swh:1:snp:49cd9498d6cccc5e78252c27dcb645bcf7bf0c91
Tip revision: 4fe89d07dcc2804c8b562f6c7896a45643d34b2f authored by Linus Torvalds on 02 October 2022, 21:09:07 UTC
Linux 6.0
Linux 6.0
Tip revision: 4fe89d0
bus.c
// 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;
}
static int host1x_device_uevent(struct device *dev,
struct kobj_uevent_env *env)
{
struct device_node *np = dev->parent->of_node;
unsigned int count = 0;
struct property *p;
const char *compat;
/*
* This duplicates most of of_device_uevent(), but the latter cannot
* be called from modules and operates on dev->of_node, which is not
* available in this case.
*
* 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.
*/
add_uevent_var(env, "OF_NAME=%pOFn", np);
add_uevent_var(env, "OF_FULLNAME=%pOF", np);
of_property_for_each_string(np, "compatible", p, compat) {
add_uevent_var(env, "OF_COMPATIBLE_%u=%s", count, compat);
count++;
}
add_uevent_var(env, "OF_COMPATIBLE_N=%u", count);
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.
*/
int 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 0;
}
}
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);
return 0;
}
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);