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  * The plane helpers share the function table structures with other helpers,
  62  * specifically also the atomic helpers. See struct &drm_plane_helper_funcs for
  63  * the details.
  64  */
  65
  66 /*
  67  * This is the minimal list of formats that seem to be safe for modeset use
  68  * with all current DRM drivers.  Most hardware can actually support more
  69  * formats than this and drivers may specify a more accurate list when
  70  * creating the primary plane.  However drivers that still call
  71  * drm_plane_init() will use this minimal format list as the default.
  72  */
  73 static const uint32_t safe_modeset_formats[] = {
  74         DRM_FORMAT_XRGB8888,
  75         DRM_FORMAT_ARGB8888,
  76 };
  77
  78 /*
  79  * Returns the connectors currently associated with a CRTC.  This function
  80  * should be called twice:  once with a NULL connector list to retrieve
  81  * the list size, and once with the properly allocated list to be filled in.
  82  */
  83 static int get_connectors_for_crtc(struct drm_crtc *crtc,
  84                                    struct drm_connector **connector_list,
  85                                    int num_connectors)
  86 {
  87         struct drm_device *dev = crtc->dev;
  88         struct drm_connector *connector;
  89         int count = 0;
  90
  91         /*
  92          * Note: Once we change the plane hooks to more fine-grained locking we
  93          * need to grab the connection_mutex here to be able to make these
  94          * checks.
  95          */
  96         WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
  97
  98         drm_for_each_connector(connector, dev) {
  99                 if (connector->encoder && connector->encoder->crtc == crtc) {
 100                         if (connector_list != NULL && count < num_connectors)
 101                                 *(connector_list++) = connector;
 102
 103                         count++;
 104                 }
 105         }
 106
 107         return count;
 108 }
 109
 110 /**
 111  * drm_plane_helper_check_update() - Check plane update for validity
 112  * @plane: plane object to update
 113  * @crtc: owning CRTC of owning plane
 114  * @fb: framebuffer to flip onto plane
 115  * @src: source coordinates in 16.16 fixed point
 116  * @dest: integer destination coordinates
 117  * @clip: integer clipping coordinates
 118  * @min_scale: minimum @src:@dest scaling factor in 16.16 fixed point
 119  * @max_scale: maximum @src:@dest scaling factor in 16.16 fixed point
 120  * @can_position: is it legal to position the plane such that it
 121  *                doesn't cover the entire crtc?  This will generally
 122  *                only be false for primary planes.
 123  * @can_update_disabled: can the plane be updated while the crtc
 124  *                       is disabled?
 125  * @visible: output parameter indicating whether plane is still visible after
 126  *           clipping
 127  *
 128  * Checks that a desired plane update is valid.  Drivers that provide
 129  * their own plane handling rather than helper-provided implementations may
 130  * still wish to call this function to avoid duplication of error checking
 131  * code.
 132  *
 133  * RETURNS:
 134  * Zero if update appears valid, error code on failure
 135  */
 136 int drm_plane_helper_check_update(struct drm_plane *plane,
 137                                     struct drm_crtc *crtc,
 138                                     struct drm_framebuffer *fb,
 139                                     struct drm_rect *src,
 140                                     struct drm_rect *dest,
 141                                     const struct drm_rect *clip,
 142                                     int min_scale,
 143                                     int max_scale,
 144                                     bool can_position,
 145                                     bool can_update_disabled,
 146                                     bool *visible)
 147 {
 148         int hscale, vscale;
 149
 150         if (!fb) {
 151                 *visible = false;
 152                 return 0;
 153         }
 154
 155         /* crtc should only be NULL when disabling (i.e., !fb) */
 156         if (WARN_ON(!crtc)) {
 157                 *visible = false;
 158                 return 0;
 159         }
 160
 161         if (!crtc->enabled && !can_update_disabled) {
 162                 DRM_DEBUG_KMS("Cannot update plane of a disabled CRTC.\n");
 163                 return -EINVAL;
 164         }
 165
 166         /* Check scaling */
 167         hscale = drm_rect_calc_hscale(src, dest, min_scale, max_scale);
 168         vscale = drm_rect_calc_vscale(src, dest, min_scale, max_scale);
 169         if (hscale < 0 || vscale < 0) {
 170                 DRM_DEBUG_KMS("Invalid scaling of plane\n");
 171                 drm_rect_debug_print("src: ", src, true);
 172                 drm_rect_debug_print("dst: ", dest, false);
 173                 return -ERANGE;
 174         }
 175
 176         *visible = drm_rect_clip_scaled(src, dest, clip, hscale, vscale);
 177         if (!*visible)
 178                 /*
 179                  * Plane isn't visible; some drivers can handle this
 180                  * so we just return success here.  Drivers that can't
 181                  * (including those that use the primary plane helper's
 182                  * update function) will return an error from their
 183                  * update_plane handler.
 184                  */
 185                 return 0;
 186
 187         if (!can_position && !drm_rect_equals(dest, clip)) {
 188                 DRM_DEBUG_KMS("Plane must cover entire CRTC\n");
 189                 drm_rect_debug_print("dst: ", dest, false);
 190                 drm_rect_debug_print("clip: ", clip, false);
 191                 return -EINVAL;
 192         }
 193
 194         return 0;
 195 }
 196 EXPORT_SYMBOL(drm_plane_helper_check_update);
 197
 198 /**
 199  * drm_primary_helper_update() - Helper for primary plane update
 200  * @plane: plane object to update
 201  * @crtc: owning CRTC of owning plane
 202  * @fb: framebuffer to flip onto plane
 203  * @crtc_x: x offset of primary plane on crtc
 204  * @crtc_y: y offset of primary plane on crtc
 205  * @crtc_w: width of primary plane rectangle on crtc
 206  * @crtc_h: height of primary plane rectangle on crtc
 207  * @src_x: x offset of @fb for panning
 208  * @src_y: y offset of @fb for panning
 209  * @src_w: width of source rectangle in @fb
 210  * @src_h: height of source rectangle in @fb
 211  *
 212  * Provides a default plane update handler for primary planes.  This is handler
 213  * is called in response to a userspace SetPlane operation on the plane with a
 214  * non-NULL framebuffer.  We call the driver's modeset handler to update the
 215  * framebuffer.
 216  *
 217  * SetPlane() on a primary plane of a disabled CRTC is not supported, and will
 218  * return an error.
 219  *
 220  * Note that we make some assumptions about hardware limitations that may not be
 221  * true for all hardware --
 222  *
 223  * 1. Primary plane cannot be repositioned.
 224  * 2. Primary plane cannot be scaled.
 225  * 3. Primary plane must cover the entire CRTC.
 226  * 4. Subpixel positioning is not supported.
 227  *
 228  * Drivers for hardware that don't have these restrictions can provide their
 229  * own implementation rather than using this helper.
 230  *
 231  * RETURNS:
 232  * Zero on success, error code on failure
 233  */
 234 int drm_primary_helper_update(struct drm_plane *plane, struct drm_crtc *crtc,
 235                               struct drm_framebuffer *fb,
 236                               int crtc_x, int crtc_y,
 237                               unsigned int crtc_w, unsigned int crtc_h,
 238                               uint32_t src_x, uint32_t src_y,
 239                               uint32_t src_w, uint32_t src_h)
 240 {
 241         struct drm_mode_set set = {
 242                 .crtc = crtc,
 243                 .fb = fb,
 244                 .mode = &crtc->mode,
 245                 .x = src_x >> 16,
 246                 .y = src_y >> 16,
 247         };
 248         struct drm_rect src = {
 249                 .x1 = src_x,
 250                 .y1 = src_y,
 251                 .x2 = src_x + src_w,
 252                 .y2 = src_y + src_h,
 253         };
 254         struct drm_rect dest = {
 255                 .x1 = crtc_x,
 256                 .y1 = crtc_y,
 257                 .x2 = crtc_x + crtc_w,
 258                 .y2 = crtc_y + crtc_h,
 259         };
 260         const struct drm_rect clip = {
 261                 .x2 = crtc->mode.hdisplay,
 262                 .y2 = crtc->mode.vdisplay,
 263         };
 264         struct drm_connector **connector_list;
 265         int num_connectors, ret;
 266         bool visible;
 267
 268         ret = drm_plane_helper_check_update(plane, crtc, fb,
 269                                             &src, &dest, &clip,
 270                                             DRM_PLANE_HELPER_NO_SCALING,
 271                                             DRM_PLANE_HELPER_NO_SCALING,
 272                                             false, false, &visible);
 273         if (ret)
 274                 return ret;
 275
 276         if (!visible)
 277                 /*
 278                  * Primary plane isn't visible.  Note that unless a driver
 279                  * provides their own disable function, this will just
 280                  * wind up returning -EINVAL to userspace.
 281                  */
 282                 return plane->funcs->disable_plane(plane);
 283
 284         /* Find current connectors for CRTC */
 285         num_connectors = get_connectors_for_crtc(crtc, NULL, 0);
 286         BUG_ON(num_connectors == 0);
 287         connector_list = kzalloc(num_connectors * sizeof(*connector_list),
 288                                  GFP_KERNEL);
 289         if (!connector_list)
 290                 return -ENOMEM;
 291         get_connectors_for_crtc(crtc, connector_list, num_connectors);
 292
 293         set.connectors = connector_list;
 294         set.num_connectors = num_connectors;
 295
 296         /*
 297          * We call set_config() directly here rather than using
 298          * drm_mode_set_config_internal.  We're reprogramming the same
 299          * connectors that were already in use, so we shouldn't need the extra
 300          * cross-CRTC fb refcounting to accomodate stealing connectors.
 301          * drm_mode_setplane() already handles the basic refcounting for the
 302          * framebuffers involved in this operation.
 303          */
 304         ret = crtc->funcs->set_config(&set);
 305
 306         kfree(connector_list);
 307         return ret;
 308 }
 309 EXPORT_SYMBOL(drm_primary_helper_update);
 310
 311 /**
 312  * drm_primary_helper_disable() - Helper for primary plane disable
 313  * @plane: plane to disable
 314  *
 315  * Provides a default plane disable handler for primary planes.  This is handler
 316  * is called in response to a userspace SetPlane operation on the plane with a
 317  * NULL framebuffer parameter.  It unconditionally fails the disable call with
 318  * -EINVAL the only way to disable the primary plane without driver support is
 319  * to disable the entier CRTC. Which does not match the plane ->disable hook.
 320  *
 321  * Note that some hardware may be able to disable the primary plane without
 322  * disabling the whole CRTC.  Drivers for such hardware should provide their
 323  * own disable handler that disables just the primary plane (and they'll likely
 324  * need to provide their own update handler as well to properly re-enable a
 325  * disabled primary plane).
 326  *
 327  * RETURNS:
 328  * Unconditionally returns -EINVAL.
 329  */
 330 int drm_primary_helper_disable(struct drm_plane *plane)
 331 {
 332         return -EINVAL;
 333 }
 334 EXPORT_SYMBOL(drm_primary_helper_disable);
 335
 336 /**
 337  * drm_primary_helper_destroy() - Helper for primary plane destruction
 338  * @plane: plane to destroy
 339  *
 340  * Provides a default plane destroy handler for primary planes.  This handler
 341  * is called during CRTC destruction.  We disable the primary plane, remove
 342  * it from the DRM plane list, and deallocate the plane structure.
 343  */
 344 void drm_primary_helper_destroy(struct drm_plane *plane)
 345 {
 346         drm_plane_cleanup(plane);
 347         kfree(plane);
 348 }
 349 EXPORT_SYMBOL(drm_primary_helper_destroy);
 350
 351 const struct drm_plane_funcs drm_primary_helper_funcs = {
 352         .update_plane = drm_primary_helper_update,
 353         .disable_plane = drm_primary_helper_disable,
 354         .destroy = drm_primary_helper_destroy,
 355 };
 356 EXPORT_SYMBOL(drm_primary_helper_funcs);
 357
 358 static struct drm_plane *create_primary_plane(struct drm_device *dev)
 359 {
 360         struct drm_plane *primary;
 361         int ret;
 362
 363         primary = kzalloc(sizeof(*primary), GFP_KERNEL);
 364         if (primary == NULL) {
 365                 DRM_DEBUG_KMS("Failed to allocate primary plane\n");
 366                 return NULL;
 367         }
 368
 369         /*
 370          * Remove the format_default field from drm_plane when dropping
 371          * this helper.
 372          */
 373         primary->format_default = true;
 374
 375         /* possible_crtc's will be filled in later by crtc_init */
 376         ret = drm_universal_plane_init(dev, primary, 0,
 377                                        &drm_primary_helper_funcs,
 378                                        safe_modeset_formats,
 379                                        ARRAY_SIZE(safe_modeset_formats),
 380                                        DRM_PLANE_TYPE_PRIMARY, NULL);
 381         if (ret) {
 382                 kfree(primary);
 383                 primary = NULL;
 384         }
 385
 386         return primary;
 387 }
 388
 389 /**
 390  * drm_crtc_init - Legacy CRTC initialization function
 391  * @dev: DRM device
 392  * @crtc: CRTC object to init
 393  * @funcs: callbacks for the new CRTC
 394  *
 395  * Initialize a CRTC object with a default helper-provided primary plane and no
 396  * cursor plane.
 397  *
 398  * Returns:
 399  * Zero on success, error code on failure.
 400  */
 401 int drm_crtc_init(struct drm_device *dev, struct drm_crtc *crtc,
 402                   const struct drm_crtc_funcs *funcs)
 403 {
 404         struct drm_plane *primary;
 405
 406         primary = create_primary_plane(dev);
 407         return drm_crtc_init_with_planes(dev, crtc, primary, NULL, funcs,
 408                                          NULL);
 409 }
 410 EXPORT_SYMBOL(drm_crtc_init);
 411
 412 int drm_plane_helper_commit(struct drm_plane *plane,
 413                             struct drm_plane_state *plane_state,
 414                             struct drm_framebuffer *old_fb)
 415 {
 416         const struct drm_plane_helper_funcs *plane_funcs;
 417         struct drm_crtc *crtc[2];
 418         const struct drm_crtc_helper_funcs *crtc_funcs[2];
 419         int i, ret = 0;
 420
 421         plane_funcs = plane->helper_private;
 422
 423         /* Since this is a transitional helper we can't assume that plane->state
 424          * is always valid. Hence we need to use plane->crtc instead of
 425          * plane->state->crtc as the old crtc. */
 426         crtc[0] = plane->crtc;
 427         crtc[1] = crtc[0] != plane_state->crtc ? plane_state->crtc : NULL;
 428
 429         for (i = 0; i < 2; i++)
 430                 crtc_funcs[i] = crtc[i] ? crtc[i]->helper_private : NULL;
 431
 432         if (plane_funcs->atomic_check) {
 433                 ret = plane_funcs->atomic_check(plane, plane_state);
 434                 if (ret)
 435                         goto out;
 436         }
 437
 438         if (plane_funcs->prepare_fb && plane_state->fb &&
 439             plane_state->fb != old_fb) {
 440                 ret = plane_funcs->prepare_fb(plane,
 441                                               plane_state);
 442                 if (ret)
 443                         goto out;
 444         }
 445
 446         /* Point of no return, commit sw state. */
 447         swap(plane->state, plane_state);
 448
 449         for (i = 0; i < 2; i++) {
 450                 if (crtc_funcs[i] && crtc_funcs[i]->atomic_begin)
 451                         crtc_funcs[i]->atomic_begin(crtc[i], crtc[i]->state);
 452         }
 453
 454         /*
 455          * Drivers may optionally implement the ->atomic_disable callback, so
 456          * special-case that here.
 457          */
 458         if (drm_atomic_plane_disabling(plane, plane_state) &&
 459             plane_funcs->atomic_disable)
 460                 plane_funcs->atomic_disable(plane, plane_state);
 461         else
 462                 plane_funcs->atomic_update(plane, plane_state);
 463
 464         for (i = 0; i < 2; i++) {
 465                 if (crtc_funcs[i] && crtc_funcs[i]->atomic_flush)
 466                         crtc_funcs[i]->atomic_flush(crtc[i], crtc[i]->state);
 467         }
 468
 469         /*
 470          * If we only moved the plane and didn't change fb's, there's no need to
 471          * wait for vblank.
 472          */
 473         if (plane->state->fb == old_fb)
 474                 goto out;
 475
 476         for (i = 0; i < 2; i++) {
 477                 if (!crtc[i])
 478                         continue;
 479
 480                 if (crtc[i]->cursor == plane)
 481                         continue;
 482
 483                 /* There's no other way to figure out whether the crtc is running. */
 484                 ret = drm_crtc_vblank_get(crtc[i]);
 485                 if (ret == 0) {
 486                         drm_crtc_wait_one_vblank(crtc[i]);
 487                         drm_crtc_vblank_put(crtc[i]);
 488                 }
 489
 490                 ret = 0;
 491         }
 492
 493         if (plane_funcs->cleanup_fb)
 494                 plane_funcs->cleanup_fb(plane, plane_state);
 495 out:
 496         if (plane_state) {
 497                 if (plane->funcs->atomic_destroy_state)
 498                         plane->funcs->atomic_destroy_state(plane, plane_state);
 499                 else
 500                         drm_atomic_helper_plane_destroy_state(plane, plane_state);
 501         }
 502
 503         return ret;
 504 }
 505
 506 /**
 507  * drm_plane_helper_update() - Transitional helper for plane update
 508  * @plane: plane object to update
 509  * @crtc: owning CRTC of owning plane
 510  * @fb: framebuffer to flip onto plane
 511  * @crtc_x: x offset of primary plane on crtc
 512  * @crtc_y: y offset of primary plane on crtc
 513  * @crtc_w: width of primary plane rectangle on crtc
 514  * @crtc_h: height of primary plane rectangle on crtc
 515  * @src_x: x offset of @fb for panning
 516  * @src_y: y offset of @fb for panning
 517  * @src_w: width of source rectangle in @fb
 518  * @src_h: height of source rectangle in @fb
 519  *
 520  * Provides a default plane update handler using the atomic plane update
 521  * functions. It is fully left to the driver to check plane constraints and
 522  * handle corner-cases like a fully occluded or otherwise invisible plane.
 523  *
 524  * This is useful for piecewise transitioning of a driver to the atomic helpers.
 525  *
 526  * RETURNS:
 527  * Zero on success, error code on failure
 528  */
 529 int drm_plane_helper_update(struct drm_plane *plane, struct drm_crtc *crtc,
 530                             struct drm_framebuffer *fb,
 531                             int crtc_x, int crtc_y,
 532                             unsigned int crtc_w, unsigned int crtc_h,
 533                             uint32_t src_x, uint32_t src_y,
 534                             uint32_t src_w, uint32_t src_h)
 535 {
 536         struct drm_plane_state *plane_state;
 537
 538         if (plane->funcs->atomic_duplicate_state)
 539                 plane_state = plane->funcs->atomic_duplicate_state(plane);
 540         else {
 541                 if (!plane->state)
 542                         drm_atomic_helper_plane_reset(plane);
 543
 544                 plane_state = drm_atomic_helper_plane_duplicate_state(plane);
 545         }
 546         if (!plane_state)
 547                 return -ENOMEM;
 548         plane_state->plane = plane;
 549
 550         plane_state->crtc = crtc;
 551         drm_atomic_set_fb_for_plane(plane_state, fb);
 552         plane_state->crtc_x = crtc_x;
 553         plane_state->crtc_y = crtc_y;
 554         plane_state->crtc_h = crtc_h;
 555         plane_state->crtc_w = crtc_w;
 556         plane_state->src_x = src_x;
 557         plane_state->src_y = src_y;
 558         plane_state->src_h = src_h;
 559         plane_state->src_w = src_w;
 560
 561         return drm_plane_helper_commit(plane, plane_state, plane->fb);
 562 }
 563 EXPORT_SYMBOL(drm_plane_helper_update);
 564
 565 /**
 566  * drm_plane_helper_disable() - Transitional helper for plane disable
 567  * @plane: plane to disable
 568  *
 569  * Provides a default plane disable handler using the atomic plane update
 570  * functions. It is fully left to the driver to check plane constraints and
 571  * handle corner-cases like a fully occluded or otherwise invisible plane.
 572  *
 573  * This is useful for piecewise transitioning of a driver to the atomic helpers.
 574  *
 575  * RETURNS:
 576  * Zero on success, error code on failure
 577  */
 578 int drm_plane_helper_disable(struct drm_plane *plane)
 579 {
 580         struct drm_plane_state *plane_state;
 581
 582         /* crtc helpers love to call disable functions for already disabled hw
 583          * functions. So cope with that. */
 584         if (!plane->crtc)
 585                 return 0;
 586
 587         if (plane->funcs->atomic_duplicate_state)
 588                 plane_state = plane->funcs->atomic_duplicate_state(plane);
 589         else {
 590                 if (!plane->state)
 591                         drm_atomic_helper_plane_reset(plane);
 592
 593                 plane_state = drm_atomic_helper_plane_duplicate_state(plane);
 594         }
 595         if (!plane_state)
 596                 return -ENOMEM;
 597         plane_state->plane = plane;
 598
 599         plane_state->crtc = NULL;
 600         drm_atomic_set_fb_for_plane(plane_state, NULL);
 601
 602         return drm_plane_helper_commit(plane, plane_state, plane->fb);
 603 }
 604 EXPORT_SYMBOL(drm_plane_helper_disable);