drivers/gpu/drm/drm_plane_helper.c

   1 /*
   2  * Copyright (C) 2014 Intel Corporation
   3  *
   4  * DRM universal plane helper functions
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the "Software"),
   8  * to deal in the Software without restriction, including without limitation
   9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  10  * and/or sell copies of the Software, and to permit persons to whom the
  11  * Software is furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice (including the next
  14  * paragraph) shall be included in all copies or substantial portions of the
  15  * Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  22  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  23  * SOFTWARE.
  24  */
  25
  26 #include <linux/list.h>
  27 #include <drm/drmP.h>
  28 #include <drm/drm_plane_helper.h>
  29 #include <drm/drm_rect.h>
  30 #include <drm/drm_atomic.h>
  31 #include <drm/drm_crtc_helper.h>
  32 #include <drm/drm_atomic_helper.h>
  33
  34 #define SUBPIXEL_MASK 0xffff
  35
  36 /**
  37  * DOC: overview
  38  *
  39  * This helper library has two parts. The first part has support to implement
  40  * primary plane support on top of the normal CRTC configuration interface.
  41  * Since the legacy ->set_config interface ties the primary plane together with
  42  * the CRTC state this does not allow userspace to disable the primary plane
  43  * itself.  To avoid too much duplicated code use
  44  * drm_plane_helper_check_update() which can be used to enforce the same
  45  * restrictions as primary planes had thus. The default primary plane only
  46  * expose XRBG8888 and ARGB8888 as valid pixel formats for the attached
  47  * framebuffer.
  48  *
  49  * Drivers are highly recommended to implement proper support for primary
  50  * planes, and newly merged drivers must not rely upon these transitional
  51  * helpers.
  52  *
  53  * The second part also implements transitional helpers which allow drivers to
  54  * gradually switch to the atomic helper infrastructure for plane updates. Once
  55  * that switch is complete drivers shouldn't use these any longer, instead using
  56  * the proper legacy implementations for update and disable plane hooks provided
  57  * by the atomic helpers.
  58  *
  59  * Again drivers are strongly urged to switch to the new interfaces.
  60  */
  61
  62 /*
  63  * This is the minimal list of formats that seem to be safe for modeset use
  64  * with all current DRM drivers.  Most hardware can actually support more
  65  * formats than this and drivers may specify a more accurate list when
  66  * creating the primary plane.  However drivers that still call
  67  * drm_plane_init() will use this minimal format list as the default.
  68  */
  69 static const uint32_t safe_modeset_formats[] = {
  70         DRM_FORMAT_XRGB8888,
  71         DRM_FORMAT_ARGB8888,
  72 };
  73
  74 /*
  75  * Returns the connectors currently associated with a CRTC.  This function
  76  * should be called twice:  once with a NULL connector list to retrieve
  77  * the list size, and once with the properly allocated list to be filled in.
  78  */
  79 static int get_connectors_for_crtc(struct drm_crtc *crtc,
  80                                    struct drm_connector **connector_list,
  81                                    int num_connectors)
  82 {
  83         struct drm_device *dev = crtc->dev;
  84         struct drm_connector *connector;
  85         int count = 0;
  86
  87         /*
  88          * Note: Once we change the plane hooks to more fine-grained locking we
  89          * need to grab the connection_mutex here to be able to make these
  90          * checks.
  91          */
  92         WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
  93
  94         drm_for_each_connector(connector, dev) {
  95                 if (connector->encoder && connector->encoder->crtc == crtc) {
  96                         if (connector_list != NULL && count < num_connectors)
  97                                 *(connector_list++) = connector;
  98
  99                         count++;
 100                 }
 101         }
 102
 103         return count;
 104 }
 105
 106 /**
 107  * drm_plane_helper_check_update() - Check plane update for validity
 108  * @plane: plane object to update
 109  * @crtc: owning CRTC of owning plane
 110  * @fb: framebuffer to flip onto plane
 111  * @src: source coordinates in 16.16 fixed point
 112  * @dest: integer destination coordinates
 113  * @clip: integer clipping coordinates
 114  * @min_scale: minimum @src:@dest scaling factor in 16.16 fixed point
 115  * @max_scale: maximum @src:@dest scaling factor in 16.16 fixed point
 116  * @can_position: is it legal to position the plane such that it
 117  *                doesn't cover the entire crtc?  This will generally
 118  *                only be false for primary planes.
 119  * @can_update_disabled: can the plane be updated while the crtc
 120  *                       is disabled?
 121  * @visible: output parameter indicating whether plane is still visible after
 122  *           clipping
 123  *
 124  * Checks that a desired plane update is valid.  Drivers that provide
 125  * their own plane handling rather than helper-provided implementations may
 126  * still wish to call this function to avoid duplication of error checking
 127  * code.
 128  *
 129  * RETURNS:
 130  * Zero if update appears valid, error code on failure
 131  */
 132 int drm_plane_helper_check_update(struct drm_plane *plane,
 133                                     struct drm_crtc *crtc,
 134                                     struct drm_framebuffer *fb,
 135                                     struct drm_rect *src,
 136                                     struct drm_rect *dest,
 137                                     const struct drm_rect *clip,
 138                                     int min_scale,
 139                                     int max_scale,
 140                                     bool can_position,
 141                                     bool can_update_disabled,
 142                                     bool *visible)
 143 {
 144         int hscale, vscale;
 145
 146         if (!fb) {
 147                 *visible = false;
 148                 return 0;
 149         }
 150
 151         /* crtc should only be NULL when disabling (i.e., !fb) */
 152         if (WARN_ON(!crtc)) {
 153                 *visible = false;
 154                 return 0;
 155         }
 156
 157         if (!crtc->enabled && !can_update_disabled) {
 158                 DRM_DEBUG_KMS("Cannot update plane of a disabled CRTC.\n");
 159                 return -EINVAL;
 160         }
 161
 162         /* Check scaling */
 163         hscale = drm_rect_calc_hscale(src, dest, min_scale, max_scale);
 164         vscale = drm_rect_calc_vscale(src, dest, min_scale, max_scale);
 165         if (hscale < 0 || vscale < 0) {
 166                 DRM_DEBUG_KMS("Invalid scaling of plane\n");
 167                 return -ERANGE;
 168         }
 169
 170         *visible = drm_rect_clip_scaled(src, dest, clip, hscale, vscale);
 171         if (!*visible)
 172                 /*
 173                  * Plane isn't visible; some drivers can handle this
 174                  * so we just return success here.  Drivers that can't
 175                  * (including those that use the primary plane helper's
 176                  * update function) will return an error from their
 177                  * update_plane handler.
 178                  */
 179                 return 0;
 180
 181         if (!can_position && !drm_rect_equals(dest, clip)) {
 182                 DRM_DEBUG_KMS("Plane must cover entire CRTC\n");
 183                 return -EINVAL;
 184         }
 185
 186         return 0;
 187 }
 188 EXPORT_SYMBOL(drm_plane_helper_check_update);
 189
 190 /**
 191  * drm_primary_helper_update() - Helper for primary plane update
 192  * @plane: plane object to update
 193  * @crtc: owning CRTC of owning plane
 194  * @fb: framebuffer to flip onto plane
 195  * @crtc_x: x offset of primary plane on crtc
 196  * @crtc_y: y offset of primary plane on crtc
 197  * @crtc_w: width of primary plane rectangle on crtc
 198  * @crtc_h: height of primary plane rectangle on crtc
 199  * @src_x: x offset of @fb for panning
 200  * @src_y: y offset of @fb for panning
 201  * @src_w: width of source rectangle in @fb
 202  * @src_h: height of source rectangle in @fb
 203  *
 204  * Provides a default plane update handler for primary planes.  This is handler
 205  * is called in response to a userspace SetPlane operation on the plane with a
 206  * non-NULL framebuffer.  We call the driver's modeset handler to update the
 207  * framebuffer.
 208  *
 209  * SetPlane() on a primary plane of a disabled CRTC is not supported, and will
 210  * return an error.
 211  *
 212  * Note that we make some assumptions about hardware limitations that may not be
 213  * true for all hardware --
 214  *   1) Primary plane cannot be repositioned.
 215  *   2) Primary plane cannot be scaled.
 216  *   3) Primary plane must cover the entire CRTC.
 217  *   4) Subpixel positioning is not supported.
 218  * Drivers for hardware that don't have these restrictions can provide their
 219  * own implementation rather than using this helper.
 220  *
 221  * RETURNS:
 222  * Zero on success, error code on failure
 223  */
 224 int drm_primary_helper_update(struct drm_plane *plane, struct drm_crtc *crtc,
 225                               struct drm_framebuffer *fb,
 226                               int crtc_x, int crtc_y,
 227                               unsigned int crtc_w, unsigned int crtc_h,
 228                               uint32_t src_x, uint32_t src_y,
 229                               uint32_t src_w, uint32_t src_h)
 230 {
 231         struct drm_mode_set set = {
 232                 .crtc = crtc,
 233                 .fb = fb,
 234                 .mode = &crtc->mode,
 235                 .x = src_x >> 16,
 236                 .y = src_y >> 16,
 237         };
 238         struct drm_rect src = {
 239                 .x1 = src_x,
 240                 .y1 = src_y,
 241                 .x2 = src_x + src_w,
 242                 .y2 = src_y + src_h,
 243         };
 244         struct drm_rect dest = {
 245                 .x1 = crtc_x,
 246                 .y1 = crtc_y,
 247                 .x2 = crtc_x + crtc_w,
 248                 .y2 = crtc_y + crtc_h,
 249         };
 250         const struct drm_rect clip = {
 251                 .x2 = crtc->mode.hdisplay,
 252                 .y2 = crtc->mode.vdisplay,
 253         };
 254         struct drm_connector **connector_list;
 255         int num_connectors, ret;
 256         bool visible;
 257
 258         ret = drm_plane_helper_check_update(plane, crtc, fb,
 259                                             &src, &dest, &clip,
 260                                             DRM_PLANE_HELPER_NO_SCALING,
 261                                             DRM_PLANE_HELPER_NO_SCALING,
 262                                             false, false, &visible);
 263         if (ret)
 264                 return ret;
 265
 266         if (!visible)
 267                 /*
 268                  * Primary plane isn't visible.  Note that unless a driver
 269                  * provides their own disable function, this will just
 270                  * wind up returning -EINVAL to userspace.
 271                  */
 272                 return plane->funcs->disable_plane(plane);
 273
 274         /* Find current connectors for CRTC */
 275         num_connectors = get_connectors_for_crtc(crtc, NULL, 0);
 276         BUG_ON(num_connectors == 0);
 277         connector_list = kzalloc(num_connectors * sizeof(*connector_list),
 278                                  GFP_KERNEL);
 279         if (!connector_list)
 280                 return -ENOMEM;
 281         get_connectors_for_crtc(crtc, connector_list, num_connectors);
 282
 283         set.connectors = connector_list;
 284         set.num_connectors = num_connectors;
 285
 286         /*
 287          * We call set_config() directly here rather than using
 288          * drm_mode_set_config_internal.  We're reprogramming the same
 289          * connectors that were already in use, so we shouldn't need the extra
 290          * cross-CRTC fb refcounting to accomodate stealing connectors.
 291          * drm_mode_setplane() already handles the basic refcounting for the
 292          * framebuffers involved in this operation.
 293          */
 294         ret = crtc->funcs->set_config(&set);
 295
 296         kfree(connector_list);
 297         return ret;
 298 }
 299 EXPORT_SYMBOL(drm_primary_helper_update);
 300
 301 /**
 302  * drm_primary_helper_disable() - Helper for primary plane disable
 303  * @plane: plane to disable
 304  *
 305  * Provides a default plane disable handler for primary planes.  This is handler
 306  * is called in response to a userspace SetPlane operation on the plane with a
 307  * NULL framebuffer parameter.  It unconditionally fails the disable call with
 308  * -EINVAL the only way to disable the primary plane without driver support is
 309  * to disable the entier CRTC. Which does not match the plane ->disable hook.
 310  *
 311  * Note that some hardware may be able to disable the primary plane without
 312  * disabling the whole CRTC.  Drivers for such hardware should provide their
 313  * own disable handler that disables just the primary plane (and they'll likely
 314  * need to provide their own update handler as well to properly re-enable a
 315  * disabled primary plane).
 316  *
 317  * RETURNS:
 318  * Unconditionally returns -EINVAL.
 319  */
 320 int drm_primary_helper_disable(struct drm_plane *plane)
 321 {
 322         return -EINVAL;
 323 }
 324 EXPORT_SYMBOL(drm_primary_helper_disable);
 325
 326 /**
 327  * drm_primary_helper_destroy() - Helper for primary plane destruction
 328  * @plane: plane to destroy
 329  *
 330  * Provides a default plane destroy handler for primary planes.  This handler
 331  * is called during CRTC destruction.  We disable the primary plane, remove
 332  * it from the DRM plane list, and deallocate the plane structure.
 333  */
 334 void drm_primary_helper_destroy(struct drm_plane *plane)
 335 {
 336         drm_plane_cleanup(plane);
 337         kfree(plane);
 338 }
 339 EXPORT_SYMBOL(drm_primary_helper_destroy);
 340
 341 const struct drm_plane_funcs drm_primary_helper_funcs = {
 342         .update_plane = drm_primary_helper_update,
 343         .disable_plane = drm_primary_helper_disable,
 344         .destroy = drm_primary_helper_destroy,
 345 };
 346 EXPORT_SYMBOL(drm_primary_helper_funcs);
 347
 348 static struct drm_plane *create_primary_plane(struct drm_device *dev)
 349 {
 350         struct drm_plane *primary;
 351         int ret;
 352
 353         primary = kzalloc(sizeof(*primary), GFP_KERNEL);
 354         if (primary == NULL) {
 355                 DRM_DEBUG_KMS("Failed to allocate primary plane\n");
 356                 return NULL;
 357         }
 358
 359         /*
 360          * Remove the format_default field from drm_plane when dropping
 361          * this helper.
 362          */
 363         primary->format_default = true;
 364
 365         /* possible_crtc's will be filled in later by crtc_init */
 366         ret = drm_universal_plane_init(dev, primary, 0,
 367                                        &drm_primary_helper_funcs,
 368                                        safe_modeset_formats,
 369                                        ARRAY_SIZE(safe_modeset_formats),
 370                                        DRM_PLANE_TYPE_PRIMARY);
 371         if (ret) {
 372                 kfree(primary);
 373                 primary = NULL;
 374         }
 375
 376         return primary;
 377 }
 378
 379 /**
 380  * drm_crtc_init - Legacy CRTC initialization function
 381  * @dev: DRM device
 382  * @crtc: CRTC object to init
 383  * @funcs: callbacks for the new CRTC
 384  *
 385  * Initialize a CRTC object with a default helper-provided primary plane and no
 386  * cursor plane.
 387  *
 388  * Returns:
 389  * Zero on success, error code on failure.
 390  */
 391 int drm_crtc_init(struct drm_device *dev, struct drm_crtc *crtc,
 392                   const struct drm_crtc_funcs *funcs)
 393 {
 394         struct drm_plane *primary;
 395
 396         primary = create_primary_plane(dev);
 397         return drm_crtc_init_with_planes(dev, crtc, primary, NULL, funcs);
 398 }
 399 EXPORT_SYMBOL(drm_crtc_init);
 400
 401 int drm_plane_helper_commit(struct drm_plane *plane,
 402                             struct drm_plane_state *plane_state,
 403                             struct drm_framebuffer *old_fb)
 404 {
 405         const struct drm_plane_helper_funcs *plane_funcs;
 406         struct drm_crtc *crtc[2];
 407         const struct drm_crtc_helper_funcs *crtc_funcs[2];
 408         int i, ret = 0;
 409
 410         plane_funcs = plane->helper_private;
 411
 412         /* Since this is a transitional helper we can't assume that plane->state
 413          * is always valid. Hence we need to use plane->crtc instead of
 414          * plane->state->crtc as the old crtc. */
 415         crtc[0] = plane->crtc;
 416         crtc[1] = crtc[0] != plane_state->crtc ? plane_state->crtc : NULL;
 417
 418         for (i = 0; i < 2; i++)
 419                 crtc_funcs[i] = crtc[i] ? crtc[i]->helper_private : NULL;
 420
 421         if (plane_funcs->atomic_check) {
 422                 ret = plane_funcs->atomic_check(plane, plane_state);
 423                 if (ret)
 424                         goto out;
 425         }
 426
 427         if (plane_funcs->prepare_fb && plane_state->fb &&
 428             plane_state->fb != old_fb) {
 429                 ret = plane_funcs->prepare_fb(plane,
 430                                               plane_state);
 431                 if (ret)
 432                         goto out;
 433         }
 434
 435         /* Point of no return, commit sw state. */
 436         swap(plane->state, plane_state);
 437
 438         for (i = 0; i < 2; i++) {
 439                 if (crtc_funcs[i] && crtc_funcs[i]->atomic_begin)
 440                         crtc_funcs[i]->atomic_begin(crtc[i], crtc[i]->state);
 441         }
 442
 443         /*
 444          * Drivers may optionally implement the ->atomic_disable callback, so
 445          * special-case that here.
 446          */
 447         if (drm_atomic_plane_disabling(plane, plane_state) &&
 448             plane_funcs->atomic_disable)
 449                 plane_funcs->atomic_disable(plane, plane_state);
 450         else
 451                 plane_funcs->atomic_update(plane, plane_state);
 452
 453         for (i = 0; i < 2; i++) {
 454                 if (crtc_funcs[i] && crtc_funcs[i]->atomic_flush)
 455                         crtc_funcs[i]->atomic_flush(crtc[i], crtc[i]->state);
 456         }
 457
 458         /*
 459          * If we only moved the plane and didn't change fb's, there's no need to
 460          * wait for vblank.
 461          */
 462         if (plane->state->fb == old_fb)
 463                 goto out;
 464
 465         for (i = 0; i < 2; i++) {
 466                 if (!crtc[i])
 467                         continue;
 468
 469                 if (crtc[i]->cursor == plane)
 470                         continue;
 471
 472                 /* There's no other way to figure out whether the crtc is running. */
 473                 ret = drm_crtc_vblank_get(crtc[i]);
 474                 if (ret == 0) {
 475                         drm_crtc_wait_one_vblank(crtc[i]);
 476                         drm_crtc_vblank_put(crtc[i]);
 477                 }
 478
 479                 ret = 0;
 480         }
 481
 482         if (plane_funcs->cleanup_fb)
 483                 plane_funcs->cleanup_fb(plane, plane_state);
 484 out:
 485         if (plane_state) {
 486                 if (plane->funcs->atomic_destroy_state)
 487                         plane->funcs->atomic_destroy_state(plane, plane_state);
 488                 else
 489                         drm_atomic_helper_plane_destroy_state(plane, plane_state);
 490         }
 491
 492         return ret;
 493 }
 494
 495 /**
 496  * drm_plane_helper_update() - Transitional helper for plane update
 497  * @plane: plane object to update
 498  * @crtc: owning CRTC of owning plane
 499  * @fb: framebuffer to flip onto plane
 500  * @crtc_x: x offset of primary plane on crtc
 501  * @crtc_y: y offset of primary plane on crtc
 502  * @crtc_w: width of primary plane rectangle on crtc
 503  * @crtc_h: height of primary plane rectangle on crtc
 504  * @src_x: x offset of @fb for panning
 505  * @src_y: y offset of @fb for panning
 506  * @src_w: width of source rectangle in @fb
 507  * @src_h: height of source rectangle in @fb
 508  *
 509  * Provides a default plane update handler using the atomic plane update
 510  * functions. It is fully left to the driver to check plane constraints and
 511  * handle corner-cases like a fully occluded or otherwise invisible plane.
 512  *
 513  * This is useful for piecewise transitioning of a driver to the atomic helpers.
 514  *
 515  * RETURNS:
 516  * Zero on success, error code on failure
 517  */
 518 int drm_plane_helper_update(struct drm_plane *plane, struct drm_crtc *crtc,
 519                             struct drm_framebuffer *fb,
 520                             int crtc_x, int crtc_y,
 521                             unsigned int crtc_w, unsigned int crtc_h,
 522                             uint32_t src_x, uint32_t src_y,
 523                             uint32_t src_w, uint32_t src_h)
 524 {
 525         struct drm_plane_state *plane_state;
 526
 527         if (plane->funcs->atomic_duplicate_state)
 528                 plane_state = plane->funcs->atomic_duplicate_state(plane);
 529         else {
 530                 if (!plane->state)
 531                         drm_atomic_helper_plane_reset(plane);
 532
 533                 plane_state = drm_atomic_helper_plane_duplicate_state(plane);
 534         }
 535         if (!plane_state)
 536                 return -ENOMEM;
 537         plane_state->plane = plane;
 538
 539         plane_state->crtc = crtc;
 540         drm_atomic_set_fb_for_plane(plane_state, fb);
 541         plane_state->crtc_x = crtc_x;
 542         plane_state->crtc_y = crtc_y;
 543         plane_state->crtc_h = crtc_h;
 544         plane_state->crtc_w = crtc_w;
 545         plane_state->src_x = src_x;
 546         plane_state->src_y = src_y;
 547         plane_state->src_h = src_h;
 548         plane_state->src_w = src_w;
 549
 550         return drm_plane_helper_commit(plane, plane_state, plane->fb);
 551 }
 552 EXPORT_SYMBOL(drm_plane_helper_update);
 553
 554 /**
 555  * drm_plane_helper_disable() - Transitional helper for plane disable
 556  * @plane: plane to disable
 557  *
 558  * Provides a default plane disable handler using the atomic plane update
 559  * functions. It is fully left to the driver to check plane constraints and
 560  * handle corner-cases like a fully occluded or otherwise invisible plane.
 561  *
 562  * This is useful for piecewise transitioning of a driver to the atomic helpers.
 563  *
 564  * RETURNS:
 565  * Zero on success, error code on failure
 566  */
 567 int drm_plane_helper_disable(struct drm_plane *plane)
 568 {
 569         struct drm_plane_state *plane_state;
 570
 571         /* crtc helpers love to call disable functions for already disabled hw
 572          * functions. So cope with that. */
 573         if (!plane->crtc)
 574                 return 0;
 575
 576         if (plane->funcs->atomic_duplicate_state)
 577                 plane_state = plane->funcs->atomic_duplicate_state(plane);
 578         else {
 579                 if (!plane->state)
 580                         drm_atomic_helper_plane_reset(plane);
 581
 582                 plane_state = drm_atomic_helper_plane_duplicate_state(plane);
 583         }
 584         if (!plane_state)
 585                 return -ENOMEM;
 586         plane_state->plane = plane;
 587
 588         plane_state->crtc = NULL;
 589         drm_atomic_set_fb_for_plane(plane_state, NULL);
 590
 591         return drm_plane_helper_commit(plane, plane_state, plane->fb);
 592 }
 593 EXPORT_SYMBOL(drm_plane_helper_disable);