summaryrefslogtreecommitdiff
path: root/drivers/gpu/drm/drm_client.c
blob: c3027115d05527e30b04a8ca83fed1553004166b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
// SPDX-License-Identifier: GPL-2.0 or MIT
/*
 * Copyright 2018 Noralf Trønnes
 */

#include <linux/iosys-map.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/seq_file.h>
#include <linux/slab.h>

#include <drm/drm_client.h>
#include <drm/drm_debugfs.h>
#include <drm/drm_device.h>
#include <drm/drm_drv.h>
#include <drm/drm_file.h>
#include <drm/drm_fourcc.h>
#include <drm/drm_framebuffer.h>
#include <drm/drm_gem.h>
#include <drm/drm_mode.h>
#include <drm/drm_print.h>

#include "drm_crtc_internal.h"
#include "drm_internal.h"

/**
 * DOC: overview
 *
 * This library provides support for clients running in the kernel like fbdev and bootsplash.
 *
 * GEM drivers which provide a GEM based dumb buffer with a virtual address are supported.
 */

static int drm_client_open(struct drm_client_dev *client)
{
	struct drm_device *dev = client->dev;
	struct drm_file *file;

	file = drm_file_alloc(dev->primary);
	if (IS_ERR(file))
		return PTR_ERR(file);

	mutex_lock(&dev->filelist_mutex);
	list_add(&file->lhead, &dev->filelist_internal);
	mutex_unlock(&dev->filelist_mutex);

	client->file = file;

	return 0;
}

static void drm_client_close(struct drm_client_dev *client)
{
	struct drm_device *dev = client->dev;

	mutex_lock(&dev->filelist_mutex);
	list_del(&client->file->lhead);
	mutex_unlock(&dev->filelist_mutex);

	drm_file_free(client->file);
}

/**
 * drm_client_init - Initialise a DRM client
 * @dev: DRM device
 * @client: DRM client
 * @name: Client name
 * @funcs: DRM client functions (optional)
 *
 * This initialises the client and opens a &drm_file.
 * Use drm_client_register() to complete the process.
 * The caller needs to hold a reference on @dev before calling this function.
 * The client is freed when the &drm_device is unregistered. See drm_client_release().
 *
 * Returns:
 * Zero on success or negative error code on failure.
 */
int drm_client_init(struct drm_device *dev, struct drm_client_dev *client,
		    const char *name, const struct drm_client_funcs *funcs)
{
	int ret;

	if (!drm_core_check_feature(dev, DRIVER_MODESET) || !dev->driver->dumb_create)
		return -EOPNOTSUPP;

	if (funcs && !try_module_get(funcs->owner))
		return -ENODEV;

	client->dev = dev;
	client->name = name;
	client->funcs = funcs;

	ret = drm_client_modeset_create(client);
	if (ret)
		goto err_put_module;

	ret = drm_client_open(client);
	if (ret)
		goto err_free;

	drm_dev_get(dev);

	return 0;

err_free:
	drm_client_modeset_free(client);
err_put_module:
	if (funcs)
		module_put(funcs->owner);

	return ret;
}
EXPORT_SYMBOL(drm_client_init);

/**
 * drm_client_register - Register client
 * @client: DRM client
 *
 * Add the client to the &drm_device client list to activate its callbacks.
 * @client must be initialized by a call to drm_client_init(). After
 * drm_client_register() it is no longer permissible to call drm_client_release()
 * directly (outside the unregister callback), instead cleanup will happen
 * automatically on driver unload.
 *
 * Registering a client generates a hotplug event that allows the client
 * to set up its display from pre-existing outputs. The client must have
 * initialized its state to able to handle the hotplug event successfully.
 */
void drm_client_register(struct drm_client_dev *client)
{
	struct drm_device *dev = client->dev;
	int ret;

	mutex_lock(&dev->clientlist_mutex);
	list_add(&client->list, &dev->clientlist);

	if (client->funcs && client->funcs->hotplug) {
		/*
		 * Perform an initial hotplug event to pick up the
		 * display configuration for the client. This step
		 * has to be performed *after* registering the client
		 * in the list of clients, or a concurrent hotplug
		 * event might be lost; leaving the display off.
		 *
		 * Hold the clientlist_mutex as for a regular hotplug
		 * event.
		 */
		ret = client->funcs->hotplug(client);
		if (ret)
			drm_dbg_kms(dev, "client hotplug ret=%d\n", ret);
	}
	mutex_unlock(&dev->clientlist_mutex);
}
EXPORT_SYMBOL(drm_client_register);

/**
 * drm_client_release - Release DRM client resources
 * @client: DRM client
 *
 * Releases resources by closing the &drm_file that was opened by drm_client_init().
 * It is called automatically if the &drm_client_funcs.unregister callback is _not_ set.
 *
 * This function should only be called from the unregister callback. An exception
 * is fbdev which cannot free the buffer if userspace has open file descriptors.
 *
 * Note:
 * Clients cannot initiate a release by themselves. This is done to keep the code simple.
 * The driver has to be unloaded before the client can be unloaded.
 */
void drm_client_release(struct drm_client_dev *client)
{
	struct drm_device *dev = client->dev;

	drm_dbg_kms(dev, "%s\n", client->name);

	drm_client_modeset_free(client);
	drm_client_close(client);
	drm_dev_put(dev);
	if (client->funcs)
		module_put(client->funcs->owner);
}
EXPORT_SYMBOL(drm_client_release);

void drm_client_dev_unregister(struct drm_device *dev)
{
	struct drm_client_dev *client, *tmp;

	if (!drm_core_check_feature(dev, DRIVER_MODESET))
		return;

	mutex_lock(&dev->clientlist_mutex);
	list_for_each_entry_safe(client, tmp, &dev->clientlist, list) {
		list_del(&client->list);
		if (client->funcs && client->funcs->unregister) {
			client->funcs->unregister(client);
		} else {
			drm_client_release(client);
			kfree(client);
		}
	}
	mutex_unlock(&dev->clientlist_mutex);
}

/**
 * drm_client_dev_hotplug - Send hotplug event to clients
 * @dev: DRM device
 *
 * This function calls the &drm_client_funcs.hotplug callback on the attached clients.
 *
 * drm_kms_helper_hotplug_event() calls this function, so drivers that use it
 * don't need to call this function themselves.
 */
void drm_client_dev_hotplug(struct drm_device *dev)
{
	struct drm_client_dev *client;
	int ret;

	if (!drm_core_check_feature(dev, DRIVER_MODESET))
		return;

	if (!dev->mode_config.num_connector) {
		drm_dbg_kms(dev, "No connectors found, will not send hotplug events!\n");
		return;
	}

	mutex_lock(&dev->clientlist_mutex);
	list_for_each_entry(client, &dev->clientlist, list) {
		if (!client->funcs || !client->funcs->hotplug)
			continue;

		if (client->hotplug_failed)
			continue;

		ret = client->funcs->hotplug(client);
		drm_dbg_kms(dev, "%s: ret=%d\n", client->name, ret);
		if (ret)
			client->hotplug_failed = true;
	}
	mutex_unlock(&dev->clientlist_mutex);
}
EXPORT_SYMBOL(drm_client_dev_hotplug);

void drm_client_dev_restore(struct drm_device *dev)
{
	struct drm_client_dev *client;
	int ret;

	if (!drm_core_check_feature(dev, DRIVER_MODESET))
		return;

	mutex_lock(&dev->clientlist_mutex);
	list_for_each_entry(client, &dev->clientlist, list) {
		if (!client->funcs || !client->funcs->restore)
			continue;

		ret = client->funcs->restore(client);
		drm_dbg_kms(dev, "%s: ret=%d\n", client->name, ret);
		if (!ret) /* The first one to return zero gets the privilege to restore */
			break;
	}
	mutex_unlock(&dev->clientlist_mutex);
}

static void drm_client_buffer_delete(struct drm_client_buffer *buffer)
{
	if (buffer->gem) {
		drm_gem_vunmap_unlocked(buffer->gem, &buffer->map);
		drm_gem_object_put(buffer->gem);
	}

	kfree(buffer);
}

static struct drm_client_buffer *
drm_client_buffer_create(struct drm_client_dev *client, u32 width, u32 height,
			 u32 format, u32 *handle)
{
	const struct drm_format_info *info = drm_format_info(format);
	struct drm_mode_create_dumb dumb_args = { };
	struct drm_device *dev = client->dev;
	struct drm_client_buffer *buffer;
	struct drm_gem_object *obj;
	int ret;

	buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
	if (!buffer)
		return ERR_PTR(-ENOMEM);

	buffer->client = client;

	dumb_args.width = width;
	dumb_args.height = height;
	dumb_args.bpp = drm_format_info_bpp(info, 0);
	ret = drm_mode_create_dumb(dev, &dumb_args, client->file);
	if (ret)
		goto err_delete;

	obj = drm_gem_object_lookup(client->file, dumb_args.handle);
	if (!obj)  {
		ret = -ENOENT;
		goto err_delete;
	}

	buffer->pitch = dumb_args.pitch;
	buffer->gem = obj;
	*handle = dumb_args.handle;

	return buffer;

err_delete:
	drm_client_buffer_delete(buffer);

	return ERR_PTR(ret);
}

/**
 * drm_client_buffer_vmap - Map DRM client buffer into address space
 * @buffer: DRM client buffer
 * @map_copy: Returns the mapped memory's address
 *
 * This function maps a client buffer into kernel address space. If the
 * buffer is already mapped, it returns the existing mapping's address.
 *
 * Client buffer mappings are not ref'counted. Each call to
 * drm_client_buffer_vmap() should be followed by a call to
 * drm_client_buffer_vunmap(); or the client buffer should be mapped
 * throughout its lifetime.
 *
 * The returned address is a copy of the internal value. In contrast to
 * other vmap interfaces, you don't need it for the client's vunmap
 * function. So you can modify it at will during blit and draw operations.
 *
 * Returns:
 *	0 on success, or a negative errno code otherwise.
 */
int
drm_client_buffer_vmap(struct drm_client_buffer *buffer,
		       struct iosys_map *map_copy)
{
	struct iosys_map *map = &buffer->map;
	int ret;

	/*
	 * FIXME: The dependency on GEM here isn't required, we could
	 * convert the driver handle to a dma-buf instead and use the
	 * backend-agnostic dma-buf vmap support instead. This would
	 * require that the handle2fd prime ioctl is reworked to pull the
	 * fd_install step out of the driver backend hooks, to make that
	 * final step optional for internal users.
	 */
	ret = drm_gem_vmap_unlocked(buffer->gem, map);
	if (ret)
		return ret;

	*map_copy = *map;

	return 0;
}
EXPORT_SYMBOL(drm_client_buffer_vmap);

/**
 * drm_client_buffer_vunmap - Unmap DRM client buffer
 * @buffer: DRM client buffer
 *
 * This function removes a client buffer's memory mapping. Calling this
 * function is only required by clients that manage their buffer mappings
 * by themselves.
 */
void drm_client_buffer_vunmap(struct drm_client_buffer *buffer)
{
	struct iosys_map *map = &buffer->map;

	drm_gem_vunmap_unlocked(buffer->gem, map);
}
EXPORT_SYMBOL(drm_client_buffer_vunmap);

static void drm_client_buffer_rmfb(struct drm_client_buffer *buffer)
{
	int ret;

	if (!buffer->fb)
		return;

	ret = drm_mode_rmfb(buffer->client->dev, buffer->fb->base.id, buffer->client->file);
	if (ret)
		drm_err(buffer->client->dev,
			"Error removing FB:%u (%d)\n", buffer->fb->base.id, ret);

	buffer->fb = NULL;
}

static int drm_client_buffer_addfb(struct drm_client_buffer *buffer,
				   u32 width, u32 height, u32 format,
				   u32 handle)
{
	struct drm_client_dev *client = buffer->client;
	struct drm_mode_fb_cmd2 fb_req = { };
	int ret;

	fb_req.width = width;
	fb_req.height = height;
	fb_req.pixel_format = format;
	fb_req.handles[0] = handle;
	fb_req.pitches[0] = buffer->pitch;

	ret = drm_mode_addfb2(client->dev, &fb_req, client->file);
	if (ret)
		return ret;

	buffer->fb = drm_framebuffer_lookup(client->dev, buffer->client->file, fb_req.fb_id);
	if (WARN_ON(!buffer->fb))
		return -ENOENT;

	/* drop the reference we picked up in framebuffer lookup */
	drm_framebuffer_put(buffer->fb);

	strscpy(buffer->fb->comm, client->name, TASK_COMM_LEN);

	return 0;
}

/**
 * drm_client_framebuffer_create - Create a client framebuffer
 * @client: DRM client
 * @width: Framebuffer width
 * @height: Framebuffer height
 * @format: Buffer format
 *
 * This function creates a &drm_client_buffer which consists of a
 * &drm_framebuffer backed by a dumb buffer.
 * Call drm_client_framebuffer_delete() to free the buffer.
 *
 * Returns:
 * Pointer to a client buffer or an error pointer on failure.
 */
struct drm_client_buffer *
drm_client_framebuffer_create(struct drm_client_dev *client, u32 width, u32 height, u32 format)
{
	struct drm_client_buffer *buffer;
	u32 handle;
	int ret;

	buffer = drm_client_buffer_create(client, width, height, format,
					  &handle);
	if (IS_ERR(buffer))
		return buffer;

	ret = drm_client_buffer_addfb(buffer, width, height, format, handle);

	/*
	 * The handle is only needed for creating the framebuffer, destroy it
	 * again to solve a circular dependency should anybody export the GEM
	 * object as DMA-buf. The framebuffer and our buffer structure are still
	 * holding references to the GEM object to prevent its destruction.
	 */
	drm_mode_destroy_dumb(client->dev, handle, client->file);

	if (ret) {
		drm_client_buffer_delete(buffer);
		return ERR_PTR(ret);
	}

	return buffer;
}
EXPORT_SYMBOL(drm_client_framebuffer_create);

/**
 * drm_client_framebuffer_delete - Delete a client framebuffer
 * @buffer: DRM client buffer (can be NULL)
 */
void drm_client_framebuffer_delete(struct drm_client_buffer *buffer)
{
	if (!buffer)
		return;

	drm_client_buffer_rmfb(buffer);
	drm_client_buffer_delete(buffer);
}
EXPORT_SYMBOL(drm_client_framebuffer_delete);

/**
 * drm_client_framebuffer_flush - Manually flush client framebuffer
 * @buffer: DRM client buffer (can be NULL)
 * @rect: Damage rectangle (if NULL flushes all)
 *
 * This calls &drm_framebuffer_funcs->dirty (if present) to flush buffer changes
 * for drivers that need it.
 *
 * Returns:
 * Zero on success or negative error code on failure.
 */
int drm_client_framebuffer_flush(struct drm_client_buffer *buffer, struct drm_rect *rect)
{
	if (!buffer || !buffer->fb || !buffer->fb->funcs->dirty)
		return 0;

	if (rect) {
		struct drm_clip_rect clip = {
			.x1 = rect->x1,
			.y1 = rect->y1,
			.x2 = rect->x2,
			.y2 = rect->y2,
		};

		return buffer->fb->funcs->dirty(buffer->fb, buffer->client->file,
						0, 0, &clip, 1);
	}

	return buffer->fb->funcs->dirty(buffer->fb, buffer->client->file,
					0, 0, NULL, 0);
}
EXPORT_SYMBOL(drm_client_framebuffer_flush);

#ifdef CONFIG_DEBUG_FS
static int drm_client_debugfs_internal_clients(struct seq_file *m, void *data)
{
	struct drm_debugfs_entry *entry = m->private;
	struct drm_device *dev = entry->dev;
	struct drm_printer p = drm_seq_file_printer(m);
	struct drm_client_dev *client;

	mutex_lock(&dev->clientlist_mutex);
	list_for_each_entry(client, &dev->clientlist, list)
		drm_printf(&p, "%s\n", client->name);
	mutex_unlock(&dev->clientlist_mutex);

	return 0;
}

static const struct drm_debugfs_info drm_client_debugfs_list[] = {
	{ "internal_clients", drm_client_debugfs_internal_clients, 0 },
};

void drm_client_debugfs_init(struct drm_device *dev)
{
	drm_debugfs_add_files(dev, drm_client_debugfs_list,
			      ARRAY_SIZE(drm_client_debugfs_list));
}
#endif