xref: /openbmc/linux/drivers/gpu/drm/drm_atomic.c (revision d97ffe78)
1 /*
2  * Copyright (C) 2014 Red Hat
3  * Copyright (C) 2014 Intel Corp.
4  *
5  * Permission is hereby granted, free of charge, to any person obtaining a
6  * copy of this software and associated documentation files (the "Software"),
7  * to deal in the Software without restriction, including without limitation
8  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9  * and/or sell copies of the Software, and to permit persons to whom the
10  * Software is furnished to do so, subject to the following conditions:
11  *
12  * The above copyright notice and this permission notice shall be included in
13  * all copies or substantial portions of the Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
19  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
20  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
21  * OTHER DEALINGS IN THE SOFTWARE.
22  *
23  * Authors:
24  * Rob Clark <robdclark@gmail.com>
25  * Daniel Vetter <daniel.vetter@ffwll.ch>
26  */
27 
28 
29 #include <drm/drmP.h>
30 #include <drm/drm_atomic.h>
31 #include <drm/drm_mode.h>
32 #include <drm/drm_plane_helper.h>
33 
34 #include "drm_crtc_internal.h"
35 
36 static void crtc_commit_free(struct kref *kref)
37 {
38 	struct drm_crtc_commit *commit =
39 		container_of(kref, struct drm_crtc_commit, ref);
40 
41 	kfree(commit);
42 }
43 
44 void drm_crtc_commit_put(struct drm_crtc_commit *commit)
45 {
46 	kref_put(&commit->ref, crtc_commit_free);
47 }
48 EXPORT_SYMBOL(drm_crtc_commit_put);
49 
50 /**
51  * drm_atomic_state_default_release -
52  * release memory initialized by drm_atomic_state_init
53  * @state: atomic state
54  *
55  * Free all the memory allocated by drm_atomic_state_init.
56  * This is useful for drivers that subclass the atomic state.
57  */
58 void drm_atomic_state_default_release(struct drm_atomic_state *state)
59 {
60 	kfree(state->connectors);
61 	kfree(state->crtcs);
62 	kfree(state->planes);
63 }
64 EXPORT_SYMBOL(drm_atomic_state_default_release);
65 
66 /**
67  * drm_atomic_state_init - init new atomic state
68  * @dev: DRM device
69  * @state: atomic state
70  *
71  * Default implementation for filling in a new atomic state.
72  * This is useful for drivers that subclass the atomic state.
73  */
74 int
75 drm_atomic_state_init(struct drm_device *dev, struct drm_atomic_state *state)
76 {
77 	/* TODO legacy paths should maybe do a better job about
78 	 * setting this appropriately?
79 	 */
80 	state->allow_modeset = true;
81 
82 	state->crtcs = kcalloc(dev->mode_config.num_crtc,
83 			       sizeof(*state->crtcs), GFP_KERNEL);
84 	if (!state->crtcs)
85 		goto fail;
86 	state->planes = kcalloc(dev->mode_config.num_total_plane,
87 				sizeof(*state->planes), GFP_KERNEL);
88 	if (!state->planes)
89 		goto fail;
90 
91 	state->dev = dev;
92 
93 	DRM_DEBUG_ATOMIC("Allocated atomic state %p\n", state);
94 
95 	return 0;
96 fail:
97 	drm_atomic_state_default_release(state);
98 	return -ENOMEM;
99 }
100 EXPORT_SYMBOL(drm_atomic_state_init);
101 
102 /**
103  * drm_atomic_state_alloc - allocate atomic state
104  * @dev: DRM device
105  *
106  * This allocates an empty atomic state to track updates.
107  */
108 struct drm_atomic_state *
109 drm_atomic_state_alloc(struct drm_device *dev)
110 {
111 	struct drm_mode_config *config = &dev->mode_config;
112 	struct drm_atomic_state *state;
113 
114 	if (!config->funcs->atomic_state_alloc) {
115 		state = kzalloc(sizeof(*state), GFP_KERNEL);
116 		if (!state)
117 			return NULL;
118 		if (drm_atomic_state_init(dev, state) < 0) {
119 			kfree(state);
120 			return NULL;
121 		}
122 		return state;
123 	}
124 
125 	return config->funcs->atomic_state_alloc(dev);
126 }
127 EXPORT_SYMBOL(drm_atomic_state_alloc);
128 
129 /**
130  * drm_atomic_state_default_clear - clear base atomic state
131  * @state: atomic state
132  *
133  * Default implementation for clearing atomic state.
134  * This is useful for drivers that subclass the atomic state.
135  */
136 void drm_atomic_state_default_clear(struct drm_atomic_state *state)
137 {
138 	struct drm_device *dev = state->dev;
139 	struct drm_mode_config *config = &dev->mode_config;
140 	int i;
141 
142 	DRM_DEBUG_ATOMIC("Clearing atomic state %p\n", state);
143 
144 	for (i = 0; i < state->num_connector; i++) {
145 		struct drm_connector *connector = state->connectors[i].ptr;
146 
147 		if (!connector)
148 			continue;
149 
150 		connector->funcs->atomic_destroy_state(connector,
151 						       state->connectors[i].state);
152 		state->connectors[i].ptr = NULL;
153 		state->connectors[i].state = NULL;
154 		drm_connector_unreference(connector);
155 	}
156 
157 	for (i = 0; i < config->num_crtc; i++) {
158 		struct drm_crtc *crtc = state->crtcs[i].ptr;
159 
160 		if (!crtc)
161 			continue;
162 
163 		crtc->funcs->atomic_destroy_state(crtc,
164 						  state->crtcs[i].state);
165 
166 		if (state->crtcs[i].commit) {
167 			kfree(state->crtcs[i].commit->event);
168 			state->crtcs[i].commit->event = NULL;
169 			drm_crtc_commit_put(state->crtcs[i].commit);
170 		}
171 
172 		state->crtcs[i].commit = NULL;
173 		state->crtcs[i].ptr = NULL;
174 		state->crtcs[i].state = NULL;
175 	}
176 
177 	for (i = 0; i < config->num_total_plane; i++) {
178 		struct drm_plane *plane = state->planes[i].ptr;
179 
180 		if (!plane)
181 			continue;
182 
183 		plane->funcs->atomic_destroy_state(plane,
184 						   state->planes[i].state);
185 		state->planes[i].ptr = NULL;
186 		state->planes[i].state = NULL;
187 	}
188 }
189 EXPORT_SYMBOL(drm_atomic_state_default_clear);
190 
191 /**
192  * drm_atomic_state_clear - clear state object
193  * @state: atomic state
194  *
195  * When the w/w mutex algorithm detects a deadlock we need to back off and drop
196  * all locks. So someone else could sneak in and change the current modeset
197  * configuration. Which means that all the state assembled in @state is no
198  * longer an atomic update to the current state, but to some arbitrary earlier
199  * state. Which could break assumptions the driver's ->atomic_check likely
200  * relies on.
201  *
202  * Hence we must clear all cached state and completely start over, using this
203  * function.
204  */
205 void drm_atomic_state_clear(struct drm_atomic_state *state)
206 {
207 	struct drm_device *dev = state->dev;
208 	struct drm_mode_config *config = &dev->mode_config;
209 
210 	if (config->funcs->atomic_state_clear)
211 		config->funcs->atomic_state_clear(state);
212 	else
213 		drm_atomic_state_default_clear(state);
214 }
215 EXPORT_SYMBOL(drm_atomic_state_clear);
216 
217 /**
218  * drm_atomic_state_free - free all memory for an atomic state
219  * @state: atomic state to deallocate
220  *
221  * This frees all memory associated with an atomic state, including all the
222  * per-object state for planes, crtcs and connectors.
223  */
224 void drm_atomic_state_free(struct drm_atomic_state *state)
225 {
226 	struct drm_device *dev;
227 	struct drm_mode_config *config;
228 
229 	if (!state)
230 		return;
231 
232 	dev = state->dev;
233 	config = &dev->mode_config;
234 
235 	drm_atomic_state_clear(state);
236 
237 	DRM_DEBUG_ATOMIC("Freeing atomic state %p\n", state);
238 
239 	if (config->funcs->atomic_state_free) {
240 		config->funcs->atomic_state_free(state);
241 	} else {
242 		drm_atomic_state_default_release(state);
243 		kfree(state);
244 	}
245 }
246 EXPORT_SYMBOL(drm_atomic_state_free);
247 
248 /**
249  * drm_atomic_get_crtc_state - get crtc state
250  * @state: global atomic state object
251  * @crtc: crtc to get state object for
252  *
253  * This function returns the crtc state for the given crtc, allocating it if
254  * needed. It will also grab the relevant crtc lock to make sure that the state
255  * is consistent.
256  *
257  * Returns:
258  *
259  * Either the allocated state or the error code encoded into the pointer. When
260  * the error is EDEADLK then the w/w mutex code has detected a deadlock and the
261  * entire atomic sequence must be restarted. All other errors are fatal.
262  */
263 struct drm_crtc_state *
264 drm_atomic_get_crtc_state(struct drm_atomic_state *state,
265 			  struct drm_crtc *crtc)
266 {
267 	int ret, index = drm_crtc_index(crtc);
268 	struct drm_crtc_state *crtc_state;
269 
270 	WARN_ON(!state->acquire_ctx);
271 
272 	crtc_state = drm_atomic_get_existing_crtc_state(state, crtc);
273 	if (crtc_state)
274 		return crtc_state;
275 
276 	ret = drm_modeset_lock(&crtc->mutex, state->acquire_ctx);
277 	if (ret)
278 		return ERR_PTR(ret);
279 
280 	crtc_state = crtc->funcs->atomic_duplicate_state(crtc);
281 	if (!crtc_state)
282 		return ERR_PTR(-ENOMEM);
283 
284 	state->crtcs[index].state = crtc_state;
285 	state->crtcs[index].ptr = crtc;
286 	crtc_state->state = state;
287 
288 	DRM_DEBUG_ATOMIC("Added [CRTC:%d:%s] %p state to %p\n",
289 			 crtc->base.id, crtc->name, crtc_state, state);
290 
291 	return crtc_state;
292 }
293 EXPORT_SYMBOL(drm_atomic_get_crtc_state);
294 
295 /**
296  * drm_atomic_set_mode_for_crtc - set mode for CRTC
297  * @state: the CRTC whose incoming state to update
298  * @mode: kernel-internal mode to use for the CRTC, or NULL to disable
299  *
300  * Set a mode (originating from the kernel) on the desired CRTC state. Does
301  * not change any other state properties, including enable, active, or
302  * mode_changed.
303  *
304  * RETURNS:
305  * Zero on success, error code on failure. Cannot return -EDEADLK.
306  */
307 int drm_atomic_set_mode_for_crtc(struct drm_crtc_state *state,
308 				 struct drm_display_mode *mode)
309 {
310 	struct drm_mode_modeinfo umode;
311 
312 	/* Early return for no change. */
313 	if (mode && memcmp(&state->mode, mode, sizeof(*mode)) == 0)
314 		return 0;
315 
316 	drm_property_unreference_blob(state->mode_blob);
317 	state->mode_blob = NULL;
318 
319 	if (mode) {
320 		drm_mode_convert_to_umode(&umode, mode);
321 		state->mode_blob =
322 			drm_property_create_blob(state->crtc->dev,
323 		                                 sizeof(umode),
324 		                                 &umode);
325 		if (IS_ERR(state->mode_blob))
326 			return PTR_ERR(state->mode_blob);
327 
328 		drm_mode_copy(&state->mode, mode);
329 		state->enable = true;
330 		DRM_DEBUG_ATOMIC("Set [MODE:%s] for CRTC state %p\n",
331 				 mode->name, state);
332 	} else {
333 		memset(&state->mode, 0, sizeof(state->mode));
334 		state->enable = false;
335 		DRM_DEBUG_ATOMIC("Set [NOMODE] for CRTC state %p\n",
336 				 state);
337 	}
338 
339 	return 0;
340 }
341 EXPORT_SYMBOL(drm_atomic_set_mode_for_crtc);
342 
343 /**
344  * drm_atomic_set_mode_prop_for_crtc - set mode for CRTC
345  * @state: the CRTC whose incoming state to update
346  * @blob: pointer to blob property to use for mode
347  *
348  * Set a mode (originating from a blob property) on the desired CRTC state.
349  * This function will take a reference on the blob property for the CRTC state,
350  * and release the reference held on the state's existing mode property, if any
351  * was set.
352  *
353  * RETURNS:
354  * Zero on success, error code on failure. Cannot return -EDEADLK.
355  */
356 int drm_atomic_set_mode_prop_for_crtc(struct drm_crtc_state *state,
357                                       struct drm_property_blob *blob)
358 {
359 	if (blob == state->mode_blob)
360 		return 0;
361 
362 	drm_property_unreference_blob(state->mode_blob);
363 	state->mode_blob = NULL;
364 
365 	memset(&state->mode, 0, sizeof(state->mode));
366 
367 	if (blob) {
368 		if (blob->length != sizeof(struct drm_mode_modeinfo) ||
369 		    drm_mode_convert_umode(&state->mode,
370 		                           (const struct drm_mode_modeinfo *)
371 		                            blob->data))
372 			return -EINVAL;
373 
374 		state->mode_blob = drm_property_reference_blob(blob);
375 		state->enable = true;
376 		DRM_DEBUG_ATOMIC("Set [MODE:%s] for CRTC state %p\n",
377 				 state->mode.name, state);
378 	} else {
379 		state->enable = false;
380 		DRM_DEBUG_ATOMIC("Set [NOMODE] for CRTC state %p\n",
381 				 state);
382 	}
383 
384 	return 0;
385 }
386 EXPORT_SYMBOL(drm_atomic_set_mode_prop_for_crtc);
387 
388 /**
389  * drm_atomic_replace_property_blob - replace a blob property
390  * @blob: a pointer to the member blob to be replaced
391  * @new_blob: the new blob to replace with
392  * @replaced: whether the blob has been replaced
393  *
394  * RETURNS:
395  * Zero on success, error code on failure
396  */
397 static void
398 drm_atomic_replace_property_blob(struct drm_property_blob **blob,
399 				 struct drm_property_blob *new_blob,
400 				 bool *replaced)
401 {
402 	struct drm_property_blob *old_blob = *blob;
403 
404 	if (old_blob == new_blob)
405 		return;
406 
407 	drm_property_unreference_blob(old_blob);
408 	if (new_blob)
409 		drm_property_reference_blob(new_blob);
410 	*blob = new_blob;
411 	*replaced = true;
412 
413 	return;
414 }
415 
416 static int
417 drm_atomic_replace_property_blob_from_id(struct drm_crtc *crtc,
418 					 struct drm_property_blob **blob,
419 					 uint64_t blob_id,
420 					 ssize_t expected_size,
421 					 bool *replaced)
422 {
423 	struct drm_device *dev = crtc->dev;
424 	struct drm_property_blob *new_blob = NULL;
425 
426 	if (blob_id != 0) {
427 		new_blob = drm_property_lookup_blob(dev, blob_id);
428 		if (new_blob == NULL)
429 			return -EINVAL;
430 		if (expected_size > 0 && expected_size != new_blob->length)
431 			return -EINVAL;
432 	}
433 
434 	drm_atomic_replace_property_blob(blob, new_blob, replaced);
435 
436 	return 0;
437 }
438 
439 /**
440  * drm_atomic_crtc_set_property - set property on CRTC
441  * @crtc: the drm CRTC to set a property on
442  * @state: the state object to update with the new property value
443  * @property: the property to set
444  * @val: the new property value
445  *
446  * Use this instead of calling crtc->atomic_set_property directly.
447  * This function handles generic/core properties and calls out to
448  * driver's ->atomic_set_property() for driver properties.  To ensure
449  * consistent behavior you must call this function rather than the
450  * driver hook directly.
451  *
452  * RETURNS:
453  * Zero on success, error code on failure
454  */
455 int drm_atomic_crtc_set_property(struct drm_crtc *crtc,
456 		struct drm_crtc_state *state, struct drm_property *property,
457 		uint64_t val)
458 {
459 	struct drm_device *dev = crtc->dev;
460 	struct drm_mode_config *config = &dev->mode_config;
461 	bool replaced = false;
462 	int ret;
463 
464 	if (property == config->prop_active)
465 		state->active = val;
466 	else if (property == config->prop_mode_id) {
467 		struct drm_property_blob *mode =
468 			drm_property_lookup_blob(dev, val);
469 		ret = drm_atomic_set_mode_prop_for_crtc(state, mode);
470 		drm_property_unreference_blob(mode);
471 		return ret;
472 	} else if (property == config->degamma_lut_property) {
473 		ret = drm_atomic_replace_property_blob_from_id(crtc,
474 					&state->degamma_lut,
475 					val,
476 					-1,
477 					&replaced);
478 		state->color_mgmt_changed = replaced;
479 		return ret;
480 	} else if (property == config->ctm_property) {
481 		ret = drm_atomic_replace_property_blob_from_id(crtc,
482 					&state->ctm,
483 					val,
484 					sizeof(struct drm_color_ctm),
485 					&replaced);
486 		state->color_mgmt_changed = replaced;
487 		return ret;
488 	} else if (property == config->gamma_lut_property) {
489 		ret = drm_atomic_replace_property_blob_from_id(crtc,
490 					&state->gamma_lut,
491 					val,
492 					-1,
493 					&replaced);
494 		state->color_mgmt_changed = replaced;
495 		return ret;
496 	} else if (crtc->funcs->atomic_set_property)
497 		return crtc->funcs->atomic_set_property(crtc, state, property, val);
498 	else
499 		return -EINVAL;
500 
501 	return 0;
502 }
503 EXPORT_SYMBOL(drm_atomic_crtc_set_property);
504 
505 /**
506  * drm_atomic_crtc_get_property - get property value from CRTC state
507  * @crtc: the drm CRTC to set a property on
508  * @state: the state object to get the property value from
509  * @property: the property to set
510  * @val: return location for the property value
511  *
512  * This function handles generic/core properties and calls out to
513  * driver's ->atomic_get_property() for driver properties.  To ensure
514  * consistent behavior you must call this function rather than the
515  * driver hook directly.
516  *
517  * RETURNS:
518  * Zero on success, error code on failure
519  */
520 static int
521 drm_atomic_crtc_get_property(struct drm_crtc *crtc,
522 		const struct drm_crtc_state *state,
523 		struct drm_property *property, uint64_t *val)
524 {
525 	struct drm_device *dev = crtc->dev;
526 	struct drm_mode_config *config = &dev->mode_config;
527 
528 	if (property == config->prop_active)
529 		*val = state->active;
530 	else if (property == config->prop_mode_id)
531 		*val = (state->mode_blob) ? state->mode_blob->base.id : 0;
532 	else if (property == config->degamma_lut_property)
533 		*val = (state->degamma_lut) ? state->degamma_lut->base.id : 0;
534 	else if (property == config->ctm_property)
535 		*val = (state->ctm) ? state->ctm->base.id : 0;
536 	else if (property == config->gamma_lut_property)
537 		*val = (state->gamma_lut) ? state->gamma_lut->base.id : 0;
538 	else if (crtc->funcs->atomic_get_property)
539 		return crtc->funcs->atomic_get_property(crtc, state, property, val);
540 	else
541 		return -EINVAL;
542 
543 	return 0;
544 }
545 
546 /**
547  * drm_atomic_crtc_check - check crtc state
548  * @crtc: crtc to check
549  * @state: crtc state to check
550  *
551  * Provides core sanity checks for crtc state.
552  *
553  * RETURNS:
554  * Zero on success, error code on failure
555  */
556 static int drm_atomic_crtc_check(struct drm_crtc *crtc,
557 		struct drm_crtc_state *state)
558 {
559 	/* NOTE: we explicitly don't enforce constraints such as primary
560 	 * layer covering entire screen, since that is something we want
561 	 * to allow (on hw that supports it).  For hw that does not, it
562 	 * should be checked in driver's crtc->atomic_check() vfunc.
563 	 *
564 	 * TODO: Add generic modeset state checks once we support those.
565 	 */
566 
567 	if (state->active && !state->enable) {
568 		DRM_DEBUG_ATOMIC("[CRTC:%d:%s] active without enabled\n",
569 				 crtc->base.id, crtc->name);
570 		return -EINVAL;
571 	}
572 
573 	/* The state->enable vs. state->mode_blob checks can be WARN_ON,
574 	 * as this is a kernel-internal detail that userspace should never
575 	 * be able to trigger. */
576 	if (drm_core_check_feature(crtc->dev, DRIVER_ATOMIC) &&
577 	    WARN_ON(state->enable && !state->mode_blob)) {
578 		DRM_DEBUG_ATOMIC("[CRTC:%d:%s] enabled without mode blob\n",
579 				 crtc->base.id, crtc->name);
580 		return -EINVAL;
581 	}
582 
583 	if (drm_core_check_feature(crtc->dev, DRIVER_ATOMIC) &&
584 	    WARN_ON(!state->enable && state->mode_blob)) {
585 		DRM_DEBUG_ATOMIC("[CRTC:%d:%s] disabled with mode blob\n",
586 				 crtc->base.id, crtc->name);
587 		return -EINVAL;
588 	}
589 
590 	/*
591 	 * Reject event generation for when a CRTC is off and stays off.
592 	 * It wouldn't be hard to implement this, but userspace has a track
593 	 * record of happily burning through 100% cpu (or worse, crash) when the
594 	 * display pipe is suspended. To avoid all that fun just reject updates
595 	 * that ask for events since likely that indicates a bug in the
596 	 * compositor's drawing loop. This is consistent with the vblank IOCTL
597 	 * and legacy page_flip IOCTL which also reject service on a disabled
598 	 * pipe.
599 	 */
600 	if (state->event && !state->active && !crtc->state->active) {
601 		DRM_DEBUG_ATOMIC("[CRTC:%d] requesting event but off\n",
602 				 crtc->base.id);
603 		return -EINVAL;
604 	}
605 
606 	return 0;
607 }
608 
609 /**
610  * drm_atomic_get_plane_state - get plane state
611  * @state: global atomic state object
612  * @plane: plane to get state object for
613  *
614  * This function returns the plane state for the given plane, allocating it if
615  * needed. It will also grab the relevant plane lock to make sure that the state
616  * is consistent.
617  *
618  * Returns:
619  *
620  * Either the allocated state or the error code encoded into the pointer. When
621  * the error is EDEADLK then the w/w mutex code has detected a deadlock and the
622  * entire atomic sequence must be restarted. All other errors are fatal.
623  */
624 struct drm_plane_state *
625 drm_atomic_get_plane_state(struct drm_atomic_state *state,
626 			  struct drm_plane *plane)
627 {
628 	int ret, index = drm_plane_index(plane);
629 	struct drm_plane_state *plane_state;
630 
631 	WARN_ON(!state->acquire_ctx);
632 
633 	plane_state = drm_atomic_get_existing_plane_state(state, plane);
634 	if (plane_state)
635 		return plane_state;
636 
637 	ret = drm_modeset_lock(&plane->mutex, state->acquire_ctx);
638 	if (ret)
639 		return ERR_PTR(ret);
640 
641 	plane_state = plane->funcs->atomic_duplicate_state(plane);
642 	if (!plane_state)
643 		return ERR_PTR(-ENOMEM);
644 
645 	state->planes[index].state = plane_state;
646 	state->planes[index].ptr = plane;
647 	plane_state->state = state;
648 
649 	DRM_DEBUG_ATOMIC("Added [PLANE:%d:%s] %p state to %p\n",
650 			 plane->base.id, plane->name, plane_state, state);
651 
652 	if (plane_state->crtc) {
653 		struct drm_crtc_state *crtc_state;
654 
655 		crtc_state = drm_atomic_get_crtc_state(state,
656 						       plane_state->crtc);
657 		if (IS_ERR(crtc_state))
658 			return ERR_CAST(crtc_state);
659 	}
660 
661 	return plane_state;
662 }
663 EXPORT_SYMBOL(drm_atomic_get_plane_state);
664 
665 /**
666  * drm_atomic_plane_set_property - set property on plane
667  * @plane: the drm plane to set a property on
668  * @state: the state object to update with the new property value
669  * @property: the property to set
670  * @val: the new property value
671  *
672  * Use this instead of calling plane->atomic_set_property directly.
673  * This function handles generic/core properties and calls out to
674  * driver's ->atomic_set_property() for driver properties.  To ensure
675  * consistent behavior you must call this function rather than the
676  * driver hook directly.
677  *
678  * RETURNS:
679  * Zero on success, error code on failure
680  */
681 int drm_atomic_plane_set_property(struct drm_plane *plane,
682 		struct drm_plane_state *state, struct drm_property *property,
683 		uint64_t val)
684 {
685 	struct drm_device *dev = plane->dev;
686 	struct drm_mode_config *config = &dev->mode_config;
687 
688 	if (property == config->prop_fb_id) {
689 		struct drm_framebuffer *fb = drm_framebuffer_lookup(dev, val);
690 		drm_atomic_set_fb_for_plane(state, fb);
691 		if (fb)
692 			drm_framebuffer_unreference(fb);
693 	} else if (property == config->prop_crtc_id) {
694 		struct drm_crtc *crtc = drm_crtc_find(dev, val);
695 		return drm_atomic_set_crtc_for_plane(state, crtc);
696 	} else if (property == config->prop_crtc_x) {
697 		state->crtc_x = U642I64(val);
698 	} else if (property == config->prop_crtc_y) {
699 		state->crtc_y = U642I64(val);
700 	} else if (property == config->prop_crtc_w) {
701 		state->crtc_w = val;
702 	} else if (property == config->prop_crtc_h) {
703 		state->crtc_h = val;
704 	} else if (property == config->prop_src_x) {
705 		state->src_x = val;
706 	} else if (property == config->prop_src_y) {
707 		state->src_y = val;
708 	} else if (property == config->prop_src_w) {
709 		state->src_w = val;
710 	} else if (property == config->prop_src_h) {
711 		state->src_h = val;
712 	} else if (property == config->rotation_property) {
713 		state->rotation = val;
714 	} else if (plane->funcs->atomic_set_property) {
715 		return plane->funcs->atomic_set_property(plane, state,
716 				property, val);
717 	} else {
718 		return -EINVAL;
719 	}
720 
721 	return 0;
722 }
723 EXPORT_SYMBOL(drm_atomic_plane_set_property);
724 
725 /**
726  * drm_atomic_plane_get_property - get property value from plane state
727  * @plane: the drm plane to set a property on
728  * @state: the state object to get the property value from
729  * @property: the property to set
730  * @val: return location for the property value
731  *
732  * This function handles generic/core properties and calls out to
733  * driver's ->atomic_get_property() for driver properties.  To ensure
734  * consistent behavior you must call this function rather than the
735  * driver hook directly.
736  *
737  * RETURNS:
738  * Zero on success, error code on failure
739  */
740 static int
741 drm_atomic_plane_get_property(struct drm_plane *plane,
742 		const struct drm_plane_state *state,
743 		struct drm_property *property, uint64_t *val)
744 {
745 	struct drm_device *dev = plane->dev;
746 	struct drm_mode_config *config = &dev->mode_config;
747 
748 	if (property == config->prop_fb_id) {
749 		*val = (state->fb) ? state->fb->base.id : 0;
750 	} else if (property == config->prop_crtc_id) {
751 		*val = (state->crtc) ? state->crtc->base.id : 0;
752 	} else if (property == config->prop_crtc_x) {
753 		*val = I642U64(state->crtc_x);
754 	} else if (property == config->prop_crtc_y) {
755 		*val = I642U64(state->crtc_y);
756 	} else if (property == config->prop_crtc_w) {
757 		*val = state->crtc_w;
758 	} else if (property == config->prop_crtc_h) {
759 		*val = state->crtc_h;
760 	} else if (property == config->prop_src_x) {
761 		*val = state->src_x;
762 	} else if (property == config->prop_src_y) {
763 		*val = state->src_y;
764 	} else if (property == config->prop_src_w) {
765 		*val = state->src_w;
766 	} else if (property == config->prop_src_h) {
767 		*val = state->src_h;
768 	} else if (property == config->rotation_property) {
769 		*val = state->rotation;
770 	} else if (plane->funcs->atomic_get_property) {
771 		return plane->funcs->atomic_get_property(plane, state, property, val);
772 	} else {
773 		return -EINVAL;
774 	}
775 
776 	return 0;
777 }
778 
779 static bool
780 plane_switching_crtc(struct drm_atomic_state *state,
781 		     struct drm_plane *plane,
782 		     struct drm_plane_state *plane_state)
783 {
784 	if (!plane->state->crtc || !plane_state->crtc)
785 		return false;
786 
787 	if (plane->state->crtc == plane_state->crtc)
788 		return false;
789 
790 	/* This could be refined, but currently there's no helper or driver code
791 	 * to implement direct switching of active planes nor userspace to take
792 	 * advantage of more direct plane switching without the intermediate
793 	 * full OFF state.
794 	 */
795 	return true;
796 }
797 
798 /**
799  * drm_atomic_plane_check - check plane state
800  * @plane: plane to check
801  * @state: plane state to check
802  *
803  * Provides core sanity checks for plane state.
804  *
805  * RETURNS:
806  * Zero on success, error code on failure
807  */
808 static int drm_atomic_plane_check(struct drm_plane *plane,
809 		struct drm_plane_state *state)
810 {
811 	unsigned int fb_width, fb_height;
812 	int ret;
813 
814 	/* either *both* CRTC and FB must be set, or neither */
815 	if (WARN_ON(state->crtc && !state->fb)) {
816 		DRM_DEBUG_ATOMIC("CRTC set but no FB\n");
817 		return -EINVAL;
818 	} else if (WARN_ON(state->fb && !state->crtc)) {
819 		DRM_DEBUG_ATOMIC("FB set but no CRTC\n");
820 		return -EINVAL;
821 	}
822 
823 	/* if disabled, we don't care about the rest of the state: */
824 	if (!state->crtc)
825 		return 0;
826 
827 	/* Check whether this plane is usable on this CRTC */
828 	if (!(plane->possible_crtcs & drm_crtc_mask(state->crtc))) {
829 		DRM_DEBUG_ATOMIC("Invalid crtc for plane\n");
830 		return -EINVAL;
831 	}
832 
833 	/* Check whether this plane supports the fb pixel format. */
834 	ret = drm_plane_check_pixel_format(plane, state->fb->pixel_format);
835 	if (ret) {
836 		DRM_DEBUG_ATOMIC("Invalid pixel format %s\n",
837 				 drm_get_format_name(state->fb->pixel_format));
838 		return ret;
839 	}
840 
841 	/* Give drivers some help against integer overflows */
842 	if (state->crtc_w > INT_MAX ||
843 	    state->crtc_x > INT_MAX - (int32_t) state->crtc_w ||
844 	    state->crtc_h > INT_MAX ||
845 	    state->crtc_y > INT_MAX - (int32_t) state->crtc_h) {
846 		DRM_DEBUG_ATOMIC("Invalid CRTC coordinates %ux%u+%d+%d\n",
847 				 state->crtc_w, state->crtc_h,
848 				 state->crtc_x, state->crtc_y);
849 		return -ERANGE;
850 	}
851 
852 	fb_width = state->fb->width << 16;
853 	fb_height = state->fb->height << 16;
854 
855 	/* Make sure source coordinates are inside the fb. */
856 	if (state->src_w > fb_width ||
857 	    state->src_x > fb_width - state->src_w ||
858 	    state->src_h > fb_height ||
859 	    state->src_y > fb_height - state->src_h) {
860 		DRM_DEBUG_ATOMIC("Invalid source coordinates "
861 				 "%u.%06ux%u.%06u+%u.%06u+%u.%06u\n",
862 				 state->src_w >> 16, ((state->src_w & 0xffff) * 15625) >> 10,
863 				 state->src_h >> 16, ((state->src_h & 0xffff) * 15625) >> 10,
864 				 state->src_x >> 16, ((state->src_x & 0xffff) * 15625) >> 10,
865 				 state->src_y >> 16, ((state->src_y & 0xffff) * 15625) >> 10);
866 		return -ENOSPC;
867 	}
868 
869 	if (plane_switching_crtc(state->state, plane, state)) {
870 		DRM_DEBUG_ATOMIC("[PLANE:%d:%s] switching CRTC directly\n",
871 				 plane->base.id, plane->name);
872 		return -EINVAL;
873 	}
874 
875 	return 0;
876 }
877 
878 /**
879  * drm_atomic_get_connector_state - get connector state
880  * @state: global atomic state object
881  * @connector: connector to get state object for
882  *
883  * This function returns the connector state for the given connector,
884  * allocating it if needed. It will also grab the relevant connector lock to
885  * make sure that the state is consistent.
886  *
887  * Returns:
888  *
889  * Either the allocated state or the error code encoded into the pointer. When
890  * the error is EDEADLK then the w/w mutex code has detected a deadlock and the
891  * entire atomic sequence must be restarted. All other errors are fatal.
892  */
893 struct drm_connector_state *
894 drm_atomic_get_connector_state(struct drm_atomic_state *state,
895 			  struct drm_connector *connector)
896 {
897 	int ret, index;
898 	struct drm_mode_config *config = &connector->dev->mode_config;
899 	struct drm_connector_state *connector_state;
900 
901 	WARN_ON(!state->acquire_ctx);
902 
903 	ret = drm_modeset_lock(&config->connection_mutex, state->acquire_ctx);
904 	if (ret)
905 		return ERR_PTR(ret);
906 
907 	index = drm_connector_index(connector);
908 
909 	if (index >= state->num_connector) {
910 		struct __drm_connnectors_state *c;
911 		int alloc = max(index + 1, config->num_connector);
912 
913 		c = krealloc(state->connectors, alloc * sizeof(*state->connectors), GFP_KERNEL);
914 		if (!c)
915 			return ERR_PTR(-ENOMEM);
916 
917 		state->connectors = c;
918 		memset(&state->connectors[state->num_connector], 0,
919 		       sizeof(*state->connectors) * (alloc - state->num_connector));
920 
921 		state->num_connector = alloc;
922 	}
923 
924 	if (state->connectors[index].state)
925 		return state->connectors[index].state;
926 
927 	connector_state = connector->funcs->atomic_duplicate_state(connector);
928 	if (!connector_state)
929 		return ERR_PTR(-ENOMEM);
930 
931 	drm_connector_reference(connector);
932 	state->connectors[index].state = connector_state;
933 	state->connectors[index].ptr = connector;
934 	connector_state->state = state;
935 
936 	DRM_DEBUG_ATOMIC("Added [CONNECTOR:%d] %p state to %p\n",
937 			 connector->base.id, connector_state, state);
938 
939 	if (connector_state->crtc) {
940 		struct drm_crtc_state *crtc_state;
941 
942 		crtc_state = drm_atomic_get_crtc_state(state,
943 						       connector_state->crtc);
944 		if (IS_ERR(crtc_state))
945 			return ERR_CAST(crtc_state);
946 	}
947 
948 	return connector_state;
949 }
950 EXPORT_SYMBOL(drm_atomic_get_connector_state);
951 
952 /**
953  * drm_atomic_connector_set_property - set property on connector.
954  * @connector: the drm connector to set a property on
955  * @state: the state object to update with the new property value
956  * @property: the property to set
957  * @val: the new property value
958  *
959  * Use this instead of calling connector->atomic_set_property directly.
960  * This function handles generic/core properties and calls out to
961  * driver's ->atomic_set_property() for driver properties.  To ensure
962  * consistent behavior you must call this function rather than the
963  * driver hook directly.
964  *
965  * RETURNS:
966  * Zero on success, error code on failure
967  */
968 int drm_atomic_connector_set_property(struct drm_connector *connector,
969 		struct drm_connector_state *state, struct drm_property *property,
970 		uint64_t val)
971 {
972 	struct drm_device *dev = connector->dev;
973 	struct drm_mode_config *config = &dev->mode_config;
974 
975 	if (property == config->prop_crtc_id) {
976 		struct drm_crtc *crtc = drm_crtc_find(dev, val);
977 		return drm_atomic_set_crtc_for_connector(state, crtc);
978 	} else if (property == config->dpms_property) {
979 		/* setting DPMS property requires special handling, which
980 		 * is done in legacy setprop path for us.  Disallow (for
981 		 * now?) atomic writes to DPMS property:
982 		 */
983 		return -EINVAL;
984 	} else if (connector->funcs->atomic_set_property) {
985 		return connector->funcs->atomic_set_property(connector,
986 				state, property, val);
987 	} else {
988 		return -EINVAL;
989 	}
990 }
991 EXPORT_SYMBOL(drm_atomic_connector_set_property);
992 
993 /**
994  * drm_atomic_connector_get_property - get property value from connector state
995  * @connector: the drm connector to set a property on
996  * @state: the state object to get the property value from
997  * @property: the property to set
998  * @val: return location for the property value
999  *
1000  * This function handles generic/core properties and calls out to
1001  * driver's ->atomic_get_property() for driver properties.  To ensure
1002  * consistent behavior you must call this function rather than the
1003  * driver hook directly.
1004  *
1005  * RETURNS:
1006  * Zero on success, error code on failure
1007  */
1008 static int
1009 drm_atomic_connector_get_property(struct drm_connector *connector,
1010 		const struct drm_connector_state *state,
1011 		struct drm_property *property, uint64_t *val)
1012 {
1013 	struct drm_device *dev = connector->dev;
1014 	struct drm_mode_config *config = &dev->mode_config;
1015 
1016 	if (property == config->prop_crtc_id) {
1017 		*val = (state->crtc) ? state->crtc->base.id : 0;
1018 	} else if (property == config->dpms_property) {
1019 		*val = connector->dpms;
1020 	} else if (connector->funcs->atomic_get_property) {
1021 		return connector->funcs->atomic_get_property(connector,
1022 				state, property, val);
1023 	} else {
1024 		return -EINVAL;
1025 	}
1026 
1027 	return 0;
1028 }
1029 
1030 int drm_atomic_get_property(struct drm_mode_object *obj,
1031 		struct drm_property *property, uint64_t *val)
1032 {
1033 	struct drm_device *dev = property->dev;
1034 	int ret;
1035 
1036 	switch (obj->type) {
1037 	case DRM_MODE_OBJECT_CONNECTOR: {
1038 		struct drm_connector *connector = obj_to_connector(obj);
1039 		WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
1040 		ret = drm_atomic_connector_get_property(connector,
1041 				connector->state, property, val);
1042 		break;
1043 	}
1044 	case DRM_MODE_OBJECT_CRTC: {
1045 		struct drm_crtc *crtc = obj_to_crtc(obj);
1046 		WARN_ON(!drm_modeset_is_locked(&crtc->mutex));
1047 		ret = drm_atomic_crtc_get_property(crtc,
1048 				crtc->state, property, val);
1049 		break;
1050 	}
1051 	case DRM_MODE_OBJECT_PLANE: {
1052 		struct drm_plane *plane = obj_to_plane(obj);
1053 		WARN_ON(!drm_modeset_is_locked(&plane->mutex));
1054 		ret = drm_atomic_plane_get_property(plane,
1055 				plane->state, property, val);
1056 		break;
1057 	}
1058 	default:
1059 		ret = -EINVAL;
1060 		break;
1061 	}
1062 
1063 	return ret;
1064 }
1065 
1066 /**
1067  * drm_atomic_set_crtc_for_plane - set crtc for plane
1068  * @plane_state: the plane whose incoming state to update
1069  * @crtc: crtc to use for the plane
1070  *
1071  * Changing the assigned crtc for a plane requires us to grab the lock and state
1072  * for the new crtc, as needed. This function takes care of all these details
1073  * besides updating the pointer in the state object itself.
1074  *
1075  * Returns:
1076  * 0 on success or can fail with -EDEADLK or -ENOMEM. When the error is EDEADLK
1077  * then the w/w mutex code has detected a deadlock and the entire atomic
1078  * sequence must be restarted. All other errors are fatal.
1079  */
1080 int
1081 drm_atomic_set_crtc_for_plane(struct drm_plane_state *plane_state,
1082 			      struct drm_crtc *crtc)
1083 {
1084 	struct drm_plane *plane = plane_state->plane;
1085 	struct drm_crtc_state *crtc_state;
1086 
1087 	if (plane_state->crtc) {
1088 		crtc_state = drm_atomic_get_crtc_state(plane_state->state,
1089 						       plane_state->crtc);
1090 		if (WARN_ON(IS_ERR(crtc_state)))
1091 			return PTR_ERR(crtc_state);
1092 
1093 		crtc_state->plane_mask &= ~(1 << drm_plane_index(plane));
1094 	}
1095 
1096 	plane_state->crtc = crtc;
1097 
1098 	if (crtc) {
1099 		crtc_state = drm_atomic_get_crtc_state(plane_state->state,
1100 						       crtc);
1101 		if (IS_ERR(crtc_state))
1102 			return PTR_ERR(crtc_state);
1103 		crtc_state->plane_mask |= (1 << drm_plane_index(plane));
1104 	}
1105 
1106 	if (crtc)
1107 		DRM_DEBUG_ATOMIC("Link plane state %p to [CRTC:%d:%s]\n",
1108 				 plane_state, crtc->base.id, crtc->name);
1109 	else
1110 		DRM_DEBUG_ATOMIC("Link plane state %p to [NOCRTC]\n",
1111 				 plane_state);
1112 
1113 	return 0;
1114 }
1115 EXPORT_SYMBOL(drm_atomic_set_crtc_for_plane);
1116 
1117 /**
1118  * drm_atomic_set_fb_for_plane - set framebuffer for plane
1119  * @plane_state: atomic state object for the plane
1120  * @fb: fb to use for the plane
1121  *
1122  * Changing the assigned framebuffer for a plane requires us to grab a reference
1123  * to the new fb and drop the reference to the old fb, if there is one. This
1124  * function takes care of all these details besides updating the pointer in the
1125  * state object itself.
1126  */
1127 void
1128 drm_atomic_set_fb_for_plane(struct drm_plane_state *plane_state,
1129 			    struct drm_framebuffer *fb)
1130 {
1131 	if (plane_state->fb)
1132 		drm_framebuffer_unreference(plane_state->fb);
1133 	if (fb)
1134 		drm_framebuffer_reference(fb);
1135 	plane_state->fb = fb;
1136 
1137 	if (fb)
1138 		DRM_DEBUG_ATOMIC("Set [FB:%d] for plane state %p\n",
1139 				 fb->base.id, plane_state);
1140 	else
1141 		DRM_DEBUG_ATOMIC("Set [NOFB] for plane state %p\n",
1142 				 plane_state);
1143 }
1144 EXPORT_SYMBOL(drm_atomic_set_fb_for_plane);
1145 
1146 /**
1147  * drm_atomic_set_crtc_for_connector - set crtc for connector
1148  * @conn_state: atomic state object for the connector
1149  * @crtc: crtc to use for the connector
1150  *
1151  * Changing the assigned crtc for a connector requires us to grab the lock and
1152  * state for the new crtc, as needed. This function takes care of all these
1153  * details besides updating the pointer in the state object itself.
1154  *
1155  * Returns:
1156  * 0 on success or can fail with -EDEADLK or -ENOMEM. When the error is EDEADLK
1157  * then the w/w mutex code has detected a deadlock and the entire atomic
1158  * sequence must be restarted. All other errors are fatal.
1159  */
1160 int
1161 drm_atomic_set_crtc_for_connector(struct drm_connector_state *conn_state,
1162 				  struct drm_crtc *crtc)
1163 {
1164 	struct drm_crtc_state *crtc_state;
1165 
1166 	if (conn_state->crtc == crtc)
1167 		return 0;
1168 
1169 	if (conn_state->crtc) {
1170 		crtc_state = drm_atomic_get_existing_crtc_state(conn_state->state,
1171 								conn_state->crtc);
1172 
1173 		crtc_state->connector_mask &=
1174 			~(1 << drm_connector_index(conn_state->connector));
1175 
1176 		drm_connector_unreference(conn_state->connector);
1177 		conn_state->crtc = NULL;
1178 	}
1179 
1180 	if (crtc) {
1181 		crtc_state = drm_atomic_get_crtc_state(conn_state->state, crtc);
1182 		if (IS_ERR(crtc_state))
1183 			return PTR_ERR(crtc_state);
1184 
1185 		crtc_state->connector_mask |=
1186 			1 << drm_connector_index(conn_state->connector);
1187 
1188 		drm_connector_reference(conn_state->connector);
1189 		conn_state->crtc = crtc;
1190 
1191 		DRM_DEBUG_ATOMIC("Link connector state %p to [CRTC:%d:%s]\n",
1192 				 conn_state, crtc->base.id, crtc->name);
1193 	} else {
1194 		DRM_DEBUG_ATOMIC("Link connector state %p to [NOCRTC]\n",
1195 				 conn_state);
1196 	}
1197 
1198 	return 0;
1199 }
1200 EXPORT_SYMBOL(drm_atomic_set_crtc_for_connector);
1201 
1202 /**
1203  * drm_atomic_add_affected_connectors - add connectors for crtc
1204  * @state: atomic state
1205  * @crtc: DRM crtc
1206  *
1207  * This function walks the current configuration and adds all connectors
1208  * currently using @crtc to the atomic configuration @state. Note that this
1209  * function must acquire the connection mutex. This can potentially cause
1210  * unneeded seralization if the update is just for the planes on one crtc. Hence
1211  * drivers and helpers should only call this when really needed (e.g. when a
1212  * full modeset needs to happen due to some change).
1213  *
1214  * Returns:
1215  * 0 on success or can fail with -EDEADLK or -ENOMEM. When the error is EDEADLK
1216  * then the w/w mutex code has detected a deadlock and the entire atomic
1217  * sequence must be restarted. All other errors are fatal.
1218  */
1219 int
1220 drm_atomic_add_affected_connectors(struct drm_atomic_state *state,
1221 				   struct drm_crtc *crtc)
1222 {
1223 	struct drm_mode_config *config = &state->dev->mode_config;
1224 	struct drm_connector *connector;
1225 	struct drm_connector_state *conn_state;
1226 	int ret;
1227 
1228 	ret = drm_modeset_lock(&config->connection_mutex, state->acquire_ctx);
1229 	if (ret)
1230 		return ret;
1231 
1232 	DRM_DEBUG_ATOMIC("Adding all current connectors for [CRTC:%d:%s] to %p\n",
1233 			 crtc->base.id, crtc->name, state);
1234 
1235 	/*
1236 	 * Changed connectors are already in @state, so only need to look at the
1237 	 * current configuration.
1238 	 */
1239 	drm_for_each_connector(connector, state->dev) {
1240 		if (connector->state->crtc != crtc)
1241 			continue;
1242 
1243 		conn_state = drm_atomic_get_connector_state(state, connector);
1244 		if (IS_ERR(conn_state))
1245 			return PTR_ERR(conn_state);
1246 	}
1247 
1248 	return 0;
1249 }
1250 EXPORT_SYMBOL(drm_atomic_add_affected_connectors);
1251 
1252 /**
1253  * drm_atomic_add_affected_planes - add planes for crtc
1254  * @state: atomic state
1255  * @crtc: DRM crtc
1256  *
1257  * This function walks the current configuration and adds all planes
1258  * currently used by @crtc to the atomic configuration @state. This is useful
1259  * when an atomic commit also needs to check all currently enabled plane on
1260  * @crtc, e.g. when changing the mode. It's also useful when re-enabling a CRTC
1261  * to avoid special code to force-enable all planes.
1262  *
1263  * Since acquiring a plane state will always also acquire the w/w mutex of the
1264  * current CRTC for that plane (if there is any) adding all the plane states for
1265  * a CRTC will not reduce parallism of atomic updates.
1266  *
1267  * Returns:
1268  * 0 on success or can fail with -EDEADLK or -ENOMEM. When the error is EDEADLK
1269  * then the w/w mutex code has detected a deadlock and the entire atomic
1270  * sequence must be restarted. All other errors are fatal.
1271  */
1272 int
1273 drm_atomic_add_affected_planes(struct drm_atomic_state *state,
1274 			       struct drm_crtc *crtc)
1275 {
1276 	struct drm_plane *plane;
1277 
1278 	WARN_ON(!drm_atomic_get_existing_crtc_state(state, crtc));
1279 
1280 	drm_for_each_plane_mask(plane, state->dev, crtc->state->plane_mask) {
1281 		struct drm_plane_state *plane_state =
1282 			drm_atomic_get_plane_state(state, plane);
1283 
1284 		if (IS_ERR(plane_state))
1285 			return PTR_ERR(plane_state);
1286 	}
1287 	return 0;
1288 }
1289 EXPORT_SYMBOL(drm_atomic_add_affected_planes);
1290 
1291 /**
1292  * drm_atomic_legacy_backoff - locking backoff for legacy ioctls
1293  * @state: atomic state
1294  *
1295  * This function should be used by legacy entry points which don't understand
1296  * -EDEADLK semantics. For simplicity this one will grab all modeset locks after
1297  * the slowpath completed.
1298  */
1299 void drm_atomic_legacy_backoff(struct drm_atomic_state *state)
1300 {
1301 	struct drm_device *dev = state->dev;
1302 	unsigned crtc_mask = 0;
1303 	struct drm_crtc *crtc;
1304 	int ret;
1305 	bool global = false;
1306 
1307 	drm_for_each_crtc(crtc, dev) {
1308 		if (crtc->acquire_ctx != state->acquire_ctx)
1309 			continue;
1310 
1311 		crtc_mask |= drm_crtc_mask(crtc);
1312 		crtc->acquire_ctx = NULL;
1313 	}
1314 
1315 	if (WARN_ON(dev->mode_config.acquire_ctx == state->acquire_ctx)) {
1316 		global = true;
1317 
1318 		dev->mode_config.acquire_ctx = NULL;
1319 	}
1320 
1321 retry:
1322 	drm_modeset_backoff(state->acquire_ctx);
1323 
1324 	ret = drm_modeset_lock_all_ctx(dev, state->acquire_ctx);
1325 	if (ret)
1326 		goto retry;
1327 
1328 	drm_for_each_crtc(crtc, dev)
1329 		if (drm_crtc_mask(crtc) & crtc_mask)
1330 			crtc->acquire_ctx = state->acquire_ctx;
1331 
1332 	if (global)
1333 		dev->mode_config.acquire_ctx = state->acquire_ctx;
1334 }
1335 EXPORT_SYMBOL(drm_atomic_legacy_backoff);
1336 
1337 /**
1338  * drm_atomic_check_only - check whether a given config would work
1339  * @state: atomic configuration to check
1340  *
1341  * Note that this function can return -EDEADLK if the driver needed to acquire
1342  * more locks but encountered a deadlock. The caller must then do the usual w/w
1343  * backoff dance and restart. All other errors are fatal.
1344  *
1345  * Returns:
1346  * 0 on success, negative error code on failure.
1347  */
1348 int drm_atomic_check_only(struct drm_atomic_state *state)
1349 {
1350 	struct drm_device *dev = state->dev;
1351 	struct drm_mode_config *config = &dev->mode_config;
1352 	struct drm_plane *plane;
1353 	struct drm_plane_state *plane_state;
1354 	struct drm_crtc *crtc;
1355 	struct drm_crtc_state *crtc_state;
1356 	int i, ret = 0;
1357 
1358 	DRM_DEBUG_ATOMIC("checking %p\n", state);
1359 
1360 	for_each_plane_in_state(state, plane, plane_state, i) {
1361 		ret = drm_atomic_plane_check(plane, plane_state);
1362 		if (ret) {
1363 			DRM_DEBUG_ATOMIC("[PLANE:%d:%s] atomic core check failed\n",
1364 					 plane->base.id, plane->name);
1365 			return ret;
1366 		}
1367 	}
1368 
1369 	for_each_crtc_in_state(state, crtc, crtc_state, i) {
1370 		ret = drm_atomic_crtc_check(crtc, crtc_state);
1371 		if (ret) {
1372 			DRM_DEBUG_ATOMIC("[CRTC:%d:%s] atomic core check failed\n",
1373 					 crtc->base.id, crtc->name);
1374 			return ret;
1375 		}
1376 	}
1377 
1378 	if (config->funcs->atomic_check)
1379 		ret = config->funcs->atomic_check(state->dev, state);
1380 
1381 	if (!state->allow_modeset) {
1382 		for_each_crtc_in_state(state, crtc, crtc_state, i) {
1383 			if (drm_atomic_crtc_needs_modeset(crtc_state)) {
1384 				DRM_DEBUG_ATOMIC("[CRTC:%d:%s] requires full modeset\n",
1385 						 crtc->base.id, crtc->name);
1386 				return -EINVAL;
1387 			}
1388 		}
1389 	}
1390 
1391 	return ret;
1392 }
1393 EXPORT_SYMBOL(drm_atomic_check_only);
1394 
1395 /**
1396  * drm_atomic_commit - commit configuration atomically
1397  * @state: atomic configuration to check
1398  *
1399  * Note that this function can return -EDEADLK if the driver needed to acquire
1400  * more locks but encountered a deadlock. The caller must then do the usual w/w
1401  * backoff dance and restart. All other errors are fatal.
1402  *
1403  * Also note that on successful execution ownership of @state is transferred
1404  * from the caller of this function to the function itself. The caller must not
1405  * free or in any other way access @state. If the function fails then the caller
1406  * must clean up @state itself.
1407  *
1408  * Returns:
1409  * 0 on success, negative error code on failure.
1410  */
1411 int drm_atomic_commit(struct drm_atomic_state *state)
1412 {
1413 	struct drm_mode_config *config = &state->dev->mode_config;
1414 	int ret;
1415 
1416 	ret = drm_atomic_check_only(state);
1417 	if (ret)
1418 		return ret;
1419 
1420 	DRM_DEBUG_ATOMIC("commiting %p\n", state);
1421 
1422 	return config->funcs->atomic_commit(state->dev, state, false);
1423 }
1424 EXPORT_SYMBOL(drm_atomic_commit);
1425 
1426 /**
1427  * drm_atomic_nonblocking_commit - atomic&nonblocking configuration commit
1428  * @state: atomic configuration to check
1429  *
1430  * Note that this function can return -EDEADLK if the driver needed to acquire
1431  * more locks but encountered a deadlock. The caller must then do the usual w/w
1432  * backoff dance and restart. All other errors are fatal.
1433  *
1434  * Also note that on successful execution ownership of @state is transferred
1435  * from the caller of this function to the function itself. The caller must not
1436  * free or in any other way access @state. If the function fails then the caller
1437  * must clean up @state itself.
1438  *
1439  * Returns:
1440  * 0 on success, negative error code on failure.
1441  */
1442 int drm_atomic_nonblocking_commit(struct drm_atomic_state *state)
1443 {
1444 	struct drm_mode_config *config = &state->dev->mode_config;
1445 	int ret;
1446 
1447 	ret = drm_atomic_check_only(state);
1448 	if (ret)
1449 		return ret;
1450 
1451 	DRM_DEBUG_ATOMIC("commiting %p nonblocking\n", state);
1452 
1453 	return config->funcs->atomic_commit(state->dev, state, true);
1454 }
1455 EXPORT_SYMBOL(drm_atomic_nonblocking_commit);
1456 
1457 /*
1458  * The big monstor ioctl
1459  */
1460 
1461 static struct drm_pending_vblank_event *create_vblank_event(
1462 		struct drm_device *dev, struct drm_file *file_priv,
1463 		struct fence *fence, uint64_t user_data)
1464 {
1465 	struct drm_pending_vblank_event *e = NULL;
1466 	int ret;
1467 
1468 	e = kzalloc(sizeof *e, GFP_KERNEL);
1469 	if (!e)
1470 		return NULL;
1471 
1472 	e->event.base.type = DRM_EVENT_FLIP_COMPLETE;
1473 	e->event.base.length = sizeof(e->event);
1474 	e->event.user_data = user_data;
1475 
1476 	if (file_priv) {
1477 		ret = drm_event_reserve_init(dev, file_priv, &e->base,
1478 					     &e->event.base);
1479 		if (ret) {
1480 			kfree(e);
1481 			return NULL;
1482 		}
1483 	}
1484 
1485 	e->base.fence = fence;
1486 
1487 	return e;
1488 }
1489 
1490 static int atomic_set_prop(struct drm_atomic_state *state,
1491 		struct drm_mode_object *obj, struct drm_property *prop,
1492 		uint64_t prop_value)
1493 {
1494 	struct drm_mode_object *ref;
1495 	int ret;
1496 
1497 	if (!drm_property_change_valid_get(prop, prop_value, &ref))
1498 		return -EINVAL;
1499 
1500 	switch (obj->type) {
1501 	case DRM_MODE_OBJECT_CONNECTOR: {
1502 		struct drm_connector *connector = obj_to_connector(obj);
1503 		struct drm_connector_state *connector_state;
1504 
1505 		connector_state = drm_atomic_get_connector_state(state, connector);
1506 		if (IS_ERR(connector_state)) {
1507 			ret = PTR_ERR(connector_state);
1508 			break;
1509 		}
1510 
1511 		ret = drm_atomic_connector_set_property(connector,
1512 				connector_state, prop, prop_value);
1513 		break;
1514 	}
1515 	case DRM_MODE_OBJECT_CRTC: {
1516 		struct drm_crtc *crtc = obj_to_crtc(obj);
1517 		struct drm_crtc_state *crtc_state;
1518 
1519 		crtc_state = drm_atomic_get_crtc_state(state, crtc);
1520 		if (IS_ERR(crtc_state)) {
1521 			ret = PTR_ERR(crtc_state);
1522 			break;
1523 		}
1524 
1525 		ret = drm_atomic_crtc_set_property(crtc,
1526 				crtc_state, prop, prop_value);
1527 		break;
1528 	}
1529 	case DRM_MODE_OBJECT_PLANE: {
1530 		struct drm_plane *plane = obj_to_plane(obj);
1531 		struct drm_plane_state *plane_state;
1532 
1533 		plane_state = drm_atomic_get_plane_state(state, plane);
1534 		if (IS_ERR(plane_state)) {
1535 			ret = PTR_ERR(plane_state);
1536 			break;
1537 		}
1538 
1539 		ret = drm_atomic_plane_set_property(plane,
1540 				plane_state, prop, prop_value);
1541 		break;
1542 	}
1543 	default:
1544 		ret = -EINVAL;
1545 		break;
1546 	}
1547 
1548 	drm_property_change_valid_put(prop, ref);
1549 	return ret;
1550 }
1551 
1552 /**
1553  * drm_atomic_clean_old_fb -- Unset old_fb pointers and set plane->fb pointers.
1554  *
1555  * @dev: drm device to check.
1556  * @plane_mask: plane mask for planes that were updated.
1557  * @ret: return value, can be -EDEADLK for a retry.
1558  *
1559  * Before doing an update plane->old_fb is set to plane->fb,
1560  * but before dropping the locks old_fb needs to be set to NULL
1561  * and plane->fb updated. This is a common operation for each
1562  * atomic update, so this call is split off as a helper.
1563  */
1564 void drm_atomic_clean_old_fb(struct drm_device *dev,
1565 			     unsigned plane_mask,
1566 			     int ret)
1567 {
1568 	struct drm_plane *plane;
1569 
1570 	/* if succeeded, fixup legacy plane crtc/fb ptrs before dropping
1571 	 * locks (ie. while it is still safe to deref plane->state).  We
1572 	 * need to do this here because the driver entry points cannot
1573 	 * distinguish between legacy and atomic ioctls.
1574 	 */
1575 	drm_for_each_plane_mask(plane, dev, plane_mask) {
1576 		if (ret == 0) {
1577 			struct drm_framebuffer *new_fb = plane->state->fb;
1578 			if (new_fb)
1579 				drm_framebuffer_reference(new_fb);
1580 			plane->fb = new_fb;
1581 			plane->crtc = plane->state->crtc;
1582 
1583 			if (plane->old_fb)
1584 				drm_framebuffer_unreference(plane->old_fb);
1585 		}
1586 		plane->old_fb = NULL;
1587 	}
1588 }
1589 EXPORT_SYMBOL(drm_atomic_clean_old_fb);
1590 
1591 int drm_mode_atomic_ioctl(struct drm_device *dev,
1592 			  void *data, struct drm_file *file_priv)
1593 {
1594 	struct drm_mode_atomic *arg = data;
1595 	uint32_t __user *objs_ptr = (uint32_t __user *)(unsigned long)(arg->objs_ptr);
1596 	uint32_t __user *count_props_ptr = (uint32_t __user *)(unsigned long)(arg->count_props_ptr);
1597 	uint32_t __user *props_ptr = (uint32_t __user *)(unsigned long)(arg->props_ptr);
1598 	uint64_t __user *prop_values_ptr = (uint64_t __user *)(unsigned long)(arg->prop_values_ptr);
1599 	unsigned int copied_objs, copied_props;
1600 	struct drm_atomic_state *state;
1601 	struct drm_modeset_acquire_ctx ctx;
1602 	struct drm_plane *plane;
1603 	struct drm_crtc *crtc;
1604 	struct drm_crtc_state *crtc_state;
1605 	unsigned plane_mask;
1606 	int ret = 0;
1607 	unsigned int i, j;
1608 
1609 	/* disallow for drivers not supporting atomic: */
1610 	if (!drm_core_check_feature(dev, DRIVER_ATOMIC))
1611 		return -EINVAL;
1612 
1613 	/* disallow for userspace that has not enabled atomic cap (even
1614 	 * though this may be a bit overkill, since legacy userspace
1615 	 * wouldn't know how to call this ioctl)
1616 	 */
1617 	if (!file_priv->atomic)
1618 		return -EINVAL;
1619 
1620 	if (arg->flags & ~DRM_MODE_ATOMIC_FLAGS)
1621 		return -EINVAL;
1622 
1623 	if (arg->reserved)
1624 		return -EINVAL;
1625 
1626 	if ((arg->flags & DRM_MODE_PAGE_FLIP_ASYNC) &&
1627 			!dev->mode_config.async_page_flip)
1628 		return -EINVAL;
1629 
1630 	/* can't test and expect an event at the same time. */
1631 	if ((arg->flags & DRM_MODE_ATOMIC_TEST_ONLY) &&
1632 			(arg->flags & DRM_MODE_PAGE_FLIP_EVENT))
1633 		return -EINVAL;
1634 
1635 	drm_modeset_acquire_init(&ctx, 0);
1636 
1637 	state = drm_atomic_state_alloc(dev);
1638 	if (!state)
1639 		return -ENOMEM;
1640 
1641 	state->acquire_ctx = &ctx;
1642 	state->allow_modeset = !!(arg->flags & DRM_MODE_ATOMIC_ALLOW_MODESET);
1643 
1644 retry:
1645 	plane_mask = 0;
1646 	copied_objs = 0;
1647 	copied_props = 0;
1648 
1649 	for (i = 0; i < arg->count_objs; i++) {
1650 		uint32_t obj_id, count_props;
1651 		struct drm_mode_object *obj;
1652 
1653 		if (get_user(obj_id, objs_ptr + copied_objs)) {
1654 			ret = -EFAULT;
1655 			goto out;
1656 		}
1657 
1658 		obj = drm_mode_object_find(dev, obj_id, DRM_MODE_OBJECT_ANY);
1659 		if (!obj) {
1660 			ret = -ENOENT;
1661 			goto out;
1662 		}
1663 
1664 		if (!obj->properties) {
1665 			drm_mode_object_unreference(obj);
1666 			ret = -ENOENT;
1667 			goto out;
1668 		}
1669 
1670 		if (get_user(count_props, count_props_ptr + copied_objs)) {
1671 			drm_mode_object_unreference(obj);
1672 			ret = -EFAULT;
1673 			goto out;
1674 		}
1675 
1676 		copied_objs++;
1677 
1678 		for (j = 0; j < count_props; j++) {
1679 			uint32_t prop_id;
1680 			uint64_t prop_value;
1681 			struct drm_property *prop;
1682 
1683 			if (get_user(prop_id, props_ptr + copied_props)) {
1684 				drm_mode_object_unreference(obj);
1685 				ret = -EFAULT;
1686 				goto out;
1687 			}
1688 
1689 			prop = drm_property_find(dev, prop_id);
1690 			if (!prop) {
1691 				drm_mode_object_unreference(obj);
1692 				ret = -ENOENT;
1693 				goto out;
1694 			}
1695 
1696 			if (copy_from_user(&prop_value,
1697 					   prop_values_ptr + copied_props,
1698 					   sizeof(prop_value))) {
1699 				drm_mode_object_unreference(obj);
1700 				ret = -EFAULT;
1701 				goto out;
1702 			}
1703 
1704 			ret = atomic_set_prop(state, obj, prop, prop_value);
1705 			if (ret) {
1706 				drm_mode_object_unreference(obj);
1707 				goto out;
1708 			}
1709 
1710 			copied_props++;
1711 		}
1712 
1713 		if (obj->type == DRM_MODE_OBJECT_PLANE && count_props &&
1714 		    !(arg->flags & DRM_MODE_ATOMIC_TEST_ONLY)) {
1715 			plane = obj_to_plane(obj);
1716 			plane_mask |= (1 << drm_plane_index(plane));
1717 			plane->old_fb = plane->fb;
1718 		}
1719 		drm_mode_object_unreference(obj);
1720 	}
1721 
1722 	if (arg->flags & DRM_MODE_PAGE_FLIP_EVENT) {
1723 		for_each_crtc_in_state(state, crtc, crtc_state, i) {
1724 			struct drm_pending_vblank_event *e;
1725 
1726 			e = create_vblank_event(dev, file_priv, NULL,
1727 						arg->user_data);
1728 			if (!e) {
1729 				ret = -ENOMEM;
1730 				goto out;
1731 			}
1732 
1733 			crtc_state->event = e;
1734 		}
1735 	}
1736 
1737 	if (arg->flags & DRM_MODE_ATOMIC_TEST_ONLY) {
1738 		/*
1739 		 * Unlike commit, check_only does not clean up state.
1740 		 * Below we call drm_atomic_state_free for it.
1741 		 */
1742 		ret = drm_atomic_check_only(state);
1743 	} else if (arg->flags & DRM_MODE_ATOMIC_NONBLOCK) {
1744 		ret = drm_atomic_nonblocking_commit(state);
1745 	} else {
1746 		ret = drm_atomic_commit(state);
1747 	}
1748 
1749 out:
1750 	drm_atomic_clean_old_fb(dev, plane_mask, ret);
1751 
1752 	if (ret && arg->flags & DRM_MODE_PAGE_FLIP_EVENT) {
1753 		/*
1754 		 * TEST_ONLY and PAGE_FLIP_EVENT are mutually exclusive,
1755 		 * if they weren't, this code should be called on success
1756 		 * for TEST_ONLY too.
1757 		 */
1758 
1759 		for_each_crtc_in_state(state, crtc, crtc_state, i) {
1760 			if (!crtc_state->event)
1761 				continue;
1762 
1763 			drm_event_cancel_free(dev, &crtc_state->event->base);
1764 		}
1765 	}
1766 
1767 	if (ret == -EDEADLK) {
1768 		drm_atomic_state_clear(state);
1769 		drm_modeset_backoff(&ctx);
1770 		goto retry;
1771 	}
1772 
1773 	if (ret || arg->flags & DRM_MODE_ATOMIC_TEST_ONLY)
1774 		drm_atomic_state_free(state);
1775 
1776 	drm_modeset_drop_locks(&ctx);
1777 	drm_modeset_acquire_fini(&ctx);
1778 
1779 	return ret;
1780 }
1781