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 #include <linux/module.h> 10 11 #include <drm/drm_damage_helper.h> 12 #include <drm/drm_fb_helper.h> 13 #include <drm/drm_fourcc.h> 14 #include <drm/drm_framebuffer.h> 15 #include <drm/drm_gem.h> 16 #include <drm/drm_gem_framebuffer_helper.h> 17 #include <drm/drm_modeset_helper.h> 18 19 #include "drm_internal.h" 20 21 MODULE_IMPORT_NS(DMA_BUF); 22 23 #define AFBC_HEADER_SIZE 16 24 #define AFBC_TH_LAYOUT_ALIGNMENT 8 25 #define AFBC_HDR_ALIGN 64 26 #define AFBC_SUPERBLOCK_PIXELS 256 27 #define AFBC_SUPERBLOCK_ALIGNMENT 128 28 #define AFBC_TH_BODY_START_ALIGNMENT 4096 29 30 /** 31 * DOC: overview 32 * 33 * This library provides helpers for drivers that don't subclass 34 * &drm_framebuffer and use &drm_gem_object for their backing storage. 35 * 36 * Drivers without additional needs to validate framebuffers can simply use 37 * drm_gem_fb_create() and everything is wired up automatically. Other drivers 38 * can use all parts independently. 39 */ 40 41 /** 42 * drm_gem_fb_get_obj() - Get GEM object backing the framebuffer 43 * @fb: Framebuffer 44 * @plane: Plane index 45 * 46 * No additional reference is taken beyond the one that the &drm_frambuffer 47 * already holds. 48 * 49 * Returns: 50 * Pointer to &drm_gem_object for the given framebuffer and plane index or NULL 51 * if it does not exist. 52 */ 53 struct drm_gem_object *drm_gem_fb_get_obj(struct drm_framebuffer *fb, 54 unsigned int plane) 55 { 56 if (plane >= ARRAY_SIZE(fb->obj)) 57 return NULL; 58 59 return fb->obj[plane]; 60 } 61 EXPORT_SYMBOL_GPL(drm_gem_fb_get_obj); 62 63 static int 64 drm_gem_fb_init(struct drm_device *dev, 65 struct drm_framebuffer *fb, 66 const struct drm_mode_fb_cmd2 *mode_cmd, 67 struct drm_gem_object **obj, unsigned int num_planes, 68 const struct drm_framebuffer_funcs *funcs) 69 { 70 unsigned int i; 71 int ret; 72 73 drm_helper_mode_fill_fb_struct(dev, fb, mode_cmd); 74 75 for (i = 0; i < num_planes; i++) 76 fb->obj[i] = obj[i]; 77 78 ret = drm_framebuffer_init(dev, fb, funcs); 79 if (ret) 80 drm_err(dev, "Failed to init framebuffer: %d\n", ret); 81 82 return ret; 83 } 84 85 /** 86 * drm_gem_fb_destroy - Free GEM backed framebuffer 87 * @fb: Framebuffer 88 * 89 * Frees a GEM backed framebuffer with its backing buffer(s) and the structure 90 * itself. Drivers can use this as their &drm_framebuffer_funcs->destroy 91 * callback. 92 */ 93 void drm_gem_fb_destroy(struct drm_framebuffer *fb) 94 { 95 size_t i; 96 97 for (i = 0; i < ARRAY_SIZE(fb->obj); i++) 98 drm_gem_object_put(fb->obj[i]); 99 100 drm_framebuffer_cleanup(fb); 101 kfree(fb); 102 } 103 EXPORT_SYMBOL(drm_gem_fb_destroy); 104 105 /** 106 * drm_gem_fb_create_handle - Create handle for GEM backed framebuffer 107 * @fb: Framebuffer 108 * @file: DRM file to register the handle for 109 * @handle: Pointer to return the created handle 110 * 111 * This function creates a handle for the GEM object backing the framebuffer. 112 * Drivers can use this as their &drm_framebuffer_funcs->create_handle 113 * callback. The GETFB IOCTL calls into this callback. 114 * 115 * Returns: 116 * 0 on success or a negative error code on failure. 117 */ 118 int drm_gem_fb_create_handle(struct drm_framebuffer *fb, struct drm_file *file, 119 unsigned int *handle) 120 { 121 return drm_gem_handle_create(file, fb->obj[0], handle); 122 } 123 EXPORT_SYMBOL(drm_gem_fb_create_handle); 124 125 /** 126 * drm_gem_fb_init_with_funcs() - Helper function for implementing 127 * &drm_mode_config_funcs.fb_create 128 * callback in cases when the driver 129 * allocates a subclass of 130 * struct drm_framebuffer 131 * @dev: DRM device 132 * @fb: framebuffer object 133 * @file: DRM file that holds the GEM handle(s) backing the framebuffer 134 * @mode_cmd: Metadata from the userspace framebuffer creation request 135 * @funcs: vtable to be used for the new framebuffer object 136 * 137 * This function can be used to set &drm_framebuffer_funcs for drivers that need 138 * custom framebuffer callbacks. Use drm_gem_fb_create() if you don't need to 139 * change &drm_framebuffer_funcs. The function does buffer size validation. 140 * The buffer size validation is for a general case, though, so users should 141 * pay attention to the checks being appropriate for them or, at least, 142 * non-conflicting. 143 * 144 * Returns: 145 * Zero or a negative error code. 146 */ 147 int drm_gem_fb_init_with_funcs(struct drm_device *dev, 148 struct drm_framebuffer *fb, 149 struct drm_file *file, 150 const struct drm_mode_fb_cmd2 *mode_cmd, 151 const struct drm_framebuffer_funcs *funcs) 152 { 153 const struct drm_format_info *info; 154 struct drm_gem_object *objs[DRM_FORMAT_MAX_PLANES]; 155 unsigned int i; 156 int ret; 157 158 info = drm_get_format_info(dev, mode_cmd); 159 if (!info) { 160 drm_dbg_kms(dev, "Failed to get FB format info\n"); 161 return -EINVAL; 162 } 163 164 for (i = 0; i < info->num_planes; i++) { 165 unsigned int width = mode_cmd->width / (i ? info->hsub : 1); 166 unsigned int height = mode_cmd->height / (i ? info->vsub : 1); 167 unsigned int min_size; 168 169 objs[i] = drm_gem_object_lookup(file, mode_cmd->handles[i]); 170 if (!objs[i]) { 171 drm_dbg_kms(dev, "Failed to lookup GEM object\n"); 172 ret = -ENOENT; 173 goto err_gem_object_put; 174 } 175 176 min_size = (height - 1) * mode_cmd->pitches[i] 177 + drm_format_info_min_pitch(info, i, width) 178 + mode_cmd->offsets[i]; 179 180 if (objs[i]->size < min_size) { 181 drm_dbg_kms(dev, 182 "GEM object size (%zu) smaller than minimum size (%u) for plane %d\n", 183 objs[i]->size, min_size, i); 184 drm_gem_object_put(objs[i]); 185 ret = -EINVAL; 186 goto err_gem_object_put; 187 } 188 } 189 190 ret = drm_gem_fb_init(dev, fb, mode_cmd, objs, i, funcs); 191 if (ret) 192 goto err_gem_object_put; 193 194 return 0; 195 196 err_gem_object_put: 197 while (i > 0) { 198 --i; 199 drm_gem_object_put(objs[i]); 200 } 201 return ret; 202 } 203 EXPORT_SYMBOL_GPL(drm_gem_fb_init_with_funcs); 204 205 /** 206 * drm_gem_fb_create_with_funcs() - Helper function for the 207 * &drm_mode_config_funcs.fb_create 208 * callback 209 * @dev: DRM device 210 * @file: DRM file that holds the GEM handle(s) backing the framebuffer 211 * @mode_cmd: Metadata from the userspace framebuffer creation request 212 * @funcs: vtable to be used for the new framebuffer object 213 * 214 * This function can be used to set &drm_framebuffer_funcs for drivers that need 215 * custom framebuffer callbacks. Use drm_gem_fb_create() if you don't need to 216 * change &drm_framebuffer_funcs. The function does buffer size validation. 217 * 218 * Returns: 219 * Pointer to a &drm_framebuffer on success or an error pointer on failure. 220 */ 221 struct drm_framebuffer * 222 drm_gem_fb_create_with_funcs(struct drm_device *dev, struct drm_file *file, 223 const struct drm_mode_fb_cmd2 *mode_cmd, 224 const struct drm_framebuffer_funcs *funcs) 225 { 226 struct drm_framebuffer *fb; 227 int ret; 228 229 fb = kzalloc(sizeof(*fb), GFP_KERNEL); 230 if (!fb) 231 return ERR_PTR(-ENOMEM); 232 233 ret = drm_gem_fb_init_with_funcs(dev, fb, file, mode_cmd, funcs); 234 if (ret) { 235 kfree(fb); 236 return ERR_PTR(ret); 237 } 238 239 return fb; 240 } 241 EXPORT_SYMBOL_GPL(drm_gem_fb_create_with_funcs); 242 243 static const struct drm_framebuffer_funcs drm_gem_fb_funcs = { 244 .destroy = drm_gem_fb_destroy, 245 .create_handle = drm_gem_fb_create_handle, 246 }; 247 248 /** 249 * drm_gem_fb_create() - Helper function for the 250 * &drm_mode_config_funcs.fb_create callback 251 * @dev: DRM device 252 * @file: DRM file that holds the GEM handle(s) backing the framebuffer 253 * @mode_cmd: Metadata from the userspace framebuffer creation request 254 * 255 * This function creates a new framebuffer object described by 256 * &drm_mode_fb_cmd2. This description includes handles for the buffer(s) 257 * backing the framebuffer. 258 * 259 * If your hardware has special alignment or pitch requirements these should be 260 * checked before calling this function. The function does buffer size 261 * validation. Use drm_gem_fb_create_with_dirty() if you need framebuffer 262 * flushing. 263 * 264 * Drivers can use this as their &drm_mode_config_funcs.fb_create callback. 265 * The ADDFB2 IOCTL calls into this callback. 266 * 267 * Returns: 268 * Pointer to a &drm_framebuffer on success or an error pointer on failure. 269 */ 270 struct drm_framebuffer * 271 drm_gem_fb_create(struct drm_device *dev, struct drm_file *file, 272 const struct drm_mode_fb_cmd2 *mode_cmd) 273 { 274 return drm_gem_fb_create_with_funcs(dev, file, mode_cmd, 275 &drm_gem_fb_funcs); 276 } 277 EXPORT_SYMBOL_GPL(drm_gem_fb_create); 278 279 static const struct drm_framebuffer_funcs drm_gem_fb_funcs_dirtyfb = { 280 .destroy = drm_gem_fb_destroy, 281 .create_handle = drm_gem_fb_create_handle, 282 .dirty = drm_atomic_helper_dirtyfb, 283 }; 284 285 /** 286 * drm_gem_fb_create_with_dirty() - Helper function for the 287 * &drm_mode_config_funcs.fb_create callback 288 * @dev: DRM device 289 * @file: DRM file that holds the GEM handle(s) backing the framebuffer 290 * @mode_cmd: Metadata from the userspace framebuffer creation request 291 * 292 * This function creates a new framebuffer object described by 293 * &drm_mode_fb_cmd2. This description includes handles for the buffer(s) 294 * backing the framebuffer. drm_atomic_helper_dirtyfb() is used for the dirty 295 * callback giving framebuffer flushing through the atomic machinery. Use 296 * drm_gem_fb_create() if you don't need the dirty callback. 297 * The function does buffer size validation. 298 * 299 * Drivers should also call drm_plane_enable_fb_damage_clips() on all planes 300 * to enable userspace to use damage clips also with the ATOMIC IOCTL. 301 * 302 * Drivers can use this as their &drm_mode_config_funcs.fb_create callback. 303 * The ADDFB2 IOCTL calls into this callback. 304 * 305 * Returns: 306 * Pointer to a &drm_framebuffer on success or an error pointer on failure. 307 */ 308 struct drm_framebuffer * 309 drm_gem_fb_create_with_dirty(struct drm_device *dev, struct drm_file *file, 310 const struct drm_mode_fb_cmd2 *mode_cmd) 311 { 312 return drm_gem_fb_create_with_funcs(dev, file, mode_cmd, 313 &drm_gem_fb_funcs_dirtyfb); 314 } 315 EXPORT_SYMBOL_GPL(drm_gem_fb_create_with_dirty); 316 317 /** 318 * drm_gem_fb_vmap - maps all framebuffer BOs into kernel address space 319 * @fb: the framebuffer 320 * @map: returns the mapping's address for each BO 321 * @data: returns the data address for each BO, can be NULL 322 * 323 * This function maps all buffer objects of the given framebuffer into 324 * kernel address space and stores them in struct iosys_map. If the 325 * mapping operation fails for one of the BOs, the function unmaps the 326 * already established mappings automatically. 327 * 328 * Callers that want to access a BO's stored data should pass @data. 329 * The argument returns the addresses of the data stored in each BO. This 330 * is different from @map if the framebuffer's offsets field is non-zero. 331 * 332 * See drm_gem_fb_vunmap() for unmapping. 333 * 334 * Returns: 335 * 0 on success, or a negative errno code otherwise. 336 */ 337 int drm_gem_fb_vmap(struct drm_framebuffer *fb, 338 struct iosys_map map[static DRM_FORMAT_MAX_PLANES], 339 struct iosys_map data[DRM_FORMAT_MAX_PLANES]) 340 { 341 struct drm_gem_object *obj; 342 unsigned int i; 343 int ret; 344 345 for (i = 0; i < DRM_FORMAT_MAX_PLANES; ++i) { 346 obj = drm_gem_fb_get_obj(fb, i); 347 if (!obj) { 348 iosys_map_clear(&map[i]); 349 continue; 350 } 351 ret = drm_gem_vmap(obj, &map[i]); 352 if (ret) 353 goto err_drm_gem_vunmap; 354 } 355 356 if (data) { 357 for (i = 0; i < DRM_FORMAT_MAX_PLANES; ++i) { 358 memcpy(&data[i], &map[i], sizeof(data[i])); 359 if (iosys_map_is_null(&data[i])) 360 continue; 361 iosys_map_incr(&data[i], fb->offsets[i]); 362 } 363 } 364 365 return 0; 366 367 err_drm_gem_vunmap: 368 while (i) { 369 --i; 370 obj = drm_gem_fb_get_obj(fb, i); 371 if (!obj) 372 continue; 373 drm_gem_vunmap(obj, &map[i]); 374 } 375 return ret; 376 } 377 EXPORT_SYMBOL(drm_gem_fb_vmap); 378 379 /** 380 * drm_gem_fb_vunmap - unmaps framebuffer BOs from kernel address space 381 * @fb: the framebuffer 382 * @map: mapping addresses as returned by drm_gem_fb_vmap() 383 * 384 * This function unmaps all buffer objects of the given framebuffer. 385 * 386 * See drm_gem_fb_vmap() for more information. 387 */ 388 void drm_gem_fb_vunmap(struct drm_framebuffer *fb, 389 struct iosys_map map[static DRM_FORMAT_MAX_PLANES]) 390 { 391 unsigned int i = DRM_FORMAT_MAX_PLANES; 392 struct drm_gem_object *obj; 393 394 while (i) { 395 --i; 396 obj = drm_gem_fb_get_obj(fb, i); 397 if (!obj) 398 continue; 399 if (iosys_map_is_null(&map[i])) 400 continue; 401 drm_gem_vunmap(obj, &map[i]); 402 } 403 } 404 EXPORT_SYMBOL(drm_gem_fb_vunmap); 405 406 /** 407 * drm_gem_fb_begin_cpu_access - prepares GEM buffer objects for CPU access 408 * @fb: the framebuffer 409 * @dir: access mode 410 * 411 * Prepares a framebuffer's GEM buffer objects for CPU access. This function 412 * must be called before accessing the BO data within the kernel. For imported 413 * BOs, the function calls dma_buf_begin_cpu_access(). 414 * 415 * See drm_gem_fb_end_cpu_access() for signalling the end of CPU access. 416 * 417 * Returns: 418 * 0 on success, or a negative errno code otherwise. 419 */ 420 int drm_gem_fb_begin_cpu_access(struct drm_framebuffer *fb, enum dma_data_direction dir) 421 { 422 struct dma_buf_attachment *import_attach; 423 struct drm_gem_object *obj; 424 size_t i; 425 int ret, ret2; 426 427 for (i = 0; i < ARRAY_SIZE(fb->obj); ++i) { 428 obj = drm_gem_fb_get_obj(fb, i); 429 if (!obj) 430 continue; 431 import_attach = obj->import_attach; 432 if (!import_attach) 433 continue; 434 ret = dma_buf_begin_cpu_access(import_attach->dmabuf, dir); 435 if (ret) 436 goto err_dma_buf_end_cpu_access; 437 } 438 439 return 0; 440 441 err_dma_buf_end_cpu_access: 442 while (i) { 443 --i; 444 obj = drm_gem_fb_get_obj(fb, i); 445 if (!obj) 446 continue; 447 import_attach = obj->import_attach; 448 if (!import_attach) 449 continue; 450 ret2 = dma_buf_end_cpu_access(import_attach->dmabuf, dir); 451 if (ret2) { 452 drm_err(fb->dev, 453 "dma_buf_end_cpu_access() failed during error handling: %d\n", 454 ret2); 455 } 456 } 457 458 return ret; 459 } 460 EXPORT_SYMBOL(drm_gem_fb_begin_cpu_access); 461 462 /** 463 * drm_gem_fb_end_cpu_access - signals end of CPU access to GEM buffer objects 464 * @fb: the framebuffer 465 * @dir: access mode 466 * 467 * Signals the end of CPU access to the given framebuffer's GEM buffer objects. This 468 * function must be paired with a corresponding call to drm_gem_fb_begin_cpu_access(). 469 * For imported BOs, the function calls dma_buf_end_cpu_access(). 470 * 471 * See also drm_gem_fb_begin_cpu_access(). 472 */ 473 void drm_gem_fb_end_cpu_access(struct drm_framebuffer *fb, enum dma_data_direction dir) 474 { 475 size_t i = ARRAY_SIZE(fb->obj); 476 struct dma_buf_attachment *import_attach; 477 struct drm_gem_object *obj; 478 int ret; 479 480 while (i) { 481 --i; 482 obj = drm_gem_fb_get_obj(fb, i); 483 if (!obj) 484 continue; 485 import_attach = obj->import_attach; 486 if (!import_attach) 487 continue; 488 ret = dma_buf_end_cpu_access(import_attach->dmabuf, dir); 489 if (ret) 490 drm_err(fb->dev, "dma_buf_end_cpu_access() failed: %d\n", ret); 491 } 492 } 493 EXPORT_SYMBOL(drm_gem_fb_end_cpu_access); 494 495 static __u32 drm_gem_afbc_get_bpp(struct drm_device *dev, 496 const struct drm_mode_fb_cmd2 *mode_cmd) 497 { 498 const struct drm_format_info *info; 499 500 info = drm_get_format_info(dev, mode_cmd); 501 502 /* use whatever a driver has set */ 503 if (info->cpp[0]) 504 return info->cpp[0] * 8; 505 506 /* guess otherwise */ 507 switch (info->format) { 508 case DRM_FORMAT_YUV420_8BIT: 509 return 12; 510 case DRM_FORMAT_YUV420_10BIT: 511 return 15; 512 case DRM_FORMAT_VUY101010: 513 return 30; 514 default: 515 break; 516 } 517 518 /* all attempts failed */ 519 return 0; 520 } 521 522 static int drm_gem_afbc_min_size(struct drm_device *dev, 523 const struct drm_mode_fb_cmd2 *mode_cmd, 524 struct drm_afbc_framebuffer *afbc_fb) 525 { 526 __u32 n_blocks, w_alignment, h_alignment, hdr_alignment; 527 /* remove bpp when all users properly encode cpp in drm_format_info */ 528 __u32 bpp; 529 530 switch (mode_cmd->modifier[0] & AFBC_FORMAT_MOD_BLOCK_SIZE_MASK) { 531 case AFBC_FORMAT_MOD_BLOCK_SIZE_16x16: 532 afbc_fb->block_width = 16; 533 afbc_fb->block_height = 16; 534 break; 535 case AFBC_FORMAT_MOD_BLOCK_SIZE_32x8: 536 afbc_fb->block_width = 32; 537 afbc_fb->block_height = 8; 538 break; 539 /* no user exists yet - fall through */ 540 case AFBC_FORMAT_MOD_BLOCK_SIZE_64x4: 541 case AFBC_FORMAT_MOD_BLOCK_SIZE_32x8_64x4: 542 default: 543 drm_dbg_kms(dev, "Invalid AFBC_FORMAT_MOD_BLOCK_SIZE: %lld.\n", 544 mode_cmd->modifier[0] 545 & AFBC_FORMAT_MOD_BLOCK_SIZE_MASK); 546 return -EINVAL; 547 } 548 549 /* tiled header afbc */ 550 w_alignment = afbc_fb->block_width; 551 h_alignment = afbc_fb->block_height; 552 hdr_alignment = AFBC_HDR_ALIGN; 553 if (mode_cmd->modifier[0] & AFBC_FORMAT_MOD_TILED) { 554 w_alignment *= AFBC_TH_LAYOUT_ALIGNMENT; 555 h_alignment *= AFBC_TH_LAYOUT_ALIGNMENT; 556 hdr_alignment = AFBC_TH_BODY_START_ALIGNMENT; 557 } 558 559 afbc_fb->aligned_width = ALIGN(mode_cmd->width, w_alignment); 560 afbc_fb->aligned_height = ALIGN(mode_cmd->height, h_alignment); 561 afbc_fb->offset = mode_cmd->offsets[0]; 562 563 bpp = drm_gem_afbc_get_bpp(dev, mode_cmd); 564 if (!bpp) { 565 drm_dbg_kms(dev, "Invalid AFBC bpp value: %d\n", bpp); 566 return -EINVAL; 567 } 568 569 n_blocks = (afbc_fb->aligned_width * afbc_fb->aligned_height) 570 / AFBC_SUPERBLOCK_PIXELS; 571 afbc_fb->afbc_size = ALIGN(n_blocks * AFBC_HEADER_SIZE, hdr_alignment); 572 afbc_fb->afbc_size += n_blocks * ALIGN(bpp * AFBC_SUPERBLOCK_PIXELS / 8, 573 AFBC_SUPERBLOCK_ALIGNMENT); 574 575 return 0; 576 } 577 578 /** 579 * drm_gem_fb_afbc_init() - Helper function for drivers using afbc to 580 * fill and validate all the afbc-specific 581 * struct drm_afbc_framebuffer members 582 * 583 * @dev: DRM device 584 * @afbc_fb: afbc-specific framebuffer 585 * @mode_cmd: Metadata from the userspace framebuffer creation request 586 * @afbc_fb: afbc framebuffer 587 * 588 * This function can be used by drivers which support afbc to complete 589 * the preparation of struct drm_afbc_framebuffer. It must be called after 590 * allocating the said struct and calling drm_gem_fb_init_with_funcs(). 591 * It is caller's responsibility to put afbc_fb->base.obj objects in case 592 * the call is unsuccessful. 593 * 594 * Returns: 595 * Zero on success or a negative error value on failure. 596 */ 597 int drm_gem_fb_afbc_init(struct drm_device *dev, 598 const struct drm_mode_fb_cmd2 *mode_cmd, 599 struct drm_afbc_framebuffer *afbc_fb) 600 { 601 const struct drm_format_info *info; 602 struct drm_gem_object **objs; 603 int ret; 604 605 objs = afbc_fb->base.obj; 606 info = drm_get_format_info(dev, mode_cmd); 607 if (!info) 608 return -EINVAL; 609 610 ret = drm_gem_afbc_min_size(dev, mode_cmd, afbc_fb); 611 if (ret < 0) 612 return ret; 613 614 if (objs[0]->size < afbc_fb->afbc_size) 615 return -EINVAL; 616 617 return 0; 618 } 619 EXPORT_SYMBOL_GPL(drm_gem_fb_afbc_init); 620