drivers/gpu/drm/drm_atomic.c

   1 /*
   2  * Copyright (C) 2014 Red Hat
   3  * Copyright (C) 2014 Intel Corp.
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a
   6  * copy of this software and associated documentation files (the "Software"),
   7  * to deal in the Software without restriction, including without limitation
   8  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   9  * and/or sell copies of the Software, and to permit persons to whom the
  10  * Software is furnished to do so, subject to the following conditions:
  11  *
  12  * The above copyright notice and this permission notice shall be included in
  13  * all copies or substantial portions of the Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
  19  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  20  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  21  * OTHER DEALINGS IN THE SOFTWARE.
  22  *
  23  * Authors:
  24  * Rob Clark <robdclark@gmail.com>
  25  * Daniel Vetter <daniel.vetter@ffwll.ch>
  26  */
  27
  28
  29 #include <drm/drmP.h>
  30 #include <drm/drm_atomic.h>
  31 #include <drm/drm_plane_helper.h>
  32
  33 static void kfree_state(struct drm_atomic_state *state)
  34 {
  35         kfree(state->connectors);
  36         kfree(state->connector_states);
  37         kfree(state->crtcs);
  38         kfree(state->crtc_states);
  39         kfree(state->planes);
  40         kfree(state->plane_states);
  41         kfree(state);
  42 }
  43
  44 /**
  45  * drm_atomic_state_alloc - allocate atomic state
  46  * @dev: DRM device
  47  *
  48  * This allocates an empty atomic state to track updates.
  49  */
  50 struct drm_atomic_state *
  51 drm_atomic_state_alloc(struct drm_device *dev)
  52 {
  53         struct drm_atomic_state *state;
  54
  55         state = kzalloc(sizeof(*state), GFP_KERNEL);
  56         if (!state)
  57                 return NULL;
  58
  59         state->crtcs = kcalloc(dev->mode_config.num_crtc,
  60                                sizeof(*state->crtcs), GFP_KERNEL);
  61         if (!state->crtcs)
  62                 goto fail;
  63         state->crtc_states = kcalloc(dev->mode_config.num_crtc,
  64                                      sizeof(*state->crtc_states), GFP_KERNEL);
  65         if (!state->crtc_states)
  66                 goto fail;
  67         state->planes = kcalloc(dev->mode_config.num_total_plane,
  68                                 sizeof(*state->planes), GFP_KERNEL);
  69         if (!state->planes)
  70                 goto fail;
  71         state->plane_states = kcalloc(dev->mode_config.num_total_plane,
  72                                       sizeof(*state->plane_states), GFP_KERNEL);
  73         if (!state->plane_states)
  74                 goto fail;
  75         state->connectors = kcalloc(dev->mode_config.num_connector,
  76                                     sizeof(*state->connectors),
  77                                     GFP_KERNEL);
  78         if (!state->connectors)
  79                 goto fail;
  80         state->connector_states = kcalloc(dev->mode_config.num_connector,
  81                                           sizeof(*state->connector_states),
  82                                           GFP_KERNEL);
  83         if (!state->connector_states)
  84                 goto fail;
  85
  86         state->dev = dev;
  87
  88         DRM_DEBUG_KMS("Allocate atomic state %p\n", state);
  89
  90         return state;
  91 fail:
  92         kfree_state(state);
  93
  94         return NULL;
  95 }
  96 EXPORT_SYMBOL(drm_atomic_state_alloc);
  97
  98 /**
  99  * drm_atomic_state_clear - clear state object
 100  * @state: atomic state
 101  *
 102  * When the w/w mutex algorithm detects a deadlock we need to back off and drop
 103  * all locks. So someone else could sneak in and change the current modeset
 104  * configuration. Which means that all the state assembled in @state is no
 105  * longer an atomic update to the current state, but to some arbitrary earlier
 106  * state. Which could break assumptions the driver's ->atomic_check likely
 107  * relies on.
 108  *
 109  * Hence we must clear all cached state and completely start over, using this
 110  * function.
 111  */
 112 void drm_atomic_state_clear(struct drm_atomic_state *state)
 113 {
 114         struct drm_device *dev = state->dev;
 115         int i;
 116
 117         DRM_DEBUG_KMS("Clearing atomic state %p\n", state);
 118
 119         for (i = 0; i < dev->mode_config.num_connector; i++) {
 120                 struct drm_connector *connector = state->connectors[i];
 121
 122                 if (!connector)
 123                         continue;
 124
 125                 connector->funcs->atomic_destroy_state(connector,
 126                                                        state->connector_states[i]);
 127         }
 128
 129         for (i = 0; i < dev->mode_config.num_crtc; i++) {
 130                 struct drm_crtc *crtc = state->crtcs[i];
 131
 132                 if (!crtc)
 133                         continue;
 134
 135                 crtc->funcs->atomic_destroy_state(crtc,
 136                                                   state->crtc_states[i]);
 137         }
 138
 139         for (i = 0; i < dev->mode_config.num_total_plane; i++) {
 140                 struct drm_plane *plane = state->planes[i];
 141
 142                 if (!plane)
 143                         continue;
 144
 145                 plane->funcs->atomic_destroy_state(plane,
 146                                                    state->plane_states[i]);
 147         }
 148 }
 149 EXPORT_SYMBOL(drm_atomic_state_clear);
 150
 151 /**
 152  * drm_atomic_state_free - free all memory for an atomic state
 153  * @state: atomic state to deallocate
 154  *
 155  * This frees all memory associated with an atomic state, including all the
 156  * per-object state for planes, crtcs and connectors.
 157  */
 158 void drm_atomic_state_free(struct drm_atomic_state *state)
 159 {
 160         drm_atomic_state_clear(state);
 161
 162         DRM_DEBUG_KMS("Freeing atomic state %p\n", state);
 163
 164         kfree_state(state);
 165 }
 166 EXPORT_SYMBOL(drm_atomic_state_free);
 167
 168 /**
 169  * drm_atomic_get_crtc_state - get crtc state
 170  * @state: global atomic state object
 171  * @crtc: crtc to get state object for
 172  *
 173  * This function returns the crtc state for the given crtc, allocating it if
 174  * needed. It will also grab the relevant crtc lock to make sure that the state
 175  * is consistent.
 176  *
 177  * Returns:
 178  *
 179  * Either the allocated state or the error code encoded into the pointer. When
 180  * the error is EDEADLK then the w/w mutex code has detected a deadlock and the
 181  * entire atomic sequence must be restarted. All other errors are fatal.
 182  */
 183 struct drm_crtc_state *
 184 drm_atomic_get_crtc_state(struct drm_atomic_state *state,
 185                           struct drm_crtc *crtc)
 186 {
 187         int ret, index;
 188         struct drm_crtc_state *crtc_state;
 189
 190         index = drm_crtc_index(crtc);
 191
 192         if (state->crtc_states[index])
 193                 return state->crtc_states[index];
 194
 195         ret = drm_modeset_lock(&crtc->mutex, state->acquire_ctx);
 196         if (ret)
 197                 return ERR_PTR(ret);
 198
 199         crtc_state = crtc->funcs->atomic_duplicate_state(crtc);
 200         if (!crtc_state)
 201                 return ERR_PTR(-ENOMEM);
 202
 203         state->crtc_states[index] = crtc_state;
 204         state->crtcs[index] = crtc;
 205         crtc_state->state = state;
 206
 207         DRM_DEBUG_KMS("Added [CRTC:%d] %p state to %p\n",
 208                       crtc->base.id, crtc_state, state);
 209
 210         return crtc_state;
 211 }
 212 EXPORT_SYMBOL(drm_atomic_get_crtc_state);
 213
 214 /**
 215  * drm_atomic_get_plane_state - get plane state
 216  * @state: global atomic state object
 217  * @plane: plane to get state object for
 218  *
 219  * This function returns the plane state for the given plane, allocating it if
 220  * needed. It will also grab the relevant plane lock to make sure that the state
 221  * is consistent.
 222  *
 223  * Returns:
 224  *
 225  * Either the allocated state or the error code encoded into the pointer. When
 226  * the error is EDEADLK then the w/w mutex code has detected a deadlock and the
 227  * entire atomic sequence must be restarted. All other errors are fatal.
 228  */
 229 struct drm_plane_state *
 230 drm_atomic_get_plane_state(struct drm_atomic_state *state,
 231                           struct drm_plane *plane)
 232 {
 233         int ret, index;
 234         struct drm_plane_state *plane_state;
 235
 236         index = drm_plane_index(plane);
 237
 238         if (state->plane_states[index])
 239                 return state->plane_states[index];
 240
 241         /*
 242          * TODO: We currently don't have per-plane mutexes. So instead of trying
 243          * crazy tricks with deferring plane->crtc and hoping for the best just
 244          * grab all crtc locks. Once we have per-plane locks we must update this
 245          * to only take the plane mutex.
 246          */
 247         ret = drm_modeset_lock_all_crtcs(state->dev, state->acquire_ctx);
 248         if (ret)
 249                 return ERR_PTR(ret);
 250
 251         plane_state = plane->funcs->atomic_duplicate_state(plane);
 252         if (!plane_state)
 253                 return ERR_PTR(-ENOMEM);
 254
 255         state->plane_states[index] = plane_state;
 256         state->planes[index] = plane;
 257         plane_state->state = state;
 258
 259         DRM_DEBUG_KMS("Added [PLANE:%d] %p state to %p\n",
 260                       plane->base.id, plane_state, state);
 261
 262         if (plane_state->crtc) {
 263                 struct drm_crtc_state *crtc_state;
 264
 265                 crtc_state = drm_atomic_get_crtc_state(state,
 266                                                        plane_state->crtc);
 267                 if (IS_ERR(crtc_state))
 268                         return ERR_CAST(crtc_state);
 269         }
 270
 271         return plane_state;
 272 }
 273 EXPORT_SYMBOL(drm_atomic_get_plane_state);
 274
 275 /**
 276  * drm_atomic_get_connector_state - get connector state
 277  * @state: global atomic state object
 278  * @connector: connector to get state object for
 279  *
 280  * This function returns the connector state for the given connector,
 281  * allocating it if needed. It will also grab the relevant connector lock to
 282  * make sure that the state is consistent.
 283  *
 284  * Returns:
 285  *
 286  * Either the allocated state or the error code encoded into the pointer. When
 287  * the error is EDEADLK then the w/w mutex code has detected a deadlock and the
 288  * entire atomic sequence must be restarted. All other errors are fatal.
 289  */
 290 struct drm_connector_state *
 291 drm_atomic_get_connector_state(struct drm_atomic_state *state,
 292                           struct drm_connector *connector)
 293 {
 294         int ret, index;
 295         struct drm_mode_config *config = &connector->dev->mode_config;
 296         struct drm_connector_state *connector_state;
 297
 298         index = drm_connector_index(connector);
 299
 300         if (state->connector_states[index])
 301                 return state->connector_states[index];
 302
 303         ret = drm_modeset_lock(&config->connection_mutex, state->acquire_ctx);
 304         if (ret)
 305                 return ERR_PTR(ret);
 306
 307         connector_state = connector->funcs->atomic_duplicate_state(connector);
 308         if (!connector_state)
 309                 return ERR_PTR(-ENOMEM);
 310
 311         state->connector_states[index] = connector_state;
 312         state->connectors[index] = connector;
 313         connector_state->state = state;
 314
 315         DRM_DEBUG_KMS("Added [CONNECTOR:%d] %p state to %p\n",
 316                       connector->base.id, connector_state, state);
 317
 318         if (connector_state->crtc) {
 319                 struct drm_crtc_state *crtc_state;
 320
 321                 crtc_state = drm_atomic_get_crtc_state(state,
 322                                                        connector_state->crtc);
 323                 if (IS_ERR(crtc_state))
 324                         return ERR_CAST(crtc_state);
 325         }
 326
 327         return connector_state;
 328 }
 329 EXPORT_SYMBOL(drm_atomic_get_connector_state);
 330
 331 /**
 332  * drm_atomic_set_crtc_for_plane - set crtc for plane
 333  * @plane_state: atomic state object for the plane
 334  * @crtc: crtc to use for the plane
 335  *
 336  * Changing the assigned crtc for a plane requires us to grab the lock and state
 337  * for the new crtc, as needed. This function takes care of all these details
 338  * besides updating the pointer in the state object itself.
 339  *
 340  * Returns:
 341  * 0 on success or can fail with -EDEADLK or -ENOMEM. When the error is EDEADLK
 342  * then the w/w mutex code has detected a deadlock and the entire atomic
 343  * sequence must be restarted. All other errors are fatal.
 344  */
 345 int
 346 drm_atomic_set_crtc_for_plane(struct drm_plane_state *plane_state,
 347                               struct drm_crtc *crtc)
 348 {
 349         struct drm_crtc_state *crtc_state;
 350
 351         if (crtc) {
 352                 crtc_state = drm_atomic_get_crtc_state(plane_state->state,
 353                                                        crtc);
 354                 if (IS_ERR(crtc_state))
 355                         return PTR_ERR(crtc_state);
 356         }
 357
 358         plane_state->crtc = crtc;
 359
 360         if (crtc)
 361                 DRM_DEBUG_KMS("Link plane state %p to [CRTC:%d]\n",
 362                               plane_state, crtc->base.id);
 363         else
 364                 DRM_DEBUG_KMS("Link plane state %p to [NOCRTC]\n", plane_state);
 365
 366         return 0;
 367 }
 368 EXPORT_SYMBOL(drm_atomic_set_crtc_for_plane);
 369
 370 /**
 371  * drm_atomic_set_crtc_for_connector - set crtc for connector
 372  * @conn_state: atomic state object for the connector
 373  * @crtc: crtc to use for the connector
 374  *
 375  * Changing the assigned crtc for a connector requires us to grab the lock and
 376  * state for the new crtc, as needed. This function takes care of all these
 377  * details besides updating the pointer in the state object itself.
 378  *
 379  * Returns:
 380  * 0 on success or can fail with -EDEADLK or -ENOMEM. When the error is EDEADLK
 381  * then the w/w mutex code has detected a deadlock and the entire atomic
 382  * sequence must be restarted. All other errors are fatal.
 383  */
 384 int
 385 drm_atomic_set_crtc_for_connector(struct drm_connector_state *conn_state,
 386                                   struct drm_crtc *crtc)
 387 {
 388         struct drm_crtc_state *crtc_state;
 389
 390         if (crtc) {
 391                 crtc_state = drm_atomic_get_crtc_state(conn_state->state, crtc);
 392                 if (IS_ERR(crtc_state))
 393                         return PTR_ERR(crtc_state);
 394         }
 395
 396         conn_state->crtc = crtc;
 397
 398         if (crtc)
 399                 DRM_DEBUG_KMS("Link connector state %p to [CRTC:%d]\n",
 400                               conn_state, crtc->base.id);
 401         else
 402                 DRM_DEBUG_KMS("Link connector state %p to [NOCRTC]\n",
 403                               conn_state);
 404
 405         return 0;
 406 }
 407 EXPORT_SYMBOL(drm_atomic_set_crtc_for_connector);
 408
 409 /**
 410  * drm_atomic_add_affected_connectors - add connectors for crtc
 411  * @state: atomic state
 412  * @crtc: DRM crtc
 413  *
 414  * This function walks the current configuration and adds all connectors
 415  * currently using @crtc to the atomic configuration @state. Note that this
 416  * function must acquire the connection mutex. This can potentially cause
 417  * unneeded seralization if the update is just for the planes on one crtc. Hence
 418  * drivers and helpers should only call this when really needed (e.g. when a
 419  * full modeset needs to happen due to some change).
 420  *
 421  * Returns:
 422  * 0 on success or can fail with -EDEADLK or -ENOMEM. When the error is EDEADLK
 423  * then the w/w mutex code has detected a deadlock and the entire atomic
 424  * sequence must be restarted. All other errors are fatal.
 425  */
 426 int
 427 drm_atomic_add_affected_connectors(struct drm_atomic_state *state,
 428                                    struct drm_crtc *crtc)
 429 {
 430         struct drm_mode_config *config = &state->dev->mode_config;
 431         struct drm_connector *connector;
 432         struct drm_connector_state *conn_state;
 433         int ret;
 434
 435         ret = drm_modeset_lock(&config->connection_mutex, state->acquire_ctx);
 436         if (ret)
 437                 return ret;
 438
 439         DRM_DEBUG_KMS("Adding all current connectors for [CRTC:%d] to %p\n",
 440                       crtc->base.id, state);
 441
 442         /*
 443          * Changed connectors are already in @state, so only need to look at the
 444          * current configuration.
 445          */
 446         list_for_each_entry(connector, &config->connector_list, head) {
 447                 if (connector->state->crtc != crtc)
 448                         continue;
 449
 450                 conn_state = drm_atomic_get_connector_state(state, connector);
 451                 if (IS_ERR(conn_state))
 452                         return PTR_ERR(conn_state);
 453         }
 454
 455         return 0;
 456 }
 457 EXPORT_SYMBOL(drm_atomic_add_affected_connectors);
 458
 459 /**
 460  * drm_atomic_connectors_for_crtc - count number of connected outputs
 461  * @state: atomic state
 462  * @crtc: DRM crtc
 463  *
 464  * This function counts all connectors which will be connected to @crtc
 465  * according to @state. Useful to recompute the enable state for @crtc.
 466  */
 467 int
 468 drm_atomic_connectors_for_crtc(struct drm_atomic_state *state,
 469                                struct drm_crtc *crtc)
 470 {
 471         int nconnectors = state->dev->mode_config.num_connector;
 472         int i, num_connected_connectors = 0;
 473
 474         for (i = 0; i < nconnectors; i++) {
 475                 struct drm_connector_state *conn_state;
 476
 477                 conn_state = state->connector_states[i];
 478
 479                 if (conn_state && conn_state->crtc == crtc)
 480                         num_connected_connectors++;
 481         }
 482
 483         DRM_DEBUG_KMS("State %p has %i connectors for [CRTC:%d]\n",
 484                       state, num_connected_connectors, crtc->base.id);
 485
 486         return num_connected_connectors;
 487 }
 488 EXPORT_SYMBOL(drm_atomic_connectors_for_crtc);
 489
 490 /**
 491  * drm_atomic_legacy_backoff - locking backoff for legacy ioctls
 492  * @state: atomic state
 493  *
 494  * This function should be used by legacy entry points which don't understand
 495  * -EDEADLK semantics. For simplicity this one will grab all modeset locks after
 496  *  the slowpath completed.
 497  */
 498 void drm_atomic_legacy_backoff(struct drm_atomic_state *state)
 499 {
 500         int ret;
 501
 502 retry:
 503         drm_modeset_backoff(state->acquire_ctx);
 504
 505         ret = drm_modeset_lock(&state->dev->mode_config.connection_mutex,
 506                                state->acquire_ctx);
 507         if (ret)
 508                 goto retry;
 509         ret = drm_modeset_lock_all_crtcs(state->dev,
 510                                          state->acquire_ctx);
 511         if (ret)
 512                 goto retry;
 513 }
 514 EXPORT_SYMBOL(drm_atomic_legacy_backoff);
 515
 516 /**
 517  * drm_atomic_check_only - check whether a given config would work
 518  * @state: atomic configuration to check
 519  *
 520  * Note that this function can return -EDEADLK if the driver needed to acquire
 521  * more locks but encountered a deadlock. The caller must then do the usual w/w
 522  * backoff dance and restart. All other errors are fatal.
 523  *
 524  * Returns:
 525  * 0 on success, negative error code on failure.
 526  */
 527 int drm_atomic_check_only(struct drm_atomic_state *state)
 528 {
 529         struct drm_mode_config *config = &state->dev->mode_config;
 530
 531         DRM_DEBUG_KMS("checking %p\n", state);
 532
 533         if (config->funcs->atomic_check)
 534                 return config->funcs->atomic_check(state->dev, state);
 535         else
 536                 return 0;
 537 }
 538 EXPORT_SYMBOL(drm_atomic_check_only);
 539
 540 /**
 541  * drm_atomic_commit - commit configuration atomically
 542  * @state: atomic configuration to check
 543  *
 544  * Note that this function can return -EDEADLK if the driver needed to acquire
 545  * more locks but encountered a deadlock. The caller must then do the usual w/w
 546  * backoff dance and restart. All other errors are fatal.
 547  *
 548  * Also note that on successful execution ownership of @state is transferred
 549  * from the caller of this function to the function itself. The caller must not
 550  * free or in any other way access @state. If the function fails then the caller
 551  * must clean up @state itself.
 552  *
 553  * Returns:
 554  * 0 on success, negative error code on failure.
 555  */
 556 int drm_atomic_commit(struct drm_atomic_state *state)
 557 {
 558         struct drm_mode_config *config = &state->dev->mode_config;
 559         int ret;
 560
 561         ret = drm_atomic_check_only(state);
 562         if (ret)
 563                 return ret;
 564
 565         DRM_DEBUG_KMS("commiting %p\n", state);
 566
 567         return config->funcs->atomic_commit(state->dev, state, false);
 568 }
 569 EXPORT_SYMBOL(drm_atomic_commit);
 570
 571 /**
 572  * drm_atomic_async_commit - atomic&async configuration commit
 573  * @state: atomic configuration to check
 574  *
 575  * Note that this function can return -EDEADLK if the driver needed to acquire
 576  * more locks but encountered a deadlock. The caller must then do the usual w/w
 577  * backoff dance and restart. All other errors are fatal.
 578  *
 579  * Also note that on successful execution ownership of @state is transferred
 580  * from the caller of this function to the function itself. The caller must not
 581  * free or in any other way access @state. If the function fails then the caller
 582  * must clean up @state itself.
 583  *
 584  * Returns:
 585  * 0 on success, negative error code on failure.
 586  */
 587 int drm_atomic_async_commit(struct drm_atomic_state *state)
 588 {
 589         struct drm_mode_config *config = &state->dev->mode_config;
 590         int ret;
 591
 592         ret = drm_atomic_check_only(state);
 593         if (ret)
 594                 return ret;
 595
 596         DRM_DEBUG_KMS("commiting %p asynchronously\n", state);
 597
 598         return config->funcs->atomic_commit(state->dev, state, true);
 599 }
 600 EXPORT_SYMBOL(drm_atomic_async_commit);