projects/linux·blob master · refs

465 lines · 12.4 KiB

1// SPDX-License-Identifier: GPL-2.0 or MIT
2/*
3 * Copyright 2018 Noralf Trønnes
4 */
5
6#include <linux/export.h>
7#include <linux/iosys-map.h>
8#include <linux/list.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_client_event.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_gem_framebuffer_helper.h>
22#include <drm/drm_mode.h>
23#include <drm/drm_print.h>
24
25#include "drm_crtc_internal.h"
26#include "drm_internal.h"
27
28/**
29 * DOC: overview
30 *
31 * This library provides support for clients running in the kernel like fbdev and bootsplash.
32 *
33 * GEM drivers which provide a GEM based dumb buffer with a virtual address are supported.
34 */
35
36static int drm_client_open(struct drm_client_dev *client)
37{
38 struct drm_device *dev = client->dev;
39 struct drm_file *file;
40
41 file = drm_file_alloc(dev->primary);
42 if (IS_ERR(file))
43 return PTR_ERR(file);
44
45 mutex_lock(&dev->filelist_mutex);
46 list_add(&file->lhead, &dev->filelist_internal);
47 mutex_unlock(&dev->filelist_mutex);
48
49 client->file = file;
50
51 return 0;
52}
53
54static void drm_client_close(struct drm_client_dev *client)
55{
56 struct drm_device *dev = client->dev;
57
58 mutex_lock(&dev->filelist_mutex);
59 list_del(&client->file->lhead);
60 mutex_unlock(&dev->filelist_mutex);
61
62 drm_file_free(client->file);
63}
64
65/**
66 * drm_client_init - Initialise a DRM client
67 * @dev: DRM device
68 * @client: DRM client
69 * @name: Client name
70 * @funcs: DRM client functions (optional)
71 *
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().
76 *
77 * Returns:
78 * Zero on success or negative error code on failure.
79 */
80int drm_client_init(struct drm_device *dev, struct drm_client_dev *client,
81 const char *name, const struct drm_client_funcs *funcs)
82{
83 int ret;
84
85 if (!drm_core_check_feature(dev, DRIVER_MODESET) || !dev->driver->dumb_create)
86 return -EOPNOTSUPP;
87
88 client->dev = dev;
89 client->name = name;
90 client->funcs = funcs;
91
92 ret = drm_client_modeset_create(client);
93 if (ret)
94 return ret;
95
96 ret = drm_client_open(client);
97 if (ret)
98 goto err_free;
99
100 drm_dev_get(dev);
101
102 return 0;
103
104err_free:
105 drm_client_modeset_free(client);
106 return ret;
107}
108EXPORT_SYMBOL(drm_client_init);
109
110/**
111 * drm_client_register - Register client
112 * @client: DRM client
113 *
114 * Add the client to the &drm_device client list to activate its callbacks.
115 * @client must be initialized by a call to drm_client_init(). After
116 * drm_client_register() it is no longer permissible to call drm_client_release()
117 * directly (outside the unregister callback), instead cleanup will happen
118 * automatically on driver unload.
119 *
120 * Registering a client generates a hotplug event that allows the client
121 * to set up its display from pre-existing outputs. The client must have
122 * initialized its state to able to handle the hotplug event successfully.
123 */
124void drm_client_register(struct drm_client_dev *client)
125{
126 struct drm_device *dev = client->dev;
127 int ret;
128
129 mutex_lock(&dev->clientlist_mutex);
130 list_add(&client->list, &dev->clientlist);
131
132 if (client->funcs && client->funcs->hotplug) {
133 /*
134 * Perform an initial hotplug event to pick up the
135 * display configuration for the client. This step
136 * has to be performed *after* registering the client
137 * in the list of clients, or a concurrent hotplug
138 * event might be lost; leaving the display off.
139 *
140 * Hold the clientlist_mutex as for a regular hotplug
141 * event.
142 */
143 ret = client->funcs->hotplug(client);
144 if (ret)
145 drm_dbg_kms(dev, "client hotplug ret=%d\n", ret);
146 }
147 mutex_unlock(&dev->clientlist_mutex);
148}
149EXPORT_SYMBOL(drm_client_register);
150
151/**
152 * drm_client_release - Release DRM client resources
153 * @client: DRM client
154 *
155 * Releases resources by closing the &drm_file that was opened by drm_client_init().
156 * It is called automatically if the &drm_client_funcs.unregister callback is _not_ set.
157 *
158 * This function should only be called from the unregister callback. An exception
159 * is fbdev which cannot free the buffer if userspace has open file descriptors.
160 *
161 * Note:
162 * Clients cannot initiate a release by themselves. This is done to keep the code simple.
163 * The driver has to be unloaded before the client can be unloaded.
164 */
165void drm_client_release(struct drm_client_dev *client)
166{
167 struct drm_device *dev = client->dev;
168
169 drm_dbg_kms(dev, "%s\n", client->name);
170
171 drm_client_modeset_free(client);
172 drm_client_close(client);
173
174 if (client->funcs && client->funcs->free)
175 client->funcs->free(client);
176
177 drm_dev_put(dev);
178}
179EXPORT_SYMBOL(drm_client_release);
180
181/**
182 * drm_client_buffer_delete - Delete a client buffer
183 * @buffer: DRM client buffer
184 */
185void drm_client_buffer_delete(struct drm_client_buffer *buffer)
186{
187 struct drm_gem_object *gem;
188 int ret;
189
190 if (!buffer)
191 return;
192
193 gem = buffer->fb->obj[0];
194 drm_gem_vunmap(gem, &buffer->map);
195
196 ret = drm_mode_rmfb(buffer->client->dev, buffer->fb->base.id, buffer->client->file);
197 if (ret)
198 drm_err(buffer->client->dev,
199 "Error removing FB:%u (%d)\n", buffer->fb->base.id, ret);
200
201 drm_gem_object_put(buffer->gem);
202
203 kfree(buffer);
204}
205EXPORT_SYMBOL(drm_client_buffer_delete);
206
207struct drm_client_buffer *
208drm_client_buffer_create(struct drm_client_dev *client, u32 width, u32 height,
209 u32 format, u32 handle, u32 pitch)
210{
211 struct drm_mode_fb_cmd2 fb_req = {
212 .width = width,
213 .height = height,
214 .pixel_format = format,
215 .handles = {
216 handle,
217 },
218 .pitches = {
219 pitch,
220 },
221 };
222 struct drm_device *dev = client->dev;
223 struct drm_client_buffer *buffer;
224 struct drm_gem_object *obj;
225 struct drm_framebuffer *fb;
226 int ret;
227
228 buffer = kzalloc_obj(*buffer);
229 if (!buffer)
230 return ERR_PTR(-ENOMEM);
231
232 buffer->client = client;
233
234 obj = drm_gem_object_lookup(client->file, handle);
235 if (!obj) {
236 ret = -ENOENT;
237 goto err_delete;
238 }
239
240 ret = drm_mode_addfb2(dev, &fb_req, client->file);
241 if (ret)
242 goto err_drm_gem_object_put;
243
244 fb = drm_framebuffer_lookup(dev, client->file, fb_req.fb_id);
245 if (drm_WARN_ON(dev, !fb)) {
246 ret = -ENOENT;
247 goto err_drm_mode_rmfb;
248 }
249
250 /* drop the reference we picked up in framebuffer lookup */
251 drm_framebuffer_put(fb);
252
253 strscpy(fb->comm, client->name, TASK_COMM_LEN);
254
255 buffer->gem = obj;
256 buffer->fb = fb;
257
258 return buffer;
259
260err_drm_mode_rmfb:
261 drm_mode_rmfb(dev, fb_req.fb_id, client->file);
262err_drm_gem_object_put:
263 drm_gem_object_put(obj);
264err_delete:
265 kfree(buffer);
266 return ERR_PTR(ret);
267}
268EXPORT_SYMBOL(drm_client_buffer_create);
269
270/**
271 * drm_client_buffer_vmap_local - Map DRM client buffer into address space
272 * @buffer: DRM client buffer
273 * @map_copy: Returns the mapped memory's address
274 *
275 * This function maps a client buffer into kernel address space. If the
276 * buffer is already mapped, it returns the existing mapping's address.
277 *
278 * Client buffer mappings are not ref'counted. Each call to
279 * drm_client_buffer_vmap_local() should be closely followed by a call to
280 * drm_client_buffer_vunmap_local(). See drm_client_buffer_vmap() for
281 * long-term mappings.
282 *
283 * The returned address is a copy of the internal value. In contrast to
284 * other vmap interfaces, you don't need it for the client's vunmap
285 * function. So you can modify it at will during blit and draw operations.
286 *
287 * Returns:
288 * 0 on success, or a negative errno code otherwise.
289 */
290int drm_client_buffer_vmap_local(struct drm_client_buffer *buffer,
291 struct iosys_map *map_copy)
292{
293 struct drm_gem_object *gem = buffer->fb->obj[0];
294 struct iosys_map *map = &buffer->map;
295 int ret;
296
297 drm_gem_lock(gem);
298
299 ret = drm_gem_vmap_locked(gem, map);
300 if (ret)
301 goto err_drm_gem_vmap_unlocked;
302 *map_copy = *map;
303
304 return 0;
305
306err_drm_gem_vmap_unlocked:
307 drm_gem_unlock(gem);
308 return ret;
309}
310EXPORT_SYMBOL(drm_client_buffer_vmap_local);
311
312/**
313 * drm_client_buffer_vunmap_local - Unmap DRM client buffer
314 * @buffer: DRM client buffer
315 *
316 * This function removes a client buffer's memory mapping established
317 * with drm_client_buffer_vunmap_local(). Calling this function is only
318 * required by clients that manage their buffer mappings by themselves.
319 */
320void drm_client_buffer_vunmap_local(struct drm_client_buffer *buffer)
321{
322 struct drm_gem_object *gem = buffer->fb->obj[0];
323 struct iosys_map *map = &buffer->map;
324
325 drm_gem_vunmap_locked(gem, map);
326 drm_gem_unlock(gem);
327}
328EXPORT_SYMBOL(drm_client_buffer_vunmap_local);
329
330/**
331 * drm_client_buffer_vmap - Map DRM client buffer into address space
332 * @buffer: DRM client buffer
333 * @map_copy: Returns the mapped memory's address
334 *
335 * This function maps a client buffer into kernel address space. If the
336 * buffer is already mapped, it returns the existing mapping's address.
337 *
338 * Client buffer mappings are not ref'counted. Each call to
339 * drm_client_buffer_vmap() should be followed by a call to
340 * drm_client_buffer_vunmap(); or the client buffer should be mapped
341 * throughout its lifetime.
342 *
343 * The returned address is a copy of the internal value. In contrast to
344 * other vmap interfaces, you don't need it for the client's vunmap
345 * function. So you can modify it at will during blit and draw operations.
346 *
347 * Returns:
348 * 0 on success, or a negative errno code otherwise.
349 */
350int drm_client_buffer_vmap(struct drm_client_buffer *buffer,
351 struct iosys_map *map_copy)
352{
353 struct drm_gem_object *gem = buffer->fb->obj[0];
354 int ret;
355
356 ret = drm_gem_vmap(gem, &buffer->map);
357 if (ret)
358 return ret;
359 *map_copy = buffer->map;
360
361 return 0;
362}
363EXPORT_SYMBOL(drm_client_buffer_vmap);
364
365/**
366 * drm_client_buffer_vunmap - Unmap DRM client buffer
367 * @buffer: DRM client buffer
368 *
369 * This function removes a client buffer's memory mapping. Calling this
370 * function is only required by clients that manage their buffer mappings
371 * by themselves.
372 */
373void drm_client_buffer_vunmap(struct drm_client_buffer *buffer)
374{
375 struct drm_gem_object *gem = buffer->fb->obj[0];
376
377 drm_gem_vunmap(gem, &buffer->map);
378}
379EXPORT_SYMBOL(drm_client_buffer_vunmap);
380
381/**
382 * drm_client_buffer_create_dumb - Create a client buffer backed by a dumb buffer
383 * @client: DRM client
384 * @width: Framebuffer width
385 * @height: Framebuffer height
386 * @format: Buffer format
387 *
388 * This function creates a &drm_client_buffer which consists of a
389 * &drm_framebuffer backed by a dumb buffer.
390 * Call drm_client_buffer_delete() to free the buffer.
391 *
392 * Returns:
393 * Pointer to a client buffer or an error pointer on failure.
394 */
395struct drm_client_buffer *
396drm_client_buffer_create_dumb(struct drm_client_dev *client, u32 width, u32 height, u32 format)
397{
398 const struct drm_format_info *info = drm_format_info(format);
399 struct drm_device *dev = client->dev;
400 struct drm_mode_create_dumb dumb_args = { };
401 struct drm_client_buffer *buffer;
402 int ret;
403
404 dumb_args.width = width;
405 dumb_args.height = height;
406 dumb_args.bpp = drm_format_info_bpp(info, 0);
407 ret = drm_mode_create_dumb(dev, &dumb_args, client->file);
408 if (ret)
409 return ERR_PTR(ret);
410
411 buffer = drm_client_buffer_create(client, width, height, format,
412 dumb_args.handle, dumb_args.pitch);
413 if (IS_ERR(buffer)) {
414 ret = PTR_ERR(buffer);
415 goto err_drm_mode_destroy_dumb;
416 }
417
418 /*
419 * The handle is only needed for creating the framebuffer, destroy it
420 * again to solve a circular dependency should anybody export the GEM
421 * object as DMA-buf. The framebuffer and our buffer structure are still
422 * holding references to the GEM object to prevent its destruction.
423 */
424 drm_mode_destroy_dumb(client->dev, dumb_args.handle, client->file);
425
426 return buffer;
427
428err_drm_mode_destroy_dumb:
429 drm_mode_destroy_dumb(client->dev, dumb_args.handle, client->file);
430 return ERR_PTR(ret);
431}
432EXPORT_SYMBOL(drm_client_buffer_create_dumb);
433
434/**
435 * drm_client_buffer_flush - Manually flush client buffer
436 * @buffer: DRM client buffer
437 * @rect: Damage rectangle (if NULL flushes all)
438 *
439 * This calls &drm_framebuffer_funcs->dirty (if present) to flush buffer changes
440 * for drivers that need it.
441 *
442 * Returns:
443 * Zero on success or negative error code on failure.
444 */
445int drm_client_buffer_flush(struct drm_client_buffer *buffer, struct drm_rect *rect)
446{
447 if (!buffer || !buffer->fb || !buffer->fb->funcs->dirty)
448 return 0;
449
450 if (rect) {
451 struct drm_clip_rect clip = {
452 .x1 = rect->x1,
453 .y1 = rect->y1,
454 .x2 = rect->x2,
455 .y2 = rect->y2,
456 };
457
458 return buffer->fb->funcs->dirty(buffer->fb, buffer->client->file,
459 0, 0, &clip, 1);
460 }
461
462 return buffer->fb->funcs->dirty(buffer->fb, buffer->client->file,
463 0, 0, NULL, 0);
464}
465EXPORT_SYMBOL(drm_client_buffer_flush);