drivers/gpu/drm/drm_atomic_state_helper.c

   1 /*
   2  * Copyright (C) 2018 Intel Corp.
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice shall be included in
  12  * all copies or substantial portions of the Software.
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  17  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
  18  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  19  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  20  * OTHER DEALINGS IN THE SOFTWARE.
  21  *
  22  * Authors:
  23  * Rob Clark <robdclark@gmail.com>
  24  * Daniel Vetter <daniel.vetter@ffwll.ch>
  25  */
  26
  27 #include <drm/drm_atomic.h>
  28 #include <drm/drm_atomic_state_helper.h>
  29 #include <drm/drm_bridge.h>
  30 #include <drm/drm_connector.h>
  31 #include <drm/drm_crtc.h>
  32 #include <drm/drm_device.h>
  33 #include <drm/drm_plane.h>
  34 #include <drm/drm_print.h>
  35 #include <drm/drm_vblank.h>
  36 #include <drm/drm_writeback.h>
  37
  38 #include <linux/slab.h>
  39 #include <linux/dma-fence.h>
  40
  41 /**
  42  * DOC: atomic state reset and initialization
  43  *
  44  * Both the drm core and the atomic helpers assume that there is always the full
  45  * and correct atomic software state for all connectors, CRTCs and planes
  46  * available. Which is a bit a problem on driver load and also after system
  47  * suspend. One way to solve this is to have a hardware state read-out
  48  * infrastructure which reconstructs the full software state (e.g. the i915
  49  * driver).
  50  *
  51  * The simpler solution is to just reset the software state to everything off,
  52  * which is easiest to do by calling drm_mode_config_reset(). To facilitate this
  53  * the atomic helpers provide default reset implementations for all hooks.
  54  *
  55  * On the upside the precise state tracking of atomic simplifies system suspend
  56  * and resume a lot. For drivers using drm_mode_config_reset() a complete recipe
  57  * is implemented in drm_atomic_helper_suspend() and drm_atomic_helper_resume().
  58  * For other drivers the building blocks are split out, see the documentation
  59  * for these functions.
  60  */
  61
  62 /**
  63  * __drm_atomic_helper_crtc_state_reset - reset the CRTC state
  64  * @crtc_state: atomic CRTC state, must not be NULL
  65  * @crtc: CRTC object, must not be NULL
  66  *
  67  * Initializes the newly allocated @crtc_state with default
  68  * values. This is useful for drivers that subclass the CRTC state.
  69  */
  70 void
  71 __drm_atomic_helper_crtc_state_reset(struct drm_crtc_state *crtc_state,
  72                                      struct drm_crtc *crtc)
  73 {
  74         crtc_state->crtc = crtc;
  75 }
  76 EXPORT_SYMBOL(__drm_atomic_helper_crtc_state_reset);
  77
  78 /**
  79  * __drm_atomic_helper_crtc_reset - reset state on CRTC
  80  * @crtc: drm CRTC
  81  * @crtc_state: CRTC state to assign
  82  *
  83  * Initializes the newly allocated @crtc_state and assigns it to
  84  * the &drm_crtc->state pointer of @crtc, usually required when
  85  * initializing the drivers or when called from the &drm_crtc_funcs.reset
  86  * hook.
  87  *
  88  * This is useful for drivers that subclass the CRTC state.
  89  */
  90 void
  91 __drm_atomic_helper_crtc_reset(struct drm_crtc *crtc,
  92                                struct drm_crtc_state *crtc_state)
  93 {
  94         if (crtc_state)
  95                 __drm_atomic_helper_crtc_state_reset(crtc_state, crtc);
  96
  97         if (drm_dev_has_vblank(crtc->dev))
  98                 drm_crtc_vblank_reset(crtc);
  99
 100         crtc->state = crtc_state;
 101 }
 102 EXPORT_SYMBOL(__drm_atomic_helper_crtc_reset);
 103
 104 /**
 105  * drm_atomic_helper_crtc_reset - default &drm_crtc_funcs.reset hook for CRTCs
 106  * @crtc: drm CRTC
 107  *
 108  * Resets the atomic state for @crtc by freeing the state pointer (which might
 109  * be NULL, e.g. at driver load time) and allocating a new empty state object.
 110  */
 111 void drm_atomic_helper_crtc_reset(struct drm_crtc *crtc)
 112 {
 113         struct drm_crtc_state *crtc_state =
 114                 kzalloc(sizeof(*crtc->state), GFP_KERNEL);
 115
 116         if (crtc->state)
 117                 crtc->funcs->atomic_destroy_state(crtc, crtc->state);
 118
 119         __drm_atomic_helper_crtc_reset(crtc, crtc_state);
 120 }
 121 EXPORT_SYMBOL(drm_atomic_helper_crtc_reset);
 122
 123 /**
 124  * __drm_atomic_helper_crtc_duplicate_state - copy atomic CRTC state
 125  * @crtc: CRTC object
 126  * @state: atomic CRTC state
 127  *
 128  * Copies atomic state from a CRTC's current state and resets inferred values.
 129  * This is useful for drivers that subclass the CRTC state.
 130  */
 131 void __drm_atomic_helper_crtc_duplicate_state(struct drm_crtc *crtc,
 132                                               struct drm_crtc_state *state)
 133 {
 134         memcpy(state, crtc->state, sizeof(*state));
 135
 136         if (state->mode_blob)
 137                 drm_property_blob_get(state->mode_blob);
 138         if (state->degamma_lut)
 139                 drm_property_blob_get(state->degamma_lut);
 140         if (state->ctm)
 141                 drm_property_blob_get(state->ctm);
 142         if (state->gamma_lut)
 143                 drm_property_blob_get(state->gamma_lut);
 144         state->mode_changed = false;
 145         state->active_changed = false;
 146         state->planes_changed = false;
 147         state->connectors_changed = false;
 148         state->color_mgmt_changed = false;
 149         state->zpos_changed = false;
 150         state->commit = NULL;
 151         state->event = NULL;
 152         state->async_flip = false;
 153
 154         /* Self refresh should be canceled when a new update is available */
 155         state->active = drm_atomic_crtc_effectively_active(state);
 156         state->self_refresh_active = false;
 157 }
 158 EXPORT_SYMBOL(__drm_atomic_helper_crtc_duplicate_state);
 159
 160 /**
 161  * drm_atomic_helper_crtc_duplicate_state - default state duplicate hook
 162  * @crtc: drm CRTC
 163  *
 164  * Default CRTC state duplicate hook for drivers which don't have their own
 165  * subclassed CRTC state structure.
 166  */
 167 struct drm_crtc_state *
 168 drm_atomic_helper_crtc_duplicate_state(struct drm_crtc *crtc)
 169 {
 170         struct drm_crtc_state *state;
 171
 172         if (WARN_ON(!crtc->state))
 173                 return NULL;
 174
 175         state = kmalloc(sizeof(*state), GFP_KERNEL);
 176         if (state)
 177                 __drm_atomic_helper_crtc_duplicate_state(crtc, state);
 178
 179         return state;
 180 }
 181 EXPORT_SYMBOL(drm_atomic_helper_crtc_duplicate_state);
 182
 183 /**
 184  * __drm_atomic_helper_crtc_destroy_state - release CRTC state
 185  * @state: CRTC state object to release
 186  *
 187  * Releases all resources stored in the CRTC state without actually freeing
 188  * the memory of the CRTC state. This is useful for drivers that subclass the
 189  * CRTC state.
 190  */
 191 void __drm_atomic_helper_crtc_destroy_state(struct drm_crtc_state *state)
 192 {
 193         if (state->commit) {
 194                 /*
 195                  * In the event that a non-blocking commit returns
 196                  * -ERESTARTSYS before the commit_tail work is queued, we will
 197                  * have an extra reference to the commit object. Release it, if
 198                  * the event has not been consumed by the worker.
 199                  *
 200                  * state->event may be freed, so we can't directly look at
 201                  * state->event->base.completion.
 202                  */
 203                 if (state->event && state->commit->abort_completion)
 204                         drm_crtc_commit_put(state->commit);
 205
 206                 kfree(state->commit->event);
 207                 state->commit->event = NULL;
 208
 209                 drm_crtc_commit_put(state->commit);
 210         }
 211
 212         drm_property_blob_put(state->mode_blob);
 213         drm_property_blob_put(state->degamma_lut);
 214         drm_property_blob_put(state->ctm);
 215         drm_property_blob_put(state->gamma_lut);
 216 }
 217 EXPORT_SYMBOL(__drm_atomic_helper_crtc_destroy_state);
 218
 219 /**
 220  * drm_atomic_helper_crtc_destroy_state - default state destroy hook
 221  * @crtc: drm CRTC
 222  * @state: CRTC state object to release
 223  *
 224  * Default CRTC state destroy hook for drivers which don't have their own
 225  * subclassed CRTC state structure.
 226  */
 227 void drm_atomic_helper_crtc_destroy_state(struct drm_crtc *crtc,
 228                                           struct drm_crtc_state *state)
 229 {
 230         __drm_atomic_helper_crtc_destroy_state(state);
 231         kfree(state);
 232 }
 233 EXPORT_SYMBOL(drm_atomic_helper_crtc_destroy_state);
 234
 235 /**
 236  * __drm_atomic_helper_plane_state_reset - resets plane state to default values
 237  * @plane_state: atomic plane state, must not be NULL
 238  * @plane: plane object, must not be NULL
 239  *
 240  * Initializes the newly allocated @plane_state with default
 241  * values. This is useful for drivers that subclass the CRTC state.
 242  */
 243 void __drm_atomic_helper_plane_state_reset(struct drm_plane_state *plane_state,
 244                                            struct drm_plane *plane)
 245 {
 246         u64 val;
 247
 248         plane_state->plane = plane;
 249         plane_state->rotation = DRM_MODE_ROTATE_0;
 250
 251         plane_state->alpha = DRM_BLEND_ALPHA_OPAQUE;
 252         plane_state->pixel_blend_mode = DRM_MODE_BLEND_PREMULTI;
 253
 254         if (plane->color_encoding_property) {
 255                 if (!drm_object_property_get_default_value(&plane->base,
 256                                                            plane->color_encoding_property,
 257                                                            &val))
 258                         plane_state->color_encoding = val;
 259         }
 260
 261         if (plane->color_range_property) {
 262                 if (!drm_object_property_get_default_value(&plane->base,
 263                                                            plane->color_range_property,
 264                                                            &val))
 265                         plane_state->color_range = val;
 266         }
 267
 268         if (plane->zpos_property) {
 269                 if (!drm_object_property_get_default_value(&plane->base,
 270                                                            plane->zpos_property,
 271                                                            &val)) {
 272                         plane_state->zpos = val;
 273                         plane_state->normalized_zpos = val;
 274                 }
 275         }
 276 }
 277 EXPORT_SYMBOL(__drm_atomic_helper_plane_state_reset);
 278
 279 /**
 280  * __drm_atomic_helper_plane_reset - reset state on plane
 281  * @plane: drm plane
 282  * @plane_state: plane state to assign
 283  *
 284  * Initializes the newly allocated @plane_state and assigns it to
 285  * the &drm_crtc->state pointer of @plane, usually required when
 286  * initializing the drivers or when called from the &drm_plane_funcs.reset
 287  * hook.
 288  *
 289  * This is useful for drivers that subclass the plane state.
 290  */
 291 void __drm_atomic_helper_plane_reset(struct drm_plane *plane,
 292                                      struct drm_plane_state *plane_state)
 293 {
 294         if (plane_state)
 295                 __drm_atomic_helper_plane_state_reset(plane_state, plane);
 296
 297         plane->state = plane_state;
 298 }
 299 EXPORT_SYMBOL(__drm_atomic_helper_plane_reset);
 300
 301 /**
 302  * drm_atomic_helper_plane_reset - default &drm_plane_funcs.reset hook for planes
 303  * @plane: drm plane
 304  *
 305  * Resets the atomic state for @plane by freeing the state pointer (which might
 306  * be NULL, e.g. at driver load time) and allocating a new empty state object.
 307  */
 308 void drm_atomic_helper_plane_reset(struct drm_plane *plane)
 309 {
 310         if (plane->state)
 311                 __drm_atomic_helper_plane_destroy_state(plane->state);
 312
 313         kfree(plane->state);
 314         plane->state = kzalloc(sizeof(*plane->state), GFP_KERNEL);
 315         if (plane->state)
 316                 __drm_atomic_helper_plane_reset(plane, plane->state);
 317 }
 318 EXPORT_SYMBOL(drm_atomic_helper_plane_reset);
 319
 320 /**
 321  * __drm_atomic_helper_plane_duplicate_state - copy atomic plane state
 322  * @plane: plane object
 323  * @state: atomic plane state
 324  *
 325  * Copies atomic state from a plane's current state. This is useful for
 326  * drivers that subclass the plane state.
 327  */
 328 void __drm_atomic_helper_plane_duplicate_state(struct drm_plane *plane,
 329                                                struct drm_plane_state *state)
 330 {
 331         memcpy(state, plane->state, sizeof(*state));
 332
 333         if (state->fb)
 334                 drm_framebuffer_get(state->fb);
 335
 336         state->fence = NULL;
 337         state->commit = NULL;
 338         state->fb_damage_clips = NULL;
 339 }
 340 EXPORT_SYMBOL(__drm_atomic_helper_plane_duplicate_state);
 341
 342 /**
 343  * drm_atomic_helper_plane_duplicate_state - default state duplicate hook
 344  * @plane: drm plane
 345  *
 346  * Default plane state duplicate hook for drivers which don't have their own
 347  * subclassed plane state structure.
 348  */
 349 struct drm_plane_state *
 350 drm_atomic_helper_plane_duplicate_state(struct drm_plane *plane)
 351 {
 352         struct drm_plane_state *state;
 353
 354         if (WARN_ON(!plane->state))
 355                 return NULL;
 356
 357         state = kmalloc(sizeof(*state), GFP_KERNEL);
 358         if (state)
 359                 __drm_atomic_helper_plane_duplicate_state(plane, state);
 360
 361         return state;
 362 }
 363 EXPORT_SYMBOL(drm_atomic_helper_plane_duplicate_state);
 364
 365 /**
 366  * __drm_atomic_helper_plane_destroy_state - release plane state
 367  * @state: plane state object to release
 368  *
 369  * Releases all resources stored in the plane state without actually freeing
 370  * the memory of the plane state. This is useful for drivers that subclass the
 371  * plane state.
 372  */
 373 void __drm_atomic_helper_plane_destroy_state(struct drm_plane_state *state)
 374 {
 375         if (state->fb)
 376                 drm_framebuffer_put(state->fb);
 377
 378         if (state->fence)
 379                 dma_fence_put(state->fence);
 380
 381         if (state->commit)
 382                 drm_crtc_commit_put(state->commit);
 383
 384         drm_property_blob_put(state->fb_damage_clips);
 385 }
 386 EXPORT_SYMBOL(__drm_atomic_helper_plane_destroy_state);
 387
 388 /**
 389  * drm_atomic_helper_plane_destroy_state - default state destroy hook
 390  * @plane: drm plane
 391  * @state: plane state object to release
 392  *
 393  * Default plane state destroy hook for drivers which don't have their own
 394  * subclassed plane state structure.
 395  */
 396 void drm_atomic_helper_plane_destroy_state(struct drm_plane *plane,
 397                                            struct drm_plane_state *state)
 398 {
 399         __drm_atomic_helper_plane_destroy_state(state);
 400         kfree(state);
 401 }
 402 EXPORT_SYMBOL(drm_atomic_helper_plane_destroy_state);
 403
 404 /**
 405  * __drm_atomic_helper_connector_state_reset - reset the connector state
 406  * @conn_state: atomic connector state, must not be NULL
 407  * @connector: connectotr object, must not be NULL
 408  *
 409  * Initializes the newly allocated @conn_state with default
 410  * values. This is useful for drivers that subclass the connector state.
 411  */
 412 void
 413 __drm_atomic_helper_connector_state_reset(struct drm_connector_state *conn_state,
 414                                           struct drm_connector *connector)
 415 {
 416         conn_state->connector = connector;
 417 }
 418 EXPORT_SYMBOL(__drm_atomic_helper_connector_state_reset);
 419
 420 /**
 421  * __drm_atomic_helper_connector_reset - reset state on connector
 422  * @connector: drm connector
 423  * @conn_state: connector state to assign
 424  *
 425  * Initializes the newly allocated @conn_state and assigns it to
 426  * the &drm_connector->state pointer of @connector, usually required when
 427  * initializing the drivers or when called from the &drm_connector_funcs.reset
 428  * hook.
 429  *
 430  * This is useful for drivers that subclass the connector state.
 431  */
 432 void
 433 __drm_atomic_helper_connector_reset(struct drm_connector *connector,
 434                                     struct drm_connector_state *conn_state)
 435 {
 436         if (conn_state)
 437                 __drm_atomic_helper_connector_state_reset(conn_state, connector);
 438
 439         connector->state = conn_state;
 440 }
 441 EXPORT_SYMBOL(__drm_atomic_helper_connector_reset);
 442
 443 /**
 444  * drm_atomic_helper_connector_reset - default &drm_connector_funcs.reset hook for connectors
 445  * @connector: drm connector
 446  *
 447  * Resets the atomic state for @connector by freeing the state pointer (which
 448  * might be NULL, e.g. at driver load time) and allocating a new empty state
 449  * object.
 450  */
 451 void drm_atomic_helper_connector_reset(struct drm_connector *connector)
 452 {
 453         struct drm_connector_state *conn_state =
 454                 kzalloc(sizeof(*conn_state), GFP_KERNEL);
 455
 456         if (connector->state)
 457                 __drm_atomic_helper_connector_destroy_state(connector->state);
 458
 459         kfree(connector->state);
 460         __drm_atomic_helper_connector_reset(connector, conn_state);
 461 }
 462 EXPORT_SYMBOL(drm_atomic_helper_connector_reset);
 463
 464 /**
 465  * drm_atomic_helper_connector_tv_reset - Resets TV connector properties
 466  * @connector: DRM connector
 467  *
 468  * Resets the TV-related properties attached to a connector.
 469  */
 470 void drm_atomic_helper_connector_tv_reset(struct drm_connector *connector)
 471 {
 472         struct drm_cmdline_mode *cmdline = &connector->cmdline_mode;
 473         struct drm_connector_state *state = connector->state;
 474
 475         state->tv.margins.left = cmdline->tv_margins.left;
 476         state->tv.margins.right = cmdline->tv_margins.right;
 477         state->tv.margins.top = cmdline->tv_margins.top;
 478         state->tv.margins.bottom = cmdline->tv_margins.bottom;
 479 }
 480 EXPORT_SYMBOL(drm_atomic_helper_connector_tv_reset);
 481
 482 /**
 483  * __drm_atomic_helper_connector_duplicate_state - copy atomic connector state
 484  * @connector: connector object
 485  * @state: atomic connector state
 486  *
 487  * Copies atomic state from a connector's current state. This is useful for
 488  * drivers that subclass the connector state.
 489  */
 490 void
 491 __drm_atomic_helper_connector_duplicate_state(struct drm_connector *connector,
 492                                             struct drm_connector_state *state)
 493 {
 494         memcpy(state, connector->state, sizeof(*state));
 495         if (state->crtc)
 496                 drm_connector_get(connector);
 497         state->commit = NULL;
 498
 499         if (state->hdr_output_metadata)
 500                 drm_property_blob_get(state->hdr_output_metadata);
 501
 502         /* Don't copy over a writeback job, they are used only once */
 503         state->writeback_job = NULL;
 504 }
 505 EXPORT_SYMBOL(__drm_atomic_helper_connector_duplicate_state);
 506
 507 /**
 508  * drm_atomic_helper_connector_duplicate_state - default state duplicate hook
 509  * @connector: drm connector
 510  *
 511  * Default connector state duplicate hook for drivers which don't have their own
 512  * subclassed connector state structure.
 513  */
 514 struct drm_connector_state *
 515 drm_atomic_helper_connector_duplicate_state(struct drm_connector *connector)
 516 {
 517         struct drm_connector_state *state;
 518
 519         if (WARN_ON(!connector->state))
 520                 return NULL;
 521
 522         state = kmalloc(sizeof(*state), GFP_KERNEL);
 523         if (state)
 524                 __drm_atomic_helper_connector_duplicate_state(connector, state);
 525
 526         return state;
 527 }
 528 EXPORT_SYMBOL(drm_atomic_helper_connector_duplicate_state);
 529
 530 /**
 531  * __drm_atomic_helper_connector_destroy_state - release connector state
 532  * @state: connector state object to release
 533  *
 534  * Releases all resources stored in the connector state without actually
 535  * freeing the memory of the connector state. This is useful for drivers that
 536  * subclass the connector state.
 537  */
 538 void
 539 __drm_atomic_helper_connector_destroy_state(struct drm_connector_state *state)
 540 {
 541         if (state->crtc)
 542                 drm_connector_put(state->connector);
 543
 544         if (state->commit)
 545                 drm_crtc_commit_put(state->commit);
 546
 547         if (state->writeback_job)
 548                 drm_writeback_cleanup_job(state->writeback_job);
 549
 550         drm_property_blob_put(state->hdr_output_metadata);
 551 }
 552 EXPORT_SYMBOL(__drm_atomic_helper_connector_destroy_state);
 553
 554 /**
 555  * drm_atomic_helper_connector_destroy_state - default state destroy hook
 556  * @connector: drm connector
 557  * @state: connector state object to release
 558  *
 559  * Default connector state destroy hook for drivers which don't have their own
 560  * subclassed connector state structure.
 561  */
 562 void drm_atomic_helper_connector_destroy_state(struct drm_connector *connector,
 563                                           struct drm_connector_state *state)
 564 {
 565         __drm_atomic_helper_connector_destroy_state(state);
 566         kfree(state);
 567 }
 568 EXPORT_SYMBOL(drm_atomic_helper_connector_destroy_state);
 569
 570 /**
 571  * __drm_atomic_helper_private_obj_duplicate_state - copy atomic private state
 572  * @obj: CRTC object
 573  * @state: new private object state
 574  *
 575  * Copies atomic state from a private objects's current state and resets inferred values.
 576  * This is useful for drivers that subclass the private state.
 577  */
 578 void __drm_atomic_helper_private_obj_duplicate_state(struct drm_private_obj *obj,
 579                                                      struct drm_private_state *state)
 580 {
 581         memcpy(state, obj->state, sizeof(*state));
 582 }
 583 EXPORT_SYMBOL(__drm_atomic_helper_private_obj_duplicate_state);
 584
 585 /**
 586  * __drm_atomic_helper_bridge_duplicate_state() - Copy atomic bridge state
 587  * @bridge: bridge object
 588  * @state: atomic bridge state
 589  *
 590  * Copies atomic state from a bridge's current state and resets inferred values.
 591  * This is useful for drivers that subclass the bridge state.
 592  */
 593 void __drm_atomic_helper_bridge_duplicate_state(struct drm_bridge *bridge,
 594                                                 struct drm_bridge_state *state)
 595 {
 596         __drm_atomic_helper_private_obj_duplicate_state(&bridge->base,
 597                                                         &state->base);
 598         state->bridge = bridge;
 599 }
 600 EXPORT_SYMBOL(__drm_atomic_helper_bridge_duplicate_state);
 601
 602 /**
 603  * drm_atomic_helper_bridge_duplicate_state() - Duplicate a bridge state object
 604  * @bridge: bridge object
 605  *
 606  * Allocates a new bridge state and initializes it with the current bridge
 607  * state values. This helper is meant to be used as a bridge
 608  * &drm_bridge_funcs.atomic_duplicate_state hook for bridges that don't
 609  * subclass the bridge state.
 610  */
 611 struct drm_bridge_state *
 612 drm_atomic_helper_bridge_duplicate_state(struct drm_bridge *bridge)
 613 {
 614         struct drm_bridge_state *new;
 615
 616         if (WARN_ON(!bridge->base.state))
 617                 return NULL;
 618
 619         new = kzalloc(sizeof(*new), GFP_KERNEL);
 620         if (new)
 621                 __drm_atomic_helper_bridge_duplicate_state(bridge, new);
 622
 623         return new;
 624 }
 625 EXPORT_SYMBOL(drm_atomic_helper_bridge_duplicate_state);
 626
 627 /**
 628  * drm_atomic_helper_bridge_destroy_state() - Destroy a bridge state object
 629  * @bridge: the bridge this state refers to
 630  * @state: bridge state to destroy
 631  *
 632  * Destroys a bridge state previously created by
 633  * &drm_atomic_helper_bridge_reset() or
 634  * &drm_atomic_helper_bridge_duplicate_state(). This helper is meant to be
 635  * used as a bridge &drm_bridge_funcs.atomic_destroy_state hook for bridges
 636  * that don't subclass the bridge state.
 637  */
 638 void drm_atomic_helper_bridge_destroy_state(struct drm_bridge *bridge,
 639                                             struct drm_bridge_state *state)
 640 {
 641         kfree(state);
 642 }
 643 EXPORT_SYMBOL(drm_atomic_helper_bridge_destroy_state);
 644
 645 /**
 646  * __drm_atomic_helper_bridge_reset() - Initialize a bridge state to its
 647  *                                      default
 648  * @bridge: the bridge this state refers to
 649  * @state: bridge state to initialize
 650  *
 651  * Initializes the bridge state to default values. This is meant to be called
 652  * by the bridge &drm_bridge_funcs.atomic_reset hook for bridges that subclass
 653  * the bridge state.
 654  */
 655 void __drm_atomic_helper_bridge_reset(struct drm_bridge *bridge,
 656                                       struct drm_bridge_state *state)
 657 {
 658         memset(state, 0, sizeof(*state));
 659         state->bridge = bridge;
 660 }
 661 EXPORT_SYMBOL(__drm_atomic_helper_bridge_reset);
 662
 663 /**
 664  * drm_atomic_helper_bridge_reset() - Allocate and initialize a bridge state
 665  *                                    to its default
 666  * @bridge: the bridge this state refers to
 667  *
 668  * Allocates the bridge state and initializes it to default values. This helper
 669  * is meant to be used as a bridge &drm_bridge_funcs.atomic_reset hook for
 670  * bridges that don't subclass the bridge state.
 671  */
 672 struct drm_bridge_state *
 673 drm_atomic_helper_bridge_reset(struct drm_bridge *bridge)
 674 {
 675         struct drm_bridge_state *bridge_state;
 676
 677         bridge_state = kzalloc(sizeof(*bridge_state), GFP_KERNEL);
 678         if (!bridge_state)
 679                 return ERR_PTR(-ENOMEM);
 680
 681         __drm_atomic_helper_bridge_reset(bridge, bridge_state);
 682         return bridge_state;
 683 }
 684 EXPORT_SYMBOL(drm_atomic_helper_bridge_reset);