drivers/gpu/drm/ttm/ttm_bo_vm.c

   1 /* SPDX-License-Identifier: GPL-2.0 OR MIT */
   2 /**************************************************************************
   3  *
   4  * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
   5  * All Rights Reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the
   9  * "Software"), to deal in the Software without restriction, including
  10  * without limitation the rights to use, copy, modify, merge, publish,
  11  * distribute, sub license, and/or sell copies of the Software, and to
  12  * permit persons to whom the Software is furnished to do so, subject to
  13  * the following conditions:
  14  *
  15  * The above copyright notice and this permission notice (including the
  16  * next paragraph) shall be included in all copies or substantial portions
  17  * of the Software.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  20  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
  22  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
  23  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  24  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  25  * USE OR OTHER DEALINGS IN THE SOFTWARE.
  26  *
  27  **************************************************************************/
  28 /*
  29  * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
  30  */
  31
  32 #define pr_fmt(fmt) "[TTM] " fmt
  33
  34 #include <drm/ttm/ttm_module.h>
  35 #include <drm/ttm/ttm_bo_driver.h>
  36 #include <drm/ttm/ttm_placement.h>
  37 #include <drm/drm_vma_manager.h>
  38 #include <linux/mm.h>
  39 #include <linux/pfn_t.h>
  40 #include <linux/rbtree.h>
  41 #include <linux/module.h>
  42 #include <linux/uaccess.h>
  43 #include <linux/mem_encrypt.h>
  44
  45 static vm_fault_t ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo,
  46                                 struct vm_fault *vmf)
  47 {
  48         vm_fault_t ret = 0;
  49         int err = 0;
  50
  51         if (likely(!bo->moving))
  52                 goto out_unlock;
  53
  54         /*
  55          * Quick non-stalling check for idle.
  56          */
  57         if (dma_fence_is_signaled(bo->moving))
  58                 goto out_clear;
  59
  60         /*
  61          * If possible, avoid waiting for GPU with mmap_lock
  62          * held.  We only do this if the fault allows retry and this
  63          * is the first attempt.
  64          */
  65         if (fault_flag_allow_retry_first(vmf->flags)) {
  66                 ret = VM_FAULT_RETRY;
  67                 if (vmf->flags & FAULT_FLAG_RETRY_NOWAIT)
  68                         goto out_unlock;
  69
  70                 ttm_bo_get(bo);
  71                 mmap_read_unlock(vmf->vma->vm_mm);
  72                 (void) dma_fence_wait(bo->moving, true);
  73                 dma_resv_unlock(bo->base.resv);
  74                 ttm_bo_put(bo);
  75                 goto out_unlock;
  76         }
  77
  78         /*
  79          * Ordinary wait.
  80          */
  81         err = dma_fence_wait(bo->moving, true);
  82         if (unlikely(err != 0)) {
  83                 ret = (err != -ERESTARTSYS) ? VM_FAULT_SIGBUS :
  84                         VM_FAULT_NOPAGE;
  85                 goto out_unlock;
  86         }
  87
  88 out_clear:
  89         dma_fence_put(bo->moving);
  90         bo->moving = NULL;
  91
  92 out_unlock:
  93         return ret;
  94 }
  95
  96 static unsigned long ttm_bo_io_mem_pfn(struct ttm_buffer_object *bo,
  97                                        unsigned long page_offset)
  98 {
  99         struct ttm_bo_device *bdev = bo->bdev;
 100
 101         if (bdev->driver->io_mem_pfn)
 102                 return bdev->driver->io_mem_pfn(bo, page_offset);
 103
 104         return (bo->mem.bus.offset >> PAGE_SHIFT) + page_offset;
 105 }
 106
 107 /**
 108  * ttm_bo_vm_reserve - Reserve a buffer object in a retryable vm callback
 109  * @bo: The buffer object
 110  * @vmf: The fault structure handed to the callback
 111  *
 112  * vm callbacks like fault() and *_mkwrite() allow for the mm_sem to be dropped
 113  * during long waits, and after the wait the callback will be restarted. This
 114  * is to allow other threads using the same virtual memory space concurrent
 115  * access to map(), unmap() completely unrelated buffer objects. TTM buffer
 116  * object reservations sometimes wait for GPU and should therefore be
 117  * considered long waits. This function reserves the buffer object interruptibly
 118  * taking this into account. Starvation is avoided by the vm system not
 119  * allowing too many repeated restarts.
 120  * This function is intended to be used in customized fault() and _mkwrite()
 121  * handlers.
 122  *
 123  * Return:
 124  *    0 on success and the bo was reserved.
 125  *    VM_FAULT_RETRY if blocking wait.
 126  *    VM_FAULT_NOPAGE if blocking wait and retrying was not allowed.
 127  */
 128 vm_fault_t ttm_bo_vm_reserve(struct ttm_buffer_object *bo,
 129                              struct vm_fault *vmf)
 130 {
 131         /*
 132          * Work around locking order reversal in fault / nopfn
 133          * between mmap_lock and bo_reserve: Perform a trylock operation
 134          * for reserve, and if it fails, retry the fault after waiting
 135          * for the buffer to become unreserved.
 136          */
 137         if (unlikely(!dma_resv_trylock(bo->base.resv))) {
 138                 /*
 139                  * If the fault allows retry and this is the first
 140                  * fault attempt, we try to release the mmap_lock
 141                  * before waiting
 142                  */
 143                 if (fault_flag_allow_retry_first(vmf->flags)) {
 144                         if (!(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) {
 145                                 ttm_bo_get(bo);
 146                                 mmap_read_unlock(vmf->vma->vm_mm);
 147                                 if (!dma_resv_lock_interruptible(bo->base.resv,
 148                                                                  NULL))
 149                                         dma_resv_unlock(bo->base.resv);
 150                                 ttm_bo_put(bo);
 151                         }
 152
 153                         return VM_FAULT_RETRY;
 154                 }
 155
 156                 if (dma_resv_lock_interruptible(bo->base.resv, NULL))
 157                         return VM_FAULT_NOPAGE;
 158         }
 159
 160         return 0;
 161 }
 162 EXPORT_SYMBOL(ttm_bo_vm_reserve);
 163
 164 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 165 /**
 166  * ttm_bo_vm_insert_huge - Insert a pfn for PUD or PMD faults
 167  * @vmf: Fault data
 168  * @bo: The buffer object
 169  * @page_offset: Page offset from bo start
 170  * @fault_page_size: The size of the fault in pages.
 171  * @pgprot: The page protections.
 172  * Does additional checking whether it's possible to insert a PUD or PMD
 173  * pfn and performs the insertion.
 174  *
 175  * Return: VM_FAULT_NOPAGE on successful insertion, VM_FAULT_FALLBACK if
 176  * a huge fault was not possible, or on insertion error.
 177  */
 178 static vm_fault_t ttm_bo_vm_insert_huge(struct vm_fault *vmf,
 179                                         struct ttm_buffer_object *bo,
 180                                         pgoff_t page_offset,
 181                                         pgoff_t fault_page_size,
 182                                         pgprot_t pgprot)
 183 {
 184         pgoff_t i;
 185         vm_fault_t ret;
 186         unsigned long pfn;
 187         pfn_t pfnt;
 188         struct ttm_tt *ttm = bo->ttm;
 189         bool write = vmf->flags & FAULT_FLAG_WRITE;
 190
 191         /* Fault should not cross bo boundary. */
 192         page_offset &= ~(fault_page_size - 1);
 193         if (page_offset + fault_page_size > bo->num_pages)
 194                 goto out_fallback;
 195
 196         if (bo->mem.bus.is_iomem)
 197                 pfn = ttm_bo_io_mem_pfn(bo, page_offset);
 198         else
 199                 pfn = page_to_pfn(ttm->pages[page_offset]);
 200
 201         /* pfn must be fault_page_size aligned. */
 202         if ((pfn & (fault_page_size - 1)) != 0)
 203                 goto out_fallback;
 204
 205         /* Check that memory is contiguous. */
 206         if (!bo->mem.bus.is_iomem) {
 207                 for (i = 1; i < fault_page_size; ++i) {
 208                         if (page_to_pfn(ttm->pages[page_offset + i]) != pfn + i)
 209                                 goto out_fallback;
 210                 }
 211         } else if (bo->bdev->driver->io_mem_pfn) {
 212                 for (i = 1; i < fault_page_size; ++i) {
 213                         if (ttm_bo_io_mem_pfn(bo, page_offset + i) != pfn + i)
 214                                 goto out_fallback;
 215                 }
 216         }
 217
 218         pfnt = __pfn_to_pfn_t(pfn, PFN_DEV);
 219         if (fault_page_size == (HPAGE_PMD_SIZE >> PAGE_SHIFT))
 220                 ret = vmf_insert_pfn_pmd_prot(vmf, pfnt, pgprot, write);
 221 #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
 222         else if (fault_page_size == (HPAGE_PUD_SIZE >> PAGE_SHIFT))
 223                 ret = vmf_insert_pfn_pud_prot(vmf, pfnt, pgprot, write);
 224 #endif
 225         else
 226                 WARN_ON_ONCE(ret = VM_FAULT_FALLBACK);
 227
 228         if (ret != VM_FAULT_NOPAGE)
 229                 goto out_fallback;
 230
 231         return VM_FAULT_NOPAGE;
 232 out_fallback:
 233         count_vm_event(THP_FAULT_FALLBACK);
 234         return VM_FAULT_FALLBACK;
 235 }
 236 #else
 237 static vm_fault_t ttm_bo_vm_insert_huge(struct vm_fault *vmf,
 238                                         struct ttm_buffer_object *bo,
 239                                         pgoff_t page_offset,
 240                                         pgoff_t fault_page_size,
 241                                         pgprot_t pgprot)
 242 {
 243         return VM_FAULT_FALLBACK;
 244 }
 245 #endif
 246
 247 /**
 248  * ttm_bo_vm_fault_reserved - TTM fault helper
 249  * @vmf: The struct vm_fault given as argument to the fault callback
 250  * @prot: The page protection to be used for this memory area.
 251  * @num_prefault: Maximum number of prefault pages. The caller may want to
 252  * specify this based on madvice settings and the size of the GPU object
 253  * backed by the memory.
 254  * @fault_page_size: The size of the fault in pages.
 255  *
 256  * This function inserts one or more page table entries pointing to the
 257  * memory backing the buffer object, and then returns a return code
 258  * instructing the caller to retry the page access.
 259  *
 260  * Return:
 261  *   VM_FAULT_NOPAGE on success or pending signal
 262  *   VM_FAULT_SIGBUS on unspecified error
 263  *   VM_FAULT_OOM on out-of-memory
 264  *   VM_FAULT_RETRY if retryable wait
 265  */
 266 vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf,
 267                                     pgprot_t prot,
 268                                     pgoff_t num_prefault,
 269                                     pgoff_t fault_page_size)
 270 {
 271         struct vm_area_struct *vma = vmf->vma;
 272         struct ttm_buffer_object *bo = vma->vm_private_data;
 273         struct ttm_bo_device *bdev = bo->bdev;
 274         unsigned long page_offset;
 275         unsigned long page_last;
 276         unsigned long pfn;
 277         struct ttm_tt *ttm = NULL;
 278         struct page *page;
 279         int err;
 280         pgoff_t i;
 281         vm_fault_t ret = VM_FAULT_NOPAGE;
 282         unsigned long address = vmf->address;
 283
 284         /*
 285          * Refuse to fault imported pages. This should be handled
 286          * (if at all) by redirecting mmap to the exporter.
 287          */
 288         if (bo->ttm && (bo->ttm->page_flags & TTM_PAGE_FLAG_SG))
 289                 return VM_FAULT_SIGBUS;
 290
 291         if (bdev->driver->fault_reserve_notify) {
 292                 struct dma_fence *moving = dma_fence_get(bo->moving);
 293
 294                 err = bdev->driver->fault_reserve_notify(bo);
 295                 switch (err) {
 296                 case 0:
 297                         break;
 298                 case -EBUSY:
 299                 case -ERESTARTSYS:
 300                         dma_fence_put(moving);
 301                         return VM_FAULT_NOPAGE;
 302                 default:
 303                         dma_fence_put(moving);
 304                         return VM_FAULT_SIGBUS;
 305                 }
 306
 307                 if (bo->moving != moving) {
 308                         ttm_bo_move_to_lru_tail_unlocked(bo);
 309                 }
 310                 dma_fence_put(moving);
 311         }
 312
 313         /*
 314          * Wait for buffer data in transit, due to a pipelined
 315          * move.
 316          */
 317         ret = ttm_bo_vm_fault_idle(bo, vmf);
 318         if (unlikely(ret != 0))
 319                 return ret;
 320
 321         err = ttm_mem_io_reserve(bdev, &bo->mem);
 322         if (unlikely(err != 0))
 323                 return VM_FAULT_SIGBUS;
 324
 325         page_offset = ((address - vma->vm_start) >> PAGE_SHIFT) +
 326                 vma->vm_pgoff - drm_vma_node_start(&bo->base.vma_node);
 327         page_last = vma_pages(vma) + vma->vm_pgoff -
 328                 drm_vma_node_start(&bo->base.vma_node);
 329
 330         if (unlikely(page_offset >= bo->num_pages))
 331                 return VM_FAULT_SIGBUS;
 332
 333         prot = ttm_io_prot(bo->mem.placement, prot);
 334         if (!bo->mem.bus.is_iomem) {
 335                 struct ttm_operation_ctx ctx = {
 336                         .interruptible = false,
 337                         .no_wait_gpu = false,
 338                         .flags = TTM_OPT_FLAG_FORCE_ALLOC
 339
 340                 };
 341
 342                 ttm = bo->ttm;
 343                 if (ttm_tt_populate(bdev, bo->ttm, &ctx))
 344                         return VM_FAULT_OOM;
 345         } else {
 346                 /* Iomem should not be marked encrypted */
 347                 prot = pgprot_decrypted(prot);
 348         }
 349
 350         /* We don't prefault on huge faults. Yet. */
 351         if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && fault_page_size != 1)
 352                 return ttm_bo_vm_insert_huge(vmf, bo, page_offset,
 353                                              fault_page_size, prot);
 354
 355         /*
 356          * Speculatively prefault a number of pages. Only error on
 357          * first page.
 358          */
 359         for (i = 0; i < num_prefault; ++i) {
 360                 if (bo->mem.bus.is_iomem) {
 361                         pfn = ttm_bo_io_mem_pfn(bo, page_offset);
 362                 } else {
 363                         page = ttm->pages[page_offset];
 364                         if (unlikely(!page && i == 0)) {
 365                                 return VM_FAULT_OOM;
 366                         } else if (unlikely(!page)) {
 367                                 break;
 368                         }
 369                         page->index = drm_vma_node_start(&bo->base.vma_node) +
 370                                 page_offset;
 371                         pfn = page_to_pfn(page);
 372                 }
 373
 374                 /*
 375                  * Note that the value of @prot at this point may differ from
 376                  * the value of @vma->vm_page_prot in the caching- and
 377                  * encryption bits. This is because the exact location of the
 378                  * data may not be known at mmap() time and may also change
 379                  * at arbitrary times while the data is mmap'ed.
 380                  * See vmf_insert_mixed_prot() for a discussion.
 381                  */
 382                 if (vma->vm_flags & VM_MIXEDMAP)
 383                         ret = vmf_insert_mixed_prot(vma, address,
 384                                                     __pfn_to_pfn_t(pfn, PFN_DEV),
 385                                                     prot);
 386                 else
 387                         ret = vmf_insert_pfn_prot(vma, address, pfn, prot);
 388
 389                 /* Never error on prefaulted PTEs */
 390                 if (unlikely((ret & VM_FAULT_ERROR))) {
 391                         if (i == 0)
 392                                 return VM_FAULT_NOPAGE;
 393                         else
 394                                 break;
 395                 }
 396
 397                 address += PAGE_SIZE;
 398                 if (unlikely(++page_offset >= page_last))
 399                         break;
 400         }
 401         return ret;
 402 }
 403 EXPORT_SYMBOL(ttm_bo_vm_fault_reserved);
 404
 405 vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf)
 406 {
 407         struct vm_area_struct *vma = vmf->vma;
 408         pgprot_t prot;
 409         struct ttm_buffer_object *bo = vma->vm_private_data;
 410         vm_fault_t ret;
 411
 412         ret = ttm_bo_vm_reserve(bo, vmf);
 413         if (ret)
 414                 return ret;
 415
 416         prot = vma->vm_page_prot;
 417         ret = ttm_bo_vm_fault_reserved(vmf, prot, TTM_BO_VM_NUM_PREFAULT, 1);
 418         if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT))
 419                 return ret;
 420
 421         dma_resv_unlock(bo->base.resv);
 422
 423         return ret;
 424 }
 425 EXPORT_SYMBOL(ttm_bo_vm_fault);
 426
 427 void ttm_bo_vm_open(struct vm_area_struct *vma)
 428 {
 429         struct ttm_buffer_object *bo = vma->vm_private_data;
 430
 431         WARN_ON(bo->bdev->dev_mapping != vma->vm_file->f_mapping);
 432
 433         ttm_bo_get(bo);
 434 }
 435 EXPORT_SYMBOL(ttm_bo_vm_open);
 436
 437 void ttm_bo_vm_close(struct vm_area_struct *vma)
 438 {
 439         struct ttm_buffer_object *bo = vma->vm_private_data;
 440
 441         ttm_bo_put(bo);
 442         vma->vm_private_data = NULL;
 443 }
 444 EXPORT_SYMBOL(ttm_bo_vm_close);
 445
 446 static int ttm_bo_vm_access_kmap(struct ttm_buffer_object *bo,
 447                                  unsigned long offset,
 448                                  uint8_t *buf, int len, int write)
 449 {
 450         unsigned long page = offset >> PAGE_SHIFT;
 451         unsigned long bytes_left = len;
 452         int ret;
 453
 454         /* Copy a page at a time, that way no extra virtual address
 455          * mapping is needed
 456          */
 457         offset -= page << PAGE_SHIFT;
 458         do {
 459                 unsigned long bytes = min(bytes_left, PAGE_SIZE - offset);
 460                 struct ttm_bo_kmap_obj map;
 461                 void *ptr;
 462                 bool is_iomem;
 463
 464                 ret = ttm_bo_kmap(bo, page, 1, &map);
 465                 if (ret)
 466                         return ret;
 467
 468                 ptr = (uint8_t *)ttm_kmap_obj_virtual(&map, &is_iomem) + offset;
 469                 WARN_ON_ONCE(is_iomem);
 470                 if (write)
 471                         memcpy(ptr, buf, bytes);
 472                 else
 473                         memcpy(buf, ptr, bytes);
 474                 ttm_bo_kunmap(&map);
 475
 476                 page++;
 477                 buf += bytes;
 478                 bytes_left -= bytes;
 479                 offset = 0;
 480         } while (bytes_left);
 481
 482         return len;
 483 }
 484
 485 int ttm_bo_vm_access(struct vm_area_struct *vma, unsigned long addr,
 486                      void *buf, int len, int write)
 487 {
 488         struct ttm_buffer_object *bo = vma->vm_private_data;
 489         unsigned long offset = (addr) - vma->vm_start +
 490                 ((vma->vm_pgoff - drm_vma_node_start(&bo->base.vma_node))
 491                  << PAGE_SHIFT);
 492         int ret;
 493
 494         if (len < 1 || (offset + len) >> PAGE_SHIFT > bo->num_pages)
 495                 return -EIO;
 496
 497         ret = ttm_bo_reserve(bo, true, false, NULL);
 498         if (ret)
 499                 return ret;
 500
 501         switch (bo->mem.mem_type) {
 502         case TTM_PL_SYSTEM:
 503                 fallthrough;
 504         case TTM_PL_TT:
 505                 ret = ttm_bo_vm_access_kmap(bo, offset, buf, len, write);
 506                 break;
 507         default:
 508                 if (bo->bdev->driver->access_memory)
 509                         ret = bo->bdev->driver->access_memory(
 510                                 bo, offset, buf, len, write);
 511                 else
 512                         ret = -EIO;
 513         }
 514
 515         ttm_bo_unreserve(bo);
 516
 517         return ret;
 518 }
 519 EXPORT_SYMBOL(ttm_bo_vm_access);
 520
 521 static const struct vm_operations_struct ttm_bo_vm_ops = {
 522         .fault = ttm_bo_vm_fault,
 523         .open = ttm_bo_vm_open,
 524         .close = ttm_bo_vm_close,
 525         .access = ttm_bo_vm_access,
 526 };
 527
 528 static struct ttm_buffer_object *ttm_bo_vm_lookup(struct ttm_bo_device *bdev,
 529                                                   unsigned long offset,
 530                                                   unsigned long pages)
 531 {
 532         struct drm_vma_offset_node *node;
 533         struct ttm_buffer_object *bo = NULL;
 534
 535         drm_vma_offset_lock_lookup(bdev->vma_manager);
 536
 537         node = drm_vma_offset_lookup_locked(bdev->vma_manager, offset, pages);
 538         if (likely(node)) {
 539                 bo = container_of(node, struct ttm_buffer_object,
 540                                   base.vma_node);
 541                 bo = ttm_bo_get_unless_zero(bo);
 542         }
 543
 544         drm_vma_offset_unlock_lookup(bdev->vma_manager);
 545
 546         if (!bo)
 547                 pr_err("Could not find buffer object to map\n");
 548
 549         return bo;
 550 }
 551
 552 static void ttm_bo_mmap_vma_setup(struct ttm_buffer_object *bo, struct vm_area_struct *vma)
 553 {
 554         vma->vm_ops = &ttm_bo_vm_ops;
 555
 556         /*
 557          * Note: We're transferring the bo reference to
 558          * vma->vm_private_data here.
 559          */
 560
 561         vma->vm_private_data = bo;
 562
 563         /*
 564          * We'd like to use VM_PFNMAP on shared mappings, where
 565          * (vma->vm_flags & VM_SHARED) != 0, for performance reasons,
 566          * but for some reason VM_PFNMAP + x86 PAT + write-combine is very
 567          * bad for performance. Until that has been sorted out, use
 568          * VM_MIXEDMAP on all mappings. See freedesktop.org bug #75719
 569          */
 570         vma->vm_flags |= VM_MIXEDMAP;
 571         vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
 572 }
 573
 574 int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma,
 575                 struct ttm_bo_device *bdev)
 576 {
 577         struct ttm_bo_driver *driver;
 578         struct ttm_buffer_object *bo;
 579         int ret;
 580
 581         if (unlikely(vma->vm_pgoff < DRM_FILE_PAGE_OFFSET_START))
 582                 return -EINVAL;
 583
 584         bo = ttm_bo_vm_lookup(bdev, vma->vm_pgoff, vma_pages(vma));
 585         if (unlikely(!bo))
 586                 return -EINVAL;
 587
 588         driver = bo->bdev->driver;
 589         if (unlikely(!driver->verify_access)) {
 590                 ret = -EPERM;
 591                 goto out_unref;
 592         }
 593         ret = driver->verify_access(bo, filp);
 594         if (unlikely(ret != 0))
 595                 goto out_unref;
 596
 597         ttm_bo_mmap_vma_setup(bo, vma);
 598         return 0;
 599 out_unref:
 600         ttm_bo_put(bo);
 601         return ret;
 602 }
 603 EXPORT_SYMBOL(ttm_bo_mmap);
 604
 605 int ttm_bo_mmap_obj(struct vm_area_struct *vma, struct ttm_buffer_object *bo)
 606 {
 607         ttm_bo_get(bo);
 608         ttm_bo_mmap_vma_setup(bo, vma);
 609         return 0;
 610 }
 611 EXPORT_SYMBOL(ttm_bo_mmap_obj);