Merge tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Don't destroy user event fields when removal fails

   User event fields are destroyed before the event is removed from
   visibility. But that can fail leaving the still visible event with no
   fields. Move the destroying of the fields to after the event is
   successfully removed from visibility.

 - Initialize function graph state is fork before calling
   copy_exec_state()

   For non-CLONE_VM forks, copy_exec_state() allocates a new
   task_exec_state. If that allocation fails, ftrace_graph_exit_task()
   will free the tasks ret_stack pointer. Since that pointer is still
   using the parent's ret_stack, it mistakenly frees the parent's
   pointer too.

   Call ftrace_graph_init() on the task first which will NULL out the
   new tasks's ret_stack and if the copy fails, it will not free
   anything.

 - Remove FGRAPH_MAX_INDEX

   The macro FGRAPH_MAX_INDEX was added but never used. Remove it.

 - Save ent_size in function graph printing of nested functions

   The function graph tracer needs to look at the next event to see if
   the next event is the return of the current function entry. If it is,
   it prints a single line:

	ktime_get();

   Otherwise it prints it like a nested function:

	tick_nohz_irq_exit() {
	    ktime_get();
	    kcpustat_irq_exit();
	}

   In order to look at the next event, it must save the current event so
   that it has the information to print from it. It saves the event in
   the iterator descriptor called "ent". What it doesn't save is the
   ent_size of the event which is now used to know if the function graph
   arguments are to be printed. The peek doesn't save the size so the
   size used happens to be that of the size of the last event that was
   seen.

   Save the entry event size in the iterator descriptor so that the
   correct size is used.

 - Fix several errors with freeing data in the histogram code

   The histogram code had a lot of leaked or or incorrect accounting
   when failures happen. Correct them.

 - Fix histogram regression of .percent and .graph modifiers

   Up until 6.3 histogram values could have "percent" or "graph"
   modifiers that changed how they were printed. But a change that added
   restricting histograms values from being strings, stack traces and
   other modifiers inadvertently prevented them from using the percent
   and graph modifiers, which were legal use cases for values.

   Put back the percent and graph modifiers.

 - Fix various typos in the comments

 - Set the trace_clock before initializing a histogram with clock
   argument

   The histogram API allows the user to specific which trace clock to
   use via a "clock=" string. The histogram is set up first before the
   clock is checked. If the passed in clock is not valid, it exits
   without fully fixing up the histogram leaving it on the list and a
   use-after-free can trigger.

   Update the clock argument first and if it fails then exit gracefully
   before the histogram trigger is placed on any lists.

 - Restore :mod: trailer after parsing in ftrace_set_clr_event

   The function ftrace_set_clr_event() modifies the parse string and
   needs to put it back to what was passed in. It searches for ":mod:"
   via a strsep() but fails to put back the first ':' in the string.

   Add back the ':' in the passed in string.

 - Take trace_array reference when opening a tracer options file

   The options files are dynamically created and some tracers add their
   own options. When a tracer adds their own list of options, the
   trace_array holding them has an array to hold the list of options for
   each tracer. This array increases in size via a krealloc(), and the
   new entry gets a newly allocated array to hold the options of the new
   tracer being added.

   The element in each entry of the tracer's option array holds a
   pointer back to the trace_array, a pointer to the tracer it is
   associated to, a pointer to the flags of the option.

   The issue is that these arrays are freed when the trace_array is
   freed when its instance it represents is removed from the instances
   directory. There's a race that an open of one of these options files
   can happen when the instance is being removed.

   Add a new helper function to be called by the open function of the
   options file to iterate all existing trace_arrays under a lock and
   find the one that has the given option element in one of it's tracer
   arrays. If found, then update the associated trace_array's reference
   counter to keep it from being freed. If not found, have the open call
   return -ENODEV.

 - Disable interrupts when acquiring the lock in rb_wake_up_waiters()

   The function rb_wake_up_waiters() assumes it will be called in
   interrupt context and does not disable irqs when taking
   cpu_buffer->reader_lock, which can be called in hard interrupt
   context. The issue is in PREEMPT_RT, this function is called in
   thread context leaving this lock open to a deadlock.

   Take the lock with interrupts disabled.

 - Use rcu_assign_pointer() for tmp_ops filter hash

   The tmp_ops used in update_ftrace_direct_mod() assigns its
   filter_hash field directly, but that field is annotated as __rcu and
   sparse complains. Assign it with rcu_assign_pointer()

 - Fix use-after-free in enable_trigger_private_data_free()

   The trace_event_call is accessed through the event_trigger_data's
   trace_event_file pointer to put the trace_event_call on freeing. The
   issue is that the trace_event_file data may have been freed already
   causing a use-after-free. Add a field to the event_trigger_data that
   points directly to the trace_event_call so that it can decrement its
   reference directly without needing to go through the
   trace_event_file.

 - Fix accounting of buffer data remote headers

   trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount
   the number of pages is needed for the asked for size as it doesn't
   take into account the meta data on each page. Add a helper function
   to do the calculation properly and use that in these functions.

 - Catch nr_page_va overflow in ring_buffer_desc sizing

   The number of pages per remote ring buffer is capped by
   ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to
   overflow that field would silently allocate a descriptor smaller than
   what was asked for.

 - Do not resize the subbuf order if any per_cpu buffer is disabled

   The mmapping of ring buffers disables resizing the subbuffers, but it
   is done per-cpu whereas the subbuf size change is done for all the
   per_cpu buffers under the buffer->mutex. It could change the size of
   some while the mapping is happening on others. Have the resize of the
   subbuf order check all the per_cpu buffers under the lock to see if
   any of them is disabled before starting and causing an inconsistency
   between buffers that are being mapped.

* tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (25 commits)
  ring-buffer: Check resize_disabled before publishing the new subbuf order
  tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing
  tracing/remotes: Account for ring buffer page header in size calculation
  tracing: Don't dereference trace_event_file in deferred trigger free
  ftrace: Use rcu_assign_pointer() for tmp_ops filter hash
  ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters()
  tracing: Take trace_array reference when opening a tracer options file
  tracing: Fix ring_buffer_read_page_size() kernel-doc
  tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event()
  tracing: Fix memory corruption from a "STACKTRACE" histogram key
  tracing: Fix memory corruption from the histogram stacktrace modifier
  tracing: Undo the registration when enabling the histogram trigger fails
  tracing: Take the reference before publishing the named histogram trigger
  tracing: Set the trace clock before registering the histogram trigger
  tracing: Fix typo "preceeded" in comment
  tracing: Fix typo "availabe" in comment
  tracing: Let histogram values keep the percent and graph modifiers
  tracing: Keep the entry count when the histogram stats allocation fails
  tracing: Free histogram the field rejected for a bad modifier
  tracing: Free histogram the var ref when its initialization fails
  ...

1 files changed, 944 insertions, 0 deletions

diff --git a/drivers/cdx/cdx.c b/drivers/cdx/cdx.c
new file mode 100644
index 000000000..a118a89a7
--- /dev/null
+++ b/drivers/cdx/cdx.c
@@ -0,0 +1,944 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * CDX bus driver.
+ *
+ * Copyright (C) 2022-2023, Advanced Micro Devices, Inc.
+ */
+
+/*
+ * Architecture Overview
+ * =====================
+ * CDX is a Hardware Architecture designed for AMD FPGA devices. It
+ * consists of sophisticated mechanism for interaction between FPGA,
+ * Firmware and the APUs (Application CPUs).
+ *
+ * Firmware resides on RPU (Realtime CPUs) which interacts with
+ * the FPGA program manager and the APUs. The RPU provides memory-mapped
+ * interface (RPU if) which is used to communicate with APUs.
+ *
+ * The diagram below shows an overview of the CDX architecture:
+ *
+ *          +--------------------------------------+
+ *          |    Application CPUs (APU)            |
+ *          |                                      |
+ *          |                    CDX device drivers|
+ *          |     Linux OS                |        |
+ *          |                        CDX bus       |
+ *          |                             |        |
+ *          |                     CDX controller   |
+ *          |                             |        |
+ *          +-----------------------------|--------+
+ *                                        | (discover, config,
+ *                                        |  reset, rescan)
+ *                                        |
+ *          +------------------------| RPU if |----+
+ *          |                             |        |
+ *          |                             V        |
+ *          |          Realtime CPUs (RPU)         |
+ *          |                                      |
+ *          +--------------------------------------+
+ *                                |
+ *          +---------------------|----------------+
+ *          |  FPGA               |                |
+ *          |      +-----------------------+       |
+ *          |      |           |           |       |
+ *          | +-------+    +-------+   +-------+   |
+ *          | | dev 1 |    | dev 2 |   | dev 3 |   |
+ *          | +-------+    +-------+   +-------+   |
+ *          +--------------------------------------+
+ *
+ * The RPU firmware extracts the device information from the loaded FPGA
+ * image and implements a mechanism that allows the APU drivers to
+ * enumerate such devices (device personality and resource details) via
+ * a dedicated communication channel. RPU mediates operations such as
+ * discover, reset and rescan of the FPGA devices for the APU. This is
+ * done using memory mapped interface provided by the RPU to APU.
+ */
+
+#include <linux/init.h>
+#include <linux/irqdomain.h>
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+#include <linux/idr.h>
+#include <linux/cdx/cdx_bus.h>
+#include <linux/iommu.h>
+#include <linux/dma-map-ops.h>
+#include <linux/debugfs.h>
+#include "cdx.h"
+
+/* Default DMA mask for devices on a CDX bus */
+#define CDX_DEFAULT_DMA_MASK	(~0ULL)
+#define MAX_CDX_CONTROLLERS 16
+
+/* IDA for CDX controllers registered with the CDX bus */
+static DEFINE_IDA(cdx_controller_ida);
+/* Lock to protect controller ops */
+static DEFINE_MUTEX(cdx_controller_lock);
+/* Debugfs dir for cdx bus */
+static struct dentry *cdx_debugfs_dir;
+
+static char *compat_node_name = "xlnx,versal-net-cdx";
+
+static void cdx_destroy_res_attr(struct cdx_device *cdx_dev, int num);
+
+/**
+ * cdx_dev_reset - Reset a CDX device
+ * @dev: CDX device
+ *
+ * Return: -errno on failure, 0 on success.
+ */
+int cdx_dev_reset(struct device *dev)
+{
+	struct cdx_device *cdx_dev = to_cdx_device(dev);
+	struct cdx_controller *cdx = cdx_dev->cdx;
+	struct cdx_device_config dev_config = {0};
+	struct cdx_driver *cdx_drv;
+	int ret;
+
+	cdx_drv = to_cdx_driver(dev->driver);
+	/* Notify driver that device is being reset */
+	if (cdx_drv && cdx_drv->reset_prepare)
+		cdx_drv->reset_prepare(cdx_dev);
+
+	dev_config.type = CDX_DEV_RESET_CONF;
+	ret = cdx->ops->dev_configure(cdx, cdx_dev->bus_num,
+				      cdx_dev->dev_num, &dev_config);
+	if (ret)
+		dev_err(dev, "cdx device reset failed\n");
+
+	/* Notify driver that device reset is complete */
+	if (cdx_drv && cdx_drv->reset_done)
+		cdx_drv->reset_done(cdx_dev);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(cdx_dev_reset);
+
+/**
+ * reset_cdx_device - Reset a CDX device
+ * @dev: CDX device
+ * @data: This is always passed as NULL, and is not used in this API,
+ *    but is required here as the device_for_each_child() API expects
+ *    the passed function to have this as an argument.
+ *
+ * Return: -errno on failure, 0 on success.
+ */
+static int reset_cdx_device(struct device *dev, void *data)
+{
+	return cdx_dev_reset(dev);
+}
+
+/**
+ * cdx_unregister_device - Unregister a CDX device
+ * @dev: CDX device
+ * @data: This is always passed as NULL, and is not used in this API,
+ *	  but is required here as the bus_for_each_dev() API expects
+ *	  the passed function (cdx_unregister_device) to have this
+ *	  as an argument.
+ *
+ * Return: 0 on success.
+ */
+static int cdx_unregister_device(struct device *dev,
+				 void *data)
+{
+	struct cdx_device *cdx_dev = to_cdx_device(dev);
+	struct cdx_controller *cdx = cdx_dev->cdx;
+
+	if (cdx_dev->is_bus) {
+		device_for_each_child(dev, NULL, cdx_unregister_device);
+		if (cdx_dev->enabled && cdx->ops->bus_disable)
+			cdx->ops->bus_disable(cdx, cdx_dev->bus_num);
+	} else {
+		cdx_destroy_res_attr(cdx_dev, MAX_CDX_DEV_RESOURCES);
+		debugfs_remove_recursive(cdx_dev->debugfs_dir);
+	}
+
+	/*
+	 * Do not free cdx_dev here as it would be freed in
+	 * cdx_device_release() called from within put_device().
+	 */
+	device_del(&cdx_dev->dev);
+	put_device(&cdx_dev->dev);
+
+	return 0;
+}
+
+static void cdx_unregister_devices(const struct bus_type *bus)
+{
+	/* Reset all the devices attached to cdx bus */
+	bus_for_each_dev(bus, NULL, NULL, cdx_unregister_device);
+}
+
+/**
+ * cdx_match_one_device - Tell if a CDX device structure has a matching
+ *			  CDX device id structure
+ * @id: single CDX device id structure to match
+ * @dev: the CDX device structure to match against
+ *
+ * Return: matching cdx_device_id structure or NULL if there is no match.
+ */
+static inline const struct cdx_device_id *
+cdx_match_one_device(const struct cdx_device_id *id,
+		     const struct cdx_device *dev)
+{
+	/* Use vendor ID and device ID for matching */
+	if ((id->vendor == CDX_ANY_ID || id->vendor == dev->vendor) &&
+	    (id->device == CDX_ANY_ID || id->device == dev->device) &&
+	    (id->subvendor == CDX_ANY_ID || id->subvendor == dev->subsystem_vendor) &&
+	    (id->subdevice == CDX_ANY_ID || id->subdevice == dev->subsystem_device) &&
+	    !((id->class ^ dev->class) & id->class_mask))
+		return id;
+	return NULL;
+}
+
+/**
+ * cdx_match_id - See if a CDX device matches a given cdx_id table
+ * @ids: array of CDX device ID structures to search in
+ * @dev: the CDX device structure to match against.
+ *
+ * Used by a driver to check whether a CDX device is in its list of
+ * supported devices. Returns the matching cdx_device_id structure or
+ * NULL if there is no match.
+ *
+ * Return: matching cdx_device_id structure or NULL if there is no match.
+ */
+static inline const struct cdx_device_id *
+cdx_match_id(const struct cdx_device_id *ids, struct cdx_device *dev)
+{
+	if (ids) {
+		while (ids->vendor || ids->device) {
+			if (cdx_match_one_device(ids, dev))
+				return ids;
+			ids++;
+		}
+	}
+	return NULL;
+}
+
+int cdx_set_master(struct cdx_device *cdx_dev)
+{
+	struct cdx_controller *cdx = cdx_dev->cdx;
+	struct cdx_device_config dev_config;
+	int ret = -EOPNOTSUPP;
+
+	dev_config.type = CDX_DEV_BUS_MASTER_CONF;
+	dev_config.bus_master_enable = true;
+	if (cdx->ops->dev_configure)
+		ret = cdx->ops->dev_configure(cdx, cdx_dev->bus_num,
+					      cdx_dev->dev_num, &dev_config);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(cdx_set_master);
+
+int cdx_clear_master(struct cdx_device *cdx_dev)
+{
+	struct cdx_controller *cdx = cdx_dev->cdx;
+	struct cdx_device_config dev_config;
+	int ret = -EOPNOTSUPP;
+
+	dev_config.type = CDX_DEV_BUS_MASTER_CONF;
+	dev_config.bus_master_enable = false;
+	if (cdx->ops->dev_configure)
+		ret = cdx->ops->dev_configure(cdx, cdx_dev->bus_num,
+					      cdx_dev->dev_num, &dev_config);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(cdx_clear_master);
+
+/**
+ * cdx_bus_match - device to driver matching callback
+ * @dev: the cdx device to match against
+ * @drv: the device driver to search for matching cdx device
+ * structures
+ *
+ * Return: true on success, false otherwise.
+ */
+static int cdx_bus_match(struct device *dev, const struct device_driver *drv)
+{
+	struct cdx_device *cdx_dev = to_cdx_device(dev);
+	const struct cdx_driver *cdx_drv = to_cdx_driver(drv);
+	const struct cdx_device_id *found_id = NULL;
+	const struct cdx_device_id *ids;
+	int ret;
+
+	if (cdx_dev->is_bus)
+		return false;
+
+	ids = cdx_drv->match_id_table;
+
+	/* When driver_override is set, only bind to the matching driver */
+	ret = device_match_driver_override(dev, drv);
+	if (ret == 0)
+		return false;
+
+	found_id = cdx_match_id(ids, cdx_dev);
+	if (!found_id)
+		return false;
+
+	do {
+		/*
+		 * In case override_only was set, enforce driver_override
+		 * matching.
+		 */
+		if (!found_id->override_only)
+			return true;
+		if (ret > 0)
+			return true;
+
+		ids = found_id + 1;
+		found_id = cdx_match_id(ids, cdx_dev);
+	} while (found_id);
+
+	return false;
+}
+
+static int cdx_probe(struct device *dev)
+{
+	struct cdx_driver *cdx_drv = to_cdx_driver(dev->driver);
+	struct cdx_device *cdx_dev = to_cdx_device(dev);
+	struct cdx_controller *cdx = cdx_dev->cdx;
+	int error;
+
+	/*
+	 * Setup MSI device data so that generic MSI alloc/free can
+	 * be used by the device driver.
+	 */
+	if (IS_ENABLED(CONFIG_GENERIC_MSI_IRQ) && cdx->msi_domain) {
+		error = msi_setup_device_data(&cdx_dev->dev);
+		if (error)
+			return error;
+	}
+
+	error = cdx_drv->probe(cdx_dev);
+	if (error) {
+		dev_err_probe(dev, error, "%s failed\n", __func__);
+		return error;
+	}
+
+	return 0;
+}
+
+static void cdx_remove(struct device *dev)
+{
+	struct cdx_driver *cdx_drv = to_cdx_driver(dev->driver);
+	struct cdx_device *cdx_dev = to_cdx_device(dev);
+
+	if (cdx_drv && cdx_drv->remove)
+		cdx_drv->remove(cdx_dev);
+}
+
+static void cdx_shutdown(struct device *dev)
+{
+	struct cdx_driver *cdx_drv = to_cdx_driver(dev->driver);
+	struct cdx_device *cdx_dev = to_cdx_device(dev);
+	struct cdx_controller *cdx = cdx_dev->cdx;
+
+	if (cdx_dev->is_bus && cdx_dev->enabled && cdx->ops->bus_disable)
+		cdx->ops->bus_disable(cdx, cdx_dev->bus_num);
+	if (cdx_drv && cdx_drv->shutdown)
+		cdx_drv->shutdown(cdx_dev);
+}
+
+static int cdx_dma_configure(struct device *dev)
+{
+	struct cdx_driver *cdx_drv = to_cdx_driver(dev->driver);
+	struct cdx_device *cdx_dev = to_cdx_device(dev);
+	struct cdx_controller *cdx = cdx_dev->cdx;
+	u32 input_id = cdx_dev->req_id;
+	int ret;
+
+	ret = of_dma_configure_id(dev, cdx->dev->of_node, 0, &input_id);
+	if (ret && ret != -EPROBE_DEFER) {
+		dev_err(dev, "of_dma_configure_id() failed\n");
+		return ret;
+	}
+
+	/* @cdx_drv may not be valid when we're called from the IOMMU layer */
+	if (!ret && dev->driver && !cdx_drv->driver_managed_dma) {
+		ret = iommu_device_use_default_domain(dev);
+		if (ret)
+			arch_teardown_dma_ops(dev);
+	}
+
+	return 0;
+}
+
+static void cdx_dma_cleanup(struct device *dev)
+{
+	struct cdx_driver *cdx_drv = to_cdx_driver(dev->driver);
+
+	if (!cdx_drv->driver_managed_dma)
+		iommu_device_unuse_default_domain(dev);
+}
+
+/* show configuration fields */
+#define cdx_config_attr(field, format_string)	\
+static ssize_t	\
+field##_show(struct device *dev, struct device_attribute *attr, char *buf)	\
+{	\
+	struct cdx_device *cdx_dev = to_cdx_device(dev);	\
+	return sysfs_emit(buf, format_string, cdx_dev->field);	\
+}	\
+static DEVICE_ATTR_RO(field)
+
+cdx_config_attr(vendor, "0x%04x\n");
+cdx_config_attr(device, "0x%04x\n");
+cdx_config_attr(subsystem_vendor, "0x%04x\n");
+cdx_config_attr(subsystem_device, "0x%04x\n");
+cdx_config_attr(revision, "0x%02x\n");
+cdx_config_attr(class, "0x%06x\n");
+
+static ssize_t remove_store(struct device *dev,
+			    struct device_attribute *attr,
+			    const char *buf, size_t count)
+{
+	bool val;
+
+	if (kstrtobool(buf, &val) < 0)
+		return -EINVAL;
+
+	if (!val)
+		return -EINVAL;
+
+	if (device_remove_file_self(dev, attr)) {
+		int ret;
+
+		ret = cdx_unregister_device(dev, NULL);
+		if (ret)
+			return ret;
+	}
+
+	return count;
+}
+static DEVICE_ATTR_WO(remove);
+
+static ssize_t reset_store(struct device *dev, struct device_attribute *attr,
+			   const char *buf, size_t count)
+{
+	struct cdx_device *cdx_dev = to_cdx_device(dev);
+	bool val;
+	int ret;
+
+	if (kstrtobool(buf, &val) < 0)
+		return -EINVAL;
+
+	if (!val)
+		return -EINVAL;
+
+	if (cdx_dev->is_bus)
+		/* Reset all the devices attached to cdx bus */
+		ret = device_for_each_child(dev, NULL, reset_cdx_device);
+	else
+		ret = cdx_dev_reset(dev);
+
+	return ret < 0 ? ret : count;
+}
+static DEVICE_ATTR_WO(reset);
+
+static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
+			     char *buf)
+{
+	struct cdx_device *cdx_dev = to_cdx_device(dev);
+
+	return sprintf(buf, "cdx:v%04Xd%04Xsv%04Xsd%04Xc%06X\n", cdx_dev->vendor,
+			cdx_dev->device, cdx_dev->subsystem_vendor, cdx_dev->subsystem_device,
+			cdx_dev->class);
+}
+static DEVICE_ATTR_RO(modalias);
+
+static ssize_t enable_store(struct device *dev, struct device_attribute *attr,
+			    const char *buf, size_t count)
+{
+	struct cdx_device *cdx_dev = to_cdx_device(dev);
+	struct cdx_controller *cdx = cdx_dev->cdx;
+	bool enable;
+	int ret;
+
+	if (kstrtobool(buf, &enable) < 0)
+		return -EINVAL;
+
+	if (enable == cdx_dev->enabled)
+		return count;
+
+	if (enable && cdx->ops->bus_enable)
+		ret = cdx->ops->bus_enable(cdx, cdx_dev->bus_num);
+	else if (!enable && cdx->ops->bus_disable)
+		ret = cdx->ops->bus_disable(cdx, cdx_dev->bus_num);
+	else
+		ret = -EOPNOTSUPP;
+
+	if (!ret)
+		cdx_dev->enabled = enable;
+
+	return ret < 0 ? ret : count;
+}
+
+static ssize_t enable_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct cdx_device *cdx_dev = to_cdx_device(dev);
+
+	return sysfs_emit(buf, "%u\n", cdx_dev->enabled);
+}
+static DEVICE_ATTR_RW(enable);
+
+static umode_t cdx_dev_attrs_are_visible(struct kobject *kobj, struct attribute *a, int n)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct cdx_device *cdx_dev;
+
+	cdx_dev = to_cdx_device(dev);
+	if (!cdx_dev->is_bus)
+		return a->mode;
+
+	return 0;
+}
+
+static umode_t cdx_bus_attrs_are_visible(struct kobject *kobj, struct attribute *a, int n)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct cdx_device *cdx_dev;
+
+	cdx_dev = to_cdx_device(dev);
+	if (cdx_dev->is_bus)
+		return a->mode;
+
+	return 0;
+}
+
+static struct attribute *cdx_dev_attrs[] = {
+	&dev_attr_remove.attr,
+	&dev_attr_reset.attr,
+	&dev_attr_vendor.attr,
+	&dev_attr_device.attr,
+	&dev_attr_subsystem_vendor.attr,
+	&dev_attr_subsystem_device.attr,
+	&dev_attr_class.attr,
+	&dev_attr_revision.attr,
+	&dev_attr_modalias.attr,
+	NULL,
+};
+
+static const struct attribute_group cdx_dev_group = {
+	.attrs = cdx_dev_attrs,
+	.is_visible = cdx_dev_attrs_are_visible,
+};
+
+static struct attribute *cdx_bus_dev_attrs[] = {
+	&dev_attr_enable.attr,
+	&dev_attr_reset.attr,
+	NULL,
+};
+
+static const struct attribute_group cdx_bus_dev_group = {
+	.attrs = cdx_bus_dev_attrs,
+	.is_visible = cdx_bus_attrs_are_visible,
+};
+
+static const struct attribute_group *cdx_dev_groups[] = {
+	&cdx_dev_group,
+	&cdx_bus_dev_group,
+	NULL,
+};
+
+static int cdx_debug_resource_show(struct seq_file *s, void *data)
+{
+	struct cdx_device *cdx_dev = s->private;
+	int i;
+
+	for (i = 0; i < MAX_CDX_DEV_RESOURCES; i++) {
+		struct resource *res =  &cdx_dev->res[i];
+
+		seq_printf(s, "%pr\n", res);
+	}
+
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(cdx_debug_resource);
+
+static void cdx_device_debugfs_init(struct cdx_device *cdx_dev)
+{
+	cdx_dev->debugfs_dir = debugfs_create_dir(dev_name(&cdx_dev->dev), cdx_debugfs_dir);
+	if (IS_ERR(cdx_dev->debugfs_dir))
+		return;
+
+	debugfs_create_file("resource", 0444, cdx_dev->debugfs_dir, cdx_dev,
+			    &cdx_debug_resource_fops);
+}
+
+static ssize_t rescan_store(const struct bus_type *bus,
+			    const char *buf, size_t count)
+{
+	struct cdx_controller *cdx;
+	struct platform_device *pd;
+	bool val;
+
+	if (kstrtobool(buf, &val) < 0)
+		return -EINVAL;
+
+	if (!val)
+		return -EINVAL;
+
+	guard(mutex)(&cdx_controller_lock);
+
+	/* Unregister all the devices on the bus */
+	cdx_unregister_devices(&cdx_bus_type);
+
+	/* Rescan all the devices */
+	for_each_compatible_node_scoped(np, NULL, compat_node_name) {
+		pd = of_find_device_by_node(np);
+		if (!pd)
+			return -EINVAL;
+
+		cdx = platform_get_drvdata(pd);
+		if (cdx && cdx->controller_registered && cdx->ops->scan)
+			cdx->ops->scan(cdx);
+
+		put_device(&pd->dev);
+	}
+
+	return count;
+}
+static BUS_ATTR_WO(rescan);
+
+static struct attribute *cdx_bus_attrs[] = {
+	&bus_attr_rescan.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(cdx_bus);
+
+const struct bus_type cdx_bus_type = {
+	.name		= "cdx",
+	.driver_override = true,
+	.match		= cdx_bus_match,
+	.probe		= cdx_probe,
+	.remove		= cdx_remove,
+	.shutdown	= cdx_shutdown,
+	.dma_configure	= cdx_dma_configure,
+	.dma_cleanup	= cdx_dma_cleanup,
+	.bus_groups	= cdx_bus_groups,
+	.dev_groups	= cdx_dev_groups,
+};
+EXPORT_SYMBOL_GPL(cdx_bus_type);
+
+int __cdx_driver_register(struct cdx_driver *cdx_driver,
+			  struct module *owner)
+{
+	int error;
+
+	cdx_driver->driver.owner = owner;
+	cdx_driver->driver.bus = &cdx_bus_type;
+
+	error = driver_register(&cdx_driver->driver);
+	if (error) {
+		pr_err("driver_register() failed for %s: %d\n",
+		       cdx_driver->driver.name, error);
+		return error;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(__cdx_driver_register);
+
+void cdx_driver_unregister(struct cdx_driver *cdx_driver)
+{
+	driver_unregister(&cdx_driver->driver);
+}
+EXPORT_SYMBOL_GPL(cdx_driver_unregister);
+
+static void cdx_device_release(struct device *dev)
+{
+	struct cdx_device *cdx_dev = to_cdx_device(dev);
+
+	kfree(cdx_dev);
+}
+
+static const struct vm_operations_struct cdx_phys_vm_ops = {
+#ifdef CONFIG_HAVE_IOREMAP_PROT
+	.access = generic_access_phys,
+#endif
+};
+
+/**
+ * cdx_mmap_resource - map a CDX resource into user memory space
+ * @fp: File pointer. Not used in this function, but required where
+ *      this API is registered as a callback.
+ * @kobj: kobject for mapping
+ * @attr: struct bin_attribute for the file being mapped
+ * @vma: struct vm_area_struct passed into the mmap
+ *
+ * Use the regular CDX mapping routines to map a CDX resource into userspace.
+ *
+ * Return: true on success, false otherwise.
+ */
+static int cdx_mmap_resource(struct file *fp, struct kobject *kobj,
+			     const struct bin_attribute *attr,
+			     struct vm_area_struct *vma)
+{
+	struct cdx_device *cdx_dev = to_cdx_device(kobj_to_dev(kobj));
+	int num = (unsigned long)attr->private;
+	struct resource *res;
+	unsigned long size;
+
+	res = &cdx_dev->res[num];
+	if (iomem_is_exclusive(res->start))
+		return -EINVAL;
+
+	/* Make sure the caller is mapping a valid resource for this device */
+	size = ((cdx_resource_len(cdx_dev, num) - 1) >> PAGE_SHIFT) + 1;
+	if (vma->vm_pgoff + vma_pages(vma) > size)
+		return -EINVAL;
+
+	/*
+	 * Map memory region and vm->vm_pgoff is expected to be an
+	 * offset within that region.
+	 */
+	vma->vm_page_prot = pgprot_device(vma->vm_page_prot);
+	vma->vm_pgoff += (cdx_resource_start(cdx_dev, num) >> PAGE_SHIFT);
+	vma->vm_ops = &cdx_phys_vm_ops;
+	return io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
+				  vma->vm_end - vma->vm_start,
+				  vma->vm_page_prot);
+}
+
+static void cdx_destroy_res_attr(struct cdx_device *cdx_dev, int num)
+{
+	int i;
+
+	/* removing the bin attributes */
+	for (i = 0; i < num; i++) {
+		struct bin_attribute *res_attr;
+
+		res_attr = cdx_dev->res_attr[i];
+		if (res_attr) {
+			sysfs_remove_bin_file(&cdx_dev->dev.kobj, res_attr);
+			kfree(res_attr);
+		}
+	}
+}
+
+#define CDX_RES_ATTR_NAME_LEN	10
+static int cdx_create_res_attr(struct cdx_device *cdx_dev, int num)
+{
+	struct bin_attribute *res_attr;
+	char *res_attr_name;
+	int ret;
+
+	res_attr = kzalloc(sizeof(*res_attr) + CDX_RES_ATTR_NAME_LEN, GFP_ATOMIC);
+	if (!res_attr)
+		return -ENOMEM;
+
+	res_attr_name = (char *)(res_attr + 1);
+
+	sysfs_bin_attr_init(res_attr);
+
+	sprintf(res_attr_name, "resource%d", num);
+
+	res_attr->mmap = cdx_mmap_resource;
+	res_attr->attr.name = res_attr_name;
+	res_attr->attr.mode = 0600;
+	res_attr->size = cdx_resource_len(cdx_dev, num);
+	res_attr->private = (void *)(unsigned long)num;
+	ret = sysfs_create_bin_file(&cdx_dev->dev.kobj, res_attr);
+	if (ret) {
+		kfree(res_attr);
+		return ret;
+	}
+
+	cdx_dev->res_attr[num] = res_attr;
+
+	return ret;
+}
+
+int cdx_device_add(struct cdx_dev_params *dev_params)
+{
+	struct cdx_controller *cdx = dev_params->cdx;
+	struct cdx_device *cdx_dev;
+	int ret, i;
+
+	cdx_dev = kzalloc_obj(*cdx_dev);
+	if (!cdx_dev)
+		return -ENOMEM;
+
+	/* Populate resource */
+	memcpy(cdx_dev->res, dev_params->res, sizeof(struct resource) *
+		dev_params->res_count);
+	cdx_dev->res_count = dev_params->res_count;
+
+	/* Populate CDX dev params */
+	cdx_dev->req_id = dev_params->req_id;
+	cdx_dev->msi_dev_id = dev_params->msi_dev_id;
+	cdx_dev->vendor = dev_params->vendor;
+	cdx_dev->device = dev_params->device;
+	cdx_dev->subsystem_vendor = dev_params->subsys_vendor;
+	cdx_dev->subsystem_device = dev_params->subsys_device;
+	cdx_dev->class = dev_params->class;
+	cdx_dev->revision = dev_params->revision;
+	cdx_dev->bus_num = dev_params->bus_num;
+	cdx_dev->dev_num = dev_params->dev_num;
+	cdx_dev->cdx = dev_params->cdx;
+	cdx_dev->dma_mask = CDX_DEFAULT_DMA_MASK;
+
+	/* Initialize generic device */
+	device_initialize(&cdx_dev->dev);
+	cdx_dev->dev.parent = dev_params->parent;
+	cdx_dev->dev.bus = &cdx_bus_type;
+	cdx_dev->dev.dma_mask = &cdx_dev->dma_mask;
+	cdx_dev->dev.release = cdx_device_release;
+	cdx_dev->msi_write_pending = false;
+	mutex_init(&cdx_dev->irqchip_lock);
+
+	/* Set Name */
+	dev_set_name(&cdx_dev->dev, "cdx-%02x:%02x",
+		     ((cdx->id << CDX_CONTROLLER_ID_SHIFT) | (cdx_dev->bus_num & CDX_BUS_NUM_MASK)),
+		     cdx_dev->dev_num);
+
+	if (IS_ENABLED(CONFIG_GENERIC_MSI_IRQ) && cdx->msi_domain) {
+		cdx_dev->num_msi = dev_params->num_msi;
+		dev_set_msi_domain(&cdx_dev->dev, cdx->msi_domain);
+	}
+
+	ret = device_add(&cdx_dev->dev);
+	if (ret) {
+		dev_err(&cdx_dev->dev,
+			"cdx device add failed: %d", ret);
+		goto fail;
+	}
+
+	/* Create resource<N> attributes */
+	for (i = 0; i < MAX_CDX_DEV_RESOURCES; i++) {
+		if (cdx_resource_flags(cdx_dev, i) & IORESOURCE_MEM) {
+			/* skip empty resources */
+			if (!cdx_resource_len(cdx_dev, i))
+				continue;
+
+			ret = cdx_create_res_attr(cdx_dev, i);
+			if (ret != 0) {
+				dev_err(&cdx_dev->dev,
+					"cdx device resource<%d> file creation failed: %d", i, ret);
+				goto resource_create_fail;
+			}
+		}
+	}
+
+	cdx_device_debugfs_init(cdx_dev);
+
+	return 0;
+resource_create_fail:
+	cdx_destroy_res_attr(cdx_dev, i);
+	device_del(&cdx_dev->dev);
+fail:
+	/*
+	 * Do not free cdx_dev here as it would be freed in
+	 * cdx_device_release() called from put_device().
+	 */
+	put_device(&cdx_dev->dev);
+
+	return ret;
+}
+EXPORT_SYMBOL_NS_GPL(cdx_device_add, "CDX_BUS_CONTROLLER");
+
+struct device *cdx_bus_add(struct cdx_controller *cdx, u8 bus_num)
+{
+	struct cdx_device *cdx_dev;
+	int ret;
+
+	cdx_dev = kzalloc_obj(*cdx_dev);
+	if (!cdx_dev)
+		return NULL;
+
+	device_initialize(&cdx_dev->dev);
+	cdx_dev->cdx = cdx;
+
+	cdx_dev->dev.parent = cdx->dev;
+	cdx_dev->dev.bus = &cdx_bus_type;
+	cdx_dev->dev.release = cdx_device_release;
+	cdx_dev->is_bus = true;
+	cdx_dev->bus_num = bus_num;
+
+	dev_set_name(&cdx_dev->dev, "cdx-%02x",
+		     ((cdx->id << CDX_CONTROLLER_ID_SHIFT) | (bus_num & CDX_BUS_NUM_MASK)));
+
+	ret = device_add(&cdx_dev->dev);
+	if (ret) {
+		dev_err(&cdx_dev->dev, "cdx bus device add failed: %d\n", ret);
+		goto device_add_fail;
+	}
+
+	if (cdx->ops->bus_enable) {
+		ret = cdx->ops->bus_enable(cdx, bus_num);
+		if (ret && ret != -EALREADY) {
+			dev_err(cdx->dev, "cdx bus enable failed: %d\n", ret);
+			goto bus_enable_fail;
+		}
+	}
+
+	cdx_dev->enabled = true;
+	return &cdx_dev->dev;
+
+bus_enable_fail:
+	device_del(&cdx_dev->dev);
+device_add_fail:
+	put_device(&cdx_dev->dev);
+
+	return NULL;
+}
+EXPORT_SYMBOL_NS_GPL(cdx_bus_add, "CDX_BUS_CONTROLLER");
+
+int cdx_register_controller(struct cdx_controller *cdx)
+{
+	int ret;
+
+	ret = ida_alloc_range(&cdx_controller_ida, 0,  MAX_CDX_CONTROLLERS - 1, GFP_KERNEL);
+	if (ret < 0) {
+		dev_err(cdx->dev,
+			"No free index available. Maximum controllers already registered\n");
+		cdx->id = (u8)MAX_CDX_CONTROLLERS;
+		return ret;
+	}
+
+	mutex_lock(&cdx_controller_lock);
+	cdx->id = ret;
+
+	/* Scan all the devices */
+	if (cdx->ops->scan)
+		cdx->ops->scan(cdx);
+	cdx->controller_registered = true;
+	mutex_unlock(&cdx_controller_lock);
+
+	return 0;
+}
+EXPORT_SYMBOL_NS_GPL(cdx_register_controller, "CDX_BUS_CONTROLLER");
+
+void cdx_unregister_controller(struct cdx_controller *cdx)
+{
+	if (cdx->id >= MAX_CDX_CONTROLLERS)
+		return;
+
+	mutex_lock(&cdx_controller_lock);
+
+	cdx->controller_registered = false;
+	device_for_each_child(cdx->dev, NULL, cdx_unregister_device);
+	ida_free(&cdx_controller_ida, cdx->id);
+
+	mutex_unlock(&cdx_controller_lock);
+}
+EXPORT_SYMBOL_NS_GPL(cdx_unregister_controller, "CDX_BUS_CONTROLLER");
+
+static int __init cdx_bus_init(void)
+{
+	int ret;
+
+	ret = bus_register(&cdx_bus_type);
+	if (!ret)
+		cdx_debugfs_dir = debugfs_create_dir(cdx_bus_type.name, NULL);
+
+	return ret;
+}
+postcore_initcall(cdx_bus_init);