1 // SPDX-License-Identifier: GPL-2.0-or-later 2 3 #include <linux/iosys-map.h> 4 #include <linux/module.h> 5 6 #include <drm/drm_debugfs.h> 7 #include <drm/drm_device.h> 8 #include <drm/drm_drv.h> 9 #include <drm/drm_file.h> 10 #include <drm/drm_framebuffer.h> 11 #include <drm/drm_gem_atomic_helper.h> 12 #include <drm/drm_gem_ttm_helper.h> 13 #include <drm/drm_gem_vram_helper.h> 14 #include <drm/drm_managed.h> 15 #include <drm/drm_mode.h> 16 #include <drm/drm_plane.h> 17 #include <drm/drm_prime.h> 18 #include <drm/drm_simple_kms_helper.h> 19 20 #include <drm/ttm/ttm_range_manager.h> 21 22 static const struct drm_gem_object_funcs drm_gem_vram_object_funcs; 23 24 /** 25 * DOC: overview 26 * 27 * This library provides &struct drm_gem_vram_object (GEM VRAM), a GEM 28 * buffer object that is backed by video RAM (VRAM). It can be used for 29 * framebuffer devices with dedicated memory. 30 * 31 * The data structure &struct drm_vram_mm and its helpers implement a memory 32 * manager for simple framebuffer devices with dedicated video memory. GEM 33 * VRAM buffer objects are either placed in the video memory or remain evicted 34 * to system memory. 35 * 36 * With the GEM interface userspace applications create, manage and destroy 37 * graphics buffers, such as an on-screen framebuffer. GEM does not provide 38 * an implementation of these interfaces. It's up to the DRM driver to 39 * provide an implementation that suits the hardware. If the hardware device 40 * contains dedicated video memory, the DRM driver can use the VRAM helper 41 * library. Each active buffer object is stored in video RAM. Active 42 * buffer are used for drawing the current frame, typically something like 43 * the frame's scanout buffer or the cursor image. If there's no more space 44 * left in VRAM, inactive GEM objects can be moved to system memory. 45 * 46 * To initialize the VRAM helper library call drmm_vram_helper_alloc_mm(). 47 * The function allocates and initializes an instance of &struct drm_vram_mm 48 * in &struct drm_device.vram_mm . Use &DRM_GEM_VRAM_DRIVER to initialize 49 * &struct drm_driver and &DRM_VRAM_MM_FILE_OPERATIONS to initialize 50 * &struct file_operations; as illustrated below. 51 * 52 * .. code-block:: c 53 * 54 * struct file_operations fops ={ 55 * .owner = THIS_MODULE, 56 * DRM_VRAM_MM_FILE_OPERATION 57 * }; 58 * struct drm_driver drv = { 59 * .driver_feature = DRM_ ... , 60 * .fops = &fops, 61 * DRM_GEM_VRAM_DRIVER 62 * }; 63 * 64 * int init_drm_driver() 65 * { 66 * struct drm_device *dev; 67 * uint64_t vram_base; 68 * unsigned long vram_size; 69 * int ret; 70 * 71 * // setup device, vram base and size 72 * // ... 73 * 74 * ret = drmm_vram_helper_alloc_mm(dev, vram_base, vram_size); 75 * if (ret) 76 * return ret; 77 * return 0; 78 * } 79 * 80 * This creates an instance of &struct drm_vram_mm, exports DRM userspace 81 * interfaces for GEM buffer management and initializes file operations to 82 * allow for accessing created GEM buffers. With this setup, the DRM driver 83 * manages an area of video RAM with VRAM MM and provides GEM VRAM objects 84 * to userspace. 85 * 86 * You don't have to clean up the instance of VRAM MM. 87 * drmm_vram_helper_alloc_mm() is a managed interface that installs a 88 * clean-up handler to run during the DRM device's release. 89 * 90 * For drawing or scanout operations, rsp. buffer objects have to be pinned 91 * in video RAM. Call drm_gem_vram_pin() with &DRM_GEM_VRAM_PL_FLAG_VRAM or 92 * &DRM_GEM_VRAM_PL_FLAG_SYSTEM to pin a buffer object in video RAM or system 93 * memory. Call drm_gem_vram_unpin() to release the pinned object afterwards. 94 * 95 * A buffer object that is pinned in video RAM has a fixed address within that 96 * memory region. Call drm_gem_vram_offset() to retrieve this value. Typically 97 * it's used to program the hardware's scanout engine for framebuffers, set 98 * the cursor overlay's image for a mouse cursor, or use it as input to the 99 * hardware's drawing engine. 100 * 101 * To access a buffer object's memory from the DRM driver, call 102 * drm_gem_vram_vmap(). It maps the buffer into kernel address 103 * space and returns the memory address. Use drm_gem_vram_vunmap() to 104 * release the mapping. 105 */ 106 107 /* 108 * Buffer-objects helpers 109 */ 110 111 static void drm_gem_vram_cleanup(struct drm_gem_vram_object *gbo) 112 { 113 /* We got here via ttm_bo_put(), which means that the 114 * TTM buffer object in 'bo' has already been cleaned 115 * up; only release the GEM object. 116 */ 117 118 WARN_ON(gbo->vmap_use_count); 119 WARN_ON(iosys_map_is_set(&gbo->map)); 120 121 drm_gem_object_release(&gbo->bo.base); 122 } 123 124 static void drm_gem_vram_destroy(struct drm_gem_vram_object *gbo) 125 { 126 drm_gem_vram_cleanup(gbo); 127 kfree(gbo); 128 } 129 130 static void ttm_buffer_object_destroy(struct ttm_buffer_object *bo) 131 { 132 struct drm_gem_vram_object *gbo = drm_gem_vram_of_bo(bo); 133 134 drm_gem_vram_destroy(gbo); 135 } 136 137 static void drm_gem_vram_placement(struct drm_gem_vram_object *gbo, 138 unsigned long pl_flag) 139 { 140 u32 invariant_flags = 0; 141 unsigned int i; 142 unsigned int c = 0; 143 144 if (pl_flag & DRM_GEM_VRAM_PL_FLAG_TOPDOWN) 145 invariant_flags = TTM_PL_FLAG_TOPDOWN; 146 147 gbo->placement.placement = gbo->placements; 148 gbo->placement.busy_placement = gbo->placements; 149 150 if (pl_flag & DRM_GEM_VRAM_PL_FLAG_VRAM) { 151 gbo->placements[c].mem_type = TTM_PL_VRAM; 152 gbo->placements[c++].flags = invariant_flags; 153 } 154 155 if (pl_flag & DRM_GEM_VRAM_PL_FLAG_SYSTEM || !c) { 156 gbo->placements[c].mem_type = TTM_PL_SYSTEM; 157 gbo->placements[c++].flags = invariant_flags; 158 } 159 160 gbo->placement.num_placement = c; 161 gbo->placement.num_busy_placement = c; 162 163 for (i = 0; i < c; ++i) { 164 gbo->placements[i].fpfn = 0; 165 gbo->placements[i].lpfn = 0; 166 } 167 } 168 169 /** 170 * drm_gem_vram_create() - Creates a VRAM-backed GEM object 171 * @dev: the DRM device 172 * @size: the buffer size in bytes 173 * @pg_align: the buffer's alignment in multiples of the page size 174 * 175 * GEM objects are allocated by calling struct drm_driver.gem_create_object, 176 * if set. Otherwise kzalloc() will be used. Drivers can set their own GEM 177 * object functions in struct drm_driver.gem_create_object. If no functions 178 * are set, the new GEM object will use the default functions from GEM VRAM 179 * helpers. 180 * 181 * Returns: 182 * A new instance of &struct drm_gem_vram_object on success, or 183 * an ERR_PTR()-encoded error code otherwise. 184 */ 185 struct drm_gem_vram_object *drm_gem_vram_create(struct drm_device *dev, 186 size_t size, 187 unsigned long pg_align) 188 { 189 struct drm_gem_vram_object *gbo; 190 struct drm_gem_object *gem; 191 struct drm_vram_mm *vmm = dev->vram_mm; 192 struct ttm_device *bdev; 193 int ret; 194 195 if (WARN_ONCE(!vmm, "VRAM MM not initialized")) 196 return ERR_PTR(-EINVAL); 197 198 if (dev->driver->gem_create_object) { 199 gem = dev->driver->gem_create_object(dev, size); 200 if (IS_ERR(gem)) 201 return ERR_CAST(gem); 202 gbo = drm_gem_vram_of_gem(gem); 203 } else { 204 gbo = kzalloc(sizeof(*gbo), GFP_KERNEL); 205 if (!gbo) 206 return ERR_PTR(-ENOMEM); 207 gem = &gbo->bo.base; 208 } 209 210 if (!gem->funcs) 211 gem->funcs = &drm_gem_vram_object_funcs; 212 213 ret = drm_gem_object_init(dev, gem, size); 214 if (ret) { 215 kfree(gbo); 216 return ERR_PTR(ret); 217 } 218 219 bdev = &vmm->bdev; 220 221 gbo->bo.bdev = bdev; 222 drm_gem_vram_placement(gbo, DRM_GEM_VRAM_PL_FLAG_SYSTEM); 223 224 /* 225 * A failing ttm_bo_init will call ttm_buffer_object_destroy 226 * to release gbo->bo.base and kfree gbo. 227 */ 228 ret = ttm_bo_init(bdev, &gbo->bo, size, ttm_bo_type_device, 229 &gbo->placement, pg_align, false, NULL, NULL, 230 ttm_buffer_object_destroy); 231 if (ret) 232 return ERR_PTR(ret); 233 234 return gbo; 235 } 236 EXPORT_SYMBOL(drm_gem_vram_create); 237 238 /** 239 * drm_gem_vram_put() - Releases a reference to a VRAM-backed GEM object 240 * @gbo: the GEM VRAM object 241 * 242 * See ttm_bo_put() for more information. 243 */ 244 void drm_gem_vram_put(struct drm_gem_vram_object *gbo) 245 { 246 ttm_bo_put(&gbo->bo); 247 } 248 EXPORT_SYMBOL(drm_gem_vram_put); 249 250 static u64 drm_gem_vram_pg_offset(struct drm_gem_vram_object *gbo) 251 { 252 /* Keep TTM behavior for now, remove when drivers are audited */ 253 if (WARN_ON_ONCE(!gbo->bo.resource || 254 gbo->bo.resource->mem_type == TTM_PL_SYSTEM)) 255 return 0; 256 257 return gbo->bo.resource->start; 258 } 259 260 /** 261 * drm_gem_vram_offset() - \ 262 Returns a GEM VRAM object's offset in video memory 263 * @gbo: the GEM VRAM object 264 * 265 * This function returns the buffer object's offset in the device's video 266 * memory. The buffer object has to be pinned to %TTM_PL_VRAM. 267 * 268 * Returns: 269 * The buffer object's offset in video memory on success, or 270 * a negative errno code otherwise. 271 */ 272 s64 drm_gem_vram_offset(struct drm_gem_vram_object *gbo) 273 { 274 if (WARN_ON_ONCE(!gbo->bo.pin_count)) 275 return (s64)-ENODEV; 276 return drm_gem_vram_pg_offset(gbo) << PAGE_SHIFT; 277 } 278 EXPORT_SYMBOL(drm_gem_vram_offset); 279 280 static int drm_gem_vram_pin_locked(struct drm_gem_vram_object *gbo, 281 unsigned long pl_flag) 282 { 283 struct ttm_operation_ctx ctx = { false, false }; 284 int ret; 285 286 if (gbo->bo.pin_count) 287 goto out; 288 289 if (pl_flag) 290 drm_gem_vram_placement(gbo, pl_flag); 291 292 ret = ttm_bo_validate(&gbo->bo, &gbo->placement, &ctx); 293 if (ret < 0) 294 return ret; 295 296 out: 297 ttm_bo_pin(&gbo->bo); 298 299 return 0; 300 } 301 302 /** 303 * drm_gem_vram_pin() - Pins a GEM VRAM object in a region. 304 * @gbo: the GEM VRAM object 305 * @pl_flag: a bitmask of possible memory regions 306 * 307 * Pinning a buffer object ensures that it is not evicted from 308 * a memory region. A pinned buffer object has to be unpinned before 309 * it can be pinned to another region. If the pl_flag argument is 0, 310 * the buffer is pinned at its current location (video RAM or system 311 * memory). 312 * 313 * Small buffer objects, such as cursor images, can lead to memory 314 * fragmentation if they are pinned in the middle of video RAM. This 315 * is especially a problem on devices with only a small amount of 316 * video RAM. Fragmentation can prevent the primary framebuffer from 317 * fitting in, even though there's enough memory overall. The modifier 318 * DRM_GEM_VRAM_PL_FLAG_TOPDOWN marks the buffer object to be pinned 319 * at the high end of the memory region to avoid fragmentation. 320 * 321 * Returns: 322 * 0 on success, or 323 * a negative error code otherwise. 324 */ 325 int drm_gem_vram_pin(struct drm_gem_vram_object *gbo, unsigned long pl_flag) 326 { 327 int ret; 328 329 ret = ttm_bo_reserve(&gbo->bo, true, false, NULL); 330 if (ret) 331 return ret; 332 ret = drm_gem_vram_pin_locked(gbo, pl_flag); 333 ttm_bo_unreserve(&gbo->bo); 334 335 return ret; 336 } 337 EXPORT_SYMBOL(drm_gem_vram_pin); 338 339 static void drm_gem_vram_unpin_locked(struct drm_gem_vram_object *gbo) 340 { 341 ttm_bo_unpin(&gbo->bo); 342 } 343 344 /** 345 * drm_gem_vram_unpin() - Unpins a GEM VRAM object 346 * @gbo: the GEM VRAM object 347 * 348 * Returns: 349 * 0 on success, or 350 * a negative error code otherwise. 351 */ 352 int drm_gem_vram_unpin(struct drm_gem_vram_object *gbo) 353 { 354 int ret; 355 356 ret = ttm_bo_reserve(&gbo->bo, true, false, NULL); 357 if (ret) 358 return ret; 359 360 drm_gem_vram_unpin_locked(gbo); 361 ttm_bo_unreserve(&gbo->bo); 362 363 return 0; 364 } 365 EXPORT_SYMBOL(drm_gem_vram_unpin); 366 367 static int drm_gem_vram_kmap_locked(struct drm_gem_vram_object *gbo, 368 struct iosys_map *map) 369 { 370 int ret; 371 372 if (gbo->vmap_use_count > 0) 373 goto out; 374 375 /* 376 * VRAM helpers unmap the BO only on demand. So the previous 377 * page mapping might still be around. Only vmap if the there's 378 * no mapping present. 379 */ 380 if (iosys_map_is_null(&gbo->map)) { 381 ret = ttm_bo_vmap(&gbo->bo, &gbo->map); 382 if (ret) 383 return ret; 384 } 385 386 out: 387 ++gbo->vmap_use_count; 388 *map = gbo->map; 389 390 return 0; 391 } 392 393 static void drm_gem_vram_kunmap_locked(struct drm_gem_vram_object *gbo, 394 struct iosys_map *map) 395 { 396 struct drm_device *dev = gbo->bo.base.dev; 397 398 if (drm_WARN_ON_ONCE(dev, !gbo->vmap_use_count)) 399 return; 400 401 if (drm_WARN_ON_ONCE(dev, !iosys_map_is_equal(&gbo->map, map))) 402 return; /* BUG: map not mapped from this BO */ 403 404 if (--gbo->vmap_use_count > 0) 405 return; 406 407 /* 408 * Permanently mapping and unmapping buffers adds overhead from 409 * updating the page tables and creates debugging output. Therefore, 410 * we delay the actual unmap operation until the BO gets evicted 411 * from memory. See drm_gem_vram_bo_driver_move_notify(). 412 */ 413 } 414 415 /** 416 * drm_gem_vram_vmap() - Pins and maps a GEM VRAM object into kernel address 417 * space 418 * @gbo: The GEM VRAM object to map 419 * @map: Returns the kernel virtual address of the VRAM GEM object's backing 420 * store. 421 * 422 * The vmap function pins a GEM VRAM object to its current location, either 423 * system or video memory, and maps its buffer into kernel address space. 424 * As pinned object cannot be relocated, you should avoid pinning objects 425 * permanently. Call drm_gem_vram_vunmap() with the returned address to 426 * unmap and unpin the GEM VRAM object. 427 * 428 * Returns: 429 * 0 on success, or a negative error code otherwise. 430 */ 431 int drm_gem_vram_vmap(struct drm_gem_vram_object *gbo, struct iosys_map *map) 432 { 433 int ret; 434 435 ret = ttm_bo_reserve(&gbo->bo, true, false, NULL); 436 if (ret) 437 return ret; 438 439 ret = drm_gem_vram_pin_locked(gbo, 0); 440 if (ret) 441 goto err_ttm_bo_unreserve; 442 ret = drm_gem_vram_kmap_locked(gbo, map); 443 if (ret) 444 goto err_drm_gem_vram_unpin_locked; 445 446 ttm_bo_unreserve(&gbo->bo); 447 448 return 0; 449 450 err_drm_gem_vram_unpin_locked: 451 drm_gem_vram_unpin_locked(gbo); 452 err_ttm_bo_unreserve: 453 ttm_bo_unreserve(&gbo->bo); 454 return ret; 455 } 456 EXPORT_SYMBOL(drm_gem_vram_vmap); 457 458 /** 459 * drm_gem_vram_vunmap() - Unmaps and unpins a GEM VRAM object 460 * @gbo: The GEM VRAM object to unmap 461 * @map: Kernel virtual address where the VRAM GEM object was mapped 462 * 463 * A call to drm_gem_vram_vunmap() unmaps and unpins a GEM VRAM buffer. See 464 * the documentation for drm_gem_vram_vmap() for more information. 465 */ 466 void drm_gem_vram_vunmap(struct drm_gem_vram_object *gbo, 467 struct iosys_map *map) 468 { 469 int ret; 470 471 ret = ttm_bo_reserve(&gbo->bo, false, false, NULL); 472 if (WARN_ONCE(ret, "ttm_bo_reserve_failed(): ret=%d\n", ret)) 473 return; 474 475 drm_gem_vram_kunmap_locked(gbo, map); 476 drm_gem_vram_unpin_locked(gbo); 477 478 ttm_bo_unreserve(&gbo->bo); 479 } 480 EXPORT_SYMBOL(drm_gem_vram_vunmap); 481 482 /** 483 * drm_gem_vram_fill_create_dumb() - \ 484 Helper for implementing &struct drm_driver.dumb_create 485 * @file: the DRM file 486 * @dev: the DRM device 487 * @pg_align: the buffer's alignment in multiples of the page size 488 * @pitch_align: the scanline's alignment in powers of 2 489 * @args: the arguments as provided to \ 490 &struct drm_driver.dumb_create 491 * 492 * This helper function fills &struct drm_mode_create_dumb, which is used 493 * by &struct drm_driver.dumb_create. Implementations of this interface 494 * should forwards their arguments to this helper, plus the driver-specific 495 * parameters. 496 * 497 * Returns: 498 * 0 on success, or 499 * a negative error code otherwise. 500 */ 501 int drm_gem_vram_fill_create_dumb(struct drm_file *file, 502 struct drm_device *dev, 503 unsigned long pg_align, 504 unsigned long pitch_align, 505 struct drm_mode_create_dumb *args) 506 { 507 size_t pitch, size; 508 struct drm_gem_vram_object *gbo; 509 int ret; 510 u32 handle; 511 512 pitch = args->width * DIV_ROUND_UP(args->bpp, 8); 513 if (pitch_align) { 514 if (WARN_ON_ONCE(!is_power_of_2(pitch_align))) 515 return -EINVAL; 516 pitch = ALIGN(pitch, pitch_align); 517 } 518 size = pitch * args->height; 519 520 size = roundup(size, PAGE_SIZE); 521 if (!size) 522 return -EINVAL; 523 524 gbo = drm_gem_vram_create(dev, size, pg_align); 525 if (IS_ERR(gbo)) 526 return PTR_ERR(gbo); 527 528 ret = drm_gem_handle_create(file, &gbo->bo.base, &handle); 529 if (ret) 530 goto err_drm_gem_object_put; 531 532 drm_gem_object_put(&gbo->bo.base); 533 534 args->pitch = pitch; 535 args->size = size; 536 args->handle = handle; 537 538 return 0; 539 540 err_drm_gem_object_put: 541 drm_gem_object_put(&gbo->bo.base); 542 return ret; 543 } 544 EXPORT_SYMBOL(drm_gem_vram_fill_create_dumb); 545 546 /* 547 * Helpers for struct ttm_device_funcs 548 */ 549 550 static bool drm_is_gem_vram(struct ttm_buffer_object *bo) 551 { 552 return (bo->destroy == ttm_buffer_object_destroy); 553 } 554 555 static void drm_gem_vram_bo_driver_evict_flags(struct drm_gem_vram_object *gbo, 556 struct ttm_placement *pl) 557 { 558 drm_gem_vram_placement(gbo, DRM_GEM_VRAM_PL_FLAG_SYSTEM); 559 *pl = gbo->placement; 560 } 561 562 static void drm_gem_vram_bo_driver_move_notify(struct drm_gem_vram_object *gbo) 563 { 564 struct ttm_buffer_object *bo = &gbo->bo; 565 struct drm_device *dev = bo->base.dev; 566 567 if (drm_WARN_ON_ONCE(dev, gbo->vmap_use_count)) 568 return; 569 570 ttm_bo_vunmap(bo, &gbo->map); 571 iosys_map_clear(&gbo->map); /* explicitly clear mapping for next vmap call */ 572 } 573 574 static int drm_gem_vram_bo_driver_move(struct drm_gem_vram_object *gbo, 575 bool evict, 576 struct ttm_operation_ctx *ctx, 577 struct ttm_resource *new_mem) 578 { 579 drm_gem_vram_bo_driver_move_notify(gbo); 580 return ttm_bo_move_memcpy(&gbo->bo, ctx, new_mem); 581 } 582 583 /* 584 * Helpers for struct drm_gem_object_funcs 585 */ 586 587 /** 588 * drm_gem_vram_object_free() - \ 589 Implements &struct drm_gem_object_funcs.free 590 * @gem: GEM object. Refers to &struct drm_gem_vram_object.gem 591 */ 592 static void drm_gem_vram_object_free(struct drm_gem_object *gem) 593 { 594 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem); 595 596 drm_gem_vram_put(gbo); 597 } 598 599 /* 600 * Helpers for dump buffers 601 */ 602 603 /** 604 * drm_gem_vram_driver_dumb_create() - \ 605 Implements &struct drm_driver.dumb_create 606 * @file: the DRM file 607 * @dev: the DRM device 608 * @args: the arguments as provided to \ 609 &struct drm_driver.dumb_create 610 * 611 * This function requires the driver to use @drm_device.vram_mm for its 612 * instance of VRAM MM. 613 * 614 * Returns: 615 * 0 on success, or 616 * a negative error code otherwise. 617 */ 618 int drm_gem_vram_driver_dumb_create(struct drm_file *file, 619 struct drm_device *dev, 620 struct drm_mode_create_dumb *args) 621 { 622 if (WARN_ONCE(!dev->vram_mm, "VRAM MM not initialized")) 623 return -EINVAL; 624 625 return drm_gem_vram_fill_create_dumb(file, dev, 0, 0, args); 626 } 627 EXPORT_SYMBOL(drm_gem_vram_driver_dumb_create); 628 629 /* 630 * Helpers for struct drm_plane_helper_funcs 631 */ 632 633 /** 634 * drm_gem_vram_plane_helper_prepare_fb() - \ 635 * Implements &struct drm_plane_helper_funcs.prepare_fb 636 * @plane: a DRM plane 637 * @new_state: the plane's new state 638 * 639 * During plane updates, this function sets the plane's fence and 640 * pins the GEM VRAM objects of the plane's new framebuffer to VRAM. 641 * Call drm_gem_vram_plane_helper_cleanup_fb() to unpin them. 642 * 643 * Returns: 644 * 0 on success, or 645 * a negative errno code otherwise. 646 */ 647 int 648 drm_gem_vram_plane_helper_prepare_fb(struct drm_plane *plane, 649 struct drm_plane_state *new_state) 650 { 651 size_t i; 652 struct drm_gem_vram_object *gbo; 653 int ret; 654 655 if (!new_state->fb) 656 return 0; 657 658 for (i = 0; i < ARRAY_SIZE(new_state->fb->obj); ++i) { 659 if (!new_state->fb->obj[i]) 660 continue; 661 gbo = drm_gem_vram_of_gem(new_state->fb->obj[i]); 662 ret = drm_gem_vram_pin(gbo, DRM_GEM_VRAM_PL_FLAG_VRAM); 663 if (ret) 664 goto err_drm_gem_vram_unpin; 665 } 666 667 ret = drm_gem_plane_helper_prepare_fb(plane, new_state); 668 if (ret) 669 goto err_drm_gem_vram_unpin; 670 671 return 0; 672 673 err_drm_gem_vram_unpin: 674 while (i) { 675 --i; 676 gbo = drm_gem_vram_of_gem(new_state->fb->obj[i]); 677 drm_gem_vram_unpin(gbo); 678 } 679 return ret; 680 } 681 EXPORT_SYMBOL(drm_gem_vram_plane_helper_prepare_fb); 682 683 /** 684 * drm_gem_vram_plane_helper_cleanup_fb() - \ 685 * Implements &struct drm_plane_helper_funcs.cleanup_fb 686 * @plane: a DRM plane 687 * @old_state: the plane's old state 688 * 689 * During plane updates, this function unpins the GEM VRAM 690 * objects of the plane's old framebuffer from VRAM. Complements 691 * drm_gem_vram_plane_helper_prepare_fb(). 692 */ 693 void 694 drm_gem_vram_plane_helper_cleanup_fb(struct drm_plane *plane, 695 struct drm_plane_state *old_state) 696 { 697 size_t i; 698 struct drm_gem_vram_object *gbo; 699 700 if (!old_state->fb) 701 return; 702 703 for (i = 0; i < ARRAY_SIZE(old_state->fb->obj); ++i) { 704 if (!old_state->fb->obj[i]) 705 continue; 706 gbo = drm_gem_vram_of_gem(old_state->fb->obj[i]); 707 drm_gem_vram_unpin(gbo); 708 } 709 } 710 EXPORT_SYMBOL(drm_gem_vram_plane_helper_cleanup_fb); 711 712 /* 713 * Helpers for struct drm_simple_display_pipe_funcs 714 */ 715 716 /** 717 * drm_gem_vram_simple_display_pipe_prepare_fb() - \ 718 * Implements &struct drm_simple_display_pipe_funcs.prepare_fb 719 * @pipe: a simple display pipe 720 * @new_state: the plane's new state 721 * 722 * During plane updates, this function pins the GEM VRAM 723 * objects of the plane's new framebuffer to VRAM. Call 724 * drm_gem_vram_simple_display_pipe_cleanup_fb() to unpin them. 725 * 726 * Returns: 727 * 0 on success, or 728 * a negative errno code otherwise. 729 */ 730 int drm_gem_vram_simple_display_pipe_prepare_fb( 731 struct drm_simple_display_pipe *pipe, 732 struct drm_plane_state *new_state) 733 { 734 return drm_gem_vram_plane_helper_prepare_fb(&pipe->plane, new_state); 735 } 736 EXPORT_SYMBOL(drm_gem_vram_simple_display_pipe_prepare_fb); 737 738 /** 739 * drm_gem_vram_simple_display_pipe_cleanup_fb() - \ 740 * Implements &struct drm_simple_display_pipe_funcs.cleanup_fb 741 * @pipe: a simple display pipe 742 * @old_state: the plane's old state 743 * 744 * During plane updates, this function unpins the GEM VRAM 745 * objects of the plane's old framebuffer from VRAM. Complements 746 * drm_gem_vram_simple_display_pipe_prepare_fb(). 747 */ 748 void drm_gem_vram_simple_display_pipe_cleanup_fb( 749 struct drm_simple_display_pipe *pipe, 750 struct drm_plane_state *old_state) 751 { 752 drm_gem_vram_plane_helper_cleanup_fb(&pipe->plane, old_state); 753 } 754 EXPORT_SYMBOL(drm_gem_vram_simple_display_pipe_cleanup_fb); 755 756 /* 757 * PRIME helpers 758 */ 759 760 /** 761 * drm_gem_vram_object_pin() - \ 762 Implements &struct drm_gem_object_funcs.pin 763 * @gem: The GEM object to pin 764 * 765 * Returns: 766 * 0 on success, or 767 * a negative errno code otherwise. 768 */ 769 static int drm_gem_vram_object_pin(struct drm_gem_object *gem) 770 { 771 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem); 772 773 /* Fbdev console emulation is the use case of these PRIME 774 * helpers. This may involve updating a hardware buffer from 775 * a shadow FB. We pin the buffer to it's current location 776 * (either video RAM or system memory) to prevent it from 777 * being relocated during the update operation. If you require 778 * the buffer to be pinned to VRAM, implement a callback that 779 * sets the flags accordingly. 780 */ 781 return drm_gem_vram_pin(gbo, 0); 782 } 783 784 /** 785 * drm_gem_vram_object_unpin() - \ 786 Implements &struct drm_gem_object_funcs.unpin 787 * @gem: The GEM object to unpin 788 */ 789 static void drm_gem_vram_object_unpin(struct drm_gem_object *gem) 790 { 791 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem); 792 793 drm_gem_vram_unpin(gbo); 794 } 795 796 /** 797 * drm_gem_vram_object_vmap() - 798 * Implements &struct drm_gem_object_funcs.vmap 799 * @gem: The GEM object to map 800 * @map: Returns the kernel virtual address of the VRAM GEM object's backing 801 * store. 802 * 803 * Returns: 804 * 0 on success, or a negative error code otherwise. 805 */ 806 static int drm_gem_vram_object_vmap(struct drm_gem_object *gem, 807 struct iosys_map *map) 808 { 809 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem); 810 811 return drm_gem_vram_vmap(gbo, map); 812 } 813 814 /** 815 * drm_gem_vram_object_vunmap() - 816 * Implements &struct drm_gem_object_funcs.vunmap 817 * @gem: The GEM object to unmap 818 * @map: Kernel virtual address where the VRAM GEM object was mapped 819 */ 820 static void drm_gem_vram_object_vunmap(struct drm_gem_object *gem, 821 struct iosys_map *map) 822 { 823 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem); 824 825 drm_gem_vram_vunmap(gbo, map); 826 } 827 828 /* 829 * GEM object funcs 830 */ 831 832 static const struct drm_gem_object_funcs drm_gem_vram_object_funcs = { 833 .free = drm_gem_vram_object_free, 834 .pin = drm_gem_vram_object_pin, 835 .unpin = drm_gem_vram_object_unpin, 836 .vmap = drm_gem_vram_object_vmap, 837 .vunmap = drm_gem_vram_object_vunmap, 838 .mmap = drm_gem_ttm_mmap, 839 .print_info = drm_gem_ttm_print_info, 840 }; 841 842 /* 843 * VRAM memory manager 844 */ 845 846 /* 847 * TTM TT 848 */ 849 850 static void bo_driver_ttm_tt_destroy(struct ttm_device *bdev, struct ttm_tt *tt) 851 { 852 ttm_tt_fini(tt); 853 kfree(tt); 854 } 855 856 /* 857 * TTM BO device 858 */ 859 860 static struct ttm_tt *bo_driver_ttm_tt_create(struct ttm_buffer_object *bo, 861 uint32_t page_flags) 862 { 863 struct ttm_tt *tt; 864 int ret; 865 866 tt = kzalloc(sizeof(*tt), GFP_KERNEL); 867 if (!tt) 868 return NULL; 869 870 ret = ttm_tt_init(tt, bo, page_flags, ttm_cached, 0); 871 if (ret < 0) 872 goto err_ttm_tt_init; 873 874 return tt; 875 876 err_ttm_tt_init: 877 kfree(tt); 878 return NULL; 879 } 880 881 static void bo_driver_evict_flags(struct ttm_buffer_object *bo, 882 struct ttm_placement *placement) 883 { 884 struct drm_gem_vram_object *gbo; 885 886 /* TTM may pass BOs that are not GEM VRAM BOs. */ 887 if (!drm_is_gem_vram(bo)) 888 return; 889 890 gbo = drm_gem_vram_of_bo(bo); 891 892 drm_gem_vram_bo_driver_evict_flags(gbo, placement); 893 } 894 895 static void bo_driver_delete_mem_notify(struct ttm_buffer_object *bo) 896 { 897 struct drm_gem_vram_object *gbo; 898 899 /* TTM may pass BOs that are not GEM VRAM BOs. */ 900 if (!drm_is_gem_vram(bo)) 901 return; 902 903 gbo = drm_gem_vram_of_bo(bo); 904 905 drm_gem_vram_bo_driver_move_notify(gbo); 906 } 907 908 static int bo_driver_move(struct ttm_buffer_object *bo, 909 bool evict, 910 struct ttm_operation_ctx *ctx, 911 struct ttm_resource *new_mem, 912 struct ttm_place *hop) 913 { 914 struct drm_gem_vram_object *gbo; 915 916 gbo = drm_gem_vram_of_bo(bo); 917 918 return drm_gem_vram_bo_driver_move(gbo, evict, ctx, new_mem); 919 } 920 921 static int bo_driver_io_mem_reserve(struct ttm_device *bdev, 922 struct ttm_resource *mem) 923 { 924 struct drm_vram_mm *vmm = drm_vram_mm_of_bdev(bdev); 925 926 switch (mem->mem_type) { 927 case TTM_PL_SYSTEM: /* nothing to do */ 928 break; 929 case TTM_PL_VRAM: 930 mem->bus.offset = (mem->start << PAGE_SHIFT) + vmm->vram_base; 931 mem->bus.is_iomem = true; 932 mem->bus.caching = ttm_write_combined; 933 break; 934 default: 935 return -EINVAL; 936 } 937 938 return 0; 939 } 940 941 static struct ttm_device_funcs bo_driver = { 942 .ttm_tt_create = bo_driver_ttm_tt_create, 943 .ttm_tt_destroy = bo_driver_ttm_tt_destroy, 944 .eviction_valuable = ttm_bo_eviction_valuable, 945 .evict_flags = bo_driver_evict_flags, 946 .move = bo_driver_move, 947 .delete_mem_notify = bo_driver_delete_mem_notify, 948 .io_mem_reserve = bo_driver_io_mem_reserve, 949 }; 950 951 /* 952 * struct drm_vram_mm 953 */ 954 955 static int drm_vram_mm_debugfs(struct seq_file *m, void *data) 956 { 957 struct drm_info_node *node = (struct drm_info_node *) m->private; 958 struct drm_vram_mm *vmm = node->minor->dev->vram_mm; 959 struct ttm_resource_manager *man = ttm_manager_type(&vmm->bdev, TTM_PL_VRAM); 960 struct drm_printer p = drm_seq_file_printer(m); 961 962 ttm_resource_manager_debug(man, &p); 963 return 0; 964 } 965 966 static const struct drm_info_list drm_vram_mm_debugfs_list[] = { 967 { "vram-mm", drm_vram_mm_debugfs, 0, NULL }, 968 }; 969 970 /** 971 * drm_vram_mm_debugfs_init() - Register VRAM MM debugfs file. 972 * 973 * @minor: drm minor device. 974 * 975 */ 976 void drm_vram_mm_debugfs_init(struct drm_minor *minor) 977 { 978 drm_debugfs_create_files(drm_vram_mm_debugfs_list, 979 ARRAY_SIZE(drm_vram_mm_debugfs_list), 980 minor->debugfs_root, minor); 981 } 982 EXPORT_SYMBOL(drm_vram_mm_debugfs_init); 983 984 static int drm_vram_mm_init(struct drm_vram_mm *vmm, struct drm_device *dev, 985 uint64_t vram_base, size_t vram_size) 986 { 987 int ret; 988 989 vmm->vram_base = vram_base; 990 vmm->vram_size = vram_size; 991 992 ret = ttm_device_init(&vmm->bdev, &bo_driver, dev->dev, 993 dev->anon_inode->i_mapping, 994 dev->vma_offset_manager, 995 false, true); 996 if (ret) 997 return ret; 998 999 ret = ttm_range_man_init(&vmm->bdev, TTM_PL_VRAM, 1000 false, vram_size >> PAGE_SHIFT); 1001 if (ret) 1002 return ret; 1003 1004 return 0; 1005 } 1006 1007 static void drm_vram_mm_cleanup(struct drm_vram_mm *vmm) 1008 { 1009 ttm_range_man_fini(&vmm->bdev, TTM_PL_VRAM); 1010 ttm_device_fini(&vmm->bdev); 1011 } 1012 1013 /* 1014 * Helpers for integration with struct drm_device 1015 */ 1016 1017 static struct drm_vram_mm *drm_vram_helper_alloc_mm(struct drm_device *dev, uint64_t vram_base, 1018 size_t vram_size) 1019 { 1020 int ret; 1021 1022 if (WARN_ON(dev->vram_mm)) 1023 return dev->vram_mm; 1024 1025 dev->vram_mm = kzalloc(sizeof(*dev->vram_mm), GFP_KERNEL); 1026 if (!dev->vram_mm) 1027 return ERR_PTR(-ENOMEM); 1028 1029 ret = drm_vram_mm_init(dev->vram_mm, dev, vram_base, vram_size); 1030 if (ret) 1031 goto err_kfree; 1032 1033 return dev->vram_mm; 1034 1035 err_kfree: 1036 kfree(dev->vram_mm); 1037 dev->vram_mm = NULL; 1038 return ERR_PTR(ret); 1039 } 1040 1041 static void drm_vram_helper_release_mm(struct drm_device *dev) 1042 { 1043 if (!dev->vram_mm) 1044 return; 1045 1046 drm_vram_mm_cleanup(dev->vram_mm); 1047 kfree(dev->vram_mm); 1048 dev->vram_mm = NULL; 1049 } 1050 1051 static void drm_vram_mm_release(struct drm_device *dev, void *ptr) 1052 { 1053 drm_vram_helper_release_mm(dev); 1054 } 1055 1056 /** 1057 * drmm_vram_helper_init - Initializes a device's instance of 1058 * &struct drm_vram_mm 1059 * @dev: the DRM device 1060 * @vram_base: the base address of the video memory 1061 * @vram_size: the size of the video memory in bytes 1062 * 1063 * Creates a new instance of &struct drm_vram_mm and stores it in 1064 * struct &drm_device.vram_mm. The instance is auto-managed and cleaned 1065 * up as part of device cleanup. Calling this function multiple times 1066 * will generate an error message. 1067 * 1068 * Returns: 1069 * 0 on success, or a negative errno code otherwise. 1070 */ 1071 int drmm_vram_helper_init(struct drm_device *dev, uint64_t vram_base, 1072 size_t vram_size) 1073 { 1074 struct drm_vram_mm *vram_mm; 1075 1076 if (drm_WARN_ON_ONCE(dev, dev->vram_mm)) 1077 return 0; 1078 1079 vram_mm = drm_vram_helper_alloc_mm(dev, vram_base, vram_size); 1080 if (IS_ERR(vram_mm)) 1081 return PTR_ERR(vram_mm); 1082 return drmm_add_action_or_reset(dev, drm_vram_mm_release, NULL); 1083 } 1084 EXPORT_SYMBOL(drmm_vram_helper_init); 1085 1086 /* 1087 * Mode-config helpers 1088 */ 1089 1090 static enum drm_mode_status 1091 drm_vram_helper_mode_valid_internal(struct drm_device *dev, 1092 const struct drm_display_mode *mode, 1093 unsigned long max_bpp) 1094 { 1095 struct drm_vram_mm *vmm = dev->vram_mm; 1096 unsigned long fbsize, fbpages, max_fbpages; 1097 1098 if (WARN_ON(!dev->vram_mm)) 1099 return MODE_BAD; 1100 1101 max_fbpages = (vmm->vram_size / 2) >> PAGE_SHIFT; 1102 1103 fbsize = mode->hdisplay * mode->vdisplay * max_bpp; 1104 fbpages = DIV_ROUND_UP(fbsize, PAGE_SIZE); 1105 1106 if (fbpages > max_fbpages) 1107 return MODE_MEM; 1108 1109 return MODE_OK; 1110 } 1111 1112 /** 1113 * drm_vram_helper_mode_valid - Tests if a display mode's 1114 * framebuffer fits into the available video memory. 1115 * @dev: the DRM device 1116 * @mode: the mode to test 1117 * 1118 * This function tests if enough video memory is available for using the 1119 * specified display mode. Atomic modesetting requires importing the 1120 * designated framebuffer into video memory before evicting the active 1121 * one. Hence, any framebuffer may consume at most half of the available 1122 * VRAM. Display modes that require a larger framebuffer can not be used, 1123 * even if the CRTC does support them. Each framebuffer is assumed to 1124 * have 32-bit color depth. 1125 * 1126 * Note: 1127 * The function can only test if the display mode is supported in 1128 * general. If there are too many framebuffers pinned to video memory, 1129 * a display mode may still not be usable in practice. The color depth of 1130 * 32-bit fits all current use case. A more flexible test can be added 1131 * when necessary. 1132 * 1133 * Returns: 1134 * MODE_OK if the display mode is supported, or an error code of type 1135 * enum drm_mode_status otherwise. 1136 */ 1137 enum drm_mode_status 1138 drm_vram_helper_mode_valid(struct drm_device *dev, 1139 const struct drm_display_mode *mode) 1140 { 1141 static const unsigned long max_bpp = 4; /* DRM_FORMAT_XRGB8888 */ 1142 1143 return drm_vram_helper_mode_valid_internal(dev, mode, max_bpp); 1144 } 1145 EXPORT_SYMBOL(drm_vram_helper_mode_valid); 1146 1147 MODULE_DESCRIPTION("DRM VRAM memory-management helpers"); 1148 MODULE_LICENSE("GPL"); 1149