drivers/gpu/drm/drm_bufs.c

   1 /*
   2  * Legacy: Generic DRM Buffer Management
   3  *
   4  * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
   5  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
   6  * All Rights Reserved.
   7  *
   8  * Author: Rickard E. (Rik) Faith <[email protected]>
   9  * Author: Gareth Hughes <[email protected]>
  10  *
  11  * Permission is hereby granted, free of charge, to any person obtaining a
  12  * copy of this software and associated documentation files (the "Software"),
  13  * to deal in the Software without restriction, including without limitation
  14  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  15  * and/or sell copies of the Software, and to permit persons to whom the
  16  * Software is furnished to do so, subject to the following conditions:
  17  *
  18  * The above copyright notice and this permission notice (including the next
  19  * paragraph) shall be included in all copies or substantial portions of the
  20  * Software.
  21  *
  22  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  23  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  25  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  26  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  27  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  28  * OTHER DEALINGS IN THE SOFTWARE.
  29  */
  30
  31 #include <linux/vmalloc.h>
  32 #include <linux/slab.h>
  33 #include <linux/log2.h>
  34 #include <linux/export.h>
  35 #include <asm/shmparam.h>
  36 #include <drm/drmP.h>
  37 #include "drm_legacy.h"
  38
  39 #include <linux/nospec.h>
  40
  41 static struct drm_map_list *drm_find_matching_map(struct drm_device *dev,
  42                                                   struct drm_local_map *map)
  43 {
  44         struct drm_map_list *entry;
  45         list_for_each_entry(entry, &dev->maplist, head) {
  46                 /*
  47                  * Because the kernel-userspace ABI is fixed at a 32-bit offset
  48                  * while PCI resources may live above that, we only compare the
  49                  * lower 32 bits of the map offset for maps of type
  50                  * _DRM_FRAMEBUFFER or _DRM_REGISTERS.
  51                  * It is assumed that if a driver have more than one resource
  52                  * of each type, the lower 32 bits are different.
  53                  */
  54                 if (!entry->map ||
  55                     map->type != entry->map->type ||
  56                     entry->master != dev->master)
  57                         continue;
  58                 switch (map->type) {
  59                 case _DRM_SHM:
  60                         if (map->flags != _DRM_CONTAINS_LOCK)
  61                                 break;
  62                         return entry;
  63                 case _DRM_REGISTERS:
  64                 case _DRM_FRAME_BUFFER:
  65                         if ((entry->map->offset & 0xffffffff) ==
  66                             (map->offset & 0xffffffff))
  67                                 return entry;
  68                 default: /* Make gcc happy */
  69                         ;
  70                 }
  71                 if (entry->map->offset == map->offset)
  72                         return entry;
  73         }
  74
  75         return NULL;
  76 }
  77
  78 static int drm_map_handle(struct drm_device *dev, struct drm_hash_item *hash,
  79                           unsigned long user_token, int hashed_handle, int shm)
  80 {
  81         int use_hashed_handle, shift;
  82         unsigned long add;
  83
  84 #if (BITS_PER_LONG == 64)
  85         use_hashed_handle = ((user_token & 0xFFFFFFFF00000000UL) || hashed_handle);
  86 #elif (BITS_PER_LONG == 32)
  87         use_hashed_handle = hashed_handle;
  88 #else
  89 #error Unsupported long size. Neither 64 nor 32 bits.
  90 #endif
  91
  92         if (!use_hashed_handle) {
  93                 int ret;
  94                 hash->key = user_token >> PAGE_SHIFT;
  95                 ret = drm_ht_insert_item(&dev->map_hash, hash);
  96                 if (ret != -EINVAL)
  97                         return ret;
  98         }
  99
 100         shift = 0;
 101         add = DRM_MAP_HASH_OFFSET >> PAGE_SHIFT;
 102         if (shm && (SHMLBA > PAGE_SIZE)) {
 103                 int bits = ilog2(SHMLBA >> PAGE_SHIFT) + 1;
 104
 105                 /* For shared memory, we have to preserve the SHMLBA
 106                  * bits of the eventual vma->vm_pgoff value during
 107                  * mmap().  Otherwise we run into cache aliasing problems
 108                  * on some platforms.  On these platforms, the pgoff of
 109                  * a mmap() request is used to pick a suitable virtual
 110                  * address for the mmap() region such that it will not
 111                  * cause cache aliasing problems.
 112                  *
 113                  * Therefore, make sure the SHMLBA relevant bits of the
 114                  * hash value we use are equal to those in the original
 115                  * kernel virtual address.
 116                  */
 117                 shift = bits;
 118                 add |= ((user_token >> PAGE_SHIFT) & ((1UL << bits) - 1UL));
 119         }
 120
 121         return drm_ht_just_insert_please(&dev->map_hash, hash,
 122                                          user_token, 32 - PAGE_SHIFT - 3,
 123                                          shift, add);
 124 }
 125
 126 /**
 127  * Core function to create a range of memory available for mapping by a
 128  * non-root process.
 129  *
 130  * Adjusts the memory offset to its absolute value according to the mapping
 131  * type.  Adds the map to the map list drm_device::maplist. Adds MTRR's where
 132  * applicable and if supported by the kernel.
 133  */
 134 static int drm_addmap_core(struct drm_device *dev, resource_size_t offset,
 135                            unsigned int size, enum drm_map_type type,
 136                            enum drm_map_flags flags,
 137                            struct drm_map_list **maplist)
 138 {
 139         struct drm_local_map *map;
 140         struct drm_map_list *list;
 141         drm_dma_handle_t *dmah;
 142         unsigned long user_token;
 143         int ret;
 144
 145         map = kmalloc(sizeof(*map), GFP_KERNEL);
 146         if (!map)
 147                 return -ENOMEM;
 148
 149         map->offset = offset;
 150         map->size = size;
 151         map->flags = flags;
 152         map->type = type;
 153
 154         /* Only allow shared memory to be removable since we only keep enough
 155          * book keeping information about shared memory to allow for removal
 156          * when processes fork.
 157          */
 158         if ((map->flags & _DRM_REMOVABLE) && map->type != _DRM_SHM) {
 159                 kfree(map);
 160                 return -EINVAL;
 161         }
 162         DRM_DEBUG("offset = 0x%08llx, size = 0x%08lx, type = %d\n",
 163                   (unsigned long long)map->offset, map->size, map->type);
 164
 165         /* page-align _DRM_SHM maps. They are allocated here so there is no security
 166          * hole created by that and it works around various broken drivers that use
 167          * a non-aligned quantity to map the SAREA. --BenH
 168          */
 169         if (map->type == _DRM_SHM)
 170                 map->size = PAGE_ALIGN(map->size);
 171
 172         if ((map->offset & (~(resource_size_t)PAGE_MASK)) || (map->size & (~PAGE_MASK))) {
 173                 kfree(map);
 174                 return -EINVAL;
 175         }
 176         map->mtrr = -1;
 177         map->handle = NULL;
 178
 179         switch (map->type) {
 180         case _DRM_REGISTERS:
 181         case _DRM_FRAME_BUFFER:
 182 #if !defined(__sparc__) && !defined(__alpha__) && !defined(__ia64__) && !defined(__powerpc64__) && !defined(__x86_64__) && !defined(__arm__)
 183                 if (map->offset + (map->size-1) < map->offset ||
 184                     map->offset < virt_to_phys(high_memory)) {
 185                         kfree(map);
 186                         return -EINVAL;
 187                 }
 188 #endif
 189                 /* Some drivers preinitialize some maps, without the X Server
 190                  * needing to be aware of it.  Therefore, we just return success
 191                  * when the server tries to create a duplicate map.
 192                  */
 193                 list = drm_find_matching_map(dev, map);
 194                 if (list != NULL) {
 195                         if (list->map->size != map->size) {
 196                                 DRM_DEBUG("Matching maps of type %d with "
 197                                           "mismatched sizes, (%ld vs %ld)\n",
 198                                           map->type, map->size,
 199                                           list->map->size);
 200                                 list->map->size = map->size;
 201                         }
 202
 203                         kfree(map);
 204                         *maplist = list;
 205                         return 0;
 206                 }
 207
 208                 if (map->type == _DRM_FRAME_BUFFER ||
 209                     (map->flags & _DRM_WRITE_COMBINING)) {
 210                         map->mtrr =
 211                                 arch_phys_wc_add(map->offset, map->size);
 212                 }
 213                 if (map->type == _DRM_REGISTERS) {
 214                         if (map->flags & _DRM_WRITE_COMBINING)
 215                                 map->handle = ioremap_wc(map->offset,
 216                                                          map->size);
 217                         else
 218                                 map->handle = ioremap(map->offset, map->size);
 219                         if (!map->handle) {
 220                                 kfree(map);
 221                                 return -ENOMEM;
 222                         }
 223                 }
 224
 225                 break;
 226         case _DRM_SHM:
 227                 list = drm_find_matching_map(dev, map);
 228                 if (list != NULL) {
 229                         if (list->map->size != map->size) {
 230                                 DRM_DEBUG("Matching maps of type %d with "
 231                                           "mismatched sizes, (%ld vs %ld)\n",
 232                                           map->type, map->size, list->map->size);
 233                                 list->map->size = map->size;
 234                         }
 235
 236                         kfree(map);
 237                         *maplist = list;
 238                         return 0;
 239                 }
 240                 map->handle = vmalloc_user(map->size);
 241                 DRM_DEBUG("%lu %d %p\n",
 242                           map->size, order_base_2(map->size), map->handle);
 243                 if (!map->handle) {
 244                         kfree(map);
 245                         return -ENOMEM;
 246                 }
 247                 map->offset = (unsigned long)map->handle;
 248                 if (map->flags & _DRM_CONTAINS_LOCK) {
 249                         /* Prevent a 2nd X Server from creating a 2nd lock */
 250                         if (dev->master->lock.hw_lock != NULL) {
 251                                 vfree(map->handle);
 252                                 kfree(map);
 253                                 return -EBUSY;
 254                         }
 255                         dev->sigdata.lock = dev->master->lock.hw_lock = map->handle;    /* Pointer to lock */
 256                 }
 257                 break;
 258         case _DRM_AGP: {
 259                 struct drm_agp_mem *entry;
 260                 int valid = 0;
 261
 262                 if (!dev->agp) {
 263                         kfree(map);
 264                         return -EINVAL;
 265                 }
 266 #ifdef __alpha__
 267                 map->offset += dev->hose->mem_space->start;
 268 #endif
 269                 /* In some cases (i810 driver), user space may have already
 270                  * added the AGP base itself, because dev->agp->base previously
 271                  * only got set during AGP enable.  So, only add the base
 272                  * address if the map's offset isn't already within the
 273                  * aperture.
 274                  */
 275                 if (map->offset < dev->agp->base ||
 276                     map->offset > dev->agp->base +
 277                     dev->agp->agp_info.aper_size * 1024 * 1024 - 1) {
 278                         map->offset += dev->agp->base;
 279                 }
 280                 map->mtrr = dev->agp->agp_mtrr; /* for getmap */
 281
 282                 /* This assumes the DRM is in total control of AGP space.
 283                  * It's not always the case as AGP can be in the control
 284                  * of user space (i.e. i810 driver). So this loop will get
 285                  * skipped and we double check that dev->agp->memory is
 286                  * actually set as well as being invalid before EPERM'ing
 287                  */
 288                 list_for_each_entry(entry, &dev->agp->memory, head) {
 289                         if ((map->offset >= entry->bound) &&
 290                             (map->offset + map->size <= entry->bound + entry->pages * PAGE_SIZE)) {
 291                                 valid = 1;
 292                                 break;
 293                         }
 294                 }
 295                 if (!list_empty(&dev->agp->memory) && !valid) {
 296                         kfree(map);
 297                         return -EPERM;
 298                 }
 299                 DRM_DEBUG("AGP offset = 0x%08llx, size = 0x%08lx\n",
 300                           (unsigned long long)map->offset, map->size);
 301
 302                 break;
 303         }
 304         case _DRM_SCATTER_GATHER:
 305                 if (!dev->sg) {
 306                         kfree(map);
 307                         return -EINVAL;
 308                 }
 309                 map->offset += (unsigned long)dev->sg->virtual;
 310                 break;
 311         case _DRM_CONSISTENT:
 312                 /* dma_addr_t is 64bit on i386 with CONFIG_HIGHMEM64G,
 313                  * As we're limiting the address to 2^32-1 (or less),
 314                  * casting it down to 32 bits is no problem, but we
 315                  * need to point to a 64bit variable first. */
 316                 dmah = drm_pci_alloc(dev, map->size, map->size);
 317                 if (!dmah) {
 318                         kfree(map);
 319                         return -ENOMEM;
 320                 }
 321                 map->handle = dmah->vaddr;
 322                 map->offset = (unsigned long)dmah->busaddr;
 323                 kfree(dmah);
 324                 break;
 325         default:
 326                 kfree(map);
 327                 return -EINVAL;
 328         }
 329
 330         list = kzalloc(sizeof(*list), GFP_KERNEL);
 331         if (!list) {
 332                 if (map->type == _DRM_REGISTERS)
 333                         iounmap(map->handle);
 334                 kfree(map);
 335                 return -EINVAL;
 336         }
 337         list->map = map;
 338
 339         mutex_lock(&dev->struct_mutex);
 340         list_add(&list->head, &dev->maplist);
 341
 342         /* Assign a 32-bit handle */
 343         /* We do it here so that dev->struct_mutex protects the increment */
 344         user_token = (map->type == _DRM_SHM) ? (unsigned long)map->handle :
 345                 map->offset;
 346         ret = drm_map_handle(dev, &list->hash, user_token, 0,
 347                              (map->type == _DRM_SHM));
 348         if (ret) {
 349                 if (map->type == _DRM_REGISTERS)
 350                         iounmap(map->handle);
 351                 kfree(map);
 352                 kfree(list);
 353                 mutex_unlock(&dev->struct_mutex);
 354                 return ret;
 355         }
 356
 357         list->user_token = list->hash.key << PAGE_SHIFT;
 358         mutex_unlock(&dev->struct_mutex);
 359
 360         if (!(map->flags & _DRM_DRIVER))
 361                 list->master = dev->master;
 362         *maplist = list;
 363         return 0;
 364 }
 365
 366 int drm_legacy_addmap(struct drm_device *dev, resource_size_t offset,
 367                       unsigned int size, enum drm_map_type type,
 368                       enum drm_map_flags flags, struct drm_local_map **map_ptr)
 369 {
 370         struct drm_map_list *list;
 371         int rc;
 372
 373         rc = drm_addmap_core(dev, offset, size, type, flags, &list);
 374         if (!rc)
 375                 *map_ptr = list->map;
 376         return rc;
 377 }
 378 EXPORT_SYMBOL(drm_legacy_addmap);
 379
 380 struct drm_local_map *drm_legacy_findmap(struct drm_device *dev,
 381                                          unsigned int token)
 382 {
 383         struct drm_map_list *_entry;
 384         list_for_each_entry(_entry, &dev->maplist, head)
 385                 if (_entry->user_token == token)
 386                         return _entry->map;
 387         return NULL;
 388 }
 389 EXPORT_SYMBOL(drm_legacy_findmap);
 390
 391 /**
 392  * Ioctl to specify a range of memory that is available for mapping by a
 393  * non-root process.
 394  *
 395  * \param inode device inode.
 396  * \param file_priv DRM file private.
 397  * \param cmd command.
 398  * \param arg pointer to a drm_map structure.
 399  * \return zero on success or a negative value on error.
 400  *
 401  */
 402 int drm_legacy_addmap_ioctl(struct drm_device *dev, void *data,
 403                             struct drm_file *file_priv)
 404 {
 405         struct drm_map *map = data;
 406         struct drm_map_list *maplist;
 407         int err;
 408
 409         if (!(capable(CAP_SYS_ADMIN) || map->type == _DRM_AGP || map->type == _DRM_SHM))
 410                 return -EPERM;
 411
 412         if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
 413             !drm_core_check_feature(dev, DRIVER_LEGACY))
 414                 return -EOPNOTSUPP;
 415
 416         err = drm_addmap_core(dev, map->offset, map->size, map->type,
 417                               map->flags, &maplist);
 418
 419         if (err)
 420                 return err;
 421
 422         /* avoid a warning on 64-bit, this casting isn't very nice, but the API is set so too late */
 423         map->handle = (void *)(unsigned long)maplist->user_token;
 424
 425         /*
 426          * It appears that there are no users of this value whatsoever --
 427          * drmAddMap just discards it.  Let's not encourage its use.
 428          * (Keeping drm_addmap_core's returned mtrr value would be wrong --
 429          *  it's not a real mtrr index anymore.)
 430          */
 431         map->mtrr = -1;
 432
 433         return 0;
 434 }
 435
 436 /*
 437  * Get a mapping information.
 438  *
 439  * \param inode device inode.
 440  * \param file_priv DRM file private.
 441  * \param cmd command.
 442  * \param arg user argument, pointing to a drm_map structure.
 443  *
 444  * \return zero on success or a negative number on failure.
 445  *
 446  * Searches for the mapping with the specified offset and copies its information
 447  * into userspace
 448  */
 449 int drm_legacy_getmap_ioctl(struct drm_device *dev, void *data,
 450                             struct drm_file *file_priv)
 451 {
 452         struct drm_map *map = data;
 453         struct drm_map_list *r_list = NULL;
 454         struct list_head *list;
 455         int idx;
 456         int i;
 457
 458         if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
 459             !drm_core_check_feature(dev, DRIVER_LEGACY))
 460                 return -EOPNOTSUPP;
 461
 462         idx = map->offset;
 463         if (idx < 0)
 464                 return -EINVAL;
 465
 466         i = 0;
 467         mutex_lock(&dev->struct_mutex);
 468         list_for_each(list, &dev->maplist) {
 469                 if (i == idx) {
 470                         r_list = list_entry(list, struct drm_map_list, head);
 471                         break;
 472                 }
 473                 i++;
 474         }
 475         if (!r_list || !r_list->map) {
 476                 mutex_unlock(&dev->struct_mutex);
 477                 return -EINVAL;
 478         }
 479
 480         map->offset = r_list->map->offset;
 481         map->size = r_list->map->size;
 482         map->type = r_list->map->type;
 483         map->flags = r_list->map->flags;
 484         map->handle = (void *)(unsigned long) r_list->user_token;
 485         map->mtrr = arch_phys_wc_index(r_list->map->mtrr);
 486
 487         mutex_unlock(&dev->struct_mutex);
 488
 489         return 0;
 490 }
 491
 492 /**
 493  * Remove a map private from list and deallocate resources if the mapping
 494  * isn't in use.
 495  *
 496  * Searches the map on drm_device::maplist, removes it from the list, see if
 497  * it's being used, and free any associated resource (such as MTRR's) if it's not
 498  * being on use.
 499  *
 500  * \sa drm_legacy_addmap
 501  */
 502 int drm_legacy_rmmap_locked(struct drm_device *dev, struct drm_local_map *map)
 503 {
 504         struct drm_map_list *r_list = NULL, *list_t;
 505         drm_dma_handle_t dmah;
 506         int found = 0;
 507         struct drm_master *master;
 508
 509         /* Find the list entry for the map and remove it */
 510         list_for_each_entry_safe(r_list, list_t, &dev->maplist, head) {
 511                 if (r_list->map == map) {
 512                         master = r_list->master;
 513                         list_del(&r_list->head);
 514                         drm_ht_remove_key(&dev->map_hash,
 515                                           r_list->user_token >> PAGE_SHIFT);
 516                         kfree(r_list);
 517                         found = 1;
 518                         break;
 519                 }
 520         }
 521
 522         if (!found)
 523                 return -EINVAL;
 524
 525         switch (map->type) {
 526         case _DRM_REGISTERS:
 527                 iounmap(map->handle);
 528                 /* FALLTHROUGH */
 529         case _DRM_FRAME_BUFFER:
 530                 arch_phys_wc_del(map->mtrr);
 531                 break;
 532         case _DRM_SHM:
 533                 vfree(map->handle);
 534                 if (master) {
 535                         if (dev->sigdata.lock == master->lock.hw_lock)
 536                                 dev->sigdata.lock = NULL;
 537                         master->lock.hw_lock = NULL;   /* SHM removed */
 538                         master->lock.file_priv = NULL;
 539                         wake_up_interruptible_all(&master->lock.lock_queue);
 540                 }
 541                 break;
 542         case _DRM_AGP:
 543         case _DRM_SCATTER_GATHER:
 544                 break;
 545         case _DRM_CONSISTENT:
 546                 dmah.vaddr = map->handle;
 547                 dmah.busaddr = map->offset;
 548                 dmah.size = map->size;
 549                 __drm_legacy_pci_free(dev, &dmah);
 550                 break;
 551         }
 552         kfree(map);
 553
 554         return 0;
 555 }
 556 EXPORT_SYMBOL(drm_legacy_rmmap_locked);
 557
 558 void drm_legacy_rmmap(struct drm_device *dev, struct drm_local_map *map)
 559 {
 560         if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
 561             !drm_core_check_feature(dev, DRIVER_LEGACY))
 562                 return;
 563
 564         mutex_lock(&dev->struct_mutex);
 565         drm_legacy_rmmap_locked(dev, map);
 566         mutex_unlock(&dev->struct_mutex);
 567 }
 568 EXPORT_SYMBOL(drm_legacy_rmmap);
 569
 570 void drm_legacy_master_rmmaps(struct drm_device *dev, struct drm_master *master)
 571 {
 572         struct drm_map_list *r_list, *list_temp;
 573
 574         if (!drm_core_check_feature(dev, DRIVER_LEGACY))
 575                 return;
 576
 577         mutex_lock(&dev->struct_mutex);
 578         list_for_each_entry_safe(r_list, list_temp, &dev->maplist, head) {
 579                 if (r_list->master == master) {
 580                         drm_legacy_rmmap_locked(dev, r_list->map);
 581                         r_list = NULL;
 582                 }
 583         }
 584         mutex_unlock(&dev->struct_mutex);
 585 }
 586
 587 /* The rmmap ioctl appears to be unnecessary.  All mappings are torn down on
 588  * the last close of the device, and this is necessary for cleanup when things
 589  * exit uncleanly.  Therefore, having userland manually remove mappings seems
 590  * like a pointless exercise since they're going away anyway.
 591  *
 592  * One use case might be after addmap is allowed for normal users for SHM and
 593  * gets used by drivers that the server doesn't need to care about.  This seems
 594  * unlikely.
 595  *
 596  * \param inode device inode.
 597  * \param file_priv DRM file private.
 598  * \param cmd command.
 599  * \param arg pointer to a struct drm_map structure.
 600  * \return zero on success or a negative value on error.
 601  */
 602 int drm_legacy_rmmap_ioctl(struct drm_device *dev, void *data,
 603                            struct drm_file *file_priv)
 604 {
 605         struct drm_map *request = data;
 606         struct drm_local_map *map = NULL;
 607         struct drm_map_list *r_list;
 608         int ret;
 609
 610         if (!drm_core_check_feature(dev, DRIVER_KMS_LEGACY_CONTEXT) &&
 611             !drm_core_check_feature(dev, DRIVER_LEGACY))
 612                 return -EOPNOTSUPP;
 613
 614         mutex_lock(&dev->struct_mutex);
 615         list_for_each_entry(r_list, &dev->maplist, head) {
 616                 if (r_list->map &&
 617                     r_list->user_token == (unsigned long)request->handle &&
 618                     r_list->map->flags & _DRM_REMOVABLE) {
 619                         map = r_list->map;
 620                         break;
 621                 }
 622         }
 623
 624         /* List has wrapped around to the head pointer, or it's empty we didn't
 625          * find anything.
 626          */
 627         if (list_empty(&dev->maplist) || !map) {
 628                 mutex_unlock(&dev->struct_mutex);
 629                 return -EINVAL;
 630         }
 631
 632         /* Register and framebuffer maps are permanent */
 633         if ((map->type == _DRM_REGISTERS) || (map->type == _DRM_FRAME_BUFFER)) {
 634                 mutex_unlock(&dev->struct_mutex);
 635                 return 0;
 636         }
 637
 638         ret = drm_legacy_rmmap_locked(dev, map);
 639
 640         mutex_unlock(&dev->struct_mutex);
 641
 642         return ret;
 643 }
 644
 645 /**
 646  * Cleanup after an error on one of the addbufs() functions.
 647  *
 648  * \param dev DRM device.
 649  * \param entry buffer entry where the error occurred.
 650  *
 651  * Frees any pages and buffers associated with the given entry.
 652  */
 653 static void drm_cleanup_buf_error(struct drm_device *dev,
 654                                   struct drm_buf_entry *entry)
 655 {
 656         int i;
 657
 658         if (entry->seg_count) {
 659                 for (i = 0; i < entry->seg_count; i++) {
 660                         if (entry->seglist[i]) {
 661                                 drm_pci_free(dev, entry->seglist[i]);
 662                         }
 663                 }
 664                 kfree(entry->seglist);
 665
 666                 entry->seg_count = 0;
 667         }
 668
 669         if (entry->buf_count) {
 670                 for (i = 0; i < entry->buf_count; i++) {
 671                         kfree(entry->buflist[i].dev_private);
 672                 }
 673                 kfree(entry->buflist);
 674
 675                 entry->buf_count = 0;
 676         }
 677 }
 678
 679 #if IS_ENABLED(CONFIG_AGP)
 680 /**
 681  * Add AGP buffers for DMA transfers.
 682  *
 683  * \param dev struct drm_device to which the buffers are to be added.
 684  * \param request pointer to a struct drm_buf_desc describing the request.
 685  * \return zero on success or a negative number on failure.
 686  *
 687  * After some sanity checks creates a drm_buf structure for each buffer and
 688  * reallocates the buffer list of the same size order to accommodate the new
 689  * buffers.
 690  */
 691 int drm_legacy_addbufs_agp(struct drm_device *dev,
 692                            struct drm_buf_desc *request)
 693 {
 694         struct drm_device_dma *dma = dev->dma;
 695         struct drm_buf_entry *entry;
 696         struct drm_agp_mem *agp_entry;
 697         struct drm_buf *buf;
 698         unsigned long offset;
 699         unsigned long agp_offset;
 700         int count;
 701         int order;
 702         int size;
 703         int alignment;
 704         int page_order;
 705         int total;
 706         int byte_count;
 707         int i, valid;
 708         struct drm_buf **temp_buflist;
 709
 710         if (!dma)
 711                 return -EINVAL;
 712
 713         count = request->count;
 714         order = order_base_2(request->size);
 715         size = 1 << order;
 716
 717         alignment = (request->flags & _DRM_PAGE_ALIGN)
 718             ? PAGE_ALIGN(size) : size;
 719         page_order = order - PAGE_SHIFT > 0 ? order - PAGE_SHIFT : 0;
 720         total = PAGE_SIZE << page_order;
 721
 722         byte_count = 0;
 723         agp_offset = dev->agp->base + request->agp_start;
 724
 725         DRM_DEBUG("count:      %d\n", count);
 726         DRM_DEBUG("order:      %d\n", order);
 727         DRM_DEBUG("size:       %d\n", size);
 728         DRM_DEBUG("agp_offset: %lx\n", agp_offset);
 729         DRM_DEBUG("alignment:  %d\n", alignment);
 730         DRM_DEBUG("page_order: %d\n", page_order);
 731         DRM_DEBUG("total:      %d\n", total);
 732
 733         if (order < DRM_MIN_ORDER || order > DRM_MAX_ORDER)
 734                 return -EINVAL;
 735
 736         /* Make sure buffers are located in AGP memory that we own */
 737         valid = 0;
 738         list_for_each_entry(agp_entry, &dev->agp->memory, head) {
 739                 if ((agp_offset >= agp_entry->bound) &&
 740                     (agp_offset + total * count <= agp_entry->bound + agp_entry->pages * PAGE_SIZE)) {
 741                         valid = 1;
 742                         break;
 743                 }
 744         }
 745         if (!list_empty(&dev->agp->memory) && !valid) {
 746                 DRM_DEBUG("zone invalid\n");
 747                 return -EINVAL;
 748         }
 749         spin_lock(&dev->buf_lock);
 750         if (dev->buf_use) {
 751                 spin_unlock(&dev->buf_lock);
 752                 return -EBUSY;
 753         }
 754         atomic_inc(&dev->buf_alloc);
 755         spin_unlock(&dev->buf_lock);
 756
 757         mutex_lock(&dev->struct_mutex);
 758         entry = &dma->bufs[order];
 759         if (entry->buf_count) {
 760                 mutex_unlock(&dev->struct_mutex);
 761                 atomic_dec(&dev->buf_alloc);
 762                 return -ENOMEM; /* May only call once for each order */
 763         }
 764
 765         if (count < 0 || count > 4096) {
 766                 mutex_unlock(&dev->struct_mutex);
 767                 atomic_dec(&dev->buf_alloc);
 768                 return -EINVAL;
 769         }
 770
 771         entry->buflist = kcalloc(count, sizeof(*entry->buflist), GFP_KERNEL);
 772         if (!entry->buflist) {
 773                 mutex_unlock(&dev->struct_mutex);
 774                 atomic_dec(&dev->buf_alloc);
 775                 return -ENOMEM;
 776         }
 777
 778         entry->buf_size = size;
 779         entry->page_order = page_order;
 780
 781         offset = 0;
 782
 783         while (entry->buf_count < count) {
 784                 buf = &entry->buflist[entry->buf_count];
 785                 buf->idx = dma->buf_count + entry->buf_count;
 786                 buf->total = alignment;
 787                 buf->order = order;
 788                 buf->used = 0;
 789
 790                 buf->offset = (dma->byte_count + offset);
 791                 buf->bus_address = agp_offset + offset;
 792                 buf->address = (void *)(agp_offset + offset);
 793                 buf->next = NULL;
 794                 buf->waiting = 0;
 795                 buf->pending = 0;
 796                 buf->file_priv = NULL;
 797
 798                 buf->dev_priv_size = dev->driver->dev_priv_size;
 799                 buf->dev_private = kzalloc(buf->dev_priv_size, GFP_KERNEL);
 800                 if (!buf->dev_private) {
 801                         /* Set count correctly so we free the proper amount. */
 802                         entry->buf_count = count;
 803                         drm_cleanup_buf_error(dev, entry);
 804                         mutex_unlock(&dev->struct_mutex);
 805                         atomic_dec(&dev->buf_alloc);
 806                         return -ENOMEM;
 807                 }
 808
 809                 DRM_DEBUG("buffer %d @ %p\n", entry->buf_count, buf->address);
 810
 811                 offset += alignment;
 812                 entry->buf_count++;
 813                 byte_count += PAGE_SIZE << page_order;
 814         }
 815
 816         DRM_DEBUG("byte_count: %d\n", byte_count);
 817
 818         temp_buflist = krealloc(dma->buflist,
 819                                 (dma->buf_count + entry->buf_count) *
 820                                 sizeof(*dma->buflist), GFP_KERNEL);
 821         if (!temp_buflist) {
 822                 /* Free the entry because it isn't valid */
 823                 drm_cleanup_buf_error(dev, entry);
 824                 mutex_unlock(&dev->struct_mutex);
 825                 atomic_dec(&dev->buf_alloc);
 826                 return -ENOMEM;
 827         }
 828         dma->buflist = temp_buflist;
 829
 830         for (i = 0; i < entry->buf_count; i++) {
 831                 dma->buflist[i + dma->buf_count] = &entry->buflist[i];
 832         }
 833
 834         dma->buf_count += entry->buf_count;
 835         dma->seg_count += entry->seg_count;
 836         dma->page_count += byte_count >> PAGE_SHIFT;
 837         dma->byte_count += byte_count;
 838
 839         DRM_DEBUG("dma->buf_count : %d\n", dma->buf_count);
 840         DRM_DEBUG("entry->buf_count : %d\n", entry->buf_count);
 841
 842         mutex_unlock(&dev->struct_mutex);
 843
 844         request->count = entry->buf_count;
 845         request->size = size;
 846
 847         dma->flags = _DRM_DMA_USE_AGP;
 848
 849         atomic_dec(&dev->buf_alloc);
 850         return 0;
 851 }
 852 EXPORT_SYMBOL(drm_legacy_addbufs_agp);
 853 #endif /* CONFIG_AGP */
 854
 855 int drm_legacy_addbufs_pci(struct drm_device *dev,
 856                            struct drm_buf_desc *request)
 857 {
 858         struct drm_device_dma *dma = dev->dma;
 859         int count;
 860         int order;
 861         int size;
 862         int total;
 863         int page_order;
 864         struct drm_buf_entry *entry;
 865         drm_dma_handle_t *dmah;
 866         struct drm_buf *buf;
 867         int alignment;
 868         unsigned long offset;
 869         int i;
 870         int byte_count;
 871         int page_count;
 872         unsigned long *temp_pagelist;
 873         struct drm_buf **temp_buflist;
 874
 875         if (!drm_core_check_feature(dev, DRIVER_PCI_DMA))
 876                 return -EOPNOTSUPP;
 877
 878         if (!dma)
 879                 return -EINVAL;
 880
 881         if (!capable(CAP_SYS_ADMIN))
 882                 return -EPERM;
 883
 884         count = request->count;
 885         order = order_base_2(request->size);
 886         size = 1 << order;
 887
 888         DRM_DEBUG("count=%d, size=%d (%d), order=%d\n",
 889                   request->count, request->size, size, order);
 890
 891         if (order < DRM_MIN_ORDER || order > DRM_MAX_ORDER)
 892                 return -EINVAL;
 893
 894         alignment = (request->flags & _DRM_PAGE_ALIGN)
 895             ? PAGE_ALIGN(size) : size;
 896         page_order = order - PAGE_SHIFT > 0 ? order - PAGE_SHIFT : 0;
 897         total = PAGE_SIZE << page_order;
 898
 899         spin_lock(&dev->buf_lock);
 900         if (dev->buf_use) {
 901                 spin_unlock(&dev->buf_lock);
 902                 return -EBUSY;
 903         }
 904         atomic_inc(&dev->buf_alloc);
 905         spin_unlock(&dev->buf_lock);
 906
 907         mutex_lock(&dev->struct_mutex);
 908         entry = &dma->bufs[order];
 909         if (entry->buf_count) {
 910                 mutex_unlock(&dev->struct_mutex);
 911                 atomic_dec(&dev->buf_alloc);
 912                 return -ENOMEM; /* May only call once for each order */
 913         }
 914
 915         if (count < 0 || count > 4096) {
 916                 mutex_unlock(&dev->struct_mutex);
 917                 atomic_dec(&dev->buf_alloc);
 918                 return -EINVAL;
 919         }
 920
 921         entry->buflist = kcalloc(count, sizeof(*entry->buflist), GFP_KERNEL);
 922         if (!entry->buflist) {
 923                 mutex_unlock(&dev->struct_mutex);
 924                 atomic_dec(&dev->buf_alloc);
 925                 return -ENOMEM;
 926         }
 927
 928         entry->seglist = kcalloc(count, sizeof(*entry->seglist), GFP_KERNEL);
 929         if (!entry->seglist) {
 930                 kfree(entry->buflist);
 931                 mutex_unlock(&dev->struct_mutex);
 932                 atomic_dec(&dev->buf_alloc);
 933                 return -ENOMEM;
 934         }
 935
 936         /* Keep the original pagelist until we know all the allocations
 937          * have succeeded
 938          */
 939         temp_pagelist = kmalloc_array(dma->page_count + (count << page_order),
 940                                       sizeof(*dma->pagelist),
 941                                       GFP_KERNEL);
 942         if (!temp_pagelist) {
 943                 kfree(entry->buflist);
 944                 kfree(entry->seglist);
 945                 mutex_unlock(&dev->struct_mutex);
 946                 atomic_dec(&dev->buf_alloc);
 947                 return -ENOMEM;
 948         }
 949         memcpy(temp_pagelist,
 950                dma->pagelist, dma->page_count * sizeof(*dma->pagelist));
 951         DRM_DEBUG("pagelist: %d entries\n",
 952                   dma->page_count + (count << page_order));
 953
 954         entry->buf_size = size;
 955         entry->page_order = page_order;
 956         byte_count = 0;
 957         page_count = 0;
 958
 959         while (entry->buf_count < count) {
 960
 961                 dmah = drm_pci_alloc(dev, PAGE_SIZE << page_order, 0x1000);
 962
 963                 if (!dmah) {
 964                         /* Set count correctly so we free the proper amount. */
 965                         entry->buf_count = count;
 966                         entry->seg_count = count;
 967                         drm_cleanup_buf_error(dev, entry);
 968                         kfree(temp_pagelist);
 969                         mutex_unlock(&dev->struct_mutex);
 970                         atomic_dec(&dev->buf_alloc);
 971                         return -ENOMEM;
 972                 }
 973                 entry->seglist[entry->seg_count++] = dmah;
 974                 for (i = 0; i < (1 << page_order); i++) {
 975                         DRM_DEBUG("page %d @ 0x%08lx\n",
 976                                   dma->page_count + page_count,
 977                                   (unsigned long)dmah->vaddr + PAGE_SIZE * i);
 978                         temp_pagelist[dma->page_count + page_count++]
 979                                 = (unsigned long)dmah->vaddr + PAGE_SIZE * i;
 980                 }
 981                 for (offset = 0;
 982                      offset + size <= total && entry->buf_count < count;
 983                      offset += alignment, ++entry->buf_count) {
 984                         buf = &entry->buflist[entry->buf_count];
 985                         buf->idx = dma->buf_count + entry->buf_count;
 986                         buf->total = alignment;
 987                         buf->order = order;
 988                         buf->used = 0;
 989                         buf->offset = (dma->byte_count + byte_count + offset);
 990                         buf->address = (void *)(dmah->vaddr + offset);
 991                         buf->bus_address = dmah->busaddr + offset;
 992                         buf->next = NULL;
 993                         buf->waiting = 0;
 994                         buf->pending = 0;
 995                         buf->file_priv = NULL;
 996
 997                         buf->dev_priv_size = dev->driver->dev_priv_size;
 998                         buf->dev_private = kzalloc(buf->dev_priv_size,
 999                                                 GFP_KERNEL);
1000                         if (!buf->dev_private) {
1001                                 /* Set count correctly so we free the proper amount. */
1002                                 entry->buf_count = count;
1003                                 entry->seg_count = count;
1004                                 drm_cleanup_buf_error(dev, entry);
1005                                 kfree(temp_pagelist);
1006                                 mutex_unlock(&dev->struct_mutex);
1007                                 atomic_dec(&dev->buf_alloc);
1008                                 return -ENOMEM;
1009                         }
1010
1011                         DRM_DEBUG("buffer %d @ %p\n",
1012                                   entry->buf_count, buf->address);
1013                 }
1014                 byte_count += PAGE_SIZE << page_order;
1015         }
1016
1017         temp_buflist = krealloc(dma->buflist,
1018                                 (dma->buf_count + entry->buf_count) *
1019                                 sizeof(*dma->buflist), GFP_KERNEL);
1020         if (!temp_buflist) {
1021                 /* Free the entry because it isn't valid */
1022                 drm_cleanup_buf_error(dev, entry);
1023                 kfree(temp_pagelist);
1024                 mutex_unlock(&dev->struct_mutex);
1025                 atomic_dec(&dev->buf_alloc);
1026                 return -ENOMEM;
1027         }
1028         dma->buflist = temp_buflist;
1029
1030         for (i = 0; i < entry->buf_count; i++) {
1031                 dma->buflist[i + dma->buf_count] = &entry->buflist[i];
1032         }
1033
1034         /* No allocations failed, so now we can replace the original pagelist
1035          * with the new one.
1036          */
1037         if (dma->page_count) {
1038                 kfree(dma->pagelist);
1039         }
1040         dma->pagelist = temp_pagelist;
1041
1042         dma->buf_count += entry->buf_count;
1043         dma->seg_count += entry->seg_count;
1044         dma->page_count += entry->seg_count << page_order;
1045         dma->byte_count += PAGE_SIZE * (entry->seg_count << page_order);
1046
1047         mutex_unlock(&dev->struct_mutex);
1048
1049         request->count = entry->buf_count;
1050         request->size = size;
1051
1052         if (request->flags & _DRM_PCI_BUFFER_RO)
1053                 dma->flags = _DRM_DMA_USE_PCI_RO;
1054
1055         atomic_dec(&dev->buf_alloc);
1056         return 0;
1057
1058 }
1059 EXPORT_SYMBOL(drm_legacy_addbufs_pci);
1060
1061 static int drm_legacy_addbufs_sg(struct drm_device *dev,
1062                                  struct drm_buf_desc *request)
1063 {
1064         struct drm_device_dma *dma = dev->dma;
1065         struct drm_buf_entry *entry;
1066         struct drm_buf *buf;
1067         unsigned long offset;
1068         unsigned long agp_offset;
1069         int count;
1070         int order;
1071         int size;
1072         int alignment;
1073         int page_order;
1074         int total;
1075         int byte_count;
1076         int i;
1077         struct drm_buf **temp_buflist;
1078
1079         if (!drm_core_check_feature(dev, DRIVER_SG))
1080                 return -EOPNOTSUPP;
1081
1082         if (!dma)
1083                 return -EINVAL;
1084
1085         if (!capable(CAP_SYS_ADMIN))
1086                 return -EPERM;
1087
1088         count = request->count;
1089         order = order_base_2(request->size);
1090         size = 1 << order;
1091
1092         alignment = (request->flags & _DRM_PAGE_ALIGN)
1093             ? PAGE_ALIGN(size) : size;
1094         page_order = order - PAGE_SHIFT > 0 ? order - PAGE_SHIFT : 0;
1095         total = PAGE_SIZE << page_order;
1096
1097         byte_count = 0;
1098         agp_offset = request->agp_start;
1099
1100         DRM_DEBUG("count:      %d\n", count);
1101         DRM_DEBUG("order:      %d\n", order);
1102         DRM_DEBUG("size:       %d\n", size);
1103         DRM_DEBUG("agp_offset: %lu\n", agp_offset);
1104         DRM_DEBUG("alignment:  %d\n", alignment);
1105         DRM_DEBUG("page_order: %d\n", page_order);
1106         DRM_DEBUG("total:      %d\n", total);
1107
1108         if (order < DRM_MIN_ORDER || order > DRM_MAX_ORDER)
1109                 return -EINVAL;
1110
1111         spin_lock(&dev->buf_lock);
1112         if (dev->buf_use) {
1113                 spin_unlock(&dev->buf_lock);
1114                 return -EBUSY;
1115         }
1116         atomic_inc(&dev->buf_alloc);
1117         spin_unlock(&dev->buf_lock);
1118
1119         mutex_lock(&dev->struct_mutex);
1120         entry = &dma->bufs[order];
1121         if (entry->buf_count) {
1122                 mutex_unlock(&dev->struct_mutex);
1123                 atomic_dec(&dev->buf_alloc);
1124                 return -ENOMEM; /* May only call once for each order */
1125         }
1126
1127         if (count < 0 || count > 4096) {
1128                 mutex_unlock(&dev->struct_mutex);
1129                 atomic_dec(&dev->buf_alloc);
1130                 return -EINVAL;
1131         }
1132
1133         entry->buflist = kcalloc(count, sizeof(*entry->buflist), GFP_KERNEL);
1134         if (!entry->buflist) {
1135                 mutex_unlock(&dev->struct_mutex);
1136                 atomic_dec(&dev->buf_alloc);
1137                 return -ENOMEM;
1138         }
1139
1140         entry->buf_size = size;
1141         entry->page_order = page_order;
1142
1143         offset = 0;
1144
1145         while (entry->buf_count < count) {
1146                 buf = &entry->buflist[entry->buf_count];
1147                 buf->idx = dma->buf_count + entry->buf_count;
1148                 buf->total = alignment;
1149                 buf->order = order;
1150                 buf->used = 0;
1151
1152                 buf->offset = (dma->byte_count + offset);
1153                 buf->bus_address = agp_offset + offset;
1154                 buf->address = (void *)(agp_offset + offset
1155                                         + (unsigned long)dev->sg->virtual);
1156                 buf->next = NULL;
1157                 buf->waiting = 0;
1158                 buf->pending = 0;
1159                 buf->file_priv = NULL;
1160
1161                 buf->dev_priv_size = dev->driver->dev_priv_size;
1162                 buf->dev_private = kzalloc(buf->dev_priv_size, GFP_KERNEL);
1163                 if (!buf->dev_private) {
1164                         /* Set count correctly so we free the proper amount. */
1165                         entry->buf_count = count;
1166                         drm_cleanup_buf_error(dev, entry);
1167                         mutex_unlock(&dev->struct_mutex);
1168                         atomic_dec(&dev->buf_alloc);
1169                         return -ENOMEM;
1170                 }
1171
1172                 DRM_DEBUG("buffer %d @ %p\n", entry->buf_count, buf->address);
1173
1174                 offset += alignment;
1175                 entry->buf_count++;
1176                 byte_count += PAGE_SIZE << page_order;
1177         }
1178
1179         DRM_DEBUG("byte_count: %d\n", byte_count);
1180
1181         temp_buflist = krealloc(dma->buflist,
1182                                 (dma->buf_count + entry->buf_count) *
1183                                 sizeof(*dma->buflist), GFP_KERNEL);
1184         if (!temp_buflist) {
1185                 /* Free the entry because it isn't valid */
1186                 drm_cleanup_buf_error(dev, entry);
1187                 mutex_unlock(&dev->struct_mutex);
1188                 atomic_dec(&dev->buf_alloc);
1189                 return -ENOMEM;
1190         }
1191         dma->buflist = temp_buflist;
1192
1193         for (i = 0; i < entry->buf_count; i++) {
1194                 dma->buflist[i + dma->buf_count] = &entry->buflist[i];
1195         }
1196
1197         dma->buf_count += entry->buf_count;
1198         dma->seg_count += entry->seg_count;
1199         dma->page_count += byte_count >> PAGE_SHIFT;
1200         dma->byte_count += byte_count;
1201
1202         DRM_DEBUG("dma->buf_count : %d\n", dma->buf_count);
1203         DRM_DEBUG("entry->buf_count : %d\n", entry->buf_count);
1204
1205         mutex_unlock(&dev->struct_mutex);
1206
1207         request->count = entry->buf_count;
1208         request->size = size;
1209
1210         dma->flags = _DRM_DMA_USE_SG;
1211
1212         atomic_dec(&dev->buf_alloc);
1213         return 0;
1214 }
1215
1216 /**
1217  * Add buffers for DMA transfers (ioctl).
1218  *
1219  * \param inode device inode.
1220  * \param file_priv DRM file private.
1221  * \param cmd command.
1222  * \param arg pointer to a struct drm_buf_desc request.
1223  * \return zero on success or a negative number on failure.
1224  *
1225  * According with the memory type specified in drm_buf_desc::flags and the
1226  * build options, it dispatches the call either to addbufs_agp(),
1227  * addbufs_sg() or addbufs_pci() for AGP, scatter-gather or consistent
1228  * PCI memory respectively.
1229  */
1230 int drm_legacy_addbufs(struct drm_device *dev, void *data,
1231                        struct drm_file *file_priv)
1232 {
1233         struct drm_buf_desc *request = data;
1234         int ret;
1235
1236         if (!drm_core_check_feature(dev, DRIVER_LEGACY))
1237                 return -EOPNOTSUPP;
1238
1239         if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
1240                 return -EOPNOTSUPP;
1241
1242 #if IS_ENABLED(CONFIG_AGP)
1243         if (request->flags & _DRM_AGP_BUFFER)
1244                 ret = drm_legacy_addbufs_agp(dev, request);
1245         else
1246 #endif
1247         if (request->flags & _DRM_SG_BUFFER)
1248                 ret = drm_legacy_addbufs_sg(dev, request);
1249         else if (request->flags & _DRM_FB_BUFFER)
1250                 ret = -EINVAL;
1251         else
1252                 ret = drm_legacy_addbufs_pci(dev, request);
1253
1254         return ret;
1255 }
1256
1257 /**
1258  * Get information about the buffer mappings.
1259  *
1260  * This was originally mean for debugging purposes, or by a sophisticated
1261  * client library to determine how best to use the available buffers (e.g.,
1262  * large buffers can be used for image transfer).
1263  *
1264  * \param inode device inode.
1265  * \param file_priv DRM file private.
1266  * \param cmd command.
1267  * \param arg pointer to a drm_buf_info structure.
1268  * \return zero on success or a negative number on failure.
1269  *
1270  * Increments drm_device::buf_use while holding the drm_device::buf_lock
1271  * lock, preventing of allocating more buffers after this call. Information
1272  * about each requested buffer is then copied into user space.
1273  */
1274 int __drm_legacy_infobufs(struct drm_device *dev,
1275                         void *data, int *p,
1276                         int (*f)(void *, int, struct drm_buf_entry *))
1277 {
1278         struct drm_device_dma *dma = dev->dma;
1279         int i;
1280         int count;
1281
1282         if (!drm_core_check_feature(dev, DRIVER_LEGACY))
1283                 return -EOPNOTSUPP;
1284
1285         if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
1286                 return -EOPNOTSUPP;
1287
1288         if (!dma)
1289                 return -EINVAL;
1290
1291         spin_lock(&dev->buf_lock);
1292         if (atomic_read(&dev->buf_alloc)) {
1293                 spin_unlock(&dev->buf_lock);
1294                 return -EBUSY;
1295         }
1296         ++dev->buf_use;         /* Can't allocate more after this call */
1297         spin_unlock(&dev->buf_lock);
1298
1299         for (i = 0, count = 0; i < DRM_MAX_ORDER + 1; i++) {
1300                 if (dma->bufs[i].buf_count)
1301                         ++count;
1302         }
1303
1304         DRM_DEBUG("count = %d\n", count);
1305
1306         if (*p >= count) {
1307                 for (i = 0, count = 0; i < DRM_MAX_ORDER + 1; i++) {
1308                         struct drm_buf_entry *from = &dma->bufs[i];
1309                         if (from->buf_count) {
1310                                 if (f(data, count, from) < 0)
1311                                         return -EFAULT;
1312                                 DRM_DEBUG("%d %d %d %d %d\n",
1313                                           i,
1314                                           dma->bufs[i].buf_count,
1315                                           dma->bufs[i].buf_size,
1316                                           dma->bufs[i].low_mark,
1317                                           dma->bufs[i].high_mark);
1318                                 ++count;
1319                         }
1320                 }
1321         }
1322         *p = count;
1323
1324         return 0;
1325 }
1326
1327 static int copy_one_buf(void *data, int count, struct drm_buf_entry *from)
1328 {
1329         struct drm_buf_info *request = data;
1330         struct drm_buf_desc __user *to = &request->list[count];
1331         struct drm_buf_desc v = {.count = from->buf_count,
1332                                  .size = from->buf_size,
1333                                  .low_mark = from->low_mark,
1334                                  .high_mark = from->high_mark};
1335         return copy_to_user(to, &v, offsetof(struct drm_buf_desc, flags));
1336 }
1337
1338 int drm_legacy_infobufs(struct drm_device *dev, void *data,
1339                         struct drm_file *file_priv)
1340 {
1341         struct drm_buf_info *request = data;
1342         return __drm_legacy_infobufs(dev, data, &request->count, copy_one_buf);
1343 }
1344
1345 /**
1346  * Specifies a low and high water mark for buffer allocation
1347  *
1348  * \param inode device inode.
1349  * \param file_priv DRM file private.
1350  * \param cmd command.
1351  * \param arg a pointer to a drm_buf_desc structure.
1352  * \return zero on success or a negative number on failure.
1353  *
1354  * Verifies that the size order is bounded between the admissible orders and
1355  * updates the respective drm_device_dma::bufs entry low and high water mark.
1356  *
1357  * \note This ioctl is deprecated and mostly never used.
1358  */
1359 int drm_legacy_markbufs(struct drm_device *dev, void *data,
1360                         struct drm_file *file_priv)
1361 {
1362         struct drm_device_dma *dma = dev->dma;
1363         struct drm_buf_desc *request = data;
1364         int order;
1365         struct drm_buf_entry *entry;
1366
1367         if (!drm_core_check_feature(dev, DRIVER_LEGACY))
1368                 return -EOPNOTSUPP;
1369
1370         if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
1371                 return -EOPNOTSUPP;
1372
1373         if (!dma)
1374                 return -EINVAL;
1375
1376         DRM_DEBUG("%d, %d, %d\n",
1377                   request->size, request->low_mark, request->high_mark);
1378         order = order_base_2(request->size);
1379         if (order < DRM_MIN_ORDER || order > DRM_MAX_ORDER)
1380                 return -EINVAL;
1381         entry = &dma->bufs[order];
1382
1383         if (request->low_mark < 0 || request->low_mark > entry->buf_count)
1384                 return -EINVAL;
1385         if (request->high_mark < 0 || request->high_mark > entry->buf_count)
1386                 return -EINVAL;
1387
1388         entry->low_mark = request->low_mark;
1389         entry->high_mark = request->high_mark;
1390
1391         return 0;
1392 }
1393
1394 /**
1395  * Unreserve the buffers in list, previously reserved using drmDMA.
1396  *
1397  * \param inode device inode.
1398  * \param file_priv DRM file private.
1399  * \param cmd command.
1400  * \param arg pointer to a drm_buf_free structure.
1401  * \return zero on success or a negative number on failure.
1402  *
1403  * Calls free_buffer() for each used buffer.
1404  * This function is primarily used for debugging.
1405  */
1406 int drm_legacy_freebufs(struct drm_device *dev, void *data,
1407                         struct drm_file *file_priv)
1408 {
1409         struct drm_device_dma *dma = dev->dma;
1410         struct drm_buf_free *request = data;
1411         int i;
1412         int idx;
1413         struct drm_buf *buf;
1414
1415         if (!drm_core_check_feature(dev, DRIVER_LEGACY))
1416                 return -EOPNOTSUPP;
1417
1418         if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
1419                 return -EOPNOTSUPP;
1420
1421         if (!dma)
1422                 return -EINVAL;
1423
1424         DRM_DEBUG("%d\n", request->count);
1425         for (i = 0; i < request->count; i++) {
1426                 if (copy_from_user(&idx, &request->list[i], sizeof(idx)))
1427                         return -EFAULT;
1428                 if (idx < 0 || idx >= dma->buf_count) {
1429                         DRM_ERROR("Index %d (of %d max)\n",
1430                                   idx, dma->buf_count - 1);
1431                         return -EINVAL;
1432                 }
1433                 idx = array_index_nospec(idx, dma->buf_count);
1434                 buf = dma->buflist[idx];
1435                 if (buf->file_priv != file_priv) {
1436                         DRM_ERROR("Process %d freeing buffer not owned\n",
1437                                   task_pid_nr(current));
1438                         return -EINVAL;
1439                 }
1440                 drm_legacy_free_buffer(dev, buf);
1441         }
1442
1443         return 0;
1444 }
1445
1446 /**
1447  * Maps all of the DMA buffers into client-virtual space (ioctl).
1448  *
1449  * \param inode device inode.
1450  * \param file_priv DRM file private.
1451  * \param cmd command.
1452  * \param arg pointer to a drm_buf_map structure.
1453  * \return zero on success or a negative number on failure.
1454  *
1455  * Maps the AGP, SG or PCI buffer region with vm_mmap(), and copies information
1456  * about each buffer into user space. For PCI buffers, it calls vm_mmap() with
1457  * offset equal to 0, which drm_mmap() interpretes as PCI buffers and calls
1458  * drm_mmap_dma().
1459  */
1460 int __drm_legacy_mapbufs(struct drm_device *dev, void *data, int *p,
1461                          void __user **v,
1462                          int (*f)(void *, int, unsigned long,
1463                                  struct drm_buf *),
1464                                  struct drm_file *file_priv)
1465 {
1466         struct drm_device_dma *dma = dev->dma;
1467         int retcode = 0;
1468         unsigned long virtual;
1469         int i;
1470
1471         if (!drm_core_check_feature(dev, DRIVER_LEGACY))
1472                 return -EOPNOTSUPP;
1473
1474         if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
1475                 return -EOPNOTSUPP;
1476
1477         if (!dma)
1478                 return -EINVAL;
1479
1480         spin_lock(&dev->buf_lock);
1481         if (atomic_read(&dev->buf_alloc)) {
1482                 spin_unlock(&dev->buf_lock);
1483                 return -EBUSY;
1484         }
1485         dev->buf_use++;         /* Can't allocate more after this call */
1486         spin_unlock(&dev->buf_lock);
1487
1488         if (*p >= dma->buf_count) {
1489                 if ((dev->agp && (dma->flags & _DRM_DMA_USE_AGP))
1490                     || (drm_core_check_feature(dev, DRIVER_SG)
1491                         && (dma->flags & _DRM_DMA_USE_SG))) {
1492                         struct drm_local_map *map = dev->agp_buffer_map;
1493                         unsigned long token = dev->agp_buffer_token;
1494
1495                         if (!map) {
1496                                 retcode = -EINVAL;
1497                                 goto done;
1498                         }
1499                         virtual = vm_mmap(file_priv->filp, 0, map->size,
1500                                           PROT_READ | PROT_WRITE,
1501                                           MAP_SHARED,
1502                                           token);
1503                 } else {
1504                         virtual = vm_mmap(file_priv->filp, 0, dma->byte_count,
1505                                           PROT_READ | PROT_WRITE,
1506                                           MAP_SHARED, 0);
1507                 }
1508                 if (virtual > -1024UL) {
1509                         /* Real error */
1510                         retcode = (signed long)virtual;
1511                         goto done;
1512                 }
1513                 *v = (void __user *)virtual;
1514
1515                 for (i = 0; i < dma->buf_count; i++) {
1516                         if (f(data, i, virtual, dma->buflist[i]) < 0) {
1517                                 retcode = -EFAULT;
1518                                 goto done;
1519                         }
1520                 }
1521         }
1522       done:
1523         *p = dma->buf_count;
1524         DRM_DEBUG("%d buffers, retcode = %d\n", *p, retcode);
1525
1526         return retcode;
1527 }
1528
1529 static int map_one_buf(void *data, int idx, unsigned long virtual,
1530                         struct drm_buf *buf)
1531 {
1532         struct drm_buf_map *request = data;
1533         unsigned long address = virtual + buf->offset;  /* *** */
1534
1535         if (copy_to_user(&request->list[idx].idx, &buf->idx,
1536                          sizeof(request->list[0].idx)))
1537                 return -EFAULT;
1538         if (copy_to_user(&request->list[idx].total, &buf->total,
1539                          sizeof(request->list[0].total)))
1540                 return -EFAULT;
1541         if (clear_user(&request->list[idx].used, sizeof(int)))
1542                 return -EFAULT;
1543         if (copy_to_user(&request->list[idx].address, &address,
1544                          sizeof(address)))
1545                 return -EFAULT;
1546         return 0;
1547 }
1548
1549 int drm_legacy_mapbufs(struct drm_device *dev, void *data,
1550                        struct drm_file *file_priv)
1551 {
1552         struct drm_buf_map *request = data;
1553         return __drm_legacy_mapbufs(dev, data, &request->count,
1554                                     &request->virtual, map_one_buf,
1555                                     file_priv);
1556 }
1557
1558 int drm_legacy_dma_ioctl(struct drm_device *dev, void *data,
1559                   struct drm_file *file_priv)
1560 {
1561         if (!drm_core_check_feature(dev, DRIVER_LEGACY))
1562                 return -EOPNOTSUPP;
1563
1564         if (dev->driver->dma_ioctl)
1565                 return dev->driver->dma_ioctl(dev, data, file_priv);
1566         else
1567                 return -EINVAL;
1568 }
1569
1570 struct drm_local_map *drm_legacy_getsarea(struct drm_device *dev)
1571 {
1572         struct drm_map_list *entry;
1573
1574         list_for_each_entry(entry, &dev->maplist, head) {
1575                 if (entry->map && entry->map->type == _DRM_SHM &&
1576                     (entry->map->flags & _DRM_CONTAINS_LOCK)) {
1577                         return entry->map;
1578                 }
1579         }
1580         return NULL;
1581 }
1582 EXPORT_SYMBOL(drm_legacy_getsarea);