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