1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright 2018 Noralf Trønnes
6 #include <linux/list.h>
7 #include <linux/module.h>
8 #include <linux/mutex.h>
9 #include <linux/seq_file.h>
10 #include <linux/slab.h>
12 #include <drm/drm_client.h>
13 #include <drm/drm_debugfs.h>
14 #include <drm/drm_device.h>
15 #include <drm/drm_drv.h>
16 #include <drm/drm_file.h>
17 #include <drm/drm_fourcc.h>
18 #include <drm/drm_gem.h>
19 #include <drm/drm_mode.h>
20 #include <drm/drm_print.h>
23 #include "drm_crtc_internal.h"
24 #include "drm_internal.h"
29 * This library provides support for clients running in the kernel like fbdev and bootsplash.
30 * Currently it's only partially implemented, just enough to support fbdev.
32 * GEM drivers which provide a GEM based dumb buffer with a virtual address are supported.
35 static int drm_client_open(struct drm_client_dev *client)
37 struct drm_device *dev = client->dev;
38 struct drm_file *file;
40 file = drm_file_alloc(dev->primary);
44 mutex_lock(&dev->filelist_mutex);
45 list_add(&file->lhead, &dev->filelist_internal);
46 mutex_unlock(&dev->filelist_mutex);
53 static void drm_client_close(struct drm_client_dev *client)
55 struct drm_device *dev = client->dev;
57 mutex_lock(&dev->filelist_mutex);
58 list_del(&client->file->lhead);
59 mutex_unlock(&dev->filelist_mutex);
61 drm_file_free(client->file);
63 EXPORT_SYMBOL(drm_client_close);
66 * drm_client_init - Initialise a DRM client
70 * @funcs: DRM client functions (optional)
72 * This initialises the client and opens a &drm_file.
73 * Use drm_client_register() to complete the process.
74 * The caller needs to hold a reference on @dev before calling this function.
75 * The client is freed when the &drm_device is unregistered. See drm_client_release().
78 * Zero on success or negative error code on failure.
80 int drm_client_init(struct drm_device *dev, struct drm_client_dev *client,
81 const char *name, const struct drm_client_funcs *funcs)
85 if (!drm_core_check_feature(dev, DRIVER_MODESET) || !dev->driver->dumb_create)
88 if (funcs && !try_module_get(funcs->owner))
93 client->funcs = funcs;
95 ret = drm_client_open(client);
105 module_put(funcs->owner);
109 EXPORT_SYMBOL(drm_client_init);
112 * drm_client_register - Register client
113 * @client: DRM client
115 * Add the client to the &drm_device client list to activate its callbacks.
116 * @client must be initialized by a call to drm_client_init(). After
117 * drm_client_register() it is no longer permissible to call drm_client_release()
118 * directly (outside the unregister callback), instead cleanup will happen
119 * automatically on driver unload.
121 void drm_client_register(struct drm_client_dev *client)
123 struct drm_device *dev = client->dev;
125 mutex_lock(&dev->clientlist_mutex);
126 list_add(&client->list, &dev->clientlist);
127 mutex_unlock(&dev->clientlist_mutex);
129 EXPORT_SYMBOL(drm_client_register);
132 * drm_client_release - Release DRM client resources
133 * @client: DRM client
135 * Releases resources by closing the &drm_file that was opened by drm_client_init().
136 * It is called automatically if the &drm_client_funcs.unregister callback is _not_ set.
138 * This function should only be called from the unregister callback. An exception
139 * is fbdev which cannot free the buffer if userspace has open file descriptors.
142 * Clients cannot initiate a release by themselves. This is done to keep the code simple.
143 * The driver has to be unloaded before the client can be unloaded.
145 void drm_client_release(struct drm_client_dev *client)
147 struct drm_device *dev = client->dev;
149 DRM_DEV_DEBUG_KMS(dev->dev, "%s\n", client->name);
151 drm_client_close(client);
154 module_put(client->funcs->owner);
156 EXPORT_SYMBOL(drm_client_release);
158 void drm_client_dev_unregister(struct drm_device *dev)
160 struct drm_client_dev *client, *tmp;
162 if (!drm_core_check_feature(dev, DRIVER_MODESET))
165 mutex_lock(&dev->clientlist_mutex);
166 list_for_each_entry_safe(client, tmp, &dev->clientlist, list) {
167 list_del(&client->list);
168 if (client->funcs && client->funcs->unregister) {
169 client->funcs->unregister(client);
171 drm_client_release(client);
175 mutex_unlock(&dev->clientlist_mutex);
179 * drm_client_dev_hotplug - Send hotplug event to clients
182 * This function calls the &drm_client_funcs.hotplug callback on the attached clients.
184 * drm_kms_helper_hotplug_event() calls this function, so drivers that use it
185 * don't need to call this function themselves.
187 void drm_client_dev_hotplug(struct drm_device *dev)
189 struct drm_client_dev *client;
192 if (!drm_core_check_feature(dev, DRIVER_MODESET))
195 mutex_lock(&dev->clientlist_mutex);
196 list_for_each_entry(client, &dev->clientlist, list) {
197 if (!client->funcs || !client->funcs->hotplug)
200 ret = client->funcs->hotplug(client);
201 DRM_DEV_DEBUG_KMS(dev->dev, "%s: ret=%d\n", client->name, ret);
203 mutex_unlock(&dev->clientlist_mutex);
205 EXPORT_SYMBOL(drm_client_dev_hotplug);
207 void drm_client_dev_restore(struct drm_device *dev)
209 struct drm_client_dev *client;
212 if (!drm_core_check_feature(dev, DRIVER_MODESET))
215 mutex_lock(&dev->clientlist_mutex);
216 list_for_each_entry(client, &dev->clientlist, list) {
217 if (!client->funcs || !client->funcs->restore)
220 ret = client->funcs->restore(client);
221 DRM_DEV_DEBUG_KMS(dev->dev, "%s: ret=%d\n", client->name, ret);
222 if (!ret) /* The first one to return zero gets the privilege to restore */
225 mutex_unlock(&dev->clientlist_mutex);
228 static void drm_client_buffer_delete(struct drm_client_buffer *buffer)
230 struct drm_device *dev = buffer->client->dev;
232 drm_gem_vunmap(buffer->gem, buffer->vaddr);
235 drm_gem_object_put_unlocked(buffer->gem);
238 drm_mode_destroy_dumb(dev, buffer->handle, buffer->client->file);
243 static struct drm_client_buffer *
244 drm_client_buffer_create(struct drm_client_dev *client, u32 width, u32 height, u32 format)
246 struct drm_mode_create_dumb dumb_args = { };
247 struct drm_device *dev = client->dev;
248 struct drm_client_buffer *buffer;
249 struct drm_gem_object *obj;
253 buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
255 return ERR_PTR(-ENOMEM);
257 buffer->client = client;
259 dumb_args.width = width;
260 dumb_args.height = height;
261 dumb_args.bpp = drm_format_plane_cpp(format, 0) * 8;
262 ret = drm_mode_create_dumb(dev, &dumb_args, client->file);
266 buffer->handle = dumb_args.handle;
267 buffer->pitch = dumb_args.pitch;
269 obj = drm_gem_object_lookup(client->file, dumb_args.handle);
278 * FIXME: The dependency on GEM here isn't required, we could
279 * convert the driver handle to a dma-buf instead and use the
280 * backend-agnostic dma-buf vmap support instead. This would
281 * require that the handle2fd prime ioctl is reworked to pull the
282 * fd_install step out of the driver backend hooks, to make that
283 * final step optional for internal users.
285 vaddr = drm_gem_vmap(obj);
287 ret = PTR_ERR(vaddr);
291 buffer->vaddr = vaddr;
296 drm_client_buffer_delete(buffer);
301 static void drm_client_buffer_rmfb(struct drm_client_buffer *buffer)
308 ret = drm_mode_rmfb(buffer->client->dev, buffer->fb->base.id, buffer->client->file);
310 DRM_DEV_ERROR(buffer->client->dev->dev,
311 "Error removing FB:%u (%d)\n", buffer->fb->base.id, ret);
316 static int drm_client_buffer_addfb(struct drm_client_buffer *buffer,
317 u32 width, u32 height, u32 format)
319 struct drm_client_dev *client = buffer->client;
320 struct drm_mode_fb_cmd fb_req = { };
321 const struct drm_format_info *info;
324 info = drm_format_info(format);
325 fb_req.bpp = info->cpp[0] * 8;
326 fb_req.depth = info->depth;
327 fb_req.width = width;
328 fb_req.height = height;
329 fb_req.handle = buffer->handle;
330 fb_req.pitch = buffer->pitch;
332 ret = drm_mode_addfb(client->dev, &fb_req, client->file);
336 buffer->fb = drm_framebuffer_lookup(client->dev, buffer->client->file, fb_req.fb_id);
337 if (WARN_ON(!buffer->fb))
340 /* drop the reference we picked up in framebuffer lookup */
341 drm_framebuffer_put(buffer->fb);
343 strscpy(buffer->fb->comm, client->name, TASK_COMM_LEN);
349 * drm_client_framebuffer_create - Create a client framebuffer
350 * @client: DRM client
351 * @width: Framebuffer width
352 * @height: Framebuffer height
353 * @format: Buffer format
355 * This function creates a &drm_client_buffer which consists of a
356 * &drm_framebuffer backed by a dumb buffer.
357 * Call drm_client_framebuffer_delete() to free the buffer.
360 * Pointer to a client buffer or an error pointer on failure.
362 struct drm_client_buffer *
363 drm_client_framebuffer_create(struct drm_client_dev *client, u32 width, u32 height, u32 format)
365 struct drm_client_buffer *buffer;
368 buffer = drm_client_buffer_create(client, width, height, format);
372 ret = drm_client_buffer_addfb(buffer, width, height, format);
374 drm_client_buffer_delete(buffer);
380 EXPORT_SYMBOL(drm_client_framebuffer_create);
383 * drm_client_framebuffer_delete - Delete a client framebuffer
384 * @buffer: DRM client buffer (can be NULL)
386 void drm_client_framebuffer_delete(struct drm_client_buffer *buffer)
391 drm_client_buffer_rmfb(buffer);
392 drm_client_buffer_delete(buffer);
394 EXPORT_SYMBOL(drm_client_framebuffer_delete);
396 #ifdef CONFIG_DEBUG_FS
397 static int drm_client_debugfs_internal_clients(struct seq_file *m, void *data)
399 struct drm_info_node *node = m->private;
400 struct drm_device *dev = node->minor->dev;
401 struct drm_printer p = drm_seq_file_printer(m);
402 struct drm_client_dev *client;
404 mutex_lock(&dev->clientlist_mutex);
405 list_for_each_entry(client, &dev->clientlist, list)
406 drm_printf(&p, "%s\n", client->name);
407 mutex_unlock(&dev->clientlist_mutex);
412 static const struct drm_info_list drm_client_debugfs_list[] = {
413 { "internal_clients", drm_client_debugfs_internal_clients, 0 },
416 int drm_client_debugfs_init(struct drm_minor *minor)
418 return drm_debugfs_create_files(drm_client_debugfs_list,
419 ARRAY_SIZE(drm_client_debugfs_list),
420 minor->debugfs_root, minor);