1 // SPDX-License-Identifier: GPL-2.0-or-later 2 3 #include <linux/module.h> 4 5 #include <drm/drm_debugfs.h> 6 #include <drm/drm_device.h> 7 #include <drm/drm_drv.h> 8 #include <drm/drm_file.h> 9 #include <drm/drm_framebuffer.h> 10 #include <drm/drm_gem_framebuffer_helper.h> 11 #include <drm/drm_gem_ttm_helper.h> 12 #include <drm/drm_gem_vram_helper.h> 13 #include <drm/drm_managed.h> 14 #include <drm/drm_mode.h> 15 #include <drm/drm_plane.h> 16 #include <drm/drm_prime.h> 17 #include <drm/drm_simple_kms_helper.h> 18 #include <drm/ttm/ttm_page_alloc.h> 19 20 static const struct drm_gem_object_funcs drm_gem_vram_object_funcs; 21 22 /** 23 * DOC: overview 24 * 25 * This library provides &struct drm_gem_vram_object (GEM VRAM), a GEM 26 * buffer object that is backed by video RAM (VRAM). It can be used for 27 * framebuffer devices with dedicated memory. 28 * 29 * The data structure &struct drm_vram_mm and its helpers implement a memory 30 * manager for simple framebuffer devices with dedicated video memory. GEM 31 * VRAM buffer objects are either placed in the video memory or remain evicted 32 * to system memory. 33 * 34 * With the GEM interface userspace applications create, manage and destroy 35 * graphics buffers, such as an on-screen framebuffer. GEM does not provide 36 * an implementation of these interfaces. It's up to the DRM driver to 37 * provide an implementation that suits the hardware. If the hardware device 38 * contains dedicated video memory, the DRM driver can use the VRAM helper 39 * library. Each active buffer object is stored in video RAM. Active 40 * buffer are used for drawing the current frame, typically something like 41 * the frame's scanout buffer or the cursor image. If there's no more space 42 * left in VRAM, inactive GEM objects can be moved to system memory. 43 * 44 * To initialize the VRAM helper library call drmm_vram_helper_alloc_mm(). 45 * The function allocates and initializes an instance of &struct drm_vram_mm 46 * in &struct drm_device.vram_mm . Use &DRM_GEM_VRAM_DRIVER to initialize 47 * &struct drm_driver and &DRM_VRAM_MM_FILE_OPERATIONS to initialize 48 * &struct file_operations; as illustrated below. 49 * 50 * .. code-block:: c 51 * 52 * struct file_operations fops ={ 53 * .owner = THIS_MODULE, 54 * DRM_VRAM_MM_FILE_OPERATION 55 * }; 56 * struct drm_driver drv = { 57 * .driver_feature = DRM_ ... , 58 * .fops = &fops, 59 * DRM_GEM_VRAM_DRIVER 60 * }; 61 * 62 * int init_drm_driver() 63 * { 64 * struct drm_device *dev; 65 * uint64_t vram_base; 66 * unsigned long vram_size; 67 * int ret; 68 * 69 * // setup device, vram base and size 70 * // ... 71 * 72 * ret = drmm_vram_helper_alloc_mm(dev, vram_base, vram_size); 73 * if (ret) 74 * return ret; 75 * return 0; 76 * } 77 * 78 * This creates an instance of &struct drm_vram_mm, exports DRM userspace 79 * interfaces for GEM buffer management and initializes file operations to 80 * allow for accessing created GEM buffers. With this setup, the DRM driver 81 * manages an area of video RAM with VRAM MM and provides GEM VRAM objects 82 * to userspace. 83 * 84 * You don't have to clean up the instance of VRAM MM. 85 * drmm_vram_helper_alloc_mm() is a managed interface that installs a 86 * clean-up handler to run during the DRM device's release. 87 * 88 * For drawing or scanout operations, rsp. buffer objects have to be pinned 89 * in video RAM. Call drm_gem_vram_pin() with &DRM_GEM_VRAM_PL_FLAG_VRAM or 90 * &DRM_GEM_VRAM_PL_FLAG_SYSTEM to pin a buffer object in video RAM or system 91 * memory. Call drm_gem_vram_unpin() to release the pinned object afterwards. 92 * 93 * A buffer object that is pinned in video RAM has a fixed address within that 94 * memory region. Call drm_gem_vram_offset() to retrieve this value. Typically 95 * it's used to program the hardware's scanout engine for framebuffers, set 96 * the cursor overlay's image for a mouse cursor, or use it as input to the 97 * hardware's draing engine. 98 * 99 * To access a buffer object's memory from the DRM driver, call 100 * drm_gem_vram_kmap(). It (optionally) maps the buffer into kernel address 101 * space and returns the memory address. Use drm_gem_vram_kunmap() to 102 * release the mapping. 103 */ 104 105 /* 106 * Buffer-objects helpers 107 */ 108 109 static void drm_gem_vram_cleanup(struct drm_gem_vram_object *gbo) 110 { 111 /* We got here via ttm_bo_put(), which means that the 112 * TTM buffer object in 'bo' has already been cleaned 113 * up; only release the GEM object. 114 */ 115 116 WARN_ON(gbo->kmap_use_count); 117 WARN_ON(gbo->kmap.virtual); 118 119 drm_gem_object_release(&gbo->bo.base); 120 } 121 122 static void drm_gem_vram_destroy(struct drm_gem_vram_object *gbo) 123 { 124 drm_gem_vram_cleanup(gbo); 125 kfree(gbo); 126 } 127 128 static void ttm_buffer_object_destroy(struct ttm_buffer_object *bo) 129 { 130 struct drm_gem_vram_object *gbo = drm_gem_vram_of_bo(bo); 131 132 drm_gem_vram_destroy(gbo); 133 } 134 135 static void drm_gem_vram_placement(struct drm_gem_vram_object *gbo, 136 unsigned long pl_flag) 137 { 138 unsigned int i; 139 unsigned int c = 0; 140 u32 invariant_flags = pl_flag & TTM_PL_FLAG_TOPDOWN; 141 142 gbo->placement.placement = gbo->placements; 143 gbo->placement.busy_placement = gbo->placements; 144 145 if (pl_flag & TTM_PL_FLAG_VRAM) 146 gbo->placements[c++].flags = TTM_PL_FLAG_WC | 147 TTM_PL_FLAG_UNCACHED | 148 TTM_PL_FLAG_VRAM | 149 invariant_flags; 150 151 if (pl_flag & TTM_PL_FLAG_SYSTEM) 152 gbo->placements[c++].flags = TTM_PL_MASK_CACHING | 153 TTM_PL_FLAG_SYSTEM | 154 invariant_flags; 155 156 if (!c) 157 gbo->placements[c++].flags = TTM_PL_MASK_CACHING | 158 TTM_PL_FLAG_SYSTEM | 159 invariant_flags; 160 161 gbo->placement.num_placement = c; 162 gbo->placement.num_busy_placement = c; 163 164 for (i = 0; i < c; ++i) { 165 gbo->placements[i].fpfn = 0; 166 gbo->placements[i].lpfn = 0; 167 } 168 } 169 170 static int drm_gem_vram_init(struct drm_device *dev, 171 struct drm_gem_vram_object *gbo, 172 size_t size, unsigned long pg_align) 173 { 174 struct drm_vram_mm *vmm = dev->vram_mm; 175 struct ttm_bo_device *bdev; 176 int ret; 177 size_t acc_size; 178 179 if (WARN_ONCE(!vmm, "VRAM MM not initialized")) 180 return -EINVAL; 181 bdev = &vmm->bdev; 182 183 gbo->bo.base.funcs = &drm_gem_vram_object_funcs; 184 185 ret = drm_gem_object_init(dev, &gbo->bo.base, size); 186 if (ret) 187 return ret; 188 189 acc_size = ttm_bo_dma_acc_size(bdev, size, sizeof(*gbo)); 190 191 gbo->bo.bdev = bdev; 192 drm_gem_vram_placement(gbo, TTM_PL_FLAG_VRAM | TTM_PL_FLAG_SYSTEM); 193 194 ret = ttm_bo_init(bdev, &gbo->bo, size, ttm_bo_type_device, 195 &gbo->placement, pg_align, false, acc_size, 196 NULL, NULL, ttm_buffer_object_destroy); 197 if (ret) 198 goto err_drm_gem_object_release; 199 200 return 0; 201 202 err_drm_gem_object_release: 203 drm_gem_object_release(&gbo->bo.base); 204 return ret; 205 } 206 207 /** 208 * drm_gem_vram_create() - Creates a VRAM-backed GEM object 209 * @dev: the DRM device 210 * @size: the buffer size in bytes 211 * @pg_align: the buffer's alignment in multiples of the page size 212 * 213 * Returns: 214 * A new instance of &struct drm_gem_vram_object on success, or 215 * an ERR_PTR()-encoded error code otherwise. 216 */ 217 struct drm_gem_vram_object *drm_gem_vram_create(struct drm_device *dev, 218 size_t size, 219 unsigned long pg_align) 220 { 221 struct drm_gem_vram_object *gbo; 222 int ret; 223 224 if (dev->driver->gem_create_object) { 225 struct drm_gem_object *gem = 226 dev->driver->gem_create_object(dev, size); 227 if (!gem) 228 return ERR_PTR(-ENOMEM); 229 gbo = drm_gem_vram_of_gem(gem); 230 } else { 231 gbo = kzalloc(sizeof(*gbo), GFP_KERNEL); 232 if (!gbo) 233 return ERR_PTR(-ENOMEM); 234 } 235 236 ret = drm_gem_vram_init(dev, gbo, size, pg_align); 237 if (ret < 0) 238 goto err_kfree; 239 240 return gbo; 241 242 err_kfree: 243 kfree(gbo); 244 return ERR_PTR(ret); 245 } 246 EXPORT_SYMBOL(drm_gem_vram_create); 247 248 /** 249 * drm_gem_vram_put() - Releases a reference to a VRAM-backed GEM object 250 * @gbo: the GEM VRAM object 251 * 252 * See ttm_bo_put() for more information. 253 */ 254 void drm_gem_vram_put(struct drm_gem_vram_object *gbo) 255 { 256 ttm_bo_put(&gbo->bo); 257 } 258 EXPORT_SYMBOL(drm_gem_vram_put); 259 260 /** 261 * drm_gem_vram_mmap_offset() - Returns a GEM VRAM object's mmap offset 262 * @gbo: the GEM VRAM object 263 * 264 * See drm_vma_node_offset_addr() for more information. 265 * 266 * Returns: 267 * The buffer object's offset for userspace mappings on success, or 268 * 0 if no offset is allocated. 269 */ 270 u64 drm_gem_vram_mmap_offset(struct drm_gem_vram_object *gbo) 271 { 272 return drm_vma_node_offset_addr(&gbo->bo.base.vma_node); 273 } 274 EXPORT_SYMBOL(drm_gem_vram_mmap_offset); 275 276 static u64 drm_gem_vram_pg_offset(struct drm_gem_vram_object *gbo) 277 { 278 /* Keep TTM behavior for now, remove when drivers are audited */ 279 if (WARN_ON_ONCE(!gbo->bo.mem.mm_node)) 280 return 0; 281 282 return gbo->bo.mem.start; 283 } 284 285 /** 286 * drm_gem_vram_offset() - \ 287 Returns a GEM VRAM object's offset in video memory 288 * @gbo: the GEM VRAM object 289 * 290 * This function returns the buffer object's offset in the device's video 291 * memory. The buffer object has to be pinned to %TTM_PL_VRAM. 292 * 293 * Returns: 294 * The buffer object's offset in video memory on success, or 295 * a negative errno code otherwise. 296 */ 297 s64 drm_gem_vram_offset(struct drm_gem_vram_object *gbo) 298 { 299 if (WARN_ON_ONCE(!gbo->pin_count)) 300 return (s64)-ENODEV; 301 return drm_gem_vram_pg_offset(gbo) << PAGE_SHIFT; 302 } 303 EXPORT_SYMBOL(drm_gem_vram_offset); 304 305 static int drm_gem_vram_pin_locked(struct drm_gem_vram_object *gbo, 306 unsigned long pl_flag) 307 { 308 int i, ret; 309 struct ttm_operation_ctx ctx = { false, false }; 310 311 if (gbo->pin_count) 312 goto out; 313 314 if (pl_flag) 315 drm_gem_vram_placement(gbo, pl_flag); 316 317 for (i = 0; i < gbo->placement.num_placement; ++i) 318 gbo->placements[i].flags |= TTM_PL_FLAG_NO_EVICT; 319 320 ret = ttm_bo_validate(&gbo->bo, &gbo->placement, &ctx); 321 if (ret < 0) 322 return ret; 323 324 out: 325 ++gbo->pin_count; 326 327 return 0; 328 } 329 330 /** 331 * drm_gem_vram_pin() - Pins a GEM VRAM object in a region. 332 * @gbo: the GEM VRAM object 333 * @pl_flag: a bitmask of possible memory regions 334 * 335 * Pinning a buffer object ensures that it is not evicted from 336 * a memory region. A pinned buffer object has to be unpinned before 337 * it can be pinned to another region. If the pl_flag argument is 0, 338 * the buffer is pinned at its current location (video RAM or system 339 * memory). 340 * 341 * Small buffer objects, such as cursor images, can lead to memory 342 * fragmentation if they are pinned in the middle of video RAM. This 343 * is especially a problem on devices with only a small amount of 344 * video RAM. Fragmentation can prevent the primary framebuffer from 345 * fitting in, even though there's enough memory overall. The modifier 346 * DRM_GEM_VRAM_PL_FLAG_TOPDOWN marks the buffer object to be pinned 347 * at the high end of the memory region to avoid fragmentation. 348 * 349 * Returns: 350 * 0 on success, or 351 * a negative error code otherwise. 352 */ 353 int drm_gem_vram_pin(struct drm_gem_vram_object *gbo, unsigned long pl_flag) 354 { 355 int ret; 356 357 ret = ttm_bo_reserve(&gbo->bo, true, false, NULL); 358 if (ret) 359 return ret; 360 ret = drm_gem_vram_pin_locked(gbo, pl_flag); 361 ttm_bo_unreserve(&gbo->bo); 362 363 return ret; 364 } 365 EXPORT_SYMBOL(drm_gem_vram_pin); 366 367 static int drm_gem_vram_unpin_locked(struct drm_gem_vram_object *gbo) 368 { 369 int i, ret; 370 struct ttm_operation_ctx ctx = { false, false }; 371 372 if (WARN_ON_ONCE(!gbo->pin_count)) 373 return 0; 374 375 --gbo->pin_count; 376 if (gbo->pin_count) 377 return 0; 378 379 for (i = 0; i < gbo->placement.num_placement ; ++i) 380 gbo->placements[i].flags &= ~TTM_PL_FLAG_NO_EVICT; 381 382 ret = ttm_bo_validate(&gbo->bo, &gbo->placement, &ctx); 383 if (ret < 0) 384 return ret; 385 386 return 0; 387 } 388 389 /** 390 * drm_gem_vram_unpin() - Unpins a GEM VRAM object 391 * @gbo: the GEM VRAM object 392 * 393 * Returns: 394 * 0 on success, or 395 * a negative error code otherwise. 396 */ 397 int drm_gem_vram_unpin(struct drm_gem_vram_object *gbo) 398 { 399 int ret; 400 401 ret = ttm_bo_reserve(&gbo->bo, true, false, NULL); 402 if (ret) 403 return ret; 404 ret = drm_gem_vram_unpin_locked(gbo); 405 ttm_bo_unreserve(&gbo->bo); 406 407 return ret; 408 } 409 EXPORT_SYMBOL(drm_gem_vram_unpin); 410 411 static void *drm_gem_vram_kmap_locked(struct drm_gem_vram_object *gbo, 412 bool map, bool *is_iomem) 413 { 414 int ret; 415 struct ttm_bo_kmap_obj *kmap = &gbo->kmap; 416 417 if (gbo->kmap_use_count > 0) 418 goto out; 419 420 if (kmap->virtual || !map) 421 goto out; 422 423 ret = ttm_bo_kmap(&gbo->bo, 0, gbo->bo.num_pages, kmap); 424 if (ret) 425 return ERR_PTR(ret); 426 427 out: 428 if (!kmap->virtual) { 429 if (is_iomem) 430 *is_iomem = false; 431 return NULL; /* not mapped; don't increment ref */ 432 } 433 ++gbo->kmap_use_count; 434 if (is_iomem) 435 return ttm_kmap_obj_virtual(kmap, is_iomem); 436 return kmap->virtual; 437 } 438 439 /** 440 * drm_gem_vram_kmap() - Maps a GEM VRAM object into kernel address space 441 * @gbo: the GEM VRAM object 442 * @map: establish a mapping if necessary 443 * @is_iomem: returns true if the mapped memory is I/O memory, or false \ 444 otherwise; can be NULL 445 * 446 * This function maps the buffer object into the kernel's address space 447 * or returns the current mapping. If the parameter map is false, the 448 * function only queries the current mapping, but does not establish a 449 * new one. 450 * 451 * Returns: 452 * The buffers virtual address if mapped, or 453 * NULL if not mapped, or 454 * an ERR_PTR()-encoded error code otherwise. 455 */ 456 void *drm_gem_vram_kmap(struct drm_gem_vram_object *gbo, bool map, 457 bool *is_iomem) 458 { 459 int ret; 460 void *virtual; 461 462 ret = ttm_bo_reserve(&gbo->bo, true, false, NULL); 463 if (ret) 464 return ERR_PTR(ret); 465 virtual = drm_gem_vram_kmap_locked(gbo, map, is_iomem); 466 ttm_bo_unreserve(&gbo->bo); 467 468 return virtual; 469 } 470 EXPORT_SYMBOL(drm_gem_vram_kmap); 471 472 static void drm_gem_vram_kunmap_locked(struct drm_gem_vram_object *gbo) 473 { 474 if (WARN_ON_ONCE(!gbo->kmap_use_count)) 475 return; 476 if (--gbo->kmap_use_count > 0) 477 return; 478 479 /* 480 * Permanently mapping and unmapping buffers adds overhead from 481 * updating the page tables and creates debugging output. Therefore, 482 * we delay the actual unmap operation until the BO gets evicted 483 * from memory. See drm_gem_vram_bo_driver_move_notify(). 484 */ 485 } 486 487 /** 488 * drm_gem_vram_kunmap() - Unmaps a GEM VRAM object 489 * @gbo: the GEM VRAM object 490 */ 491 void drm_gem_vram_kunmap(struct drm_gem_vram_object *gbo) 492 { 493 int ret; 494 495 ret = ttm_bo_reserve(&gbo->bo, false, false, NULL); 496 if (WARN_ONCE(ret, "ttm_bo_reserve_failed(): ret=%d\n", ret)) 497 return; 498 drm_gem_vram_kunmap_locked(gbo); 499 ttm_bo_unreserve(&gbo->bo); 500 } 501 EXPORT_SYMBOL(drm_gem_vram_kunmap); 502 503 /** 504 * drm_gem_vram_vmap() - Pins and maps a GEM VRAM object into kernel address 505 * space 506 * @gbo: The GEM VRAM object to map 507 * 508 * The vmap function pins a GEM VRAM object to its current location, either 509 * system or video memory, and maps its buffer into kernel address space. 510 * As pinned object cannot be relocated, you should avoid pinning objects 511 * permanently. Call drm_gem_vram_vunmap() with the returned address to 512 * unmap and unpin the GEM VRAM object. 513 * 514 * If you have special requirements for the pinning or mapping operations, 515 * call drm_gem_vram_pin() and drm_gem_vram_kmap() directly. 516 * 517 * Returns: 518 * The buffer's virtual address on success, or 519 * an ERR_PTR()-encoded error code otherwise. 520 */ 521 void *drm_gem_vram_vmap(struct drm_gem_vram_object *gbo) 522 { 523 int ret; 524 void *base; 525 526 ret = ttm_bo_reserve(&gbo->bo, true, false, NULL); 527 if (ret) 528 return ERR_PTR(ret); 529 530 ret = drm_gem_vram_pin_locked(gbo, 0); 531 if (ret) 532 goto err_ttm_bo_unreserve; 533 base = drm_gem_vram_kmap_locked(gbo, true, NULL); 534 if (IS_ERR(base)) { 535 ret = PTR_ERR(base); 536 goto err_drm_gem_vram_unpin_locked; 537 } 538 539 ttm_bo_unreserve(&gbo->bo); 540 541 return base; 542 543 err_drm_gem_vram_unpin_locked: 544 drm_gem_vram_unpin_locked(gbo); 545 err_ttm_bo_unreserve: 546 ttm_bo_unreserve(&gbo->bo); 547 return ERR_PTR(ret); 548 } 549 EXPORT_SYMBOL(drm_gem_vram_vmap); 550 551 /** 552 * drm_gem_vram_vunmap() - Unmaps and unpins a GEM VRAM object 553 * @gbo: The GEM VRAM object to unmap 554 * @vaddr: The mapping's base address as returned by drm_gem_vram_vmap() 555 * 556 * A call to drm_gem_vram_vunmap() unmaps and unpins a GEM VRAM buffer. See 557 * the documentation for drm_gem_vram_vmap() for more information. 558 */ 559 void drm_gem_vram_vunmap(struct drm_gem_vram_object *gbo, void *vaddr) 560 { 561 int ret; 562 563 ret = ttm_bo_reserve(&gbo->bo, false, false, NULL); 564 if (WARN_ONCE(ret, "ttm_bo_reserve_failed(): ret=%d\n", ret)) 565 return; 566 567 drm_gem_vram_kunmap_locked(gbo); 568 drm_gem_vram_unpin_locked(gbo); 569 570 ttm_bo_unreserve(&gbo->bo); 571 } 572 EXPORT_SYMBOL(drm_gem_vram_vunmap); 573 574 /** 575 * drm_gem_vram_fill_create_dumb() - \ 576 Helper for implementing &struct drm_driver.dumb_create 577 * @file: the DRM file 578 * @dev: the DRM device 579 * @pg_align: the buffer's alignment in multiples of the page size 580 * @pitch_align: the scanline's alignment in powers of 2 581 * @args: the arguments as provided to \ 582 &struct drm_driver.dumb_create 583 * 584 * This helper function fills &struct drm_mode_create_dumb, which is used 585 * by &struct drm_driver.dumb_create. Implementations of this interface 586 * should forwards their arguments to this helper, plus the driver-specific 587 * parameters. 588 * 589 * Returns: 590 * 0 on success, or 591 * a negative error code otherwise. 592 */ 593 int drm_gem_vram_fill_create_dumb(struct drm_file *file, 594 struct drm_device *dev, 595 unsigned long pg_align, 596 unsigned long pitch_align, 597 struct drm_mode_create_dumb *args) 598 { 599 size_t pitch, size; 600 struct drm_gem_vram_object *gbo; 601 int ret; 602 u32 handle; 603 604 pitch = args->width * DIV_ROUND_UP(args->bpp, 8); 605 if (pitch_align) { 606 if (WARN_ON_ONCE(!is_power_of_2(pitch_align))) 607 return -EINVAL; 608 pitch = ALIGN(pitch, pitch_align); 609 } 610 size = pitch * args->height; 611 612 size = roundup(size, PAGE_SIZE); 613 if (!size) 614 return -EINVAL; 615 616 gbo = drm_gem_vram_create(dev, size, pg_align); 617 if (IS_ERR(gbo)) 618 return PTR_ERR(gbo); 619 620 ret = drm_gem_handle_create(file, &gbo->bo.base, &handle); 621 if (ret) 622 goto err_drm_gem_object_put; 623 624 drm_gem_object_put(&gbo->bo.base); 625 626 args->pitch = pitch; 627 args->size = size; 628 args->handle = handle; 629 630 return 0; 631 632 err_drm_gem_object_put: 633 drm_gem_object_put(&gbo->bo.base); 634 return ret; 635 } 636 EXPORT_SYMBOL(drm_gem_vram_fill_create_dumb); 637 638 /* 639 * Helpers for struct ttm_bo_driver 640 */ 641 642 static bool drm_is_gem_vram(struct ttm_buffer_object *bo) 643 { 644 return (bo->destroy == ttm_buffer_object_destroy); 645 } 646 647 static void drm_gem_vram_bo_driver_evict_flags(struct drm_gem_vram_object *gbo, 648 struct ttm_placement *pl) 649 { 650 drm_gem_vram_placement(gbo, TTM_PL_FLAG_SYSTEM); 651 *pl = gbo->placement; 652 } 653 654 static void drm_gem_vram_bo_driver_move_notify(struct drm_gem_vram_object *gbo, 655 bool evict, 656 struct ttm_mem_reg *new_mem) 657 { 658 struct ttm_bo_kmap_obj *kmap = &gbo->kmap; 659 660 if (WARN_ON_ONCE(gbo->kmap_use_count)) 661 return; 662 663 if (!kmap->virtual) 664 return; 665 ttm_bo_kunmap(kmap); 666 kmap->virtual = NULL; 667 } 668 669 /* 670 * Helpers for struct drm_gem_object_funcs 671 */ 672 673 /** 674 * drm_gem_vram_object_free() - \ 675 Implements &struct drm_gem_object_funcs.free 676 * @gem: GEM object. Refers to &struct drm_gem_vram_object.gem 677 */ 678 static void drm_gem_vram_object_free(struct drm_gem_object *gem) 679 { 680 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem); 681 682 drm_gem_vram_put(gbo); 683 } 684 685 /* 686 * Helpers for dump buffers 687 */ 688 689 /** 690 * drm_gem_vram_driver_create_dumb() - \ 691 Implements &struct drm_driver.dumb_create 692 * @file: the DRM file 693 * @dev: the DRM device 694 * @args: the arguments as provided to \ 695 &struct drm_driver.dumb_create 696 * 697 * This function requires the driver to use @drm_device.vram_mm for its 698 * instance of VRAM MM. 699 * 700 * Returns: 701 * 0 on success, or 702 * a negative error code otherwise. 703 */ 704 int drm_gem_vram_driver_dumb_create(struct drm_file *file, 705 struct drm_device *dev, 706 struct drm_mode_create_dumb *args) 707 { 708 if (WARN_ONCE(!dev->vram_mm, "VRAM MM not initialized")) 709 return -EINVAL; 710 711 return drm_gem_vram_fill_create_dumb(file, dev, 0, 0, args); 712 } 713 EXPORT_SYMBOL(drm_gem_vram_driver_dumb_create); 714 715 /** 716 * drm_gem_vram_driver_dumb_mmap_offset() - \ 717 Implements &struct drm_driver.dumb_mmap_offset 718 * @file: DRM file pointer. 719 * @dev: DRM device. 720 * @handle: GEM handle 721 * @offset: Returns the mapping's memory offset on success 722 * 723 * Returns: 724 * 0 on success, or 725 * a negative errno code otherwise. 726 */ 727 int drm_gem_vram_driver_dumb_mmap_offset(struct drm_file *file, 728 struct drm_device *dev, 729 uint32_t handle, uint64_t *offset) 730 { 731 struct drm_gem_object *gem; 732 struct drm_gem_vram_object *gbo; 733 734 gem = drm_gem_object_lookup(file, handle); 735 if (!gem) 736 return -ENOENT; 737 738 gbo = drm_gem_vram_of_gem(gem); 739 *offset = drm_gem_vram_mmap_offset(gbo); 740 741 drm_gem_object_put(gem); 742 743 return 0; 744 } 745 EXPORT_SYMBOL(drm_gem_vram_driver_dumb_mmap_offset); 746 747 /* 748 * Helpers for struct drm_plane_helper_funcs 749 */ 750 751 /** 752 * drm_gem_vram_plane_helper_prepare_fb() - \ 753 * Implements &struct drm_plane_helper_funcs.prepare_fb 754 * @plane: a DRM plane 755 * @new_state: the plane's new state 756 * 757 * During plane updates, this function sets the plane's fence and 758 * pins the GEM VRAM objects of the plane's new framebuffer to VRAM. 759 * Call drm_gem_vram_plane_helper_cleanup_fb() to unpin them. 760 * 761 * Returns: 762 * 0 on success, or 763 * a negative errno code otherwise. 764 */ 765 int 766 drm_gem_vram_plane_helper_prepare_fb(struct drm_plane *plane, 767 struct drm_plane_state *new_state) 768 { 769 size_t i; 770 struct drm_gem_vram_object *gbo; 771 int ret; 772 773 if (!new_state->fb) 774 return 0; 775 776 for (i = 0; i < ARRAY_SIZE(new_state->fb->obj); ++i) { 777 if (!new_state->fb->obj[i]) 778 continue; 779 gbo = drm_gem_vram_of_gem(new_state->fb->obj[i]); 780 ret = drm_gem_vram_pin(gbo, DRM_GEM_VRAM_PL_FLAG_VRAM); 781 if (ret) 782 goto err_drm_gem_vram_unpin; 783 } 784 785 ret = drm_gem_fb_prepare_fb(plane, new_state); 786 if (ret) 787 goto err_drm_gem_vram_unpin; 788 789 return 0; 790 791 err_drm_gem_vram_unpin: 792 while (i) { 793 --i; 794 gbo = drm_gem_vram_of_gem(new_state->fb->obj[i]); 795 drm_gem_vram_unpin(gbo); 796 } 797 return ret; 798 } 799 EXPORT_SYMBOL(drm_gem_vram_plane_helper_prepare_fb); 800 801 /** 802 * drm_gem_vram_plane_helper_cleanup_fb() - \ 803 * Implements &struct drm_plane_helper_funcs.cleanup_fb 804 * @plane: a DRM plane 805 * @old_state: the plane's old state 806 * 807 * During plane updates, this function unpins the GEM VRAM 808 * objects of the plane's old framebuffer from VRAM. Complements 809 * drm_gem_vram_plane_helper_prepare_fb(). 810 */ 811 void 812 drm_gem_vram_plane_helper_cleanup_fb(struct drm_plane *plane, 813 struct drm_plane_state *old_state) 814 { 815 size_t i; 816 struct drm_gem_vram_object *gbo; 817 818 if (!old_state->fb) 819 return; 820 821 for (i = 0; i < ARRAY_SIZE(old_state->fb->obj); ++i) { 822 if (!old_state->fb->obj[i]) 823 continue; 824 gbo = drm_gem_vram_of_gem(old_state->fb->obj[i]); 825 drm_gem_vram_unpin(gbo); 826 } 827 } 828 EXPORT_SYMBOL(drm_gem_vram_plane_helper_cleanup_fb); 829 830 /* 831 * Helpers for struct drm_simple_display_pipe_funcs 832 */ 833 834 /** 835 * drm_gem_vram_simple_display_pipe_prepare_fb() - \ 836 * Implements &struct drm_simple_display_pipe_funcs.prepare_fb 837 * @pipe: a simple display pipe 838 * @new_state: the plane's new state 839 * 840 * During plane updates, this function pins the GEM VRAM 841 * objects of the plane's new framebuffer to VRAM. Call 842 * drm_gem_vram_simple_display_pipe_cleanup_fb() to unpin them. 843 * 844 * Returns: 845 * 0 on success, or 846 * a negative errno code otherwise. 847 */ 848 int drm_gem_vram_simple_display_pipe_prepare_fb( 849 struct drm_simple_display_pipe *pipe, 850 struct drm_plane_state *new_state) 851 { 852 return drm_gem_vram_plane_helper_prepare_fb(&pipe->plane, new_state); 853 } 854 EXPORT_SYMBOL(drm_gem_vram_simple_display_pipe_prepare_fb); 855 856 /** 857 * drm_gem_vram_simple_display_pipe_cleanup_fb() - \ 858 * Implements &struct drm_simple_display_pipe_funcs.cleanup_fb 859 * @pipe: a simple display pipe 860 * @old_state: the plane's old state 861 * 862 * During plane updates, this function unpins the GEM VRAM 863 * objects of the plane's old framebuffer from VRAM. Complements 864 * drm_gem_vram_simple_display_pipe_prepare_fb(). 865 */ 866 void drm_gem_vram_simple_display_pipe_cleanup_fb( 867 struct drm_simple_display_pipe *pipe, 868 struct drm_plane_state *old_state) 869 { 870 drm_gem_vram_plane_helper_cleanup_fb(&pipe->plane, old_state); 871 } 872 EXPORT_SYMBOL(drm_gem_vram_simple_display_pipe_cleanup_fb); 873 874 /* 875 * PRIME helpers 876 */ 877 878 /** 879 * drm_gem_vram_object_pin() - \ 880 Implements &struct drm_gem_object_funcs.pin 881 * @gem: The GEM object to pin 882 * 883 * Returns: 884 * 0 on success, or 885 * a negative errno code otherwise. 886 */ 887 static int drm_gem_vram_object_pin(struct drm_gem_object *gem) 888 { 889 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem); 890 891 /* Fbdev console emulation is the use case of these PRIME 892 * helpers. This may involve updating a hardware buffer from 893 * a shadow FB. We pin the buffer to it's current location 894 * (either video RAM or system memory) to prevent it from 895 * being relocated during the update operation. If you require 896 * the buffer to be pinned to VRAM, implement a callback that 897 * sets the flags accordingly. 898 */ 899 return drm_gem_vram_pin(gbo, 0); 900 } 901 902 /** 903 * drm_gem_vram_object_unpin() - \ 904 Implements &struct drm_gem_object_funcs.unpin 905 * @gem: The GEM object to unpin 906 */ 907 static void drm_gem_vram_object_unpin(struct drm_gem_object *gem) 908 { 909 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem); 910 911 drm_gem_vram_unpin(gbo); 912 } 913 914 /** 915 * drm_gem_vram_object_vmap() - \ 916 Implements &struct drm_gem_object_funcs.vmap 917 * @gem: The GEM object to map 918 * 919 * Returns: 920 * The buffers virtual address on success, or 921 * NULL otherwise. 922 */ 923 static void *drm_gem_vram_object_vmap(struct drm_gem_object *gem) 924 { 925 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem); 926 void *base; 927 928 base = drm_gem_vram_vmap(gbo); 929 if (IS_ERR(base)) 930 return NULL; 931 return base; 932 } 933 934 /** 935 * drm_gem_vram_object_vunmap() - \ 936 Implements &struct drm_gem_object_funcs.vunmap 937 * @gem: The GEM object to unmap 938 * @vaddr: The mapping's base address 939 */ 940 static void drm_gem_vram_object_vunmap(struct drm_gem_object *gem, 941 void *vaddr) 942 { 943 struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem); 944 945 drm_gem_vram_vunmap(gbo, vaddr); 946 } 947 948 /* 949 * GEM object funcs 950 */ 951 952 static const struct drm_gem_object_funcs drm_gem_vram_object_funcs = { 953 .free = drm_gem_vram_object_free, 954 .pin = drm_gem_vram_object_pin, 955 .unpin = drm_gem_vram_object_unpin, 956 .vmap = drm_gem_vram_object_vmap, 957 .vunmap = drm_gem_vram_object_vunmap, 958 .mmap = drm_gem_ttm_mmap, 959 .print_info = drm_gem_ttm_print_info, 960 }; 961 962 /* 963 * VRAM memory manager 964 */ 965 966 /* 967 * TTM TT 968 */ 969 970 static void backend_func_destroy(struct ttm_tt *tt) 971 { 972 ttm_tt_fini(tt); 973 kfree(tt); 974 } 975 976 static struct ttm_backend_func backend_func = { 977 .destroy = backend_func_destroy 978 }; 979 980 /* 981 * TTM BO device 982 */ 983 984 static struct ttm_tt *bo_driver_ttm_tt_create(struct ttm_buffer_object *bo, 985 uint32_t page_flags) 986 { 987 struct ttm_tt *tt; 988 int ret; 989 990 tt = kzalloc(sizeof(*tt), GFP_KERNEL); 991 if (!tt) 992 return NULL; 993 994 tt->func = &backend_func; 995 996 ret = ttm_tt_init(tt, bo, page_flags); 997 if (ret < 0) 998 goto err_ttm_tt_init; 999 1000 return tt; 1001 1002 err_ttm_tt_init: 1003 kfree(tt); 1004 return NULL; 1005 } 1006 1007 static int bo_driver_init_mem_type(struct ttm_bo_device *bdev, uint32_t type, 1008 struct ttm_mem_type_manager *man) 1009 { 1010 switch (type) { 1011 case TTM_PL_SYSTEM: 1012 man->flags = 0; 1013 man->available_caching = TTM_PL_MASK_CACHING; 1014 man->default_caching = TTM_PL_FLAG_CACHED; 1015 break; 1016 case TTM_PL_VRAM: 1017 man->func = &ttm_bo_manager_func; 1018 man->flags = TTM_MEMTYPE_FLAG_FIXED; 1019 man->available_caching = TTM_PL_FLAG_UNCACHED | 1020 TTM_PL_FLAG_WC; 1021 man->default_caching = TTM_PL_FLAG_WC; 1022 break; 1023 default: 1024 return -EINVAL; 1025 } 1026 return 0; 1027 } 1028 1029 static void bo_driver_evict_flags(struct ttm_buffer_object *bo, 1030 struct ttm_placement *placement) 1031 { 1032 struct drm_gem_vram_object *gbo; 1033 1034 /* TTM may pass BOs that are not GEM VRAM BOs. */ 1035 if (!drm_is_gem_vram(bo)) 1036 return; 1037 1038 gbo = drm_gem_vram_of_bo(bo); 1039 1040 drm_gem_vram_bo_driver_evict_flags(gbo, placement); 1041 } 1042 1043 static void bo_driver_move_notify(struct ttm_buffer_object *bo, 1044 bool evict, 1045 struct ttm_mem_reg *new_mem) 1046 { 1047 struct drm_gem_vram_object *gbo; 1048 1049 /* TTM may pass BOs that are not GEM VRAM BOs. */ 1050 if (!drm_is_gem_vram(bo)) 1051 return; 1052 1053 gbo = drm_gem_vram_of_bo(bo); 1054 1055 drm_gem_vram_bo_driver_move_notify(gbo, evict, new_mem); 1056 } 1057 1058 static int bo_driver_io_mem_reserve(struct ttm_bo_device *bdev, 1059 struct ttm_mem_reg *mem) 1060 { 1061 struct drm_vram_mm *vmm = drm_vram_mm_of_bdev(bdev); 1062 1063 mem->bus.addr = NULL; 1064 mem->bus.size = mem->num_pages << PAGE_SHIFT; 1065 1066 switch (mem->mem_type) { 1067 case TTM_PL_SYSTEM: /* nothing to do */ 1068 mem->bus.offset = 0; 1069 mem->bus.base = 0; 1070 mem->bus.is_iomem = false; 1071 break; 1072 case TTM_PL_VRAM: 1073 mem->bus.offset = mem->start << PAGE_SHIFT; 1074 mem->bus.base = vmm->vram_base; 1075 mem->bus.is_iomem = true; 1076 break; 1077 default: 1078 return -EINVAL; 1079 } 1080 1081 return 0; 1082 } 1083 1084 static struct ttm_bo_driver bo_driver = { 1085 .ttm_tt_create = bo_driver_ttm_tt_create, 1086 .ttm_tt_populate = ttm_pool_populate, 1087 .ttm_tt_unpopulate = ttm_pool_unpopulate, 1088 .init_mem_type = bo_driver_init_mem_type, 1089 .eviction_valuable = ttm_bo_eviction_valuable, 1090 .evict_flags = bo_driver_evict_flags, 1091 .move_notify = bo_driver_move_notify, 1092 .io_mem_reserve = bo_driver_io_mem_reserve, 1093 }; 1094 1095 /* 1096 * struct drm_vram_mm 1097 */ 1098 1099 static int drm_vram_mm_debugfs(struct seq_file *m, void *data) 1100 { 1101 struct drm_info_node *node = (struct drm_info_node *) m->private; 1102 struct drm_vram_mm *vmm = node->minor->dev->vram_mm; 1103 struct drm_mm *mm = vmm->bdev.man[TTM_PL_VRAM].priv; 1104 struct drm_printer p = drm_seq_file_printer(m); 1105 1106 spin_lock(&ttm_bo_glob.lru_lock); 1107 drm_mm_print(mm, &p); 1108 spin_unlock(&ttm_bo_glob.lru_lock); 1109 return 0; 1110 } 1111 1112 static const struct drm_info_list drm_vram_mm_debugfs_list[] = { 1113 { "vram-mm", drm_vram_mm_debugfs, 0, NULL }, 1114 }; 1115 1116 /** 1117 * drm_vram_mm_debugfs_init() - Register VRAM MM debugfs file. 1118 * 1119 * @minor: drm minor device. 1120 * 1121 */ 1122 void drm_vram_mm_debugfs_init(struct drm_minor *minor) 1123 { 1124 drm_debugfs_create_files(drm_vram_mm_debugfs_list, 1125 ARRAY_SIZE(drm_vram_mm_debugfs_list), 1126 minor->debugfs_root, minor); 1127 } 1128 EXPORT_SYMBOL(drm_vram_mm_debugfs_init); 1129 1130 static int drm_vram_mm_init(struct drm_vram_mm *vmm, struct drm_device *dev, 1131 uint64_t vram_base, size_t vram_size) 1132 { 1133 int ret; 1134 1135 vmm->vram_base = vram_base; 1136 vmm->vram_size = vram_size; 1137 1138 ret = ttm_bo_device_init(&vmm->bdev, &bo_driver, 1139 dev->anon_inode->i_mapping, 1140 dev->vma_offset_manager, 1141 true); 1142 if (ret) 1143 return ret; 1144 1145 ret = ttm_bo_init_mm(&vmm->bdev, TTM_PL_VRAM, vram_size >> PAGE_SHIFT); 1146 if (ret) 1147 return ret; 1148 1149 return 0; 1150 } 1151 1152 static void drm_vram_mm_cleanup(struct drm_vram_mm *vmm) 1153 { 1154 ttm_bo_device_release(&vmm->bdev); 1155 } 1156 1157 /* 1158 * Helpers for integration with struct drm_device 1159 */ 1160 1161 /* deprecated; use drmm_vram_mm_init() */ 1162 struct drm_vram_mm *drm_vram_helper_alloc_mm( 1163 struct drm_device *dev, uint64_t vram_base, size_t vram_size) 1164 { 1165 int ret; 1166 1167 if (WARN_ON(dev->vram_mm)) 1168 return dev->vram_mm; 1169 1170 dev->vram_mm = kzalloc(sizeof(*dev->vram_mm), GFP_KERNEL); 1171 if (!dev->vram_mm) 1172 return ERR_PTR(-ENOMEM); 1173 1174 ret = drm_vram_mm_init(dev->vram_mm, dev, vram_base, vram_size); 1175 if (ret) 1176 goto err_kfree; 1177 1178 return dev->vram_mm; 1179 1180 err_kfree: 1181 kfree(dev->vram_mm); 1182 dev->vram_mm = NULL; 1183 return ERR_PTR(ret); 1184 } 1185 EXPORT_SYMBOL(drm_vram_helper_alloc_mm); 1186 1187 void drm_vram_helper_release_mm(struct drm_device *dev) 1188 { 1189 if (!dev->vram_mm) 1190 return; 1191 1192 drm_vram_mm_cleanup(dev->vram_mm); 1193 kfree(dev->vram_mm); 1194 dev->vram_mm = NULL; 1195 } 1196 EXPORT_SYMBOL(drm_vram_helper_release_mm); 1197 1198 static void drm_vram_mm_release(struct drm_device *dev, void *ptr) 1199 { 1200 drm_vram_helper_release_mm(dev); 1201 } 1202 1203 /** 1204 * drmm_vram_helper_init - Initializes a device's instance of 1205 * &struct drm_vram_mm 1206 * @dev: the DRM device 1207 * @vram_base: the base address of the video memory 1208 * @vram_size: the size of the video memory in bytes 1209 * 1210 * Creates a new instance of &struct drm_vram_mm and stores it in 1211 * struct &drm_device.vram_mm. The instance is auto-managed and cleaned 1212 * up as part of device cleanup. Calling this function multiple times 1213 * will generate an error message. 1214 * 1215 * Returns: 1216 * 0 on success, or a negative errno code otherwise. 1217 */ 1218 int drmm_vram_helper_init(struct drm_device *dev, uint64_t vram_base, 1219 size_t vram_size) 1220 { 1221 struct drm_vram_mm *vram_mm; 1222 1223 if (drm_WARN_ON_ONCE(dev, dev->vram_mm)) 1224 return 0; 1225 1226 vram_mm = drm_vram_helper_alloc_mm(dev, vram_base, vram_size); 1227 if (IS_ERR(vram_mm)) 1228 return PTR_ERR(vram_mm); 1229 return drmm_add_action_or_reset(dev, drm_vram_mm_release, NULL); 1230 } 1231 EXPORT_SYMBOL(drmm_vram_helper_init); 1232 1233 /* 1234 * Mode-config helpers 1235 */ 1236 1237 static enum drm_mode_status 1238 drm_vram_helper_mode_valid_internal(struct drm_device *dev, 1239 const struct drm_display_mode *mode, 1240 unsigned long max_bpp) 1241 { 1242 struct drm_vram_mm *vmm = dev->vram_mm; 1243 unsigned long fbsize, fbpages, max_fbpages; 1244 1245 if (WARN_ON(!dev->vram_mm)) 1246 return MODE_BAD; 1247 1248 max_fbpages = (vmm->vram_size / 2) >> PAGE_SHIFT; 1249 1250 fbsize = mode->hdisplay * mode->vdisplay * max_bpp; 1251 fbpages = DIV_ROUND_UP(fbsize, PAGE_SIZE); 1252 1253 if (fbpages > max_fbpages) 1254 return MODE_MEM; 1255 1256 return MODE_OK; 1257 } 1258 1259 /** 1260 * drm_vram_helper_mode_valid - Tests if a display mode's 1261 * framebuffer fits into the available video memory. 1262 * @dev: the DRM device 1263 * @mode: the mode to test 1264 * 1265 * This function tests if enough video memory is available for using the 1266 * specified display mode. Atomic modesetting requires importing the 1267 * designated framebuffer into video memory before evicting the active 1268 * one. Hence, any framebuffer may consume at most half of the available 1269 * VRAM. Display modes that require a larger framebuffer can not be used, 1270 * even if the CRTC does support them. Each framebuffer is assumed to 1271 * have 32-bit color depth. 1272 * 1273 * Note: 1274 * The function can only test if the display mode is supported in 1275 * general. If there are too many framebuffers pinned to video memory, 1276 * a display mode may still not be usable in practice. The color depth of 1277 * 32-bit fits all current use case. A more flexible test can be added 1278 * when necessary. 1279 * 1280 * Returns: 1281 * MODE_OK if the display mode is supported, or an error code of type 1282 * enum drm_mode_status otherwise. 1283 */ 1284 enum drm_mode_status 1285 drm_vram_helper_mode_valid(struct drm_device *dev, 1286 const struct drm_display_mode *mode) 1287 { 1288 static const unsigned long max_bpp = 4; /* DRM_FORMAT_XRGB8888 */ 1289 1290 return drm_vram_helper_mode_valid_internal(dev, mode, max_bpp); 1291 } 1292 EXPORT_SYMBOL(drm_vram_helper_mode_valid); 1293 1294 MODULE_DESCRIPTION("DRM VRAM memory-management helpers"); 1295 MODULE_LICENSE("GPL"); 1296