drivers/char/drm/drm_vm.c

   1 /**
   2  * \file drm_vm.c
   3  * Memory mapping for DRM
   4  *
   5  * \author Rickard E. (Rik) Faith <faith@valinux.com>
   6  * \author Gareth Hughes <gareth@valinux.com>
   7  */
   8
   9 /*
  10  * Created: Mon Jan  4 08:58:31 1999 by faith@valinux.com
  11  *
  12  * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
  13  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
  14  * All Rights Reserved.
  15  *
  16  * Permission is hereby granted, free of charge, to any person obtaining a
  17  * copy of this software and associated documentation files (the "Software"),
  18  * to deal in the Software without restriction, including without limitation
  19  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  20  * and/or sell copies of the Software, and to permit persons to whom the
  21  * Software is furnished to do so, subject to the following conditions:
  22  *
  23  * The above copyright notice and this permission notice (including the next
  24  * paragraph) shall be included in all copies or substantial portions of the
  25  * Software.
  26  *
  27  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  28  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  29  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  30  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  31  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  32  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  33  * OTHER DEALINGS IN THE SOFTWARE.
  34  */
  35
  36 #include "drmP.h"
  37 #if defined(__ia64__)
  38 #include <linux/efi.h>
  39 #endif
  40
  41 static void drm_vm_open(struct vm_area_struct *vma);
  42 static void drm_vm_close(struct vm_area_struct *vma);
  43
  44 static pgprot_t drm_io_prot(uint32_t map_type, struct vm_area_struct *vma)
  45 {
  46         pgprot_t tmp = vm_get_page_prot(vma->vm_flags);
  47
  48 #if defined(__i386__) || defined(__x86_64__)
  49         if (boot_cpu_data.x86 > 3 && map_type != _DRM_AGP) {
  50                 pgprot_val(tmp) |= _PAGE_PCD;
  51                 pgprot_val(tmp) &= ~_PAGE_PWT;
  52         }
  53 #elif defined(__powerpc__)
  54         pgprot_val(tmp) |= _PAGE_NO_CACHE;
  55         if (map_type == _DRM_REGISTERS)
  56                 pgprot_val(tmp) |= _PAGE_GUARDED;
  57 #elif defined(__ia64__)
  58         if (efi_range_is_wc(vma->vm_start, vma->vm_end -
  59                                     vma->vm_start))
  60                 tmp = pgprot_writecombine(tmp);
  61         else
  62                 tmp = pgprot_noncached(tmp);
  63 #elif defined(__sparc__)
  64         tmp = pgprot_noncached(tmp);
  65 #endif
  66         return tmp;
  67 }
  68
  69 static pgprot_t drm_dma_prot(uint32_t map_type, struct vm_area_struct *vma)
  70 {
  71         pgprot_t tmp = vm_get_page_prot(vma->vm_flags);
  72
  73 #if defined(__powerpc__) && defined(CONFIG_NOT_COHERENT_CACHE)
  74         tmp |= _PAGE_NO_CACHE;
  75 #endif
  76         return tmp;
  77 }
  78
  79 /**
  80  * \c fault method for AGP virtual memory.
  81  *
  82  * \param vma virtual memory area.
  83  * \param address access address.
  84  * \return pointer to the page structure.
  85  *
  86  * Find the right map and if it's AGP memory find the real physical page to
  87  * map, get the page, increment the use count and return it.
  88  */
  89 #if __OS_HAS_AGP
  90 static int drm_do_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
  91 {
  92         struct drm_file *priv = vma->vm_file->private_data;
  93         struct drm_device *dev = priv->head->dev;
  94         struct drm_map *map = NULL;
  95         struct drm_map_list *r_list;
  96         struct drm_hash_item *hash;
  97
  98         /*
  99          * Find the right map
 100          */
 101         if (!drm_core_has_AGP(dev))
 102                 goto vm_fault_error;
 103
 104         if (!dev->agp || !dev->agp->cant_use_aperture)
 105                 goto vm_fault_error;
 106
 107         if (drm_ht_find_item(&dev->map_hash, vma->vm_pgoff, &hash))
 108                 goto vm_fault_error;
 109
 110         r_list = drm_hash_entry(hash, struct drm_map_list, hash);
 111         map = r_list->map;
 112
 113         if (map && map->type == _DRM_AGP) {
 114                 /*
 115                  * Using vm_pgoff as a selector forces us to use this unusual
 116                  * addressing scheme.
 117                  */
 118                 unsigned long offset = (unsigned long)vmf->virtual_address -
 119                                                                 vma->vm_start;
 120                 unsigned long baddr = map->offset + offset;
 121                 struct drm_agp_mem *agpmem;
 122                 struct page *page;
 123
 124 #ifdef __alpha__
 125                 /*
 126                  * Adjust to a bus-relative address
 127                  */
 128                 baddr -= dev->hose->mem_space->start;
 129 #endif
 130
 131                 /*
 132                  * It's AGP memory - find the real physical page to map
 133                  */
 134                 list_for_each_entry(agpmem, &dev->agp->memory, head) {
 135                         if (agpmem->bound <= baddr &&
 136                             agpmem->bound + agpmem->pages * PAGE_SIZE > baddr)
 137                                 break;
 138                 }
 139
 140                 if (!agpmem)
 141                         goto vm_fault_error;
 142
 143                 /*
 144                  * Get the page, inc the use count, and return it
 145                  */
 146                 offset = (baddr - agpmem->bound) >> PAGE_SHIFT;
 147                 page = virt_to_page(__va(agpmem->memory->memory[offset]));
 148                 get_page(page);
 149                 vmf->page = page;
 150
 151                 DRM_DEBUG
 152                     ("baddr = 0x%lx page = 0x%p, offset = 0x%lx, count=%d\n",
 153                      baddr, __va(agpmem->memory->memory[offset]), offset,
 154                      page_count(page));
 155                 return 0;
 156         }
 157 vm_fault_error:
 158         return VM_FAULT_SIGBUS; /* Disallow mremap */
 159 }
 160 #else                           /* __OS_HAS_AGP */
 161 static int drm_do_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 162 {
 163         return VM_FAULT_SIGBUS;
 164 }
 165 #endif                          /* __OS_HAS_AGP */
 166
 167 /**
 168  * \c nopage method for shared virtual memory.
 169  *
 170  * \param vma virtual memory area.
 171  * \param address access address.
 172  * \return pointer to the page structure.
 173  *
 174  * Get the mapping, find the real physical page to map, get the page, and
 175  * return it.
 176  */
 177 static int drm_do_vm_shm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 178 {
 179         struct drm_map *map = (struct drm_map *) vma->vm_private_data;
 180         unsigned long offset;
 181         unsigned long i;
 182         struct page *page;
 183
 184         if (!map)
 185                 return VM_FAULT_SIGBUS; /* Nothing allocated */
 186
 187         offset = (unsigned long)vmf->virtual_address - vma->vm_start;
 188         i = (unsigned long)map->handle + offset;
 189         page = vmalloc_to_page((void *)i);
 190         if (!page)
 191                 return VM_FAULT_SIGBUS;
 192         get_page(page);
 193         vmf->page = page;
 194
 195         DRM_DEBUG("shm_fault 0x%lx\n", offset);
 196         return 0;
 197 }
 198
 199 /**
 200  * \c close method for shared virtual memory.
 201  *
 202  * \param vma virtual memory area.
 203  *
 204  * Deletes map information if we are the last
 205  * person to close a mapping and it's not in the global maplist.
 206  */
 207 static void drm_vm_shm_close(struct vm_area_struct *vma)
 208 {
 209         struct drm_file *priv = vma->vm_file->private_data;
 210         struct drm_device *dev = priv->head->dev;
 211         struct drm_vma_entry *pt, *temp;
 212         struct drm_map *map;
 213         struct drm_map_list *r_list;
 214         int found_maps = 0;
 215
 216         DRM_DEBUG("0x%08lx,0x%08lx\n",
 217                   vma->vm_start, vma->vm_end - vma->vm_start);
 218         atomic_dec(&dev->vma_count);
 219
 220         map = vma->vm_private_data;
 221
 222         mutex_lock(&dev->struct_mutex);
 223         list_for_each_entry_safe(pt, temp, &dev->vmalist, head) {
 224                 if (pt->vma->vm_private_data == map)
 225                         found_maps++;
 226                 if (pt->vma == vma) {
 227                         list_del(&pt->head);
 228                         drm_free(pt, sizeof(*pt), DRM_MEM_VMAS);
 229                 }
 230         }
 231
 232         /* We were the only map that was found */
 233         if (found_maps == 1 && map->flags & _DRM_REMOVABLE) {
 234                 /* Check to see if we are in the maplist, if we are not, then
 235                  * we delete this mappings information.
 236                  */
 237                 found_maps = 0;
 238                 list_for_each_entry(r_list, &dev->maplist, head) {
 239                         if (r_list->map == map)
 240                                 found_maps++;
 241                 }
 242
 243                 if (!found_maps) {
 244                         drm_dma_handle_t dmah;
 245
 246                         switch (map->type) {
 247                         case _DRM_REGISTERS:
 248                         case _DRM_FRAME_BUFFER:
 249                                 if (drm_core_has_MTRR(dev) && map->mtrr >= 0) {
 250                                         int retcode;
 251                                         retcode = mtrr_del(map->mtrr,
 252                                                            map->offset,
 253                                                            map->size);
 254                                         DRM_DEBUG("mtrr_del = %d\n", retcode);
 255                                 }
 256                                 iounmap(map->handle);
 257                                 break;
 258                         case _DRM_SHM:
 259                                 vfree(map->handle);
 260                                 break;
 261                         case _DRM_AGP:
 262                         case _DRM_SCATTER_GATHER:
 263                                 break;
 264                         case _DRM_CONSISTENT:
 265                                 dmah.vaddr = map->handle;
 266                                 dmah.busaddr = map->offset;
 267                                 dmah.size = map->size;
 268                                 __drm_pci_free(dev, &dmah);
 269                                 break;
 270                         }
 271                         drm_free(map, sizeof(*map), DRM_MEM_MAPS);
 272                 }
 273         }
 274         mutex_unlock(&dev->struct_mutex);
 275 }
 276
 277 /**
 278  * \c fault method for DMA virtual memory.
 279  *
 280  * \param vma virtual memory area.
 281  * \param address access address.
 282  * \return pointer to the page structure.
 283  *
 284  * Determine the page number from the page offset and get it from drm_device_dma::pagelist.
 285  */
 286 static int drm_do_vm_dma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 287 {
 288         struct drm_file *priv = vma->vm_file->private_data;
 289         struct drm_device *dev = priv->head->dev;
 290         struct drm_device_dma *dma = dev->dma;
 291         unsigned long offset;
 292         unsigned long page_nr;
 293         struct page *page;
 294
 295         if (!dma)
 296                 return VM_FAULT_SIGBUS; /* Error */
 297         if (!dma->pagelist)
 298                 return VM_FAULT_SIGBUS; /* Nothing allocated */
 299
 300         offset = (unsigned long)vmf->virtual_address - vma->vm_start;   /* vm_[pg]off[set] should be 0 */
 301         page_nr = offset >> PAGE_SHIFT; /* page_nr could just be vmf->pgoff */
 302         page = virt_to_page((dma->pagelist[page_nr] + (offset & (~PAGE_MASK))));
 303
 304         get_page(page);
 305         vmf->page = page;
 306
 307         DRM_DEBUG("dma_fault 0x%lx (page %lu)\n", offset, page_nr);
 308         return 0;
 309 }
 310
 311 /**
 312  * \c fault method for scatter-gather virtual memory.
 313  *
 314  * \param vma virtual memory area.
 315  * \param address access address.
 316  * \return pointer to the page structure.
 317  *
 318  * Determine the map offset from the page offset and get it from drm_sg_mem::pagelist.
 319  */
 320 static int drm_do_vm_sg_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 321 {
 322         struct drm_map *map = (struct drm_map *) vma->vm_private_data;
 323         struct drm_file *priv = vma->vm_file->private_data;
 324         struct drm_device *dev = priv->head->dev;
 325         struct drm_sg_mem *entry = dev->sg;
 326         unsigned long offset;
 327         unsigned long map_offset;
 328         unsigned long page_offset;
 329         struct page *page;
 330
 331         if (!entry)
 332                 return VM_FAULT_SIGBUS; /* Error */
 333         if (!entry->pagelist)
 334                 return VM_FAULT_SIGBUS; /* Nothing allocated */
 335
 336         offset = (unsigned long)vmf->virtual_address - vma->vm_start;
 337         map_offset = map->offset - (unsigned long)dev->sg->virtual;
 338         page_offset = (offset >> PAGE_SHIFT) + (map_offset >> PAGE_SHIFT);
 339         page = entry->pagelist[page_offset];
 340         get_page(page);
 341         vmf->page = page;
 342
 343         return 0;
 344 }
 345
 346 static int drm_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 347 {
 348         return drm_do_vm_fault(vma, vmf);
 349 }
 350
 351 static int drm_vm_shm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 352 {
 353         return drm_do_vm_shm_fault(vma, vmf);
 354 }
 355
 356 static int drm_vm_dma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 357 {
 358         return drm_do_vm_dma_fault(vma, vmf);
 359 }
 360
 361 static int drm_vm_sg_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 362 {
 363         return drm_do_vm_sg_fault(vma, vmf);
 364 }
 365
 366 /** AGP virtual memory operations */
 367 static struct vm_operations_struct drm_vm_ops = {
 368         .fault = drm_vm_fault,
 369         .open = drm_vm_open,
 370         .close = drm_vm_close,
 371 };
 372
 373 /** Shared virtual memory operations */
 374 static struct vm_operations_struct drm_vm_shm_ops = {
 375         .fault = drm_vm_shm_fault,
 376         .open = drm_vm_open,
 377         .close = drm_vm_shm_close,
 378 };
 379
 380 /** DMA virtual memory operations */
 381 static struct vm_operations_struct drm_vm_dma_ops = {
 382         .fault = drm_vm_dma_fault,
 383         .open = drm_vm_open,
 384         .close = drm_vm_close,
 385 };
 386
 387 /** Scatter-gather virtual memory operations */
 388 static struct vm_operations_struct drm_vm_sg_ops = {
 389         .fault = drm_vm_sg_fault,
 390         .open = drm_vm_open,
 391         .close = drm_vm_close,
 392 };
 393
 394 /**
 395  * \c open method for shared virtual memory.
 396  *
 397  * \param vma virtual memory area.
 398  *
 399  * Create a new drm_vma_entry structure as the \p vma private data entry and
 400  * add it to drm_device::vmalist.
 401  */
 402 static void drm_vm_open_locked(struct vm_area_struct *vma)
 403 {
 404         struct drm_file *priv = vma->vm_file->private_data;
 405         struct drm_device *dev = priv->head->dev;
 406         struct drm_vma_entry *vma_entry;
 407
 408         DRM_DEBUG("0x%08lx,0x%08lx\n",
 409                   vma->vm_start, vma->vm_end - vma->vm_start);
 410         atomic_inc(&dev->vma_count);
 411
 412         vma_entry = drm_alloc(sizeof(*vma_entry), DRM_MEM_VMAS);
 413         if (vma_entry) {
 414                 vma_entry->vma = vma;
 415                 vma_entry->pid = current->pid;
 416                 list_add(&vma_entry->head, &dev->vmalist);
 417         }
 418 }
 419
 420 static void drm_vm_open(struct vm_area_struct *vma)
 421 {
 422         struct drm_file *priv = vma->vm_file->private_data;
 423         struct drm_device *dev = priv->head->dev;
 424
 425         mutex_lock(&dev->struct_mutex);
 426         drm_vm_open_locked(vma);
 427         mutex_unlock(&dev->struct_mutex);
 428 }
 429
 430 /**
 431  * \c close method for all virtual memory types.
 432  *
 433  * \param vma virtual memory area.
 434  *
 435  * Search the \p vma private data entry in drm_device::vmalist, unlink it, and
 436  * free it.
 437  */
 438 static void drm_vm_close(struct vm_area_struct *vma)
 439 {
 440         struct drm_file *priv = vma->vm_file->private_data;
 441         struct drm_device *dev = priv->head->dev;
 442         struct drm_vma_entry *pt, *temp;
 443
 444         DRM_DEBUG("0x%08lx,0x%08lx\n",
 445                   vma->vm_start, vma->vm_end - vma->vm_start);
 446         atomic_dec(&dev->vma_count);
 447
 448         mutex_lock(&dev->struct_mutex);
 449         list_for_each_entry_safe(pt, temp, &dev->vmalist, head) {
 450                 if (pt->vma == vma) {
 451                         list_del(&pt->head);
 452                         drm_free(pt, sizeof(*pt), DRM_MEM_VMAS);
 453                         break;
 454                 }
 455         }
 456         mutex_unlock(&dev->struct_mutex);
 457 }
 458
 459 /**
 460  * mmap DMA memory.
 461  *
 462  * \param file_priv DRM file private.
 463  * \param vma virtual memory area.
 464  * \return zero on success or a negative number on failure.
 465  *
 466  * Sets the virtual memory area operations structure to vm_dma_ops, the file
 467  * pointer, and calls vm_open().
 468  */
 469 static int drm_mmap_dma(struct file *filp, struct vm_area_struct *vma)
 470 {
 471         struct drm_file *priv = filp->private_data;
 472         struct drm_device *dev;
 473         struct drm_device_dma *dma;
 474         unsigned long length = vma->vm_end - vma->vm_start;
 475
 476         dev = priv->head->dev;
 477         dma = dev->dma;
 478         DRM_DEBUG("start = 0x%lx, end = 0x%lx, page offset = 0x%lx\n",
 479                   vma->vm_start, vma->vm_end, vma->vm_pgoff);
 480
 481         /* Length must match exact page count */
 482         if (!dma || (length >> PAGE_SHIFT) != dma->page_count) {
 483                 return -EINVAL;
 484         }
 485
 486         if (!capable(CAP_SYS_ADMIN) &&
 487             (dma->flags & _DRM_DMA_USE_PCI_RO)) {
 488                 vma->vm_flags &= ~(VM_WRITE | VM_MAYWRITE);
 489 #if defined(__i386__) || defined(__x86_64__)
 490                 pgprot_val(vma->vm_page_prot) &= ~_PAGE_RW;
 491 #else
 492                 /* Ye gads this is ugly.  With more thought
 493                    we could move this up higher and use
 494                    `protection_map' instead.  */
 495                 vma->vm_page_prot =
 496                     __pgprot(pte_val
 497                              (pte_wrprotect
 498                               (__pte(pgprot_val(vma->vm_page_prot)))));
 499 #endif
 500         }
 501
 502         vma->vm_ops = &drm_vm_dma_ops;
 503
 504         vma->vm_flags |= VM_RESERVED;   /* Don't swap */
 505         vma->vm_flags |= VM_DONTEXPAND;
 506
 507         vma->vm_file = filp;    /* Needed for drm_vm_open() */
 508         drm_vm_open_locked(vma);
 509         return 0;
 510 }
 511
 512 unsigned long drm_core_get_map_ofs(struct drm_map * map)
 513 {
 514         return map->offset;
 515 }
 516
 517 EXPORT_SYMBOL(drm_core_get_map_ofs);
 518
 519 unsigned long drm_core_get_reg_ofs(struct drm_device *dev)
 520 {
 521 #ifdef __alpha__
 522         return dev->hose->dense_mem_base - dev->hose->mem_space->start;
 523 #else
 524         return 0;
 525 #endif
 526 }
 527
 528 EXPORT_SYMBOL(drm_core_get_reg_ofs);
 529
 530 /**
 531  * mmap DMA memory.
 532  *
 533  * \param file_priv DRM file private.
 534  * \param vma virtual memory area.
 535  * \return zero on success or a negative number on failure.
 536  *
 537  * If the virtual memory area has no offset associated with it then it's a DMA
 538  * area, so calls mmap_dma(). Otherwise searches the map in drm_device::maplist,
 539  * checks that the restricted flag is not set, sets the virtual memory operations
 540  * according to the mapping type and remaps the pages. Finally sets the file
 541  * pointer and calls vm_open().
 542  */
 543 static int drm_mmap_locked(struct file *filp, struct vm_area_struct *vma)
 544 {
 545         struct drm_file *priv = filp->private_data;
 546         struct drm_device *dev = priv->head->dev;
 547         struct drm_map *map = NULL;
 548         unsigned long offset = 0;
 549         struct drm_hash_item *hash;
 550
 551         DRM_DEBUG("start = 0x%lx, end = 0x%lx, page offset = 0x%lx\n",
 552                   vma->vm_start, vma->vm_end, vma->vm_pgoff);
 553
 554         if (!priv->authenticated)
 555                 return -EACCES;
 556
 557         /* We check for "dma". On Apple's UniNorth, it's valid to have
 558          * the AGP mapped at physical address 0
 559          * --BenH.
 560          */
 561         if (!vma->vm_pgoff
 562 #if __OS_HAS_AGP
 563             && (!dev->agp
 564                 || dev->agp->agp_info.device->vendor != PCI_VENDOR_ID_APPLE)
 565 #endif
 566             )
 567                 return drm_mmap_dma(filp, vma);
 568
 569         if (drm_ht_find_item(&dev->map_hash, vma->vm_pgoff, &hash)) {
 570                 DRM_ERROR("Could not find map\n");
 571                 return -EINVAL;
 572         }
 573
 574         map = drm_hash_entry(hash, struct drm_map_list, hash)->map;
 575         if (!map || ((map->flags & _DRM_RESTRICTED) && !capable(CAP_SYS_ADMIN)))
 576                 return -EPERM;
 577
 578         /* Check for valid size. */
 579         if (map->size < vma->vm_end - vma->vm_start)
 580                 return -EINVAL;
 581
 582         if (!capable(CAP_SYS_ADMIN) && (map->flags & _DRM_READ_ONLY)) {
 583                 vma->vm_flags &= ~(VM_WRITE | VM_MAYWRITE);
 584 #if defined(__i386__) || defined(__x86_64__)
 585                 pgprot_val(vma->vm_page_prot) &= ~_PAGE_RW;
 586 #else
 587                 /* Ye gads this is ugly.  With more thought
 588                    we could move this up higher and use
 589                    `protection_map' instead.  */
 590                 vma->vm_page_prot =
 591                     __pgprot(pte_val
 592                              (pte_wrprotect
 593                               (__pte(pgprot_val(vma->vm_page_prot)))));
 594 #endif
 595         }
 596
 597         switch (map->type) {
 598         case _DRM_AGP:
 599                 if (drm_core_has_AGP(dev) && dev->agp->cant_use_aperture) {
 600                         /*
 601                          * On some platforms we can't talk to bus dma address from the CPU, so for
 602                          * memory of type DRM_AGP, we'll deal with sorting out the real physical
 603                          * pages and mappings in fault()
 604                          */
 605 #if defined(__powerpc__)
 606                         pgprot_val(vma->vm_page_prot) |= _PAGE_NO_CACHE;
 607 #endif
 608                         vma->vm_ops = &drm_vm_ops;
 609                         break;
 610                 }
 611                 /* fall through to _DRM_FRAME_BUFFER... */
 612         case _DRM_FRAME_BUFFER:
 613         case _DRM_REGISTERS:
 614                 offset = dev->driver->get_reg_ofs(dev);
 615                 vma->vm_flags |= VM_IO; /* not in core dump */
 616                 vma->vm_page_prot = drm_io_prot(map->type, vma);
 617                 if (io_remap_pfn_range(vma, vma->vm_start,
 618                                        (map->offset + offset) >> PAGE_SHIFT,
 619                                        vma->vm_end - vma->vm_start,
 620                                        vma->vm_page_prot))
 621                         return -EAGAIN;
 622                 DRM_DEBUG("   Type = %d; start = 0x%lx, end = 0x%lx,"
 623                           " offset = 0x%lx\n",
 624                           map->type,
 625                           vma->vm_start, vma->vm_end, map->offset + offset);
 626                 vma->vm_ops = &drm_vm_ops;
 627                 break;
 628         case _DRM_CONSISTENT:
 629                 /* Consistent memory is really like shared memory. But
 630                  * it's allocated in a different way, so avoid fault */
 631                 if (remap_pfn_range(vma, vma->vm_start,
 632                     page_to_pfn(virt_to_page(map->handle)),
 633                     vma->vm_end - vma->vm_start, vma->vm_page_prot))
 634                         return -EAGAIN;
 635                 vma->vm_page_prot = drm_dma_prot(map->type, vma);
 636         /* fall through to _DRM_SHM */
 637         case _DRM_SHM:
 638                 vma->vm_ops = &drm_vm_shm_ops;
 639                 vma->vm_private_data = (void *)map;
 640                 /* Don't let this area swap.  Change when
 641                    DRM_KERNEL advisory is supported. */
 642                 vma->vm_flags |= VM_RESERVED;
 643                 vma->vm_page_prot = drm_dma_prot(map->type, vma);
 644                 break;
 645         case _DRM_SCATTER_GATHER:
 646                 vma->vm_ops = &drm_vm_sg_ops;
 647                 vma->vm_private_data = (void *)map;
 648                 vma->vm_flags |= VM_RESERVED;
 649                 break;
 650         default:
 651                 return -EINVAL; /* This should never happen. */
 652         }
 653         vma->vm_flags |= VM_RESERVED;   /* Don't swap */
 654         vma->vm_flags |= VM_DONTEXPAND;
 655
 656         vma->vm_file = filp;    /* Needed for drm_vm_open() */
 657         drm_vm_open_locked(vma);
 658         return 0;
 659 }
 660
 661 int drm_mmap(struct file *filp, struct vm_area_struct *vma)
 662 {
 663         struct drm_file *priv = filp->private_data;
 664         struct drm_device *dev = priv->head->dev;
 665         int ret;
 666
 667         mutex_lock(&dev->struct_mutex);
 668         ret = drm_mmap_locked(filp, vma);
 669         mutex_unlock(&dev->struct_mutex);
 670
 671         return ret;
 672 }
 673 EXPORT_SYMBOL(drm_mmap);