xref: /linux/drivers/gpu/drm/drm_atomic_helper.c (revision bb60b8b35a7350585dc4bc2847479cea47f139d4)
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 #include <drm/drmP.h>
29 #include <drm/drm_atomic.h>
30 #include <drm/drm_plane_helper.h>
31 #include <drm/drm_crtc_helper.h>
32 #include <drm/drm_atomic_helper.h>
33 #include <linux/dma-fence.h>
34 
35 #include "drm_crtc_internal.h"
36 
37 /**
38  * DOC: overview
39  *
40  * This helper library provides implementations of check and commit functions on
41  * top of the CRTC modeset helper callbacks and the plane helper callbacks. It
42  * also provides convenience implementations for the atomic state handling
43  * callbacks for drivers which don't need to subclass the drm core structures to
44  * add their own additional internal state.
45  *
46  * This library also provides default implementations for the check callback in
47  * drm_atomic_helper_check() and for the commit callback with
48  * drm_atomic_helper_commit(). But the individual stages and callbacks are
49  * exposed to allow drivers to mix and match and e.g. use the plane helpers only
50  * together with a driver private modeset implementation.
51  *
52  * This library also provides implementations for all the legacy driver
53  * interfaces on top of the atomic interface. See drm_atomic_helper_set_config(),
54  * drm_atomic_helper_disable_plane(), drm_atomic_helper_disable_plane() and the
55  * various functions to implement set_property callbacks. New drivers must not
56  * implement these functions themselves but must use the provided helpers.
57  *
58  * The atomic helper uses the same function table structures as all other
59  * modesetting helpers. See the documentation for struct &drm_crtc_helper_funcs,
60  * struct &drm_encoder_helper_funcs and struct &drm_connector_helper_funcs. It
61  * also shares the struct &drm_plane_helper_funcs function table with the plane
62  * helpers.
63  */
64 static void
65 drm_atomic_helper_plane_changed(struct drm_atomic_state *state,
66 				struct drm_plane_state *plane_state,
67 				struct drm_plane *plane)
68 {
69 	struct drm_crtc_state *crtc_state;
70 
71 	if (plane->state->crtc) {
72 		crtc_state = drm_atomic_get_existing_crtc_state(state,
73 								plane->state->crtc);
74 
75 		if (WARN_ON(!crtc_state))
76 			return;
77 
78 		crtc_state->planes_changed = true;
79 	}
80 
81 	if (plane_state->crtc) {
82 		crtc_state = drm_atomic_get_existing_crtc_state(state,
83 								plane_state->crtc);
84 
85 		if (WARN_ON(!crtc_state))
86 			return;
87 
88 		crtc_state->planes_changed = true;
89 	}
90 }
91 
92 static int handle_conflicting_encoders(struct drm_atomic_state *state,
93 				       bool disable_conflicting_encoders)
94 {
95 	struct drm_connector_state *conn_state;
96 	struct drm_connector *connector;
97 	struct drm_encoder *encoder;
98 	unsigned encoder_mask = 0;
99 	int i, ret;
100 
101 	/*
102 	 * First loop, find all newly assigned encoders from the connectors
103 	 * part of the state. If the same encoder is assigned to multiple
104 	 * connectors bail out.
105 	 */
106 	for_each_connector_in_state(state, connector, conn_state, i) {
107 		const struct drm_connector_helper_funcs *funcs = connector->helper_private;
108 		struct drm_encoder *new_encoder;
109 
110 		if (!conn_state->crtc)
111 			continue;
112 
113 		if (funcs->atomic_best_encoder)
114 			new_encoder = funcs->atomic_best_encoder(connector, conn_state);
115 		else if (funcs->best_encoder)
116 			new_encoder = funcs->best_encoder(connector);
117 		else
118 			new_encoder = drm_atomic_helper_best_encoder(connector);
119 
120 		if (new_encoder) {
121 			if (encoder_mask & (1 << drm_encoder_index(new_encoder))) {
122 				DRM_DEBUG_ATOMIC("[ENCODER:%d:%s] on [CONNECTOR:%d:%s] already assigned\n",
123 					new_encoder->base.id, new_encoder->name,
124 					connector->base.id, connector->name);
125 
126 				return -EINVAL;
127 			}
128 
129 			encoder_mask |= 1 << drm_encoder_index(new_encoder);
130 		}
131 	}
132 
133 	if (!encoder_mask)
134 		return 0;
135 
136 	/*
137 	 * Second loop, iterate over all connectors not part of the state.
138 	 *
139 	 * If a conflicting encoder is found and disable_conflicting_encoders
140 	 * is not set, an error is returned. Userspace can provide a solution
141 	 * through the atomic ioctl.
142 	 *
143 	 * If the flag is set conflicting connectors are removed from the crtc
144 	 * and the crtc is disabled if no encoder is left. This preserves
145 	 * compatibility with the legacy set_config behavior.
146 	 */
147 	drm_for_each_connector(connector, state->dev) {
148 		struct drm_crtc_state *crtc_state;
149 
150 		if (drm_atomic_get_existing_connector_state(state, connector))
151 			continue;
152 
153 		encoder = connector->state->best_encoder;
154 		if (!encoder || !(encoder_mask & (1 << drm_encoder_index(encoder))))
155 			continue;
156 
157 		if (!disable_conflicting_encoders) {
158 			DRM_DEBUG_ATOMIC("[ENCODER:%d:%s] in use on [CRTC:%d:%s] by [CONNECTOR:%d:%s]\n",
159 					 encoder->base.id, encoder->name,
160 					 connector->state->crtc->base.id,
161 					 connector->state->crtc->name,
162 					 connector->base.id, connector->name);
163 			return -EINVAL;
164 		}
165 
166 		conn_state = drm_atomic_get_connector_state(state, connector);
167 		if (IS_ERR(conn_state))
168 			return PTR_ERR(conn_state);
169 
170 		DRM_DEBUG_ATOMIC("[ENCODER:%d:%s] in use on [CRTC:%d:%s], disabling [CONNECTOR:%d:%s]\n",
171 				 encoder->base.id, encoder->name,
172 				 conn_state->crtc->base.id, conn_state->crtc->name,
173 				 connector->base.id, connector->name);
174 
175 		crtc_state = drm_atomic_get_existing_crtc_state(state, conn_state->crtc);
176 
177 		ret = drm_atomic_set_crtc_for_connector(conn_state, NULL);
178 		if (ret)
179 			return ret;
180 
181 		if (!crtc_state->connector_mask) {
182 			ret = drm_atomic_set_mode_prop_for_crtc(crtc_state,
183 								NULL);
184 			if (ret < 0)
185 				return ret;
186 
187 			crtc_state->active = false;
188 		}
189 	}
190 
191 	return 0;
192 }
193 
194 static void
195 set_best_encoder(struct drm_atomic_state *state,
196 		 struct drm_connector_state *conn_state,
197 		 struct drm_encoder *encoder)
198 {
199 	struct drm_crtc_state *crtc_state;
200 	struct drm_crtc *crtc;
201 
202 	if (conn_state->best_encoder) {
203 		/* Unset the encoder_mask in the old crtc state. */
204 		crtc = conn_state->connector->state->crtc;
205 
206 		/* A NULL crtc is an error here because we should have
207 		 *  duplicated a NULL best_encoder when crtc was NULL.
208 		 * As an exception restoring duplicated atomic state
209 		 * during resume is allowed, so don't warn when
210 		 * best_encoder is equal to encoder we intend to set.
211 		 */
212 		WARN_ON(!crtc && encoder != conn_state->best_encoder);
213 		if (crtc) {
214 			crtc_state = drm_atomic_get_existing_crtc_state(state, crtc);
215 
216 			crtc_state->encoder_mask &=
217 				~(1 << drm_encoder_index(conn_state->best_encoder));
218 		}
219 	}
220 
221 	if (encoder) {
222 		crtc = conn_state->crtc;
223 		WARN_ON(!crtc);
224 		if (crtc) {
225 			crtc_state = drm_atomic_get_existing_crtc_state(state, crtc);
226 
227 			crtc_state->encoder_mask |=
228 				1 << drm_encoder_index(encoder);
229 		}
230 	}
231 
232 	conn_state->best_encoder = encoder;
233 }
234 
235 static void
236 steal_encoder(struct drm_atomic_state *state,
237 	      struct drm_encoder *encoder)
238 {
239 	struct drm_crtc_state *crtc_state;
240 	struct drm_connector *connector;
241 	struct drm_connector_state *connector_state;
242 	int i;
243 
244 	for_each_connector_in_state(state, connector, connector_state, i) {
245 		struct drm_crtc *encoder_crtc;
246 
247 		if (connector_state->best_encoder != encoder)
248 			continue;
249 
250 		encoder_crtc = connector->state->crtc;
251 
252 		DRM_DEBUG_ATOMIC("[ENCODER:%d:%s] in use on [CRTC:%d:%s], stealing it\n",
253 				 encoder->base.id, encoder->name,
254 				 encoder_crtc->base.id, encoder_crtc->name);
255 
256 		set_best_encoder(state, connector_state, NULL);
257 
258 		crtc_state = drm_atomic_get_existing_crtc_state(state, encoder_crtc);
259 		crtc_state->connectors_changed = true;
260 
261 		return;
262 	}
263 }
264 
265 static int
266 update_connector_routing(struct drm_atomic_state *state,
267 			 struct drm_connector *connector,
268 			 struct drm_connector_state *connector_state)
269 {
270 	const struct drm_connector_helper_funcs *funcs;
271 	struct drm_encoder *new_encoder;
272 	struct drm_crtc_state *crtc_state;
273 
274 	DRM_DEBUG_ATOMIC("Updating routing for [CONNECTOR:%d:%s]\n",
275 			 connector->base.id,
276 			 connector->name);
277 
278 	if (connector->state->crtc != connector_state->crtc) {
279 		if (connector->state->crtc) {
280 			crtc_state = drm_atomic_get_existing_crtc_state(state, connector->state->crtc);
281 			crtc_state->connectors_changed = true;
282 		}
283 
284 		if (connector_state->crtc) {
285 			crtc_state = drm_atomic_get_existing_crtc_state(state, connector_state->crtc);
286 			crtc_state->connectors_changed = true;
287 		}
288 	}
289 
290 	if (!connector_state->crtc) {
291 		DRM_DEBUG_ATOMIC("Disabling [CONNECTOR:%d:%s]\n",
292 				connector->base.id,
293 				connector->name);
294 
295 		set_best_encoder(state, connector_state, NULL);
296 
297 		return 0;
298 	}
299 
300 	funcs = connector->helper_private;
301 
302 	if (funcs->atomic_best_encoder)
303 		new_encoder = funcs->atomic_best_encoder(connector,
304 							 connector_state);
305 	else if (funcs->best_encoder)
306 		new_encoder = funcs->best_encoder(connector);
307 	else
308 		new_encoder = drm_atomic_helper_best_encoder(connector);
309 
310 	if (!new_encoder) {
311 		DRM_DEBUG_ATOMIC("No suitable encoder found for [CONNECTOR:%d:%s]\n",
312 				 connector->base.id,
313 				 connector->name);
314 		return -EINVAL;
315 	}
316 
317 	if (!drm_encoder_crtc_ok(new_encoder, connector_state->crtc)) {
318 		DRM_DEBUG_ATOMIC("[ENCODER:%d:%s] incompatible with [CRTC:%d]\n",
319 				 new_encoder->base.id,
320 				 new_encoder->name,
321 				 connector_state->crtc->base.id);
322 		return -EINVAL;
323 	}
324 
325 	if (new_encoder == connector_state->best_encoder) {
326 		set_best_encoder(state, connector_state, new_encoder);
327 
328 		DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] keeps [ENCODER:%d:%s], now on [CRTC:%d:%s]\n",
329 				 connector->base.id,
330 				 connector->name,
331 				 new_encoder->base.id,
332 				 new_encoder->name,
333 				 connector_state->crtc->base.id,
334 				 connector_state->crtc->name);
335 
336 		return 0;
337 	}
338 
339 	steal_encoder(state, new_encoder);
340 
341 	set_best_encoder(state, connector_state, new_encoder);
342 
343 	crtc_state = drm_atomic_get_existing_crtc_state(state, connector_state->crtc);
344 	crtc_state->connectors_changed = true;
345 
346 	DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] using [ENCODER:%d:%s] on [CRTC:%d:%s]\n",
347 			 connector->base.id,
348 			 connector->name,
349 			 new_encoder->base.id,
350 			 new_encoder->name,
351 			 connector_state->crtc->base.id,
352 			 connector_state->crtc->name);
353 
354 	return 0;
355 }
356 
357 static int
358 mode_fixup(struct drm_atomic_state *state)
359 {
360 	struct drm_crtc *crtc;
361 	struct drm_crtc_state *crtc_state;
362 	struct drm_connector *connector;
363 	struct drm_connector_state *conn_state;
364 	int i;
365 	bool ret;
366 
367 	for_each_crtc_in_state(state, crtc, crtc_state, i) {
368 		if (!crtc_state->mode_changed &&
369 		    !crtc_state->connectors_changed)
370 			continue;
371 
372 		drm_mode_copy(&crtc_state->adjusted_mode, &crtc_state->mode);
373 	}
374 
375 	for_each_connector_in_state(state, connector, conn_state, i) {
376 		const struct drm_encoder_helper_funcs *funcs;
377 		struct drm_encoder *encoder;
378 
379 		WARN_ON(!!conn_state->best_encoder != !!conn_state->crtc);
380 
381 		if (!conn_state->crtc || !conn_state->best_encoder)
382 			continue;
383 
384 		crtc_state = drm_atomic_get_existing_crtc_state(state,
385 								conn_state->crtc);
386 
387 		/*
388 		 * Each encoder has at most one connector (since we always steal
389 		 * it away), so we won't call ->mode_fixup twice.
390 		 */
391 		encoder = conn_state->best_encoder;
392 		funcs = encoder->helper_private;
393 
394 		ret = drm_bridge_mode_fixup(encoder->bridge, &crtc_state->mode,
395 				&crtc_state->adjusted_mode);
396 		if (!ret) {
397 			DRM_DEBUG_ATOMIC("Bridge fixup failed\n");
398 			return -EINVAL;
399 		}
400 
401 		if (funcs && funcs->atomic_check) {
402 			ret = funcs->atomic_check(encoder, crtc_state,
403 						  conn_state);
404 			if (ret) {
405 				DRM_DEBUG_ATOMIC("[ENCODER:%d:%s] check failed\n",
406 						 encoder->base.id, encoder->name);
407 				return ret;
408 			}
409 		} else if (funcs && funcs->mode_fixup) {
410 			ret = funcs->mode_fixup(encoder, &crtc_state->mode,
411 						&crtc_state->adjusted_mode);
412 			if (!ret) {
413 				DRM_DEBUG_ATOMIC("[ENCODER:%d:%s] fixup failed\n",
414 						 encoder->base.id, encoder->name);
415 				return -EINVAL;
416 			}
417 		}
418 	}
419 
420 	for_each_crtc_in_state(state, crtc, crtc_state, i) {
421 		const struct drm_crtc_helper_funcs *funcs;
422 
423 		if (!crtc_state->enable)
424 			continue;
425 
426 		if (!crtc_state->mode_changed &&
427 		    !crtc_state->connectors_changed)
428 			continue;
429 
430 		funcs = crtc->helper_private;
431 		if (!funcs->mode_fixup)
432 			continue;
433 
434 		ret = funcs->mode_fixup(crtc, &crtc_state->mode,
435 					&crtc_state->adjusted_mode);
436 		if (!ret) {
437 			DRM_DEBUG_ATOMIC("[CRTC:%d:%s] fixup failed\n",
438 					 crtc->base.id, crtc->name);
439 			return -EINVAL;
440 		}
441 	}
442 
443 	return 0;
444 }
445 
446 /**
447  * drm_atomic_helper_check_modeset - validate state object for modeset changes
448  * @dev: DRM device
449  * @state: the driver state object
450  *
451  * Check the state object to see if the requested state is physically possible.
452  * This does all the crtc and connector related computations for an atomic
453  * update and adds any additional connectors needed for full modesets and calls
454  * down into ->mode_fixup functions of the driver backend.
455  *
456  * crtc_state->mode_changed is set when the input mode is changed.
457  * crtc_state->connectors_changed is set when a connector is added or
458  * removed from the crtc.
459  * crtc_state->active_changed is set when crtc_state->active changes,
460  * which is used for dpms.
461  * See also: drm_atomic_crtc_needs_modeset()
462  *
463  * IMPORTANT:
464  *
465  * Drivers which set ->mode_changed (e.g. in their ->atomic_check hooks if a
466  * plane update can't be done without a full modeset) _must_ call this function
467  * afterwards after that change. It is permitted to call this function multiple
468  * times for the same update, e.g. when the ->atomic_check functions depend upon
469  * the adjusted dotclock for fifo space allocation and watermark computation.
470  *
471  * RETURNS:
472  * Zero for success or -errno
473  */
474 int
475 drm_atomic_helper_check_modeset(struct drm_device *dev,
476 				struct drm_atomic_state *state)
477 {
478 	struct drm_crtc *crtc;
479 	struct drm_crtc_state *crtc_state;
480 	struct drm_connector *connector;
481 	struct drm_connector_state *connector_state;
482 	int i, ret;
483 
484 	for_each_crtc_in_state(state, crtc, crtc_state, i) {
485 		if (!drm_mode_equal(&crtc->state->mode, &crtc_state->mode)) {
486 			DRM_DEBUG_ATOMIC("[CRTC:%d:%s] mode changed\n",
487 					 crtc->base.id, crtc->name);
488 			crtc_state->mode_changed = true;
489 		}
490 
491 		if (crtc->state->enable != crtc_state->enable) {
492 			DRM_DEBUG_ATOMIC("[CRTC:%d:%s] enable changed\n",
493 					 crtc->base.id, crtc->name);
494 
495 			/*
496 			 * For clarity this assignment is done here, but
497 			 * enable == 0 is only true when there are no
498 			 * connectors and a NULL mode.
499 			 *
500 			 * The other way around is true as well. enable != 0
501 			 * iff connectors are attached and a mode is set.
502 			 */
503 			crtc_state->mode_changed = true;
504 			crtc_state->connectors_changed = true;
505 		}
506 	}
507 
508 	ret = handle_conflicting_encoders(state, state->legacy_set_config);
509 	if (ret)
510 		return ret;
511 
512 	for_each_connector_in_state(state, connector, connector_state, i) {
513 		/*
514 		 * This only sets crtc->connectors_changed for routing changes,
515 		 * drivers must set crtc->connectors_changed themselves when
516 		 * connector properties need to be updated.
517 		 */
518 		ret = update_connector_routing(state, connector,
519 					       connector_state);
520 		if (ret)
521 			return ret;
522 	}
523 
524 	/*
525 	 * After all the routing has been prepared we need to add in any
526 	 * connector which is itself unchanged, but who's crtc changes it's
527 	 * configuration. This must be done before calling mode_fixup in case a
528 	 * crtc only changed its mode but has the same set of connectors.
529 	 */
530 	for_each_crtc_in_state(state, crtc, crtc_state, i) {
531 		bool has_connectors =
532 			!!crtc_state->connector_mask;
533 
534 		/*
535 		 * We must set ->active_changed after walking connectors for
536 		 * otherwise an update that only changes active would result in
537 		 * a full modeset because update_connector_routing force that.
538 		 */
539 		if (crtc->state->active != crtc_state->active) {
540 			DRM_DEBUG_ATOMIC("[CRTC:%d:%s] active changed\n",
541 					 crtc->base.id, crtc->name);
542 			crtc_state->active_changed = true;
543 		}
544 
545 		if (!drm_atomic_crtc_needs_modeset(crtc_state))
546 			continue;
547 
548 		DRM_DEBUG_ATOMIC("[CRTC:%d:%s] needs all connectors, enable: %c, active: %c\n",
549 				 crtc->base.id, crtc->name,
550 				 crtc_state->enable ? 'y' : 'n',
551 				 crtc_state->active ? 'y' : 'n');
552 
553 		ret = drm_atomic_add_affected_connectors(state, crtc);
554 		if (ret != 0)
555 			return ret;
556 
557 		ret = drm_atomic_add_affected_planes(state, crtc);
558 		if (ret != 0)
559 			return ret;
560 
561 		if (crtc_state->enable != has_connectors) {
562 			DRM_DEBUG_ATOMIC("[CRTC:%d:%s] enabled/connectors mismatch\n",
563 					 crtc->base.id, crtc->name);
564 
565 			return -EINVAL;
566 		}
567 	}
568 
569 	return mode_fixup(state);
570 }
571 EXPORT_SYMBOL(drm_atomic_helper_check_modeset);
572 
573 /**
574  * drm_atomic_helper_check_planes - validate state object for planes changes
575  * @dev: DRM device
576  * @state: the driver state object
577  *
578  * Check the state object to see if the requested state is physically possible.
579  * This does all the plane update related checks using by calling into the
580  * ->atomic_check hooks provided by the driver.
581  *
582  * It also sets crtc_state->planes_changed to indicate that a crtc has
583  * updated planes.
584  *
585  * RETURNS:
586  * Zero for success or -errno
587  */
588 int
589 drm_atomic_helper_check_planes(struct drm_device *dev,
590 			       struct drm_atomic_state *state)
591 {
592 	struct drm_crtc *crtc;
593 	struct drm_crtc_state *crtc_state;
594 	struct drm_plane *plane;
595 	struct drm_plane_state *plane_state;
596 	int i, ret = 0;
597 
598 	for_each_plane_in_state(state, plane, plane_state, i) {
599 		const struct drm_plane_helper_funcs *funcs;
600 
601 		funcs = plane->helper_private;
602 
603 		drm_atomic_helper_plane_changed(state, plane_state, plane);
604 
605 		if (!funcs || !funcs->atomic_check)
606 			continue;
607 
608 		ret = funcs->atomic_check(plane, plane_state);
609 		if (ret) {
610 			DRM_DEBUG_ATOMIC("[PLANE:%d:%s] atomic driver check failed\n",
611 					 plane->base.id, plane->name);
612 			return ret;
613 		}
614 	}
615 
616 	for_each_crtc_in_state(state, crtc, crtc_state, i) {
617 		const struct drm_crtc_helper_funcs *funcs;
618 
619 		funcs = crtc->helper_private;
620 
621 		if (!funcs || !funcs->atomic_check)
622 			continue;
623 
624 		ret = funcs->atomic_check(crtc, crtc_state);
625 		if (ret) {
626 			DRM_DEBUG_ATOMIC("[CRTC:%d:%s] atomic driver check failed\n",
627 					 crtc->base.id, crtc->name);
628 			return ret;
629 		}
630 	}
631 
632 	return ret;
633 }
634 EXPORT_SYMBOL(drm_atomic_helper_check_planes);
635 
636 /**
637  * drm_atomic_helper_check - validate state object
638  * @dev: DRM device
639  * @state: the driver state object
640  *
641  * Check the state object to see if the requested state is physically possible.
642  * Only crtcs and planes have check callbacks, so for any additional (global)
643  * checking that a driver needs it can simply wrap that around this function.
644  * Drivers without such needs can directly use this as their ->atomic_check()
645  * callback.
646  *
647  * This just wraps the two parts of the state checking for planes and modeset
648  * state in the default order: First it calls drm_atomic_helper_check_modeset()
649  * and then drm_atomic_helper_check_planes(). The assumption is that the
650  * ->atomic_check functions depend upon an updated adjusted_mode.clock to
651  * e.g. properly compute watermarks.
652  *
653  * RETURNS:
654  * Zero for success or -errno
655  */
656 int drm_atomic_helper_check(struct drm_device *dev,
657 			    struct drm_atomic_state *state)
658 {
659 	int ret;
660 
661 	ret = drm_atomic_helper_check_modeset(dev, state);
662 	if (ret)
663 		return ret;
664 
665 	ret = drm_atomic_helper_check_planes(dev, state);
666 	if (ret)
667 		return ret;
668 
669 	return ret;
670 }
671 EXPORT_SYMBOL(drm_atomic_helper_check);
672 
673 static void
674 disable_outputs(struct drm_device *dev, struct drm_atomic_state *old_state)
675 {
676 	struct drm_connector *connector;
677 	struct drm_connector_state *old_conn_state;
678 	struct drm_crtc *crtc;
679 	struct drm_crtc_state *old_crtc_state;
680 	int i;
681 
682 	for_each_connector_in_state(old_state, connector, old_conn_state, i) {
683 		const struct drm_encoder_helper_funcs *funcs;
684 		struct drm_encoder *encoder;
685 
686 		/* Shut down everything that's in the changeset and currently
687 		 * still on. So need to check the old, saved state. */
688 		if (!old_conn_state->crtc)
689 			continue;
690 
691 		old_crtc_state = drm_atomic_get_existing_crtc_state(old_state,
692 								    old_conn_state->crtc);
693 
694 		if (!old_crtc_state->active ||
695 		    !drm_atomic_crtc_needs_modeset(old_conn_state->crtc->state))
696 			continue;
697 
698 		encoder = old_conn_state->best_encoder;
699 
700 		/* We shouldn't get this far if we didn't previously have
701 		 * an encoder.. but WARN_ON() rather than explode.
702 		 */
703 		if (WARN_ON(!encoder))
704 			continue;
705 
706 		funcs = encoder->helper_private;
707 
708 		DRM_DEBUG_ATOMIC("disabling [ENCODER:%d:%s]\n",
709 				 encoder->base.id, encoder->name);
710 
711 		/*
712 		 * Each encoder has at most one connector (since we always steal
713 		 * it away), so we won't call disable hooks twice.
714 		 */
715 		drm_bridge_disable(encoder->bridge);
716 
717 		/* Right function depends upon target state. */
718 		if (funcs) {
719 			if (connector->state->crtc && funcs->prepare)
720 				funcs->prepare(encoder);
721 			else if (funcs->disable)
722 				funcs->disable(encoder);
723 			else if (funcs->dpms)
724 				funcs->dpms(encoder, DRM_MODE_DPMS_OFF);
725 		}
726 
727 		drm_bridge_post_disable(encoder->bridge);
728 	}
729 
730 	for_each_crtc_in_state(old_state, crtc, old_crtc_state, i) {
731 		const struct drm_crtc_helper_funcs *funcs;
732 
733 		/* Shut down everything that needs a full modeset. */
734 		if (!drm_atomic_crtc_needs_modeset(crtc->state))
735 			continue;
736 
737 		if (!old_crtc_state->active)
738 			continue;
739 
740 		funcs = crtc->helper_private;
741 
742 		DRM_DEBUG_ATOMIC("disabling [CRTC:%d:%s]\n",
743 				 crtc->base.id, crtc->name);
744 
745 
746 		/* Right function depends upon target state. */
747 		if (crtc->state->enable && funcs->prepare)
748 			funcs->prepare(crtc);
749 		else if (funcs->atomic_disable)
750 			funcs->atomic_disable(crtc, old_crtc_state);
751 		else if (funcs->disable)
752 			funcs->disable(crtc);
753 		else
754 			funcs->dpms(crtc, DRM_MODE_DPMS_OFF);
755 	}
756 }
757 
758 /**
759  * drm_atomic_helper_update_legacy_modeset_state - update legacy modeset state
760  * @dev: DRM device
761  * @old_state: atomic state object with old state structures
762  *
763  * This function updates all the various legacy modeset state pointers in
764  * connectors, encoders and crtcs. It also updates the timestamping constants
765  * used for precise vblank timestamps by calling
766  * drm_calc_timestamping_constants().
767  *
768  * Drivers can use this for building their own atomic commit if they don't have
769  * a pure helper-based modeset implementation.
770  */
771 void
772 drm_atomic_helper_update_legacy_modeset_state(struct drm_device *dev,
773 					      struct drm_atomic_state *old_state)
774 {
775 	struct drm_connector *connector;
776 	struct drm_connector_state *old_conn_state;
777 	struct drm_crtc *crtc;
778 	struct drm_crtc_state *old_crtc_state;
779 	int i;
780 
781 	/* clear out existing links and update dpms */
782 	for_each_connector_in_state(old_state, connector, old_conn_state, i) {
783 		if (connector->encoder) {
784 			WARN_ON(!connector->encoder->crtc);
785 
786 			connector->encoder->crtc = NULL;
787 			connector->encoder = NULL;
788 		}
789 
790 		crtc = connector->state->crtc;
791 		if ((!crtc && old_conn_state->crtc) ||
792 		    (crtc && drm_atomic_crtc_needs_modeset(crtc->state))) {
793 			struct drm_property *dpms_prop =
794 				dev->mode_config.dpms_property;
795 			int mode = DRM_MODE_DPMS_OFF;
796 
797 			if (crtc && crtc->state->active)
798 				mode = DRM_MODE_DPMS_ON;
799 
800 			connector->dpms = mode;
801 			drm_object_property_set_value(&connector->base,
802 						      dpms_prop, mode);
803 		}
804 	}
805 
806 	/* set new links */
807 	for_each_connector_in_state(old_state, connector, old_conn_state, i) {
808 		if (!connector->state->crtc)
809 			continue;
810 
811 		if (WARN_ON(!connector->state->best_encoder))
812 			continue;
813 
814 		connector->encoder = connector->state->best_encoder;
815 		connector->encoder->crtc = connector->state->crtc;
816 	}
817 
818 	/* set legacy state in the crtc structure */
819 	for_each_crtc_in_state(old_state, crtc, old_crtc_state, i) {
820 		struct drm_plane *primary = crtc->primary;
821 
822 		crtc->mode = crtc->state->mode;
823 		crtc->enabled = crtc->state->enable;
824 
825 		if (drm_atomic_get_existing_plane_state(old_state, primary) &&
826 		    primary->state->crtc == crtc) {
827 			crtc->x = primary->state->src_x >> 16;
828 			crtc->y = primary->state->src_y >> 16;
829 		}
830 
831 		if (crtc->state->enable)
832 			drm_calc_timestamping_constants(crtc,
833 							&crtc->state->adjusted_mode);
834 	}
835 }
836 EXPORT_SYMBOL(drm_atomic_helper_update_legacy_modeset_state);
837 
838 static void
839 crtc_set_mode(struct drm_device *dev, struct drm_atomic_state *old_state)
840 {
841 	struct drm_crtc *crtc;
842 	struct drm_crtc_state *old_crtc_state;
843 	struct drm_connector *connector;
844 	struct drm_connector_state *old_conn_state;
845 	int i;
846 
847 	for_each_crtc_in_state(old_state, crtc, old_crtc_state, i) {
848 		const struct drm_crtc_helper_funcs *funcs;
849 
850 		if (!crtc->state->mode_changed)
851 			continue;
852 
853 		funcs = crtc->helper_private;
854 
855 		if (crtc->state->enable && funcs->mode_set_nofb) {
856 			DRM_DEBUG_ATOMIC("modeset on [CRTC:%d:%s]\n",
857 					 crtc->base.id, crtc->name);
858 
859 			funcs->mode_set_nofb(crtc);
860 		}
861 	}
862 
863 	for_each_connector_in_state(old_state, connector, old_conn_state, i) {
864 		const struct drm_encoder_helper_funcs *funcs;
865 		struct drm_crtc_state *new_crtc_state;
866 		struct drm_encoder *encoder;
867 		struct drm_display_mode *mode, *adjusted_mode;
868 
869 		if (!connector->state->best_encoder)
870 			continue;
871 
872 		encoder = connector->state->best_encoder;
873 		funcs = encoder->helper_private;
874 		new_crtc_state = connector->state->crtc->state;
875 		mode = &new_crtc_state->mode;
876 		adjusted_mode = &new_crtc_state->adjusted_mode;
877 
878 		if (!new_crtc_state->mode_changed)
879 			continue;
880 
881 		DRM_DEBUG_ATOMIC("modeset on [ENCODER:%d:%s]\n",
882 				 encoder->base.id, encoder->name);
883 
884 		/*
885 		 * Each encoder has at most one connector (since we always steal
886 		 * it away), so we won't call mode_set hooks twice.
887 		 */
888 		if (funcs && funcs->atomic_mode_set) {
889 			funcs->atomic_mode_set(encoder, new_crtc_state,
890 					       connector->state);
891 		} else if (funcs && funcs->mode_set) {
892 			funcs->mode_set(encoder, mode, adjusted_mode);
893 		}
894 
895 		drm_bridge_mode_set(encoder->bridge, mode, adjusted_mode);
896 	}
897 }
898 
899 /**
900  * drm_atomic_helper_commit_modeset_disables - modeset commit to disable outputs
901  * @dev: DRM device
902  * @old_state: atomic state object with old state structures
903  *
904  * This function shuts down all the outputs that need to be shut down and
905  * prepares them (if required) with the new mode.
906  *
907  * For compatibility with legacy crtc helpers this should be called before
908  * drm_atomic_helper_commit_planes(), which is what the default commit function
909  * does. But drivers with different needs can group the modeset commits together
910  * and do the plane commits at the end. This is useful for drivers doing runtime
911  * PM since planes updates then only happen when the CRTC is actually enabled.
912  */
913 void drm_atomic_helper_commit_modeset_disables(struct drm_device *dev,
914 					       struct drm_atomic_state *old_state)
915 {
916 	disable_outputs(dev, old_state);
917 
918 	drm_atomic_helper_update_legacy_modeset_state(dev, old_state);
919 
920 	crtc_set_mode(dev, old_state);
921 }
922 EXPORT_SYMBOL(drm_atomic_helper_commit_modeset_disables);
923 
924 /**
925  * drm_atomic_helper_commit_modeset_enables - modeset commit to enable outputs
926  * @dev: DRM device
927  * @old_state: atomic state object with old state structures
928  *
929  * This function enables all the outputs with the new configuration which had to
930  * be turned off for the update.
931  *
932  * For compatibility with legacy crtc helpers this should be called after
933  * drm_atomic_helper_commit_planes(), which is what the default commit function
934  * does. But drivers with different needs can group the modeset commits together
935  * and do the plane commits at the end. This is useful for drivers doing runtime
936  * PM since planes updates then only happen when the CRTC is actually enabled.
937  */
938 void drm_atomic_helper_commit_modeset_enables(struct drm_device *dev,
939 					      struct drm_atomic_state *old_state)
940 {
941 	struct drm_crtc *crtc;
942 	struct drm_crtc_state *old_crtc_state;
943 	struct drm_connector *connector;
944 	struct drm_connector_state *old_conn_state;
945 	int i;
946 
947 	for_each_crtc_in_state(old_state, crtc, old_crtc_state, i) {
948 		const struct drm_crtc_helper_funcs *funcs;
949 
950 		/* Need to filter out CRTCs where only planes change. */
951 		if (!drm_atomic_crtc_needs_modeset(crtc->state))
952 			continue;
953 
954 		if (!crtc->state->active)
955 			continue;
956 
957 		funcs = crtc->helper_private;
958 
959 		if (crtc->state->enable) {
960 			DRM_DEBUG_ATOMIC("enabling [CRTC:%d:%s]\n",
961 					 crtc->base.id, crtc->name);
962 
963 			if (funcs->enable)
964 				funcs->enable(crtc);
965 			else
966 				funcs->commit(crtc);
967 		}
968 	}
969 
970 	for_each_connector_in_state(old_state, connector, old_conn_state, i) {
971 		const struct drm_encoder_helper_funcs *funcs;
972 		struct drm_encoder *encoder;
973 
974 		if (!connector->state->best_encoder)
975 			continue;
976 
977 		if (!connector->state->crtc->state->active ||
978 		    !drm_atomic_crtc_needs_modeset(connector->state->crtc->state))
979 			continue;
980 
981 		encoder = connector->state->best_encoder;
982 		funcs = encoder->helper_private;
983 
984 		DRM_DEBUG_ATOMIC("enabling [ENCODER:%d:%s]\n",
985 				 encoder->base.id, encoder->name);
986 
987 		/*
988 		 * Each encoder has at most one connector (since we always steal
989 		 * it away), so we won't call enable hooks twice.
990 		 */
991 		drm_bridge_pre_enable(encoder->bridge);
992 
993 		if (funcs) {
994 			if (funcs->enable)
995 				funcs->enable(encoder);
996 			else if (funcs->commit)
997 				funcs->commit(encoder);
998 		}
999 
1000 		drm_bridge_enable(encoder->bridge);
1001 	}
1002 }
1003 EXPORT_SYMBOL(drm_atomic_helper_commit_modeset_enables);
1004 
1005 /**
1006  * drm_atomic_helper_wait_for_fences - wait for fences stashed in plane state
1007  * @dev: DRM device
1008  * @state: atomic state object with old state structures
1009  * @pre_swap: If true, do an interruptible wait, and @state is the new state.
1010  * 	Otherwise @state is the old state.
1011  *
1012  * For implicit sync, driver should fish the exclusive fence out from the
1013  * incoming fb's and stash it in the drm_plane_state.  This is called after
1014  * drm_atomic_helper_swap_state() so it uses the current plane state (and
1015  * just uses the atomic state to find the changed planes)
1016  *
1017  * Note that @pre_swap is needed since the point where we block for fences moves
1018  * around depending upon whether an atomic commit is blocking or
1019  * non-blocking. For async commit all waiting needs to happen after
1020  * drm_atomic_helper_swap_state() is called, but for synchronous commits we want
1021  * to wait **before** we do anything that can't be easily rolled back. That is
1022  * before we call drm_atomic_helper_swap_state().
1023  *
1024  * Returns zero if success or < 0 if dma_fence_wait() fails.
1025  */
1026 int drm_atomic_helper_wait_for_fences(struct drm_device *dev,
1027 				      struct drm_atomic_state *state,
1028 				      bool pre_swap)
1029 {
1030 	struct drm_plane *plane;
1031 	struct drm_plane_state *plane_state;
1032 	int i, ret;
1033 
1034 	for_each_plane_in_state(state, plane, plane_state, i) {
1035 		if (!pre_swap)
1036 			plane_state = plane->state;
1037 
1038 		if (!plane_state->fence)
1039 			continue;
1040 
1041 		WARN_ON(!plane_state->fb);
1042 
1043 		/*
1044 		 * If waiting for fences pre-swap (ie: nonblock), userspace can
1045 		 * still interrupt the operation. Instead of blocking until the
1046 		 * timer expires, make the wait interruptible.
1047 		 */
1048 		ret = dma_fence_wait(plane_state->fence, pre_swap);
1049 		if (ret)
1050 			return ret;
1051 
1052 		dma_fence_put(plane_state->fence);
1053 		plane_state->fence = NULL;
1054 	}
1055 
1056 	return 0;
1057 }
1058 EXPORT_SYMBOL(drm_atomic_helper_wait_for_fences);
1059 
1060 /**
1061  * drm_atomic_helper_framebuffer_changed - check if framebuffer has changed
1062  * @dev: DRM device
1063  * @old_state: atomic state object with old state structures
1064  * @crtc: DRM crtc
1065  *
1066  * Checks whether the framebuffer used for this CRTC changes as a result of
1067  * the atomic update.  This is useful for drivers which cannot use
1068  * drm_atomic_helper_wait_for_vblanks() and need to reimplement its
1069  * functionality.
1070  *
1071  * Returns:
1072  * true if the framebuffer changed.
1073  */
1074 bool drm_atomic_helper_framebuffer_changed(struct drm_device *dev,
1075 					   struct drm_atomic_state *old_state,
1076 					   struct drm_crtc *crtc)
1077 {
1078 	struct drm_plane *plane;
1079 	struct drm_plane_state *old_plane_state;
1080 	int i;
1081 
1082 	for_each_plane_in_state(old_state, plane, old_plane_state, i) {
1083 		if (plane->state->crtc != crtc &&
1084 		    old_plane_state->crtc != crtc)
1085 			continue;
1086 
1087 		if (plane->state->fb != old_plane_state->fb)
1088 			return true;
1089 	}
1090 
1091 	return false;
1092 }
1093 EXPORT_SYMBOL(drm_atomic_helper_framebuffer_changed);
1094 
1095 /**
1096  * drm_atomic_helper_wait_for_vblanks - wait for vblank on crtcs
1097  * @dev: DRM device
1098  * @old_state: atomic state object with old state structures
1099  *
1100  * Helper to, after atomic commit, wait for vblanks on all effected
1101  * crtcs (ie. before cleaning up old framebuffers using
1102  * drm_atomic_helper_cleanup_planes()). It will only wait on crtcs where the
1103  * framebuffers have actually changed to optimize for the legacy cursor and
1104  * plane update use-case.
1105  */
1106 void
1107 drm_atomic_helper_wait_for_vblanks(struct drm_device *dev,
1108 		struct drm_atomic_state *old_state)
1109 {
1110 	struct drm_crtc *crtc;
1111 	struct drm_crtc_state *old_crtc_state;
1112 	int i, ret;
1113 
1114 	for_each_crtc_in_state(old_state, crtc, old_crtc_state, i) {
1115 		/* No one cares about the old state, so abuse it for tracking
1116 		 * and store whether we hold a vblank reference (and should do a
1117 		 * vblank wait) in the ->enable boolean. */
1118 		old_crtc_state->enable = false;
1119 
1120 		if (!crtc->state->enable)
1121 			continue;
1122 
1123 		/* Legacy cursor ioctls are completely unsynced, and userspace
1124 		 * relies on that (by doing tons of cursor updates). */
1125 		if (old_state->legacy_cursor_update)
1126 			continue;
1127 
1128 		if (!drm_atomic_helper_framebuffer_changed(dev,
1129 				old_state, crtc))
1130 			continue;
1131 
1132 		ret = drm_crtc_vblank_get(crtc);
1133 		if (ret != 0)
1134 			continue;
1135 
1136 		old_crtc_state->enable = true;
1137 		old_crtc_state->last_vblank_count = drm_crtc_vblank_count(crtc);
1138 	}
1139 
1140 	for_each_crtc_in_state(old_state, crtc, old_crtc_state, i) {
1141 		if (!old_crtc_state->enable)
1142 			continue;
1143 
1144 		ret = wait_event_timeout(dev->vblank[i].queue,
1145 				old_crtc_state->last_vblank_count !=
1146 					drm_crtc_vblank_count(crtc),
1147 				msecs_to_jiffies(50));
1148 
1149 		WARN(!ret, "[CRTC:%d] vblank wait timed out\n", crtc->base.id);
1150 
1151 		drm_crtc_vblank_put(crtc);
1152 	}
1153 }
1154 EXPORT_SYMBOL(drm_atomic_helper_wait_for_vblanks);
1155 
1156 /**
1157  * drm_atomic_helper_commit_tail - commit atomic update to hardware
1158  * @old_state: atomic state object with old state structures
1159  *
1160  * This is the default implemenation for the ->atomic_commit_tail() hook of the
1161  * &drm_mode_config_helper_funcs vtable.
1162  *
1163  * Note that the default ordering of how the various stages are called is to
1164  * match the legacy modeset helper library closest. One peculiarity of that is
1165  * that it doesn't mesh well with runtime PM at all.
1166  *
1167  * For drivers supporting runtime PM the recommended sequence is instead ::
1168  *
1169  *     drm_atomic_helper_commit_modeset_disables(dev, old_state);
1170  *
1171  *     drm_atomic_helper_commit_modeset_enables(dev, old_state);
1172  *
1173  *     drm_atomic_helper_commit_planes(dev, old_state,
1174  *                                     DRM_PLANE_COMMIT_ACTIVE_ONLY);
1175  *
1176  * for committing the atomic update to hardware.  See the kerneldoc entries for
1177  * these three functions for more details.
1178  */
1179 void drm_atomic_helper_commit_tail(struct drm_atomic_state *old_state)
1180 {
1181 	struct drm_device *dev = old_state->dev;
1182 
1183 	drm_atomic_helper_commit_modeset_disables(dev, old_state);
1184 
1185 	drm_atomic_helper_commit_planes(dev, old_state, 0);
1186 
1187 	drm_atomic_helper_commit_modeset_enables(dev, old_state);
1188 
1189 	drm_atomic_helper_commit_hw_done(old_state);
1190 
1191 	drm_atomic_helper_wait_for_vblanks(dev, old_state);
1192 
1193 	drm_atomic_helper_cleanup_planes(dev, old_state);
1194 }
1195 EXPORT_SYMBOL(drm_atomic_helper_commit_tail);
1196 
1197 static void commit_tail(struct drm_atomic_state *old_state)
1198 {
1199 	struct drm_device *dev = old_state->dev;
1200 	struct drm_mode_config_helper_funcs *funcs;
1201 
1202 	funcs = dev->mode_config.helper_private;
1203 
1204 	drm_atomic_helper_wait_for_fences(dev, old_state, false);
1205 
1206 	drm_atomic_helper_wait_for_dependencies(old_state);
1207 
1208 	if (funcs && funcs->atomic_commit_tail)
1209 		funcs->atomic_commit_tail(old_state);
1210 	else
1211 		drm_atomic_helper_commit_tail(old_state);
1212 
1213 	drm_atomic_helper_commit_cleanup_done(old_state);
1214 
1215 	drm_atomic_state_put(old_state);
1216 }
1217 
1218 static void commit_work(struct work_struct *work)
1219 {
1220 	struct drm_atomic_state *state = container_of(work,
1221 						      struct drm_atomic_state,
1222 						      commit_work);
1223 	commit_tail(state);
1224 }
1225 
1226 /**
1227  * drm_atomic_helper_commit - commit validated state object
1228  * @dev: DRM device
1229  * @state: the driver state object
1230  * @nonblock: whether nonblocking behavior is requested.
1231  *
1232  * This function commits a with drm_atomic_helper_check() pre-validated state
1233  * object. This can still fail when e.g. the framebuffer reservation fails. This
1234  * function implements nonblocking commits, using
1235  * drm_atomic_helper_setup_commit() and related functions.
1236  *
1237  * Committing the actual hardware state is done through the
1238  * ->atomic_commit_tail() callback of the &drm_mode_config_helper_funcs vtable,
1239  * or it's default implementation drm_atomic_helper_commit_tail().
1240  *
1241  * RETURNS:
1242  * Zero for success or -errno.
1243  */
1244 int drm_atomic_helper_commit(struct drm_device *dev,
1245 			     struct drm_atomic_state *state,
1246 			     bool nonblock)
1247 {
1248 	int ret;
1249 
1250 	ret = drm_atomic_helper_setup_commit(state, nonblock);
1251 	if (ret)
1252 		return ret;
1253 
1254 	INIT_WORK(&state->commit_work, commit_work);
1255 
1256 	ret = drm_atomic_helper_prepare_planes(dev, state);
1257 	if (ret)
1258 		return ret;
1259 
1260 	if (!nonblock) {
1261 		ret = drm_atomic_helper_wait_for_fences(dev, state, true);
1262 		if (ret) {
1263 			drm_atomic_helper_cleanup_planes(dev, state);
1264 			return ret;
1265 		}
1266 	}
1267 
1268 	/*
1269 	 * This is the point of no return - everything below never fails except
1270 	 * when the hw goes bonghits. Which means we can commit the new state on
1271 	 * the software side now.
1272 	 */
1273 
1274 	drm_atomic_helper_swap_state(state, true);
1275 
1276 	/*
1277 	 * Everything below can be run asynchronously without the need to grab
1278 	 * any modeset locks at all under one condition: It must be guaranteed
1279 	 * that the asynchronous work has either been cancelled (if the driver
1280 	 * supports it, which at least requires that the framebuffers get
1281 	 * cleaned up with drm_atomic_helper_cleanup_planes()) or completed
1282 	 * before the new state gets committed on the software side with
1283 	 * drm_atomic_helper_swap_state().
1284 	 *
1285 	 * This scheme allows new atomic state updates to be prepared and
1286 	 * checked in parallel to the asynchronous completion of the previous
1287 	 * update. Which is important since compositors need to figure out the
1288 	 * composition of the next frame right after having submitted the
1289 	 * current layout.
1290 	 *
1291 	 * NOTE: Commit work has multiple phases, first hardware commit, then
1292 	 * cleanup. We want them to overlap, hence need system_unbound_wq to
1293 	 * make sure work items don't artifically stall on each another.
1294 	 */
1295 
1296 	drm_atomic_state_get(state);
1297 	if (nonblock)
1298 		queue_work(system_unbound_wq, &state->commit_work);
1299 	else
1300 		commit_tail(state);
1301 
1302 	return 0;
1303 }
1304 EXPORT_SYMBOL(drm_atomic_helper_commit);
1305 
1306 /**
1307  * DOC: implementing nonblocking commit
1308  *
1309  * Nonblocking atomic commits have to be implemented in the following sequence:
1310  *
1311  * 1. Run drm_atomic_helper_prepare_planes() first. This is the only function
1312  * which commit needs to call which can fail, so we want to run it first and
1313  * synchronously.
1314  *
1315  * 2. Synchronize with any outstanding nonblocking commit worker threads which
1316  * might be affected the new state update. This can be done by either cancelling
1317  * or flushing the work items, depending upon whether the driver can deal with
1318  * cancelled updates. Note that it is important to ensure that the framebuffer
1319  * cleanup is still done when cancelling.
1320  *
1321  * Asynchronous workers need to have sufficient parallelism to be able to run
1322  * different atomic commits on different CRTCs in parallel. The simplest way to
1323  * achive this is by running them on the &system_unbound_wq work queue. Note
1324  * that drivers are not required to split up atomic commits and run an
1325  * individual commit in parallel - userspace is supposed to do that if it cares.
1326  * But it might be beneficial to do that for modesets, since those necessarily
1327  * must be done as one global operation, and enabling or disabling a CRTC can
1328  * take a long time. But even that is not required.
1329  *
1330  * 3. The software state is updated synchronously with
1331  * drm_atomic_helper_swap_state(). Doing this under the protection of all modeset
1332  * locks means concurrent callers never see inconsistent state. And doing this
1333  * while it's guaranteed that no relevant nonblocking worker runs means that
1334  * nonblocking workers do not need grab any locks. Actually they must not grab
1335  * locks, for otherwise the work flushing will deadlock.
1336  *
1337  * 4. Schedule a work item to do all subsequent steps, using the split-out
1338  * commit helpers: a) pre-plane commit b) plane commit c) post-plane commit and
1339  * then cleaning up the framebuffers after the old framebuffer is no longer
1340  * being displayed.
1341  *
1342  * The above scheme is implemented in the atomic helper libraries in
1343  * drm_atomic_helper_commit() using a bunch of helper functions. See
1344  * drm_atomic_helper_setup_commit() for a starting point.
1345  */
1346 
1347 static int stall_checks(struct drm_crtc *crtc, bool nonblock)
1348 {
1349 	struct drm_crtc_commit *commit, *stall_commit = NULL;
1350 	bool completed = true;
1351 	int i;
1352 	long ret = 0;
1353 
1354 	spin_lock(&crtc->commit_lock);
1355 	i = 0;
1356 	list_for_each_entry(commit, &crtc->commit_list, commit_entry) {
1357 		if (i == 0) {
1358 			completed = try_wait_for_completion(&commit->flip_done);
1359 			/* Userspace is not allowed to get ahead of the previous
1360 			 * commit with nonblocking ones. */
1361 			if (!completed && nonblock) {
1362 				spin_unlock(&crtc->commit_lock);
1363 				return -EBUSY;
1364 			}
1365 		} else if (i == 1) {
1366 			stall_commit = commit;
1367 			drm_crtc_commit_get(stall_commit);
1368 			break;
1369 		}
1370 
1371 		i++;
1372 	}
1373 	spin_unlock(&crtc->commit_lock);
1374 
1375 	if (!stall_commit)
1376 		return 0;
1377 
1378 	/* We don't want to let commits get ahead of cleanup work too much,
1379 	 * stalling on 2nd previous commit means triple-buffer won't ever stall.
1380 	 */
1381 	ret = wait_for_completion_interruptible_timeout(&stall_commit->cleanup_done,
1382 							10*HZ);
1383 	if (ret == 0)
1384 		DRM_ERROR("[CRTC:%d:%s] cleanup_done timed out\n",
1385 			  crtc->base.id, crtc->name);
1386 
1387 	drm_crtc_commit_put(stall_commit);
1388 
1389 	return ret < 0 ? ret : 0;
1390 }
1391 
1392 /**
1393  * drm_atomic_helper_setup_commit - setup possibly nonblocking commit
1394  * @state: new modeset state to be committed
1395  * @nonblock: whether nonblocking behavior is requested.
1396  *
1397  * This function prepares @state to be used by the atomic helper's support for
1398  * nonblocking commits. Drivers using the nonblocking commit infrastructure
1399  * should always call this function from their ->atomic_commit hook.
1400  *
1401  * To be able to use this support drivers need to use a few more helper
1402  * functions. drm_atomic_helper_wait_for_dependencies() must be called before
1403  * actually committing the hardware state, and for nonblocking commits this call
1404  * must be placed in the async worker. See also drm_atomic_helper_swap_state()
1405  * and it's stall parameter, for when a driver's commit hooks look at the
1406  * ->state pointers of struct &drm_crtc, &drm_plane or &drm_connector directly.
1407  *
1408  * Completion of the hardware commit step must be signalled using
1409  * drm_atomic_helper_commit_hw_done(). After this step the driver is not allowed
1410  * to read or change any permanent software or hardware modeset state. The only
1411  * exception is state protected by other means than &drm_modeset_lock locks.
1412  * Only the free standing @state with pointers to the old state structures can
1413  * be inspected, e.g. to clean up old buffers using
1414  * drm_atomic_helper_cleanup_planes().
1415  *
1416  * At the very end, before cleaning up @state drivers must call
1417  * drm_atomic_helper_commit_cleanup_done().
1418  *
1419  * This is all implemented by in drm_atomic_helper_commit(), giving drivers a
1420  * complete and esay-to-use default implementation of the atomic_commit() hook.
1421  *
1422  * The tracking of asynchronously executed and still pending commits is done
1423  * using the core structure &drm_crtc_commit.
1424  *
1425  * By default there's no need to clean up resources allocated by this function
1426  * explicitly: drm_atomic_state_default_clear() will take care of that
1427  * automatically.
1428  *
1429  * Returns:
1430  *
1431  * 0 on success. -EBUSY when userspace schedules nonblocking commits too fast,
1432  * -ENOMEM on allocation failures and -EINTR when a signal is pending.
1433  */
1434 int drm_atomic_helper_setup_commit(struct drm_atomic_state *state,
1435 				   bool nonblock)
1436 {
1437 	struct drm_crtc *crtc;
1438 	struct drm_crtc_state *crtc_state;
1439 	struct drm_crtc_commit *commit;
1440 	int i, ret;
1441 
1442 	for_each_crtc_in_state(state, crtc, crtc_state, i) {
1443 		commit = kzalloc(sizeof(*commit), GFP_KERNEL);
1444 		if (!commit)
1445 			return -ENOMEM;
1446 
1447 		init_completion(&commit->flip_done);
1448 		init_completion(&commit->hw_done);
1449 		init_completion(&commit->cleanup_done);
1450 		INIT_LIST_HEAD(&commit->commit_entry);
1451 		kref_init(&commit->ref);
1452 		commit->crtc = crtc;
1453 
1454 		state->crtcs[i].commit = commit;
1455 
1456 		ret = stall_checks(crtc, nonblock);
1457 		if (ret)
1458 			return ret;
1459 
1460 		/* Drivers only send out events when at least either current or
1461 		 * new CRTC state is active. Complete right away if everything
1462 		 * stays off. */
1463 		if (!crtc->state->active && !crtc_state->active) {
1464 			complete_all(&commit->flip_done);
1465 			continue;
1466 		}
1467 
1468 		/* Legacy cursor updates are fully unsynced. */
1469 		if (state->legacy_cursor_update) {
1470 			complete_all(&commit->flip_done);
1471 			continue;
1472 		}
1473 
1474 		if (!crtc_state->event) {
1475 			commit->event = kzalloc(sizeof(*commit->event),
1476 						GFP_KERNEL);
1477 			if (!commit->event)
1478 				return -ENOMEM;
1479 
1480 			crtc_state->event = commit->event;
1481 		}
1482 
1483 		crtc_state->event->base.completion = &commit->flip_done;
1484 	}
1485 
1486 	return 0;
1487 }
1488 EXPORT_SYMBOL(drm_atomic_helper_setup_commit);
1489 
1490 
1491 static struct drm_crtc_commit *preceeding_commit(struct drm_crtc *crtc)
1492 {
1493 	struct drm_crtc_commit *commit;
1494 	int i = 0;
1495 
1496 	list_for_each_entry(commit, &crtc->commit_list, commit_entry) {
1497 		/* skip the first entry, that's the current commit */
1498 		if (i == 1)
1499 			return commit;
1500 		i++;
1501 	}
1502 
1503 	return NULL;
1504 }
1505 
1506 /**
1507  * drm_atomic_helper_wait_for_dependencies - wait for required preceeding commits
1508  * @old_state: atomic state object with old state structures
1509  *
1510  * This function waits for all preceeding commits that touch the same CRTC as
1511  * @old_state to both be committed to the hardware (as signalled by
1512  * drm_atomic_helper_commit_hw_done) and executed by the hardware (as signalled
1513  * by calling drm_crtc_vblank_send_event on the event member of
1514  * &drm_crtc_state).
1515  *
1516  * This is part of the atomic helper support for nonblocking commits, see
1517  * drm_atomic_helper_setup_commit() for an overview.
1518  */
1519 void drm_atomic_helper_wait_for_dependencies(struct drm_atomic_state *old_state)
1520 {
1521 	struct drm_crtc *crtc;
1522 	struct drm_crtc_state *crtc_state;
1523 	struct drm_crtc_commit *commit;
1524 	int i;
1525 	long ret;
1526 
1527 	for_each_crtc_in_state(old_state, crtc, crtc_state, i) {
1528 		spin_lock(&crtc->commit_lock);
1529 		commit = preceeding_commit(crtc);
1530 		if (commit)
1531 			drm_crtc_commit_get(commit);
1532 		spin_unlock(&crtc->commit_lock);
1533 
1534 		if (!commit)
1535 			continue;
1536 
1537 		ret = wait_for_completion_timeout(&commit->hw_done,
1538 						  10*HZ);
1539 		if (ret == 0)
1540 			DRM_ERROR("[CRTC:%d:%s] hw_done timed out\n",
1541 				  crtc->base.id, crtc->name);
1542 
1543 		/* Currently no support for overwriting flips, hence
1544 		 * stall for previous one to execute completely. */
1545 		ret = wait_for_completion_timeout(&commit->flip_done,
1546 						  10*HZ);
1547 		if (ret == 0)
1548 			DRM_ERROR("[CRTC:%d:%s] flip_done timed out\n",
1549 				  crtc->base.id, crtc->name);
1550 
1551 		drm_crtc_commit_put(commit);
1552 	}
1553 }
1554 EXPORT_SYMBOL(drm_atomic_helper_wait_for_dependencies);
1555 
1556 /**
1557  * drm_atomic_helper_commit_hw_done - setup possible nonblocking commit
1558  * @old_state: atomic state object with old state structures
1559  *
1560  * This function is used to signal completion of the hardware commit step. After
1561  * this step the driver is not allowed to read or change any permanent software
1562  * or hardware modeset state. The only exception is state protected by other
1563  * means than &drm_modeset_lock locks.
1564  *
1565  * Drivers should try to postpone any expensive or delayed cleanup work after
1566  * this function is called.
1567  *
1568  * This is part of the atomic helper support for nonblocking commits, see
1569  * drm_atomic_helper_setup_commit() for an overview.
1570  */
1571 void drm_atomic_helper_commit_hw_done(struct drm_atomic_state *old_state)
1572 {
1573 	struct drm_crtc *crtc;
1574 	struct drm_crtc_state *crtc_state;
1575 	struct drm_crtc_commit *commit;
1576 	int i;
1577 
1578 	for_each_crtc_in_state(old_state, crtc, crtc_state, i) {
1579 		commit = old_state->crtcs[i].commit;
1580 		if (!commit)
1581 			continue;
1582 
1583 		/* backend must have consumed any event by now */
1584 		WARN_ON(crtc->state->event);
1585 		spin_lock(&crtc->commit_lock);
1586 		complete_all(&commit->hw_done);
1587 		spin_unlock(&crtc->commit_lock);
1588 	}
1589 }
1590 EXPORT_SYMBOL(drm_atomic_helper_commit_hw_done);
1591 
1592 /**
1593  * drm_atomic_helper_commit_cleanup_done - signal completion of commit
1594  * @old_state: atomic state object with old state structures
1595  *
1596  * This signals completion of the atomic update @old_state, including any
1597  * cleanup work. If used, it must be called right before calling
1598  * drm_atomic_state_put().
1599  *
1600  * This is part of the atomic helper support for nonblocking commits, see
1601  * drm_atomic_helper_setup_commit() for an overview.
1602  */
1603 void drm_atomic_helper_commit_cleanup_done(struct drm_atomic_state *old_state)
1604 {
1605 	struct drm_crtc *crtc;
1606 	struct drm_crtc_state *crtc_state;
1607 	struct drm_crtc_commit *commit;
1608 	int i;
1609 	long ret;
1610 
1611 	for_each_crtc_in_state(old_state, crtc, crtc_state, i) {
1612 		commit = old_state->crtcs[i].commit;
1613 		if (WARN_ON(!commit))
1614 			continue;
1615 
1616 		spin_lock(&crtc->commit_lock);
1617 		complete_all(&commit->cleanup_done);
1618 		WARN_ON(!try_wait_for_completion(&commit->hw_done));
1619 
1620 		/* commit_list borrows our reference, need to remove before we
1621 		 * clean up our drm_atomic_state. But only after it actually
1622 		 * completed, otherwise subsequent commits won't stall properly. */
1623 		if (try_wait_for_completion(&commit->flip_done))
1624 			goto del_commit;
1625 
1626 		spin_unlock(&crtc->commit_lock);
1627 
1628 		/* We must wait for the vblank event to signal our completion
1629 		 * before releasing our reference, since the vblank work does
1630 		 * not hold a reference of its own. */
1631 		ret = wait_for_completion_timeout(&commit->flip_done,
1632 						  10*HZ);
1633 		if (ret == 0)
1634 			DRM_ERROR("[CRTC:%d:%s] flip_done timed out\n",
1635 				  crtc->base.id, crtc->name);
1636 
1637 		spin_lock(&crtc->commit_lock);
1638 del_commit:
1639 		list_del(&commit->commit_entry);
1640 		spin_unlock(&crtc->commit_lock);
1641 	}
1642 }
1643 EXPORT_SYMBOL(drm_atomic_helper_commit_cleanup_done);
1644 
1645 /**
1646  * drm_atomic_helper_prepare_planes - prepare plane resources before commit
1647  * @dev: DRM device
1648  * @state: atomic state object with new state structures
1649  *
1650  * This function prepares plane state, specifically framebuffers, for the new
1651  * configuration. If any failure is encountered this function will call
1652  * ->cleanup_fb on any already successfully prepared framebuffer.
1653  *
1654  * Returns:
1655  * 0 on success, negative error code on failure.
1656  */
1657 int drm_atomic_helper_prepare_planes(struct drm_device *dev,
1658 				     struct drm_atomic_state *state)
1659 {
1660 	struct drm_plane *plane;
1661 	struct drm_plane_state *plane_state;
1662 	int ret, i, j;
1663 
1664 	for_each_plane_in_state(state, plane, plane_state, i) {
1665 		const struct drm_plane_helper_funcs *funcs;
1666 
1667 		funcs = plane->helper_private;
1668 
1669 		if (!drm_atomic_helper_framebuffer_changed(dev, state, plane_state->crtc))
1670 			continue;
1671 
1672 		if (funcs->prepare_fb) {
1673 			ret = funcs->prepare_fb(plane, plane_state);
1674 			if (ret)
1675 				goto fail;
1676 		}
1677 	}
1678 
1679 	return 0;
1680 
1681 fail:
1682 	for_each_plane_in_state(state, plane, plane_state, j) {
1683 		const struct drm_plane_helper_funcs *funcs;
1684 
1685 		if (j >= i)
1686 			continue;
1687 
1688 		if (!drm_atomic_helper_framebuffer_changed(dev, state, plane_state->crtc))
1689 			continue;
1690 
1691 		funcs = plane->helper_private;
1692 
1693 		if (funcs->cleanup_fb)
1694 			funcs->cleanup_fb(plane, plane_state);
1695 	}
1696 
1697 	return ret;
1698 }
1699 EXPORT_SYMBOL(drm_atomic_helper_prepare_planes);
1700 
1701 static bool plane_crtc_active(const struct drm_plane_state *state)
1702 {
1703 	return state->crtc && state->crtc->state->active;
1704 }
1705 
1706 /**
1707  * drm_atomic_helper_commit_planes - commit plane state
1708  * @dev: DRM device
1709  * @old_state: atomic state object with old state structures
1710  * @flags: flags for committing plane state
1711  *
1712  * This function commits the new plane state using the plane and atomic helper
1713  * functions for planes and crtcs. It assumes that the atomic state has already
1714  * been pushed into the relevant object state pointers, since this step can no
1715  * longer fail.
1716  *
1717  * It still requires the global state object @old_state to know which planes and
1718  * crtcs need to be updated though.
1719  *
1720  * Note that this function does all plane updates across all CRTCs in one step.
1721  * If the hardware can't support this approach look at
1722  * drm_atomic_helper_commit_planes_on_crtc() instead.
1723  *
1724  * Plane parameters can be updated by applications while the associated CRTC is
1725  * disabled. The DRM/KMS core will store the parameters in the plane state,
1726  * which will be available to the driver when the CRTC is turned on. As a result
1727  * most drivers don't need to be immediately notified of plane updates for a
1728  * disabled CRTC.
1729  *
1730  * Unless otherwise needed, drivers are advised to set the ACTIVE_ONLY flag in
1731  * @flags in order not to receive plane update notifications related to a
1732  * disabled CRTC. This avoids the need to manually ignore plane updates in
1733  * driver code when the driver and/or hardware can't or just don't need to deal
1734  * with updates on disabled CRTCs, for example when supporting runtime PM.
1735  *
1736  * Drivers may set the NO_DISABLE_AFTER_MODESET flag in @flags if the relevant
1737  * display controllers require to disable a CRTC's planes when the CRTC is
1738  * disabled. This function would skip the ->atomic_disable call for a plane if
1739  * the CRTC of the old plane state needs a modesetting operation. Of course,
1740  * the drivers need to disable the planes in their CRTC disable callbacks
1741  * since no one else would do that.
1742  *
1743  * The drm_atomic_helper_commit() default implementation doesn't set the
1744  * ACTIVE_ONLY flag to most closely match the behaviour of the legacy helpers.
1745  * This should not be copied blindly by drivers.
1746  */
1747 void drm_atomic_helper_commit_planes(struct drm_device *dev,
1748 				     struct drm_atomic_state *old_state,
1749 				     uint32_t flags)
1750 {
1751 	struct drm_crtc *crtc;
1752 	struct drm_crtc_state *old_crtc_state;
1753 	struct drm_plane *plane;
1754 	struct drm_plane_state *old_plane_state;
1755 	int i;
1756 	bool active_only = flags & DRM_PLANE_COMMIT_ACTIVE_ONLY;
1757 	bool no_disable = flags & DRM_PLANE_COMMIT_NO_DISABLE_AFTER_MODESET;
1758 
1759 	for_each_crtc_in_state(old_state, crtc, old_crtc_state, i) {
1760 		const struct drm_crtc_helper_funcs *funcs;
1761 
1762 		funcs = crtc->helper_private;
1763 
1764 		if (!funcs || !funcs->atomic_begin)
1765 			continue;
1766 
1767 		if (active_only && !crtc->state->active)
1768 			continue;
1769 
1770 		funcs->atomic_begin(crtc, old_crtc_state);
1771 	}
1772 
1773 	for_each_plane_in_state(old_state, plane, old_plane_state, i) {
1774 		const struct drm_plane_helper_funcs *funcs;
1775 		bool disabling;
1776 
1777 		funcs = plane->helper_private;
1778 
1779 		if (!funcs)
1780 			continue;
1781 
1782 		disabling = drm_atomic_plane_disabling(plane, old_plane_state);
1783 
1784 		if (active_only) {
1785 			/*
1786 			 * Skip planes related to inactive CRTCs. If the plane
1787 			 * is enabled use the state of the current CRTC. If the
1788 			 * plane is being disabled use the state of the old
1789 			 * CRTC to avoid skipping planes being disabled on an
1790 			 * active CRTC.
1791 			 */
1792 			if (!disabling && !plane_crtc_active(plane->state))
1793 				continue;
1794 			if (disabling && !plane_crtc_active(old_plane_state))
1795 				continue;
1796 		}
1797 
1798 		/*
1799 		 * Special-case disabling the plane if drivers support it.
1800 		 */
1801 		if (disabling && funcs->atomic_disable) {
1802 			struct drm_crtc_state *crtc_state;
1803 
1804 			crtc_state = old_plane_state->crtc->state;
1805 
1806 			if (drm_atomic_crtc_needs_modeset(crtc_state) &&
1807 			    no_disable)
1808 				continue;
1809 
1810 			funcs->atomic_disable(plane, old_plane_state);
1811 		} else if (plane->state->crtc || disabling) {
1812 			funcs->atomic_update(plane, old_plane_state);
1813 		}
1814 	}
1815 
1816 	for_each_crtc_in_state(old_state, crtc, old_crtc_state, i) {
1817 		const struct drm_crtc_helper_funcs *funcs;
1818 
1819 		funcs = crtc->helper_private;
1820 
1821 		if (!funcs || !funcs->atomic_flush)
1822 			continue;
1823 
1824 		if (active_only && !crtc->state->active)
1825 			continue;
1826 
1827 		funcs->atomic_flush(crtc, old_crtc_state);
1828 	}
1829 }
1830 EXPORT_SYMBOL(drm_atomic_helper_commit_planes);
1831 
1832 /**
1833  * drm_atomic_helper_commit_planes_on_crtc - commit plane state for a crtc
1834  * @old_crtc_state: atomic state object with the old crtc state
1835  *
1836  * This function commits the new plane state using the plane and atomic helper
1837  * functions for planes on the specific crtc. It assumes that the atomic state
1838  * has already been pushed into the relevant object state pointers, since this
1839  * step can no longer fail.
1840  *
1841  * This function is useful when plane updates should be done crtc-by-crtc
1842  * instead of one global step like drm_atomic_helper_commit_planes() does.
1843  *
1844  * This function can only be savely used when planes are not allowed to move
1845  * between different CRTCs because this function doesn't handle inter-CRTC
1846  * depencies. Callers need to ensure that either no such depencies exist,
1847  * resolve them through ordering of commit calls or through some other means.
1848  */
1849 void
1850 drm_atomic_helper_commit_planes_on_crtc(struct drm_crtc_state *old_crtc_state)
1851 {
1852 	const struct drm_crtc_helper_funcs *crtc_funcs;
1853 	struct drm_crtc *crtc = old_crtc_state->crtc;
1854 	struct drm_atomic_state *old_state = old_crtc_state->state;
1855 	struct drm_plane *plane;
1856 	unsigned plane_mask;
1857 
1858 	plane_mask = old_crtc_state->plane_mask;
1859 	plane_mask |= crtc->state->plane_mask;
1860 
1861 	crtc_funcs = crtc->helper_private;
1862 	if (crtc_funcs && crtc_funcs->atomic_begin)
1863 		crtc_funcs->atomic_begin(crtc, old_crtc_state);
1864 
1865 	drm_for_each_plane_mask(plane, crtc->dev, plane_mask) {
1866 		struct drm_plane_state *old_plane_state =
1867 			drm_atomic_get_existing_plane_state(old_state, plane);
1868 		const struct drm_plane_helper_funcs *plane_funcs;
1869 
1870 		plane_funcs = plane->helper_private;
1871 
1872 		if (!old_plane_state || !plane_funcs)
1873 			continue;
1874 
1875 		WARN_ON(plane->state->crtc && plane->state->crtc != crtc);
1876 
1877 		if (drm_atomic_plane_disabling(plane, old_plane_state) &&
1878 		    plane_funcs->atomic_disable)
1879 			plane_funcs->atomic_disable(plane, old_plane_state);
1880 		else if (plane->state->crtc ||
1881 			 drm_atomic_plane_disabling(plane, old_plane_state))
1882 			plane_funcs->atomic_update(plane, old_plane_state);
1883 	}
1884 
1885 	if (crtc_funcs && crtc_funcs->atomic_flush)
1886 		crtc_funcs->atomic_flush(crtc, old_crtc_state);
1887 }
1888 EXPORT_SYMBOL(drm_atomic_helper_commit_planes_on_crtc);
1889 
1890 /**
1891  * drm_atomic_helper_disable_planes_on_crtc - helper to disable CRTC's planes
1892  * @old_crtc_state: atomic state object with the old CRTC state
1893  * @atomic: if set, synchronize with CRTC's atomic_begin/flush hooks
1894  *
1895  * Disables all planes associated with the given CRTC. This can be
1896  * used for instance in the CRTC helper atomic_disable callback to disable
1897  * all planes.
1898  *
1899  * If the atomic-parameter is set the function calls the CRTC's
1900  * atomic_begin hook before and atomic_flush hook after disabling the
1901  * planes.
1902  *
1903  * It is a bug to call this function without having implemented the
1904  * ->atomic_disable() plane hook.
1905  */
1906 void
1907 drm_atomic_helper_disable_planes_on_crtc(struct drm_crtc_state *old_crtc_state,
1908 					 bool atomic)
1909 {
1910 	struct drm_crtc *crtc = old_crtc_state->crtc;
1911 	const struct drm_crtc_helper_funcs *crtc_funcs =
1912 		crtc->helper_private;
1913 	struct drm_plane *plane;
1914 
1915 	if (atomic && crtc_funcs && crtc_funcs->atomic_begin)
1916 		crtc_funcs->atomic_begin(crtc, NULL);
1917 
1918 	drm_atomic_crtc_state_for_each_plane(plane, old_crtc_state) {
1919 		const struct drm_plane_helper_funcs *plane_funcs =
1920 			plane->helper_private;
1921 
1922 		if (!plane_funcs)
1923 			continue;
1924 
1925 		WARN_ON(!plane_funcs->atomic_disable);
1926 		if (plane_funcs->atomic_disable)
1927 			plane_funcs->atomic_disable(plane, NULL);
1928 	}
1929 
1930 	if (atomic && crtc_funcs && crtc_funcs->atomic_flush)
1931 		crtc_funcs->atomic_flush(crtc, NULL);
1932 }
1933 EXPORT_SYMBOL(drm_atomic_helper_disable_planes_on_crtc);
1934 
1935 /**
1936  * drm_atomic_helper_cleanup_planes - cleanup plane resources after commit
1937  * @dev: DRM device
1938  * @old_state: atomic state object with old state structures
1939  *
1940  * This function cleans up plane state, specifically framebuffers, from the old
1941  * configuration. Hence the old configuration must be perserved in @old_state to
1942  * be able to call this function.
1943  *
1944  * This function must also be called on the new state when the atomic update
1945  * fails at any point after calling drm_atomic_helper_prepare_planes().
1946  */
1947 void drm_atomic_helper_cleanup_planes(struct drm_device *dev,
1948 				      struct drm_atomic_state *old_state)
1949 {
1950 	struct drm_plane *plane;
1951 	struct drm_plane_state *plane_state;
1952 	int i;
1953 
1954 	for_each_plane_in_state(old_state, plane, plane_state, i) {
1955 		const struct drm_plane_helper_funcs *funcs;
1956 
1957 		if (!drm_atomic_helper_framebuffer_changed(dev, old_state, plane_state->crtc))
1958 			continue;
1959 
1960 		funcs = plane->helper_private;
1961 
1962 		if (funcs->cleanup_fb)
1963 			funcs->cleanup_fb(plane, plane_state);
1964 	}
1965 }
1966 EXPORT_SYMBOL(drm_atomic_helper_cleanup_planes);
1967 
1968 /**
1969  * drm_atomic_helper_swap_state - store atomic state into current sw state
1970  * @state: atomic state
1971  * @stall: stall for proceeding commits
1972  *
1973  * This function stores the atomic state into the current state pointers in all
1974  * driver objects. It should be called after all failing steps have been done
1975  * and succeeded, but before the actual hardware state is committed.
1976  *
1977  * For cleanup and error recovery the current state for all changed objects will
1978  * be swaped into @state.
1979  *
1980  * With that sequence it fits perfectly into the plane prepare/cleanup sequence:
1981  *
1982  * 1. Call drm_atomic_helper_prepare_planes() with the staged atomic state.
1983  *
1984  * 2. Do any other steps that might fail.
1985  *
1986  * 3. Put the staged state into the current state pointers with this function.
1987  *
1988  * 4. Actually commit the hardware state.
1989  *
1990  * 5. Call drm_atomic_helper_cleanup_planes() with @state, which since step 3
1991  * contains the old state. Also do any other cleanup required with that state.
1992  *
1993  * @stall must be set when nonblocking commits for this driver directly access
1994  * the ->state pointer of &drm_plane, &drm_crtc or &drm_connector. With the
1995  * current atomic helpers this is almost always the case, since the helpers
1996  * don't pass the right state structures to the callbacks.
1997  */
1998 void drm_atomic_helper_swap_state(struct drm_atomic_state *state,
1999 				  bool stall)
2000 {
2001 	int i;
2002 	long ret;
2003 	struct drm_connector *connector;
2004 	struct drm_connector_state *conn_state;
2005 	struct drm_crtc *crtc;
2006 	struct drm_crtc_state *crtc_state;
2007 	struct drm_plane *plane;
2008 	struct drm_plane_state *plane_state;
2009 	struct drm_crtc_commit *commit;
2010 
2011 	if (stall) {
2012 		for_each_crtc_in_state(state, crtc, crtc_state, i) {
2013 			spin_lock(&crtc->commit_lock);
2014 			commit = list_first_entry_or_null(&crtc->commit_list,
2015 					struct drm_crtc_commit, commit_entry);
2016 			if (commit)
2017 				drm_crtc_commit_get(commit);
2018 			spin_unlock(&crtc->commit_lock);
2019 
2020 			if (!commit)
2021 				continue;
2022 
2023 			ret = wait_for_completion_timeout(&commit->hw_done,
2024 							  10*HZ);
2025 			if (ret == 0)
2026 				DRM_ERROR("[CRTC:%d:%s] hw_done timed out\n",
2027 					  crtc->base.id, crtc->name);
2028 			drm_crtc_commit_put(commit);
2029 		}
2030 	}
2031 
2032 	for_each_connector_in_state(state, connector, conn_state, i) {
2033 		connector->state->state = state;
2034 		swap(state->connectors[i].state, connector->state);
2035 		connector->state->state = NULL;
2036 	}
2037 
2038 	for_each_crtc_in_state(state, crtc, crtc_state, i) {
2039 		crtc->state->state = state;
2040 		swap(state->crtcs[i].state, crtc->state);
2041 		crtc->state->state = NULL;
2042 
2043 		if (state->crtcs[i].commit) {
2044 			spin_lock(&crtc->commit_lock);
2045 			list_add(&state->crtcs[i].commit->commit_entry,
2046 				 &crtc->commit_list);
2047 			spin_unlock(&crtc->commit_lock);
2048 
2049 			state->crtcs[i].commit->event = NULL;
2050 		}
2051 	}
2052 
2053 	for_each_plane_in_state(state, plane, plane_state, i) {
2054 		plane->state->state = state;
2055 		swap(state->planes[i].state, plane->state);
2056 		plane->state->state = NULL;
2057 	}
2058 }
2059 EXPORT_SYMBOL(drm_atomic_helper_swap_state);
2060 
2061 /**
2062  * drm_atomic_helper_update_plane - Helper for primary plane update using atomic
2063  * @plane: plane object to update
2064  * @crtc: owning CRTC of owning plane
2065  * @fb: framebuffer to flip onto plane
2066  * @crtc_x: x offset of primary plane on crtc
2067  * @crtc_y: y offset of primary plane on crtc
2068  * @crtc_w: width of primary plane rectangle on crtc
2069  * @crtc_h: height of primary plane rectangle on crtc
2070  * @src_x: x offset of @fb for panning
2071  * @src_y: y offset of @fb for panning
2072  * @src_w: width of source rectangle in @fb
2073  * @src_h: height of source rectangle in @fb
2074  *
2075  * Provides a default plane update handler using the atomic driver interface.
2076  *
2077  * RETURNS:
2078  * Zero on success, error code on failure
2079  */
2080 int drm_atomic_helper_update_plane(struct drm_plane *plane,
2081 				   struct drm_crtc *crtc,
2082 				   struct drm_framebuffer *fb,
2083 				   int crtc_x, int crtc_y,
2084 				   unsigned int crtc_w, unsigned int crtc_h,
2085 				   uint32_t src_x, uint32_t src_y,
2086 				   uint32_t src_w, uint32_t src_h)
2087 {
2088 	struct drm_atomic_state *state;
2089 	struct drm_plane_state *plane_state;
2090 	int ret = 0;
2091 
2092 	state = drm_atomic_state_alloc(plane->dev);
2093 	if (!state)
2094 		return -ENOMEM;
2095 
2096 	state->acquire_ctx = drm_modeset_legacy_acquire_ctx(crtc);
2097 retry:
2098 	plane_state = drm_atomic_get_plane_state(state, plane);
2099 	if (IS_ERR(plane_state)) {
2100 		ret = PTR_ERR(plane_state);
2101 		goto fail;
2102 	}
2103 
2104 	ret = drm_atomic_set_crtc_for_plane(plane_state, crtc);
2105 	if (ret != 0)
2106 		goto fail;
2107 	drm_atomic_set_fb_for_plane(plane_state, fb);
2108 	plane_state->crtc_x = crtc_x;
2109 	plane_state->crtc_y = crtc_y;
2110 	plane_state->crtc_w = crtc_w;
2111 	plane_state->crtc_h = crtc_h;
2112 	plane_state->src_x = src_x;
2113 	plane_state->src_y = src_y;
2114 	plane_state->src_w = src_w;
2115 	plane_state->src_h = src_h;
2116 
2117 	if (plane == crtc->cursor)
2118 		state->legacy_cursor_update = true;
2119 
2120 	ret = drm_atomic_commit(state);
2121 fail:
2122 	if (ret == -EDEADLK)
2123 		goto backoff;
2124 
2125 	drm_atomic_state_put(state);
2126 	return ret;
2127 
2128 backoff:
2129 	drm_atomic_state_clear(state);
2130 	drm_atomic_legacy_backoff(state);
2131 
2132 	/*
2133 	 * Someone might have exchanged the framebuffer while we dropped locks
2134 	 * in the backoff code. We need to fix up the fb refcount tracking the
2135 	 * core does for us.
2136 	 */
2137 	plane->old_fb = plane->fb;
2138 
2139 	goto retry;
2140 }
2141 EXPORT_SYMBOL(drm_atomic_helper_update_plane);
2142 
2143 /**
2144  * drm_atomic_helper_disable_plane - Helper for primary plane disable using * atomic
2145  * @plane: plane to disable
2146  *
2147  * Provides a default plane disable handler using the atomic driver interface.
2148  *
2149  * RETURNS:
2150  * Zero on success, error code on failure
2151  */
2152 int drm_atomic_helper_disable_plane(struct drm_plane *plane)
2153 {
2154 	struct drm_atomic_state *state;
2155 	struct drm_plane_state *plane_state;
2156 	int ret = 0;
2157 
2158 	/*
2159 	 * FIXME: Without plane->crtc set we can't get at the implicit legacy
2160 	 * acquire context. The real fix will be to wire the acquire ctx through
2161 	 * everywhere we need it, but meanwhile prevent chaos by just skipping
2162 	 * this noop. The critical case is the cursor ioctls which a) only grab
2163 	 * crtc/cursor-plane locks (so we need the crtc to get at the right
2164 	 * acquire context) and b) can try to disable the plane multiple times.
2165 	 */
2166 	if (!plane->crtc)
2167 		return 0;
2168 
2169 	state = drm_atomic_state_alloc(plane->dev);
2170 	if (!state)
2171 		return -ENOMEM;
2172 
2173 	state->acquire_ctx = drm_modeset_legacy_acquire_ctx(plane->crtc);
2174 retry:
2175 	plane_state = drm_atomic_get_plane_state(state, plane);
2176 	if (IS_ERR(plane_state)) {
2177 		ret = PTR_ERR(plane_state);
2178 		goto fail;
2179 	}
2180 
2181 	if (plane_state->crtc && (plane == plane->crtc->cursor))
2182 		plane_state->state->legacy_cursor_update = true;
2183 
2184 	ret = __drm_atomic_helper_disable_plane(plane, plane_state);
2185 	if (ret != 0)
2186 		goto fail;
2187 
2188 	ret = drm_atomic_commit(state);
2189 fail:
2190 	if (ret == -EDEADLK)
2191 		goto backoff;
2192 
2193 	drm_atomic_state_put(state);
2194 	return ret;
2195 
2196 backoff:
2197 	drm_atomic_state_clear(state);
2198 	drm_atomic_legacy_backoff(state);
2199 
2200 	/*
2201 	 * Someone might have exchanged the framebuffer while we dropped locks
2202 	 * in the backoff code. We need to fix up the fb refcount tracking the
2203 	 * core does for us.
2204 	 */
2205 	plane->old_fb = plane->fb;
2206 
2207 	goto retry;
2208 }
2209 EXPORT_SYMBOL(drm_atomic_helper_disable_plane);
2210 
2211 /* just used from fb-helper and atomic-helper: */
2212 int __drm_atomic_helper_disable_plane(struct drm_plane *plane,
2213 		struct drm_plane_state *plane_state)
2214 {
2215 	int ret;
2216 
2217 	ret = drm_atomic_set_crtc_for_plane(plane_state, NULL);
2218 	if (ret != 0)
2219 		return ret;
2220 
2221 	drm_atomic_set_fb_for_plane(plane_state, NULL);
2222 	plane_state->crtc_x = 0;
2223 	plane_state->crtc_y = 0;
2224 	plane_state->crtc_w = 0;
2225 	plane_state->crtc_h = 0;
2226 	plane_state->src_x = 0;
2227 	plane_state->src_y = 0;
2228 	plane_state->src_w = 0;
2229 	plane_state->src_h = 0;
2230 
2231 	return 0;
2232 }
2233 
2234 static int update_output_state(struct drm_atomic_state *state,
2235 			       struct drm_mode_set *set)
2236 {
2237 	struct drm_device *dev = set->crtc->dev;
2238 	struct drm_crtc *crtc;
2239 	struct drm_crtc_state *crtc_state;
2240 	struct drm_connector *connector;
2241 	struct drm_connector_state *conn_state;
2242 	int ret, i;
2243 
2244 	ret = drm_modeset_lock(&dev->mode_config.connection_mutex,
2245 			       state->acquire_ctx);
2246 	if (ret)
2247 		return ret;
2248 
2249 	/* First disable all connectors on the target crtc. */
2250 	ret = drm_atomic_add_affected_connectors(state, set->crtc);
2251 	if (ret)
2252 		return ret;
2253 
2254 	for_each_connector_in_state(state, connector, conn_state, i) {
2255 		if (conn_state->crtc == set->crtc) {
2256 			ret = drm_atomic_set_crtc_for_connector(conn_state,
2257 								NULL);
2258 			if (ret)
2259 				return ret;
2260 		}
2261 	}
2262 
2263 	/* Then set all connectors from set->connectors on the target crtc */
2264 	for (i = 0; i < set->num_connectors; i++) {
2265 		conn_state = drm_atomic_get_connector_state(state,
2266 							    set->connectors[i]);
2267 		if (IS_ERR(conn_state))
2268 			return PTR_ERR(conn_state);
2269 
2270 		ret = drm_atomic_set_crtc_for_connector(conn_state,
2271 							set->crtc);
2272 		if (ret)
2273 			return ret;
2274 	}
2275 
2276 	for_each_crtc_in_state(state, crtc, crtc_state, i) {
2277 		/* Don't update ->enable for the CRTC in the set_config request,
2278 		 * since a mismatch would indicate a bug in the upper layers.
2279 		 * The actual modeset code later on will catch any
2280 		 * inconsistencies here. */
2281 		if (crtc == set->crtc)
2282 			continue;
2283 
2284 		if (!crtc_state->connector_mask) {
2285 			ret = drm_atomic_set_mode_prop_for_crtc(crtc_state,
2286 								NULL);
2287 			if (ret < 0)
2288 				return ret;
2289 
2290 			crtc_state->active = false;
2291 		}
2292 	}
2293 
2294 	return 0;
2295 }
2296 
2297 /**
2298  * drm_atomic_helper_set_config - set a new config from userspace
2299  * @set: mode set configuration
2300  *
2301  * Provides a default crtc set_config handler using the atomic driver interface.
2302  *
2303  * Returns:
2304  * Returns 0 on success, negative errno numbers on failure.
2305  */
2306 int drm_atomic_helper_set_config(struct drm_mode_set *set)
2307 {
2308 	struct drm_atomic_state *state;
2309 	struct drm_crtc *crtc = set->crtc;
2310 	int ret = 0;
2311 
2312 	state = drm_atomic_state_alloc(crtc->dev);
2313 	if (!state)
2314 		return -ENOMEM;
2315 
2316 	state->legacy_set_config = true;
2317 	state->acquire_ctx = drm_modeset_legacy_acquire_ctx(crtc);
2318 retry:
2319 	ret = __drm_atomic_helper_set_config(set, state);
2320 	if (ret != 0)
2321 		goto fail;
2322 
2323 	ret = drm_atomic_commit(state);
2324 fail:
2325 	if (ret == -EDEADLK)
2326 		goto backoff;
2327 
2328 	drm_atomic_state_put(state);
2329 	return ret;
2330 
2331 backoff:
2332 	drm_atomic_state_clear(state);
2333 	drm_atomic_legacy_backoff(state);
2334 
2335 	/*
2336 	 * Someone might have exchanged the framebuffer while we dropped locks
2337 	 * in the backoff code. We need to fix up the fb refcount tracking the
2338 	 * core does for us.
2339 	 */
2340 	crtc->primary->old_fb = crtc->primary->fb;
2341 
2342 	goto retry;
2343 }
2344 EXPORT_SYMBOL(drm_atomic_helper_set_config);
2345 
2346 /* just used from fb-helper and atomic-helper: */
2347 int __drm_atomic_helper_set_config(struct drm_mode_set *set,
2348 		struct drm_atomic_state *state)
2349 {
2350 	struct drm_crtc_state *crtc_state;
2351 	struct drm_plane_state *primary_state;
2352 	struct drm_crtc *crtc = set->crtc;
2353 	int hdisplay, vdisplay;
2354 	int ret;
2355 
2356 	crtc_state = drm_atomic_get_crtc_state(state, crtc);
2357 	if (IS_ERR(crtc_state))
2358 		return PTR_ERR(crtc_state);
2359 
2360 	primary_state = drm_atomic_get_plane_state(state, crtc->primary);
2361 	if (IS_ERR(primary_state))
2362 		return PTR_ERR(primary_state);
2363 
2364 	if (!set->mode) {
2365 		WARN_ON(set->fb);
2366 		WARN_ON(set->num_connectors);
2367 
2368 		ret = drm_atomic_set_mode_for_crtc(crtc_state, NULL);
2369 		if (ret != 0)
2370 			return ret;
2371 
2372 		crtc_state->active = false;
2373 
2374 		ret = drm_atomic_set_crtc_for_plane(primary_state, NULL);
2375 		if (ret != 0)
2376 			return ret;
2377 
2378 		drm_atomic_set_fb_for_plane(primary_state, NULL);
2379 
2380 		goto commit;
2381 	}
2382 
2383 	WARN_ON(!set->fb);
2384 	WARN_ON(!set->num_connectors);
2385 
2386 	ret = drm_atomic_set_mode_for_crtc(crtc_state, set->mode);
2387 	if (ret != 0)
2388 		return ret;
2389 
2390 	crtc_state->active = true;
2391 
2392 	ret = drm_atomic_set_crtc_for_plane(primary_state, crtc);
2393 	if (ret != 0)
2394 		return ret;
2395 
2396 	drm_crtc_get_hv_timing(set->mode, &hdisplay, &vdisplay);
2397 
2398 	drm_atomic_set_fb_for_plane(primary_state, set->fb);
2399 	primary_state->crtc_x = 0;
2400 	primary_state->crtc_y = 0;
2401 	primary_state->crtc_w = hdisplay;
2402 	primary_state->crtc_h = vdisplay;
2403 	primary_state->src_x = set->x << 16;
2404 	primary_state->src_y = set->y << 16;
2405 	if (drm_rotation_90_or_270(primary_state->rotation)) {
2406 		primary_state->src_w = vdisplay << 16;
2407 		primary_state->src_h = hdisplay << 16;
2408 	} else {
2409 		primary_state->src_w = hdisplay << 16;
2410 		primary_state->src_h = vdisplay << 16;
2411 	}
2412 
2413 commit:
2414 	ret = update_output_state(state, set);
2415 	if (ret)
2416 		return ret;
2417 
2418 	return 0;
2419 }
2420 
2421 /**
2422  * drm_atomic_helper_disable_all - disable all currently active outputs
2423  * @dev: DRM device
2424  * @ctx: lock acquisition context
2425  *
2426  * Loops through all connectors, finding those that aren't turned off and then
2427  * turns them off by setting their DPMS mode to OFF and deactivating the CRTC
2428  * that they are connected to.
2429  *
2430  * This is used for example in suspend/resume to disable all currently active
2431  * functions when suspending.
2432  *
2433  * Note that if callers haven't already acquired all modeset locks this might
2434  * return -EDEADLK, which must be handled by calling drm_modeset_backoff().
2435  *
2436  * Returns:
2437  * 0 on success or a negative error code on failure.
2438  *
2439  * See also:
2440  * drm_atomic_helper_suspend(), drm_atomic_helper_resume()
2441  */
2442 int drm_atomic_helper_disable_all(struct drm_device *dev,
2443 				  struct drm_modeset_acquire_ctx *ctx)
2444 {
2445 	struct drm_atomic_state *state;
2446 	struct drm_connector *conn;
2447 	int err;
2448 
2449 	state = drm_atomic_state_alloc(dev);
2450 	if (!state)
2451 		return -ENOMEM;
2452 
2453 	state->acquire_ctx = ctx;
2454 
2455 	drm_for_each_connector(conn, dev) {
2456 		struct drm_crtc *crtc = conn->state->crtc;
2457 		struct drm_crtc_state *crtc_state;
2458 
2459 		if (!crtc || conn->dpms != DRM_MODE_DPMS_ON)
2460 			continue;
2461 
2462 		crtc_state = drm_atomic_get_crtc_state(state, crtc);
2463 		if (IS_ERR(crtc_state)) {
2464 			err = PTR_ERR(crtc_state);
2465 			goto free;
2466 		}
2467 
2468 		crtc_state->active = false;
2469 	}
2470 
2471 	err = drm_atomic_commit(state);
2472 free:
2473 	drm_atomic_state_put(state);
2474 	return err;
2475 }
2476 EXPORT_SYMBOL(drm_atomic_helper_disable_all);
2477 
2478 /**
2479  * drm_atomic_helper_suspend - subsystem-level suspend helper
2480  * @dev: DRM device
2481  *
2482  * Duplicates the current atomic state, disables all active outputs and then
2483  * returns a pointer to the original atomic state to the caller. Drivers can
2484  * pass this pointer to the drm_atomic_helper_resume() helper upon resume to
2485  * restore the output configuration that was active at the time the system
2486  * entered suspend.
2487  *
2488  * Note that it is potentially unsafe to use this. The atomic state object
2489  * returned by this function is assumed to be persistent. Drivers must ensure
2490  * that this holds true. Before calling this function, drivers must make sure
2491  * to suspend fbdev emulation so that nothing can be using the device.
2492  *
2493  * Returns:
2494  * A pointer to a copy of the state before suspend on success or an ERR_PTR()-
2495  * encoded error code on failure. Drivers should store the returned atomic
2496  * state object and pass it to the drm_atomic_helper_resume() helper upon
2497  * resume.
2498  *
2499  * See also:
2500  * drm_atomic_helper_duplicate_state(), drm_atomic_helper_disable_all(),
2501  * drm_atomic_helper_resume()
2502  */
2503 struct drm_atomic_state *drm_atomic_helper_suspend(struct drm_device *dev)
2504 {
2505 	struct drm_modeset_acquire_ctx ctx;
2506 	struct drm_atomic_state *state;
2507 	int err;
2508 
2509 	drm_modeset_acquire_init(&ctx, 0);
2510 
2511 retry:
2512 	err = drm_modeset_lock_all_ctx(dev, &ctx);
2513 	if (err < 0) {
2514 		state = ERR_PTR(err);
2515 		goto unlock;
2516 	}
2517 
2518 	state = drm_atomic_helper_duplicate_state(dev, &ctx);
2519 	if (IS_ERR(state))
2520 		goto unlock;
2521 
2522 	err = drm_atomic_helper_disable_all(dev, &ctx);
2523 	if (err < 0) {
2524 		drm_atomic_state_put(state);
2525 		state = ERR_PTR(err);
2526 		goto unlock;
2527 	}
2528 
2529 unlock:
2530 	if (PTR_ERR(state) == -EDEADLK) {
2531 		drm_modeset_backoff(&ctx);
2532 		goto retry;
2533 	}
2534 
2535 	drm_modeset_drop_locks(&ctx);
2536 	drm_modeset_acquire_fini(&ctx);
2537 	return state;
2538 }
2539 EXPORT_SYMBOL(drm_atomic_helper_suspend);
2540 
2541 /**
2542  * drm_atomic_helper_resume - subsystem-level resume helper
2543  * @dev: DRM device
2544  * @state: atomic state to resume to
2545  *
2546  * Calls drm_mode_config_reset() to synchronize hardware and software states,
2547  * grabs all modeset locks and commits the atomic state object. This can be
2548  * used in conjunction with the drm_atomic_helper_suspend() helper to
2549  * implement suspend/resume for drivers that support atomic mode-setting.
2550  *
2551  * Returns:
2552  * 0 on success or a negative error code on failure.
2553  *
2554  * See also:
2555  * drm_atomic_helper_suspend()
2556  */
2557 int drm_atomic_helper_resume(struct drm_device *dev,
2558 			     struct drm_atomic_state *state)
2559 {
2560 	struct drm_mode_config *config = &dev->mode_config;
2561 	int err;
2562 
2563 	drm_mode_config_reset(dev);
2564 	drm_modeset_lock_all(dev);
2565 	state->acquire_ctx = config->acquire_ctx;
2566 	err = drm_atomic_commit(state);
2567 	drm_modeset_unlock_all(dev);
2568 
2569 	return err;
2570 }
2571 EXPORT_SYMBOL(drm_atomic_helper_resume);
2572 
2573 /**
2574  * drm_atomic_helper_crtc_set_property - helper for crtc properties
2575  * @crtc: DRM crtc
2576  * @property: DRM property
2577  * @val: value of property
2578  *
2579  * Provides a default crtc set_property handler using the atomic driver
2580  * interface.
2581  *
2582  * RETURNS:
2583  * Zero on success, error code on failure
2584  */
2585 int
2586 drm_atomic_helper_crtc_set_property(struct drm_crtc *crtc,
2587 				    struct drm_property *property,
2588 				    uint64_t val)
2589 {
2590 	struct drm_atomic_state *state;
2591 	struct drm_crtc_state *crtc_state;
2592 	int ret = 0;
2593 
2594 	state = drm_atomic_state_alloc(crtc->dev);
2595 	if (!state)
2596 		return -ENOMEM;
2597 
2598 	/* ->set_property is always called with all locks held. */
2599 	state->acquire_ctx = crtc->dev->mode_config.acquire_ctx;
2600 retry:
2601 	crtc_state = drm_atomic_get_crtc_state(state, crtc);
2602 	if (IS_ERR(crtc_state)) {
2603 		ret = PTR_ERR(crtc_state);
2604 		goto fail;
2605 	}
2606 
2607 	ret = drm_atomic_crtc_set_property(crtc, crtc_state,
2608 			property, val);
2609 	if (ret)
2610 		goto fail;
2611 
2612 	ret = drm_atomic_commit(state);
2613 fail:
2614 	if (ret == -EDEADLK)
2615 		goto backoff;
2616 
2617 	drm_atomic_state_put(state);
2618 	return ret;
2619 
2620 backoff:
2621 	drm_atomic_state_clear(state);
2622 	drm_atomic_legacy_backoff(state);
2623 
2624 	goto retry;
2625 }
2626 EXPORT_SYMBOL(drm_atomic_helper_crtc_set_property);
2627 
2628 /**
2629  * drm_atomic_helper_plane_set_property - helper for plane properties
2630  * @plane: DRM plane
2631  * @property: DRM property
2632  * @val: value of property
2633  *
2634  * Provides a default plane set_property handler using the atomic driver
2635  * interface.
2636  *
2637  * RETURNS:
2638  * Zero on success, error code on failure
2639  */
2640 int
2641 drm_atomic_helper_plane_set_property(struct drm_plane *plane,
2642 				    struct drm_property *property,
2643 				    uint64_t val)
2644 {
2645 	struct drm_atomic_state *state;
2646 	struct drm_plane_state *plane_state;
2647 	int ret = 0;
2648 
2649 	state = drm_atomic_state_alloc(plane->dev);
2650 	if (!state)
2651 		return -ENOMEM;
2652 
2653 	/* ->set_property is always called with all locks held. */
2654 	state->acquire_ctx = plane->dev->mode_config.acquire_ctx;
2655 retry:
2656 	plane_state = drm_atomic_get_plane_state(state, plane);
2657 	if (IS_ERR(plane_state)) {
2658 		ret = PTR_ERR(plane_state);
2659 		goto fail;
2660 	}
2661 
2662 	ret = drm_atomic_plane_set_property(plane, plane_state,
2663 			property, val);
2664 	if (ret)
2665 		goto fail;
2666 
2667 	ret = drm_atomic_commit(state);
2668 fail:
2669 	if (ret == -EDEADLK)
2670 		goto backoff;
2671 
2672 	drm_atomic_state_put(state);
2673 	return ret;
2674 
2675 backoff:
2676 	drm_atomic_state_clear(state);
2677 	drm_atomic_legacy_backoff(state);
2678 
2679 	goto retry;
2680 }
2681 EXPORT_SYMBOL(drm_atomic_helper_plane_set_property);
2682 
2683 /**
2684  * drm_atomic_helper_connector_set_property - helper for connector properties
2685  * @connector: DRM connector
2686  * @property: DRM property
2687  * @val: value of property
2688  *
2689  * Provides a default connector set_property handler using the atomic driver
2690  * interface.
2691  *
2692  * RETURNS:
2693  * Zero on success, error code on failure
2694  */
2695 int
2696 drm_atomic_helper_connector_set_property(struct drm_connector *connector,
2697 				    struct drm_property *property,
2698 				    uint64_t val)
2699 {
2700 	struct drm_atomic_state *state;
2701 	struct drm_connector_state *connector_state;
2702 	int ret = 0;
2703 
2704 	state = drm_atomic_state_alloc(connector->dev);
2705 	if (!state)
2706 		return -ENOMEM;
2707 
2708 	/* ->set_property is always called with all locks held. */
2709 	state->acquire_ctx = connector->dev->mode_config.acquire_ctx;
2710 retry:
2711 	connector_state = drm_atomic_get_connector_state(state, connector);
2712 	if (IS_ERR(connector_state)) {
2713 		ret = PTR_ERR(connector_state);
2714 		goto fail;
2715 	}
2716 
2717 	ret = drm_atomic_connector_set_property(connector, connector_state,
2718 			property, val);
2719 	if (ret)
2720 		goto fail;
2721 
2722 	ret = drm_atomic_commit(state);
2723 fail:
2724 	if (ret == -EDEADLK)
2725 		goto backoff;
2726 
2727 	drm_atomic_state_put(state);
2728 	return ret;
2729 
2730 backoff:
2731 	drm_atomic_state_clear(state);
2732 	drm_atomic_legacy_backoff(state);
2733 
2734 	goto retry;
2735 }
2736 EXPORT_SYMBOL(drm_atomic_helper_connector_set_property);
2737 
2738 /**
2739  * drm_atomic_helper_page_flip - execute a legacy page flip
2740  * @crtc: DRM crtc
2741  * @fb: DRM framebuffer
2742  * @event: optional DRM event to signal upon completion
2743  * @flags: flip flags for non-vblank sync'ed updates
2744  *
2745  * Provides a default page flip implementation using the atomic driver interface.
2746  *
2747  * Note that for now so called async page flips (i.e. updates which are not
2748  * synchronized to vblank) are not supported, since the atomic interfaces have
2749  * no provisions for this yet.
2750  *
2751  * Returns:
2752  * Returns 0 on success, negative errno numbers on failure.
2753  */
2754 int drm_atomic_helper_page_flip(struct drm_crtc *crtc,
2755 				struct drm_framebuffer *fb,
2756 				struct drm_pending_vblank_event *event,
2757 				uint32_t flags)
2758 {
2759 	struct drm_plane *plane = crtc->primary;
2760 	struct drm_atomic_state *state;
2761 	struct drm_plane_state *plane_state;
2762 	struct drm_crtc_state *crtc_state;
2763 	int ret = 0;
2764 
2765 	if (flags & DRM_MODE_PAGE_FLIP_ASYNC)
2766 		return -EINVAL;
2767 
2768 	state = drm_atomic_state_alloc(plane->dev);
2769 	if (!state)
2770 		return -ENOMEM;
2771 
2772 	state->acquire_ctx = drm_modeset_legacy_acquire_ctx(crtc);
2773 retry:
2774 	crtc_state = drm_atomic_get_crtc_state(state, crtc);
2775 	if (IS_ERR(crtc_state)) {
2776 		ret = PTR_ERR(crtc_state);
2777 		goto fail;
2778 	}
2779 	crtc_state->event = event;
2780 
2781 	plane_state = drm_atomic_get_plane_state(state, plane);
2782 	if (IS_ERR(plane_state)) {
2783 		ret = PTR_ERR(plane_state);
2784 		goto fail;
2785 	}
2786 
2787 	ret = drm_atomic_set_crtc_for_plane(plane_state, crtc);
2788 	if (ret != 0)
2789 		goto fail;
2790 	drm_atomic_set_fb_for_plane(plane_state, fb);
2791 
2792 	/* Make sure we don't accidentally do a full modeset. */
2793 	state->allow_modeset = false;
2794 	if (!crtc_state->active) {
2795 		DRM_DEBUG_ATOMIC("[CRTC:%d] disabled, rejecting legacy flip\n",
2796 				 crtc->base.id);
2797 		ret = -EINVAL;
2798 		goto fail;
2799 	}
2800 
2801 	ret = drm_atomic_nonblocking_commit(state);
2802 fail:
2803 	if (ret == -EDEADLK)
2804 		goto backoff;
2805 
2806 	drm_atomic_state_put(state);
2807 	return ret;
2808 
2809 backoff:
2810 	drm_atomic_state_clear(state);
2811 	drm_atomic_legacy_backoff(state);
2812 
2813 	/*
2814 	 * Someone might have exchanged the framebuffer while we dropped locks
2815 	 * in the backoff code. We need to fix up the fb refcount tracking the
2816 	 * core does for us.
2817 	 */
2818 	plane->old_fb = plane->fb;
2819 
2820 	goto retry;
2821 }
2822 EXPORT_SYMBOL(drm_atomic_helper_page_flip);
2823 
2824 /**
2825  * drm_atomic_helper_connector_dpms() - connector dpms helper implementation
2826  * @connector: affected connector
2827  * @mode: DPMS mode
2828  *
2829  * This is the main helper function provided by the atomic helper framework for
2830  * implementing the legacy DPMS connector interface. It computes the new desired
2831  * ->active state for the corresponding CRTC (if the connector is enabled) and
2832  * updates it.
2833  *
2834  * Returns:
2835  * Returns 0 on success, negative errno numbers on failure.
2836  */
2837 int drm_atomic_helper_connector_dpms(struct drm_connector *connector,
2838 				     int mode)
2839 {
2840 	struct drm_mode_config *config = &connector->dev->mode_config;
2841 	struct drm_atomic_state *state;
2842 	struct drm_crtc_state *crtc_state;
2843 	struct drm_crtc *crtc;
2844 	struct drm_connector *tmp_connector;
2845 	int ret;
2846 	bool active = false;
2847 	int old_mode = connector->dpms;
2848 
2849 	if (mode != DRM_MODE_DPMS_ON)
2850 		mode = DRM_MODE_DPMS_OFF;
2851 
2852 	connector->dpms = mode;
2853 	crtc = connector->state->crtc;
2854 
2855 	if (!crtc)
2856 		return 0;
2857 
2858 	state = drm_atomic_state_alloc(connector->dev);
2859 	if (!state)
2860 		return -ENOMEM;
2861 
2862 	state->acquire_ctx = drm_modeset_legacy_acquire_ctx(crtc);
2863 retry:
2864 	crtc_state = drm_atomic_get_crtc_state(state, crtc);
2865 	if (IS_ERR(crtc_state)) {
2866 		ret = PTR_ERR(crtc_state);
2867 		goto fail;
2868 	}
2869 
2870 	WARN_ON(!drm_modeset_is_locked(&config->connection_mutex));
2871 
2872 	drm_for_each_connector(tmp_connector, connector->dev) {
2873 		if (tmp_connector->state->crtc != crtc)
2874 			continue;
2875 
2876 		if (tmp_connector->dpms == DRM_MODE_DPMS_ON) {
2877 			active = true;
2878 			break;
2879 		}
2880 	}
2881 	crtc_state->active = active;
2882 
2883 	ret = drm_atomic_commit(state);
2884 fail:
2885 	if (ret == -EDEADLK)
2886 		goto backoff;
2887 	if (ret != 0)
2888 		connector->dpms = old_mode;
2889 	drm_atomic_state_put(state);
2890 	return ret;
2891 
2892 backoff:
2893 	drm_atomic_state_clear(state);
2894 	drm_atomic_legacy_backoff(state);
2895 
2896 	goto retry;
2897 }
2898 EXPORT_SYMBOL(drm_atomic_helper_connector_dpms);
2899 
2900 /**
2901  * drm_atomic_helper_best_encoder - Helper for &drm_connector_helper_funcs
2902  *                                  ->best_encoder callback
2903  * @connector: Connector control structure
2904  *
2905  * This is a &drm_connector_helper_funcs ->best_encoder callback helper for
2906  * connectors that support exactly 1 encoder, statically determined at driver
2907  * init time.
2908  */
2909 struct drm_encoder *
2910 drm_atomic_helper_best_encoder(struct drm_connector *connector)
2911 {
2912 	WARN_ON(connector->encoder_ids[1]);
2913 	return drm_encoder_find(connector->dev, connector->encoder_ids[0]);
2914 }
2915 EXPORT_SYMBOL(drm_atomic_helper_best_encoder);
2916 
2917 /**
2918  * DOC: atomic state reset and initialization
2919  *
2920  * Both the drm core and the atomic helpers assume that there is always the full
2921  * and correct atomic software state for all connectors, CRTCs and planes
2922  * available. Which is a bit a problem on driver load and also after system
2923  * suspend. One way to solve this is to have a hardware state read-out
2924  * infrastructure which reconstructs the full software state (e.g. the i915
2925  * driver).
2926  *
2927  * The simpler solution is to just reset the software state to everything off,
2928  * which is easiest to do by calling drm_mode_config_reset(). To facilitate this
2929  * the atomic helpers provide default reset implementations for all hooks.
2930  *
2931  * On the upside the precise state tracking of atomic simplifies system suspend
2932  * and resume a lot. For drivers using drm_mode_config_reset() a complete recipe
2933  * is implemented in drm_atomic_helper_suspend() and drm_atomic_helper_resume().
2934  * For other drivers the building blocks are split out, see the documentation
2935  * for these functions.
2936  */
2937 
2938 /**
2939  * drm_atomic_helper_crtc_reset - default ->reset hook for CRTCs
2940  * @crtc: drm CRTC
2941  *
2942  * Resets the atomic state for @crtc by freeing the state pointer (which might
2943  * be NULL, e.g. at driver load time) and allocating a new empty state object.
2944  */
2945 void drm_atomic_helper_crtc_reset(struct drm_crtc *crtc)
2946 {
2947 	if (crtc->state)
2948 		__drm_atomic_helper_crtc_destroy_state(crtc->state);
2949 
2950 	kfree(crtc->state);
2951 	crtc->state = kzalloc(sizeof(*crtc->state), GFP_KERNEL);
2952 
2953 	if (crtc->state)
2954 		crtc->state->crtc = crtc;
2955 }
2956 EXPORT_SYMBOL(drm_atomic_helper_crtc_reset);
2957 
2958 /**
2959  * __drm_atomic_helper_crtc_duplicate_state - copy atomic CRTC state
2960  * @crtc: CRTC object
2961  * @state: atomic CRTC state
2962  *
2963  * Copies atomic state from a CRTC's current state and resets inferred values.
2964  * This is useful for drivers that subclass the CRTC state.
2965  */
2966 void __drm_atomic_helper_crtc_duplicate_state(struct drm_crtc *crtc,
2967 					      struct drm_crtc_state *state)
2968 {
2969 	memcpy(state, crtc->state, sizeof(*state));
2970 
2971 	if (state->mode_blob)
2972 		drm_property_reference_blob(state->mode_blob);
2973 	if (state->degamma_lut)
2974 		drm_property_reference_blob(state->degamma_lut);
2975 	if (state->ctm)
2976 		drm_property_reference_blob(state->ctm);
2977 	if (state->gamma_lut)
2978 		drm_property_reference_blob(state->gamma_lut);
2979 	state->mode_changed = false;
2980 	state->active_changed = false;
2981 	state->planes_changed = false;
2982 	state->connectors_changed = false;
2983 	state->color_mgmt_changed = false;
2984 	state->zpos_changed = false;
2985 	state->event = NULL;
2986 }
2987 EXPORT_SYMBOL(__drm_atomic_helper_crtc_duplicate_state);
2988 
2989 /**
2990  * drm_atomic_helper_crtc_duplicate_state - default state duplicate hook
2991  * @crtc: drm CRTC
2992  *
2993  * Default CRTC state duplicate hook for drivers which don't have their own
2994  * subclassed CRTC state structure.
2995  */
2996 struct drm_crtc_state *
2997 drm_atomic_helper_crtc_duplicate_state(struct drm_crtc *crtc)
2998 {
2999 	struct drm_crtc_state *state;
3000 
3001 	if (WARN_ON(!crtc->state))
3002 		return NULL;
3003 
3004 	state = kmalloc(sizeof(*state), GFP_KERNEL);
3005 	if (state)
3006 		__drm_atomic_helper_crtc_duplicate_state(crtc, state);
3007 
3008 	return state;
3009 }
3010 EXPORT_SYMBOL(drm_atomic_helper_crtc_duplicate_state);
3011 
3012 /**
3013  * __drm_atomic_helper_crtc_destroy_state - release CRTC state
3014  * @state: CRTC state object to release
3015  *
3016  * Releases all resources stored in the CRTC state without actually freeing
3017  * the memory of the CRTC state. This is useful for drivers that subclass the
3018  * CRTC state.
3019  */
3020 void __drm_atomic_helper_crtc_destroy_state(struct drm_crtc_state *state)
3021 {
3022 	drm_property_unreference_blob(state->mode_blob);
3023 	drm_property_unreference_blob(state->degamma_lut);
3024 	drm_property_unreference_blob(state->ctm);
3025 	drm_property_unreference_blob(state->gamma_lut);
3026 }
3027 EXPORT_SYMBOL(__drm_atomic_helper_crtc_destroy_state);
3028 
3029 /**
3030  * drm_atomic_helper_crtc_destroy_state - default state destroy hook
3031  * @crtc: drm CRTC
3032  * @state: CRTC state object to release
3033  *
3034  * Default CRTC state destroy hook for drivers which don't have their own
3035  * subclassed CRTC state structure.
3036  */
3037 void drm_atomic_helper_crtc_destroy_state(struct drm_crtc *crtc,
3038 					  struct drm_crtc_state *state)
3039 {
3040 	__drm_atomic_helper_crtc_destroy_state(state);
3041 	kfree(state);
3042 }
3043 EXPORT_SYMBOL(drm_atomic_helper_crtc_destroy_state);
3044 
3045 /**
3046  * drm_atomic_helper_plane_reset - default ->reset hook for planes
3047  * @plane: drm plane
3048  *
3049  * Resets the atomic state for @plane by freeing the state pointer (which might
3050  * be NULL, e.g. at driver load time) and allocating a new empty state object.
3051  */
3052 void drm_atomic_helper_plane_reset(struct drm_plane *plane)
3053 {
3054 	if (plane->state)
3055 		__drm_atomic_helper_plane_destroy_state(plane->state);
3056 
3057 	kfree(plane->state);
3058 	plane->state = kzalloc(sizeof(*plane->state), GFP_KERNEL);
3059 
3060 	if (plane->state) {
3061 		plane->state->plane = plane;
3062 		plane->state->rotation = DRM_ROTATE_0;
3063 	}
3064 }
3065 EXPORT_SYMBOL(drm_atomic_helper_plane_reset);
3066 
3067 /**
3068  * __drm_atomic_helper_plane_duplicate_state - copy atomic plane state
3069  * @plane: plane object
3070  * @state: atomic plane state
3071  *
3072  * Copies atomic state from a plane's current state. This is useful for
3073  * drivers that subclass the plane state.
3074  */
3075 void __drm_atomic_helper_plane_duplicate_state(struct drm_plane *plane,
3076 					       struct drm_plane_state *state)
3077 {
3078 	memcpy(state, plane->state, sizeof(*state));
3079 
3080 	if (state->fb)
3081 		drm_framebuffer_reference(state->fb);
3082 
3083 	state->fence = NULL;
3084 }
3085 EXPORT_SYMBOL(__drm_atomic_helper_plane_duplicate_state);
3086 
3087 /**
3088  * drm_atomic_helper_plane_duplicate_state - default state duplicate hook
3089  * @plane: drm plane
3090  *
3091  * Default plane state duplicate hook for drivers which don't have their own
3092  * subclassed plane state structure.
3093  */
3094 struct drm_plane_state *
3095 drm_atomic_helper_plane_duplicate_state(struct drm_plane *plane)
3096 {
3097 	struct drm_plane_state *state;
3098 
3099 	if (WARN_ON(!plane->state))
3100 		return NULL;
3101 
3102 	state = kmalloc(sizeof(*state), GFP_KERNEL);
3103 	if (state)
3104 		__drm_atomic_helper_plane_duplicate_state(plane, state);
3105 
3106 	return state;
3107 }
3108 EXPORT_SYMBOL(drm_atomic_helper_plane_duplicate_state);
3109 
3110 /**
3111  * __drm_atomic_helper_plane_destroy_state - release plane state
3112  * @state: plane state object to release
3113  *
3114  * Releases all resources stored in the plane state without actually freeing
3115  * the memory of the plane state. This is useful for drivers that subclass the
3116  * plane state.
3117  */
3118 void __drm_atomic_helper_plane_destroy_state(struct drm_plane_state *state)
3119 {
3120 	if (state->fb)
3121 		drm_framebuffer_unreference(state->fb);
3122 
3123 	if (state->fence)
3124 		dma_fence_put(state->fence);
3125 }
3126 EXPORT_SYMBOL(__drm_atomic_helper_plane_destroy_state);
3127 
3128 /**
3129  * drm_atomic_helper_plane_destroy_state - default state destroy hook
3130  * @plane: drm plane
3131  * @state: plane state object to release
3132  *
3133  * Default plane state destroy hook for drivers which don't have their own
3134  * subclassed plane state structure.
3135  */
3136 void drm_atomic_helper_plane_destroy_state(struct drm_plane *plane,
3137 					   struct drm_plane_state *state)
3138 {
3139 	__drm_atomic_helper_plane_destroy_state(state);
3140 	kfree(state);
3141 }
3142 EXPORT_SYMBOL(drm_atomic_helper_plane_destroy_state);
3143 
3144 /**
3145  * __drm_atomic_helper_connector_reset - reset state on connector
3146  * @connector: drm connector
3147  * @conn_state: connector state to assign
3148  *
3149  * Initializes the newly allocated @conn_state and assigns it to
3150  * #connector ->state, usually required when initializing the drivers
3151  * or when called from the ->reset hook.
3152  *
3153  * This is useful for drivers that subclass the connector state.
3154  */
3155 void
3156 __drm_atomic_helper_connector_reset(struct drm_connector *connector,
3157 				    struct drm_connector_state *conn_state)
3158 {
3159 	if (conn_state)
3160 		conn_state->connector = connector;
3161 
3162 	connector->state = conn_state;
3163 }
3164 EXPORT_SYMBOL(__drm_atomic_helper_connector_reset);
3165 
3166 /**
3167  * drm_atomic_helper_connector_reset - default ->reset hook for connectors
3168  * @connector: drm connector
3169  *
3170  * Resets the atomic state for @connector by freeing the state pointer (which
3171  * might be NULL, e.g. at driver load time) and allocating a new empty state
3172  * object.
3173  */
3174 void drm_atomic_helper_connector_reset(struct drm_connector *connector)
3175 {
3176 	struct drm_connector_state *conn_state =
3177 		kzalloc(sizeof(*conn_state), GFP_KERNEL);
3178 
3179 	if (connector->state)
3180 		__drm_atomic_helper_connector_destroy_state(connector->state);
3181 
3182 	kfree(connector->state);
3183 	__drm_atomic_helper_connector_reset(connector, conn_state);
3184 }
3185 EXPORT_SYMBOL(drm_atomic_helper_connector_reset);
3186 
3187 /**
3188  * __drm_atomic_helper_connector_duplicate_state - copy atomic connector state
3189  * @connector: connector object
3190  * @state: atomic connector state
3191  *
3192  * Copies atomic state from a connector's current state. This is useful for
3193  * drivers that subclass the connector state.
3194  */
3195 void
3196 __drm_atomic_helper_connector_duplicate_state(struct drm_connector *connector,
3197 					    struct drm_connector_state *state)
3198 {
3199 	memcpy(state, connector->state, sizeof(*state));
3200 	if (state->crtc)
3201 		drm_connector_reference(connector);
3202 }
3203 EXPORT_SYMBOL(__drm_atomic_helper_connector_duplicate_state);
3204 
3205 /**
3206  * drm_atomic_helper_connector_duplicate_state - default state duplicate hook
3207  * @connector: drm connector
3208  *
3209  * Default connector state duplicate hook for drivers which don't have their own
3210  * subclassed connector state structure.
3211  */
3212 struct drm_connector_state *
3213 drm_atomic_helper_connector_duplicate_state(struct drm_connector *connector)
3214 {
3215 	struct drm_connector_state *state;
3216 
3217 	if (WARN_ON(!connector->state))
3218 		return NULL;
3219 
3220 	state = kmalloc(sizeof(*state), GFP_KERNEL);
3221 	if (state)
3222 		__drm_atomic_helper_connector_duplicate_state(connector, state);
3223 
3224 	return state;
3225 }
3226 EXPORT_SYMBOL(drm_atomic_helper_connector_duplicate_state);
3227 
3228 /**
3229  * drm_atomic_helper_duplicate_state - duplicate an atomic state object
3230  * @dev: DRM device
3231  * @ctx: lock acquisition context
3232  *
3233  * Makes a copy of the current atomic state by looping over all objects and
3234  * duplicating their respective states. This is used for example by suspend/
3235  * resume support code to save the state prior to suspend such that it can
3236  * be restored upon resume.
3237  *
3238  * Note that this treats atomic state as persistent between save and restore.
3239  * Drivers must make sure that this is possible and won't result in confusion
3240  * or erroneous behaviour.
3241  *
3242  * Note that if callers haven't already acquired all modeset locks this might
3243  * return -EDEADLK, which must be handled by calling drm_modeset_backoff().
3244  *
3245  * Returns:
3246  * A pointer to the copy of the atomic state object on success or an
3247  * ERR_PTR()-encoded error code on failure.
3248  *
3249  * See also:
3250  * drm_atomic_helper_suspend(), drm_atomic_helper_resume()
3251  */
3252 struct drm_atomic_state *
3253 drm_atomic_helper_duplicate_state(struct drm_device *dev,
3254 				  struct drm_modeset_acquire_ctx *ctx)
3255 {
3256 	struct drm_atomic_state *state;
3257 	struct drm_connector *conn;
3258 	struct drm_plane *plane;
3259 	struct drm_crtc *crtc;
3260 	int err = 0;
3261 
3262 	state = drm_atomic_state_alloc(dev);
3263 	if (!state)
3264 		return ERR_PTR(-ENOMEM);
3265 
3266 	state->acquire_ctx = ctx;
3267 
3268 	drm_for_each_crtc(crtc, dev) {
3269 		struct drm_crtc_state *crtc_state;
3270 
3271 		crtc_state = drm_atomic_get_crtc_state(state, crtc);
3272 		if (IS_ERR(crtc_state)) {
3273 			err = PTR_ERR(crtc_state);
3274 			goto free;
3275 		}
3276 	}
3277 
3278 	drm_for_each_plane(plane, dev) {
3279 		struct drm_plane_state *plane_state;
3280 
3281 		plane_state = drm_atomic_get_plane_state(state, plane);
3282 		if (IS_ERR(plane_state)) {
3283 			err = PTR_ERR(plane_state);
3284 			goto free;
3285 		}
3286 	}
3287 
3288 	drm_for_each_connector(conn, dev) {
3289 		struct drm_connector_state *conn_state;
3290 
3291 		conn_state = drm_atomic_get_connector_state(state, conn);
3292 		if (IS_ERR(conn_state)) {
3293 			err = PTR_ERR(conn_state);
3294 			goto free;
3295 		}
3296 	}
3297 
3298 	/* clear the acquire context so that it isn't accidentally reused */
3299 	state->acquire_ctx = NULL;
3300 
3301 free:
3302 	if (err < 0) {
3303 		drm_atomic_state_put(state);
3304 		state = ERR_PTR(err);
3305 	}
3306 
3307 	return state;
3308 }
3309 EXPORT_SYMBOL(drm_atomic_helper_duplicate_state);
3310 
3311 /**
3312  * __drm_atomic_helper_connector_destroy_state - release connector state
3313  * @state: connector state object to release
3314  *
3315  * Releases all resources stored in the connector state without actually
3316  * freeing the memory of the connector state. This is useful for drivers that
3317  * subclass the connector state.
3318  */
3319 void
3320 __drm_atomic_helper_connector_destroy_state(struct drm_connector_state *state)
3321 {
3322 	/*
3323 	 * This is currently a placeholder so that drivers that subclass the
3324 	 * state will automatically do the right thing if code is ever added
3325 	 * to this function.
3326 	 */
3327 	if (state->crtc)
3328 		drm_connector_unreference(state->connector);
3329 }
3330 EXPORT_SYMBOL(__drm_atomic_helper_connector_destroy_state);
3331 
3332 /**
3333  * drm_atomic_helper_connector_destroy_state - default state destroy hook
3334  * @connector: drm connector
3335  * @state: connector state object to release
3336  *
3337  * Default connector state destroy hook for drivers which don't have their own
3338  * subclassed connector state structure.
3339  */
3340 void drm_atomic_helper_connector_destroy_state(struct drm_connector *connector,
3341 					  struct drm_connector_state *state)
3342 {
3343 	__drm_atomic_helper_connector_destroy_state(state);
3344 	kfree(state);
3345 }
3346 EXPORT_SYMBOL(drm_atomic_helper_connector_destroy_state);
3347 
3348 /**
3349  * drm_atomic_helper_legacy_gamma_set - set the legacy gamma correction table
3350  * @crtc: CRTC object
3351  * @red: red correction table
3352  * @green: green correction table
3353  * @blue: green correction table
3354  * @size: size of the tables
3355  *
3356  * Implements support for legacy gamma correction table for drivers
3357  * that support color management through the DEGAMMA_LUT/GAMMA_LUT
3358  * properties.
3359  */
3360 int drm_atomic_helper_legacy_gamma_set(struct drm_crtc *crtc,
3361 				       u16 *red, u16 *green, u16 *blue,
3362 				       uint32_t size)
3363 {
3364 	struct drm_device *dev = crtc->dev;
3365 	struct drm_mode_config *config = &dev->mode_config;
3366 	struct drm_atomic_state *state;
3367 	struct drm_crtc_state *crtc_state;
3368 	struct drm_property_blob *blob = NULL;
3369 	struct drm_color_lut *blob_data;
3370 	int i, ret = 0;
3371 
3372 	state = drm_atomic_state_alloc(crtc->dev);
3373 	if (!state)
3374 		return -ENOMEM;
3375 
3376 	blob = drm_property_create_blob(dev,
3377 					sizeof(struct drm_color_lut) * size,
3378 					NULL);
3379 	if (IS_ERR(blob)) {
3380 		ret = PTR_ERR(blob);
3381 		blob = NULL;
3382 		goto fail;
3383 	}
3384 
3385 	/* Prepare GAMMA_LUT with the legacy values. */
3386 	blob_data = (struct drm_color_lut *) blob->data;
3387 	for (i = 0; i < size; i++) {
3388 		blob_data[i].red = red[i];
3389 		blob_data[i].green = green[i];
3390 		blob_data[i].blue = blue[i];
3391 	}
3392 
3393 	state->acquire_ctx = crtc->dev->mode_config.acquire_ctx;
3394 retry:
3395 	crtc_state = drm_atomic_get_crtc_state(state, crtc);
3396 	if (IS_ERR(crtc_state)) {
3397 		ret = PTR_ERR(crtc_state);
3398 		goto fail;
3399 	}
3400 
3401 	/* Reset DEGAMMA_LUT and CTM properties. */
3402 	ret = drm_atomic_crtc_set_property(crtc, crtc_state,
3403 			config->degamma_lut_property, 0);
3404 	if (ret)
3405 		goto fail;
3406 
3407 	ret = drm_atomic_crtc_set_property(crtc, crtc_state,
3408 			config->ctm_property, 0);
3409 	if (ret)
3410 		goto fail;
3411 
3412 	ret = drm_atomic_crtc_set_property(crtc, crtc_state,
3413 			config->gamma_lut_property, blob->base.id);
3414 	if (ret)
3415 		goto fail;
3416 
3417 	ret = drm_atomic_commit(state);
3418 fail:
3419 	if (ret == -EDEADLK)
3420 		goto backoff;
3421 
3422 	drm_atomic_state_put(state);
3423 	drm_property_unreference_blob(blob);
3424 	return ret;
3425 
3426 backoff:
3427 	drm_atomic_state_clear(state);
3428 	drm_atomic_legacy_backoff(state);
3429 
3430 	goto retry;
3431 }
3432 EXPORT_SYMBOL(drm_atomic_helper_legacy_gamma_set);
3433