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/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_framebuffer.h>
19 #include <drm/drm_gem.h>
20 #include <drm/drm_mode.h>
21 #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.
31 * GEM drivers which provide a GEM based dumb buffer with a virtual address are supported.
34 static int drm_client_open(struct drm_client_dev *client)
36 struct drm_device *dev = client->dev;
37 struct drm_file *file;
39 file = drm_file_alloc(dev->primary);
43 mutex_lock(&dev->filelist_mutex);
44 list_add(&file->lhead, &dev->filelist_internal);
45 mutex_unlock(&dev->filelist_mutex);
52 static void drm_client_close(struct drm_client_dev *client)
54 struct drm_device *dev = client->dev;
56 mutex_lock(&dev->filelist_mutex);
57 list_del(&client->file->lhead);
58 mutex_unlock(&dev->filelist_mutex);
60 drm_file_free(client->file);
64 * drm_client_init - Initialise a DRM client
68 * @funcs: DRM client functions (optional)
70 * This initialises the client and opens a &drm_file.
71 * Use drm_client_register() to complete the process.
72 * The caller needs to hold a reference on @dev before calling this function.
73 * The client is freed when the &drm_device is unregistered. See drm_client_release().
76 * Zero on success or negative error code on failure.
78 int drm_client_init(struct drm_device *dev, struct drm_client_dev *client,
79 const char *name, const struct drm_client_funcs *funcs)
83 if (!drm_core_check_feature(dev, DRIVER_MODESET) || !dev->driver->dumb_create)
88 client->funcs = funcs;
90 ret = drm_client_modeset_create(client);
94 ret = drm_client_open(client);
103 drm_client_modeset_free(client);
106 EXPORT_SYMBOL(drm_client_init);
109 * drm_client_register - Register client
110 * @client: DRM client
112 * Add the client to the &drm_device client list to activate its callbacks.
113 * @client must be initialized by a call to drm_client_init(). After
114 * drm_client_register() it is no longer permissible to call drm_client_release()
115 * directly (outside the unregister callback), instead cleanup will happen
116 * automatically on driver unload.
118 * Registering a client generates a hotplug event that allows the client
119 * to set up its display from pre-existing outputs. The client must have
120 * initialized its state to able to handle the hotplug event successfully.
122 void drm_client_register(struct drm_client_dev *client)
124 struct drm_device *dev = client->dev;
127 mutex_lock(&dev->clientlist_mutex);
128 list_add(&client->list, &dev->clientlist);
130 if (client->funcs && client->funcs->hotplug) {
132 * Perform an initial hotplug event to pick up the
133 * display configuration for the client. This step
134 * has to be performed *after* registering the client
135 * in the list of clients, or a concurrent hotplug
136 * event might be lost; leaving the display off.
138 * Hold the clientlist_mutex as for a regular hotplug
141 ret = client->funcs->hotplug(client);
143 drm_dbg_kms(dev, "client hotplug ret=%d\n", ret);
145 mutex_unlock(&dev->clientlist_mutex);
147 EXPORT_SYMBOL(drm_client_register);
150 * drm_client_release - Release DRM client resources
151 * @client: DRM client
153 * Releases resources by closing the &drm_file that was opened by drm_client_init().
154 * It is called automatically if the &drm_client_funcs.unregister callback is _not_ set.
156 * This function should only be called from the unregister callback. An exception
157 * is fbdev which cannot free the buffer if userspace has open file descriptors.
160 * Clients cannot initiate a release by themselves. This is done to keep the code simple.
161 * The driver has to be unloaded before the client can be unloaded.
163 void drm_client_release(struct drm_client_dev *client)
165 struct drm_device *dev = client->dev;
167 drm_dbg_kms(dev, "%s\n", client->name);
169 drm_client_modeset_free(client);
170 drm_client_close(client);
173 EXPORT_SYMBOL(drm_client_release);
175 void drm_client_dev_unregister(struct drm_device *dev)
177 struct drm_client_dev *client, *tmp;
179 if (!drm_core_check_feature(dev, DRIVER_MODESET))
182 mutex_lock(&dev->clientlist_mutex);
183 list_for_each_entry_safe(client, tmp, &dev->clientlist, list) {
184 list_del(&client->list);
185 if (client->funcs && client->funcs->unregister) {
186 client->funcs->unregister(client);
188 drm_client_release(client);
192 mutex_unlock(&dev->clientlist_mutex);
196 * drm_client_dev_hotplug - Send hotplug event to clients
199 * This function calls the &drm_client_funcs.hotplug callback on the attached clients.
201 * drm_kms_helper_hotplug_event() calls this function, so drivers that use it
202 * don't need to call this function themselves.
204 void drm_client_dev_hotplug(struct drm_device *dev)
206 struct drm_client_dev *client;
209 if (!drm_core_check_feature(dev, DRIVER_MODESET))
212 if (!dev->mode_config.num_connector) {
213 drm_dbg_kms(dev, "No connectors found, will not send hotplug events!\n");
217 mutex_lock(&dev->clientlist_mutex);
218 list_for_each_entry(client, &dev->clientlist, list) {
219 if (!client->funcs || !client->funcs->hotplug)
222 if (client->hotplug_failed)
225 ret = client->funcs->hotplug(client);
226 drm_dbg_kms(dev, "%s: ret=%d\n", client->name, ret);
228 client->hotplug_failed = true;
230 mutex_unlock(&dev->clientlist_mutex);
232 EXPORT_SYMBOL(drm_client_dev_hotplug);
234 void drm_client_dev_restore(struct drm_device *dev)
236 struct drm_client_dev *client;
239 if (!drm_core_check_feature(dev, DRIVER_MODESET))
242 mutex_lock(&dev->clientlist_mutex);
243 list_for_each_entry(client, &dev->clientlist, list) {
244 if (!client->funcs || !client->funcs->restore)
247 ret = client->funcs->restore(client);
248 drm_dbg_kms(dev, "%s: ret=%d\n", client->name, ret);
249 if (!ret) /* The first one to return zero gets the privilege to restore */
252 mutex_unlock(&dev->clientlist_mutex);
255 static void drm_client_buffer_delete(struct drm_client_buffer *buffer)
258 drm_gem_vunmap_unlocked(buffer->gem, &buffer->map);
259 drm_gem_object_put(buffer->gem);
265 static struct drm_client_buffer *
266 drm_client_buffer_create(struct drm_client_dev *client, u32 width, u32 height,
267 u32 format, u32 *handle)
269 const struct drm_format_info *info = drm_format_info(format);
270 struct drm_mode_create_dumb dumb_args = { };
271 struct drm_device *dev = client->dev;
272 struct drm_client_buffer *buffer;
273 struct drm_gem_object *obj;
276 buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
278 return ERR_PTR(-ENOMEM);
280 buffer->client = client;
282 dumb_args.width = width;
283 dumb_args.height = height;
284 dumb_args.bpp = drm_format_info_bpp(info, 0);
285 ret = drm_mode_create_dumb(dev, &dumb_args, client->file);
289 obj = drm_gem_object_lookup(client->file, dumb_args.handle);
295 buffer->pitch = dumb_args.pitch;
297 *handle = dumb_args.handle;
302 drm_client_buffer_delete(buffer);
308 * drm_client_buffer_vmap - Map DRM client buffer into address space
309 * @buffer: DRM client buffer
310 * @map_copy: Returns the mapped memory's address
312 * This function maps a client buffer into kernel address space. If the
313 * buffer is already mapped, it returns the existing mapping's address.
315 * Client buffer mappings are not ref'counted. Each call to
316 * drm_client_buffer_vmap() should be followed by a call to
317 * drm_client_buffer_vunmap(); or the client buffer should be mapped
318 * throughout its lifetime.
320 * The returned address is a copy of the internal value. In contrast to
321 * other vmap interfaces, you don't need it for the client's vunmap
322 * function. So you can modify it at will during blit and draw operations.
325 * 0 on success, or a negative errno code otherwise.
328 drm_client_buffer_vmap(struct drm_client_buffer *buffer,
329 struct iosys_map *map_copy)
331 struct iosys_map *map = &buffer->map;
335 * FIXME: The dependency on GEM here isn't required, we could
336 * convert the driver handle to a dma-buf instead and use the
337 * backend-agnostic dma-buf vmap support instead. This would
338 * require that the handle2fd prime ioctl is reworked to pull the
339 * fd_install step out of the driver backend hooks, to make that
340 * final step optional for internal users.
342 ret = drm_gem_vmap_unlocked(buffer->gem, map);
350 EXPORT_SYMBOL(drm_client_buffer_vmap);
353 * drm_client_buffer_vunmap - Unmap DRM client buffer
354 * @buffer: DRM client buffer
356 * This function removes a client buffer's memory mapping. Calling this
357 * function is only required by clients that manage their buffer mappings
360 void drm_client_buffer_vunmap(struct drm_client_buffer *buffer)
362 struct iosys_map *map = &buffer->map;
364 drm_gem_vunmap_unlocked(buffer->gem, map);
366 EXPORT_SYMBOL(drm_client_buffer_vunmap);
368 static void drm_client_buffer_rmfb(struct drm_client_buffer *buffer)
375 ret = drm_mode_rmfb(buffer->client->dev, buffer->fb->base.id, buffer->client->file);
377 drm_err(buffer->client->dev,
378 "Error removing FB:%u (%d)\n", buffer->fb->base.id, ret);
383 static int drm_client_buffer_addfb(struct drm_client_buffer *buffer,
384 u32 width, u32 height, u32 format,
387 struct drm_client_dev *client = buffer->client;
388 struct drm_mode_fb_cmd2 fb_req = { };
391 fb_req.width = width;
392 fb_req.height = height;
393 fb_req.pixel_format = format;
394 fb_req.handles[0] = handle;
395 fb_req.pitches[0] = buffer->pitch;
397 ret = drm_mode_addfb2(client->dev, &fb_req, client->file);
401 buffer->fb = drm_framebuffer_lookup(client->dev, buffer->client->file, fb_req.fb_id);
402 if (WARN_ON(!buffer->fb))
405 /* drop the reference we picked up in framebuffer lookup */
406 drm_framebuffer_put(buffer->fb);
408 strscpy(buffer->fb->comm, client->name, TASK_COMM_LEN);
414 * drm_client_framebuffer_create - Create a client framebuffer
415 * @client: DRM client
416 * @width: Framebuffer width
417 * @height: Framebuffer height
418 * @format: Buffer format
420 * This function creates a &drm_client_buffer which consists of a
421 * &drm_framebuffer backed by a dumb buffer.
422 * Call drm_client_framebuffer_delete() to free the buffer.
425 * Pointer to a client buffer or an error pointer on failure.
427 struct drm_client_buffer *
428 drm_client_framebuffer_create(struct drm_client_dev *client, u32 width, u32 height, u32 format)
430 struct drm_client_buffer *buffer;
434 buffer = drm_client_buffer_create(client, width, height, format,
439 ret = drm_client_buffer_addfb(buffer, width, height, format, handle);
442 * The handle is only needed for creating the framebuffer, destroy it
443 * again to solve a circular dependency should anybody export the GEM
444 * object as DMA-buf. The framebuffer and our buffer structure are still
445 * holding references to the GEM object to prevent its destruction.
447 drm_mode_destroy_dumb(client->dev, handle, client->file);
450 drm_client_buffer_delete(buffer);
456 EXPORT_SYMBOL(drm_client_framebuffer_create);
459 * drm_client_framebuffer_delete - Delete a client framebuffer
460 * @buffer: DRM client buffer (can be NULL)
462 void drm_client_framebuffer_delete(struct drm_client_buffer *buffer)
467 drm_client_buffer_rmfb(buffer);
468 drm_client_buffer_delete(buffer);
470 EXPORT_SYMBOL(drm_client_framebuffer_delete);
473 * drm_client_framebuffer_flush - Manually flush client framebuffer
474 * @buffer: DRM client buffer (can be NULL)
475 * @rect: Damage rectangle (if NULL flushes all)
477 * This calls &drm_framebuffer_funcs->dirty (if present) to flush buffer changes
478 * for drivers that need it.
481 * Zero on success or negative error code on failure.
483 int drm_client_framebuffer_flush(struct drm_client_buffer *buffer, struct drm_rect *rect)
485 if (!buffer || !buffer->fb || !buffer->fb->funcs->dirty)
489 struct drm_clip_rect clip = {
496 return buffer->fb->funcs->dirty(buffer->fb, buffer->client->file,
500 return buffer->fb->funcs->dirty(buffer->fb, buffer->client->file,
503 EXPORT_SYMBOL(drm_client_framebuffer_flush);
505 #ifdef CONFIG_DEBUG_FS
506 static int drm_client_debugfs_internal_clients(struct seq_file *m, void *data)
508 struct drm_debugfs_entry *entry = m->private;
509 struct drm_device *dev = entry->dev;
510 struct drm_printer p = drm_seq_file_printer(m);
511 struct drm_client_dev *client;
513 mutex_lock(&dev->clientlist_mutex);
514 list_for_each_entry(client, &dev->clientlist, list)
515 drm_printf(&p, "%s\n", client->name);
516 mutex_unlock(&dev->clientlist_mutex);
521 static const struct drm_debugfs_info drm_client_debugfs_list[] = {
522 { "internal_clients", drm_client_debugfs_internal_clients, 0 },
525 void drm_client_debugfs_init(struct drm_device *dev)
527 drm_debugfs_add_files(dev, drm_client_debugfs_list,
528 ARRAY_SIZE(drm_client_debugfs_list));