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(minor: dev->primary);
42 if (IS_ERR(ptr: file))
43 return PTR_ERR(ptr: file);
44
45 mutex_lock(&dev->filelist_mutex);
46 list_add(new: &file->lhead, head: &dev->filelist_internal);
47 mutex_unlock(lock: &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(entry: &client->file->lhead);
60 mutex_unlock(lock: &dev->filelist_mutex);
61
62 drm_file_free(file: 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, feature: 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(new: &client->list, head: &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(lock: &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(obj: gem, map: &buffer->map);
195
196 ret = drm_mode_rmfb(dev: buffer->client->dev, fb_id: buffer->fb->base.id, file_priv: 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(obj: buffer->gem);
202
203 kfree(objp: buffer);
204}
205EXPORT_SYMBOL(drm_client_buffer_delete);
206
207static struct 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(sizeof(*buffer), GFP_KERNEL);
229 if (!buffer)
230 return ERR_PTR(error: -ENOMEM);
231
232 buffer->client = client;
233
234 obj = drm_gem_object_lookup(filp: client->file, handle);
235 if (!obj) {
236 ret = -ENOENT;
237 goto err_delete;
238 }
239
240 ret = drm_mode_addfb2(dev, data: &fb_req, file_priv: client->file);
241 if (ret)
242 goto err_drm_gem_object_put;
243
244 fb = drm_framebuffer_lookup(dev, file_priv: client->file, id: 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_id: fb_req.fb_id, file_priv: client->file);
262err_drm_gem_object_put:
263 drm_gem_object_put(obj);
264err_delete:
265 kfree(objp: buffer);
266 return ERR_PTR(error: ret);
267}
268
269/**
270 * drm_client_buffer_vmap_local - Map DRM client buffer into address space
271 * @buffer: DRM client buffer
272 * @map_copy: Returns the mapped memory's address
273 *
274 * This function maps a client buffer into kernel address space. If the
275 * buffer is already mapped, it returns the existing mapping's address.
276 *
277 * Client buffer mappings are not ref'counted. Each call to
278 * drm_client_buffer_vmap_local() should be closely followed by a call to
279 * drm_client_buffer_vunmap_local(). See drm_client_buffer_vmap() for
280 * long-term mappings.
281 *
282 * The returned address is a copy of the internal value. In contrast to
283 * other vmap interfaces, you don't need it for the client's vunmap
284 * function. So you can modify it at will during blit and draw operations.
285 *
286 * Returns:
287 * 0 on success, or a negative errno code otherwise.
288 */
289int drm_client_buffer_vmap_local(struct drm_client_buffer *buffer,
290 struct iosys_map *map_copy)
291{
292 struct drm_gem_object *gem = buffer->fb->obj[0];
293 struct iosys_map *map = &buffer->map;
294 int ret;
295
296 drm_gem_lock(obj: gem);
297
298 ret = drm_gem_vmap_locked(obj: gem, map);
299 if (ret)
300 goto err_drm_gem_vmap_unlocked;
301 *map_copy = *map;
302
303 return 0;
304
305err_drm_gem_vmap_unlocked:
306 drm_gem_unlock(obj: gem);
307 return ret;
308}
309EXPORT_SYMBOL(drm_client_buffer_vmap_local);
310
311/**
312 * drm_client_buffer_vunmap_local - Unmap DRM client buffer
313 * @buffer: DRM client buffer
314 *
315 * This function removes a client buffer's memory mapping established
316 * with drm_client_buffer_vunmap_local(). Calling this function is only
317 * required by clients that manage their buffer mappings by themselves.
318 */
319void drm_client_buffer_vunmap_local(struct drm_client_buffer *buffer)
320{
321 struct drm_gem_object *gem = buffer->fb->obj[0];
322 struct iosys_map *map = &buffer->map;
323
324 drm_gem_vunmap_locked(obj: gem, map);
325 drm_gem_unlock(obj: gem);
326}
327EXPORT_SYMBOL(drm_client_buffer_vunmap_local);
328
329/**
330 * drm_client_buffer_vmap - Map DRM client buffer into address space
331 * @buffer: DRM client buffer
332 * @map_copy: Returns the mapped memory's address
333 *
334 * This function maps a client buffer into kernel address space. If the
335 * buffer is already mapped, it returns the existing mapping's address.
336 *
337 * Client buffer mappings are not ref'counted. Each call to
338 * drm_client_buffer_vmap() should be followed by a call to
339 * drm_client_buffer_vunmap(); or the client buffer should be mapped
340 * throughout its lifetime.
341 *
342 * The returned address is a copy of the internal value. In contrast to
343 * other vmap interfaces, you don't need it for the client's vunmap
344 * function. So you can modify it at will during blit and draw operations.
345 *
346 * Returns:
347 * 0 on success, or a negative errno code otherwise.
348 */
349int drm_client_buffer_vmap(struct drm_client_buffer *buffer,
350 struct iosys_map *map_copy)
351{
352 struct drm_gem_object *gem = buffer->fb->obj[0];
353 int ret;
354
355 ret = drm_gem_vmap(obj: gem, map: &buffer->map);
356 if (ret)
357 return ret;
358 *map_copy = buffer->map;
359
360 return 0;
361}
362EXPORT_SYMBOL(drm_client_buffer_vmap);
363
364/**
365 * drm_client_buffer_vunmap - Unmap DRM client buffer
366 * @buffer: DRM client buffer
367 *
368 * This function removes a client buffer's memory mapping. Calling this
369 * function is only required by clients that manage their buffer mappings
370 * by themselves.
371 */
372void drm_client_buffer_vunmap(struct drm_client_buffer *buffer)
373{
374 struct drm_gem_object *gem = buffer->fb->obj[0];
375
376 drm_gem_vunmap(obj: gem, map: &buffer->map);
377}
378EXPORT_SYMBOL(drm_client_buffer_vunmap);
379
380/**
381 * drm_client_buffer_create_dumb - Create a client buffer backed by a dumb buffer
382 * @client: DRM client
383 * @width: Framebuffer width
384 * @height: Framebuffer height
385 * @format: Buffer format
386 *
387 * This function creates a &drm_client_buffer which consists of a
388 * &drm_framebuffer backed by a dumb buffer.
389 * Call drm_client_buffer_delete() to free the buffer.
390 *
391 * Returns:
392 * Pointer to a client buffer or an error pointer on failure.
393 */
394struct drm_client_buffer *
395drm_client_buffer_create_dumb(struct drm_client_dev *client, u32 width, u32 height, u32 format)
396{
397 const struct drm_format_info *info = drm_format_info(format);
398 struct drm_device *dev = client->dev;
399 struct drm_mode_create_dumb dumb_args = { };
400 struct drm_client_buffer *buffer;
401 int ret;
402
403 dumb_args.width = width;
404 dumb_args.height = height;
405 dumb_args.bpp = drm_format_info_bpp(info, plane: 0);
406 ret = drm_mode_create_dumb(dev, args: &dumb_args, file_priv: client->file);
407 if (ret)
408 return ERR_PTR(error: ret);
409
410 buffer = drm_client_buffer_create(client, width, height, format,
411 handle: dumb_args.handle, pitch: dumb_args.pitch);
412 if (IS_ERR(ptr: buffer)) {
413 ret = PTR_ERR(ptr: buffer);
414 goto err_drm_mode_destroy_dumb;
415 }
416
417 /*
418 * The handle is only needed for creating the framebuffer, destroy it
419 * again to solve a circular dependency should anybody export the GEM
420 * object as DMA-buf. The framebuffer and our buffer structure are still
421 * holding references to the GEM object to prevent its destruction.
422 */
423 drm_mode_destroy_dumb(dev: client->dev, handle: dumb_args.handle, file_priv: client->file);
424
425 return buffer;
426
427err_drm_mode_destroy_dumb:
428 drm_mode_destroy_dumb(dev: client->dev, handle: dumb_args.handle, file_priv: client->file);
429 return ERR_PTR(error: ret);
430}
431EXPORT_SYMBOL(drm_client_buffer_create_dumb);
432
433/**
434 * drm_client_buffer_flush - Manually flush client buffer
435 * @buffer: DRM client buffer
436 * @rect: Damage rectangle (if NULL flushes all)
437 *
438 * This calls &drm_framebuffer_funcs->dirty (if present) to flush buffer changes
439 * for drivers that need it.
440 *
441 * Returns:
442 * Zero on success or negative error code on failure.
443 */
444int drm_client_buffer_flush(struct drm_client_buffer *buffer, struct drm_rect *rect)
445{
446 if (!buffer || !buffer->fb || !buffer->fb->funcs->dirty)
447 return 0;
448
449 if (rect) {
450 struct drm_clip_rect clip = {
451 .x1 = rect->x1,
452 .y1 = rect->y1,
453 .x2 = rect->x2,
454 .y2 = rect->y2,
455 };
456
457 return buffer->fb->funcs->dirty(buffer->fb, buffer->client->file,
458 0, 0, &clip, 1);
459 }
460
461 return buffer->fb->funcs->dirty(buffer->fb, buffer->client->file,
462 0, 0, NULL, 0);
463}
464EXPORT_SYMBOL(drm_client_buffer_flush);
465

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