1 /* 2 * Copyright © 2008 Intel Corporation 3 * 4 * Permission is hereby granted, free of charge, to any person obtaining a 5 * copy of this software and associated documentation files (the "Software"), 6 * to deal in the Software without restriction, including without limitation 7 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 8 * and/or sell copies of the Software, and to permit persons to whom the 9 * Software is furnished to do so, subject to the following conditions: 10 * 11 * The above copyright notice and this permission notice (including the next 12 * paragraph) shall be included in all copies or substantial portions of the 13 * Software. 14 * 15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 21 * IN THE SOFTWARE. 22 * 23 * Authors: 24 * Eric Anholt <eric@anholt.net> 25 * 26 */ 27 28 #include <linux/dma-buf.h> 29 #include <linux/file.h> 30 #include <linux/fs.h> 31 #include <linux/iosys-map.h> 32 #include <linux/mem_encrypt.h> 33 #include <linux/mm.h> 34 #include <linux/mman.h> 35 #include <linux/module.h> 36 #include <linux/pagemap.h> 37 #include <linux/pagevec.h> 38 #include <linux/shmem_fs.h> 39 #include <linux/slab.h> 40 #include <linux/string_helpers.h> 41 #include <linux/types.h> 42 #include <linux/uaccess.h> 43 44 #include <drm/drm.h> 45 #include <drm/drm_device.h> 46 #include <drm/drm_drv.h> 47 #include <drm/drm_file.h> 48 #include <drm/drm_gem.h> 49 #include <drm/drm_managed.h> 50 #include <drm/drm_print.h> 51 #include <drm/drm_vma_manager.h> 52 53 #include "drm_internal.h" 54 55 /** @file drm_gem.c 56 * 57 * This file provides some of the base ioctls and library routines for 58 * the graphics memory manager implemented by each device driver. 59 * 60 * Because various devices have different requirements in terms of 61 * synchronization and migration strategies, implementing that is left up to 62 * the driver, and all that the general API provides should be generic -- 63 * allocating objects, reading/writing data with the cpu, freeing objects. 64 * Even there, platform-dependent optimizations for reading/writing data with 65 * the CPU mean we'll likely hook those out to driver-specific calls. However, 66 * the DRI2 implementation wants to have at least allocate/mmap be generic. 67 * 68 * The goal was to have swap-backed object allocation managed through 69 * struct file. However, file descriptors as handles to a struct file have 70 * two major failings: 71 * - Process limits prevent more than 1024 or so being used at a time by 72 * default. 73 * - Inability to allocate high fds will aggravate the X Server's select() 74 * handling, and likely that of many GL client applications as well. 75 * 76 * This led to a plan of using our own integer IDs (called handles, following 77 * DRM terminology) to mimic fds, and implement the fd syscalls we need as 78 * ioctls. The objects themselves will still include the struct file so 79 * that we can transition to fds if the required kernel infrastructure shows 80 * up at a later date, and as our interface with shmfs for memory allocation. 81 */ 82 83 static void 84 drm_gem_init_release(struct drm_device *dev, void *ptr) 85 { 86 drm_vma_offset_manager_destroy(dev->vma_offset_manager); 87 } 88 89 /** 90 * drm_gem_init - Initialize the GEM device fields 91 * @dev: drm_devic structure to initialize 92 */ 93 int 94 drm_gem_init(struct drm_device *dev) 95 { 96 struct drm_vma_offset_manager *vma_offset_manager; 97 98 mutex_init(&dev->object_name_lock); 99 idr_init_base(&dev->object_name_idr, 1); 100 101 vma_offset_manager = drmm_kzalloc(dev, sizeof(*vma_offset_manager), 102 GFP_KERNEL); 103 if (!vma_offset_manager) { 104 DRM_ERROR("out of memory\n"); 105 return -ENOMEM; 106 } 107 108 dev->vma_offset_manager = vma_offset_manager; 109 drm_vma_offset_manager_init(vma_offset_manager, 110 DRM_FILE_PAGE_OFFSET_START, 111 DRM_FILE_PAGE_OFFSET_SIZE); 112 113 return drmm_add_action(dev, drm_gem_init_release, NULL); 114 } 115 116 /** 117 * drm_gem_object_init - initialize an allocated shmem-backed GEM object 118 * @dev: drm_device the object should be initialized for 119 * @obj: drm_gem_object to initialize 120 * @size: object size 121 * 122 * Initialize an already allocated GEM object of the specified size with 123 * shmfs backing store. 124 */ 125 int drm_gem_object_init(struct drm_device *dev, 126 struct drm_gem_object *obj, size_t size) 127 { 128 struct file *filp; 129 130 drm_gem_private_object_init(dev, obj, size); 131 132 filp = shmem_file_setup("drm mm object", size, VM_NORESERVE); 133 if (IS_ERR(filp)) 134 return PTR_ERR(filp); 135 136 obj->filp = filp; 137 138 return 0; 139 } 140 EXPORT_SYMBOL(drm_gem_object_init); 141 142 /** 143 * drm_gem_private_object_init - initialize an allocated private GEM object 144 * @dev: drm_device the object should be initialized for 145 * @obj: drm_gem_object to initialize 146 * @size: object size 147 * 148 * Initialize an already allocated GEM object of the specified size with 149 * no GEM provided backing store. Instead the caller is responsible for 150 * backing the object and handling it. 151 */ 152 void drm_gem_private_object_init(struct drm_device *dev, 153 struct drm_gem_object *obj, size_t size) 154 { 155 BUG_ON((size & (PAGE_SIZE - 1)) != 0); 156 157 obj->dev = dev; 158 obj->filp = NULL; 159 160 kref_init(&obj->refcount); 161 obj->handle_count = 0; 162 obj->size = size; 163 dma_resv_init(&obj->_resv); 164 if (!obj->resv) 165 obj->resv = &obj->_resv; 166 167 if (drm_core_check_feature(dev, DRIVER_GEM_GPUVA)) 168 drm_gem_gpuva_init(obj); 169 170 drm_vma_node_reset(&obj->vma_node); 171 INIT_LIST_HEAD(&obj->lru_node); 172 } 173 EXPORT_SYMBOL(drm_gem_private_object_init); 174 175 /** 176 * drm_gem_private_object_fini - Finalize a failed drm_gem_object 177 * @obj: drm_gem_object 178 * 179 * Uninitialize an already allocated GEM object when it initialized failed 180 */ 181 void drm_gem_private_object_fini(struct drm_gem_object *obj) 182 { 183 WARN_ON(obj->dma_buf); 184 185 dma_resv_fini(&obj->_resv); 186 } 187 EXPORT_SYMBOL(drm_gem_private_object_fini); 188 189 /** 190 * drm_gem_object_handle_free - release resources bound to userspace handles 191 * @obj: GEM object to clean up. 192 * 193 * Called after the last handle to the object has been closed 194 * 195 * Removes any name for the object. Note that this must be 196 * called before drm_gem_object_free or we'll be touching 197 * freed memory 198 */ 199 static void drm_gem_object_handle_free(struct drm_gem_object *obj) 200 { 201 struct drm_device *dev = obj->dev; 202 203 /* Remove any name for this object */ 204 if (obj->name) { 205 idr_remove(&dev->object_name_idr, obj->name); 206 obj->name = 0; 207 } 208 } 209 210 static void drm_gem_object_exported_dma_buf_free(struct drm_gem_object *obj) 211 { 212 /* Unbreak the reference cycle if we have an exported dma_buf. */ 213 if (obj->dma_buf) { 214 dma_buf_put(obj->dma_buf); 215 obj->dma_buf = NULL; 216 } 217 } 218 219 static void 220 drm_gem_object_handle_put_unlocked(struct drm_gem_object *obj) 221 { 222 struct drm_device *dev = obj->dev; 223 bool final = false; 224 225 if (WARN_ON(READ_ONCE(obj->handle_count) == 0)) 226 return; 227 228 /* 229 * Must bump handle count first as this may be the last 230 * ref, in which case the object would disappear before we 231 * checked for a name 232 */ 233 234 mutex_lock(&dev->object_name_lock); 235 if (--obj->handle_count == 0) { 236 drm_gem_object_handle_free(obj); 237 drm_gem_object_exported_dma_buf_free(obj); 238 final = true; 239 } 240 mutex_unlock(&dev->object_name_lock); 241 242 if (final) 243 drm_gem_object_put(obj); 244 } 245 246 /* 247 * Called at device or object close to release the file's 248 * handle references on objects. 249 */ 250 static int 251 drm_gem_object_release_handle(int id, void *ptr, void *data) 252 { 253 struct drm_file *file_priv = data; 254 struct drm_gem_object *obj = ptr; 255 256 if (obj->funcs->close) 257 obj->funcs->close(obj, file_priv); 258 259 drm_prime_remove_buf_handle(&file_priv->prime, id); 260 drm_vma_node_revoke(&obj->vma_node, file_priv); 261 262 drm_gem_object_handle_put_unlocked(obj); 263 264 return 0; 265 } 266 267 /** 268 * drm_gem_handle_delete - deletes the given file-private handle 269 * @filp: drm file-private structure to use for the handle look up 270 * @handle: userspace handle to delete 271 * 272 * Removes the GEM handle from the @filp lookup table which has been added with 273 * drm_gem_handle_create(). If this is the last handle also cleans up linked 274 * resources like GEM names. 275 */ 276 int 277 drm_gem_handle_delete(struct drm_file *filp, u32 handle) 278 { 279 struct drm_gem_object *obj; 280 281 spin_lock(&filp->table_lock); 282 283 /* Check if we currently have a reference on the object */ 284 obj = idr_replace(&filp->object_idr, NULL, handle); 285 spin_unlock(&filp->table_lock); 286 if (IS_ERR_OR_NULL(obj)) 287 return -EINVAL; 288 289 /* Release driver's reference and decrement refcount. */ 290 drm_gem_object_release_handle(handle, obj, filp); 291 292 /* And finally make the handle available for future allocations. */ 293 spin_lock(&filp->table_lock); 294 idr_remove(&filp->object_idr, handle); 295 spin_unlock(&filp->table_lock); 296 297 return 0; 298 } 299 EXPORT_SYMBOL(drm_gem_handle_delete); 300 301 /** 302 * drm_gem_dumb_map_offset - return the fake mmap offset for a gem object 303 * @file: drm file-private structure containing the gem object 304 * @dev: corresponding drm_device 305 * @handle: gem object handle 306 * @offset: return location for the fake mmap offset 307 * 308 * This implements the &drm_driver.dumb_map_offset kms driver callback for 309 * drivers which use gem to manage their backing storage. 310 * 311 * Returns: 312 * 0 on success or a negative error code on failure. 313 */ 314 int drm_gem_dumb_map_offset(struct drm_file *file, struct drm_device *dev, 315 u32 handle, u64 *offset) 316 { 317 struct drm_gem_object *obj; 318 int ret; 319 320 obj = drm_gem_object_lookup(file, handle); 321 if (!obj) 322 return -ENOENT; 323 324 /* Don't allow imported objects to be mapped */ 325 if (obj->import_attach) { 326 ret = -EINVAL; 327 goto out; 328 } 329 330 ret = drm_gem_create_mmap_offset(obj); 331 if (ret) 332 goto out; 333 334 *offset = drm_vma_node_offset_addr(&obj->vma_node); 335 out: 336 drm_gem_object_put(obj); 337 338 return ret; 339 } 340 EXPORT_SYMBOL_GPL(drm_gem_dumb_map_offset); 341 342 /** 343 * drm_gem_handle_create_tail - internal functions to create a handle 344 * @file_priv: drm file-private structure to register the handle for 345 * @obj: object to register 346 * @handlep: pointer to return the created handle to the caller 347 * 348 * This expects the &drm_device.object_name_lock to be held already and will 349 * drop it before returning. Used to avoid races in establishing new handles 350 * when importing an object from either an flink name or a dma-buf. 351 * 352 * Handles must be release again through drm_gem_handle_delete(). This is done 353 * when userspace closes @file_priv for all attached handles, or through the 354 * GEM_CLOSE ioctl for individual handles. 355 */ 356 int 357 drm_gem_handle_create_tail(struct drm_file *file_priv, 358 struct drm_gem_object *obj, 359 u32 *handlep) 360 { 361 struct drm_device *dev = obj->dev; 362 u32 handle; 363 int ret; 364 365 WARN_ON(!mutex_is_locked(&dev->object_name_lock)); 366 if (obj->handle_count++ == 0) 367 drm_gem_object_get(obj); 368 369 /* 370 * Get the user-visible handle using idr. Preload and perform 371 * allocation under our spinlock. 372 */ 373 idr_preload(GFP_KERNEL); 374 spin_lock(&file_priv->table_lock); 375 376 ret = idr_alloc(&file_priv->object_idr, obj, 1, 0, GFP_NOWAIT); 377 378 spin_unlock(&file_priv->table_lock); 379 idr_preload_end(); 380 381 mutex_unlock(&dev->object_name_lock); 382 if (ret < 0) 383 goto err_unref; 384 385 handle = ret; 386 387 ret = drm_vma_node_allow(&obj->vma_node, file_priv); 388 if (ret) 389 goto err_remove; 390 391 if (obj->funcs->open) { 392 ret = obj->funcs->open(obj, file_priv); 393 if (ret) 394 goto err_revoke; 395 } 396 397 *handlep = handle; 398 return 0; 399 400 err_revoke: 401 drm_vma_node_revoke(&obj->vma_node, file_priv); 402 err_remove: 403 spin_lock(&file_priv->table_lock); 404 idr_remove(&file_priv->object_idr, handle); 405 spin_unlock(&file_priv->table_lock); 406 err_unref: 407 drm_gem_object_handle_put_unlocked(obj); 408 return ret; 409 } 410 411 /** 412 * drm_gem_handle_create - create a gem handle for an object 413 * @file_priv: drm file-private structure to register the handle for 414 * @obj: object to register 415 * @handlep: pointer to return the created handle to the caller 416 * 417 * Create a handle for this object. This adds a handle reference to the object, 418 * which includes a regular reference count. Callers will likely want to 419 * dereference the object afterwards. 420 * 421 * Since this publishes @obj to userspace it must be fully set up by this point, 422 * drivers must call this last in their buffer object creation callbacks. 423 */ 424 int drm_gem_handle_create(struct drm_file *file_priv, 425 struct drm_gem_object *obj, 426 u32 *handlep) 427 { 428 mutex_lock(&obj->dev->object_name_lock); 429 430 return drm_gem_handle_create_tail(file_priv, obj, handlep); 431 } 432 EXPORT_SYMBOL(drm_gem_handle_create); 433 434 435 /** 436 * drm_gem_free_mmap_offset - release a fake mmap offset for an object 437 * @obj: obj in question 438 * 439 * This routine frees fake offsets allocated by drm_gem_create_mmap_offset(). 440 * 441 * Note that drm_gem_object_release() already calls this function, so drivers 442 * don't have to take care of releasing the mmap offset themselves when freeing 443 * the GEM object. 444 */ 445 void 446 drm_gem_free_mmap_offset(struct drm_gem_object *obj) 447 { 448 struct drm_device *dev = obj->dev; 449 450 drm_vma_offset_remove(dev->vma_offset_manager, &obj->vma_node); 451 } 452 EXPORT_SYMBOL(drm_gem_free_mmap_offset); 453 454 /** 455 * drm_gem_create_mmap_offset_size - create a fake mmap offset for an object 456 * @obj: obj in question 457 * @size: the virtual size 458 * 459 * GEM memory mapping works by handing back to userspace a fake mmap offset 460 * it can use in a subsequent mmap(2) call. The DRM core code then looks 461 * up the object based on the offset and sets up the various memory mapping 462 * structures. 463 * 464 * This routine allocates and attaches a fake offset for @obj, in cases where 465 * the virtual size differs from the physical size (ie. &drm_gem_object.size). 466 * Otherwise just use drm_gem_create_mmap_offset(). 467 * 468 * This function is idempotent and handles an already allocated mmap offset 469 * transparently. Drivers do not need to check for this case. 470 */ 471 int 472 drm_gem_create_mmap_offset_size(struct drm_gem_object *obj, size_t size) 473 { 474 struct drm_device *dev = obj->dev; 475 476 return drm_vma_offset_add(dev->vma_offset_manager, &obj->vma_node, 477 size / PAGE_SIZE); 478 } 479 EXPORT_SYMBOL(drm_gem_create_mmap_offset_size); 480 481 /** 482 * drm_gem_create_mmap_offset - create a fake mmap offset for an object 483 * @obj: obj in question 484 * 485 * GEM memory mapping works by handing back to userspace a fake mmap offset 486 * it can use in a subsequent mmap(2) call. The DRM core code then looks 487 * up the object based on the offset and sets up the various memory mapping 488 * structures. 489 * 490 * This routine allocates and attaches a fake offset for @obj. 491 * 492 * Drivers can call drm_gem_free_mmap_offset() before freeing @obj to release 493 * the fake offset again. 494 */ 495 int drm_gem_create_mmap_offset(struct drm_gem_object *obj) 496 { 497 return drm_gem_create_mmap_offset_size(obj, obj->size); 498 } 499 EXPORT_SYMBOL(drm_gem_create_mmap_offset); 500 501 /* 502 * Move folios to appropriate lru and release the folios, decrementing the 503 * ref count of those folios. 504 */ 505 static void drm_gem_check_release_batch(struct folio_batch *fbatch) 506 { 507 check_move_unevictable_folios(fbatch); 508 __folio_batch_release(fbatch); 509 cond_resched(); 510 } 511 512 /** 513 * drm_gem_get_pages - helper to allocate backing pages for a GEM object 514 * from shmem 515 * @obj: obj in question 516 * 517 * This reads the page-array of the shmem-backing storage of the given gem 518 * object. An array of pages is returned. If a page is not allocated or 519 * swapped-out, this will allocate/swap-in the required pages. Note that the 520 * whole object is covered by the page-array and pinned in memory. 521 * 522 * Use drm_gem_put_pages() to release the array and unpin all pages. 523 * 524 * This uses the GFP-mask set on the shmem-mapping (see mapping_set_gfp_mask()). 525 * If you require other GFP-masks, you have to do those allocations yourself. 526 * 527 * Note that you are not allowed to change gfp-zones during runtime. That is, 528 * shmem_read_mapping_page_gfp() must be called with the same gfp_zone(gfp) as 529 * set during initialization. If you have special zone constraints, set them 530 * after drm_gem_object_init() via mapping_set_gfp_mask(). shmem-core takes care 531 * to keep pages in the required zone during swap-in. 532 * 533 * This function is only valid on objects initialized with 534 * drm_gem_object_init(), but not for those initialized with 535 * drm_gem_private_object_init() only. 536 */ 537 struct page **drm_gem_get_pages(struct drm_gem_object *obj) 538 { 539 struct address_space *mapping; 540 struct page **pages; 541 struct folio *folio; 542 struct folio_batch fbatch; 543 long i, j, npages; 544 545 if (WARN_ON(!obj->filp)) 546 return ERR_PTR(-EINVAL); 547 548 /* This is the shared memory object that backs the GEM resource */ 549 mapping = obj->filp->f_mapping; 550 551 /* We already BUG_ON() for non-page-aligned sizes in 552 * drm_gem_object_init(), so we should never hit this unless 553 * driver author is doing something really wrong: 554 */ 555 WARN_ON((obj->size & (PAGE_SIZE - 1)) != 0); 556 557 npages = obj->size >> PAGE_SHIFT; 558 559 pages = kvmalloc_array(npages, sizeof(struct page *), GFP_KERNEL); 560 if (pages == NULL) 561 return ERR_PTR(-ENOMEM); 562 563 mapping_set_unevictable(mapping); 564 565 i = 0; 566 while (i < npages) { 567 long nr; 568 folio = shmem_read_folio_gfp(mapping, i, 569 mapping_gfp_mask(mapping)); 570 if (IS_ERR(folio)) 571 goto fail; 572 nr = min(npages - i, folio_nr_pages(folio)); 573 for (j = 0; j < nr; j++, i++) 574 pages[i] = folio_file_page(folio, i); 575 576 /* Make sure shmem keeps __GFP_DMA32 allocated pages in the 577 * correct region during swapin. Note that this requires 578 * __GFP_DMA32 to be set in mapping_gfp_mask(inode->i_mapping) 579 * so shmem can relocate pages during swapin if required. 580 */ 581 BUG_ON(mapping_gfp_constraint(mapping, __GFP_DMA32) && 582 (folio_pfn(folio) >= 0x00100000UL)); 583 } 584 585 return pages; 586 587 fail: 588 mapping_clear_unevictable(mapping); 589 folio_batch_init(&fbatch); 590 j = 0; 591 while (j < i) { 592 struct folio *f = page_folio(pages[j]); 593 if (!folio_batch_add(&fbatch, f)) 594 drm_gem_check_release_batch(&fbatch); 595 j += folio_nr_pages(f); 596 } 597 if (fbatch.nr) 598 drm_gem_check_release_batch(&fbatch); 599 600 kvfree(pages); 601 return ERR_CAST(folio); 602 } 603 EXPORT_SYMBOL(drm_gem_get_pages); 604 605 /** 606 * drm_gem_put_pages - helper to free backing pages for a GEM object 607 * @obj: obj in question 608 * @pages: pages to free 609 * @dirty: if true, pages will be marked as dirty 610 * @accessed: if true, the pages will be marked as accessed 611 */ 612 void drm_gem_put_pages(struct drm_gem_object *obj, struct page **pages, 613 bool dirty, bool accessed) 614 { 615 int i, npages; 616 struct address_space *mapping; 617 struct folio_batch fbatch; 618 619 mapping = file_inode(obj->filp)->i_mapping; 620 mapping_clear_unevictable(mapping); 621 622 /* We already BUG_ON() for non-page-aligned sizes in 623 * drm_gem_object_init(), so we should never hit this unless 624 * driver author is doing something really wrong: 625 */ 626 WARN_ON((obj->size & (PAGE_SIZE - 1)) != 0); 627 628 npages = obj->size >> PAGE_SHIFT; 629 630 folio_batch_init(&fbatch); 631 for (i = 0; i < npages; i++) { 632 struct folio *folio; 633 634 if (!pages[i]) 635 continue; 636 folio = page_folio(pages[i]); 637 638 if (dirty) 639 folio_mark_dirty(folio); 640 641 if (accessed) 642 folio_mark_accessed(folio); 643 644 /* Undo the reference we took when populating the table */ 645 if (!folio_batch_add(&fbatch, folio)) 646 drm_gem_check_release_batch(&fbatch); 647 i += folio_nr_pages(folio) - 1; 648 } 649 if (folio_batch_count(&fbatch)) 650 drm_gem_check_release_batch(&fbatch); 651 652 kvfree(pages); 653 } 654 EXPORT_SYMBOL(drm_gem_put_pages); 655 656 static int objects_lookup(struct drm_file *filp, u32 *handle, int count, 657 struct drm_gem_object **objs) 658 { 659 int i, ret = 0; 660 struct drm_gem_object *obj; 661 662 spin_lock(&filp->table_lock); 663 664 for (i = 0; i < count; i++) { 665 /* Check if we currently have a reference on the object */ 666 obj = idr_find(&filp->object_idr, handle[i]); 667 if (!obj) { 668 ret = -ENOENT; 669 break; 670 } 671 drm_gem_object_get(obj); 672 objs[i] = obj; 673 } 674 spin_unlock(&filp->table_lock); 675 676 return ret; 677 } 678 679 /** 680 * drm_gem_objects_lookup - look up GEM objects from an array of handles 681 * @filp: DRM file private date 682 * @bo_handles: user pointer to array of userspace handle 683 * @count: size of handle array 684 * @objs_out: returned pointer to array of drm_gem_object pointers 685 * 686 * Takes an array of userspace handles and returns a newly allocated array of 687 * GEM objects. 688 * 689 * For a single handle lookup, use drm_gem_object_lookup(). 690 * 691 * Returns: 692 * 693 * @objs filled in with GEM object pointers. Returned GEM objects need to be 694 * released with drm_gem_object_put(). -ENOENT is returned on a lookup 695 * failure. 0 is returned on success. 696 * 697 */ 698 int drm_gem_objects_lookup(struct drm_file *filp, void __user *bo_handles, 699 int count, struct drm_gem_object ***objs_out) 700 { 701 int ret; 702 u32 *handles; 703 struct drm_gem_object **objs; 704 705 if (!count) 706 return 0; 707 708 objs = kvmalloc_array(count, sizeof(struct drm_gem_object *), 709 GFP_KERNEL | __GFP_ZERO); 710 if (!objs) 711 return -ENOMEM; 712 713 *objs_out = objs; 714 715 handles = kvmalloc_array(count, sizeof(u32), GFP_KERNEL); 716 if (!handles) { 717 ret = -ENOMEM; 718 goto out; 719 } 720 721 if (copy_from_user(handles, bo_handles, count * sizeof(u32))) { 722 ret = -EFAULT; 723 DRM_DEBUG("Failed to copy in GEM handles\n"); 724 goto out; 725 } 726 727 ret = objects_lookup(filp, handles, count, objs); 728 out: 729 kvfree(handles); 730 return ret; 731 732 } 733 EXPORT_SYMBOL(drm_gem_objects_lookup); 734 735 /** 736 * drm_gem_object_lookup - look up a GEM object from its handle 737 * @filp: DRM file private date 738 * @handle: userspace handle 739 * 740 * Returns: 741 * 742 * A reference to the object named by the handle if such exists on @filp, NULL 743 * otherwise. 744 * 745 * If looking up an array of handles, use drm_gem_objects_lookup(). 746 */ 747 struct drm_gem_object * 748 drm_gem_object_lookup(struct drm_file *filp, u32 handle) 749 { 750 struct drm_gem_object *obj = NULL; 751 752 objects_lookup(filp, &handle, 1, &obj); 753 return obj; 754 } 755 EXPORT_SYMBOL(drm_gem_object_lookup); 756 757 /** 758 * drm_gem_dma_resv_wait - Wait on GEM object's reservation's objects 759 * shared and/or exclusive fences. 760 * @filep: DRM file private date 761 * @handle: userspace handle 762 * @wait_all: if true, wait on all fences, else wait on just exclusive fence 763 * @timeout: timeout value in jiffies or zero to return immediately 764 * 765 * Returns: 766 * 767 * Returns -ERESTARTSYS if interrupted, 0 if the wait timed out, or 768 * greater than 0 on success. 769 */ 770 long drm_gem_dma_resv_wait(struct drm_file *filep, u32 handle, 771 bool wait_all, unsigned long timeout) 772 { 773 long ret; 774 struct drm_gem_object *obj; 775 776 obj = drm_gem_object_lookup(filep, handle); 777 if (!obj) { 778 DRM_DEBUG("Failed to look up GEM BO %d\n", handle); 779 return -EINVAL; 780 } 781 782 ret = dma_resv_wait_timeout(obj->resv, dma_resv_usage_rw(wait_all), 783 true, timeout); 784 if (ret == 0) 785 ret = -ETIME; 786 else if (ret > 0) 787 ret = 0; 788 789 drm_gem_object_put(obj); 790 791 return ret; 792 } 793 EXPORT_SYMBOL(drm_gem_dma_resv_wait); 794 795 /** 796 * drm_gem_close_ioctl - implementation of the GEM_CLOSE ioctl 797 * @dev: drm_device 798 * @data: ioctl data 799 * @file_priv: drm file-private structure 800 * 801 * Releases the handle to an mm object. 802 */ 803 int 804 drm_gem_close_ioctl(struct drm_device *dev, void *data, 805 struct drm_file *file_priv) 806 { 807 struct drm_gem_close *args = data; 808 int ret; 809 810 if (!drm_core_check_feature(dev, DRIVER_GEM)) 811 return -EOPNOTSUPP; 812 813 ret = drm_gem_handle_delete(file_priv, args->handle); 814 815 return ret; 816 } 817 818 /** 819 * drm_gem_flink_ioctl - implementation of the GEM_FLINK ioctl 820 * @dev: drm_device 821 * @data: ioctl data 822 * @file_priv: drm file-private structure 823 * 824 * Create a global name for an object, returning the name. 825 * 826 * Note that the name does not hold a reference; when the object 827 * is freed, the name goes away. 828 */ 829 int 830 drm_gem_flink_ioctl(struct drm_device *dev, void *data, 831 struct drm_file *file_priv) 832 { 833 struct drm_gem_flink *args = data; 834 struct drm_gem_object *obj; 835 int ret; 836 837 if (!drm_core_check_feature(dev, DRIVER_GEM)) 838 return -EOPNOTSUPP; 839 840 obj = drm_gem_object_lookup(file_priv, args->handle); 841 if (obj == NULL) 842 return -ENOENT; 843 844 mutex_lock(&dev->object_name_lock); 845 /* prevent races with concurrent gem_close. */ 846 if (obj->handle_count == 0) { 847 ret = -ENOENT; 848 goto err; 849 } 850 851 if (!obj->name) { 852 ret = idr_alloc(&dev->object_name_idr, obj, 1, 0, GFP_KERNEL); 853 if (ret < 0) 854 goto err; 855 856 obj->name = ret; 857 } 858 859 args->name = (uint64_t) obj->name; 860 ret = 0; 861 862 err: 863 mutex_unlock(&dev->object_name_lock); 864 drm_gem_object_put(obj); 865 return ret; 866 } 867 868 /** 869 * drm_gem_open_ioctl - implementation of the GEM_OPEN ioctl 870 * @dev: drm_device 871 * @data: ioctl data 872 * @file_priv: drm file-private structure 873 * 874 * Open an object using the global name, returning a handle and the size. 875 * 876 * This handle (of course) holds a reference to the object, so the object 877 * will not go away until the handle is deleted. 878 */ 879 int 880 drm_gem_open_ioctl(struct drm_device *dev, void *data, 881 struct drm_file *file_priv) 882 { 883 struct drm_gem_open *args = data; 884 struct drm_gem_object *obj; 885 int ret; 886 u32 handle; 887 888 if (!drm_core_check_feature(dev, DRIVER_GEM)) 889 return -EOPNOTSUPP; 890 891 mutex_lock(&dev->object_name_lock); 892 obj = idr_find(&dev->object_name_idr, (int) args->name); 893 if (obj) { 894 drm_gem_object_get(obj); 895 } else { 896 mutex_unlock(&dev->object_name_lock); 897 return -ENOENT; 898 } 899 900 /* drm_gem_handle_create_tail unlocks dev->object_name_lock. */ 901 ret = drm_gem_handle_create_tail(file_priv, obj, &handle); 902 if (ret) 903 goto err; 904 905 args->handle = handle; 906 args->size = obj->size; 907 908 err: 909 drm_gem_object_put(obj); 910 return ret; 911 } 912 913 /** 914 * drm_gem_open - initializes GEM file-private structures at devnode open time 915 * @dev: drm_device which is being opened by userspace 916 * @file_private: drm file-private structure to set up 917 * 918 * Called at device open time, sets up the structure for handling refcounting 919 * of mm objects. 920 */ 921 void 922 drm_gem_open(struct drm_device *dev, struct drm_file *file_private) 923 { 924 idr_init_base(&file_private->object_idr, 1); 925 spin_lock_init(&file_private->table_lock); 926 } 927 928 /** 929 * drm_gem_release - release file-private GEM resources 930 * @dev: drm_device which is being closed by userspace 931 * @file_private: drm file-private structure to clean up 932 * 933 * Called at close time when the filp is going away. 934 * 935 * Releases any remaining references on objects by this filp. 936 */ 937 void 938 drm_gem_release(struct drm_device *dev, struct drm_file *file_private) 939 { 940 idr_for_each(&file_private->object_idr, 941 &drm_gem_object_release_handle, file_private); 942 idr_destroy(&file_private->object_idr); 943 } 944 945 /** 946 * drm_gem_object_release - release GEM buffer object resources 947 * @obj: GEM buffer object 948 * 949 * This releases any structures and resources used by @obj and is the inverse of 950 * drm_gem_object_init(). 951 */ 952 void 953 drm_gem_object_release(struct drm_gem_object *obj) 954 { 955 if (obj->filp) 956 fput(obj->filp); 957 958 drm_gem_private_object_fini(obj); 959 960 drm_gem_free_mmap_offset(obj); 961 drm_gem_lru_remove(obj); 962 } 963 EXPORT_SYMBOL(drm_gem_object_release); 964 965 /** 966 * drm_gem_object_free - free a GEM object 967 * @kref: kref of the object to free 968 * 969 * Called after the last reference to the object has been lost. 970 * 971 * Frees the object 972 */ 973 void 974 drm_gem_object_free(struct kref *kref) 975 { 976 struct drm_gem_object *obj = 977 container_of(kref, struct drm_gem_object, refcount); 978 979 if (WARN_ON(!obj->funcs->free)) 980 return; 981 982 obj->funcs->free(obj); 983 } 984 EXPORT_SYMBOL(drm_gem_object_free); 985 986 /** 987 * drm_gem_vm_open - vma->ops->open implementation for GEM 988 * @vma: VM area structure 989 * 990 * This function implements the #vm_operations_struct open() callback for GEM 991 * drivers. This must be used together with drm_gem_vm_close(). 992 */ 993 void drm_gem_vm_open(struct vm_area_struct *vma) 994 { 995 struct drm_gem_object *obj = vma->vm_private_data; 996 997 drm_gem_object_get(obj); 998 } 999 EXPORT_SYMBOL(drm_gem_vm_open); 1000 1001 /** 1002 * drm_gem_vm_close - vma->ops->close implementation for GEM 1003 * @vma: VM area structure 1004 * 1005 * This function implements the #vm_operations_struct close() callback for GEM 1006 * drivers. This must be used together with drm_gem_vm_open(). 1007 */ 1008 void drm_gem_vm_close(struct vm_area_struct *vma) 1009 { 1010 struct drm_gem_object *obj = vma->vm_private_data; 1011 1012 drm_gem_object_put(obj); 1013 } 1014 EXPORT_SYMBOL(drm_gem_vm_close); 1015 1016 /** 1017 * drm_gem_mmap_obj - memory map a GEM object 1018 * @obj: the GEM object to map 1019 * @obj_size: the object size to be mapped, in bytes 1020 * @vma: VMA for the area to be mapped 1021 * 1022 * Set up the VMA to prepare mapping of the GEM object using the GEM object's 1023 * vm_ops. Depending on their requirements, GEM objects can either 1024 * provide a fault handler in their vm_ops (in which case any accesses to 1025 * the object will be trapped, to perform migration, GTT binding, surface 1026 * register allocation, or performance monitoring), or mmap the buffer memory 1027 * synchronously after calling drm_gem_mmap_obj. 1028 * 1029 * This function is mainly intended to implement the DMABUF mmap operation, when 1030 * the GEM object is not looked up based on its fake offset. To implement the 1031 * DRM mmap operation, drivers should use the drm_gem_mmap() function. 1032 * 1033 * drm_gem_mmap_obj() assumes the user is granted access to the buffer while 1034 * drm_gem_mmap() prevents unprivileged users from mapping random objects. So 1035 * callers must verify access restrictions before calling this helper. 1036 * 1037 * Return 0 or success or -EINVAL if the object size is smaller than the VMA 1038 * size, or if no vm_ops are provided. 1039 */ 1040 int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size, 1041 struct vm_area_struct *vma) 1042 { 1043 int ret; 1044 1045 /* Check for valid size. */ 1046 if (obj_size < vma->vm_end - vma->vm_start) 1047 return -EINVAL; 1048 1049 /* Take a ref for this mapping of the object, so that the fault 1050 * handler can dereference the mmap offset's pointer to the object. 1051 * This reference is cleaned up by the corresponding vm_close 1052 * (which should happen whether the vma was created by this call, or 1053 * by a vm_open due to mremap or partial unmap or whatever). 1054 */ 1055 drm_gem_object_get(obj); 1056 1057 vma->vm_private_data = obj; 1058 vma->vm_ops = obj->funcs->vm_ops; 1059 1060 if (obj->funcs->mmap) { 1061 ret = obj->funcs->mmap(obj, vma); 1062 if (ret) 1063 goto err_drm_gem_object_put; 1064 WARN_ON(!(vma->vm_flags & VM_DONTEXPAND)); 1065 } else { 1066 if (!vma->vm_ops) { 1067 ret = -EINVAL; 1068 goto err_drm_gem_object_put; 1069 } 1070 1071 vm_flags_set(vma, VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP); 1072 vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags)); 1073 vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot); 1074 } 1075 1076 return 0; 1077 1078 err_drm_gem_object_put: 1079 drm_gem_object_put(obj); 1080 return ret; 1081 } 1082 EXPORT_SYMBOL(drm_gem_mmap_obj); 1083 1084 /** 1085 * drm_gem_mmap - memory map routine for GEM objects 1086 * @filp: DRM file pointer 1087 * @vma: VMA for the area to be mapped 1088 * 1089 * If a driver supports GEM object mapping, mmap calls on the DRM file 1090 * descriptor will end up here. 1091 * 1092 * Look up the GEM object based on the offset passed in (vma->vm_pgoff will 1093 * contain the fake offset we created when the GTT map ioctl was called on 1094 * the object) and map it with a call to drm_gem_mmap_obj(). 1095 * 1096 * If the caller is not granted access to the buffer object, the mmap will fail 1097 * with EACCES. Please see the vma manager for more information. 1098 */ 1099 int drm_gem_mmap(struct file *filp, struct vm_area_struct *vma) 1100 { 1101 struct drm_file *priv = filp->private_data; 1102 struct drm_device *dev = priv->minor->dev; 1103 struct drm_gem_object *obj = NULL; 1104 struct drm_vma_offset_node *node; 1105 int ret; 1106 1107 if (drm_dev_is_unplugged(dev)) 1108 return -ENODEV; 1109 1110 drm_vma_offset_lock_lookup(dev->vma_offset_manager); 1111 node = drm_vma_offset_exact_lookup_locked(dev->vma_offset_manager, 1112 vma->vm_pgoff, 1113 vma_pages(vma)); 1114 if (likely(node)) { 1115 obj = container_of(node, struct drm_gem_object, vma_node); 1116 /* 1117 * When the object is being freed, after it hits 0-refcnt it 1118 * proceeds to tear down the object. In the process it will 1119 * attempt to remove the VMA offset and so acquire this 1120 * mgr->vm_lock. Therefore if we find an object with a 0-refcnt 1121 * that matches our range, we know it is in the process of being 1122 * destroyed and will be freed as soon as we release the lock - 1123 * so we have to check for the 0-refcnted object and treat it as 1124 * invalid. 1125 */ 1126 if (!kref_get_unless_zero(&obj->refcount)) 1127 obj = NULL; 1128 } 1129 drm_vma_offset_unlock_lookup(dev->vma_offset_manager); 1130 1131 if (!obj) 1132 return -EINVAL; 1133 1134 if (!drm_vma_node_is_allowed(node, priv)) { 1135 drm_gem_object_put(obj); 1136 return -EACCES; 1137 } 1138 1139 ret = drm_gem_mmap_obj(obj, drm_vma_node_size(node) << PAGE_SHIFT, 1140 vma); 1141 1142 drm_gem_object_put(obj); 1143 1144 return ret; 1145 } 1146 EXPORT_SYMBOL(drm_gem_mmap); 1147 1148 void drm_gem_print_info(struct drm_printer *p, unsigned int indent, 1149 const struct drm_gem_object *obj) 1150 { 1151 drm_printf_indent(p, indent, "name=%d\n", obj->name); 1152 drm_printf_indent(p, indent, "refcount=%u\n", 1153 kref_read(&obj->refcount)); 1154 drm_printf_indent(p, indent, "start=%08lx\n", 1155 drm_vma_node_start(&obj->vma_node)); 1156 drm_printf_indent(p, indent, "size=%zu\n", obj->size); 1157 drm_printf_indent(p, indent, "imported=%s\n", 1158 str_yes_no(obj->import_attach)); 1159 1160 if (obj->funcs->print_info) 1161 obj->funcs->print_info(p, indent, obj); 1162 } 1163 1164 int drm_gem_pin(struct drm_gem_object *obj) 1165 { 1166 if (obj->funcs->pin) 1167 return obj->funcs->pin(obj); 1168 1169 return 0; 1170 } 1171 1172 void drm_gem_unpin(struct drm_gem_object *obj) 1173 { 1174 if (obj->funcs->unpin) 1175 obj->funcs->unpin(obj); 1176 } 1177 1178 int drm_gem_vmap(struct drm_gem_object *obj, struct iosys_map *map) 1179 { 1180 int ret; 1181 1182 dma_resv_assert_held(obj->resv); 1183 1184 if (!obj->funcs->vmap) 1185 return -EOPNOTSUPP; 1186 1187 ret = obj->funcs->vmap(obj, map); 1188 if (ret) 1189 return ret; 1190 else if (iosys_map_is_null(map)) 1191 return -ENOMEM; 1192 1193 return 0; 1194 } 1195 EXPORT_SYMBOL(drm_gem_vmap); 1196 1197 void drm_gem_vunmap(struct drm_gem_object *obj, struct iosys_map *map) 1198 { 1199 dma_resv_assert_held(obj->resv); 1200 1201 if (iosys_map_is_null(map)) 1202 return; 1203 1204 if (obj->funcs->vunmap) 1205 obj->funcs->vunmap(obj, map); 1206 1207 /* Always set the mapping to NULL. Callers may rely on this. */ 1208 iosys_map_clear(map); 1209 } 1210 EXPORT_SYMBOL(drm_gem_vunmap); 1211 1212 int drm_gem_vmap_unlocked(struct drm_gem_object *obj, struct iosys_map *map) 1213 { 1214 int ret; 1215 1216 dma_resv_lock(obj->resv, NULL); 1217 ret = drm_gem_vmap(obj, map); 1218 dma_resv_unlock(obj->resv); 1219 1220 return ret; 1221 } 1222 EXPORT_SYMBOL(drm_gem_vmap_unlocked); 1223 1224 void drm_gem_vunmap_unlocked(struct drm_gem_object *obj, struct iosys_map *map) 1225 { 1226 dma_resv_lock(obj->resv, NULL); 1227 drm_gem_vunmap(obj, map); 1228 dma_resv_unlock(obj->resv); 1229 } 1230 EXPORT_SYMBOL(drm_gem_vunmap_unlocked); 1231 1232 /** 1233 * drm_gem_lock_reservations - Sets up the ww context and acquires 1234 * the lock on an array of GEM objects. 1235 * 1236 * Once you've locked your reservations, you'll want to set up space 1237 * for your shared fences (if applicable), submit your job, then 1238 * drm_gem_unlock_reservations(). 1239 * 1240 * @objs: drm_gem_objects to lock 1241 * @count: Number of objects in @objs 1242 * @acquire_ctx: struct ww_acquire_ctx that will be initialized as 1243 * part of tracking this set of locked reservations. 1244 */ 1245 int 1246 drm_gem_lock_reservations(struct drm_gem_object **objs, int count, 1247 struct ww_acquire_ctx *acquire_ctx) 1248 { 1249 int contended = -1; 1250 int i, ret; 1251 1252 ww_acquire_init(acquire_ctx, &reservation_ww_class); 1253 1254 retry: 1255 if (contended != -1) { 1256 struct drm_gem_object *obj = objs[contended]; 1257 1258 ret = dma_resv_lock_slow_interruptible(obj->resv, 1259 acquire_ctx); 1260 if (ret) { 1261 ww_acquire_fini(acquire_ctx); 1262 return ret; 1263 } 1264 } 1265 1266 for (i = 0; i < count; i++) { 1267 if (i == contended) 1268 continue; 1269 1270 ret = dma_resv_lock_interruptible(objs[i]->resv, 1271 acquire_ctx); 1272 if (ret) { 1273 int j; 1274 1275 for (j = 0; j < i; j++) 1276 dma_resv_unlock(objs[j]->resv); 1277 1278 if (contended != -1 && contended >= i) 1279 dma_resv_unlock(objs[contended]->resv); 1280 1281 if (ret == -EDEADLK) { 1282 contended = i; 1283 goto retry; 1284 } 1285 1286 ww_acquire_fini(acquire_ctx); 1287 return ret; 1288 } 1289 } 1290 1291 ww_acquire_done(acquire_ctx); 1292 1293 return 0; 1294 } 1295 EXPORT_SYMBOL(drm_gem_lock_reservations); 1296 1297 void 1298 drm_gem_unlock_reservations(struct drm_gem_object **objs, int count, 1299 struct ww_acquire_ctx *acquire_ctx) 1300 { 1301 int i; 1302 1303 for (i = 0; i < count; i++) 1304 dma_resv_unlock(objs[i]->resv); 1305 1306 ww_acquire_fini(acquire_ctx); 1307 } 1308 EXPORT_SYMBOL(drm_gem_unlock_reservations); 1309 1310 /** 1311 * drm_gem_lru_init - initialize a LRU 1312 * 1313 * @lru: The LRU to initialize 1314 * @lock: The lock protecting the LRU 1315 */ 1316 void 1317 drm_gem_lru_init(struct drm_gem_lru *lru, struct mutex *lock) 1318 { 1319 lru->lock = lock; 1320 lru->count = 0; 1321 INIT_LIST_HEAD(&lru->list); 1322 } 1323 EXPORT_SYMBOL(drm_gem_lru_init); 1324 1325 static void 1326 drm_gem_lru_remove_locked(struct drm_gem_object *obj) 1327 { 1328 obj->lru->count -= obj->size >> PAGE_SHIFT; 1329 WARN_ON(obj->lru->count < 0); 1330 list_del(&obj->lru_node); 1331 obj->lru = NULL; 1332 } 1333 1334 /** 1335 * drm_gem_lru_remove - remove object from whatever LRU it is in 1336 * 1337 * If the object is currently in any LRU, remove it. 1338 * 1339 * @obj: The GEM object to remove from current LRU 1340 */ 1341 void 1342 drm_gem_lru_remove(struct drm_gem_object *obj) 1343 { 1344 struct drm_gem_lru *lru = obj->lru; 1345 1346 if (!lru) 1347 return; 1348 1349 mutex_lock(lru->lock); 1350 drm_gem_lru_remove_locked(obj); 1351 mutex_unlock(lru->lock); 1352 } 1353 EXPORT_SYMBOL(drm_gem_lru_remove); 1354 1355 /** 1356 * drm_gem_lru_move_tail_locked - move the object to the tail of the LRU 1357 * 1358 * Like &drm_gem_lru_move_tail but lru lock must be held 1359 * 1360 * @lru: The LRU to move the object into. 1361 * @obj: The GEM object to move into this LRU 1362 */ 1363 void 1364 drm_gem_lru_move_tail_locked(struct drm_gem_lru *lru, struct drm_gem_object *obj) 1365 { 1366 lockdep_assert_held_once(lru->lock); 1367 1368 if (obj->lru) 1369 drm_gem_lru_remove_locked(obj); 1370 1371 lru->count += obj->size >> PAGE_SHIFT; 1372 list_add_tail(&obj->lru_node, &lru->list); 1373 obj->lru = lru; 1374 } 1375 EXPORT_SYMBOL(drm_gem_lru_move_tail_locked); 1376 1377 /** 1378 * drm_gem_lru_move_tail - move the object to the tail of the LRU 1379 * 1380 * If the object is already in this LRU it will be moved to the 1381 * tail. Otherwise it will be removed from whichever other LRU 1382 * it is in (if any) and moved into this LRU. 1383 * 1384 * @lru: The LRU to move the object into. 1385 * @obj: The GEM object to move into this LRU 1386 */ 1387 void 1388 drm_gem_lru_move_tail(struct drm_gem_lru *lru, struct drm_gem_object *obj) 1389 { 1390 mutex_lock(lru->lock); 1391 drm_gem_lru_move_tail_locked(lru, obj); 1392 mutex_unlock(lru->lock); 1393 } 1394 EXPORT_SYMBOL(drm_gem_lru_move_tail); 1395 1396 /** 1397 * drm_gem_lru_scan - helper to implement shrinker.scan_objects 1398 * 1399 * If the shrink callback succeeds, it is expected that the driver 1400 * move the object out of this LRU. 1401 * 1402 * If the LRU possibly contain active buffers, it is the responsibility 1403 * of the shrink callback to check for this (ie. dma_resv_test_signaled()) 1404 * or if necessary block until the buffer becomes idle. 1405 * 1406 * @lru: The LRU to scan 1407 * @nr_to_scan: The number of pages to try to reclaim 1408 * @remaining: The number of pages left to reclaim, should be initialized by caller 1409 * @shrink: Callback to try to shrink/reclaim the object. 1410 */ 1411 unsigned long 1412 drm_gem_lru_scan(struct drm_gem_lru *lru, 1413 unsigned int nr_to_scan, 1414 unsigned long *remaining, 1415 bool (*shrink)(struct drm_gem_object *obj)) 1416 { 1417 struct drm_gem_lru still_in_lru; 1418 struct drm_gem_object *obj; 1419 unsigned freed = 0; 1420 1421 drm_gem_lru_init(&still_in_lru, lru->lock); 1422 1423 mutex_lock(lru->lock); 1424 1425 while (freed < nr_to_scan) { 1426 obj = list_first_entry_or_null(&lru->list, typeof(*obj), lru_node); 1427 1428 if (!obj) 1429 break; 1430 1431 drm_gem_lru_move_tail_locked(&still_in_lru, obj); 1432 1433 /* 1434 * If it's in the process of being freed, gem_object->free() 1435 * may be blocked on lock waiting to remove it. So just 1436 * skip it. 1437 */ 1438 if (!kref_get_unless_zero(&obj->refcount)) 1439 continue; 1440 1441 /* 1442 * Now that we own a reference, we can drop the lock for the 1443 * rest of the loop body, to reduce contention with other 1444 * code paths that need the LRU lock 1445 */ 1446 mutex_unlock(lru->lock); 1447 1448 /* 1449 * Note that this still needs to be trylock, since we can 1450 * hit shrinker in response to trying to get backing pages 1451 * for this obj (ie. while it's lock is already held) 1452 */ 1453 if (!dma_resv_trylock(obj->resv)) { 1454 *remaining += obj->size >> PAGE_SHIFT; 1455 goto tail; 1456 } 1457 1458 if (shrink(obj)) { 1459 freed += obj->size >> PAGE_SHIFT; 1460 1461 /* 1462 * If we succeeded in releasing the object's backing 1463 * pages, we expect the driver to have moved the object 1464 * out of this LRU 1465 */ 1466 WARN_ON(obj->lru == &still_in_lru); 1467 WARN_ON(obj->lru == lru); 1468 } 1469 1470 dma_resv_unlock(obj->resv); 1471 1472 tail: 1473 drm_gem_object_put(obj); 1474 mutex_lock(lru->lock); 1475 } 1476 1477 /* 1478 * Move objects we've skipped over out of the temporary still_in_lru 1479 * back into this LRU 1480 */ 1481 list_for_each_entry (obj, &still_in_lru.list, lru_node) 1482 obj->lru = lru; 1483 list_splice_tail(&still_in_lru.list, &lru->list); 1484 lru->count += still_in_lru.count; 1485 1486 mutex_unlock(lru->lock); 1487 1488 return freed; 1489 } 1490 EXPORT_SYMBOL(drm_gem_lru_scan); 1491 1492 /** 1493 * drm_gem_evict - helper to evict backing pages for a GEM object 1494 * @obj: obj in question 1495 */ 1496 int drm_gem_evict(struct drm_gem_object *obj) 1497 { 1498 dma_resv_assert_held(obj->resv); 1499 1500 if (!dma_resv_test_signaled(obj->resv, DMA_RESV_USAGE_READ)) 1501 return -EBUSY; 1502 1503 if (obj->funcs->evict) 1504 return obj->funcs->evict(obj); 1505 1506 return 0; 1507 } 1508 EXPORT_SYMBOL(drm_gem_evict); 1509