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                 drm_rect_debug_print("src: ", src, true);
 168                 drm_rect_debug_print("dst: ", dest, false);
 169                 return -ERANGE;
 170         }
 171
 172         *visible = drm_rect_clip_scaled(src, dest, clip, hscale, vscale);
 173         if (!*visible)
 174                 /*
 175                  * Plane isn't visible; some drivers can handle this
 176                  * so we just return success here.  Drivers that can't
 177                  * (including those that use the primary plane helper's
 178                  * update function) will return an error from their
 179                  * update_plane handler.
 180                  */
 181                 return 0;
 182
 183         if (!can_position && !drm_rect_equals(dest, clip)) {
 184                 DRM_DEBUG_KMS("Plane must cover entire CRTC\n");
 185                 drm_rect_debug_print("dst: ", dest, false);
 186                 drm_rect_debug_print("clip: ", clip, false);
 187                 return -EINVAL;
 188         }
 189
 190         return 0;
 191 }
 192 EXPORT_SYMBOL(drm_plane_helper_check_update);
 193
 194 /**
 195  * drm_primary_helper_update() - Helper for primary plane update
 196  * @plane: plane object to update
 197  * @crtc: owning CRTC of owning plane
 198  * @fb: framebuffer to flip onto plane
 199  * @crtc_x: x offset of primary plane on crtc
 200  * @crtc_y: y offset of primary plane on crtc
 201  * @crtc_w: width of primary plane rectangle on crtc
 202  * @crtc_h: height of primary plane rectangle on crtc
 203  * @src_x: x offset of @fb for panning
 204  * @src_y: y offset of @fb for panning
 205  * @src_w: width of source rectangle in @fb
 206  * @src_h: height of source rectangle in @fb
 207  *
 208  * Provides a default plane update handler for primary planes.  This is handler
 209  * is called in response to a userspace SetPlane operation on the plane with a
 210  * non-NULL framebuffer.  We call the driver's modeset handler to update the
 211  * framebuffer.
 212  *
 213  * SetPlane() on a primary plane of a disabled CRTC is not supported, and will
 214  * return an error.
 215  *
 216  * Note that we make some assumptions about hardware limitations that may not be
 217  * true for all hardware --
 218  *   1) Primary plane cannot be repositioned.
 219  *   2) Primary plane cannot be scaled.
 220  *   3) Primary plane must cover the entire CRTC.
 221  *   4) Subpixel positioning is not supported.
 222  * Drivers for hardware that don't have these restrictions can provide their
 223  * own implementation rather than using this helper.
 224  *
 225  * RETURNS:
 226  * Zero on success, error code on failure
 227  */
 228 int drm_primary_helper_update(struct drm_plane *plane, struct drm_crtc *crtc,
 229                               struct drm_framebuffer *fb,
 230                               int crtc_x, int crtc_y,
 231                               unsigned int crtc_w, unsigned int crtc_h,
 232                               uint32_t src_x, uint32_t src_y,
 233                               uint32_t src_w, uint32_t src_h)
 234 {
 235         struct drm_mode_set set = {
 236                 .crtc = crtc,
 237                 .fb = fb,
 238                 .mode = &crtc->mode,
 239                 .x = src_x >> 16,
 240                 .y = src_y >> 16,
 241         };
 242         struct drm_rect src = {
 243                 .x1 = src_x,
 244                 .y1 = src_y,
 245                 .x2 = src_x + src_w,
 246                 .y2 = src_y + src_h,
 247         };
 248         struct drm_rect dest = {
 249                 .x1 = crtc_x,
 250                 .y1 = crtc_y,
 251                 .x2 = crtc_x + crtc_w,
 252                 .y2 = crtc_y + crtc_h,
 253         };
 254         const struct drm_rect clip = {
 255                 .x2 = crtc->mode.hdisplay,
 256                 .y2 = crtc->mode.vdisplay,
 257         };
 258         struct drm_connector **connector_list;
 259         int num_connectors, ret;
 260         bool visible;
 261
 262         ret = drm_plane_helper_check_update(plane, crtc, fb,
 263                                             &src, &dest, &clip,
 264                                             DRM_PLANE_HELPER_NO_SCALING,
 265                                             DRM_PLANE_HELPER_NO_SCALING,
 266                                             false, false, &visible);
 267         if (ret)
 268                 return ret;
 269
 270         if (!visible)
 271                 /*
 272                  * Primary plane isn't visible.  Note that unless a driver
 273                  * provides their own disable function, this will just
 274                  * wind up returning -EINVAL to userspace.
 275                  */
 276                 return plane->funcs->disable_plane(plane);
 277
 278         /* Find current connectors for CRTC */
 279         num_connectors = get_connectors_for_crtc(crtc, NULL, 0);
 280         BUG_ON(num_connectors == 0);
 281         connector_list = kzalloc(num_connectors * sizeof(*connector_list),
 282                                  GFP_KERNEL);
 283         if (!connector_list)
 284                 return -ENOMEM;
 285         get_connectors_for_crtc(crtc, connector_list, num_connectors);
 286
 287         set.connectors = connector_list;
 288         set.num_connectors = num_connectors;
 289
 290         /*
 291          * We call set_config() directly here rather than using
 292          * drm_mode_set_config_internal.  We're reprogramming the same
 293          * connectors that were already in use, so we shouldn't need the extra
 294          * cross-CRTC fb refcounting to accomodate stealing connectors.
 295          * drm_mode_setplane() already handles the basic refcounting for the
 296          * framebuffers involved in this operation.
 297          */
 298         ret = crtc->funcs->set_config(&set);
 299
 300         kfree(connector_list);
 301         return ret;
 302 }
 303 EXPORT_SYMBOL(drm_primary_helper_update);
 304
 305 /**
 306  * drm_primary_helper_disable() - Helper for primary plane disable
 307  * @plane: plane to disable
 308  *
 309  * Provides a default plane disable handler for primary planes.  This is handler
 310  * is called in response to a userspace SetPlane operation on the plane with a
 311  * NULL framebuffer parameter.  It unconditionally fails the disable call with
 312  * -EINVAL the only way to disable the primary plane without driver support is
 313  * to disable the entier CRTC. Which does not match the plane ->disable hook.
 314  *
 315  * Note that some hardware may be able to disable the primary plane without
 316  * disabling the whole CRTC.  Drivers for such hardware should provide their
 317  * own disable handler that disables just the primary plane (and they'll likely
 318  * need to provide their own update handler as well to properly re-enable a
 319  * disabled primary plane).
 320  *
 321  * RETURNS:
 322  * Unconditionally returns -EINVAL.
 323  */
 324 int drm_primary_helper_disable(struct drm_plane *plane)
 325 {
 326         return -EINVAL;
 327 }
 328 EXPORT_SYMBOL(drm_primary_helper_disable);
 329
 330 /**
 331  * drm_primary_helper_destroy() - Helper for primary plane destruction
 332  * @plane: plane to destroy
 333  *
 334  * Provides a default plane destroy handler for primary planes.  This handler
 335  * is called during CRTC destruction.  We disable the primary plane, remove
 336  * it from the DRM plane list, and deallocate the plane structure.
 337  */
 338 void drm_primary_helper_destroy(struct drm_plane *plane)
 339 {
 340         drm_plane_cleanup(plane);
 341         kfree(plane);
 342 }
 343 EXPORT_SYMBOL(drm_primary_helper_destroy);
 344
 345 const struct drm_plane_funcs drm_primary_helper_funcs = {
 346         .update_plane = drm_primary_helper_update,
 347         .disable_plane = drm_primary_helper_disable,
 348         .destroy = drm_primary_helper_destroy,
 349 };
 350 EXPORT_SYMBOL(drm_primary_helper_funcs);
 351
 352 static struct drm_plane *create_primary_plane(struct drm_device *dev)
 353 {
 354         struct drm_plane *primary;
 355         int ret;
 356
 357         primary = kzalloc(sizeof(*primary), GFP_KERNEL);
 358         if (primary == NULL) {
 359                 DRM_DEBUG_KMS("Failed to allocate primary plane\n");
 360                 return NULL;
 361         }
 362
 363         /*
 364          * Remove the format_default field from drm_plane when dropping
 365          * this helper.
 366          */
 367         primary->format_default = true;
 368
 369         /* possible_crtc's will be filled in later by crtc_init */
 370         ret = drm_universal_plane_init(dev, primary, 0,
 371                                        &drm_primary_helper_funcs,
 372                                        safe_modeset_formats,
 373                                        ARRAY_SIZE(safe_modeset_formats),
 374                                        DRM_PLANE_TYPE_PRIMARY);
 375         if (ret) {
 376                 kfree(primary);
 377                 primary = NULL;
 378         }
 379
 380         return primary;
 381 }
 382
 383 /**
 384  * drm_crtc_init - Legacy CRTC initialization function
 385  * @dev: DRM device
 386  * @crtc: CRTC object to init
 387  * @funcs: callbacks for the new CRTC
 388  *
 389  * Initialize a CRTC object with a default helper-provided primary plane and no
 390  * cursor plane.
 391  *
 392  * Returns:
 393  * Zero on success, error code on failure.
 394  */
 395 int drm_crtc_init(struct drm_device *dev, struct drm_crtc *crtc,
 396                   const struct drm_crtc_funcs *funcs)
 397 {
 398         struct drm_plane *primary;
 399
 400         primary = create_primary_plane(dev);
 401         return drm_crtc_init_with_planes(dev, crtc, primary, NULL, funcs);
 402 }
 403 EXPORT_SYMBOL(drm_crtc_init);
 404
 405 int drm_plane_helper_commit(struct drm_plane *plane,
 406                             struct drm_plane_state *plane_state,
 407                             struct drm_framebuffer *old_fb)
 408 {
 409         const struct drm_plane_helper_funcs *plane_funcs;
 410         struct drm_crtc *crtc[2];
 411         const struct drm_crtc_helper_funcs *crtc_funcs[2];
 412         int i, ret = 0;
 413
 414         plane_funcs = plane->helper_private;
 415
 416         /* Since this is a transitional helper we can't assume that plane->state
 417          * is always valid. Hence we need to use plane->crtc instead of
 418          * plane->state->crtc as the old crtc. */
 419         crtc[0] = plane->crtc;
 420         crtc[1] = crtc[0] != plane_state->crtc ? plane_state->crtc : NULL;
 421
 422         for (i = 0; i < 2; i++)
 423                 crtc_funcs[i] = crtc[i] ? crtc[i]->helper_private : NULL;
 424
 425         if (plane_funcs->atomic_check) {
 426                 ret = plane_funcs->atomic_check(plane, plane_state);
 427                 if (ret)
 428                         goto out;
 429         }
 430
 431         if (plane_funcs->prepare_fb && plane_state->fb &&
 432             plane_state->fb != old_fb) {
 433                 ret = plane_funcs->prepare_fb(plane,
 434                                               plane_state);
 435                 if (ret)
 436                         goto out;
 437         }
 438
 439         /* Point of no return, commit sw state. */
 440         swap(plane->state, plane_state);
 441
 442         for (i = 0; i < 2; i++) {
 443                 if (crtc_funcs[i] && crtc_funcs[i]->atomic_begin)
 444                         crtc_funcs[i]->atomic_begin(crtc[i], crtc[i]->state);
 445         }
 446
 447         /*
 448          * Drivers may optionally implement the ->atomic_disable callback, so
 449          * special-case that here.
 450          */
 451         if (drm_atomic_plane_disabling(plane, plane_state) &&
 452             plane_funcs->atomic_disable)
 453                 plane_funcs->atomic_disable(plane, plane_state);
 454         else
 455                 plane_funcs->atomic_update(plane, plane_state);
 456
 457         for (i = 0; i < 2; i++) {
 458                 if (crtc_funcs[i] && crtc_funcs[i]->atomic_flush)
 459                         crtc_funcs[i]->atomic_flush(crtc[i], crtc[i]->state);
 460         }
 461
 462         /*
 463          * If we only moved the plane and didn't change fb's, there's no need to
 464          * wait for vblank.
 465          */
 466         if (plane->state->fb == old_fb)
 467                 goto out;
 468
 469         for (i = 0; i < 2; i++) {
 470                 if (!crtc[i])
 471                         continue;
 472
 473                 if (crtc[i]->cursor == plane)
 474                         continue;
 475
 476                 /* There's no other way to figure out whether the crtc is running. */
 477                 ret = drm_crtc_vblank_get(crtc[i]);
 478                 if (ret == 0) {
 479                         drm_crtc_wait_one_vblank(crtc[i]);
 480                         drm_crtc_vblank_put(crtc[i]);
 481                 }
 482
 483                 ret = 0;
 484         }
 485
 486         if (plane_funcs->cleanup_fb)
 487                 plane_funcs->cleanup_fb(plane, plane_state);
 488 out:
 489         if (plane_state) {
 490                 if (plane->funcs->atomic_destroy_state)
 491                         plane->funcs->atomic_destroy_state(plane, plane_state);
 492                 else
 493                         drm_atomic_helper_plane_destroy_state(plane, plane_state);
 494         }
 495
 496         return ret;
 497 }
 498
 499 /**
 500  * drm_plane_helper_update() - Transitional helper for plane update
 501  * @plane: plane object to update
 502  * @crtc: owning CRTC of owning plane
 503  * @fb: framebuffer to flip onto plane
 504  * @crtc_x: x offset of primary plane on crtc
 505  * @crtc_y: y offset of primary plane on crtc
 506  * @crtc_w: width of primary plane rectangle on crtc
 507  * @crtc_h: height of primary plane rectangle on crtc
 508  * @src_x: x offset of @fb for panning
 509  * @src_y: y offset of @fb for panning
 510  * @src_w: width of source rectangle in @fb
 511  * @src_h: height of source rectangle in @fb
 512  *
 513  * Provides a default plane update handler using the atomic plane update
 514  * functions. It is fully left to the driver to check plane constraints and
 515  * handle corner-cases like a fully occluded or otherwise invisible plane.
 516  *
 517  * This is useful for piecewise transitioning of a driver to the atomic helpers.
 518  *
 519  * RETURNS:
 520  * Zero on success, error code on failure
 521  */
 522 int drm_plane_helper_update(struct drm_plane *plane, struct drm_crtc *crtc,
 523                             struct drm_framebuffer *fb,
 524                             int crtc_x, int crtc_y,
 525                             unsigned int crtc_w, unsigned int crtc_h,
 526                             uint32_t src_x, uint32_t src_y,
 527                             uint32_t src_w, uint32_t src_h)
 528 {
 529         struct drm_plane_state *plane_state;
 530
 531         if (plane->funcs->atomic_duplicate_state)
 532                 plane_state = plane->funcs->atomic_duplicate_state(plane);
 533         else {
 534                 if (!plane->state)
 535                         drm_atomic_helper_plane_reset(plane);
 536
 537                 plane_state = drm_atomic_helper_plane_duplicate_state(plane);
 538         }
 539         if (!plane_state)
 540                 return -ENOMEM;
 541         plane_state->plane = plane;
 542
 543         plane_state->crtc = crtc;
 544         drm_atomic_set_fb_for_plane(plane_state, fb);
 545         plane_state->crtc_x = crtc_x;
 546         plane_state->crtc_y = crtc_y;
 547         plane_state->crtc_h = crtc_h;
 548         plane_state->crtc_w = crtc_w;
 549         plane_state->src_x = src_x;
 550         plane_state->src_y = src_y;
 551         plane_state->src_h = src_h;
 552         plane_state->src_w = src_w;
 553
 554         return drm_plane_helper_commit(plane, plane_state, plane->fb);
 555 }
 556 EXPORT_SYMBOL(drm_plane_helper_update);
 557
 558 /**
 559  * drm_plane_helper_disable() - Transitional helper for plane disable
 560  * @plane: plane to disable
 561  *
 562  * Provides a default plane disable handler using the atomic plane update
 563  * functions. It is fully left to the driver to check plane constraints and
 564  * handle corner-cases like a fully occluded or otherwise invisible plane.
 565  *
 566  * This is useful for piecewise transitioning of a driver to the atomic helpers.
 567  *
 568  * RETURNS:
 569  * Zero on success, error code on failure
 570  */
 571 int drm_plane_helper_disable(struct drm_plane *plane)
 572 {
 573         struct drm_plane_state *plane_state;
 574
 575         /* crtc helpers love to call disable functions for already disabled hw
 576          * functions. So cope with that. */
 577         if (!plane->crtc)
 578                 return 0;
 579
 580         if (plane->funcs->atomic_duplicate_state)
 581                 plane_state = plane->funcs->atomic_duplicate_state(plane);
 582         else {
 583                 if (!plane->state)
 584                         drm_atomic_helper_plane_reset(plane);
 585
 586                 plane_state = drm_atomic_helper_plane_duplicate_state(plane);
 587         }
 588         if (!plane_state)
 589                 return -ENOMEM;
 590         plane_state->plane = plane;
 591
 592         plane_state->crtc = NULL;
 593         drm_atomic_set_fb_for_plane(plane_state, NULL);
 594
 595         return drm_plane_helper_commit(plane, plane_state, plane->fb);
 596 }
 597 EXPORT_SYMBOL(drm_plane_helper_disable);