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/types.h> 29 #include <linux/slab.h> 30 #include <linux/mm.h> 31 #include <linux/uaccess.h> 32 #include <linux/fs.h> 33 #include <linux/file.h> 34 #include <linux/module.h> 35 #include <linux/mman.h> 36 #include <linux/pagemap.h> 37 #include <linux/shmem_fs.h> 38 #include <linux/dma-buf.h> 39 #include <drm/drmP.h> 40 #include <drm/drm_vma_manager.h> 41 42 /** @file drm_gem.c 43 * 44 * This file provides some of the base ioctls and library routines for 45 * the graphics memory manager implemented by each device driver. 46 * 47 * Because various devices have different requirements in terms of 48 * synchronization and migration strategies, implementing that is left up to 49 * the driver, and all that the general API provides should be generic -- 50 * allocating objects, reading/writing data with the cpu, freeing objects. 51 * Even there, platform-dependent optimizations for reading/writing data with 52 * the CPU mean we'll likely hook those out to driver-specific calls. However, 53 * the DRI2 implementation wants to have at least allocate/mmap be generic. 54 * 55 * The goal was to have swap-backed object allocation managed through 56 * struct file. However, file descriptors as handles to a struct file have 57 * two major failings: 58 * - Process limits prevent more than 1024 or so being used at a time by 59 * default. 60 * - Inability to allocate high fds will aggravate the X Server's select() 61 * handling, and likely that of many GL client applications as well. 62 * 63 * This led to a plan of using our own integer IDs (called handles, following 64 * DRM terminology) to mimic fds, and implement the fd syscalls we need as 65 * ioctls. The objects themselves will still include the struct file so 66 * that we can transition to fds if the required kernel infrastructure shows 67 * up at a later date, and as our interface with shmfs for memory allocation. 68 */ 69 70 /* 71 * We make up offsets for buffer objects so we can recognize them at 72 * mmap time. 73 */ 74 75 /* pgoff in mmap is an unsigned long, so we need to make sure that 76 * the faked up offset will fit 77 */ 78 79 #if BITS_PER_LONG == 64 80 #define DRM_FILE_PAGE_OFFSET_START ((0xFFFFFFFFUL >> PAGE_SHIFT) + 1) 81 #define DRM_FILE_PAGE_OFFSET_SIZE ((0xFFFFFFFFUL >> PAGE_SHIFT) * 16) 82 #else 83 #define DRM_FILE_PAGE_OFFSET_START ((0xFFFFFFFUL >> PAGE_SHIFT) + 1) 84 #define DRM_FILE_PAGE_OFFSET_SIZE ((0xFFFFFFFUL >> PAGE_SHIFT) * 16) 85 #endif 86 87 /** 88 * drm_gem_init - Initialize the GEM device fields 89 * @dev: drm_devic structure to initialize 90 */ 91 int 92 drm_gem_init(struct drm_device *dev) 93 { 94 struct drm_vma_offset_manager *vma_offset_manager; 95 96 mutex_init(&dev->object_name_lock); 97 idr_init(&dev->object_name_idr); 98 99 vma_offset_manager = kzalloc(sizeof(*vma_offset_manager), GFP_KERNEL); 100 if (!vma_offset_manager) { 101 DRM_ERROR("out of memory\n"); 102 return -ENOMEM; 103 } 104 105 dev->vma_offset_manager = vma_offset_manager; 106 drm_vma_offset_manager_init(vma_offset_manager, 107 DRM_FILE_PAGE_OFFSET_START, 108 DRM_FILE_PAGE_OFFSET_SIZE); 109 110 return 0; 111 } 112 113 void 114 drm_gem_destroy(struct drm_device *dev) 115 { 116 117 drm_vma_offset_manager_destroy(dev->vma_offset_manager); 118 kfree(dev->vma_offset_manager); 119 dev->vma_offset_manager = NULL; 120 } 121 122 /** 123 * drm_gem_object_init - initialize an allocated shmem-backed GEM object 124 * @dev: drm_device the object should be initialized for 125 * @obj: drm_gem_object to initialize 126 * @size: object size 127 * 128 * Initialize an already allocated GEM object of the specified size with 129 * shmfs backing store. 130 */ 131 int drm_gem_object_init(struct drm_device *dev, 132 struct drm_gem_object *obj, size_t size) 133 { 134 struct file *filp; 135 136 drm_gem_private_object_init(dev, obj, size); 137 138 filp = shmem_file_setup("drm mm object", size, VM_NORESERVE); 139 if (IS_ERR(filp)) 140 return PTR_ERR(filp); 141 142 obj->filp = filp; 143 144 return 0; 145 } 146 EXPORT_SYMBOL(drm_gem_object_init); 147 148 /** 149 * drm_gem_object_init - initialize an allocated private GEM object 150 * @dev: drm_device the object should be initialized for 151 * @obj: drm_gem_object to initialize 152 * @size: object size 153 * 154 * Initialize an already allocated GEM object of the specified size with 155 * no GEM provided backing store. Instead the caller is responsible for 156 * backing the object and handling it. 157 */ 158 void drm_gem_private_object_init(struct drm_device *dev, 159 struct drm_gem_object *obj, size_t size) 160 { 161 BUG_ON((size & (PAGE_SIZE - 1)) != 0); 162 163 obj->dev = dev; 164 obj->filp = NULL; 165 166 kref_init(&obj->refcount); 167 obj->handle_count = 0; 168 obj->size = size; 169 drm_vma_node_reset(&obj->vma_node); 170 } 171 EXPORT_SYMBOL(drm_gem_private_object_init); 172 173 static void 174 drm_gem_remove_prime_handles(struct drm_gem_object *obj, struct drm_file *filp) 175 { 176 /* 177 * Note: obj->dma_buf can't disappear as long as we still hold a 178 * handle reference in obj->handle_count. 179 */ 180 mutex_lock(&filp->prime.lock); 181 if (obj->dma_buf) { 182 drm_prime_remove_buf_handle_locked(&filp->prime, 183 obj->dma_buf); 184 } 185 mutex_unlock(&filp->prime.lock); 186 } 187 188 /** 189 * drm_gem_object_free - release resources bound to userspace handles 190 * @obj: GEM object to clean up. 191 * 192 * Called after the last handle to the object has been closed 193 * 194 * Removes any name for the object. Note that this must be 195 * called before drm_gem_object_free or we'll be touching 196 * freed memory 197 */ 198 static void drm_gem_object_handle_free(struct drm_gem_object *obj) 199 { 200 struct drm_device *dev = obj->dev; 201 202 /* Remove any name for this object */ 203 if (obj->name) { 204 idr_remove(&dev->object_name_idr, obj->name); 205 obj->name = 0; 206 } 207 } 208 209 static void drm_gem_object_exported_dma_buf_free(struct drm_gem_object *obj) 210 { 211 /* Unbreak the reference cycle if we have an exported dma_buf. */ 212 if (obj->dma_buf) { 213 dma_buf_put(obj->dma_buf); 214 obj->dma_buf = NULL; 215 } 216 } 217 218 static void 219 drm_gem_object_handle_unreference_unlocked(struct drm_gem_object *obj) 220 { 221 if (WARN_ON(obj->handle_count == 0)) 222 return; 223 224 /* 225 * Must bump handle count first as this may be the last 226 * ref, in which case the object would disappear before we 227 * checked for a name 228 */ 229 230 mutex_lock(&obj->dev->object_name_lock); 231 if (--obj->handle_count == 0) { 232 drm_gem_object_handle_free(obj); 233 drm_gem_object_exported_dma_buf_free(obj); 234 } 235 mutex_unlock(&obj->dev->object_name_lock); 236 237 drm_gem_object_unreference_unlocked(obj); 238 } 239 240 /** 241 * drm_gem_handle_delete - deletes the given file-private handle 242 * @filp: drm file-private structure to use for the handle look up 243 * @handle: userspace handle to delete 244 * 245 * Removes the GEM handle from the @filp lookup table and if this is the last 246 * handle also cleans up linked resources like GEM names. 247 */ 248 int 249 drm_gem_handle_delete(struct drm_file *filp, u32 handle) 250 { 251 struct drm_device *dev; 252 struct drm_gem_object *obj; 253 254 /* This is gross. The idr system doesn't let us try a delete and 255 * return an error code. It just spews if you fail at deleting. 256 * So, we have to grab a lock around finding the object and then 257 * doing the delete on it and dropping the refcount, or the user 258 * could race us to double-decrement the refcount and cause a 259 * use-after-free later. Given the frequency of our handle lookups, 260 * we may want to use ida for number allocation and a hash table 261 * for the pointers, anyway. 262 */ 263 spin_lock(&filp->table_lock); 264 265 /* Check if we currently have a reference on the object */ 266 obj = idr_find(&filp->object_idr, handle); 267 if (obj == NULL) { 268 spin_unlock(&filp->table_lock); 269 return -EINVAL; 270 } 271 dev = obj->dev; 272 273 /* Release reference and decrement refcount. */ 274 idr_remove(&filp->object_idr, handle); 275 spin_unlock(&filp->table_lock); 276 277 if (drm_core_check_feature(dev, DRIVER_PRIME)) 278 drm_gem_remove_prime_handles(obj, filp); 279 drm_vma_node_revoke(&obj->vma_node, filp->filp); 280 281 if (dev->driver->gem_close_object) 282 dev->driver->gem_close_object(obj, filp); 283 drm_gem_object_handle_unreference_unlocked(obj); 284 285 return 0; 286 } 287 EXPORT_SYMBOL(drm_gem_handle_delete); 288 289 /** 290 * drm_gem_dumb_destroy - dumb fb callback helper for gem based drivers 291 * @file: drm file-private structure to remove the dumb handle from 292 * @dev: corresponding drm_device 293 * @handle: the dumb handle to remove 294 * 295 * This implements the ->dumb_destroy kms driver callback for drivers which use 296 * gem to manage their backing storage. 297 */ 298 int drm_gem_dumb_destroy(struct drm_file *file, 299 struct drm_device *dev, 300 uint32_t handle) 301 { 302 return drm_gem_handle_delete(file, handle); 303 } 304 EXPORT_SYMBOL(drm_gem_dumb_destroy); 305 306 /** 307 * drm_gem_handle_create_tail - internal functions to create a handle 308 * @file_priv: drm file-private structure to register the handle for 309 * @obj: object to register 310 * @handlep: pionter to return the created handle to the caller 311 * 312 * This expects the dev->object_name_lock to be held already and will drop it 313 * before returning. Used to avoid races in establishing new handles when 314 * importing an object from either an flink name or a dma-buf. 315 */ 316 int 317 drm_gem_handle_create_tail(struct drm_file *file_priv, 318 struct drm_gem_object *obj, 319 u32 *handlep) 320 { 321 struct drm_device *dev = obj->dev; 322 int ret; 323 324 WARN_ON(!mutex_is_locked(&dev->object_name_lock)); 325 326 /* 327 * Get the user-visible handle using idr. Preload and perform 328 * allocation under our spinlock. 329 */ 330 idr_preload(GFP_KERNEL); 331 spin_lock(&file_priv->table_lock); 332 333 ret = idr_alloc(&file_priv->object_idr, obj, 1, 0, GFP_NOWAIT); 334 drm_gem_object_reference(obj); 335 obj->handle_count++; 336 spin_unlock(&file_priv->table_lock); 337 idr_preload_end(); 338 mutex_unlock(&dev->object_name_lock); 339 if (ret < 0) { 340 drm_gem_object_handle_unreference_unlocked(obj); 341 return ret; 342 } 343 *handlep = ret; 344 345 ret = drm_vma_node_allow(&obj->vma_node, file_priv->filp); 346 if (ret) { 347 drm_gem_handle_delete(file_priv, *handlep); 348 return ret; 349 } 350 351 if (dev->driver->gem_open_object) { 352 ret = dev->driver->gem_open_object(obj, file_priv); 353 if (ret) { 354 drm_gem_handle_delete(file_priv, *handlep); 355 return ret; 356 } 357 } 358 359 return 0; 360 } 361 362 /** 363 * gem_handle_create - create a gem handle for an object 364 * @file_priv: drm file-private structure to register the handle for 365 * @obj: object to register 366 * @handlep: pionter to return the created handle to the caller 367 * 368 * Create a handle for this object. This adds a handle reference 369 * to the object, which includes a regular reference count. Callers 370 * will likely want to dereference the object afterwards. 371 */ 372 int 373 drm_gem_handle_create(struct drm_file *file_priv, 374 struct drm_gem_object *obj, 375 u32 *handlep) 376 { 377 mutex_lock(&obj->dev->object_name_lock); 378 379 return drm_gem_handle_create_tail(file_priv, obj, handlep); 380 } 381 EXPORT_SYMBOL(drm_gem_handle_create); 382 383 384 /** 385 * drm_gem_free_mmap_offset - release a fake mmap offset for an object 386 * @obj: obj in question 387 * 388 * This routine frees fake offsets allocated by drm_gem_create_mmap_offset(). 389 */ 390 void 391 drm_gem_free_mmap_offset(struct drm_gem_object *obj) 392 { 393 struct drm_device *dev = obj->dev; 394 395 drm_vma_offset_remove(dev->vma_offset_manager, &obj->vma_node); 396 } 397 EXPORT_SYMBOL(drm_gem_free_mmap_offset); 398 399 /** 400 * drm_gem_create_mmap_offset_size - create a fake mmap offset for an object 401 * @obj: obj in question 402 * @size: the virtual size 403 * 404 * GEM memory mapping works by handing back to userspace a fake mmap offset 405 * it can use in a subsequent mmap(2) call. The DRM core code then looks 406 * up the object based on the offset and sets up the various memory mapping 407 * structures. 408 * 409 * This routine allocates and attaches a fake offset for @obj, in cases where 410 * the virtual size differs from the physical size (ie. obj->size). Otherwise 411 * just use drm_gem_create_mmap_offset(). 412 */ 413 int 414 drm_gem_create_mmap_offset_size(struct drm_gem_object *obj, size_t size) 415 { 416 struct drm_device *dev = obj->dev; 417 418 return drm_vma_offset_add(dev->vma_offset_manager, &obj->vma_node, 419 size / PAGE_SIZE); 420 } 421 EXPORT_SYMBOL(drm_gem_create_mmap_offset_size); 422 423 /** 424 * drm_gem_create_mmap_offset - create a fake mmap offset for an object 425 * @obj: obj in question 426 * 427 * GEM memory mapping works by handing back to userspace a fake mmap offset 428 * it can use in a subsequent mmap(2) call. The DRM core code then looks 429 * up the object based on the offset and sets up the various memory mapping 430 * structures. 431 * 432 * This routine allocates and attaches a fake offset for @obj. 433 */ 434 int drm_gem_create_mmap_offset(struct drm_gem_object *obj) 435 { 436 return drm_gem_create_mmap_offset_size(obj, obj->size); 437 } 438 EXPORT_SYMBOL(drm_gem_create_mmap_offset); 439 440 /** 441 * drm_gem_get_pages - helper to allocate backing pages for a GEM object 442 * from shmem 443 * @obj: obj in question 444 * @gfpmask: gfp mask of requested pages 445 */ 446 struct page **drm_gem_get_pages(struct drm_gem_object *obj, gfp_t gfpmask) 447 { 448 struct inode *inode; 449 struct address_space *mapping; 450 struct page *p, **pages; 451 int i, npages; 452 453 /* This is the shared memory object that backs the GEM resource */ 454 inode = file_inode(obj->filp); 455 mapping = inode->i_mapping; 456 457 /* We already BUG_ON() for non-page-aligned sizes in 458 * drm_gem_object_init(), so we should never hit this unless 459 * driver author is doing something really wrong: 460 */ 461 WARN_ON((obj->size & (PAGE_SIZE - 1)) != 0); 462 463 npages = obj->size >> PAGE_SHIFT; 464 465 pages = drm_malloc_ab(npages, sizeof(struct page *)); 466 if (pages == NULL) 467 return ERR_PTR(-ENOMEM); 468 469 gfpmask |= mapping_gfp_mask(mapping); 470 471 for (i = 0; i < npages; i++) { 472 p = shmem_read_mapping_page_gfp(mapping, i, gfpmask); 473 if (IS_ERR(p)) 474 goto fail; 475 pages[i] = p; 476 477 /* Make sure shmem keeps __GFP_DMA32 allocated pages in the 478 * correct region during swapin. Note that this requires 479 * __GFP_DMA32 to be set in mapping_gfp_mask(inode->i_mapping) 480 * so shmem can relocate pages during swapin if required. 481 */ 482 BUG_ON((gfpmask & __GFP_DMA32) && 483 (page_to_pfn(p) >= 0x00100000UL)); 484 } 485 486 return pages; 487 488 fail: 489 while (i--) 490 page_cache_release(pages[i]); 491 492 drm_free_large(pages); 493 return ERR_CAST(p); 494 } 495 EXPORT_SYMBOL(drm_gem_get_pages); 496 497 /** 498 * drm_gem_put_pages - helper to free backing pages for a GEM object 499 * @obj: obj in question 500 * @pages: pages to free 501 * @dirty: if true, pages will be marked as dirty 502 * @accessed: if true, the pages will be marked as accessed 503 */ 504 void drm_gem_put_pages(struct drm_gem_object *obj, struct page **pages, 505 bool dirty, bool accessed) 506 { 507 int i, npages; 508 509 /* We already BUG_ON() for non-page-aligned sizes in 510 * drm_gem_object_init(), so we should never hit this unless 511 * driver author is doing something really wrong: 512 */ 513 WARN_ON((obj->size & (PAGE_SIZE - 1)) != 0); 514 515 npages = obj->size >> PAGE_SHIFT; 516 517 for (i = 0; i < npages; i++) { 518 if (dirty) 519 set_page_dirty(pages[i]); 520 521 if (accessed) 522 mark_page_accessed(pages[i]); 523 524 /* Undo the reference we took when populating the table */ 525 page_cache_release(pages[i]); 526 } 527 528 drm_free_large(pages); 529 } 530 EXPORT_SYMBOL(drm_gem_put_pages); 531 532 /** Returns a reference to the object named by the handle. */ 533 struct drm_gem_object * 534 drm_gem_object_lookup(struct drm_device *dev, struct drm_file *filp, 535 u32 handle) 536 { 537 struct drm_gem_object *obj; 538 539 spin_lock(&filp->table_lock); 540 541 /* Check if we currently have a reference on the object */ 542 obj = idr_find(&filp->object_idr, handle); 543 if (obj == NULL) { 544 spin_unlock(&filp->table_lock); 545 return NULL; 546 } 547 548 drm_gem_object_reference(obj); 549 550 spin_unlock(&filp->table_lock); 551 552 return obj; 553 } 554 EXPORT_SYMBOL(drm_gem_object_lookup); 555 556 /** 557 * drm_gem_close_ioctl - implementation of the GEM_CLOSE ioctl 558 * @dev: drm_device 559 * @data: ioctl data 560 * @file_priv: drm file-private structure 561 * 562 * Releases the handle to an mm object. 563 */ 564 int 565 drm_gem_close_ioctl(struct drm_device *dev, void *data, 566 struct drm_file *file_priv) 567 { 568 struct drm_gem_close *args = data; 569 int ret; 570 571 if (!(dev->driver->driver_features & DRIVER_GEM)) 572 return -ENODEV; 573 574 ret = drm_gem_handle_delete(file_priv, args->handle); 575 576 return ret; 577 } 578 579 /** 580 * drm_gem_flink_ioctl - implementation of the GEM_FLINK ioctl 581 * @dev: drm_device 582 * @data: ioctl data 583 * @file_priv: drm file-private structure 584 * 585 * Create a global name for an object, returning the name. 586 * 587 * Note that the name does not hold a reference; when the object 588 * is freed, the name goes away. 589 */ 590 int 591 drm_gem_flink_ioctl(struct drm_device *dev, void *data, 592 struct drm_file *file_priv) 593 { 594 struct drm_gem_flink *args = data; 595 struct drm_gem_object *obj; 596 int ret; 597 598 if (!(dev->driver->driver_features & DRIVER_GEM)) 599 return -ENODEV; 600 601 obj = drm_gem_object_lookup(dev, file_priv, args->handle); 602 if (obj == NULL) 603 return -ENOENT; 604 605 mutex_lock(&dev->object_name_lock); 606 idr_preload(GFP_KERNEL); 607 /* prevent races with concurrent gem_close. */ 608 if (obj->handle_count == 0) { 609 ret = -ENOENT; 610 goto err; 611 } 612 613 if (!obj->name) { 614 ret = idr_alloc(&dev->object_name_idr, obj, 1, 0, GFP_NOWAIT); 615 if (ret < 0) 616 goto err; 617 618 obj->name = ret; 619 } 620 621 args->name = (uint64_t) obj->name; 622 ret = 0; 623 624 err: 625 idr_preload_end(); 626 mutex_unlock(&dev->object_name_lock); 627 drm_gem_object_unreference_unlocked(obj); 628 return ret; 629 } 630 631 /** 632 * drm_gem_open - implementation of the GEM_OPEN ioctl 633 * @dev: drm_device 634 * @data: ioctl data 635 * @file_priv: drm file-private structure 636 * 637 * Open an object using the global name, returning a handle and the size. 638 * 639 * This handle (of course) holds a reference to the object, so the object 640 * will not go away until the handle is deleted. 641 */ 642 int 643 drm_gem_open_ioctl(struct drm_device *dev, void *data, 644 struct drm_file *file_priv) 645 { 646 struct drm_gem_open *args = data; 647 struct drm_gem_object *obj; 648 int ret; 649 u32 handle; 650 651 if (!(dev->driver->driver_features & DRIVER_GEM)) 652 return -ENODEV; 653 654 mutex_lock(&dev->object_name_lock); 655 obj = idr_find(&dev->object_name_idr, (int) args->name); 656 if (obj) { 657 drm_gem_object_reference(obj); 658 } else { 659 mutex_unlock(&dev->object_name_lock); 660 return -ENOENT; 661 } 662 663 /* drm_gem_handle_create_tail unlocks dev->object_name_lock. */ 664 ret = drm_gem_handle_create_tail(file_priv, obj, &handle); 665 drm_gem_object_unreference_unlocked(obj); 666 if (ret) 667 return ret; 668 669 args->handle = handle; 670 args->size = obj->size; 671 672 return 0; 673 } 674 675 /** 676 * gem_gem_open - initalizes GEM file-private structures at devnode open time 677 * @dev: drm_device which is being opened by userspace 678 * @file_private: drm file-private structure to set up 679 * 680 * Called at device open time, sets up the structure for handling refcounting 681 * of mm objects. 682 */ 683 void 684 drm_gem_open(struct drm_device *dev, struct drm_file *file_private) 685 { 686 idr_init(&file_private->object_idr); 687 spin_lock_init(&file_private->table_lock); 688 } 689 690 /* 691 * Called at device close to release the file's 692 * handle references on objects. 693 */ 694 static int 695 drm_gem_object_release_handle(int id, void *ptr, void *data) 696 { 697 struct drm_file *file_priv = data; 698 struct drm_gem_object *obj = ptr; 699 struct drm_device *dev = obj->dev; 700 701 if (drm_core_check_feature(dev, DRIVER_PRIME)) 702 drm_gem_remove_prime_handles(obj, file_priv); 703 drm_vma_node_revoke(&obj->vma_node, file_priv->filp); 704 705 if (dev->driver->gem_close_object) 706 dev->driver->gem_close_object(obj, file_priv); 707 708 drm_gem_object_handle_unreference_unlocked(obj); 709 710 return 0; 711 } 712 713 /** 714 * drm_gem_release - release file-private GEM resources 715 * @dev: drm_device which is being closed by userspace 716 * @file_private: drm file-private structure to clean up 717 * 718 * Called at close time when the filp is going away. 719 * 720 * Releases any remaining references on objects by this filp. 721 */ 722 void 723 drm_gem_release(struct drm_device *dev, struct drm_file *file_private) 724 { 725 idr_for_each(&file_private->object_idr, 726 &drm_gem_object_release_handle, file_private); 727 idr_destroy(&file_private->object_idr); 728 } 729 730 void 731 drm_gem_object_release(struct drm_gem_object *obj) 732 { 733 WARN_ON(obj->dma_buf); 734 735 if (obj->filp) 736 fput(obj->filp); 737 738 drm_gem_free_mmap_offset(obj); 739 } 740 EXPORT_SYMBOL(drm_gem_object_release); 741 742 /** 743 * drm_gem_object_free - free a GEM object 744 * @kref: kref of the object to free 745 * 746 * Called after the last reference to the object has been lost. 747 * Must be called holding struct_ mutex 748 * 749 * Frees the object 750 */ 751 void 752 drm_gem_object_free(struct kref *kref) 753 { 754 struct drm_gem_object *obj = (struct drm_gem_object *) kref; 755 struct drm_device *dev = obj->dev; 756 757 BUG_ON(!mutex_is_locked(&dev->struct_mutex)); 758 759 if (dev->driver->gem_free_object != NULL) 760 dev->driver->gem_free_object(obj); 761 } 762 EXPORT_SYMBOL(drm_gem_object_free); 763 764 void drm_gem_vm_open(struct vm_area_struct *vma) 765 { 766 struct drm_gem_object *obj = vma->vm_private_data; 767 768 drm_gem_object_reference(obj); 769 770 mutex_lock(&obj->dev->struct_mutex); 771 drm_vm_open_locked(obj->dev, vma); 772 mutex_unlock(&obj->dev->struct_mutex); 773 } 774 EXPORT_SYMBOL(drm_gem_vm_open); 775 776 void drm_gem_vm_close(struct vm_area_struct *vma) 777 { 778 struct drm_gem_object *obj = vma->vm_private_data; 779 struct drm_device *dev = obj->dev; 780 781 mutex_lock(&dev->struct_mutex); 782 drm_vm_close_locked(obj->dev, vma); 783 drm_gem_object_unreference(obj); 784 mutex_unlock(&dev->struct_mutex); 785 } 786 EXPORT_SYMBOL(drm_gem_vm_close); 787 788 /** 789 * drm_gem_mmap_obj - memory map a GEM object 790 * @obj: the GEM object to map 791 * @obj_size: the object size to be mapped, in bytes 792 * @vma: VMA for the area to be mapped 793 * 794 * Set up the VMA to prepare mapping of the GEM object using the gem_vm_ops 795 * provided by the driver. Depending on their requirements, drivers can either 796 * provide a fault handler in their gem_vm_ops (in which case any accesses to 797 * the object will be trapped, to perform migration, GTT binding, surface 798 * register allocation, or performance monitoring), or mmap the buffer memory 799 * synchronously after calling drm_gem_mmap_obj. 800 * 801 * This function is mainly intended to implement the DMABUF mmap operation, when 802 * the GEM object is not looked up based on its fake offset. To implement the 803 * DRM mmap operation, drivers should use the drm_gem_mmap() function. 804 * 805 * drm_gem_mmap_obj() assumes the user is granted access to the buffer while 806 * drm_gem_mmap() prevents unprivileged users from mapping random objects. So 807 * callers must verify access restrictions before calling this helper. 808 * 809 * NOTE: This function has to be protected with dev->struct_mutex 810 * 811 * Return 0 or success or -EINVAL if the object size is smaller than the VMA 812 * size, or if no gem_vm_ops are provided. 813 */ 814 int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size, 815 struct vm_area_struct *vma) 816 { 817 struct drm_device *dev = obj->dev; 818 819 lockdep_assert_held(&dev->struct_mutex); 820 821 /* Check for valid size. */ 822 if (obj_size < vma->vm_end - vma->vm_start) 823 return -EINVAL; 824 825 if (!dev->driver->gem_vm_ops) 826 return -EINVAL; 827 828 vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP; 829 vma->vm_ops = dev->driver->gem_vm_ops; 830 vma->vm_private_data = obj; 831 vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags)); 832 833 /* Take a ref for this mapping of the object, so that the fault 834 * handler can dereference the mmap offset's pointer to the object. 835 * This reference is cleaned up by the corresponding vm_close 836 * (which should happen whether the vma was created by this call, or 837 * by a vm_open due to mremap or partial unmap or whatever). 838 */ 839 drm_gem_object_reference(obj); 840 841 drm_vm_open_locked(dev, vma); 842 return 0; 843 } 844 EXPORT_SYMBOL(drm_gem_mmap_obj); 845 846 /** 847 * drm_gem_mmap - memory map routine for GEM objects 848 * @filp: DRM file pointer 849 * @vma: VMA for the area to be mapped 850 * 851 * If a driver supports GEM object mapping, mmap calls on the DRM file 852 * descriptor will end up here. 853 * 854 * Look up the GEM object based on the offset passed in (vma->vm_pgoff will 855 * contain the fake offset we created when the GTT map ioctl was called on 856 * the object) and map it with a call to drm_gem_mmap_obj(). 857 * 858 * If the caller is not granted access to the buffer object, the mmap will fail 859 * with EACCES. Please see the vma manager for more information. 860 */ 861 int drm_gem_mmap(struct file *filp, struct vm_area_struct *vma) 862 { 863 struct drm_file *priv = filp->private_data; 864 struct drm_device *dev = priv->minor->dev; 865 struct drm_gem_object *obj; 866 struct drm_vma_offset_node *node; 867 int ret; 868 869 if (drm_device_is_unplugged(dev)) 870 return -ENODEV; 871 872 mutex_lock(&dev->struct_mutex); 873 874 node = drm_vma_offset_exact_lookup(dev->vma_offset_manager, 875 vma->vm_pgoff, 876 vma_pages(vma)); 877 if (!node) { 878 mutex_unlock(&dev->struct_mutex); 879 return drm_mmap(filp, vma); 880 } else if (!drm_vma_node_is_allowed(node, filp)) { 881 mutex_unlock(&dev->struct_mutex); 882 return -EACCES; 883 } 884 885 obj = container_of(node, struct drm_gem_object, vma_node); 886 ret = drm_gem_mmap_obj(obj, drm_vma_node_size(node) << PAGE_SHIFT, vma); 887 888 mutex_unlock(&dev->struct_mutex); 889 890 return ret; 891 } 892 EXPORT_SYMBOL(drm_gem_mmap); 893