1// SPDX-License-Identifier: GPL-2.0 or MIT
2/*
3 * Copyright 2018 Noralf Trønnes
4 */
5
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>
12
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>
23
24#include "drm_crtc_internal.h"
25#include "drm_internal.h"
26
27/**
28 * DOC: overview
29 *
30 * This library provides support for clients running in the kernel like fbdev and bootsplash.
31 *
32 * GEM drivers which provide a GEM based dumb buffer with a virtual address are supported.
33 */
34
35static int drm_client_open(struct drm_client_dev *client)
36{
37 struct drm_device *dev = client->dev;
38 struct drm_file *file;
39
40 file = drm_file_alloc(minor: dev->primary);
41 if (IS_ERR(ptr: file))
42 return PTR_ERR(ptr: file);
43
44 mutex_lock(&dev->filelist_mutex);
45 list_add(new: &file->lhead, head: &dev->filelist_internal);
46 mutex_unlock(lock: &dev->filelist_mutex);
47
48 client->file = file;
49
50 return 0;
51}
52
53static void drm_client_close(struct drm_client_dev *client)
54{
55 struct drm_device *dev = client->dev;
56
57 mutex_lock(&dev->filelist_mutex);
58 list_del(entry: &client->file->lhead);
59 mutex_unlock(lock: &dev->filelist_mutex);
60
61 drm_file_free(file: client->file);
62}
63
64/**
65 * drm_client_init - Initialise a DRM client
66 * @dev: DRM device
67 * @client: DRM client
68 * @name: Client name
69 * @funcs: DRM client functions (optional)
70 *
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().
75 *
76 * Returns:
77 * Zero on success or negative error code on failure.
78 */
79int drm_client_init(struct drm_device *dev, struct drm_client_dev *client,
80 const char *name, const struct drm_client_funcs *funcs)
81{
82 int ret;
83
84 if (!drm_core_check_feature(dev, feature: DRIVER_MODESET) || !dev->driver->dumb_create)
85 return -EOPNOTSUPP;
86
87 if (funcs && !try_module_get(module: funcs->owner))
88 return -ENODEV;
89
90 client->dev = dev;
91 client->name = name;
92 client->funcs = funcs;
93
94 ret = drm_client_modeset_create(client);
95 if (ret)
96 goto err_put_module;
97
98 ret = drm_client_open(client);
99 if (ret)
100 goto err_free;
101
102 drm_dev_get(dev);
103
104 return 0;
105
106err_free:
107 drm_client_modeset_free(client);
108err_put_module:
109 if (funcs)
110 module_put(module: funcs->owner);
111
112 return ret;
113}
114EXPORT_SYMBOL(drm_client_init);
115
116/**
117 * drm_client_register - Register client
118 * @client: DRM client
119 *
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.
125 *
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.
129 */
130void drm_client_register(struct drm_client_dev *client)
131{
132 struct drm_device *dev = client->dev;
133 int ret;
134
135 mutex_lock(&dev->clientlist_mutex);
136 list_add(new: &client->list, head: &dev->clientlist);
137
138 if (client->funcs && client->funcs->hotplug) {
139 /*
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.
145 *
146 * Hold the clientlist_mutex as for a regular hotplug
147 * event.
148 */
149 ret = client->funcs->hotplug(client);
150 if (ret)
151 drm_dbg_kms(dev, "client hotplug ret=%d\n", ret);
152 }
153 mutex_unlock(lock: &dev->clientlist_mutex);
154}
155EXPORT_SYMBOL(drm_client_register);
156
157/**
158 * drm_client_release - Release DRM client resources
159 * @client: DRM client
160 *
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.
163 *
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.
166 *
167 * Note:
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.
170 */
171void drm_client_release(struct drm_client_dev *client)
172{
173 struct drm_device *dev = client->dev;
174
175 drm_dbg_kms(dev, "%s\n", client->name);
176
177 drm_client_modeset_free(client);
178 drm_client_close(client);
179 drm_dev_put(dev);
180 if (client->funcs)
181 module_put(module: client->funcs->owner);
182}
183EXPORT_SYMBOL(drm_client_release);
184
185void drm_client_dev_unregister(struct drm_device *dev)
186{
187 struct drm_client_dev *client, *tmp;
188
189 if (!drm_core_check_feature(dev, feature: DRIVER_MODESET))
190 return;
191
192 mutex_lock(&dev->clientlist_mutex);
193 list_for_each_entry_safe(client, tmp, &dev->clientlist, list) {
194 list_del(entry: &client->list);
195 if (client->funcs && client->funcs->unregister) {
196 client->funcs->unregister(client);
197 } else {
198 drm_client_release(client);
199 kfree(objp: client);
200 }
201 }
202 mutex_unlock(lock: &dev->clientlist_mutex);
203}
204
205/**
206 * drm_client_dev_hotplug - Send hotplug event to clients
207 * @dev: DRM device
208 *
209 * This function calls the &drm_client_funcs.hotplug callback on the attached clients.
210 *
211 * drm_kms_helper_hotplug_event() calls this function, so drivers that use it
212 * don't need to call this function themselves.
213 */
214void drm_client_dev_hotplug(struct drm_device *dev)
215{
216 struct drm_client_dev *client;
217 int ret;
218
219 if (!drm_core_check_feature(dev, feature: DRIVER_MODESET))
220 return;
221
222 if (!dev->mode_config.num_connector) {
223 drm_dbg_kms(dev, "No connectors found, will not send hotplug events!\n");
224 return;
225 }
226
227 mutex_lock(&dev->clientlist_mutex);
228 list_for_each_entry(client, &dev->clientlist, list) {
229 if (!client->funcs || !client->funcs->hotplug)
230 continue;
231
232 if (client->hotplug_failed)
233 continue;
234
235 ret = client->funcs->hotplug(client);
236 drm_dbg_kms(dev, "%s: ret=%d\n", client->name, ret);
237 if (ret)
238 client->hotplug_failed = true;
239 }
240 mutex_unlock(lock: &dev->clientlist_mutex);
241}
242EXPORT_SYMBOL(drm_client_dev_hotplug);
243
244void drm_client_dev_restore(struct drm_device *dev)
245{
246 struct drm_client_dev *client;
247 int ret;
248
249 if (!drm_core_check_feature(dev, feature: DRIVER_MODESET))
250 return;
251
252 mutex_lock(&dev->clientlist_mutex);
253 list_for_each_entry(client, &dev->clientlist, list) {
254 if (!client->funcs || !client->funcs->restore)
255 continue;
256
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 */
260 break;
261 }
262 mutex_unlock(lock: &dev->clientlist_mutex);
263}
264
265static void drm_client_buffer_delete(struct drm_client_buffer *buffer)
266{
267 if (buffer->gem) {
268 drm_gem_vunmap_unlocked(obj: buffer->gem, map: &buffer->map);
269 drm_gem_object_put(obj: buffer->gem);
270 }
271
272 kfree(objp: buffer);
273}
274
275static struct drm_client_buffer *
276drm_client_buffer_create(struct drm_client_dev *client, u32 width, u32 height,
277 u32 format, u32 *handle)
278{
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;
284 int ret;
285
286 buffer = kzalloc(size: sizeof(*buffer), GFP_KERNEL);
287 if (!buffer)
288 return ERR_PTR(error: -ENOMEM);
289
290 buffer->client = client;
291
292 dumb_args.width = width;
293 dumb_args.height = height;
294 dumb_args.bpp = drm_format_info_bpp(info, plane: 0);
295 ret = drm_mode_create_dumb(dev, args: &dumb_args, file_priv: client->file);
296 if (ret)
297 goto err_delete;
298
299 obj = drm_gem_object_lookup(filp: client->file, handle: dumb_args.handle);
300 if (!obj) {
301 ret = -ENOENT;
302 goto err_delete;
303 }
304
305 buffer->pitch = dumb_args.pitch;
306 buffer->gem = obj;
307 *handle = dumb_args.handle;
308
309 return buffer;
310
311err_delete:
312 drm_client_buffer_delete(buffer);
313
314 return ERR_PTR(error: ret);
315}
316
317/**
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
321 *
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.
324 *
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.
329 *
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.
333 *
334 * Returns:
335 * 0 on success, or a negative errno code otherwise.
336 */
337int
338drm_client_buffer_vmap(struct drm_client_buffer *buffer,
339 struct iosys_map *map_copy)
340{
341 struct iosys_map *map = &buffer->map;
342 int ret;
343
344 /*
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.
351 */
352 ret = drm_gem_vmap_unlocked(obj: buffer->gem, map);
353 if (ret)
354 return ret;
355
356 *map_copy = *map;
357
358 return 0;
359}
360EXPORT_SYMBOL(drm_client_buffer_vmap);
361
362/**
363 * drm_client_buffer_vunmap - Unmap DRM client buffer
364 * @buffer: DRM client buffer
365 *
366 * This function removes a client buffer's memory mapping. Calling this
367 * function is only required by clients that manage their buffer mappings
368 * by themselves.
369 */
370void drm_client_buffer_vunmap(struct drm_client_buffer *buffer)
371{
372 struct iosys_map *map = &buffer->map;
373
374 drm_gem_vunmap_unlocked(obj: buffer->gem, map);
375}
376EXPORT_SYMBOL(drm_client_buffer_vunmap);
377
378static void drm_client_buffer_rmfb(struct drm_client_buffer *buffer)
379{
380 int ret;
381
382 if (!buffer->fb)
383 return;
384
385 ret = drm_mode_rmfb(dev: buffer->client->dev, fb_id: buffer->fb->base.id, file_priv: buffer->client->file);
386 if (ret)
387 drm_err(buffer->client->dev,
388 "Error removing FB:%u (%d)\n", buffer->fb->base.id, ret);
389
390 buffer->fb = NULL;
391}
392
393static int drm_client_buffer_addfb(struct drm_client_buffer *buffer,
394 u32 width, u32 height, u32 format,
395 u32 handle)
396{
397 struct drm_client_dev *client = buffer->client;
398 struct drm_mode_fb_cmd2 fb_req = { };
399 int ret;
400
401 fb_req.width = width;
402 fb_req.height = height;
403 fb_req.pixel_format = format;
404 fb_req.handles[0] = handle;
405 fb_req.pitches[0] = buffer->pitch;
406
407 ret = drm_mode_addfb2(dev: client->dev, data: &fb_req, file_priv: client->file);
408 if (ret)
409 return ret;
410
411 buffer->fb = drm_framebuffer_lookup(dev: client->dev, file_priv: buffer->client->file, id: fb_req.fb_id);
412 if (WARN_ON(!buffer->fb))
413 return -ENOENT;
414
415 /* drop the reference we picked up in framebuffer lookup */
416 drm_framebuffer_put(fb: buffer->fb);
417
418 strscpy(p: buffer->fb->comm, q: client->name, size: TASK_COMM_LEN);
419
420 return 0;
421}
422
423/**
424 * drm_client_framebuffer_create - Create a client framebuffer
425 * @client: DRM client
426 * @width: Framebuffer width
427 * @height: Framebuffer height
428 * @format: Buffer format
429 *
430 * This function creates a &drm_client_buffer which consists of a
431 * &drm_framebuffer backed by a dumb buffer.
432 * Call drm_client_framebuffer_delete() to free the buffer.
433 *
434 * Returns:
435 * Pointer to a client buffer or an error pointer on failure.
436 */
437struct drm_client_buffer *
438drm_client_framebuffer_create(struct drm_client_dev *client, u32 width, u32 height, u32 format)
439{
440 struct drm_client_buffer *buffer;
441 u32 handle;
442 int ret;
443
444 buffer = drm_client_buffer_create(client, width, height, format,
445 handle: &handle);
446 if (IS_ERR(ptr: buffer))
447 return buffer;
448
449 ret = drm_client_buffer_addfb(buffer, width, height, format, handle);
450
451 /*
452 * The handle is only needed for creating the framebuffer, destroy it
453 * again to solve a circular dependency should anybody export the GEM
454 * object as DMA-buf. The framebuffer and our buffer structure are still
455 * holding references to the GEM object to prevent its destruction.
456 */
457 drm_mode_destroy_dumb(dev: client->dev, handle, file_priv: client->file);
458
459 if (ret) {
460 drm_client_buffer_delete(buffer);
461 return ERR_PTR(error: ret);
462 }
463
464 return buffer;
465}
466EXPORT_SYMBOL(drm_client_framebuffer_create);
467
468/**
469 * drm_client_framebuffer_delete - Delete a client framebuffer
470 * @buffer: DRM client buffer (can be NULL)
471 */
472void drm_client_framebuffer_delete(struct drm_client_buffer *buffer)
473{
474 if (!buffer)
475 return;
476
477 drm_client_buffer_rmfb(buffer);
478 drm_client_buffer_delete(buffer);
479}
480EXPORT_SYMBOL(drm_client_framebuffer_delete);
481
482/**
483 * drm_client_framebuffer_flush - Manually flush client framebuffer
484 * @buffer: DRM client buffer (can be NULL)
485 * @rect: Damage rectangle (if NULL flushes all)
486 *
487 * This calls &drm_framebuffer_funcs->dirty (if present) to flush buffer changes
488 * for drivers that need it.
489 *
490 * Returns:
491 * Zero on success or negative error code on failure.
492 */
493int drm_client_framebuffer_flush(struct drm_client_buffer *buffer, struct drm_rect *rect)
494{
495 if (!buffer || !buffer->fb || !buffer->fb->funcs->dirty)
496 return 0;
497
498 if (rect) {
499 struct drm_clip_rect clip = {
500 .x1 = rect->x1,
501 .y1 = rect->y1,
502 .x2 = rect->x2,
503 .y2 = rect->y2,
504 };
505
506 return buffer->fb->funcs->dirty(buffer->fb, buffer->client->file,
507 0, 0, &clip, 1);
508 }
509
510 return buffer->fb->funcs->dirty(buffer->fb, buffer->client->file,
511 0, 0, NULL, 0);
512}
513EXPORT_SYMBOL(drm_client_framebuffer_flush);
514
515#ifdef CONFIG_DEBUG_FS
516static int drm_client_debugfs_internal_clients(struct seq_file *m, void *data)
517{
518 struct drm_debugfs_entry *entry = m->private;
519 struct drm_device *dev = entry->dev;
520 struct drm_printer p = drm_seq_file_printer(f: m);
521 struct drm_client_dev *client;
522
523 mutex_lock(&dev->clientlist_mutex);
524 list_for_each_entry(client, &dev->clientlist, list)
525 drm_printf(p: &p, f: "%s\n", client->name);
526 mutex_unlock(lock: &dev->clientlist_mutex);
527
528 return 0;
529}
530
531static const struct drm_debugfs_info drm_client_debugfs_list[] = {
532 { "internal_clients", drm_client_debugfs_internal_clients, 0 },
533};
534
535void drm_client_debugfs_init(struct drm_device *dev)
536{
537 drm_debugfs_add_files(dev, files: drm_client_debugfs_list,
538 ARRAY_SIZE(drm_client_debugfs_list));
539}
540#endif
541

source code of linux/drivers/gpu/drm/drm_client.c