summaryrefslogtreecommitdiff
path: root/drivers/gpu/drm/drm_atomic_state_helper.c
blob: 3b6d3bdbd099680f4eb322ebcdb78f3ba1a0dfcb (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
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
/*
 * Copyright (C) 2018 Intel Corp.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 *
 * Authors:
 * Rob Clark <robdclark@gmail.com>
 * Daniel Vetter <daniel.vetter@ffwll.ch>
 */

#include <drm/drm_atomic.h>
#include <drm/drm_atomic_state_helper.h>
#include <drm/drm_bridge.h>
#include <drm/drm_connector.h>
#include <drm/drm_crtc.h>
#include <drm/drm_device.h>
#include <drm/drm_plane.h>
#include <drm/drm_print.h>
#include <drm/drm_vblank.h>
#include <drm/drm_writeback.h>

#include <linux/slab.h>
#include <linux/dma-fence.h>

/**
 * DOC: atomic state reset and initialization
 *
 * Both the drm core and the atomic helpers assume that there is always the full
 * and correct atomic software state for all connectors, CRTCs and planes
 * available. Which is a bit a problem on driver load and also after system
 * suspend. One way to solve this is to have a hardware state read-out
 * infrastructure which reconstructs the full software state (e.g. the i915
 * driver).
 *
 * The simpler solution is to just reset the software state to everything off,
 * which is easiest to do by calling drm_mode_config_reset(). To facilitate this
 * the atomic helpers provide default reset implementations for all hooks.
 *
 * On the upside the precise state tracking of atomic simplifies system suspend
 * and resume a lot. For drivers using drm_mode_config_reset() a complete recipe
 * is implemented in drm_atomic_helper_suspend() and drm_atomic_helper_resume().
 * For other drivers the building blocks are split out, see the documentation
 * for these functions.
 */

/**
 * __drm_atomic_helper_crtc_state_reset - reset the CRTC state
 * @crtc_state: atomic CRTC state, must not be NULL
 * @crtc: CRTC object, must not be NULL
 *
 * Initializes the newly allocated @crtc_state with default
 * values. This is useful for drivers that subclass the CRTC state.
 */
void
__drm_atomic_helper_crtc_state_reset(struct drm_crtc_state *crtc_state,
				     struct drm_crtc *crtc)
{
	crtc_state->crtc = crtc;
}
EXPORT_SYMBOL(__drm_atomic_helper_crtc_state_reset);

/**
 * __drm_atomic_helper_crtc_reset - reset state on CRTC
 * @crtc: drm CRTC
 * @crtc_state: CRTC state to assign
 *
 * Initializes the newly allocated @crtc_state and assigns it to
 * the &drm_crtc->state pointer of @crtc, usually required when
 * initializing the drivers or when called from the &drm_crtc_funcs.reset
 * hook.
 *
 * This is useful for drivers that subclass the CRTC state.
 */
void
__drm_atomic_helper_crtc_reset(struct drm_crtc *crtc,
			       struct drm_crtc_state *crtc_state)
{
	if (crtc_state)
		__drm_atomic_helper_crtc_state_reset(crtc_state, crtc);

	if (drm_dev_has_vblank(crtc->dev))
		drm_crtc_vblank_reset(crtc);

	crtc->state = crtc_state;
}
EXPORT_SYMBOL(__drm_atomic_helper_crtc_reset);

/**
 * drm_atomic_helper_crtc_reset - default &drm_crtc_funcs.reset hook for CRTCs
 * @crtc: drm CRTC
 *
 * Resets the atomic state for @crtc by freeing the state pointer (which might
 * be NULL, e.g. at driver load time) and allocating a new empty state object.
 */
void drm_atomic_helper_crtc_reset(struct drm_crtc *crtc)
{
	struct drm_crtc_state *crtc_state =
		kzalloc(sizeof(*crtc->state), GFP_KERNEL);

	if (crtc->state)
		crtc->funcs->atomic_destroy_state(crtc, crtc->state);

	__drm_atomic_helper_crtc_reset(crtc, crtc_state);
}
EXPORT_SYMBOL(drm_atomic_helper_crtc_reset);

/**
 * __drm_atomic_helper_crtc_duplicate_state - copy atomic CRTC state
 * @crtc: CRTC object
 * @state: atomic CRTC state
 *
 * Copies atomic state from a CRTC's current state and resets inferred values.
 * This is useful for drivers that subclass the CRTC state.
 */
void __drm_atomic_helper_crtc_duplicate_state(struct drm_crtc *crtc,
					      struct drm_crtc_state *state)
{
	memcpy(state, crtc->state, sizeof(*state));

	if (state->mode_blob)
		drm_property_blob_get(state->mode_blob);
	if (state->degamma_lut)
		drm_property_blob_get(state->degamma_lut);
	if (state->ctm)
		drm_property_blob_get(state->ctm);
	if (state->gamma_lut)
		drm_property_blob_get(state->gamma_lut);
	state->mode_changed = false;
	state->active_changed = false;
	state->planes_changed = false;
	state->connectors_changed = false;
	state->color_mgmt_changed = false;
	state->zpos_changed = false;
	state->commit = NULL;
	state->event = NULL;
	state->async_flip = false;

	/* Self refresh should be canceled when a new update is available */
	state->active = drm_atomic_crtc_effectively_active(state);
	state->self_refresh_active = false;
}
EXPORT_SYMBOL(__drm_atomic_helper_crtc_duplicate_state);

/**
 * drm_atomic_helper_crtc_duplicate_state - default state duplicate hook
 * @crtc: drm CRTC
 *
 * Default CRTC state duplicate hook for drivers which don't have their own
 * subclassed CRTC state structure.
 */
struct drm_crtc_state *
drm_atomic_helper_crtc_duplicate_state(struct drm_crtc *crtc)
{
	struct drm_crtc_state *state;

	if (WARN_ON(!crtc->state))
		return NULL;

	state = kmalloc(sizeof(*state), GFP_KERNEL);
	if (state)
		__drm_atomic_helper_crtc_duplicate_state(crtc, state);

	return state;
}
EXPORT_SYMBOL(drm_atomic_helper_crtc_duplicate_state);

/**
 * __drm_atomic_helper_crtc_destroy_state - release CRTC state
 * @state: CRTC state object to release
 *
 * Releases all resources stored in the CRTC state without actually freeing
 * the memory of the CRTC state. This is useful for drivers that subclass the
 * CRTC state.
 */
void __drm_atomic_helper_crtc_destroy_state(struct drm_crtc_state *state)
{
	if (state->commit) {
		/*
		 * In the event that a non-blocking commit returns
		 * -ERESTARTSYS before the commit_tail work is queued, we will
		 * have an extra reference to the commit object. Release it, if
		 * the event has not been consumed by the worker.
		 *
		 * state->event may be freed, so we can't directly look at
		 * state->event->base.completion.
		 */
		if (state->event && state->commit->abort_completion)
			drm_crtc_commit_put(state->commit);

		kfree(state->commit->event);
		state->commit->event = NULL;

		drm_crtc_commit_put(state->commit);
	}

	drm_property_blob_put(state->mode_blob);
	drm_property_blob_put(state->degamma_lut);
	drm_property_blob_put(state->ctm);
	drm_property_blob_put(state->gamma_lut);
}
EXPORT_SYMBOL(__drm_atomic_helper_crtc_destroy_state);

/**
 * drm_atomic_helper_crtc_destroy_state - default state destroy hook
 * @crtc: drm CRTC
 * @state: CRTC state object to release
 *
 * Default CRTC state destroy hook for drivers which don't have their own
 * subclassed CRTC state structure.
 */
void drm_atomic_helper_crtc_destroy_state(struct drm_crtc *crtc,
					  struct drm_crtc_state *state)
{
	__drm_atomic_helper_crtc_destroy_state(state);
	kfree(state);
}
EXPORT_SYMBOL(drm_atomic_helper_crtc_destroy_state);

/**
 * __drm_atomic_helper_plane_state_reset - resets plane state to default values
 * @plane_state: atomic plane state, must not be NULL
 * @plane: plane object, must not be NULL
 *
 * Initializes the newly allocated @plane_state with default
 * values. This is useful for drivers that subclass the CRTC state.
 */
void __drm_atomic_helper_plane_state_reset(struct drm_plane_state *plane_state,
					   struct drm_plane *plane)
{
	u64 val;

	plane_state->plane = plane;
	plane_state->rotation = DRM_MODE_ROTATE_0;

	plane_state->alpha = DRM_BLEND_ALPHA_OPAQUE;
	plane_state->pixel_blend_mode = DRM_MODE_BLEND_PREMULTI;

	if (plane->color_encoding_property) {
		if (!drm_object_property_get_default_value(&plane->base,
							   plane->color_encoding_property,
							   &val))
			plane_state->color_encoding = val;
	}

	if (plane->color_range_property) {
		if (!drm_object_property_get_default_value(&plane->base,
							   plane->color_range_property,
							   &val))
			plane_state->color_range = val;
	}

	if (plane->zpos_property) {
		if (!drm_object_property_get_default_value(&plane->base,
							   plane->zpos_property,
							   &val)) {
			plane_state->zpos = val;
			plane_state->normalized_zpos = val;
		}
	}
}
EXPORT_SYMBOL(__drm_atomic_helper_plane_state_reset);

/**
 * __drm_atomic_helper_plane_reset - reset state on plane
 * @plane: drm plane
 * @plane_state: plane state to assign
 *
 * Initializes the newly allocated @plane_state and assigns it to
 * the &drm_crtc->state pointer of @plane, usually required when
 * initializing the drivers or when called from the &drm_plane_funcs.reset
 * hook.
 *
 * This is useful for drivers that subclass the plane state.
 */
void __drm_atomic_helper_plane_reset(struct drm_plane *plane,
				     struct drm_plane_state *plane_state)
{
	if (plane_state)
		__drm_atomic_helper_plane_state_reset(plane_state, plane);

	plane->state = plane_state;
}
EXPORT_SYMBOL(__drm_atomic_helper_plane_reset);

/**
 * drm_atomic_helper_plane_reset - default &drm_plane_funcs.reset hook for planes
 * @plane: drm plane
 *
 * Resets the atomic state for @plane by freeing the state pointer (which might
 * be NULL, e.g. at driver load time) and allocating a new empty state object.
 */
void drm_atomic_helper_plane_reset(struct drm_plane *plane)
{
	if (plane->state)
		__drm_atomic_helper_plane_destroy_state(plane->state);

	kfree(plane->state);
	plane->state = kzalloc(sizeof(*plane->state), GFP_KERNEL);
	if (plane->state)
		__drm_atomic_helper_plane_reset(plane, plane->state);
}
EXPORT_SYMBOL(drm_atomic_helper_plane_reset);

/**
 * __drm_atomic_helper_plane_duplicate_state - copy atomic plane state
 * @plane: plane object
 * @state: atomic plane state
 *
 * Copies atomic state from a plane's current state. This is useful for
 * drivers that subclass the plane state.
 */
void __drm_atomic_helper_plane_duplicate_state(struct drm_plane *plane,
					       struct drm_plane_state *state)
{
	memcpy(state, plane->state, sizeof(*state));

	if (state->fb)
		drm_framebuffer_get(state->fb);

	state->fence = NULL;
	state->commit = NULL;
	state->fb_damage_clips = NULL;
}
EXPORT_SYMBOL(__drm_atomic_helper_plane_duplicate_state);

/**
 * drm_atomic_helper_plane_duplicate_state - default state duplicate hook
 * @plane: drm plane
 *
 * Default plane state duplicate hook for drivers which don't have their own
 * subclassed plane state structure.
 */
struct drm_plane_state *
drm_atomic_helper_plane_duplicate_state(struct drm_plane *plane)
{
	struct drm_plane_state *state;

	if (WARN_ON(!plane->state))
		return NULL;

	state = kmalloc(sizeof(*state), GFP_KERNEL);
	if (state)
		__drm_atomic_helper_plane_duplicate_state(plane, state);

	return state;
}
EXPORT_SYMBOL(drm_atomic_helper_plane_duplicate_state);

/**
 * __drm_atomic_helper_plane_destroy_state - release plane state
 * @state: plane state object to release
 *
 * Releases all resources stored in the plane state without actually freeing
 * the memory of the plane state. This is useful for drivers that subclass the
 * plane state.
 */
void __drm_atomic_helper_plane_destroy_state(struct drm_plane_state *state)
{
	if (state->fb)
		drm_framebuffer_put(state->fb);

	if (state->fence)
		dma_fence_put(state->fence);

	if (state->commit)
		drm_crtc_commit_put(state->commit);

	drm_property_blob_put(state->fb_damage_clips);
}
EXPORT_SYMBOL(__drm_atomic_helper_plane_destroy_state);

/**
 * drm_atomic_helper_plane_destroy_state - default state destroy hook
 * @plane: drm plane
 * @state: plane state object to release
 *
 * Default plane state destroy hook for drivers which don't have their own
 * subclassed plane state structure.
 */
void drm_atomic_helper_plane_destroy_state(struct drm_plane *plane,
					   struct drm_plane_state *state)
{
	__drm_atomic_helper_plane_destroy_state(state);
	kfree(state);
}
EXPORT_SYMBOL(drm_atomic_helper_plane_destroy_state);

/**
 * __drm_atomic_helper_connector_state_reset - reset the connector state
 * @conn_state: atomic connector state, must not be NULL
 * @connector: connectotr object, must not be NULL
 *
 * Initializes the newly allocated @conn_state with default
 * values. This is useful for drivers that subclass the connector state.
 */
void
__drm_atomic_helper_connector_state_reset(struct drm_connector_state *conn_state,
					  struct drm_connector *connector)
{
	conn_state->connector = connector;
}
EXPORT_SYMBOL(__drm_atomic_helper_connector_state_reset);

/**
 * __drm_atomic_helper_connector_reset - reset state on connector
 * @connector: drm connector
 * @conn_state: connector state to assign
 *
 * Initializes the newly allocated @conn_state and assigns it to
 * the &drm_connector->state pointer of @connector, usually required when
 * initializing the drivers or when called from the &drm_connector_funcs.reset
 * hook.
 *
 * This is useful for drivers that subclass the connector state.
 */
void
__drm_atomic_helper_connector_reset(struct drm_connector *connector,
				    struct drm_connector_state *conn_state)
{
	if (conn_state)
		__drm_atomic_helper_connector_state_reset(conn_state, connector);

	connector->state = conn_state;
}
EXPORT_SYMBOL(__drm_atomic_helper_connector_reset);

/**
 * drm_atomic_helper_connector_reset - default &drm_connector_funcs.reset hook for connectors
 * @connector: drm connector
 *
 * Resets the atomic state for @connector by freeing the state pointer (which
 * might be NULL, e.g. at driver load time) and allocating a new empty state
 * object.
 */
void drm_atomic_helper_connector_reset(struct drm_connector *connector)
{
	struct drm_connector_state *conn_state =
		kzalloc(sizeof(*conn_state), GFP_KERNEL);

	if (connector->state)
		__drm_atomic_helper_connector_destroy_state(connector->state);

	kfree(connector->state);
	__drm_atomic_helper_connector_reset(connector, conn_state);
}
EXPORT_SYMBOL(drm_atomic_helper_connector_reset);

/**
 * drm_atomic_helper_connector_tv_reset - Resets TV connector properties
 * @connector: DRM connector
 *
 * Resets the TV-related properties attached to a connector.
 */
void drm_atomic_helper_connector_tv_reset(struct drm_connector *connector)
{
	struct drm_cmdline_mode *cmdline = &connector->cmdline_mode;
	struct drm_connector_state *state = connector->state;

	state->tv.margins.left = cmdline->tv_margins.left;
	state->tv.margins.right = cmdline->tv_margins.right;
	state->tv.margins.top = cmdline->tv_margins.top;
	state->tv.margins.bottom = cmdline->tv_margins.bottom;
}
EXPORT_SYMBOL(drm_atomic_helper_connector_tv_reset);

/**
 * __drm_atomic_helper_connector_duplicate_state - copy atomic connector state
 * @connector: connector object
 * @state: atomic connector state
 *
 * Copies atomic state from a connector's current state. This is useful for
 * drivers that subclass the connector state.
 */
void
__drm_atomic_helper_connector_duplicate_state(struct drm_connector *connector,
					    struct drm_connector_state *state)
{
	memcpy(state, connector->state, sizeof(*state));
	if (state->crtc)
		drm_connector_get(connector);
	state->commit = NULL;

	if (state->hdr_output_metadata)
		drm_property_blob_get(state->hdr_output_metadata);

	/* Don't copy over a writeback job, they are used only once */
	state->writeback_job = NULL;
}
EXPORT_SYMBOL(__drm_atomic_helper_connector_duplicate_state);

/**
 * drm_atomic_helper_connector_duplicate_state - default state duplicate hook
 * @connector: drm connector
 *
 * Default connector state duplicate hook for drivers which don't have their own
 * subclassed connector state structure.
 */
struct drm_connector_state *
drm_atomic_helper_connector_duplicate_state(struct drm_connector *connector)
{
	struct drm_connector_state *state;

	if (WARN_ON(!connector->state))
		return NULL;

	state = kmalloc(sizeof(*state), GFP_KERNEL);
	if (state)
		__drm_atomic_helper_connector_duplicate_state(connector, state);

	return state;
}
EXPORT_SYMBOL(drm_atomic_helper_connector_duplicate_state);

/**
 * __drm_atomic_helper_connector_destroy_state - release connector state
 * @state: connector state object to release
 *
 * Releases all resources stored in the connector state without actually
 * freeing the memory of the connector state. This is useful for drivers that
 * subclass the connector state.
 */
void
__drm_atomic_helper_connector_destroy_state(struct drm_connector_state *state)
{
	if (state->crtc)
		drm_connector_put(state->connector);

	if (state->commit)
		drm_crtc_commit_put(state->commit);

	if (state->writeback_job)
		drm_writeback_cleanup_job(state->writeback_job);

	drm_property_blob_put(state->hdr_output_metadata);
}
EXPORT_SYMBOL(__drm_atomic_helper_connector_destroy_state);

/**
 * drm_atomic_helper_connector_destroy_state - default state destroy hook
 * @connector: drm connector
 * @state: connector state object to release
 *
 * Default connector state destroy hook for drivers which don't have their own
 * subclassed connector state structure.
 */
void drm_atomic_helper_connector_destroy_state(struct drm_connector *connector,
					  struct drm_connector_state *state)
{
	__drm_atomic_helper_connector_destroy_state(state);
	kfree(state);
}
EXPORT_SYMBOL(drm_atomic_helper_connector_destroy_state);

/**
 * __drm_atomic_helper_private_obj_duplicate_state - copy atomic private state
 * @obj: CRTC object
 * @state: new private object state
 *
 * Copies atomic state from a private objects's current state and resets inferred values.
 * This is useful for drivers that subclass the private state.
 */
void __drm_atomic_helper_private_obj_duplicate_state(struct drm_private_obj *obj,
						     struct drm_private_state *state)
{
	memcpy(state, obj->state, sizeof(*state));
}
EXPORT_SYMBOL(__drm_atomic_helper_private_obj_duplicate_state);

/**
 * __drm_atomic_helper_bridge_duplicate_state() - Copy atomic bridge state
 * @bridge: bridge object
 * @state: atomic bridge state
 *
 * Copies atomic state from a bridge's current state and resets inferred values.
 * This is useful for drivers that subclass the bridge state.
 */
void __drm_atomic_helper_bridge_duplicate_state(struct drm_bridge *bridge,
						struct drm_bridge_state *state)
{
	__drm_atomic_helper_private_obj_duplicate_state(&bridge->base,
							&state->base);
	state->bridge = bridge;
}
EXPORT_SYMBOL(__drm_atomic_helper_bridge_duplicate_state);

/**
 * drm_atomic_helper_bridge_duplicate_state() - Duplicate a bridge state object
 * @bridge: bridge object
 *
 * Allocates a new bridge state and initializes it with the current bridge
 * state values. This helper is meant to be used as a bridge
 * &drm_bridge_funcs.atomic_duplicate_state hook for bridges that don't
 * subclass the bridge state.
 */
struct drm_bridge_state *
drm_atomic_helper_bridge_duplicate_state(struct drm_bridge *bridge)
{
	struct drm_bridge_state *new;

	if (WARN_ON(!bridge->base.state))
		return NULL;

	new = kzalloc(sizeof(*new), GFP_KERNEL);
	if (new)
		__drm_atomic_helper_bridge_duplicate_state(bridge, new);

	return new;
}
EXPORT_SYMBOL(drm_atomic_helper_bridge_duplicate_state);

/**
 * drm_atomic_helper_bridge_destroy_state() - Destroy a bridge state object
 * @bridge: the bridge this state refers to
 * @state: bridge state to destroy
 *
 * Destroys a bridge state previously created by
 * &drm_atomic_helper_bridge_reset() or
 * &drm_atomic_helper_bridge_duplicate_state(). This helper is meant to be
 * used as a bridge &drm_bridge_funcs.atomic_destroy_state hook for bridges
 * that don't subclass the bridge state.
 */
void drm_atomic_helper_bridge_destroy_state(struct drm_bridge *bridge,
					    struct drm_bridge_state *state)
{
	kfree(state);
}
EXPORT_SYMBOL(drm_atomic_helper_bridge_destroy_state);

/**
 * __drm_atomic_helper_bridge_reset() - Initialize a bridge state to its
 *					default
 * @bridge: the bridge this state refers to
 * @state: bridge state to initialize
 *
 * Initializes the bridge state to default values. This is meant to be called
 * by the bridge &drm_bridge_funcs.atomic_reset hook for bridges that subclass
 * the bridge state.
 */
void __drm_atomic_helper_bridge_reset(struct drm_bridge *bridge,
				      struct drm_bridge_state *state)
{
	memset(state, 0, sizeof(*state));
	state->bridge = bridge;
}
EXPORT_SYMBOL(__drm_atomic_helper_bridge_reset);

/**
 * drm_atomic_helper_bridge_reset() - Allocate and initialize a bridge state
 *				      to its default
 * @bridge: the bridge this state refers to
 *
 * Allocates the bridge state and initializes it to default values. This helper
 * is meant to be used as a bridge &drm_bridge_funcs.atomic_reset hook for
 * bridges that don't subclass the bridge state.
 */
struct drm_bridge_state *
drm_atomic_helper_bridge_reset(struct drm_bridge *bridge)
{
	struct drm_bridge_state *bridge_state;

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

	__drm_atomic_helper_bridge_reset(bridge, bridge_state);
	return bridge_state;
}
EXPORT_SYMBOL(drm_atomic_helper_bridge_reset);