Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 965 insertions, 0 deletions

diff --git a/drivers/gpu/host1x/bus.c b/drivers/gpu/host1x/bus.c
new file mode 100644
index 0000000000..84d042796d
--- /dev/null
+++ b/drivers/gpu/host1x/bus.c
@@ -0,0 +1,965 @@
+// 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;
+	struct device_node *child;
+	int err;
+
+	subdev = kzalloc(sizeof(*subdev), GFP_KERNEL);
+	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(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? */
+				of_node_put(child);
+				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)
+{
+	struct device_node *np;
+	int err;
+
+	for_each_child_of_node(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) {
+				of_node_put(np);
+				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->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->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, 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_dma_configure(struct device *dev)
+{
+	return of_dma_configure(dev, dev->of_node, true);
+}
+
+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,
+};
+
+struct bus_type host1x_bus_type = {
+	.name = "host1x",
+	.match = host1x_device_match,
+	.uevent = host1x_device_uevent,
+	.dma_configure = host1x_dma_configure,
+	.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(sizeof(*device), GFP_KERNEL);
+	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;
+
+	of_dma_configure(&device->dev, host1x->dev->of_node, true);
+
+	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) {
+		kfree(device);
+		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);
+
+	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;
+}
+
+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 int 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)
+		return driver->remove(device);
+
+	return 0;
+}
+
+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 (driver->shutdown)
+		driver->shutdown(device);
+}
+
+/**
+ * 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;
+	driver->driver.probe = host1x_device_probe;
+	driver->driver.remove = host1x_device_remove;
+	driver->driver.shutdown = host1x_device_shutdown;
+
+	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);
+
+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);
+				goto unlock;
+			}
+		}
+	}
+
+	mapping = bo->ops->pin(dev, bo, dir);
+	if (IS_ERR(mapping))
+		goto unlock;
+
+	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 reference count to track the copy in the cache */
+		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);
+}
+
+void host1x_bo_unpin(struct host1x_bo_mapping *mapping)
+{
+	struct host1x_bo_cache *cache = mapping->cache;
+
+	if (cache)
+		mutex_lock(&cache->lock);
+
+	kref_put(&mapping->ref, __host1x_bo_unpin);
+
+	if (cache)
+		mutex_unlock(&cache->lock);
+}
+EXPORT_SYMBOL(host1x_bo_unpin);