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/dma-buf.h> 9 #include <linux/dma-fence.h> 10 #include <linux/dma-resv.h> 11 #include <linux/slab.h> 12 13 #include <drm/drm_atomic.h> 14 #include <drm/drm_atomic_uapi.h> 15 #include <drm/drm_damage_helper.h> 16 #include <drm/drm_fb_helper.h> 17 #include <drm/drm_fourcc.h> 18 #include <drm/drm_framebuffer.h> 19 #include <drm/drm_gem.h> 20 #include <drm/drm_gem_framebuffer_helper.h> 21 #include <drm/drm_modeset_helper.h> 22 #include <drm/drm_simple_kms_helper.h> 23 24 #define AFBC_HEADER_SIZE 16 25 #define AFBC_TH_LAYOUT_ALIGNMENT 8 26 #define AFBC_HDR_ALIGN 64 27 #define AFBC_SUPERBLOCK_PIXELS 256 28 #define AFBC_SUPERBLOCK_ALIGNMENT 128 29 #define AFBC_TH_BODY_START_ALIGNMENT 4096 30 31 /** 32 * DOC: overview 33 * 34 * This library provides helpers for drivers that don't subclass 35 * &drm_framebuffer and use &drm_gem_object for their backing storage. 36 * 37 * Drivers without additional needs to validate framebuffers can simply use 38 * drm_gem_fb_create() and everything is wired up automatically. Other drivers 39 * can use all parts independently. 40 */ 41 42 /** 43 * drm_gem_fb_get_obj() - Get GEM object backing the framebuffer 44 * @fb: Framebuffer 45 * @plane: Plane index 46 * 47 * No additional reference is taken beyond the one that the &drm_frambuffer 48 * already holds. 49 * 50 * Returns: 51 * Pointer to &drm_gem_object for the given framebuffer and plane index or NULL 52 * if it does not exist. 53 */ 54 struct drm_gem_object *drm_gem_fb_get_obj(struct drm_framebuffer *fb, 55 unsigned int plane) 56 { 57 if (plane >= 4) 58 return NULL; 59 60 return fb->obj[plane]; 61 } 62 EXPORT_SYMBOL_GPL(drm_gem_fb_get_obj); 63 64 static int 65 drm_gem_fb_init(struct drm_device *dev, 66 struct drm_framebuffer *fb, 67 const struct drm_mode_fb_cmd2 *mode_cmd, 68 struct drm_gem_object **obj, unsigned int num_planes, 69 const struct drm_framebuffer_funcs *funcs) 70 { 71 int ret, i; 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 int i; 96 97 for (i = 0; i < 4; 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[4]; 155 int ret, i; 156 157 info = drm_get_format_info(dev, mode_cmd); 158 if (!info) 159 return -EINVAL; 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_gem_object_put(objs[i]); 179 ret = -EINVAL; 180 goto err_gem_object_put; 181 } 182 } 183 184 ret = drm_gem_fb_init(dev, fb, mode_cmd, objs, i, funcs); 185 if (ret) 186 goto err_gem_object_put; 187 188 return 0; 189 190 err_gem_object_put: 191 for (i--; i >= 0; i--) 192 drm_gem_object_put(objs[i]); 193 194 return ret; 195 } 196 EXPORT_SYMBOL_GPL(drm_gem_fb_init_with_funcs); 197 198 /** 199 * drm_gem_fb_create_with_funcs() - Helper function for the 200 * &drm_mode_config_funcs.fb_create 201 * callback 202 * @dev: DRM device 203 * @file: DRM file that holds the GEM handle(s) backing the framebuffer 204 * @mode_cmd: Metadata from the userspace framebuffer creation request 205 * @funcs: vtable to be used for the new framebuffer object 206 * 207 * This function can be used to set &drm_framebuffer_funcs for drivers that need 208 * custom framebuffer callbacks. Use drm_gem_fb_create() if you don't need to 209 * change &drm_framebuffer_funcs. The function does buffer size validation. 210 * 211 * Returns: 212 * Pointer to a &drm_framebuffer on success or an error pointer on failure. 213 */ 214 struct drm_framebuffer * 215 drm_gem_fb_create_with_funcs(struct drm_device *dev, struct drm_file *file, 216 const struct drm_mode_fb_cmd2 *mode_cmd, 217 const struct drm_framebuffer_funcs *funcs) 218 { 219 struct drm_framebuffer *fb; 220 int ret; 221 222 fb = kzalloc(sizeof(*fb), GFP_KERNEL); 223 if (!fb) 224 return ERR_PTR(-ENOMEM); 225 226 ret = drm_gem_fb_init_with_funcs(dev, fb, file, mode_cmd, funcs); 227 if (ret) { 228 kfree(fb); 229 return ERR_PTR(ret); 230 } 231 232 return fb; 233 } 234 EXPORT_SYMBOL_GPL(drm_gem_fb_create_with_funcs); 235 236 static const struct drm_framebuffer_funcs drm_gem_fb_funcs = { 237 .destroy = drm_gem_fb_destroy, 238 .create_handle = drm_gem_fb_create_handle, 239 }; 240 241 /** 242 * drm_gem_fb_create() - Helper function for the 243 * &drm_mode_config_funcs.fb_create callback 244 * @dev: DRM device 245 * @file: DRM file that holds the GEM handle(s) backing the framebuffer 246 * @mode_cmd: Metadata from the userspace framebuffer creation request 247 * 248 * This function creates a new framebuffer object described by 249 * &drm_mode_fb_cmd2. This description includes handles for the buffer(s) 250 * backing the framebuffer. 251 * 252 * If your hardware has special alignment or pitch requirements these should be 253 * checked before calling this function. The function does buffer size 254 * validation. Use drm_gem_fb_create_with_dirty() if you need framebuffer 255 * flushing. 256 * 257 * Drivers can use this as their &drm_mode_config_funcs.fb_create callback. 258 * The ADDFB2 IOCTL calls into this callback. 259 * 260 * Returns: 261 * Pointer to a &drm_framebuffer on success or an error pointer on failure. 262 */ 263 struct drm_framebuffer * 264 drm_gem_fb_create(struct drm_device *dev, struct drm_file *file, 265 const struct drm_mode_fb_cmd2 *mode_cmd) 266 { 267 return drm_gem_fb_create_with_funcs(dev, file, mode_cmd, 268 &drm_gem_fb_funcs); 269 } 270 EXPORT_SYMBOL_GPL(drm_gem_fb_create); 271 272 static const struct drm_framebuffer_funcs drm_gem_fb_funcs_dirtyfb = { 273 .destroy = drm_gem_fb_destroy, 274 .create_handle = drm_gem_fb_create_handle, 275 .dirty = drm_atomic_helper_dirtyfb, 276 }; 277 278 /** 279 * drm_gem_fb_create_with_dirty() - Helper function for the 280 * &drm_mode_config_funcs.fb_create callback 281 * @dev: DRM device 282 * @file: DRM file that holds the GEM handle(s) backing the framebuffer 283 * @mode_cmd: Metadata from the userspace framebuffer creation request 284 * 285 * This function creates a new framebuffer object described by 286 * &drm_mode_fb_cmd2. This description includes handles for the buffer(s) 287 * backing the framebuffer. drm_atomic_helper_dirtyfb() is used for the dirty 288 * callback giving framebuffer flushing through the atomic machinery. Use 289 * drm_gem_fb_create() if you don't need the dirty callback. 290 * The function does buffer size validation. 291 * 292 * Drivers should also call drm_plane_enable_fb_damage_clips() on all planes 293 * to enable userspace to use damage clips also with the ATOMIC IOCTL. 294 * 295 * Drivers can use this as their &drm_mode_config_funcs.fb_create callback. 296 * The ADDFB2 IOCTL calls into this callback. 297 * 298 * Returns: 299 * Pointer to a &drm_framebuffer on success or an error pointer on failure. 300 */ 301 struct drm_framebuffer * 302 drm_gem_fb_create_with_dirty(struct drm_device *dev, struct drm_file *file, 303 const struct drm_mode_fb_cmd2 *mode_cmd) 304 { 305 return drm_gem_fb_create_with_funcs(dev, file, mode_cmd, 306 &drm_gem_fb_funcs_dirtyfb); 307 } 308 EXPORT_SYMBOL_GPL(drm_gem_fb_create_with_dirty); 309 310 static __u32 drm_gem_afbc_get_bpp(struct drm_device *dev, 311 const struct drm_mode_fb_cmd2 *mode_cmd) 312 { 313 const struct drm_format_info *info; 314 315 info = drm_get_format_info(dev, mode_cmd); 316 317 /* use whatever a driver has set */ 318 if (info->cpp[0]) 319 return info->cpp[0] * 8; 320 321 /* guess otherwise */ 322 switch (info->format) { 323 case DRM_FORMAT_YUV420_8BIT: 324 return 12; 325 case DRM_FORMAT_YUV420_10BIT: 326 return 15; 327 case DRM_FORMAT_VUY101010: 328 return 30; 329 default: 330 break; 331 } 332 333 /* all attempts failed */ 334 return 0; 335 } 336 337 static int drm_gem_afbc_min_size(struct drm_device *dev, 338 const struct drm_mode_fb_cmd2 *mode_cmd, 339 struct drm_afbc_framebuffer *afbc_fb) 340 { 341 __u32 n_blocks, w_alignment, h_alignment, hdr_alignment; 342 /* remove bpp when all users properly encode cpp in drm_format_info */ 343 __u32 bpp; 344 345 switch (mode_cmd->modifier[0] & AFBC_FORMAT_MOD_BLOCK_SIZE_MASK) { 346 case AFBC_FORMAT_MOD_BLOCK_SIZE_16x16: 347 afbc_fb->block_width = 16; 348 afbc_fb->block_height = 16; 349 break; 350 case AFBC_FORMAT_MOD_BLOCK_SIZE_32x8: 351 afbc_fb->block_width = 32; 352 afbc_fb->block_height = 8; 353 break; 354 /* no user exists yet - fall through */ 355 case AFBC_FORMAT_MOD_BLOCK_SIZE_64x4: 356 case AFBC_FORMAT_MOD_BLOCK_SIZE_32x8_64x4: 357 default: 358 drm_dbg_kms(dev, "Invalid AFBC_FORMAT_MOD_BLOCK_SIZE: %lld.\n", 359 mode_cmd->modifier[0] 360 & AFBC_FORMAT_MOD_BLOCK_SIZE_MASK); 361 return -EINVAL; 362 } 363 364 /* tiled header afbc */ 365 w_alignment = afbc_fb->block_width; 366 h_alignment = afbc_fb->block_height; 367 hdr_alignment = AFBC_HDR_ALIGN; 368 if (mode_cmd->modifier[0] & AFBC_FORMAT_MOD_TILED) { 369 w_alignment *= AFBC_TH_LAYOUT_ALIGNMENT; 370 h_alignment *= AFBC_TH_LAYOUT_ALIGNMENT; 371 hdr_alignment = AFBC_TH_BODY_START_ALIGNMENT; 372 } 373 374 afbc_fb->aligned_width = ALIGN(mode_cmd->width, w_alignment); 375 afbc_fb->aligned_height = ALIGN(mode_cmd->height, h_alignment); 376 afbc_fb->offset = mode_cmd->offsets[0]; 377 378 bpp = drm_gem_afbc_get_bpp(dev, mode_cmd); 379 if (!bpp) { 380 drm_dbg_kms(dev, "Invalid AFBC bpp value: %d\n", bpp); 381 return -EINVAL; 382 } 383 384 n_blocks = (afbc_fb->aligned_width * afbc_fb->aligned_height) 385 / AFBC_SUPERBLOCK_PIXELS; 386 afbc_fb->afbc_size = ALIGN(n_blocks * AFBC_HEADER_SIZE, hdr_alignment); 387 afbc_fb->afbc_size += n_blocks * ALIGN(bpp * AFBC_SUPERBLOCK_PIXELS / 8, 388 AFBC_SUPERBLOCK_ALIGNMENT); 389 390 return 0; 391 } 392 393 /** 394 * drm_gem_fb_afbc_init() - Helper function for drivers using afbc to 395 * fill and validate all the afbc-specific 396 * struct drm_afbc_framebuffer members 397 * 398 * @dev: DRM device 399 * @afbc_fb: afbc-specific framebuffer 400 * @mode_cmd: Metadata from the userspace framebuffer creation request 401 * @afbc_fb: afbc framebuffer 402 * 403 * This function can be used by drivers which support afbc to complete 404 * the preparation of struct drm_afbc_framebuffer. It must be called after 405 * allocating the said struct and calling drm_gem_fb_init_with_funcs(). 406 * It is caller's responsibility to put afbc_fb->base.obj objects in case 407 * the call is unsuccessful. 408 * 409 * Returns: 410 * Zero on success or a negative error value on failure. 411 */ 412 int drm_gem_fb_afbc_init(struct drm_device *dev, 413 const struct drm_mode_fb_cmd2 *mode_cmd, 414 struct drm_afbc_framebuffer *afbc_fb) 415 { 416 const struct drm_format_info *info; 417 struct drm_gem_object **objs; 418 int ret; 419 420 objs = afbc_fb->base.obj; 421 info = drm_get_format_info(dev, mode_cmd); 422 if (!info) 423 return -EINVAL; 424 425 ret = drm_gem_afbc_min_size(dev, mode_cmd, afbc_fb); 426 if (ret < 0) 427 return ret; 428 429 if (objs[0]->size < afbc_fb->afbc_size) 430 return -EINVAL; 431 432 return 0; 433 } 434 EXPORT_SYMBOL_GPL(drm_gem_fb_afbc_init); 435 436 /** 437 * drm_gem_fb_prepare_fb() - Prepare a GEM backed framebuffer 438 * @plane: Plane 439 * @state: Plane state the fence will be attached to 440 * 441 * This function extracts the exclusive fence from &drm_gem_object.resv and 442 * attaches it to plane state for the atomic helper to wait on. This is 443 * necessary to correctly implement implicit synchronization for any buffers 444 * shared as a struct &dma_buf. This function can be used as the 445 * &drm_plane_helper_funcs.prepare_fb callback. 446 * 447 * There is no need for &drm_plane_helper_funcs.cleanup_fb hook for simple 448 * gem based framebuffer drivers which have their buffers always pinned in 449 * memory. 450 * 451 * See drm_atomic_set_fence_for_plane() for a discussion of implicit and 452 * explicit fencing in atomic modeset updates. 453 */ 454 int drm_gem_fb_prepare_fb(struct drm_plane *plane, 455 struct drm_plane_state *state) 456 { 457 struct drm_gem_object *obj; 458 struct dma_fence *fence; 459 460 if (!state->fb) 461 return 0; 462 463 obj = drm_gem_fb_get_obj(state->fb, 0); 464 fence = dma_resv_get_excl_rcu(obj->resv); 465 drm_atomic_set_fence_for_plane(state, fence); 466 467 return 0; 468 } 469 EXPORT_SYMBOL_GPL(drm_gem_fb_prepare_fb); 470 471 /** 472 * drm_gem_fb_simple_display_pipe_prepare_fb - prepare_fb helper for 473 * &drm_simple_display_pipe 474 * @pipe: Simple display pipe 475 * @plane_state: Plane state 476 * 477 * This function uses drm_gem_fb_prepare_fb() to extract the exclusive fence 478 * from &drm_gem_object.resv and attaches it to plane state for the atomic 479 * helper to wait on. This is necessary to correctly implement implicit 480 * synchronization for any buffers shared as a struct &dma_buf. Drivers can use 481 * this as their &drm_simple_display_pipe_funcs.prepare_fb callback. 482 * 483 * See drm_atomic_set_fence_for_plane() for a discussion of implicit and 484 * explicit fencing in atomic modeset updates. 485 */ 486 int drm_gem_fb_simple_display_pipe_prepare_fb(struct drm_simple_display_pipe *pipe, 487 struct drm_plane_state *plane_state) 488 { 489 return drm_gem_fb_prepare_fb(&pipe->plane, plane_state); 490 } 491 EXPORT_SYMBOL(drm_gem_fb_simple_display_pipe_prepare_fb); 492