1 // SPDX-License-Identifier: GPL-2.0 or MIT
3 * Copyright 2018 Noralf Trønnes
6 #include <linux/iosys-map.h>
7 #include <linux/list.h>
8 #include <linux/module.h>
9 #include <linux/mutex.h>
10 #include <linux/seq_file.h>
11 #include <linux/slab.h>
13 #include <drm/drm_client.h>
14 #include <drm/drm_debugfs.h>
15 #include <drm/drm_device.h>
16 #include <drm/drm_drv.h>
17 #include <drm/drm_file.h>
18 #include <drm/drm_fourcc.h>
19 #include <drm/drm_framebuffer.h>
20 #include <drm/drm_gem.h>
21 #include <drm/drm_mode.h>
22 #include <drm/drm_print.h>
24 #include "drm_crtc_internal.h"
25 #include "drm_internal.h"
30 * This library provides support for clients running in the kernel like fbdev and bootsplash.
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);
65 * drm_client_init - Initialise a DRM client
69 * @funcs: DRM client functions (optional)
71 * This initialises the client and opens a &drm_file.
72 * Use drm_client_register() to complete the process.
73 * The caller needs to hold a reference on @dev before calling this function.
74 * The client is freed when the &drm_device is unregistered. See drm_client_release().
77 * Zero on success or negative error code on failure.
79 int drm_client_init(struct drm_device *dev, struct drm_client_dev *client,
80 const char *name, const struct drm_client_funcs *funcs)
84 if (!drm_core_check_feature(dev, DRIVER_MODESET) || !dev->driver->dumb_create)
87 if (funcs && !try_module_get(funcs->owner))
92 client->funcs = funcs;
94 ret = drm_client_modeset_create(client);
98 ret = drm_client_open(client);
107 drm_client_modeset_free(client);
110 module_put(funcs->owner);
114 EXPORT_SYMBOL(drm_client_init);
117 * drm_client_register - Register client
118 * @client: DRM client
120 * Add the client to the &drm_device client list to activate its callbacks.
121 * @client must be initialized by a call to drm_client_init(). After
122 * drm_client_register() it is no longer permissible to call drm_client_release()
123 * directly (outside the unregister callback), instead cleanup will happen
124 * automatically on driver unload.
126 * Registering a client generates a hotplug event that allows the client
127 * to set up its display from pre-existing outputs. The client must have
128 * initialized its state to able to handle the hotplug event successfully.
130 void drm_client_register(struct drm_client_dev *client)
132 struct drm_device *dev = client->dev;
135 mutex_lock(&dev->clientlist_mutex);
136 list_add(&client->list, &dev->clientlist);
138 if (client->funcs && client->funcs->hotplug) {
140 * Perform an initial hotplug event to pick up the
141 * display configuration for the client. This step
142 * has to be performed *after* registering the client
143 * in the list of clients, or a concurrent hotplug
144 * event might be lost; leaving the display off.
146 * Hold the clientlist_mutex as for a regular hotplug
149 ret = client->funcs->hotplug(client);
151 drm_dbg_kms(dev, "client hotplug ret=%d\n", ret);
153 mutex_unlock(&dev->clientlist_mutex);
155 EXPORT_SYMBOL(drm_client_register);
158 * drm_client_release - Release DRM client resources
159 * @client: DRM client
161 * Releases resources by closing the &drm_file that was opened by drm_client_init().
162 * It is called automatically if the &drm_client_funcs.unregister callback is _not_ set.
164 * This function should only be called from the unregister callback. An exception
165 * is fbdev which cannot free the buffer if userspace has open file descriptors.
168 * Clients cannot initiate a release by themselves. This is done to keep the code simple.
169 * The driver has to be unloaded before the client can be unloaded.
171 void drm_client_release(struct drm_client_dev *client)
173 struct drm_device *dev = client->dev;
175 drm_dbg_kms(dev, "%s\n", client->name);
177 drm_client_modeset_free(client);
178 drm_client_close(client);
181 module_put(client->funcs->owner);
183 EXPORT_SYMBOL(drm_client_release);
185 void drm_client_dev_unregister(struct drm_device *dev)
187 struct drm_client_dev *client, *tmp;
189 if (!drm_core_check_feature(dev, DRIVER_MODESET))
192 mutex_lock(&dev->clientlist_mutex);
193 list_for_each_entry_safe(client, tmp, &dev->clientlist, list) {
194 list_del(&client->list);
195 if (client->funcs && client->funcs->unregister) {
196 client->funcs->unregister(client);
198 drm_client_release(client);
202 mutex_unlock(&dev->clientlist_mutex);
206 * drm_client_dev_hotplug - Send hotplug event to clients
209 * This function calls the &drm_client_funcs.hotplug callback on the attached clients.
211 * drm_kms_helper_hotplug_event() calls this function, so drivers that use it
212 * don't need to call this function themselves.
214 void drm_client_dev_hotplug(struct drm_device *dev)
216 struct drm_client_dev *client;
219 if (!drm_core_check_feature(dev, DRIVER_MODESET))
222 if (!dev->mode_config.num_connector) {
223 drm_dbg_kms(dev, "No connectors found, will not send hotplug events!\n");
227 mutex_lock(&dev->clientlist_mutex);
228 list_for_each_entry(client, &dev->clientlist, list) {
229 if (!client->funcs || !client->funcs->hotplug)
232 if (client->hotplug_failed)
235 ret = client->funcs->hotplug(client);
236 drm_dbg_kms(dev, "%s: ret=%d\n", client->name, ret);
238 client->hotplug_failed = true;
240 mutex_unlock(&dev->clientlist_mutex);
242 EXPORT_SYMBOL(drm_client_dev_hotplug);
244 void drm_client_dev_restore(struct drm_device *dev)
246 struct drm_client_dev *client;
249 if (!drm_core_check_feature(dev, DRIVER_MODESET))
252 mutex_lock(&dev->clientlist_mutex);
253 list_for_each_entry(client, &dev->clientlist, list) {
254 if (!client->funcs || !client->funcs->restore)
257 ret = client->funcs->restore(client);
258 drm_dbg_kms(dev, "%s: ret=%d\n", client->name, ret);
259 if (!ret) /* The first one to return zero gets the privilege to restore */
262 mutex_unlock(&dev->clientlist_mutex);
265 static void drm_client_buffer_delete(struct drm_client_buffer *buffer)
268 drm_gem_vunmap_unlocked(buffer->gem, &buffer->map);
269 drm_gem_object_put(buffer->gem);
275 static struct drm_client_buffer *
276 drm_client_buffer_create(struct drm_client_dev *client, u32 width, u32 height,
277 u32 format, u32 *handle)
279 const struct drm_format_info *info = drm_format_info(format);
280 struct drm_mode_create_dumb dumb_args = { };
281 struct drm_device *dev = client->dev;
282 struct drm_client_buffer *buffer;
283 struct drm_gem_object *obj;
286 buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
288 return ERR_PTR(-ENOMEM);
290 buffer->client = client;
292 dumb_args.width = width;
293 dumb_args.height = height;
294 dumb_args.bpp = drm_format_info_bpp(info, 0);
295 ret = drm_mode_create_dumb(dev, &dumb_args, client->file);
299 obj = drm_gem_object_lookup(client->file, dumb_args.handle);
305 buffer->pitch = dumb_args.pitch;
307 *handle = dumb_args.handle;
312 drm_client_buffer_delete(buffer);
318 * drm_client_buffer_vmap - Map DRM client buffer into address space
319 * @buffer: DRM client buffer
320 * @map_copy: Returns the mapped memory's address
322 * This function maps a client buffer into kernel address space. If the
323 * buffer is already mapped, it returns the existing mapping's address.
325 * Client buffer mappings are not ref'counted. Each call to
326 * drm_client_buffer_vmap() should be followed by a call to
327 * drm_client_buffer_vunmap(); or the client buffer should be mapped
328 * throughout its lifetime.
330 * The returned address is a copy of the internal value. In contrast to
331 * other vmap interfaces, you don't need it for the client's vunmap
332 * function. So you can modify it at will during blit and draw operations.
335 * 0 on success, or a negative errno code otherwise.
338 drm_client_buffer_vmap(struct drm_client_buffer *buffer,
339 struct iosys_map *map_copy)
341 struct iosys_map *map = &buffer->map;
345 * FIXME: The dependency on GEM here isn't required, we could
346 * convert the driver handle to a dma-buf instead and use the
347 * backend-agnostic dma-buf vmap support instead. This would
348 * require that the handle2fd prime ioctl is reworked to pull the
349 * fd_install step out of the driver backend hooks, to make that
350 * final step optional for internal users.
352 ret = drm_gem_vmap_unlocked(buffer->gem, map);
360 EXPORT_SYMBOL(drm_client_buffer_vmap);
363 * drm_client_buffer_vunmap - Unmap DRM client buffer
364 * @buffer: DRM client buffer
366 * This function removes a client buffer's memory mapping. Calling this
367 * function is only required by clients that manage their buffer mappings
370 void drm_client_buffer_vunmap(struct drm_client_buffer *buffer)
372 struct iosys_map *map = &buffer->map;
374 drm_gem_vunmap_unlocked(buffer->gem, map);
376 EXPORT_SYMBOL(drm_client_buffer_vunmap);
378 static void drm_client_buffer_rmfb(struct drm_client_buffer *buffer)
385 ret = drm_mode_rmfb(buffer->client->dev, buffer->fb->base.id, buffer->client->file);
387 drm_err(buffer->client->dev,
388 "Error removing FB:%u (%d)\n", buffer->fb->base.id, ret);
393 static int drm_client_buffer_addfb(struct drm_client_buffer *buffer,
394 u32 width, u32 height, u32 format,
397 struct drm_client_dev *client = buffer->client;
398 struct drm_mode_fb_cmd fb_req = { };
399 const struct drm_format_info *info;
402 info = drm_format_info(format);
403 fb_req.bpp = drm_format_info_bpp(info, 0);
404 fb_req.depth = info->depth;
405 fb_req.width = width;
406 fb_req.height = height;
407 fb_req.handle = handle;
408 fb_req.pitch = buffer->pitch;
410 ret = drm_mode_addfb(client->dev, &fb_req, client->file);
414 buffer->fb = drm_framebuffer_lookup(client->dev, buffer->client->file, fb_req.fb_id);
415 if (WARN_ON(!buffer->fb))
418 /* drop the reference we picked up in framebuffer lookup */
419 drm_framebuffer_put(buffer->fb);
421 strscpy(buffer->fb->comm, client->name, TASK_COMM_LEN);
427 * drm_client_framebuffer_create - Create a client framebuffer
428 * @client: DRM client
429 * @width: Framebuffer width
430 * @height: Framebuffer height
431 * @format: Buffer format
433 * This function creates a &drm_client_buffer which consists of a
434 * &drm_framebuffer backed by a dumb buffer.
435 * Call drm_client_framebuffer_delete() to free the buffer.
438 * Pointer to a client buffer or an error pointer on failure.
440 struct drm_client_buffer *
441 drm_client_framebuffer_create(struct drm_client_dev *client, u32 width, u32 height, u32 format)
443 struct drm_client_buffer *buffer;
447 buffer = drm_client_buffer_create(client, width, height, format,
452 ret = drm_client_buffer_addfb(buffer, width, height, format, handle);
455 * The handle is only needed for creating the framebuffer, destroy it
456 * again to solve a circular dependency should anybody export the GEM
457 * object as DMA-buf. The framebuffer and our buffer structure are still
458 * holding references to the GEM object to prevent its destruction.
460 drm_mode_destroy_dumb(client->dev, handle, client->file);
463 drm_client_buffer_delete(buffer);
469 EXPORT_SYMBOL(drm_client_framebuffer_create);
472 * drm_client_framebuffer_delete - Delete a client framebuffer
473 * @buffer: DRM client buffer (can be NULL)
475 void drm_client_framebuffer_delete(struct drm_client_buffer *buffer)
480 drm_client_buffer_rmfb(buffer);
481 drm_client_buffer_delete(buffer);
483 EXPORT_SYMBOL(drm_client_framebuffer_delete);
486 * drm_client_framebuffer_flush - Manually flush client framebuffer
487 * @buffer: DRM client buffer (can be NULL)
488 * @rect: Damage rectangle (if NULL flushes all)
490 * This calls &drm_framebuffer_funcs->dirty (if present) to flush buffer changes
491 * for drivers that need it.
494 * Zero on success or negative error code on failure.
496 int drm_client_framebuffer_flush(struct drm_client_buffer *buffer, struct drm_rect *rect)
498 if (!buffer || !buffer->fb || !buffer->fb->funcs->dirty)
502 struct drm_clip_rect clip = {
509 return buffer->fb->funcs->dirty(buffer->fb, buffer->client->file,
513 return buffer->fb->funcs->dirty(buffer->fb, buffer->client->file,
516 EXPORT_SYMBOL(drm_client_framebuffer_flush);
518 #ifdef CONFIG_DEBUG_FS
519 static int drm_client_debugfs_internal_clients(struct seq_file *m, void *data)
521 struct drm_debugfs_entry *entry = m->private;
522 struct drm_device *dev = entry->dev;
523 struct drm_printer p = drm_seq_file_printer(m);
524 struct drm_client_dev *client;
526 mutex_lock(&dev->clientlist_mutex);
527 list_for_each_entry(client, &dev->clientlist, list)
528 drm_printf(&p, "%s\n", client->name);
529 mutex_unlock(&dev->clientlist_mutex);
534 static const struct drm_debugfs_info drm_client_debugfs_list[] = {
535 { "internal_clients", drm_client_debugfs_internal_clients, 0 },
538 void drm_client_debugfs_init(struct drm_minor *minor)
540 drm_debugfs_add_files(minor->dev, drm_client_debugfs_list,
541 ARRAY_SIZE(drm_client_debugfs_list));