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/export.h> 30 #include <linux/file.h> 31 #include <linux/fs.h> 32 #include <linux/iosys-map.h> 33 #include <linux/mem_encrypt.h> 34 #include <linux/mm.h> 35 #include <linux/mman.h> 36 #include <linux/module.h> 37 #include <linux/pagemap.h> 38 #include <linux/pagevec.h> 39 #include <linux/shmem_fs.h> 40 #include <linux/slab.h> 41 #include <linux/string_helpers.h> 42 #include <linux/types.h> 43 #include <linux/uaccess.h> 44 45 #include <drm/drm.h> 46 #include <drm/drm_device.h> 47 #include <drm/drm_drv.h> 48 #include <drm/drm_file.h> 49 #include <drm/drm_gem.h> 50 #include <drm/drm_managed.h> 51 #include <drm/drm_print.h> 52 #include <drm/drm_vma_manager.h> 53 54 #include "drm_internal.h" 55 56 /** @file drm_gem.c 57 * 58 * This file provides some of the base ioctls and library routines for 59 * the graphics memory manager implemented by each device driver. 60 * 61 * Because various devices have different requirements in terms of 62 * synchronization and migration strategies, implementing that is left up to 63 * the driver, and all that the general API provides should be generic -- 64 * allocating objects, reading/writing data with the cpu, freeing objects. 65 * Even there, platform-dependent optimizations for reading/writing data with 66 * the CPU mean we'll likely hook those out to driver-specific calls. However, 67 * the DRI2 implementation wants to have at least allocate/mmap be generic. 68 * 69 * The goal was to have swap-backed object allocation managed through 70 * struct file. However, file descriptors as handles to a struct file have 71 * two major failings: 72 * - Process limits prevent more than 1024 or so being used at a time by 73 * default. 74 * - Inability to allocate high fds will aggravate the X Server's select() 75 * handling, and likely that of many GL client applications as well. 76 * 77 * This led to a plan of using our own integer IDs (called handles, following 78 * DRM terminology) to mimic fds, and implement the fd syscalls we need as 79 * ioctls. The objects themselves will still include the struct file so 80 * that we can transition to fds if the required kernel infrastructure shows 81 * up at a later date, and as our interface with shmfs for memory allocation. 82 */ 83 84 static void 85 drm_gem_init_release(struct drm_device *dev, void *ptr) 86 { 87 drm_vma_offset_manager_destroy(dev->vma_offset_manager); 88 } 89 90 /** 91 * drm_gem_init - Initialize the GEM device fields 92 * @dev: drm_devic structure to initialize 93 */ 94 int 95 drm_gem_init(struct drm_device *dev) 96 { 97 struct drm_vma_offset_manager *vma_offset_manager; 98 99 mutex_init(&dev->object_name_lock); 100 idr_init_base(&dev->object_name_idr, 1); 101 102 vma_offset_manager = drmm_kzalloc(dev, sizeof(*vma_offset_manager), 103 GFP_KERNEL); 104 if (!vma_offset_manager) { 105 DRM_ERROR("out of memory\n"); 106 return -ENOMEM; 107 } 108 109 dev->vma_offset_manager = vma_offset_manager; 110 drm_vma_offset_manager_init(vma_offset_manager, 111 DRM_FILE_PAGE_OFFSET_START, 112 DRM_FILE_PAGE_OFFSET_SIZE); 113 114 return drmm_add_action(dev, drm_gem_init_release, NULL); 115 } 116 117 /** 118 * drm_gem_object_init_with_mnt - initialize an allocated shmem-backed GEM 119 * object in a given shmfs mountpoint 120 * 121 * @dev: drm_device the object should be initialized for 122 * @obj: drm_gem_object to initialize 123 * @size: object size 124 * @gemfs: tmpfs mount where the GEM object will be created. If NULL, use 125 * the usual tmpfs mountpoint (`shm_mnt`). 126 * 127 * Initialize an already allocated GEM object of the specified size with 128 * shmfs backing store. 129 */ 130 int drm_gem_object_init_with_mnt(struct drm_device *dev, 131 struct drm_gem_object *obj, size_t size, 132 struct vfsmount *gemfs) 133 { 134 struct file *filp; 135 136 drm_gem_private_object_init(dev, obj, size); 137 138 if (gemfs) 139 filp = shmem_file_setup_with_mnt(gemfs, "drm mm object", size, 140 VM_NORESERVE); 141 else 142 filp = shmem_file_setup("drm mm object", size, VM_NORESERVE); 143 144 if (IS_ERR(filp)) 145 return PTR_ERR(filp); 146 147 obj->filp = filp; 148 149 return 0; 150 } 151 EXPORT_SYMBOL(drm_gem_object_init_with_mnt); 152 153 /** 154 * drm_gem_object_init - initialize an allocated shmem-backed GEM object 155 * @dev: drm_device the object should be initialized for 156 * @obj: drm_gem_object to initialize 157 * @size: object size 158 * 159 * Initialize an already allocated GEM object of the specified size with 160 * shmfs backing store. 161 */ 162 int drm_gem_object_init(struct drm_device *dev, struct drm_gem_object *obj, 163 size_t size) 164 { 165 return drm_gem_object_init_with_mnt(dev, obj, size, NULL); 166 } 167 EXPORT_SYMBOL(drm_gem_object_init); 168 169 /** 170 * drm_gem_private_object_init - initialize an allocated private GEM object 171 * @dev: drm_device the object should be initialized for 172 * @obj: drm_gem_object to initialize 173 * @size: object size 174 * 175 * Initialize an already allocated GEM object of the specified size with 176 * no GEM provided backing store. Instead the caller is responsible for 177 * backing the object and handling it. 178 */ 179 void drm_gem_private_object_init(struct drm_device *dev, 180 struct drm_gem_object *obj, size_t size) 181 { 182 BUG_ON((size & (PAGE_SIZE - 1)) != 0); 183 184 obj->dev = dev; 185 obj->filp = NULL; 186 187 kref_init(&obj->refcount); 188 obj->handle_count = 0; 189 obj->size = size; 190 dma_resv_init(&obj->_resv); 191 if (!obj->resv) 192 obj->resv = &obj->_resv; 193 194 if (drm_core_check_feature(dev, DRIVER_GEM_GPUVA)) 195 drm_gem_gpuva_init(obj); 196 197 drm_vma_node_reset(&obj->vma_node); 198 INIT_LIST_HEAD(&obj->lru_node); 199 } 200 EXPORT_SYMBOL(drm_gem_private_object_init); 201 202 /** 203 * drm_gem_private_object_fini - Finalize a failed drm_gem_object 204 * @obj: drm_gem_object 205 * 206 * Uninitialize an already allocated GEM object when it initialized failed 207 */ 208 void drm_gem_private_object_fini(struct drm_gem_object *obj) 209 { 210 WARN_ON(obj->dma_buf); 211 212 dma_resv_fini(&obj->_resv); 213 } 214 EXPORT_SYMBOL(drm_gem_private_object_fini); 215 216 /** 217 * drm_gem_object_handle_free - release resources bound to userspace handles 218 * @obj: GEM object to clean up. 219 * 220 * Called after the last handle to the object has been closed 221 * 222 * Removes any name for the object. Note that this must be 223 * called before drm_gem_object_free or we'll be touching 224 * freed memory 225 */ 226 static void drm_gem_object_handle_free(struct drm_gem_object *obj) 227 { 228 struct drm_device *dev = obj->dev; 229 230 /* Remove any name for this object */ 231 if (obj->name) { 232 idr_remove(&dev->object_name_idr, obj->name); 233 obj->name = 0; 234 } 235 } 236 237 static void drm_gem_object_exported_dma_buf_free(struct drm_gem_object *obj) 238 { 239 /* Unbreak the reference cycle if we have an exported dma_buf. */ 240 if (obj->dma_buf) { 241 dma_buf_put(obj->dma_buf); 242 obj->dma_buf = NULL; 243 } 244 } 245 246 static void 247 drm_gem_object_handle_put_unlocked(struct drm_gem_object *obj) 248 { 249 struct drm_device *dev = obj->dev; 250 bool final = false; 251 252 if (WARN_ON(READ_ONCE(obj->handle_count) == 0)) 253 return; 254 255 /* 256 * Must bump handle count first as this may be the last 257 * ref, in which case the object would disappear before we 258 * checked for a name 259 */ 260 261 mutex_lock(&dev->object_name_lock); 262 if (--obj->handle_count == 0) { 263 drm_gem_object_handle_free(obj); 264 drm_gem_object_exported_dma_buf_free(obj); 265 final = true; 266 } 267 mutex_unlock(&dev->object_name_lock); 268 269 if (final) 270 drm_gem_object_put(obj); 271 } 272 273 /* 274 * Called at device or object close to release the file's 275 * handle references on objects. 276 */ 277 static int 278 drm_gem_object_release_handle(int id, void *ptr, void *data) 279 { 280 struct drm_file *file_priv = data; 281 struct drm_gem_object *obj = ptr; 282 283 if (obj->funcs->close) 284 obj->funcs->close(obj, file_priv); 285 286 drm_prime_remove_buf_handle(&file_priv->prime, id); 287 drm_vma_node_revoke(&obj->vma_node, file_priv); 288 289 drm_gem_object_handle_put_unlocked(obj); 290 291 return 0; 292 } 293 294 /** 295 * drm_gem_handle_delete - deletes the given file-private handle 296 * @filp: drm file-private structure to use for the handle look up 297 * @handle: userspace handle to delete 298 * 299 * Removes the GEM handle from the @filp lookup table which has been added with 300 * drm_gem_handle_create(). If this is the last handle also cleans up linked 301 * resources like GEM names. 302 */ 303 int 304 drm_gem_handle_delete(struct drm_file *filp, u32 handle) 305 { 306 struct drm_gem_object *obj; 307 308 spin_lock(&filp->table_lock); 309 310 /* Check if we currently have a reference on the object */ 311 obj = idr_replace(&filp->object_idr, NULL, handle); 312 spin_unlock(&filp->table_lock); 313 if (IS_ERR_OR_NULL(obj)) 314 return -EINVAL; 315 316 /* Release driver's reference and decrement refcount. */ 317 drm_gem_object_release_handle(handle, obj, filp); 318 319 /* And finally make the handle available for future allocations. */ 320 spin_lock(&filp->table_lock); 321 idr_remove(&filp->object_idr, handle); 322 spin_unlock(&filp->table_lock); 323 324 return 0; 325 } 326 EXPORT_SYMBOL(drm_gem_handle_delete); 327 328 /** 329 * drm_gem_dumb_map_offset - return the fake mmap offset for a gem object 330 * @file: drm file-private structure containing the gem object 331 * @dev: corresponding drm_device 332 * @handle: gem object handle 333 * @offset: return location for the fake mmap offset 334 * 335 * This implements the &drm_driver.dumb_map_offset kms driver callback for 336 * drivers which use gem to manage their backing storage. 337 * 338 * Returns: 339 * 0 on success or a negative error code on failure. 340 */ 341 int drm_gem_dumb_map_offset(struct drm_file *file, struct drm_device *dev, 342 u32 handle, u64 *offset) 343 { 344 struct drm_gem_object *obj; 345 int ret; 346 347 obj = drm_gem_object_lookup(file, handle); 348 if (!obj) 349 return -ENOENT; 350 351 /* Don't allow imported objects to be mapped */ 352 if (drm_gem_is_imported(obj)) { 353 ret = -EINVAL; 354 goto out; 355 } 356 357 ret = drm_gem_create_mmap_offset(obj); 358 if (ret) 359 goto out; 360 361 *offset = drm_vma_node_offset_addr(&obj->vma_node); 362 out: 363 drm_gem_object_put(obj); 364 365 return ret; 366 } 367 EXPORT_SYMBOL_GPL(drm_gem_dumb_map_offset); 368 369 /** 370 * drm_gem_handle_create_tail - internal functions to create a handle 371 * @file_priv: drm file-private structure to register the handle for 372 * @obj: object to register 373 * @handlep: pointer to return the created handle to the caller 374 * 375 * This expects the &drm_device.object_name_lock to be held already and will 376 * drop it before returning. Used to avoid races in establishing new handles 377 * when importing an object from either an flink name or a dma-buf. 378 * 379 * Handles must be release again through drm_gem_handle_delete(). This is done 380 * when userspace closes @file_priv for all attached handles, or through the 381 * GEM_CLOSE ioctl for individual handles. 382 */ 383 int 384 drm_gem_handle_create_tail(struct drm_file *file_priv, 385 struct drm_gem_object *obj, 386 u32 *handlep) 387 { 388 struct drm_device *dev = obj->dev; 389 u32 handle; 390 int ret; 391 392 WARN_ON(!mutex_is_locked(&dev->object_name_lock)); 393 if (obj->handle_count++ == 0) 394 drm_gem_object_get(obj); 395 396 /* 397 * Get the user-visible handle using idr. Preload and perform 398 * allocation under our spinlock. 399 */ 400 idr_preload(GFP_KERNEL); 401 spin_lock(&file_priv->table_lock); 402 403 ret = idr_alloc(&file_priv->object_idr, obj, 1, 0, GFP_NOWAIT); 404 405 spin_unlock(&file_priv->table_lock); 406 idr_preload_end(); 407 408 mutex_unlock(&dev->object_name_lock); 409 if (ret < 0) 410 goto err_unref; 411 412 handle = ret; 413 414 ret = drm_vma_node_allow(&obj->vma_node, file_priv); 415 if (ret) 416 goto err_remove; 417 418 if (obj->funcs->open) { 419 ret = obj->funcs->open(obj, file_priv); 420 if (ret) 421 goto err_revoke; 422 } 423 424 *handlep = handle; 425 return 0; 426 427 err_revoke: 428 drm_vma_node_revoke(&obj->vma_node, file_priv); 429 err_remove: 430 spin_lock(&file_priv->table_lock); 431 idr_remove(&file_priv->object_idr, handle); 432 spin_unlock(&file_priv->table_lock); 433 err_unref: 434 drm_gem_object_handle_put_unlocked(obj); 435 return ret; 436 } 437 438 /** 439 * drm_gem_handle_create - create a gem handle for an object 440 * @file_priv: drm file-private structure to register the handle for 441 * @obj: object to register 442 * @handlep: pointer to return the created handle to the caller 443 * 444 * Create a handle for this object. This adds a handle reference to the object, 445 * which includes a regular reference count. Callers will likely want to 446 * dereference the object afterwards. 447 * 448 * Since this publishes @obj to userspace it must be fully set up by this point, 449 * drivers must call this last in their buffer object creation callbacks. 450 */ 451 int drm_gem_handle_create(struct drm_file *file_priv, 452 struct drm_gem_object *obj, 453 u32 *handlep) 454 { 455 mutex_lock(&obj->dev->object_name_lock); 456 457 return drm_gem_handle_create_tail(file_priv, obj, handlep); 458 } 459 EXPORT_SYMBOL(drm_gem_handle_create); 460 461 462 /** 463 * drm_gem_free_mmap_offset - release a fake mmap offset for an object 464 * @obj: obj in question 465 * 466 * This routine frees fake offsets allocated by drm_gem_create_mmap_offset(). 467 * 468 * Note that drm_gem_object_release() already calls this function, so drivers 469 * don't have to take care of releasing the mmap offset themselves when freeing 470 * the GEM object. 471 */ 472 void 473 drm_gem_free_mmap_offset(struct drm_gem_object *obj) 474 { 475 struct drm_device *dev = obj->dev; 476 477 drm_vma_offset_remove(dev->vma_offset_manager, &obj->vma_node); 478 } 479 EXPORT_SYMBOL(drm_gem_free_mmap_offset); 480 481 /** 482 * drm_gem_create_mmap_offset_size - create a fake mmap offset for an object 483 * @obj: obj in question 484 * @size: the virtual size 485 * 486 * GEM memory mapping works by handing back to userspace a fake mmap offset 487 * it can use in a subsequent mmap(2) call. The DRM core code then looks 488 * up the object based on the offset and sets up the various memory mapping 489 * structures. 490 * 491 * This routine allocates and attaches a fake offset for @obj, in cases where 492 * the virtual size differs from the physical size (ie. &drm_gem_object.size). 493 * Otherwise just use drm_gem_create_mmap_offset(). 494 * 495 * This function is idempotent and handles an already allocated mmap offset 496 * transparently. Drivers do not need to check for this case. 497 */ 498 int 499 drm_gem_create_mmap_offset_size(struct drm_gem_object *obj, size_t size) 500 { 501 struct drm_device *dev = obj->dev; 502 503 return drm_vma_offset_add(dev->vma_offset_manager, &obj->vma_node, 504 size / PAGE_SIZE); 505 } 506 EXPORT_SYMBOL(drm_gem_create_mmap_offset_size); 507 508 /** 509 * drm_gem_create_mmap_offset - create a fake mmap offset for an object 510 * @obj: obj in question 511 * 512 * GEM memory mapping works by handing back to userspace a fake mmap offset 513 * it can use in a subsequent mmap(2) call. The DRM core code then looks 514 * up the object based on the offset and sets up the various memory mapping 515 * structures. 516 * 517 * This routine allocates and attaches a fake offset for @obj. 518 * 519 * Drivers can call drm_gem_free_mmap_offset() before freeing @obj to release 520 * the fake offset again. 521 */ 522 int drm_gem_create_mmap_offset(struct drm_gem_object *obj) 523 { 524 return drm_gem_create_mmap_offset_size(obj, obj->size); 525 } 526 EXPORT_SYMBOL(drm_gem_create_mmap_offset); 527 528 /* 529 * Move folios to appropriate lru and release the folios, decrementing the 530 * ref count of those folios. 531 */ 532 static void drm_gem_check_release_batch(struct folio_batch *fbatch) 533 { 534 check_move_unevictable_folios(fbatch); 535 __folio_batch_release(fbatch); 536 cond_resched(); 537 } 538 539 /** 540 * drm_gem_get_pages - helper to allocate backing pages for a GEM object 541 * from shmem 542 * @obj: obj in question 543 * 544 * This reads the page-array of the shmem-backing storage of the given gem 545 * object. An array of pages is returned. If a page is not allocated or 546 * swapped-out, this will allocate/swap-in the required pages. Note that the 547 * whole object is covered by the page-array and pinned in memory. 548 * 549 * Use drm_gem_put_pages() to release the array and unpin all pages. 550 * 551 * This uses the GFP-mask set on the shmem-mapping (see mapping_set_gfp_mask()). 552 * If you require other GFP-masks, you have to do those allocations yourself. 553 * 554 * Note that you are not allowed to change gfp-zones during runtime. That is, 555 * shmem_read_mapping_page_gfp() must be called with the same gfp_zone(gfp) as 556 * set during initialization. If you have special zone constraints, set them 557 * after drm_gem_object_init() via mapping_set_gfp_mask(). shmem-core takes care 558 * to keep pages in the required zone during swap-in. 559 * 560 * This function is only valid on objects initialized with 561 * drm_gem_object_init(), but not for those initialized with 562 * drm_gem_private_object_init() only. 563 */ 564 struct page **drm_gem_get_pages(struct drm_gem_object *obj) 565 { 566 struct address_space *mapping; 567 struct page **pages; 568 struct folio *folio; 569 struct folio_batch fbatch; 570 long i, j, npages; 571 572 if (WARN_ON(!obj->filp)) 573 return ERR_PTR(-EINVAL); 574 575 /* This is the shared memory object that backs the GEM resource */ 576 mapping = obj->filp->f_mapping; 577 578 /* We already BUG_ON() for non-page-aligned sizes in 579 * drm_gem_object_init(), so we should never hit this unless 580 * driver author is doing something really wrong: 581 */ 582 WARN_ON((obj->size & (PAGE_SIZE - 1)) != 0); 583 584 npages = obj->size >> PAGE_SHIFT; 585 586 pages = kvmalloc_array(npages, sizeof(struct page *), GFP_KERNEL); 587 if (pages == NULL) 588 return ERR_PTR(-ENOMEM); 589 590 mapping_set_unevictable(mapping); 591 592 i = 0; 593 while (i < npages) { 594 long nr; 595 folio = shmem_read_folio_gfp(mapping, i, 596 mapping_gfp_mask(mapping)); 597 if (IS_ERR(folio)) 598 goto fail; 599 nr = min(npages - i, folio_nr_pages(folio)); 600 for (j = 0; j < nr; j++, i++) 601 pages[i] = folio_file_page(folio, i); 602 603 /* Make sure shmem keeps __GFP_DMA32 allocated pages in the 604 * correct region during swapin. Note that this requires 605 * __GFP_DMA32 to be set in mapping_gfp_mask(inode->i_mapping) 606 * so shmem can relocate pages during swapin if required. 607 */ 608 BUG_ON(mapping_gfp_constraint(mapping, __GFP_DMA32) && 609 (folio_pfn(folio) >= 0x00100000UL)); 610 } 611 612 return pages; 613 614 fail: 615 mapping_clear_unevictable(mapping); 616 folio_batch_init(&fbatch); 617 j = 0; 618 while (j < i) { 619 struct folio *f = page_folio(pages[j]); 620 if (!folio_batch_add(&fbatch, f)) 621 drm_gem_check_release_batch(&fbatch); 622 j += folio_nr_pages(f); 623 } 624 if (fbatch.nr) 625 drm_gem_check_release_batch(&fbatch); 626 627 kvfree(pages); 628 return ERR_CAST(folio); 629 } 630 EXPORT_SYMBOL(drm_gem_get_pages); 631 632 /** 633 * drm_gem_put_pages - helper to free backing pages for a GEM object 634 * @obj: obj in question 635 * @pages: pages to free 636 * @dirty: if true, pages will be marked as dirty 637 * @accessed: if true, the pages will be marked as accessed 638 */ 639 void drm_gem_put_pages(struct drm_gem_object *obj, struct page **pages, 640 bool dirty, bool accessed) 641 { 642 int i, npages; 643 struct address_space *mapping; 644 struct folio_batch fbatch; 645 646 mapping = file_inode(obj->filp)->i_mapping; 647 mapping_clear_unevictable(mapping); 648 649 /* We already BUG_ON() for non-page-aligned sizes in 650 * drm_gem_object_init(), so we should never hit this unless 651 * driver author is doing something really wrong: 652 */ 653 WARN_ON((obj->size & (PAGE_SIZE - 1)) != 0); 654 655 npages = obj->size >> PAGE_SHIFT; 656 657 folio_batch_init(&fbatch); 658 for (i = 0; i < npages; i++) { 659 struct folio *folio; 660 661 if (!pages[i]) 662 continue; 663 folio = page_folio(pages[i]); 664 665 if (dirty) 666 folio_mark_dirty(folio); 667 668 if (accessed) 669 folio_mark_accessed(folio); 670 671 /* Undo the reference we took when populating the table */ 672 if (!folio_batch_add(&fbatch, folio)) 673 drm_gem_check_release_batch(&fbatch); 674 i += folio_nr_pages(folio) - 1; 675 } 676 if (folio_batch_count(&fbatch)) 677 drm_gem_check_release_batch(&fbatch); 678 679 kvfree(pages); 680 } 681 EXPORT_SYMBOL(drm_gem_put_pages); 682 683 static int objects_lookup(struct drm_file *filp, u32 *handle, int count, 684 struct drm_gem_object **objs) 685 { 686 int i, ret = 0; 687 struct drm_gem_object *obj; 688 689 spin_lock(&filp->table_lock); 690 691 for (i = 0; i < count; i++) { 692 /* Check if we currently have a reference on the object */ 693 obj = idr_find(&filp->object_idr, handle[i]); 694 if (!obj) { 695 ret = -ENOENT; 696 break; 697 } 698 drm_gem_object_get(obj); 699 objs[i] = obj; 700 } 701 spin_unlock(&filp->table_lock); 702 703 return ret; 704 } 705 706 /** 707 * drm_gem_objects_lookup - look up GEM objects from an array of handles 708 * @filp: DRM file private date 709 * @bo_handles: user pointer to array of userspace handle 710 * @count: size of handle array 711 * @objs_out: returned pointer to array of drm_gem_object pointers 712 * 713 * Takes an array of userspace handles and returns a newly allocated array of 714 * GEM objects. 715 * 716 * For a single handle lookup, use drm_gem_object_lookup(). 717 * 718 * Returns: 719 * @objs filled in with GEM object pointers. Returned GEM objects need to be 720 * released with drm_gem_object_put(). -ENOENT is returned on a lookup 721 * failure. 0 is returned on success. 722 * 723 */ 724 int drm_gem_objects_lookup(struct drm_file *filp, void __user *bo_handles, 725 int count, struct drm_gem_object ***objs_out) 726 { 727 int ret; 728 u32 *handles; 729 struct drm_gem_object **objs; 730 731 if (!count) 732 return 0; 733 734 objs = kvmalloc_array(count, sizeof(struct drm_gem_object *), 735 GFP_KERNEL | __GFP_ZERO); 736 if (!objs) 737 return -ENOMEM; 738 739 *objs_out = objs; 740 741 handles = kvmalloc_array(count, sizeof(u32), GFP_KERNEL); 742 if (!handles) { 743 ret = -ENOMEM; 744 goto out; 745 } 746 747 if (copy_from_user(handles, bo_handles, count * sizeof(u32))) { 748 ret = -EFAULT; 749 DRM_DEBUG("Failed to copy in GEM handles\n"); 750 goto out; 751 } 752 753 ret = objects_lookup(filp, handles, count, objs); 754 out: 755 kvfree(handles); 756 return ret; 757 758 } 759 EXPORT_SYMBOL(drm_gem_objects_lookup); 760 761 /** 762 * drm_gem_object_lookup - look up a GEM object from its handle 763 * @filp: DRM file private date 764 * @handle: userspace handle 765 * 766 * If looking up an array of handles, use drm_gem_objects_lookup(). 767 * 768 * Returns: 769 * A reference to the object named by the handle if such exists on @filp, NULL 770 * otherwise. 771 */ 772 struct drm_gem_object * 773 drm_gem_object_lookup(struct drm_file *filp, u32 handle) 774 { 775 struct drm_gem_object *obj = NULL; 776 777 objects_lookup(filp, &handle, 1, &obj); 778 return obj; 779 } 780 EXPORT_SYMBOL(drm_gem_object_lookup); 781 782 /** 783 * drm_gem_dma_resv_wait - Wait on GEM object's reservation's objects 784 * shared and/or exclusive fences. 785 * @filep: DRM file private date 786 * @handle: userspace handle 787 * @wait_all: if true, wait on all fences, else wait on just exclusive fence 788 * @timeout: timeout value in jiffies or zero to return immediately 789 * 790 * Returns: 791 * Returns -ERESTARTSYS if interrupted, 0 if the wait timed out, or 792 * greater than 0 on success. 793 */ 794 long drm_gem_dma_resv_wait(struct drm_file *filep, u32 handle, 795 bool wait_all, unsigned long timeout) 796 { 797 long ret; 798 struct drm_gem_object *obj; 799 800 obj = drm_gem_object_lookup(filep, handle); 801 if (!obj) { 802 DRM_DEBUG("Failed to look up GEM BO %d\n", handle); 803 return -EINVAL; 804 } 805 806 ret = dma_resv_wait_timeout(obj->resv, dma_resv_usage_rw(wait_all), 807 true, timeout); 808 if (ret == 0) 809 ret = -ETIME; 810 else if (ret > 0) 811 ret = 0; 812 813 drm_gem_object_put(obj); 814 815 return ret; 816 } 817 EXPORT_SYMBOL(drm_gem_dma_resv_wait); 818 819 /** 820 * drm_gem_close_ioctl - implementation of the GEM_CLOSE ioctl 821 * @dev: drm_device 822 * @data: ioctl data 823 * @file_priv: drm file-private structure 824 * 825 * Releases the handle to an mm object. 826 */ 827 int 828 drm_gem_close_ioctl(struct drm_device *dev, void *data, 829 struct drm_file *file_priv) 830 { 831 struct drm_gem_close *args = data; 832 int ret; 833 834 if (!drm_core_check_feature(dev, DRIVER_GEM)) 835 return -EOPNOTSUPP; 836 837 ret = drm_gem_handle_delete(file_priv, args->handle); 838 839 return ret; 840 } 841 842 /** 843 * drm_gem_flink_ioctl - implementation of the GEM_FLINK ioctl 844 * @dev: drm_device 845 * @data: ioctl data 846 * @file_priv: drm file-private structure 847 * 848 * Create a global name for an object, returning the name. 849 * 850 * Note that the name does not hold a reference; when the object 851 * is freed, the name goes away. 852 */ 853 int 854 drm_gem_flink_ioctl(struct drm_device *dev, void *data, 855 struct drm_file *file_priv) 856 { 857 struct drm_gem_flink *args = data; 858 struct drm_gem_object *obj; 859 int ret; 860 861 if (!drm_core_check_feature(dev, DRIVER_GEM)) 862 return -EOPNOTSUPP; 863 864 obj = drm_gem_object_lookup(file_priv, args->handle); 865 if (obj == NULL) 866 return -ENOENT; 867 868 mutex_lock(&dev->object_name_lock); 869 /* prevent races with concurrent gem_close. */ 870 if (obj->handle_count == 0) { 871 ret = -ENOENT; 872 goto err; 873 } 874 875 if (!obj->name) { 876 ret = idr_alloc(&dev->object_name_idr, obj, 1, 0, GFP_KERNEL); 877 if (ret < 0) 878 goto err; 879 880 obj->name = ret; 881 } 882 883 args->name = (uint64_t) obj->name; 884 ret = 0; 885 886 err: 887 mutex_unlock(&dev->object_name_lock); 888 drm_gem_object_put(obj); 889 return ret; 890 } 891 892 /** 893 * drm_gem_open_ioctl - implementation of the GEM_OPEN ioctl 894 * @dev: drm_device 895 * @data: ioctl data 896 * @file_priv: drm file-private structure 897 * 898 * Open an object using the global name, returning a handle and the size. 899 * 900 * This handle (of course) holds a reference to the object, so the object 901 * will not go away until the handle is deleted. 902 */ 903 int 904 drm_gem_open_ioctl(struct drm_device *dev, void *data, 905 struct drm_file *file_priv) 906 { 907 struct drm_gem_open *args = data; 908 struct drm_gem_object *obj; 909 int ret; 910 u32 handle; 911 912 if (!drm_core_check_feature(dev, DRIVER_GEM)) 913 return -EOPNOTSUPP; 914 915 mutex_lock(&dev->object_name_lock); 916 obj = idr_find(&dev->object_name_idr, (int) args->name); 917 if (obj) { 918 drm_gem_object_get(obj); 919 } else { 920 mutex_unlock(&dev->object_name_lock); 921 return -ENOENT; 922 } 923 924 /* drm_gem_handle_create_tail unlocks dev->object_name_lock. */ 925 ret = drm_gem_handle_create_tail(file_priv, obj, &handle); 926 if (ret) 927 goto err; 928 929 args->handle = handle; 930 args->size = obj->size; 931 932 err: 933 drm_gem_object_put(obj); 934 return ret; 935 } 936 937 /** 938 * drm_gem_open - initializes GEM file-private structures at devnode open time 939 * @dev: drm_device which is being opened by userspace 940 * @file_private: drm file-private structure to set up 941 * 942 * Called at device open time, sets up the structure for handling refcounting 943 * of mm objects. 944 */ 945 void 946 drm_gem_open(struct drm_device *dev, struct drm_file *file_private) 947 { 948 idr_init_base(&file_private->object_idr, 1); 949 spin_lock_init(&file_private->table_lock); 950 } 951 952 /** 953 * drm_gem_release - release file-private GEM resources 954 * @dev: drm_device which is being closed by userspace 955 * @file_private: drm file-private structure to clean up 956 * 957 * Called at close time when the filp is going away. 958 * 959 * Releases any remaining references on objects by this filp. 960 */ 961 void 962 drm_gem_release(struct drm_device *dev, struct drm_file *file_private) 963 { 964 idr_for_each(&file_private->object_idr, 965 &drm_gem_object_release_handle, file_private); 966 idr_destroy(&file_private->object_idr); 967 } 968 969 /** 970 * drm_gem_object_release - release GEM buffer object resources 971 * @obj: GEM buffer object 972 * 973 * This releases any structures and resources used by @obj and is the inverse of 974 * drm_gem_object_init(). 975 */ 976 void 977 drm_gem_object_release(struct drm_gem_object *obj) 978 { 979 if (obj->filp) 980 fput(obj->filp); 981 982 drm_gem_private_object_fini(obj); 983 984 drm_gem_free_mmap_offset(obj); 985 drm_gem_lru_remove(obj); 986 } 987 EXPORT_SYMBOL(drm_gem_object_release); 988 989 /** 990 * drm_gem_object_free - free a GEM object 991 * @kref: kref of the object to free 992 * 993 * Called after the last reference to the object has been lost. 994 * 995 * Frees the object 996 */ 997 void 998 drm_gem_object_free(struct kref *kref) 999 { 1000 struct drm_gem_object *obj = 1001 container_of(kref, struct drm_gem_object, refcount); 1002 1003 if (WARN_ON(!obj->funcs->free)) 1004 return; 1005 1006 obj->funcs->free(obj); 1007 } 1008 EXPORT_SYMBOL(drm_gem_object_free); 1009 1010 /** 1011 * drm_gem_vm_open - vma->ops->open implementation for GEM 1012 * @vma: VM area structure 1013 * 1014 * This function implements the #vm_operations_struct open() callback for GEM 1015 * drivers. This must be used together with drm_gem_vm_close(). 1016 */ 1017 void drm_gem_vm_open(struct vm_area_struct *vma) 1018 { 1019 struct drm_gem_object *obj = vma->vm_private_data; 1020 1021 drm_gem_object_get(obj); 1022 } 1023 EXPORT_SYMBOL(drm_gem_vm_open); 1024 1025 /** 1026 * drm_gem_vm_close - vma->ops->close implementation for GEM 1027 * @vma: VM area structure 1028 * 1029 * This function implements the #vm_operations_struct close() callback for GEM 1030 * drivers. This must be used together with drm_gem_vm_open(). 1031 */ 1032 void drm_gem_vm_close(struct vm_area_struct *vma) 1033 { 1034 struct drm_gem_object *obj = vma->vm_private_data; 1035 1036 drm_gem_object_put(obj); 1037 } 1038 EXPORT_SYMBOL(drm_gem_vm_close); 1039 1040 /** 1041 * drm_gem_mmap_obj - memory map a GEM object 1042 * @obj: the GEM object to map 1043 * @obj_size: the object size to be mapped, in bytes 1044 * @vma: VMA for the area to be mapped 1045 * 1046 * Set up the VMA to prepare mapping of the GEM object using the GEM object's 1047 * vm_ops. Depending on their requirements, GEM objects can either 1048 * provide a fault handler in their vm_ops (in which case any accesses to 1049 * the object will be trapped, to perform migration, GTT binding, surface 1050 * register allocation, or performance monitoring), or mmap the buffer memory 1051 * synchronously after calling drm_gem_mmap_obj. 1052 * 1053 * This function is mainly intended to implement the DMABUF mmap operation, when 1054 * the GEM object is not looked up based on its fake offset. To implement the 1055 * DRM mmap operation, drivers should use the drm_gem_mmap() function. 1056 * 1057 * drm_gem_mmap_obj() assumes the user is granted access to the buffer while 1058 * drm_gem_mmap() prevents unprivileged users from mapping random objects. So 1059 * callers must verify access restrictions before calling this helper. 1060 * 1061 * Return 0 or success or -EINVAL if the object size is smaller than the VMA 1062 * size, or if no vm_ops are provided. 1063 */ 1064 int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size, 1065 struct vm_area_struct *vma) 1066 { 1067 int ret; 1068 1069 /* Check for valid size. */ 1070 if (obj_size < vma->vm_end - vma->vm_start) 1071 return -EINVAL; 1072 1073 /* Take a ref for this mapping of the object, so that the fault 1074 * handler can dereference the mmap offset's pointer to the object. 1075 * This reference is cleaned up by the corresponding vm_close 1076 * (which should happen whether the vma was created by this call, or 1077 * by a vm_open due to mremap or partial unmap or whatever). 1078 */ 1079 drm_gem_object_get(obj); 1080 1081 vma->vm_private_data = obj; 1082 vma->vm_ops = obj->funcs->vm_ops; 1083 1084 if (obj->funcs->mmap) { 1085 ret = obj->funcs->mmap(obj, vma); 1086 if (ret) 1087 goto err_drm_gem_object_put; 1088 WARN_ON(!(vma->vm_flags & VM_DONTEXPAND)); 1089 } else { 1090 if (!vma->vm_ops) { 1091 ret = -EINVAL; 1092 goto err_drm_gem_object_put; 1093 } 1094 1095 vm_flags_set(vma, VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP); 1096 vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags)); 1097 vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot); 1098 } 1099 1100 return 0; 1101 1102 err_drm_gem_object_put: 1103 drm_gem_object_put(obj); 1104 return ret; 1105 } 1106 EXPORT_SYMBOL(drm_gem_mmap_obj); 1107 1108 /** 1109 * drm_gem_mmap - memory map routine for GEM objects 1110 * @filp: DRM file pointer 1111 * @vma: VMA for the area to be mapped 1112 * 1113 * If a driver supports GEM object mapping, mmap calls on the DRM file 1114 * descriptor will end up here. 1115 * 1116 * Look up the GEM object based on the offset passed in (vma->vm_pgoff will 1117 * contain the fake offset we created when the GTT map ioctl was called on 1118 * the object) and map it with a call to drm_gem_mmap_obj(). 1119 * 1120 * If the caller is not granted access to the buffer object, the mmap will fail 1121 * with EACCES. Please see the vma manager for more information. 1122 */ 1123 int drm_gem_mmap(struct file *filp, struct vm_area_struct *vma) 1124 { 1125 struct drm_file *priv = filp->private_data; 1126 struct drm_device *dev = priv->minor->dev; 1127 struct drm_gem_object *obj = NULL; 1128 struct drm_vma_offset_node *node; 1129 int ret; 1130 1131 if (drm_dev_is_unplugged(dev)) 1132 return -ENODEV; 1133 1134 drm_vma_offset_lock_lookup(dev->vma_offset_manager); 1135 node = drm_vma_offset_exact_lookup_locked(dev->vma_offset_manager, 1136 vma->vm_pgoff, 1137 vma_pages(vma)); 1138 if (likely(node)) { 1139 obj = container_of(node, struct drm_gem_object, vma_node); 1140 /* 1141 * When the object is being freed, after it hits 0-refcnt it 1142 * proceeds to tear down the object. In the process it will 1143 * attempt to remove the VMA offset and so acquire this 1144 * mgr->vm_lock. Therefore if we find an object with a 0-refcnt 1145 * that matches our range, we know it is in the process of being 1146 * destroyed and will be freed as soon as we release the lock - 1147 * so we have to check for the 0-refcnted object and treat it as 1148 * invalid. 1149 */ 1150 if (!kref_get_unless_zero(&obj->refcount)) 1151 obj = NULL; 1152 } 1153 drm_vma_offset_unlock_lookup(dev->vma_offset_manager); 1154 1155 if (!obj) 1156 return -EINVAL; 1157 1158 if (!drm_vma_node_is_allowed(node, priv)) { 1159 drm_gem_object_put(obj); 1160 return -EACCES; 1161 } 1162 1163 ret = drm_gem_mmap_obj(obj, drm_vma_node_size(node) << PAGE_SHIFT, 1164 vma); 1165 1166 drm_gem_object_put(obj); 1167 1168 return ret; 1169 } 1170 EXPORT_SYMBOL(drm_gem_mmap); 1171 1172 void drm_gem_print_info(struct drm_printer *p, unsigned int indent, 1173 const struct drm_gem_object *obj) 1174 { 1175 drm_printf_indent(p, indent, "name=%d\n", obj->name); 1176 drm_printf_indent(p, indent, "refcount=%u\n", 1177 kref_read(&obj->refcount)); 1178 drm_printf_indent(p, indent, "start=%08lx\n", 1179 drm_vma_node_start(&obj->vma_node)); 1180 drm_printf_indent(p, indent, "size=%zu\n", obj->size); 1181 drm_printf_indent(p, indent, "imported=%s\n", 1182 str_yes_no(drm_gem_is_imported(obj))); 1183 1184 if (obj->funcs->print_info) 1185 obj->funcs->print_info(p, indent, obj); 1186 } 1187 1188 int drm_gem_vmap_locked(struct drm_gem_object *obj, struct iosys_map *map) 1189 { 1190 int ret; 1191 1192 dma_resv_assert_held(obj->resv); 1193 1194 if (!obj->funcs->vmap) 1195 return -EOPNOTSUPP; 1196 1197 ret = obj->funcs->vmap(obj, map); 1198 if (ret) 1199 return ret; 1200 else if (iosys_map_is_null(map)) 1201 return -ENOMEM; 1202 1203 return 0; 1204 } 1205 EXPORT_SYMBOL(drm_gem_vmap_locked); 1206 1207 void drm_gem_vunmap_locked(struct drm_gem_object *obj, struct iosys_map *map) 1208 { 1209 dma_resv_assert_held(obj->resv); 1210 1211 if (iosys_map_is_null(map)) 1212 return; 1213 1214 if (obj->funcs->vunmap) 1215 obj->funcs->vunmap(obj, map); 1216 1217 /* Always set the mapping to NULL. Callers may rely on this. */ 1218 iosys_map_clear(map); 1219 } 1220 EXPORT_SYMBOL(drm_gem_vunmap_locked); 1221 1222 void drm_gem_lock(struct drm_gem_object *obj) 1223 { 1224 dma_resv_lock(obj->resv, NULL); 1225 } 1226 EXPORT_SYMBOL(drm_gem_lock); 1227 1228 void drm_gem_unlock(struct drm_gem_object *obj) 1229 { 1230 dma_resv_unlock(obj->resv); 1231 } 1232 EXPORT_SYMBOL(drm_gem_unlock); 1233 1234 int drm_gem_vmap(struct drm_gem_object *obj, struct iosys_map *map) 1235 { 1236 int ret; 1237 1238 dma_resv_lock(obj->resv, NULL); 1239 ret = drm_gem_vmap_locked(obj, map); 1240 dma_resv_unlock(obj->resv); 1241 1242 return ret; 1243 } 1244 EXPORT_SYMBOL(drm_gem_vmap); 1245 1246 void drm_gem_vunmap(struct drm_gem_object *obj, struct iosys_map *map) 1247 { 1248 dma_resv_lock(obj->resv, NULL); 1249 drm_gem_vunmap_locked(obj, map); 1250 dma_resv_unlock(obj->resv); 1251 } 1252 EXPORT_SYMBOL(drm_gem_vunmap); 1253 1254 /** 1255 * drm_gem_lock_reservations - Sets up the ww context and acquires 1256 * the lock on an array of GEM objects. 1257 * 1258 * Once you've locked your reservations, you'll want to set up space 1259 * for your shared fences (if applicable), submit your job, then 1260 * drm_gem_unlock_reservations(). 1261 * 1262 * @objs: drm_gem_objects to lock 1263 * @count: Number of objects in @objs 1264 * @acquire_ctx: struct ww_acquire_ctx that will be initialized as 1265 * part of tracking this set of locked reservations. 1266 */ 1267 int 1268 drm_gem_lock_reservations(struct drm_gem_object **objs, int count, 1269 struct ww_acquire_ctx *acquire_ctx) 1270 { 1271 int contended = -1; 1272 int i, ret; 1273 1274 ww_acquire_init(acquire_ctx, &reservation_ww_class); 1275 1276 retry: 1277 if (contended != -1) { 1278 struct drm_gem_object *obj = objs[contended]; 1279 1280 ret = dma_resv_lock_slow_interruptible(obj->resv, 1281 acquire_ctx); 1282 if (ret) { 1283 ww_acquire_fini(acquire_ctx); 1284 return ret; 1285 } 1286 } 1287 1288 for (i = 0; i < count; i++) { 1289 if (i == contended) 1290 continue; 1291 1292 ret = dma_resv_lock_interruptible(objs[i]->resv, 1293 acquire_ctx); 1294 if (ret) { 1295 int j; 1296 1297 for (j = 0; j < i; j++) 1298 dma_resv_unlock(objs[j]->resv); 1299 1300 if (contended != -1 && contended >= i) 1301 dma_resv_unlock(objs[contended]->resv); 1302 1303 if (ret == -EDEADLK) { 1304 contended = i; 1305 goto retry; 1306 } 1307 1308 ww_acquire_fini(acquire_ctx); 1309 return ret; 1310 } 1311 } 1312 1313 ww_acquire_done(acquire_ctx); 1314 1315 return 0; 1316 } 1317 EXPORT_SYMBOL(drm_gem_lock_reservations); 1318 1319 void 1320 drm_gem_unlock_reservations(struct drm_gem_object **objs, int count, 1321 struct ww_acquire_ctx *acquire_ctx) 1322 { 1323 int i; 1324 1325 for (i = 0; i < count; i++) 1326 dma_resv_unlock(objs[i]->resv); 1327 1328 ww_acquire_fini(acquire_ctx); 1329 } 1330 EXPORT_SYMBOL(drm_gem_unlock_reservations); 1331 1332 /** 1333 * drm_gem_lru_init - initialize a LRU 1334 * 1335 * @lru: The LRU to initialize 1336 * @lock: The lock protecting the LRU 1337 */ 1338 void 1339 drm_gem_lru_init(struct drm_gem_lru *lru, struct mutex *lock) 1340 { 1341 lru->lock = lock; 1342 lru->count = 0; 1343 INIT_LIST_HEAD(&lru->list); 1344 } 1345 EXPORT_SYMBOL(drm_gem_lru_init); 1346 1347 static void 1348 drm_gem_lru_remove_locked(struct drm_gem_object *obj) 1349 { 1350 obj->lru->count -= obj->size >> PAGE_SHIFT; 1351 WARN_ON(obj->lru->count < 0); 1352 list_del(&obj->lru_node); 1353 obj->lru = NULL; 1354 } 1355 1356 /** 1357 * drm_gem_lru_remove - remove object from whatever LRU it is in 1358 * 1359 * If the object is currently in any LRU, remove it. 1360 * 1361 * @obj: The GEM object to remove from current LRU 1362 */ 1363 void 1364 drm_gem_lru_remove(struct drm_gem_object *obj) 1365 { 1366 struct drm_gem_lru *lru = obj->lru; 1367 1368 if (!lru) 1369 return; 1370 1371 mutex_lock(lru->lock); 1372 drm_gem_lru_remove_locked(obj); 1373 mutex_unlock(lru->lock); 1374 } 1375 EXPORT_SYMBOL(drm_gem_lru_remove); 1376 1377 /** 1378 * drm_gem_lru_move_tail_locked - move the object to the tail of the LRU 1379 * 1380 * Like &drm_gem_lru_move_tail but lru lock must be held 1381 * 1382 * @lru: The LRU to move the object into. 1383 * @obj: The GEM object to move into this LRU 1384 */ 1385 void 1386 drm_gem_lru_move_tail_locked(struct drm_gem_lru *lru, struct drm_gem_object *obj) 1387 { 1388 lockdep_assert_held_once(lru->lock); 1389 1390 if (obj->lru) 1391 drm_gem_lru_remove_locked(obj); 1392 1393 lru->count += obj->size >> PAGE_SHIFT; 1394 list_add_tail(&obj->lru_node, &lru->list); 1395 obj->lru = lru; 1396 } 1397 EXPORT_SYMBOL(drm_gem_lru_move_tail_locked); 1398 1399 /** 1400 * drm_gem_lru_move_tail - move the object to the tail of the LRU 1401 * 1402 * If the object is already in this LRU it will be moved to the 1403 * tail. Otherwise it will be removed from whichever other LRU 1404 * it is in (if any) and moved into this LRU. 1405 * 1406 * @lru: The LRU to move the object into. 1407 * @obj: The GEM object to move into this LRU 1408 */ 1409 void 1410 drm_gem_lru_move_tail(struct drm_gem_lru *lru, struct drm_gem_object *obj) 1411 { 1412 mutex_lock(lru->lock); 1413 drm_gem_lru_move_tail_locked(lru, obj); 1414 mutex_unlock(lru->lock); 1415 } 1416 EXPORT_SYMBOL(drm_gem_lru_move_tail); 1417 1418 /** 1419 * drm_gem_lru_scan - helper to implement shrinker.scan_objects 1420 * 1421 * If the shrink callback succeeds, it is expected that the driver 1422 * move the object out of this LRU. 1423 * 1424 * If the LRU possibly contain active buffers, it is the responsibility 1425 * of the shrink callback to check for this (ie. dma_resv_test_signaled()) 1426 * or if necessary block until the buffer becomes idle. 1427 * 1428 * @lru: The LRU to scan 1429 * @nr_to_scan: The number of pages to try to reclaim 1430 * @remaining: The number of pages left to reclaim, should be initialized by caller 1431 * @shrink: Callback to try to shrink/reclaim the object. 1432 * @ticket: Optional ww_acquire_ctx context to use for locking 1433 */ 1434 unsigned long 1435 drm_gem_lru_scan(struct drm_gem_lru *lru, 1436 unsigned int nr_to_scan, 1437 unsigned long *remaining, 1438 bool (*shrink)(struct drm_gem_object *obj, struct ww_acquire_ctx *ticket), 1439 struct ww_acquire_ctx *ticket) 1440 { 1441 struct drm_gem_lru still_in_lru; 1442 struct drm_gem_object *obj; 1443 unsigned freed = 0; 1444 1445 drm_gem_lru_init(&still_in_lru, lru->lock); 1446 1447 mutex_lock(lru->lock); 1448 1449 while (freed < nr_to_scan) { 1450 obj = list_first_entry_or_null(&lru->list, typeof(*obj), lru_node); 1451 1452 if (!obj) 1453 break; 1454 1455 drm_gem_lru_move_tail_locked(&still_in_lru, obj); 1456 1457 /* 1458 * If it's in the process of being freed, gem_object->free() 1459 * may be blocked on lock waiting to remove it. So just 1460 * skip it. 1461 */ 1462 if (!kref_get_unless_zero(&obj->refcount)) 1463 continue; 1464 1465 /* 1466 * Now that we own a reference, we can drop the lock for the 1467 * rest of the loop body, to reduce contention with other 1468 * code paths that need the LRU lock 1469 */ 1470 mutex_unlock(lru->lock); 1471 1472 if (ticket) 1473 ww_acquire_init(ticket, &reservation_ww_class); 1474 1475 /* 1476 * Note that this still needs to be trylock, since we can 1477 * hit shrinker in response to trying to get backing pages 1478 * for this obj (ie. while it's lock is already held) 1479 */ 1480 if (!ww_mutex_trylock(&obj->resv->lock, ticket)) { 1481 *remaining += obj->size >> PAGE_SHIFT; 1482 goto tail; 1483 } 1484 1485 if (shrink(obj, ticket)) { 1486 freed += obj->size >> PAGE_SHIFT; 1487 1488 /* 1489 * If we succeeded in releasing the object's backing 1490 * pages, we expect the driver to have moved the object 1491 * out of this LRU 1492 */ 1493 WARN_ON(obj->lru == &still_in_lru); 1494 WARN_ON(obj->lru == lru); 1495 } 1496 1497 dma_resv_unlock(obj->resv); 1498 1499 if (ticket) 1500 ww_acquire_fini(ticket); 1501 1502 tail: 1503 drm_gem_object_put(obj); 1504 mutex_lock(lru->lock); 1505 } 1506 1507 /* 1508 * Move objects we've skipped over out of the temporary still_in_lru 1509 * back into this LRU 1510 */ 1511 list_for_each_entry (obj, &still_in_lru.list, lru_node) 1512 obj->lru = lru; 1513 list_splice_tail(&still_in_lru.list, &lru->list); 1514 lru->count += still_in_lru.count; 1515 1516 mutex_unlock(lru->lock); 1517 1518 return freed; 1519 } 1520 EXPORT_SYMBOL(drm_gem_lru_scan); 1521 1522 /** 1523 * drm_gem_evict_locked - helper to evict backing pages for a GEM object 1524 * @obj: obj in question 1525 */ 1526 int drm_gem_evict_locked(struct drm_gem_object *obj) 1527 { 1528 dma_resv_assert_held(obj->resv); 1529 1530 if (!dma_resv_test_signaled(obj->resv, DMA_RESV_USAGE_READ)) 1531 return -EBUSY; 1532 1533 if (obj->funcs->evict) 1534 return obj->funcs->evict(obj); 1535 1536 return 0; 1537 } 1538 EXPORT_SYMBOL(drm_gem_evict_locked); 1539