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, 1021 insertions, 0 deletions

diff --git a/drivers/gpu/host1x/bus.c b/drivers/gpu/host1x/bus.c
new file mode 100644
index 000000000..733f53e69
--- /dev/null
+++ b/drivers/gpu/host1x/bus.c
@@ -0,0 +1,1021 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2012 Avionic Design GmbH
+ * Copyright (C) 2012-2013, NVIDIA Corporation
+ */
+
+#include <linux/debugfs.h>
+#include <linux/dma-mapping.h>
+#include <linux/host1x.h>
+#include <linux/of.h>
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+#include <linux/of_device.h>
+
+#include "bus.h"
+#include "dev.h"
+
+static DEFINE_MUTEX(clients_lock);
+static LIST_HEAD(clients);
+
+static DEFINE_MUTEX(drivers_lock);
+static LIST_HEAD(drivers);
+
+static DEFINE_MUTEX(devices_lock);
+static LIST_HEAD(devices);
+
+struct host1x_subdev {
+	struct host1x_client *client;
+	struct device_node *np;
+	struct list_head list;
+};
+
+/**
+ * host1x_subdev_add() - add a new subdevice with an associated device node
+ * @device: host1x device to add the subdevice to
+ * @driver: host1x driver containing the subdevices
+ * @np: device node
+ */
+static int host1x_subdev_add(struct host1x_device *device,
+			     struct host1x_driver *driver,
+			     struct device_node *np)
+{
+	struct host1x_subdev *subdev;
+	int err;
+
+	subdev = kzalloc_obj(*subdev);
+	if (!subdev)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&subdev->list);
+	subdev->np = of_node_get(np);
+
+	mutex_lock(&device->subdevs_lock);
+	list_add_tail(&subdev->list, &device->subdevs);
+	mutex_unlock(&device->subdevs_lock);
+
+	/* recursively add children */
+	for_each_child_of_node_scoped(np, child) {
+		if (of_match_node(driver->subdevs, child) &&
+		    of_device_is_available(child)) {
+			err = host1x_subdev_add(device, driver, child);
+			if (err < 0) {
+				/* XXX cleanup? */
+				return err;
+			}
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * host1x_subdev_del() - remove subdevice
+ * @subdev: subdevice to remove
+ */
+static void host1x_subdev_del(struct host1x_subdev *subdev)
+{
+	list_del(&subdev->list);
+	of_node_put(subdev->np);
+	kfree(subdev);
+}
+
+/**
+ * host1x_device_parse_dt() - scan device tree and add matching subdevices
+ * @device: host1x logical device
+ * @driver: host1x driver
+ */
+static int host1x_device_parse_dt(struct host1x_device *device,
+				  struct host1x_driver *driver)
+{
+	int err;
+
+	for_each_child_of_node_scoped(device->dev.parent->of_node, np) {
+		if (of_match_node(driver->subdevs, np) &&
+		    of_device_is_available(np)) {
+			err = host1x_subdev_add(device, driver, np);
+			if (err < 0)
+				return err;
+		}
+	}
+
+	return 0;
+}
+
+static void host1x_subdev_register(struct host1x_device *device,
+				   struct host1x_subdev *subdev,
+				   struct host1x_client *client)
+{
+	int err;
+
+	/*
+	 * Move the subdevice to the list of active (registered) subdevices
+	 * and associate it with a client. At the same time, associate the
+	 * client with its parent device.
+	 */
+	mutex_lock(&device->subdevs_lock);
+	mutex_lock(&device->clients_lock);
+	list_move_tail(&client->list, &device->clients);
+	list_move_tail(&subdev->list, &device->active);
+	client->host = &device->dev;
+	subdev->client = client;
+	mutex_unlock(&device->clients_lock);
+	mutex_unlock(&device->subdevs_lock);
+
+	if (list_empty(&device->subdevs)) {
+		err = device_add(&device->dev);
+		if (err < 0)
+			dev_err(&device->dev, "failed to add: %d\n", err);
+		else
+			device->registered = true;
+	}
+}
+
+static void __host1x_subdev_unregister(struct host1x_device *device,
+				       struct host1x_subdev *subdev)
+{
+	struct host1x_client *client = subdev->client;
+
+	/*
+	 * If all subdevices have been activated, we're about to remove the
+	 * first active subdevice, so unload the driver first.
+	 */
+	if (list_empty(&device->subdevs)) {
+		if (device->registered) {
+			device->registered = false;
+			device_del(&device->dev);
+		}
+	}
+
+	/*
+	 * Move the subdevice back to the list of idle subdevices and remove
+	 * it from list of clients.
+	 */
+	mutex_lock(&device->clients_lock);
+	subdev->client = NULL;
+	client->host = NULL;
+	list_move_tail(&subdev->list, &device->subdevs);
+	/*
+	 * XXX: Perhaps don't do this here, but rather explicitly remove it
+	 * when the device is about to be deleted.
+	 *
+	 * This is somewhat complicated by the fact that this function is
+	 * used to remove the subdevice when a client is unregistered but
+	 * also when the composite device is about to be removed.
+	 */
+	list_del_init(&client->list);
+	mutex_unlock(&device->clients_lock);
+}
+
+static void host1x_subdev_unregister(struct host1x_device *device,
+				     struct host1x_subdev *subdev)
+{
+	mutex_lock(&device->subdevs_lock);
+	__host1x_subdev_unregister(device, subdev);
+	mutex_unlock(&device->subdevs_lock);
+}
+
+/**
+ * host1x_device_init() - initialize a host1x logical device
+ * @device: host1x logical device
+ *
+ * The driver for the host1x logical device can call this during execution of
+ * its &host1x_driver.probe implementation to initialize each of its clients.
+ * The client drivers access the subsystem specific driver data using the
+ * &host1x_client.parent field and driver data associated with it (usually by
+ * calling dev_get_drvdata()).
+ */
+int host1x_device_init(struct host1x_device *device)
+{
+	struct host1x_client *client;
+	int err;
+
+	mutex_lock(&device->clients_lock);
+
+	list_for_each_entry(client, &device->clients, list) {
+		if (client->ops && client->ops->early_init) {
+			err = client->ops->early_init(client);
+			if (err < 0) {
+				dev_err(&device->dev, "failed to early initialize %s: %d\n",
+					dev_name(client->dev), err);
+				goto teardown_late;
+			}
+		}
+	}
+
+	list_for_each_entry(client, &device->clients, list) {
+		if (client->ops && client->ops->init) {
+			err = client->ops->init(client);
+			if (err < 0) {
+				dev_err(&device->dev,
+					"failed to initialize %s: %d\n",
+					dev_name(client->dev), err);
+				goto teardown;
+			}
+		}
+	}
+
+	mutex_unlock(&device->clients_lock);
+
+	return 0;
+
+teardown:
+	list_for_each_entry_continue_reverse(client, &device->clients, list)
+		if (client->ops && client->ops->exit)
+			client->ops->exit(client);
+
+	/* reset client to end of list for late teardown */
+	client = list_entry(&device->clients, struct host1x_client, list);
+
+teardown_late:
+	list_for_each_entry_continue_reverse(client, &device->clients, list)
+		if (client->ops && client->ops->late_exit)
+			client->ops->late_exit(client);
+
+	mutex_unlock(&device->clients_lock);
+	return err;
+}
+EXPORT_SYMBOL(host1x_device_init);
+
+/**
+ * host1x_device_exit() - uninitialize host1x logical device
+ * @device: host1x logical device
+ *
+ * When the driver for a host1x logical device is unloaded, it can call this
+ * function to tear down each of its clients. Typically this is done after a
+ * subsystem-specific data structure is removed and the functionality can no
+ * longer be used.
+ */
+int host1x_device_exit(struct host1x_device *device)
+{
+	struct host1x_client *client;
+	int err;
+
+	mutex_lock(&device->clients_lock);
+
+	list_for_each_entry_reverse(client, &device->clients, list) {
+		if (client->ops && client->ops->exit) {
+			err = client->ops->exit(client);
+			if (err < 0) {
+				dev_err(&device->dev,
+					"failed to cleanup %s: %d\n",
+					dev_name(client->dev), err);
+				mutex_unlock(&device->clients_lock);
+				return err;
+			}
+		}
+	}
+
+	list_for_each_entry_reverse(client, &device->clients, list) {
+		if (client->ops && client->ops->late_exit) {
+			err = client->ops->late_exit(client);
+			if (err < 0) {
+				dev_err(&device->dev, "failed to late cleanup %s: %d\n",
+					dev_name(client->dev), err);
+				mutex_unlock(&device->clients_lock);
+				return err;
+			}
+		}
+	}
+
+	mutex_unlock(&device->clients_lock);
+
+	return 0;
+}
+EXPORT_SYMBOL(host1x_device_exit);
+
+static int host1x_add_client(struct host1x *host1x,
+			     struct host1x_client *client)
+{
+	struct host1x_device *device;
+	struct host1x_subdev *subdev;
+
+	mutex_lock(&host1x->devices_lock);
+
+	list_for_each_entry(device, &host1x->devices, list) {
+		list_for_each_entry(subdev, &device->subdevs, list) {
+			if (subdev->np == client->dev->of_node) {
+				host1x_subdev_register(device, subdev, client);
+				mutex_unlock(&host1x->devices_lock);
+				return 0;
+			}
+		}
+	}
+
+	mutex_unlock(&host1x->devices_lock);
+	return -ENODEV;
+}
+
+static int host1x_del_client(struct host1x *host1x,
+			     struct host1x_client *client)
+{
+	struct host1x_device *device, *dt;
+	struct host1x_subdev *subdev;
+
+	mutex_lock(&host1x->devices_lock);
+
+	list_for_each_entry_safe(device, dt, &host1x->devices, list) {
+		list_for_each_entry(subdev, &device->active, list) {
+			if (subdev->client == client) {
+				host1x_subdev_unregister(device, subdev);
+				mutex_unlock(&host1x->devices_lock);
+				return 0;
+			}
+		}
+	}
+
+	mutex_unlock(&host1x->devices_lock);
+	return -ENODEV;
+}
+
+static int host1x_device_match(struct device *dev, const struct device_driver *drv)
+{
+	return strcmp(dev_name(dev), drv->name) == 0;
+}
+
+/*
+ * Note that this is really only needed for backwards compatibility
+ * with libdrm, which parses this information from sysfs and will
+ * fail if it can't find the OF_FULLNAME, specifically.
+ */
+static int host1x_device_uevent(const struct device *dev,
+				struct kobj_uevent_env *env)
+{
+	of_device_uevent(dev->parent, env);
+
+	return 0;
+}
+
+static int host1x_device_probe(struct device *dev)
+{
+	struct host1x_driver *driver = to_host1x_driver(dev->driver);
+	struct host1x_device *device = to_host1x_device(dev);
+
+	if (driver->probe)
+		return driver->probe(device);
+
+	return 0;
+}
+
+static void host1x_device_remove(struct device *dev)
+{
+	struct host1x_driver *driver = to_host1x_driver(dev->driver);
+	struct host1x_device *device = to_host1x_device(dev);
+
+	if (driver->remove)
+		driver->remove(device);
+}
+
+static void host1x_device_shutdown(struct device *dev)
+{
+	struct host1x_driver *driver = to_host1x_driver(dev->driver);
+	struct host1x_device *device = to_host1x_device(dev);
+
+	if (dev->driver && driver->shutdown)
+		driver->shutdown(device);
+}
+
+
+static const struct dev_pm_ops host1x_device_pm_ops = {
+	.suspend = pm_generic_suspend,
+	.resume = pm_generic_resume,
+	.freeze = pm_generic_freeze,
+	.thaw = pm_generic_thaw,
+	.poweroff = pm_generic_poweroff,
+	.restore = pm_generic_restore,
+};
+
+const struct bus_type host1x_bus_type = {
+	.name = "host1x",
+	.match = host1x_device_match,
+	.uevent = host1x_device_uevent,
+	.probe = host1x_device_probe,
+	.remove = host1x_device_remove,
+	.shutdown = host1x_device_shutdown,
+	.pm = &host1x_device_pm_ops,
+};
+
+static void __host1x_device_del(struct host1x_device *device)
+{
+	struct host1x_subdev *subdev, *sd;
+	struct host1x_client *client, *cl;
+
+	mutex_lock(&device->subdevs_lock);
+
+	/* unregister subdevices */
+	list_for_each_entry_safe(subdev, sd, &device->active, list) {
+		/*
+		 * host1x_subdev_unregister() will remove the client from
+		 * any lists, so we'll need to manually add it back to the
+		 * list of idle clients.
+		 *
+		 * XXX: Alternatively, perhaps don't remove the client from
+		 * any lists in host1x_subdev_unregister() and instead do
+		 * that explicitly from host1x_unregister_client()?
+		 */
+		client = subdev->client;
+
+		__host1x_subdev_unregister(device, subdev);
+
+		/* add the client to the list of idle clients */
+		mutex_lock(&clients_lock);
+		list_add_tail(&client->list, &clients);
+		mutex_unlock(&clients_lock);
+	}
+
+	/* remove subdevices */
+	list_for_each_entry_safe(subdev, sd, &device->subdevs, list)
+		host1x_subdev_del(subdev);
+
+	mutex_unlock(&device->subdevs_lock);
+
+	/* move clients to idle list */
+	mutex_lock(&clients_lock);
+	mutex_lock(&device->clients_lock);
+
+	list_for_each_entry_safe(client, cl, &device->clients, list)
+		list_move_tail(&client->list, &clients);
+
+	mutex_unlock(&device->clients_lock);
+	mutex_unlock(&clients_lock);
+
+	/* finally remove the device */
+	list_del_init(&device->list);
+}
+
+static void host1x_device_release(struct device *dev)
+{
+	struct host1x_device *device = to_host1x_device(dev);
+
+	__host1x_device_del(device);
+	kfree(device);
+}
+
+static int host1x_device_add(struct host1x *host1x,
+			     struct host1x_driver *driver)
+{
+	struct host1x_client *client, *tmp;
+	struct host1x_subdev *subdev;
+	struct host1x_device *device;
+	int err;
+
+	device = kzalloc_obj(*device);
+	if (!device)
+		return -ENOMEM;
+
+	device_initialize(&device->dev);
+
+	mutex_init(&device->subdevs_lock);
+	INIT_LIST_HEAD(&device->subdevs);
+	INIT_LIST_HEAD(&device->active);
+	mutex_init(&device->clients_lock);
+	INIT_LIST_HEAD(&device->clients);
+	INIT_LIST_HEAD(&device->list);
+	device->driver = driver;
+
+	device->dev.coherent_dma_mask = host1x->dev->coherent_dma_mask;
+	device->dev.dma_mask = &device->dev.coherent_dma_mask;
+	dev_set_name(&device->dev, "%s", driver->driver.name);
+	device->dev.release = host1x_device_release;
+	device->dev.bus = &host1x_bus_type;
+	device->dev.parent = host1x->dev;
+
+	device->dev.dma_parms = &device->dma_parms;
+	dma_set_max_seg_size(&device->dev, UINT_MAX);
+
+	err = host1x_device_parse_dt(device, driver);
+	if (err < 0) {
+		put_device(&device->dev);
+		return err;
+	}
+
+	list_add_tail(&device->list, &host1x->devices);
+
+	mutex_lock(&clients_lock);
+
+	list_for_each_entry_safe(client, tmp, &clients, list) {
+		list_for_each_entry(subdev, &device->subdevs, list) {
+			if (subdev->np == client->dev->of_node) {
+				host1x_subdev_register(device, subdev, client);
+				break;
+			}
+		}
+	}
+
+	mutex_unlock(&clients_lock);
+
+	/*
+	 * Add device even if there are no subdevs to ensure syncpoint functionality
+	 * is available regardless of whether any engine subdevices are present
+	 */
+	if (list_empty(&device->subdevs) && !device->registered) {
+		err = device_add(&device->dev);
+		if (err < 0)
+			dev_err(&device->dev, "failed to add device: %d\n", err);
+		else
+			device->registered = true;
+	}
+
+	return 0;
+}
+
+/*
+ * Removes a device by first unregistering any subdevices and then removing
+ * itself from the list of devices.
+ *
+ * This function must be called with the host1x->devices_lock held.
+ */
+static void host1x_device_del(struct host1x *host1x,
+			      struct host1x_device *device)
+{
+	if (device->registered) {
+		device->registered = false;
+		device_del(&device->dev);
+	}
+
+	put_device(&device->dev);
+}
+
+static void host1x_attach_driver(struct host1x *host1x,
+				 struct host1x_driver *driver)
+{
+	struct host1x_device *device;
+	int err;
+
+	mutex_lock(&host1x->devices_lock);
+
+	list_for_each_entry(device, &host1x->devices, list) {
+		if (device->driver == driver) {
+			mutex_unlock(&host1x->devices_lock);
+			return;
+		}
+	}
+
+	err = host1x_device_add(host1x, driver);
+	if (err < 0)
+		dev_err(host1x->dev, "failed to allocate device: %d\n", err);
+
+	mutex_unlock(&host1x->devices_lock);
+}
+
+static void host1x_detach_driver(struct host1x *host1x,
+				 struct host1x_driver *driver)
+{
+	struct host1x_device *device, *tmp;
+
+	mutex_lock(&host1x->devices_lock);
+
+	list_for_each_entry_safe(device, tmp, &host1x->devices, list)
+		if (device->driver == driver)
+			host1x_device_del(host1x, device);
+
+	mutex_unlock(&host1x->devices_lock);
+}
+
+static int host1x_devices_show(struct seq_file *s, void *data)
+{
+	struct host1x *host1x = s->private;
+	struct host1x_device *device;
+
+	mutex_lock(&host1x->devices_lock);
+
+	list_for_each_entry(device, &host1x->devices, list) {
+		struct host1x_subdev *subdev;
+
+		seq_printf(s, "%s\n", dev_name(&device->dev));
+
+		mutex_lock(&device->subdevs_lock);
+
+		list_for_each_entry(subdev, &device->active, list)
+			seq_printf(s, "  %pOFf: %s\n", subdev->np,
+				   dev_name(subdev->client->dev));
+
+		list_for_each_entry(subdev, &device->subdevs, list)
+			seq_printf(s, "  %pOFf:\n", subdev->np);
+
+		mutex_unlock(&device->subdevs_lock);
+	}
+
+	mutex_unlock(&host1x->devices_lock);
+
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(host1x_devices);
+
+/**
+ * host1x_register() - register a host1x controller
+ * @host1x: host1x controller
+ *
+ * The host1x controller driver uses this to register a host1x controller with
+ * the infrastructure. Note that all Tegra SoC generations have only ever come
+ * with a single host1x instance, so this function is somewhat academic.
+ */
+int host1x_register(struct host1x *host1x)
+{
+	struct host1x_driver *driver;
+
+	mutex_lock(&devices_lock);
+	list_add_tail(&host1x->list, &devices);
+	mutex_unlock(&devices_lock);
+
+	mutex_lock(&drivers_lock);
+
+	list_for_each_entry(driver, &drivers, list)
+		host1x_attach_driver(host1x, driver);
+
+	mutex_unlock(&drivers_lock);
+
+	debugfs_create_file("devices", S_IRUGO, host1x->debugfs, host1x,
+			    &host1x_devices_fops);
+
+	return 0;
+}
+
+/**
+ * host1x_unregister() - unregister a host1x controller
+ * @host1x: host1x controller
+ *
+ * The host1x controller driver uses this to remove a host1x controller from
+ * the infrastructure.
+ */
+int host1x_unregister(struct host1x *host1x)
+{
+	struct host1x_driver *driver;
+
+	mutex_lock(&drivers_lock);
+
+	list_for_each_entry(driver, &drivers, list)
+		host1x_detach_driver(host1x, driver);
+
+	mutex_unlock(&drivers_lock);
+
+	mutex_lock(&devices_lock);
+	list_del_init(&host1x->list);
+	mutex_unlock(&devices_lock);
+
+	return 0;
+}
+
+/**
+ * host1x_driver_register_full() - register a host1x driver
+ * @driver: host1x driver
+ * @owner: owner module
+ *
+ * Drivers for host1x logical devices call this function to register a driver
+ * with the infrastructure. Note that since these drive logical devices, the
+ * registration of the driver actually triggers tho logical device creation.
+ * A logical device will be created for each host1x instance.
+ */
+int host1x_driver_register_full(struct host1x_driver *driver,
+				struct module *owner)
+{
+	struct host1x *host1x;
+
+	INIT_LIST_HEAD(&driver->list);
+
+	mutex_lock(&drivers_lock);
+	list_add_tail(&driver->list, &drivers);
+	mutex_unlock(&drivers_lock);
+
+	mutex_lock(&devices_lock);
+
+	list_for_each_entry(host1x, &devices, list)
+		host1x_attach_driver(host1x, driver);
+
+	mutex_unlock(&devices_lock);
+
+	driver->driver.bus = &host1x_bus_type;
+	driver->driver.owner = owner;
+
+	return driver_register(&driver->driver);
+}
+EXPORT_SYMBOL(host1x_driver_register_full);
+
+/**
+ * host1x_driver_unregister() - unregister a host1x driver
+ * @driver: host1x driver
+ *
+ * Unbinds the driver from each of the host1x logical devices that it is
+ * bound to, effectively removing the subsystem devices that they represent.
+ */
+void host1x_driver_unregister(struct host1x_driver *driver)
+{
+	struct host1x *host1x;
+
+	driver_unregister(&driver->driver);
+
+	mutex_lock(&devices_lock);
+
+	list_for_each_entry(host1x, &devices, list)
+		host1x_detach_driver(host1x, driver);
+
+	mutex_unlock(&devices_lock);
+
+	mutex_lock(&drivers_lock);
+	list_del_init(&driver->list);
+	mutex_unlock(&drivers_lock);
+}
+EXPORT_SYMBOL(host1x_driver_unregister);
+
+/**
+ * __host1x_client_init() - initialize a host1x client
+ * @client: host1x client
+ * @key: lock class key for the client-specific mutex
+ */
+void __host1x_client_init(struct host1x_client *client, struct lock_class_key *key)
+{
+	host1x_bo_cache_init(&client->cache);
+	INIT_LIST_HEAD(&client->list);
+	__mutex_init(&client->lock, "host1x client lock", key);
+	client->usecount = 0;
+}
+EXPORT_SYMBOL(__host1x_client_init);
+
+/**
+ * host1x_client_exit() - uninitialize a host1x client
+ * @client: host1x client
+ */
+void host1x_client_exit(struct host1x_client *client)
+{
+	mutex_destroy(&client->lock);
+}
+EXPORT_SYMBOL(host1x_client_exit);
+
+/**
+ * __host1x_client_register() - register a host1x client
+ * @client: host1x client
+ *
+ * Registers a host1x client with each host1x controller instance. Note that
+ * each client will only match their parent host1x controller and will only be
+ * associated with that instance. Once all clients have been registered with
+ * their parent host1x controller, the infrastructure will set up the logical
+ * device and call host1x_device_init(), which will in turn call each client's
+ * &host1x_client_ops.init implementation.
+ */
+int __host1x_client_register(struct host1x_client *client)
+{
+	struct host1x *host1x;
+	int err;
+
+	mutex_lock(&devices_lock);
+
+	list_for_each_entry(host1x, &devices, list) {
+		err = host1x_add_client(host1x, client);
+		if (!err) {
+			mutex_unlock(&devices_lock);
+			return 0;
+		}
+	}
+
+	mutex_unlock(&devices_lock);
+
+	mutex_lock(&clients_lock);
+	list_add_tail(&client->list, &clients);
+	mutex_unlock(&clients_lock);
+
+	return 0;
+}
+EXPORT_SYMBOL(__host1x_client_register);
+
+/**
+ * host1x_client_unregister() - unregister a host1x client
+ * @client: host1x client
+ *
+ * Removes a host1x client from its host1x controller instance. If a logical
+ * device has already been initialized, it will be torn down.
+ */
+void host1x_client_unregister(struct host1x_client *client)
+{
+	struct host1x_client *c;
+	struct host1x *host1x;
+	int err;
+
+	mutex_lock(&devices_lock);
+
+	list_for_each_entry(host1x, &devices, list) {
+		err = host1x_del_client(host1x, client);
+		if (!err) {
+			mutex_unlock(&devices_lock);
+			return;
+		}
+	}
+
+	mutex_unlock(&devices_lock);
+	mutex_lock(&clients_lock);
+
+	list_for_each_entry(c, &clients, list) {
+		if (c == client) {
+			list_del_init(&c->list);
+			break;
+		}
+	}
+
+	mutex_unlock(&clients_lock);
+
+	host1x_bo_cache_destroy(&client->cache);
+}
+EXPORT_SYMBOL(host1x_client_unregister);
+
+int host1x_client_suspend(struct host1x_client *client)
+{
+	int err = 0;
+
+	mutex_lock(&client->lock);
+
+	if (client->usecount == 1) {
+		if (client->ops && client->ops->suspend) {
+			err = client->ops->suspend(client);
+			if (err < 0)
+				goto unlock;
+		}
+	}
+
+	client->usecount--;
+	dev_dbg(client->dev, "use count: %u\n", client->usecount);
+
+	if (client->parent) {
+		err = host1x_client_suspend(client->parent);
+		if (err < 0)
+			goto resume;
+	}
+
+	goto unlock;
+
+resume:
+	if (client->usecount == 0)
+		if (client->ops && client->ops->resume)
+			client->ops->resume(client);
+
+	client->usecount++;
+unlock:
+	mutex_unlock(&client->lock);
+	return err;
+}
+EXPORT_SYMBOL(host1x_client_suspend);
+
+int host1x_client_resume(struct host1x_client *client)
+{
+	int err = 0;
+
+	mutex_lock(&client->lock);
+
+	if (client->parent) {
+		err = host1x_client_resume(client->parent);
+		if (err < 0)
+			goto unlock;
+	}
+
+	if (client->usecount == 0) {
+		if (client->ops && client->ops->resume) {
+			err = client->ops->resume(client);
+			if (err < 0)
+				goto suspend;
+		}
+	}
+
+	client->usecount++;
+	dev_dbg(client->dev, "use count: %u\n", client->usecount);
+
+	goto unlock;
+
+suspend:
+	if (client->parent)
+		host1x_client_suspend(client->parent);
+unlock:
+	mutex_unlock(&client->lock);
+	return err;
+}
+EXPORT_SYMBOL(host1x_client_resume);
+
+/**
+ * host1x_bo_pin() - Create a DMA mapping for the buffer object
+ * @dev: Device onto which DMA map to
+ * @bo: Buffer object to map
+ * @dir: DMA direction
+ * @cache: Cache in which to store mapping, or NULL
+ *
+ * Creates a DMA mapping pointing to @bo for @dev. The refcount of @bo is incremented
+ * until host1x_bo_unpin is called.
+ *
+ * If @cache is specified, the mapping is also stored in the cache and not released
+ * until @bo is freed (refcount drops to zero). This improves performance when a buffer
+ * is pinned and unpinned frequently as in the case of display use.
+ */
+struct host1x_bo_mapping *host1x_bo_pin(struct device *dev, struct host1x_bo *bo,
+					enum dma_data_direction dir,
+					struct host1x_bo_cache *cache)
+{
+	struct host1x_bo_mapping *mapping;
+
+	if (cache) {
+		mutex_lock(&cache->lock);
+
+		list_for_each_entry(mapping, &cache->mappings, entry) {
+			if (mapping->bo == bo && mapping->direction == dir) {
+				kref_get(&mapping->ref);
+				host1x_bo_get(bo);
+				goto unlock;
+			}
+		}
+	}
+
+	mapping = bo->ops->pin(dev, bo, dir);
+	if (IS_ERR(mapping))
+		goto unlock;
+
+	host1x_bo_get(bo);
+
+	spin_lock(&mapping->bo->lock);
+	list_add_tail(&mapping->list, &bo->mappings);
+	spin_unlock(&mapping->bo->lock);
+
+	if (cache) {
+		INIT_LIST_HEAD(&mapping->entry);
+		mapping->cache = cache;
+
+		list_add_tail(&mapping->entry, &cache->mappings);
+
+		/*
+		 * Bump the mapping reference count to track the mapping in the cache,
+		 * but do not bump the BO's refcount. This allows the BO to still get freed,
+		 * triggering the release of the cache mapping through
+		 * host1x_bo_clear_cached_mappings.
+		 */
+		kref_get(&mapping->ref);
+	}
+
+unlock:
+	if (cache)
+		mutex_unlock(&cache->lock);
+
+	return mapping;
+}
+EXPORT_SYMBOL(host1x_bo_pin);
+
+static void __host1x_bo_unpin(struct kref *ref)
+{
+	struct host1x_bo_mapping *mapping = to_host1x_bo_mapping(ref);
+
+	/*
+	 * When the last reference of the mapping goes away, make sure to remove the mapping from
+	 * the cache.
+	 */
+	if (mapping->cache)
+		list_del(&mapping->entry);
+
+	spin_lock(&mapping->bo->lock);
+	list_del(&mapping->list);
+	spin_unlock(&mapping->bo->lock);
+
+	mapping->bo->ops->unpin(mapping);
+}
+
+/**
+ * host1x_bo_unpin() - Release an established DMA mapping of a buffer object
+ * @mapping: Mapping to release
+ *
+ * Unmaps the given @mapping, unless it is cached. Decreases the refcount on
+ * the underlying buffer object.
+ */
+void host1x_bo_unpin(struct host1x_bo_mapping *mapping)
+{
+	struct host1x_bo_cache *cache = mapping->cache;
+	struct host1x_bo *bo = mapping->bo;
+
+	if (cache)
+		mutex_lock(&cache->lock);
+
+	kref_put(&mapping->ref, __host1x_bo_unpin);
+
+	if (cache)
+		mutex_unlock(&cache->lock);
+
+	host1x_bo_put(bo);
+}
+EXPORT_SYMBOL(host1x_bo_unpin);
+
+/**
+ * host1x_bo_clear_cached_mappings() - Remove all cached mappings pointing at a bo
+ * @bo: Buffer object to release mappings of
+ *
+ * Drops references to any mappings pointing to @bo left in any caches. This must
+ * be called by any host1x_bo implementers that may be pinned with caching enabled
+ * before freeing the bo.
+ */
+void host1x_bo_clear_cached_mappings(struct host1x_bo *bo)
+{
+	struct host1x_bo_mapping *mapping, *tmp;
+	struct host1x_bo_cache *cache;
+
+	list_for_each_entry_safe(mapping, tmp, &bo->mappings, list) {
+		cache = mapping->cache;
+		if (WARN_ON(!cache))
+			continue;
+
+		mutex_lock(&cache->lock);
+		WARN_ON(kref_read(&mapping->ref) != 1);
+		__host1x_bo_unpin(&mapping->ref);
+		mutex_unlock(&cache->lock);
+	}
+}
+EXPORT_SYMBOL(host1x_bo_clear_cached_mappings);