Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

7 files changed, 1294 insertions, 0 deletions

diff --git a/drivers/mcb/Kconfig b/drivers/mcb/Kconfig
new file mode 100644
index 000000000..0a883486f
--- /dev/null
+++ b/drivers/mcb/Kconfig
@@ -0,0 +1,41 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# MEN Chameleon Bus (MCB) support
+#
+
+menuconfig MCB
+	   tristate "MCB support"
+	   default n
+	   depends on HAS_IOMEM
+	   help
+
+	   The MCB (MEN Chameleon Bus) is a Bus specific to MEN Mikroelektronik
+	   FPGA based devices. It is used to identify MCB based IP-Cores within
+	   an FPGA and provide the necessary framework for instantiating drivers
+	   for these devices.
+
+	   If build as a module, the module is called mcb.ko
+
+if MCB
+config MCB_PCI
+	   tristate "PCI based MCB carrier"
+	   default n
+	   depends on PCI
+	   help
+
+	   This is a MCB carrier on a PCI device. Both PCI attached on-board
+	   FPGAs as well as CompactPCI attached MCB FPGAs are supported with
+	   this driver.
+
+	   If build as a module, the module is called mcb-pci.ko
+
+config MCB_LPC
+	   tristate "LPC (non PCI) based MCB carrier"
+	   default n
+	   help
+
+	   This is a MCB carrier on a LPC or non PCI device.
+
+	   If build as a module, the module is called mcb-lpc.ko
+
+endif # MCB
diff --git a/drivers/mcb/Makefile b/drivers/mcb/Makefile
new file mode 100644
index 000000000..77073c592
--- /dev/null
+++ b/drivers/mcb/Makefile
@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj-$(CONFIG_MCB) += mcb.o
+
+mcb-y += mcb-core.o
+mcb-y += mcb-parse.o
+
+obj-$(CONFIG_MCB_PCI) += mcb-pci.o
+obj-$(CONFIG_MCB_LPC) += mcb-lpc.o
diff --git a/drivers/mcb/mcb-core.c b/drivers/mcb/mcb-core.c
new file mode 100644
index 000000000..e6e7c11ba
--- /dev/null
+++ b/drivers/mcb/mcb-core.c
@@ -0,0 +1,519 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * MEN Chameleon Bus.
+ *
+ * Copyright (C) 2013 MEN Mikroelektronik GmbH (www.men.de)
+ * Author: Johannes Thumshirn <johannes.thumshirn@men.de>
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/idr.h>
+#include <linux/mcb.h>
+
+static DEFINE_IDA(mcb_ida);
+
+static const struct mcb_device_id *mcb_match_id(const struct mcb_device_id *ids,
+						struct mcb_device *dev)
+{
+	if (ids) {
+		while (ids->device) {
+			if (ids->device == dev->id)
+				return ids;
+			ids++;
+		}
+	}
+
+	return NULL;
+}
+
+static int mcb_match(struct device *dev, const struct device_driver *drv)
+{
+	const struct mcb_driver *mdrv = to_mcb_driver(drv);
+	struct mcb_device *mdev = to_mcb_device(dev);
+	const struct mcb_device_id *found_id;
+
+	found_id = mcb_match_id(mdrv->id_table, mdev);
+	if (found_id)
+		return 1;
+
+	return 0;
+}
+
+static int mcb_uevent(const struct device *dev, struct kobj_uevent_env *env)
+{
+	const struct mcb_device *mdev = to_mcb_device(dev);
+	int ret;
+
+	ret = add_uevent_var(env, "MODALIAS=mcb:16z%03d", mdev->id);
+	if (ret)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static int mcb_probe(struct device *dev)
+{
+	struct mcb_driver *mdrv = to_mcb_driver(dev->driver);
+	struct mcb_device *mdev = to_mcb_device(dev);
+	const struct mcb_device_id *found_id;
+	struct module *carrier_mod;
+	int ret;
+
+	found_id = mcb_match_id(mdrv->id_table, mdev);
+	if (!found_id)
+		return -ENODEV;
+
+	carrier_mod = mdev->dev.parent->driver->owner;
+	if (!try_module_get(carrier_mod))
+		return -EINVAL;
+
+	get_device(dev);
+	ret = mdrv->probe(mdev, found_id);
+	if (ret) {
+		module_put(carrier_mod);
+		put_device(dev);
+	}
+
+	return ret;
+}
+
+static void mcb_remove(struct device *dev)
+{
+	struct mcb_driver *mdrv = to_mcb_driver(dev->driver);
+	struct mcb_device *mdev = to_mcb_device(dev);
+	struct module *carrier_mod;
+
+	if (mdrv->remove)
+		mdrv->remove(mdev);
+
+	carrier_mod = mdev->dev.parent->driver->owner;
+	module_put(carrier_mod);
+
+	put_device(&mdev->dev);
+}
+
+static void mcb_shutdown(struct device *dev)
+{
+	struct mcb_driver *mdrv = to_mcb_driver(dev->driver);
+	struct mcb_device *mdev = to_mcb_device(dev);
+
+	if (mdrv && mdrv->shutdown)
+		mdrv->shutdown(mdev);
+}
+
+static ssize_t revision_show(struct device *dev, struct device_attribute *attr,
+			 char *buf)
+{
+	struct mcb_bus *bus = to_mcb_bus(dev);
+
+	return sysfs_emit(buf, "%d\n", bus->revision);
+}
+static DEVICE_ATTR_RO(revision);
+
+static ssize_t model_show(struct device *dev, struct device_attribute *attr,
+			 char *buf)
+{
+	struct mcb_bus *bus = to_mcb_bus(dev);
+
+	return sysfs_emit(buf, "%c\n", bus->model);
+}
+static DEVICE_ATTR_RO(model);
+
+static ssize_t minor_show(struct device *dev, struct device_attribute *attr,
+			 char *buf)
+{
+	struct mcb_bus *bus = to_mcb_bus(dev);
+
+	return sysfs_emit(buf, "%d\n", bus->minor);
+}
+static DEVICE_ATTR_RO(minor);
+
+static ssize_t name_show(struct device *dev, struct device_attribute *attr,
+			 char *buf)
+{
+	struct mcb_bus *bus = to_mcb_bus(dev);
+
+	return sysfs_emit(buf, "%s\n", bus->name);
+}
+static DEVICE_ATTR_RO(name);
+
+static struct attribute *mcb_bus_attrs[] = {
+	&dev_attr_revision.attr,
+	&dev_attr_model.attr,
+	&dev_attr_minor.attr,
+	&dev_attr_name.attr,
+	NULL,
+};
+
+static const struct attribute_group mcb_carrier_group = {
+	.attrs = mcb_bus_attrs,
+};
+
+static const struct attribute_group *mcb_carrier_groups[] = {
+	&mcb_carrier_group,
+	NULL,
+};
+
+
+static const struct bus_type mcb_bus_type = {
+	.name = "mcb",
+	.match = mcb_match,
+	.uevent = mcb_uevent,
+	.probe = mcb_probe,
+	.remove = mcb_remove,
+	.shutdown = mcb_shutdown,
+};
+
+static const struct device_type mcb_carrier_device_type = {
+	.name = "mcb-carrier",
+	.groups = mcb_carrier_groups,
+};
+
+/**
+ * __mcb_register_driver() - Register a @mcb_driver at the system
+ * @drv: The @mcb_driver
+ * @owner: The @mcb_driver's module
+ * @mod_name: The name of the @mcb_driver's module
+ *
+ * Register a @mcb_driver at the system. Perform a sanity check, if
+ * .probe method is provided by the driver.
+ */
+int __mcb_register_driver(struct mcb_driver *drv, struct module *owner,
+			const char *mod_name)
+{
+	if (!drv->probe)
+		return -EINVAL;
+
+	drv->driver.owner = owner;
+	drv->driver.bus = &mcb_bus_type;
+	drv->driver.mod_name = mod_name;
+
+	return driver_register(&drv->driver);
+}
+EXPORT_SYMBOL_NS_GPL(__mcb_register_driver, "MCB");
+
+/**
+ * mcb_unregister_driver() - Unregister a @mcb_driver from the system
+ * @drv: The @mcb_driver
+ *
+ * Unregister a @mcb_driver from the system.
+ */
+void mcb_unregister_driver(struct mcb_driver *drv)
+{
+	driver_unregister(&drv->driver);
+}
+EXPORT_SYMBOL_NS_GPL(mcb_unregister_driver, "MCB");
+
+static void mcb_release_dev(struct device *dev)
+{
+	struct mcb_device *mdev = to_mcb_device(dev);
+
+	mcb_bus_put(mdev->bus);
+	kfree(mdev);
+}
+
+/**
+ * mcb_device_register() - Register a mcb_device
+ * @bus: The @mcb_bus of the device
+ * @dev: The @mcb_device
+ *
+ * Register a specific @mcb_device at a @mcb_bus and the system itself.
+ */
+int mcb_device_register(struct mcb_bus *bus, struct mcb_device *dev)
+{
+	int ret;
+	int device_id;
+
+	device_initialize(&dev->dev);
+	mcb_bus_get(bus);
+	dev->dev.bus = &mcb_bus_type;
+	dev->dev.parent = bus->dev.parent;
+	dev->dev.release = mcb_release_dev;
+	dev->dma_dev = bus->carrier;
+
+	device_id = dev->id;
+	dev_set_name(&dev->dev, "mcb%d-16z%03d-%d:%d:%d",
+		bus->bus_nr, device_id, dev->inst, dev->group, dev->var);
+
+	ret = device_add(&dev->dev);
+	if (ret < 0) {
+		pr_err("Failed registering device 16z%03d on bus mcb%d (%d)\n",
+			device_id, bus->bus_nr, ret);
+		goto out;
+	}
+
+	return 0;
+
+out:
+	put_device(&dev->dev);
+
+	return ret;
+}
+EXPORT_SYMBOL_NS_GPL(mcb_device_register, "MCB");
+
+static void mcb_free_bus(struct device *dev)
+{
+	struct mcb_bus *bus = to_mcb_bus(dev);
+
+	put_device(bus->carrier);
+	ida_free(&mcb_ida, bus->bus_nr);
+	kfree(bus);
+}
+
+/**
+ * mcb_alloc_bus() - Allocate a new @mcb_bus
+ * @carrier: generic &struct device for the carrier device
+ *
+ * Allocate a new @mcb_bus.
+ */
+struct mcb_bus *mcb_alloc_bus(struct device *carrier)
+{
+	struct mcb_bus *bus;
+	int bus_nr;
+	int rc;
+
+	bus = kzalloc_obj(struct mcb_bus);
+	if (!bus)
+		return ERR_PTR(-ENOMEM);
+
+	bus_nr = ida_alloc(&mcb_ida, GFP_KERNEL);
+	if (bus_nr < 0) {
+		kfree(bus);
+		return ERR_PTR(bus_nr);
+	}
+
+	bus->bus_nr = bus_nr;
+	bus->carrier = get_device(carrier);
+
+	device_initialize(&bus->dev);
+	bus->dev.parent = carrier;
+	bus->dev.bus = &mcb_bus_type;
+	bus->dev.type = &mcb_carrier_device_type;
+	bus->dev.release = mcb_free_bus;
+
+	dev_set_name(&bus->dev, "mcb:%d", bus_nr);
+	rc = device_add(&bus->dev);
+	if (rc)
+		goto err_put;
+
+	return bus;
+
+err_put:
+	put_device(&bus->dev);
+	return ERR_PTR(rc);
+}
+EXPORT_SYMBOL_NS_GPL(mcb_alloc_bus, "MCB");
+
+static int __mcb_devices_unregister(struct device *dev, void *data)
+{
+	device_unregister(dev);
+	return 0;
+}
+
+static void mcb_devices_unregister(struct mcb_bus *bus)
+{
+	bus_for_each_dev(bus->dev.bus, NULL, NULL, __mcb_devices_unregister);
+}
+/**
+ * mcb_release_bus() - Free a @mcb_bus
+ * @bus: The @mcb_bus to release
+ *
+ * Release an allocated @mcb_bus from the system.
+ */
+void mcb_release_bus(struct mcb_bus *bus)
+{
+	mcb_devices_unregister(bus);
+}
+EXPORT_SYMBOL_NS_GPL(mcb_release_bus, "MCB");
+
+/**
+ * mcb_bus_get() - Increment refcnt
+ * @bus: The @mcb_bus
+ *
+ * Get a @mcb_bus' ref
+ */
+struct mcb_bus *mcb_bus_get(struct mcb_bus *bus)
+{
+	if (bus)
+		get_device(&bus->dev);
+
+	return bus;
+}
+EXPORT_SYMBOL_NS_GPL(mcb_bus_get, "MCB");
+
+/**
+ * mcb_bus_put() - Decrement refcnt
+ * @bus: The @mcb_bus
+ *
+ * Release a @mcb_bus' ref
+ */
+void mcb_bus_put(struct mcb_bus *bus)
+{
+	if (bus)
+		put_device(&bus->dev);
+}
+EXPORT_SYMBOL_NS_GPL(mcb_bus_put, "MCB");
+
+/**
+ * mcb_alloc_dev() - Allocate a device
+ * @bus: The @mcb_bus the device is part of
+ *
+ * Allocate a @mcb_device and add bus.
+ */
+struct mcb_device *mcb_alloc_dev(struct mcb_bus *bus)
+{
+	struct mcb_device *dev;
+
+	dev = kzalloc_obj(struct mcb_device);
+	if (!dev)
+		return NULL;
+
+	dev->bus = bus;
+
+	return dev;
+}
+EXPORT_SYMBOL_NS_GPL(mcb_alloc_dev, "MCB");
+
+/**
+ * mcb_free_dev() - Free @mcb_device
+ * @dev: The device to free
+ *
+ * Free a @mcb_device
+ */
+void mcb_free_dev(struct mcb_device *dev)
+{
+	kfree(dev);
+}
+EXPORT_SYMBOL_NS_GPL(mcb_free_dev, "MCB");
+
+static int __mcb_bus_add_devices(struct device *dev, void *data)
+{
+	int retval;
+
+	retval = device_attach(dev);
+	if (retval < 0) {
+		dev_err(dev, "Error adding device (%d)\n", retval);
+		return retval;
+	}
+
+	return 0;
+}
+
+/**
+ * mcb_bus_add_devices() - Add devices in the bus' internal device list
+ * @bus: The @mcb_bus we add the devices
+ *
+ * Add devices in the bus' internal device list to the system.
+ */
+void mcb_bus_add_devices(const struct mcb_bus *bus)
+{
+	bus_for_each_dev(bus->dev.bus, NULL, NULL, __mcb_bus_add_devices);
+}
+EXPORT_SYMBOL_NS_GPL(mcb_bus_add_devices, "MCB");
+
+/**
+ * mcb_get_resource() - get a resource for a mcb device
+ * @dev: the mcb device
+ * @type: the type of resource
+ */
+struct resource *mcb_get_resource(struct mcb_device *dev, unsigned int type)
+{
+	if (type == IORESOURCE_MEM)
+		return &dev->mem;
+	else if (type == IORESOURCE_IRQ)
+		return &dev->irq;
+	else
+		return NULL;
+}
+EXPORT_SYMBOL_NS_GPL(mcb_get_resource, "MCB");
+
+/**
+ * mcb_request_mem() - Request memory
+ * @dev: The @mcb_device the memory is for
+ * @name: The name for the memory reference.
+ *
+ * Request memory for a @mcb_device. If @name is NULL the driver name will
+ * be used.
+ */
+struct resource *mcb_request_mem(struct mcb_device *dev, const char *name)
+{
+	struct resource *mem;
+	u32 size;
+
+	if (!name)
+		name = dev->dev.driver->name;
+
+	size = resource_size(&dev->mem);
+
+	mem = request_mem_region(dev->mem.start, size, name);
+	if (!mem)
+		return ERR_PTR(-EBUSY);
+
+	return mem;
+}
+EXPORT_SYMBOL_NS_GPL(mcb_request_mem, "MCB");
+
+/**
+ * mcb_release_mem() - Release memory requested by device
+ * @mem: The memory resource to be released
+ *
+ * Release memory that was prior requested via @mcb_request_mem().
+ */
+void mcb_release_mem(struct resource *mem)
+{
+	u32 size;
+
+	size = resource_size(mem);
+	release_mem_region(mem->start, size);
+}
+EXPORT_SYMBOL_NS_GPL(mcb_release_mem, "MCB");
+
+static int __mcb_get_irq(struct mcb_device *dev)
+{
+	struct resource *irq;
+
+	irq = mcb_get_resource(dev, IORESOURCE_IRQ);
+
+	return irq->start;
+}
+
+/**
+ * mcb_get_irq() - Get device's IRQ number
+ * @dev: The @mcb_device the IRQ is for
+ *
+ * Get the IRQ number of a given @mcb_device.
+ */
+int mcb_get_irq(struct mcb_device *dev)
+{
+	struct mcb_bus *bus = dev->bus;
+
+	if (bus->get_irq)
+		return bus->get_irq(dev);
+
+	return __mcb_get_irq(dev);
+}
+EXPORT_SYMBOL_NS_GPL(mcb_get_irq, "MCB");
+
+static int mcb_init(void)
+{
+	return bus_register(&mcb_bus_type);
+}
+
+static void mcb_exit(void)
+{
+	ida_destroy(&mcb_ida);
+	bus_unregister(&mcb_bus_type);
+}
+
+/* mcb must be initialized after PCI but before the chameleon drivers.
+ * That means we must use some initcall between subsys_initcall and
+ * device_initcall.
+ */
+fs_initcall(mcb_init);
+module_exit(mcb_exit);
+
+MODULE_DESCRIPTION("MEN Chameleon Bus Driver");
+MODULE_AUTHOR("Johannes Thumshirn <johannes.thumshirn@men.de>");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/mcb/mcb-internal.h b/drivers/mcb/mcb-internal.h
new file mode 100644
index 000000000..3602cb3b2
--- /dev/null
+++ b/drivers/mcb/mcb-internal.h
@@ -0,0 +1,128 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __MCB_INTERNAL
+#define __MCB_INTERNAL
+
+#include <linux/types.h>
+
+#define PCI_VENDOR_ID_MEN		0x1a88
+#define PCI_DEVICE_ID_MEN_CHAMELEON	0x4d45
+#define CHAMELEONV2_MAGIC		0xabce
+#define CHAM_HEADER_SIZE		0x200
+
+enum chameleon_descriptor_type {
+	CHAMELEON_DTYPE_GENERAL = 0x0,
+	CHAMELEON_DTYPE_BRIDGE = 0x1,
+	CHAMELEON_DTYPE_CPU = 0x2,
+	CHAMELEON_DTYPE_BAR = 0x3,
+	CHAMELEON_DTYPE_END = 0xf,
+};
+
+enum chameleon_bus_type {
+	CHAMELEON_BUS_WISHBONE,
+	CHAMELEON_BUS_AVALON,
+	CHAMELEON_BUS_LPC,
+	CHAMELEON_BUS_ISA,
+};
+
+/**
+ * struct chameleon_fpga_header
+ *
+ * @revision:	Revison of Chameleon table in FPGA
+ * @model:	Chameleon table model ASCII char
+ * @minor:	Revision minor
+ * @bus_type:	Bus type (usually %CHAMELEON_BUS_WISHBONE)
+ * @magic:	Chameleon header magic number (0xabce for version 2)
+ * @reserved:	Reserved
+ * @filename:	Filename of FPGA bitstream
+ */
+struct chameleon_fpga_header {
+	u8 revision;
+	char model;
+	u8 minor;
+	u8 bus_type;
+	u16 magic;
+	u16 reserved;
+	/* This one has no '\0' at the end!!! */
+	char filename[CHAMELEON_FILENAME_LEN];
+} __packed;
+#define HEADER_MAGIC_OFFSET 0x4
+
+/**
+ * struct chameleon_gdd - Chameleon General Device Descriptor
+ *
+ * @irq:	the position in the FPGA's IRQ controller vector
+ * @rev:	the revision of the variant's implementation
+ * @var:	the variant of the IP core
+ * @dev:	the device  the IP core is
+ * @dtype:	device descriptor type
+ * @bar:	BAR offset that must be added to module offset
+ * @inst:	the instance number of the device, 0 is first instance
+ * @group:	the group the device belongs to (0 = no group)
+ * @reserved:	reserved
+ * @offset:	beginning of the address window of desired module
+ * @size:	size of the module's address window
+ */
+struct chameleon_gdd {
+	__le32 reg1;
+	__le32 reg2;
+	__le32 offset;
+	__le32 size;
+
+} __packed;
+
+/* GDD Register 1 fields */
+#define GDD_IRQ(x) ((x) & 0x1f)
+#define GDD_REV(x) (((x) >> 5) & 0x3f)
+#define GDD_VAR(x) (((x) >> 11) & 0x3f)
+#define GDD_DEV(x) (((x) >> 18) & 0x3ff)
+#define GDD_DTY(x) (((x) >> 28) & 0xf)
+
+/* GDD Register 2 fields */
+#define GDD_BAR(x) ((x) & 0x7)
+#define GDD_INS(x) (((x) >> 3) & 0x3f)
+#define GDD_GRP(x) (((x) >> 9) & 0x3f)
+
+/**
+ * struct chameleon_bdd - Chameleon Bridge Device Descriptor
+ *
+ * @irq:	the position in the FPGA's IRQ controller vector
+ * @rev:	the revision of the variant's implementation
+ * @var:	the variant of the IP core
+ * @dev:	the device  the IP core is
+ * @dtype:	device descriptor type
+ * @bar:	BAR offset that must be added to module offset
+ * @inst:	the instance number of the device, 0 is first instance
+ * @dbar:	destination bar from the bus _behind_ the bridge
+ * @chamoff:	offset within the BAR of the source bus
+ * @offset:
+ * @size:
+ */
+struct chameleon_bdd {
+	unsigned int irq:6;
+	unsigned int rev:6;
+	unsigned int var:6;
+	unsigned int dev:10;
+	unsigned int dtype:4;
+	unsigned int bar:3;
+	unsigned int inst:6;
+	unsigned int dbar:3;
+	unsigned int group:6;
+	unsigned int reserved:14;
+	u32 chamoff;
+	u32 offset;
+	u32 size;
+} __packed;
+
+struct chameleon_bar {
+	u32 addr;
+	u32 size;
+};
+
+#define BAR_CNT(x) ((x) & 0x07)
+#define CHAMELEON_BAR_MAX	6
+#define BAR_DESC_SIZE(x)	((x) * sizeof(struct chameleon_bar) + sizeof(__le32))
+
+int chameleon_parse_cells(struct mcb_bus *bus, phys_addr_t mapbase,
+			  void __iomem *base);
+
+#endif
diff --git a/drivers/mcb/mcb-lpc.c b/drivers/mcb/mcb-lpc.c
new file mode 100644
index 000000000..070aa787a
--- /dev/null
+++ b/drivers/mcb/mcb-lpc.c
@@ -0,0 +1,187 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * MEN Chameleon Bus.
+ *
+ * Copyright (C) 2014 MEN Mikroelektronik GmbH (www.men.de)
+ * Author: Andreas Werner <andreas.werner@men.de>
+ */
+
+#include <linux/platform_device.h>
+#include <linux/module.h>
+#include <linux/dmi.h>
+#include <linux/mcb.h>
+#include <linux/io.h>
+#include "mcb-internal.h"
+
+struct priv {
+	struct mcb_bus *bus;
+	struct resource *mem;
+	void __iomem *base;
+};
+
+static int mcb_lpc_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+	struct priv *priv;
+	int ret = 0, table_size;
+
+	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!priv->mem) {
+		dev_err(&pdev->dev, "No Memory resource\n");
+		return -ENODEV;
+	}
+
+	res = devm_request_mem_region(&pdev->dev, priv->mem->start,
+				      resource_size(priv->mem),
+				      KBUILD_MODNAME);
+	if (!res) {
+		dev_err(&pdev->dev, "Failed to request IO memory\n");
+		return -EBUSY;
+	}
+
+	priv->base = devm_ioremap(&pdev->dev, priv->mem->start,
+				  resource_size(priv->mem));
+	if (!priv->base) {
+		dev_err(&pdev->dev, "Cannot ioremap\n");
+		return -ENOMEM;
+	}
+
+	platform_set_drvdata(pdev, priv);
+
+	priv->bus = mcb_alloc_bus(&pdev->dev);
+	if (IS_ERR(priv->bus))
+		return PTR_ERR(priv->bus);
+
+	ret = chameleon_parse_cells(priv->bus, priv->mem->start, priv->base);
+	if (ret < 0) {
+		goto out_mcb_bus;
+	}
+
+	table_size = ret;
+
+	if (table_size < CHAM_HEADER_SIZE) {
+		/* Release the previous resources */
+		devm_iounmap(&pdev->dev, priv->base);
+		devm_release_mem_region(&pdev->dev, priv->mem->start, resource_size(priv->mem));
+
+		/* Then, allocate it again with the actual chameleon table size */
+		res = devm_request_mem_region(&pdev->dev, priv->mem->start,
+					      table_size,
+					      KBUILD_MODNAME);
+		if (!res) {
+			dev_err(&pdev->dev, "Failed to request PCI memory\n");
+			ret = -EBUSY;
+			goto out_mcb_bus;
+		}
+
+		priv->base = devm_ioremap(&pdev->dev, priv->mem->start, table_size);
+		if (!priv->base) {
+			dev_err(&pdev->dev, "Cannot ioremap\n");
+			ret = -ENOMEM;
+			goto out_mcb_bus;
+		}
+
+		platform_set_drvdata(pdev, priv);
+	}
+
+	mcb_bus_add_devices(priv->bus);
+
+	return 0;
+
+out_mcb_bus:
+	mcb_release_bus(priv->bus);
+	return ret;
+}
+
+static void mcb_lpc_remove(struct platform_device *pdev)
+{
+	struct priv *priv = platform_get_drvdata(pdev);
+
+	mcb_release_bus(priv->bus);
+}
+
+static struct platform_device *mcb_lpc_pdev;
+
+static int mcb_lpc_create_platform_device(const struct dmi_system_id *id)
+{
+	struct resource *res = id->driver_data;
+	int ret;
+
+	mcb_lpc_pdev = platform_device_alloc("mcb-lpc", -1);
+	if (!mcb_lpc_pdev)
+		return -ENOMEM;
+
+	ret = platform_device_add_resources(mcb_lpc_pdev, res, 1);
+	if (ret)
+		goto out_put;
+
+	ret = platform_device_add(mcb_lpc_pdev);
+	if (ret)
+		goto out_put;
+
+	return 0;
+
+out_put:
+	platform_device_put(mcb_lpc_pdev);
+	return ret;
+}
+
+static struct resource sc24_fpga_resource = DEFINE_RES_MEM(0xe000e000, CHAM_HEADER_SIZE);
+static struct resource sc31_fpga_resource = DEFINE_RES_MEM(0xf000e000, CHAM_HEADER_SIZE);
+
+static struct platform_driver mcb_lpc_driver = {
+	.driver		= {
+		.name = "mcb-lpc",
+	},
+	.probe		= mcb_lpc_probe,
+	.remove		= mcb_lpc_remove,
+};
+
+static const struct dmi_system_id mcb_lpc_dmi_table[] = {
+	{
+		.ident = "SC24",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "MEN"),
+			DMI_MATCH(DMI_PRODUCT_VERSION, "14SC24"),
+		},
+		.driver_data = (void *)&sc24_fpga_resource,
+		.callback = mcb_lpc_create_platform_device,
+	},
+	{
+		.ident = "SC31",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "MEN"),
+			DMI_MATCH(DMI_PRODUCT_VERSION, "14SC31"),
+		},
+		.driver_data = (void *)&sc31_fpga_resource,
+		.callback = mcb_lpc_create_platform_device,
+	},
+	{}
+};
+MODULE_DEVICE_TABLE(dmi, mcb_lpc_dmi_table);
+
+static int __init mcb_lpc_init(void)
+{
+	if (!dmi_check_system(mcb_lpc_dmi_table))
+		return -ENODEV;
+
+	return platform_driver_register(&mcb_lpc_driver);
+}
+
+static void __exit mcb_lpc_exit(void)
+{
+	platform_device_unregister(mcb_lpc_pdev);
+	platform_driver_unregister(&mcb_lpc_driver);
+}
+
+module_init(mcb_lpc_init);
+module_exit(mcb_lpc_exit);
+
+MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("MCB over LPC support");
+MODULE_IMPORT_NS("MCB");
diff --git a/drivers/mcb/mcb-parse.c b/drivers/mcb/mcb-parse.c
new file mode 100644
index 000000000..7e09a0ea8
--- /dev/null
+++ b/drivers/mcb/mcb-parse.c
@@ -0,0 +1,253 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/types.h>
+#include <linux/ioport.h>
+#include <linux/slab.h>
+#include <linux/export.h>
+#include <linux/io.h>
+#include <linux/mcb.h>
+
+#include "mcb-internal.h"
+
+#define for_each_chameleon_cell(dtype, p)	\
+	for ((dtype) = get_next_dtype((p));	\
+	     (dtype) != CHAMELEON_DTYPE_END;	\
+	     (dtype) = get_next_dtype((p)))
+
+static inline uint32_t get_next_dtype(void __iomem *p)
+{
+	uint32_t dtype;
+
+	dtype = readl(p);
+	return dtype >> 28;
+}
+
+static int chameleon_parse_bdd(struct mcb_bus *bus,
+			struct chameleon_bar *cb,
+			void __iomem *base)
+{
+	return 0;
+}
+
+static int chameleon_parse_gdd(struct mcb_bus *bus,
+			struct chameleon_bar *cb,
+			void __iomem *base, int bar_count)
+{
+	struct chameleon_gdd __iomem *gdd =
+		(struct chameleon_gdd __iomem *) base;
+	struct mcb_device *mdev;
+	u32 dev_mapbase;
+	u32 offset;
+	u32 size;
+	int ret;
+	__le32 reg1;
+	__le32 reg2;
+
+	mdev = mcb_alloc_dev(bus);
+	if (!mdev)
+		return -ENOMEM;
+
+	reg1 = readl(&gdd->reg1);
+	reg2 = readl(&gdd->reg2);
+	offset = readl(&gdd->offset);
+	size = readl(&gdd->size);
+
+	mdev->id = GDD_DEV(reg1);
+	mdev->rev = GDD_REV(reg1);
+	mdev->var = GDD_VAR(reg1);
+	mdev->bar = GDD_BAR(reg2);
+	mdev->group = GDD_GRP(reg2);
+	mdev->inst = GDD_INS(reg2);
+
+	/*
+	 * If the BAR is missing, dev_mapbase is zero, or if the
+	 * device is IO mapped we just print a warning and go on with the
+	 * next device, instead of completely stop the gdd parser
+	 */
+	if (mdev->bar > bar_count - 1) {
+		pr_info("No BAR for 16z%03d\n", mdev->id);
+		ret = 0;
+		goto err;
+	}
+
+	dev_mapbase = cb[mdev->bar].addr;
+	if (!dev_mapbase) {
+		pr_info("BAR not assigned for 16z%03d\n", mdev->id);
+		ret = 0;
+		goto err;
+	}
+
+	if (dev_mapbase & 0x01) {
+		pr_info("IO mapped Device (16z%03d) not yet supported\n",
+			mdev->id);
+		ret = 0;
+		goto err;
+	}
+
+	pr_debug("Found a 16z%03d\n", mdev->id);
+
+	mdev->irq.start = GDD_IRQ(reg1);
+	mdev->irq.end = GDD_IRQ(reg1);
+	mdev->irq.flags = IORESOURCE_IRQ;
+
+	mdev->mem.start = dev_mapbase + offset;
+
+	mdev->mem.end = mdev->mem.start + size - 1;
+	mdev->mem.flags = IORESOURCE_MEM;
+
+	ret = mcb_device_register(bus, mdev);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+
+err:
+	mcb_free_dev(mdev);
+
+	return ret;
+}
+
+static void chameleon_parse_bar(void __iomem *base,
+				struct chameleon_bar *cb, int bar_count)
+{
+	char __iomem *p = base;
+	int i;
+
+	/* skip reg1 */
+	p += sizeof(__le32);
+
+	for (i = 0; i < bar_count; i++) {
+		cb[i].addr = readl(p);
+		cb[i].size = readl(p + 4);
+
+		p += sizeof(struct chameleon_bar);
+	}
+}
+
+static int chameleon_get_bar(void __iomem **base, phys_addr_t mapbase,
+			     struct chameleon_bar **cb)
+{
+	struct chameleon_bar *c;
+	int bar_count;
+	__le32 reg;
+	u32 dtype;
+
+	/*
+	 * For those devices which are not connected
+	 * to the PCI Bus (e.g. LPC) there is a bar
+	 * descriptor located directly after the
+	 * chameleon header. This header is comparable
+	 * to a PCI header.
+	 */
+	dtype = get_next_dtype(*base);
+	if (dtype == CHAMELEON_DTYPE_BAR) {
+		reg = readl(*base);
+
+		bar_count = BAR_CNT(reg);
+		if (bar_count <= 0 || bar_count > CHAMELEON_BAR_MAX)
+			return -ENODEV;
+
+		c = kzalloc_objs(struct chameleon_bar, bar_count);
+		if (!c)
+			return -ENOMEM;
+
+		chameleon_parse_bar(*base, c, bar_count);
+		*base += BAR_DESC_SIZE(bar_count);
+	} else {
+		c = kzalloc_obj(struct chameleon_bar);
+		if (!c)
+			return -ENOMEM;
+
+		bar_count = 1;
+		c->addr = mapbase;
+	}
+
+	*cb = c;
+
+	return bar_count;
+}
+
+int chameleon_parse_cells(struct mcb_bus *bus, phys_addr_t mapbase,
+			void __iomem *base)
+{
+	struct chameleon_fpga_header *header;
+	struct chameleon_bar *cb;
+	void __iomem *p = base;
+	int num_cells = 0;
+	uint32_t dtype;
+	int bar_count;
+	int ret;
+	u32 hsize;
+	u32 table_size;
+
+	hsize = sizeof(struct chameleon_fpga_header);
+
+	header = kzalloc(hsize, GFP_KERNEL);
+	if (!header)
+		return -ENOMEM;
+
+	/* Extract header information */
+	memcpy_fromio(header, p, hsize);
+	/* We only support chameleon v2 at the moment */
+	header->magic = le16_to_cpu(header->magic);
+	if (header->magic != CHAMELEONV2_MAGIC) {
+		pr_err("Unsupported chameleon version 0x%x\n",
+				header->magic);
+		ret = -ENODEV;
+		goto free_header;
+	}
+	p += hsize;
+
+	bus->revision = header->revision;
+	bus->model = header->model;
+	bus->minor = header->minor;
+	snprintf(bus->name, CHAMELEON_FILENAME_LEN + 1, "%s",
+		 header->filename);
+
+	bar_count = chameleon_get_bar(&p, mapbase, &cb);
+	if (bar_count < 0) {
+		ret = bar_count;
+		goto free_header;
+	}
+
+	for_each_chameleon_cell(dtype, p) {
+		switch (dtype) {
+		case CHAMELEON_DTYPE_GENERAL:
+			ret = chameleon_parse_gdd(bus, cb, p, bar_count);
+			if (ret < 0)
+				goto free_bar;
+			p += sizeof(struct chameleon_gdd);
+			break;
+		case CHAMELEON_DTYPE_BRIDGE:
+			chameleon_parse_bdd(bus, cb, p);
+			p += sizeof(struct chameleon_bdd);
+			break;
+		case CHAMELEON_DTYPE_END:
+			break;
+		default:
+			pr_err("Invalid chameleon descriptor type 0x%x\n",
+				dtype);
+			ret = -EINVAL;
+			goto free_bar;
+		}
+		num_cells++;
+	}
+
+	if (num_cells == 0) {
+		ret = -EINVAL;
+		goto free_bar;
+	}
+
+	table_size = p - base;
+	pr_debug("%d cell(s) found. Chameleon table size: 0x%04x bytes\n", num_cells, table_size);
+	kfree(cb);
+	kfree(header);
+	return table_size;
+
+free_bar:
+	kfree(cb);
+free_header:
+	kfree(header);
+
+	return ret;
+}
+EXPORT_SYMBOL_NS_GPL(chameleon_parse_cells, "MCB");
diff --git a/drivers/mcb/mcb-pci.c b/drivers/mcb/mcb-pci.c
new file mode 100644
index 000000000..f1353da6e
--- /dev/null
+++ b/drivers/mcb/mcb-pci.c
@@ -0,0 +1,157 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * MEN Chameleon Bus.
+ *
+ * Copyright (C) 2014 MEN Mikroelektronik GmbH (www.men.de)
+ * Author: Johannes Thumshirn <johannes.thumshirn@men.de>
+ */
+
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/mcb.h>
+
+#include "mcb-internal.h"
+
+struct priv {
+	struct mcb_bus *bus;
+	phys_addr_t mapbase;
+	void __iomem *base;
+};
+
+static int mcb_pci_get_irq(struct mcb_device *mdev)
+{
+	struct mcb_bus *mbus = mdev->bus;
+	struct device *dev = mbus->carrier;
+	struct pci_dev *pdev = to_pci_dev(dev);
+
+	return pdev->irq;
+}
+
+static int mcb_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
+{
+	struct resource *res;
+	struct priv *priv;
+	int ret, table_size;
+	unsigned long flags;
+
+	priv = devm_kzalloc(&pdev->dev, sizeof(struct priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	ret = pci_enable_device(pdev);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to enable PCI device\n");
+		return -ENODEV;
+	}
+	pci_set_master(pdev);
+
+	flags = pci_resource_flags(pdev, 0);
+	if (flags & IORESOURCE_IO) {
+		ret = -ENOTSUPP;
+		dev_err(&pdev->dev,
+			"IO mapped PCI devices are not supported\n");
+		goto out_disable;
+	}
+
+	priv->mapbase = pci_resource_start(pdev, 0);
+	if (!priv->mapbase) {
+		dev_err(&pdev->dev, "No PCI resource\n");
+		ret = -ENODEV;
+		goto out_disable;
+	}
+
+	res = devm_request_mem_region(&pdev->dev, priv->mapbase,
+				      CHAM_HEADER_SIZE,
+				      KBUILD_MODNAME);
+	if (!res) {
+		dev_err(&pdev->dev, "Failed to request PCI memory\n");
+		ret = -EBUSY;
+		goto out_disable;
+	}
+
+	priv->base = devm_ioremap(&pdev->dev, priv->mapbase, CHAM_HEADER_SIZE);
+	if (!priv->base) {
+		dev_err(&pdev->dev, "Cannot ioremap\n");
+		ret = -ENOMEM;
+		goto out_disable;
+	}
+
+	pci_set_drvdata(pdev, priv);
+
+	priv->bus = mcb_alloc_bus(&pdev->dev);
+	if (IS_ERR(priv->bus)) {
+		ret = PTR_ERR(priv->bus);
+		goto out_disable;
+	}
+
+	priv->bus->get_irq = mcb_pci_get_irq;
+
+	ret = chameleon_parse_cells(priv->bus, priv->mapbase, priv->base);
+	if (ret < 0)
+		goto out_mcb_bus;
+
+	table_size = ret;
+
+	if (table_size < CHAM_HEADER_SIZE) {
+		/* Release the previous resources */
+		devm_iounmap(&pdev->dev, priv->base);
+		devm_release_mem_region(&pdev->dev, priv->mapbase, CHAM_HEADER_SIZE);
+
+		/* Then, allocate it again with the actual chameleon table size */
+		res = devm_request_mem_region(&pdev->dev, priv->mapbase,
+						table_size,
+						KBUILD_MODNAME);
+		if (!res) {
+			dev_err(&pdev->dev, "Failed to request PCI memory\n");
+			ret = -EBUSY;
+			goto out_mcb_bus;
+		}
+
+		priv->base = devm_ioremap(&pdev->dev, priv->mapbase, table_size);
+		if (!priv->base) {
+			dev_err(&pdev->dev, "Cannot ioremap\n");
+			ret = -ENOMEM;
+			goto out_mcb_bus;
+		}
+	}
+
+	mcb_bus_add_devices(priv->bus);
+
+	return 0;
+
+out_mcb_bus:
+	mcb_release_bus(priv->bus);
+out_disable:
+	pci_disable_device(pdev);
+	return ret;
+}
+
+static void mcb_pci_remove(struct pci_dev *pdev)
+{
+	struct priv *priv = pci_get_drvdata(pdev);
+
+	mcb_release_bus(priv->bus);
+
+	pci_disable_device(pdev);
+}
+
+static const struct pci_device_id mcb_pci_tbl[] = {
+	{ PCI_DEVICE(PCI_VENDOR_ID_MEN, PCI_DEVICE_ID_MEN_CHAMELEON) },
+	{ PCI_DEVICE(PCI_VENDOR_ID_ALTERA, PCI_DEVICE_ID_MEN_CHAMELEON) },
+	{ 0 },
+};
+MODULE_DEVICE_TABLE(pci, mcb_pci_tbl);
+
+static struct pci_driver mcb_pci_driver = {
+	.name = "mcb-pci",
+	.id_table = mcb_pci_tbl,
+	.probe = mcb_pci_probe,
+	.remove = mcb_pci_remove,
+};
+
+module_pci_driver(mcb_pci_driver);
+
+MODULE_AUTHOR("Johannes Thumshirn <johannes.thumshirn@men.de>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("MCB over PCI support");
+MODULE_IMPORT_NS("MCB");