_max != NULL)
+		*size_max = peer->mws[widx].size_max;
+
+	return 0;
+}
+
+/*
+ * idt_ntb_peer_mw_count() - number of outbound memory windows
+ *			     (NTB API callback)
+ * @ntb:	NTB device context.
+ *
+ * Outbound memory windows parameters have been determined based on the
+ * BAR setup registers value, which are mostly constants within one session.
+ *
+ * Return: the number of memory windows.
+ */
+static int idt_ntb_peer_mw_count(struct ntb_dev *ntb)
+{
+	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+
+	return ndev->mw_cnt;
+}
+
+/*
+ * idt_ntb_peer_mw_get_addr() - get map address of an outbound memory window
+ *				(NTB API callback)
+ * @ntb:	NTB device context.
+ * @widx:	Memory window index (within ntb_peer_mw_count() return value).
+ * @base:	OUT - the base address of mapping region.
+ * @size:	OUT - the size of mapping region.
+ *
+ * Return just parameters of BAR resources mapping. Size reflects just the size
+ * of the resource
+ *
+ * Return: Zero on success, otherwise a negative error number.
+ */
+static int idt_ntb_peer_mw_get_addr(struct ntb_dev *ntb, int widx,
+				    phys_addr_t *base, resource_size_t *size)
+{
+	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+
+	if (widx < 0 || ndev->mw_cnt <= widx)
+		return -EINVAL;
+
+	/* Mapping address is just properly shifted BAR resource start */
+	if (base != NULL)
+		*base = pci_resource_start(ntb->pdev, ndev->mws[widx].bar) +
+			ndev->mws[widx].idx * ndev->mws[widx].size_max;
+
+	/* Mapping size has already been calculated at MWs scanning */
+	if (size != NULL)
+		*size = ndev->mws[widx].size_max;
+
+	return 0;
+}
+
+/*
+ * idt_ntb_peer_mw_set_trans() - set a translation address of a memory window
+ *				 (NTB API callback)
+ * @ntb:	NTB device context.
+ * @pidx:	Port index of peer device the translation address received from.
+ * @widx:	Memory window index.
+ * @addr:	The dma address of the shared memory to access.
+ * @size:	The size of the shared memory to access.
+ *
+ * The Direct address translation and LUT base translation is initialized a
+ * bit differenet. Although the parameters restriction are now determined by
+ * the same code.
+ *
+ * Return: Zero on success, otherwise an error number.
+ */
+static int idt_ntb_peer_mw_set_trans(struct ntb_dev *ntb, int pidx, int widx,
+				     u64 addr, resource_size_t size)
+{
+	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+	struct idt_mw_cfg *mw_cfg;
+	u32 data = 0, lutoff = 0;
+
+	if (pidx < 0 || ndev->peer_cnt <= pidx)
+		return -EINVAL;
+
+	if (widx < 0 || ndev->mw_cnt <= widx)
+		return -EINVAL;
+
+	/*
+	 * Retrieve the memory window config to make sure the passed arguments
+	 * fit it restrictions
+	 */
+	mw_cfg = &ndev->mws[widx];
+	if (!IS_ALIGNED(addr, mw_cfg->addr_align))
+		return -EINVAL;
+	if (!IS_ALIGNED(size, mw_cfg->size_align) || size > mw_cfg->size_max)
+		return -EINVAL;
+
+	/* DIR and LUT based translations are initialized differently */
+	if (mw_cfg->type == IDT_MW_DIR) {
+		const struct idt_ntb_bar *bar = &ntdata_tbl.bars[mw_cfg->bar];
+		u64 limit;
+		/* Set destination partition of translation */
+		data = idt_nt_read(ndev, bar->setup);
+		data = SET_FIELD(BARSETUP_TPART, data, ndev->peers[pidx].part);
+		idt_nt_write(ndev, bar->setup, data);
+		/* Set translation base address */
+		idt_nt_write(ndev, bar->ltbase, (u32)addr);
+		idt_nt_write(ndev, bar->utbase, (u32)(addr >> 32));
+		/* Set the custom BAR aperture limit */
+		limit = pci_bus_address(ntb->pdev, mw_cfg->bar) + size;
+		idt_nt_write(ndev, bar->limit, (u32)limit);
+		if (IS_FLD_SET(BARSETUP_TYPE, data, 64))
+			idt_nt_write(ndev, (bar + 1)->limit, (limit >> 32));
+	} else {
+		unsigned long irqflags;
+		/* Initialize corresponding LUT entry */
+		lutoff = SET_FIELD(LUTOFFSET_INDEX, 0, mw_cfg->idx) |
+			 SET_FIELD(LUTOFFSET_BAR, 0, mw_cfg->bar);
+		data = SET_FIELD(LUTUDATA_PART, 0, ndev->peers[pidx].part) |
+			IDT_LUTUDATA_VALID;
+		spin_lock_irqsave(&ndev->lut_lock, irqflags);
+		idt_nt_write(ndev, IDT_NT_LUTOFFSET, lutoff);
+		idt_nt_write(ndev, IDT_NT_LUTLDATA, (u32)addr);
+		idt_nt_write(ndev, IDT_NT_LUTMDATA, (u32)(addr >> 32));
+		idt_nt_write(ndev, IDT_NT_LUTUDATA, data);
+		spin_unlock_irqrestore(&ndev->lut_lock, irqflags);
+		/* Limit address isn't specified since size is fixed for LUT */
+	}
+
+	return 0;
+}
+
+/*
+ * idt_ntb_peer_mw_clear_trans() - clear the outbound MW translation address
+ *				   (NTB API callback)
+ * @ntb:	NTB device context.
+ * @pidx:	Port index of peer device.
+ * @widx:	Memory window index.
+ *
+ * It effectively disables the translation over the specified outbound MW.
+ *
+ * Return: Zero on success, otherwise an error number.
+ */
+static int idt_ntb_peer_mw_clear_trans(struct ntb_dev *ntb, int pidx,
+					int widx)
+{
+	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+	struct idt_mw_cfg *mw_cfg;
+
+	if (pidx < 0 || ndev->peer_cnt <= pidx)
+		return -EINVAL;
+
+	if (widx < 0 || ndev->mw_cnt <= widx)
+		return -EINVAL;
+
+	mw_cfg = &ndev->mws[widx];
+
+	/* DIR and LUT based translations are initialized differently */
+	if (mw_cfg->type == IDT_MW_DIR) {
+		const struct idt_ntb_bar *bar = &ntdata_tbl.bars[mw_cfg->bar];
+		u32 data;
+		/* Read BARSETUP to check BAR type */
+		data = idt_nt_read(ndev, bar->setup);
+		/* Disable translation by specifying zero BAR limit */
+		idt_nt_write(ndev, bar->limit, 0);
+		if (IS_FLD_SET(BARSETUP_TYPE, data, 64))
+			idt_nt_write(ndev, (bar + 1)->limit, 0);
+	} else {
+		unsigned long irqflags;
+		u32 lutoff;
+		/* Clear the corresponding LUT entry up */
+		lutoff = SET_FIELD(LUTOFFSET_INDEX, 0, mw_cfg->idx) |
+			 SET_FIELD(LUTOFFSET_BAR, 0, mw_cfg->bar);
+		spin_lock_irqsave(&ndev->lut_lock, irqflags);
+		idt_nt_write(ndev, IDT_NT_LUTOFFSET, lutoff);
+		idt_nt_write(ndev, IDT_NT_LUTLDATA, 0);
+		idt_nt_write(ndev, IDT_NT_LUTMDATA, 0);
+		idt_nt_write(ndev, IDT_NT_LUTUDATA, 0);
+		spin_unlock_irqrestore(&ndev->lut_lock, irqflags);
+	}
+
+	return 0;
+}
+
+/*=============================================================================
+ *                          5. Doorbell operations
+ *
+ *    Doorbell functionality of IDT PCIe-switches is pretty unusual. First of
+ * all there is global doorbell register which state can be changed by any
+ * NT-function of the IDT device in accordance with global permissions. These
+ * permissions configs are not supported by NTB API, so it must be done by
+ * either BIOS or EEPROM settings. In the same way the state of the global
+ * doorbell is reflected to the NT-functions local inbound doorbell registers.
+ * It can lead to situations when client driver sets some peer doorbell bits
+ * and get them bounced back to local inbound doorbell if permissions are
+ * granted.
+ *    Secondly there is just one IRQ vector for Doorbell, Message, Temperature
+ * and Switch events, so if client driver left any of Doorbell bits set and
+ * some other event occurred, the driver will be notified of Doorbell event
+ * again.
+ *=============================================================================
+ */
+
+/*
+ * idt_db_isr() - doorbell event ISR
+ * @ndev:	IDT NTB hardware driver descriptor
+ * @ntint_sts:	NT-function interrupt status
+ *
+ * Doorbell event happans when DBELL bit of NTINTSTS switches from 0 to 1.
+ * It happens only when unmasked doorbell bits are set to ones on completely
+ * zeroed doorbell register.
+ * The method is called from PCIe ISR bottom-half routine.
+ */
+static void idt_db_isr(struct idt_ntb_dev *ndev, u32 ntint_sts)
+{
+	/*
+	 * Doorbell IRQ status will be cleaned only when client
+	 * driver unsets all the doorbell bits.
+	 */
+	dev_dbg(&ndev->ntb.pdev->dev, "DB IRQ detected %#08x", ntint_sts);
+
+	/* Notify the client driver of possible doorbell state change */
+	ntb_db_event(&ndev->ntb, 0);
+}
+
+/*
+ * idt_ntb_db_valid_mask() - get a mask of doorbell bits supported by the ntb
+ *			     (NTB API callback)
+ * @ntb:	NTB device context.
+ *
+ * IDT PCIe-switches expose just one Doorbell register of DWORD size.
+ *
+ * Return: A mask of doorbell bits supported by the ntb.
+ */
+static u64 idt_ntb_db_valid_mask(struct ntb_dev *ntb)
+{
+	return IDT_DBELL_MASK;
+}
+
+/*
+ * idt_ntb_db_read() - read the local doorbell register (NTB API callback)
+ * @ntb:	NTB device context.
+ *
+ * There is just on inbound doorbell register of each NT-function, so
+ * this method return it value.
+ *
+ * Return: The bits currently set in the local doorbell register.
+ */
+static u64 idt_ntb_db_read(struct ntb_dev *ntb)
+{
+	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+
+	return idt_nt_read(ndev, IDT_NT_INDBELLSTS);
+}
+
+/*
+ * idt_ntb_db_clear() - clear bits in the local doorbell register
+ *			(NTB API callback)
+ * @ntb:	NTB device context.
+ * @db_bits:	Doorbell bits to clear.
+ *
+ * Clear bits of inbound doorbell register by writing ones to it.
+ *
+ * NOTE! Invalid bits are always considered cleared so it's not an error
+ * to clear them over.
+ *
+ * Return: always zero as success.
+ */
+static int idt_ntb_db_clear(struct ntb_dev *ntb, u64 db_bits)
+{
+	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+
+	idt_nt_write(ndev, IDT_NT_INDBELLSTS, (u32)db_bits);
+
+	return 0;
+}
+
+/*
+ * idt_ntb_db_read_mask() - read the local doorbell mask (NTB API callback)
+ * @ntb:	NTB device context.
+ *
+ * Each inbound doorbell bit can be masked from generating IRQ by setting
+ * the corresponding bit in inbound doorbell mask. So this method returns
+ * the value of the register.
+ *
+ * Return: The bits currently set in the local doorbell mask register.
+ */
+static u64 idt_ntb_db_read_mask(struct ntb_dev *ntb)
+{
+	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+
+	return idt_nt_read(ndev, IDT_NT_INDBELLMSK);
+}
+
+/*
+ * idt_ntb_db_set_mask() - set bits in the local doorbell mask
+ *			   (NTB API callback)
+ * @ntb:	NTB device context.
+ * @db_bits:	Doorbell mask bits to set.
+ *
+ * The inbound doorbell register mask value must be read, then OR'ed with
+ * passed field and only then set back.
+ *
+ * Return: zero on success, negative error if invalid argument passed.
+ */
+static int idt_ntb_db_set_mask(struct ntb_dev *ntb, u64 db_bits)
+{
+	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+
+	return idt_reg_set_bits(ndev, IDT_NT_INDBELLMSK, &ndev->db_mask_lock,
+				IDT_DBELL_MASK, db_bits);
+}
+
+/*
+ * idt_ntb_db_clear_mask() - clear bits in the local doorbell mask
+ *			     (NTB API callback)
+ * @ntb:	NTB device context.
+ * @db_bits:	Doorbell bits to clear.
+ *
+ * The method just clears the set bits up in accordance with the passed
+ * bitfield. IDT PCIe-switch shall generate an interrupt if there hasn't
+ * been any unmasked bit set before current unmasking. Otherwise IRQ won't
+ * be generated since there is only one IRQ vector for all doorbells.
+ *
+ * Return: always zero as success
+ */
+static int idt_ntb_db_clear_mask(struct ntb_dev *ntb, u64 db_bits)
+{
+	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+
+	idt_reg_clear_bits(ndev, IDT_NT_INDBELLMSK, &ndev->db_mask_lock,
+			   db_bits);
+
+	return 0;
+}
+
+/*
+ * idt_ntb_peer_db_set() - set bits in the peer doorbell register
+ *			   (NTB API callback)
+ * @ntb:	NTB device context.
+ * @db_bits:	Doorbell bits to set.
+ *
+ * IDT PCIe-switches exposes local outbound doorbell register to change peer
+ * inbound doorbell register state.
+ *
+ * Return: zero on success, negative error if invalid argument passed.
+ */
+static int idt_ntb_peer_db_set(struct ntb_dev *ntb, u64 db_bits)
+{
+	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+
+	if (db_bits & ~(u64)IDT_DBELL_MASK)
+		return -EINVAL;
+
+	idt_nt_write(ndev, IDT_NT_OUTDBELLSET, (u32)db_bits);
+	return 0;
+}
+
+/*=============================================================================
+ *                          6. Messaging operations
+ *
+ *    Each NT-function of IDT PCIe-switch has four inbound and four outbound
+ * message registers. Each outbound message register can be connected to one or
+ * even more than one peer inbound message registers by setting global
+ * configurations. Since NTB API permits one-on-one message registers mapping
+ * only, the driver acts in according with that restriction.
+ *=============================================================================
+ */
+
+/*
+ * idt_init_msg() - initialize messaging interface
+ * @ndev:	IDT NTB hardware driver descriptor
+ *
+ * Just initialize the message registers routing tables locker.
+ */
+static void idt_init_msg(struct idt_ntb_dev *ndev)
+{
+	unsigned char midx;
+
+	/* Init the messages routing table lockers */
+	for (midx = 0; midx < IDT_MSG_CNT; midx++)
+		spin_lock_init(&ndev->msg_locks[midx]);
+
+	dev_dbg(&ndev->ntb.pdev->dev, "NTB Messaging initialized");
+}
+
+/*
+ * idt_msg_isr() - message event ISR
+ * @ndev:	IDT NTB hardware driver descriptor
+ * @ntint_sts:	NT-function interrupt status
+ *
+ * Message event happens when MSG bit of NTINTSTS switches from 0 to 1.
+ * It happens only when unmasked message status bits are set to ones on
+ * completely zeroed message status register.
+ * The method is called from PCIe ISR bottom-half routine.
+ */
+static void idt_msg_isr(struct idt_ntb_dev *ndev, u32 ntint_sts)
+{
+	/*
+	 * Message IRQ status will be cleaned only when client
+	 * driver unsets all the message status bits.
+	 */
+	dev_dbg(&ndev->ntb.pdev->dev, "Message IRQ detected %#08x", ntint_sts);
+
+	/* Notify the client driver of possible message status change */
+	ntb_msg_event(&ndev->ntb);
+}
+
+/*
+ * idt_ntb_msg_count() - get the number of message registers (NTB API callback)
+ * @ntb:	NTB device context.
+ *
+ * IDT PCIe-switches support four message registers.
+ *
+ * Return: the number of message registers.
+ */
+static int idt_ntb_msg_count(struct ntb_dev *ntb)
+{
+	return IDT_MSG_CNT;
+}
+
+/*
+ * idt_ntb_msg_inbits() - get a bitfield of inbound message registers status
+ *			  (NTB API callback)
+ * @ntb:	NTB device context.
+ *
+ * NT message status register is shared between inbound and outbound message
+ * registers status
+ *
+ * Return: bitfield of inbound message registers.
+ */
+static u64 idt_ntb_msg_inbits(struct ntb_dev *ntb)
+{
+	return (u64)IDT_INMSG_MASK;
+}
+
+/*
+ * idt_ntb_msg_outbits() - get a bitfield of outbound message registers status
+ *			  (NTB API callback)
+ * @ntb:	NTB device context.
+ *
+ * NT message status register is shared between inbound and outbound message
+ * registers status
+ *
+ * Return: bitfield of outbound message registers.
+ */
+static u64 idt_ntb_msg_outbits(struct ntb_dev *ntb)
+{
+	return (u64)IDT_OUTMSG_MASK;
+}
+
+/*
+ * idt_ntb_msg_read_sts() - read the message registers status (NTB API callback)
+ * @ntb:	NTB device context.
+ *
+ * IDT PCIe-switches expose message status registers to notify drivers of
+ * incoming data and failures in case if peer message register isn't freed.
+ *
+ * Return: status bits of message registers
+ */
+static u64 idt_ntb_msg_read_sts(struct ntb_dev *ntb)
+{
+	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+
+	return idt_nt_read(ndev, IDT_NT_MSGSTS);
+}
+
+/*
+ * idt_ntb_msg_clear_sts() - clear status bits of message registers
+ *			     (NTB API callback)
+ * @ntb:	NTB device context.
+ * @sts_bits:	Status bits to clear.
+ *
+ * Clear bits in the status register by writing ones.
+ *
+ * NOTE! Invalid bits are always considered cleared so it's not an error
+ * to clear them over.
+ *
+ * Return: always zero as success.
+ */
+static int idt_ntb_msg_clear_sts(struct ntb_dev *ntb, u64 sts_bits)
+{
+	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+
+	idt_nt_write(ndev, IDT_NT_MSGSTS, sts_bits);
+
+	return 0;
+}
+
+/*
+ * idt_ntb_msg_set_mask() - set mask of message register status bits
+ *			    (NTB API callback)
+ * @ntb:	NTB device context.
+ * @mask_bits:	Mask bits.
+ *
+ * Mask the message status bits from raising an IRQ.
+ *
+ * Return: zero on success, negative error if invalid argument passed.
+ */
+static int idt_ntb_msg_set_mask(struct ntb_dev *ntb, u64 mask_bits)
+{
+	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+
+	return idt_reg_set_bits(ndev, IDT_NT_MSGSTSMSK, &ndev->msg_mask_lock,
+				IDT_MSG_MASK, mask_bits);
+}
+
+/*
+ * idt_ntb_msg_clear_mask() - clear message registers mask
+ *			      (NTB API callback)
+ * @ntb:	NTB device context.
+ * @mask_bits:	Mask bits.
+ *
+ * Clear mask of message status bits IRQs.
+ *
+ * Return: always zero as success.
+ */
+static int idt_ntb_msg_clear_mask(struct ntb_dev *ntb, u64 mask_bits)
+{
+	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+
+	idt_reg_clear_bits(ndev, IDT_NT_MSGSTSMSK, &ndev->msg_mask_lock,
+			   mask_bits);
+
+	return 0;
+}
+
+/*
+ * idt_ntb_msg_read() - read message register with specified index
+ *			(NTB API callback)
+ * @ntb:	NTB device context.
+ * @pidx:	OUT - Port index of peer device a message retrieved from
+ * @midx:	Message register index
+ *
+ * Read data from the specified message register and source register.
+ *
+ * Return: inbound message register value.
+ */
+static u32 idt_ntb_msg_read(struct ntb_dev *ntb, int *pidx, int midx)
+{
+	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+
+	if (midx < 0 || IDT_MSG_CNT <= midx)
+		return ~(u32)0;
+
+	/* Retrieve source port index of the message */
+	if (pidx != NULL) {
+		u32 srcpart;
+
+		srcpart = idt_nt_read(ndev, ntdata_tbl.msgs[midx].src);
+		*pidx = ndev->part_idx_map[srcpart];
+
+		/* Sanity check partition index (for initial case) */
+		if (*pidx == -EINVAL)
+			*pidx = 0;
+	}
+
+	/* Retrieve data of the corresponding message register */
+	return idt_nt_read(ndev, ntdata_tbl.msgs[midx].in);
+}
+
+/*
+ * idt_ntb_peer_msg_write() - write data to the specified message register
+ *			      (NTB API callback)
+ * @ntb:	NTB device context.
+ * @pidx:	Port index of peer device a message being sent to
+ * @midx:	Message register index
+ * @msg:	Data to send
+ *
+ * Just try to send data to a peer. Message status register should be
+ * checked by client driver.
+ *
+ * Return: zero on success, negative error if invalid argument passed.
+ */
+static int idt_ntb_peer_msg_write(struct ntb_dev *ntb, int pidx, int midx,
+				  u32 msg)
+{
+	struct idt_ntb_dev *ndev = to_ndev_ntb(ntb);
+	unsigned long irqflags;
+	u32 swpmsgctl = 0;
+
+	if (midx < 0 || IDT_MSG_CNT <= midx)
+		return -EINVAL;
+
+	if (pidx < 0 || ndev->peer_cnt <= pidx)
+		return -EINVAL;
+
+	/* Collect the routing information */
+	swpmsgctl = SET_FIELD(SWPxMSGCTL_REG, 0, midx) |
+		    SET_FIELD(SWPxMSGCTL_PART, 0, ndev->peers[pidx].part);
+
+	/* Lock the messages routing table of the specified register */
+	spin_lock_irqsave(&ndev->msg_locks[midx], irqflags);
+	/* Set the route and send the data */
+	idt_sw_write(ndev, partdata_tbl[ndev->part].msgctl[midx], swpmsgctl);
+	idt_nt_write(ndev, ntdata_tbl.msgs[midx].out, msg);
+	/* Unlock the messages routing table */
+	spin_unlock_irqrestore(&ndev->msg_locks[midx], irqflags);
+
+	/* Client driver shall check the status register */
+	return 0;
+}
+
+/*=============================================================================
+ *                      7. Temperature sensor operations
+ *
+ *    IDT PCIe-switch has an embedded temperature sensor, which can be used to
+ * check current chip core temperature. Since a workload environment can be
+ * different on different platforms, an offset and ADC/filter settings can be
+ * specified. Although the offset configuration is only exposed to the sysfs
+ * hwmon interface at the moment. The rest of the settings can be adjusted
+ * for instance by the BIOS/EEPROM firmware.
+ *=============================================================================
+ */
+
+/*
+ * idt_get_deg() - convert millidegree Celsius value to just degree
+ * @mdegC:	IN - millidegree Celsius value
+ *
+ * Return: Degree corresponding to the passed millidegree value
+ */
+static inline s8 idt_get_deg(long mdegC)
+{
+	return mdegC / 1000;
+}
+
+/*
+ * idt_get_frac() - retrieve 0/0.5 fraction of the millidegree Celsius value
+ * @mdegC:	IN - millidegree Celsius value
+ *
+ * Return: 0/0.5 degree fraction of the passed millidegree value
+ */
+static inline u8 idt_get_deg_frac(long mdegC)
+{
+	return (mdegC % 1000) >= 500 ? 5 : 0;
+}
+
+/*
+ * idt_get_temp_fmt() - convert millidegree Celsius value to 0:7:1 format
+ * @mdegC:	IN - millidegree Celsius value
+ *
+ * Return: 0:7:1 format acceptable by the IDT temperature sensor
+ */
+static inline u8 idt_temp_get_fmt(long mdegC)
+{
+	return (idt_get_deg(mdegC) << 1) | (idt_get_deg_frac(mdegC) ? 1 : 0);
+}
+
+/*
+ * idt_get_temp_sval() - convert temp sample to signed millidegree Celsius
+ * @data:	IN - shifted to LSB 8-bits temperature sample
+ *
+ * Return: signed millidegree Celsius
+ */
+static inline long idt_get_temp_sval(u32 data)
+{
+	return ((s8)data / 2) * 1000 + (data & 0x1 ? 500 : 0);
+}
+
+/*
+ * idt_get_temp_sval() - convert temp sample to unsigned millidegree Celsius
+ * @data:	IN - shifted to LSB 8-bits temperature sample
+ *
+ * Return: unsigned millidegree Celsius
+ */
+static inline long idt_get_temp_uval(u32 data)
+{
+	return (data / 2) * 1000 + (data & 0x1 ? 500 : 0);
+}
+
+/*
+ * idt_read_temp() - read temperature from chip sensor
+ * @ntb:	NTB device context.
+ * @type:	IN - type of the temperature value to read
+ * @val:	OUT - integer value of temperature in millidegree Celsius
+ */
+static void idt_read_temp(struct idt_ntb_dev *ndev,
+			  const enum idt_temp_val type, long *val)
+{
+	u32 data;
+
+	/* Alter the temperature field in accordance with the passed type */
+	switch (type) {
+	case IDT_TEMP_CUR:
+		data = GET_FIELD(TMPSTS_TEMP,
+				 idt_sw_read(ndev, IDT_SW_TMPSTS));
+		break;
+	case IDT_TEMP_LOW:
+		data = GET_FIELD(TMPSTS_LTEMP,
+				 idt_sw_read(ndev, IDT_SW_TMPSTS));
+		break;
+	case IDT_TEMP_HIGH:
+		data = GET_FIELD(TMPSTS_HTEMP,
+				 idt_sw_read(ndev, IDT_SW_TMPSTS));
+		break;
+	case IDT_TEMP_OFFSET:
+		/* This is the only field with signed 0:7:1 format */
+		data = GET_FIELD(TMPADJ_OFFSET,
+				 idt_sw_read(ndev, IDT_SW_TMPADJ));
+		*val = idt_get_temp_sval(data);
+		return;
+	default:
+		data = GET_FIELD(TMPSTS_TEMP,
+				 idt_sw_read(ndev, IDT_SW_TMPSTS));
+		break;
+	}
+
+	/* The rest of the fields accept unsigned 0:7:1 format */
+	*val = idt_get_temp_uval(data);
+}
+
+/*
+ * idt_write_temp() - write temperature to the chip sensor register
+ * @ntb:	NTB device context.
+ * @type:	IN - type of the temperature value to change
+ * @val:	IN - integer value of temperature in millidegree Celsius
+ */
+static void idt_write_temp(struct idt_ntb_dev *ndev,
+			   const enum idt_temp_val type, const long val)
+{
+	unsigned int reg;
+	u32 data;
+	u8 fmt;
+
+	/* Retrieve the properly formatted temperature value */
+	fmt = idt_temp_get_fmt(val);
+
+	mutex_lock(&ndev->hwmon_mtx);
+	switch (type) {
+	case IDT_TEMP_LOW:
+		reg = IDT_SW_TMPALARM;
+		data = SET_FIELD(TMPALARM_LTEMP, idt_sw_read(ndev, reg), fmt) &
+			~IDT_TMPALARM_IRQ_MASK;
+		break;
+	case IDT_TEMP_HIGH:
+		reg = IDT_SW_TMPALARM;
+		data = SET_FIELD(TMPALARM_HTEMP, idt_sw_read(ndev, reg), fmt) &
+			~IDT_TMPALARM_IRQ_MASK;
+		break;
+	case IDT_TEMP_OFFSET:
+		reg = IDT_SW_TMPADJ;
+		data = SET_FIELD(TMPADJ_OFFSET, idt_sw_read(ndev, reg), fmt);
+		break;
+	default:
+		goto inval_spin_unlock;
+	}
+
+	idt_sw_write(ndev, reg, data);
+
+inval_spin_unlock:
+	mutex_unlock(&ndev->hwmon_mtx);
+}
+
+/*
+ * idt_sysfs_show_temp() - printout corresponding temperature value
+ * @dev:	Pointer to the NTB device structure
+ * @da:		Sensor device attribute structure
+ * @buf:	Buffer to print temperature out
+ *
+ * Return: Number of written symbols or negative error
+ */
+static ssize_t idt_sysfs_show_temp(struct device *dev,
+				   struct device_attribute *da, char *buf)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
+	struct idt_ntb_dev *ndev = dev_get_drvdata(dev);
+	enum idt_temp_val type = attr->index;
+	long mdeg;
+
+	idt_read_temp(ndev, type, &mdeg);
+	return sprintf(buf, "%ld\n", mdeg);
+}
+
+/*
+ * idt_sysfs_set_temp() - set corresponding temperature value
+ * @dev:	Pointer to the NTB device structure
+ * @da:		Sensor device attribute structure
+ * @buf:	Buffer to print temperature out
+ * @count:	Size of the passed buffer
+ *
+ * Return: Number of written symbols or negative error
+ */
+static ssize_t idt_sysfs_set_temp(struct device *dev,
+				  struct device_attribute *da, const char *buf,
+				  size_t count)
+{
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
+	struct idt_ntb_dev *ndev = dev_get_drvdata(dev);
+	enum idt_temp_val type = attr->index;
+	long mdeg;
+	int ret;
+
+	ret = kstrtol(buf, 10, &mdeg);
+	if (ret)
+		return ret;
+
+	/* Clamp the passed value in accordance with the type */
+	if (type == IDT_TEMP_OFFSET)
+		mdeg = clamp_val(mdeg, IDT_TEMP_MIN_OFFSET,
+				 IDT_TEMP_MAX_OFFSET);
+	else
+		mdeg = clamp_val(mdeg, IDT_TEMP_MIN_MDEG, IDT_TEMP_MAX_MDEG);
+
+	idt_write_temp(ndev, type, mdeg);
+
+	return count;
+}
+
+/*
+ * idt_sysfs_reset_hist() - reset temperature history
+ * @dev:	Pointer to the NTB device structure
+ * @da:		Sensor device attribute structure
+ * @buf:	Buffer to print temperature out
+ * @count:	Size of the passed buffer
+ *
+ * Return: Number of written symbols or negative error
+ */
+static ssize_t idt_sysfs_reset_hist(struct device *dev,
+				    struct device_attribute *da,
+				    const char *buf, size_t count)
+{
+	struct idt_ntb_dev *ndev = dev_get_drvdata(dev);
+
+	/* Just set the maximal value to the lowest temperature field and
+	 * minimal value to the highest temperature field
+	 */
+	idt_write_temp(ndev, IDT_TEMP_LOW, IDT_TEMP_MAX_MDEG);
+	idt_write_temp(ndev, IDT_TEMP_HIGH, IDT_TEMP_MIN_MDEG);
+
+	return count;
+}
+
+/*
+ * Hwmon IDT sysfs attributes
+ */
+static SENSOR_DEVICE_ATTR(temp1_input, 0444, idt_sysfs_show_temp, NULL,
+			  IDT_TEMP_CUR);
+static SENSOR_DEVICE_ATTR(temp1_lowest, 0444, idt_sysfs_show_temp, NULL,
+			  IDT_TEMP_LOW);
+static SENSOR_DEVICE_ATTR(temp1_highest, 0444, idt_sysfs_show_temp, NULL,
+			  IDT_TEMP_HIGH);
+static SENSOR_DEVICE_ATTR(temp1_offset, 0644, idt_sysfs_show_temp,
+			  idt_sysfs_set_temp, IDT_TEMP_OFFSET);
+static DEVICE_ATTR(temp1_reset_history, 0200, NULL, idt_sysfs_reset_hist);
+
+/*
+ * Hwmon IDT sysfs attributes group
+ */
+static struct attribute *idt_temp_attrs[] = {
+	&sensor_dev_attr_temp1_input.dev_attr.attr,
+	&sensor_dev_attr_temp1_lowest.dev_attr.attr,
+	&sensor_dev_attr_temp1_highest.dev_attr.attr,
+	&sensor_dev_attr_temp1_offset.dev_attr.attr,
+	&dev_attr_temp1_reset_history.attr,
+	NULL
+};
+ATTRIBUTE_GROUPS(idt_temp);
+
+/*
+ * idt_init_temp() - initialize temperature sensor interface
+ * @ndev:	IDT NTB hardware driver descriptor
+ *
+ * Simple sensor initializarion method is responsible for device switching
+ * on and resource management based hwmon interface registration. Note, that
+ * since the device is shared we won't disable it on remove, but leave it
+ * working until the system is powered off.
+ */
+static void idt_init_temp(struct idt_ntb_dev *ndev)
+{
+	struct device *hwmon;
+
+	/* Enable sensor if it hasn't been already */
+	idt_sw_write(ndev, IDT_SW_TMPCTL, 0x0);
+
+	/* Initialize hwmon interface fields */
+	mutex_init(&ndev->hwmon_mtx);
+
+	hwmon = devm_hwmon_device_register_with_groups(&ndev->ntb.pdev->dev,
+		ndev->swcfg->name, ndev, idt_temp_groups);
+	if (IS_ERR(hwmon)) {
+		dev_err(&ndev->ntb.pdev->dev, "Couldn't create hwmon device");
+		return;
+	}
+
+	dev_dbg(&ndev->ntb.pdev->dev, "Temperature HWmon interface registered");
+}
+
+/*=============================================================================
+ *                           8. ISRs related operations
+ *
+ *    IDT PCIe-switch has strangely developed IRQ system. There is just one
+ * interrupt vector for doorbell and message registers. So the hardware driver
+ * can't determine actual source of IRQ if, for example, message event happened
+ * while any of unmasked doorbell is still set. The similar situation may be if
+ * switch or temperature sensor events pop up. The difference is that SEVENT
+ * and TMPSENSOR bits of NT interrupt status register can be cleaned by
+ * IRQ handler so a next interrupt request won't have false handling of
+ * corresponding events.
+ *    The hardware driver has only bottom-half handler of the IRQ, since if any
+ * of events happened the device won't raise it again before the last one is
+ * handled by clearing of corresponding NTINTSTS bit.
+ *=============================================================================
+ */
+
+static irqreturn_t idt_thread_isr(int irq, void *devid);
+
+/*
+ * idt_init_isr() - initialize PCIe interrupt handler
+ * @ndev:	IDT NTB hardware driver descriptor
+ *
+ * Return: zero on success, otherwise a negative error number.
+ */
+static int idt_init_isr(struct idt_ntb_dev *ndev)
+{
+	struct pci_dev *pdev = ndev->ntb.pdev;
+	u32 ntint_mask;
+	int ret;
+
+	/* Allocate just one interrupt vector for the ISR */
+	ret = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSI | PCI_IRQ_INTX);
+	if (ret != 1) {
+		dev_err(&pdev->dev, "Failed to allocate IRQ vector");
+		return ret;
+	}
+
+	/* Retrieve the IRQ vector */
+	ret = pci_irq_vector(pdev, 0);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "Failed to get IRQ vector");
+		goto err_free_vectors;
+	}
+
+	/* Set the IRQ handler */
+	ret = devm_request_threaded_irq(&pdev->dev, ret, NULL, idt_thread_isr,
+					IRQF_ONESHOT, NTB_IRQNAME, ndev);
+	if (ret != 0) {
+		dev_err(&pdev->dev, "Failed to set MSI IRQ handler, %d", ret);
+		goto err_free_vectors;
+	}
+
+	/* Unmask Message/Doorbell/SE interrupts */
+	ntint_mask = idt_nt_read(ndev, IDT_NT_NTINTMSK) & ~IDT_NTINTMSK_ALL;
+	idt_nt_write(ndev, IDT_NT_NTINTMSK, ntint_mask);
+
+	/* From now on the interrupts are enabled */
+	dev_dbg(&pdev->dev, "NTB interrupts initialized");
+
+	return 0;
+
+err_free_vectors:
+	pci_free_irq_vectors(pdev);
+
+	return ret;
+}
+
+/*
+ * idt_deinit_ist() - deinitialize PCIe interrupt handler
+ * @ndev:	IDT NTB hardware driver descriptor
+ *
+ * Disable corresponding interrupts and free allocated IRQ vectors.
+ */
+static void idt_deinit_isr(struct idt_ntb_dev *ndev)
+{
+	struct pci_dev *pdev = ndev->ntb.pdev;
+	u32 ntint_mask;
+
+	/* Mask interrupts back */
+	ntint_mask = idt_nt_read(ndev, IDT_NT_NTINTMSK) | IDT_NTINTMSK_ALL;
+	idt_nt_write(ndev, IDT_NT_NTINTMSK, ntint_mask);
+
+	/* Manually free IRQ otherwise PCI free irq vectors will fail */
+	devm_free_irq(&pdev->dev, pci_irq_vector(pdev, 0), ndev);
+
+	/* Free allocated IRQ vectors */
+	pci_free_irq_vectors(pdev);
+
+	dev_dbg(&pdev->dev, "NTB interrupts deinitialized");
+}
+
+/*
+ * idt_thread_isr() - NT function interrupts handler
+ * @irq:	IRQ number
+ * @devid:	Custom buffer
+ *
+ * It reads current NT interrupts state register and handles all the event
+ * it declares.
+ * The method is bottom-half routine of actual default PCIe IRQ handler.
+ */
+static irqreturn_t idt_thread_isr(int irq, void *devid)
+{
+	struct idt_ntb_dev *ndev = devid;
+	bool handled = false;
+	u32 ntint_sts;
+
+	/* Read the NT interrupts status register */
+	ntint_sts = idt_nt_read(ndev, IDT_NT_NTINTSTS);
+
+	/* Handle messaging interrupts */
+	if (ntint_sts & IDT_NTINTSTS_MSG) {
+		idt_msg_isr(ndev, ntint_sts);
+		handled = true;
+	}
+
+	/* Handle doorbell interrupts */
+	if (ntint_sts & IDT_NTINTSTS_DBELL) {
+		idt_db_isr(ndev, ntint_sts);
+		handled = true;
+	}
+
+	/* Handle switch event interrupts */
+	if (ntint_sts & IDT_NTINTSTS_SEVENT) {
+		idt_se_isr(ndev, ntint_sts);
+		handled = true;
+	}
+
+	dev_dbg(&ndev->ntb.pdev->dev, "IDT IRQs 0x%08x handled", ntint_sts);
+
+	return handled ? IRQ_HANDLED : IRQ_NONE;
+}
+
+/*===========================================================================
+ *                     9. NTB hardware driver initialization
+ *===========================================================================
+ */
+
+/*
+ * NTB API operations
+ */
+static const struct ntb_dev_ops idt_ntb_ops = {
+	.port_number		= idt_ntb_port_number,
+	.peer_port_count	= idt_ntb_peer_port_count,
+	.peer_port_number	= idt_ntb_peer_port_number,
+	.peer_port_idx		= idt_ntb_peer_port_idx,
+	.link_is_up		= idt_ntb_link_is_up,
+	.link_enable		= idt_ntb_link_enable,
+	.link_disable		= idt_ntb_link_disable,
+	.mw_count		= idt_ntb_mw_count,
+	.mw_get_align		= idt_ntb_mw_get_align,
+	.peer_mw_count		= idt_ntb_peer_mw_count,
+	.peer_mw_get_addr	= idt_ntb_peer_mw_get_addr,
+	.peer_mw_set_trans	= idt_ntb_peer_mw_set_trans,
+	.peer_mw_clear_trans	= idt_ntb_peer_mw_clear_trans,
+	.db_valid_mask		= idt_ntb_db_valid_mask,
+	.db_read		= idt_ntb_db_read,
+	.db_clear		= idt_ntb_db_clear,
+	.db_read_mask		= idt_ntb_db_read_mask,
+	.db_set_mask		= idt_ntb_db_set_mask,
+	.db_clear_mask		= idt_ntb_db_clear_mask,
+	.peer_db_set		= idt_ntb_peer_db_set,
+	.msg_count		= idt_ntb_msg_count,
+	.msg_inbits		= idt_ntb_msg_inbits,
+	.msg_outbits		= idt_ntb_msg_outbits,
+	.msg_read_sts		= idt_ntb_msg_read_sts,
+	.msg_clear_sts		= idt_ntb_msg_clear_sts,
+	.msg_set_mask		= idt_ntb_msg_set_mask,
+	.msg_clear_mask		= idt_ntb_msg_clear_mask,
+	.msg_read		= idt_ntb_msg_read,
+	.peer_msg_write		= idt_ntb_peer_msg_write
+};
+
+/*
+ * idt_register_device() - register IDT NTB device
+ * @ndev:	IDT NTB hardware driver descriptor
+ *
+ * Return: zero on success, otherwise a negative error number.
+ */
+static int idt_register_device(struct idt_ntb_dev *ndev)
+{
+	int ret;
+
+	/* Initialize the rest of NTB device structure and register it */
+	ndev->ntb.ops = &idt_ntb_ops;
+	ndev->ntb.topo = NTB_TOPO_SWITCH;
+
+	ret = ntb_register_device(&ndev->ntb);
+	if (ret != 0) {
+		dev_err(&ndev->ntb.pdev->dev, "Failed to register NTB device");
+		return ret;
+	}
+
+	dev_dbg(&ndev->ntb.pdev->dev, "NTB device successfully registered");
+
+	return 0;
+}
+
+/*
+ * idt_unregister_device() - unregister IDT NTB device
+ * @ndev:	IDT NTB hardware driver descriptor
+ */
+static void idt_unregister_device(struct idt_ntb_dev *ndev)
+{
+	/* Just unregister the NTB device */
+	ntb_unregister_device(&ndev->ntb);
+
+	dev_dbg(&ndev->ntb.pdev->dev, "NTB device unregistered");
+}
+
+/*=============================================================================
+ *                        10. DebugFS node initialization
+ *=============================================================================
+ */
+
+static ssize_t idt_dbgfs_info_read(struct file *filp, char __user *ubuf,
+				   size_t count, loff_t *offp);
+
+/*
+ * Driver DebugFS info file operations
+ */
+static const struct file_operations idt_dbgfs_info_ops = {
+	.owner = THIS_MODULE,
+	.open = simple_open,
+	.read = idt_dbgfs_info_read
+};
+
+/*
+ * idt_dbgfs_info_read() - DebugFS read info node callback
+ * @file:	File node descriptor.
+ * @ubuf:	User-space buffer to put data to
+ * @count:	Size of the buffer
+ * @offp:	Offset within the buffer
+ */
+static ssize_t idt_dbgfs_info_read(struct file *filp, char __user *ubuf,
+				   size_t count, loff_t *offp)
+{
+	struct idt_ntb_dev *ndev = filp->private_data;
+	unsigned char idx, pidx, cnt;
+	unsigned long irqflags, mdeg;
+	ssize_t ret = 0, off = 0;
+	enum ntb_speed speed;
+	enum ntb_width width;
+	char *strbuf;
+	size_t size;
+	u32 data;
+
+	/* Lets limit the buffer size the way the Intel/AMD drivers do */
+	size = min_t(size_t, count, 0x1000U);
+
+	/* Allocate the memory for the buffer */
+	strbuf = kmalloc(size, GFP_KERNEL);
+	if (strbuf == NULL)
+		return -ENOMEM;
+
+	/* Put the data into the string buffer */
+	off += scnprintf(strbuf + off, size - off,
+		"\n\t\tIDT NTB device Information:\n\n");
+
+	/* General local device configurations */
+	off += scnprintf(strbuf + off, size - off,
+		"Local Port %hhu, Partition %hhu\n", ndev->port, ndev->part);
+
+	/* Peer ports information */
+	off += scnprintf(strbuf + off, size - off, "Peers:\n");
+	for (idx = 0; idx < ndev->peer_cnt; idx++) {
+		off += scnprintf(strbuf + off, size - off,
+			"\t%hhu. Port %hhu, Partition %hhu\n",
+			idx, ndev->peers[idx].port, ndev->peers[idx].part);
+	}
+
+	/* Links status */
+	data = idt_ntb_link_is_up(&ndev->ntb, &speed, &width);
+	off += scnprintf(strbuf + off, size - off,
+		"NTB link status\t- 0x%08x, ", data);
+	off += scnprintf(strbuf + off, size - off, "PCIe Gen %d x%d lanes\n",
+		speed, width);
+
+	/* Mapping table entries */
+	off += scnprintf(strbuf + off, size - off, "NTB Mapping Table:\n");
+	for (idx = 0; idx < IDT_MTBL_ENTRY_CNT; idx++) {
+		spin_lock_irqsave(&ndev->mtbl_lock, irqflags);
+		idt_nt_write(ndev, IDT_NT_NTMTBLADDR, idx);
+		data = idt_nt_read(ndev, IDT_NT_NTMTBLDATA);
+		spin_unlock_irqrestore(&ndev->mtbl_lock, irqflags);
+
+		/* Print valid entries only */
+		if (data & IDT_NTMTBLDATA_VALID) {
+			off += scnprintf(strbuf + off, size - off,
+				"\t%hhu. Partition %d, Requester ID 0x%04x\n",
+				idx, GET_FIELD(NTMTBLDATA_PART, data),
+				GET_FIELD(NTMTBLDATA_REQID, data));
+		}
+	}
+	off += scnprintf(strbuf + off, size - off, "\n");
+
+	/* Outbound memory windows information */
+	off += scnprintf(strbuf + off, size - off,
+		"Outbound Memory Windows:\n");
+	for (idx = 0; idx < ndev->mw_cnt; idx += cnt) {
+		data = ndev->mws[idx].type;
+		cnt = idt_get_mw_count(data);
+
+		/* Print Memory Window information */
+		if (data == IDT_MW_DIR)
+			off += scnprintf(strbuf + off, size - off,
+				"\t%hhu.\t", idx);
+		else
+			off += scnprintf(strbuf + off, size - off,
+				"\t%hhu-%d.\t", idx, idx + cnt - 1);
+
+		off += scnprintf(strbuf + off, size - off, "%s BAR%hhu, ",
+			idt_get_mw_name(data), ndev->mws[idx].bar);
+
+		off += scnprintf(strbuf + off, size - off,
+			"Address align 0x%08llx, ", ndev->mws[idx].addr_align);
+
+		off += scnprintf(strbuf + off, size - off,
+			"Size align 0x%08llx, Size max %llu\n",
+			ndev->mws[idx].size_align, ndev->mws[idx].size_max);
+	}
+
+	/* Inbound memory windows information */
+	for (pidx = 0; pidx < ndev->peer_cnt; pidx++) {
+		off += scnprintf(strbuf + off, size - off,
+			"Inbound Memory Windows for peer %hhu (Port %hhu):\n",
+			pidx, ndev->peers[pidx].port);
+
+		/* Print Memory Windows information */
+		for (idx = 0; idx < ndev->peers[pidx].mw_cnt; idx += cnt) {
+			data = ndev->peers[pidx].mws[idx].type;
+			cnt = idt_get_mw_count(data);
+
+			if (data == IDT_MW_DIR)
+				off += scnprintf(strbuf + off, size - off,
+					"\t%hhu.\t", idx);
+			else
+				off += scnprintf(strbuf + off, size - off,
+					"\t%hhu-%d.\t", idx, idx + cnt - 1);
+
+			off += scnprintf(strbuf + off, size - off,
+				"%s BAR%hhu, ", idt_get_mw_name(data),
+				ndev->peers[pidx].mws[idx].bar);
+
+			off += scnprintf(strbuf + off, size - off,
+				"Address align 0x%08llx, ",
+				ndev->peers[pidx].mws[idx].addr_align);
+
+			off += scnprintf(strbuf + off, size - off,
+				"Size align 0x%08llx, Size max %llu\n",
+				ndev->peers[pidx].mws[idx].size_align,
+				ndev->peers[pidx].mws[idx].size_max);
+		}
+	}
+	off += scnprintf(strbuf + off, size - off, "\n");
+
+	/* Doorbell information */
+	data = idt_sw_read(ndev, IDT_SW_GDBELLSTS);
+	off += scnprintf(strbuf + off, size - off,
+		 "Global Doorbell state\t- 0x%08x\n", data);
+	data = idt_ntb_db_read(&ndev->ntb);
+	off += scnprintf(strbuf + off, size - off,
+		 "Local  Doorbell state\t- 0x%08x\n", data);
+	data = idt_nt_read(ndev, IDT_NT_INDBELLMSK);
+	off += scnprintf(strbuf + off, size - off,
+		 "Local  Doorbell mask\t- 0x%08x\n", data);
+	off += scnprintf(strbuf + off, size - off, "\n");
+
+	/* Messaging information */
+	off += scnprintf(strbuf + off, size - off,
+		 "Message event valid\t- 0x%08x\n", IDT_MSG_MASK);
+	data = idt_ntb_msg_read_sts(&ndev->ntb);
+	off += scnprintf(strbuf + off, size - off,
+		 "Message event status\t- 0x%08x\n", data);
+	data = idt_nt_read(ndev, IDT_NT_MSGSTSMSK);
+	off += scnprintf(strbuf + off, size - off,
+		 "Message event mask\t- 0x%08x\n", data);
+	off += scnprintf(strbuf + off, size - off,
+		 "Message data:\n");
+	for (idx = 0; idx < IDT_MSG_CNT; idx++) {
+		int src;
+		data = idt_ntb_msg_read(&ndev->ntb, &src, idx);
+		off += scnprintf(strbuf + off, size - off,
+			"\t%hhu. 0x%08x from peer %d (Port %hhu)\n",
+			idx, data, src, ndev->peers[src].port);
+	}
+	off += scnprintf(strbuf + off, size - off, "\n");
+
+	/* Current temperature */
+	idt_read_temp(ndev, IDT_TEMP_CUR, &mdeg);
+	off += scnprintf(strbuf + off, size - off,
+		"Switch temperature\t\t- %hhd.%hhuC\n",
+		idt_get_deg(mdeg), idt_get_deg_frac(mdeg));
+
+	/* Copy the buffer to the User Space */
+	ret = simple_read_from_buffer(ubuf, count, offp, strbuf, off);
+	kfree(strbuf);
+
+	return ret;
+}
+
+/*
+ * idt_init_dbgfs() - initialize DebugFS node
+ * @ndev:	IDT NTB hardware driver descriptor
+ *
+ * Return: zero on success, otherwise a negative error number.
+ */
+static int idt_init_dbgfs(struct idt_ntb_dev *ndev)
+{
+	char devname[64];
+
+	/* If the top directory is not created then do nothing */
+	if (IS_ERR_OR_NULL(dbgfs_topdir)) {
+		dev_info(&ndev->ntb.pdev->dev, "Top DebugFS directory absent");
+		return PTR_ERR_OR_ZERO(dbgfs_topdir);
+	}
+
+	/* Create the info file node */
+	snprintf(devname, 64, "info:%s", pci_name(ndev->ntb.pdev));
+	ndev->dbgfs_info = debugfs_create_file(devname, 0400, dbgfs_topdir,
+		ndev, &idt_dbgfs_info_ops);
+	if (IS_ERR(ndev->dbgfs_info)) {
+		dev_dbg(&ndev->ntb.pdev->dev, "Failed to create DebugFS node");
+		return PTR_ERR(ndev->dbgfs_info);
+	}
+
+	dev_dbg(&ndev->ntb.pdev->dev, "NTB device DebugFS node created");
+
+	return 0;
+}
+
+/*
+ * idt_deinit_dbgfs() - deinitialize DebugFS node
+ * @ndev:	IDT NTB hardware driver descriptor
+ *
+ * Just discard the info node from DebugFS
+ */
+static void idt_deinit_dbgfs(struct idt_ntb_dev *ndev)
+{
+	debugfs_remove(ndev->dbgfs_info);
+
+	dev_dbg(&ndev->ntb.pdev->dev, "NTB device DebugFS node discarded");
+}
+
+/*=============================================================================
+ *                     11. Basic PCIe device initialization
+ *=============================================================================
+ */
+
+/*
+ * idt_check_setup() - Check whether the IDT PCIe-switch is properly
+ *		       pre-initialized
+ * @pdev:	Pointer to the PCI device descriptor
+ *
+ * Return: zero on success, otherwise a negative error number.
+ */
+static int idt_check_setup(struct pci_dev *pdev)
+{
+	u32 data;
+	int ret;
+
+	/* Read the BARSETUP0 */
+	ret = pci_read_config_dword(pdev, IDT_NT_BARSETUP0, &data);
+	if (ret != 0) {
+		dev_err(&pdev->dev,
+			"Failed to read BARSETUP0 config register");
+		return ret;
+	}
+
+	/* Check whether the BAR0 register is enabled to be of config space */
+	if (!(data & IDT_BARSETUP_EN) || !(data & IDT_BARSETUP_MODE_CFG)) {
+		dev_err(&pdev->dev, "BAR0 doesn't map config space");
+		return -EINVAL;
+	}
+
+	/* Configuration space BAR0 must have certain size */
+	if ((data & IDT_BARSETUP_SIZE_MASK) != IDT_BARSETUP_SIZE_CFG) {
+		dev_err(&pdev->dev, "Invalid size of config space");
+		return -EINVAL;
+	}
+
+	dev_dbg(&pdev->dev, "NTB device pre-initialized correctly");
+
+	return 0;
+}
+
+/*
+ * Create the IDT PCIe-switch driver descriptor
+ * @pdev:	Pointer to the PCI device descriptor
+ * @id:		IDT PCIe-device configuration
+ *
+ * It just allocates a memory for IDT PCIe-switch device structure and
+ * initializes some commonly used fields.
+ *
+ * No need of release method, since managed device resource is used for
+ * memory allocation.
+ *
+ * Return: pointer to the descriptor, otherwise a negative error number.
+ */
+static struct idt_ntb_dev *idt_create_dev(struct pci_dev *pdev,
+					  const struct pci_device_id *id)
+{
+	struct idt_ntb_dev *ndev;
+
+	/* Allocate memory for the IDT PCIe-device descriptor */
+	ndev = devm_kzalloc(&pdev->dev, sizeof(*ndev), GFP_KERNEL);
+	if (!ndev) {
+		dev_err(&pdev->dev, "Memory allocation failed for descriptor");
+		return ERR_PTR(-ENOMEM);
+	}
+
+	/* Save the IDT PCIe-switch ports configuration */
+	ndev->swcfg = (struct idt_89hpes_cfg *)id->driver_data;
+	/* Save the PCI-device pointer inside the NTB device structure */
+	ndev->ntb.pdev = pdev;
+
+	/* Initialize spin locker of Doorbell, Message and GASA registers */
+	spin_lock_init(&ndev->db_mask_lock);
+	spin_lock_init(&ndev->msg_mask_lock);
+	spin_lock_init(&ndev->gasa_lock);
+
+	dev_info(&pdev->dev, "IDT %s discovered", ndev->swcfg->name);
+
+	dev_dbg(&pdev->dev, "NTB device descriptor created");
+
+	return ndev;
+}
+
+/*
+ * idt_init_pci() - initialize the basic PCI-related subsystem
+ * @ndev:	Pointer to the IDT PCIe-switch driver descriptor
+ *
+ * Managed device resources will be freed automatically in case of failure or
+ * driver detachment.
+ *
+ * Return: zero on success, otherwise negative error number.
+ */
+static int idt_init_pci(struct idt_ntb_dev *ndev)
+{
+	struct pci_dev *pdev = ndev->ntb.pdev;
+	int ret;
+
+	/* Initialize the bit mask of PCI/NTB DMA */
+	ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
+	if (ret != 0) {
+		ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
+		if (ret != 0) {
+			dev_err(&pdev->dev, "Failed to set DMA bit mask\n");
+			return ret;
+		}
+		dev_warn(&pdev->dev, "Cannot set DMA highmem bit mask\n");
+	}
+
+	/*
+	 * The PCI core enables device error reporting. It's not critical to
+	 * have AER disabled in the kernel.
+	 *
+	 * Cleanup nonfatal error status before getting to init.
+	 */
+	pci_aer_clear_nonfatal_status(pdev);
+
+	/* First enable the PCI device */
+	ret = pcim_enable_device(pdev);
+	if (ret != 0) {
+		dev_err(&pdev->dev, "Failed to enable PCIe device\n");
+		return ret;
+	}
+
+	/*
+	 * Enable the bus mastering, which effectively enables MSI IRQs and
+	 * Request TLPs translation
+	 */
+	pci_set_master(pdev);
+
+	/* Request all BARs resources */
+	ret = pcim_request_all_regions(pdev, NTB_NAME);
+	if (ret != 0) {
+		dev_err(&pdev->dev, "Failed to request resources\n");
+		goto err_clear_master;
+	}
+
+	/* ioremap BAR0 - PCI configuration space */
+	ndev->cfgspc = pcim_iomap(pdev, 0, 0);
+	if (!ndev->cfgspc) {
+		dev_err(&pdev->dev, "Failed to ioremap BAR 0\n");
+		ret = -ENOMEM;
+		goto err_clear_master;
+	}
+
+	/* Put the IDT driver data pointer to the PCI-device private pointer */
+	pci_set_drvdata(pdev, ndev);
+
+	dev_dbg(&pdev->dev, "NT-function PCIe interface initialized");
+
+	return 0;
+
+err_clear_master:
+	pci_clear_master(pdev);
+
+	return ret;
+}
+
+/*
+ * idt_deinit_pci() - deinitialize the basic PCI-related subsystem
+ * @ndev:	Pointer to the IDT PCIe-switch driver descriptor
+ *
+ * Managed resources will be freed on the driver detachment
+ */
+static void idt_deinit_pci(struct idt_ntb_dev *ndev)
+{
+	struct pci_dev *pdev = ndev->ntb.pdev;
+
+	/* Clean up the PCI-device private data pointer */
+	pci_set_drvdata(pdev, NULL);
+
+	/* Clear the bus master disabling the Request TLPs translation */
+	pci_clear_master(pdev);
+
+	dev_dbg(&pdev->dev, "NT-function PCIe interface cleared");
+}
+
+/*===========================================================================
+ *                       12. PCI bus callback functions
+ *===========================================================================
+ */
+
+/*
+ * idt_pci_probe() - PCI device probe callback
+ * @pdev:	Pointer to PCI device structure
+ * @id:		PCIe device custom descriptor
+ *
+ * Return: zero on success, otherwise negative error number
+ */
+static int idt_pci_probe(struct pci_dev *pdev,
+			 const struct pci_device_id *id)
+{
+	struct idt_ntb_dev *ndev;
+	int ret;
+
+	/* Check whether IDT PCIe-switch is properly pre-initialized */
+	ret = idt_check_setup(pdev);
+	if (ret != 0)
+		return ret;
+
+	/* Allocate the memory for IDT NTB device data */
+	ndev = idt_create_dev(pdev, id);
+	if (IS_ERR(ndev))
+		return PTR_ERR(ndev);
+
+	/* Initialize the basic PCI subsystem of the device */
+	ret = idt_init_pci(ndev);
+	if (ret != 0)
+		return ret;
+
+	/* Scan ports of the IDT PCIe-switch */
+	(void)idt_scan_ports(ndev);
+
+	/* Initialize NTB link events subsystem */
+	idt_init_link(ndev);
+
+	/* Initialize MWs subsystem */
+	ret = idt_init_mws(ndev);
+	if (ret != 0)
+		goto err_deinit_link;
+
+	/* Initialize Messaging subsystem */
+	idt_init_msg(ndev);
+
+	/* Initialize hwmon interface */
+	idt_init_temp(ndev);
+
+	/* Initialize IDT interrupts handler */
+	ret = idt_init_isr(ndev);
+	if (ret != 0)
+		goto err_deinit_link;
+
+	/* Register IDT NTB devices on the NTB bus */
+	ret = idt_register_device(ndev);
+	if (ret != 0)
+		goto err_deinit_isr;
+
+	/* Initialize DebugFS info node */
+	(void)idt_init_dbgfs(ndev);
+
+	/* IDT PCIe-switch NTB driver is finally initialized */
+	dev_info(&pdev->dev, "IDT NTB device is ready");
+
+	/* May the force be with us... */
+	return 0;
+
+err_deinit_isr:
+	idt_deinit_isr(ndev);
+err_deinit_link:
+	idt_deinit_link(ndev);
+	idt_deinit_pci(ndev);
+
+	return ret;
+}
+
+/*
+ * idt_pci_probe() - PCI device remove callback
+ * @pdev:	Pointer to PCI device structure
+ */
+static void idt_pci_remove(struct pci_dev *pdev)
+{
+	struct idt_ntb_dev *ndev = pci_get_drvdata(pdev);
+
+	/* Deinit the DebugFS node */
+	idt_deinit_dbgfs(ndev);
+
+	/* Unregister NTB device */
+	idt_unregister_device(ndev);
+
+	/* Stop the interrupts handling */
+	idt_deinit_isr(ndev);
+
+	/* Deinitialize link event subsystem */
+	idt_deinit_link(ndev);
+
+	/* Deinit basic PCI subsystem */
+	idt_deinit_pci(ndev);
+
+	/* IDT PCIe-switch NTB driver is finally initialized */
+	dev_info(&pdev->dev, "IDT NTB device is removed");
+
+	/* Sayonara... */
+}
+
+/*
+ * IDT PCIe-switch models ports configuration structures
+ */
+static const struct idt_89hpes_cfg idt_89hpes24nt6ag2_config = {
+	.name = "89HPES24NT6AG2",
+	.port_cnt = 6, .ports = {0, 2, 4, 6, 8, 12}
+};
+static const struct idt_89hpes_cfg idt_89hpes32nt8ag2_config = {
+	.name = "89HPES32NT8AG2",
+	.port_cnt = 8, .ports = {0, 2, 4, 6, 8, 12, 16, 20}
+};
+static const struct idt_89hpes_cfg idt_89hpes32nt8bg2_config = {
+	.name = "89HPES32NT8BG2",
+	.port_cnt = 8, .ports = {0, 2, 4, 6, 8, 12, 16, 20}
+};
+static const struct idt_89hpes_cfg idt_89hpes12nt12g2_config = {
+	.name = "89HPES12NT12G2",
+	.port_cnt = 3, .ports = {0, 8, 16}
+};
+static const struct idt_89hpes_cfg idt_89hpes16nt16g2_config = {
+	.name = "89HPES16NT16G2",
+	.port_cnt = 4, .ports = {0, 8, 12, 16}
+};
+static const struct idt_89hpes_cfg idt_89hpes24nt24g2_config = {
+	.name = "89HPES24NT24G2",
+	.port_cnt = 8, .ports = {0, 2, 4, 6, 8, 12, 16, 20}
+};
+static const struct idt_89hpes_cfg idt_89hpes32nt24ag2_config = {
+	.name = "89HPES32NT24AG2",
+	.port_cnt = 8, .ports = {0, 2, 4, 6, 8, 12, 16, 20}
+};
+static const struct idt_89hpes_cfg idt_89hpes32nt24bg2_config = {
+	.name = "89HPES32NT24BG2",
+	.port_cnt = 8, .ports = {0, 2, 4, 6, 8, 12, 16, 20}
+};
+
+/*
+ * PCI-ids table of the supported IDT PCIe-switch devices
+ */
+static const struct pci_device_id idt_pci_tbl[] = {
+	{IDT_PCI_DEVICE_IDS(89HPES24NT6AG2,  idt_89hpes24nt6ag2_config)},
+	{IDT_PCI_DEVICE_IDS(89HPES32NT8AG2,  idt_89hpes32nt8ag2_config)},
+	{IDT_PCI_DEVICE_IDS(89HPES32NT8BG2,  idt_89hpes32nt8bg2_config)},
+	{IDT_PCI_DEVICE_IDS(89HPES12NT12G2,  idt_89hpes12nt12g2_config)},
+	{IDT_PCI_DEVICE_IDS(89HPES16NT16G2,  idt_89hpes16nt16g2_config)},
+	{IDT_PCI_DEVICE_IDS(89HPES24NT24G2,  idt_89hpes24nt24g2_config)},
+	{IDT_PCI_DEVICE_IDS(89HPES32NT24AG2, idt_89hpes32nt24ag2_config)},
+	{IDT_PCI_DEVICE_IDS(89HPES32NT24BG2, idt_89hpes32nt24bg2_config)},
+	{0}
+};
+MODULE_DEVICE_TABLE(pci, idt_pci_tbl);
+
+/*
+ * IDT PCIe-switch NT-function device driver structure definition
+ */
+static struct pci_driver idt_pci_driver = {
+	.name		= KBUILD_MODNAME,
+	.probe		= idt_pci_probe,
+	.remove		= idt_pci_remove,
+	.id_table	= idt_pci_tbl,
+};
+
+static int __init idt_pci_driver_init(void)
+{
+	int ret;
+	pr_info("%s %s\n", NTB_DESC, NTB_VER);
+
+	/* Create the top DebugFS directory if the FS is initialized */
+	if (debugfs_initialized())
+		dbgfs_topdir = debugfs_create_dir(KBUILD_MODNAME, NULL);
+
+	/* Register the NTB hardware driver to handle the PCI device */
+	ret = pci_register_driver(&idt_pci_driver);
+	if (ret)
+		debugfs_remove_recursive(dbgfs_topdir);
+
+	return ret;
+}
+module_init(idt_pci_driver_init);
+
+static void __exit idt_pci_driver_exit(void)
+{
+	/* Unregister the NTB hardware driver */
+	pci_unregister_driver(&idt_pci_driver);
+
+	/* Discard the top DebugFS directory */
+	debugfs_remove_recursive(dbgfs_topdir);
+}
+module_exit(idt_pci_driver_exit);
+
diff --git a/drivers/ntb/hw/idt/ntb_hw_idt.h b/drivers/ntb/hw/idt/ntb_hw_idt.h
new file mode 100644
index 000000000..2f1aa121b
--- /dev/null
+++ b/drivers/ntb/hw/idt/ntb_hw_idt.h
@@ -0,0 +1,1226 @@
+/*
+ *   This file is provided under a GPLv2 license.  When using or
+ *   redistributing this file, you may do so under that license.
+ *
+ *   GPL LICENSE SUMMARY
+ *
+ *   Copyright (C) 2016-2018 T-Platforms JSC All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or modify it
+ *   under the terms and conditions of the GNU General Public License,
+ *   version 2, as published by the Free Software Foundation.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+ *   Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License along
+ *   with this program; if not, one can be found http://www.gnu.org/licenses/.
+ *
+ *   The full GNU General Public License is included in this distribution in
+ *   the file called "COPYING".
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * IDT PCIe-switch NTB Linux driver
+ *
+ * Contact Information:
+ * Serge Semin <fancer.lancer@gmail.com>, <Sergey.Semin@t-platforms.ru>
+ */
+
+#ifndef NTB_HW_IDT_H
+#define NTB_HW_IDT_H
+
+#include <linux/types.h>
+#include <linux/pci.h>
+#include <linux/pci_ids.h>
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+#include <linux/mutex.h>
+#include <linux/ntb.h>
+
+/*
+ * Macro is used to create the struct pci_device_id that matches
+ * the supported IDT PCIe-switches
+ * @devname: Capitalized name of the particular device
+ * @data: Variable passed to the driver of the particular device
+ */
+#define IDT_PCI_DEVICE_IDS(devname, data) \
+	.vendor = PCI_VENDOR_ID_IDT, .device = PCI_DEVICE_ID_IDT_##devname, \
+	.subvendor = PCI_ANY_ID, .subdevice = PCI_ANY_ID, \
+	.class = (PCI_CLASS_BRIDGE_OTHER << 8), .class_mask = (0xFFFF00), \
+	.driver_data = (kernel_ulong_t)&data
+
+/*
+ * IDT PCIe-switches device IDs
+ */
+#define PCI_DEVICE_ID_IDT_89HPES24NT6AG2  0x8091
+#define PCI_DEVICE_ID_IDT_89HPES32NT8AG2  0x808F
+#define PCI_DEVICE_ID_IDT_89HPES32NT8BG2  0x8088
+#define PCI_DEVICE_ID_IDT_89HPES12NT12G2  0x8092
+#define PCI_DEVICE_ID_IDT_89HPES16NT16G2  0x8090
+#define PCI_DEVICE_ID_IDT_89HPES24NT24G2  0x808E
+#define PCI_DEVICE_ID_IDT_89HPES32NT24AG2 0x808C
+#define PCI_DEVICE_ID_IDT_89HPES32NT24BG2 0x808A
+
+/*
+ * NT-function Configuration Space registers
+ * NOTE 1) The IDT PCIe-switch internal data is little-endian
+ *      so it must be taken into account in the driver
+ *      internals.
+ *      2) Additionally the registers should be accessed either
+ *      with byte-enables corresponding to their native size or
+ *      the size of one DWORD
+ *
+ * So to simplify the driver code, there is only DWORD-sized read/write
+ * operations utilized.
+ */
+/* PCI Express Configuration Space */
+/* PCI Express command/status register	(DWORD) */
+#define IDT_NT_PCICMDSTS		0x00004U
+/* PCI Express Device Capabilities	(DWORD) */
+#define IDT_NT_PCIEDCAP			0x00044U
+/* PCI Express Device Control/Status	(WORD+WORD) */
+#define IDT_NT_PCIEDCTLSTS		0x00048U
+/* PCI Express Link Capabilities	(DWORD) */
+#define IDT_NT_PCIELCAP			0x0004CU
+/* PCI Express Link Control/Status	(WORD+WORD) */
+#define IDT_NT_PCIELCTLSTS		0x00050U
+/* PCI Express Device Capabilities 2	(DWORD) */
+#define IDT_NT_PCIEDCAP2		0x00064U
+/* PCI Express Device Control 2		(WORD+WORD) */
+#define IDT_NT_PCIEDCTL2		0x00068U
+/* PCI Power Management Control and Status (DWORD) */
+#define IDT_NT_PMCSR			0x000C4U
+/*==========================================*/
+/* IDT Proprietary NT-port-specific registers */
+/* NT-function main control registers */
+/* NT Endpoint Control			(DWORD) */
+#define IDT_NT_NTCTL			0x00400U
+/* NT Endpoint Interrupt Status/Mask	(DWORD) */
+#define IDT_NT_NTINTSTS			0x00404U
+#define IDT_NT_NTINTMSK			0x00408U
+/* NT Endpoint Signal Data		(DWORD) */
+#define IDT_NT_NTSDATA			0x0040CU
+/* NT Endpoint Global Signal		(DWORD) */
+#define IDT_NT_NTGSIGNAL		0x00410U
+/* Internal Error Reporting Mask 0/1	(DWORD) */
+#define IDT_NT_NTIERRORMSK0		0x00414U
+#define IDT_NT_NTIERRORMSK1		0x00418U
+/* Doorbel registers */
+/* NT Outbound Doorbell Set		(DWORD) */
+#define IDT_NT_OUTDBELLSET		0x00420U
+/* NT Inbound Doorbell Status/Mask	(DWORD) */
+#define IDT_NT_INDBELLSTS		0x00428U
+#define IDT_NT_INDBELLMSK		0x0042CU
+/* Message registers */
+/* Outbound Message N			(DWORD) */
+#define IDT_NT_OUTMSG0			0x00430U
+#define IDT_NT_OUTMSG1			0x00434U
+#define IDT_NT_OUTMSG2			0x00438U
+#define IDT_NT_OUTMSG3			0x0043CU
+/* Inbound Message N			(DWORD) */
+#define IDT_NT_INMSG0			0x00440U
+#define IDT_NT_INMSG1			0x00444U
+#define IDT_NT_INMSG2			0x00448U
+#define IDT_NT_INMSG3			0x0044CU
+/* Inbound Message Source N		(DWORD) */
+#define IDT_NT_INMSGSRC0		0x00450U
+#define IDT_NT_INMSGSRC1		0x00454U
+#define IDT_NT_INMSGSRC2		0x00458U
+#define IDT_NT_INMSGSRC3		0x0045CU
+/* Message Status			(DWORD) */
+#define IDT_NT_MSGSTS			0x00460U
+/* Message Status Mask			(DWORD) */
+#define IDT_NT_MSGSTSMSK		0x00464U
+/* BAR-setup registers */
+/* BAR N Setup/Limit Address/Lower and Upper Translated Base Address (DWORD) */
+#define IDT_NT_BARSETUP0		0x00470U
+#define IDT_NT_BARLIMIT0		0x00474U
+#define IDT_NT_BARLTBASE0		0x00478U
+#define IDT_NT_BARUTBASE0		0x0047CU
+#define IDT_NT_BARSETUP1		0x00480U
+#define IDT_NT_BARLIMIT1		0x00484U
+#define IDT_NT_BARLTBASE1		0x00488U
+#define IDT_NT_BARUTBASE1		0x0048CU
+#define IDT_NT_BARSETUP2		0x00490U
+#define IDT_NT_BARLIMIT2		0x00494U
+#define IDT_NT_BARLTBASE2		0x00498U
+#define IDT_NT_BARUTBASE2		0x0049CU
+#define IDT_NT_BARSETUP3		0x004A0U
+#define IDT_NT_BARLIMIT3		0x004A4U
+#define IDT_NT_BARLTBASE3		0x004A8U
+#define IDT_NT_BARUTBASE3		0x004ACU
+#define IDT_NT_BARSETUP4		0x004B0U
+#define IDT_NT_BARLIMIT4		0x004B4U
+#define IDT_NT_BARLTBASE4		0x004B8U
+#define IDT_NT_BARUTBASE4		0x004BCU
+#define IDT_NT_BARSETUP5		0x004C0U
+#define IDT_NT_BARLIMIT5		0x004C4U
+#define IDT_NT_BARLTBASE5		0x004C8U
+#define IDT_NT_BARUTBASE5		0x004CCU
+/* NT mapping table registers */
+/* NT Mapping Table Address/Status/Data	(DWORD) */
+#define IDT_NT_NTMTBLADDR		0x004D0U
+#define IDT_NT_NTMTBLSTS		0x004D4U
+#define IDT_NT_NTMTBLDATA		0x004D8U
+/* Requester ID (Bus:Device:Function) Capture	(DWORD) */
+#define IDT_NT_REQIDCAP			0x004DCU
+/* Memory Windows Lookup table registers */
+/* Lookup Table Offset/Lower, Middle and Upper data	(DWORD) */
+#define IDT_NT_LUTOFFSET		0x004E0U
+#define IDT_NT_LUTLDATA			0x004E4U
+#define IDT_NT_LUTMDATA			0x004E8U
+#define IDT_NT_LUTUDATA			0x004ECU
+/* NT Endpoint Uncorrectable/Correctable Errors Emulation registers (DWORD) */
+#define IDT_NT_NTUEEM			0x004F0U
+#define IDT_NT_NTCEEM			0x004F4U
+/* Global Address Space Access/Data registers	(DWARD) */
+#define IDT_NT_GASAADDR			0x00FF8U
+#define IDT_NT_GASADATA			0x00FFCU
+
+/*
+ * IDT PCIe-switch Global Configuration and Status registers
+ */
+/* Port N Configuration register in global space */
+/* PCI Express command/status and link control/status registers (WORD+WORD) */
+#define IDT_SW_NTP0_PCIECMDSTS		0x01004U
+#define IDT_SW_NTP0_PCIELCTLSTS		0x01050U
+/* NT-function control register		(DWORD) */
+#define IDT_SW_NTP0_NTCTL		0x01400U
+/* BAR setup/limit/base address registers (DWORD) */
+#define IDT_SW_NTP0_BARSETUP0		0x01470U
+#define IDT_SW_NTP0_BARLIMIT0		0x01474U
+#define IDT_SW_NTP0_BARLTBASE0		0x01478U
+#define IDT_SW_NTP0_BARUTBASE0		0x0147CU
+#define IDT_SW_NTP0_BARSETUP1		0x01480U
+#define IDT_SW_NTP0_BARLIMIT1		0x01484U
+#define IDT_SW_NTP0_BARLTBASE1		0x01488U
+#define IDT_SW_NTP0_BARUTBASE1		0x0148CU
+#define IDT_SW_NTP0_BARSETUP2		0x01490U
+#define IDT_SW_NTP0_BARLIMIT2		0x01494U
+#define IDT_SW_NTP0_BARLTBASE2		0x01498U
+#define IDT_SW_NTP0_BARUTBASE2		0x0149CU
+#define IDT_SW_NTP0_BARSETUP3		0x014A0U
+#define IDT_SW_NTP0_BARLIMIT3		0x014A4U
+#define IDT_SW_NTP0_BARLTBASE3		0x014A8U
+#define IDT_SW_NTP0_BARUTBASE3		0x014ACU
+#define IDT_SW_NTP0_BARSETUP4		0x014B0U
+#define IDT_SW_NTP0_BARLIMIT4		0x014B4U
+#define IDT_SW_NTP0_BARLTBASE4		0x014B8U
+#define IDT_SW_NTP0_BARUTBASE4		0x014BCU
+#define IDT_SW_NTP0_BARSETUP5		0x014C0U
+#define IDT_SW_NTP0_BARLIMIT5		0x014C4U
+#define IDT_SW_NTP0_BARLTBASE5		0x014C8U
+#define IDT_SW_NTP0_BARUTBASE5		0x014CCU
+/* PCI Express command/status and link control/status registers (WORD+WORD) */
+#define IDT_SW_NTP2_PCIECMDSTS		0x05004U
+#define IDT_SW_NTP2_PCIELCTLSTS		0x05050U
+/* NT-function control register		(DWORD) */
+#define IDT_SW_NTP2_NTCTL		0x05400U
+/* BAR setup/limit/base address registers (DWORD) */
+#define IDT_SW_NTP2_BARSETUP0		0x05470U
+#define IDT_SW_NTP2_BARLIMIT0		0x05474U
+#define IDT_SW_NTP2_BARLTBASE0		0x05478U
+#define IDT_SW_NTP2_BARUTBASE0		0x0547CU
+#define IDT_SW_NTP2_BARSETUP1		0x05480U
+#define IDT_SW_NTP2_BARLIMIT1		0x05484U
+#define IDT_SW_NTP2_BARLTBASE1		0x05488U
+#define IDT_SW_NTP2_BARUTBASE1		0x0548CU
+#define IDT_SW_NTP2_BARSETUP2		0x05490U
+#define IDT_SW_NTP2_BARLIMIT2		0x05494U
+#define IDT_SW_NTP2_BARLTBASE2		0x05498U
+#define IDT_SW_NTP2_BARUTBASE2		0x0549CU
+#define IDT_SW_NTP2_BARSETUP3		0x054A0U
+#define IDT_SW_NTP2_BARLIMIT3		0x054A4U
+#define IDT_SW_NTP2_BARLTBASE3		0x054A8U
+#define IDT_SW_NTP2_BARUTBASE3		0x054ACU
+#define IDT_SW_NTP2_BARSETUP4		0x054B0U
+#define IDT_SW_NTP2_BARLIMIT4		0x054B4U
+#define IDT_SW_NTP2_BARLTBASE4		0x054B8U
+#define IDT_SW_NTP2_BARUTBASE4		0x054BCU
+#define IDT_SW_NTP2_BARSETUP5		0x054C0U
+#define IDT_SW_NTP2_BARLIMIT5		0x054C4U
+#define IDT_SW_NTP2_BARLTBASE5		0x054C8U
+#define IDT_SW_NTP2_BARUTBASE5		0x054CCU
+/* PCI Express command/status and link control/status registers (WORD+WORD) */
+#define IDT_SW_NTP4_PCIECMDSTS		0x09004U
+#define IDT_SW_NTP4_PCIELCTLSTS		0x09050U
+/* NT-function control register		(DWORD) */
+#define IDT_SW_NTP4_NTCTL		0x09400U
+/* BAR setup/limit/base address registers (DWORD) */
+#define IDT_SW_NTP4_BARSETUP0		0x09470U
+#define IDT_SW_NTP4_BARLIMIT0		0x09474U
+#define IDT_SW_NTP4_BARLTBASE0		0x09478U
+#define IDT_SW_NTP4_BARUTBASE0		0x0947CU
+#define IDT_SW_NTP4_BARSETUP1		0x09480U
+#define IDT_SW_NTP4_BARLIMIT1		0x09484U
+#define IDT_SW_NTP4_BARLTBASE1		0x09488U
+#define IDT_SW_NTP4_BARUTBASE1		0x0948CU
+#define IDT_SW_NTP4_BARSETUP2		0x09490U
+#define IDT_SW_NTP4_BARLIMIT2		0x09494U
+#define IDT_SW_NTP4_BARLTBASE2		0x09498U
+#define IDT_SW_NTP4_BARUTBASE2		0x0949CU
+#define IDT_SW_NTP4_BARSETUP3		0x094A0U
+#define IDT_SW_NTP4_BARLIMIT3		0x094A4U
+#define IDT_SW_NTP4_BARLTBASE3		0x094A8U
+#define IDT_SW_NTP4_BARUTBASE3		0x094ACU
+#define IDT_SW_NTP4_BARSETUP4		0x094B0U
+#define IDT_SW_NTP4_BARLIMIT4		0x094B4U
+#define IDT_SW_NTP4_BARLTBASE4		0x094B8U
+#define IDT_SW_NTP4_BARUTBASE4		0x094BCU
+#define IDT_SW_NTP4_BARSETUP5		0x094C0U
+#define IDT_SW_NTP4_BARLIMIT5		0x094C4U
+#define IDT_SW_NTP4_BARLTBASE5		0x094C8U
+#define IDT_SW_NTP4_BARUTBASE5		0x094CCU
+/* PCI Express command/status and link control/status registers (WORD+WORD) */
+#define IDT_SW_NTP6_PCIECMDSTS		0x0D004U
+#define IDT_SW_NTP6_PCIELCTLSTS		0x0D050U
+/* NT-function control register		(DWORD) */
+#define IDT_SW_NTP6_NTCTL		0x0D400U
+/* BAR setup/limit/base address registers (DWORD) */
+#define IDT_SW_NTP6_BARSETUP0		0x0D470U
+#define IDT_SW_NTP6_BARLIMIT0		0x0D474U
+#define IDT_SW_NTP6_BARLTBASE0		0x0D478U
+#define IDT_SW_NTP6_BARUTBASE0		0x0D47CU
+#define IDT_SW_NTP6_BARSETUP1		0x0D480U
+#define IDT_SW_NTP6_BARLIMIT1		0x0D484U
+#define IDT_SW_NTP6_BARLTBASE1		0x0D488U
+#define IDT_SW_NTP6_BARUTBASE1		0x0D48CU
+#define IDT_SW_NTP6_BARSETUP2		0x0D490U
+#define IDT_SW_NTP6_BARLIMIT2		0x0D494U
+#define IDT_SW_NTP6_BARLTBASE2		0x0D498U
+#define IDT_SW_NTP6_BARUTBASE2		0x0D49CU
+#define IDT_SW_NTP6_BARSETUP3		0x0D4A0U
+#define IDT_SW_NTP6_BARLIMIT3		0x0D4A4U
+#define IDT_SW_NTP6_BARLTBASE3		0x0D4A8U
+#define IDT_SW_NTP6_BARUTBASE3		0x0D4ACU
+#define IDT_SW_NTP6_BARSETUP4		0x0D4B0U
+#define IDT_SW_NTP6_BARLIMIT4		0x0D4B4U
+#define IDT_SW_NTP6_BARLTBASE4		0x0D4B8U
+#define IDT_SW_NTP6_BARUTBASE4		0x0D4BCU
+#define IDT_SW_NTP6_BARSETUP5		0x0D4C0U
+#define IDT_SW_NTP6_BARLIMIT5		0x0D4C4U
+#define IDT_SW_NTP6_BARLTBASE5		0x0D4C8U
+#define IDT_SW_NTP6_BARUTBASE5		0x0D4CCU
+/* PCI Express command/status and link control/status registers (WORD+WORD) */
+#define IDT_SW_NTP8_PCIECMDSTS		0x11004U
+#define IDT_SW_NTP8_PCIELCTLSTS		0x11050U
+/* NT-function control register		(DWORD) */
+#define IDT_SW_NTP8_NTCTL		0x11400U
+/* BAR setup/limit/base address registers (DWORD) */
+#define IDT_SW_NTP8_BARSETUP0		0x11470U
+#define IDT_SW_NTP8_BARLIMIT0		0x11474U
+#define IDT_SW_NTP8_BARLTBASE0		0x11478U
+#define IDT_SW_NTP8_BARUTBASE0		0x1147CU
+#define IDT_SW_NTP8_BARSETUP1		0x11480U
+#define IDT_SW_NTP8_BARLIMIT1		0x11484U
+#define IDT_SW_NTP8_BARLTBASE1		0x11488U
+#define IDT_SW_NTP8_BARUTBASE1		0x1148CU
+#define IDT_SW_NTP8_BARSETUP2		0x11490U
+#define IDT_SW_NTP8_BARLIMIT2		0x11494U
+#define IDT_SW_NTP8_BARLTBASE2		0x11498U
+#define IDT_SW_NTP8_BARUTBASE2		0x1149CU
+#define IDT_SW_NTP8_BARSETUP3		0x114A0U
+#define IDT_SW_NTP8_BARLIMIT3		0x114A4U
+#define IDT_SW_NTP8_BARLTBASE3		0x114A8U
+#define IDT_SW_NTP8_BARUTBASE3		0x114ACU
+#define IDT_SW_NTP8_BARSETUP4		0x114B0U
+#define IDT_SW_NTP8_BARLIMIT4		0x114B4U
+#define IDT_SW_NTP8_BARLTBASE4		0x114B8U
+#define IDT_SW_NTP8_BARUTBASE4		0x114BCU
+#define IDT_SW_NTP8_BARSETUP5		0x114C0U
+#define IDT_SW_NTP8_BARLIMIT5		0x114C4U
+#define IDT_SW_NTP8_BARLTBASE5		0x114C8U
+#define IDT_SW_NTP8_BARUTBASE5		0x114CCU
+/* PCI Express command/status and link control/status registers (WORD+WORD) */
+#define IDT_SW_NTP12_PCIECMDSTS		0x19004U
+#define IDT_SW_NTP12_PCIELCTLSTS	0x19050U
+/* NT-function control register		(DWORD) */
+#define IDT_SW_NTP12_NTCTL		0x19400U
+/* BAR setup/limit/base address registers (DWORD) */
+#define IDT_SW_NTP12_BARSETUP0		0x19470U
+#define IDT_SW_NTP12_BARLIMIT0		0x19474U
+#define IDT_SW_NTP12_BARLTBASE0		0x19478U
+#define IDT_SW_NTP12_BARUTBASE0		0x1947CU
+#define IDT_SW_NTP12_BARSETUP1		0x19480U
+#define IDT_SW_NTP12_BARLIMIT1		0x19484U
+#define IDT_SW_NTP12_BARLTBASE1		0x19488U
+#define IDT_SW_NTP12_BARUTBASE1		0x1948CU
+#define IDT_SW_NTP12_BARSETUP2		0x19490U
+#define IDT_SW_NTP12_BARLIMIT2		0x19494U
+#define IDT_SW_NTP12_BARLTBASE2		0x19498U
+#define IDT_SW_NTP12_BARUTBASE2		0x1949CU
+#define IDT_SW_NTP12_BARSETUP3		0x194A0U
+#define IDT_SW_NTP12_BARLIMIT3		0x194A4U
+#define IDT_SW_NTP12_BARLTBASE3		0x194A8U
+#define IDT_SW_NTP12_BARUTBASE3		0x194ACU
+#define IDT_SW_NTP12_BARSETUP4		0x194B0U
+#define IDT_SW_NTP12_BARLIMIT4		0x194B4U
+#define IDT_SW_NTP12_BARLTBASE4		0x194B8U
+#define IDT_SW_NTP12_BARUTBASE4		0x194BCU
+#define IDT_SW_NTP12_BARSETUP5		0x194C0U
+#define IDT_SW_NTP12_BARLIMIT5		0x194C4U
+#define IDT_SW_NTP12_BARLTBASE5		0x194C8U
+#define IDT_SW_NTP12_BARUTBASE5		0x194CCU
+/* PCI Express command/status and link control/status registers (WORD+WORD) */
+#define IDT_SW_NTP16_PCIECMDSTS		0x21004U
+#define IDT_SW_NTP16_PCIELCTLSTS	0x21050U
+/* NT-function control register		(DWORD) */
+#define IDT_SW_NTP16_NTCTL		0x21400U
+/* BAR setup/limit/base address registers (DWORD) */
+#define IDT_SW_NTP16_BARSETUP0		0x21470U
+#define IDT_SW_NTP16_BARLIMIT0		0x21474U
+#define IDT_SW_NTP16_BARLTBASE0		0x21478U
+#define IDT_SW_NTP16_BARUTBASE0		0x2147CU
+#define IDT_SW_NTP16_BARSETUP1		0x21480U
+#define IDT_SW_NTP16_BARLIMIT1		0x21484U
+#define IDT_SW_NTP16_BARLTBASE1		0x21488U
+#define IDT_SW_NTP16_BARUTBASE1		0x2148CU
+#define IDT_SW_NTP16_BARSETUP2		0x21490U
+#define IDT_SW_NTP16_BARLIMIT2		0x21494U
+#define IDT_SW_NTP16_BARLTBASE2		0x21498U
+#define IDT_SW_NTP16_BARUTBASE2		0x2149CU
+#define IDT_SW_NTP16_BARSETUP3		0x214A0U
+#define IDT_SW_NTP16_BARLIMIT3		0x214A4U
+#define IDT_SW_NTP16_BARLTBASE3		0x214A8U
+#define IDT_SW_NTP16_BARUTBASE3		0x214ACU
+#define IDT_SW_NTP16_BARSETUP4		0x214B0U
+#define IDT_SW_NTP16_BARLIMIT4		0x214B4U
+#define IDT_SW_NTP16_BARLTBASE4		0x214B8U
+#define IDT_SW_NTP16_BARUTBASE4		0x214BCU
+#define IDT_SW_NTP16_BARSETUP5		0x214C0U
+#define IDT_SW_NTP16_BARLIMIT5		0x214C4U
+#define IDT_SW_NTP16_BARLTBASE5		0x214C8U
+#define IDT_SW_NTP16_BARUTBASE5		0x214CCU
+/* PCI Express command/status and link control/status registers (WORD+WORD) */
+#define IDT_SW_NTP20_PCIECMDSTS		0x29004U
+#define IDT_SW_NTP20_PCIELCTLSTS	0x29050U
+/* NT-function control register		(DWORD) */
+#define IDT_SW_NTP20_NTCTL		0x29400U
+/* BAR setup/limit/base address registers (DWORD) */
+#define IDT_SW_NTP20_BARSETUP0		0x29470U
+#define IDT_SW_NTP20_BARLIMIT0		0x29474U
+#define IDT_SW_NTP20_BARLTBASE0		0x29478U
+#define IDT_SW_NTP20_BARUTBASE0		0x2947CU
+#define IDT_SW_NTP20_BARSETUP1		0x29480U
+#define IDT_SW_NTP20_BARLIMIT1		0x29484U
+#define IDT_SW_NTP20_BARLTBASE1		0x29488U
+#define IDT_SW_NTP20_BARUTBASE1		0x2948CU
+#define IDT_SW_NTP20_BARSETUP2		0x29490U
+#define IDT_SW_NTP20_BARLIMIT2		0x29494U
+#define IDT_SW_NTP20_BARLTBASE2		0x29498U
+#define IDT_SW_NTP20_BARUTBASE2		0x2949CU
+#define IDT_SW_NTP20_BARSETUP3		0x294A0U
+#define IDT_SW_NTP20_BARLIMIT3		0x294A4U
+#define IDT_SW_NTP20_BARLTBASE3		0x294A8U
+#define IDT_SW_NTP20_BARUTBASE3		0x294ACU
+#define IDT_SW_NTP20_BARSETUP4		0x294B0U
+#define IDT_SW_NTP20_BARLIMIT4		0x294B4U
+#define IDT_SW_NTP20_BARLTBASE4		0x294B8U
+#define IDT_SW_NTP20_BARUTBASE4		0x294BCU
+#define IDT_SW_NTP20_BARSETUP5		0x294C0U
+#define IDT_SW_NTP20_BARLIMIT5		0x294C4U
+#define IDT_SW_NTP20_BARLTBASE5		0x294C8U
+#define IDT_SW_NTP20_BARUTBASE5		0x294CCU
+/* IDT PCIe-switch control register	(DWORD) */
+#define IDT_SW_CTL			0x3E000U
+/* Boot Configuration Vector Status	(DWORD) */
+#define IDT_SW_BCVSTS			0x3E004U
+/* Port Clocking Mode			(DWORD) */
+#define IDT_SW_PCLKMODE			0x3E008U
+/* Reset Drain Delay			(DWORD) */
+#define IDT_SW_RDRAINDELAY		0x3E080U
+/* Port Operating Mode Change Drain Delay (DWORD) */
+#define IDT_SW_POMCDELAY		0x3E084U
+/* Side Effect Delay			(DWORD) */
+#define IDT_SW_SEDELAY			0x3E088U
+/* Upstream Secondary Bus Reset Delay	(DWORD) */
+#define IDT_SW_SSBRDELAY		0x3E08CU
+/* Switch partition N Control/Status/Failover registers */
+#define IDT_SW_SWPART0CTL		0x3E100U
+#define IDT_SW_SWPART0STS		0x3E104U
+#define IDT_SW_SWPART0FCTL		0x3E108U
+#define IDT_SW_SWPART1CTL		0x3E120U
+#define IDT_SW_SWPART1STS		0x3E124U
+#define IDT_SW_SWPART1FCTL		0x3E128U
+#define IDT_SW_SWPART2CTL		0x3E140U
+#define IDT_SW_SWPART2STS		0x3E144U
+#define IDT_SW_SWPART2FCTL		0x3E148U
+#define IDT_SW_SWPART3CTL		0x3E160U
+#define IDT_SW_SWPART3STS		0x3E164U
+#define IDT_SW_SWPART3FCTL		0x3E168U
+#define IDT_SW_SWPART4CTL		0x3E180U
+#define IDT_SW_SWPART4STS		0x3E184U
+#define IDT_SW_SWPART4FCTL		0x3E188U
+#define IDT_SW_SWPART5CTL		0x3E1A0U
+#define IDT_SW_SWPART5STS		0x3E1A4U
+#define IDT_SW_SWPART5FCTL		0x3E1A8U
+#define IDT_SW_SWPART6CTL		0x3E1C0U
+#define IDT_SW_SWPART6STS		0x3E1C4U
+#define IDT_SW_SWPART6FCTL		0x3E1C8U
+#define IDT_SW_SWPART7CTL		0x3E1E0U
+#define IDT_SW_SWPART7STS		0x3E1E4U
+#define IDT_SW_SWPART7FCTL		0x3E1E8U
+/* Switch port N control and status registers */
+#define IDT_SW_SWPORT0CTL		0x3E200U
+#define IDT_SW_SWPORT0STS		0x3E204U
+#define IDT_SW_SWPORT0FCTL		0x3E208U
+#define IDT_SW_SWPORT2CTL		0x3E240U
+#define IDT_SW_SWPORT2STS		0x3E244U
+#define IDT_SW_SWPORT2FCTL		0x3E248U
+#define IDT_SW_SWPORT4CTL		0x3E280U
+#define IDT_SW_SWPORT4STS		0x3E284U
+#define IDT_SW_SWPORT4FCTL		0x3E288U
+#define IDT_SW_SWPORT6CTL		0x3E2C0U
+#define IDT_SW_SWPORT6STS		0x3E2C4U
+#define IDT_SW_SWPORT6FCTL		0x3E2C8U
+#define IDT_SW_SWPORT8CTL		0x3E300U
+#define IDT_SW_SWPORT8STS		0x3E304U
+#define IDT_SW_SWPORT8FCTL		0x3E308U
+#define IDT_SW_SWPORT12CTL		0x3E380U
+#define IDT_SW_SWPORT12STS		0x3E384U
+#define IDT_SW_SWPORT12FCTL		0x3E388U
+#define IDT_SW_SWPORT16CTL		0x3E400U
+#define IDT_SW_SWPORT16STS		0x3E404U
+#define IDT_SW_SWPORT16FCTL		0x3E408U
+#define IDT_SW_SWPORT20CTL		0x3E480U
+#define IDT_SW_SWPORT20STS		0x3E484U
+#define IDT_SW_SWPORT20FCTL		0x3E488U
+/* Switch Event registers */
+/* Switch Event Status/Mask/Partition mask (DWORD) */
+#define IDT_SW_SESTS			0x3EC00U
+#define IDT_SW_SEMSK			0x3EC04U
+#define IDT_SW_SEPMSK			0x3EC08U
+/* Switch Event Link Up/Down Status/Mask (DWORD) */
+#define IDT_SW_SELINKUPSTS		0x3EC0CU
+#define IDT_SW_SELINKUPMSK		0x3EC10U
+#define IDT_SW_SELINKDNSTS		0x3EC14U
+#define IDT_SW_SELINKDNMSK		0x3EC18U
+/* Switch Event Fundamental Reset Status/Mask (DWORD) */
+#define IDT_SW_SEFRSTSTS		0x3EC1CU
+#define IDT_SW_SEFRSTMSK		0x3EC20U
+/* Switch Event Hot Reset Status/Mask	(DWORD) */
+#define IDT_SW_SEHRSTSTS		0x3EC24U
+#define IDT_SW_SEHRSTMSK		0x3EC28U
+/* Switch Event Failover Mask		(DWORD) */
+#define IDT_SW_SEFOVRMSK		0x3EC2CU
+/* Switch Event Global Signal Status/Mask (DWORD) */
+#define IDT_SW_SEGSIGSTS		0x3EC30U
+#define IDT_SW_SEGSIGMSK		0x3EC34U
+/* NT Global Doorbell Status		(DWORD) */
+#define IDT_SW_GDBELLSTS		0x3EC3CU
+/* Switch partition N message M control (msgs routing table) (DWORD) */
+#define IDT_SW_SWP0MSGCTL0		0x3EE00U
+#define IDT_SW_SWP1MSGCTL0		0x3EE04U
+#define IDT_SW_SWP2MSGCTL0		0x3EE08U
+#define IDT_SW_SWP3MSGCTL0		0x3EE0CU
+#define IDT_SW_SWP4MSGCTL0		0x3EE10U
+#define IDT_SW_SWP5MSGCTL0		0x3EE14U
+#define IDT_SW_SWP6MSGCTL0		0x3EE18U
+#define IDT_SW_SWP7MSGCTL0		0x3EE1CU
+#define IDT_SW_SWP0MSGCTL1		0x3EE20U
+#define IDT_SW_SWP1MSGCTL1		0x3EE24U
+#define IDT_SW_SWP2MSGCTL1		0x3EE28U
+#define IDT_SW_SWP3MSGCTL1		0x3EE2CU
+#define IDT_SW_SWP4MSGCTL1		0x3EE30U
+#define IDT_SW_SWP5MSGCTL1		0x3EE34U
+#define IDT_SW_SWP6MSGCTL1		0x3EE38U
+#define IDT_SW_SWP7MSGCTL1		0x3EE3CU
+#define IDT_SW_SWP0MSGCTL2		0x3EE40U
+#define IDT_SW_SWP1MSGCTL2		0x3EE44U
+#define IDT_SW_SWP2MSGCTL2		0x3EE48U
+#define IDT_SW_SWP3MSGCTL2		0x3EE4CU
+#define IDT_SW_SWP4MSGCTL2		0x3EE50U
+#define IDT_SW_SWP5MSGCTL2		0x3EE54U
+#define IDT_SW_SWP6MSGCTL2		0x3EE58U
+#define IDT_SW_SWP7MSGCTL2		0x3EE5CU
+#define IDT_SW_SWP0MSGCTL3		0x3EE60U
+#define IDT_SW_SWP1MSGCTL3		0x3EE64U
+#define IDT_SW_SWP2MSGCTL3		0x3EE68U
+#define IDT_SW_SWP3MSGCTL3		0x3EE6CU
+#define IDT_SW_SWP4MSGCTL3		0x3EE70U
+#define IDT_SW_SWP5MSGCTL3		0x3EE74U
+#define IDT_SW_SWP6MSGCTL3		0x3EE78U
+#define IDT_SW_SWP7MSGCTL3		0x3EE7CU
+/* SMBus Status and Control registers	(DWORD) */
+#define IDT_SW_SMBUSSTS			0x3F188U
+#define IDT_SW_SMBUSCTL			0x3F18CU
+/* Serial EEPROM Interface		(DWORD) */
+#define IDT_SW_EEPROMINTF		0x3F190U
+/* MBus I/O Expander Address N		(DWORD) */
+#define IDT_SW_IOEXPADDR0		0x3F198U
+#define IDT_SW_IOEXPADDR1		0x3F19CU
+#define IDT_SW_IOEXPADDR2		0x3F1A0U
+#define IDT_SW_IOEXPADDR3		0x3F1A4U
+#define IDT_SW_IOEXPADDR4		0x3F1A8U
+#define IDT_SW_IOEXPADDR5		0x3F1ACU
+/* General Purpose Events Control and Status registers (DWORD) */
+#define IDT_SW_GPECTL			0x3F1B0U
+#define IDT_SW_GPESTS			0x3F1B4U
+/* Temperature sensor Control/Status/Alarm/Adjustment/Slope registers */
+#define IDT_SW_TMPCTL			0x3F1D4U
+#define IDT_SW_TMPSTS			0x3F1D8U
+#define IDT_SW_TMPALARM			0x3F1DCU
+#define IDT_SW_TMPADJ			0x3F1E0U
+#define IDT_SW_TSSLOPE			0x3F1E4U
+/* SMBus Configuration Block header log	(DWORD) */
+#define IDT_SW_SMBUSCBHL		0x3F1E8U
+
+/*
+ * Common registers related constants
+ * @IDT_REG_ALIGN:	Registers alignment used in the driver
+ * @IDT_REG_PCI_MAX:	Maximum PCI configuration space register value
+ * @IDT_REG_SW_MAX:	Maximum global register value
+ */
+#define IDT_REG_ALIGN			4
+#define IDT_REG_PCI_MAX			0x00FFFU
+#define IDT_REG_SW_MAX			0x3FFFFU
+
+/*
+ * PCICMDSTS register fields related constants
+ * @IDT_PCICMDSTS_IOAE:	I/O access enable
+ * @IDT_PCICMDSTS_MAE:	Memory access enable
+ * @IDT_PCICMDSTS_BME:	Bus master enable
+ */
+#define IDT_PCICMDSTS_IOAE		0x00000001U
+#define IDT_PCICMDSTS_MAE		0x00000002U
+#define IDT_PCICMDSTS_BME		0x00000004U
+
+/*
+ * PCIEDCAP register fields related constants
+ * @IDT_PCIEDCAP_MPAYLOAD_MASK:	 Maximum payload size mask
+ * @IDT_PCIEDCAP_MPAYLOAD_FLD:	 Maximum payload size field offset
+ * @IDT_PCIEDCAP_MPAYLOAD_S128:	 Max supported payload size of 128 bytes
+ * @IDT_PCIEDCAP_MPAYLOAD_S256:	 Max supported payload size of 256 bytes
+ * @IDT_PCIEDCAP_MPAYLOAD_S512:	 Max supported payload size of 512 bytes
+ * @IDT_PCIEDCAP_MPAYLOAD_S1024: Max supported payload size of 1024 bytes
+ * @IDT_PCIEDCAP_MPAYLOAD_S2048: Max supported payload size of 2048 bytes
+ */
+#define IDT_PCIEDCAP_MPAYLOAD_MASK	0x00000007U
+#define IDT_PCIEDCAP_MPAYLOAD_FLD	0
+#define IDT_PCIEDCAP_MPAYLOAD_S128	0x00000000U
+#define IDT_PCIEDCAP_MPAYLOAD_S256	0x00000001U
+#define IDT_PCIEDCAP_MPAYLOAD_S512	0x00000002U
+#define IDT_PCIEDCAP_MPAYLOAD_S1024	0x00000003U
+#define IDT_PCIEDCAP_MPAYLOAD_S2048	0x00000004U
+
+/*
+ * PCIEDCTLSTS registers fields related constants
+ * @IDT_PCIEDCTL_MPS_MASK:	Maximum payload size mask
+ * @IDT_PCIEDCTL_MPS_FLD:	MPS field offset
+ * @IDT_PCIEDCTL_MPS_S128:	Max payload size of 128 bytes
+ * @IDT_PCIEDCTL_MPS_S256:	Max payload size of 256 bytes
+ * @IDT_PCIEDCTL_MPS_S512:	Max payload size of 512 bytes
+ * @IDT_PCIEDCTL_MPS_S1024:	Max payload size of 1024 bytes
+ * @IDT_PCIEDCTL_MPS_S2048:	Max payload size of 2048 bytes
+ * @IDT_PCIEDCTL_MPS_S4096:	Max payload size of 4096 bytes
+ */
+#define IDT_PCIEDCTLSTS_MPS_MASK	0x000000E0U
+#define IDT_PCIEDCTLSTS_MPS_FLD		5
+#define IDT_PCIEDCTLSTS_MPS_S128	0x00000000U
+#define IDT_PCIEDCTLSTS_MPS_S256	0x00000020U
+#define IDT_PCIEDCTLSTS_MPS_S512	0x00000040U
+#define IDT_PCIEDCTLSTS_MPS_S1024	0x00000060U
+#define IDT_PCIEDCTLSTS_MPS_S2048	0x00000080U
+#define IDT_PCIEDCTLSTS_MPS_S4096	0x000000A0U
+
+/*
+ * PCIELCAP register fields related constants
+ * @IDT_PCIELCAP_PORTNUM_MASK:	Port number field mask
+ * @IDT_PCIELCAP_PORTNUM_FLD:	Port number field offset
+ */
+#define IDT_PCIELCAP_PORTNUM_MASK	0xFF000000U
+#define IDT_PCIELCAP_PORTNUM_FLD	24
+
+/*
+ * PCIELCTLSTS registers fields related constants
+ * @IDT_PCIELSTS_CLS_MASK:	Current link speed mask
+ * @IDT_PCIELSTS_CLS_FLD:	Current link speed field offset
+ * @IDT_PCIELSTS_NLW_MASK:	Negotiated link width mask
+ * @IDT_PCIELSTS_NLW_FLD:	Negotiated link width field offset
+ * @IDT_PCIELSTS_SCLK_COM:	Common slot clock configuration
+ */
+#define IDT_PCIELCTLSTS_CLS_MASK	0x000F0000U
+#define IDT_PCIELCTLSTS_CLS_FLD		16
+#define IDT_PCIELCTLSTS_NLW_MASK	0x03F00000U
+#define IDT_PCIELCTLSTS_NLW_FLD		20
+#define IDT_PCIELCTLSTS_SCLK_COM	0x10000000U
+
+/*
+ * NTCTL register fields related constants
+ * @IDT_NTCTL_IDPROTDIS:	ID Protection check disable (disable MTBL)
+ * @IDT_NTCTL_CPEN:		Completion enable
+ * @IDT_NTCTL_RNS:		Request no snoop processing (if MTBL disabled)
+ * @IDT_NTCTL_ATP:		Address type processing (if MTBL disabled)
+ */
+#define IDT_NTCTL_IDPROTDIS		0x00000001U
+#define IDT_NTCTL_CPEN			0x00000002U
+#define IDT_NTCTL_RNS			0x00000004U
+#define IDT_NTCTL_ATP			0x00000008U
+
+/*
+ * NTINTSTS register fields related constants
+ * @IDT_NTINTSTS_MSG:		Message interrupt bit
+ * @IDT_NTINTSTS_DBELL:		Doorbell interrupt bit
+ * @IDT_NTINTSTS_SEVENT:	Switch Event interrupt bit
+ * @IDT_NTINTSTS_TMPSENSOR:	Temperature sensor interrupt bit
+ */
+#define IDT_NTINTSTS_MSG		0x00000001U
+#define IDT_NTINTSTS_DBELL		0x00000002U
+#define IDT_NTINTSTS_SEVENT		0x00000008U
+#define IDT_NTINTSTS_TMPSENSOR		0x00000080U
+
+/*
+ * NTINTMSK register fields related constants
+ * @IDT_NTINTMSK_MSG:		Message interrupt mask bit
+ * @IDT_NTINTMSK_DBELL:		Doorbell interrupt mask bit
+ * @IDT_NTINTMSK_SEVENT:	Switch Event interrupt mask bit
+ * @IDT_NTINTMSK_TMPSENSOR:	Temperature sensor interrupt mask bit
+ * @IDT_NTINTMSK_ALL:		NTB-related interrupts mask
+ */
+#define IDT_NTINTMSK_MSG		0x00000001U
+#define IDT_NTINTMSK_DBELL		0x00000002U
+#define IDT_NTINTMSK_SEVENT		0x00000008U
+#define IDT_NTINTMSK_TMPSENSOR		0x00000080U
+#define IDT_NTINTMSK_ALL \
+	(IDT_NTINTMSK_MSG | IDT_NTINTMSK_DBELL | IDT_NTINTMSK_SEVENT)
+
+/*
+ * NTGSIGNAL register fields related constants
+ * @IDT_NTGSIGNAL_SET:	Set global signal of the local partition
+ */
+#define IDT_NTGSIGNAL_SET		0x00000001U
+
+/*
+ * BARSETUP register fields related constants
+ * @IDT_BARSETUP_TYPE_MASK:	Mask of the TYPE field
+ * @IDT_BARSETUP_TYPE_32:	32-bit addressing BAR
+ * @IDT_BARSETUP_TYPE_64:	64-bit addressing BAR
+ * @IDT_BARSETUP_PREF:		Value of the BAR prefetchable field
+ * @IDT_BARSETUP_SIZE_MASK:	Mask of the SIZE field
+ * @IDT_BARSETUP_SIZE_FLD:	SIZE field offset
+ * @IDT_BARSETUP_SIZE_CFG:	SIZE field value in case of config space MODE
+ * @IDT_BARSETUP_MODE_CFG:	Configuration space BAR mode
+ * @IDT_BARSETUP_ATRAN_MASK:	ATRAN field mask
+ * @IDT_BARSETUP_ATRAN_FLD:	ATRAN field offset
+ * @IDT_BARSETUP_ATRAN_DIR:	Direct address translation memory window
+ * @IDT_BARSETUP_ATRAN_LUT12:	12-entry lookup table
+ * @IDT_BARSETUP_ATRAN_LUT24:	24-entry lookup table
+ * @IDT_BARSETUP_TPART_MASK:	TPART field mask
+ * @IDT_BARSETUP_TPART_FLD:	TPART field offset
+ * @IDT_BARSETUP_EN:		BAR enable bit
+ */
+#define IDT_BARSETUP_TYPE_MASK		0x00000006U
+#define IDT_BARSETUP_TYPE_FLD		0
+#define IDT_BARSETUP_TYPE_32		0x00000000U
+#define IDT_BARSETUP_TYPE_64		0x00000004U
+#define IDT_BARSETUP_PREF		0x00000008U
+#define IDT_BARSETUP_SIZE_MASK		0x000003F0U
+#define IDT_BARSETUP_SIZE_FLD		4
+#define IDT_BARSETUP_SIZE_CFG		0x000000C0U
+#define IDT_BARSETUP_MODE_CFG		0x00000400U
+#define IDT_BARSETUP_ATRAN_MASK		0x00001800U
+#define IDT_BARSETUP_ATRAN_FLD		11
+#define IDT_BARSETUP_ATRAN_DIR		0x00000000U
+#define IDT_BARSETUP_ATRAN_LUT12	0x00000800U
+#define IDT_BARSETUP_ATRAN_LUT24	0x00001000U
+#define IDT_BARSETUP_TPART_MASK		0x0000E000U
+#define IDT_BARSETUP_TPART_FLD		13
+#define IDT_BARSETUP_EN			0x80000000U
+
+/*
+ * NTMTBLDATA register fields related constants
+ * @IDT_NTMTBLDATA_VALID:	Set the MTBL entry being valid
+ * @IDT_NTMTBLDATA_REQID_MASK:	Bus:Device:Function field mask
+ * @IDT_NTMTBLDATA_REQID_FLD:	Bus:Device:Function field offset
+ * @IDT_NTMTBLDATA_PART_MASK:	Partition field mask
+ * @IDT_NTMTBLDATA_PART_FLD:	Partition field offset
+ * @IDT_NTMTBLDATA_ATP_TRANS:	Enable AT field translation on request TLPs
+ * @IDT_NTMTBLDATA_CNS_INV:	Enable No Snoop attribute inversion of
+ *				Completion TLPs
+ * @IDT_NTMTBLDATA_RNS_INV:	Enable No Snoop attribute inversion of
+ *				Request TLPs
+ */
+#define IDT_NTMTBLDATA_VALID		0x00000001U
+#define IDT_NTMTBLDATA_REQID_MASK	0x0001FFFEU
+#define IDT_NTMTBLDATA_REQID_FLD	1
+#define IDT_NTMTBLDATA_PART_MASK	0x000E0000U
+#define IDT_NTMTBLDATA_PART_FLD		17
+#define IDT_NTMTBLDATA_ATP_TRANS	0x20000000U
+#define IDT_NTMTBLDATA_CNS_INV		0x40000000U
+#define IDT_NTMTBLDATA_RNS_INV		0x80000000U
+
+/*
+ * REQIDCAP register fields related constants
+ * @IDT_REQIDCAP_REQID_MASK:	Request ID field mask
+ * @IDT_REQIDCAP_REQID_FLD:	Request ID field offset
+ */
+#define IDT_REQIDCAP_REQID_MASK		0x0000FFFFU
+#define IDT_REQIDCAP_REQID_FLD		0
+
+/*
+ * LUTOFFSET register fields related constants
+ * @IDT_LUTOFFSET_INDEX_MASK:	Lookup table index field mask
+ * @IDT_LUTOFFSET_INDEX_FLD:	Lookup table index field offset
+ * @IDT_LUTOFFSET_BAR_MASK:	Lookup table BAR select field mask
+ * @IDT_LUTOFFSET_BAR_FLD:	Lookup table BAR select field offset
+ */
+#define IDT_LUTOFFSET_INDEX_MASK	0x0000001FU
+#define IDT_LUTOFFSET_INDEX_FLD		0
+#define IDT_LUTOFFSET_BAR_MASK		0x00000700U
+#define IDT_LUTOFFSET_BAR_FLD		8
+
+/*
+ * LUTUDATA register fields related constants
+ * @IDT_LUTUDATA_PART_MASK:	Partition field mask
+ * @IDT_LUTUDATA_PART_FLD:	Partition field offset
+ * @IDT_LUTUDATA_VALID:		Lookup table entry valid bit
+ */
+#define IDT_LUTUDATA_PART_MASK		0x0000000FU
+#define IDT_LUTUDATA_PART_FLD		0
+#define IDT_LUTUDATA_VALID		0x80000000U
+
+/*
+ * SWPARTxSTS register fields related constants
+ * @IDT_SWPARTxSTS_SCI:		Switch partition state change initiated
+ * @IDT_SWPARTxSTS_SCC:		Switch partition state change completed
+ * @IDT_SWPARTxSTS_STATE_MASK:	Switch partition state mask
+ * @IDT_SWPARTxSTS_STATE_FLD:	Switch partition state field offset
+ * @IDT_SWPARTxSTS_STATE_DIS:	Switch partition disabled
+ * @IDT_SWPARTxSTS_STATE_ACT:	Switch partition enabled
+ * @IDT_SWPARTxSTS_STATE_RES:	Switch partition in reset
+ * @IDT_SWPARTxSTS_US:		Switch partition has upstream port
+ * @IDT_SWPARTxSTS_USID_MASK:	Switch partition upstream port ID mask
+ * @IDT_SWPARTxSTS_USID_FLD:	Switch partition upstream port ID field offset
+ * @IDT_SWPARTxSTS_NT:		Upstream port has NT function
+ * @IDT_SWPARTxSTS_DMA:		Upstream port has DMA function
+ */
+#define IDT_SWPARTxSTS_SCI		0x00000001U
+#define IDT_SWPARTxSTS_SCC		0x00000002U
+#define IDT_SWPARTxSTS_STATE_MASK	0x00000060U
+#define IDT_SWPARTxSTS_STATE_FLD	5
+#define IDT_SWPARTxSTS_STATE_DIS	0x00000000U
+#define IDT_SWPARTxSTS_STATE_ACT	0x00000020U
+#define IDT_SWPARTxSTS_STATE_RES	0x00000060U
+#define IDT_SWPARTxSTS_US		0x00000100U
+#define IDT_SWPARTxSTS_USID_MASK	0x00003E00U
+#define IDT_SWPARTxSTS_USID_FLD		9
+#define IDT_SWPARTxSTS_NT		0x00004000U
+#define IDT_SWPARTxSTS_DMA		0x00008000U
+
+/*
+ * SWPORTxSTS register fields related constants
+ * @IDT_SWPORTxSTS_OMCI:	Operation mode change initiated
+ * @IDT_SWPORTxSTS_OMCC:	Operation mode change completed
+ * @IDT_SWPORTxSTS_LINKUP:	Link up status
+ * @IDT_SWPORTxSTS_DS:		Port lanes behave as downstream lanes
+ * @IDT_SWPORTxSTS_MODE_MASK:	Port mode field mask
+ * @IDT_SWPORTxSTS_MODE_FLD:	Port mode field offset
+ * @IDT_SWPORTxSTS_MODE_DIS:	Port mode - disabled
+ * @IDT_SWPORTxSTS_MODE_DS:	Port mode - downstream switch port
+ * @IDT_SWPORTxSTS_MODE_US:	Port mode - upstream switch port
+ * @IDT_SWPORTxSTS_MODE_NT:	Port mode - NT function
+ * @IDT_SWPORTxSTS_MODE_USNT:	Port mode - upstream switch port with NTB
+ * @IDT_SWPORTxSTS_MODE_UNAT:	Port mode - unattached
+ * @IDT_SWPORTxSTS_MODE_USDMA:	Port mode - upstream switch port with DMA
+ * @IDT_SWPORTxSTS_MODE_USNTDMA:Port mode - upstream port with NTB and DMA
+ * @IDT_SWPORTxSTS_MODE_NTDMA:	Port mode - NT function with DMA
+ * @IDT_SWPORTxSTS_SWPART_MASK:	Port partition field mask
+ * @IDT_SWPORTxSTS_SWPART_FLD:	Port partition field offset
+ * @IDT_SWPORTxSTS_DEVNUM_MASK:	Port device number field mask
+ * @IDT_SWPORTxSTS_DEVNUM_FLD:	Port device number field offset
+ */
+#define IDT_SWPORTxSTS_OMCI		0x00000001U
+#define IDT_SWPORTxSTS_OMCC		0x00000002U
+#define IDT_SWPORTxSTS_LINKUP		0x00000010U
+#define IDT_SWPORTxSTS_DS		0x00000020U
+#define IDT_SWPORTxSTS_MODE_MASK	0x000003C0U
+#define IDT_SWPORTxSTS_MODE_FLD		6
+#define IDT_SWPORTxSTS_MODE_DIS		0x00000000U
+#define IDT_SWPORTxSTS_MODE_DS		0x00000040U
+#define IDT_SWPORTxSTS_MODE_US		0x00000080U
+#define IDT_SWPORTxSTS_MODE_NT		0x000000C0U
+#define IDT_SWPORTxSTS_MODE_USNT	0x00000100U
+#define IDT_SWPORTxSTS_MODE_UNAT	0x00000140U
+#define IDT_SWPORTxSTS_MODE_USDMA	0x00000180U
+#define IDT_SWPORTxSTS_MODE_USNTDMA	0x000001C0U
+#define IDT_SWPORTxSTS_MODE_NTDMA	0x00000200U
+#define IDT_SWPORTxSTS_SWPART_MASK	0x00001C00U
+#define IDT_SWPORTxSTS_SWPART_FLD	10
+#define IDT_SWPORTxSTS_DEVNUM_MASK	0x001F0000U
+#define IDT_SWPORTxSTS_DEVNUM_FLD	16
+
+/*
+ * SEMSK register fields related constants
+ * @IDT_SEMSK_LINKUP:	Link Up event mask bit
+ * @IDT_SEMSK_LINKDN:	Link Down event mask bit
+ * @IDT_SEMSK_GSIGNAL:	Global Signal event mask bit
+ */
+#define IDT_SEMSK_LINKUP		0x00000001U
+#define IDT_SEMSK_LINKDN		0x00000002U
+#define IDT_SEMSK_GSIGNAL		0x00000020U
+
+/*
+ * SWPxMSGCTL register fields related constants
+ * @IDT_SWPxMSGCTL_REG_MASK:	Register select field mask
+ * @IDT_SWPxMSGCTL_REG_FLD:	Register select field offset
+ * @IDT_SWPxMSGCTL_PART_MASK:	Partition select field mask
+ * @IDT_SWPxMSGCTL_PART_FLD:	Partition select field offset
+ */
+#define IDT_SWPxMSGCTL_REG_MASK		0x00000003U
+#define IDT_SWPxMSGCTL_REG_FLD		0
+#define IDT_SWPxMSGCTL_PART_MASK	0x00000070U
+#define IDT_SWPxMSGCTL_PART_FLD		4
+
+/*
+ * TMPCTL register fields related constants
+ * @IDT_TMPCTL_LTH_MASK:	Low temperature threshold field mask
+ * @IDT_TMPCTL_LTH_FLD:		Low temperature threshold field offset
+ * @IDT_TMPCTL_MTH_MASK:	Middle temperature threshold field mask
+ * @IDT_TMPCTL_MTH_FLD:		Middle temperature threshold field offset
+ * @IDT_TMPCTL_HTH_MASK:	High temperature threshold field mask
+ * @IDT_TMPCTL_HTH_FLD:		High temperature threshold field offset
+ * @IDT_TMPCTL_PDOWN:		Temperature sensor power down
+ */
+#define IDT_TMPCTL_LTH_MASK		0x000000FFU
+#define IDT_TMPCTL_LTH_FLD		0
+#define IDT_TMPCTL_MTH_MASK		0x0000FF00U
+#define IDT_TMPCTL_MTH_FLD		8
+#define IDT_TMPCTL_HTH_MASK		0x00FF0000U
+#define IDT_TMPCTL_HTH_FLD		16
+#define IDT_TMPCTL_PDOWN		0x80000000U
+
+/*
+ * TMPSTS register fields related constants
+ * @IDT_TMPSTS_TEMP_MASK:	Current temperature field mask
+ * @IDT_TMPSTS_TEMP_FLD:	Current temperature field offset
+ * @IDT_TMPSTS_LTEMP_MASK:	Lowest temperature field mask
+ * @IDT_TMPSTS_LTEMP_FLD:	Lowest temperature field offset
+ * @IDT_TMPSTS_HTEMP_MASK:	Highest temperature field mask
+ * @IDT_TMPSTS_HTEMP_FLD:	Highest temperature field offset
+ */
+#define IDT_TMPSTS_TEMP_MASK		0x000000FFU
+#define IDT_TMPSTS_TEMP_FLD		0
+#define IDT_TMPSTS_LTEMP_MASK		0x0000FF00U
+#define IDT_TMPSTS_LTEMP_FLD		8
+#define IDT_TMPSTS_HTEMP_MASK		0x00FF0000U
+#define IDT_TMPSTS_HTEMP_FLD		16
+
+/*
+ * TMPALARM register fields related constants
+ * @IDT_TMPALARM_LTEMP_MASK:	Lowest temperature field mask
+ * @IDT_TMPALARM_LTEMP_FLD:	Lowest temperature field offset
+ * @IDT_TMPALARM_HTEMP_MASK:	Highest temperature field mask
+ * @IDT_TMPALARM_HTEMP_FLD:	Highest temperature field offset
+ * @IDT_TMPALARM_IRQ_MASK:	Alarm IRQ status mask
+ */
+#define IDT_TMPALARM_LTEMP_MASK		0x0000FF00U
+#define IDT_TMPALARM_LTEMP_FLD		8
+#define IDT_TMPALARM_HTEMP_MASK		0x00FF0000U
+#define IDT_TMPALARM_HTEMP_FLD		16
+#define IDT_TMPALARM_IRQ_MASK		0x3F000000U
+
+/*
+ * TMPADJ register fields related constants
+ * @IDT_TMPADJ_OFFSET_MASK:	Temperature value offset field mask
+ * @IDT_TMPADJ_OFFSET_FLD:	Temperature value offset field offset
+ */
+#define IDT_TMPADJ_OFFSET_MASK		0x000000FFU
+#define IDT_TMPADJ_OFFSET_FLD		0
+
+/*
+ * Helper macro to get/set the corresponding field value
+ * @GET_FIELD:		Retrieve the value of the corresponding field
+ * @SET_FIELD:		Set the specified field up
+ * @IS_FLD_SET:		Check whether a field is set with value
+ */
+#define GET_FIELD(field, data) \
+	(((u32)(data) & IDT_ ##field## _MASK) >> IDT_ ##field## _FLD)
+#define SET_FIELD(field, data, value) \
+	(((u32)(data) & ~IDT_ ##field## _MASK) | \
+	 ((u32)(value) << IDT_ ##field## _FLD))
+#define IS_FLD_SET(field, data, value) \
+	(((u32)(data) & IDT_ ##field## _MASK) == IDT_ ##field## _ ##value)
+
+/*
+ * Useful registers masks:
+ * @IDT_DBELL_MASK:	Doorbell bits mask
+ * @IDT_OUTMSG_MASK:	Out messages status bits mask
+ * @IDT_INMSG_MASK:	In messages status bits mask
+ * @IDT_MSG_MASK:	Any message status bits mask
+ */
+#define IDT_DBELL_MASK		((u32)0xFFFFFFFFU)
+#define IDT_OUTMSG_MASK		((u32)0x0000000FU)
+#define IDT_INMSG_MASK		((u32)0x000F0000U)
+#define IDT_MSG_MASK		(IDT_INMSG_MASK | IDT_OUTMSG_MASK)
+
+/*
+ * Number of IDT NTB resources:
+ * @IDT_MSG_CNT:	Number of Message registers
+ * @IDT_BAR_CNT:	Number of BARs of each port
+ * @IDT_MTBL_ENTRY_CNT:	Number mapping table entries
+ */
+#define IDT_MSG_CNT		4
+#define IDT_BAR_CNT		6
+#define IDT_MTBL_ENTRY_CNT	64
+
+/*
+ * General IDT PCIe-switch constant
+ * @IDT_MAX_NR_PORTS:	Maximum number of ports per IDT PCIe-switch
+ * @IDT_MAX_NR_PARTS:	Maximum number of partitions per IDT PCIe-switch
+ * @IDT_MAX_NR_PEERS:	Maximum number of NT-peers per IDT PCIe-switch
+ * @IDT_MAX_NR_MWS:	Maximum number of Memory Widows
+ * @IDT_PCIE_REGSIZE:	Size of the registers in bytes
+ * @IDT_TRANS_ALIGN:	Alignment of translated base address
+ * @IDT_DIR_SIZE_ALIGN:	Alignment of size setting for direct translated MWs.
+ *			Even though the lower 10 bits are reserved, they are
+ *			treated by IDT as one's so basically there is no any
+ *			alignment of size limit for DIR address translation.
+ */
+#define IDT_MAX_NR_PORTS	24
+#define IDT_MAX_NR_PARTS	8
+#define IDT_MAX_NR_PEERS	8
+#define IDT_MAX_NR_MWS		29
+#define IDT_PCIE_REGSIZE	4
+#define IDT_TRANS_ALIGN		4
+#define IDT_DIR_SIZE_ALIGN	1
+
+/*
+ * IDT PCIe-switch temperature sensor value limits
+ * @IDT_TEMP_MIN_MDEG:	Minimal integer value of temperature
+ * @IDT_TEMP_MAX_MDEG:	Maximal integer value of temperature
+ * @IDT_TEMP_MIN_OFFSET:Minimal integer value of temperature offset
+ * @IDT_TEMP_MAX_OFFSET:Maximal integer value of temperature offset
+ */
+#define IDT_TEMP_MIN_MDEG	0
+#define IDT_TEMP_MAX_MDEG	127500
+#define IDT_TEMP_MIN_OFFSET	-64000
+#define IDT_TEMP_MAX_OFFSET	63500
+
+/*
+ * Temperature sensor values enumeration
+ * @IDT_TEMP_CUR:	Current temperature
+ * @IDT_TEMP_LOW:	Lowest historical temperature
+ * @IDT_TEMP_HIGH:	Highest historical temperature
+ * @IDT_TEMP_OFFSET:	Current temperature offset
+ */
+enum idt_temp_val {
+	IDT_TEMP_CUR,
+	IDT_TEMP_LOW,
+	IDT_TEMP_HIGH,
+	IDT_TEMP_OFFSET
+};
+
+/*
+ * IDT Memory Windows type. Depending on the device settings, IDT supports
+ * Direct Address Translation MW registers and Lookup Table registers
+ * @IDT_MW_DIR:		Direct address translation
+ * @IDT_MW_LUT12:	12-entry lookup table entry
+ * @IDT_MW_LUT24:	24-entry lookup table entry
+ *
+ * NOTE These values are exactly the same as one of the BARSETUP ATRAN field
+ */
+enum idt_mw_type {
+	IDT_MW_DIR = 0x0,
+	IDT_MW_LUT12 = 0x1,
+	IDT_MW_LUT24 = 0x2
+};
+
+/*
+ * IDT PCIe-switch model private data
+ * @name:	Device name
+ * @port_cnt:	Total number of NT endpoint ports
+ * @ports:	Port ids
+ */
+struct idt_89hpes_cfg {
+	char *name;
+	unsigned char port_cnt;
+	unsigned char ports[];
+};
+
+/*
+ * Memory window configuration structure
+ * @type:	Type of the memory window (direct address translation or lookup
+ *		table)
+ *
+ * @bar:	PCIe BAR the memory window referenced to
+ * @idx:	Index of the memory window within the BAR
+ *
+ * @addr_align:	Alignment of translated address
+ * @size_align:	Alignment of memory window size
+ * @size_max:	Maximum size of memory window
+ */
+struct idt_mw_cfg {
+	enum idt_mw_type type;
+
+	unsigned char bar;
+	unsigned char idx;
+
+	u64 addr_align;
+	u64 size_align;
+	u64 size_max;
+};
+
+/*
+ * Description structure of peer IDT NT-functions:
+ * @port:		NT-function port
+ * @part:		NT-function partition
+ *
+ * @mw_cnt:		Number of memory windows supported by NT-function
+ * @mws:		Array of memory windows descriptors
+ */
+struct idt_ntb_peer {
+	unsigned char port;
+	unsigned char part;
+
+	unsigned char mw_cnt;
+	struct idt_mw_cfg *mws;
+};
+
+/*
+ * Description structure of local IDT NT-function:
+ * @ntb:		Linux NTB-device description structure
+ * @swcfg:		Pointer to the structure of local IDT PCIe-switch
+ *			specific cofnfigurations
+ *
+ * @port:		Local NT-function port
+ * @part:		Local NT-function partition
+ *
+ * @peer_cnt:		Number of peers with activated NTB-function
+ * @peers:		Array of peers descripting structures
+ * @port_idx_map:	Map of port number -> peer index
+ * @part_idx_map:	Map of partition number -> peer index
+ *
+ * @mtbl_lock:		Mapping table access lock
+ *
+ * @mw_cnt:		Number of memory windows supported by NT-function
+ * @mws:		Array of memory windows descriptors
+ * @lut_lock:		Lookup table access lock
+ *
+ * @msg_locks:		Message registers mapping table lockers
+ *
+ * @cfgspc:		Virtual address of the memory mapped configuration
+ *			space of the NT-function
+ * @db_mask_lock:	Doorbell mask register lock
+ * @msg_mask_lock:	Message mask register lock
+ * @gasa_lock:		GASA registers access lock
+ *
+ * @hwmon_mtx:		Temperature sensor interface update mutex
+ *
+ * @dbgfs_info:		DebugFS info node
+ */
+struct idt_ntb_dev {
+	struct ntb_dev ntb;
+	struct idt_89hpes_cfg *swcfg;
+
+	unsigned char port;
+	unsigned char part;
+
+	unsigned char peer_cnt;
+	struct idt_ntb_peer peers[IDT_MAX_NR_PEERS];
+	char port_idx_map[IDT_MAX_NR_PORTS];
+	char part_idx_map[IDT_MAX_NR_PARTS];
+
+	spinlock_t mtbl_lock;
+
+	unsigned char mw_cnt;
+	struct idt_mw_cfg *mws;
+	spinlock_t lut_lock;
+
+	spinlock_t msg_locks[IDT_MSG_CNT];
+
+	void __iomem *cfgspc;
+	spinlock_t db_mask_lock;
+	spinlock_t msg_mask_lock;
+	spinlock_t gasa_lock;
+
+	struct mutex hwmon_mtx;
+
+	struct dentry *dbgfs_info;
+};
+#define to_ndev_ntb(__ntb) container_of(__ntb, struct idt_ntb_dev, ntb)
+
+/*
+ * Descriptor of the IDT PCIe-switch BAR resources
+ * @setup:	BAR setup register
+ * @limit:	BAR limit register
+ * @ltbase:	Lower translated base address
+ * @utbase:	Upper translated base address
+ */
+struct idt_ntb_bar {
+	unsigned int setup;
+	unsigned int limit;
+	unsigned int ltbase;
+	unsigned int utbase;
+};
+
+/*
+ * Descriptor of the IDT PCIe-switch message resources
+ * @in:		Inbound message register
+ * @out:	Outbound message register
+ * @src:	Source of inbound message register
+ */
+struct idt_ntb_msg {
+	unsigned int in;
+	unsigned int out;
+	unsigned int src;
+};
+
+/*
+ * Descriptor of the IDT PCIe-switch NT-function specific parameters in the
+ * PCI Configuration Space
+ * @bars:	BARs related registers
+ * @msgs:	Messaging related registers
+ */
+struct idt_ntb_regs {
+	struct idt_ntb_bar bars[IDT_BAR_CNT];
+	struct idt_ntb_msg msgs[IDT_MSG_CNT];
+};
+
+/*
+ * Descriptor of the IDT PCIe-switch port specific parameters in the
+ * Global Configuration Space
+ * @pcicmdsts:	 PCI command/status register
+ * @pcielctlsts: PCIe link control/status
+ *
+ * @ctl:	Port control register
+ * @sts:	Port status register
+ *
+ * @bars:	BARs related registers
+ */
+struct idt_ntb_port {
+	unsigned int pcicmdsts;
+	unsigned int pcielctlsts;
+	unsigned int ntctl;
+
+	unsigned int ctl;
+	unsigned int sts;
+
+	struct idt_ntb_bar bars[IDT_BAR_CNT];
+};
+
+/*
+ * Descriptor of the IDT PCIe-switch partition specific parameters.
+ * @ctl:	Partition control register in the Global Address Space
+ * @sts:	Partition status register in the Global Address Space
+ * @msgctl:	Messages control registers
+ */
+struct idt_ntb_part {
+	unsigned int ctl;
+	unsigned int sts;
+	unsigned int msgctl[IDT_MSG_CNT];
+};
+
+#endif /* NTB_HW_IDT_H */
diff --git a/drivers/ntb/hw/intel/Kconfig b/drivers/ntb/hw/intel/Kconfig
new file mode 100644
index 000000000..ed4d6dd57
--- /dev/null
+++ b/drivers/ntb/hw/intel/Kconfig
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config NTB_INTEL
+	tristate "Intel Non-Transparent Bridge support"
+	depends on X86_64
+	help
+	 This driver supports Intel NTB on capable Xeon and Atom hardware.
+
+	 If unsure, say N.
diff --git a/drivers/ntb/hw/intel/Makefile b/drivers/ntb/hw/intel/Makefile
new file mode 100644
index 000000000..f80da0ba1
--- /dev/null
+++ b/drivers/ntb/hw/intel/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_NTB_INTEL) += ntb_hw_intel.o
+ntb_hw_intel-y := ntb_hw_gen1.o ntb_hw_gen3.o ntb_hw_gen4.o
diff --git a/drivers/ntb/hw/intel/ntb_hw_gen1.c b/drivers/ntb/hw/intel/ntb_hw_gen1.c
new file mode 100644
index 000000000..944d10b48
--- /dev/null
+++ b/drivers/ntb/hw/intel/ntb_hw_gen1.c
@@ -0,0 +1,2091 @@
+/*
+ * This file is provided under a dual BSD/GPLv2 license.  When using or
+ *   redistributing this file, you may do so under either license.
+ *
+ *   GPL LICENSE SUMMARY
+ *
+ *   Copyright(c) 2012 Intel Corporation. All rights reserved.
+ *   Copyright (C) 2015 EMC Corporation. All Rights Reserved.
+ *   Copyright (C) 2016 T-Platforms. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of version 2 of the GNU General Public License as
+ *   published by the Free Software Foundation.
+ *
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2012 Intel Corporation. All rights reserved.
+ *   Copyright (C) 2015 EMC Corporation. All Rights Reserved.
+ *   Copyright (C) 2016 T-Platforms. All Rights Reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copy
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Intel PCIe NTB Linux driver
+ */
+
+#include <linux/debugfs.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/random.h>
+#include <linux/slab.h>
+#include <linux/ntb.h>
+
+#include "ntb_hw_intel.h"
+#include "ntb_hw_gen1.h"
+#include "ntb_hw_gen3.h"
+#include "ntb_hw_gen4.h"
+
+#define NTB_NAME	"ntb_hw_intel"
+#define NTB_DESC	"Intel(R) PCI-E Non-Transparent Bridge Driver"
+#define NTB_VER		"2.0"
+
+MODULE_DESCRIPTION(NTB_DESC);
+MODULE_VERSION(NTB_VER);
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_AUTHOR("Intel Corporation");
+
+#define bar0_off(base, bar) ((base) + ((bar) << 2))
+#define bar2_off(base, bar) bar0_off(base, (bar) - 2)
+
+static const struct intel_ntb_reg xeon_reg;
+static const struct intel_ntb_alt_reg xeon_pri_reg;
+static const struct intel_ntb_alt_reg xeon_sec_reg;
+static const struct intel_ntb_alt_reg xeon_b2b_reg;
+static const struct intel_ntb_xlat_reg xeon_pri_xlat;
+static const struct intel_ntb_xlat_reg xeon_sec_xlat;
+static const struct ntb_dev_ops intel_ntb_ops;
+
+static const struct file_operations intel_ntb_debugfs_info;
+static struct dentry *debugfs_dir;
+
+static int b2b_mw_idx = -1;
+module_param(b2b_mw_idx, int, 0644);
+MODULE_PARM_DESC(b2b_mw_idx, "Use this mw idx to access the peer ntb.  A "
+		 "value of zero or positive starts from first mw idx, and a "
+		 "negative value starts from last mw idx.  Both sides MUST "
+		 "set the same value here!");
+
+static unsigned int b2b_mw_share;
+module_param(b2b_mw_share, uint, 0644);
+MODULE_PARM_DESC(b2b_mw_share, "If the b2b mw is large enough, configure the "
+		 "ntb so that the peer ntb only occupies the first half of "
+		 "the mw, so the second half can still be used as a mw.  Both "
+		 "sides MUST set the same value here!");
+
+module_param_named(xeon_b2b_usd_bar2_addr64,
+		   xeon_b2b_usd_addr.bar2_addr64, ullong, 0644);
+MODULE_PARM_DESC(xeon_b2b_usd_bar2_addr64,
+		 "XEON B2B USD BAR 2 64-bit address");
+
+module_param_named(xeon_b2b_usd_bar4_addr64,
+		   xeon_b2b_usd_addr.bar4_addr64, ullong, 0644);
+MODULE_PARM_DESC(xeon_b2b_usd_bar4_addr64,
+		 "XEON B2B USD BAR 4 64-bit address");
+
+module_param_named(xeon_b2b_usd_bar4_addr32,
+		   xeon_b2b_usd_addr.bar4_addr32, ullong, 0644);
+MODULE_PARM_DESC(xeon_b2b_usd_bar4_addr32,
+		 "XEON B2B USD split-BAR 4 32-bit address");
+
+module_param_named(xeon_b2b_usd_bar5_addr32,
+		   xeon_b2b_usd_addr.bar5_addr32, ullong, 0644);
+MODULE_PARM_DESC(xeon_b2b_usd_bar5_addr32,
+		 "XEON B2B USD split-BAR 5 32-bit address");
+
+module_param_named(xeon_b2b_dsd_bar2_addr64,
+		   xeon_b2b_dsd_addr.bar2_addr64, ullong, 0644);
+MODULE_PARM_DESC(xeon_b2b_dsd_bar2_addr64,
+		 "XEON B2B DSD BAR 2 64-bit address");
+
+module_param_named(xeon_b2b_dsd_bar4_addr64,
+		   xeon_b2b_dsd_addr.bar4_addr64, ullong, 0644);
+MODULE_PARM_DESC(xeon_b2b_dsd_bar4_addr64,
+		 "XEON B2B DSD BAR 4 64-bit address");
+
+module_param_named(xeon_b2b_dsd_bar4_addr32,
+		   xeon_b2b_dsd_addr.bar4_addr32, ullong, 0644);
+MODULE_PARM_DESC(xeon_b2b_dsd_bar4_addr32,
+		 "XEON B2B DSD split-BAR 4 32-bit address");
+
+module_param_named(xeon_b2b_dsd_bar5_addr32,
+		   xeon_b2b_dsd_addr.bar5_addr32, ullong, 0644);
+MODULE_PARM_DESC(xeon_b2b_dsd_bar5_addr32,
+		 "XEON B2B DSD split-BAR 5 32-bit address");
+
+
+static int xeon_init_isr(struct intel_ntb_dev *ndev);
+
+static inline void ndev_reset_unsafe_flags(struct intel_ntb_dev *ndev)
+{
+	ndev->unsafe_flags = 0;
+	ndev->unsafe_flags_ignore = 0;
+
+	/* Only B2B has a workaround to avoid SDOORBELL */
+	if (ndev->hwerr_flags & NTB_HWERR_SDOORBELL_LOCKUP)
+		if (!ntb_topo_is_b2b(ndev->ntb.topo))
+			ndev->unsafe_flags |= NTB_UNSAFE_DB;
+
+	/* No low level workaround to avoid SB01BASE */
+	if (ndev->hwerr_flags & NTB_HWERR_SB01BASE_LOCKUP) {
+		ndev->unsafe_flags |= NTB_UNSAFE_DB;
+		ndev->unsafe_flags |= NTB_UNSAFE_SPAD;
+	}
+}
+
+static inline int ndev_is_unsafe(struct intel_ntb_dev *ndev,
+				 unsigned long flag)
+{
+	return !!(flag & ndev->unsafe_flags & ~ndev->unsafe_flags_ignore);
+}
+
+static inline int ndev_ignore_unsafe(struct intel_ntb_dev *ndev,
+				     unsigned long flag)
+{
+	flag &= ndev->unsafe_flags;
+	ndev->unsafe_flags_ignore |= flag;
+
+	return !!flag;
+}
+
+int ndev_mw_to_bar(struct intel_ntb_dev *ndev, int idx)
+{
+	if (idx < 0 || idx >= ndev->mw_count)
+		return -EINVAL;
+	return ndev->reg->mw_bar[idx];
+}
+
+void ndev_db_addr(struct intel_ntb_dev *ndev,
+			       phys_addr_t *db_addr, resource_size_t *db_size,
+			       phys_addr_t reg_addr, unsigned long reg)
+{
+	if (ndev_is_unsafe(ndev, NTB_UNSAFE_DB))
+		pr_warn_once("%s: NTB unsafe doorbell access", __func__);
+
+	if (db_addr) {
+		*db_addr = reg_addr + reg;
+		dev_dbg(&ndev->ntb.pdev->dev, "Peer db addr %llx\n", *db_addr);
+	}
+
+	if (db_size) {
+		*db_size = ndev->reg->db_size;
+		dev_dbg(&ndev->ntb.pdev->dev, "Peer db size %llx\n", *db_size);
+	}
+}
+
+u64 ndev_db_read(struct intel_ntb_dev *ndev,
+			       void __iomem *mmio)
+{
+	if (ndev_is_unsafe(ndev, NTB_UNSAFE_DB))
+		pr_warn_once("%s: NTB unsafe doorbell access", __func__);
+
+	return ndev->reg->db_ioread(mmio);
+}
+
+int ndev_db_write(struct intel_ntb_dev *ndev, u64 db_bits,
+				void __iomem *mmio)
+{
+	if (ndev_is_unsafe(ndev, NTB_UNSAFE_DB))
+		pr_warn_once("%s: NTB unsafe doorbell access", __func__);
+
+	if (db_bits & ~ndev->db_valid_mask)
+		return -EINVAL;
+
+	ndev->reg->db_iowrite(db_bits, mmio);
+
+	return 0;
+}
+
+static inline int ndev_db_set_mask(struct intel_ntb_dev *ndev, u64 db_bits,
+				   void __iomem *mmio)
+{
+	unsigned long irqflags;
+
+	if (ndev_is_unsafe(ndev, NTB_UNSAFE_DB))
+		pr_warn_once("%s: NTB unsafe doorbell access", __func__);
+
+	if (db_bits & ~ndev->db_valid_mask)
+		return -EINVAL;
+
+	spin_lock_irqsave(&ndev->db_mask_lock, irqflags);
+	{
+		ndev->db_mask |= db_bits;
+		ndev->reg->db_iowrite(ndev->db_mask, mmio);
+	}
+	spin_unlock_irqrestore(&ndev->db_mask_lock, irqflags);
+
+	return 0;
+}
+
+static inline int ndev_db_clear_mask(struct intel_ntb_dev *ndev, u64 db_bits,
+				     void __iomem *mmio)
+{
+	unsigned long irqflags;
+
+	if (ndev_is_unsafe(ndev, NTB_UNSAFE_DB))
+		pr_warn_once("%s: NTB unsafe doorbell access", __func__);
+
+	if (db_bits & ~ndev->db_valid_mask)
+		return -EINVAL;
+
+	spin_lock_irqsave(&ndev->db_mask_lock, irqflags);
+	{
+		ndev->db_mask &= ~db_bits;
+		ndev->reg->db_iowrite(ndev->db_mask, mmio);
+	}
+	spin_unlock_irqrestore(&ndev->db_mask_lock, irqflags);
+
+	return 0;
+}
+
+static inline u64 ndev_vec_mask(struct intel_ntb_dev *ndev, int db_vector)
+{
+	u64 shift, mask;
+
+	shift = ndev->db_vec_shift;
+	mask = BIT_ULL(shift) - 1;
+
+	return mask << (shift * db_vector);
+}
+
+static inline int ndev_spad_addr(struct intel_ntb_dev *ndev, int idx,
+				 phys_addr_t *spad_addr, phys_addr_t reg_addr,
+				 unsigned long reg)
+{
+	if (ndev_is_unsafe(ndev, NTB_UNSAFE_SPAD))
+		pr_warn_once("%s: NTB unsafe scratchpad access", __func__);
+
+	if (idx < 0 || idx >= ndev->spad_count)
+		return -EINVAL;
+
+	if (spad_addr) {
+		*spad_addr = reg_addr + reg + (idx << 2);
+		dev_dbg(&ndev->ntb.pdev->dev, "Peer spad addr %llx\n",
+			*spad_addr);
+	}
+
+	return 0;
+}
+
+static inline u32 ndev_spad_read(struct intel_ntb_dev *ndev, int idx,
+				 void __iomem *mmio)
+{
+	if (ndev_is_unsafe(ndev, NTB_UNSAFE_SPAD))
+		pr_warn_once("%s: NTB unsafe scratchpad access", __func__);
+
+	if (idx < 0 || idx >= ndev->spad_count)
+		return 0;
+
+	return ioread32(mmio + (idx << 2));
+}
+
+static inline int ndev_spad_write(struct intel_ntb_dev *ndev, int idx, u32 val,
+				  void __iomem *mmio)
+{
+	if (ndev_is_unsafe(ndev, NTB_UNSAFE_SPAD))
+		pr_warn_once("%s: NTB unsafe scratchpad access", __func__);
+
+	if (idx < 0 || idx >= ndev->spad_count)
+		return -EINVAL;
+
+	iowrite32(val, mmio + (idx << 2));
+
+	return 0;
+}
+
+static irqreturn_t ndev_interrupt(struct intel_ntb_dev *ndev, int vec)
+{
+	u64 vec_mask;
+
+	vec_mask = ndev_vec_mask(ndev, vec);
+
+	if ((ndev->hwerr_flags & NTB_HWERR_MSIX_VECTOR32_BAD) && (vec == 31))
+		vec_mask |= ndev->db_link_mask;
+
+	dev_dbg(&ndev->ntb.pdev->dev, "vec %d vec_mask %llx\n", vec, vec_mask);
+
+	ndev->last_ts = jiffies;
+
+	if (vec_mask & ndev->db_link_mask) {
+		if (ndev->reg->poll_link(ndev))
+			ntb_link_event(&ndev->ntb);
+	}
+
+	if (vec_mask & ndev->db_valid_mask)
+		ntb_db_event(&ndev->ntb, vec);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t ndev_vec_isr(int irq, void *dev)
+{
+	struct intel_ntb_vec *nvec = dev;
+
+	dev_dbg(&nvec->ndev->ntb.pdev->dev, "irq: %d  nvec->num: %d\n",
+		irq, nvec->num);
+
+	return ndev_interrupt(nvec->ndev, nvec->num);
+}
+
+static irqreturn_t ndev_irq_isr(int irq, void *dev)
+{
+	struct intel_ntb_dev *ndev = dev;
+
+	return ndev_interrupt(ndev, irq - ndev->ntb.pdev->irq);
+}
+
+int ndev_init_isr(struct intel_ntb_dev *ndev,
+			 int msix_min, int msix_max,
+			 int msix_shift, int total_shift)
+{
+	struct pci_dev *pdev;
+	int rc, i, msix_count, node;
+
+	pdev = ndev->ntb.pdev;
+
+	node = dev_to_node(&pdev->dev);
+
+	/* Mask all doorbell interrupts */
+	ndev->db_mask = ndev->db_valid_mask;
+	ndev->reg->db_iowrite(ndev->db_mask,
+			      ndev->self_mmio +
+			      ndev->self_reg->db_mask);
+
+	/* Try to set up msix irq */
+
+	ndev->vec = kcalloc_node(msix_max, sizeof(*ndev->vec),
+				 GFP_KERNEL, node);
+	if (!ndev->vec)
+		goto err_msix_vec_alloc;
+
+	ndev->msix = kcalloc_node(msix_max, sizeof(*ndev->msix),
+				  GFP_KERNEL, node);
+	if (!ndev->msix)
+		goto err_msix_alloc;
+
+	for (i = 0; i < msix_max; ++i)
+		ndev->msix[i].entry = i;
+
+	msix_count = pci_enable_msix_range(pdev, ndev->msix,
+					   msix_min, msix_max);
+	if (msix_count < 0)
+		goto err_msix_enable;
+
+	for (i = 0; i < msix_count; ++i) {
+		ndev->vec[i].ndev = ndev;
+		ndev->vec[i].num = i;
+		rc = request_irq(ndev->msix[i].vector, ndev_vec_isr, 0,
+				 "ndev_vec_isr", &ndev->vec[i]);
+		if (rc)
+			goto err_msix_request;
+	}
+
+	dev_dbg(&pdev->dev, "Using %d msix interrupts\n", msix_count);
+	ndev->db_vec_count = msix_count;
+	ndev->db_vec_shift = msix_shift;
+	return 0;
+
+err_msix_request:
+	while (i-- > 0)
+		free_irq(ndev->msix[i].vector, &ndev->vec[i]);
+	pci_disable_msix(pdev);
+err_msix_enable:
+	kfree(ndev->msix);
+err_msix_alloc:
+	kfree(ndev->vec);
+err_msix_vec_alloc:
+	ndev->msix = NULL;
+	ndev->vec = NULL;
+
+	/* Try to set up msi irq */
+
+	rc = pci_enable_msi(pdev);
+	if (rc)
+		goto err_msi_enable;
+
+	rc = request_irq(pdev->irq, ndev_irq_isr, 0,
+			 "ndev_irq_isr", ndev);
+	if (rc)
+		goto err_msi_request;
+
+	dev_dbg(&pdev->dev, "Using msi interrupts\n");
+	ndev->db_vec_count = 1;
+	ndev->db_vec_shift = total_shift;
+	return 0;
+
+err_msi_request:
+	pci_disable_msi(pdev);
+err_msi_enable:
+
+	/* Try to set up intx irq */
+
+	pci_intx(pdev, 1);
+
+	rc = request_irq(pdev->irq, ndev_irq_isr, IRQF_SHARED,
+			 "ndev_irq_isr", ndev);
+	if (rc)
+		goto err_intx_request;
+
+	dev_dbg(&pdev->dev, "Using intx interrupts\n");
+	ndev->db_vec_count = 1;
+	ndev->db_vec_shift = total_shift;
+	return 0;
+
+err_intx_request:
+	return rc;
+}
+
+static void ndev_deinit_isr(struct intel_ntb_dev *ndev)
+{
+	struct pci_dev *pdev;
+	int i;
+
+	pdev = ndev->ntb.pdev;
+
+	/* Mask all doorbell interrupts */
+	ndev->db_mask = ndev->db_valid_mask;
+	ndev->reg->db_iowrite(ndev->db_mask,
+			      ndev->self_mmio +
+			      ndev->self_reg->db_mask);
+
+	if (ndev->msix) {
+		i = ndev->db_vec_count;
+		while (i--)
+			free_irq(ndev->msix[i].vector, &ndev->vec[i]);
+		pci_disable_msix(pdev);
+		kfree(ndev->msix);
+		kfree(ndev->vec);
+	} else {
+		free_irq(pdev->irq, ndev);
+		if (pci_dev_msi_enabled(pdev))
+			pci_disable_msi(pdev);
+	}
+}
+
+static ssize_t ndev_ntb_debugfs_read(struct file *filp, char __user *ubuf,
+				     size_t count, loff_t *offp)
+{
+	struct intel_ntb_dev *ndev;
+	struct pci_dev *pdev;
+	void __iomem *mmio;
+	char *buf;
+	size_t buf_size;
+	ssize_t ret, off;
+	union { u64 v64; u32 v32; u16 v16; u8 v8; } u;
+
+	ndev = filp->private_data;
+	pdev = ndev->ntb.pdev;
+	mmio = ndev->self_mmio;
+
+	buf_size = min(count, 0x800ul);
+
+	buf = kmalloc(buf_size, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	off = 0;
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "NTB Device Information:\n");
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "Connection Topology -\t%s\n",
+			 ntb_topo_string(ndev->ntb.topo));
+
+	if (ndev->b2b_idx != UINT_MAX) {
+		off += scnprintf(buf + off, buf_size - off,
+				 "B2B MW Idx -\t\t%u\n", ndev->b2b_idx);
+		off += scnprintf(buf + off, buf_size - off,
+				 "B2B Offset -\t\t%#lx\n", ndev->b2b_off);
+	}
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "BAR4 Split -\t\t%s\n",
+			 ndev->bar4_split ? "yes" : "no");
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "NTB CTL -\t\t%#06x\n", ndev->ntb_ctl);
+	off += scnprintf(buf + off, buf_size - off,
+			 "LNK STA -\t\t%#06x\n", ndev->lnk_sta);
+
+	if (!ndev->reg->link_is_up(ndev)) {
+		off += scnprintf(buf + off, buf_size - off,
+				 "Link Status -\t\tDown\n");
+	} else {
+		off += scnprintf(buf + off, buf_size - off,
+				 "Link Status -\t\tUp\n");
+		off += scnprintf(buf + off, buf_size - off,
+				 "Link Speed -\t\tPCI-E Gen %u\n",
+				 NTB_LNK_STA_SPEED(ndev->lnk_sta));
+		off += scnprintf(buf + off, buf_size - off,
+				 "Link Width -\t\tx%u\n",
+				 NTB_LNK_STA_WIDTH(ndev->lnk_sta));
+	}
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "Memory Window Count -\t%u\n", ndev->mw_count);
+	off += scnprintf(buf + off, buf_size - off,
+			 "Scratchpad Count -\t%u\n", ndev->spad_count);
+	off += scnprintf(buf + off, buf_size - off,
+			 "Doorbell Count -\t%u\n", ndev->db_count);
+	off += scnprintf(buf + off, buf_size - off,
+			 "Doorbell Vector Count -\t%u\n", ndev->db_vec_count);
+	off += scnprintf(buf + off, buf_size - off,
+			 "Doorbell Vector Shift -\t%u\n", ndev->db_vec_shift);
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "Doorbell Valid Mask -\t%#llx\n", ndev->db_valid_mask);
+	off += scnprintf(buf + off, buf_size - off,
+			 "Doorbell Link Mask -\t%#llx\n", ndev->db_link_mask);
+	off += scnprintf(buf + off, buf_size - off,
+			 "Doorbell Mask Cached -\t%#llx\n", ndev->db_mask);
+
+	u.v64 = ndev_db_read(ndev, mmio + ndev->self_reg->db_mask);
+	off += scnprintf(buf + off, buf_size - off,
+			 "Doorbell Mask -\t\t%#llx\n", u.v64);
+
+	u.v64 = ndev_db_read(ndev, mmio + ndev->self_reg->db_bell);
+	off += scnprintf(buf + off, buf_size - off,
+			 "Doorbell Bell -\t\t%#llx\n", u.v64);
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "\nNTB Window Size:\n");
+
+	pci_read_config_byte(pdev, XEON_PBAR23SZ_OFFSET, &u.v8);
+	off += scnprintf(buf + off, buf_size - off,
+			 "PBAR23SZ %hhu\n", u.v8);
+	if (!ndev->bar4_split) {
+		pci_read_config_byte(pdev, XEON_PBAR45SZ_OFFSET, &u.v8);
+		off += scnprintf(buf + off, buf_size - off,
+				 "PBAR45SZ %hhu\n", u.v8);
+	} else {
+		pci_read_config_byte(pdev, XEON_PBAR4SZ_OFFSET, &u.v8);
+		off += scnprintf(buf + off, buf_size - off,
+				 "PBAR4SZ %hhu\n", u.v8);
+		pci_read_config_byte(pdev, XEON_PBAR5SZ_OFFSET, &u.v8);
+		off += scnprintf(buf + off, buf_size - off,
+				 "PBAR5SZ %hhu\n", u.v8);
+	}
+
+	pci_read_config_byte(pdev, XEON_SBAR23SZ_OFFSET, &u.v8);
+	off += scnprintf(buf + off, buf_size - off,
+			 "SBAR23SZ %hhu\n", u.v8);
+	if (!ndev->bar4_split) {
+		pci_read_config_byte(pdev, XEON_SBAR45SZ_OFFSET, &u.v8);
+		off += scnprintf(buf + off, buf_size - off,
+				 "SBAR45SZ %hhu\n", u.v8);
+	} else {
+		pci_read_config_byte(pdev, XEON_SBAR4SZ_OFFSET, &u.v8);
+		off += scnprintf(buf + off, buf_size - off,
+				 "SBAR4SZ %hhu\n", u.v8);
+		pci_read_config_byte(pdev, XEON_SBAR5SZ_OFFSET, &u.v8);
+		off += scnprintf(buf + off, buf_size - off,
+				 "SBAR5SZ %hhu\n", u.v8);
+	}
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "\nNTB Incoming XLAT:\n");
+
+	u.v64 = ioread64(mmio + bar2_off(ndev->xlat_reg->bar2_xlat, 2));
+	off += scnprintf(buf + off, buf_size - off,
+			 "XLAT23 -\t\t%#018llx\n", u.v64);
+
+	if (ndev->bar4_split) {
+		u.v32 = ioread32(mmio + bar2_off(ndev->xlat_reg->bar2_xlat, 4));
+		off += scnprintf(buf + off, buf_size - off,
+				 "XLAT4 -\t\t\t%#06x\n", u.v32);
+
+		u.v32 = ioread32(mmio + bar2_off(ndev->xlat_reg->bar2_xlat, 5));
+		off += scnprintf(buf + off, buf_size - off,
+				 "XLAT5 -\t\t\t%#06x\n", u.v32);
+	} else {
+		u.v64 = ioread64(mmio + bar2_off(ndev->xlat_reg->bar2_xlat, 4));
+		off += scnprintf(buf + off, buf_size - off,
+				 "XLAT45 -\t\t%#018llx\n", u.v64);
+	}
+
+	u.v64 = ioread64(mmio + bar2_off(ndev->xlat_reg->bar2_limit, 2));
+	off += scnprintf(buf + off, buf_size - off,
+			 "LMT23 -\t\t\t%#018llx\n", u.v64);
+
+	if (ndev->bar4_split) {
+		u.v32 = ioread32(mmio + bar2_off(ndev->xlat_reg->bar2_limit, 4));
+		off += scnprintf(buf + off, buf_size - off,
+				 "LMT4 -\t\t\t%#06x\n", u.v32);
+		u.v32 = ioread32(mmio + bar2_off(ndev->xlat_reg->bar2_limit, 5));
+		off += scnprintf(buf + off, buf_size - off,
+				 "LMT5 -\t\t\t%#06x\n", u.v32);
+	} else {
+		u.v64 = ioread64(mmio + bar2_off(ndev->xlat_reg->bar2_limit, 4));
+		off += scnprintf(buf + off, buf_size - off,
+				 "LMT45 -\t\t\t%#018llx\n", u.v64);
+	}
+
+	if (pdev_is_gen1(pdev)) {
+		if (ntb_topo_is_b2b(ndev->ntb.topo)) {
+			off += scnprintf(buf + off, buf_size - off,
+					 "\nNTB Outgoing B2B XLAT:\n");
+
+			u.v64 = ioread64(mmio + XEON_PBAR23XLAT_OFFSET);
+			off += scnprintf(buf + off, buf_size - off,
+					 "B2B XLAT23 -\t\t%#018llx\n", u.v64);
+
+			if (ndev->bar4_split) {
+				u.v32 = ioread32(mmio + XEON_PBAR4XLAT_OFFSET);
+				off += scnprintf(buf + off, buf_size - off,
+						 "B2B XLAT4 -\t\t%#06x\n",
+						 u.v32);
+				u.v32 = ioread32(mmio + XEON_PBAR5XLAT_OFFSET);
+				off += scnprintf(buf + off, buf_size - off,
+						 "B2B XLAT5 -\t\t%#06x\n",
+						 u.v32);
+			} else {
+				u.v64 = ioread64(mmio + XEON_PBAR45XLAT_OFFSET);
+				off += scnprintf(buf + off, buf_size - off,
+						 "B2B XLAT45 -\t\t%#018llx\n",
+						 u.v64);
+			}
+
+			u.v64 = ioread64(mmio + XEON_PBAR23LMT_OFFSET);
+			off += scnprintf(buf + off, buf_size - off,
+					 "B2B LMT23 -\t\t%#018llx\n", u.v64);
+
+			if (ndev->bar4_split) {
+				u.v32 = ioread32(mmio + XEON_PBAR4LMT_OFFSET);
+				off += scnprintf(buf + off, buf_size - off,
+						 "B2B LMT4 -\t\t%#06x\n",
+						 u.v32);
+				u.v32 = ioread32(mmio + XEON_PBAR5LMT_OFFSET);
+				off += scnprintf(buf + off, buf_size - off,
+						 "B2B LMT5 -\t\t%#06x\n",
+						 u.v32);
+			} else {
+				u.v64 = ioread64(mmio + XEON_PBAR45LMT_OFFSET);
+				off += scnprintf(buf + off, buf_size - off,
+						 "B2B LMT45 -\t\t%#018llx\n",
+						 u.v64);
+			}
+
+			off += scnprintf(buf + off, buf_size - off,
+					 "\nNTB Secondary BAR:\n");
+
+			u.v64 = ioread64(mmio + XEON_SBAR0BASE_OFFSET);
+			off += scnprintf(buf + off, buf_size - off,
+					 "SBAR01 -\t\t%#018llx\n", u.v64);
+
+			u.v64 = ioread64(mmio + XEON_SBAR23BASE_OFFSET);
+			off += scnprintf(buf + off, buf_size - off,
+					 "SBAR23 -\t\t%#018llx\n", u.v64);
+
+			if (ndev->bar4_split) {
+				u.v32 = ioread32(mmio + XEON_SBAR4BASE_OFFSET);
+				off += scnprintf(buf + off, buf_size - off,
+						 "SBAR4 -\t\t\t%#06x\n", u.v32);
+				u.v32 = ioread32(mmio + XEON_SBAR5BASE_OFFSET);
+				off += scnprintf(buf + off, buf_size - off,
+						 "SBAR5 -\t\t\t%#06x\n", u.v32);
+			} else {
+				u.v64 = ioread64(mmio + XEON_SBAR45BASE_OFFSET);
+				off += scnprintf(buf + off, buf_size - off,
+						 "SBAR45 -\t\t%#018llx\n",
+						 u.v64);
+			}
+		}
+
+		off += scnprintf(buf + off, buf_size - off,
+				 "\nXEON NTB Statistics:\n");
+
+		u.v16 = ioread16(mmio + XEON_USMEMMISS_OFFSET);
+		off += scnprintf(buf + off, buf_size - off,
+				 "Upstream Memory Miss -\t%u\n", u.v16);
+
+		off += scnprintf(buf + off, buf_size - off,
+				 "\nXEON NTB Hardware Errors:\n");
+
+		if (!pci_read_config_word(pdev,
+					  XEON_DEVSTS_OFFSET, &u.v16))
+			off += scnprintf(buf + off, buf_size - off,
+					 "DEVSTS -\t\t%#06x\n", u.v16);
+
+		if (!pci_read_config_word(pdev,
+					  XEON_LINK_STATUS_OFFSET, &u.v16))
+			off += scnprintf(buf + off, buf_size - off,
+					 "LNKSTS -\t\t%#06x\n", u.v16);
+
+		if (!pci_read_config_dword(pdev,
+					   XEON_UNCERRSTS_OFFSET, &u.v32))
+			off += scnprintf(buf + off, buf_size - off,
+					 "UNCERRSTS -\t\t%#06x\n", u.v32);
+
+		if (!pci_read_config_dword(pdev,
+					   XEON_CORERRSTS_OFFSET, &u.v32))
+			off += scnprintf(buf + off, buf_size - off,
+					 "CORERRSTS -\t\t%#06x\n", u.v32);
+	}
+
+	ret = simple_read_from_buffer(ubuf, count, offp, buf, off);
+	kfree(buf);
+	return ret;
+}
+
+static ssize_t ndev_debugfs_read(struct file *filp, char __user *ubuf,
+				 size_t count, loff_t *offp)
+{
+	struct intel_ntb_dev *ndev = filp->private_data;
+
+	if (pdev_is_gen1(ndev->ntb.pdev))
+		return ndev_ntb_debugfs_read(filp, ubuf, count, offp);
+	else if (pdev_is_gen3(ndev->ntb.pdev))
+		return ndev_ntb3_debugfs_read(filp, ubuf, count, offp);
+	else if (pdev_is_gen4(ndev->ntb.pdev) || pdev_is_gen5(ndev->ntb.pdev) ||
+		 pdev_is_gen6(ndev->ntb.pdev))
+		return ndev_ntb4_debugfs_read(filp, ubuf, count, offp);
+
+	return -ENXIO;
+}
+
+static void ndev_init_debugfs(struct intel_ntb_dev *ndev)
+{
+	if (!debugfs_dir) {
+		ndev->debugfs_dir = NULL;
+		ndev->debugfs_info = NULL;
+	} else {
+		ndev->debugfs_dir =
+			debugfs_create_dir(pci_name(ndev->ntb.pdev),
+					   debugfs_dir);
+		if (IS_ERR(ndev->debugfs_dir))
+			ndev->debugfs_info = NULL;
+		else
+			ndev->debugfs_info =
+				debugfs_create_file("info", S_IRUSR,
+						    ndev->debugfs_dir, ndev,
+						    &intel_ntb_debugfs_info);
+	}
+}
+
+static void ndev_deinit_debugfs(struct intel_ntb_dev *ndev)
+{
+	debugfs_remove_recursive(ndev->debugfs_dir);
+}
+
+int intel_ntb_mw_count(struct ntb_dev *ntb, int pidx)
+{
+	if (pidx != NTB_DEF_PEER_IDX)
+		return -EINVAL;
+
+	return ntb_ndev(ntb)->mw_count;
+}
+
+int intel_ntb_mw_get_align(struct ntb_dev *ntb, int pidx, int idx,
+			   resource_size_t *addr_align,
+			   resource_size_t *size_align,
+			   resource_size_t *size_max)
+{
+	struct intel_ntb_dev *ndev = ntb_ndev(ntb);
+	resource_size_t bar_size, mw_size;
+	int bar;
+
+	if (pidx != NTB_DEF_PEER_IDX)
+		return -EINVAL;
+
+	if (idx >= ndev->b2b_idx && !ndev->b2b_off)
+		idx += 1;
+
+	bar = ndev_mw_to_bar(ndev, idx);
+	if (bar < 0)
+		return bar;
+
+	bar_size = pci_resource_len(ndev->ntb.pdev, bar);
+
+	if (idx == ndev->b2b_idx)
+		mw_size = bar_size - ndev->b2b_off;
+	else
+		mw_size = bar_size;
+
+	if (addr_align)
+		*addr_align = pci_resource_len(ndev->ntb.pdev, bar);
+
+	if (size_align)
+		*size_align = 1;
+
+	if (size_max)
+		*size_max = mw_size;
+
+	return 0;
+}
+
+static int intel_ntb_mw_set_trans(struct ntb_dev *ntb, int pidx, int idx,
+				  dma_addr_t addr, resource_size_t size)
+{
+	struct intel_ntb_dev *ndev = ntb_ndev(ntb);
+	unsigned long base_reg, xlat_reg, limit_reg;
+	resource_size_t bar_size, mw_size;
+	void __iomem *mmio;
+	u64 base, limit, reg_val;
+	int bar;
+
+	if (pidx != NTB_DEF_PEER_IDX)
+		return -EINVAL;
+
+	if (idx >= ndev->b2b_idx && !ndev->b2b_off)
+		idx += 1;
+
+	bar = ndev_mw_to_bar(ndev, idx);
+	if (bar < 0)
+		return bar;
+
+	bar_size = pci_resource_len(ndev->ntb.pdev, bar);
+
+	if (idx == ndev->b2b_idx)
+		mw_size = bar_size - ndev->b2b_off;
+	else
+		mw_size = bar_size;
+
+	/* hardware requires that addr is aligned to bar size */
+	if (addr & (bar_size - 1))
+		return -EINVAL;
+
+	/* make sure the range fits in the usable mw size */
+	if (size > mw_size)
+		return -EINVAL;
+
+	mmio = ndev->self_mmio;
+	base_reg = bar0_off(ndev->xlat_reg->bar0_base, bar);
+	xlat_reg = bar2_off(ndev->xlat_reg->bar2_xlat, bar);
+	limit_reg = bar2_off(ndev->xlat_reg->bar2_limit, bar);
+
+	if (bar < 4 || !ndev->bar4_split) {
+		base = ioread64(mmio + base_reg) & NTB_BAR_MASK_64;
+
+		/* Set the limit if supported, if size is not mw_size */
+		if (limit_reg && size != mw_size)
+			limit = base + size;
+		else
+			limit = 0;
+
+		/* set and verify setting the translation address */
+		iowrite64(addr, mmio + xlat_reg);
+		reg_val = ioread64(mmio + xlat_reg);
+		if (reg_val != addr) {
+			iowrite64(0, mmio + xlat_reg);
+			return -EIO;
+		}
+
+		/* set and verify setting the limit */
+		iowrite64(limit, mmio + limit_reg);
+		reg_val = ioread64(mmio + limit_reg);
+		if (reg_val != limit) {
+			iowrite64(base, mmio + limit_reg);
+			iowrite64(0, mmio + xlat_reg);
+			return -EIO;
+		}
+	} else {
+		/* split bar addr range must all be 32 bit */
+		if (addr & (~0ull << 32))
+			return -EINVAL;
+		if ((addr + size) & (~0ull << 32))
+			return -EINVAL;
+
+		base = ioread32(mmio + base_reg) & NTB_BAR_MASK_32;
+
+		/* Set the limit if supported, if size is not mw_size */
+		if (limit_reg && size != mw_size)
+			limit = base + size;
+		else
+			limit = 0;
+
+		/* set and verify setting the translation address */
+		iowrite32(addr, mmio + xlat_reg);
+		reg_val = ioread32(mmio + xlat_reg);
+		if (reg_val != addr) {
+			iowrite32(0, mmio + xlat_reg);
+			return -EIO;
+		}
+
+		/* set and verify setting the limit */
+		iowrite32(limit, mmio + limit_reg);
+		reg_val = ioread32(mmio + limit_reg);
+		if (reg_val != limit) {
+			iowrite32(base, mmio + limit_reg);
+			iowrite32(0, mmio + xlat_reg);
+			return -EIO;
+		}
+	}
+
+	return 0;
+}
+
+u64 intel_ntb_link_is_up(struct ntb_dev *ntb, enum ntb_speed *speed,
+			 enum ntb_width *width)
+{
+	struct intel_ntb_dev *ndev = ntb_ndev(ntb);
+
+	if (ndev->reg->link_is_up(ndev)) {
+		if (speed)
+			*speed = NTB_LNK_STA_SPEED(ndev->lnk_sta);
+		if (width)
+			*width = NTB_LNK_STA_WIDTH(ndev->lnk_sta);
+		return 1;
+	} else {
+		/* TODO MAYBE: is it possible to observe the link speed and
+		 * width while link is training? */
+		if (speed)
+			*speed = NTB_SPEED_NONE;
+		if (width)
+			*width = NTB_WIDTH_NONE;
+		return 0;
+	}
+}
+
+static int intel_ntb_link_enable(struct ntb_dev *ntb,
+				 enum ntb_speed max_speed,
+				 enum ntb_width max_width)
+{
+	struct intel_ntb_dev *ndev;
+	u32 ntb_ctl;
+
+	ndev = container_of(ntb, struct intel_ntb_dev, ntb);
+
+	if (ndev->ntb.topo == NTB_TOPO_SEC)
+		return -EINVAL;
+
+	dev_dbg(&ntb->pdev->dev,
+		"Enabling link with max_speed %d max_width %d\n",
+		max_speed, max_width);
+	if (max_speed != NTB_SPEED_AUTO)
+		dev_dbg(&ntb->pdev->dev, "ignoring max_speed %d\n", max_speed);
+	if (max_width != NTB_WIDTH_AUTO)
+		dev_dbg(&ntb->pdev->dev, "ignoring max_width %d\n", max_width);
+
+	ntb_ctl = ioread32(ndev->self_mmio + ndev->reg->ntb_ctl);
+	ntb_ctl &= ~(NTB_CTL_DISABLE | NTB_CTL_CFG_LOCK);
+	ntb_ctl |= NTB_CTL_P2S_BAR2_SNOOP | NTB_CTL_S2P_BAR2_SNOOP;
+	ntb_ctl |= NTB_CTL_P2S_BAR4_SNOOP | NTB_CTL_S2P_BAR4_SNOOP;
+	if (ndev->bar4_split)
+		ntb_ctl |= NTB_CTL_P2S_BAR5_SNOOP | NTB_CTL_S2P_BAR5_SNOOP;
+	iowrite32(ntb_ctl, ndev->self_mmio + ndev->reg->ntb_ctl);
+
+	return 0;
+}
+
+int intel_ntb_link_disable(struct ntb_dev *ntb)
+{
+	struct intel_ntb_dev *ndev;
+	u32 ntb_cntl;
+
+	ndev = container_of(ntb, struct intel_ntb_dev, ntb);
+
+	if (ndev->ntb.topo == NTB_TOPO_SEC)
+		return -EINVAL;
+
+	dev_dbg(&ntb->pdev->dev, "Disabling link\n");
+
+	/* Bring NTB link down */
+	ntb_cntl = ioread32(ndev->self_mmio + ndev->reg->ntb_ctl);
+	ntb_cntl &= ~(NTB_CTL_P2S_BAR2_SNOOP | NTB_CTL_S2P_BAR2_SNOOP);
+	ntb_cntl &= ~(NTB_CTL_P2S_BAR4_SNOOP | NTB_CTL_S2P_BAR4_SNOOP);
+	if (ndev->bar4_split)
+		ntb_cntl &= ~(NTB_CTL_P2S_BAR5_SNOOP | NTB_CTL_S2P_BAR5_SNOOP);
+	ntb_cntl |= NTB_CTL_DISABLE | NTB_CTL_CFG_LOCK;
+	iowrite32(ntb_cntl, ndev->self_mmio + ndev->reg->ntb_ctl);
+
+	return 0;
+}
+
+int intel_ntb_peer_mw_count(struct ntb_dev *ntb)
+{
+	/* Numbers of inbound and outbound memory windows match */
+	return ntb_ndev(ntb)->mw_count;
+}
+
+int intel_ntb_peer_mw_get_addr(struct ntb_dev *ntb, int idx,
+			       phys_addr_t *base, resource_size_t *size)
+{
+	struct intel_ntb_dev *ndev = ntb_ndev(ntb);
+	int bar;
+
+	if (idx >= ndev->b2b_idx && !ndev->b2b_off)
+		idx += 1;
+
+	bar = ndev_mw_to_bar(ndev, idx);
+	if (bar < 0)
+		return bar;
+
+	if (base)
+		*base = pci_resource_start(ndev->ntb.pdev, bar) +
+			(idx == ndev->b2b_idx ? ndev->b2b_off : 0);
+
+	if (size)
+		*size = pci_resource_len(ndev->ntb.pdev, bar) -
+			(idx == ndev->b2b_idx ? ndev->b2b_off : 0);
+
+	return 0;
+}
+
+static int intel_ntb_db_is_unsafe(struct ntb_dev *ntb)
+{
+	return ndev_ignore_unsafe(ntb_ndev(ntb), NTB_UNSAFE_DB);
+}
+
+u64 intel_ntb_db_valid_mask(struct ntb_dev *ntb)
+{
+	return ntb_ndev(ntb)->db_valid_mask;
+}
+
+int intel_ntb_db_vector_count(struct ntb_dev *ntb)
+{
+	struct intel_ntb_dev *ndev;
+
+	ndev = container_of(ntb, struct intel_ntb_dev, ntb);
+
+	return ndev->db_vec_count;
+}
+
+u64 intel_ntb_db_vector_mask(struct ntb_dev *ntb, int db_vector)
+{
+	struct intel_ntb_dev *ndev = ntb_ndev(ntb);
+
+	if (db_vector < 0 || db_vector > ndev->db_vec_count)
+		return 0;
+
+	return ndev->db_valid_mask & ndev_vec_mask(ndev, db_vector);
+}
+
+static u64 intel_ntb_db_read(struct ntb_dev *ntb)
+{
+	struct intel_ntb_dev *ndev = ntb_ndev(ntb);
+
+	return ndev_db_read(ndev,
+			    ndev->self_mmio +
+			    ndev->self_reg->db_bell);
+}
+
+static int intel_ntb_db_clear(struct ntb_dev *ntb, u64 db_bits)
+{
+	struct intel_ntb_dev *ndev = ntb_ndev(ntb);
+
+	return ndev_db_write(ndev, db_bits,
+			     ndev->self_mmio +
+			     ndev->self_reg->db_bell);
+}
+
+int intel_ntb_db_set_mask(struct ntb_dev *ntb, u64 db_bits)
+{
+	struct intel_ntb_dev *ndev = ntb_ndev(ntb);
+
+	return ndev_db_set_mask(ndev, db_bits,
+				ndev->self_mmio +
+				ndev->self_reg->db_mask);
+}
+
+int intel_ntb_db_clear_mask(struct ntb_dev *ntb, u64 db_bits)
+{
+	struct intel_ntb_dev *ndev = ntb_ndev(ntb);
+
+	return ndev_db_clear_mask(ndev, db_bits,
+				  ndev->self_mmio +
+				  ndev->self_reg->db_mask);
+}
+
+static int intel_ntb_peer_db_addr(struct ntb_dev *ntb, phys_addr_t *db_addr,
+			   resource_size_t *db_size, u64 *db_data, int db_bit)
+{
+	u64 db_bits;
+	struct intel_ntb_dev *ndev = ntb_ndev(ntb);
+
+	if (unlikely(db_bit >= BITS_PER_LONG_LONG))
+		return -EINVAL;
+
+	db_bits = BIT_ULL(db_bit);
+
+	if (unlikely(db_bits & ~ntb_ndev(ntb)->db_valid_mask))
+		return -EINVAL;
+
+	ndev_db_addr(ndev, db_addr, db_size, ndev->peer_addr,
+			    ndev->peer_reg->db_bell);
+
+	if (db_data)
+		*db_data = db_bits;
+
+
+	return 0;
+}
+
+static int intel_ntb_peer_db_set(struct ntb_dev *ntb, u64 db_bits)
+{
+	struct intel_ntb_dev *ndev = ntb_ndev(ntb);
+
+	return ndev_db_write(ndev, db_bits,
+			     ndev->peer_mmio +
+			     ndev->peer_reg->db_bell);
+}
+
+int intel_ntb_spad_is_unsafe(struct ntb_dev *ntb)
+{
+	return ndev_ignore_unsafe(ntb_ndev(ntb), NTB_UNSAFE_SPAD);
+}
+
+int intel_ntb_spad_count(struct ntb_dev *ntb)
+{
+	struct intel_ntb_dev *ndev;
+
+	ndev = container_of(ntb, struct intel_ntb_dev, ntb);
+
+	return ndev->spad_count;
+}
+
+u32 intel_ntb_spad_read(struct ntb_dev *ntb, int idx)
+{
+	struct intel_ntb_dev *ndev = ntb_ndev(ntb);
+
+	return ndev_spad_read(ndev, idx,
+			      ndev->self_mmio +
+			      ndev->self_reg->spad);
+}
+
+int intel_ntb_spad_write(struct ntb_dev *ntb, int idx, u32 val)
+{
+	struct intel_ntb_dev *ndev = ntb_ndev(ntb);
+
+	return ndev_spad_write(ndev, idx, val,
+			       ndev->self_mmio +
+			       ndev->self_reg->spad);
+}
+
+int intel_ntb_peer_spad_addr(struct ntb_dev *ntb, int pidx, int sidx,
+			     phys_addr_t *spad_addr)
+{
+	struct intel_ntb_dev *ndev = ntb_ndev(ntb);
+
+	return ndev_spad_addr(ndev, sidx, spad_addr, ndev->peer_addr,
+			      ndev->peer_reg->spad);
+}
+
+u32 intel_ntb_peer_spad_read(struct ntb_dev *ntb, int pidx, int sidx)
+{
+	struct intel_ntb_dev *ndev = ntb_ndev(ntb);
+
+	return ndev_spad_read(ndev, sidx,
+			      ndev->peer_mmio +
+			      ndev->peer_reg->spad);
+}
+
+int intel_ntb_peer_spad_write(struct ntb_dev *ntb, int pidx, int sidx,
+			      u32 val)
+{
+	struct intel_ntb_dev *ndev = ntb_ndev(ntb);
+
+	return ndev_spad_write(ndev, sidx, val,
+			       ndev->peer_mmio +
+			       ndev->peer_reg->spad);
+}
+
+static u64 xeon_db_ioread(const void __iomem *mmio)
+{
+	return (u64)ioread16(mmio);
+}
+
+static void xeon_db_iowrite(u64 bits, void __iomem *mmio)
+{
+	iowrite16((u16)bits, mmio);
+}
+
+static int xeon_poll_link(struct intel_ntb_dev *ndev)
+{
+	u16 reg_val;
+	int rc;
+
+	ndev->reg->db_iowrite(ndev->db_link_mask,
+			      ndev->self_mmio +
+			      ndev->self_reg->db_bell);
+
+	rc = pci_read_config_word(ndev->ntb.pdev,
+				  XEON_LINK_STATUS_OFFSET, &reg_val);
+	if (rc)
+		return 0;
+
+	if (reg_val == ndev->lnk_sta)
+		return 0;
+
+	ndev->lnk_sta = reg_val;
+
+	return 1;
+}
+
+int xeon_link_is_up(struct intel_ntb_dev *ndev)
+{
+	if (ndev->ntb.topo == NTB_TOPO_SEC)
+		return 1;
+
+	return NTB_LNK_STA_ACTIVE(ndev->lnk_sta);
+}
+
+enum ntb_topo xeon_ppd_topo(struct intel_ntb_dev *ndev, u8 ppd)
+{
+	switch (ppd & XEON_PPD_TOPO_MASK) {
+	case XEON_PPD_TOPO_B2B_USD:
+		return NTB_TOPO_B2B_USD;
+
+	case XEON_PPD_TOPO_B2B_DSD:
+		return NTB_TOPO_B2B_DSD;
+
+	case XEON_PPD_TOPO_PRI_USD:
+	case XEON_PPD_TOPO_PRI_DSD: /* accept bogus PRI_DSD */
+		return NTB_TOPO_PRI;
+
+	case XEON_PPD_TOPO_SEC_USD:
+	case XEON_PPD_TOPO_SEC_DSD: /* accept bogus SEC_DSD */
+		return NTB_TOPO_SEC;
+	}
+
+	return NTB_TOPO_NONE;
+}
+
+static inline int xeon_ppd_bar4_split(struct intel_ntb_dev *ndev, u8 ppd)
+{
+	if (ppd & XEON_PPD_SPLIT_BAR_MASK) {
+		dev_dbg(&ndev->ntb.pdev->dev, "PPD %d split bar\n", ppd);
+		return 1;
+	}
+	return 0;
+}
+
+static int xeon_init_isr(struct intel_ntb_dev *ndev)
+{
+	return ndev_init_isr(ndev, XEON_DB_MSIX_VECTOR_COUNT,
+			     XEON_DB_MSIX_VECTOR_COUNT,
+			     XEON_DB_MSIX_VECTOR_SHIFT,
+			     XEON_DB_TOTAL_SHIFT);
+}
+
+static void xeon_deinit_isr(struct intel_ntb_dev *ndev)
+{
+	ndev_deinit_isr(ndev);
+}
+
+static int xeon_setup_b2b_mw(struct intel_ntb_dev *ndev,
+			     const struct intel_b2b_addr *addr,
+			     const struct intel_b2b_addr *peer_addr)
+{
+	struct pci_dev *pdev;
+	void __iomem *mmio;
+	resource_size_t bar_size;
+	phys_addr_t bar_addr;
+	int b2b_bar;
+	u8 bar_sz;
+
+	pdev = ndev->ntb.pdev;
+	mmio = ndev->self_mmio;
+
+	if (ndev->b2b_idx == UINT_MAX) {
+		dev_dbg(&pdev->dev, "not using b2b mw\n");
+		b2b_bar = 0;
+		ndev->b2b_off = 0;
+	} else {
+		b2b_bar = ndev_mw_to_bar(ndev, ndev->b2b_idx);
+		if (b2b_bar < 0)
+			return -EIO;
+
+		dev_dbg(&pdev->dev, "using b2b mw bar %d\n", b2b_bar);
+
+		bar_size = pci_resource_len(ndev->ntb.pdev, b2b_bar);
+
+		dev_dbg(&pdev->dev, "b2b bar size %#llx\n", bar_size);
+
+		if (b2b_mw_share && XEON_B2B_MIN_SIZE <= bar_size >> 1) {
+			dev_dbg(&pdev->dev, "b2b using first half of bar\n");
+			ndev->b2b_off = bar_size >> 1;
+		} else if (XEON_B2B_MIN_SIZE <= bar_size) {
+			dev_dbg(&pdev->dev, "b2b using whole bar\n");
+			ndev->b2b_off = 0;
+			--ndev->mw_count;
+		} else {
+			dev_dbg(&pdev->dev, "b2b bar size is too small\n");
+			return -EIO;
+		}
+	}
+
+	/* Reset the secondary bar sizes to match the primary bar sizes,
+	 * except disable or halve the size of the b2b secondary bar.
+	 *
+	 * Note: code for each specific bar size register, because the register
+	 * offsets are not in a consistent order (bar5sz comes after ppd, odd).
+	 */
+	pci_read_config_byte(pdev, XEON_PBAR23SZ_OFFSET, &bar_sz);
+	dev_dbg(&pdev->dev, "PBAR23SZ %#x\n", bar_sz);
+	if (b2b_bar == 2) {
+		if (ndev->b2b_off)
+			bar_sz -= 1;
+		else
+			bar_sz = 0;
+	}
+	pci_write_config_byte(pdev, XEON_SBAR23SZ_OFFSET, bar_sz);
+	pci_read_config_byte(pdev, XEON_SBAR23SZ_OFFSET, &bar_sz);
+	dev_dbg(&pdev->dev, "SBAR23SZ %#x\n", bar_sz);
+
+	if (!ndev->bar4_split) {
+		pci_read_config_byte(pdev, XEON_PBAR45SZ_OFFSET, &bar_sz);
+		dev_dbg(&pdev->dev, "PBAR45SZ %#x\n", bar_sz);
+		if (b2b_bar == 4) {
+			if (ndev->b2b_off)
+				bar_sz -= 1;
+			else
+				bar_sz = 0;
+		}
+		pci_write_config_byte(pdev, XEON_SBAR45SZ_OFFSET, bar_sz);
+		pci_read_config_byte(pdev, XEON_SBAR45SZ_OFFSET, &bar_sz);
+		dev_dbg(&pdev->dev, "SBAR45SZ %#x\n", bar_sz);
+	} else {
+		pci_read_config_byte(pdev, XEON_PBAR4SZ_OFFSET, &bar_sz);
+		dev_dbg(&pdev->dev, "PBAR4SZ %#x\n", bar_sz);
+		if (b2b_bar == 4) {
+			if (ndev->b2b_off)
+				bar_sz -= 1;
+			else
+				bar_sz = 0;
+		}
+		pci_write_config_byte(pdev, XEON_SBAR4SZ_OFFSET, bar_sz);
+		pci_read_config_byte(pdev, XEON_SBAR4SZ_OFFSET, &bar_sz);
+		dev_dbg(&pdev->dev, "SBAR4SZ %#x\n", bar_sz);
+
+		pci_read_config_byte(pdev, XEON_PBAR5SZ_OFFSET, &bar_sz);
+		dev_dbg(&pdev->dev, "PBAR5SZ %#x\n", bar_sz);
+		if (b2b_bar == 5) {
+			if (ndev->b2b_off)
+				bar_sz -= 1;
+			else
+				bar_sz = 0;
+		}
+		pci_write_config_byte(pdev, XEON_SBAR5SZ_OFFSET, bar_sz);
+		pci_read_config_byte(pdev, XEON_SBAR5SZ_OFFSET, &bar_sz);
+		dev_dbg(&pdev->dev, "SBAR5SZ %#x\n", bar_sz);
+	}
+
+	/* SBAR01 hit by first part of the b2b bar */
+	if (b2b_bar == 0)
+		bar_addr = addr->bar0_addr;
+	else if (b2b_bar == 2)
+		bar_addr = addr->bar2_addr64;
+	else if (b2b_bar == 4 && !ndev->bar4_split)
+		bar_addr = addr->bar4_addr64;
+	else if (b2b_bar == 4)
+		bar_addr = addr->bar4_addr32;
+	else if (b2b_bar == 5)
+		bar_addr = addr->bar5_addr32;
+	else
+		return -EIO;
+
+	dev_dbg(&pdev->dev, "SBAR01 %#018llx\n", bar_addr);
+	iowrite64(bar_addr, mmio + XEON_SBAR0BASE_OFFSET);
+
+	/* Other SBAR are normally hit by the PBAR xlat, except for b2b bar.
+	 * The b2b bar is either disabled above, or configured half-size, and
+	 * it starts at the PBAR xlat + offset.
+	 */
+
+	bar_addr = addr->bar2_addr64 + (b2b_bar == 2 ? ndev->b2b_off : 0);
+	iowrite64(bar_addr, mmio + XEON_SBAR23BASE_OFFSET);
+	bar_addr = ioread64(mmio + XEON_SBAR23BASE_OFFSET);
+	dev_dbg(&pdev->dev, "SBAR23 %#018llx\n", bar_addr);
+
+	if (!ndev->bar4_split) {
+		bar_addr = addr->bar4_addr64 +
+			(b2b_bar == 4 ? ndev->b2b_off : 0);
+		iowrite64(bar_addr, mmio + XEON_SBAR45BASE_OFFSET);
+		bar_addr = ioread64(mmio + XEON_SBAR45BASE_OFFSET);
+		dev_dbg(&pdev->dev, "SBAR45 %#018llx\n", bar_addr);
+	} else {
+		bar_addr = addr->bar4_addr32 +
+			(b2b_bar == 4 ? ndev->b2b_off : 0);
+		iowrite32(bar_addr, mmio + XEON_SBAR4BASE_OFFSET);
+		bar_addr = ioread32(mmio + XEON_SBAR4BASE_OFFSET);
+		dev_dbg(&pdev->dev, "SBAR4 %#010llx\n", bar_addr);
+
+		bar_addr = addr->bar5_addr32 +
+			(b2b_bar == 5 ? ndev->b2b_off : 0);
+		iowrite32(bar_addr, mmio + XEON_SBAR5BASE_OFFSET);
+		bar_addr = ioread32(mmio + XEON_SBAR5BASE_OFFSET);
+		dev_dbg(&pdev->dev, "SBAR5 %#010llx\n", bar_addr);
+	}
+
+	/* setup incoming bar limits == base addrs (zero length windows) */
+
+	bar_addr = addr->bar2_addr64 + (b2b_bar == 2 ? ndev->b2b_off : 0);
+	iowrite64(bar_addr, mmio + XEON_SBAR23LMT_OFFSET);
+	bar_addr = ioread64(mmio + XEON_SBAR23LMT_OFFSET);
+	dev_dbg(&pdev->dev, "SBAR23LMT %#018llx\n", bar_addr);
+
+	if (!ndev->bar4_split) {
+		bar_addr = addr->bar4_addr64 +
+			(b2b_bar == 4 ? ndev->b2b_off : 0);
+		iowrite64(bar_addr, mmio + XEON_SBAR45LMT_OFFSET);
+		bar_addr = ioread64(mmio + XEON_SBAR45LMT_OFFSET);
+		dev_dbg(&pdev->dev, "SBAR45LMT %#018llx\n", bar_addr);
+	} else {
+		bar_addr = addr->bar4_addr32 +
+			(b2b_bar == 4 ? ndev->b2b_off : 0);
+		iowrite32(bar_addr, mmio + XEON_SBAR4LMT_OFFSET);
+		bar_addr = ioread32(mmio + XEON_SBAR4LMT_OFFSET);
+		dev_dbg(&pdev->dev, "SBAR4LMT %#010llx\n", bar_addr);
+
+		bar_addr = addr->bar5_addr32 +
+			(b2b_bar == 5 ? ndev->b2b_off : 0);
+		iowrite32(bar_addr, mmio + XEON_SBAR5LMT_OFFSET);
+		bar_addr = ioread32(mmio + XEON_SBAR5LMT_OFFSET);
+		dev_dbg(&pdev->dev, "SBAR5LMT %#05llx\n", bar_addr);
+	}
+
+	/* zero incoming translation addrs */
+	iowrite64(0, mmio + XEON_SBAR23XLAT_OFFSET);
+
+	if (!ndev->bar4_split) {
+		iowrite64(0, mmio + XEON_SBAR45XLAT_OFFSET);
+	} else {
+		iowrite32(0, mmio + XEON_SBAR4XLAT_OFFSET);
+		iowrite32(0, mmio + XEON_SBAR5XLAT_OFFSET);
+	}
+
+	/* zero outgoing translation limits (whole bar size windows) */
+	iowrite64(0, mmio + XEON_PBAR23LMT_OFFSET);
+	if (!ndev->bar4_split) {
+		iowrite64(0, mmio + XEON_PBAR45LMT_OFFSET);
+	} else {
+		iowrite32(0, mmio + XEON_PBAR4LMT_OFFSET);
+		iowrite32(0, mmio + XEON_PBAR5LMT_OFFSET);
+	}
+
+	/* set outgoing translation offsets */
+	bar_addr = peer_addr->bar2_addr64;
+	iowrite64(bar_addr, mmio + XEON_PBAR23XLAT_OFFSET);
+	bar_addr = ioread64(mmio + XEON_PBAR23XLAT_OFFSET);
+	dev_dbg(&pdev->dev, "PBAR23XLAT %#018llx\n", bar_addr);
+
+	if (!ndev->bar4_split) {
+		bar_addr = peer_addr->bar4_addr64;
+		iowrite64(bar_addr, mmio + XEON_PBAR45XLAT_OFFSET);
+		bar_addr = ioread64(mmio + XEON_PBAR45XLAT_OFFSET);
+		dev_dbg(&pdev->dev, "PBAR45XLAT %#018llx\n", bar_addr);
+	} else {
+		bar_addr = peer_addr->bar4_addr32;
+		iowrite32(bar_addr, mmio + XEON_PBAR4XLAT_OFFSET);
+		bar_addr = ioread32(mmio + XEON_PBAR4XLAT_OFFSET);
+		dev_dbg(&pdev->dev, "PBAR4XLAT %#010llx\n", bar_addr);
+
+		bar_addr = peer_addr->bar5_addr32;
+		iowrite32(bar_addr, mmio + XEON_PBAR5XLAT_OFFSET);
+		bar_addr = ioread32(mmio + XEON_PBAR5XLAT_OFFSET);
+		dev_dbg(&pdev->dev, "PBAR5XLAT %#010llx\n", bar_addr);
+	}
+
+	/* set the translation offset for b2b registers */
+	if (b2b_bar == 0)
+		bar_addr = peer_addr->bar0_addr;
+	else if (b2b_bar == 2)
+		bar_addr = peer_addr->bar2_addr64;
+	else if (b2b_bar == 4 && !ndev->bar4_split)
+		bar_addr = peer_addr->bar4_addr64;
+	else if (b2b_bar == 4)
+		bar_addr = peer_addr->bar4_addr32;
+	else if (b2b_bar == 5)
+		bar_addr = peer_addr->bar5_addr32;
+	else
+		return -EIO;
+
+	/* B2B_XLAT_OFFSET is 64bit, but can only take 32bit writes */
+	dev_dbg(&pdev->dev, "B2BXLAT %#018llx\n", bar_addr);
+	iowrite32(bar_addr, mmio + XEON_B2B_XLAT_OFFSETL);
+	iowrite32(bar_addr >> 32, mmio + XEON_B2B_XLAT_OFFSETU);
+
+	if (b2b_bar) {
+		/* map peer ntb mmio config space registers */
+		ndev->peer_mmio = pci_iomap(pdev, b2b_bar,
+					    XEON_B2B_MIN_SIZE);
+		if (!ndev->peer_mmio)
+			return -EIO;
+
+		ndev->peer_addr = pci_resource_start(pdev, b2b_bar);
+	}
+
+	return 0;
+}
+
+static int xeon_init_ntb(struct intel_ntb_dev *ndev)
+{
+	struct device *dev = &ndev->ntb.pdev->dev;
+	int rc;
+	u32 ntb_ctl;
+
+	if (ndev->bar4_split)
+		ndev->mw_count = HSX_SPLIT_BAR_MW_COUNT;
+	else
+		ndev->mw_count = XEON_MW_COUNT;
+
+	ndev->spad_count = XEON_SPAD_COUNT;
+	ndev->db_count = XEON_DB_COUNT;
+	ndev->db_link_mask = XEON_DB_LINK_BIT;
+
+	switch (ndev->ntb.topo) {
+	case NTB_TOPO_PRI:
+		if (ndev->hwerr_flags & NTB_HWERR_SDOORBELL_LOCKUP) {
+			dev_err(dev, "NTB Primary config disabled\n");
+			return -EINVAL;
+		}
+
+		/* enable link to allow secondary side device to appear */
+		ntb_ctl = ioread32(ndev->self_mmio + ndev->reg->ntb_ctl);
+		ntb_ctl &= ~NTB_CTL_DISABLE;
+		iowrite32(ntb_ctl, ndev->self_mmio + ndev->reg->ntb_ctl);
+
+		/* use half the spads for the peer */
+		ndev->spad_count >>= 1;
+		ndev->self_reg = &xeon_pri_reg;
+		ndev->peer_reg = &xeon_sec_reg;
+		ndev->xlat_reg = &xeon_sec_xlat;
+		break;
+
+	case NTB_TOPO_SEC:
+		if (ndev->hwerr_flags & NTB_HWERR_SDOORBELL_LOCKUP) {
+			dev_err(dev, "NTB Secondary config disabled\n");
+			return -EINVAL;
+		}
+		/* use half the spads for the peer */
+		ndev->spad_count >>= 1;
+		ndev->self_reg = &xeon_sec_reg;
+		ndev->peer_reg = &xeon_pri_reg;
+		ndev->xlat_reg = &xeon_pri_xlat;
+		break;
+
+	case NTB_TOPO_B2B_USD:
+	case NTB_TOPO_B2B_DSD:
+		ndev->self_reg = &xeon_pri_reg;
+		ndev->peer_reg = &xeon_b2b_reg;
+		ndev->xlat_reg = &xeon_sec_xlat;
+
+		if (ndev->hwerr_flags & NTB_HWERR_SDOORBELL_LOCKUP) {
+			ndev->peer_reg = &xeon_pri_reg;
+
+			if (b2b_mw_idx < 0)
+				ndev->b2b_idx = b2b_mw_idx + ndev->mw_count;
+			else
+				ndev->b2b_idx = b2b_mw_idx;
+
+			if (ndev->b2b_idx >= ndev->mw_count) {
+				dev_dbg(dev,
+					"b2b_mw_idx %d invalid for mw_count %u\n",
+					b2b_mw_idx, ndev->mw_count);
+				return -EINVAL;
+			}
+
+			dev_dbg(dev, "setting up b2b mw idx %d means %d\n",
+				b2b_mw_idx, ndev->b2b_idx);
+
+		} else if (ndev->hwerr_flags & NTB_HWERR_B2BDOORBELL_BIT14) {
+			dev_warn(dev, "Reduce doorbell count by 1\n");
+			ndev->db_count -= 1;
+		}
+
+		if (ndev->ntb.topo == NTB_TOPO_B2B_USD) {
+			rc = xeon_setup_b2b_mw(ndev,
+					       &xeon_b2b_dsd_addr,
+					       &xeon_b2b_usd_addr);
+		} else {
+			rc = xeon_setup_b2b_mw(ndev,
+					       &xeon_b2b_usd_addr,
+					       &xeon_b2b_dsd_addr);
+		}
+		if (rc)
+			return rc;
+
+		/* Enable Bus Master and Memory Space on the secondary side */
+		iowrite16(PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER,
+			  ndev->self_mmio + XEON_SPCICMD_OFFSET);
+
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	ndev->db_valid_mask = BIT_ULL(ndev->db_count) - 1;
+
+	ndev->reg->db_iowrite(ndev->db_valid_mask,
+			      ndev->self_mmio +
+			      ndev->self_reg->db_mask);
+
+	return 0;
+}
+
+static int xeon_init_dev(struct intel_ntb_dev *ndev)
+{
+	struct pci_dev *pdev;
+	u8 ppd;
+	int rc, mem;
+
+	pdev = ndev->ntb.pdev;
+
+	switch (pdev->device) {
+	/* There is a Xeon hardware errata related to writes to SDOORBELL or
+	 * B2BDOORBELL in conjunction with inbound access to NTB MMIO Space,
+	 * which may hang the system.  To workaround this use the second memory
+	 * window to access the interrupt and scratch pad registers on the
+	 * remote system.
+	 */
+	case PCI_DEVICE_ID_INTEL_NTB_SS_JSF:
+	case PCI_DEVICE_ID_INTEL_NTB_PS_JSF:
+	case PCI_DEVICE_ID_INTEL_NTB_B2B_JSF:
+	case PCI_DEVICE_ID_INTEL_NTB_SS_SNB:
+	case PCI_DEVICE_ID_INTEL_NTB_PS_SNB:
+	case PCI_DEVICE_ID_INTEL_NTB_B2B_SNB:
+	case PCI_DEVICE_ID_INTEL_NTB_SS_IVT:
+	case PCI_DEVICE_ID_INTEL_NTB_PS_IVT:
+	case PCI_DEVICE_ID_INTEL_NTB_B2B_IVT:
+	case PCI_DEVICE_ID_INTEL_NTB_SS_HSX:
+	case PCI_DEVICE_ID_INTEL_NTB_PS_HSX:
+	case PCI_DEVICE_ID_INTEL_NTB_B2B_HSX:
+	case PCI_DEVICE_ID_INTEL_NTB_SS_BDX:
+	case PCI_DEVICE_ID_INTEL_NTB_PS_BDX:
+	case PCI_DEVICE_ID_INTEL_NTB_B2B_BDX:
+		ndev->hwerr_flags |= NTB_HWERR_SDOORBELL_LOCKUP;
+		break;
+	}
+
+	switch (pdev->device) {
+	/* There is a hardware errata related to accessing any register in
+	 * SB01BASE in the presence of bidirectional traffic crossing the NTB.
+	 */
+	case PCI_DEVICE_ID_INTEL_NTB_SS_IVT:
+	case PCI_DEVICE_ID_INTEL_NTB_PS_IVT:
+	case PCI_DEVICE_ID_INTEL_NTB_B2B_IVT:
+	case PCI_DEVICE_ID_INTEL_NTB_SS_HSX:
+	case PCI_DEVICE_ID_INTEL_NTB_PS_HSX:
+	case PCI_DEVICE_ID_INTEL_NTB_B2B_HSX:
+	case PCI_DEVICE_ID_INTEL_NTB_SS_BDX:
+	case PCI_DEVICE_ID_INTEL_NTB_PS_BDX:
+	case PCI_DEVICE_ID_INTEL_NTB_B2B_BDX:
+		ndev->hwerr_flags |= NTB_HWERR_SB01BASE_LOCKUP;
+		break;
+	}
+
+	switch (pdev->device) {
+	/* HW Errata on bit 14 of b2bdoorbell register.  Writes will not be
+	 * mirrored to the remote system.  Shrink the number of bits by one,
+	 * since bit 14 is the last bit.
+	 */
+	case PCI_DEVICE_ID_INTEL_NTB_SS_JSF:
+	case PCI_DEVICE_ID_INTEL_NTB_PS_JSF:
+	case PCI_DEVICE_ID_INTEL_NTB_B2B_JSF:
+	case PCI_DEVICE_ID_INTEL_NTB_SS_SNB:
+	case PCI_DEVICE_ID_INTEL_NTB_PS_SNB:
+	case PCI_DEVICE_ID_INTEL_NTB_B2B_SNB:
+	case PCI_DEVICE_ID_INTEL_NTB_SS_IVT:
+	case PCI_DEVICE_ID_INTEL_NTB_PS_IVT:
+	case PCI_DEVICE_ID_INTEL_NTB_B2B_IVT:
+	case PCI_DEVICE_ID_INTEL_NTB_SS_HSX:
+	case PCI_DEVICE_ID_INTEL_NTB_PS_HSX:
+	case PCI_DEVICE_ID_INTEL_NTB_B2B_HSX:
+	case PCI_DEVICE_ID_INTEL_NTB_SS_BDX:
+	case PCI_DEVICE_ID_INTEL_NTB_PS_BDX:
+	case PCI_DEVICE_ID_INTEL_NTB_B2B_BDX:
+		ndev->hwerr_flags |= NTB_HWERR_B2BDOORBELL_BIT14;
+		break;
+	}
+
+	ndev->reg = &xeon_reg;
+
+	rc = pci_read_config_byte(pdev, XEON_PPD_OFFSET, &ppd);
+	if (rc)
+		return -EIO;
+
+	ndev->ntb.topo = xeon_ppd_topo(ndev, ppd);
+	dev_dbg(&pdev->dev, "ppd %#x topo %s\n", ppd,
+		ntb_topo_string(ndev->ntb.topo));
+	if (ndev->ntb.topo == NTB_TOPO_NONE)
+		return -EINVAL;
+
+	if (ndev->ntb.topo != NTB_TOPO_SEC) {
+		ndev->bar4_split = xeon_ppd_bar4_split(ndev, ppd);
+		dev_dbg(&pdev->dev, "ppd %#x bar4_split %d\n",
+			ppd, ndev->bar4_split);
+	} else {
+		/* This is a way for transparent BAR to figure out if we are
+		 * doing split BAR or not. There is no way for the hw on the
+		 * transparent side to know and set the PPD.
+		 */
+		mem = pci_select_bars(pdev, IORESOURCE_MEM);
+		ndev->bar4_split = hweight32(mem) ==
+			HSX_SPLIT_BAR_MW_COUNT + 1;
+		dev_dbg(&pdev->dev, "mem %#x bar4_split %d\n",
+			mem, ndev->bar4_split);
+	}
+
+	rc = xeon_init_ntb(ndev);
+	if (rc)
+		return rc;
+
+	return xeon_init_isr(ndev);
+}
+
+static void xeon_deinit_dev(struct intel_ntb_dev *ndev)
+{
+	xeon_deinit_isr(ndev);
+}
+
+static int intel_ntb_init_pci(struct intel_ntb_dev *ndev, struct pci_dev *pdev)
+{
+	int rc;
+
+	pci_set_drvdata(pdev, ndev);
+
+	rc = pci_enable_device(pdev);
+	if (rc)
+		goto err_pci_enable;
+
+	rc = pci_request_regions(pdev, NTB_NAME);
+	if (rc)
+		goto err_pci_regions;
+
+	pci_set_master(pdev);
+
+	rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
+	if (rc) {
+		rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
+		if (rc)
+			goto err_dma_mask;
+		dev_warn(&pdev->dev, "Cannot DMA highmem\n");
+	}
+
+	ndev->self_mmio = pci_iomap(pdev, 0, 0);
+	if (!ndev->self_mmio) {
+		rc = -EIO;
+		goto err_mmio;
+	}
+	ndev->peer_mmio = ndev->self_mmio;
+	ndev->peer_addr = pci_resource_start(pdev, 0);
+
+	return 0;
+
+err_mmio:
+err_dma_mask:
+	pci_release_regions(pdev);
+err_pci_regions:
+	pci_disable_device(pdev);
+err_pci_enable:
+	pci_set_drvdata(pdev, NULL);
+	return rc;
+}
+
+static void intel_ntb_deinit_pci(struct intel_ntb_dev *ndev)
+{
+	struct pci_dev *pdev = ndev->ntb.pdev;
+
+	if (ndev->peer_mmio && ndev->peer_mmio != ndev->self_mmio)
+		pci_iounmap(pdev, ndev->peer_mmio);
+	pci_iounmap(pdev, ndev->self_mmio);
+
+	pci_release_regions(pdev);
+	pci_disable_device(pdev);
+	pci_set_drvdata(pdev, NULL);
+}
+
+static inline void ndev_init_struct(struct intel_ntb_dev *ndev,
+				    struct pci_dev *pdev)
+{
+	ndev->ntb.pdev = pdev;
+	ndev->ntb.topo = NTB_TOPO_NONE;
+	ndev->ntb.ops = &intel_ntb_ops;
+
+	ndev->b2b_off = 0;
+	ndev->b2b_idx = UINT_MAX;
+
+	ndev->bar4_split = 0;
+
+	ndev->mw_count = 0;
+	ndev->spad_count = 0;
+	ndev->db_count = 0;
+	ndev->db_vec_count = 0;
+	ndev->db_vec_shift = 0;
+
+	ndev->ntb_ctl = 0;
+	ndev->lnk_sta = 0;
+
+	ndev->db_valid_mask = 0;
+	ndev->db_link_mask = 0;
+	ndev->db_mask = 0;
+
+	spin_lock_init(&ndev->db_mask_lock);
+}
+
+static int intel_ntb_pci_probe(struct pci_dev *pdev,
+			       const struct pci_device_id *id)
+{
+	struct intel_ntb_dev *ndev;
+	int rc, node;
+
+	node = dev_to_node(&pdev->dev);
+	ndev = kzalloc_node(sizeof(*ndev), GFP_KERNEL, node);
+	if (!ndev) {
+		rc = -ENOMEM;
+		goto err_ndev;
+	}
+
+	ndev_init_struct(ndev, pdev);
+
+	if (pdev_is_gen1(pdev)) {
+		rc = intel_ntb_init_pci(ndev, pdev);
+		if (rc)
+			goto err_init_pci;
+
+		rc = xeon_init_dev(ndev);
+		if (rc)
+			goto err_init_dev;
+	} else if (pdev_is_gen3(pdev)) {
+		ndev->ntb.ops = &intel_ntb3_ops;
+		rc = intel_ntb_init_pci(ndev, pdev);
+		if (rc)
+			goto err_init_pci;
+
+		rc = gen3_init_dev(ndev);
+		if (rc)
+			goto err_init_dev;
+	} else if (pdev_is_gen4(pdev) || pdev_is_gen5(pdev) ||
+		   pdev_is_gen6(pdev)) {
+		ndev->ntb.ops = &intel_ntb4_ops;
+		rc = intel_ntb_init_pci(ndev, pdev);
+		if (rc)
+			goto err_init_pci;
+
+		rc = gen4_init_dev(ndev);
+		if (rc)
+			goto err_init_dev;
+	} else {
+		rc = -EINVAL;
+		goto err_init_pci;
+	}
+
+	ndev_reset_unsafe_flags(ndev);
+
+	ndev->reg->poll_link(ndev);
+
+	ndev_init_debugfs(ndev);
+
+	rc = ntb_register_device(&ndev->ntb);
+	if (rc)
+		goto err_register;
+
+	dev_info(&pdev->dev, "NTB device registered.\n");
+
+	return 0;
+
+err_register:
+	ndev_deinit_debugfs(ndev);
+	if (pdev_is_gen1(pdev) || pdev_is_gen3(pdev) ||
+	    pdev_is_gen4(pdev) || pdev_is_gen5(pdev) ||
+	    pdev_is_gen6(pdev))
+		xeon_deinit_dev(ndev);
+err_init_dev:
+	intel_ntb_deinit_pci(ndev);
+err_init_pci:
+	kfree(ndev);
+err_ndev:
+	return rc;
+}
+
+static void intel_ntb_pci_remove(struct pci_dev *pdev)
+{
+	struct intel_ntb_dev *ndev = pci_get_drvdata(pdev);
+
+	ntb_unregister_device(&ndev->ntb);
+	ndev_deinit_debugfs(ndev);
+	if (pdev_is_gen1(pdev) || pdev_is_gen3(pdev) ||
+	    pdev_is_gen4(pdev) || pdev_is_gen5(pdev) ||
+	    pdev_is_gen6(pdev))
+		xeon_deinit_dev(ndev);
+	intel_ntb_deinit_pci(ndev);
+	kfree(ndev);
+}
+
+static const struct intel_ntb_reg xeon_reg = {
+	.poll_link		= xeon_poll_link,
+	.link_is_up		= xeon_link_is_up,
+	.db_ioread		= xeon_db_ioread,
+	.db_iowrite		= xeon_db_iowrite,
+	.db_size		= sizeof(u32),
+	.ntb_ctl		= XEON_NTBCNTL_OFFSET,
+	.mw_bar			= {2, 4, 5},
+};
+
+static const struct intel_ntb_alt_reg xeon_pri_reg = {
+	.db_bell		= XEON_PDOORBELL_OFFSET,
+	.db_mask		= XEON_PDBMSK_OFFSET,
+	.spad			= XEON_SPAD_OFFSET,
+};
+
+static const struct intel_ntb_alt_reg xeon_sec_reg = {
+	.db_bell		= XEON_SDOORBELL_OFFSET,
+	.db_mask		= XEON_SDBMSK_OFFSET,
+	/* second half of the scratchpads */
+	.spad			= XEON_SPAD_OFFSET + (XEON_SPAD_COUNT << 1),
+};
+
+static const struct intel_ntb_alt_reg xeon_b2b_reg = {
+	.db_bell		= XEON_B2B_DOORBELL_OFFSET,
+	.spad			= XEON_B2B_SPAD_OFFSET,
+};
+
+static const struct intel_ntb_xlat_reg xeon_pri_xlat = {
+	/* Note: no primary .bar0_base visible to the secondary side.
+	 *
+	 * The secondary side cannot get the base address stored in primary
+	 * bars.  The base address is necessary to set the limit register to
+	 * any value other than zero, or unlimited.
+	 *
+	 * WITHOUT THE BASE ADDRESS, THE SECONDARY SIDE CANNOT DISABLE the
+	 * window by setting the limit equal to base, nor can it limit the size
+	 * of the memory window by setting the limit to base + size.
+	 */
+	.bar2_limit		= XEON_PBAR23LMT_OFFSET,
+	.bar2_xlat		= XEON_PBAR23XLAT_OFFSET,
+};
+
+static const struct intel_ntb_xlat_reg xeon_sec_xlat = {
+	.bar0_base		= XEON_SBAR0BASE_OFFSET,
+	.bar2_limit		= XEON_SBAR23LMT_OFFSET,
+	.bar2_xlat		= XEON_SBAR23XLAT_OFFSET,
+};
+
+struct intel_b2b_addr xeon_b2b_usd_addr = {
+	.bar2_addr64		= XEON_B2B_BAR2_ADDR64,
+	.bar4_addr64		= XEON_B2B_BAR4_ADDR64,
+	.bar4_addr32		= XEON_B2B_BAR4_ADDR32,
+	.bar5_addr32		= XEON_B2B_BAR5_ADDR32,
+};
+
+struct intel_b2b_addr xeon_b2b_dsd_addr = {
+	.bar2_addr64		= XEON_B2B_BAR2_ADDR64,
+	.bar4_addr64		= XEON_B2B_BAR4_ADDR64,
+	.bar4_addr32		= XEON_B2B_BAR4_ADDR32,
+	.bar5_addr32		= XEON_B2B_BAR5_ADDR32,
+};
+
+/* operations for primary side of local ntb */
+static const struct ntb_dev_ops intel_ntb_ops = {
+	.mw_count		= intel_ntb_mw_count,
+	.mw_get_align		= intel_ntb_mw_get_align,
+	.mw_set_trans		= intel_ntb_mw_set_trans,
+	.peer_mw_count		= intel_ntb_peer_mw_count,
+	.peer_mw_get_addr	= intel_ntb_peer_mw_get_addr,
+	.link_is_up		= intel_ntb_link_is_up,
+	.link_enable		= intel_ntb_link_enable,
+	.link_disable		= intel_ntb_link_disable,
+	.db_is_unsafe		= intel_ntb_db_is_unsafe,
+	.db_valid_mask		= intel_ntb_db_valid_mask,
+	.db_vector_count	= intel_ntb_db_vector_count,
+	.db_vector_mask		= intel_ntb_db_vector_mask,
+	.db_read		= intel_ntb_db_read,
+	.db_clear		= intel_ntb_db_clear,
+	.db_set_mask		= intel_ntb_db_set_mask,
+	.db_clear_mask		= intel_ntb_db_clear_mask,
+	.peer_db_addr		= intel_ntb_peer_db_addr,
+	.peer_db_set		= intel_ntb_peer_db_set,
+	.spad_is_unsafe		= intel_ntb_spad_is_unsafe,
+	.spad_count		= intel_ntb_spad_count,
+	.spad_read		= intel_ntb_spad_read,
+	.spad_write		= intel_ntb_spad_write,
+	.peer_spad_addr		= intel_ntb_peer_spad_addr,
+	.peer_spad_read		= intel_ntb_peer_spad_read,
+	.peer_spad_write	= intel_ntb_peer_spad_write,
+};
+
+static const struct file_operations intel_ntb_debugfs_info = {
+	.owner = THIS_MODULE,
+	.open = simple_open,
+	.read = ndev_debugfs_read,
+};
+
+static const struct pci_device_id intel_ntb_pci_tbl[] = {
+	/* GEN1 */
+	{PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_B2B_JSF)},
+	{PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_B2B_SNB)},
+	{PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_B2B_IVT)},
+	{PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_B2B_HSX)},
+	{PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_B2B_BDX)},
+	{PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_PS_JSF)},
+	{PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_PS_SNB)},
+	{PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_PS_IVT)},
+	{PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_PS_HSX)},
+	{PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_PS_BDX)},
+	{PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_SS_JSF)},
+	{PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_SS_SNB)},
+	{PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_SS_IVT)},
+	{PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_SS_HSX)},
+	{PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_SS_BDX)},
+
+	/* GEN3 */
+	{PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_B2B_SKX)},
+
+	/* GEN4 */
+	{PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_B2B_ICX)},
+	/* GEN5 PCIe */
+	{PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_B2B_GNR)},
+	/* GEN6 PCIe */
+	{PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_B2B_DMR)},
+	{0}
+};
+MODULE_DEVICE_TABLE(pci, intel_ntb_pci_tbl);
+
+static struct pci_driver intel_ntb_pci_driver = {
+	.name = KBUILD_MODNAME,
+	.id_table = intel_ntb_pci_tbl,
+	.probe = intel_ntb_pci_probe,
+	.remove = intel_ntb_pci_remove,
+};
+
+static int __init intel_ntb_pci_driver_init(void)
+{
+	int ret;
+	pr_info("%s %s\n", NTB_DESC, NTB_VER);
+
+	if (debugfs_initialized())
+		debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
+
+	ret = pci_register_driver(&intel_ntb_pci_driver);
+	if (ret)
+		debugfs_remove_recursive(debugfs_dir);
+
+	return ret;
+}
+module_init(intel_ntb_pci_driver_init);
+
+static void __exit intel_ntb_pci_driver_exit(void)
+{
+	pci_unregister_driver(&intel_ntb_pci_driver);
+
+	debugfs_remove_recursive(debugfs_dir);
+}
+module_exit(intel_ntb_pci_driver_exit);
diff --git a/drivers/ntb/hw/intel/ntb_hw_gen1.h b/drivers/ntb/hw/intel/ntb_hw_gen1.h
new file mode 100644
index 000000000..344249fc1
--- /dev/null
+++ b/drivers/ntb/hw/intel/ntb_hw_gen1.h
@@ -0,0 +1,185 @@
+/*
+ * This file is provided under a dual BSD/GPLv2 license.  When using or
+ *   redistributing this file, you may do so under either license.
+ *
+ *   GPL LICENSE SUMMARY
+ *
+ *   Copyright(c) 2012-2017 Intel Corporation. All rights reserved.
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of version 2 of the GNU General Public License as
+ *   published by the Free Software Foundation.
+ *
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2012-2017 Intel Corporation. All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copy
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef _NTB_INTEL_GEN1_H_
+#define _NTB_INTEL_GEN1_H_
+
+#include "ntb_hw_intel.h"
+
+/* Intel Gen1 Xeon hardware */
+#define XEON_PBAR23LMT_OFFSET		0x0000
+#define XEON_PBAR45LMT_OFFSET		0x0008
+#define XEON_PBAR4LMT_OFFSET		0x0008
+#define XEON_PBAR5LMT_OFFSET		0x000c
+#define XEON_PBAR23XLAT_OFFSET		0x0010
+#define XEON_PBAR45XLAT_OFFSET		0x0018
+#define XEON_PBAR4XLAT_OFFSET		0x0018
+#define XEON_PBAR5XLAT_OFFSET		0x001c
+#define XEON_SBAR23LMT_OFFSET		0x0020
+#define XEON_SBAR45LMT_OFFSET		0x0028
+#define XEON_SBAR4LMT_OFFSET		0x0028
+#define XEON_SBAR5LMT_OFFSET		0x002c
+#define XEON_SBAR23XLAT_OFFSET		0x0030
+#define XEON_SBAR45XLAT_OFFSET		0x0038
+#define XEON_SBAR4XLAT_OFFSET		0x0038
+#define XEON_SBAR5XLAT_OFFSET		0x003c
+#define XEON_SBAR0BASE_OFFSET		0x0040
+#define XEON_SBAR23BASE_OFFSET		0x0048
+#define XEON_SBAR45BASE_OFFSET		0x0050
+#define XEON_SBAR4BASE_OFFSET		0x0050
+#define XEON_SBAR5BASE_OFFSET		0x0054
+#define XEON_SBDF_OFFSET		0x005c
+#define XEON_NTBCNTL_OFFSET		0x0058
+#define XEON_PDOORBELL_OFFSET		0x0060
+#define XEON_PDBMSK_OFFSET		0x0062
+#define XEON_SDOORBELL_OFFSET		0x0064
+#define XEON_SDBMSK_OFFSET		0x0066
+#define XEON_USMEMMISS_OFFSET		0x0070
+#define XEON_SPAD_OFFSET		0x0080
+#define XEON_PBAR23SZ_OFFSET		0x00d0
+#define XEON_PBAR45SZ_OFFSET		0x00d1
+#define XEON_PBAR4SZ_OFFSET		0x00d1
+#define XEON_SBAR23SZ_OFFSET		0x00d2
+#define XEON_SBAR45SZ_OFFSET		0x00d3
+#define XEON_SBAR4SZ_OFFSET		0x00d3
+#define XEON_PPD_OFFSET			0x00d4
+#define XEON_PBAR5SZ_OFFSET		0x00d5
+#define XEON_SBAR5SZ_OFFSET		0x00d6
+#define XEON_WCCNTRL_OFFSET		0x00e0
+#define XEON_UNCERRSTS_OFFSET		0x014c
+#define XEON_CORERRSTS_OFFSET		0x0158
+#define XEON_LINK_STATUS_OFFSET		0x01a2
+#define XEON_SPCICMD_OFFSET		0x0504
+#define XEON_DEVCTRL_OFFSET		0x0598
+#define XEON_DEVSTS_OFFSET		0x059a
+#define XEON_SLINK_STATUS_OFFSET	0x05a2
+#define XEON_B2B_SPAD_OFFSET		0x0100
+#define XEON_B2B_DOORBELL_OFFSET	0x0140
+#define XEON_B2B_XLAT_OFFSETL		0x0144
+#define XEON_B2B_XLAT_OFFSETU		0x0148
+#define XEON_PPD_CONN_MASK		0x03
+#define XEON_PPD_CONN_TRANSPARENT	0x00
+#define XEON_PPD_CONN_B2B		0x01
+#define XEON_PPD_CONN_RP		0x02
+#define XEON_PPD_DEV_MASK		0x10
+#define XEON_PPD_DEV_USD		0x00
+#define XEON_PPD_DEV_DSD		0x10
+#define XEON_PPD_SPLIT_BAR_MASK		0x40
+
+#define XEON_PPD_TOPO_MASK	(XEON_PPD_CONN_MASK | XEON_PPD_DEV_MASK)
+#define XEON_PPD_TOPO_PRI_USD	(XEON_PPD_CONN_RP | XEON_PPD_DEV_USD)
+#define XEON_PPD_TOPO_PRI_DSD	(XEON_PPD_CONN_RP | XEON_PPD_DEV_DSD)
+#define XEON_PPD_TOPO_SEC_USD	(XEON_PPD_CONN_TRANSPARENT | XEON_PPD_DEV_USD)
+#define XEON_PPD_TOPO_SEC_DSD	(XEON_PPD_CONN_TRANSPARENT | XEON_PPD_DEV_DSD)
+#define XEON_PPD_TOPO_B2B_USD	(XEON_PPD_CONN_B2B | XEON_PPD_DEV_USD)
+#define XEON_PPD_TOPO_B2B_DSD	(XEON_PPD_CONN_B2B | XEON_PPD_DEV_DSD)
+
+#define XEON_MW_COUNT			2
+#define HSX_SPLIT_BAR_MW_COUNT		3
+#define XEON_DB_COUNT			15
+#define XEON_DB_LINK			15
+#define XEON_DB_LINK_BIT			BIT_ULL(XEON_DB_LINK)
+#define XEON_DB_MSIX_VECTOR_COUNT	4
+#define XEON_DB_MSIX_VECTOR_SHIFT	5
+#define XEON_DB_TOTAL_SHIFT		16
+#define XEON_SPAD_COUNT			16
+
+/* Use the following addresses for translation between b2b ntb devices in case
+ * the hardware default values are not reliable. */
+#define XEON_B2B_BAR0_ADDR	0x1000000000000000ull
+#define XEON_B2B_BAR2_ADDR64	0x2000000000000000ull
+#define XEON_B2B_BAR4_ADDR64	0x4000000000000000ull
+#define XEON_B2B_BAR4_ADDR32	0x20000000u
+#define XEON_B2B_BAR5_ADDR32	0x40000000u
+
+/* The peer ntb secondary config space is 32KB fixed size */
+#define XEON_B2B_MIN_SIZE		0x8000
+
+/* flags to indicate hardware errata */
+#define NTB_HWERR_SDOORBELL_LOCKUP	BIT_ULL(0)
+#define NTB_HWERR_SB01BASE_LOCKUP	BIT_ULL(1)
+#define NTB_HWERR_B2BDOORBELL_BIT14	BIT_ULL(2)
+#define NTB_HWERR_MSIX_VECTOR32_BAD	BIT_ULL(3)
+#define NTB_HWERR_BAR_ALIGN		BIT_ULL(4)
+#define NTB_HWERR_LTR_BAD		BIT_ULL(5)
+
+extern struct intel_b2b_addr xeon_b2b_usd_addr;
+extern struct intel_b2b_addr xeon_b2b_dsd_addr;
+
+int ndev_init_isr(struct intel_ntb_dev *ndev, int msix_min, int msix_max,
+		int msix_shift, int total_shift);
+enum ntb_topo xeon_ppd_topo(struct intel_ntb_dev *ndev, u8 ppd);
+void ndev_db_addr(struct intel_ntb_dev *ndev,
+				phys_addr_t *db_addr, resource_size_t *db_size,
+				phys_addr_t reg_addr, unsigned long reg);
+u64 ndev_db_read(struct intel_ntb_dev *ndev, void __iomem *mmio);
+int ndev_db_write(struct intel_ntb_dev *ndev, u64 db_bits,
+				void __iomem *mmio);
+int ndev_mw_to_bar(struct intel_ntb_dev *ndev, int idx);
+int intel_ntb_mw_count(struct ntb_dev *ntb, int pidx);
+int intel_ntb_mw_get_align(struct ntb_dev *ntb, int pidx, int idx,
+		resource_size_t *addr_align, resource_size_t *size_align,
+		resource_size_t *size_max);
+int intel_ntb_peer_mw_count(struct ntb_dev *ntb);
+int intel_ntb_peer_mw_get_addr(struct ntb_dev *ntb, int idx,
+		phys_addr_t *base, resource_size_t *size);
+u64 intel_ntb_link_is_up(struct ntb_dev *ntb, enum ntb_speed *speed,
+		enum ntb_width *width);
+int intel_ntb_link_disable(struct ntb_dev *ntb);
+u64 intel_ntb_db_valid_mask(struct ntb_dev *ntb);
+int intel_ntb_db_vector_count(struct ntb_dev *ntb);
+u64 intel_ntb_db_vector_mask(struct ntb_dev *ntb, int db_vector);
+int intel_ntb_db_set_mask(struct ntb_dev *ntb, u64 db_bits);
+int intel_ntb_db_clear_mask(struct ntb_dev *ntb, u64 db_bits);
+int intel_ntb_spad_is_unsafe(struct ntb_dev *ntb);
+int intel_ntb_spad_count(struct ntb_dev *ntb);
+u32 intel_ntb_spad_read(struct ntb_dev *ntb, int idx);
+int intel_ntb_spad_write(struct ntb_dev *ntb, int idx, u32 val);
+u32 intel_ntb_peer_spad_read(struct ntb_dev *ntb, int pidx, int sidx);
+int intel_ntb_peer_spad_write(struct ntb_dev *ntb, int pidx, int sidx,
+		u32 val);
+int intel_ntb_peer_spad_addr(struct ntb_dev *ntb, int pidx, int sidx,
+				    phys_addr_t *spad_addr);
+int xeon_link_is_up(struct intel_ntb_dev *ndev);
+
+#endif
diff --git a/drivers/ntb/hw/intel/ntb_hw_gen3.c b/drivers/ntb/hw/intel/ntb_hw_gen3.c
new file mode 100644
index 000000000..a5aa96a31
--- /dev/null
+++ b/drivers/ntb/hw/intel/ntb_hw_gen3.c
@@ -0,0 +1,630 @@
+/*
+ * This file is provided under a dual BSD/GPLv2 license.  When using or
+ *   redistributing this file, you may do so under either license.
+ *
+ *   GPL LICENSE SUMMARY
+ *
+ *   Copyright(c) 2017 Intel Corporation. All rights reserved.
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of version 2 of the GNU General Public License as
+ *   published by the Free Software Foundation.
+ *
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2017 Intel Corporation. All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copy
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Intel PCIe GEN3 NTB Linux driver
+ *
+ */
+
+#include <linux/debugfs.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/random.h>
+#include <linux/slab.h>
+#include <linux/ntb.h>
+
+#include "ntb_hw_intel.h"
+#include "ntb_hw_gen1.h"
+#include "ntb_hw_gen3.h"
+
+static int gen3_poll_link(struct intel_ntb_dev *ndev);
+
+static const struct intel_ntb_reg gen3_reg = {
+	.poll_link		= gen3_poll_link,
+	.link_is_up		= xeon_link_is_up,
+	.db_ioread		= gen3_db_ioread,
+	.db_iowrite		= gen3_db_iowrite,
+	.db_size		= sizeof(u32),
+	.ntb_ctl		= GEN3_NTBCNTL_OFFSET,
+	.mw_bar			= {2, 4},
+};
+
+static const struct intel_ntb_alt_reg gen3_pri_reg = {
+	.db_bell		= GEN3_EM_DOORBELL_OFFSET,
+	.db_clear		= GEN3_IM_INT_STATUS_OFFSET,
+	.db_mask		= GEN3_IM_INT_DISABLE_OFFSET,
+	.spad			= GEN3_IM_SPAD_OFFSET,
+};
+
+static const struct intel_ntb_alt_reg gen3_b2b_reg = {
+	.db_bell		= GEN3_IM_DOORBELL_OFFSET,
+	.db_clear		= GEN3_EM_INT_STATUS_OFFSET,
+	.db_mask		= GEN3_EM_INT_DISABLE_OFFSET,
+	.spad			= GEN3_B2B_SPAD_OFFSET,
+};
+
+static const struct intel_ntb_xlat_reg gen3_sec_xlat = {
+/*	.bar0_base		= GEN3_EMBAR0_OFFSET, */
+	.bar2_limit		= GEN3_IMBAR1XLMT_OFFSET,
+	.bar2_xlat		= GEN3_IMBAR1XBASE_OFFSET,
+};
+
+static int gen3_poll_link(struct intel_ntb_dev *ndev)
+{
+	u16 reg_val;
+	int rc;
+
+	ndev->reg->db_iowrite(ndev->db_link_mask,
+			      ndev->self_mmio +
+			      ndev->self_reg->db_clear);
+
+	rc = pci_read_config_word(ndev->ntb.pdev,
+				  GEN3_LINK_STATUS_OFFSET, &reg_val);
+	if (rc)
+		return 0;
+
+	if (reg_val == ndev->lnk_sta)
+		return 0;
+
+	ndev->lnk_sta = reg_val;
+
+	return 1;
+}
+
+static int gen3_init_isr(struct intel_ntb_dev *ndev)
+{
+	int i;
+
+	/*
+	 * The MSIX vectors and the interrupt status bits are not lined up
+	 * on Skylake. By default the link status bit is bit 32, however it
+	 * is by default MSIX vector0. We need to fixup to line them up.
+	 * The vectors at reset is 1-32,0. We need to reprogram to 0-32.
+	 */
+
+	for (i = 0; i < GEN3_DB_MSIX_VECTOR_COUNT; i++)
+		iowrite8(i, ndev->self_mmio + GEN3_INTVEC_OFFSET + i);
+
+	/* move link status down one as workaround */
+	if (ndev->hwerr_flags & NTB_HWERR_MSIX_VECTOR32_BAD) {
+		iowrite8(GEN3_DB_MSIX_VECTOR_COUNT - 2,
+			 ndev->self_mmio + GEN3_INTVEC_OFFSET +
+			 (GEN3_DB_MSIX_VECTOR_COUNT - 1));
+	}
+
+	return ndev_init_isr(ndev, GEN3_DB_MSIX_VECTOR_COUNT,
+			     GEN3_DB_MSIX_VECTOR_COUNT,
+			     GEN3_DB_MSIX_VECTOR_SHIFT,
+			     GEN3_DB_TOTAL_SHIFT);
+}
+
+static int gen3_setup_b2b_mw(struct intel_ntb_dev *ndev,
+			    const struct intel_b2b_addr *addr,
+			    const struct intel_b2b_addr *peer_addr)
+{
+	struct pci_dev *pdev;
+	void __iomem *mmio;
+	phys_addr_t bar_addr;
+
+	pdev = ndev->ntb.pdev;
+	mmio = ndev->self_mmio;
+
+	/* setup incoming bar limits == base addrs (zero length windows) */
+	bar_addr = addr->bar2_addr64;
+	iowrite64(bar_addr, mmio + GEN3_IMBAR1XLMT_OFFSET);
+	bar_addr = ioread64(mmio + GEN3_IMBAR1XLMT_OFFSET);
+	dev_dbg(&pdev->dev, "IMBAR1XLMT %#018llx\n", bar_addr);
+
+	bar_addr = addr->bar4_addr64;
+	iowrite64(bar_addr, mmio + GEN3_IMBAR2XLMT_OFFSET);
+	bar_addr = ioread64(mmio + GEN3_IMBAR2XLMT_OFFSET);
+	dev_dbg(&pdev->dev, "IMBAR2XLMT %#018llx\n", bar_addr);
+
+	/* zero incoming translation addrs */
+	iowrite64(0, mmio + GEN3_IMBAR1XBASE_OFFSET);
+	iowrite64(0, mmio + GEN3_IMBAR2XBASE_OFFSET);
+
+	ndev->peer_mmio = ndev->self_mmio;
+
+	return 0;
+}
+
+static int gen3_init_ntb(struct intel_ntb_dev *ndev)
+{
+	int rc;
+
+
+	ndev->mw_count = XEON_MW_COUNT;
+	ndev->spad_count = GEN3_SPAD_COUNT;
+	ndev->db_count = GEN3_DB_COUNT;
+	ndev->db_link_mask = GEN3_DB_LINK_BIT;
+
+	/* DB fixup for using 31 right now */
+	if (ndev->hwerr_flags & NTB_HWERR_MSIX_VECTOR32_BAD)
+		ndev->db_link_mask |= BIT_ULL(31);
+
+	switch (ndev->ntb.topo) {
+	case NTB_TOPO_B2B_USD:
+	case NTB_TOPO_B2B_DSD:
+		ndev->self_reg = &gen3_pri_reg;
+		ndev->peer_reg = &gen3_b2b_reg;
+		ndev->xlat_reg = &gen3_sec_xlat;
+
+		if (ndev->ntb.topo == NTB_TOPO_B2B_USD) {
+			rc = gen3_setup_b2b_mw(ndev,
+					      &xeon_b2b_dsd_addr,
+					      &xeon_b2b_usd_addr);
+		} else {
+			rc = gen3_setup_b2b_mw(ndev,
+					      &xeon_b2b_usd_addr,
+					      &xeon_b2b_dsd_addr);
+		}
+
+		if (rc)
+			return rc;
+
+		/* Enable Bus Master and Memory Space on the secondary side */
+		iowrite16(PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER,
+			  ndev->self_mmio + GEN3_SPCICMD_OFFSET);
+
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	ndev->db_valid_mask = BIT_ULL(ndev->db_count) - 1;
+	/* Make sure we are not using DB's used for link status */
+	if (ndev->hwerr_flags & NTB_HWERR_MSIX_VECTOR32_BAD)
+		ndev->db_valid_mask &= ~ndev->db_link_mask;
+
+	ndev->reg->db_iowrite(ndev->db_valid_mask,
+			      ndev->self_mmio +
+			      ndev->self_reg->db_mask);
+
+	return 0;
+}
+
+int gen3_init_dev(struct intel_ntb_dev *ndev)
+{
+	struct pci_dev *pdev;
+	u8 ppd;
+	int rc;
+
+	pdev = ndev->ntb.pdev;
+
+	ndev->reg = &gen3_reg;
+
+	rc = pci_read_config_byte(pdev, XEON_PPD_OFFSET, &ppd);
+	if (rc)
+		return -EIO;
+
+	ndev->ntb.topo = xeon_ppd_topo(ndev, ppd);
+	dev_dbg(&pdev->dev, "ppd %#x topo %s\n", ppd,
+		ntb_topo_string(ndev->ntb.topo));
+	if (ndev->ntb.topo == NTB_TOPO_NONE)
+		return -EINVAL;
+
+	ndev->hwerr_flags |= NTB_HWERR_MSIX_VECTOR32_BAD;
+
+	rc = gen3_init_ntb(ndev);
+	if (rc)
+		return rc;
+
+	return gen3_init_isr(ndev);
+}
+
+ssize_t ndev_ntb3_debugfs_read(struct file *filp, char __user *ubuf,
+				      size_t count, loff_t *offp)
+{
+	struct intel_ntb_dev *ndev;
+	void __iomem *mmio;
+	char *buf;
+	size_t buf_size;
+	ssize_t ret, off;
+	union { u64 v64; u32 v32; u16 v16; } u;
+
+	ndev = filp->private_data;
+	mmio = ndev->self_mmio;
+
+	buf_size = min(count, 0x800ul);
+
+	buf = kmalloc(buf_size, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	off = 0;
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "NTB Device Information:\n");
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "Connection Topology -\t%s\n",
+			 ntb_topo_string(ndev->ntb.topo));
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "NTB CTL -\t\t%#06x\n", ndev->ntb_ctl);
+	off += scnprintf(buf + off, buf_size - off,
+			 "LNK STA -\t\t%#06x\n", ndev->lnk_sta);
+
+	if (!ndev->reg->link_is_up(ndev))
+		off += scnprintf(buf + off, buf_size - off,
+				 "Link Status -\t\tDown\n");
+	else {
+		off += scnprintf(buf + off, buf_size - off,
+				 "Link Status -\t\tUp\n");
+		off += scnprintf(buf + off, buf_size - off,
+				 "Link Speed -\t\tPCI-E Gen %u\n",
+				 NTB_LNK_STA_SPEED(ndev->lnk_sta));
+		off += scnprintf(buf + off, buf_size - off,
+				 "Link Width -\t\tx%u\n",
+				 NTB_LNK_STA_WIDTH(ndev->lnk_sta));
+	}
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "Memory Window Count -\t%u\n", ndev->mw_count);
+	off += scnprintf(buf + off, buf_size - off,
+			 "Scratchpad Count -\t%u\n", ndev->spad_count);
+	off += scnprintf(buf + off, buf_size - off,
+			 "Doorbell Count -\t%u\n", ndev->db_count);
+	off += scnprintf(buf + off, buf_size - off,
+			 "Doorbell Vector Count -\t%u\n", ndev->db_vec_count);
+	off += scnprintf(buf + off, buf_size - off,
+			 "Doorbell Vector Shift -\t%u\n", ndev->db_vec_shift);
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "Doorbell Valid Mask -\t%#llx\n", ndev->db_valid_mask);
+	off += scnprintf(buf + off, buf_size - off,
+			 "Doorbell Link Mask -\t%#llx\n", ndev->db_link_mask);
+	off += scnprintf(buf + off, buf_size - off,
+			 "Doorbell Mask Cached -\t%#llx\n", ndev->db_mask);
+
+	u.v64 = ndev_db_read(ndev, mmio + ndev->self_reg->db_mask);
+	off += scnprintf(buf + off, buf_size - off,
+			 "Doorbell Mask -\t\t%#llx\n", u.v64);
+
+	u.v64 = ndev_db_read(ndev, mmio + ndev->self_reg->db_bell);
+	off += scnprintf(buf + off, buf_size - off,
+			 "Doorbell Bell -\t\t%#llx\n", u.v64);
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "\nNTB Incoming XLAT:\n");
+
+	u.v64 = ioread64(mmio + GEN3_IMBAR1XBASE_OFFSET);
+	off += scnprintf(buf + off, buf_size - off,
+			 "IMBAR1XBASE -\t\t%#018llx\n", u.v64);
+
+	u.v64 = ioread64(mmio + GEN3_IMBAR2XBASE_OFFSET);
+	off += scnprintf(buf + off, buf_size - off,
+			 "IMBAR2XBASE -\t\t%#018llx\n", u.v64);
+
+	u.v64 = ioread64(mmio + GEN3_IMBAR1XLMT_OFFSET);
+	off += scnprintf(buf + off, buf_size - off,
+			 "IMBAR1XLMT -\t\t\t%#018llx\n", u.v64);
+
+	u.v64 = ioread64(mmio + GEN3_IMBAR2XLMT_OFFSET);
+	off += scnprintf(buf + off, buf_size - off,
+			 "IMBAR2XLMT -\t\t\t%#018llx\n", u.v64);
+
+	if (ntb_topo_is_b2b(ndev->ntb.topo)) {
+		off += scnprintf(buf + off, buf_size - off,
+				 "\nNTB Outgoing B2B XLAT:\n");
+
+		u.v64 = ioread64(mmio + GEN3_EMBAR1XBASE_OFFSET);
+		off += scnprintf(buf + off, buf_size - off,
+				 "EMBAR1XBASE -\t\t%#018llx\n", u.v64);
+
+		u.v64 = ioread64(mmio + GEN3_EMBAR2XBASE_OFFSET);
+		off += scnprintf(buf + off, buf_size - off,
+				 "EMBAR2XBASE -\t\t%#018llx\n", u.v64);
+
+		u.v64 = ioread64(mmio + GEN3_EMBAR1XLMT_OFFSET);
+		off += scnprintf(buf + off, buf_size - off,
+				 "EMBAR1XLMT -\t\t%#018llx\n", u.v64);
+
+		u.v64 = ioread64(mmio + GEN3_EMBAR2XLMT_OFFSET);
+		off += scnprintf(buf + off, buf_size - off,
+				 "EMBAR2XLMT -\t\t%#018llx\n", u.v64);
+
+		off += scnprintf(buf + off, buf_size - off,
+				 "\nNTB Secondary BAR:\n");
+
+		u.v64 = ioread64(mmio + GEN3_EMBAR0_OFFSET);
+		off += scnprintf(buf + off, buf_size - off,
+				 "EMBAR0 -\t\t%#018llx\n", u.v64);
+
+		u.v64 = ioread64(mmio + GEN3_EMBAR1_OFFSET);
+		off += scnprintf(buf + off, buf_size - off,
+				 "EMBAR1 -\t\t%#018llx\n", u.v64);
+
+		u.v64 = ioread64(mmio + GEN3_EMBAR2_OFFSET);
+		off += scnprintf(buf + off, buf_size - off,
+				 "EMBAR2 -\t\t%#018llx\n", u.v64);
+	}
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "\nNTB Statistics:\n");
+
+	u.v16 = ioread16(mmio + GEN3_USMEMMISS_OFFSET);
+	off += scnprintf(buf + off, buf_size - off,
+			 "Upstream Memory Miss -\t%u\n", u.v16);
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "\nNTB Hardware Errors:\n");
+
+	if (!pci_read_config_word(ndev->ntb.pdev,
+				  GEN3_DEVSTS_OFFSET, &u.v16))
+		off += scnprintf(buf + off, buf_size - off,
+				 "DEVSTS -\t\t%#06x\n", u.v16);
+
+	if (!pci_read_config_word(ndev->ntb.pdev,
+				  GEN3_LINK_STATUS_OFFSET, &u.v16))
+		off += scnprintf(buf + off, buf_size - off,
+				 "LNKSTS -\t\t%#06x\n", u.v16);
+
+	if (!pci_read_config_dword(ndev->ntb.pdev,
+				   GEN3_UNCERRSTS_OFFSET, &u.v32))
+		off += scnprintf(buf + off, buf_size - off,
+				 "UNCERRSTS -\t\t%#06x\n", u.v32);
+
+	if (!pci_read_config_dword(ndev->ntb.pdev,
+				   GEN3_CORERRSTS_OFFSET, &u.v32))
+		off += scnprintf(buf + off, buf_size - off,
+				 "CORERRSTS -\t\t%#06x\n", u.v32);
+
+	ret = simple_read_from_buffer(ubuf, count, offp, buf, off);
+	kfree(buf);
+	return ret;
+}
+
+int intel_ntb3_link_enable(struct ntb_dev *ntb, enum ntb_speed max_speed,
+		enum ntb_width max_width)
+{
+	struct intel_ntb_dev *ndev;
+	u32 ntb_ctl;
+
+	ndev = container_of(ntb, struct intel_ntb_dev, ntb);
+
+	dev_dbg(&ntb->pdev->dev,
+		"Enabling link with max_speed %d max_width %d\n",
+		max_speed, max_width);
+
+	if (max_speed != NTB_SPEED_AUTO)
+		dev_dbg(&ntb->pdev->dev, "ignoring max_speed %d\n", max_speed);
+	if (max_width != NTB_WIDTH_AUTO)
+		dev_dbg(&ntb->pdev->dev, "ignoring max_width %d\n", max_width);
+
+	ntb_ctl = ioread32(ndev->self_mmio + ndev->reg->ntb_ctl);
+	ntb_ctl &= ~(NTB_CTL_DISABLE | NTB_CTL_CFG_LOCK);
+	ntb_ctl |= NTB_CTL_P2S_BAR2_SNOOP | NTB_CTL_S2P_BAR2_SNOOP;
+	ntb_ctl |= NTB_CTL_P2S_BAR4_SNOOP | NTB_CTL_S2P_BAR4_SNOOP;
+	iowrite32(ntb_ctl, ndev->self_mmio + ndev->reg->ntb_ctl);
+
+	return 0;
+}
+static int intel_ntb3_mw_set_trans(struct ntb_dev *ntb, int pidx, int idx,
+				   dma_addr_t addr, resource_size_t size)
+{
+	struct intel_ntb_dev *ndev = ntb_ndev(ntb);
+	unsigned long xlat_reg, limit_reg;
+	resource_size_t bar_size, mw_size;
+	void __iomem *mmio;
+	u64 base, limit, reg_val;
+	int bar;
+
+	if (pidx != NTB_DEF_PEER_IDX)
+		return -EINVAL;
+
+	if (idx >= ndev->b2b_idx && !ndev->b2b_off)
+		idx += 1;
+
+	bar = ndev_mw_to_bar(ndev, idx);
+	if (bar < 0)
+		return bar;
+
+	bar_size = pci_resource_len(ndev->ntb.pdev, bar);
+
+	if (idx == ndev->b2b_idx)
+		mw_size = bar_size - ndev->b2b_off;
+	else
+		mw_size = bar_size;
+
+	/* hardware requires that addr is aligned to bar size */
+	if (addr & (bar_size - 1))
+		return -EINVAL;
+
+	/* make sure the range fits in the usable mw size */
+	if (size > mw_size)
+		return -EINVAL;
+
+	mmio = ndev->self_mmio;
+	xlat_reg = ndev->xlat_reg->bar2_xlat + (idx * 0x10);
+	limit_reg = ndev->xlat_reg->bar2_limit + (idx * 0x10);
+	base = pci_resource_start(ndev->ntb.pdev, bar);
+
+	/* Set the limit if supported, if size is not mw_size */
+	if (limit_reg && size != mw_size)
+		limit = base + size;
+	else
+		limit = base + mw_size;
+
+	/* set and verify setting the translation address */
+	iowrite64(addr, mmio + xlat_reg);
+	reg_val = ioread64(mmio + xlat_reg);
+	if (reg_val != addr) {
+		iowrite64(0, mmio + xlat_reg);
+		return -EIO;
+	}
+
+	dev_dbg(&ntb->pdev->dev, "BAR %d IMBARXBASE: %#Lx\n", bar, reg_val);
+
+	/* set and verify setting the limit */
+	iowrite64(limit, mmio + limit_reg);
+	reg_val = ioread64(mmio + limit_reg);
+	if (reg_val != limit) {
+		iowrite64(base, mmio + limit_reg);
+		iowrite64(0, mmio + xlat_reg);
+		return -EIO;
+	}
+
+	dev_dbg(&ntb->pdev->dev, "BAR %d IMBARXLMT: %#Lx\n", bar, reg_val);
+
+	/* setup the EP */
+	limit_reg = ndev->xlat_reg->bar2_limit + (idx * 0x10) + 0x4000;
+	base = ioread64(mmio + GEN3_EMBAR1_OFFSET + (8 * idx));
+	base &= ~0xf;
+
+	if (limit_reg && size != mw_size)
+		limit = base + size;
+	else
+		limit = base + mw_size;
+
+	/* set and verify setting the limit */
+	iowrite64(limit, mmio + limit_reg);
+	reg_val = ioread64(mmio + limit_reg);
+	if (reg_val != limit) {
+		iowrite64(base, mmio + limit_reg);
+		iowrite64(0, mmio + xlat_reg);
+		return -EIO;
+	}
+
+	dev_dbg(&ntb->pdev->dev, "BAR %d EMBARXLMT: %#Lx\n", bar, reg_val);
+
+	return 0;
+}
+
+int intel_ntb3_peer_db_addr(struct ntb_dev *ntb, phys_addr_t *db_addr,
+				   resource_size_t *db_size,
+				   u64 *db_data, int db_bit)
+{
+	phys_addr_t db_addr_base;
+	struct intel_ntb_dev *ndev = ntb_ndev(ntb);
+
+	if (unlikely(db_bit >= BITS_PER_LONG_LONG))
+		return -EINVAL;
+
+	if (unlikely(BIT_ULL(db_bit) & ~ntb_ndev(ntb)->db_valid_mask))
+		return -EINVAL;
+
+	ndev_db_addr(ndev, &db_addr_base, db_size, ndev->peer_addr,
+				ndev->peer_reg->db_bell);
+
+	if (db_addr) {
+		*db_addr = db_addr_base + (db_bit * 4);
+		dev_dbg(&ndev->ntb.pdev->dev, "Peer db addr %llx db bit %d\n",
+				*db_addr, db_bit);
+	}
+
+	if (db_data) {
+		*db_data = 1;
+		dev_dbg(&ndev->ntb.pdev->dev, "Peer db data %llx db bit %d\n",
+				*db_data, db_bit);
+	}
+
+	return 0;
+}
+
+int intel_ntb3_peer_db_set(struct ntb_dev *ntb, u64 db_bits)
+{
+	struct intel_ntb_dev *ndev = ntb_ndev(ntb);
+	int bit;
+
+	if (db_bits & ~ndev->db_valid_mask)
+		return -EINVAL;
+
+	while (db_bits) {
+		bit = __ffs(db_bits);
+		iowrite32(1, ndev->peer_mmio +
+				ndev->peer_reg->db_bell + (bit * 4));
+		db_bits &= db_bits - 1;
+	}
+
+	return 0;
+}
+
+u64 intel_ntb3_db_read(struct ntb_dev *ntb)
+{
+	struct intel_ntb_dev *ndev = ntb_ndev(ntb);
+
+	return ndev_db_read(ndev,
+			    ndev->self_mmio +
+			    ndev->self_reg->db_clear);
+}
+
+int intel_ntb3_db_clear(struct ntb_dev *ntb, u64 db_bits)
+{
+	struct intel_ntb_dev *ndev = ntb_ndev(ntb);
+
+	return ndev_db_write(ndev, db_bits,
+			     ndev->self_mmio +
+			     ndev->self_reg->db_clear);
+}
+
+const struct ntb_dev_ops intel_ntb3_ops = {
+	.mw_count		= intel_ntb_mw_count,
+	.mw_get_align		= intel_ntb_mw_get_align,
+	.mw_set_trans		= intel_ntb3_mw_set_trans,
+	.peer_mw_count		= intel_ntb_peer_mw_count,
+	.peer_mw_get_addr	= intel_ntb_peer_mw_get_addr,
+	.link_is_up		= intel_ntb_link_is_up,
+	.link_enable		= intel_ntb3_link_enable,
+	.link_disable		= intel_ntb_link_disable,
+	.db_valid_mask		= intel_ntb_db_valid_mask,
+	.db_vector_count	= intel_ntb_db_vector_count,
+	.db_vector_mask		= intel_ntb_db_vector_mask,
+	.db_read		= intel_ntb3_db_read,
+	.db_clear		= intel_ntb3_db_clear,
+	.db_set_mask		= intel_ntb_db_set_mask,
+	.db_clear_mask		= intel_ntb_db_clear_mask,
+	.peer_db_addr		= intel_ntb3_peer_db_addr,
+	.peer_db_set		= intel_ntb3_peer_db_set,
+	.spad_is_unsafe		= intel_ntb_spad_is_unsafe,
+	.spad_count		= intel_ntb_spad_count,
+	.spad_read		= intel_ntb_spad_read,
+	.spad_write		= intel_ntb_spad_write,
+	.peer_spad_addr		= intel_ntb_peer_spad_addr,
+	.peer_spad_read		= intel_ntb_peer_spad_read,
+	.peer_spad_write	= intel_ntb_peer_spad_write,
+};
+
diff --git a/drivers/ntb/hw/intel/ntb_hw_gen3.h b/drivers/ntb/hw/intel/ntb_hw_gen3.h
new file mode 100644
index 000000000..dea939899
--- /dev/null
+++ b/drivers/ntb/hw/intel/ntb_hw_gen3.h
@@ -0,0 +1,118 @@
+/*
+ * This file is provided under a dual BSD/GPLv2 license.  When using or
+ *   redistributing this file, you may do so under either license.
+ *
+ *   GPL LICENSE SUMMARY
+ *
+ *   Copyright(c) 2012-2017 Intel Corporation. All rights reserved.
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of version 2 of the GNU General Public License as
+ *   published by the Free Software Foundation.
+ *
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2012-2017 Intel Corporation. All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copy
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef _NTB_INTEL_GEN3_H_
+#define _NTB_INTEL_GEN3_H_
+
+#include "ntb_hw_intel.h"
+
+/* Intel Skylake Xeon hardware */
+#define GEN3_IMBAR1SZ_OFFSET		0x00d0
+#define GEN3_IMBAR2SZ_OFFSET		0x00d1
+#define GEN3_EMBAR1SZ_OFFSET		0x00d2
+#define GEN3_EMBAR2SZ_OFFSET		0x00d3
+#define GEN3_DEVCTRL_OFFSET		0x0098
+#define GEN3_DEVSTS_OFFSET		0x009a
+#define GEN3_UNCERRSTS_OFFSET		0x014c
+#define GEN3_CORERRSTS_OFFSET		0x0158
+#define GEN3_LINK_STATUS_OFFSET		0x01a2
+
+#define GEN3_NTBCNTL_OFFSET		0x0000
+#define GEN3_IMBAR1XBASE_OFFSET		0x0010		/* SBAR2XLAT */
+#define GEN3_IMBAR1XLMT_OFFSET		0x0018		/* SBAR2LMT */
+#define GEN3_IMBAR2XBASE_OFFSET		0x0020		/* SBAR4XLAT */
+#define GEN3_IMBAR2XLMT_OFFSET		0x0028		/* SBAR4LMT */
+#define GEN3_IM_INT_STATUS_OFFSET	0x0040
+#define GEN3_IM_INT_DISABLE_OFFSET	0x0048
+#define GEN3_IM_SPAD_OFFSET		0x0080		/* SPAD */
+#define GEN3_USMEMMISS_OFFSET		0x0070
+#define GEN3_INTVEC_OFFSET		0x00d0
+#define GEN3_IM_DOORBELL_OFFSET		0x0100		/* SDOORBELL0 */
+#define GEN3_B2B_SPAD_OFFSET		0x0180		/* B2B SPAD */
+#define GEN3_EMBAR0XBASE_OFFSET		0x4008		/* B2B_XLAT */
+#define GEN3_EMBAR1XBASE_OFFSET		0x4010		/* PBAR2XLAT */
+#define GEN3_EMBAR1XLMT_OFFSET		0x4018		/* PBAR2LMT */
+#define GEN3_EMBAR2XBASE_OFFSET		0x4020		/* PBAR4XLAT */
+#define GEN3_EMBAR2XLMT_OFFSET		0x4028		/* PBAR4LMT */
+#define GEN3_EM_INT_STATUS_OFFSET	0x4040
+#define GEN3_EM_INT_DISABLE_OFFSET	0x4048
+#define GEN3_EM_SPAD_OFFSET		0x4080		/* remote SPAD */
+#define GEN3_EM_DOORBELL_OFFSET		0x4100		/* PDOORBELL0 */
+#define GEN3_SPCICMD_OFFSET		0x4504		/* SPCICMD */
+#define GEN3_EMBAR0_OFFSET		0x4510		/* SBAR0BASE */
+#define GEN3_EMBAR1_OFFSET		0x4518		/* SBAR23BASE */
+#define GEN3_EMBAR2_OFFSET		0x4520		/* SBAR45BASE */
+
+#define GEN3_DB_COUNT			32
+#define GEN3_DB_LINK			32
+#define GEN3_DB_LINK_BIT		BIT_ULL(GEN3_DB_LINK)
+#define GEN3_DB_MSIX_VECTOR_COUNT	33
+#define GEN3_DB_MSIX_VECTOR_SHIFT	1
+#define GEN3_DB_TOTAL_SHIFT		33
+#define GEN3_SPAD_COUNT			16
+
+static inline u64 gen3_db_ioread(const void __iomem *mmio)
+{
+	return ioread64(mmio);
+}
+
+static inline void gen3_db_iowrite(u64 bits, void __iomem *mmio)
+{
+	iowrite64(bits, mmio);
+}
+
+ssize_t ndev_ntb3_debugfs_read(struct file *filp, char __user *ubuf,
+				      size_t count, loff_t *offp);
+int gen3_init_dev(struct intel_ntb_dev *ndev);
+int intel_ntb3_link_enable(struct ntb_dev *ntb, enum ntb_speed max_speed,
+		enum ntb_width max_width);
+u64 intel_ntb3_db_read(struct ntb_dev *ntb);
+int intel_ntb3_db_clear(struct ntb_dev *ntb, u64 db_bits);
+int intel_ntb3_peer_db_set(struct ntb_dev *ntb, u64 db_bits);
+int intel_ntb3_peer_db_addr(struct ntb_dev *ntb, phys_addr_t *db_addr,
+				resource_size_t *db_size,
+				u64 *db_data, int db_bit);
+
+extern const struct ntb_dev_ops intel_ntb3_ops;
+
+#endif
diff --git a/drivers/ntb/hw/intel/ntb_hw_gen4.c b/drivers/ntb/hw/intel/ntb_hw_gen4.c
new file mode 100644
index 000000000..a221a978a
--- /dev/null
+++ b/drivers/ntb/hw/intel/ntb_hw_gen4.c
@@ -0,0 +1,604 @@
+// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+/* Copyright(c) 2020 Intel Corporation. All rights reserved. */
+#include <linux/debugfs.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/random.h>
+#include <linux/slab.h>
+#include <linux/ntb.h>
+#include <linux/log2.h>
+
+#include "ntb_hw_intel.h"
+#include "ntb_hw_gen1.h"
+#include "ntb_hw_gen3.h"
+#include "ntb_hw_gen4.h"
+
+static int gen4_poll_link(struct intel_ntb_dev *ndev);
+static int gen4_link_is_up(struct intel_ntb_dev *ndev);
+
+static const struct intel_ntb_reg gen4_reg = {
+	.poll_link		= gen4_poll_link,
+	.link_is_up		= gen4_link_is_up,
+	.db_ioread		= gen3_db_ioread,
+	.db_iowrite		= gen3_db_iowrite,
+	.db_size		= sizeof(u32),
+	.ntb_ctl		= GEN4_NTBCNTL_OFFSET,
+	.mw_bar			= {2, 4},
+};
+
+static const struct intel_ntb_alt_reg gen4_pri_reg = {
+	.db_clear		= GEN4_IM_INT_STATUS_OFFSET,
+	.db_mask		= GEN4_IM_INT_DISABLE_OFFSET,
+	.spad			= GEN4_IM_SPAD_OFFSET,
+};
+
+static const struct intel_ntb_xlat_reg gen4_sec_xlat = {
+	.bar2_limit		= GEN4_IM23XLMT_OFFSET,
+	.bar2_xlat		= GEN4_IM23XBASE_OFFSET,
+	.bar2_idx		= GEN4_IM23XBASEIDX_OFFSET,
+};
+
+static const struct intel_ntb_alt_reg gen4_b2b_reg = {
+	.db_bell		= GEN4_IM_DOORBELL_OFFSET,
+	.spad			= GEN4_EM_SPAD_OFFSET,
+};
+
+static u64 get_ppd0(struct pci_dev *pdev)
+{
+	if (pdev_is_gen4(pdev) || pdev_is_gen5(pdev))
+		return GEN4_PPD0_OFFSET;
+	else if (pdev_is_gen6(pdev))
+		return GEN6_PPD0_OFFSET;
+
+	return ULLONG_MAX;
+}
+
+static int gen4_poll_link(struct intel_ntb_dev *ndev)
+{
+	u16 reg_val;
+
+	/*
+	 * We need to write to DLLSCS bit in the SLOTSTS before we
+	 * can clear the hardware link interrupt on ICX NTB.
+	 */
+	iowrite16(GEN4_SLOTSTS_DLLSCS, ndev->self_mmio + GEN4_SLOTSTS);
+	ndev->reg->db_iowrite(ndev->db_link_mask,
+			      ndev->self_mmio +
+			      ndev->self_reg->db_clear);
+
+	reg_val = ioread16(ndev->self_mmio + GEN4_LINK_STATUS_OFFSET);
+	if (reg_val == ndev->lnk_sta)
+		return 0;
+
+	ndev->lnk_sta = reg_val;
+
+	return 1;
+}
+
+static int gen4_link_is_up(struct intel_ntb_dev *ndev)
+{
+	return NTB_LNK_STA_ACTIVE(ndev->lnk_sta);
+}
+
+static int gen4_init_isr(struct intel_ntb_dev *ndev)
+{
+	int i;
+
+	/*
+	 * The MSIX vectors and the interrupt status bits are not lined up
+	 * on Gen3 (Skylake) and Gen4. By default the link status bit is bit
+	 * 32, however it is by default MSIX vector0. We need to fixup to
+	 * line them up. The vectors at reset is 1-32,0. We need to reprogram
+	 * to 0-32.
+	 */
+	for (i = 0; i < GEN4_DB_MSIX_VECTOR_COUNT; i++)
+		iowrite8(i, ndev->self_mmio + GEN4_INTVEC_OFFSET + i);
+
+	return ndev_init_isr(ndev, GEN4_DB_MSIX_VECTOR_COUNT,
+			     GEN4_DB_MSIX_VECTOR_COUNT,
+			     GEN4_DB_MSIX_VECTOR_SHIFT,
+			     GEN4_DB_TOTAL_SHIFT);
+}
+
+static int gen4_setup_b2b_mw(struct intel_ntb_dev *ndev,
+			    const struct intel_b2b_addr *addr,
+			    const struct intel_b2b_addr *peer_addr)
+{
+	struct pci_dev *pdev;
+	void __iomem *mmio;
+	phys_addr_t bar_addr;
+
+	pdev = ndev->ntb.pdev;
+	mmio = ndev->self_mmio;
+
+	/* setup incoming bar limits == base addrs (zero length windows) */
+	bar_addr = addr->bar2_addr64;
+	iowrite64(bar_addr, mmio + GEN4_IM23XLMT_OFFSET);
+	bar_addr = ioread64(mmio + GEN4_IM23XLMT_OFFSET);
+	dev_dbg(&pdev->dev, "IM23XLMT %#018llx\n", bar_addr);
+
+	bar_addr = addr->bar4_addr64;
+	iowrite64(bar_addr, mmio + GEN4_IM45XLMT_OFFSET);
+	bar_addr = ioread64(mmio + GEN4_IM45XLMT_OFFSET);
+	dev_dbg(&pdev->dev, "IM45XLMT %#018llx\n", bar_addr);
+
+	/* zero incoming translation addrs */
+	iowrite64(0, mmio + GEN4_IM23XBASE_OFFSET);
+	iowrite64(0, mmio + GEN4_IM45XBASE_OFFSET);
+
+	ndev->peer_mmio = ndev->self_mmio;
+
+	return 0;
+}
+
+static int gen4_init_ntb(struct intel_ntb_dev *ndev)
+{
+	int rc;
+
+
+	ndev->mw_count = XEON_MW_COUNT;
+	ndev->spad_count = GEN4_SPAD_COUNT;
+	ndev->db_count = GEN4_DB_COUNT;
+	ndev->db_link_mask = GEN4_DB_LINK_BIT;
+
+	ndev->self_reg = &gen4_pri_reg;
+	ndev->xlat_reg = &gen4_sec_xlat;
+	ndev->peer_reg = &gen4_b2b_reg;
+
+	if (ndev->ntb.topo == NTB_TOPO_B2B_USD)
+		rc = gen4_setup_b2b_mw(ndev, &xeon_b2b_dsd_addr,
+				&xeon_b2b_usd_addr);
+	else
+		rc = gen4_setup_b2b_mw(ndev, &xeon_b2b_usd_addr,
+				&xeon_b2b_dsd_addr);
+	if (rc)
+		return rc;
+
+	ndev->db_valid_mask = BIT_ULL(ndev->db_count) - 1;
+
+	ndev->reg->db_iowrite(ndev->db_valid_mask,
+			      ndev->self_mmio +
+			      ndev->self_reg->db_mask);
+
+	return 0;
+}
+
+static enum ntb_topo gen4_ppd_topo(struct intel_ntb_dev *ndev, u32 ppd)
+{
+	switch (ppd & GEN4_PPD_TOPO_MASK) {
+	case GEN4_PPD_TOPO_B2B_USD:
+		return NTB_TOPO_B2B_USD;
+	case GEN4_PPD_TOPO_B2B_DSD:
+		return NTB_TOPO_B2B_DSD;
+	}
+
+	return NTB_TOPO_NONE;
+}
+
+static enum ntb_topo spr_ppd_topo(struct intel_ntb_dev *ndev, u32 ppd)
+{
+	switch (ppd & SPR_PPD_TOPO_MASK) {
+	case SPR_PPD_TOPO_B2B_USD:
+		return NTB_TOPO_B2B_USD;
+	case SPR_PPD_TOPO_B2B_DSD:
+		return NTB_TOPO_B2B_DSD;
+	}
+
+	return NTB_TOPO_NONE;
+}
+
+int gen4_init_dev(struct intel_ntb_dev *ndev)
+{
+	struct pci_dev *pdev = ndev->ntb.pdev;
+	u32 ppd1;
+	u16 lnkctl;
+	int rc;
+
+	ndev->reg = &gen4_reg;
+
+	if (pdev_is_ICX(pdev)) {
+		ndev->hwerr_flags |= NTB_HWERR_BAR_ALIGN;
+		ndev->hwerr_flags |= NTB_HWERR_LTR_BAD;
+	}
+
+	ppd1 = ioread32(ndev->self_mmio + GEN4_PPD1_OFFSET);
+	if (pdev_is_ICX(pdev))
+		ndev->ntb.topo = gen4_ppd_topo(ndev, ppd1);
+	else if (pdev_is_SPR(pdev) || pdev_is_gen5(pdev) || pdev_is_gen6(pdev))
+		ndev->ntb.topo = spr_ppd_topo(ndev, ppd1);
+	dev_dbg(&pdev->dev, "ppd %#x topo %s\n", ppd1,
+		ntb_topo_string(ndev->ntb.topo));
+	if (ndev->ntb.topo == NTB_TOPO_NONE)
+		return -EINVAL;
+
+	rc = gen4_init_ntb(ndev);
+	if (rc)
+		return rc;
+
+	/* init link setup */
+	lnkctl = ioread16(ndev->self_mmio + GEN4_LINK_CTRL_OFFSET);
+	lnkctl |= GEN4_LINK_CTRL_LINK_DISABLE;
+	iowrite16(lnkctl, ndev->self_mmio + GEN4_LINK_CTRL_OFFSET);
+
+	return gen4_init_isr(ndev);
+}
+
+ssize_t ndev_ntb4_debugfs_read(struct file *filp, char __user *ubuf,
+				      size_t count, loff_t *offp)
+{
+	struct intel_ntb_dev *ndev;
+	void __iomem *mmio;
+	char *buf;
+	size_t buf_size;
+	ssize_t ret, off;
+	union { u64 v64; u32 v32; u16 v16; } u;
+
+	ndev = filp->private_data;
+	mmio = ndev->self_mmio;
+
+	buf_size = min(count, 0x800ul);
+
+	buf = kmalloc(buf_size, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	off = 0;
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "NTB Device Information:\n");
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "Connection Topology -\t%s\n",
+			 ntb_topo_string(ndev->ntb.topo));
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "NTB CTL -\t\t%#06x\n", ndev->ntb_ctl);
+	off += scnprintf(buf + off, buf_size - off,
+			 "LNK STA (cached) -\t\t%#06x\n", ndev->lnk_sta);
+
+	if (!ndev->reg->link_is_up(ndev))
+		off += scnprintf(buf + off, buf_size - off,
+				 "Link Status -\t\tDown\n");
+	else {
+		off += scnprintf(buf + off, buf_size - off,
+				 "Link Status -\t\tUp\n");
+		off += scnprintf(buf + off, buf_size - off,
+				 "Link Speed -\t\tPCI-E Gen %u\n",
+				 NTB_LNK_STA_SPEED(ndev->lnk_sta));
+		off += scnprintf(buf + off, buf_size - off,
+				 "Link Width -\t\tx%u\n",
+				 NTB_LNK_STA_WIDTH(ndev->lnk_sta));
+	}
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "Memory Window Count -\t%u\n", ndev->mw_count);
+	off += scnprintf(buf + off, buf_size - off,
+			 "Scratchpad Count -\t%u\n", ndev->spad_count);
+	off += scnprintf(buf + off, buf_size - off,
+			 "Doorbell Count -\t%u\n", ndev->db_count);
+	off += scnprintf(buf + off, buf_size - off,
+			 "Doorbell Vector Count -\t%u\n", ndev->db_vec_count);
+	off += scnprintf(buf + off, buf_size - off,
+			 "Doorbell Vector Shift -\t%u\n", ndev->db_vec_shift);
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "Doorbell Valid Mask -\t%#llx\n", ndev->db_valid_mask);
+	off += scnprintf(buf + off, buf_size - off,
+			 "Doorbell Link Mask -\t%#llx\n", ndev->db_link_mask);
+	off += scnprintf(buf + off, buf_size - off,
+			 "Doorbell Mask Cached -\t%#llx\n", ndev->db_mask);
+
+	u.v64 = ndev_db_read(ndev, mmio + ndev->self_reg->db_mask);
+	off += scnprintf(buf + off, buf_size - off,
+			 "Doorbell Mask -\t\t%#llx\n", u.v64);
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "\nNTB Incoming XLAT:\n");
+
+	u.v64 = ioread64(mmio + GEN4_IM23XBASE_OFFSET);
+	off += scnprintf(buf + off, buf_size - off,
+			 "IM23XBASE -\t\t%#018llx\n", u.v64);
+
+	u.v64 = ioread64(mmio + GEN4_IM45XBASE_OFFSET);
+	off += scnprintf(buf + off, buf_size - off,
+			 "IM45XBASE -\t\t%#018llx\n", u.v64);
+
+	u.v64 = ioread64(mmio + GEN4_IM23XLMT_OFFSET);
+	off += scnprintf(buf + off, buf_size - off,
+			 "IM23XLMT -\t\t\t%#018llx\n", u.v64);
+
+	u.v64 = ioread64(mmio + GEN4_IM45XLMT_OFFSET);
+	off += scnprintf(buf + off, buf_size - off,
+			 "IM45XLMT -\t\t\t%#018llx\n", u.v64);
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "\nNTB Statistics:\n");
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "\nNTB Hardware Errors:\n");
+
+	if (!pci_read_config_word(ndev->ntb.pdev,
+				  GEN4_DEVSTS_OFFSET, &u.v16))
+		off += scnprintf(buf + off, buf_size - off,
+				"DEVSTS -\t\t%#06x\n", u.v16);
+
+	u.v16 = ioread16(mmio + GEN4_LINK_STATUS_OFFSET);
+	off += scnprintf(buf + off, buf_size - off,
+			"LNKSTS -\t\t%#06x\n", u.v16);
+
+	if (!pci_read_config_dword(ndev->ntb.pdev,
+				   GEN4_UNCERRSTS_OFFSET, &u.v32))
+		off += scnprintf(buf + off, buf_size - off,
+				 "UNCERRSTS -\t\t%#06x\n", u.v32);
+
+	if (!pci_read_config_dword(ndev->ntb.pdev,
+				   GEN4_CORERRSTS_OFFSET, &u.v32))
+		off += scnprintf(buf + off, buf_size - off,
+				 "CORERRSTS -\t\t%#06x\n", u.v32);
+
+	ret = simple_read_from_buffer(ubuf, count, offp, buf, off);
+	kfree(buf);
+	return ret;
+}
+
+static int intel_ntb4_mw_set_trans(struct ntb_dev *ntb, int pidx, int idx,
+				   dma_addr_t addr, resource_size_t size)
+{
+	struct intel_ntb_dev *ndev = ntb_ndev(ntb);
+	unsigned long xlat_reg, limit_reg, idx_reg;
+	unsigned short base_idx, reg_val16;
+	resource_size_t bar_size, mw_size;
+	void __iomem *mmio;
+	u64 base, limit, reg_val;
+	int bar;
+
+	if (pidx != NTB_DEF_PEER_IDX)
+		return -EINVAL;
+
+	if (idx >= ndev->b2b_idx && !ndev->b2b_off)
+		idx += 1;
+
+	bar = ndev_mw_to_bar(ndev, idx);
+	if (bar < 0)
+		return bar;
+
+	bar_size = pci_resource_len(ndev->ntb.pdev, bar);
+
+	if (idx == ndev->b2b_idx)
+		mw_size = bar_size - ndev->b2b_off;
+	else
+		mw_size = bar_size;
+
+	if (ndev->hwerr_flags & NTB_HWERR_BAR_ALIGN) {
+		/* hardware requires that addr is aligned to bar size */
+		if (addr & (bar_size - 1))
+			return -EINVAL;
+	} else {
+		if (addr & (PAGE_SIZE - 1))
+			return -EINVAL;
+	}
+
+	/* make sure the range fits in the usable mw size */
+	if (size > mw_size)
+		return -EINVAL;
+
+	mmio = ndev->self_mmio;
+	xlat_reg = ndev->xlat_reg->bar2_xlat + (idx * 0x10);
+	limit_reg = ndev->xlat_reg->bar2_limit + (idx * 0x10);
+	base = pci_resource_start(ndev->ntb.pdev, bar);
+
+	/* Set the limit if supported, if size is not mw_size */
+	if (limit_reg && size != mw_size) {
+		limit = base + size;
+		base_idx = __ilog2_u64(size);
+	} else {
+		limit = base + mw_size;
+		base_idx = __ilog2_u64(mw_size);
+	}
+
+
+	/* set and verify setting the translation address */
+	iowrite64(addr, mmio + xlat_reg);
+	reg_val = ioread64(mmio + xlat_reg);
+	if (reg_val != addr) {
+		iowrite64(0, mmio + xlat_reg);
+		return -EIO;
+	}
+
+	dev_dbg(&ntb->pdev->dev, "BAR %d IMXBASE: %#Lx\n", bar, reg_val);
+
+	/* set and verify setting the limit */
+	iowrite64(limit, mmio + limit_reg);
+	reg_val = ioread64(mmio + limit_reg);
+	if (reg_val != limit) {
+		iowrite64(base, mmio + limit_reg);
+		iowrite64(0, mmio + xlat_reg);
+		return -EIO;
+	}
+
+	dev_dbg(&ntb->pdev->dev, "BAR %d IMXLMT: %#Lx\n", bar, reg_val);
+
+	if (ndev->hwerr_flags & NTB_HWERR_BAR_ALIGN) {
+		idx_reg = ndev->xlat_reg->bar2_idx + (idx * 0x2);
+		iowrite16(base_idx, mmio + idx_reg);
+		reg_val16 = ioread16(mmio + idx_reg);
+		if (reg_val16 != base_idx) {
+			iowrite64(base, mmio + limit_reg);
+			iowrite64(0, mmio + xlat_reg);
+			iowrite16(0, mmio + idx_reg);
+			return -EIO;
+		}
+		dev_dbg(&ntb->pdev->dev, "BAR %d IMBASEIDX: %#x\n", bar, reg_val16);
+	}
+
+
+	return 0;
+}
+
+static int intel_ntb4_link_enable(struct ntb_dev *ntb,
+		enum ntb_speed max_speed, enum ntb_width max_width)
+{
+	struct intel_ntb_dev *ndev;
+	struct pci_dev *pdev;
+	u32 ntb_ctl, ppd0;
+	u16 lnkctl;
+
+	ndev = container_of(ntb, struct intel_ntb_dev, ntb);
+	pdev = ntb->pdev;
+
+	dev_dbg(&ntb->pdev->dev,
+			"Enabling link with max_speed %d max_width %d\n",
+			max_speed, max_width);
+
+	if (max_speed != NTB_SPEED_AUTO)
+		dev_dbg(&ntb->pdev->dev,
+				"ignoring max_speed %d\n", max_speed);
+	if (max_width != NTB_WIDTH_AUTO)
+		dev_dbg(&ntb->pdev->dev,
+				"ignoring max_width %d\n", max_width);
+
+	if (!(ndev->hwerr_flags & NTB_HWERR_LTR_BAD)) {
+		u32 ltr;
+
+		/* Setup active snoop LTR values */
+		ltr = NTB_LTR_ACTIVE_REQMNT | NTB_LTR_ACTIVE_VAL | NTB_LTR_ACTIVE_LATSCALE;
+		/* Setup active non-snoop values */
+		ltr = (ltr << NTB_LTR_NS_SHIFT) | ltr;
+		iowrite32(ltr, ndev->self_mmio + GEN4_LTR_ACTIVE_OFFSET);
+
+		/* Setup idle snoop LTR values */
+		ltr = NTB_LTR_IDLE_VAL | NTB_LTR_IDLE_LATSCALE | NTB_LTR_IDLE_REQMNT;
+		/* Setup idle non-snoop values */
+		ltr = (ltr << NTB_LTR_NS_SHIFT) | ltr;
+		iowrite32(ltr, ndev->self_mmio + GEN4_LTR_IDLE_OFFSET);
+
+		/* setup PCIe LTR to active */
+		iowrite8(NTB_LTR_SWSEL_ACTIVE, ndev->self_mmio + GEN4_LTR_SWSEL_OFFSET);
+	}
+
+	ntb_ctl = NTB_CTL_E2I_BAR23_SNOOP | NTB_CTL_I2E_BAR23_SNOOP;
+	ntb_ctl |= NTB_CTL_E2I_BAR45_SNOOP | NTB_CTL_I2E_BAR45_SNOOP;
+	iowrite32(ntb_ctl, ndev->self_mmio + ndev->reg->ntb_ctl);
+
+	lnkctl = ioread16(ndev->self_mmio + GEN4_LINK_CTRL_OFFSET);
+	lnkctl &= ~GEN4_LINK_CTRL_LINK_DISABLE;
+	iowrite16(lnkctl, ndev->self_mmio + GEN4_LINK_CTRL_OFFSET);
+
+	/* start link training in PPD0 */
+	ppd0 = ioread32(ndev->self_mmio + get_ppd0(pdev));
+	ppd0 |= GEN4_PPD_LINKTRN;
+	iowrite32(ppd0, ndev->self_mmio + get_ppd0(pdev));
+
+	/* make sure link training has started */
+	ppd0 = ioread32(ndev->self_mmio + get_ppd0(pdev));
+	if (!(ppd0 & GEN4_PPD_LINKTRN)) {
+		dev_warn(&ntb->pdev->dev, "Link is not training\n");
+		return -ENXIO;
+	}
+
+	ndev->dev_up = 1;
+
+	return 0;
+}
+
+static int intel_ntb4_link_disable(struct ntb_dev *ntb)
+{
+	struct intel_ntb_dev *ndev;
+	u32 ntb_cntl;
+	u16 lnkctl;
+
+	ndev = container_of(ntb, struct intel_ntb_dev, ntb);
+
+	dev_dbg(&ntb->pdev->dev, "Disabling link\n");
+
+	/* clear the snoop bits */
+	ntb_cntl = ioread32(ndev->self_mmio + ndev->reg->ntb_ctl);
+	ntb_cntl &= ~(NTB_CTL_E2I_BAR23_SNOOP | NTB_CTL_I2E_BAR23_SNOOP);
+	ntb_cntl &= ~(NTB_CTL_E2I_BAR45_SNOOP | NTB_CTL_I2E_BAR45_SNOOP);
+	iowrite32(ntb_cntl, ndev->self_mmio + ndev->reg->ntb_ctl);
+
+	lnkctl = ioread16(ndev->self_mmio + GEN4_LINK_CTRL_OFFSET);
+	lnkctl |= GEN4_LINK_CTRL_LINK_DISABLE;
+	iowrite16(lnkctl, ndev->self_mmio + GEN4_LINK_CTRL_OFFSET);
+
+	/* set LTR to idle */
+	if (!(ndev->hwerr_flags & NTB_HWERR_LTR_BAD))
+		iowrite8(NTB_LTR_SWSEL_IDLE, ndev->self_mmio + GEN4_LTR_SWSEL_OFFSET);
+
+	ndev->dev_up = 0;
+
+	return 0;
+}
+
+static int intel_ntb4_mw_get_align(struct ntb_dev *ntb, int pidx, int idx,
+				   resource_size_t *addr_align,
+				   resource_size_t *size_align,
+				   resource_size_t *size_max)
+{
+	struct intel_ntb_dev *ndev = ntb_ndev(ntb);
+	resource_size_t bar_size, mw_size;
+	int bar;
+
+	if (pidx != NTB_DEF_PEER_IDX)
+		return -EINVAL;
+
+	if (idx >= ndev->b2b_idx && !ndev->b2b_off)
+		idx += 1;
+
+	bar = ndev_mw_to_bar(ndev, idx);
+	if (bar < 0)
+		return bar;
+
+	bar_size = pci_resource_len(ndev->ntb.pdev, bar);
+
+	if (idx == ndev->b2b_idx)
+		mw_size = bar_size - ndev->b2b_off;
+	else
+		mw_size = bar_size;
+
+	if (addr_align) {
+		if (ndev->hwerr_flags & NTB_HWERR_BAR_ALIGN)
+			*addr_align = pci_resource_len(ndev->ntb.pdev, bar);
+		else
+			*addr_align = PAGE_SIZE;
+	}
+
+	if (size_align)
+		*size_align = 1;
+
+	if (size_max)
+		*size_max = mw_size;
+
+	return 0;
+}
+
+const struct ntb_dev_ops intel_ntb4_ops = {
+	.mw_count		= intel_ntb_mw_count,
+	.mw_get_align		= intel_ntb4_mw_get_align,
+	.mw_set_trans		= intel_ntb4_mw_set_trans,
+	.peer_mw_count		= intel_ntb_peer_mw_count,
+	.peer_mw_get_addr	= intel_ntb_peer_mw_get_addr,
+	.link_is_up		= intel_ntb_link_is_up,
+	.link_enable		= intel_ntb4_link_enable,
+	.link_disable		= intel_ntb4_link_disable,
+	.db_valid_mask		= intel_ntb_db_valid_mask,
+	.db_vector_count	= intel_ntb_db_vector_count,
+	.db_vector_mask		= intel_ntb_db_vector_mask,
+	.db_read		= intel_ntb3_db_read,
+	.db_clear		= intel_ntb3_db_clear,
+	.db_set_mask		= intel_ntb_db_set_mask,
+	.db_clear_mask		= intel_ntb_db_clear_mask,
+	.peer_db_addr		= intel_ntb3_peer_db_addr,
+	.peer_db_set		= intel_ntb3_peer_db_set,
+	.spad_is_unsafe		= intel_ntb_spad_is_unsafe,
+	.spad_count		= intel_ntb_spad_count,
+	.spad_read		= intel_ntb_spad_read,
+	.spad_write		= intel_ntb_spad_write,
+	.peer_spad_addr		= intel_ntb_peer_spad_addr,
+	.peer_spad_read		= intel_ntb_peer_spad_read,
+	.peer_spad_write	= intel_ntb_peer_spad_write,
+};
+
diff --git a/drivers/ntb/hw/intel/ntb_hw_gen4.h b/drivers/ntb/hw/intel/ntb_hw_gen4.h
new file mode 100644
index 000000000..1ba8203d6
--- /dev/null
+++ b/drivers/ntb/hw/intel/ntb_hw_gen4.h
@@ -0,0 +1,133 @@
+/* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)          */
+/* Copyright(c) 2020 Intel Corporation. All rights reserved.   */
+#ifndef _NTB_INTEL_GEN4_H_
+#define _NTB_INTEL_GEN4_H_
+
+#include "ntb_hw_intel.h"
+
+/* Supported PCI device revision range for ICX */
+#define PCI_DEVICE_REVISION_ICX_MIN	0x2
+#define PCI_DEVICE_REVISION_ICX_MAX	0xF
+
+/* Intel Gen4 NTB hardware */
+/* PCIe config space */
+#define GEN4_IMBAR23SZ_OFFSET		0x00c4
+#define GEN4_IMBAR45SZ_OFFSET		0x00c5
+#define GEN4_EMBAR23SZ_OFFSET		0x00c6
+#define GEN4_EMBAR45SZ_OFFSET		0x00c7
+#define GEN4_DEVCTRL_OFFSET		0x0048
+#define GEN4_DEVSTS_OFFSET		0x004a
+#define GEN4_UNCERRSTS_OFFSET		0x0104
+#define GEN4_CORERRSTS_OFFSET		0x0110
+
+/* BAR0 MMIO */
+#define GEN4_NTBCNTL_OFFSET		0x0000
+#define GEN4_IM23XBASE_OFFSET		0x0010	/* IMBAR1XBASE */
+#define GEN4_IM23XLMT_OFFSET		0x0018  /* IMBAR1XLMT */
+#define GEN4_IM45XBASE_OFFSET		0x0020	/* IMBAR2XBASE */
+#define GEN4_IM45XLMT_OFFSET		0x0028  /* IMBAR2XLMT */
+#define GEN4_IM_INT_STATUS_OFFSET	0x0040
+#define GEN4_IM_INT_DISABLE_OFFSET	0x0048
+#define GEN4_INTVEC_OFFSET		0x0050  /* 0-32 vecs */
+#define GEN4_IM23XBASEIDX_OFFSET	0x0074
+#define GEN4_IM45XBASEIDX_OFFSET	0x0076
+#define GEN4_IM_SPAD_OFFSET		0x0080  /* 0-15 SPADs */
+#define GEN4_IM_SPAD_SEM_OFFSET		0x00c0	/* SPAD hw semaphore */
+#define GEN4_IM_SPAD_STICKY_OFFSET	0x00c4  /* sticky SPAD */
+#define GEN4_IM_DOORBELL_OFFSET		0x0100  /* 0-31 doorbells */
+#define GEN4_LTR_SWSEL_OFFSET		0x30ec
+#define GEN4_LTR_ACTIVE_OFFSET		0x30f0
+#define GEN4_LTR_IDLE_OFFSET		0x30f4
+#define GEN4_EM_SPAD_OFFSET		0x8080
+/* note, link status is now in MMIO and not config space for NTB */
+#define GEN4_LINK_CTRL_OFFSET		0xb050
+#define GEN4_LINK_STATUS_OFFSET		0xb052
+#define GEN4_PPD0_OFFSET		0xb0d4
+#define GEN4_PPD1_OFFSET		0xb4c0
+#define GEN4_LTSSMSTATEJMP		0xf040
+
+#define GEN4_PPD_CLEAR_TRN		0x0001
+#define GEN4_PPD_LINKTRN		0x0008
+#define GEN4_PPD_CONN_MASK		0x0300
+#define SPR_PPD_CONN_MASK		0x0700
+#define GEN4_PPD_CONN_B2B		0x0200
+#define GEN4_PPD_DEV_MASK		0x1000
+#define GEN4_PPD_DEV_DSD		0x1000
+#define GEN4_PPD_DEV_USD		0x0000
+#define SPR_PPD_DEV_MASK		0x4000
+#define SPR_PPD_DEV_DSD 		0x4000
+#define SPR_PPD_DEV_USD 		0x0000
+#define GEN4_LINK_CTRL_LINK_DISABLE	0x0010
+
+#define GEN4_SLOTSTS			0xb05a
+#define GEN4_SLOTSTS_DLLSCS		0x100
+
+#define GEN4_PPD_TOPO_MASK	(GEN4_PPD_CONN_MASK | GEN4_PPD_DEV_MASK)
+#define GEN4_PPD_TOPO_B2B_USD	(GEN4_PPD_CONN_B2B | GEN4_PPD_DEV_USD)
+#define GEN4_PPD_TOPO_B2B_DSD	(GEN4_PPD_CONN_B2B | GEN4_PPD_DEV_DSD)
+
+#define SPR_PPD_TOPO_MASK	(SPR_PPD_CONN_MASK | SPR_PPD_DEV_MASK)
+#define SPR_PPD_TOPO_B2B_USD	(GEN4_PPD_CONN_B2B | SPR_PPD_DEV_USD)
+#define SPR_PPD_TOPO_B2B_DSD	(GEN4_PPD_CONN_B2B | SPR_PPD_DEV_DSD)
+
+#define GEN4_DB_COUNT			32
+#define GEN4_DB_LINK			32
+#define GEN4_DB_LINK_BIT		BIT_ULL(GEN4_DB_LINK)
+#define GEN4_DB_MSIX_VECTOR_COUNT	33
+#define GEN4_DB_MSIX_VECTOR_SHIFT	1
+#define GEN4_DB_TOTAL_SHIFT		33
+#define GEN4_SPAD_COUNT			16
+
+#define NTB_CTL_E2I_BAR23_SNOOP		0x000004
+#define NTB_CTL_E2I_BAR23_NOSNOOP	0x000008
+#define NTB_CTL_I2E_BAR23_SNOOP		0x000010
+#define NTB_CTL_I2E_BAR23_NOSNOOP	0x000020
+#define NTB_CTL_E2I_BAR45_SNOOP		0x000040
+#define NTB_CTL_E2I_BAR45_NOSNOO	0x000080
+#define NTB_CTL_I2E_BAR45_SNOOP		0x000100
+#define NTB_CTL_I2E_BAR45_NOSNOOP	0x000200
+#define NTB_CTL_BUSNO_DIS_INC		0x000400
+#define NTB_CTL_LINK_DOWN		0x010000
+
+#define NTB_SJC_FORCEDETECT		0x000004
+
+#define NTB_LTR_SWSEL_ACTIVE		0x0
+#define NTB_LTR_SWSEL_IDLE		0x1
+
+#define NTB_LTR_NS_SHIFT		16
+#define NTB_LTR_ACTIVE_VAL		0x0000  /* 0 us */
+#define NTB_LTR_ACTIVE_LATSCALE		0x0800  /* 1us scale */
+#define NTB_LTR_ACTIVE_REQMNT		0x8000  /* snoop req enable */
+
+#define NTB_LTR_IDLE_VAL		0x0258  /* 600 us */
+#define NTB_LTR_IDLE_LATSCALE		0x0800  /* 1us scale */
+#define NTB_LTR_IDLE_REQMNT		0x8000  /* snoop req enable */
+
+#define GEN6_PPD0_OFFSET		0xf0d4
+
+ssize_t ndev_ntb4_debugfs_read(struct file *filp, char __user *ubuf,
+				      size_t count, loff_t *offp);
+int gen4_init_dev(struct intel_ntb_dev *ndev);
+ssize_t ndev_ntb4_debugfs_read(struct file *filp, char __user *ubuf,
+				      size_t count, loff_t *offp);
+
+extern const struct ntb_dev_ops intel_ntb4_ops;
+
+static inline int pdev_is_ICX(struct pci_dev *pdev)
+{
+	if (pdev_is_gen4(pdev) &&
+	    pdev->revision >= PCI_DEVICE_REVISION_ICX_MIN &&
+	    pdev->revision <= PCI_DEVICE_REVISION_ICX_MAX)
+		return 1;
+	return 0;
+}
+
+static inline int pdev_is_SPR(struct pci_dev *pdev)
+{
+	if (pdev_is_gen4(pdev) &&
+	    pdev->revision > PCI_DEVICE_REVISION_ICX_MAX)
+		return 1;
+	return 0;
+}
+
+#endif
diff --git a/drivers/ntb/hw/intel/ntb_hw_intel.h b/drivers/ntb/hw/intel/ntb_hw_intel.h
new file mode 100644
index 000000000..0a3a3677f
--- /dev/null
+++ b/drivers/ntb/hw/intel/ntb_hw_intel.h
@@ -0,0 +1,244 @@
+/*
+ * This file is provided under a dual BSD/GPLv2 license.  When using or
+ *   redistributing this file, you may do so under either license.
+ *
+ *   GPL LICENSE SUMMARY
+ *
+ *   Copyright(c) 2012 Intel Corporation. All rights reserved.
+ *   Copyright (C) 2015 EMC Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of version 2 of the GNU General Public License as
+ *   published by the Free Software Foundation.
+ *
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2012 Intel Corporation. All rights reserved.
+ *   Copyright (C) 2015 EMC Corporation. All Rights Reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copy
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Intel PCIe NTB Linux driver
+ */
+
+#ifndef NTB_HW_INTEL_H
+#define NTB_HW_INTEL_H
+
+#include <linux/ntb.h>
+#include <linux/pci.h>
+#include <linux/io-64-nonatomic-lo-hi.h>
+
+/* PCI device IDs */
+#define PCI_DEVICE_ID_INTEL_NTB_B2B_JSF	0x3725
+#define PCI_DEVICE_ID_INTEL_NTB_PS_JSF	0x3726
+#define PCI_DEVICE_ID_INTEL_NTB_SS_JSF	0x3727
+#define PCI_DEVICE_ID_INTEL_NTB_B2B_SNB	0x3C0D
+#define PCI_DEVICE_ID_INTEL_NTB_PS_SNB	0x3C0E
+#define PCI_DEVICE_ID_INTEL_NTB_SS_SNB	0x3C0F
+#define PCI_DEVICE_ID_INTEL_NTB_B2B_IVT	0x0E0D
+#define PCI_DEVICE_ID_INTEL_NTB_PS_IVT	0x0E0E
+#define PCI_DEVICE_ID_INTEL_NTB_SS_IVT	0x0E0F
+#define PCI_DEVICE_ID_INTEL_NTB_B2B_HSX	0x2F0D
+#define PCI_DEVICE_ID_INTEL_NTB_PS_HSX	0x2F0E
+#define PCI_DEVICE_ID_INTEL_NTB_SS_HSX	0x2F0F
+#define PCI_DEVICE_ID_INTEL_NTB_B2B_BDX	0x6F0D
+#define PCI_DEVICE_ID_INTEL_NTB_PS_BDX	0x6F0E
+#define PCI_DEVICE_ID_INTEL_NTB_SS_BDX	0x6F0F
+#define PCI_DEVICE_ID_INTEL_NTB_B2B_SKX	0x201C
+#define PCI_DEVICE_ID_INTEL_NTB_B2B_ICX	0x347e
+#define PCI_DEVICE_ID_INTEL_NTB_B2B_GNR	0x0db4
+#define PCI_DEVICE_ID_INTEL_NTB_B2B_DMR	0x7868
+
+/* Ntb control and link status */
+#define NTB_CTL_CFG_LOCK		BIT(0)
+#define NTB_CTL_DISABLE			BIT(1)
+#define NTB_CTL_S2P_BAR2_SNOOP		BIT(2)
+#define NTB_CTL_P2S_BAR2_SNOOP		BIT(4)
+#define NTB_CTL_S2P_BAR4_SNOOP		BIT(6)
+#define NTB_CTL_P2S_BAR4_SNOOP		BIT(8)
+#define NTB_CTL_S2P_BAR5_SNOOP		BIT(12)
+#define NTB_CTL_P2S_BAR5_SNOOP		BIT(14)
+
+#define NTB_LNK_STA_ACTIVE_BIT		0x2000
+#define NTB_LNK_STA_SPEED_MASK		0x000f
+#define NTB_LNK_STA_WIDTH_MASK		0x03f0
+#define NTB_LNK_STA_ACTIVE(x)		(!!((x) & NTB_LNK_STA_ACTIVE_BIT))
+#define NTB_LNK_STA_SPEED(x)		((x) & NTB_LNK_STA_SPEED_MASK)
+#define NTB_LNK_STA_WIDTH(x)		(((x) & NTB_LNK_STA_WIDTH_MASK) >> 4)
+
+/* flags to indicate unsafe api */
+#define NTB_UNSAFE_DB			BIT_ULL(0)
+#define NTB_UNSAFE_SPAD			BIT_ULL(1)
+
+#define NTB_BAR_MASK_64			~(0xfull)
+#define NTB_BAR_MASK_32			~(0xfu)
+
+struct intel_ntb_dev;
+
+struct intel_ntb_reg {
+	int (*poll_link)(struct intel_ntb_dev *ndev);
+	int (*link_is_up)(struct intel_ntb_dev *ndev);
+	u64 (*db_ioread)(const void __iomem *mmio);
+	void (*db_iowrite)(u64 db_bits, void __iomem *mmio);
+	unsigned long			ntb_ctl;
+	resource_size_t			db_size;
+	int				mw_bar[];
+};
+
+struct intel_ntb_alt_reg {
+	unsigned long			db_bell;
+	unsigned long			db_mask;
+	unsigned long			db_clear;
+	unsigned long			spad;
+};
+
+struct intel_ntb_xlat_reg {
+	unsigned long			bar0_base;
+	unsigned long			bar2_xlat;
+	unsigned long			bar2_limit;
+	unsigned short			bar2_idx;
+};
+
+struct intel_b2b_addr {
+	phys_addr_t			bar0_addr;
+	phys_addr_t			bar2_addr64;
+	phys_addr_t			bar4_addr64;
+	phys_addr_t			bar4_addr32;
+	phys_addr_t			bar5_addr32;
+};
+
+struct intel_ntb_vec {
+	struct intel_ntb_dev		*ndev;
+	int				num;
+};
+
+struct intel_ntb_dev {
+	struct ntb_dev			ntb;
+
+	/* offset of peer bar0 in b2b bar */
+	unsigned long			b2b_off;
+	/* mw idx used to access peer bar0 */
+	unsigned int			b2b_idx;
+
+	/* BAR45 is split into BAR4 and BAR5 */
+	bool				bar4_split;
+
+	u32				ntb_ctl;
+	u32				lnk_sta;
+
+	unsigned char			mw_count;
+	unsigned char			spad_count;
+	unsigned char			db_count;
+	unsigned char			db_vec_count;
+	unsigned char			db_vec_shift;
+
+	u64				db_valid_mask;
+	u64				db_link_mask;
+	u64				db_mask;
+
+	/* synchronize rmw access of db_mask and hw reg */
+	spinlock_t			db_mask_lock;
+
+	struct msix_entry		*msix;
+	struct intel_ntb_vec		*vec;
+
+	const struct intel_ntb_reg	*reg;
+	const struct intel_ntb_alt_reg	*self_reg;
+	const struct intel_ntb_alt_reg	*peer_reg;
+	const struct intel_ntb_xlat_reg	*xlat_reg;
+	void				__iomem *self_mmio;
+	void				__iomem *peer_mmio;
+	phys_addr_t			peer_addr;
+
+	unsigned long			last_ts;
+	struct delayed_work		hb_timer;
+
+	unsigned long			hwerr_flags;
+	unsigned long			unsafe_flags;
+	unsigned long			unsafe_flags_ignore;
+
+	struct dentry			*debugfs_dir;
+	struct dentry			*debugfs_info;
+
+	/* gen4 entries */
+	int				dev_up;
+};
+
+#define ntb_ndev(__ntb) container_of(__ntb, struct intel_ntb_dev, ntb)
+#define hb_ndev(__work) container_of(__work, struct intel_ntb_dev, \
+				     hb_timer.work)
+
+static inline int pdev_is_gen1(struct pci_dev *pdev)
+{
+	switch (pdev->device) {
+	case PCI_DEVICE_ID_INTEL_NTB_SS_JSF:
+	case PCI_DEVICE_ID_INTEL_NTB_SS_SNB:
+	case PCI_DEVICE_ID_INTEL_NTB_SS_IVT:
+	case PCI_DEVICE_ID_INTEL_NTB_SS_HSX:
+	case PCI_DEVICE_ID_INTEL_NTB_SS_BDX:
+	case PCI_DEVICE_ID_INTEL_NTB_PS_JSF:
+	case PCI_DEVICE_ID_INTEL_NTB_PS_SNB:
+	case PCI_DEVICE_ID_INTEL_NTB_PS_IVT:
+	case PCI_DEVICE_ID_INTEL_NTB_PS_HSX:
+	case PCI_DEVICE_ID_INTEL_NTB_PS_BDX:
+	case PCI_DEVICE_ID_INTEL_NTB_B2B_JSF:
+	case PCI_DEVICE_ID_INTEL_NTB_B2B_SNB:
+	case PCI_DEVICE_ID_INTEL_NTB_B2B_IVT:
+	case PCI_DEVICE_ID_INTEL_NTB_B2B_HSX:
+	case PCI_DEVICE_ID_INTEL_NTB_B2B_BDX:
+		return 1;
+	}
+	return 0;
+}
+
+static inline int pdev_is_gen3(struct pci_dev *pdev)
+{
+	if (pdev->device == PCI_DEVICE_ID_INTEL_NTB_B2B_SKX)
+		return 1;
+
+	return 0;
+}
+
+static inline int pdev_is_gen4(struct pci_dev *pdev)
+{
+	if (pdev->device == PCI_DEVICE_ID_INTEL_NTB_B2B_ICX)
+		return 1;
+
+	return 0;
+}
+
+static inline int pdev_is_gen5(struct pci_dev *pdev)
+{
+	return pdev->device == PCI_DEVICE_ID_INTEL_NTB_B2B_GNR;
+}
+
+static inline int pdev_is_gen6(struct pci_dev *pdev)
+{
+	return pdev->device == PCI_DEVICE_ID_INTEL_NTB_B2B_DMR;
+}
+
+#endif
diff --git a/drivers/ntb/hw/mscc/Kconfig b/drivers/ntb/hw/mscc/Kconfig
new file mode 100644
index 000000000..ea63bd829
--- /dev/null
+++ b/drivers/ntb/hw/mscc/Kconfig
@@ -0,0 +1,10 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config NTB_SWITCHTEC
+	tristate "MicroSemi Switchtec Non-Transparent Bridge Support"
+	select PCI_SW_SWITCHTEC
+	help
+	 Enables NTB support for Switchtec PCI switches. This also
+	 selects the Switchtec management driver as they share the same
+	 hardware interface.
+
+	 If unsure, say N.
diff --git a/drivers/ntb/hw/mscc/Makefile b/drivers/ntb/hw/mscc/Makefile
new file mode 100644
index 000000000..756a75abe
--- /dev/null
+++ b/drivers/ntb/hw/mscc/Makefile
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_NTB_SWITCHTEC) += ntb_hw_switchtec.o
diff --git a/drivers/ntb/hw/mscc/ntb_hw_switchtec.c b/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
new file mode 100644
index 000000000..e38540b92
--- /dev/null
+++ b/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
@@ -0,0 +1,1586 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Microsemi Switchtec(tm) PCIe Management Driver
+ * Copyright (c) 2017, Microsemi Corporation
+ */
+
+#include <linux/interrupt.h>
+#include <linux/io-64-nonatomic-lo-hi.h>
+#include <linux/delay.h>
+#include <linux/kthread.h>
+#include <linux/module.h>
+#include <linux/ntb.h>
+#include <linux/pci.h>
+#include <linux/switchtec.h>
+
+MODULE_DESCRIPTION("Microsemi Switchtec(tm) NTB Driver");
+MODULE_VERSION("0.1");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Microsemi Corporation");
+
+static ulong max_mw_size = SZ_2M;
+module_param(max_mw_size, ulong, 0644);
+MODULE_PARM_DESC(max_mw_size,
+	"Max memory window size reported to the upper layer");
+
+static bool use_lut_mws;
+module_param(use_lut_mws, bool, 0644);
+MODULE_PARM_DESC(use_lut_mws,
+		 "Enable the use of the LUT based memory windows");
+
+#define SWITCHTEC_NTB_MAGIC 0x45CC0001
+#define MAX_MWS     256
+
+struct shared_mw {
+	u32 magic;
+	u32 link_sta;
+	u32 partition_id;
+	u64 mw_sizes[MAX_MWS];
+	u32 spad[128];
+};
+
+#define MAX_DIRECT_MW ARRAY_SIZE(((struct ntb_ctrl_regs *)(0))->bar_entry)
+#define LUT_SIZE SZ_64K
+
+struct switchtec_ntb {
+	struct ntb_dev ntb;
+	struct switchtec_dev *stdev;
+
+	int self_partition;
+	int peer_partition;
+
+	int doorbell_irq;
+	int message_irq;
+
+	struct ntb_info_regs __iomem *mmio_ntb;
+	struct ntb_ctrl_regs __iomem *mmio_ctrl;
+	struct ntb_dbmsg_regs __iomem *mmio_dbmsg;
+	struct ntb_ctrl_regs __iomem *mmio_self_ctrl;
+	struct ntb_ctrl_regs __iomem *mmio_peer_ctrl;
+	struct ntb_dbmsg_regs __iomem *mmio_self_dbmsg;
+	struct ntb_dbmsg_regs __iomem *mmio_peer_dbmsg;
+
+	void __iomem *mmio_xlink_win;
+
+	struct shared_mw *self_shared;
+	struct shared_mw __iomem *peer_shared;
+	dma_addr_t self_shared_dma;
+
+	u64 db_mask;
+	u64 db_valid_mask;
+	int db_shift;
+	int db_peer_shift;
+
+	/* synchronize rmw access of db_mask and hw reg */
+	spinlock_t db_mask_lock;
+
+	int nr_direct_mw;
+	int nr_lut_mw;
+	int nr_rsvd_luts;
+	int direct_mw_to_bar[MAX_DIRECT_MW];
+
+	int peer_nr_direct_mw;
+	int peer_nr_lut_mw;
+	int peer_direct_mw_to_bar[MAX_DIRECT_MW];
+
+	bool link_is_up;
+	enum ntb_speed link_speed;
+	enum ntb_width link_width;
+	struct work_struct check_link_status_work;
+	bool link_force_down;
+};
+
+static struct switchtec_ntb *ntb_sndev(struct ntb_dev *ntb)
+{
+	return container_of(ntb, struct switchtec_ntb, ntb);
+}
+
+static int switchtec_ntb_part_op(struct switchtec_ntb *sndev,
+				 struct ntb_ctrl_regs __iomem *ctl,
+				 u32 op, int wait_status)
+{
+	static const char * const op_text[] = {
+		[NTB_CTRL_PART_OP_LOCK] = "lock",
+		[NTB_CTRL_PART_OP_CFG] = "configure",
+		[NTB_CTRL_PART_OP_RESET] = "reset",
+	};
+
+	int i;
+	u32 ps;
+	int status;
+
+	switch (op) {
+	case NTB_CTRL_PART_OP_LOCK:
+		status = NTB_CTRL_PART_STATUS_LOCKING;
+		break;
+	case NTB_CTRL_PART_OP_CFG:
+		status = NTB_CTRL_PART_STATUS_CONFIGURING;
+		break;
+	case NTB_CTRL_PART_OP_RESET:
+		status = NTB_CTRL_PART_STATUS_RESETTING;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	iowrite32(op, &ctl->partition_op);
+
+	for (i = 0; i < 1000; i++) {
+		if (msleep_interruptible(50) != 0) {
+			iowrite32(NTB_CTRL_PART_OP_RESET, &ctl->partition_op);
+			return -EINTR;
+		}
+
+		ps = ioread32(&ctl->partition_status) & 0xFFFF;
+
+		if (ps != status)
+			break;
+	}
+
+	if (ps == wait_status)
+		return 0;
+
+	if (ps == status) {
+		dev_err(&sndev->stdev->dev,
+			"Timed out while performing %s (%d). (%08x)\n",
+			op_text[op], op,
+			ioread32(&ctl->partition_status));
+
+		return -ETIMEDOUT;
+	}
+
+	return -EIO;
+}
+
+static int switchtec_ntb_send_msg(struct switchtec_ntb *sndev, int idx,
+				  u32 val)
+{
+	if (idx < 0 || idx >= ARRAY_SIZE(sndev->mmio_peer_dbmsg->omsg))
+		return -EINVAL;
+
+	iowrite32(val, &sndev->mmio_peer_dbmsg->omsg[idx].msg);
+
+	return 0;
+}
+
+static int switchtec_ntb_mw_count(struct ntb_dev *ntb, int pidx)
+{
+	struct switchtec_ntb *sndev = ntb_sndev(ntb);
+	int nr_direct_mw = sndev->peer_nr_direct_mw;
+	int nr_lut_mw = sndev->peer_nr_lut_mw - sndev->nr_rsvd_luts;
+
+	if (pidx != NTB_DEF_PEER_IDX)
+		return -EINVAL;
+
+	if (!use_lut_mws)
+		nr_lut_mw = 0;
+
+	return nr_direct_mw + nr_lut_mw;
+}
+
+static int lut_index(struct switchtec_ntb *sndev, int mw_idx)
+{
+	return mw_idx - sndev->nr_direct_mw + sndev->nr_rsvd_luts;
+}
+
+static int peer_lut_index(struct switchtec_ntb *sndev, int mw_idx)
+{
+	return mw_idx - sndev->peer_nr_direct_mw + sndev->nr_rsvd_luts;
+}
+
+static int switchtec_ntb_mw_get_align(struct ntb_dev *ntb, int pidx,
+				      int widx, resource_size_t *addr_align,
+				      resource_size_t *size_align,
+				      resource_size_t *size_max)
+{
+	struct switchtec_ntb *sndev = ntb_sndev(ntb);
+	int lut;
+	resource_size_t size;
+
+	if (pidx != NTB_DEF_PEER_IDX)
+		return -EINVAL;
+
+	lut = widx >= sndev->peer_nr_direct_mw;
+	size = ioread64(&sndev->peer_shared->mw_sizes[widx]);
+
+	if (size == 0)
+		return -EINVAL;
+
+	if (addr_align)
+		*addr_align = lut ? size : SZ_4K;
+
+	if (size_align)
+		*size_align = lut ? size : SZ_4K;
+
+	if (size_max)
+		*size_max = size;
+
+	return 0;
+}
+
+static void switchtec_ntb_mw_clr_direct(struct switchtec_ntb *sndev, int idx)
+{
+	struct ntb_ctrl_regs __iomem *ctl = sndev->mmio_peer_ctrl;
+	int bar = sndev->peer_direct_mw_to_bar[idx];
+	u32 ctl_val;
+
+	ctl_val = ioread32(&ctl->bar_entry[bar].ctl);
+	ctl_val &= ~NTB_CTRL_BAR_DIR_WIN_EN;
+	iowrite32(ctl_val, &ctl->bar_entry[bar].ctl);
+	iowrite32(0, &ctl->bar_entry[bar].win_size);
+	iowrite32(0, &ctl->bar_ext_entry[bar].win_size);
+	iowrite64(sndev->self_partition, &ctl->bar_entry[bar].xlate_addr);
+}
+
+static void switchtec_ntb_mw_clr_lut(struct switchtec_ntb *sndev, int idx)
+{
+	struct ntb_ctrl_regs __iomem *ctl = sndev->mmio_peer_ctrl;
+
+	iowrite64(0, &ctl->lut_entry[peer_lut_index(sndev, idx)]);
+}
+
+static void switchtec_ntb_mw_set_direct(struct switchtec_ntb *sndev, int idx,
+					dma_addr_t addr, resource_size_t size)
+{
+	int xlate_pos = ilog2(size);
+	int bar = sndev->peer_direct_mw_to_bar[idx];
+	struct ntb_ctrl_regs __iomem *ctl = sndev->mmio_peer_ctrl;
+	u32 ctl_val;
+
+	ctl_val = ioread32(&ctl->bar_entry[bar].ctl);
+	ctl_val |= NTB_CTRL_BAR_DIR_WIN_EN;
+
+	iowrite32(ctl_val, &ctl->bar_entry[bar].ctl);
+	iowrite32(xlate_pos | (lower_32_bits(size) & 0xFFFFF000),
+		  &ctl->bar_entry[bar].win_size);
+	iowrite32(upper_32_bits(size), &ctl->bar_ext_entry[bar].win_size);
+	iowrite64(sndev->self_partition | addr,
+		  &ctl->bar_entry[bar].xlate_addr);
+}
+
+static void switchtec_ntb_mw_set_lut(struct switchtec_ntb *sndev, int idx,
+				     dma_addr_t addr, resource_size_t size)
+{
+	struct ntb_ctrl_regs __iomem *ctl = sndev->mmio_peer_ctrl;
+
+	iowrite64((NTB_CTRL_LUT_EN | (sndev->self_partition << 1) | addr),
+		  &ctl->lut_entry[peer_lut_index(sndev, idx)]);
+}
+
+static int switchtec_ntb_mw_set_trans(struct ntb_dev *ntb, int pidx, int widx,
+				      dma_addr_t addr, resource_size_t size)
+{
+	struct switchtec_ntb *sndev = ntb_sndev(ntb);
+	struct ntb_ctrl_regs __iomem *ctl = sndev->mmio_peer_ctrl;
+	int xlate_pos = ilog2(size);
+	int nr_direct_mw = sndev->peer_nr_direct_mw;
+	int rc;
+
+	if (pidx != NTB_DEF_PEER_IDX)
+		return -EINVAL;
+
+	dev_dbg(&sndev->stdev->dev, "MW %d: part %d addr %pad size %pap\n",
+		widx, pidx, &addr, &size);
+
+	if (widx >= switchtec_ntb_mw_count(ntb, pidx))
+		return -EINVAL;
+
+	if (size != 0 && xlate_pos < 12)
+		return -EINVAL;
+
+	if (xlate_pos >= 0 && !IS_ALIGNED(addr, BIT_ULL(xlate_pos))) {
+		/*
+		 * In certain circumstances we can get a buffer that is
+		 * not aligned to its size. (Most of the time
+		 * dma_alloc_coherent ensures this). This can happen when
+		 * using large buffers allocated by the CMA
+		 * (see CMA_CONFIG_ALIGNMENT)
+		 */
+		dev_err(&sndev->stdev->dev,
+			"ERROR: Memory window address is not aligned to its size!\n");
+		return -EINVAL;
+	}
+
+	rc = switchtec_ntb_part_op(sndev, ctl, NTB_CTRL_PART_OP_LOCK,
+				   NTB_CTRL_PART_STATUS_LOCKED);
+	if (rc)
+		return rc;
+
+	if (size == 0) {
+		if (widx < nr_direct_mw)
+			switchtec_ntb_mw_clr_direct(sndev, widx);
+		else
+			switchtec_ntb_mw_clr_lut(sndev, widx);
+	} else {
+		if (widx < nr_direct_mw)
+			switchtec_ntb_mw_set_direct(sndev, widx, addr, size);
+		else
+			switchtec_ntb_mw_set_lut(sndev, widx, addr, size);
+	}
+
+	rc = switchtec_ntb_part_op(sndev, ctl, NTB_CTRL_PART_OP_CFG,
+				   NTB_CTRL_PART_STATUS_NORMAL);
+
+	if (rc == -EIO) {
+		dev_err(&sndev->stdev->dev,
+			"Hardware reported an error configuring mw %d: %08x\n",
+			widx, ioread32(&ctl->bar_error));
+
+		if (widx < nr_direct_mw)
+			switchtec_ntb_mw_clr_direct(sndev, widx);
+		else
+			switchtec_ntb_mw_clr_lut(sndev, widx);
+
+		switchtec_ntb_part_op(sndev, ctl, NTB_CTRL_PART_OP_CFG,
+				      NTB_CTRL_PART_STATUS_NORMAL);
+	}
+
+	return rc;
+}
+
+static int switchtec_ntb_peer_mw_count(struct ntb_dev *ntb)
+{
+	struct switchtec_ntb *sndev = ntb_sndev(ntb);
+	int nr_lut_mw = sndev->nr_lut_mw - sndev->nr_rsvd_luts;
+
+	return sndev->nr_direct_mw + (use_lut_mws ? nr_lut_mw : 0);
+}
+
+static int switchtec_ntb_direct_get_addr(struct switchtec_ntb *sndev,
+					 int idx, phys_addr_t *base,
+					 resource_size_t *size)
+{
+	int bar = sndev->direct_mw_to_bar[idx];
+	size_t offset = 0;
+
+	if (bar < 0)
+		return -EINVAL;
+
+	if (idx == 0) {
+		/*
+		 * This is the direct BAR shared with the LUTs
+		 * which means the actual window will be offset
+		 * by the size of all the LUT entries.
+		 */
+
+		offset = LUT_SIZE * sndev->nr_lut_mw;
+	}
+
+	if (base)
+		*base = pci_resource_start(sndev->ntb.pdev, bar) + offset;
+
+	if (size) {
+		*size = pci_resource_len(sndev->ntb.pdev, bar) - offset;
+		if (offset && *size > offset)
+			*size = offset;
+
+		if (*size > max_mw_size)
+			*size = max_mw_size;
+	}
+
+	return 0;
+}
+
+static int switchtec_ntb_lut_get_addr(struct switchtec_ntb *sndev,
+				      int idx, phys_addr_t *base,
+				      resource_size_t *size)
+{
+	int bar = sndev->direct_mw_to_bar[0];
+	int offset;
+
+	offset = LUT_SIZE * lut_index(sndev, idx);
+
+	if (base)
+		*base = pci_resource_start(sndev->ntb.pdev, bar) + offset;
+
+	if (size)
+		*size = LUT_SIZE;
+
+	return 0;
+}
+
+static int switchtec_ntb_peer_mw_get_addr(struct ntb_dev *ntb, int idx,
+					  phys_addr_t *base,
+					  resource_size_t *size)
+{
+	struct switchtec_ntb *sndev = ntb_sndev(ntb);
+
+	if (idx < sndev->nr_direct_mw)
+		return switchtec_ntb_direct_get_addr(sndev, idx, base, size);
+	else if (idx < switchtec_ntb_peer_mw_count(ntb))
+		return switchtec_ntb_lut_get_addr(sndev, idx, base, size);
+	else
+		return -EINVAL;
+}
+
+static void switchtec_ntb_part_link_speed(struct switchtec_ntb *sndev,
+					  int partition,
+					  enum ntb_speed *speed,
+					  enum ntb_width *width)
+{
+	struct switchtec_dev *stdev = sndev->stdev;
+	struct part_cfg_regs __iomem *part_cfg =
+		&stdev->mmio_part_cfg_all[partition];
+
+	u32 pff = ioread32(&part_cfg->vep_pff_inst_id) & 0xFF;
+	u32 linksta = ioread32(&stdev->mmio_pff_csr[pff].pci_cap_region[13]);
+
+	if (speed)
+		*speed = (linksta >> 16) & 0xF;
+
+	if (width)
+		*width = (linksta >> 20) & 0x3F;
+}
+
+static void switchtec_ntb_set_link_speed(struct switchtec_ntb *sndev)
+{
+	enum ntb_speed self_speed, peer_speed;
+	enum ntb_width self_width, peer_width;
+
+	if (!sndev->link_is_up) {
+		sndev->link_speed = NTB_SPEED_NONE;
+		sndev->link_width = NTB_WIDTH_NONE;
+		return;
+	}
+
+	switchtec_ntb_part_link_speed(sndev, sndev->self_partition,
+				      &self_speed, &self_width);
+	switchtec_ntb_part_link_speed(sndev, sndev->peer_partition,
+				      &peer_speed, &peer_width);
+
+	sndev->link_speed = min(self_speed, peer_speed);
+	sndev->link_width = min(self_width, peer_width);
+}
+
+static int crosslink_is_enabled(struct switchtec_ntb *sndev)
+{
+	struct ntb_info_regs __iomem *inf = sndev->mmio_ntb;
+
+	return ioread8(&inf->ntp_info[sndev->peer_partition].xlink_enabled);
+}
+
+static void crosslink_init_dbmsgs(struct switchtec_ntb *sndev)
+{
+	int i;
+	u32 msg_map = 0;
+
+	if (!crosslink_is_enabled(sndev))
+		return;
+
+	for (i = 0; i < ARRAY_SIZE(sndev->mmio_peer_dbmsg->imsg); i++) {
+		int m = i | sndev->self_partition << 2;
+
+		msg_map |= m << i * 8;
+	}
+
+	iowrite32(msg_map, &sndev->mmio_peer_dbmsg->msg_map);
+	iowrite64(sndev->db_valid_mask << sndev->db_peer_shift,
+		  &sndev->mmio_peer_dbmsg->odb_mask);
+}
+
+enum switchtec_msg {
+	LINK_MESSAGE = 0,
+	MSG_LINK_UP = 1,
+	MSG_LINK_DOWN = 2,
+	MSG_CHECK_LINK = 3,
+	MSG_LINK_FORCE_DOWN = 4,
+};
+
+static int switchtec_ntb_reinit_peer(struct switchtec_ntb *sndev);
+
+static void switchtec_ntb_link_status_update(struct switchtec_ntb *sndev)
+{
+	int link_sta;
+	int old = sndev->link_is_up;
+
+	link_sta = sndev->self_shared->link_sta;
+	if (link_sta) {
+		u64 peer = ioread64(&sndev->peer_shared->magic);
+
+		if ((peer & 0xFFFFFFFF) == SWITCHTEC_NTB_MAGIC)
+			link_sta = peer >> 32;
+		else
+			link_sta = 0;
+	}
+
+	sndev->link_is_up = link_sta;
+	switchtec_ntb_set_link_speed(sndev);
+
+	if (link_sta != old) {
+		switchtec_ntb_send_msg(sndev, LINK_MESSAGE, MSG_CHECK_LINK);
+		ntb_link_event(&sndev->ntb);
+		dev_info(&sndev->stdev->dev, "ntb link %s\n",
+			 link_sta ? "up" : "down");
+
+		if (link_sta)
+			crosslink_init_dbmsgs(sndev);
+	}
+}
+
+static void check_link_status_work(struct work_struct *work)
+{
+	struct switchtec_ntb *sndev;
+
+	sndev = container_of(work, struct switchtec_ntb,
+			     check_link_status_work);
+
+	if (sndev->link_force_down) {
+		sndev->link_force_down = false;
+		switchtec_ntb_reinit_peer(sndev);
+
+		if (sndev->link_is_up) {
+			sndev->link_is_up = 0;
+			ntb_link_event(&sndev->ntb);
+			dev_info(&sndev->stdev->dev, "ntb link forced down\n");
+		}
+
+		return;
+	}
+
+	switchtec_ntb_link_status_update(sndev);
+}
+
+static void switchtec_ntb_check_link(struct switchtec_ntb *sndev,
+				      enum switchtec_msg msg)
+{
+	if (msg == MSG_LINK_FORCE_DOWN)
+		sndev->link_force_down = true;
+
+	schedule_work(&sndev->check_link_status_work);
+}
+
+static void switchtec_ntb_link_notification(struct switchtec_dev *stdev)
+{
+	struct switchtec_ntb *sndev = stdev->sndev;
+
+	switchtec_ntb_check_link(sndev, MSG_CHECK_LINK);
+}
+
+static u64 switchtec_ntb_link_is_up(struct ntb_dev *ntb,
+				    enum ntb_speed *speed,
+				    enum ntb_width *width)
+{
+	struct switchtec_ntb *sndev = ntb_sndev(ntb);
+
+	if (speed)
+		*speed = sndev->link_speed;
+	if (width)
+		*width = sndev->link_width;
+
+	return sndev->link_is_up;
+}
+
+static int switchtec_ntb_link_enable(struct ntb_dev *ntb,
+				     enum ntb_speed max_speed,
+				     enum ntb_width max_width)
+{
+	struct switchtec_ntb *sndev = ntb_sndev(ntb);
+
+	dev_dbg(&sndev->stdev->dev, "enabling link\n");
+
+	sndev->self_shared->link_sta = 1;
+	switchtec_ntb_send_msg(sndev, LINK_MESSAGE, MSG_LINK_UP);
+
+	switchtec_ntb_link_status_update(sndev);
+
+	return 0;
+}
+
+static int switchtec_ntb_link_disable(struct ntb_dev *ntb)
+{
+	struct switchtec_ntb *sndev = ntb_sndev(ntb);
+
+	dev_dbg(&sndev->stdev->dev, "disabling link\n");
+
+	sndev->self_shared->link_sta = 0;
+	switchtec_ntb_send_msg(sndev, LINK_MESSAGE, MSG_LINK_DOWN);
+
+	switchtec_ntb_link_status_update(sndev);
+
+	return 0;
+}
+
+static u64 switchtec_ntb_db_valid_mask(struct ntb_dev *ntb)
+{
+	struct switchtec_ntb *sndev = ntb_sndev(ntb);
+
+	return sndev->db_valid_mask;
+}
+
+static int switchtec_ntb_db_vector_count(struct ntb_dev *ntb)
+{
+	return 1;
+}
+
+static u64 switchtec_ntb_db_vector_mask(struct ntb_dev *ntb, int db_vector)
+{
+	struct switchtec_ntb *sndev = ntb_sndev(ntb);
+
+	if (db_vector < 0 || db_vector > 1)
+		return 0;
+
+	return sndev->db_valid_mask;
+}
+
+static u64 switchtec_ntb_db_read(struct ntb_dev *ntb)
+{
+	u64 ret;
+	struct switchtec_ntb *sndev = ntb_sndev(ntb);
+
+	ret = ioread64(&sndev->mmio_self_dbmsg->idb) >> sndev->db_shift;
+
+	return ret & sndev->db_valid_mask;
+}
+
+static int switchtec_ntb_db_clear(struct ntb_dev *ntb, u64 db_bits)
+{
+	struct switchtec_ntb *sndev = ntb_sndev(ntb);
+
+	iowrite64(db_bits << sndev->db_shift, &sndev->mmio_self_dbmsg->idb);
+
+	return 0;
+}
+
+static int switchtec_ntb_db_set_mask(struct ntb_dev *ntb, u64 db_bits)
+{
+	unsigned long irqflags;
+	struct switchtec_ntb *sndev = ntb_sndev(ntb);
+
+	if (db_bits & ~sndev->db_valid_mask)
+		return -EINVAL;
+
+	spin_lock_irqsave(&sndev->db_mask_lock, irqflags);
+
+	sndev->db_mask |= db_bits << sndev->db_shift;
+	iowrite64(~sndev->db_mask, &sndev->mmio_self_dbmsg->idb_mask);
+
+	spin_unlock_irqrestore(&sndev->db_mask_lock, irqflags);
+
+	return 0;
+}
+
+static int switchtec_ntb_db_clear_mask(struct ntb_dev *ntb, u64 db_bits)
+{
+	unsigned long irqflags;
+	struct switchtec_ntb *sndev = ntb_sndev(ntb);
+
+	if (db_bits & ~sndev->db_valid_mask)
+		return -EINVAL;
+
+	spin_lock_irqsave(&sndev->db_mask_lock, irqflags);
+
+	sndev->db_mask &= ~(db_bits << sndev->db_shift);
+	iowrite64(~sndev->db_mask, &sndev->mmio_self_dbmsg->idb_mask);
+
+	spin_unlock_irqrestore(&sndev->db_mask_lock, irqflags);
+
+	return 0;
+}
+
+static u64 switchtec_ntb_db_read_mask(struct ntb_dev *ntb)
+{
+	struct switchtec_ntb *sndev = ntb_sndev(ntb);
+
+	return (sndev->db_mask >> sndev->db_shift) & sndev->db_valid_mask;
+}
+
+static int switchtec_ntb_peer_db_addr(struct ntb_dev *ntb,
+				      phys_addr_t *db_addr,
+				      resource_size_t *db_size,
+				      u64 *db_data,
+				      int db_bit)
+{
+	struct switchtec_ntb *sndev = ntb_sndev(ntb);
+	unsigned long offset;
+
+	if (unlikely(db_bit >= BITS_PER_LONG_LONG))
+		return -EINVAL;
+
+	offset = (unsigned long)sndev->mmio_peer_dbmsg->odb -
+		(unsigned long)sndev->stdev->mmio;
+
+	offset += sndev->db_shift / 8;
+
+	if (db_addr)
+		*db_addr = pci_resource_start(ntb->pdev, 0) + offset;
+	if (db_size)
+		*db_size = sizeof(u32);
+	if (db_data)
+		*db_data = BIT_ULL(db_bit) << sndev->db_peer_shift;
+
+	return 0;
+}
+
+static int switchtec_ntb_peer_db_set(struct ntb_dev *ntb, u64 db_bits)
+{
+	struct switchtec_ntb *sndev = ntb_sndev(ntb);
+
+	iowrite64(db_bits << sndev->db_peer_shift,
+		  &sndev->mmio_peer_dbmsg->odb);
+
+	return 0;
+}
+
+static int switchtec_ntb_spad_count(struct ntb_dev *ntb)
+{
+	struct switchtec_ntb *sndev = ntb_sndev(ntb);
+
+	return ARRAY_SIZE(sndev->self_shared->spad);
+}
+
+static u32 switchtec_ntb_spad_read(struct ntb_dev *ntb, int idx)
+{
+	struct switchtec_ntb *sndev = ntb_sndev(ntb);
+
+	if (idx < 0 || idx >= ARRAY_SIZE(sndev->self_shared->spad))
+		return 0;
+
+	if (!sndev->self_shared)
+		return 0;
+
+	return sndev->self_shared->spad[idx];
+}
+
+static int switchtec_ntb_spad_write(struct ntb_dev *ntb, int idx, u32 val)
+{
+	struct switchtec_ntb *sndev = ntb_sndev(ntb);
+
+	if (idx < 0 || idx >= ARRAY_SIZE(sndev->self_shared->spad))
+		return -EINVAL;
+
+	if (!sndev->self_shared)
+		return -EIO;
+
+	sndev->self_shared->spad[idx] = val;
+
+	return 0;
+}
+
+static u32 switchtec_ntb_peer_spad_read(struct ntb_dev *ntb, int pidx,
+					int sidx)
+{
+	struct switchtec_ntb *sndev = ntb_sndev(ntb);
+
+	if (pidx != NTB_DEF_PEER_IDX)
+		return -EINVAL;
+
+	if (sidx < 0 || sidx >= ARRAY_SIZE(sndev->peer_shared->spad))
+		return 0;
+
+	if (!sndev->peer_shared)
+		return 0;
+
+	return ioread32(&sndev->peer_shared->spad[sidx]);
+}
+
+static int switchtec_ntb_peer_spad_write(struct ntb_dev *ntb, int pidx,
+					 int sidx, u32 val)
+{
+	struct switchtec_ntb *sndev = ntb_sndev(ntb);
+
+	if (pidx != NTB_DEF_PEER_IDX)
+		return -EINVAL;
+
+	if (sidx < 0 || sidx >= ARRAY_SIZE(sndev->peer_shared->spad))
+		return -EINVAL;
+
+	if (!sndev->peer_shared)
+		return -EIO;
+
+	iowrite32(val, &sndev->peer_shared->spad[sidx]);
+
+	return 0;
+}
+
+static int switchtec_ntb_peer_spad_addr(struct ntb_dev *ntb, int pidx,
+					int sidx, phys_addr_t *spad_addr)
+{
+	struct switchtec_ntb *sndev = ntb_sndev(ntb);
+	unsigned long offset;
+
+	if (pidx != NTB_DEF_PEER_IDX)
+		return -EINVAL;
+
+	offset = (unsigned long)&sndev->peer_shared->spad[sidx] -
+		(unsigned long)sndev->stdev->mmio;
+
+	if (spad_addr)
+		*spad_addr = pci_resource_start(ntb->pdev, 0) + offset;
+
+	return 0;
+}
+
+static const struct ntb_dev_ops switchtec_ntb_ops = {
+	.mw_count		= switchtec_ntb_mw_count,
+	.mw_get_align		= switchtec_ntb_mw_get_align,
+	.mw_set_trans		= switchtec_ntb_mw_set_trans,
+	.peer_mw_count		= switchtec_ntb_peer_mw_count,
+	.peer_mw_get_addr	= switchtec_ntb_peer_mw_get_addr,
+	.link_is_up		= switchtec_ntb_link_is_up,
+	.link_enable		= switchtec_ntb_link_enable,
+	.link_disable		= switchtec_ntb_link_disable,
+	.db_valid_mask		= switchtec_ntb_db_valid_mask,
+	.db_vector_count	= switchtec_ntb_db_vector_count,
+	.db_vector_mask		= switchtec_ntb_db_vector_mask,
+	.db_read		= switchtec_ntb_db_read,
+	.db_clear		= switchtec_ntb_db_clear,
+	.db_set_mask		= switchtec_ntb_db_set_mask,
+	.db_clear_mask		= switchtec_ntb_db_clear_mask,
+	.db_read_mask		= switchtec_ntb_db_read_mask,
+	.peer_db_addr		= switchtec_ntb_peer_db_addr,
+	.peer_db_set		= switchtec_ntb_peer_db_set,
+	.spad_count		= switchtec_ntb_spad_count,
+	.spad_read		= switchtec_ntb_spad_read,
+	.spad_write		= switchtec_ntb_spad_write,
+	.peer_spad_read		= switchtec_ntb_peer_spad_read,
+	.peer_spad_write	= switchtec_ntb_peer_spad_write,
+	.peer_spad_addr		= switchtec_ntb_peer_spad_addr,
+};
+
+static int switchtec_ntb_init_sndev(struct switchtec_ntb *sndev)
+{
+	u64 tpart_vec;
+	int self;
+	u64 part_map;
+
+	sndev->ntb.pdev = sndev->stdev->pdev;
+	sndev->ntb.topo = NTB_TOPO_SWITCH;
+	sndev->ntb.ops = &switchtec_ntb_ops;
+
+	INIT_WORK(&sndev->check_link_status_work, check_link_status_work);
+	sndev->link_force_down = false;
+
+	sndev->self_partition = sndev->stdev->partition;
+
+	sndev->mmio_ntb = sndev->stdev->mmio_ntb;
+
+	self = sndev->self_partition;
+	tpart_vec = ioread32(&sndev->mmio_ntb->ntp_info[self].target_part_high);
+	tpart_vec <<= 32;
+	tpart_vec |= ioread32(&sndev->mmio_ntb->ntp_info[self].target_part_low);
+
+	part_map = ioread64(&sndev->mmio_ntb->ep_map);
+	tpart_vec &= part_map;
+	part_map &= ~(1 << sndev->self_partition);
+
+	if (!tpart_vec) {
+		if (sndev->stdev->partition_count != 2) {
+			dev_err(&sndev->stdev->dev,
+				"ntb target partition not defined\n");
+			return -ENODEV;
+		}
+
+		if (!part_map) {
+			dev_err(&sndev->stdev->dev,
+				"peer partition is not NT partition\n");
+			return -ENODEV;
+		}
+
+		sndev->peer_partition = __ffs64(part_map);
+	} else {
+		if (__ffs64(tpart_vec) != (fls64(tpart_vec) - 1)) {
+			dev_err(&sndev->stdev->dev,
+				"ntb driver only supports 1 pair of 1-1 ntb mapping\n");
+			return -ENODEV;
+		}
+
+		sndev->peer_partition = __ffs64(tpart_vec);
+		if (!(part_map & (1ULL << sndev->peer_partition))) {
+			dev_err(&sndev->stdev->dev,
+				"ntb target partition is not NT partition\n");
+			return -ENODEV;
+		}
+	}
+
+	dev_dbg(&sndev->stdev->dev, "Partition ID %d of %d\n",
+		sndev->self_partition, sndev->stdev->partition_count);
+
+	sndev->mmio_ctrl = (void * __iomem)sndev->mmio_ntb +
+		SWITCHTEC_NTB_REG_CTRL_OFFSET;
+	sndev->mmio_dbmsg = (void * __iomem)sndev->mmio_ntb +
+		SWITCHTEC_NTB_REG_DBMSG_OFFSET;
+
+	sndev->mmio_self_ctrl = &sndev->mmio_ctrl[sndev->self_partition];
+	sndev->mmio_peer_ctrl = &sndev->mmio_ctrl[sndev->peer_partition];
+	sndev->mmio_self_dbmsg = &sndev->mmio_dbmsg[sndev->self_partition];
+	sndev->mmio_peer_dbmsg = sndev->mmio_self_dbmsg;
+
+	return 0;
+}
+
+static int config_rsvd_lut_win(struct switchtec_ntb *sndev,
+			       struct ntb_ctrl_regs __iomem *ctl,
+			       int lut_idx, int partition, u64 addr)
+{
+	int peer_bar = sndev->peer_direct_mw_to_bar[0];
+	u32 ctl_val;
+	int rc;
+
+	rc = switchtec_ntb_part_op(sndev, ctl, NTB_CTRL_PART_OP_LOCK,
+				   NTB_CTRL_PART_STATUS_LOCKED);
+	if (rc)
+		return rc;
+
+	ctl_val = ioread32(&ctl->bar_entry[peer_bar].ctl);
+	ctl_val &= 0xFF;
+	ctl_val |= NTB_CTRL_BAR_LUT_WIN_EN;
+	ctl_val |= ilog2(LUT_SIZE) << 8;
+	ctl_val |= (sndev->nr_lut_mw - 1) << 14;
+	iowrite32(ctl_val, &ctl->bar_entry[peer_bar].ctl);
+
+	iowrite64((NTB_CTRL_LUT_EN | (partition << 1) | addr),
+		  &ctl->lut_entry[lut_idx]);
+
+	rc = switchtec_ntb_part_op(sndev, ctl, NTB_CTRL_PART_OP_CFG,
+				   NTB_CTRL_PART_STATUS_NORMAL);
+	if (rc) {
+		u32 bar_error, lut_error;
+
+		bar_error = ioread32(&ctl->bar_error);
+		lut_error = ioread32(&ctl->lut_error);
+		dev_err(&sndev->stdev->dev,
+			"Error setting up reserved lut window: %08x / %08x\n",
+			bar_error, lut_error);
+		return rc;
+	}
+
+	return 0;
+}
+
+static int config_req_id_table(struct switchtec_ntb *sndev,
+			       struct ntb_ctrl_regs __iomem *mmio_ctrl,
+			       int *req_ids, int count)
+{
+	int i, rc = 0;
+	u32 error;
+	u32 proxy_id;
+
+	if (ioread16(&mmio_ctrl->req_id_table_size) < count) {
+		dev_err(&sndev->stdev->dev,
+			"Not enough requester IDs available.\n");
+		return -EFAULT;
+	}
+
+	rc = switchtec_ntb_part_op(sndev, mmio_ctrl,
+				   NTB_CTRL_PART_OP_LOCK,
+				   NTB_CTRL_PART_STATUS_LOCKED);
+	if (rc)
+		return rc;
+
+	for (i = 0; i < count; i++) {
+		iowrite32(req_ids[i] << 16 | NTB_CTRL_REQ_ID_EN,
+			  &mmio_ctrl->req_id_table[i]);
+
+		proxy_id = ioread32(&mmio_ctrl->req_id_table[i]);
+		dev_dbg(&sndev->stdev->dev,
+			"Requester ID %02X:%02X.%X -> BB:%02X.%X\n",
+			req_ids[i] >> 8, (req_ids[i] >> 3) & 0x1F,
+			req_ids[i] & 0x7, (proxy_id >> 4) & 0x1F,
+			(proxy_id >> 1) & 0x7);
+	}
+
+	rc = switchtec_ntb_part_op(sndev, mmio_ctrl,
+				   NTB_CTRL_PART_OP_CFG,
+				   NTB_CTRL_PART_STATUS_NORMAL);
+
+	if (rc == -EIO) {
+		error = ioread32(&mmio_ctrl->req_id_error);
+		dev_err(&sndev->stdev->dev,
+			"Error setting up the requester ID table: %08x\n",
+			error);
+	}
+
+	return 0;
+}
+
+static int crosslink_setup_mws(struct switchtec_ntb *sndev, int ntb_lut_idx,
+			       u64 *mw_addrs, int mw_count)
+{
+	int rc, i;
+	struct ntb_ctrl_regs __iomem *ctl = sndev->mmio_self_ctrl;
+	u64 addr;
+	size_t size, offset;
+	int bar;
+	int xlate_pos;
+	u32 ctl_val;
+
+	rc = switchtec_ntb_part_op(sndev, ctl, NTB_CTRL_PART_OP_LOCK,
+				   NTB_CTRL_PART_STATUS_LOCKED);
+	if (rc)
+		return rc;
+
+	for (i = 0; i < sndev->nr_lut_mw; i++) {
+		if (i == ntb_lut_idx)
+			continue;
+
+		addr = mw_addrs[0] + LUT_SIZE * i;
+
+		iowrite64((NTB_CTRL_LUT_EN | (sndev->peer_partition << 1) |
+			   addr),
+			  &ctl->lut_entry[i]);
+	}
+
+	sndev->nr_direct_mw = min_t(int, sndev->nr_direct_mw, mw_count);
+
+	for (i = 0; i < sndev->nr_direct_mw; i++) {
+		bar = sndev->direct_mw_to_bar[i];
+		offset = (i == 0) ? LUT_SIZE * sndev->nr_lut_mw : 0;
+		addr = mw_addrs[i] + offset;
+		size = pci_resource_len(sndev->ntb.pdev, bar) - offset;
+		xlate_pos = ilog2(size);
+
+		if (offset && size > offset)
+			size = offset;
+
+		ctl_val = ioread32(&ctl->bar_entry[bar].ctl);
+		ctl_val |= NTB_CTRL_BAR_DIR_WIN_EN;
+
+		iowrite32(ctl_val, &ctl->bar_entry[bar].ctl);
+		iowrite32(xlate_pos | (lower_32_bits(size) & 0xFFFFF000),
+			  &ctl->bar_entry[bar].win_size);
+		iowrite32(upper_32_bits(size), &ctl->bar_ext_entry[bar].win_size);
+		iowrite64(sndev->peer_partition | addr,
+			  &ctl->bar_entry[bar].xlate_addr);
+	}
+
+	rc = switchtec_ntb_part_op(sndev, ctl, NTB_CTRL_PART_OP_CFG,
+				   NTB_CTRL_PART_STATUS_NORMAL);
+	if (rc) {
+		u32 bar_error, lut_error;
+
+		bar_error = ioread32(&ctl->bar_error);
+		lut_error = ioread32(&ctl->lut_error);
+		dev_err(&sndev->stdev->dev,
+			"Error setting up cross link windows: %08x / %08x\n",
+			bar_error, lut_error);
+		return rc;
+	}
+
+	return 0;
+}
+
+static int crosslink_setup_req_ids(struct switchtec_ntb *sndev,
+	struct ntb_ctrl_regs __iomem *mmio_ctrl)
+{
+	int req_ids[16];
+	int i;
+	u32 proxy_id;
+
+	for (i = 0; i < ARRAY_SIZE(req_ids); i++) {
+		proxy_id = ioread32(&sndev->mmio_self_ctrl->req_id_table[i]);
+
+		if (!(proxy_id & NTB_CTRL_REQ_ID_EN))
+			break;
+
+		req_ids[i] = ((proxy_id >> 1) & 0xFF);
+	}
+
+	return config_req_id_table(sndev, mmio_ctrl, req_ids, i);
+}
+
+/*
+ * In crosslink configuration there is a virtual partition in the
+ * middle of the two switches. The BARs in this partition have to be
+ * enumerated and assigned addresses.
+ */
+static int crosslink_enum_partition(struct switchtec_ntb *sndev,
+				    u64 *bar_addrs)
+{
+	struct part_cfg_regs __iomem *part_cfg =
+		&sndev->stdev->mmio_part_cfg_all[sndev->peer_partition];
+	u32 pff = ioread32(&part_cfg->vep_pff_inst_id) & 0xFF;
+	struct pff_csr_regs __iomem *mmio_pff =
+		&sndev->stdev->mmio_pff_csr[pff];
+	const u64 bar_space = 0x1000000000LL;
+	u64 bar_addr;
+	int bar_cnt = 0;
+	int i;
+
+	iowrite16(0x6, &mmio_pff->pcicmd);
+
+	for (i = 0; i < ARRAY_SIZE(mmio_pff->pci_bar64); i++) {
+		iowrite64(bar_space * i, &mmio_pff->pci_bar64[i]);
+		bar_addr = ioread64(&mmio_pff->pci_bar64[i]);
+		bar_addr &= ~0xf;
+
+		dev_dbg(&sndev->stdev->dev,
+			"Crosslink BAR%d addr: %llx\n",
+			i*2, bar_addr);
+
+		if (bar_addr != bar_space * i)
+			continue;
+
+		bar_addrs[bar_cnt++] = bar_addr;
+	}
+
+	return bar_cnt;
+}
+
+static int switchtec_ntb_init_crosslink(struct switchtec_ntb *sndev)
+{
+	int rc;
+	int bar = sndev->direct_mw_to_bar[0];
+	const int ntb_lut_idx = 1;
+	u64 bar_addrs[6];
+	u64 addr;
+	int offset;
+	int bar_cnt;
+
+	if (!crosslink_is_enabled(sndev))
+		return 0;
+
+	dev_info(&sndev->stdev->dev, "Using crosslink configuration\n");
+	sndev->ntb.topo = NTB_TOPO_CROSSLINK;
+
+	bar_cnt = crosslink_enum_partition(sndev, bar_addrs);
+	if (bar_cnt < sndev->nr_direct_mw + 1) {
+		dev_err(&sndev->stdev->dev,
+			"Error enumerating crosslink partition\n");
+		return -EINVAL;
+	}
+
+	addr = (bar_addrs[0] + SWITCHTEC_GAS_NTB_OFFSET +
+		SWITCHTEC_NTB_REG_DBMSG_OFFSET +
+		sizeof(struct ntb_dbmsg_regs) * sndev->peer_partition);
+
+	offset = addr & (LUT_SIZE - 1);
+	addr -= offset;
+
+	rc = config_rsvd_lut_win(sndev, sndev->mmio_self_ctrl, ntb_lut_idx,
+				 sndev->peer_partition, addr);
+	if (rc)
+		return rc;
+
+	rc = crosslink_setup_mws(sndev, ntb_lut_idx, &bar_addrs[1],
+				 bar_cnt - 1);
+	if (rc)
+		return rc;
+
+	rc = crosslink_setup_req_ids(sndev, sndev->mmio_peer_ctrl);
+	if (rc)
+		return rc;
+
+	sndev->mmio_xlink_win = pci_iomap_range(sndev->stdev->pdev, bar,
+						LUT_SIZE, LUT_SIZE);
+	if (!sndev->mmio_xlink_win) {
+		rc = -ENOMEM;
+		return rc;
+	}
+
+	sndev->mmio_peer_dbmsg = sndev->mmio_xlink_win + offset;
+	sndev->nr_rsvd_luts++;
+
+	crosslink_init_dbmsgs(sndev);
+
+	return 0;
+}
+
+static void switchtec_ntb_deinit_crosslink(struct switchtec_ntb *sndev)
+{
+	if (sndev->mmio_xlink_win)
+		pci_iounmap(sndev->stdev->pdev, sndev->mmio_xlink_win);
+}
+
+static int map_bars(int *map, struct ntb_ctrl_regs __iomem *ctrl)
+{
+	int i;
+	int cnt = 0;
+
+	for (i = 0; i < ARRAY_SIZE(ctrl->bar_entry); i++) {
+		u32 r = ioread32(&ctrl->bar_entry[i].ctl);
+
+		if (r & NTB_CTRL_BAR_VALID)
+			map[cnt++] = i;
+	}
+
+	return cnt;
+}
+
+static void switchtec_ntb_init_mw(struct switchtec_ntb *sndev)
+{
+	sndev->nr_direct_mw = map_bars(sndev->direct_mw_to_bar,
+				       sndev->mmio_self_ctrl);
+
+	sndev->nr_lut_mw = ioread16(&sndev->mmio_self_ctrl->lut_table_entries);
+	if (sndev->nr_lut_mw)
+		sndev->nr_lut_mw = rounddown_pow_of_two(sndev->nr_lut_mw);
+
+	dev_dbg(&sndev->stdev->dev, "MWs: %d direct, %d lut\n",
+		sndev->nr_direct_mw, sndev->nr_lut_mw);
+
+	sndev->peer_nr_direct_mw = map_bars(sndev->peer_direct_mw_to_bar,
+					    sndev->mmio_peer_ctrl);
+
+	sndev->peer_nr_lut_mw =
+		ioread16(&sndev->mmio_peer_ctrl->lut_table_entries);
+	if (sndev->peer_nr_lut_mw)
+		sndev->peer_nr_lut_mw = rounddown_pow_of_two(sndev->peer_nr_lut_mw);
+
+	dev_dbg(&sndev->stdev->dev, "Peer MWs: %d direct, %d lut\n",
+		sndev->peer_nr_direct_mw, sndev->peer_nr_lut_mw);
+
+}
+
+/*
+ * There are 64 doorbells in the switch hardware but this is
+ * shared among all partitions. So we must split them in half
+ * (32 for each partition). However, the message interrupts are
+ * also shared with the top 4 doorbells so we just limit this to
+ * 28 doorbells per partition.
+ *
+ * In crosslink mode, each side has it's own dbmsg register so
+ * they can each use all 60 of the available doorbells.
+ */
+static void switchtec_ntb_init_db(struct switchtec_ntb *sndev)
+{
+	sndev->db_mask = 0x0FFFFFFFFFFFFFFFULL;
+
+	if (sndev->mmio_peer_dbmsg != sndev->mmio_self_dbmsg) {
+		sndev->db_shift = 0;
+		sndev->db_peer_shift = 0;
+		sndev->db_valid_mask = sndev->db_mask;
+	} else if (sndev->self_partition < sndev->peer_partition) {
+		sndev->db_shift = 0;
+		sndev->db_peer_shift = 32;
+		sndev->db_valid_mask = 0x0FFFFFFF;
+	} else {
+		sndev->db_shift = 32;
+		sndev->db_peer_shift = 0;
+		sndev->db_valid_mask = 0x0FFFFFFF;
+	}
+
+	iowrite64(~sndev->db_mask, &sndev->mmio_self_dbmsg->idb_mask);
+	iowrite64(sndev->db_valid_mask << sndev->db_peer_shift,
+		  &sndev->mmio_peer_dbmsg->odb_mask);
+
+	dev_dbg(&sndev->stdev->dev, "dbs: shift %d/%d, mask %016llx\n",
+		sndev->db_shift, sndev->db_peer_shift, sndev->db_valid_mask);
+}
+
+static void switchtec_ntb_init_msgs(struct switchtec_ntb *sndev)
+{
+	int i;
+	u32 msg_map = 0;
+
+	for (i = 0; i < ARRAY_SIZE(sndev->mmio_self_dbmsg->imsg); i++) {
+		int m = i | sndev->peer_partition << 2;
+
+		msg_map |= m << i * 8;
+	}
+
+	iowrite32(msg_map, &sndev->mmio_self_dbmsg->msg_map);
+
+	for (i = 0; i < ARRAY_SIZE(sndev->mmio_self_dbmsg->imsg); i++)
+		iowrite64(NTB_DBMSG_IMSG_STATUS | NTB_DBMSG_IMSG_MASK,
+			  &sndev->mmio_self_dbmsg->imsg[i]);
+}
+
+static int
+switchtec_ntb_init_req_id_table(struct switchtec_ntb *sndev)
+{
+	int req_ids[2];
+
+	/*
+	 * Root Complex Requester ID (which is 0:00.0)
+	 */
+	req_ids[0] = 0;
+
+	/*
+	 * Host Bridge Requester ID (as read from the mmap address)
+	 */
+	req_ids[1] = ioread16(&sndev->mmio_ntb->requester_id);
+
+	return config_req_id_table(sndev, sndev->mmio_self_ctrl, req_ids,
+				   ARRAY_SIZE(req_ids));
+}
+
+static void switchtec_ntb_init_shared(struct switchtec_ntb *sndev)
+{
+	int i;
+
+	memset(sndev->self_shared, 0, LUT_SIZE);
+	sndev->self_shared->magic = SWITCHTEC_NTB_MAGIC;
+	sndev->self_shared->partition_id = sndev->stdev->partition;
+
+	for (i = 0; i < sndev->nr_direct_mw; i++) {
+		int bar = sndev->direct_mw_to_bar[i];
+		resource_size_t sz = pci_resource_len(sndev->stdev->pdev, bar);
+
+		if (i == 0)
+			sz = min_t(resource_size_t, sz,
+				   LUT_SIZE * sndev->nr_lut_mw);
+
+		sndev->self_shared->mw_sizes[i] = sz;
+	}
+
+	for (i = 0; i < sndev->nr_lut_mw; i++) {
+		int idx = sndev->nr_direct_mw + i;
+
+		if (idx >= MAX_MWS) {
+			dev_err(&sndev->stdev->dev,
+				"Total number of MW cannot be bigger than %d", MAX_MWS);
+			break;
+		}
+
+		sndev->self_shared->mw_sizes[idx] = LUT_SIZE;
+	}
+}
+
+static int switchtec_ntb_init_shared_mw(struct switchtec_ntb *sndev)
+{
+	int self_bar = sndev->direct_mw_to_bar[0];
+	int rc;
+
+	sndev->nr_rsvd_luts++;
+	sndev->self_shared = dma_alloc_coherent(&sndev->stdev->pdev->dev,
+						LUT_SIZE,
+						&sndev->self_shared_dma,
+						GFP_KERNEL);
+	if (!sndev->self_shared) {
+		dev_err(&sndev->stdev->dev,
+			"unable to allocate memory for shared mw\n");
+		return -ENOMEM;
+	}
+
+	switchtec_ntb_init_shared(sndev);
+
+	rc = config_rsvd_lut_win(sndev, sndev->mmio_peer_ctrl, 0,
+				 sndev->self_partition,
+				 sndev->self_shared_dma);
+	if (rc)
+		goto unalloc_and_exit;
+
+	sndev->peer_shared = pci_iomap(sndev->stdev->pdev, self_bar, LUT_SIZE);
+	if (!sndev->peer_shared) {
+		rc = -ENOMEM;
+		goto unalloc_and_exit;
+	}
+
+	dev_dbg(&sndev->stdev->dev, "Shared MW Ready\n");
+	return 0;
+
+unalloc_and_exit:
+	dma_free_coherent(&sndev->stdev->pdev->dev, LUT_SIZE,
+			  sndev->self_shared, sndev->self_shared_dma);
+
+	return rc;
+}
+
+static void switchtec_ntb_deinit_shared_mw(struct switchtec_ntb *sndev)
+{
+	if (sndev->peer_shared)
+		pci_iounmap(sndev->stdev->pdev, sndev->peer_shared);
+
+	if (sndev->self_shared)
+		dma_free_coherent(&sndev->stdev->pdev->dev, LUT_SIZE,
+				  sndev->self_shared,
+				  sndev->self_shared_dma);
+	sndev->nr_rsvd_luts--;
+}
+
+static irqreturn_t switchtec_ntb_doorbell_isr(int irq, void *dev)
+{
+	struct switchtec_ntb *sndev = dev;
+
+	dev_dbg(&sndev->stdev->dev, "doorbell\n");
+
+	ntb_db_event(&sndev->ntb, 0);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t switchtec_ntb_message_isr(int irq, void *dev)
+{
+	int i;
+	struct switchtec_ntb *sndev = dev;
+
+	for (i = 0; i < ARRAY_SIZE(sndev->mmio_self_dbmsg->imsg); i++) {
+		u64 msg = ioread64(&sndev->mmio_self_dbmsg->imsg[i]);
+
+		if (msg & NTB_DBMSG_IMSG_STATUS) {
+			dev_dbg(&sndev->stdev->dev, "message: %d %08x\n",
+				i, (u32)msg);
+			iowrite8(1, &sndev->mmio_self_dbmsg->imsg[i].status);
+
+			if (i == LINK_MESSAGE)
+				switchtec_ntb_check_link(sndev, msg);
+		}
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int switchtec_ntb_init_db_msg_irq(struct switchtec_ntb *sndev)
+{
+	int i;
+	int rc;
+	int doorbell_irq = 0;
+	int message_irq = 0;
+	int event_irq;
+	int idb_vecs = sizeof(sndev->mmio_self_dbmsg->idb_vec_map);
+
+	event_irq = ioread32(&sndev->stdev->mmio_part_cfg->vep_vector_number);
+
+	while (doorbell_irq == event_irq)
+		doorbell_irq++;
+	while (message_irq == doorbell_irq ||
+	       message_irq == event_irq)
+		message_irq++;
+
+	dev_dbg(&sndev->stdev->dev, "irqs - event: %d, db: %d, msgs: %d\n",
+		event_irq, doorbell_irq, message_irq);
+
+	for (i = 0; i < idb_vecs - 4; i++)
+		iowrite8(doorbell_irq,
+			 &sndev->mmio_self_dbmsg->idb_vec_map[i]);
+
+	for (; i < idb_vecs; i++)
+		iowrite8(message_irq,
+			 &sndev->mmio_self_dbmsg->idb_vec_map[i]);
+
+	sndev->doorbell_irq = pci_irq_vector(sndev->stdev->pdev, doorbell_irq);
+	sndev->message_irq = pci_irq_vector(sndev->stdev->pdev, message_irq);
+
+	rc = request_irq(sndev->doorbell_irq,
+			 switchtec_ntb_doorbell_isr, 0,
+			 "switchtec_ntb_doorbell", sndev);
+	if (rc)
+		return rc;
+
+	rc = request_irq(sndev->message_irq,
+			 switchtec_ntb_message_isr, 0,
+			 "switchtec_ntb_message", sndev);
+	if (rc) {
+		free_irq(sndev->doorbell_irq, sndev);
+		return rc;
+	}
+
+	return 0;
+}
+
+static void switchtec_ntb_deinit_db_msg_irq(struct switchtec_ntb *sndev)
+{
+	free_irq(sndev->doorbell_irq, sndev);
+	free_irq(sndev->message_irq, sndev);
+}
+
+static int switchtec_ntb_reinit_peer(struct switchtec_ntb *sndev)
+{
+	int rc;
+
+	if (crosslink_is_enabled(sndev))
+		return 0;
+
+	dev_info(&sndev->stdev->dev, "reinitialize shared memory window\n");
+	rc = config_rsvd_lut_win(sndev, sndev->mmio_peer_ctrl, 0,
+				 sndev->self_partition,
+				 sndev->self_shared_dma);
+	return rc;
+}
+
+static int switchtec_ntb_add(struct device *dev)
+{
+	struct switchtec_dev *stdev = to_stdev(dev);
+	struct switchtec_ntb *sndev;
+	int rc;
+
+	stdev->sndev = NULL;
+
+	if (stdev->pdev->class != (PCI_CLASS_BRIDGE_OTHER << 8))
+		return -ENODEV;
+
+	sndev = kzalloc_node(sizeof(*sndev), GFP_KERNEL, dev_to_node(dev));
+	if (!sndev)
+		return -ENOMEM;
+
+	sndev->stdev = stdev;
+	rc = switchtec_ntb_init_sndev(sndev);
+	if (rc)
+		goto free_and_exit;
+
+	switchtec_ntb_init_mw(sndev);
+
+	rc = switchtec_ntb_init_req_id_table(sndev);
+	if (rc)
+		goto free_and_exit;
+
+	rc = switchtec_ntb_init_crosslink(sndev);
+	if (rc)
+		goto free_and_exit;
+
+	switchtec_ntb_init_db(sndev);
+	switchtec_ntb_init_msgs(sndev);
+
+	rc = switchtec_ntb_init_shared_mw(sndev);
+	if (rc)
+		goto deinit_crosslink;
+
+	rc = switchtec_ntb_init_db_msg_irq(sndev);
+	if (rc)
+		goto deinit_shared_and_exit;
+
+	/*
+	 * If this host crashed, the other host may think the link is
+	 * still up. Tell them to force it down (it will go back up
+	 * once we register the ntb device).
+	 */
+	switchtec_ntb_send_msg(sndev, LINK_MESSAGE, MSG_LINK_FORCE_DOWN);
+
+	rc = ntb_register_device(&sndev->ntb);
+	if (rc)
+		goto deinit_and_exit;
+
+	stdev->sndev = sndev;
+	stdev->link_notifier = switchtec_ntb_link_notification;
+	dev_info(dev, "NTB device registered\n");
+
+	return 0;
+
+deinit_and_exit:
+	switchtec_ntb_deinit_db_msg_irq(sndev);
+deinit_shared_and_exit:
+	switchtec_ntb_deinit_shared_mw(sndev);
+deinit_crosslink:
+	switchtec_ntb_deinit_crosslink(sndev);
+free_and_exit:
+	kfree(sndev);
+	dev_err(dev, "failed to register ntb device: %d\n", rc);
+	return rc;
+}
+
+static void switchtec_ntb_remove(struct device *dev)
+{
+	struct switchtec_dev *stdev = to_stdev(dev);
+	struct switchtec_ntb *sndev = stdev->sndev;
+
+	if (!sndev)
+		return;
+
+	stdev->link_notifier = NULL;
+	stdev->sndev = NULL;
+	ntb_unregister_device(&sndev->ntb);
+	switchtec_ntb_deinit_db_msg_irq(sndev);
+	switchtec_ntb_deinit_shared_mw(sndev);
+	switchtec_ntb_deinit_crosslink(sndev);
+	cancel_work_sync(&sndev->check_link_status_work);
+	kfree(sndev);
+	dev_info(dev, "ntb device unregistered\n");
+}
+
+static struct class_interface switchtec_interface  = {
+	.add_dev = switchtec_ntb_add,
+	.remove_dev = switchtec_ntb_remove,
+};
+
+static int __init switchtec_ntb_init(void)
+{
+	switchtec_interface.class = &switchtec_class;
+	return class_interface_register(&switchtec_interface);
+}
+module_init(switchtec_ntb_init);
+
+static void __exit switchtec_ntb_exit(void)
+{
+	class_interface_unregister(&switchtec_interface);
+}
+module_exit(switchtec_ntb_exit);
diff --git a/drivers/ntb/msi.c b/drivers/ntb/msi.c
new file mode 100644
index 000000000..6817d504c
--- /dev/null
+++ b/drivers/ntb/msi.c
@@ -0,0 +1,344 @@
+// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/ntb.h>
+#include <linux/msi.h>
+#include <linux/pci.h>
+
+struct ntb_msi {
+	u64 base_addr;
+	u64 end_addr;
+
+	void (*desc_changed)(void *ctx);
+
+	u32 __iomem *peer_mws[];
+};
+
+/**
+ * ntb_msi_init() - Initialize the MSI context
+ * @ntb:	NTB device context
+ *
+ * This function must be called before any other ntb_msi function.
+ * It initializes the context for MSI operations and maps
+ * the peer memory windows.
+ *
+ * This function reserves the last N outbound memory windows (where N
+ * is the number of peers).
+ *
+ * Return: Zero on success, otherwise a negative error number.
+ */
+int ntb_msi_init(struct ntb_dev *ntb,
+		 void (*desc_changed)(void *ctx))
+{
+	phys_addr_t mw_phys_addr;
+	resource_size_t mw_size;
+	int peer_widx;
+	int peers;
+	int ret;
+	int i;
+
+	peers = ntb_peer_port_count(ntb);
+	if (peers <= 0)
+		return -EINVAL;
+
+	ntb->msi = devm_kzalloc(&ntb->dev, struct_size(ntb->msi, peer_mws, peers),
+				GFP_KERNEL);
+	if (!ntb->msi)
+		return -ENOMEM;
+
+	ntb->msi->desc_changed = desc_changed;
+
+	for (i = 0; i < peers; i++) {
+		peer_widx = ntb_peer_mw_count(ntb) - 1 - i;
+
+		ret = ntb_peer_mw_get_addr(ntb, peer_widx, &mw_phys_addr,
+					   &mw_size);
+		if (ret)
+			goto unroll;
+
+		ntb->msi->peer_mws[i] = devm_ioremap(&ntb->dev, mw_phys_addr,
+						     mw_size);
+		if (!ntb->msi->peer_mws[i]) {
+			ret = -EFAULT;
+			goto unroll;
+		}
+	}
+
+	return 0;
+
+unroll:
+	for (i = 0; i < peers; i++)
+		if (ntb->msi->peer_mws[i])
+			devm_iounmap(&ntb->dev, ntb->msi->peer_mws[i]);
+
+	devm_kfree(&ntb->dev, ntb->msi);
+	ntb->msi = NULL;
+	return ret;
+}
+EXPORT_SYMBOL(ntb_msi_init);
+
+/**
+ * ntb_msi_setup_mws() - Initialize the MSI inbound memory windows
+ * @ntb:	NTB device context
+ *
+ * This function sets up the required inbound memory windows. It should be
+ * called from a work function after a link up event.
+ *
+ * Over the entire network, this function will reserves the last N
+ * inbound memory windows for each peer (where N is the number of peers).
+ *
+ * ntb_msi_init() must be called before this function.
+ *
+ * Return: Zero on success, otherwise a negative error number.
+ */
+int ntb_msi_setup_mws(struct ntb_dev *ntb)
+{
+	struct msi_desc *desc;
+	u64 addr;
+	int peer, peer_widx;
+	resource_size_t addr_align, size_align, size_max;
+	resource_size_t mw_size = SZ_32K;
+	resource_size_t mw_min_size = mw_size;
+	int i;
+	int ret;
+
+	if (!ntb->msi)
+		return -EINVAL;
+
+	scoped_guard (msi_descs_lock, &ntb->pdev->dev) {
+		desc = msi_first_desc(&ntb->pdev->dev, MSI_DESC_ASSOCIATED);
+		addr = desc->msg.address_lo + ((uint64_t)desc->msg.address_hi << 32);
+	}
+
+	for (peer = 0; peer < ntb_peer_port_count(ntb); peer++) {
+		peer_widx = ntb_peer_highest_mw_idx(ntb, peer);
+		if (peer_widx < 0)
+			return peer_widx;
+
+		ret = ntb_mw_get_align(ntb, peer, peer_widx, &addr_align,
+				       NULL, NULL);
+		if (ret)
+			return ret;
+
+		addr &= ~(addr_align - 1);
+	}
+
+	for (peer = 0; peer < ntb_peer_port_count(ntb); peer++) {
+		peer_widx = ntb_peer_highest_mw_idx(ntb, peer);
+		if (peer_widx < 0) {
+			ret = peer_widx;
+			goto error_out;
+		}
+
+		ret = ntb_mw_get_align(ntb, peer, peer_widx, NULL,
+				       &size_align, &size_max);
+		if (ret)
+			goto error_out;
+
+		mw_size = round_up(mw_size, size_align);
+		mw_size = max(mw_size, size_max);
+		if (mw_size < mw_min_size)
+			mw_min_size = mw_size;
+
+		ret = ntb_mw_set_trans(ntb, peer, peer_widx,
+				       addr, mw_size);
+		if (ret)
+			goto error_out;
+	}
+
+	ntb->msi->base_addr = addr;
+	ntb->msi->end_addr = addr + mw_min_size;
+
+	return 0;
+
+error_out:
+	for (i = 0; i < peer; i++) {
+		peer_widx = ntb_peer_highest_mw_idx(ntb, peer);
+		if (peer_widx < 0)
+			continue;
+
+		ntb_mw_clear_trans(ntb, i, peer_widx);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL(ntb_msi_setup_mws);
+
+/**
+ * ntb_msi_clear_mws() - Clear all inbound memory windows
+ * @ntb:	NTB device context
+ *
+ * This function tears down the resources used by ntb_msi_setup_mws().
+ */
+void ntb_msi_clear_mws(struct ntb_dev *ntb)
+{
+	int peer;
+	int peer_widx;
+
+	for (peer = 0; peer < ntb_peer_port_count(ntb); peer++) {
+		peer_widx = ntb_peer_highest_mw_idx(ntb, peer);
+		if (peer_widx < 0)
+			continue;
+
+		ntb_mw_clear_trans(ntb, peer, peer_widx);
+	}
+}
+EXPORT_SYMBOL(ntb_msi_clear_mws);
+
+struct ntb_msi_devres {
+	struct ntb_dev *ntb;
+	struct msi_desc *entry;
+	struct ntb_msi_desc *msi_desc;
+};
+
+static int ntb_msi_set_desc(struct ntb_dev *ntb, struct msi_desc *entry,
+			    struct ntb_msi_desc *msi_desc)
+{
+	u64 addr;
+
+	addr = entry->msg.address_lo +
+		((uint64_t)entry->msg.address_hi << 32);
+
+	if (addr < ntb->msi->base_addr || addr >= ntb->msi->end_addr) {
+		dev_warn_once(&ntb->dev,
+			      "IRQ %d: MSI Address not within the memory window (%llx, [%llx %llx])\n",
+			      entry->irq, addr, ntb->msi->base_addr,
+			      ntb->msi->end_addr);
+		return -EFAULT;
+	}
+
+	msi_desc->addr_offset = addr - ntb->msi->base_addr;
+	msi_desc->data = entry->msg.data;
+
+	return 0;
+}
+
+static void ntb_msi_write_msg(struct msi_desc *entry, void *data)
+{
+	struct ntb_msi_devres *dr = data;
+
+	WARN_ON(ntb_msi_set_desc(dr->ntb, entry, dr->msi_desc));
+
+	if (dr->ntb->msi->desc_changed)
+		dr->ntb->msi->desc_changed(dr->ntb->ctx);
+}
+
+static void ntbm_msi_callback_release(struct device *dev, void *res)
+{
+	struct ntb_msi_devres *dr = res;
+
+	dr->entry->write_msi_msg = NULL;
+	dr->entry->write_msi_msg_data = NULL;
+}
+
+static int ntbm_msi_setup_callback(struct ntb_dev *ntb, struct msi_desc *entry,
+				   struct ntb_msi_desc *msi_desc)
+{
+	struct ntb_msi_devres *dr;
+
+	dr = devres_alloc(ntbm_msi_callback_release,
+			  sizeof(struct ntb_msi_devres), GFP_KERNEL);
+	if (!dr)
+		return -ENOMEM;
+
+	dr->ntb = ntb;
+	dr->entry = entry;
+	dr->msi_desc = msi_desc;
+
+	devres_add(&ntb->dev, dr);
+
+	dr->entry->write_msi_msg = ntb_msi_write_msg;
+	dr->entry->write_msi_msg_data = dr;
+
+	return 0;
+}
+
+/**
+ * ntbm_msi_request_threaded_irq() - allocate an MSI interrupt
+ * @ntb:	NTB device context
+ * @handler:	Function to be called when the IRQ occurs
+ * @thread_fn:  Function to be called in a threaded interrupt context. NULL
+ *              for clients which handle everything in @handler
+ * @name:    An ascii name for the claiming device, dev_name(dev) if NULL
+ * @dev_id:     A cookie passed back to the handler function
+ * @msi_desc:	MSI descriptor data which triggers the interrupt
+ *
+ * This function assigns an interrupt handler to an unused
+ * MSI interrupt and returns the descriptor used to trigger
+ * it. The descriptor can then be sent to a peer to trigger
+ * the interrupt.
+ *
+ * The interrupt resource is managed with devres so it will
+ * be automatically freed when the NTB device is torn down.
+ *
+ * If an IRQ allocated with this function needs to be freed
+ * separately, ntbm_free_irq() must be used.
+ *
+ * Return: IRQ number assigned on success, otherwise a negative error number.
+ */
+int ntbm_msi_request_threaded_irq(struct ntb_dev *ntb, irq_handler_t handler,
+				  irq_handler_t thread_fn,
+				  const char *name, void *dev_id,
+				  struct ntb_msi_desc *msi_desc)
+{
+	struct device *dev = &ntb->pdev->dev;
+	struct msi_desc *entry;
+	int ret;
+
+	if (!ntb->msi)
+		return -EINVAL;
+
+	guard(msi_descs_lock)(dev);
+	msi_for_each_desc(entry, dev, MSI_DESC_ASSOCIATED) {
+		if (irq_has_action(entry->irq))
+			continue;
+
+		ret = devm_request_threaded_irq(&ntb->dev, entry->irq, handler,
+						thread_fn, 0, name, dev_id);
+		if (ret)
+			continue;
+
+		if (ntb_msi_set_desc(ntb, entry, msi_desc)) {
+			devm_free_irq(&ntb->dev, entry->irq, dev_id);
+			continue;
+		}
+
+		ret = ntbm_msi_setup_callback(ntb, entry, msi_desc);
+		if (ret) {
+			devm_free_irq(&ntb->dev, entry->irq, dev_id);
+			return ret;
+		}
+		return entry->irq;
+	}
+	return -ENODEV;
+}
+EXPORT_SYMBOL(ntbm_msi_request_threaded_irq);
+
+/**
+ * ntb_msi_peer_trigger() - Trigger an interrupt handler on a peer
+ * @ntb:	NTB device context
+ * @peer:	Peer index
+ * @desc:	MSI descriptor data which triggers the interrupt
+ *
+ * This function triggers an interrupt on a peer. It requires
+ * the descriptor structure to have been passed from that peer
+ * by some other means.
+ *
+ * Return: Zero on success, otherwise a negative error number.
+ */
+int ntb_msi_peer_trigger(struct ntb_dev *ntb, int peer,
+			 struct ntb_msi_desc *desc)
+{
+	int idx;
+
+	if (!ntb->msi)
+		return -EINVAL;
+
+	idx = desc->addr_offset / sizeof(*ntb->msi->peer_mws[peer]);
+
+	iowrite32(desc->data, &ntb->msi->peer_mws[peer][idx]);
+
+	return 0;
+}
+EXPORT_SYMBOL(ntb_msi_peer_trigger);
diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c
new file mode 100644
index 000000000..f9caa1a65
--- /dev/null
+++ b/drivers/ntb/ntb_transport.c
@@ -0,0 +1,2566 @@
+/*
+ * This file is provided under a dual BSD/GPLv2 license.  When using or
+ *   redistributing this file, you may do so under either license.
+ *
+ *   GPL LICENSE SUMMARY
+ *
+ *   Copyright(c) 2012 Intel Corporation. All rights reserved.
+ *   Copyright (C) 2015 EMC Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of version 2 of the GNU General Public License as
+ *   published by the Free Software Foundation.
+ *
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2012 Intel Corporation. All rights reserved.
+ *   Copyright (C) 2015 EMC Corporation. All Rights Reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copy
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * PCIe NTB Transport Linux driver
+ *
+ * Contact Information:
+ * Jon Mason <jon.mason@intel.com>
+ */
+#include <linux/debugfs.h>
+#include <linux/delay.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/errno.h>
+#include <linux/export.h>
+#include <linux/interrupt.h>
+#include <linux/kthread.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/slab.h>
+#include <linux/seq_file.h>
+#include <linux/types.h>
+#include <linux/uaccess.h>
+#include <linux/mutex.h>
+#include <linux/wait.h>
+#include "linux/ntb.h"
+#include "linux/ntb_transport.h"
+
+#define NTB_TRANSPORT_VERSION	4
+#define NTB_TRANSPORT_VER	"4"
+#define NTB_TRANSPORT_NAME	"ntb_transport"
+#define NTB_TRANSPORT_DESC	"Software Queue-Pair Transport over NTB"
+#define NTB_TRANSPORT_MIN_SPADS (MW0_SZ_HIGH + 2)
+
+MODULE_DESCRIPTION(NTB_TRANSPORT_DESC);
+MODULE_VERSION(NTB_TRANSPORT_VER);
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_AUTHOR("Intel Corporation");
+
+static unsigned long max_mw_size;
+module_param(max_mw_size, ulong, 0644);
+MODULE_PARM_DESC(max_mw_size, "Limit size of large memory windows");
+
+static unsigned int transport_mtu = 0x10000;
+module_param(transport_mtu, uint, 0644);
+MODULE_PARM_DESC(transport_mtu, "Maximum size of NTB transport packets");
+
+static unsigned char max_num_clients;
+module_param(max_num_clients, byte, 0644);
+MODULE_PARM_DESC(max_num_clients, "Maximum number of NTB transport clients");
+
+static unsigned int copy_bytes = 1024;
+module_param(copy_bytes, uint, 0644);
+MODULE_PARM_DESC(copy_bytes, "Threshold under which NTB will use the CPU to copy instead of DMA");
+
+static bool use_dma;
+module_param(use_dma, bool, 0644);
+MODULE_PARM_DESC(use_dma, "Use DMA engine to perform large data copy");
+
+static bool use_msi;
+#ifdef CONFIG_NTB_MSI
+module_param(use_msi, bool, 0644);
+MODULE_PARM_DESC(use_msi, "Use MSI interrupts instead of doorbells");
+#endif
+
+static bool tx_memcpy_offload;
+module_param(tx_memcpy_offload, bool, 0644);
+MODULE_PARM_DESC(tx_memcpy_offload, "Offload TX memcpy_toio() to a kernel thread");
+
+static struct dentry *nt_debugfs_dir;
+
+/* Only two-ports NTB devices are supported */
+#define PIDX		NTB_DEF_PEER_IDX
+
+struct ntb_queue_entry {
+	/* ntb_queue list reference */
+	struct list_head entry;
+	/* pointers to data to be transferred */
+	void *cb_data;
+	void *buf;
+	unsigned int len;
+	unsigned int flags;
+	int errors;
+	unsigned int tx_index;
+	unsigned int rx_index;
+
+	struct ntb_transport_qp *qp;
+	union {
+		struct ntb_payload_header __iomem *tx_hdr;
+		struct ntb_payload_header *rx_hdr;
+	};
+};
+
+struct ntb_rx_info {
+	unsigned int entry;
+};
+
+struct ntb_transport_qp {
+	struct ntb_transport_ctx *transport;
+	struct ntb_dev *ndev;
+	void *cb_data;
+	struct dma_chan *tx_dma_chan;
+	struct dma_chan *rx_dma_chan;
+
+	bool client_ready;
+	bool link_is_up;
+	bool active;
+
+	u8 qp_num;	/* Only 64 QP's are allowed.  0-63 */
+	u64 qp_bit;
+
+	struct ntb_rx_info __iomem *rx_info;
+	struct ntb_rx_info *remote_rx_info;
+
+	void (*tx_handler)(struct ntb_transport_qp *qp, void *qp_data,
+			   void *data, int len);
+	struct list_head tx_free_q;
+	struct list_head tx_offl_q;
+	spinlock_t ntb_tx_free_q_lock;
+	spinlock_t ntb_tx_offl_q_lock;
+	void __iomem *tx_mw;
+	phys_addr_t tx_mw_phys;
+	size_t tx_mw_size;
+	dma_addr_t tx_mw_dma_addr;
+	unsigned int tx_index;
+	unsigned int tx_max_entry;
+	unsigned int tx_max_frame;
+
+	void (*rx_handler)(struct ntb_transport_qp *qp, void *qp_data,
+			   void *data, int len);
+	struct list_head rx_post_q;
+	struct list_head rx_pend_q;
+	struct list_head rx_free_q;
+	/* ntb_rx_q_lock: synchronize access to rx_XXXX_q */
+	spinlock_t ntb_rx_q_lock;
+	void *rx_buff;
+	unsigned int rx_index;
+	unsigned int rx_max_entry;
+	unsigned int rx_max_frame;
+	unsigned int rx_alloc_entry;
+	dma_cookie_t last_cookie;
+	struct tasklet_struct rxc_db_work;
+
+	void (*event_handler)(void *data, int status);
+	struct delayed_work link_work;
+	struct work_struct link_cleanup;
+
+	struct dentry *debugfs_dir;
+	struct dentry *debugfs_stats;
+
+	/* Stats */
+	u64 rx_bytes;
+	u64 rx_pkts;
+	u64 rx_ring_empty;
+	u64 rx_err_no_buf;
+	u64 rx_err_oflow;
+	u64 rx_err_ver;
+	u64 rx_memcpy;
+	u64 rx_async;
+	u64 tx_bytes;
+	u64 tx_pkts;
+	u64 tx_ring_full;
+	u64 tx_err_no_buf;
+	u64 tx_memcpy;
+	u64 tx_async;
+
+	bool use_msi;
+	int msi_irq;
+	struct ntb_msi_desc msi_desc;
+	struct ntb_msi_desc peer_msi_desc;
+
+	struct task_struct *tx_offload_thread;
+	wait_queue_head_t tx_offload_wq;
+};
+
+struct ntb_transport_mw {
+	phys_addr_t phys_addr;
+	resource_size_t phys_size;
+	void __iomem *vbase;
+	size_t xlat_size;
+	size_t buff_size;
+	size_t alloc_size;
+	void *alloc_addr;
+	void *virt_addr;
+	dma_addr_t dma_addr;
+	dma_addr_t original_dma_addr;
+};
+
+struct ntb_transport_client_dev {
+	struct list_head entry;
+	struct ntb_transport_ctx *nt;
+	struct device dev;
+};
+
+struct ntb_transport_ctx {
+	struct list_head entry;
+	struct list_head client_devs;
+
+	struct ntb_dev *ndev;
+
+	struct ntb_transport_mw *mw_vec;
+	struct ntb_transport_qp *qp_vec;
+	unsigned int mw_count;
+	unsigned int qp_count;
+	u64 qp_bitmap;
+	u64 qp_bitmap_free;
+
+	bool use_msi;
+	unsigned int msi_spad_offset;
+	u64 msi_db_mask;
+
+	bool link_is_up;
+	struct delayed_work link_work;
+	struct work_struct link_cleanup;
+
+	struct dentry *debugfs_node_dir;
+
+	/* Make sure workq of link event be executed serially */
+	struct mutex link_event_lock;
+};
+
+enum {
+	DESC_DONE_FLAG = BIT(0),
+	LINK_DOWN_FLAG = BIT(1),
+};
+
+struct ntb_payload_header {
+	unsigned int ver;
+	unsigned int len;
+	unsigned int flags;
+};
+
+enum {
+	VERSION = 0,
+	QP_LINKS,
+	NUM_QPS,
+	NUM_MWS,
+	MW0_SZ_HIGH,
+	MW0_SZ_LOW,
+};
+
+#define dev_client_dev(__dev) \
+	container_of((__dev), struct ntb_transport_client_dev, dev)
+
+#define drv_client(__drv) \
+	container_of((__drv), struct ntb_transport_client, driver)
+
+#define QP_TO_MW(nt, qp)	((qp) % nt->mw_count)
+#define NTB_QP_DEF_NUM_ENTRIES	100
+#define NTB_LINK_DOWN_TIMEOUT	10
+
+static void ntb_transport_rxc_db(unsigned long data);
+static const struct ntb_ctx_ops ntb_transport_ops;
+static struct ntb_client ntb_transport_client;
+static int ntb_async_tx_submit(struct ntb_transport_qp *qp,
+			       struct ntb_queue_entry *entry);
+static void ntb_memcpy_tx(struct ntb_queue_entry *entry, void __iomem *offset);
+static int ntb_async_rx_submit(struct ntb_queue_entry *entry, void *offset);
+static void ntb_memcpy_rx(struct ntb_queue_entry *entry, void *offset);
+static int ntb_tx_memcpy_kthread(void *data);
+
+
+static inline bool ntb_tx_offload_enabled(struct ntb_transport_qp *qp)
+{
+	return tx_memcpy_offload && qp && qp->tx_offload_thread;
+}
+
+static int ntb_transport_bus_match(struct device *dev,
+				   const struct device_driver *drv)
+{
+	return !strncmp(dev_name(dev), drv->name, strlen(drv->name));
+}
+
+static int ntb_transport_bus_probe(struct device *dev)
+{
+	const struct ntb_transport_client *client;
+	int rc;
+
+	get_device(dev);
+
+	client = drv_client(dev->driver);
+	rc = client->probe(dev);
+	if (rc)
+		put_device(dev);
+
+	return rc;
+}
+
+static void ntb_transport_bus_remove(struct device *dev)
+{
+	const struct ntb_transport_client *client;
+
+	client = drv_client(dev->driver);
+	client->remove(dev);
+
+	put_device(dev);
+}
+
+static const struct bus_type ntb_transport_bus = {
+	.name = "ntb_transport",
+	.match = ntb_transport_bus_match,
+	.probe = ntb_transport_bus_probe,
+	.remove = ntb_transport_bus_remove,
+};
+
+static LIST_HEAD(ntb_transport_list);
+
+static int ntb_bus_init(struct ntb_transport_ctx *nt)
+{
+	list_add_tail(&nt->entry, &ntb_transport_list);
+	return 0;
+}
+
+static void ntb_bus_remove(struct ntb_transport_ctx *nt)
+{
+	struct ntb_transport_client_dev *client_dev, *cd;
+
+	list_for_each_entry_safe(client_dev, cd, &nt->client_devs, entry) {
+		dev_err(client_dev->dev.parent, "%s still attached to bus, removing\n",
+			dev_name(&client_dev->dev));
+		list_del(&client_dev->entry);
+		device_unregister(&client_dev->dev);
+	}
+
+	list_del(&nt->entry);
+}
+
+static void ntb_transport_client_release(struct device *dev)
+{
+	struct ntb_transport_client_dev *client_dev;
+
+	client_dev = dev_client_dev(dev);
+	kfree(client_dev);
+}
+
+/**
+ * ntb_transport_unregister_client_dev - Unregister NTB client device
+ * @device_name: Name of NTB client device
+ *
+ * Unregister an NTB client device with the NTB transport layer
+ */
+void ntb_transport_unregister_client_dev(char *device_name)
+{
+	struct ntb_transport_client_dev *client, *cd;
+	struct ntb_transport_ctx *nt;
+
+	list_for_each_entry(nt, &ntb_transport_list, entry)
+		list_for_each_entry_safe(client, cd, &nt->client_devs, entry)
+			if (!strncmp(dev_name(&client->dev), device_name,
+				     strlen(device_name))) {
+				list_del(&client->entry);
+				device_unregister(&client->dev);
+			}
+}
+EXPORT_SYMBOL_GPL(ntb_transport_unregister_client_dev);
+
+/**
+ * ntb_transport_register_client_dev - Register NTB client device
+ * @device_name: Name of NTB client device
+ *
+ * Register an NTB client device with the NTB transport layer
+ *
+ * Returns: %0 on success or -errno code on error
+ */
+int ntb_transport_register_client_dev(char *device_name)
+{
+	struct ntb_transport_client_dev *client_dev;
+	struct ntb_transport_ctx *nt;
+	int node;
+	int rc, i = 0;
+
+	if (list_empty(&ntb_transport_list))
+		return -ENODEV;
+
+	list_for_each_entry(nt, &ntb_transport_list, entry) {
+		struct device *dev;
+
+		node = dev_to_node(&nt->ndev->dev);
+
+		client_dev = kzalloc_node(sizeof(*client_dev),
+					  GFP_KERNEL, node);
+		if (!client_dev) {
+			rc = -ENOMEM;
+			goto err;
+		}
+
+		dev = &client_dev->dev;
+
+		/* setup and register client devices */
+		dev_set_name(dev, "%s%d", device_name, i);
+		dev->bus = &ntb_transport_bus;
+		dev->release = ntb_transport_client_release;
+		dev->parent = &nt->ndev->dev;
+
+		rc = device_register(dev);
+		if (rc) {
+			put_device(dev);
+			goto err;
+		}
+
+		list_add_tail(&client_dev->entry, &nt->client_devs);
+		i++;
+	}
+
+	return 0;
+
+err:
+	ntb_transport_unregister_client_dev(device_name);
+
+	return rc;
+}
+EXPORT_SYMBOL_GPL(ntb_transport_register_client_dev);
+
+/**
+ * ntb_transport_register_client - Register NTB client driver
+ * @drv: NTB client driver to be registered
+ *
+ * Register an NTB client driver with the NTB transport layer
+ *
+ * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
+ */
+int ntb_transport_register_client(struct ntb_transport_client *drv)
+{
+	drv->driver.bus = &ntb_transport_bus;
+
+	if (list_empty(&ntb_transport_list))
+		return -ENODEV;
+
+	return driver_register(&drv->driver);
+}
+EXPORT_SYMBOL_GPL(ntb_transport_register_client);
+
+/**
+ * ntb_transport_unregister_client - Unregister NTB client driver
+ * @drv: NTB client driver to be unregistered
+ *
+ * Unregister an NTB client driver with the NTB transport layer
+ *
+ * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
+ */
+void ntb_transport_unregister_client(struct ntb_transport_client *drv)
+{
+	driver_unregister(&drv->driver);
+}
+EXPORT_SYMBOL_GPL(ntb_transport_unregister_client);
+
+static int ntb_qp_debugfs_stats_show(struct seq_file *s, void *v)
+{
+	struct ntb_transport_qp *qp = s->private;
+
+	if (!qp || !qp->link_is_up)
+		return 0;
+
+	seq_puts(s, "\nNTB QP stats:\n\n");
+
+	seq_printf(s, "rx_bytes - \t%llu\n", qp->rx_bytes);
+	seq_printf(s, "rx_pkts - \t%llu\n", qp->rx_pkts);
+	seq_printf(s, "rx_memcpy - \t%llu\n", qp->rx_memcpy);
+	seq_printf(s, "rx_async - \t%llu\n", qp->rx_async);
+	seq_printf(s, "rx_ring_empty - %llu\n", qp->rx_ring_empty);
+	seq_printf(s, "rx_err_no_buf - %llu\n", qp->rx_err_no_buf);
+	seq_printf(s, "rx_err_oflow - \t%llu\n", qp->rx_err_oflow);
+	seq_printf(s, "rx_err_ver - \t%llu\n", qp->rx_err_ver);
+	seq_printf(s, "rx_buff - \t0x%p\n", qp->rx_buff);
+	seq_printf(s, "rx_index - \t%u\n", qp->rx_index);
+	seq_printf(s, "rx_max_entry - \t%u\n", qp->rx_max_entry);
+	seq_printf(s, "rx_alloc_entry - \t%u\n\n", qp->rx_alloc_entry);
+
+	seq_printf(s, "tx_bytes - \t%llu\n", qp->tx_bytes);
+	seq_printf(s, "tx_pkts - \t%llu\n", qp->tx_pkts);
+	seq_printf(s, "tx_memcpy - \t%llu\n", qp->tx_memcpy);
+	seq_printf(s, "tx_async - \t%llu\n", qp->tx_async);
+	seq_printf(s, "tx_ring_full - \t%llu\n", qp->tx_ring_full);
+	seq_printf(s, "tx_err_no_buf - %llu\n", qp->tx_err_no_buf);
+	seq_printf(s, "tx_mw - \t0x%p\n", qp->tx_mw);
+	seq_printf(s, "tx_index (H) - \t%u\n", qp->tx_index);
+	seq_printf(s, "RRI (T) - \t%u\n", qp->remote_rx_info->entry);
+	seq_printf(s, "tx_max_entry - \t%u\n", qp->tx_max_entry);
+	seq_printf(s, "free tx - \t%u\n", ntb_transport_tx_free_entry(qp));
+	seq_putc(s, '\n');
+
+	seq_printf(s, "Using TX DMA - \t%s\n", qp->tx_dma_chan ? "Yes" : "No");
+	seq_printf(s, "Using RX DMA - \t%s\n", qp->rx_dma_chan ? "Yes" : "No");
+	seq_printf(s, "QP Link - \t%s\n", qp->link_is_up ? "Up" : "Down");
+	seq_putc(s, '\n');
+
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(ntb_qp_debugfs_stats);
+
+static void ntb_list_add(spinlock_t *lock, struct list_head *entry,
+			 struct list_head *list)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(lock, flags);
+	list_add_tail(entry, list);
+	spin_unlock_irqrestore(lock, flags);
+}
+
+static struct ntb_queue_entry *ntb_list_rm(spinlock_t *lock,
+					   struct list_head *list)
+{
+	struct ntb_queue_entry *entry;
+	unsigned long flags;
+
+	spin_lock_irqsave(lock, flags);
+	if (list_empty(list)) {
+		entry = NULL;
+		goto out;
+	}
+	entry = list_first_entry(list, struct ntb_queue_entry, entry);
+	list_del(&entry->entry);
+
+out:
+	spin_unlock_irqrestore(lock, flags);
+
+	return entry;
+}
+
+static struct ntb_queue_entry *ntb_list_mv(spinlock_t *lock,
+					   struct list_head *list,
+					   struct list_head *to_list)
+{
+	struct ntb_queue_entry *entry;
+	unsigned long flags;
+
+	spin_lock_irqsave(lock, flags);
+
+	if (list_empty(list)) {
+		entry = NULL;
+	} else {
+		entry = list_first_entry(list, struct ntb_queue_entry, entry);
+		list_move_tail(&entry->entry, to_list);
+	}
+
+	spin_unlock_irqrestore(lock, flags);
+
+	return entry;
+}
+
+static int ntb_transport_setup_qp_mw(struct ntb_transport_ctx *nt,
+				     unsigned int qp_num)
+{
+	struct ntb_transport_qp *qp = &nt->qp_vec[qp_num];
+	struct ntb_transport_mw *mw;
+	struct ntb_dev *ndev = nt->ndev;
+	struct ntb_queue_entry *entry;
+	unsigned int rx_size, num_qps_mw;
+	unsigned int mw_num, mw_count, qp_count;
+	unsigned int i;
+	int node;
+
+	mw_count = nt->mw_count;
+	qp_count = nt->qp_count;
+
+	mw_num = QP_TO_MW(nt, qp_num);
+	mw = &nt->mw_vec[mw_num];
+
+	if (!mw->virt_addr)
+		return -ENOMEM;
+
+	if (mw_num < qp_count % mw_count)
+		num_qps_mw = qp_count / mw_count + 1;
+	else
+		num_qps_mw = qp_count / mw_count;
+
+	rx_size = (unsigned int)mw->xlat_size / num_qps_mw;
+	qp->rx_buff = mw->virt_addr + rx_size * (qp_num / mw_count);
+	rx_size -= sizeof(struct ntb_rx_info);
+
+	qp->remote_rx_info = qp->rx_buff + rx_size;
+
+	/* Due to housekeeping, there must be atleast 2 buffs */
+	qp->rx_max_frame = min(transport_mtu, rx_size / 2);
+	qp->rx_max_entry = rx_size / qp->rx_max_frame;
+	qp->rx_index = 0;
+
+	/*
+	 * Checking to see if we have more entries than the default.
+	 * We should add additional entries if that is the case so we
+	 * can be in sync with the transport frames.
+	 */
+	node = dev_to_node(&ndev->dev);
+	for (i = qp->rx_alloc_entry; i < qp->rx_max_entry; i++) {
+		entry = kzalloc_node(sizeof(*entry), GFP_KERNEL, node);
+		if (!entry)
+			return -ENOMEM;
+
+		entry->qp = qp;
+		ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry,
+			     &qp->rx_free_q);
+		qp->rx_alloc_entry++;
+	}
+
+	qp->remote_rx_info->entry = qp->rx_max_entry - 1;
+
+	/* setup the hdr offsets with 0's */
+	for (i = 0; i < qp->rx_max_entry; i++) {
+		void *offset = (qp->rx_buff + qp->rx_max_frame * (i + 1) -
+				sizeof(struct ntb_payload_header));
+		memset(offset, 0, sizeof(struct ntb_payload_header));
+	}
+
+	qp->rx_pkts = 0;
+	qp->tx_pkts = 0;
+	qp->tx_index = 0;
+
+	return 0;
+}
+
+static irqreturn_t ntb_transport_isr(int irq, void *dev)
+{
+	struct ntb_transport_qp *qp = dev;
+
+	tasklet_schedule(&qp->rxc_db_work);
+
+	return IRQ_HANDLED;
+}
+
+static void ntb_transport_setup_qp_peer_msi(struct ntb_transport_ctx *nt,
+					    unsigned int qp_num)
+{
+	struct ntb_transport_qp *qp = &nt->qp_vec[qp_num];
+	int spad = qp_num * 2 + nt->msi_spad_offset;
+
+	if (!nt->use_msi)
+		return;
+
+	if (spad >= ntb_spad_count(nt->ndev))
+		return;
+
+	qp->peer_msi_desc.addr_offset =
+		ntb_peer_spad_read(qp->ndev, PIDX, spad);
+	qp->peer_msi_desc.data =
+		ntb_peer_spad_read(qp->ndev, PIDX, spad + 1);
+
+	dev_dbg(&qp->ndev->pdev->dev, "QP%d Peer MSI addr=%x data=%x\n",
+		qp_num, qp->peer_msi_desc.addr_offset, qp->peer_msi_desc.data);
+
+	if (qp->peer_msi_desc.addr_offset) {
+		qp->use_msi = true;
+		dev_info(&qp->ndev->pdev->dev,
+			 "Using MSI interrupts for QP%d\n", qp_num);
+	}
+}
+
+static void ntb_transport_setup_qp_msi(struct ntb_transport_ctx *nt,
+				       unsigned int qp_num)
+{
+	struct ntb_transport_qp *qp = &nt->qp_vec[qp_num];
+	int spad = qp_num * 2 + nt->msi_spad_offset;
+	int rc;
+
+	if (!nt->use_msi)
+		return;
+
+	if (spad >= ntb_spad_count(nt->ndev)) {
+		dev_warn_once(&qp->ndev->pdev->dev,
+			      "Not enough SPADS to use MSI interrupts\n");
+		return;
+	}
+
+	ntb_spad_write(qp->ndev, spad, 0);
+	ntb_spad_write(qp->ndev, spad + 1, 0);
+
+	if (!qp->msi_irq) {
+		qp->msi_irq = ntbm_msi_request_irq(qp->ndev, ntb_transport_isr,
+						   KBUILD_MODNAME, qp,
+						   &qp->msi_desc);
+		if (qp->msi_irq < 0) {
+			dev_warn(&qp->ndev->pdev->dev,
+				 "Unable to allocate MSI interrupt for qp%d\n",
+				 qp_num);
+			return;
+		}
+	}
+
+	rc = ntb_spad_write(qp->ndev, spad, qp->msi_desc.addr_offset);
+	if (rc)
+		goto err_free_interrupt;
+
+	rc = ntb_spad_write(qp->ndev, spad + 1, qp->msi_desc.data);
+	if (rc)
+		goto err_free_interrupt;
+
+	dev_dbg(&qp->ndev->pdev->dev, "QP%d MSI %d addr=%x data=%x\n",
+		qp_num, qp->msi_irq, qp->msi_desc.addr_offset,
+		qp->msi_desc.data);
+
+	return;
+
+err_free_interrupt:
+	devm_free_irq(&nt->ndev->dev, qp->msi_irq, qp);
+}
+
+static void ntb_transport_msi_peer_desc_changed(struct ntb_transport_ctx *nt)
+{
+	int i;
+
+	dev_dbg(&nt->ndev->pdev->dev, "Peer MSI descriptors changed");
+
+	for (i = 0; i < nt->qp_count; i++)
+		ntb_transport_setup_qp_peer_msi(nt, i);
+}
+
+static void ntb_transport_msi_desc_changed(void *data)
+{
+	struct ntb_transport_ctx *nt = data;
+	int i;
+
+	dev_dbg(&nt->ndev->pdev->dev, "MSI descriptors changed");
+
+	for (i = 0; i < nt->qp_count; i++)
+		ntb_transport_setup_qp_msi(nt, i);
+
+	ntb_peer_db_set(nt->ndev, nt->msi_db_mask);
+}
+
+static void ntb_free_mw(struct ntb_transport_ctx *nt, int num_mw)
+{
+	struct ntb_transport_mw *mw = &nt->mw_vec[num_mw];
+	struct device *dma_dev = ntb_get_dma_dev(nt->ndev);
+
+	if (!mw->virt_addr)
+		return;
+
+	ntb_mw_clear_trans(nt->ndev, PIDX, num_mw);
+	dma_free_attrs(dma_dev, mw->alloc_size, mw->alloc_addr,
+		       mw->original_dma_addr, DMA_ATTR_FORCE_CONTIGUOUS);
+	mw->xlat_size = 0;
+	mw->buff_size = 0;
+	mw->alloc_size = 0;
+	mw->alloc_addr = NULL;
+	mw->virt_addr = NULL;
+}
+
+static int ntb_alloc_mw_buffer(struct ntb_transport_mw *mw,
+			       struct device *ntb_dev, size_t align)
+{
+	dma_addr_t dma_addr;
+	void *alloc_addr, *virt_addr;
+	int rc;
+
+	/*
+	 * The buffer here is allocated against the NTB device. The reason to
+	 * use dma_alloc_*() call is to allocate a large IOVA contiguous buffer
+	 * backing the NTB BAR for the remote host to write to. During receive
+	 * processing, the data is being copied out of the receive buffer to
+	 * the kernel skbuff. When a DMA device is being used, dma_map_page()
+	 * is called on the kvaddr of the receive buffer (from dma_alloc_*())
+	 * and remapped against the DMA device. It appears to be a double
+	 * DMA mapping of buffers, but first is mapped to the NTB device and
+	 * second is to the DMA device. DMA_ATTR_FORCE_CONTIGUOUS is necessary
+	 * in order for the later dma_map_page() to not fail.
+	 */
+	alloc_addr = dma_alloc_attrs(ntb_dev, mw->alloc_size,
+				     &dma_addr, GFP_KERNEL,
+				     DMA_ATTR_FORCE_CONTIGUOUS);
+	if (!alloc_addr) {
+		dev_err(ntb_dev, "Unable to alloc MW buff of size %zu\n",
+			mw->alloc_size);
+		return -ENOMEM;
+	}
+	virt_addr = alloc_addr;
+	mw->original_dma_addr = dma_addr;
+
+	/*
+	 * we must ensure that the memory address allocated is BAR size
+	 * aligned in order for the XLAT register to take the value. This
+	 * is a requirement of the hardware. It is recommended to setup CMA
+	 * for BAR sizes equal or greater than 4MB.
+	 */
+	if (!IS_ALIGNED(dma_addr, align)) {
+		if (mw->alloc_size > mw->buff_size) {
+			virt_addr = PTR_ALIGN(alloc_addr, align);
+			dma_addr = ALIGN(dma_addr, align);
+		} else {
+			rc = -ENOMEM;
+			goto err;
+		}
+	}
+
+	mw->alloc_addr = alloc_addr;
+	mw->virt_addr = virt_addr;
+	mw->dma_addr = dma_addr;
+
+	return 0;
+
+err:
+	dma_free_attrs(ntb_dev, mw->alloc_size, alloc_addr, dma_addr,
+		       DMA_ATTR_FORCE_CONTIGUOUS);
+	return rc;
+}
+
+static int ntb_set_mw(struct ntb_transport_ctx *nt, int num_mw,
+		      resource_size_t size)
+{
+	struct ntb_transport_mw *mw = &nt->mw_vec[num_mw];
+	struct device *dma_dev = ntb_get_dma_dev(nt->ndev);
+	size_t xlat_size, buff_size;
+	resource_size_t xlat_align;
+	resource_size_t xlat_align_size;
+	int rc;
+
+	if (!size)
+		return -EINVAL;
+
+	rc = ntb_mw_get_align(nt->ndev, PIDX, num_mw, &xlat_align,
+			      &xlat_align_size, NULL);
+	if (rc)
+		return rc;
+
+	xlat_size = round_up(size, xlat_align_size);
+	buff_size = round_up(size, xlat_align);
+
+	/* No need to re-setup */
+	if (mw->xlat_size == xlat_size)
+		return 0;
+
+	if (mw->buff_size)
+		ntb_free_mw(nt, num_mw);
+
+	/* Alloc memory for receiving data.  Must be aligned */
+	mw->xlat_size = xlat_size;
+	mw->buff_size = buff_size;
+	mw->alloc_size = buff_size;
+
+	rc = ntb_alloc_mw_buffer(mw, dma_dev, xlat_align);
+	if (rc) {
+		mw->alloc_size *= 2;
+		rc = ntb_alloc_mw_buffer(mw, dma_dev, xlat_align);
+		if (rc) {
+			dev_err(dma_dev,
+				"Unable to alloc aligned MW buff\n");
+			mw->xlat_size = 0;
+			mw->buff_size = 0;
+			mw->alloc_size = 0;
+			return rc;
+		}
+	}
+
+	/* Notify HW the memory location of the receive buffer */
+	rc = ntb_mw_set_trans(nt->ndev, PIDX, num_mw, mw->dma_addr,
+			      mw->xlat_size);
+	if (rc) {
+		dev_err(dma_dev, "Unable to set mw%d translation", num_mw);
+		ntb_free_mw(nt, num_mw);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static void ntb_qp_link_context_reset(struct ntb_transport_qp *qp)
+{
+	qp->link_is_up = false;
+	qp->active = false;
+
+	qp->tx_index = 0;
+	qp->rx_index = 0;
+	qp->rx_bytes = 0;
+	qp->rx_pkts = 0;
+	qp->rx_ring_empty = 0;
+	qp->rx_err_no_buf = 0;
+	qp->rx_err_oflow = 0;
+	qp->rx_err_ver = 0;
+	qp->rx_memcpy = 0;
+	qp->rx_async = 0;
+	qp->tx_bytes = 0;
+	qp->tx_pkts = 0;
+	qp->tx_ring_full = 0;
+	qp->tx_err_no_buf = 0;
+	qp->tx_memcpy = 0;
+	qp->tx_async = 0;
+}
+
+static void ntb_qp_link_down_reset(struct ntb_transport_qp *qp)
+{
+	ntb_qp_link_context_reset(qp);
+	if (qp->remote_rx_info)
+		qp->remote_rx_info->entry = qp->rx_max_entry - 1;
+}
+
+static void ntb_qp_link_cleanup(struct ntb_transport_qp *qp)
+{
+	struct ntb_transport_ctx *nt = qp->transport;
+	struct pci_dev *pdev = nt->ndev->pdev;
+
+	dev_info(&pdev->dev, "qp %d: Link Cleanup\n", qp->qp_num);
+
+	cancel_delayed_work_sync(&qp->link_work);
+	ntb_qp_link_down_reset(qp);
+
+	if (qp->event_handler)
+		qp->event_handler(qp->cb_data, qp->link_is_up);
+}
+
+static void ntb_qp_link_cleanup_work(struct work_struct *work)
+{
+	struct ntb_transport_qp *qp = container_of(work,
+						   struct ntb_transport_qp,
+						   link_cleanup);
+	struct ntb_transport_ctx *nt = qp->transport;
+
+	ntb_qp_link_cleanup(qp);
+
+	if (nt->link_is_up)
+		schedule_delayed_work(&qp->link_work,
+				      msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
+}
+
+static void ntb_qp_link_down(struct ntb_transport_qp *qp)
+{
+	schedule_work(&qp->link_cleanup);
+}
+
+static void ntb_transport_link_cleanup(struct ntb_transport_ctx *nt)
+{
+	struct ntb_transport_qp *qp;
+	u64 qp_bitmap_alloc;
+	unsigned int i, count;
+
+	qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free;
+
+	/* Pass along the info to any clients */
+	for (i = 0; i < nt->qp_count; i++)
+		if (qp_bitmap_alloc & BIT_ULL(i)) {
+			qp = &nt->qp_vec[i];
+			ntb_qp_link_cleanup(qp);
+			cancel_work_sync(&qp->link_cleanup);
+			cancel_delayed_work_sync(&qp->link_work);
+		}
+
+	if (!nt->link_is_up)
+		cancel_delayed_work_sync(&nt->link_work);
+
+	for (i = 0; i < nt->mw_count; i++)
+		ntb_free_mw(nt, i);
+
+	/* The scratchpad registers keep the values if the remote side
+	 * goes down, blast them now to give them a sane value the next
+	 * time they are accessed
+	 */
+	count = ntb_spad_count(nt->ndev);
+	for (i = 0; i < count; i++)
+		ntb_spad_write(nt->ndev, i, 0);
+}
+
+static void ntb_transport_link_cleanup_work(struct work_struct *work)
+{
+	struct ntb_transport_ctx *nt =
+		container_of(work, struct ntb_transport_ctx, link_cleanup);
+
+	guard(mutex)(&nt->link_event_lock);
+	ntb_transport_link_cleanup(nt);
+}
+
+static void ntb_transport_event_callback(void *data)
+{
+	struct ntb_transport_ctx *nt = data;
+
+	if (ntb_link_is_up(nt->ndev, NULL, NULL) == 1)
+		schedule_delayed_work(&nt->link_work, 0);
+	else
+		schedule_work(&nt->link_cleanup);
+}
+
+static void ntb_transport_link_work(struct work_struct *work)
+{
+	struct ntb_transport_ctx *nt =
+		container_of(work, struct ntb_transport_ctx, link_work.work);
+	struct ntb_dev *ndev = nt->ndev;
+	struct pci_dev *pdev = ndev->pdev;
+	resource_size_t size;
+	u32 val;
+	int rc = 0, i, spad;
+
+	guard(mutex)(&nt->link_event_lock);
+
+	/* send the local info, in the opposite order of the way we read it */
+
+	if (nt->use_msi) {
+		rc = ntb_msi_setup_mws(ndev);
+		if (rc) {
+			dev_warn(&pdev->dev,
+				 "Failed to register MSI memory window: %d\n",
+				 rc);
+			nt->use_msi = false;
+		}
+	}
+
+	for (i = 0; i < nt->qp_count; i++)
+		ntb_transport_setup_qp_msi(nt, i);
+
+	for (i = 0; i < nt->mw_count; i++) {
+		size = nt->mw_vec[i].phys_size;
+
+		if (max_mw_size && size > max_mw_size)
+			size = max_mw_size;
+
+		spad = MW0_SZ_HIGH + (i * 2);
+		ntb_peer_spad_write(ndev, PIDX, spad, upper_32_bits(size));
+
+		spad = MW0_SZ_LOW + (i * 2);
+		ntb_peer_spad_write(ndev, PIDX, spad, lower_32_bits(size));
+	}
+
+	ntb_peer_spad_write(ndev, PIDX, NUM_MWS, nt->mw_count);
+
+	ntb_peer_spad_write(ndev, PIDX, NUM_QPS, nt->qp_count);
+
+	ntb_peer_spad_write(ndev, PIDX, VERSION, NTB_TRANSPORT_VERSION);
+
+	/* Query the remote side for its info */
+	val = ntb_spad_read(ndev, VERSION);
+	dev_dbg(&pdev->dev, "Remote version = %d\n", val);
+	if (val != NTB_TRANSPORT_VERSION)
+		goto out;
+
+	val = ntb_spad_read(ndev, NUM_QPS);
+	dev_dbg(&pdev->dev, "Remote max number of qps = %d\n", val);
+	if (val != nt->qp_count)
+		goto out;
+
+	val = ntb_spad_read(ndev, NUM_MWS);
+	dev_dbg(&pdev->dev, "Remote number of mws = %d\n", val);
+	if (val != nt->mw_count)
+		goto out;
+
+	for (i = 0; i < nt->mw_count; i++) {
+		u64 val64;
+
+		val = ntb_spad_read(ndev, MW0_SZ_HIGH + (i * 2));
+		val64 = (u64)val << 32;
+
+		val = ntb_spad_read(ndev, MW0_SZ_LOW + (i * 2));
+		val64 |= val;
+
+		dev_dbg(&pdev->dev, "Remote MW%d size = %#llx\n", i, val64);
+
+		rc = ntb_set_mw(nt, i, val64);
+		if (rc)
+			goto out1;
+	}
+
+	nt->link_is_up = true;
+
+	for (i = 0; i < nt->qp_count; i++) {
+		struct ntb_transport_qp *qp = &nt->qp_vec[i];
+
+		ntb_transport_setup_qp_mw(nt, i);
+		ntb_transport_setup_qp_peer_msi(nt, i);
+
+		if (qp->client_ready)
+			schedule_delayed_work(&qp->link_work, 0);
+	}
+
+	return;
+
+out1:
+	for (i = 0; i < nt->mw_count; i++)
+		ntb_free_mw(nt, i);
+
+	/* if there's an actual failure, we should just bail */
+	if (rc < 0)
+		return;
+
+out:
+	if (ntb_link_is_up(ndev, NULL, NULL) == 1)
+		schedule_delayed_work(&nt->link_work,
+				      msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
+}
+
+static void ntb_qp_link_work(struct work_struct *work)
+{
+	struct ntb_transport_qp *qp = container_of(work,
+						   struct ntb_transport_qp,
+						   link_work.work);
+	struct pci_dev *pdev = qp->ndev->pdev;
+	struct ntb_transport_ctx *nt = qp->transport;
+	int val;
+
+	WARN_ON(!nt->link_is_up);
+
+	val = ntb_spad_read(nt->ndev, QP_LINKS);
+
+	ntb_peer_spad_write(nt->ndev, PIDX, QP_LINKS, val | BIT(qp->qp_num));
+
+	/* query remote spad for qp ready bits */
+	dev_dbg_ratelimited(&pdev->dev, "Remote QP link status = %x\n", val);
+
+	/* See if the remote side is up */
+	if (val & BIT(qp->qp_num)) {
+		dev_info(&pdev->dev, "qp %d: Link Up\n", qp->qp_num);
+		qp->link_is_up = true;
+		qp->active = true;
+
+		if (qp->event_handler)
+			qp->event_handler(qp->cb_data, qp->link_is_up);
+
+		if (qp->active)
+			tasklet_schedule(&qp->rxc_db_work);
+	} else if (nt->link_is_up)
+		schedule_delayed_work(&qp->link_work,
+				      msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT));
+}
+
+static int ntb_transport_init_queue(struct ntb_transport_ctx *nt,
+				    unsigned int qp_num)
+{
+	struct ntb_transport_qp *qp;
+	phys_addr_t mw_base;
+	resource_size_t mw_size;
+	unsigned int num_qps_mw, tx_size;
+	unsigned int mw_num, mw_count, qp_count;
+	u64 qp_offset;
+
+	mw_count = nt->mw_count;
+	qp_count = nt->qp_count;
+
+	mw_num = QP_TO_MW(nt, qp_num);
+
+	qp = &nt->qp_vec[qp_num];
+	qp->qp_num = qp_num;
+	qp->transport = nt;
+	qp->ndev = nt->ndev;
+	qp->client_ready = false;
+	qp->event_handler = NULL;
+	ntb_qp_link_context_reset(qp);
+
+	if (mw_num < qp_count % mw_count)
+		num_qps_mw = qp_count / mw_count + 1;
+	else
+		num_qps_mw = qp_count / mw_count;
+
+	mw_base = nt->mw_vec[mw_num].phys_addr;
+	mw_size = nt->mw_vec[mw_num].phys_size;
+
+	if (max_mw_size && mw_size > max_mw_size)
+		mw_size = max_mw_size;
+
+	tx_size = (unsigned int)mw_size / num_qps_mw;
+	qp_offset = tx_size * (qp_num / mw_count);
+
+	qp->tx_mw_size = tx_size;
+	qp->tx_mw = nt->mw_vec[mw_num].vbase + qp_offset;
+	if (!qp->tx_mw)
+		return -EINVAL;
+
+	qp->tx_mw_phys = mw_base + qp_offset;
+	if (!qp->tx_mw_phys)
+		return -EINVAL;
+
+	tx_size -= sizeof(struct ntb_rx_info);
+	qp->rx_info = qp->tx_mw + tx_size;
+
+	/* Due to housekeeping, there must be atleast 2 buffs */
+	qp->tx_max_frame = min(transport_mtu, tx_size / 2);
+	qp->tx_max_entry = tx_size / qp->tx_max_frame;
+
+	if (nt->debugfs_node_dir) {
+		char debugfs_name[8];
+
+		snprintf(debugfs_name, sizeof(debugfs_name), "qp%d", qp_num);
+		qp->debugfs_dir = debugfs_create_dir(debugfs_name,
+						     nt->debugfs_node_dir);
+
+		qp->debugfs_stats = debugfs_create_file("stats", S_IRUSR,
+							qp->debugfs_dir, qp,
+							&ntb_qp_debugfs_stats_fops);
+	} else {
+		qp->debugfs_dir = NULL;
+		qp->debugfs_stats = NULL;
+	}
+
+	INIT_DELAYED_WORK(&qp->link_work, ntb_qp_link_work);
+	INIT_WORK(&qp->link_cleanup, ntb_qp_link_cleanup_work);
+
+	spin_lock_init(&qp->ntb_rx_q_lock);
+	spin_lock_init(&qp->ntb_tx_free_q_lock);
+	spin_lock_init(&qp->ntb_tx_offl_q_lock);
+
+	INIT_LIST_HEAD(&qp->rx_post_q);
+	INIT_LIST_HEAD(&qp->rx_pend_q);
+	INIT_LIST_HEAD(&qp->rx_free_q);
+	INIT_LIST_HEAD(&qp->tx_free_q);
+	INIT_LIST_HEAD(&qp->tx_offl_q);
+
+	tasklet_init(&qp->rxc_db_work, ntb_transport_rxc_db,
+		     (unsigned long)qp);
+
+	return 0;
+}
+
+static int ntb_transport_probe(struct ntb_client *self, struct ntb_dev *ndev)
+{
+	struct ntb_transport_ctx *nt;
+	struct ntb_transport_mw *mw;
+	unsigned int mw_count, qp_count, spad_count, max_mw_count_for_spads;
+	u64 qp_bitmap;
+	int node;
+	int rc, i;
+
+	mw_count = ntb_peer_mw_count(ndev);
+
+	if (!ndev->ops->mw_set_trans) {
+		dev_err(&ndev->dev, "Inbound MW based NTB API is required\n");
+		return -EINVAL;
+	}
+
+	if (ntb_db_is_unsafe(ndev))
+		dev_dbg(&ndev->dev,
+			"doorbell is unsafe, proceed anyway...\n");
+	if (ntb_spad_is_unsafe(ndev))
+		dev_dbg(&ndev->dev,
+			"scratchpad is unsafe, proceed anyway...\n");
+
+	if (ntb_peer_port_count(ndev) != NTB_DEF_PEER_CNT)
+		dev_warn(&ndev->dev, "Multi-port NTB devices unsupported\n");
+
+	node = dev_to_node(&ndev->dev);
+
+	nt = kzalloc_node(sizeof(*nt), GFP_KERNEL, node);
+	if (!nt)
+		return -ENOMEM;
+
+	nt->ndev = ndev;
+
+	/*
+	 * If we are using MSI, and have at least one extra memory window,
+	 * we will reserve the last MW for the MSI window.
+	 */
+	if (use_msi && mw_count > 1) {
+		rc = ntb_msi_init(ndev, ntb_transport_msi_desc_changed);
+		if (!rc) {
+			mw_count -= 1;
+			nt->use_msi = true;
+		}
+	}
+
+	spad_count = ntb_spad_count(ndev);
+
+	/* Limit the MW's based on the availability of scratchpads */
+
+	if (spad_count < NTB_TRANSPORT_MIN_SPADS) {
+		nt->mw_count = 0;
+		rc = -EINVAL;
+		goto err;
+	}
+
+	max_mw_count_for_spads = (spad_count - MW0_SZ_HIGH) / 2;
+	nt->mw_count = min(mw_count, max_mw_count_for_spads);
+
+	nt->msi_spad_offset = nt->mw_count * 2 + MW0_SZ_HIGH;
+
+	nt->mw_vec = kcalloc_node(mw_count, sizeof(*nt->mw_vec),
+				  GFP_KERNEL, node);
+	if (!nt->mw_vec) {
+		rc = -ENOMEM;
+		goto err;
+	}
+
+	for (i = 0; i < mw_count; i++) {
+		mw = &nt->mw_vec[i];
+
+		rc = ntb_peer_mw_get_addr(ndev, i, &mw->phys_addr,
+					  &mw->phys_size);
+		if (rc)
+			goto err1;
+
+		mw->vbase = ioremap_wc(mw->phys_addr, mw->phys_size);
+		if (!mw->vbase) {
+			rc = -ENOMEM;
+			goto err1;
+		}
+
+		mw->buff_size = 0;
+		mw->xlat_size = 0;
+		mw->virt_addr = NULL;
+		mw->dma_addr = 0;
+	}
+
+	qp_bitmap = ntb_db_valid_mask(ndev);
+
+	qp_count = ilog2(qp_bitmap);
+	if (nt->use_msi) {
+		qp_count -= 1;
+		nt->msi_db_mask = BIT_ULL(qp_count);
+		ntb_db_clear_mask(ndev, nt->msi_db_mask);
+	}
+
+	if (max_num_clients && max_num_clients < qp_count)
+		qp_count = max_num_clients;
+	else if (nt->mw_count < qp_count)
+		qp_count = nt->mw_count;
+
+	qp_bitmap &= BIT_ULL(qp_count) - 1;
+
+	nt->qp_count = qp_count;
+	nt->qp_bitmap = qp_bitmap;
+	nt->qp_bitmap_free = qp_bitmap;
+
+	nt->qp_vec = kcalloc_node(qp_count, sizeof(*nt->qp_vec),
+				  GFP_KERNEL, node);
+	if (!nt->qp_vec) {
+		rc = -ENOMEM;
+		goto err1;
+	}
+
+	if (nt_debugfs_dir) {
+		nt->debugfs_node_dir =
+			debugfs_create_dir(pci_name(ndev->pdev),
+					   nt_debugfs_dir);
+	}
+
+	for (i = 0; i < qp_count; i++) {
+		rc = ntb_transport_init_queue(nt, i);
+		if (rc)
+			goto err2;
+	}
+
+	mutex_init(&nt->link_event_lock);
+	INIT_DELAYED_WORK(&nt->link_work, ntb_transport_link_work);
+	INIT_WORK(&nt->link_cleanup, ntb_transport_link_cleanup_work);
+
+	rc = ntb_set_ctx(ndev, nt, &ntb_transport_ops);
+	if (rc)
+		goto err2;
+
+	INIT_LIST_HEAD(&nt->client_devs);
+	rc = ntb_bus_init(nt);
+	if (rc)
+		goto err3;
+
+	nt->link_is_up = false;
+	ntb_link_enable(ndev, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
+	ntb_link_event(ndev);
+
+	return 0;
+
+err3:
+	ntb_clear_ctx(ndev);
+err2:
+	kfree(nt->qp_vec);
+err1:
+	while (i--) {
+		mw = &nt->mw_vec[i];
+		iounmap(mw->vbase);
+	}
+	kfree(nt->mw_vec);
+err:
+	kfree(nt);
+	return rc;
+}
+
+static void ntb_transport_free(struct ntb_client *self, struct ntb_dev *ndev)
+{
+	struct ntb_transport_ctx *nt = ndev->ctx;
+	struct ntb_transport_qp *qp;
+	u64 qp_bitmap_alloc;
+	int i;
+
+	ntb_transport_link_cleanup(nt);
+	cancel_work_sync(&nt->link_cleanup);
+	cancel_delayed_work_sync(&nt->link_work);
+
+	qp_bitmap_alloc = nt->qp_bitmap & ~nt->qp_bitmap_free;
+
+	/* verify that all the qp's are freed */
+	for (i = 0; i < nt->qp_count; i++) {
+		qp = &nt->qp_vec[i];
+		if (qp_bitmap_alloc & BIT_ULL(i))
+			ntb_transport_free_queue(qp);
+		debugfs_remove_recursive(qp->debugfs_dir);
+	}
+
+	ntb_link_disable(ndev);
+	ntb_clear_ctx(ndev);
+
+	ntb_bus_remove(nt);
+
+	for (i = nt->mw_count; i--; ) {
+		ntb_free_mw(nt, i);
+		iounmap(nt->mw_vec[i].vbase);
+	}
+
+	kfree(nt->qp_vec);
+	kfree(nt->mw_vec);
+	kfree(nt);
+}
+
+static void ntb_complete_rxc(struct ntb_transport_qp *qp)
+{
+	struct ntb_queue_entry *entry;
+	void *cb_data;
+	unsigned int len;
+	unsigned long irqflags;
+
+	spin_lock_irqsave(&qp->ntb_rx_q_lock, irqflags);
+
+	while (!list_empty(&qp->rx_post_q)) {
+		entry = list_first_entry(&qp->rx_post_q,
+					 struct ntb_queue_entry, entry);
+		if (!(entry->flags & DESC_DONE_FLAG))
+			break;
+
+		entry->rx_hdr->flags = 0;
+		iowrite32(entry->rx_index, &qp->rx_info->entry);
+
+		cb_data = entry->cb_data;
+		len = entry->len;
+
+		list_move_tail(&entry->entry, &qp->rx_free_q);
+
+		spin_unlock_irqrestore(&qp->ntb_rx_q_lock, irqflags);
+
+		if (qp->rx_handler && qp->client_ready)
+			qp->rx_handler(qp, qp->cb_data, cb_data, len);
+
+		spin_lock_irqsave(&qp->ntb_rx_q_lock, irqflags);
+	}
+
+	spin_unlock_irqrestore(&qp->ntb_rx_q_lock, irqflags);
+}
+
+static void ntb_rx_copy_callback(void *data,
+				 const struct dmaengine_result *res)
+{
+	struct ntb_queue_entry *entry = data;
+
+	/* we need to check DMA results if we are using DMA */
+	if (res) {
+		enum dmaengine_tx_result dma_err = res->result;
+
+		switch (dma_err) {
+		case DMA_TRANS_READ_FAILED:
+		case DMA_TRANS_WRITE_FAILED:
+			entry->errors++;
+			fallthrough;
+		case DMA_TRANS_ABORTED:
+		{
+			struct ntb_transport_qp *qp = entry->qp;
+			void *offset = qp->rx_buff + qp->rx_max_frame *
+					qp->rx_index;
+
+			ntb_memcpy_rx(entry, offset);
+			qp->rx_memcpy++;
+			return;
+		}
+
+		case DMA_TRANS_NOERROR:
+		default:
+			break;
+		}
+	}
+
+	entry->flags |= DESC_DONE_FLAG;
+
+	ntb_complete_rxc(entry->qp);
+}
+
+static void ntb_memcpy_rx(struct ntb_queue_entry *entry, void *offset)
+{
+	void *buf = entry->buf;
+	size_t len = entry->len;
+
+	memcpy(buf, offset, len);
+
+	/* Ensure that the data is fully copied out before clearing the flag */
+	wmb();
+
+	ntb_rx_copy_callback(entry, NULL);
+}
+
+static int ntb_async_rx_submit(struct ntb_queue_entry *entry, void *offset)
+{
+	struct dma_async_tx_descriptor *txd;
+	struct ntb_transport_qp *qp = entry->qp;
+	struct dma_chan *chan = qp->rx_dma_chan;
+	struct dma_device *device;
+	size_t pay_off, buff_off, len;
+	struct dmaengine_unmap_data *unmap;
+	dma_cookie_t cookie;
+	void *buf = entry->buf;
+
+	len = entry->len;
+	device = chan->device;
+	pay_off = (size_t)offset & ~PAGE_MASK;
+	buff_off = (size_t)buf & ~PAGE_MASK;
+
+	if (!is_dma_copy_aligned(device, pay_off, buff_off, len))
+		goto err;
+
+	unmap = dmaengine_get_unmap_data(device->dev, 2, GFP_NOWAIT);
+	if (!unmap)
+		goto err;
+
+	unmap->len = len;
+	unmap->addr[0] = dma_map_phys(device->dev, virt_to_phys(offset),
+				      len, DMA_TO_DEVICE, 0);
+	if (dma_mapping_error(device->dev, unmap->addr[0]))
+		goto err_get_unmap;
+
+	unmap->to_cnt = 1;
+
+	unmap->addr[1] = dma_map_phys(device->dev, virt_to_phys(buf),
+				      len, DMA_FROM_DEVICE, 0);
+	if (dma_mapping_error(device->dev, unmap->addr[1]))
+		goto err_get_unmap;
+
+	unmap->from_cnt = 1;
+
+	txd = device->device_prep_dma_memcpy(chan, unmap->addr[1],
+					     unmap->addr[0], len,
+					     DMA_PREP_INTERRUPT);
+	if (!txd)
+		goto err_get_unmap;
+
+	txd->callback_result = ntb_rx_copy_callback;
+	txd->callback_param = entry;
+	dma_set_unmap(txd, unmap);
+
+	cookie = dmaengine_submit(txd);
+	if (dma_submit_error(cookie))
+		goto err_set_unmap;
+
+	dmaengine_unmap_put(unmap);
+
+	qp->last_cookie = cookie;
+
+	qp->rx_async++;
+
+	return 0;
+
+err_set_unmap:
+	dmaengine_unmap_put(unmap);
+err_get_unmap:
+	dmaengine_unmap_put(unmap);
+err:
+	return -ENXIO;
+}
+
+static void ntb_async_rx(struct ntb_queue_entry *entry, void *offset)
+{
+	struct ntb_transport_qp *qp = entry->qp;
+	struct dma_chan *chan = qp->rx_dma_chan;
+	int res;
+
+	if (!chan)
+		goto err;
+
+	if (entry->len < copy_bytes)
+		goto err;
+
+	res = ntb_async_rx_submit(entry, offset);
+	if (res < 0)
+		goto err;
+
+	qp->rx_async++;
+	return;
+
+err:
+	ntb_memcpy_rx(entry, offset);
+	qp->rx_memcpy++;
+}
+
+static int ntb_process_rxc(struct ntb_transport_qp *qp)
+{
+	struct ntb_payload_header *hdr;
+	struct ntb_queue_entry *entry;
+	void *offset;
+
+	offset = qp->rx_buff + qp->rx_max_frame * qp->rx_index;
+	hdr = offset + qp->rx_max_frame - sizeof(struct ntb_payload_header);
+
+	dev_dbg(&qp->ndev->pdev->dev, "qp %d: RX ver %u len %d flags %x\n",
+		qp->qp_num, hdr->ver, hdr->len, hdr->flags);
+
+	if (!(hdr->flags & DESC_DONE_FLAG)) {
+		dev_dbg(&qp->ndev->pdev->dev, "done flag not set\n");
+		qp->rx_ring_empty++;
+		return -EAGAIN;
+	}
+
+	if (hdr->flags & LINK_DOWN_FLAG) {
+		dev_dbg(&qp->ndev->pdev->dev, "link down flag set\n");
+		ntb_qp_link_down(qp);
+		hdr->flags = 0;
+		return -EAGAIN;
+	}
+
+	if (hdr->ver != (u32)qp->rx_pkts) {
+		dev_dbg(&qp->ndev->pdev->dev,
+			"version mismatch, expected %llu - got %u\n",
+			qp->rx_pkts, hdr->ver);
+		qp->rx_err_ver++;
+		return -EIO;
+	}
+
+	entry = ntb_list_mv(&qp->ntb_rx_q_lock, &qp->rx_pend_q, &qp->rx_post_q);
+	if (!entry) {
+		dev_dbg(&qp->ndev->pdev->dev, "no receive buffer\n");
+		qp->rx_err_no_buf++;
+		return -EAGAIN;
+	}
+
+	entry->rx_hdr = hdr;
+	entry->rx_index = qp->rx_index;
+
+	if (hdr->len > entry->len) {
+		dev_dbg(&qp->ndev->pdev->dev,
+			"receive buffer overflow! Wanted %d got %d\n",
+			hdr->len, entry->len);
+		qp->rx_err_oflow++;
+
+		entry->len = -EIO;
+		entry->flags |= DESC_DONE_FLAG;
+
+		ntb_complete_rxc(qp);
+	} else {
+		dev_dbg(&qp->ndev->pdev->dev,
+			"RX OK index %u ver %u size %d into buf size %d\n",
+			qp->rx_index, hdr->ver, hdr->len, entry->len);
+
+		qp->rx_bytes += hdr->len;
+		qp->rx_pkts++;
+
+		entry->len = hdr->len;
+
+		ntb_async_rx(entry, offset);
+	}
+
+	qp->rx_index++;
+	qp->rx_index %= qp->rx_max_entry;
+
+	return 0;
+}
+
+static void ntb_transport_rxc_db(unsigned long data)
+{
+	struct ntb_transport_qp *qp = (void *)data;
+	int rc, i;
+
+	dev_dbg(&qp->ndev->pdev->dev, "%s: doorbell %d received\n",
+		__func__, qp->qp_num);
+
+	/* Limit the number of packets processed in a single interrupt to
+	 * provide fairness to others
+	 */
+	for (i = 0; i < qp->rx_max_entry; i++) {
+		rc = ntb_process_rxc(qp);
+		if (rc)
+			break;
+	}
+
+	if (i && qp->rx_dma_chan)
+		dma_async_issue_pending(qp->rx_dma_chan);
+
+	if (i == qp->rx_max_entry) {
+		/* there is more work to do */
+		if (qp->active)
+			tasklet_schedule(&qp->rxc_db_work);
+	} else if (ntb_db_read(qp->ndev) & BIT_ULL(qp->qp_num)) {
+		/* the doorbell bit is set: clear it */
+		ntb_db_clear(qp->ndev, BIT_ULL(qp->qp_num));
+		/* ntb_db_read ensures ntb_db_clear write is committed */
+		ntb_db_read(qp->ndev);
+
+		/* an interrupt may have arrived between finishing
+		 * ntb_process_rxc and clearing the doorbell bit:
+		 * there might be some more work to do.
+		 */
+		if (qp->active)
+			tasklet_schedule(&qp->rxc_db_work);
+	}
+}
+
+static void ntb_tx_copy_callback(void *data,
+				 const struct dmaengine_result *res)
+{
+	struct ntb_payload_header __iomem *hdr;
+	struct ntb_queue_entry *entry = data;
+	struct ntb_transport_qp *qp;
+	unsigned int len;
+	void *cb_data;
+
+	qp = entry->qp;
+	hdr = entry->tx_hdr;
+	cb_data = entry->cb_data;
+	len = entry->len;
+
+	/* we need to check DMA results if we are using DMA */
+	if (res) {
+		enum dmaengine_tx_result dma_err = res->result;
+
+		switch (dma_err) {
+		case DMA_TRANS_READ_FAILED:
+		case DMA_TRANS_WRITE_FAILED:
+			entry->errors++;
+			fallthrough;
+		case DMA_TRANS_ABORTED:
+		{
+			void __iomem *offset =
+				qp->tx_mw + qp->tx_max_frame *
+				entry->tx_index;
+
+			/* resubmit via CPU */
+			ntb_memcpy_tx(entry, offset);
+			qp->tx_memcpy++;
+			return;
+		}
+
+		case DMA_TRANS_NOERROR:
+		default:
+			break;
+		}
+	}
+
+	iowrite32(entry->flags | DESC_DONE_FLAG, &hdr->flags);
+
+	/*
+	 * Make DONE flag visible before DB/MSI. WC + posted MWr may reorder
+	 * across iATU/bridge (platform-dependent). Order and flush here.
+	 */
+	dma_mb();
+	ioread32(&hdr->flags);
+
+	if (qp->use_msi)
+		ntb_msi_peer_trigger(qp->ndev, PIDX, &qp->peer_msi_desc);
+	else
+		ntb_peer_db_set(qp->ndev, BIT_ULL(qp->qp_num));
+
+	/* The entry length can only be zero if the packet is intended to be a
+	 * "link down" or similar.  Since no payload is being sent in these
+	 * cases, there is nothing to add to the completion queue.
+	 */
+	if (len > 0)
+		qp->tx_bytes += len;
+
+	ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, &qp->tx_free_q);
+
+	if (len > 0 && qp->tx_handler)
+		qp->tx_handler(qp, qp->cb_data, cb_data, len);
+}
+
+static void ntb_memcpy_tx_on_stack(struct ntb_queue_entry *entry, void __iomem *offset)
+{
+#ifdef copy_to_nontemporal
+	/*
+	 * Using non-temporal mov to improve performance on non-cached
+	 * writes. This only works if __iomem is strictly memory-like,
+	 * but that is the case on x86-64
+	 */
+	copy_to_nontemporal(offset, entry->buf, entry->len);
+#else
+	memcpy_toio(offset, entry->buf, entry->len);
+#endif
+
+	/* Ensure that the data is fully copied out before setting the flags */
+	wmb();
+
+	ntb_tx_copy_callback(entry, NULL);
+}
+
+static int ntb_tx_memcpy_kthread(void *data)
+{
+	struct ntb_transport_qp *qp = data;
+	struct ntb_queue_entry *entry, *tmp;
+	const int resched_nr = 64;
+	LIST_HEAD(local_list);
+	void __iomem *offset;
+	int processed = 0;
+
+	while (!kthread_should_stop()) {
+		spin_lock_irq(&qp->ntb_tx_offl_q_lock);
+		wait_event_interruptible_lock_irq_timeout(qp->tx_offload_wq,
+				kthread_should_stop() ||
+				!list_empty(&qp->tx_offl_q),
+				qp->ntb_tx_offl_q_lock, 5*HZ);
+		list_splice_tail_init(&qp->tx_offl_q, &local_list);
+		spin_unlock_irq(&qp->ntb_tx_offl_q_lock);
+
+		list_for_each_entry_safe(entry, tmp, &local_list, entry) {
+			list_del(&entry->entry);
+			offset = qp->tx_mw + qp->tx_max_frame * entry->tx_index;
+			ntb_memcpy_tx_on_stack(entry, offset);
+			if (++processed >= resched_nr) {
+				cond_resched();
+				processed = 0;
+			}
+		}
+		cond_resched();
+	}
+
+	return 0;
+}
+
+static void ntb_memcpy_tx(struct ntb_queue_entry *entry, void __iomem *offset)
+{
+	struct ntb_transport_qp *qp = entry->qp;
+
+	if (WARN_ON_ONCE(!qp))
+		return;
+
+	if (ntb_tx_offload_enabled(qp)) {
+		ntb_list_add(&qp->ntb_tx_offl_q_lock, &entry->entry,
+			     &qp->tx_offl_q);
+		wake_up(&qp->tx_offload_wq);
+	} else
+		ntb_memcpy_tx_on_stack(entry, offset);
+}
+
+static int ntb_async_tx_submit(struct ntb_transport_qp *qp,
+			       struct ntb_queue_entry *entry)
+{
+	struct dma_async_tx_descriptor *txd;
+	struct dma_chan *chan = qp->tx_dma_chan;
+	struct dma_device *device;
+	size_t len = entry->len;
+	void *buf = entry->buf;
+	size_t dest_off, buff_off;
+	struct dmaengine_unmap_data *unmap;
+	dma_addr_t dest;
+	dma_cookie_t cookie;
+
+	device = chan->device;
+	dest = qp->tx_mw_dma_addr + qp->tx_max_frame * entry->tx_index;
+	buff_off = (size_t)buf & ~PAGE_MASK;
+	dest_off = (size_t)dest & ~PAGE_MASK;
+
+	if (!is_dma_copy_aligned(device, buff_off, dest_off, len))
+		goto err;
+
+	unmap = dmaengine_get_unmap_data(device->dev, 1, GFP_NOWAIT);
+	if (!unmap)
+		goto err;
+
+	unmap->len = len;
+	unmap->addr[0] = dma_map_phys(device->dev, virt_to_phys(buf),
+				      len, DMA_TO_DEVICE, 0);
+	if (dma_mapping_error(device->dev, unmap->addr[0]))
+		goto err_get_unmap;
+
+	unmap->to_cnt = 1;
+
+	txd = device->device_prep_dma_memcpy(chan, dest, unmap->addr[0], len,
+					     DMA_PREP_INTERRUPT);
+	if (!txd)
+		goto err_get_unmap;
+
+	txd->callback_result = ntb_tx_copy_callback;
+	txd->callback_param = entry;
+	dma_set_unmap(txd, unmap);
+
+	cookie = dmaengine_submit(txd);
+	if (dma_submit_error(cookie))
+		goto err_set_unmap;
+
+	dmaengine_unmap_put(unmap);
+
+	dma_async_issue_pending(chan);
+
+	return 0;
+err_set_unmap:
+	dmaengine_unmap_put(unmap);
+err_get_unmap:
+	dmaengine_unmap_put(unmap);
+err:
+	return -ENXIO;
+}
+
+static void ntb_async_tx(struct ntb_transport_qp *qp,
+			 struct ntb_queue_entry *entry)
+{
+	struct ntb_payload_header __iomem *hdr;
+	struct dma_chan *chan = qp->tx_dma_chan;
+	void __iomem *offset;
+	int res;
+
+	entry->tx_index = qp->tx_index;
+	offset = qp->tx_mw + qp->tx_max_frame * entry->tx_index;
+	hdr = offset + qp->tx_max_frame - sizeof(struct ntb_payload_header);
+	entry->tx_hdr = hdr;
+
+	WARN_ON_ONCE(!ntb_transport_tx_free_entry(qp));
+	WRITE_ONCE(qp->tx_index, (qp->tx_index + 1) % qp->tx_max_entry);
+
+	iowrite32(entry->len, &hdr->len);
+	iowrite32((u32)qp->tx_pkts, &hdr->ver);
+
+	if (!chan)
+		goto err;
+
+	if (entry->len < copy_bytes)
+		goto err;
+
+	res = ntb_async_tx_submit(qp, entry);
+	if (res < 0)
+		goto err;
+
+	qp->tx_async++;
+	return;
+
+err:
+	ntb_memcpy_tx(entry, offset);
+	qp->tx_memcpy++;
+}
+
+static int ntb_process_tx(struct ntb_transport_qp *qp,
+			  struct ntb_queue_entry *entry)
+{
+	if (!ntb_transport_tx_free_entry(qp)) {
+		qp->tx_ring_full++;
+		return -EAGAIN;
+	}
+
+	ntb_async_tx(qp, entry);
+
+	qp->tx_pkts++;
+
+	return 0;
+}
+
+static void ntb_send_link_down(struct ntb_transport_qp *qp)
+{
+	struct pci_dev *pdev = qp->ndev->pdev;
+	struct ntb_queue_entry *entry;
+	int i, rc;
+
+	if (!qp->link_is_up)
+		return;
+
+	dev_info(&pdev->dev, "qp %d: Send Link Down\n", qp->qp_num);
+
+	for (i = 0; i < NTB_LINK_DOWN_TIMEOUT; i++) {
+		entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
+		if (entry)
+			break;
+		msleep(100);
+	}
+
+	if (!entry)
+		return;
+
+	entry->cb_data = NULL;
+	entry->buf = NULL;
+	entry->len = 0;
+	entry->flags = LINK_DOWN_FLAG;
+
+	rc = ntb_process_tx(qp, entry);
+	if (rc)
+		dev_err(&pdev->dev, "ntb: QP%d unable to send linkdown msg\n",
+			qp->qp_num);
+
+	ntb_qp_link_down_reset(qp);
+}
+
+static bool ntb_dma_filter_fn(struct dma_chan *chan, void *node)
+{
+	return dev_to_node(&chan->dev->device) == (int)(unsigned long)node;
+}
+
+/**
+ * ntb_transport_create_queue - Create a new NTB transport layer queue
+ * @data: pointer for callback data
+ * @client_dev: &struct device pointer
+ * @handlers: pointer to various ntb queue (callback) handlers
+ *
+ * Create a new NTB transport layer queue and provide the queue with a callback
+ * routine for both transmit and receive.  The receive callback routine will be
+ * used to pass up data when the transport has received it on the queue.   The
+ * transmit callback routine will be called when the transport has completed the
+ * transmission of the data on the queue and the data is ready to be freed.
+ *
+ * RETURNS: pointer to newly created ntb_queue, NULL on error.
+ */
+struct ntb_transport_qp *
+ntb_transport_create_queue(void *data, struct device *client_dev,
+			   const struct ntb_queue_handlers *handlers)
+{
+	struct ntb_dev *ndev;
+	struct pci_dev *pdev;
+	struct ntb_transport_ctx *nt;
+	struct ntb_queue_entry *entry;
+	struct ntb_transport_qp *qp;
+	u64 qp_bit;
+	unsigned int free_queue;
+	dma_cap_mask_t dma_mask;
+	int node;
+	int i;
+
+	ndev = dev_ntb(client_dev->parent);
+	pdev = ndev->pdev;
+	nt = ndev->ctx;
+
+	node = dev_to_node(&ndev->dev);
+
+	free_queue = ffs(nt->qp_bitmap_free);
+	if (!free_queue)
+		goto err;
+
+	/* decrement free_queue to make it zero based */
+	free_queue--;
+
+	qp = &nt->qp_vec[free_queue];
+	qp_bit = BIT_ULL(qp->qp_num);
+
+	nt->qp_bitmap_free &= ~qp_bit;
+
+	qp->cb_data = data;
+	qp->rx_handler = handlers->rx_handler;
+	qp->tx_handler = handlers->tx_handler;
+	qp->event_handler = handlers->event_handler;
+
+	init_waitqueue_head(&qp->tx_offload_wq);
+	if (tx_memcpy_offload) {
+		qp->tx_offload_thread = kthread_run(ntb_tx_memcpy_kthread, qp,
+						    "ntb-txcpy/%s/%u",
+						    pci_name(ndev->pdev), qp->qp_num);
+		if (IS_ERR(qp->tx_offload_thread)) {
+			dev_warn(&nt->ndev->dev,
+				 "tx memcpy offload thread creation failed: %ld; falling back to inline copy\n",
+				 PTR_ERR(qp->tx_offload_thread));
+			qp->tx_offload_thread = NULL;
+		}
+	} else
+		qp->tx_offload_thread = NULL;
+
+	dma_cap_zero(dma_mask);
+	dma_cap_set(DMA_MEMCPY, dma_mask);
+
+	if (use_dma) {
+		qp->tx_dma_chan =
+			dma_request_channel(dma_mask, ntb_dma_filter_fn,
+					    (void *)(unsigned long)node);
+		if (!qp->tx_dma_chan)
+			dev_info(&pdev->dev, "Unable to allocate TX DMA channel\n");
+
+		qp->rx_dma_chan =
+			dma_request_channel(dma_mask, ntb_dma_filter_fn,
+					    (void *)(unsigned long)node);
+		if (!qp->rx_dma_chan)
+			dev_info(&pdev->dev, "Unable to allocate RX DMA channel\n");
+	} else {
+		qp->tx_dma_chan = NULL;
+		qp->rx_dma_chan = NULL;
+	}
+
+	qp->tx_mw_dma_addr = 0;
+	if (qp->tx_dma_chan) {
+		qp->tx_mw_dma_addr =
+			dma_map_resource(qp->tx_dma_chan->device->dev,
+					 qp->tx_mw_phys, qp->tx_mw_size,
+					 DMA_FROM_DEVICE, 0);
+		if (dma_mapping_error(qp->tx_dma_chan->device->dev,
+				      qp->tx_mw_dma_addr)) {
+			qp->tx_mw_dma_addr = 0;
+			goto err1;
+		}
+	}
+
+	dev_dbg(&pdev->dev, "Using %s memcpy for TX\n",
+		qp->tx_dma_chan ? "DMA" : "CPU");
+
+	dev_dbg(&pdev->dev, "Using %s memcpy for RX\n",
+		qp->rx_dma_chan ? "DMA" : "CPU");
+
+	for (i = 0; i < NTB_QP_DEF_NUM_ENTRIES; i++) {
+		entry = kzalloc_node(sizeof(*entry), GFP_KERNEL, node);
+		if (!entry)
+			goto err1;
+
+		entry->qp = qp;
+		ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry,
+			     &qp->rx_free_q);
+	}
+	qp->rx_alloc_entry = NTB_QP_DEF_NUM_ENTRIES;
+
+	for (i = 0; i < qp->tx_max_entry; i++) {
+		entry = kzalloc_node(sizeof(*entry), GFP_KERNEL, node);
+		if (!entry)
+			goto err2;
+
+		entry->qp = qp;
+		ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
+			     &qp->tx_free_q);
+	}
+
+	ntb_db_clear(qp->ndev, qp_bit);
+	ntb_db_clear_mask(qp->ndev, qp_bit);
+
+	dev_info(&pdev->dev, "NTB Transport QP %d created\n", qp->qp_num);
+
+	return qp;
+
+err2:
+	while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
+		kfree(entry);
+err1:
+	qp->rx_alloc_entry = 0;
+	while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q)))
+		kfree(entry);
+	if (qp->tx_mw_dma_addr)
+		dma_unmap_resource(qp->tx_dma_chan->device->dev,
+				   qp->tx_mw_dma_addr, qp->tx_mw_size,
+				   DMA_FROM_DEVICE, 0);
+	if (qp->tx_dma_chan)
+		dma_release_channel(qp->tx_dma_chan);
+	if (qp->rx_dma_chan)
+		dma_release_channel(qp->rx_dma_chan);
+	nt->qp_bitmap_free |= qp_bit;
+err:
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(ntb_transport_create_queue);
+
+/**
+ * ntb_transport_free_queue - Frees NTB transport queue
+ * @qp: NTB queue to be freed
+ *
+ * Frees NTB transport queue
+ */
+void ntb_transport_free_queue(struct ntb_transport_qp *qp)
+{
+	struct pci_dev *pdev;
+	struct ntb_queue_entry *entry;
+	u64 qp_bit;
+
+	if (!qp)
+		return;
+
+	pdev = qp->ndev->pdev;
+
+	qp->active = false;
+
+	if (qp->tx_offload_thread) {
+		kthread_stop(qp->tx_offload_thread);
+		qp->tx_offload_thread = NULL;
+	}
+
+	if (qp->tx_dma_chan) {
+		struct dma_chan *chan = qp->tx_dma_chan;
+		/* Putting the dma_chan to NULL will force any new traffic to be
+		 * processed by the CPU instead of the DAM engine
+		 */
+		qp->tx_dma_chan = NULL;
+
+		/* Try to be nice and wait for any queued DMA engine
+		 * transactions to process before smashing it with a rock
+		 */
+		dma_sync_wait(chan, qp->last_cookie);
+		dmaengine_terminate_all(chan);
+
+		dma_unmap_resource(chan->device->dev,
+				   qp->tx_mw_dma_addr, qp->tx_mw_size,
+				   DMA_FROM_DEVICE, 0);
+
+		dma_release_channel(chan);
+	}
+
+	if (qp->rx_dma_chan) {
+		struct dma_chan *chan = qp->rx_dma_chan;
+		/* Putting the dma_chan to NULL will force any new traffic to be
+		 * processed by the CPU instead of the DAM engine
+		 */
+		qp->rx_dma_chan = NULL;
+
+		/* Try to be nice and wait for any queued DMA engine
+		 * transactions to process before smashing it with a rock
+		 */
+		dma_sync_wait(chan, qp->last_cookie);
+		dmaengine_terminate_all(chan);
+		dma_release_channel(chan);
+	}
+
+	qp_bit = BIT_ULL(qp->qp_num);
+
+	ntb_db_set_mask(qp->ndev, qp_bit);
+	tasklet_kill(&qp->rxc_db_work);
+
+	cancel_delayed_work_sync(&qp->link_work);
+
+	qp->cb_data = NULL;
+	qp->rx_handler = NULL;
+	qp->tx_handler = NULL;
+	qp->event_handler = NULL;
+
+	while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q)))
+		kfree(entry);
+
+	while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_pend_q))) {
+		dev_warn(&pdev->dev, "Freeing item from non-empty rx_pend_q\n");
+		kfree(entry);
+	}
+
+	while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_post_q))) {
+		dev_warn(&pdev->dev, "Freeing item from non-empty rx_post_q\n");
+		kfree(entry);
+	}
+
+	while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
+		kfree(entry);
+
+	while ((entry = ntb_list_rm(&qp->ntb_tx_offl_q_lock, &qp->tx_offl_q)))
+		kfree(entry);
+
+	qp->transport->qp_bitmap_free |= qp_bit;
+
+	dev_info(&pdev->dev, "NTB Transport QP %d freed\n", qp->qp_num);
+}
+EXPORT_SYMBOL_GPL(ntb_transport_free_queue);
+
+/**
+ * ntb_transport_rx_remove - Dequeues enqueued rx packet
+ * @qp: NTB queue to be freed
+ * @len: pointer to variable to write enqueued buffers length
+ *
+ * Dequeues unused buffers from receive queue.  Should only be used during
+ * shutdown of qp.
+ *
+ * RETURNS: NULL error value on error, or void* for success.
+ */
+void *ntb_transport_rx_remove(struct ntb_transport_qp *qp, unsigned int *len)
+{
+	struct ntb_queue_entry *entry;
+	void *buf;
+
+	if (!qp || qp->client_ready)
+		return NULL;
+
+	entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_pend_q);
+	if (!entry)
+		return NULL;
+
+	buf = entry->cb_data;
+	*len = entry->len;
+
+	ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry, &qp->rx_free_q);
+
+	return buf;
+}
+EXPORT_SYMBOL_GPL(ntb_transport_rx_remove);
+
+/**
+ * ntb_transport_rx_enqueue - Enqueue a new NTB queue entry
+ * @qp: NTB transport layer queue the entry is to be enqueued on
+ * @cb: per buffer pointer for callback function to use
+ * @data: pointer to data buffer that incoming packets will be copied into
+ * @len: length of the data buffer
+ *
+ * Enqueue a new receive buffer onto the transport queue into which a NTB
+ * payload can be received into.
+ *
+ * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
+ */
+int ntb_transport_rx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
+			     unsigned int len)
+{
+	struct ntb_queue_entry *entry;
+
+	if (!qp)
+		return -EINVAL;
+
+	entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q);
+	if (!entry)
+		return -ENOMEM;
+
+	entry->cb_data = cb;
+	entry->buf = data;
+	entry->len = len;
+	entry->flags = 0;
+	entry->errors = 0;
+	entry->rx_index = 0;
+
+	ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry, &qp->rx_pend_q);
+
+	if (qp->active)
+		tasklet_schedule(&qp->rxc_db_work);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ntb_transport_rx_enqueue);
+
+/**
+ * ntb_transport_tx_enqueue - Enqueue a new NTB queue entry
+ * @qp: NTB transport layer queue the entry is to be enqueued on
+ * @cb: per buffer pointer for callback function to use
+ * @data: pointer to data buffer that will be sent
+ * @len: length of the data buffer
+ *
+ * Enqueue a new transmit buffer onto the transport queue from which a NTB
+ * payload will be transmitted.  This assumes that a lock is being held to
+ * serialize access to the qp.
+ *
+ * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
+ */
+int ntb_transport_tx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data,
+			     unsigned int len)
+{
+	struct ntb_queue_entry *entry;
+	int rc;
+
+	if (!qp || !len)
+		return -EINVAL;
+
+	if (!qp->link_is_up)
+		return -ENOLINK;
+
+	if (len > qp->tx_max_frame - sizeof(struct ntb_payload_header))
+		return -EMSGSIZE;
+
+	entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q);
+	if (!entry) {
+		qp->tx_err_no_buf++;
+		return -EBUSY;
+	}
+
+	entry->cb_data = cb;
+	entry->buf = data;
+	entry->len = len;
+	entry->flags = 0;
+	entry->errors = 0;
+	entry->tx_index = 0;
+
+	rc = ntb_process_tx(qp, entry);
+	if (rc)
+		ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry,
+			     &qp->tx_free_q);
+
+	return rc;
+}
+EXPORT_SYMBOL_GPL(ntb_transport_tx_enqueue);
+
+/**
+ * ntb_transport_link_up - Notify NTB transport of client readiness to use queue
+ * @qp: NTB transport layer queue to be enabled
+ *
+ * Notify NTB transport layer of client readiness to use queue
+ */
+void ntb_transport_link_up(struct ntb_transport_qp *qp)
+{
+	if (!qp)
+		return;
+
+	qp->client_ready = true;
+
+	if (qp->transport->link_is_up)
+		schedule_delayed_work(&qp->link_work, 0);
+}
+EXPORT_SYMBOL_GPL(ntb_transport_link_up);
+
+/**
+ * ntb_transport_link_down - Notify NTB transport to no longer enqueue data
+ * @qp: NTB transport layer queue to be disabled
+ *
+ * Notify NTB transport layer of client's desire to no longer receive data on
+ * transport queue specified.  It is the client's responsibility to ensure all
+ * entries on queue are purged or otherwise handled appropriately.
+ */
+void ntb_transport_link_down(struct ntb_transport_qp *qp)
+{
+	int val;
+
+	if (!qp)
+		return;
+
+	qp->client_ready = false;
+
+	val = ntb_spad_read(qp->ndev, QP_LINKS);
+
+	ntb_peer_spad_write(qp->ndev, PIDX, QP_LINKS, val & ~BIT(qp->qp_num));
+
+	if (qp->link_is_up)
+		ntb_send_link_down(qp);
+	else
+		cancel_delayed_work_sync(&qp->link_work);
+}
+EXPORT_SYMBOL_GPL(ntb_transport_link_down);
+
+/**
+ * ntb_transport_link_query - Query transport link state
+ * @qp: NTB transport layer queue to be queried
+ *
+ * Query connectivity to the remote system of the NTB transport queue
+ *
+ * RETURNS: true for link up or false for link down
+ */
+bool ntb_transport_link_query(struct ntb_transport_qp *qp)
+{
+	if (!qp)
+		return false;
+
+	return qp->link_is_up;
+}
+EXPORT_SYMBOL_GPL(ntb_transport_link_query);
+
+/**
+ * ntb_transport_qp_num - Query the qp number
+ * @qp: NTB transport layer queue to be queried
+ *
+ * Query qp number of the NTB transport queue
+ *
+ * RETURNS: a zero based number specifying the qp number
+ */
+unsigned char ntb_transport_qp_num(struct ntb_transport_qp *qp)
+{
+	if (!qp)
+		return 0;
+
+	return qp->qp_num;
+}
+EXPORT_SYMBOL_GPL(ntb_transport_qp_num);
+
+/**
+ * ntb_transport_max_size - Query the max payload size of a qp
+ * @qp: NTB transport layer queue to be queried
+ *
+ * Query the maximum payload size permissible on the given qp
+ *
+ * RETURNS: the max payload size of a qp
+ */
+unsigned int ntb_transport_max_size(struct ntb_transport_qp *qp)
+{
+	unsigned int max_size;
+	unsigned int copy_align;
+	struct dma_chan *rx_chan, *tx_chan;
+
+	if (!qp)
+		return 0;
+
+	rx_chan = qp->rx_dma_chan;
+	tx_chan = qp->tx_dma_chan;
+
+	copy_align = max(rx_chan ? rx_chan->device->copy_align : 0,
+			 tx_chan ? tx_chan->device->copy_align : 0);
+
+	/* If DMA engine usage is possible, try to find the max size for that */
+	max_size = qp->tx_max_frame - sizeof(struct ntb_payload_header);
+	max_size = round_down(max_size, 1 << copy_align);
+
+	return max_size;
+}
+EXPORT_SYMBOL_GPL(ntb_transport_max_size);
+
+unsigned int ntb_transport_tx_free_entry(struct ntb_transport_qp *qp)
+{
+	unsigned int head = qp->tx_index;
+	unsigned int tail = qp->remote_rx_info->entry;
+
+	return tail >= head ? tail - head : qp->tx_max_entry + tail - head;
+}
+EXPORT_SYMBOL_GPL(ntb_transport_tx_free_entry);
+
+static void ntb_transport_doorbell_callback(void *data, int vector)
+{
+	struct ntb_transport_ctx *nt = data;
+	struct ntb_transport_qp *qp;
+	u64 db_bits;
+	unsigned int qp_num;
+
+	if (ntb_db_read(nt->ndev) & nt->msi_db_mask) {
+		ntb_transport_msi_peer_desc_changed(nt);
+		ntb_db_clear(nt->ndev, nt->msi_db_mask);
+	}
+
+	db_bits = (nt->qp_bitmap & ~nt->qp_bitmap_free &
+		   ntb_db_vector_mask(nt->ndev, vector));
+
+	while (db_bits) {
+		qp_num = __ffs(db_bits);
+		qp = &nt->qp_vec[qp_num];
+
+		if (qp->active)
+			tasklet_schedule(&qp->rxc_db_work);
+
+		db_bits &= ~BIT_ULL(qp_num);
+	}
+}
+
+static const struct ntb_ctx_ops ntb_transport_ops = {
+	.link_event = ntb_transport_event_callback,
+	.db_event = ntb_transport_doorbell_callback,
+};
+
+static struct ntb_client ntb_transport_client = {
+	.ops = {
+		.probe = ntb_transport_probe,
+		.remove = ntb_transport_free,
+	},
+};
+
+static int __init ntb_transport_init(void)
+{
+	int rc;
+
+	pr_info("%s, version %s\n", NTB_TRANSPORT_DESC, NTB_TRANSPORT_VER);
+
+	if (debugfs_initialized())
+		nt_debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
+
+	rc = bus_register(&ntb_transport_bus);
+	if (rc)
+		goto err_bus;
+
+	rc = ntb_register_client(&ntb_transport_client);
+	if (rc)
+		goto err_client;
+
+	return 0;
+
+err_client:
+	bus_unregister(&ntb_transport_bus);
+err_bus:
+	debugfs_remove_recursive(nt_debugfs_dir);
+	return rc;
+}
+module_init(ntb_transport_init);
+
+static void __exit ntb_transport_exit(void)
+{
+	ntb_unregister_client(&ntb_transport_client);
+	bus_unregister(&ntb_transport_bus);
+	debugfs_remove_recursive(nt_debugfs_dir);
+}
+module_exit(ntb_transport_exit);
diff --git a/drivers/ntb/test/Kconfig b/drivers/ntb/test/Kconfig
new file mode 100644
index 000000000..516b991f3
--- /dev/null
+++ b/drivers/ntb/test/Kconfig
@@ -0,0 +1,37 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config NTB_PINGPONG
+	tristate "NTB Ping Pong Test Client"
+	help
+	 This is a simple ping pong driver that exercises the scratchpads and
+	 doorbells of the ntb hardware.  This driver may be used to test that
+	 your ntb hardware and drivers are functioning at a basic level.
+
+	 If unsure, say N.
+
+config NTB_TOOL
+	tristate "NTB Debugging Tool Test Client"
+	help
+	 This is a simple debugging driver that enables the doorbell and
+	 scratchpad registers to be read and written from the debugfs.  This
+	 enables more complicated debugging to be scripted from user space.
+	 This driver may be used to test that your ntb hardware and drivers are
+	 functioning at a basic level.
+
+	 If unsure, say N.
+
+config NTB_PERF
+	tristate "NTB RAW Perf Measuring Tool"
+	help
+	 This is a tool to measure raw NTB performance by transferring data
+	 to and from the window without additional software interaction.
+
+	 If unsure, say N.
+
+config NTB_MSI_TEST
+	tristate "NTB MSI Test Client"
+	depends on NTB_MSI
+	help
+	  This tool demonstrates the use of the NTB MSI library to
+	  send MSI interrupts between peers.
+
+	  If unsure, say N.
diff --git a/drivers/ntb/test/Makefile b/drivers/ntb/test/Makefile
new file mode 100644
index 000000000..19ed91d8a
--- /dev/null
+++ b/drivers/ntb/test/Makefile
@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_NTB_PINGPONG) += ntb_pingpong.o
+obj-$(CONFIG_NTB_TOOL) += ntb_tool.o
+obj-$(CONFIG_NTB_PERF) += ntb_perf.o
+obj-$(CONFIG_NTB_MSI_TEST) += ntb_msi_test.o
diff --git a/drivers/ntb/test/ntb_msi_test.c b/drivers/ntb/test/ntb_msi_test.c
new file mode 100644
index 000000000..f52d409ba
--- /dev/null
+++ b/drivers/ntb/test/ntb_msi_test.c
@@ -0,0 +1,432 @@
+// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+
+#include <linux/module.h>
+#include <linux/debugfs.h>
+#include <linux/ntb.h>
+#include <linux/pci.h>
+#include <linux/radix-tree.h>
+#include <linux/workqueue.h>
+
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_VERSION("0.1");
+MODULE_AUTHOR("Logan Gunthorpe <logang@deltatee.com>");
+MODULE_DESCRIPTION("Test for sending MSI interrupts over an NTB memory window");
+
+static int num_irqs = 4;
+module_param(num_irqs, int, 0644);
+MODULE_PARM_DESC(num_irqs, "number of irqs to use");
+
+struct ntb_msit_ctx {
+	struct ntb_dev *ntb;
+	struct dentry *dbgfs_dir;
+	struct work_struct setup_work;
+
+	struct ntb_msit_isr_ctx {
+		int irq_idx;
+		int irq_num;
+		int occurrences;
+		struct ntb_msit_ctx *nm;
+		struct ntb_msi_desc desc;
+	} *isr_ctx;
+
+	struct ntb_msit_peer {
+		struct ntb_msit_ctx *nm;
+		int pidx;
+		int num_irqs;
+		struct completion init_comp;
+		struct ntb_msi_desc *msi_desc;
+	} peers[];
+};
+
+static struct dentry *ntb_msit_dbgfs_topdir;
+
+static irqreturn_t ntb_msit_isr(int irq, void *dev)
+{
+	struct ntb_msit_isr_ctx *isr_ctx = dev;
+	struct ntb_msit_ctx *nm = isr_ctx->nm;
+
+	dev_dbg(&nm->ntb->dev, "Interrupt Occurred: %d",
+		isr_ctx->irq_idx);
+
+	isr_ctx->occurrences++;
+
+	return IRQ_HANDLED;
+}
+
+static void ntb_msit_setup_work(struct work_struct *work)
+{
+	struct ntb_msit_ctx *nm = container_of(work, struct ntb_msit_ctx,
+					       setup_work);
+	int irq_count = 0;
+	int irq;
+	int ret;
+	uintptr_t i;
+
+	ret = ntb_msi_setup_mws(nm->ntb);
+	if (ret) {
+		dev_err(&nm->ntb->dev, "Unable to setup MSI windows: %d\n",
+			ret);
+		return;
+	}
+
+	for (i = 0; i < num_irqs; i++) {
+		nm->isr_ctx[i].irq_idx = i;
+		nm->isr_ctx[i].nm = nm;
+
+		if (!nm->isr_ctx[i].irq_num) {
+			irq = ntbm_msi_request_irq(nm->ntb, ntb_msit_isr,
+						   KBUILD_MODNAME,
+						   &nm->isr_ctx[i],
+						   &nm->isr_ctx[i].desc);
+			if (irq < 0)
+				break;
+
+			nm->isr_ctx[i].irq_num = irq;
+		}
+
+		ret = ntb_spad_write(nm->ntb, 2 * i + 1,
+				     nm->isr_ctx[i].desc.addr_offset);
+		if (ret)
+			break;
+
+		ret = ntb_spad_write(nm->ntb, 2 * i + 2,
+				     nm->isr_ctx[i].desc.data);
+		if (ret)
+			break;
+
+		irq_count++;
+	}
+
+	ntb_spad_write(nm->ntb, 0, irq_count);
+	ntb_peer_db_set(nm->ntb, BIT(ntb_port_number(nm->ntb)));
+}
+
+static void ntb_msit_desc_changed(void *ctx)
+{
+	struct ntb_msit_ctx *nm = ctx;
+	int i;
+
+	dev_dbg(&nm->ntb->dev, "MSI Descriptors Changed\n");
+
+	for (i = 0; i < num_irqs; i++) {
+		ntb_spad_write(nm->ntb, 2 * i + 1,
+			       nm->isr_ctx[i].desc.addr_offset);
+		ntb_spad_write(nm->ntb, 2 * i + 2,
+			       nm->isr_ctx[i].desc.data);
+	}
+
+	ntb_peer_db_set(nm->ntb, BIT(ntb_port_number(nm->ntb)));
+}
+
+static void ntb_msit_link_event(void *ctx)
+{
+	struct ntb_msit_ctx *nm = ctx;
+
+	if (!ntb_link_is_up(nm->ntb, NULL, NULL))
+		return;
+
+	schedule_work(&nm->setup_work);
+}
+
+static void ntb_msit_copy_peer_desc(struct ntb_msit_ctx *nm, int peer)
+{
+	int i;
+	struct ntb_msi_desc *desc = nm->peers[peer].msi_desc;
+	int irq_count = nm->peers[peer].num_irqs;
+
+	for (i = 0; i < irq_count; i++) {
+		desc[i].addr_offset = ntb_peer_spad_read(nm->ntb, peer,
+							 2 * i + 1);
+		desc[i].data = ntb_peer_spad_read(nm->ntb, peer, 2 * i + 2);
+	}
+
+	dev_info(&nm->ntb->dev, "Found %d interrupts on peer %d\n",
+		 irq_count, peer);
+
+	complete_all(&nm->peers[peer].init_comp);
+}
+
+static void ntb_msit_db_event(void *ctx, int vec)
+{
+	struct ntb_msit_ctx *nm = ctx;
+	struct ntb_msi_desc *desc;
+	u64 peer_mask = ntb_db_read(nm->ntb);
+	u32 irq_count;
+	int peer;
+
+	ntb_db_clear(nm->ntb, peer_mask);
+
+	for (peer = 0; peer < sizeof(peer_mask) * 8; peer++) {
+		if (!(peer_mask & BIT(peer)))
+			continue;
+
+		irq_count = ntb_peer_spad_read(nm->ntb, peer, 0);
+		if (irq_count == -1)
+			continue;
+
+		desc = kzalloc_objs(*desc, irq_count, GFP_ATOMIC);
+		if (!desc)
+			continue;
+
+		kfree(nm->peers[peer].msi_desc);
+		nm->peers[peer].msi_desc = desc;
+		nm->peers[peer].num_irqs = irq_count;
+
+		ntb_msit_copy_peer_desc(nm, peer);
+	}
+}
+
+static const struct ntb_ctx_ops ntb_msit_ops = {
+	.link_event = ntb_msit_link_event,
+	.db_event = ntb_msit_db_event,
+};
+
+static int ntb_msit_dbgfs_trigger(void *data, u64 idx)
+{
+	struct ntb_msit_peer *peer = data;
+
+	if (idx >= peer->num_irqs)
+		return -EINVAL;
+
+	dev_dbg(&peer->nm->ntb->dev, "trigger irq %llu on peer %u\n",
+		idx, peer->pidx);
+
+	return ntb_msi_peer_trigger(peer->nm->ntb, peer->pidx,
+				    &peer->msi_desc[idx]);
+}
+
+DEFINE_DEBUGFS_ATTRIBUTE(ntb_msit_trigger_fops, NULL,
+			 ntb_msit_dbgfs_trigger, "%llu\n");
+
+static int ntb_msit_dbgfs_port_get(void *data, u64 *port)
+{
+	struct ntb_msit_peer *peer = data;
+
+	*port = ntb_peer_port_number(peer->nm->ntb, peer->pidx);
+
+	return 0;
+}
+
+DEFINE_DEBUGFS_ATTRIBUTE(ntb_msit_port_fops, ntb_msit_dbgfs_port_get,
+			 NULL, "%llu\n");
+
+static int ntb_msit_dbgfs_count_get(void *data, u64 *count)
+{
+	struct ntb_msit_peer *peer = data;
+
+	*count = peer->num_irqs;
+
+	return 0;
+}
+
+DEFINE_DEBUGFS_ATTRIBUTE(ntb_msit_count_fops, ntb_msit_dbgfs_count_get,
+			 NULL, "%llu\n");
+
+static int ntb_msit_dbgfs_ready_get(void *data, u64 *ready)
+{
+	struct ntb_msit_peer *peer = data;
+
+	*ready = try_wait_for_completion(&peer->init_comp);
+
+	return 0;
+}
+
+static int ntb_msit_dbgfs_ready_set(void *data, u64 ready)
+{
+	struct ntb_msit_peer *peer = data;
+
+	return wait_for_completion_interruptible(&peer->init_comp);
+}
+
+DEFINE_DEBUGFS_ATTRIBUTE(ntb_msit_ready_fops, ntb_msit_dbgfs_ready_get,
+			 ntb_msit_dbgfs_ready_set, "%llu\n");
+
+static int ntb_msit_dbgfs_occurrences_get(void *data, u64 *occurrences)
+{
+	struct ntb_msit_isr_ctx *isr_ctx = data;
+
+	*occurrences = isr_ctx->occurrences;
+
+	return 0;
+}
+
+DEFINE_DEBUGFS_ATTRIBUTE(ntb_msit_occurrences_fops,
+			 ntb_msit_dbgfs_occurrences_get,
+			 NULL, "%llu\n");
+
+static int ntb_msit_dbgfs_local_port_get(void *data, u64 *port)
+{
+	struct ntb_msit_ctx *nm = data;
+
+	*port = ntb_port_number(nm->ntb);
+
+	return 0;
+}
+
+DEFINE_DEBUGFS_ATTRIBUTE(ntb_msit_local_port_fops,
+			 ntb_msit_dbgfs_local_port_get,
+			 NULL, "%llu\n");
+
+static void ntb_msit_create_dbgfs(struct ntb_msit_ctx *nm)
+{
+	struct pci_dev *pdev = nm->ntb->pdev;
+	char buf[32];
+	int i;
+	struct dentry *peer_dir;
+
+	nm->dbgfs_dir = debugfs_create_dir(pci_name(pdev),
+					   ntb_msit_dbgfs_topdir);
+	debugfs_create_file("port", 0400, nm->dbgfs_dir, nm,
+			    &ntb_msit_local_port_fops);
+
+	for (i = 0; i < ntb_peer_port_count(nm->ntb); i++) {
+		nm->peers[i].pidx = i;
+		nm->peers[i].nm = nm;
+		init_completion(&nm->peers[i].init_comp);
+
+		snprintf(buf, sizeof(buf), "peer%d", i);
+		peer_dir = debugfs_create_dir(buf, nm->dbgfs_dir);
+
+		debugfs_create_file_unsafe("trigger", 0200, peer_dir,
+					   &nm->peers[i],
+					   &ntb_msit_trigger_fops);
+
+		debugfs_create_file_unsafe("port", 0400, peer_dir,
+					   &nm->peers[i], &ntb_msit_port_fops);
+
+		debugfs_create_file_unsafe("count", 0400, peer_dir,
+					   &nm->peers[i],
+					   &ntb_msit_count_fops);
+
+		debugfs_create_file_unsafe("ready", 0600, peer_dir,
+					   &nm->peers[i],
+					   &ntb_msit_ready_fops);
+	}
+
+	for (i = 0; i < num_irqs; i++) {
+		snprintf(buf, sizeof(buf), "irq%d_occurrences", i);
+		debugfs_create_file_unsafe(buf, 0400, nm->dbgfs_dir,
+					   &nm->isr_ctx[i],
+					   &ntb_msit_occurrences_fops);
+	}
+}
+
+static void ntb_msit_remove_dbgfs(struct ntb_msit_ctx *nm)
+{
+	debugfs_remove_recursive(nm->dbgfs_dir);
+}
+
+static int ntb_msit_probe(struct ntb_client *client, struct ntb_dev *ntb)
+{
+	struct ntb_msit_ctx *nm;
+	int peers;
+	int ret;
+
+	peers = ntb_peer_port_count(ntb);
+	if (peers <= 0)
+		return -EINVAL;
+
+	if (ntb_spad_is_unsafe(ntb) || ntb_spad_count(ntb) < 2 * num_irqs + 1) {
+		dev_err(&ntb->dev, "NTB MSI test requires at least %d spads for %d irqs\n",
+			2 * num_irqs + 1, num_irqs);
+		return -EFAULT;
+	}
+
+	ret = ntb_spad_write(ntb, 0, -1);
+	if (ret) {
+		dev_err(&ntb->dev, "Unable to write spads: %d\n", ret);
+		return ret;
+	}
+
+	ret = ntb_db_clear_mask(ntb, GENMASK(peers - 1, 0));
+	if (ret) {
+		dev_err(&ntb->dev, "Unable to clear doorbell mask: %d\n", ret);
+		return ret;
+	}
+
+	ret = ntb_msi_init(ntb, ntb_msit_desc_changed);
+	if (ret) {
+		dev_err(&ntb->dev, "Unable to initialize MSI library: %d\n",
+			ret);
+		return ret;
+	}
+
+	nm = devm_kzalloc(&ntb->dev, struct_size(nm, peers, peers), GFP_KERNEL);
+	if (!nm)
+		return -ENOMEM;
+
+	nm->isr_ctx = devm_kcalloc(&ntb->dev, num_irqs, sizeof(*nm->isr_ctx),
+				   GFP_KERNEL);
+	if (!nm->isr_ctx)
+		return -ENOMEM;
+
+	INIT_WORK(&nm->setup_work, ntb_msit_setup_work);
+	nm->ntb = ntb;
+
+	ntb_msit_create_dbgfs(nm);
+
+	ret = ntb_set_ctx(ntb, nm, &ntb_msit_ops);
+	if (ret)
+		goto remove_dbgfs;
+
+	if (!nm->isr_ctx) {
+		ret = -ENOMEM;
+		goto remove_dbgfs;
+	}
+
+	ntb_link_enable(ntb, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
+
+	return 0;
+
+remove_dbgfs:
+	ntb_msit_remove_dbgfs(nm);
+	devm_kfree(&ntb->dev, nm->isr_ctx);
+	devm_kfree(&ntb->dev, nm);
+	return ret;
+}
+
+static void ntb_msit_remove(struct ntb_client *client, struct ntb_dev *ntb)
+{
+	struct ntb_msit_ctx *nm = ntb->ctx;
+	int i;
+
+	ntb_link_disable(ntb);
+	ntb_db_set_mask(ntb, ntb_db_valid_mask(ntb));
+	ntb_msi_clear_mws(ntb);
+
+	for (i = 0; i < ntb_peer_port_count(ntb); i++)
+		kfree(nm->peers[i].msi_desc);
+
+	ntb_clear_ctx(ntb);
+	ntb_msit_remove_dbgfs(nm);
+}
+
+static struct ntb_client ntb_msit_client = {
+	.ops = {
+		.probe = ntb_msit_probe,
+		.remove = ntb_msit_remove
+	}
+};
+
+static int __init ntb_msit_init(void)
+{
+	int ret;
+
+	if (debugfs_initialized())
+		ntb_msit_dbgfs_topdir = debugfs_create_dir(KBUILD_MODNAME,
+							   NULL);
+
+	ret = ntb_register_client(&ntb_msit_client);
+	if (ret)
+		debugfs_remove_recursive(ntb_msit_dbgfs_topdir);
+
+	return ret;
+}
+module_init(ntb_msit_init);
+
+static void __exit ntb_msit_exit(void)
+{
+	ntb_unregister_client(&ntb_msit_client);
+	debugfs_remove_recursive(ntb_msit_dbgfs_topdir);
+}
+module_exit(ntb_msit_exit);
diff --git a/drivers/ntb/test/ntb_perf.c b/drivers/ntb/test/ntb_perf.c
new file mode 100644
index 000000000..dfd175f79
--- /dev/null
+++ b/drivers/ntb/test/ntb_perf.c
@@ -0,0 +1,1565 @@
+/*
+ * This file is provided under a dual BSD/GPLv2 license.  When using or
+ *   redistributing this file, you may do so under either license.
+ *
+ *   GPL LICENSE SUMMARY
+ *
+ *   Copyright(c) 2015 Intel Corporation. All rights reserved.
+ *   Copyright(c) 2017 T-Platforms. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of version 2 of the GNU General Public License as
+ *   published by the Free Software Foundation.
+ *
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2015 Intel Corporation. All rights reserved.
+ *   Copyright(c) 2017 T-Platforms. All Rights Reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copy
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * PCIe NTB Perf Linux driver
+ */
+
+/*
+ * How to use this tool, by example.
+ *
+ * Assuming $DBG_DIR is something like:
+ * '/sys/kernel/debug/ntb_perf/0000:00:03.0'
+ * Suppose aside from local device there is at least one remote device
+ * connected to NTB with index 0.
+ *-----------------------------------------------------------------------------
+ * Eg: install driver with specified chunk/total orders and dma-enabled flag
+ *
+ * root@self# insmod ntb_perf.ko chunk_order=19 total_order=28 use_dma
+ *-----------------------------------------------------------------------------
+ * Eg: check NTB ports (index) and MW mapping information
+ *
+ * root@self# cat $DBG_DIR/info
+ *-----------------------------------------------------------------------------
+ * Eg: start performance test with peer (index 0) and get the test metrics
+ *
+ * root@self# echo 0 > $DBG_DIR/run
+ * root@self# cat $DBG_DIR/run
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/wait.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmaengine.h>
+#include <linux/pci.h>
+#include <linux/ktime.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/sizes.h>
+#include <linux/workqueue.h>
+#include <linux/debugfs.h>
+#include <linux/random.h>
+#include <linux/ntb.h>
+
+#define DRIVER_NAME		"ntb_perf"
+#define DRIVER_VERSION		"2.0"
+
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_VERSION(DRIVER_VERSION);
+MODULE_AUTHOR("Dave Jiang <dave.jiang@intel.com>");
+MODULE_DESCRIPTION("PCIe NTB Performance Measurement Tool");
+
+#define MAX_THREADS_CNT		32
+#define DEF_THREADS_CNT		1
+#define MAX_CHUNK_SIZE		SZ_1M
+#define MAX_CHUNK_ORDER		20 /* no larger than 1M */
+
+#define DMA_TRIES		100
+#define DMA_MDELAY		10
+
+#define MSG_TRIES		1000
+#define MSG_UDELAY_LOW		1000000
+#define MSG_UDELAY_HIGH		2000000
+
+#define PERF_BUF_LEN 1024
+
+static unsigned long max_mw_size;
+module_param(max_mw_size, ulong, 0644);
+MODULE_PARM_DESC(max_mw_size, "Upper limit of memory window size");
+
+static unsigned char chunk_order = 19; /* 512K */
+module_param(chunk_order, byte, 0644);
+MODULE_PARM_DESC(chunk_order, "Data chunk order [2^n] to transfer");
+
+static unsigned char total_order = 30; /* 1G */
+module_param(total_order, byte, 0644);
+MODULE_PARM_DESC(total_order, "Total data order [2^n] to transfer");
+
+static bool use_dma; /* default to 0 */
+module_param(use_dma, bool, 0644);
+MODULE_PARM_DESC(use_dma, "Use DMA engine to measure performance");
+
+/*==============================================================================
+ *                         Perf driver data definition
+ *==============================================================================
+ */
+
+enum perf_cmd {
+	PERF_CMD_INVAL = -1,/* invalid spad command */
+	PERF_CMD_SSIZE = 0, /* send out buffer size */
+	PERF_CMD_RSIZE = 1, /* recv in  buffer size */
+	PERF_CMD_SXLAT = 2, /* send in  buffer xlat */
+	PERF_CMD_RXLAT = 3, /* recv out buffer xlat */
+	PERF_CMD_CLEAR = 4, /* clear allocated memory */
+	PERF_STS_DONE  = 5, /* init is done */
+	PERF_STS_LNKUP = 6, /* link up state flag */
+};
+
+struct perf_ctx;
+
+struct perf_peer {
+	struct perf_ctx	*perf;
+	int pidx;
+	int gidx;
+
+	/* Outbound MW params */
+	u64 outbuf_xlat;
+	resource_size_t outbuf_size;
+	void __iomem *outbuf;
+	phys_addr_t out_phys_addr;
+	dma_addr_t dma_dst_addr;
+	/* Inbound MW params */
+	dma_addr_t inbuf_xlat;
+	resource_size_t inbuf_size;
+	void		*inbuf;
+
+	/* NTB connection setup service */
+	struct work_struct	service;
+	unsigned long		sts;
+
+	struct completion init_comp;
+};
+#define to_peer_service(__work) \
+	container_of(__work, struct perf_peer, service)
+
+struct perf_thread {
+	struct perf_ctx *perf;
+	int tidx;
+
+	/* DMA-based test sync parameters */
+	atomic_t dma_sync;
+	wait_queue_head_t dma_wait;
+	struct dma_chan *dma_chan;
+
+	/* Data source and measured statistics */
+	void *src;
+	u64 copied;
+	ktime_t duration;
+	int status;
+	struct work_struct work;
+};
+#define to_thread_work(__work) \
+	container_of(__work, struct perf_thread, work)
+
+struct perf_ctx {
+	struct ntb_dev *ntb;
+
+	/* Global device index and peers descriptors */
+	int gidx;
+	int pcnt;
+	struct perf_peer *peers;
+
+	/* Performance measuring work-threads interface */
+	unsigned long busy_flag;
+	wait_queue_head_t twait;
+	atomic_t tsync;
+	u8 tcnt;
+	struct perf_peer *test_peer;
+	struct perf_thread threads[MAX_THREADS_CNT];
+
+	/* Scratchpad/Message IO operations */
+	int (*cmd_send)(struct perf_peer *peer, enum perf_cmd cmd, u64 data);
+	int (*cmd_recv)(struct perf_ctx *perf, int *pidx, enum perf_cmd *cmd,
+			u64 *data);
+
+	struct dentry *dbgfs_dir;
+};
+
+/*
+ * Scratchpads-base commands interface
+ */
+#define PERF_SPAD_CNT(_pcnt) \
+	(3*((_pcnt) + 1))
+#define PERF_SPAD_CMD(_gidx) \
+	(3*(_gidx))
+#define PERF_SPAD_LDATA(_gidx) \
+	(3*(_gidx) + 1)
+#define PERF_SPAD_HDATA(_gidx) \
+	(3*(_gidx) + 2)
+#define PERF_SPAD_NOTIFY(_gidx) \
+	(BIT_ULL(_gidx))
+
+/*
+ * Messages-base commands interface
+ */
+#define PERF_MSG_CNT		3
+#define PERF_MSG_CMD		0
+#define PERF_MSG_LDATA		1
+#define PERF_MSG_HDATA		2
+
+/*==============================================================================
+ *                           Static data declarations
+ *==============================================================================
+ */
+
+static struct dentry *perf_dbgfs_topdir;
+
+static struct workqueue_struct *perf_wq __read_mostly;
+
+/*==============================================================================
+ *                  NTB cross-link commands execution service
+ *==============================================================================
+ */
+
+static void perf_terminate_test(struct perf_ctx *perf);
+
+static inline bool perf_link_is_up(struct perf_peer *peer)
+{
+	u64 link;
+
+	link = ntb_link_is_up(peer->perf->ntb, NULL, NULL);
+	return !!(link & BIT_ULL_MASK(peer->pidx));
+}
+
+static int perf_spad_cmd_send(struct perf_peer *peer, enum perf_cmd cmd,
+			      u64 data)
+{
+	struct perf_ctx *perf = peer->perf;
+	int try;
+	u32 sts;
+
+	dev_dbg(&perf->ntb->dev, "CMD send: %d 0x%llx\n", cmd, data);
+
+	/*
+	 * Perform predefined number of attempts before give up.
+	 * We are sending the data to the port specific scratchpad, so
+	 * to prevent a multi-port access race-condition. Additionally
+	 * there is no need in local locking since only thread-safe
+	 * service work is using this method.
+	 */
+	for (try = 0; try < MSG_TRIES; try++) {
+		if (!perf_link_is_up(peer))
+			return -ENOLINK;
+
+		sts = ntb_peer_spad_read(perf->ntb, peer->pidx,
+					 PERF_SPAD_CMD(perf->gidx));
+		if (sts != PERF_CMD_INVAL) {
+			usleep_range(MSG_UDELAY_LOW, MSG_UDELAY_HIGH);
+			continue;
+		}
+
+		ntb_peer_spad_write(perf->ntb, peer->pidx,
+				    PERF_SPAD_LDATA(perf->gidx),
+				    lower_32_bits(data));
+		ntb_peer_spad_write(perf->ntb, peer->pidx,
+				    PERF_SPAD_HDATA(perf->gidx),
+				    upper_32_bits(data));
+		ntb_peer_spad_write(perf->ntb, peer->pidx,
+				    PERF_SPAD_CMD(perf->gidx),
+				    cmd);
+		ntb_peer_db_set(perf->ntb, PERF_SPAD_NOTIFY(peer->gidx));
+
+		dev_dbg(&perf->ntb->dev, "DB ring peer %#llx\n",
+			PERF_SPAD_NOTIFY(peer->gidx));
+
+		break;
+	}
+
+	return try < MSG_TRIES ? 0 : -EAGAIN;
+}
+
+static int perf_spad_cmd_recv(struct perf_ctx *perf, int *pidx,
+			      enum perf_cmd *cmd, u64 *data)
+{
+	struct perf_peer *peer;
+	u32 val;
+
+	ntb_db_clear(perf->ntb, PERF_SPAD_NOTIFY(perf->gidx));
+
+	/*
+	 * We start scanning all over, since cleared DB may have been set
+	 * by any peer. Yes, it makes peer with smaller index being
+	 * serviced with greater priority, but it's convenient for spad
+	 * and message code unification and simplicity.
+	 */
+	for (*pidx = 0; *pidx < perf->pcnt; (*pidx)++) {
+		peer = &perf->peers[*pidx];
+
+		if (!perf_link_is_up(peer))
+			continue;
+
+		val = ntb_spad_read(perf->ntb, PERF_SPAD_CMD(peer->gidx));
+		if (val == PERF_CMD_INVAL)
+			continue;
+
+		*cmd = val;
+
+		val = ntb_spad_read(perf->ntb, PERF_SPAD_LDATA(peer->gidx));
+		*data = val;
+
+		val = ntb_spad_read(perf->ntb, PERF_SPAD_HDATA(peer->gidx));
+		*data |= (u64)val << 32;
+
+		/* Next command can be retrieved from now */
+		ntb_spad_write(perf->ntb, PERF_SPAD_CMD(peer->gidx),
+			       PERF_CMD_INVAL);
+
+		dev_dbg(&perf->ntb->dev, "CMD recv: %d 0x%llx\n", *cmd, *data);
+
+		return 0;
+	}
+
+	return -ENODATA;
+}
+
+static int perf_msg_cmd_send(struct perf_peer *peer, enum perf_cmd cmd,
+			     u64 data)
+{
+	struct perf_ctx *perf = peer->perf;
+	int try, ret;
+	u64 outbits;
+
+	dev_dbg(&perf->ntb->dev, "CMD send: %d 0x%llx\n", cmd, data);
+
+	/*
+	 * Perform predefined number of attempts before give up. Message
+	 * registers are free of race-condition problem when accessed
+	 * from different ports, so we don't need splitting registers
+	 * by global device index. We also won't have local locking,
+	 * since the method is used from service work only.
+	 */
+	outbits = ntb_msg_outbits(perf->ntb);
+	for (try = 0; try < MSG_TRIES; try++) {
+		if (!perf_link_is_up(peer))
+			return -ENOLINK;
+
+		ret = ntb_msg_clear_sts(perf->ntb, outbits);
+		if (ret)
+			return ret;
+
+		ntb_peer_msg_write(perf->ntb, peer->pidx, PERF_MSG_LDATA,
+				   lower_32_bits(data));
+
+		if (ntb_msg_read_sts(perf->ntb) & outbits) {
+			usleep_range(MSG_UDELAY_LOW, MSG_UDELAY_HIGH);
+			continue;
+		}
+
+		ntb_peer_msg_write(perf->ntb, peer->pidx, PERF_MSG_HDATA,
+				   upper_32_bits(data));
+
+		/* This call shall trigger peer message event */
+		ntb_peer_msg_write(perf->ntb, peer->pidx, PERF_MSG_CMD, cmd);
+
+		break;
+	}
+
+	return try < MSG_TRIES ? 0 : -EAGAIN;
+}
+
+static int perf_msg_cmd_recv(struct perf_ctx *perf, int *pidx,
+			     enum perf_cmd *cmd, u64 *data)
+{
+	u64 inbits;
+	u32 val;
+
+	inbits = ntb_msg_inbits(perf->ntb);
+
+	if (hweight64(ntb_msg_read_sts(perf->ntb) & inbits) < 3)
+		return -ENODATA;
+
+	val = ntb_msg_read(perf->ntb, pidx, PERF_MSG_CMD);
+	*cmd = val;
+
+	val = ntb_msg_read(perf->ntb, pidx, PERF_MSG_LDATA);
+	*data = val;
+
+	val = ntb_msg_read(perf->ntb, pidx, PERF_MSG_HDATA);
+	*data |= (u64)val << 32;
+
+	/* Next command can be retrieved from now */
+	ntb_msg_clear_sts(perf->ntb, inbits);
+
+	dev_dbg(&perf->ntb->dev, "CMD recv: %d 0x%llx\n", *cmd, *data);
+
+	return 0;
+}
+
+static int perf_cmd_send(struct perf_peer *peer, enum perf_cmd cmd, u64 data)
+{
+	struct perf_ctx *perf = peer->perf;
+
+	if (cmd == PERF_CMD_SSIZE || cmd == PERF_CMD_SXLAT)
+		return perf->cmd_send(peer, cmd, data);
+
+	dev_err(&perf->ntb->dev, "Send invalid command\n");
+	return -EINVAL;
+}
+
+static int perf_cmd_exec(struct perf_peer *peer, enum perf_cmd cmd)
+{
+	switch (cmd) {
+	case PERF_CMD_SSIZE:
+	case PERF_CMD_RSIZE:
+	case PERF_CMD_SXLAT:
+	case PERF_CMD_RXLAT:
+	case PERF_CMD_CLEAR:
+		break;
+	default:
+		dev_err(&peer->perf->ntb->dev, "Exec invalid command\n");
+		return -EINVAL;
+	}
+
+	/* No need of memory barrier, since bit ops have invernal lock */
+	set_bit(cmd, &peer->sts);
+
+	dev_dbg(&peer->perf->ntb->dev, "CMD exec: %d\n", cmd);
+
+	(void)queue_work(system_highpri_wq, &peer->service);
+
+	return 0;
+}
+
+static int perf_cmd_recv(struct perf_ctx *perf)
+{
+	struct perf_peer *peer;
+	int ret, pidx, cmd;
+	u64 data;
+
+	while (!(ret = perf->cmd_recv(perf, &pidx, &cmd, &data))) {
+		peer = &perf->peers[pidx];
+
+		switch (cmd) {
+		case PERF_CMD_SSIZE:
+			peer->inbuf_size = data;
+			return perf_cmd_exec(peer, PERF_CMD_RSIZE);
+		case PERF_CMD_SXLAT:
+			peer->outbuf_xlat = data;
+			return perf_cmd_exec(peer, PERF_CMD_RXLAT);
+		default:
+			dev_err(&perf->ntb->dev, "Recv invalid command\n");
+			return -EINVAL;
+		}
+	}
+
+	/* Return 0 if no data left to process, otherwise an error */
+	return ret == -ENODATA ? 0 : ret;
+}
+
+static void perf_link_event(void *ctx)
+{
+	struct perf_ctx *perf = ctx;
+	struct perf_peer *peer;
+	bool lnk_up;
+	int pidx;
+
+	for (pidx = 0; pidx < perf->pcnt; pidx++) {
+		peer = &perf->peers[pidx];
+
+		lnk_up = perf_link_is_up(peer);
+
+		if (lnk_up &&
+		    !test_and_set_bit(PERF_STS_LNKUP, &peer->sts)) {
+			perf_cmd_exec(peer, PERF_CMD_SSIZE);
+		} else if (!lnk_up &&
+			   test_and_clear_bit(PERF_STS_LNKUP, &peer->sts)) {
+			perf_cmd_exec(peer, PERF_CMD_CLEAR);
+		}
+	}
+}
+
+static void perf_db_event(void *ctx, int vec)
+{
+	struct perf_ctx *perf = ctx;
+
+	dev_dbg(&perf->ntb->dev, "DB vec %d mask %#llx bits %#llx\n", vec,
+		ntb_db_vector_mask(perf->ntb, vec), ntb_db_read(perf->ntb));
+
+	/* Just receive all available commands */
+	(void)perf_cmd_recv(perf);
+}
+
+static void perf_msg_event(void *ctx)
+{
+	struct perf_ctx *perf = ctx;
+
+	dev_dbg(&perf->ntb->dev, "Msg status bits %#llx\n",
+		ntb_msg_read_sts(perf->ntb));
+
+	/* Messages are only sent one-by-one */
+	(void)perf_cmd_recv(perf);
+}
+
+static const struct ntb_ctx_ops perf_ops = {
+	.link_event = perf_link_event,
+	.db_event = perf_db_event,
+	.msg_event = perf_msg_event
+};
+
+static void perf_free_outbuf(struct perf_peer *peer)
+{
+	(void)ntb_peer_mw_clear_trans(peer->perf->ntb, peer->pidx, peer->gidx);
+}
+
+static int perf_setup_outbuf(struct perf_peer *peer)
+{
+	struct perf_ctx *perf = peer->perf;
+	int ret;
+
+	/* Outbuf size can be unaligned due to custom max_mw_size */
+	ret = ntb_peer_mw_set_trans(perf->ntb, peer->pidx, peer->gidx,
+				    peer->outbuf_xlat, peer->outbuf_size);
+	if (ret) {
+		dev_err(&perf->ntb->dev, "Failed to set outbuf translation\n");
+		return ret;
+	}
+
+	/* Initialization is finally done */
+	set_bit(PERF_STS_DONE, &peer->sts);
+	complete_all(&peer->init_comp);
+
+	return 0;
+}
+
+static void perf_free_inbuf(struct perf_peer *peer)
+{
+	if (!peer->inbuf)
+		return;
+
+	(void)ntb_mw_clear_trans(peer->perf->ntb, peer->pidx, peer->gidx);
+	dma_free_coherent(&peer->perf->ntb->pdev->dev, peer->inbuf_size,
+			  peer->inbuf, peer->inbuf_xlat);
+	peer->inbuf = NULL;
+}
+
+static int perf_setup_inbuf(struct perf_peer *peer)
+{
+	resource_size_t xlat_align, size_align, size_max;
+	struct perf_ctx *perf = peer->perf;
+	int ret;
+
+	/* Get inbound MW parameters */
+	ret = ntb_mw_get_align(perf->ntb, peer->pidx, perf->gidx,
+			       &xlat_align, &size_align, &size_max);
+	if (ret) {
+		dev_err(&perf->ntb->dev, "Couldn't get inbuf restrictions\n");
+		return ret;
+	}
+
+	if (peer->inbuf_size > size_max) {
+		dev_err(&perf->ntb->dev, "Too big inbuf size %pa > %pa\n",
+			&peer->inbuf_size, &size_max);
+		return -EINVAL;
+	}
+
+	peer->inbuf_size = round_up(peer->inbuf_size, size_align);
+
+	perf_free_inbuf(peer);
+
+	peer->inbuf = dma_alloc_coherent(&perf->ntb->pdev->dev,
+					 peer->inbuf_size, &peer->inbuf_xlat,
+					 GFP_KERNEL);
+	if (!peer->inbuf) {
+		dev_err(&perf->ntb->dev, "Failed to alloc inbuf of %pa\n",
+			&peer->inbuf_size);
+		return -ENOMEM;
+	}
+	if (!IS_ALIGNED(peer->inbuf_xlat, xlat_align)) {
+		ret = -EINVAL;
+		dev_err(&perf->ntb->dev, "Unaligned inbuf allocated\n");
+		goto err_free_inbuf;
+	}
+
+	ret = ntb_mw_set_trans(perf->ntb, peer->pidx, peer->gidx,
+			       peer->inbuf_xlat, peer->inbuf_size);
+	if (ret) {
+		dev_err(&perf->ntb->dev, "Failed to set inbuf translation\n");
+		goto err_free_inbuf;
+	}
+
+	/*
+	 * We submit inbuf xlat transmission cmd for execution here to follow
+	 * the code architecture, even though this method is called from service
+	 * work itself so the command will be executed right after it returns.
+	 */
+	(void)perf_cmd_exec(peer, PERF_CMD_SXLAT);
+
+	return 0;
+
+err_free_inbuf:
+	perf_free_inbuf(peer);
+
+	return ret;
+}
+
+static void perf_service_work(struct work_struct *work)
+{
+	struct perf_peer *peer = to_peer_service(work);
+
+	if (test_and_clear_bit(PERF_CMD_SSIZE, &peer->sts))
+		perf_cmd_send(peer, PERF_CMD_SSIZE, peer->outbuf_size);
+
+	if (test_and_clear_bit(PERF_CMD_RSIZE, &peer->sts))
+		perf_setup_inbuf(peer);
+
+	if (test_and_clear_bit(PERF_CMD_SXLAT, &peer->sts))
+		perf_cmd_send(peer, PERF_CMD_SXLAT, peer->inbuf_xlat);
+
+	if (test_and_clear_bit(PERF_CMD_RXLAT, &peer->sts))
+		perf_setup_outbuf(peer);
+
+	if (test_and_clear_bit(PERF_CMD_CLEAR, &peer->sts)) {
+		init_completion(&peer->init_comp);
+		clear_bit(PERF_STS_DONE, &peer->sts);
+		if (test_bit(0, &peer->perf->busy_flag) &&
+		    peer == peer->perf->test_peer) {
+			dev_warn(&peer->perf->ntb->dev,
+				"Freeing while test on-fly\n");
+			perf_terminate_test(peer->perf);
+		}
+		perf_free_outbuf(peer);
+		perf_free_inbuf(peer);
+	}
+}
+
+static int perf_init_service(struct perf_ctx *perf)
+{
+	u64 mask;
+
+	if (ntb_peer_mw_count(perf->ntb) < perf->pcnt) {
+		dev_err(&perf->ntb->dev, "Not enough memory windows\n");
+		return -EINVAL;
+	}
+
+	if (ntb_msg_count(perf->ntb) >= PERF_MSG_CNT) {
+		perf->cmd_send = perf_msg_cmd_send;
+		perf->cmd_recv = perf_msg_cmd_recv;
+
+		dev_dbg(&perf->ntb->dev, "Message service initialized\n");
+
+		return 0;
+	}
+
+	dev_dbg(&perf->ntb->dev, "Message service unsupported\n");
+
+	mask = GENMASK_ULL(perf->pcnt, 0);
+	if (ntb_spad_count(perf->ntb) >= PERF_SPAD_CNT(perf->pcnt) &&
+	    (ntb_db_valid_mask(perf->ntb) & mask) == mask) {
+		perf->cmd_send = perf_spad_cmd_send;
+		perf->cmd_recv = perf_spad_cmd_recv;
+
+		dev_dbg(&perf->ntb->dev, "Scratchpad service initialized\n");
+
+		return 0;
+	}
+
+	dev_dbg(&perf->ntb->dev, "Scratchpad service unsupported\n");
+
+	dev_err(&perf->ntb->dev, "Command services unsupported\n");
+
+	return -EINVAL;
+}
+
+static int perf_enable_service(struct perf_ctx *perf)
+{
+	u64 mask, incmd_bit;
+	int ret, sidx, scnt;
+
+	mask = ntb_db_valid_mask(perf->ntb);
+	(void)ntb_db_set_mask(perf->ntb, mask);
+
+	ret = ntb_set_ctx(perf->ntb, perf, &perf_ops);
+	if (ret)
+		return ret;
+
+	if (perf->cmd_send == perf_msg_cmd_send) {
+		u64 inbits, outbits;
+
+		inbits = ntb_msg_inbits(perf->ntb);
+		outbits = ntb_msg_outbits(perf->ntb);
+		(void)ntb_msg_set_mask(perf->ntb, inbits | outbits);
+
+		incmd_bit = BIT_ULL(__ffs64(inbits));
+		ret = ntb_msg_clear_mask(perf->ntb, incmd_bit);
+
+		dev_dbg(&perf->ntb->dev, "MSG sts unmasked %#llx\n", incmd_bit);
+	} else {
+		scnt = ntb_spad_count(perf->ntb);
+		for (sidx = 0; sidx < scnt; sidx++)
+			ntb_spad_write(perf->ntb, sidx, PERF_CMD_INVAL);
+		incmd_bit = PERF_SPAD_NOTIFY(perf->gidx);
+		ret = ntb_db_clear_mask(perf->ntb, incmd_bit);
+
+		dev_dbg(&perf->ntb->dev, "DB bits unmasked %#llx\n", incmd_bit);
+	}
+	if (ret) {
+		ntb_clear_ctx(perf->ntb);
+		return ret;
+	}
+
+	ntb_link_enable(perf->ntb, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
+	/* Might be not necessary */
+	ntb_link_event(perf->ntb);
+
+	return 0;
+}
+
+static void perf_disable_service(struct perf_ctx *perf)
+{
+	int pidx;
+
+	if (perf->cmd_send == perf_msg_cmd_send) {
+		u64 inbits;
+
+		inbits = ntb_msg_inbits(perf->ntb);
+		(void)ntb_msg_set_mask(perf->ntb, inbits);
+	} else {
+		(void)ntb_db_set_mask(perf->ntb, PERF_SPAD_NOTIFY(perf->gidx));
+	}
+
+	ntb_clear_ctx(perf->ntb);
+
+	for (pidx = 0; pidx < perf->pcnt; pidx++)
+		perf_cmd_exec(&perf->peers[pidx], PERF_CMD_CLEAR);
+
+	for (pidx = 0; pidx < perf->pcnt; pidx++)
+		flush_work(&perf->peers[pidx].service);
+
+	for (pidx = 0; pidx < perf->pcnt; pidx++) {
+		struct perf_peer *peer = &perf->peers[pidx];
+
+		ntb_spad_write(perf->ntb, PERF_SPAD_CMD(peer->gidx), 0);
+	}
+
+	ntb_db_clear(perf->ntb, PERF_SPAD_NOTIFY(perf->gidx));
+
+	ntb_link_disable(perf->ntb);
+}
+
+/*==============================================================================
+ *                      Performance measuring work-thread
+ *==============================================================================
+ */
+
+static void perf_dma_copy_callback(void *data)
+{
+	struct perf_thread *pthr = data;
+
+	atomic_dec(&pthr->dma_sync);
+	wake_up(&pthr->dma_wait);
+}
+
+static int perf_copy_chunk(struct perf_thread *pthr,
+			   void __iomem *dst, void *src, size_t len)
+{
+	struct dma_async_tx_descriptor *tx;
+	struct dmaengine_unmap_data *unmap;
+	struct device *dma_dev;
+	int try = 0, ret = 0;
+	struct perf_peer *peer = pthr->perf->test_peer;
+	void __iomem *vbase;
+	void __iomem *dst_vaddr;
+	dma_addr_t dst_dma_addr;
+
+	if (!use_dma) {
+		memcpy_toio(dst, src, len);
+		goto ret_check_tsync;
+	}
+
+	dma_dev = pthr->dma_chan->device->dev;
+
+	if (!is_dma_copy_aligned(pthr->dma_chan->device, offset_in_page(src),
+				 offset_in_page(dst), len))
+		return -EIO;
+
+	vbase = peer->outbuf;
+	dst_vaddr = dst;
+	dst_dma_addr = peer->dma_dst_addr + (dst_vaddr - vbase);
+
+	unmap = dmaengine_get_unmap_data(dma_dev, 1, GFP_NOWAIT);
+	if (!unmap)
+		return -ENOMEM;
+
+	unmap->len = len;
+	unmap->addr[0] = dma_map_page(dma_dev, virt_to_page(src),
+		offset_in_page(src), len, DMA_TO_DEVICE);
+	if (dma_mapping_error(dma_dev, unmap->addr[0])) {
+		ret = -EIO;
+		goto err_free_resource;
+	}
+	unmap->to_cnt = 1;
+
+	do {
+		tx = dmaengine_prep_dma_memcpy(pthr->dma_chan, dst_dma_addr,
+			unmap->addr[0], len, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+		if (!tx)
+			msleep(DMA_MDELAY);
+	} while (!tx && (try++ < DMA_TRIES));
+
+	if (!tx) {
+		ret = -EIO;
+		goto err_free_resource;
+	}
+
+	tx->callback = perf_dma_copy_callback;
+	tx->callback_param = pthr;
+	dma_set_unmap(tx, unmap);
+
+	ret = dma_submit_error(dmaengine_submit(tx));
+	if (ret)
+		goto err_free_resource;
+
+	dmaengine_unmap_put(unmap);
+
+	atomic_inc(&pthr->dma_sync);
+	dma_async_issue_pending(pthr->dma_chan);
+
+ret_check_tsync:
+	return likely(atomic_read(&pthr->perf->tsync) > 0) ? 0 : -EINTR;
+
+err_free_resource:
+	dmaengine_unmap_put(unmap);
+
+	return ret;
+}
+
+static bool perf_dma_filter(struct dma_chan *chan, void *data)
+{
+	struct perf_ctx *perf = data;
+	int node;
+
+	node = dev_to_node(&perf->ntb->dev);
+
+	return node == NUMA_NO_NODE || node == dev_to_node(chan->device->dev);
+}
+
+static int perf_init_test(struct perf_thread *pthr)
+{
+	struct perf_ctx *perf = pthr->perf;
+	dma_cap_mask_t dma_mask;
+	struct perf_peer *peer = pthr->perf->test_peer;
+
+	pthr->src = kmalloc_node(perf->test_peer->outbuf_size, GFP_KERNEL,
+				 dev_to_node(&perf->ntb->dev));
+	if (!pthr->src)
+		return -ENOMEM;
+
+	get_random_bytes(pthr->src, perf->test_peer->outbuf_size);
+
+	if (!use_dma)
+		return 0;
+
+	dma_cap_zero(dma_mask);
+	dma_cap_set(DMA_MEMCPY, dma_mask);
+	pthr->dma_chan = dma_request_channel(dma_mask, perf_dma_filter, perf);
+	if (!pthr->dma_chan) {
+		dev_err(&perf->ntb->dev, "%d: Failed to get DMA channel\n",
+			pthr->tidx);
+		goto err_free;
+	}
+	peer->dma_dst_addr =
+		dma_map_resource(pthr->dma_chan->device->dev,
+				 peer->out_phys_addr, peer->outbuf_size,
+				 DMA_FROM_DEVICE, 0);
+	if (dma_mapping_error(pthr->dma_chan->device->dev,
+			      peer->dma_dst_addr)) {
+		dev_err(pthr->dma_chan->device->dev, "%d: Failed to map DMA addr\n",
+			pthr->tidx);
+		peer->dma_dst_addr = 0;
+		dma_release_channel(pthr->dma_chan);
+		goto err_free;
+	}
+	dev_dbg(pthr->dma_chan->device->dev, "%d: Map MMIO %pa to DMA addr %pad\n",
+			pthr->tidx,
+			&peer->out_phys_addr,
+			&peer->dma_dst_addr);
+
+	atomic_set(&pthr->dma_sync, 0);
+	return 0;
+
+err_free:
+	atomic_dec(&perf->tsync);
+	wake_up(&perf->twait);
+	kfree(pthr->src);
+	return -ENODEV;
+}
+
+static int perf_run_test(struct perf_thread *pthr)
+{
+	struct perf_peer *peer = pthr->perf->test_peer;
+	struct perf_ctx *perf = pthr->perf;
+	void __iomem *flt_dst, *bnd_dst;
+	u64 total_size, chunk_size;
+	void *flt_src;
+	int ret = 0;
+
+	total_size = 1ULL << total_order;
+	chunk_size = 1ULL << chunk_order;
+	chunk_size = min_t(u64, peer->outbuf_size, chunk_size);
+
+	flt_src = pthr->src;
+	bnd_dst = peer->outbuf + peer->outbuf_size;
+	flt_dst = peer->outbuf;
+
+	pthr->duration = ktime_get();
+
+	/* Copied field is cleared on test launch stage */
+	while (pthr->copied < total_size) {
+		ret = perf_copy_chunk(pthr, flt_dst, flt_src, chunk_size);
+		if (ret) {
+			dev_err(&perf->ntb->dev, "%d: Got error %d on test\n",
+				pthr->tidx, ret);
+			return ret;
+		}
+
+		pthr->copied += chunk_size;
+
+		flt_dst += chunk_size;
+		flt_src += chunk_size;
+		if (flt_dst >= bnd_dst || flt_dst < peer->outbuf) {
+			flt_dst = peer->outbuf;
+			flt_src = pthr->src;
+		}
+
+		/* Give up CPU to give a chance for other threads to use it */
+		schedule();
+	}
+
+	return 0;
+}
+
+static int perf_sync_test(struct perf_thread *pthr)
+{
+	struct perf_ctx *perf = pthr->perf;
+
+	if (!use_dma)
+		goto no_dma_ret;
+
+	wait_event(pthr->dma_wait,
+		   (atomic_read(&pthr->dma_sync) == 0 ||
+		    atomic_read(&perf->tsync) < 0));
+
+	if (atomic_read(&perf->tsync) < 0)
+		return -EINTR;
+
+no_dma_ret:
+	pthr->duration = ktime_sub(ktime_get(), pthr->duration);
+
+	dev_dbg(&perf->ntb->dev, "%d: copied %llu bytes\n",
+		pthr->tidx, pthr->copied);
+
+	dev_dbg(&perf->ntb->dev, "%d: lasted %llu usecs\n",
+		pthr->tidx, ktime_to_us(pthr->duration));
+
+	dev_dbg(&perf->ntb->dev, "%d: %llu MBytes/s\n", pthr->tidx,
+		div64_u64(pthr->copied, ktime_to_us(pthr->duration)));
+
+	return 0;
+}
+
+static void perf_clear_test(struct perf_thread *pthr)
+{
+	struct perf_ctx *perf = pthr->perf;
+
+	if (!use_dma)
+		goto no_dma_notify;
+
+	/*
+	 * If test finished without errors, termination isn't needed.
+	 * We call it anyway just to be sure of the transfers completion.
+	 */
+	(void)dmaengine_terminate_sync(pthr->dma_chan);
+	if (pthr->perf->test_peer->dma_dst_addr)
+		dma_unmap_resource(pthr->dma_chan->device->dev,
+				   pthr->perf->test_peer->dma_dst_addr,
+				   pthr->perf->test_peer->outbuf_size,
+				   DMA_FROM_DEVICE, 0);
+
+	dma_release_channel(pthr->dma_chan);
+
+no_dma_notify:
+	atomic_dec(&perf->tsync);
+	wake_up(&perf->twait);
+	kfree(pthr->src);
+}
+
+static void perf_thread_work(struct work_struct *work)
+{
+	struct perf_thread *pthr = to_thread_work(work);
+	int ret;
+
+	/*
+	 * Perform stages in compliance with use_dma flag value.
+	 * Test status is changed only if error happened, otherwise
+	 * status -ENODATA is kept while test is on-fly. Results
+	 * synchronization is performed only if test fininshed
+	 * without an error or interruption.
+	 */
+	ret = perf_init_test(pthr);
+	if (ret) {
+		pthr->status = ret;
+		return;
+	}
+
+	ret = perf_run_test(pthr);
+	if (ret) {
+		pthr->status = ret;
+		goto err_clear_test;
+	}
+
+	pthr->status = perf_sync_test(pthr);
+
+err_clear_test:
+	perf_clear_test(pthr);
+}
+
+static int perf_set_tcnt(struct perf_ctx *perf, u8 tcnt)
+{
+	if (tcnt == 0 || tcnt > MAX_THREADS_CNT)
+		return -EINVAL;
+
+	if (test_and_set_bit_lock(0, &perf->busy_flag))
+		return -EBUSY;
+
+	perf->tcnt = tcnt;
+
+	clear_bit_unlock(0, &perf->busy_flag);
+
+	return 0;
+}
+
+static void perf_terminate_test(struct perf_ctx *perf)
+{
+	int tidx;
+
+	atomic_set(&perf->tsync, -1);
+	wake_up(&perf->twait);
+
+	for (tidx = 0; tidx < MAX_THREADS_CNT; tidx++) {
+		wake_up(&perf->threads[tidx].dma_wait);
+		cancel_work_sync(&perf->threads[tidx].work);
+	}
+}
+
+static int perf_submit_test(struct perf_peer *peer)
+{
+	struct perf_ctx *perf = peer->perf;
+	struct perf_thread *pthr;
+	int tidx, ret;
+
+	ret = wait_for_completion_interruptible(&peer->init_comp);
+	if (ret < 0)
+		return ret;
+
+	if (test_and_set_bit_lock(0, &perf->busy_flag))
+		return -EBUSY;
+
+	perf->test_peer = peer;
+	atomic_set(&perf->tsync, perf->tcnt);
+
+	for (tidx = 0; tidx < MAX_THREADS_CNT; tidx++) {
+		pthr = &perf->threads[tidx];
+
+		pthr->status = -ENODATA;
+		pthr->copied = 0;
+		pthr->duration = ktime_set(0, 0);
+		if (tidx < perf->tcnt)
+			(void)queue_work(perf_wq, &pthr->work);
+	}
+
+	ret = wait_event_interruptible(perf->twait,
+				       atomic_read(&perf->tsync) <= 0);
+	if (ret == -ERESTARTSYS) {
+		perf_terminate_test(perf);
+		ret = -EINTR;
+	}
+
+	clear_bit_unlock(0, &perf->busy_flag);
+
+	return ret;
+}
+
+static int perf_read_stats(struct perf_ctx *perf, char *buf,
+			   size_t size, ssize_t *pos)
+{
+	struct perf_thread *pthr;
+	int tidx;
+
+	if (test_and_set_bit_lock(0, &perf->busy_flag))
+		return -EBUSY;
+
+	(*pos) += scnprintf(buf + *pos, size - *pos,
+		"    Peer %d test statistics:\n", perf->test_peer->pidx);
+
+	for (tidx = 0; tidx < MAX_THREADS_CNT; tidx++) {
+		pthr = &perf->threads[tidx];
+
+		if (pthr->status == -ENODATA)
+			continue;
+
+		if (pthr->status) {
+			(*pos) += scnprintf(buf + *pos, size - *pos,
+				"%d: error status %d\n", tidx, pthr->status);
+			continue;
+		}
+
+		(*pos) += scnprintf(buf + *pos, size - *pos,
+			"%d: copied %llu bytes in %llu usecs, %llu MBytes/s\n",
+			tidx, pthr->copied, ktime_to_us(pthr->duration),
+			div64_u64(pthr->copied, ktime_to_us(pthr->duration)));
+	}
+
+	clear_bit_unlock(0, &perf->busy_flag);
+
+	return 0;
+}
+
+static void perf_init_threads(struct perf_ctx *perf)
+{
+	struct perf_thread *pthr;
+	int tidx;
+
+	perf->tcnt = DEF_THREADS_CNT;
+	perf->test_peer = &perf->peers[0];
+	init_waitqueue_head(&perf->twait);
+
+	for (tidx = 0; tidx < MAX_THREADS_CNT; tidx++) {
+		pthr = &perf->threads[tidx];
+
+		pthr->perf = perf;
+		pthr->tidx = tidx;
+		pthr->status = -ENODATA;
+		init_waitqueue_head(&pthr->dma_wait);
+		INIT_WORK(&pthr->work, perf_thread_work);
+	}
+}
+
+static void perf_clear_threads(struct perf_ctx *perf)
+{
+	perf_terminate_test(perf);
+}
+
+/*==============================================================================
+ *                               DebugFS nodes
+ *==============================================================================
+ */
+
+static ssize_t perf_dbgfs_read_info(struct file *filep, char __user *ubuf,
+				    size_t size, loff_t *offp)
+{
+	struct perf_ctx *perf = filep->private_data;
+	struct perf_peer *peer;
+	size_t buf_size;
+	ssize_t pos = 0;
+	int ret, pidx;
+	char *buf;
+
+	buf_size = min_t(size_t, size, 0x1000U);
+
+	buf = kmalloc(buf_size, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	pos += scnprintf(buf + pos, buf_size - pos,
+		"    Performance measuring tool info:\n\n");
+
+	pos += scnprintf(buf + pos, buf_size - pos,
+		"Local port %d, Global index %d\n", ntb_port_number(perf->ntb),
+		perf->gidx);
+	pos += scnprintf(buf + pos, buf_size - pos, "Test status: ");
+	if (test_bit(0, &perf->busy_flag)) {
+		pos += scnprintf(buf + pos, buf_size - pos,
+			"on-fly with port %d (%d)\n",
+			ntb_peer_port_number(perf->ntb, perf->test_peer->pidx),
+			perf->test_peer->pidx);
+	} else {
+		pos += scnprintf(buf + pos, buf_size - pos, "idle\n");
+	}
+
+	for (pidx = 0; pidx < perf->pcnt; pidx++) {
+		peer = &perf->peers[pidx];
+
+		pos += scnprintf(buf + pos, buf_size - pos,
+			"Port %d (%d), Global index %d:\n",
+			ntb_peer_port_number(perf->ntb, peer->pidx), peer->pidx,
+			peer->gidx);
+
+		pos += scnprintf(buf + pos, buf_size - pos,
+			"\tLink status: %s\n",
+			test_bit(PERF_STS_LNKUP, &peer->sts) ? "up" : "down");
+
+		pos += scnprintf(buf + pos, buf_size - pos,
+			"\tOut buffer addr 0x%pK\n", peer->outbuf);
+
+		pos += scnprintf(buf + pos, buf_size - pos,
+			"\tOut buff phys addr %pap\n", &peer->out_phys_addr);
+
+		pos += scnprintf(buf + pos, buf_size - pos,
+			"\tOut buffer size %pa\n", &peer->outbuf_size);
+
+		pos += scnprintf(buf + pos, buf_size - pos,
+			"\tOut buffer xlat 0x%016llx[p]\n", peer->outbuf_xlat);
+
+		if (!peer->inbuf) {
+			pos += scnprintf(buf + pos, buf_size - pos,
+				"\tIn buffer addr: unallocated\n");
+			continue;
+		}
+
+		pos += scnprintf(buf + pos, buf_size - pos,
+			"\tIn buffer addr 0x%pK\n", peer->inbuf);
+
+		pos += scnprintf(buf + pos, buf_size - pos,
+			"\tIn buffer size %pa\n", &peer->inbuf_size);
+
+		pos += scnprintf(buf + pos, buf_size - pos,
+			"\tIn buffer xlat %pad[p]\n", &peer->inbuf_xlat);
+	}
+
+	ret = simple_read_from_buffer(ubuf, size, offp, buf, pos);
+	kfree(buf);
+
+	return ret;
+}
+
+static const struct file_operations perf_dbgfs_info = {
+	.open = simple_open,
+	.read = perf_dbgfs_read_info
+};
+
+static ssize_t perf_dbgfs_read_run(struct file *filep, char __user *ubuf,
+				   size_t size, loff_t *offp)
+{
+	struct perf_ctx *perf = filep->private_data;
+	ssize_t ret, pos = 0;
+	char *buf;
+
+	buf = kmalloc(PERF_BUF_LEN, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	ret = perf_read_stats(perf, buf, PERF_BUF_LEN, &pos);
+	if (ret)
+		goto err_free;
+
+	ret = simple_read_from_buffer(ubuf, size, offp, buf, pos);
+err_free:
+	kfree(buf);
+
+	return ret;
+}
+
+static ssize_t perf_dbgfs_write_run(struct file *filep, const char __user *ubuf,
+				    size_t size, loff_t *offp)
+{
+	struct perf_ctx *perf = filep->private_data;
+	struct perf_peer *peer;
+	int pidx, ret;
+
+	ret = kstrtoint_from_user(ubuf, size, 0, &pidx);
+	if (ret)
+		return ret;
+
+	if (pidx < 0 || pidx >= perf->pcnt)
+		return -EINVAL;
+
+	peer = &perf->peers[pidx];
+
+	ret = perf_submit_test(peer);
+	if (ret)
+		return ret;
+
+	return size;
+}
+
+static const struct file_operations perf_dbgfs_run = {
+	.open = simple_open,
+	.read = perf_dbgfs_read_run,
+	.write = perf_dbgfs_write_run
+};
+
+static ssize_t perf_dbgfs_read_tcnt(struct file *filep, char __user *ubuf,
+				    size_t size, loff_t *offp)
+{
+	struct perf_ctx *perf = filep->private_data;
+	char buf[8];
+	ssize_t pos;
+
+	pos = scnprintf(buf, sizeof(buf), "%hhu\n", perf->tcnt);
+
+	return simple_read_from_buffer(ubuf, size, offp, buf, pos);
+}
+
+static ssize_t perf_dbgfs_write_tcnt(struct file *filep,
+				     const char __user *ubuf,
+				     size_t size, loff_t *offp)
+{
+	struct perf_ctx *perf = filep->private_data;
+	int ret;
+	u8 val;
+
+	ret = kstrtou8_from_user(ubuf, size, 0, &val);
+	if (ret)
+		return ret;
+
+	ret = perf_set_tcnt(perf, val);
+	if (ret)
+		return ret;
+
+	return size;
+}
+
+static const struct file_operations perf_dbgfs_tcnt = {
+	.open = simple_open,
+	.read = perf_dbgfs_read_tcnt,
+	.write = perf_dbgfs_write_tcnt
+};
+
+static void perf_setup_dbgfs(struct perf_ctx *perf)
+{
+	struct pci_dev *pdev = perf->ntb->pdev;
+
+	perf->dbgfs_dir = debugfs_create_dir(pci_name(pdev), perf_dbgfs_topdir);
+	if (IS_ERR(perf->dbgfs_dir)) {
+		dev_warn(&perf->ntb->dev, "DebugFS unsupported\n");
+		return;
+	}
+
+	debugfs_create_file("info", 0600, perf->dbgfs_dir, perf,
+			    &perf_dbgfs_info);
+
+	debugfs_create_file("run", 0600, perf->dbgfs_dir, perf,
+			    &perf_dbgfs_run);
+
+	debugfs_create_file("threads_count", 0600, perf->dbgfs_dir, perf,
+			    &perf_dbgfs_tcnt);
+
+	/* They are made read-only for test exec safety and integrity */
+	debugfs_create_u8("chunk_order", 0500, perf->dbgfs_dir, &chunk_order);
+
+	debugfs_create_u8("total_order", 0500, perf->dbgfs_dir, &total_order);
+
+	debugfs_create_bool("use_dma", 0500, perf->dbgfs_dir, &use_dma);
+}
+
+static void perf_clear_dbgfs(struct perf_ctx *perf)
+{
+	debugfs_remove_recursive(perf->dbgfs_dir);
+}
+
+/*==============================================================================
+ *                        Basic driver initialization
+ *==============================================================================
+ */
+
+static struct perf_ctx *perf_create_data(struct ntb_dev *ntb)
+{
+	struct perf_ctx *perf;
+
+	perf = devm_kzalloc(&ntb->dev, sizeof(*perf), GFP_KERNEL);
+	if (!perf)
+		return ERR_PTR(-ENOMEM);
+
+	perf->pcnt = ntb_peer_port_count(ntb);
+	perf->peers = devm_kcalloc(&ntb->dev, perf->pcnt, sizeof(*perf->peers),
+				  GFP_KERNEL);
+	if (!perf->peers)
+		return ERR_PTR(-ENOMEM);
+
+	perf->ntb = ntb;
+
+	return perf;
+}
+
+static int perf_setup_peer_mw(struct perf_peer *peer)
+{
+	struct perf_ctx *perf = peer->perf;
+	phys_addr_t phys_addr;
+	int ret;
+
+	/* Get outbound MW parameters and map it */
+	ret = ntb_peer_mw_get_addr(perf->ntb, perf->gidx, &phys_addr,
+				   &peer->outbuf_size);
+	if (ret)
+		return ret;
+
+	peer->outbuf = devm_ioremap_wc(&perf->ntb->dev, phys_addr,
+					peer->outbuf_size);
+	if (!peer->outbuf)
+		return -ENOMEM;
+
+	peer->out_phys_addr = phys_addr;
+
+	if (max_mw_size && peer->outbuf_size > max_mw_size) {
+		peer->outbuf_size = max_mw_size;
+		dev_warn(&peer->perf->ntb->dev,
+			"Peer %d outbuf reduced to %pa\n", peer->pidx,
+			&peer->outbuf_size);
+	}
+
+	return 0;
+}
+
+static int perf_init_peers(struct perf_ctx *perf)
+{
+	struct perf_peer *peer;
+	int pidx, lport, ret;
+
+	lport = ntb_port_number(perf->ntb);
+	perf->gidx = -1;
+	for (pidx = 0; pidx < perf->pcnt; pidx++) {
+		peer = &perf->peers[pidx];
+
+		peer->perf = perf;
+		peer->pidx = pidx;
+		if (lport < ntb_peer_port_number(perf->ntb, pidx)) {
+			if (perf->gidx == -1)
+				perf->gidx = pidx;
+			peer->gidx = pidx + 1;
+		} else {
+			peer->gidx = pidx;
+		}
+		INIT_WORK(&peer->service, perf_service_work);
+		init_completion(&peer->init_comp);
+	}
+	if (perf->gidx == -1)
+		perf->gidx = pidx;
+
+	/*
+	 * Hardware with only two ports may not have unique port
+	 * numbers. In this case, the gidxs should all be zero.
+	 */
+	if (perf->pcnt == 1 &&  ntb_port_number(perf->ntb) == 0 &&
+	    ntb_peer_port_number(perf->ntb, 0) == 0) {
+		perf->gidx = 0;
+		perf->peers[0].gidx = 0;
+	}
+
+	for (pidx = 0; pidx < perf->pcnt; pidx++) {
+		ret = perf_setup_peer_mw(&perf->peers[pidx]);
+		if (ret)
+			return ret;
+	}
+
+	dev_dbg(&perf->ntb->dev, "Global port index %d\n", perf->gidx);
+
+	return 0;
+}
+
+static int perf_probe(struct ntb_client *client, struct ntb_dev *ntb)
+{
+	struct perf_ctx *perf;
+	int ret;
+
+	perf = perf_create_data(ntb);
+	if (IS_ERR(perf))
+		return PTR_ERR(perf);
+
+	ret = perf_init_peers(perf);
+	if (ret)
+		return ret;
+
+	perf_init_threads(perf);
+
+	ret = perf_init_service(perf);
+	if (ret)
+		return ret;
+
+	ret = perf_enable_service(perf);
+	if (ret)
+		return ret;
+
+	perf_setup_dbgfs(perf);
+
+	return 0;
+}
+
+static void perf_remove(struct ntb_client *client, struct ntb_dev *ntb)
+{
+	struct perf_ctx *perf = ntb->ctx;
+
+	perf_clear_dbgfs(perf);
+
+	perf_disable_service(perf);
+
+	perf_clear_threads(perf);
+}
+
+static struct ntb_client perf_client = {
+	.ops = {
+		.probe = perf_probe,
+		.remove = perf_remove
+	}
+};
+
+static int __init perf_init(void)
+{
+	int ret;
+
+	if (chunk_order > MAX_CHUNK_ORDER) {
+		chunk_order = MAX_CHUNK_ORDER;
+		pr_info("Chunk order reduced to %hhu\n", chunk_order);
+	}
+
+	if (total_order < chunk_order) {
+		total_order = chunk_order;
+		pr_info("Total data order reduced to %hhu\n", total_order);
+	}
+
+	perf_wq = alloc_workqueue("perf_wq", WQ_UNBOUND | WQ_SYSFS, 0);
+	if (!perf_wq)
+		return -ENOMEM;
+
+	if (debugfs_initialized())
+		perf_dbgfs_topdir = debugfs_create_dir(KBUILD_MODNAME, NULL);
+
+	ret = ntb_register_client(&perf_client);
+	if (ret) {
+		debugfs_remove_recursive(perf_dbgfs_topdir);
+		destroy_workqueue(perf_wq);
+	}
+
+	return ret;
+}
+module_init(perf_init);
+
+static void __exit perf_exit(void)
+{
+	ntb_unregister_client(&perf_client);
+	debugfs_remove_recursive(perf_dbgfs_topdir);
+	destroy_workqueue(perf_wq);
+}
+module_exit(perf_exit);
diff --git a/drivers/ntb/test/ntb_pingpong.c b/drivers/ntb/test/ntb_pingpong.c
new file mode 100644
index 000000000..1c1c74f4f
--- /dev/null
+++ b/drivers/ntb/test/ntb_pingpong.c
@@ -0,0 +1,432 @@
+/*
+ *   This file is provided under a dual BSD/GPLv2 license.  When using or
+ *   redistributing this file, you may do so under either license.
+ *
+ *   GPL LICENSE SUMMARY
+ *
+ *   Copyright (C) 2015 EMC Corporation. All Rights Reserved.
+ *   Copyright (C) 2017 T-Platforms. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of version 2 of the GNU General Public License as
+ *   published by the Free Software Foundation.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *   General Public License for more details.
+ *
+ *   BSD LICENSE
+ *
+ *   Copyright (C) 2015 EMC Corporation. All Rights Reserved.
+ *   Copyright (C) 2017 T-Platforms. All Rights Reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copy
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * PCIe NTB Pingpong Linux driver
+ */
+
+/*
+ * How to use this tool, by example.
+ *
+ * Assuming $DBG_DIR is something like:
+ * '/sys/kernel/debug/ntb_perf/0000:00:03.0'
+ * Suppose aside from local device there is at least one remote device
+ * connected to NTB with index 0.
+ *-----------------------------------------------------------------------------
+ * Eg: install driver with specified delay between doorbell event and response
+ *
+ * root@self# insmod ntb_pingpong.ko delay_ms=1000
+ *-----------------------------------------------------------------------------
+ * Eg: get number of ping-pong cycles performed
+ *
+ * root@self# cat $DBG_DIR/count
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/bitops.h>
+
+#include <linux/pci.h>
+#include <linux/slab.h>
+#include <linux/hrtimer.h>
+#include <linux/debugfs.h>
+
+#include <linux/ntb.h>
+
+#define DRIVER_NAME		"ntb_pingpong"
+#define DRIVER_VERSION		"2.0"
+
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_VERSION(DRIVER_VERSION);
+MODULE_AUTHOR("Allen Hubbe <Allen.Hubbe@emc.com>");
+MODULE_DESCRIPTION("PCIe NTB Simple Pingpong Client");
+
+static unsigned int unsafe;
+module_param(unsafe, uint, 0644);
+MODULE_PARM_DESC(unsafe, "Run even though ntb operations may be unsafe");
+
+static unsigned int delay_ms = 1000;
+module_param(delay_ms, uint, 0644);
+MODULE_PARM_DESC(delay_ms, "Milliseconds to delay the response to peer");
+
+struct pp_ctx {
+	struct ntb_dev *ntb;
+	struct hrtimer timer;
+	u64 in_db;
+	u64 out_db;
+	int out_pidx;
+	u64 nmask;
+	u64 pmask;
+	atomic_t count;
+	spinlock_t lock;
+	struct dentry *dbgfs_dir;
+};
+#define to_pp_timer(__timer) \
+	container_of(__timer, struct pp_ctx, timer)
+
+static struct dentry *pp_dbgfs_topdir;
+
+static int pp_find_next_peer(struct pp_ctx *pp)
+{
+	u64 link, out_db;
+	int pidx;
+
+	link = ntb_link_is_up(pp->ntb, NULL, NULL);
+
+	/* Find next available peer */
+	if (link & pp->nmask)
+		pidx = __ffs64(link & pp->nmask);
+	else if (link & pp->pmask)
+		pidx = __ffs64(link & pp->pmask);
+	else
+		return -ENODEV;
+
+	out_db = BIT_ULL(ntb_peer_port_number(pp->ntb, pidx));
+
+	spin_lock(&pp->lock);
+	pp->out_pidx = pidx;
+	pp->out_db = out_db;
+	spin_unlock(&pp->lock);
+
+	return 0;
+}
+
+static void pp_setup(struct pp_ctx *pp)
+{
+	int ret;
+
+	ntb_db_set_mask(pp->ntb, pp->in_db);
+
+	hrtimer_cancel(&pp->timer);
+
+	ret = pp_find_next_peer(pp);
+	if (ret == -ENODEV) {
+		dev_dbg(&pp->ntb->dev, "Got no peers, so cancel\n");
+		return;
+	}
+
+	dev_dbg(&pp->ntb->dev, "Ping-pong started with port %d, db %#llx\n",
+		ntb_peer_port_number(pp->ntb, pp->out_pidx), pp->out_db);
+
+	hrtimer_start(&pp->timer, ms_to_ktime(delay_ms), HRTIMER_MODE_REL);
+}
+
+static void pp_clear(struct pp_ctx *pp)
+{
+	hrtimer_cancel(&pp->timer);
+
+	ntb_db_set_mask(pp->ntb, pp->in_db);
+
+	dev_dbg(&pp->ntb->dev, "Ping-pong cancelled\n");
+}
+
+static void pp_ping(struct pp_ctx *pp)
+{
+	u32 count;
+
+	count = atomic_read(&pp->count);
+
+	spin_lock(&pp->lock);
+	ntb_peer_spad_write(pp->ntb, pp->out_pidx, 0, count);
+	ntb_peer_msg_write(pp->ntb, pp->out_pidx, 0, count);
+
+	dev_dbg(&pp->ntb->dev, "Ping port %d spad %#x, msg %#x\n",
+		ntb_peer_port_number(pp->ntb, pp->out_pidx), count, count);
+
+	ntb_peer_db_set(pp->ntb, pp->out_db);
+	ntb_db_clear_mask(pp->ntb, pp->in_db);
+	spin_unlock(&pp->lock);
+}
+
+static void pp_pong(struct pp_ctx *pp)
+{
+	u32 msg_data, spad_data;
+	int pidx = 0;
+
+	/* Read pong data */
+	spad_data = ntb_spad_read(pp->ntb, 0);
+	msg_data = ntb_msg_read(pp->ntb, &pidx, 0);
+	ntb_msg_clear_sts(pp->ntb, -1);
+
+	/*
+	 * Scratchpad and message data may differ, since message register can't
+	 * be rewritten unless status is cleared. Additionally either of them
+	 * might be unsupported
+	 */
+	dev_dbg(&pp->ntb->dev, "Pong spad %#x, msg %#x (port %d)\n",
+		spad_data, msg_data, ntb_peer_port_number(pp->ntb, pidx));
+
+	atomic_inc(&pp->count);
+
+	ntb_db_set_mask(pp->ntb, pp->in_db);
+	ntb_db_clear(pp->ntb, pp->in_db);
+
+	hrtimer_start(&pp->timer, ms_to_ktime(delay_ms), HRTIMER_MODE_REL);
+}
+
+static enum hrtimer_restart pp_timer_func(struct hrtimer *t)
+{
+	struct pp_ctx *pp = to_pp_timer(t);
+
+	pp_ping(pp);
+
+	return HRTIMER_NORESTART;
+}
+
+static void pp_link_event(void *ctx)
+{
+	struct pp_ctx *pp = ctx;
+
+	pp_setup(pp);
+}
+
+static void pp_db_event(void *ctx, int vec)
+{
+	struct pp_ctx *pp = ctx;
+
+	pp_pong(pp);
+}
+
+static const struct ntb_ctx_ops pp_ops = {
+	.link_event = pp_link_event,
+	.db_event = pp_db_event
+};
+
+static int pp_check_ntb(struct ntb_dev *ntb)
+{
+	u64 pmask;
+
+	if (ntb_db_is_unsafe(ntb)) {
+		dev_dbg(&ntb->dev, "Doorbell is unsafe\n");
+		if (!unsafe)
+			return -EINVAL;
+	}
+
+	if (ntb_spad_is_unsafe(ntb)) {
+		dev_dbg(&ntb->dev, "Scratchpad is unsafe\n");
+		if (!unsafe)
+			return -EINVAL;
+	}
+
+	pmask = GENMASK_ULL(ntb_peer_port_count(ntb), 0);
+	if ((ntb_db_valid_mask(ntb) & pmask) != pmask) {
+		dev_err(&ntb->dev, "Unsupported DB configuration\n");
+		return -EINVAL;
+	}
+
+	if (ntb_spad_count(ntb) < 1 && ntb_msg_count(ntb) < 1) {
+		dev_err(&ntb->dev, "Scratchpads and messages unsupported\n");
+		return -EINVAL;
+	} else if (ntb_spad_count(ntb) < 1) {
+		dev_dbg(&ntb->dev, "Scratchpads unsupported\n");
+	} else if (ntb_msg_count(ntb) < 1) {
+		dev_dbg(&ntb->dev, "Messages unsupported\n");
+	}
+
+	return 0;
+}
+
+static struct pp_ctx *pp_create_data(struct ntb_dev *ntb)
+{
+	struct pp_ctx *pp;
+
+	pp = devm_kzalloc(&ntb->dev, sizeof(*pp), GFP_KERNEL);
+	if (!pp)
+		return ERR_PTR(-ENOMEM);
+
+	pp->ntb = ntb;
+	atomic_set(&pp->count, 0);
+	spin_lock_init(&pp->lock);
+	hrtimer_setup(&pp->timer, pp_timer_func, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+
+	return pp;
+}
+
+static void pp_init_flds(struct pp_ctx *pp)
+{
+	int pidx, lport, pcnt;
+
+	/* Find global port index */
+	lport = ntb_port_number(pp->ntb);
+	pcnt = ntb_peer_port_count(pp->ntb);
+	for (pidx = 0; pidx < pcnt; pidx++) {
+		if (lport < ntb_peer_port_number(pp->ntb, pidx))
+			break;
+	}
+
+	pp->in_db = BIT_ULL(lport);
+	pp->pmask = GENMASK_ULL(pidx, 0) >> 1;
+	pp->nmask = GENMASK_ULL(pcnt - 1, pidx);
+
+	dev_dbg(&pp->ntb->dev, "Inbound db %#llx, prev %#llx, next %#llx\n",
+		pp->in_db, pp->pmask, pp->nmask);
+}
+
+static int pp_mask_events(struct pp_ctx *pp)
+{
+	u64 db_mask, msg_mask;
+	int ret;
+
+	db_mask = ntb_db_valid_mask(pp->ntb);
+	ret = ntb_db_set_mask(pp->ntb, db_mask);
+	if (ret)
+		return ret;
+
+	/* Skip message events masking if unsupported */
+	if (ntb_msg_count(pp->ntb) < 1)
+		return 0;
+
+	msg_mask = ntb_msg_outbits(pp->ntb) | ntb_msg_inbits(pp->ntb);
+	return ntb_msg_set_mask(pp->ntb, msg_mask);
+}
+
+static int pp_setup_ctx(struct pp_ctx *pp)
+{
+	int ret;
+
+	ret = ntb_set_ctx(pp->ntb, pp, &pp_ops);
+	if (ret)
+		return ret;
+
+	ntb_link_enable(pp->ntb, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
+	/* Might be not necessary */
+	ntb_link_event(pp->ntb);
+
+	return 0;
+}
+
+static void pp_clear_ctx(struct pp_ctx *pp)
+{
+	ntb_link_disable(pp->ntb);
+
+	ntb_clear_ctx(pp->ntb);
+}
+
+static void pp_setup_dbgfs(struct pp_ctx *pp)
+{
+	struct pci_dev *pdev = pp->ntb->pdev;
+
+	pp->dbgfs_dir = debugfs_create_dir(pci_name(pdev), pp_dbgfs_topdir);
+
+	debugfs_create_atomic_t("count", 0600, pp->dbgfs_dir, &pp->count);
+}
+
+static void pp_clear_dbgfs(struct pp_ctx *pp)
+{
+	debugfs_remove_recursive(pp->dbgfs_dir);
+}
+
+static int pp_probe(struct ntb_client *client, struct ntb_dev *ntb)
+{
+	struct pp_ctx *pp;
+	int ret;
+
+	ret = pp_check_ntb(ntb);
+	if (ret)
+		return ret;
+
+	pp = pp_create_data(ntb);
+	if (IS_ERR(pp))
+		return PTR_ERR(pp);
+
+	pp_init_flds(pp);
+
+	ret = pp_mask_events(pp);
+	if (ret)
+		return ret;
+
+	ret = pp_setup_ctx(pp);
+	if (ret)
+		return ret;
+
+	pp_setup_dbgfs(pp);
+
+	return 0;
+}
+
+static void pp_remove(struct ntb_client *client, struct ntb_dev *ntb)
+{
+	struct pp_ctx *pp = ntb->ctx;
+
+	pp_clear_dbgfs(pp);
+
+	pp_clear_ctx(pp);
+
+	pp_clear(pp);
+}
+
+static struct ntb_client pp_client = {
+	.ops = {
+		.probe = pp_probe,
+		.remove = pp_remove
+	}
+};
+
+static int __init pp_init(void)
+{
+	int ret;
+
+	if (debugfs_initialized())
+		pp_dbgfs_topdir = debugfs_create_dir(KBUILD_MODNAME, NULL);
+
+	ret = ntb_register_client(&pp_client);
+	if (ret)
+		debugfs_remove_recursive(pp_dbgfs_topdir);
+
+	return ret;
+}
+module_init(pp_init);
+
+static void __exit pp_exit(void)
+{
+	ntb_unregister_client(&pp_client);
+	debugfs_remove_recursive(pp_dbgfs_topdir);
+}
+module_exit(pp_exit);
diff --git a/drivers/ntb/test/ntb_tool.c b/drivers/ntb/test/ntb_tool.c
new file mode 100644
index 000000000..06881047f
--- /dev/null
+++ b/drivers/ntb/test/ntb_tool.c
@@ -0,0 +1,1687 @@
+/*
+ * This file is provided under a dual BSD/GPLv2 license.  When using or
+ *   redistributing this file, you may do so under either license.
+ *
+ *   GPL LICENSE SUMMARY
+ *
+ *   Copyright (C) 2015 EMC Corporation. All Rights Reserved.
+ *   Copyright (C) 2017 T-Platforms All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of version 2 of the GNU General Public License as
+ *   published by the Free Software Foundation.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *   General Public License for more details.
+ *
+ *   BSD LICENSE
+ *
+ *   Copyright (C) 2015 EMC Corporation. All Rights Reserved.
+ *   Copyright (C) 2017 T-Platforms All Rights Reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copy
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * PCIe NTB Debugging Tool Linux driver
+ */
+
+/*
+ * How to use this tool, by example.
+ *
+ * Assuming $DBG_DIR is something like:
+ * '/sys/kernel/debug/ntb_tool/0000:00:03.0'
+ * Suppose aside from local device there is at least one remote device
+ * connected to NTB with index 0.
+ *-----------------------------------------------------------------------------
+ * Eg: check local/peer device information.
+ *
+ * # Get local device port number
+ * root@self# cat $DBG_DIR/port
+ *
+ * # Check local device functionality
+ * root@self# ls $DBG_DIR
+ * db            msg1          msg_sts     peer4/        port
+ * db_event      msg2          peer0/      peer5/        spad0
+ * db_mask       msg3          peer1/      peer_db       spad1
+ * link          msg_event     peer2/      peer_db_mask  spad2
+ * msg0          msg_mask      peer3/      peer_spad     spad3
+ * # As one can see it supports:
+ * # 1) four inbound message registers
+ * # 2) four inbound scratchpads
+ * # 3) up to six peer devices
+ *
+ * # Check peer device port number
+ * root@self# cat $DBG_DIR/peer0/port
+ *
+ * # Check peer device(s) functionality to be used
+ * root@self# ls $DBG_DIR/peer0
+ * link             mw_trans0       mw_trans6        port
+ * link_event       mw_trans1       mw_trans7        spad0
+ * msg0             mw_trans2       peer_mw_trans0   spad1
+ * msg1             mw_trans3       peer_mw_trans1   spad2
+ * msg2             mw_trans4       peer_mw_trans2   spad3
+ * msg3             mw_trans5       peer_mw_trans3
+ * # As one can see we got:
+ * # 1) four outbound message registers
+ * # 2) four outbound scratchpads
+ * # 3) eight inbound memory windows
+ * # 4) four outbound memory windows
+ *-----------------------------------------------------------------------------
+ * Eg: NTB link tests
+ *
+ * # Set local link up/down
+ * root@self# echo Y > $DBG_DIR/link
+ * root@self# echo N > $DBG_DIR/link
+ *
+ * # Check if link with peer device is up/down:
+ * root@self# cat $DBG_DIR/peer0/link
+ *
+ * # Block until the link is up/down
+ * root@self# echo Y > $DBG_DIR/peer0/link_event
+ * root@self# echo N > $DBG_DIR/peer0/link_event
+ *-----------------------------------------------------------------------------
+ * Eg: Doorbell registers tests (some functionality might be absent)
+ *
+ * # Set/clear/get local doorbell
+ * root@self# echo 's 1' > $DBG_DIR/db
+ * root@self# echo 'c 1' > $DBG_DIR/db
+ * root@self# cat  $DBG_DIR/db
+ *
+ * # Set/clear/get local doorbell mask
+ * root@self# echo 's 1' > $DBG_DIR/db_mask
+ * root@self# echo 'c 1' > $DBG_DIR/db_mask
+ * root@self# cat $DBG_DIR/db_mask
+ *
+ * # Ring/clear/get peer doorbell
+ * root@peer# echo 's 1' > $DBG_DIR/peer_db
+ * root@peer# echo 'c 1' > $DBG_DIR/peer_db
+ * root@peer# cat $DBG_DIR/peer_db
+ *
+ * # Set/clear/get peer doorbell mask
+ * root@self# echo 's 1' > $DBG_DIR/peer_db_mask
+ * root@self# echo 'c 1' > $DBG_DIR/peer_db_mask
+ * root@self# cat $DBG_DIR/peer_db_mask
+ *
+ * # Block until local doorbell is set with specified value
+ * root@self# echo 1 > $DBG_DIR/db_event
+ *-----------------------------------------------------------------------------
+ * Eg: Message registers tests (functionality might be absent)
+ *
+ * # Set/clear/get in/out message registers status
+ * root@self# echo 's 1' > $DBG_DIR/msg_sts
+ * root@self# echo 'c 1' > $DBG_DIR/msg_sts
+ * root@self# cat $DBG_DIR/msg_sts
+ *
+ * # Set/clear in/out message registers mask
+ * root@self# echo 's 1' > $DBG_DIR/msg_mask
+ * root@self# echo 'c 1' > $DBG_DIR/msg_mask
+ *
+ * # Get inbound message register #0 value and source of port index
+ * root@self# cat  $DBG_DIR/msg0
+ *
+ * # Send some data to peer over outbound message register #0
+ * root@self# echo 0x01020304 > $DBG_DIR/peer0/msg0
+ *-----------------------------------------------------------------------------
+ * Eg: Scratchpad registers tests (functionality might be absent)
+ *
+ * # Write/read to/from local scratchpad register #0
+ * root@peer# echo 0x01020304 > $DBG_DIR/spad0
+ * root@peer# cat $DBG_DIR/spad0
+ *
+ * # Write/read to/from peer scratchpad register #0
+ * root@peer# echo 0x01020304 > $DBG_DIR/peer0/spad0
+ * root@peer# cat $DBG_DIR/peer0/spad0
+ *-----------------------------------------------------------------------------
+ * Eg: Memory windows tests
+ *
+ * # Create inbound memory window buffer of specified size/get its base address
+ * root@peer# echo 16384 > $DBG_DIR/peer0/mw_trans0
+ * root@peer# cat $DBG_DIR/peer0/mw_trans0
+ *
+ * # Write/read data to/from inbound memory window
+ * root@peer# echo Hello > $DBG_DIR/peer0/mw0
+ * root@peer# head -c 7 $DBG_DIR/peer0/mw0
+ *
+ * # Map outbound memory window/check it settings (on peer device)
+ * root@peer# echo 0xADD0BA5E:16384 > $DBG_DIR/peer0/peer_mw_trans0
+ * root@peer# cat $DBG_DIR/peer0/peer_mw_trans0
+ *
+ * # Write/read data to/from outbound memory window (on peer device)
+ * root@peer# echo olleH > $DBG_DIR/peer0/peer_mw0
+ * root@peer# head -c 7 $DBG_DIR/peer0/peer_mw0
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#include <linux/debugfs.h>
+#include <linux/dma-mapping.h>
+#include <linux/pci.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+
+#include <linux/ntb.h>
+
+#define DRIVER_NAME		"ntb_tool"
+#define DRIVER_VERSION		"2.0"
+
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_VERSION(DRIVER_VERSION);
+MODULE_AUTHOR("Allen Hubbe <Allen.Hubbe@emc.com>");
+MODULE_DESCRIPTION("PCIe NTB Debugging Tool");
+
+/*
+ * Inbound and outbound memory windows descriptor. Union members selection
+ * depends on the MW type the structure describes. mm_base/dma_base are the
+ * virtual and DMA address of an inbound MW. io_base/tr_base are the MMIO
+ * mapped virtual and xlat addresses of an outbound MW respectively.
+ */
+struct tool_mw {
+	int widx;
+	int pidx;
+	struct tool_ctx *tc;
+	union {
+		u8 *mm_base;
+		u8 __iomem *io_base;
+	};
+	union {
+		dma_addr_t dma_base;
+		u64 tr_base;
+	};
+	resource_size_t size;
+	struct dentry *dbgfs_file;
+};
+
+/*
+ * Wrapper structure is used to distinguish the outbound MW peers reference
+ * within the corresponding DebugFS directory IO operation.
+ */
+struct tool_mw_wrap {
+	int pidx;
+	struct tool_mw *mw;
+};
+
+struct tool_msg {
+	int midx;
+	int pidx;
+	struct tool_ctx *tc;
+};
+
+struct tool_spad {
+	int sidx;
+	int pidx;
+	struct tool_ctx *tc;
+};
+
+struct tool_peer {
+	int pidx;
+	struct tool_ctx *tc;
+	int inmw_cnt;
+	struct tool_mw *inmws;
+	int outmw_cnt;
+	struct tool_mw_wrap *outmws;
+	int outmsg_cnt;
+	struct tool_msg *outmsgs;
+	int outspad_cnt;
+	struct tool_spad *outspads;
+	struct dentry *dbgfs_dir;
+};
+
+struct tool_ctx {
+	struct ntb_dev *ntb;
+	wait_queue_head_t link_wq;
+	wait_queue_head_t db_wq;
+	wait_queue_head_t msg_wq;
+	int outmw_cnt;
+	struct tool_mw *outmws;
+	int peer_cnt;
+	struct tool_peer *peers;
+	int inmsg_cnt;
+	struct tool_msg *inmsgs;
+	int inspad_cnt;
+	struct tool_spad *inspads;
+	struct dentry *dbgfs_dir;
+};
+
+#define TOOL_FOPS_RDWR(__name, __read, __write) \
+	const struct file_operations __name = {	\
+		.owner = THIS_MODULE,		\
+		.open = simple_open,		\
+		.read = __read,			\
+		.write = __write,		\
+	}
+
+#define TOOL_BUF_LEN 32
+
+static struct dentry *tool_dbgfs_topdir;
+
+/*==============================================================================
+ *                               NTB events handlers
+ *==============================================================================
+ */
+
+static void tool_link_event(void *ctx)
+{
+	struct tool_ctx *tc = ctx;
+	enum ntb_speed speed;
+	enum ntb_width width;
+	int up;
+
+	up = ntb_link_is_up(tc->ntb, &speed, &width);
+
+	dev_dbg(&tc->ntb->dev, "link is %s speed %d width %d\n",
+		up ? "up" : "down", speed, width);
+
+	wake_up(&tc->link_wq);
+}
+
+static void tool_db_event(void *ctx, int vec)
+{
+	struct tool_ctx *tc = ctx;
+	u64 db_bits, db_mask;
+
+	db_mask = ntb_db_vector_mask(tc->ntb, vec);
+	db_bits = ntb_db_read(tc->ntb);
+
+	dev_dbg(&tc->ntb->dev, "doorbell vec %d mask %#llx bits %#llx\n",
+		vec, db_mask, db_bits);
+
+	wake_up(&tc->db_wq);
+}
+
+static void tool_msg_event(void *ctx)
+{
+	struct tool_ctx *tc = ctx;
+	u64 msg_sts;
+
+	msg_sts = ntb_msg_read_sts(tc->ntb);
+
+	dev_dbg(&tc->ntb->dev, "message bits %#llx\n", msg_sts);
+
+	wake_up(&tc->msg_wq);
+}
+
+static const struct ntb_ctx_ops tool_ops = {
+	.link_event = tool_link_event,
+	.db_event = tool_db_event,
+	.msg_event = tool_msg_event
+};
+
+/*==============================================================================
+ *                        Common read/write methods
+ *==============================================================================
+ */
+
+static ssize_t tool_fn_read(struct tool_ctx *tc, char __user *ubuf,
+			    size_t size, loff_t *offp,
+			    u64 (*fn_read)(struct ntb_dev *))
+{
+	size_t buf_size;
+	char buf[TOOL_BUF_LEN];
+	ssize_t pos;
+
+	if (!fn_read)
+		return -EINVAL;
+
+	buf_size = min(size, sizeof(buf));
+
+	pos = scnprintf(buf, buf_size, "%#llx\n", fn_read(tc->ntb));
+
+	return simple_read_from_buffer(ubuf, size, offp, buf, pos);
+}
+
+static ssize_t tool_fn_write(struct tool_ctx *tc,
+			     const char __user *ubuf,
+			     size_t size, loff_t *offp,
+			     int (*fn_set)(struct ntb_dev *, u64),
+			     int (*fn_clear)(struct ntb_dev *, u64))
+{
+	char *buf, cmd;
+	ssize_t ret;
+	u64 bits;
+	int n;
+
+	if (*offp)
+		return 0;
+
+	buf = memdup_user_nul(ubuf, size);
+	if (IS_ERR(buf))
+		return PTR_ERR(buf);
+
+	n = sscanf(buf, "%c %lli", &cmd, &bits);
+
+	kfree(buf);
+
+	if (n != 2) {
+		ret = -EINVAL;
+	} else if (cmd == 's') {
+		if (!fn_set)
+			ret = -EINVAL;
+		else
+			ret = fn_set(tc->ntb, bits);
+	} else if (cmd == 'c') {
+		if (!fn_clear)
+			ret = -EINVAL;
+		else
+			ret = fn_clear(tc->ntb, bits);
+	} else {
+		ret = -EINVAL;
+	}
+
+	return ret ? : size;
+}
+
+/*==============================================================================
+ *                            Port read/write methods
+ *==============================================================================
+ */
+
+static ssize_t tool_port_read(struct file *filep, char __user *ubuf,
+			      size_t size, loff_t *offp)
+{
+	struct tool_ctx *tc = filep->private_data;
+	char buf[TOOL_BUF_LEN];
+	int pos;
+
+	pos = scnprintf(buf, sizeof(buf), "%d\n", ntb_port_number(tc->ntb));
+
+	return simple_read_from_buffer(ubuf, size, offp, buf, pos);
+}
+
+static TOOL_FOPS_RDWR(tool_port_fops,
+		      tool_port_read,
+		      NULL);
+
+static ssize_t tool_peer_port_read(struct file *filep, char __user *ubuf,
+				   size_t size, loff_t *offp)
+{
+	struct tool_peer *peer = filep->private_data;
+	struct tool_ctx *tc = peer->tc;
+	char buf[TOOL_BUF_LEN];
+	int pos;
+
+	pos = scnprintf(buf, sizeof(buf), "%d\n",
+		ntb_peer_port_number(tc->ntb, peer->pidx));
+
+	return simple_read_from_buffer(ubuf, size, offp, buf, pos);
+}
+
+static TOOL_FOPS_RDWR(tool_peer_port_fops,
+		      tool_peer_port_read,
+		      NULL);
+
+static int tool_init_peers(struct tool_ctx *tc)
+{
+	int pidx;
+
+	tc->peer_cnt = ntb_peer_port_count(tc->ntb);
+	tc->peers = devm_kcalloc(&tc->ntb->dev, tc->peer_cnt,
+				 sizeof(*tc->peers), GFP_KERNEL);
+	if (tc->peers == NULL)
+		return -ENOMEM;
+
+	for (pidx = 0; pidx < tc->peer_cnt; pidx++) {
+		tc->peers[pidx].pidx = pidx;
+		tc->peers[pidx].tc = tc;
+	}
+
+	return 0;
+}
+
+/*==============================================================================
+ *                       Link state read/write methods
+ *==============================================================================
+ */
+
+static ssize_t tool_link_write(struct file *filep, const char __user *ubuf,
+			       size_t size, loff_t *offp)
+{
+	struct tool_ctx *tc = filep->private_data;
+	bool val;
+	int ret;
+
+	ret = kstrtobool_from_user(ubuf, size, &val);
+	if (ret)
+		return ret;
+
+	if (val)
+		ret = ntb_link_enable(tc->ntb, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
+	else
+		ret = ntb_link_disable(tc->ntb);
+
+	if (ret)
+		return ret;
+
+	return size;
+}
+
+static TOOL_FOPS_RDWR(tool_link_fops,
+		      NULL,
+		      tool_link_write);
+
+static ssize_t tool_peer_link_read(struct file *filep, char __user *ubuf,
+				   size_t size, loff_t *offp)
+{
+	struct tool_peer *peer = filep->private_data;
+	struct tool_ctx *tc = peer->tc;
+	char buf[3];
+
+	if (ntb_link_is_up(tc->ntb, NULL, NULL) & BIT(peer->pidx))
+		buf[0] = 'Y';
+	else
+		buf[0] = 'N';
+	buf[1] = '\n';
+	buf[2] = '\0';
+
+	return simple_read_from_buffer(ubuf, size, offp, buf, 2);
+}
+
+static TOOL_FOPS_RDWR(tool_peer_link_fops,
+		      tool_peer_link_read,
+		      NULL);
+
+static ssize_t tool_peer_link_event_write(struct file *filep,
+					  const char __user *ubuf,
+					  size_t size, loff_t *offp)
+{
+	struct tool_peer *peer = filep->private_data;
+	struct tool_ctx *tc = peer->tc;
+	u64 link_msk;
+	bool val;
+	int ret;
+
+	ret = kstrtobool_from_user(ubuf, size, &val);
+	if (ret)
+		return ret;
+
+	link_msk = BIT_ULL_MASK(peer->pidx);
+
+	if (wait_event_interruptible(tc->link_wq,
+		!!(ntb_link_is_up(tc->ntb, NULL, NULL) & link_msk) == val))
+		return -ERESTART;
+
+	return size;
+}
+
+static TOOL_FOPS_RDWR(tool_peer_link_event_fops,
+		      NULL,
+		      tool_peer_link_event_write);
+
+/*==============================================================================
+ *                  Memory windows read/write/setting methods
+ *==============================================================================
+ */
+
+static ssize_t tool_mw_read(struct file *filep, char __user *ubuf,
+			    size_t size, loff_t *offp)
+{
+	struct tool_mw *inmw = filep->private_data;
+
+	if (inmw->mm_base == NULL)
+		return -ENXIO;
+
+	return simple_read_from_buffer(ubuf, size, offp,
+				       inmw->mm_base, inmw->size);
+}
+
+static ssize_t tool_mw_write(struct file *filep, const char __user *ubuf,
+			     size_t size, loff_t *offp)
+{
+	struct tool_mw *inmw = filep->private_data;
+
+	if (inmw->mm_base == NULL)
+		return -ENXIO;
+
+	return simple_write_to_buffer(inmw->mm_base, inmw->size, offp,
+				      ubuf, size);
+}
+
+static TOOL_FOPS_RDWR(tool_mw_fops,
+		      tool_mw_read,
+		      tool_mw_write);
+
+static int tool_setup_mw(struct tool_ctx *tc, int pidx, int widx,
+			 size_t req_size)
+{
+	resource_size_t size, addr_align, size_align;
+	struct tool_mw *inmw = &tc->peers[pidx].inmws[widx];
+	char buf[TOOL_BUF_LEN];
+	int ret;
+
+	if (inmw->mm_base != NULL)
+		return 0;
+
+	ret = ntb_mw_get_align(tc->ntb, pidx, widx, &addr_align,
+				&size_align, &size);
+	if (ret)
+		return ret;
+
+	inmw->size = min_t(resource_size_t, req_size, size);
+	inmw->size = round_up(inmw->size, addr_align);
+	inmw->size = round_up(inmw->size, size_align);
+	inmw->mm_base = dma_alloc_coherent(&tc->ntb->pdev->dev, inmw->size,
+					   &inmw->dma_base, GFP_KERNEL);
+	if (!inmw->mm_base)
+		return -ENOMEM;
+
+	if (!IS_ALIGNED(inmw->dma_base, addr_align)) {
+		ret = -ENOMEM;
+		goto err_free_dma;
+	}
+
+	ret = ntb_mw_set_trans(tc->ntb, pidx, widx, inmw->dma_base, inmw->size);
+	if (ret)
+		goto err_free_dma;
+
+	snprintf(buf, sizeof(buf), "mw%d", widx);
+	inmw->dbgfs_file = debugfs_create_file(buf, 0600,
+					       tc->peers[pidx].dbgfs_dir, inmw,
+					       &tool_mw_fops);
+
+	return 0;
+
+err_free_dma:
+	dma_free_coherent(&tc->ntb->pdev->dev, inmw->size, inmw->mm_base,
+			  inmw->dma_base);
+	inmw->mm_base = NULL;
+	inmw->dma_base = 0;
+	inmw->size = 0;
+
+	return ret;
+}
+
+static void tool_free_mw(struct tool_ctx *tc, int pidx, int widx)
+{
+	struct tool_mw *inmw = &tc->peers[pidx].inmws[widx];
+
+	debugfs_remove(inmw->dbgfs_file);
+
+	if (inmw->mm_base != NULL) {
+		ntb_mw_clear_trans(tc->ntb, pidx, widx);
+		dma_free_coherent(&tc->ntb->pdev->dev, inmw->size,
+				  inmw->mm_base, inmw->dma_base);
+	}
+
+	inmw->mm_base = NULL;
+	inmw->dma_base = 0;
+	inmw->size = 0;
+	inmw->dbgfs_file = NULL;
+}
+
+static ssize_t tool_mw_trans_read(struct file *filep, char __user *ubuf,
+				  size_t size, loff_t *offp)
+{
+	struct tool_mw *inmw = filep->private_data;
+	resource_size_t addr_align;
+	resource_size_t size_align;
+	resource_size_t size_max;
+	ssize_t ret, off = 0;
+	size_t buf_size;
+	char *buf;
+
+	buf_size = min_t(size_t, size, 512);
+
+	buf = kmalloc(buf_size, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	ret = ntb_mw_get_align(inmw->tc->ntb, inmw->pidx, inmw->widx,
+			       &addr_align, &size_align, &size_max);
+	if (ret)
+		goto err;
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "Inbound MW     \t%d\n",
+			 inmw->widx);
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "Port           \t%d (%d)\n",
+			 ntb_peer_port_number(inmw->tc->ntb, inmw->pidx),
+			 inmw->pidx);
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "Window Address \t0x%pK\n", inmw->mm_base);
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "DMA Address    \t%pad\n",
+			 &inmw->dma_base);
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "Window Size    \t%pap\n",
+			 &inmw->size);
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "Alignment      \t%pap\n",
+			 &addr_align);
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "Size Alignment \t%pap\n",
+			 &size_align);
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "Size Max       \t%pap\n",
+			 &size_max);
+
+	ret = simple_read_from_buffer(ubuf, size, offp, buf, off);
+
+err:
+	kfree(buf);
+
+	return ret;
+}
+
+static ssize_t tool_mw_trans_write(struct file *filep, const char __user *ubuf,
+				   size_t size, loff_t *offp)
+{
+	struct tool_mw *inmw = filep->private_data;
+	unsigned int val;
+	int ret;
+
+	ret = kstrtouint_from_user(ubuf, size, 0, &val);
+	if (ret)
+		return ret;
+
+	tool_free_mw(inmw->tc, inmw->pidx, inmw->widx);
+	if (val) {
+		ret = tool_setup_mw(inmw->tc, inmw->pidx, inmw->widx, val);
+		if (ret)
+			return ret;
+	}
+
+	return size;
+}
+
+static TOOL_FOPS_RDWR(tool_mw_trans_fops,
+		      tool_mw_trans_read,
+		      tool_mw_trans_write);
+
+static ssize_t tool_peer_mw_read(struct file *filep, char __user *ubuf,
+				 size_t size, loff_t *offp)
+{
+	struct tool_mw *outmw = filep->private_data;
+	loff_t pos = *offp;
+	ssize_t ret;
+	void *buf;
+
+	if (outmw->io_base == NULL)
+		return -EIO;
+
+	if (pos >= outmw->size || !size)
+		return 0;
+
+	if (size > outmw->size - pos)
+		size = outmw->size - pos;
+
+	buf = kmalloc(size, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	memcpy_fromio(buf, outmw->io_base + pos, size);
+	ret = copy_to_user(ubuf, buf, size);
+	if (ret == size) {
+		ret = -EFAULT;
+		goto err_free;
+	}
+
+	size -= ret;
+	*offp = pos + size;
+	ret = size;
+
+err_free:
+	kfree(buf);
+
+	return ret;
+}
+
+static ssize_t tool_peer_mw_write(struct file *filep, const char __user *ubuf,
+				  size_t size, loff_t *offp)
+{
+	struct tool_mw *outmw = filep->private_data;
+	ssize_t ret;
+	loff_t pos = *offp;
+	void *buf;
+
+	if (outmw->io_base == NULL)
+		return -EIO;
+
+	if (pos >= outmw->size || !size)
+		return 0;
+	if (size > outmw->size - pos)
+		size = outmw->size - pos;
+
+	buf = kmalloc(size, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	ret = copy_from_user(buf, ubuf, size);
+	if (ret == size) {
+		ret = -EFAULT;
+		goto err_free;
+	}
+
+	size -= ret;
+	*offp = pos + size;
+	ret = size;
+
+	memcpy_toio(outmw->io_base + pos, buf, size);
+
+err_free:
+	kfree(buf);
+
+	return ret;
+}
+
+static TOOL_FOPS_RDWR(tool_peer_mw_fops,
+		      tool_peer_mw_read,
+		      tool_peer_mw_write);
+
+static int tool_setup_peer_mw(struct tool_ctx *tc, int pidx, int widx,
+			      u64 req_addr, size_t req_size)
+{
+	struct tool_mw *outmw = &tc->outmws[widx];
+	resource_size_t map_size;
+	phys_addr_t map_base;
+	char buf[TOOL_BUF_LEN];
+	int ret;
+
+	if (outmw->io_base != NULL)
+		return 0;
+
+	ret = ntb_peer_mw_get_addr(tc->ntb, widx, &map_base, &map_size);
+	if (ret)
+		return ret;
+
+	ret = ntb_peer_mw_set_trans(tc->ntb, pidx, widx, req_addr, req_size);
+	if (ret)
+		return ret;
+
+	outmw->io_base = ioremap_wc(map_base, map_size);
+	if (outmw->io_base == NULL) {
+		ret = -EFAULT;
+		goto err_clear_trans;
+	}
+
+	outmw->tr_base = req_addr;
+	outmw->size = req_size;
+	outmw->pidx = pidx;
+
+	snprintf(buf, sizeof(buf), "peer_mw%d", widx);
+	outmw->dbgfs_file = debugfs_create_file(buf, 0600,
+					       tc->peers[pidx].dbgfs_dir, outmw,
+					       &tool_peer_mw_fops);
+
+	return 0;
+
+err_clear_trans:
+	ntb_peer_mw_clear_trans(tc->ntb, pidx, widx);
+
+	return ret;
+}
+
+static void tool_free_peer_mw(struct tool_ctx *tc, int widx)
+{
+	struct tool_mw *outmw = &tc->outmws[widx];
+
+	debugfs_remove(outmw->dbgfs_file);
+
+	if (outmw->io_base != NULL) {
+		iounmap(tc->outmws[widx].io_base);
+		ntb_peer_mw_clear_trans(tc->ntb, outmw->pidx, widx);
+	}
+
+	outmw->io_base = NULL;
+	outmw->tr_base = 0;
+	outmw->size = 0;
+	outmw->pidx = -1;
+	outmw->dbgfs_file = NULL;
+}
+
+static ssize_t tool_peer_mw_trans_read(struct file *filep, char __user *ubuf,
+					size_t size, loff_t *offp)
+{
+	struct tool_mw_wrap *outmw_wrap = filep->private_data;
+	struct tool_mw *outmw = outmw_wrap->mw;
+	resource_size_t map_size;
+	phys_addr_t map_base;
+	ssize_t off = 0;
+	size_t buf_size;
+	char *buf;
+	int ret;
+
+	ret = ntb_peer_mw_get_addr(outmw->tc->ntb, outmw->widx,
+				  &map_base, &map_size);
+	if (ret)
+		return ret;
+
+	buf_size = min_t(size_t, size, 512);
+
+	buf = kmalloc(buf_size, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "Outbound MW:        \t%d\n", outmw->widx);
+
+	if (outmw->io_base != NULL) {
+		off += scnprintf(buf + off, buf_size - off,
+			"Port attached       \t%d (%d)\n",
+			ntb_peer_port_number(outmw->tc->ntb, outmw->pidx),
+			outmw->pidx);
+	} else {
+		off += scnprintf(buf + off, buf_size - off,
+				 "Port attached       \t-1 (-1)\n");
+	}
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "Virtual address     \t0x%pK\n", outmw->io_base);
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "Phys Address        \t%pap\n", &map_base);
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "Mapping Size        \t%pap\n", &map_size);
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "Translation Address \t0x%016llx\n", outmw->tr_base);
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "Window Size         \t%pap\n", &outmw->size);
+
+	ret = simple_read_from_buffer(ubuf, size, offp, buf, off);
+	kfree(buf);
+
+	return ret;
+}
+
+static ssize_t tool_peer_mw_trans_write(struct file *filep,
+					const char __user *ubuf,
+					size_t size, loff_t *offp)
+{
+	struct tool_mw_wrap *outmw_wrap = filep->private_data;
+	struct tool_mw *outmw = outmw_wrap->mw;
+	size_t buf_size, wsize;
+	char buf[TOOL_BUF_LEN];
+	int ret, n;
+	u64 addr;
+
+	buf_size = min(size, (sizeof(buf) - 1));
+	if (copy_from_user(buf, ubuf, buf_size))
+		return -EFAULT;
+
+	buf[buf_size] = '\0';
+
+	n = sscanf(buf, "%llu:%zu", &addr, &wsize);
+	if (n != 2)
+		return -EINVAL;
+
+	tool_free_peer_mw(outmw->tc, outmw->widx);
+	if (wsize) {
+		ret = tool_setup_peer_mw(outmw->tc, outmw_wrap->pidx,
+					 outmw->widx, addr, wsize);
+		if (ret)
+			return ret;
+	}
+
+	return size;
+}
+
+static TOOL_FOPS_RDWR(tool_peer_mw_trans_fops,
+		      tool_peer_mw_trans_read,
+		      tool_peer_mw_trans_write);
+
+static int tool_init_mws(struct tool_ctx *tc)
+{
+	int widx, pidx;
+
+	/* Initialize outbound memory windows */
+	tc->outmw_cnt = ntb_peer_mw_count(tc->ntb);
+	tc->outmws = devm_kcalloc(&tc->ntb->dev, tc->outmw_cnt,
+				  sizeof(*tc->outmws), GFP_KERNEL);
+	if (tc->outmws == NULL)
+		return -ENOMEM;
+
+	for (widx = 0; widx < tc->outmw_cnt; widx++) {
+		tc->outmws[widx].widx = widx;
+		tc->outmws[widx].pidx = -1;
+		tc->outmws[widx].tc = tc;
+	}
+
+	/* Initialize inbound memory windows and outbound MWs wrapper */
+	for (pidx = 0; pidx < tc->peer_cnt; pidx++) {
+		tc->peers[pidx].inmw_cnt = ntb_mw_count(tc->ntb, pidx);
+		tc->peers[pidx].inmws =
+			devm_kcalloc(&tc->ntb->dev, tc->peers[pidx].inmw_cnt,
+				    sizeof(*tc->peers[pidx].inmws), GFP_KERNEL);
+		if (tc->peers[pidx].inmws == NULL)
+			return -ENOMEM;
+
+		for (widx = 0; widx < tc->peers[pidx].inmw_cnt; widx++) {
+			tc->peers[pidx].inmws[widx].widx = widx;
+			tc->peers[pidx].inmws[widx].pidx = pidx;
+			tc->peers[pidx].inmws[widx].tc = tc;
+		}
+
+		tc->peers[pidx].outmw_cnt = ntb_peer_mw_count(tc->ntb);
+		tc->peers[pidx].outmws =
+			devm_kcalloc(&tc->ntb->dev, tc->peers[pidx].outmw_cnt,
+				   sizeof(*tc->peers[pidx].outmws), GFP_KERNEL);
+		if (tc->peers[pidx].outmws == NULL)
+			return -ENOMEM;
+
+		for (widx = 0; widx < tc->peers[pidx].outmw_cnt; widx++) {
+			tc->peers[pidx].outmws[widx].pidx = pidx;
+			tc->peers[pidx].outmws[widx].mw = &tc->outmws[widx];
+		}
+	}
+
+	return 0;
+}
+
+static void tool_clear_mws(struct tool_ctx *tc)
+{
+	int widx, pidx;
+
+	/* Free outbound memory windows */
+	for (widx = 0; widx < tc->outmw_cnt; widx++)
+		tool_free_peer_mw(tc, widx);
+
+	/* Free outbound memory windows */
+	for (pidx = 0; pidx < tc->peer_cnt; pidx++)
+		for (widx = 0; widx < tc->peers[pidx].inmw_cnt; widx++)
+			tool_free_mw(tc, pidx, widx);
+}
+
+/*==============================================================================
+ *                       Doorbell read/write methods
+ *==============================================================================
+ */
+
+static ssize_t tool_db_read(struct file *filep, char __user *ubuf,
+			    size_t size, loff_t *offp)
+{
+	struct tool_ctx *tc = filep->private_data;
+
+	return tool_fn_read(tc, ubuf, size, offp, tc->ntb->ops->db_read);
+}
+
+static ssize_t tool_db_write(struct file *filep, const char __user *ubuf,
+			     size_t size, loff_t *offp)
+{
+	struct tool_ctx *tc = filep->private_data;
+
+	return tool_fn_write(tc, ubuf, size, offp, tc->ntb->ops->db_set,
+			     tc->ntb->ops->db_clear);
+}
+
+static TOOL_FOPS_RDWR(tool_db_fops,
+		      tool_db_read,
+		      tool_db_write);
+
+static ssize_t tool_db_valid_mask_read(struct file *filep, char __user *ubuf,
+				       size_t size, loff_t *offp)
+{
+	struct tool_ctx *tc = filep->private_data;
+
+	return tool_fn_read(tc, ubuf, size, offp, tc->ntb->ops->db_valid_mask);
+}
+
+static TOOL_FOPS_RDWR(tool_db_valid_mask_fops,
+		      tool_db_valid_mask_read,
+		      NULL);
+
+static ssize_t tool_db_mask_read(struct file *filep, char __user *ubuf,
+				 size_t size, loff_t *offp)
+{
+	struct tool_ctx *tc = filep->private_data;
+
+	return tool_fn_read(tc, ubuf, size, offp, tc->ntb->ops->db_read_mask);
+}
+
+static ssize_t tool_db_mask_write(struct file *filep, const char __user *ubuf,
+			       size_t size, loff_t *offp)
+{
+	struct tool_ctx *tc = filep->private_data;
+
+	return tool_fn_write(tc, ubuf, size, offp, tc->ntb->ops->db_set_mask,
+			     tc->ntb->ops->db_clear_mask);
+}
+
+static TOOL_FOPS_RDWR(tool_db_mask_fops,
+		      tool_db_mask_read,
+		      tool_db_mask_write);
+
+static ssize_t tool_peer_db_read(struct file *filep, char __user *ubuf,
+				 size_t size, loff_t *offp)
+{
+	struct tool_ctx *tc = filep->private_data;
+
+	return tool_fn_read(tc, ubuf, size, offp, tc->ntb->ops->peer_db_read);
+}
+
+static ssize_t tool_peer_db_write(struct file *filep, const char __user *ubuf,
+				  size_t size, loff_t *offp)
+{
+	struct tool_ctx *tc = filep->private_data;
+
+	return tool_fn_write(tc, ubuf, size, offp, tc->ntb->ops->peer_db_set,
+			     tc->ntb->ops->peer_db_clear);
+}
+
+static TOOL_FOPS_RDWR(tool_peer_db_fops,
+		      tool_peer_db_read,
+		      tool_peer_db_write);
+
+static ssize_t tool_peer_db_mask_read(struct file *filep, char __user *ubuf,
+				   size_t size, loff_t *offp)
+{
+	struct tool_ctx *tc = filep->private_data;
+
+	return tool_fn_read(tc, ubuf, size, offp,
+			    tc->ntb->ops->peer_db_read_mask);
+}
+
+static ssize_t tool_peer_db_mask_write(struct file *filep,
+				       const char __user *ubuf,
+				       size_t size, loff_t *offp)
+{
+	struct tool_ctx *tc = filep->private_data;
+
+	return tool_fn_write(tc, ubuf, size, offp,
+			     tc->ntb->ops->peer_db_set_mask,
+			     tc->ntb->ops->peer_db_clear_mask);
+}
+
+static TOOL_FOPS_RDWR(tool_peer_db_mask_fops,
+		      tool_peer_db_mask_read,
+		      tool_peer_db_mask_write);
+
+static ssize_t tool_db_event_write(struct file *filep,
+				   const char __user *ubuf,
+				   size_t size, loff_t *offp)
+{
+	struct tool_ctx *tc = filep->private_data;
+	u64 val;
+	int ret;
+
+	ret = kstrtou64_from_user(ubuf, size, 0, &val);
+	if (ret)
+		return ret;
+
+	if (wait_event_interruptible(tc->db_wq, ntb_db_read(tc->ntb) == val))
+		return -ERESTART;
+
+	return size;
+}
+
+static TOOL_FOPS_RDWR(tool_db_event_fops,
+		      NULL,
+		      tool_db_event_write);
+
+/*==============================================================================
+ *                       Scratchpads read/write methods
+ *==============================================================================
+ */
+
+static ssize_t tool_spad_read(struct file *filep, char __user *ubuf,
+			      size_t size, loff_t *offp)
+{
+	struct tool_spad *spad = filep->private_data;
+	char buf[TOOL_BUF_LEN];
+	ssize_t pos;
+
+	if (!spad->tc->ntb->ops->spad_read)
+		return -EINVAL;
+
+	pos = scnprintf(buf, sizeof(buf), "%#x\n",
+		ntb_spad_read(spad->tc->ntb, spad->sidx));
+
+	return simple_read_from_buffer(ubuf, size, offp, buf, pos);
+}
+
+static ssize_t tool_spad_write(struct file *filep, const char __user *ubuf,
+			       size_t size, loff_t *offp)
+{
+	struct tool_spad *spad = filep->private_data;
+	u32 val;
+	int ret;
+
+	if (!spad->tc->ntb->ops->spad_write) {
+		dev_dbg(&spad->tc->ntb->dev, "no spad write fn\n");
+		return -EINVAL;
+	}
+
+	ret = kstrtou32_from_user(ubuf, size, 0, &val);
+	if (ret)
+		return ret;
+
+	ret = ntb_spad_write(spad->tc->ntb, spad->sidx, val);
+
+	return ret ?: size;
+}
+
+static TOOL_FOPS_RDWR(tool_spad_fops,
+		      tool_spad_read,
+		      tool_spad_write);
+
+static ssize_t tool_peer_spad_read(struct file *filep, char __user *ubuf,
+				   size_t size, loff_t *offp)
+{
+	struct tool_spad *spad = filep->private_data;
+	char buf[TOOL_BUF_LEN];
+	ssize_t pos;
+
+	if (!spad->tc->ntb->ops->peer_spad_read)
+		return -EINVAL;
+
+	pos = scnprintf(buf, sizeof(buf), "%#x\n",
+		ntb_peer_spad_read(spad->tc->ntb, spad->pidx, spad->sidx));
+
+	return simple_read_from_buffer(ubuf, size, offp, buf, pos);
+}
+
+static ssize_t tool_peer_spad_write(struct file *filep, const char __user *ubuf,
+				    size_t size, loff_t *offp)
+{
+	struct tool_spad *spad = filep->private_data;
+	u32 val;
+	int ret;
+
+	if (!spad->tc->ntb->ops->peer_spad_write) {
+		dev_dbg(&spad->tc->ntb->dev, "no spad write fn\n");
+		return -EINVAL;
+	}
+
+	ret = kstrtou32_from_user(ubuf, size, 0, &val);
+	if (ret)
+		return ret;
+
+	ret = ntb_peer_spad_write(spad->tc->ntb, spad->pidx, spad->sidx, val);
+
+	return ret ?: size;
+}
+
+static TOOL_FOPS_RDWR(tool_peer_spad_fops,
+		      tool_peer_spad_read,
+		      tool_peer_spad_write);
+
+static int tool_init_spads(struct tool_ctx *tc)
+{
+	int sidx, pidx;
+
+	/* Initialize inbound scratchpad structures */
+	tc->inspad_cnt = ntb_spad_count(tc->ntb);
+	tc->inspads = devm_kcalloc(&tc->ntb->dev, tc->inspad_cnt,
+				   sizeof(*tc->inspads), GFP_KERNEL);
+	if (tc->inspads == NULL)
+		return -ENOMEM;
+
+	for (sidx = 0; sidx < tc->inspad_cnt; sidx++) {
+		tc->inspads[sidx].sidx = sidx;
+		tc->inspads[sidx].pidx = -1;
+		tc->inspads[sidx].tc = tc;
+	}
+
+	/* Initialize outbound scratchpad structures */
+	for (pidx = 0; pidx < tc->peer_cnt; pidx++) {
+		tc->peers[pidx].outspad_cnt = ntb_spad_count(tc->ntb);
+		tc->peers[pidx].outspads =
+			devm_kcalloc(&tc->ntb->dev, tc->peers[pidx].outspad_cnt,
+				sizeof(*tc->peers[pidx].outspads), GFP_KERNEL);
+		if (tc->peers[pidx].outspads == NULL)
+			return -ENOMEM;
+
+		for (sidx = 0; sidx < tc->peers[pidx].outspad_cnt; sidx++) {
+			tc->peers[pidx].outspads[sidx].sidx = sidx;
+			tc->peers[pidx].outspads[sidx].pidx = pidx;
+			tc->peers[pidx].outspads[sidx].tc = tc;
+		}
+	}
+
+	return 0;
+}
+
+/*==============================================================================
+ *                       Messages read/write methods
+ *==============================================================================
+ */
+
+static ssize_t tool_inmsg_read(struct file *filep, char __user *ubuf,
+			       size_t size, loff_t *offp)
+{
+	struct tool_msg *msg = filep->private_data;
+	char buf[TOOL_BUF_LEN];
+	ssize_t pos;
+	u32 data;
+	int pidx;
+
+	data = ntb_msg_read(msg->tc->ntb, &pidx, msg->midx);
+
+	pos = scnprintf(buf, sizeof(buf), "0x%08x<-%d\n", data, pidx);
+
+	return simple_read_from_buffer(ubuf, size, offp, buf, pos);
+}
+
+static TOOL_FOPS_RDWR(tool_inmsg_fops,
+		      tool_inmsg_read,
+		      NULL);
+
+static ssize_t tool_outmsg_write(struct file *filep,
+				 const char __user *ubuf,
+				 size_t size, loff_t *offp)
+{
+	struct tool_msg *msg = filep->private_data;
+	u32 val;
+	int ret;
+
+	ret = kstrtou32_from_user(ubuf, size, 0, &val);
+	if (ret)
+		return ret;
+
+	ret = ntb_peer_msg_write(msg->tc->ntb, msg->pidx, msg->midx, val);
+
+	return ret ? : size;
+}
+
+static TOOL_FOPS_RDWR(tool_outmsg_fops,
+		      NULL,
+		      tool_outmsg_write);
+
+static ssize_t tool_msg_sts_read(struct file *filep, char __user *ubuf,
+				 size_t size, loff_t *offp)
+{
+	struct tool_ctx *tc = filep->private_data;
+
+	return tool_fn_read(tc, ubuf, size, offp, tc->ntb->ops->msg_read_sts);
+}
+
+static ssize_t tool_msg_sts_write(struct file *filep, const char __user *ubuf,
+				  size_t size, loff_t *offp)
+{
+	struct tool_ctx *tc = filep->private_data;
+
+	return tool_fn_write(tc, ubuf, size, offp, NULL,
+			     tc->ntb->ops->msg_clear_sts);
+}
+
+static TOOL_FOPS_RDWR(tool_msg_sts_fops,
+		      tool_msg_sts_read,
+		      tool_msg_sts_write);
+
+static ssize_t tool_msg_inbits_read(struct file *filep, char __user *ubuf,
+				    size_t size, loff_t *offp)
+{
+	struct tool_ctx *tc = filep->private_data;
+
+	return tool_fn_read(tc, ubuf, size, offp, tc->ntb->ops->msg_inbits);
+}
+
+static TOOL_FOPS_RDWR(tool_msg_inbits_fops,
+		      tool_msg_inbits_read,
+		      NULL);
+
+static ssize_t tool_msg_outbits_read(struct file *filep, char __user *ubuf,
+				     size_t size, loff_t *offp)
+{
+	struct tool_ctx *tc = filep->private_data;
+
+	return tool_fn_read(tc, ubuf, size, offp, tc->ntb->ops->msg_outbits);
+}
+
+static TOOL_FOPS_RDWR(tool_msg_outbits_fops,
+		      tool_msg_outbits_read,
+		      NULL);
+
+static ssize_t tool_msg_mask_write(struct file *filep, const char __user *ubuf,
+				   size_t size, loff_t *offp)
+{
+	struct tool_ctx *tc = filep->private_data;
+
+	return tool_fn_write(tc, ubuf, size, offp,
+			     tc->ntb->ops->msg_set_mask,
+			     tc->ntb->ops->msg_clear_mask);
+}
+
+static TOOL_FOPS_RDWR(tool_msg_mask_fops,
+		      NULL,
+		      tool_msg_mask_write);
+
+static ssize_t tool_msg_event_write(struct file *filep,
+				    const char __user *ubuf,
+				    size_t size, loff_t *offp)
+{
+	struct tool_ctx *tc = filep->private_data;
+	u64 val;
+	int ret;
+
+	ret = kstrtou64_from_user(ubuf, size, 0, &val);
+	if (ret)
+		return ret;
+
+	if (wait_event_interruptible(tc->msg_wq,
+		ntb_msg_read_sts(tc->ntb) == val))
+		return -ERESTART;
+
+	return size;
+}
+
+static TOOL_FOPS_RDWR(tool_msg_event_fops,
+		      NULL,
+		      tool_msg_event_write);
+
+static int tool_init_msgs(struct tool_ctx *tc)
+{
+	int midx, pidx;
+
+	/* Initialize inbound message structures */
+	tc->inmsg_cnt = ntb_msg_count(tc->ntb);
+	tc->inmsgs = devm_kcalloc(&tc->ntb->dev, tc->inmsg_cnt,
+				   sizeof(*tc->inmsgs), GFP_KERNEL);
+	if (tc->inmsgs == NULL)
+		return -ENOMEM;
+
+	for (midx = 0; midx < tc->inmsg_cnt; midx++) {
+		tc->inmsgs[midx].midx = midx;
+		tc->inmsgs[midx].pidx = -1;
+		tc->inmsgs[midx].tc = tc;
+	}
+
+	/* Initialize outbound message structures */
+	for (pidx = 0; pidx < tc->peer_cnt; pidx++) {
+		tc->peers[pidx].outmsg_cnt = ntb_msg_count(tc->ntb);
+		tc->peers[pidx].outmsgs =
+			devm_kcalloc(&tc->ntb->dev, tc->peers[pidx].outmsg_cnt,
+				sizeof(*tc->peers[pidx].outmsgs), GFP_KERNEL);
+		if (tc->peers[pidx].outmsgs == NULL)
+			return -ENOMEM;
+
+		for (midx = 0; midx < tc->peers[pidx].outmsg_cnt; midx++) {
+			tc->peers[pidx].outmsgs[midx].midx = midx;
+			tc->peers[pidx].outmsgs[midx].pidx = pidx;
+			tc->peers[pidx].outmsgs[midx].tc = tc;
+		}
+	}
+
+	return 0;
+}
+
+/*==============================================================================
+ *                          Initialization methods
+ *==============================================================================
+ */
+
+static struct tool_ctx *tool_create_data(struct ntb_dev *ntb)
+{
+	struct tool_ctx *tc;
+
+	tc = devm_kzalloc(&ntb->dev, sizeof(*tc), GFP_KERNEL);
+	if (tc == NULL)
+		return ERR_PTR(-ENOMEM);
+
+	tc->ntb = ntb;
+	init_waitqueue_head(&tc->link_wq);
+	init_waitqueue_head(&tc->db_wq);
+	init_waitqueue_head(&tc->msg_wq);
+
+	if (ntb_db_is_unsafe(ntb))
+		dev_dbg(&ntb->dev, "doorbell is unsafe\n");
+
+	if (ntb_spad_is_unsafe(ntb))
+		dev_dbg(&ntb->dev, "scratchpad is unsafe\n");
+
+	return tc;
+}
+
+static void tool_clear_data(struct tool_ctx *tc)
+{
+	wake_up(&tc->link_wq);
+	wake_up(&tc->db_wq);
+	wake_up(&tc->msg_wq);
+}
+
+static int tool_init_ntb(struct tool_ctx *tc)
+{
+	return ntb_set_ctx(tc->ntb, tc, &tool_ops);
+}
+
+static void tool_clear_ntb(struct tool_ctx *tc)
+{
+	ntb_clear_ctx(tc->ntb);
+	ntb_link_disable(tc->ntb);
+}
+
+static void tool_setup_dbgfs(struct tool_ctx *tc)
+{
+	int pidx, widx, sidx, midx;
+	char buf[TOOL_BUF_LEN];
+
+	/* This modules is useless without dbgfs... */
+	if (!tool_dbgfs_topdir) {
+		tc->dbgfs_dir = NULL;
+		return;
+	}
+
+	tc->dbgfs_dir = debugfs_create_dir(dev_name(&tc->ntb->dev),
+					   tool_dbgfs_topdir);
+
+	debugfs_create_file("port", 0600, tc->dbgfs_dir,
+			    tc, &tool_port_fops);
+
+	debugfs_create_file("link", 0600, tc->dbgfs_dir,
+			    tc, &tool_link_fops);
+
+	debugfs_create_file("db", 0600, tc->dbgfs_dir,
+			    tc, &tool_db_fops);
+
+	debugfs_create_file("db_valid_mask", 0600, tc->dbgfs_dir,
+			    tc, &tool_db_valid_mask_fops);
+
+	debugfs_create_file("db_mask", 0600, tc->dbgfs_dir,
+			    tc, &tool_db_mask_fops);
+
+	debugfs_create_file("db_event", 0600, tc->dbgfs_dir,
+			    tc, &tool_db_event_fops);
+
+	debugfs_create_file("peer_db", 0600, tc->dbgfs_dir,
+			    tc, &tool_peer_db_fops);
+
+	debugfs_create_file("peer_db_mask", 0600, tc->dbgfs_dir,
+			    tc, &tool_peer_db_mask_fops);
+
+	if (tc->inspad_cnt != 0) {
+		for (sidx = 0; sidx < tc->inspad_cnt; sidx++) {
+			snprintf(buf, sizeof(buf), "spad%d", sidx);
+
+			debugfs_create_file(buf, 0600, tc->dbgfs_dir,
+					   &tc->inspads[sidx], &tool_spad_fops);
+		}
+	}
+
+	if (tc->inmsg_cnt != 0) {
+		for (midx = 0; midx < tc->inmsg_cnt; midx++) {
+			snprintf(buf, sizeof(buf), "msg%d", midx);
+			debugfs_create_file(buf, 0600, tc->dbgfs_dir,
+					   &tc->inmsgs[midx], &tool_inmsg_fops);
+		}
+
+		debugfs_create_file("msg_sts", 0600, tc->dbgfs_dir,
+				    tc, &tool_msg_sts_fops);
+
+		debugfs_create_file("msg_inbits", 0600, tc->dbgfs_dir,
+				    tc, &tool_msg_inbits_fops);
+
+		debugfs_create_file("msg_outbits", 0600, tc->dbgfs_dir,
+				    tc, &tool_msg_outbits_fops);
+
+		debugfs_create_file("msg_mask", 0600, tc->dbgfs_dir,
+				    tc, &tool_msg_mask_fops);
+
+		debugfs_create_file("msg_event", 0600, tc->dbgfs_dir,
+				    tc, &tool_msg_event_fops);
+	}
+
+	for (pidx = 0; pidx < tc->peer_cnt; pidx++) {
+		snprintf(buf, sizeof(buf), "peer%d", pidx);
+		tc->peers[pidx].dbgfs_dir =
+			debugfs_create_dir(buf, tc->dbgfs_dir);
+
+		debugfs_create_file("port", 0600,
+				    tc->peers[pidx].dbgfs_dir,
+				    &tc->peers[pidx], &tool_peer_port_fops);
+
+		debugfs_create_file("link", 0200,
+				    tc->peers[pidx].dbgfs_dir,
+				    &tc->peers[pidx], &tool_peer_link_fops);
+
+		debugfs_create_file("link_event", 0200,
+				  tc->peers[pidx].dbgfs_dir,
+				  &tc->peers[pidx], &tool_peer_link_event_fops);
+
+		for (widx = 0; widx < tc->peers[pidx].inmw_cnt; widx++) {
+			snprintf(buf, sizeof(buf), "mw_trans%d", widx);
+			debugfs_create_file(buf, 0600,
+					    tc->peers[pidx].dbgfs_dir,
+					    &tc->peers[pidx].inmws[widx],
+					    &tool_mw_trans_fops);
+		}
+
+		for (widx = 0; widx < tc->peers[pidx].outmw_cnt; widx++) {
+			snprintf(buf, sizeof(buf), "peer_mw_trans%d", widx);
+			debugfs_create_file(buf, 0600,
+					    tc->peers[pidx].dbgfs_dir,
+					    &tc->peers[pidx].outmws[widx],
+					    &tool_peer_mw_trans_fops);
+		}
+
+		for (sidx = 0; sidx < tc->peers[pidx].outspad_cnt; sidx++) {
+			snprintf(buf, sizeof(buf), "spad%d", sidx);
+
+			debugfs_create_file(buf, 0600,
+					    tc->peers[pidx].dbgfs_dir,
+					    &tc->peers[pidx].outspads[sidx],
+					    &tool_peer_spad_fops);
+		}
+
+		for (midx = 0; midx < tc->peers[pidx].outmsg_cnt; midx++) {
+			snprintf(buf, sizeof(buf), "msg%d", midx);
+			debugfs_create_file(buf, 0600,
+					    tc->peers[pidx].dbgfs_dir,
+					    &tc->peers[pidx].outmsgs[midx],
+					    &tool_outmsg_fops);
+		}
+	}
+}
+
+static void tool_clear_dbgfs(struct tool_ctx *tc)
+{
+	debugfs_remove_recursive(tc->dbgfs_dir);
+}
+
+static int tool_probe(struct ntb_client *self, struct ntb_dev *ntb)
+{
+	struct tool_ctx *tc;
+	int ret;
+
+	tc = tool_create_data(ntb);
+	if (IS_ERR(tc))
+		return PTR_ERR(tc);
+
+	ret = tool_init_peers(tc);
+	if (ret != 0)
+		goto err_clear_data;
+
+	ret = tool_init_mws(tc);
+	if (ret != 0)
+		goto err_clear_data;
+
+	ret = tool_init_spads(tc);
+	if (ret != 0)
+		goto err_clear_mws;
+
+	ret = tool_init_msgs(tc);
+	if (ret != 0)
+		goto err_clear_mws;
+
+	ret = tool_init_ntb(tc);
+	if (ret != 0)
+		goto err_clear_mws;
+
+	tool_setup_dbgfs(tc);
+
+	return 0;
+
+err_clear_mws:
+	tool_clear_mws(tc);
+
+err_clear_data:
+	tool_clear_data(tc);
+
+	return ret;
+}
+
+static void tool_remove(struct ntb_client *self, struct ntb_dev *ntb)
+{
+	struct tool_ctx *tc = ntb->ctx;
+
+	tool_clear_dbgfs(tc);
+
+	tool_clear_ntb(tc);
+
+	tool_clear_mws(tc);
+
+	tool_clear_data(tc);
+}
+
+static struct ntb_client tool_client = {
+	.ops = {
+		.probe = tool_probe,
+		.remove = tool_remove,
+	}
+};
+
+static int __init tool_init(void)
+{
+	int ret;
+
+	if (debugfs_initialized())
+		tool_dbgfs_topdir = debugfs_create_dir(KBUILD_MODNAME, NULL);
+
+	ret = ntb_register_client(&tool_client);
+	if (ret)
+		debugfs_remove_recursive(tool_dbgfs_topdir);
+
+	return ret;
+}
+module_init(tool_init);
+
+static void __exit tool_exit(void)
+{
+	ntb_unregister_client(&tool_client);
+	debugfs_remove_recursive(tool_dbgfs_topdir);
+}
+module_exit(tool_exit);