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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright 2018 Noralf Trønnes
*/
#include <linux/list.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <drm/drm_client.h>
#include <drm/drm_debugfs.h>
#include <drm/drm_device.h>
#include <drm/drm_drv.h>
#include <drm/drm_file.h>
#include <drm/drm_fourcc.h>
#include <drm/drm_gem.h>
#include <drm/drm_mode.h>
#include <drm/drm_print.h>
#include <drm/drmP.h>
#include "drm_crtc_internal.h"
#include "drm_internal.h"
/**
* DOC: overview
*
* This library provides support for clients running in the kernel like fbdev and bootsplash.
* Currently it's only partially implemented, just enough to support fbdev.
*
* GEM drivers which provide a GEM based dumb buffer with a virtual address are supported.
*/
static int drm_client_open(struct drm_client_dev *client)
{
struct drm_device *dev = client->dev;
struct drm_file *file;
file = drm_file_alloc(dev->primary);
if (IS_ERR(file))
return PTR_ERR(file);
mutex_lock(&dev->filelist_mutex);
list_add(&file->lhead, &dev->filelist_internal);
mutex_unlock(&dev->filelist_mutex);
client->file = file;
return 0;
}
static void drm_client_close(struct drm_client_dev *client)
{
struct drm_device *dev = client->dev;
mutex_lock(&dev->filelist_mutex);
list_del(&client->file->lhead);
mutex_unlock(&dev->filelist_mutex);
drm_file_free(client->file);
}
EXPORT_SYMBOL(drm_client_close);
/**
* drm_client_init - Initialise a DRM client
* @dev: DRM device
* @client: DRM client
* @name: Client name
* @funcs: DRM client functions (optional)
*
* This initialises the client and opens a &drm_file. Use drm_client_add() to complete the process.
* The caller needs to hold a reference on @dev before calling this function.
* The client is freed when the &drm_device is unregistered. See drm_client_release().
*
* Returns:
* Zero on success or negative error code on failure.
*/
int drm_client_init(struct drm_device *dev, struct drm_client_dev *client,
const char *name, const struct drm_client_funcs *funcs)
{
int ret;
if (!drm_core_check_feature(dev, DRIVER_MODESET) ||
!dev->driver->dumb_create || !dev->driver->gem_prime_vmap)
return -EOPNOTSUPP;
if (funcs && !try_module_get(funcs->owner))
return -ENODEV;
client->dev = dev;
client->name = name;
client->funcs = funcs;
ret = drm_client_open(client);
if (ret)
goto err_put_module;
drm_dev_get(dev);
return 0;
err_put_module:
if (funcs)
module_put(funcs->owner);
return ret;
}
EXPORT_SYMBOL(drm_client_init);
/**
* drm_client_add - Add client to the device list
* @client: DRM client
*
* Add the client to the &drm_device client list to activate its callbacks.
* @client must be initialized by a call to drm_client_init(). After
* drm_client_add() it is no longer permissible to call drm_client_release()
* directly (outside the unregister callback), instead cleanup will happen
* automatically on driver unload.
*/
void drm_client_add(struct drm_client_dev *client)
{
struct drm_device *dev = client->dev;
mutex_lock(&dev->clientlist_mutex);
list_add(&client->list, &dev->clientlist);
mutex_unlock(&dev->clientlist_mutex);
}
EXPORT_SYMBOL(drm_client_add);
/**
* drm_client_release - Release DRM client resources
* @client: DRM client
*
* Releases resources by closing the &drm_file that was opened by drm_client_init().
* It is called automatically if the &drm_client_funcs.unregister callback is _not_ set.
*
* This function should only be called from the unregister callback. An exception
* is fbdev which cannot free the buffer if userspace has open file descriptors.
*
* Note:
* Clients cannot initiate a release by themselves. This is done to keep the code simple.
* The driver has to be unloaded before the client can be unloaded.
*/
void drm_client_release(struct drm_client_dev *client)
{
struct drm_device *dev = client->dev;
DRM_DEV_DEBUG_KMS(dev->dev, "%s\n", client->name);
drm_client_close(client);
drm_dev_put(dev);
if (client->funcs)
module_put(client->funcs->owner);
}
EXPORT_SYMBOL(drm_client_release);
void drm_client_dev_unregister(struct drm_device *dev)
{
struct drm_client_dev *client, *tmp;
if (!drm_core_check_feature(dev, DRIVER_MODESET))
return;
mutex_lock(&dev->clientlist_mutex);
list_for_each_entry_safe(client, tmp, &dev->clientlist, list) {
list_del(&client->list);
if (client->funcs && client->funcs->unregister) {
client->funcs->unregister(client);
} else {
drm_client_release(client);
kfree(client);
}
}
mutex_unlock(&dev->clientlist_mutex);
}
/**
* drm_client_dev_hotplug - Send hotplug event to clients
* @dev: DRM device
*
* This function calls the &drm_client_funcs.hotplug callback on the attached clients.
*
* drm_kms_helper_hotplug_event() calls this function, so drivers that use it
* don't need to call this function themselves.
*/
void drm_client_dev_hotplug(struct drm_device *dev)
{
struct drm_client_dev *client;
int ret;
if (!drm_core_check_feature(dev, DRIVER_MODESET))
return;
mutex_lock(&dev->clientlist_mutex);
list_for_each_entry(client, &dev->clientlist, list) {
if (!client->funcs || !client->funcs->hotplug)
continue;
ret = client->funcs->hotplug(client);
DRM_DEV_DEBUG_KMS(dev->dev, "%s: ret=%d\n", client->name, ret);
}
mutex_unlock(&dev->clientlist_mutex);
}
EXPORT_SYMBOL(drm_client_dev_hotplug);
void drm_client_dev_restore(struct drm_device *dev)
{
struct drm_client_dev *client;
int ret;
if (!drm_core_check_feature(dev, DRIVER_MODESET))
return;
mutex_lock(&dev->clientlist_mutex);
list_for_each_entry(client, &dev->clientlist, list) {
if (!client->funcs || !client->funcs->restore)
continue;
ret = client->funcs->restore(client);
DRM_DEV_DEBUG_KMS(dev->dev, "%s: ret=%d\n", client->name, ret);
if (!ret) /* The first one to return zero gets the privilege to restore */
break;
}
mutex_unlock(&dev->clientlist_mutex);
}
static void drm_client_buffer_delete(struct drm_client_buffer *buffer)
{
struct drm_device *dev = buffer->client->dev;
if (buffer->vaddr && dev->driver->gem_prime_vunmap)
dev->driver->gem_prime_vunmap(buffer->gem, buffer->vaddr);
if (buffer->gem)
drm_gem_object_put_unlocked(buffer->gem);
if (buffer->handle)
drm_mode_destroy_dumb(dev, buffer->handle, buffer->client->file);
kfree(buffer);
}
static struct drm_client_buffer *
drm_client_buffer_create(struct drm_client_dev *client, u32 width, u32 height, u32 format)
{
struct drm_mode_create_dumb dumb_args = { };
struct drm_device *dev = client->dev;
struct drm_client_buffer *buffer;
struct drm_gem_object *obj;
void *vaddr;
int ret;
buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
if (!buffer)
return ERR_PTR(-ENOMEM);
buffer->client = client;
dumb_args.width = width;
dumb_args.height = height;
dumb_args.bpp = drm_format_plane_cpp(format, 0) * 8;
ret = drm_mode_create_dumb(dev, &dumb_args, client->file);
if (ret)
goto err_delete;
buffer->handle = dumb_args.handle;
buffer->pitch = dumb_args.pitch;
obj = drm_gem_object_lookup(client->file, dumb_args.handle);
if (!obj) {
ret = -ENOENT;
goto err_delete;
}
buffer->gem = obj;
/*
* FIXME: The dependency on GEM here isn't required, we could
* convert the driver handle to a dma-buf instead and use the
* backend-agnostic dma-buf vmap support instead. This would
* require that the handle2fd prime ioctl is reworked to pull the
* fd_install step out of the driver backend hooks, to make that
* final step optional for internal users.
*/
vaddr = dev->driver->gem_prime_vmap(obj);
if (!vaddr) {
ret = -ENOMEM;
goto err_delete;
}
buffer->vaddr = vaddr;
return buffer;
err_delete:
drm_client_buffer_delete(buffer);
return ERR_PTR(ret);
}
static void drm_client_buffer_rmfb(struct drm_client_buffer *buffer)
{
int ret;
if (!buffer->fb)
return;
ret = drm_mode_rmfb(buffer->client->dev, buffer->fb->base.id, buffer->client->file);
if (ret)
DRM_DEV_ERROR(buffer->client->dev->dev,
"Error removing FB:%u (%d)\n", buffer->fb->base.id, ret);
buffer->fb = NULL;
}
static int drm_client_buffer_addfb(struct drm_client_buffer *buffer,
u32 width, u32 height, u32 format)
{
struct drm_client_dev *client = buffer->client;
struct drm_mode_fb_cmd fb_req = { };
const struct drm_format_info *info;
int ret;
info = drm_format_info(format);
fb_req.bpp = info->cpp[0] * 8;
fb_req.depth = info->depth;
fb_req.width = width;
fb_req.height = height;
fb_req.handle = buffer->handle;
fb_req.pitch = buffer->pitch;
ret = drm_mode_addfb(client->dev, &fb_req, client->file);
if (ret)
return ret;
buffer->fb = drm_framebuffer_lookup(client->dev, buffer->client->file, fb_req.fb_id);
if (WARN_ON(!buffer->fb))
return -ENOENT;
/* drop the reference we picked up in framebuffer lookup */
drm_framebuffer_put(buffer->fb);
strscpy(buffer->fb->comm, client->name, TASK_COMM_LEN);
return 0;
}
/**
* drm_client_framebuffer_create - Create a client framebuffer
* @client: DRM client
* @width: Framebuffer width
* @height: Framebuffer height
* @format: Buffer format
*
* This function creates a &drm_client_buffer which consists of a
* &drm_framebuffer backed by a dumb buffer.
* Call drm_client_framebuffer_delete() to free the buffer.
*
* Returns:
* Pointer to a client buffer or an error pointer on failure.
*/
struct drm_client_buffer *
drm_client_framebuffer_create(struct drm_client_dev *client, u32 width, u32 height, u32 format)
{
struct drm_client_buffer *buffer;
int ret;
buffer = drm_client_buffer_create(client, width, height, format);
if (IS_ERR(buffer))
return buffer;
ret = drm_client_buffer_addfb(buffer, width, height, format);
if (ret) {
drm_client_buffer_delete(buffer);
return ERR_PTR(ret);
}
return buffer;
}
EXPORT_SYMBOL(drm_client_framebuffer_create);
/**
* drm_client_framebuffer_delete - Delete a client framebuffer
* @buffer: DRM client buffer (can be NULL)
*/
void drm_client_framebuffer_delete(struct drm_client_buffer *buffer)
{
if (!buffer)
return;
drm_client_buffer_rmfb(buffer);
drm_client_buffer_delete(buffer);
}
EXPORT_SYMBOL(drm_client_framebuffer_delete);
#ifdef CONFIG_DEBUG_FS
static int drm_client_debugfs_internal_clients(struct seq_file *m, void *data)
{
struct drm_info_node *node = m->private;
struct drm_device *dev = node->minor->dev;
struct drm_printer p = drm_seq_file_printer(m);
struct drm_client_dev *client;
mutex_lock(&dev->clientlist_mutex);
list_for_each_entry(client, &dev->clientlist, list)
drm_printf(&p, "%s\n", client->name);
mutex_unlock(&dev->clientlist_mutex);
return 0;
}
static const struct drm_info_list drm_client_debugfs_list[] = {
{ "internal_clients", drm_client_debugfs_internal_clients, 0 },
};
int drm_client_debugfs_init(struct drm_minor *minor)
{
return drm_debugfs_create_files(drm_client_debugfs_list,
ARRAY_SIZE(drm_client_debugfs_list),
minor->debugfs_root, minor);
}
#endif