1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * drm gem framebuffer helper functions 4 * 5 * Copyright (C) 2017 Noralf Trønnes 6 */ 7 8 #include <linux/slab.h> 9 10 #include <drm/drm_damage_helper.h> 11 #include <drm/drm_fb_helper.h> 12 #include <drm/drm_fourcc.h> 13 #include <drm/drm_framebuffer.h> 14 #include <drm/drm_gem.h> 15 #include <drm/drm_gem_framebuffer_helper.h> 16 #include <drm/drm_modeset_helper.h> 17 18 #include "drm_internal.h" 19 20 #define AFBC_HEADER_SIZE 16 21 #define AFBC_TH_LAYOUT_ALIGNMENT 8 22 #define AFBC_HDR_ALIGN 64 23 #define AFBC_SUPERBLOCK_PIXELS 256 24 #define AFBC_SUPERBLOCK_ALIGNMENT 128 25 #define AFBC_TH_BODY_START_ALIGNMENT 4096 26 27 /** 28 * DOC: overview 29 * 30 * This library provides helpers for drivers that don't subclass 31 * &drm_framebuffer and use &drm_gem_object for their backing storage. 32 * 33 * Drivers without additional needs to validate framebuffers can simply use 34 * drm_gem_fb_create() and everything is wired up automatically. Other drivers 35 * can use all parts independently. 36 */ 37 38 /** 39 * drm_gem_fb_get_obj() - Get GEM object backing the framebuffer 40 * @fb: Framebuffer 41 * @plane: Plane index 42 * 43 * No additional reference is taken beyond the one that the &drm_frambuffer 44 * already holds. 45 * 46 * Returns: 47 * Pointer to &drm_gem_object for the given framebuffer and plane index or NULL 48 * if it does not exist. 49 */ 50 struct drm_gem_object *drm_gem_fb_get_obj(struct drm_framebuffer *fb, 51 unsigned int plane) 52 { 53 if (plane >= ARRAY_SIZE(fb->obj)) 54 return NULL; 55 56 return fb->obj[plane]; 57 } 58 EXPORT_SYMBOL_GPL(drm_gem_fb_get_obj); 59 60 static int 61 drm_gem_fb_init(struct drm_device *dev, 62 struct drm_framebuffer *fb, 63 const struct drm_mode_fb_cmd2 *mode_cmd, 64 struct drm_gem_object **obj, unsigned int num_planes, 65 const struct drm_framebuffer_funcs *funcs) 66 { 67 unsigned int i; 68 int ret; 69 70 drm_helper_mode_fill_fb_struct(dev, fb, mode_cmd); 71 72 for (i = 0; i < num_planes; i++) 73 fb->obj[i] = obj[i]; 74 75 ret = drm_framebuffer_init(dev, fb, funcs); 76 if (ret) 77 drm_err(dev, "Failed to init framebuffer: %d\n", ret); 78 79 return ret; 80 } 81 82 /** 83 * drm_gem_fb_destroy - Free GEM backed framebuffer 84 * @fb: Framebuffer 85 * 86 * Frees a GEM backed framebuffer with its backing buffer(s) and the structure 87 * itself. Drivers can use this as their &drm_framebuffer_funcs->destroy 88 * callback. 89 */ 90 void drm_gem_fb_destroy(struct drm_framebuffer *fb) 91 { 92 size_t i; 93 94 for (i = 0; i < ARRAY_SIZE(fb->obj); i++) 95 drm_gem_object_put(fb->obj[i]); 96 97 drm_framebuffer_cleanup(fb); 98 kfree(fb); 99 } 100 EXPORT_SYMBOL(drm_gem_fb_destroy); 101 102 /** 103 * drm_gem_fb_create_handle - Create handle for GEM backed framebuffer 104 * @fb: Framebuffer 105 * @file: DRM file to register the handle for 106 * @handle: Pointer to return the created handle 107 * 108 * This function creates a handle for the GEM object backing the framebuffer. 109 * Drivers can use this as their &drm_framebuffer_funcs->create_handle 110 * callback. The GETFB IOCTL calls into this callback. 111 * 112 * Returns: 113 * 0 on success or a negative error code on failure. 114 */ 115 int drm_gem_fb_create_handle(struct drm_framebuffer *fb, struct drm_file *file, 116 unsigned int *handle) 117 { 118 return drm_gem_handle_create(file, fb->obj[0], handle); 119 } 120 EXPORT_SYMBOL(drm_gem_fb_create_handle); 121 122 /** 123 * drm_gem_fb_init_with_funcs() - Helper function for implementing 124 * &drm_mode_config_funcs.fb_create 125 * callback in cases when the driver 126 * allocates a subclass of 127 * struct drm_framebuffer 128 * @dev: DRM device 129 * @fb: framebuffer object 130 * @file: DRM file that holds the GEM handle(s) backing the framebuffer 131 * @mode_cmd: Metadata from the userspace framebuffer creation request 132 * @funcs: vtable to be used for the new framebuffer object 133 * 134 * This function can be used to set &drm_framebuffer_funcs for drivers that need 135 * custom framebuffer callbacks. Use drm_gem_fb_create() if you don't need to 136 * change &drm_framebuffer_funcs. The function does buffer size validation. 137 * The buffer size validation is for a general case, though, so users should 138 * pay attention to the checks being appropriate for them or, at least, 139 * non-conflicting. 140 * 141 * Returns: 142 * Zero or a negative error code. 143 */ 144 int drm_gem_fb_init_with_funcs(struct drm_device *dev, 145 struct drm_framebuffer *fb, 146 struct drm_file *file, 147 const struct drm_mode_fb_cmd2 *mode_cmd, 148 const struct drm_framebuffer_funcs *funcs) 149 { 150 const struct drm_format_info *info; 151 struct drm_gem_object *objs[DRM_FORMAT_MAX_PLANES]; 152 unsigned int i; 153 int ret; 154 155 info = drm_get_format_info(dev, mode_cmd); 156 if (!info) { 157 drm_dbg_kms(dev, "Failed to get FB format info\n"); 158 return -EINVAL; 159 } 160 161 for (i = 0; i < info->num_planes; i++) { 162 unsigned int width = mode_cmd->width / (i ? info->hsub : 1); 163 unsigned int height = mode_cmd->height / (i ? info->vsub : 1); 164 unsigned int min_size; 165 166 objs[i] = drm_gem_object_lookup(file, mode_cmd->handles[i]); 167 if (!objs[i]) { 168 drm_dbg_kms(dev, "Failed to lookup GEM object\n"); 169 ret = -ENOENT; 170 goto err_gem_object_put; 171 } 172 173 min_size = (height - 1) * mode_cmd->pitches[i] 174 + drm_format_info_min_pitch(info, i, width) 175 + mode_cmd->offsets[i]; 176 177 if (objs[i]->size < min_size) { 178 drm_dbg_kms(dev, 179 "GEM object size (%zu) smaller than minimum size (%u) for plane %d\n", 180 objs[i]->size, min_size, i); 181 drm_gem_object_put(objs[i]); 182 ret = -EINVAL; 183 goto err_gem_object_put; 184 } 185 } 186 187 ret = drm_gem_fb_init(dev, fb, mode_cmd, objs, i, funcs); 188 if (ret) 189 goto err_gem_object_put; 190 191 return 0; 192 193 err_gem_object_put: 194 while (i > 0) { 195 --i; 196 drm_gem_object_put(objs[i]); 197 } 198 return ret; 199 } 200 EXPORT_SYMBOL_GPL(drm_gem_fb_init_with_funcs); 201 202 /** 203 * drm_gem_fb_create_with_funcs() - Helper function for the 204 * &drm_mode_config_funcs.fb_create 205 * callback 206 * @dev: DRM device 207 * @file: DRM file that holds the GEM handle(s) backing the framebuffer 208 * @mode_cmd: Metadata from the userspace framebuffer creation request 209 * @funcs: vtable to be used for the new framebuffer object 210 * 211 * This function can be used to set &drm_framebuffer_funcs for drivers that need 212 * custom framebuffer callbacks. Use drm_gem_fb_create() if you don't need to 213 * change &drm_framebuffer_funcs. The function does buffer size validation. 214 * 215 * Returns: 216 * Pointer to a &drm_framebuffer on success or an error pointer on failure. 217 */ 218 struct drm_framebuffer * 219 drm_gem_fb_create_with_funcs(struct drm_device *dev, struct drm_file *file, 220 const struct drm_mode_fb_cmd2 *mode_cmd, 221 const struct drm_framebuffer_funcs *funcs) 222 { 223 struct drm_framebuffer *fb; 224 int ret; 225 226 fb = kzalloc(sizeof(*fb), GFP_KERNEL); 227 if (!fb) 228 return ERR_PTR(-ENOMEM); 229 230 ret = drm_gem_fb_init_with_funcs(dev, fb, file, mode_cmd, funcs); 231 if (ret) { 232 kfree(fb); 233 return ERR_PTR(ret); 234 } 235 236 return fb; 237 } 238 EXPORT_SYMBOL_GPL(drm_gem_fb_create_with_funcs); 239 240 static const struct drm_framebuffer_funcs drm_gem_fb_funcs = { 241 .destroy = drm_gem_fb_destroy, 242 .create_handle = drm_gem_fb_create_handle, 243 }; 244 245 /** 246 * drm_gem_fb_create() - Helper function for the 247 * &drm_mode_config_funcs.fb_create callback 248 * @dev: DRM device 249 * @file: DRM file that holds the GEM handle(s) backing the framebuffer 250 * @mode_cmd: Metadata from the userspace framebuffer creation request 251 * 252 * This function creates a new framebuffer object described by 253 * &drm_mode_fb_cmd2. This description includes handles for the buffer(s) 254 * backing the framebuffer. 255 * 256 * If your hardware has special alignment or pitch requirements these should be 257 * checked before calling this function. The function does buffer size 258 * validation. Use drm_gem_fb_create_with_dirty() if you need framebuffer 259 * flushing. 260 * 261 * Drivers can use this as their &drm_mode_config_funcs.fb_create callback. 262 * The ADDFB2 IOCTL calls into this callback. 263 * 264 * Returns: 265 * Pointer to a &drm_framebuffer on success or an error pointer on failure. 266 */ 267 struct drm_framebuffer * 268 drm_gem_fb_create(struct drm_device *dev, struct drm_file *file, 269 const struct drm_mode_fb_cmd2 *mode_cmd) 270 { 271 return drm_gem_fb_create_with_funcs(dev, file, mode_cmd, 272 &drm_gem_fb_funcs); 273 } 274 EXPORT_SYMBOL_GPL(drm_gem_fb_create); 275 276 static const struct drm_framebuffer_funcs drm_gem_fb_funcs_dirtyfb = { 277 .destroy = drm_gem_fb_destroy, 278 .create_handle = drm_gem_fb_create_handle, 279 .dirty = drm_atomic_helper_dirtyfb, 280 }; 281 282 /** 283 * drm_gem_fb_create_with_dirty() - Helper function for the 284 * &drm_mode_config_funcs.fb_create callback 285 * @dev: DRM device 286 * @file: DRM file that holds the GEM handle(s) backing the framebuffer 287 * @mode_cmd: Metadata from the userspace framebuffer creation request 288 * 289 * This function creates a new framebuffer object described by 290 * &drm_mode_fb_cmd2. This description includes handles for the buffer(s) 291 * backing the framebuffer. drm_atomic_helper_dirtyfb() is used for the dirty 292 * callback giving framebuffer flushing through the atomic machinery. Use 293 * drm_gem_fb_create() if you don't need the dirty callback. 294 * The function does buffer size validation. 295 * 296 * Drivers should also call drm_plane_enable_fb_damage_clips() on all planes 297 * to enable userspace to use damage clips also with the ATOMIC IOCTL. 298 * 299 * Drivers can use this as their &drm_mode_config_funcs.fb_create callback. 300 * The ADDFB2 IOCTL calls into this callback. 301 * 302 * Returns: 303 * Pointer to a &drm_framebuffer on success or an error pointer on failure. 304 */ 305 struct drm_framebuffer * 306 drm_gem_fb_create_with_dirty(struct drm_device *dev, struct drm_file *file, 307 const struct drm_mode_fb_cmd2 *mode_cmd) 308 { 309 return drm_gem_fb_create_with_funcs(dev, file, mode_cmd, 310 &drm_gem_fb_funcs_dirtyfb); 311 } 312 EXPORT_SYMBOL_GPL(drm_gem_fb_create_with_dirty); 313 314 /** 315 * drm_gem_fb_vmap - maps all framebuffer BOs into kernel address space 316 * @fb: the framebuffer 317 * @map: returns the mapping's address for each BO 318 * @data: returns the data address for each BO, can be NULL 319 * 320 * This function maps all buffer objects of the given framebuffer into 321 * kernel address space and stores them in struct dma_buf_map. If the 322 * mapping operation fails for one of the BOs, the function unmaps the 323 * already established mappings automatically. 324 * 325 * Callers that want to access a BO's stored data should pass @data. 326 * The argument returns the addresses of the data stored in each BO. This 327 * is different from @map if the framebuffer's offsets field is non-zero. 328 * 329 * See drm_gem_fb_vunmap() for unmapping. 330 * 331 * Returns: 332 * 0 on success, or a negative errno code otherwise. 333 */ 334 int drm_gem_fb_vmap(struct drm_framebuffer *fb, 335 struct dma_buf_map map[static DRM_FORMAT_MAX_PLANES], 336 struct dma_buf_map data[DRM_FORMAT_MAX_PLANES]) 337 { 338 struct drm_gem_object *obj; 339 unsigned int i; 340 int ret; 341 342 for (i = 0; i < DRM_FORMAT_MAX_PLANES; ++i) { 343 obj = drm_gem_fb_get_obj(fb, i); 344 if (!obj) { 345 dma_buf_map_clear(&map[i]); 346 continue; 347 } 348 ret = drm_gem_vmap(obj, &map[i]); 349 if (ret) 350 goto err_drm_gem_vunmap; 351 } 352 353 if (data) { 354 for (i = 0; i < DRM_FORMAT_MAX_PLANES; ++i) { 355 memcpy(&data[i], &map[i], sizeof(data[i])); 356 if (dma_buf_map_is_null(&data[i])) 357 continue; 358 dma_buf_map_incr(&data[i], fb->offsets[i]); 359 } 360 } 361 362 return 0; 363 364 err_drm_gem_vunmap: 365 while (i) { 366 --i; 367 obj = drm_gem_fb_get_obj(fb, i); 368 if (!obj) 369 continue; 370 drm_gem_vunmap(obj, &map[i]); 371 } 372 return ret; 373 } 374 EXPORT_SYMBOL(drm_gem_fb_vmap); 375 376 /** 377 * drm_gem_fb_vunmap - unmaps framebuffer BOs from kernel address space 378 * @fb: the framebuffer 379 * @map: mapping addresses as returned by drm_gem_fb_vmap() 380 * 381 * This function unmaps all buffer objects of the given framebuffer. 382 * 383 * See drm_gem_fb_vmap() for more information. 384 */ 385 void drm_gem_fb_vunmap(struct drm_framebuffer *fb, 386 struct dma_buf_map map[static DRM_FORMAT_MAX_PLANES]) 387 { 388 unsigned int i = DRM_FORMAT_MAX_PLANES; 389 struct drm_gem_object *obj; 390 391 while (i) { 392 --i; 393 obj = drm_gem_fb_get_obj(fb, i); 394 if (!obj) 395 continue; 396 if (dma_buf_map_is_null(&map[i])) 397 continue; 398 drm_gem_vunmap(obj, &map[i]); 399 } 400 } 401 EXPORT_SYMBOL(drm_gem_fb_vunmap); 402 403 /** 404 * drm_gem_fb_begin_cpu_access - prepares GEM buffer objects for CPU access 405 * @fb: the framebuffer 406 * @dir: access mode 407 * 408 * Prepares a framebuffer's GEM buffer objects for CPU access. This function 409 * must be called before accessing the BO data within the kernel. For imported 410 * BOs, the function calls dma_buf_begin_cpu_access(). 411 * 412 * See drm_gem_fb_end_cpu_access() for signalling the end of CPU access. 413 * 414 * Returns: 415 * 0 on success, or a negative errno code otherwise. 416 */ 417 int drm_gem_fb_begin_cpu_access(struct drm_framebuffer *fb, enum dma_data_direction dir) 418 { 419 struct dma_buf_attachment *import_attach; 420 struct drm_gem_object *obj; 421 size_t i; 422 int ret, ret2; 423 424 for (i = 0; i < ARRAY_SIZE(fb->obj); ++i) { 425 obj = drm_gem_fb_get_obj(fb, i); 426 if (!obj) 427 continue; 428 import_attach = obj->import_attach; 429 if (!import_attach) 430 continue; 431 ret = dma_buf_begin_cpu_access(import_attach->dmabuf, dir); 432 if (ret) 433 goto err_dma_buf_end_cpu_access; 434 } 435 436 return 0; 437 438 err_dma_buf_end_cpu_access: 439 while (i) { 440 --i; 441 obj = drm_gem_fb_get_obj(fb, i); 442 if (!obj) 443 continue; 444 import_attach = obj->import_attach; 445 if (!import_attach) 446 continue; 447 ret2 = dma_buf_end_cpu_access(import_attach->dmabuf, dir); 448 if (ret2) { 449 drm_err(fb->dev, 450 "dma_buf_end_cpu_access() failed during error handling: %d\n", 451 ret2); 452 } 453 } 454 455 return ret; 456 } 457 EXPORT_SYMBOL(drm_gem_fb_begin_cpu_access); 458 459 /** 460 * drm_gem_fb_end_cpu_access - signals end of CPU access to GEM buffer objects 461 * @fb: the framebuffer 462 * @dir: access mode 463 * 464 * Signals the end of CPU access to the given framebuffer's GEM buffer objects. This 465 * function must be paired with a corresponding call to drm_gem_fb_begin_cpu_access(). 466 * For imported BOs, the function calls dma_buf_end_cpu_access(). 467 * 468 * See also drm_gem_fb_begin_cpu_access(). 469 */ 470 void drm_gem_fb_end_cpu_access(struct drm_framebuffer *fb, enum dma_data_direction dir) 471 { 472 size_t i = ARRAY_SIZE(fb->obj); 473 struct dma_buf_attachment *import_attach; 474 struct drm_gem_object *obj; 475 int ret; 476 477 while (i) { 478 --i; 479 obj = drm_gem_fb_get_obj(fb, i); 480 if (!obj) 481 continue; 482 import_attach = obj->import_attach; 483 if (!import_attach) 484 continue; 485 ret = dma_buf_end_cpu_access(import_attach->dmabuf, dir); 486 if (ret) 487 drm_err(fb->dev, "dma_buf_end_cpu_access() failed: %d\n", ret); 488 } 489 } 490 EXPORT_SYMBOL(drm_gem_fb_end_cpu_access); 491 492 static __u32 drm_gem_afbc_get_bpp(struct drm_device *dev, 493 const struct drm_mode_fb_cmd2 *mode_cmd) 494 { 495 const struct drm_format_info *info; 496 497 info = drm_get_format_info(dev, mode_cmd); 498 499 /* use whatever a driver has set */ 500 if (info->cpp[0]) 501 return info->cpp[0] * 8; 502 503 /* guess otherwise */ 504 switch (info->format) { 505 case DRM_FORMAT_YUV420_8BIT: 506 return 12; 507 case DRM_FORMAT_YUV420_10BIT: 508 return 15; 509 case DRM_FORMAT_VUY101010: 510 return 30; 511 default: 512 break; 513 } 514 515 /* all attempts failed */ 516 return 0; 517 } 518 519 static int drm_gem_afbc_min_size(struct drm_device *dev, 520 const struct drm_mode_fb_cmd2 *mode_cmd, 521 struct drm_afbc_framebuffer *afbc_fb) 522 { 523 __u32 n_blocks, w_alignment, h_alignment, hdr_alignment; 524 /* remove bpp when all users properly encode cpp in drm_format_info */ 525 __u32 bpp; 526 527 switch (mode_cmd->modifier[0] & AFBC_FORMAT_MOD_BLOCK_SIZE_MASK) { 528 case AFBC_FORMAT_MOD_BLOCK_SIZE_16x16: 529 afbc_fb->block_width = 16; 530 afbc_fb->block_height = 16; 531 break; 532 case AFBC_FORMAT_MOD_BLOCK_SIZE_32x8: 533 afbc_fb->block_width = 32; 534 afbc_fb->block_height = 8; 535 break; 536 /* no user exists yet - fall through */ 537 case AFBC_FORMAT_MOD_BLOCK_SIZE_64x4: 538 case AFBC_FORMAT_MOD_BLOCK_SIZE_32x8_64x4: 539 default: 540 drm_dbg_kms(dev, "Invalid AFBC_FORMAT_MOD_BLOCK_SIZE: %lld.\n", 541 mode_cmd->modifier[0] 542 & AFBC_FORMAT_MOD_BLOCK_SIZE_MASK); 543 return -EINVAL; 544 } 545 546 /* tiled header afbc */ 547 w_alignment = afbc_fb->block_width; 548 h_alignment = afbc_fb->block_height; 549 hdr_alignment = AFBC_HDR_ALIGN; 550 if (mode_cmd->modifier[0] & AFBC_FORMAT_MOD_TILED) { 551 w_alignment *= AFBC_TH_LAYOUT_ALIGNMENT; 552 h_alignment *= AFBC_TH_LAYOUT_ALIGNMENT; 553 hdr_alignment = AFBC_TH_BODY_START_ALIGNMENT; 554 } 555 556 afbc_fb->aligned_width = ALIGN(mode_cmd->width, w_alignment); 557 afbc_fb->aligned_height = ALIGN(mode_cmd->height, h_alignment); 558 afbc_fb->offset = mode_cmd->offsets[0]; 559 560 bpp = drm_gem_afbc_get_bpp(dev, mode_cmd); 561 if (!bpp) { 562 drm_dbg_kms(dev, "Invalid AFBC bpp value: %d\n", bpp); 563 return -EINVAL; 564 } 565 566 n_blocks = (afbc_fb->aligned_width * afbc_fb->aligned_height) 567 / AFBC_SUPERBLOCK_PIXELS; 568 afbc_fb->afbc_size = ALIGN(n_blocks * AFBC_HEADER_SIZE, hdr_alignment); 569 afbc_fb->afbc_size += n_blocks * ALIGN(bpp * AFBC_SUPERBLOCK_PIXELS / 8, 570 AFBC_SUPERBLOCK_ALIGNMENT); 571 572 return 0; 573 } 574 575 /** 576 * drm_gem_fb_afbc_init() - Helper function for drivers using afbc to 577 * fill and validate all the afbc-specific 578 * struct drm_afbc_framebuffer members 579 * 580 * @dev: DRM device 581 * @afbc_fb: afbc-specific framebuffer 582 * @mode_cmd: Metadata from the userspace framebuffer creation request 583 * @afbc_fb: afbc framebuffer 584 * 585 * This function can be used by drivers which support afbc to complete 586 * the preparation of struct drm_afbc_framebuffer. It must be called after 587 * allocating the said struct and calling drm_gem_fb_init_with_funcs(). 588 * It is caller's responsibility to put afbc_fb->base.obj objects in case 589 * the call is unsuccessful. 590 * 591 * Returns: 592 * Zero on success or a negative error value on failure. 593 */ 594 int drm_gem_fb_afbc_init(struct drm_device *dev, 595 const struct drm_mode_fb_cmd2 *mode_cmd, 596 struct drm_afbc_framebuffer *afbc_fb) 597 { 598 const struct drm_format_info *info; 599 struct drm_gem_object **objs; 600 int ret; 601 602 objs = afbc_fb->base.obj; 603 info = drm_get_format_info(dev, mode_cmd); 604 if (!info) 605 return -EINVAL; 606 607 ret = drm_gem_afbc_min_size(dev, mode_cmd, afbc_fb); 608 if (ret < 0) 609 return ret; 610 611 if (objs[0]->size < afbc_fb->afbc_size) 612 return -EINVAL; 613 614 return 0; 615 } 616 EXPORT_SYMBOL_GPL(drm_gem_fb_afbc_init); 617