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