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drm_bufs.c

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/**
 * \file drm_bufs.c
 * Generic buffer template
 *
 * \author Rickard E. (Rik) Faith <faith@valinux.com>
 * \author Gareth Hughes <gareth@valinux.com>
 */

/*
 * Created: Thu Nov 23 03:10:50 2000 by gareth@valinux.com
 *
 * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */

#include <linux/vmalloc.h>
#include "drmP.h"

unsigned long drm_get_resource_start(struct drm_device *dev, unsigned int resource)
{
      return pci_resource_start(dev->pdev, resource);
}
EXPORT_SYMBOL(drm_get_resource_start);

unsigned long drm_get_resource_len(struct drm_device *dev, unsigned int resource)
{
      return pci_resource_len(dev->pdev, resource);
}

EXPORT_SYMBOL(drm_get_resource_len);

static struct drm_map_list *drm_find_matching_map(struct drm_device *dev,
                                   drm_local_map_t *map)
{
      struct drm_map_list *entry;
      list_for_each_entry(entry, &dev->maplist, head) {
            if (entry->map && map->type == entry->map->type &&
                ((entry->map->offset == map->offset) ||
                 (map->type == _DRM_SHM && map->flags==_DRM_CONTAINS_LOCK))) {
                  return entry;
            }
      }

      return NULL;
}

static int drm_map_handle(struct drm_device *dev, struct drm_hash_item *hash,
                    unsigned long user_token, int hashed_handle)
{
      int use_hashed_handle;
#if (BITS_PER_LONG == 64)
      use_hashed_handle = ((user_token & 0xFFFFFFFF00000000UL) || hashed_handle);
#elif (BITS_PER_LONG == 32)
      use_hashed_handle = hashed_handle;
#else
#error Unsupported long size. Neither 64 nor 32 bits.
#endif

      if (!use_hashed_handle) {
            int ret;
            hash->key = user_token >> PAGE_SHIFT;
            ret = drm_ht_insert_item(&dev->map_hash, hash);
            if (ret != -EINVAL)
                  return ret;
      }
      return drm_ht_just_insert_please(&dev->map_hash, hash,
                               user_token, 32 - PAGE_SHIFT - 3,
                               0, DRM_MAP_HASH_OFFSET >> PAGE_SHIFT);
}

/**
 * Ioctl to specify a range of memory that is available for mapping by a non-root process.
 *
 * \param inode device inode.
 * \param file_priv DRM file private.
 * \param cmd command.
 * \param arg pointer to a drm_map structure.
 * \return zero on success or a negative value on error.
 *
 * Adjusts the memory offset to its absolute value according to the mapping
 * type.  Adds the map to the map list drm_device::maplist. Adds MTRR's where
 * applicable and if supported by the kernel.
 */
00104 static int drm_addmap_core(struct drm_device * dev, unsigned int offset,
                     unsigned int size, enum drm_map_type type,
                     enum drm_map_flags flags,
                     struct drm_map_list ** maplist)
{
      struct drm_map *map;
      struct drm_map_list *list;
      drm_dma_handle_t *dmah;
      unsigned long user_token;
      int ret;

      map = drm_alloc(sizeof(*map), DRM_MEM_MAPS);
      if (!map)
            return -ENOMEM;

      map->offset = offset;
      map->size = size;
      map->flags = flags;
      map->type = type;

      /* Only allow shared memory to be removable since we only keep enough
       * book keeping information about shared memory to allow for removal
       * when processes fork.
       */
      if ((map->flags & _DRM_REMOVABLE) && map->type != _DRM_SHM) {
            drm_free(map, sizeof(*map), DRM_MEM_MAPS);
            return -EINVAL;
      }
      DRM_DEBUG("offset = 0x%08lx, size = 0x%08lx, type = %d\n",
              map->offset, map->size, map->type);
      if ((map->offset & (~PAGE_MASK)) || (map->size & (~PAGE_MASK))) {
            drm_free(map, sizeof(*map), DRM_MEM_MAPS);
            return -EINVAL;
      }
      map->mtrr = -1;
      map->handle = NULL;

      switch (map->type) {
      case _DRM_REGISTERS:
      case _DRM_FRAME_BUFFER:
#if !defined(__sparc__) && !defined(__alpha__) && !defined(__ia64__) && !defined(__powerpc64__) && !defined(__x86_64__)
            if (map->offset + (map->size-1) < map->offset ||
                map->offset < virt_to_phys(high_memory)) {
                  drm_free(map, sizeof(*map), DRM_MEM_MAPS);
                  return -EINVAL;
            }
#endif
#ifdef __alpha__
            map->offset += dev->hose->mem_space->start;
#endif
            /* Some drivers preinitialize some maps, without the X Server
             * needing to be aware of it.  Therefore, we just return success
             * when the server tries to create a duplicate map.
             */
            list = drm_find_matching_map(dev, map);
            if (list != NULL) {
                  if (list->map->size != map->size) {
                        DRM_DEBUG("Matching maps of type %d with "
                                "mismatched sizes, (%ld vs %ld)\n",
                                map->type, map->size,
                                list->map->size);
                        list->map->size = map->size;
                  }

                  drm_free(map, sizeof(*map), DRM_MEM_MAPS);
                  *maplist = list;
                  return 0;
            }

            if (drm_core_has_MTRR(dev)) {
                  if (map->type == _DRM_FRAME_BUFFER ||
                      (map->flags & _DRM_WRITE_COMBINING)) {
                        map->mtrr = mtrr_add(map->offset, map->size,
                                         MTRR_TYPE_WRCOMB, 1);
                  }
            }
            if (map->type == _DRM_REGISTERS) {
                  map->handle = ioremap(map->offset, map->size);
                  if (!map->handle) {
                        drm_free(map, sizeof(*map), DRM_MEM_MAPS);
                        return -ENOMEM;
                  }
            }
                        
            break;
      case _DRM_SHM:
            list = drm_find_matching_map(dev, map);
            if (list != NULL) {
                  if(list->map->size != map->size) {
                        DRM_DEBUG("Matching maps of type %d with "
                                "mismatched sizes, (%ld vs %ld)\n",
                                map->type, map->size, list->map->size);
                        list->map->size = map->size;
                  }

                  drm_free(map, sizeof(*map), DRM_MEM_MAPS);
                  *maplist = list;
                  return 0;
            }
            map->handle = vmalloc_user(map->size);
            DRM_DEBUG("%lu %d %p\n",
                    map->size, drm_order(map->size), map->handle);
            if (!map->handle) {
                  drm_free(map, sizeof(*map), DRM_MEM_MAPS);
                  return -ENOMEM;
            }
            map->offset = (unsigned long)map->handle;
            if (map->flags & _DRM_CONTAINS_LOCK) {
                  /* Prevent a 2nd X Server from creating a 2nd lock */
                  if (dev->lock.hw_lock != NULL) {
                        vfree(map->handle);
                        drm_free(map, sizeof(*map), DRM_MEM_MAPS);
                        return -EBUSY;
                  }
                  dev->sigdata.lock = dev->lock.hw_lock = map->handle;  /* Pointer to lock */
            }
            break;
      case _DRM_AGP: {
            struct drm_agp_mem *entry;
            int valid = 0;

            if (!drm_core_has_AGP(dev)) {
                  drm_free(map, sizeof(*map), DRM_MEM_MAPS);
                  return -EINVAL;
            }
#ifdef __alpha__
            map->offset += dev->hose->mem_space->start;
#endif
            /* Note: dev->agp->base may actually be 0 when the DRM
             * is not in control of AGP space. But if user space is
             * it should already have added the AGP base itself.
             */
            map->offset += dev->agp->base;
            map->mtrr = dev->agp->agp_mtrr;     /* for getmap */

            /* This assumes the DRM is in total control of AGP space.
             * It's not always the case as AGP can be in the control
             * of user space (i.e. i810 driver). So this loop will get
             * skipped and we double check that dev->agp->memory is
             * actually set as well as being invalid before EPERM'ing
             */
            list_for_each_entry(entry, &dev->agp->memory, head) {
                  if ((map->offset >= entry->bound) &&
                      (map->offset + map->size <= entry->bound + entry->pages * PAGE_SIZE)) {
                        valid = 1;
                        break;
                  }
            }
            if (!list_empty(&dev->agp->memory) && !valid) {
                  drm_free(map, sizeof(*map), DRM_MEM_MAPS);
                  return -EPERM;
            }
            DRM_DEBUG("AGP offset = 0x%08lx, size = 0x%08lx\n", map->offset, map->size);

            break;
      }
      case _DRM_SCATTER_GATHER:
            if (!dev->sg) {
                  drm_free(map, sizeof(*map), DRM_MEM_MAPS);
                  return -EINVAL;
            }
            map->offset += (unsigned long)dev->sg->virtual;
            break;
      case _DRM_CONSISTENT:
            /* dma_addr_t is 64bit on i386 with CONFIG_HIGHMEM64G,
             * As we're limiting the address to 2^32-1 (or less),
             * casting it down to 32 bits is no problem, but we
             * need to point to a 64bit variable first. */
            dmah = drm_pci_alloc(dev, map->size, map->size, 0xffffffffUL);
            if (!dmah) {
                  drm_free(map, sizeof(*map), DRM_MEM_MAPS);
                  return -ENOMEM;
            }
            map->handle = dmah->vaddr;
            map->offset = (unsigned long)dmah->busaddr;
            kfree(dmah);
            break;
      default:
            drm_free(map, sizeof(*map), DRM_MEM_MAPS);
            return -EINVAL;
      }

      list = drm_alloc(sizeof(*list), DRM_MEM_MAPS);
      if (!list) {
            if (map->type == _DRM_REGISTERS)
                  iounmap(map->handle);
            drm_free(map, sizeof(*map), DRM_MEM_MAPS);
            return -EINVAL;
      }
      memset(list, 0, sizeof(*list));
      list->map = map;

      mutex_lock(&dev->struct_mutex);
      list_add(&list->head, &dev->maplist);

      /* Assign a 32-bit handle */
      /* We do it here so that dev->struct_mutex protects the increment */
      user_token = (map->type == _DRM_SHM) ? (unsigned long)map->handle :
            map->offset;
      ret = drm_map_handle(dev, &list->hash, user_token, 0);
      if (ret) {
            if (map->type == _DRM_REGISTERS)
                  iounmap(map->handle);
            drm_free(map, sizeof(*map), DRM_MEM_MAPS);
            drm_free(list, sizeof(*list), DRM_MEM_MAPS);
            mutex_unlock(&dev->struct_mutex);
            return ret;
      }

      list->user_token = list->hash.key << PAGE_SHIFT;
      mutex_unlock(&dev->struct_mutex);

      *maplist = list;
      return 0;
      }

int drm_addmap(struct drm_device * dev, unsigned int offset,
             unsigned int size, enum drm_map_type type,
             enum drm_map_flags flags, drm_local_map_t ** map_ptr)
{
      struct drm_map_list *list;
      int rc;

      rc = drm_addmap_core(dev, offset, size, type, flags, &list);
      if (!rc)
            *map_ptr = list->map;
      return rc;
}

EXPORT_SYMBOL(drm_addmap);

int drm_addmap_ioctl(struct drm_device *dev, void *data,
                 struct drm_file *file_priv)
{
      struct drm_map *map = data;
      struct drm_map_list *maplist;
      int err;

      if (!(capable(CAP_SYS_ADMIN) || map->type == _DRM_AGP))
            return -EPERM;

      err = drm_addmap_core(dev, map->offset, map->size, map->type,
                        map->flags, &maplist);

      if (err)
            return err;

      /* avoid a warning on 64-bit, this casting isn't very nice, but the API is set so too late */
      map->handle = (void *)(unsigned long)maplist->user_token;
      return 0;
}

/**
 * Remove a map private from list and deallocate resources if the mapping
 * isn't in use.
 *
 * \param inode device inode.
 * \param file_priv DRM file private.
 * \param cmd command.
 * \param arg pointer to a struct drm_map structure.
 * \return zero on success or a negative value on error.
 *
 * Searches the map on drm_device::maplist, removes it from the list, see if
 * its being used, and free any associate resource (such as MTRR's) if it's not
 * being on use.
 *
 * \sa drm_addmap
 */
00372 int drm_rmmap_locked(struct drm_device *dev, drm_local_map_t *map)
{
      struct drm_map_list *r_list = NULL, *list_t;
      drm_dma_handle_t dmah;
      int found = 0;

      /* Find the list entry for the map and remove it */
      list_for_each_entry_safe(r_list, list_t, &dev->maplist, head) {
            if (r_list->map == map) {
                  list_del(&r_list->head);
                  drm_ht_remove_key(&dev->map_hash,
                                r_list->user_token >> PAGE_SHIFT);
                  drm_free(r_list, sizeof(*r_list), DRM_MEM_MAPS);
                  found = 1;
                  break;
            }
      }

      if (!found)
            return -EINVAL;

      switch (map->type) {
      case _DRM_REGISTERS:
            iounmap(map->handle);
            /* FALLTHROUGH */
      case _DRM_FRAME_BUFFER:
            if (drm_core_has_MTRR(dev) && map->mtrr >= 0) {
                  int retcode;
                  retcode = mtrr_del(map->mtrr, map->offset, map->size);
                  DRM_DEBUG("mtrr_del=%d\n", retcode);
            }
            break;
      case _DRM_SHM:
            vfree(map->handle);
            break;
      case _DRM_AGP:
      case _DRM_SCATTER_GATHER:
            break;
      case _DRM_CONSISTENT:
            dmah.vaddr = map->handle;
            dmah.busaddr = map->offset;
            dmah.size = map->size;
            __drm_pci_free(dev, &dmah);
            break;
      }
      drm_free(map, sizeof(*map), DRM_MEM_MAPS);

      return 0;
}

int drm_rmmap(struct drm_device *dev, drm_local_map_t *map)
{
      int ret;

      mutex_lock(&dev->struct_mutex);
      ret = drm_rmmap_locked(dev, map);
      mutex_unlock(&dev->struct_mutex);

      return ret;
}

/* The rmmap ioctl appears to be unnecessary.  All mappings are torn down on
 * the last close of the device, and this is necessary for cleanup when things
 * exit uncleanly.  Therefore, having userland manually remove mappings seems
 * like a pointless exercise since they're going away anyway.
 *
 * One use case might be after addmap is allowed for normal users for SHM and
 * gets used by drivers that the server doesn't need to care about.  This seems
 * unlikely.
 */
int drm_rmmap_ioctl(struct drm_device *dev, void *data,
                struct drm_file *file_priv)
{
      struct drm_map *request = data;
      drm_local_map_t *map = NULL;
      struct drm_map_list *r_list;
      int ret;

      mutex_lock(&dev->struct_mutex);
      list_for_each_entry(r_list, &dev->maplist, head) {
            if (r_list->map &&
                r_list->user_token == (unsigned long)request->handle &&
                r_list->map->flags & _DRM_REMOVABLE) {
                  map = r_list->map;
                  break;
            }
      }

      /* List has wrapped around to the head pointer, or its empty we didn't
       * find anything.
       */
      if (list_empty(&dev->maplist) || !map) {
            mutex_unlock(&dev->struct_mutex);
            return -EINVAL;
      }

      /* Register and framebuffer maps are permanent */
      if ((map->type == _DRM_REGISTERS) || (map->type == _DRM_FRAME_BUFFER)) {
            mutex_unlock(&dev->struct_mutex);
            return 0;
      }

      ret = drm_rmmap_locked(dev, map);

      mutex_unlock(&dev->struct_mutex);

      return ret;
}

/**
 * Cleanup after an error on one of the addbufs() functions.
 *
 * \param dev DRM device.
 * \param entry buffer entry where the error occurred.
 *
 * Frees any pages and buffers associated with the given entry.
 */
00489 static void drm_cleanup_buf_error(struct drm_device * dev,
                          struct drm_buf_entry * entry)
{
      int i;

      if (entry->seg_count) {
            for (i = 0; i < entry->seg_count; i++) {
                  if (entry->seglist[i]) {
                        drm_pci_free(dev, entry->seglist[i]);
                  }
            }
            drm_free(entry->seglist,
                   entry->seg_count *
                   sizeof(*entry->seglist), DRM_MEM_SEGS);

            entry->seg_count = 0;
      }

      if (entry->buf_count) {
            for (i = 0; i < entry->buf_count; i++) {
                  if (entry->buflist[i].dev_private) {
                        drm_free(entry->buflist[i].dev_private,
                               entry->buflist[i].dev_priv_size,
                               DRM_MEM_BUFS);
                  }
            }
            drm_free(entry->buflist,
                   entry->buf_count *
                   sizeof(*entry->buflist), DRM_MEM_BUFS);

            entry->buf_count = 0;
      }
}

#if __OS_HAS_AGP
/**
 * Add AGP buffers for DMA transfers.
 *
 * \param dev struct drm_device to which the buffers are to be added.
 * \param request pointer to a struct drm_buf_desc describing the request.
 * \return zero on success or a negative number on failure.
 *
 * After some sanity checks creates a drm_buf structure for each buffer and
 * reallocates the buffer list of the same size order to accommodate the new
 * buffers.
 */
int drm_addbufs_agp(struct drm_device * dev, struct drm_buf_desc * request)
{
      struct drm_device_dma *dma = dev->dma;
      struct drm_buf_entry *entry;
      struct drm_agp_mem *agp_entry;
      struct drm_buf *buf;
      unsigned long offset;
      unsigned long agp_offset;
      int count;
      int order;
      int size;
      int alignment;
      int page_order;
      int total;
      int byte_count;
      int i, valid;
      struct drm_buf **temp_buflist;

      if (!dma)
            return -EINVAL;

      count = request->count;
      order = drm_order(request->size);
      size = 1 << order;

      alignment = (request->flags & _DRM_PAGE_ALIGN)
          ? PAGE_ALIGN(size) : size;
      page_order = order - PAGE_SHIFT > 0 ? order - PAGE_SHIFT : 0;
      total = PAGE_SIZE << page_order;

      byte_count = 0;
      agp_offset = dev->agp->base + request->agp_start;

      DRM_DEBUG("count:      %d\n", count);
      DRM_DEBUG("order:      %d\n", order);
      DRM_DEBUG("size:       %d\n", size);
      DRM_DEBUG("agp_offset: %lx\n", agp_offset);
      DRM_DEBUG("alignment:  %d\n", alignment);
      DRM_DEBUG("page_order: %d\n", page_order);
      DRM_DEBUG("total:      %d\n", total);

      if (order < DRM_MIN_ORDER || order > DRM_MAX_ORDER)
            return -EINVAL;
      if (dev->queue_count)
            return -EBUSY;    /* Not while in use */

      /* Make sure buffers are located in AGP memory that we own */
      valid = 0;
      list_for_each_entry(agp_entry, &dev->agp->memory, head) {
            if ((agp_offset >= agp_entry->bound) &&
                (agp_offset + total * count <= agp_entry->bound + agp_entry->pages * PAGE_SIZE)) {
                  valid = 1;
                  break;
            }
      }
      if (!list_empty(&dev->agp->memory) && !valid) {
            DRM_DEBUG("zone invalid\n");
            return -EINVAL;
      }
      spin_lock(&dev->count_lock);
      if (dev->buf_use) {
            spin_unlock(&dev->count_lock);
            return -EBUSY;
      }
      atomic_inc(&dev->buf_alloc);
      spin_unlock(&dev->count_lock);

      mutex_lock(&dev->struct_mutex);
      entry = &dma->bufs[order];
      if (entry->buf_count) {
            mutex_unlock(&dev->struct_mutex);
            atomic_dec(&dev->buf_alloc);
            return -ENOMEM;   /* May only call once for each order */
      }

      if (count < 0 || count > 4096) {
            mutex_unlock(&dev->struct_mutex);
            atomic_dec(&dev->buf_alloc);
            return -EINVAL;
      }

      entry->buflist = drm_alloc(count * sizeof(*entry->buflist),
                           DRM_MEM_BUFS);
      if (!entry->buflist) {
            mutex_unlock(&dev->struct_mutex);
            atomic_dec(&dev->buf_alloc);
            return -ENOMEM;
      }
      memset(entry->buflist, 0, count * sizeof(*entry->buflist));

      entry->buf_size = size;
      entry->page_order = page_order;

      offset = 0;

      while (entry->buf_count < count) {
            buf = &entry->buflist[entry->buf_count];
            buf->idx = dma->buf_count + entry->buf_count;
            buf->total = alignment;
            buf->order = order;
            buf->used = 0;

            buf->offset = (dma->byte_count + offset);
            buf->bus_address = agp_offset + offset;
            buf->address = (void *)(agp_offset + offset);
            buf->next = NULL;
            buf->waiting = 0;
            buf->pending = 0;
            init_waitqueue_head(&buf->dma_wait);
            buf->file_priv = NULL;

            buf->dev_priv_size = dev->driver->dev_priv_size;
            buf->dev_private = drm_alloc(buf->dev_priv_size, DRM_MEM_BUFS);
            if (!buf->dev_private) {
                  /* Set count correctly so we free the proper amount. */
                  entry->buf_count = count;
                  drm_cleanup_buf_error(dev, entry);
                  mutex_unlock(&dev->struct_mutex);
                  atomic_dec(&dev->buf_alloc);
                  return -ENOMEM;
            }
            memset(buf->dev_private, 0, buf->dev_priv_size);

            DRM_DEBUG("buffer %d @ %p\n", entry->buf_count, buf->address);

            offset += alignment;
            entry->buf_count++;
            byte_count += PAGE_SIZE << page_order;
      }

      DRM_DEBUG("byte_count: %d\n", byte_count);

      temp_buflist = drm_realloc(dma->buflist,
                           dma->buf_count * sizeof(*dma->buflist),
                           (dma->buf_count + entry->buf_count)
                           * sizeof(*dma->buflist), DRM_MEM_BUFS);
      if (!temp_buflist) {
            /* Free the entry because it isn't valid */
            drm_cleanup_buf_error(dev, entry);
            mutex_unlock(&dev->struct_mutex);
            atomic_dec(&dev->buf_alloc);
            return -ENOMEM;
      }
      dma->buflist = temp_buflist;

      for (i = 0; i < entry->buf_count; i++) {
            dma->buflist[i + dma->buf_count] = &entry->buflist[i];
      }

      dma->buf_count += entry->buf_count;
      dma->seg_count += entry->seg_count;
      dma->page_count += byte_count >> PAGE_SHIFT;
      dma->byte_count += byte_count;

      DRM_DEBUG("dma->buf_count : %d\n", dma->buf_count);
      DRM_DEBUG("entry->buf_count : %d\n", entry->buf_count);

      mutex_unlock(&dev->struct_mutex);

      request->count = entry->buf_count;
      request->size = size;

      dma->flags = _DRM_DMA_USE_AGP;

      atomic_dec(&dev->buf_alloc);
      return 0;
}
EXPORT_SYMBOL(drm_addbufs_agp);
#endif                        /* __OS_HAS_AGP */

int drm_addbufs_pci(struct drm_device * dev, struct drm_buf_desc * request)
{
      struct drm_device_dma *dma = dev->dma;
      int count;
      int order;
      int size;
      int total;
      int page_order;
      struct drm_buf_entry *entry;
      drm_dma_handle_t *dmah;
      struct drm_buf *buf;
      int alignment;
      unsigned long offset;
      int i;
      int byte_count;
      int page_count;
      unsigned long *temp_pagelist;
      struct drm_buf **temp_buflist;

      if (!drm_core_check_feature(dev, DRIVER_PCI_DMA))
            return -EINVAL;

      if (!dma)
            return -EINVAL;

      if (!capable(CAP_SYS_ADMIN))
            return -EPERM;

      count = request->count;
      order = drm_order(request->size);
      size = 1 << order;

      DRM_DEBUG("count=%d, size=%d (%d), order=%d, queue_count=%d\n",
              request->count, request->size, size, order, dev->queue_count);

      if (order < DRM_MIN_ORDER || order > DRM_MAX_ORDER)
            return -EINVAL;
      if (dev->queue_count)
            return -EBUSY;    /* Not while in use */

      alignment = (request->flags & _DRM_PAGE_ALIGN)
          ? PAGE_ALIGN(size) : size;
      page_order = order - PAGE_SHIFT > 0 ? order - PAGE_SHIFT : 0;
      total = PAGE_SIZE << page_order;

      spin_lock(&dev->count_lock);
      if (dev->buf_use) {
            spin_unlock(&dev->count_lock);
            return -EBUSY;
      }
      atomic_inc(&dev->buf_alloc);
      spin_unlock(&dev->count_lock);

      mutex_lock(&dev->struct_mutex);
      entry = &dma->bufs[order];
      if (entry->buf_count) {
            mutex_unlock(&dev->struct_mutex);
            atomic_dec(&dev->buf_alloc);
            return -ENOMEM;   /* May only call once for each order */
      }

      if (count < 0 || count > 4096) {
            mutex_unlock(&dev->struct_mutex);
            atomic_dec(&dev->buf_alloc);
            return -EINVAL;
      }

      entry->buflist = drm_alloc(count * sizeof(*entry->buflist),
                           DRM_MEM_BUFS);
      if (!entry->buflist) {
            mutex_unlock(&dev->struct_mutex);
            atomic_dec(&dev->buf_alloc);
            return -ENOMEM;
      }
      memset(entry->buflist, 0, count * sizeof(*entry->buflist));

      entry->seglist = drm_alloc(count * sizeof(*entry->seglist),
                           DRM_MEM_SEGS);
      if (!entry->seglist) {
            drm_free(entry->buflist,
                   count * sizeof(*entry->buflist), DRM_MEM_BUFS);
            mutex_unlock(&dev->struct_mutex);
            atomic_dec(&dev->buf_alloc);
            return -ENOMEM;
      }
      memset(entry->seglist, 0, count * sizeof(*entry->seglist));

      /* Keep the original pagelist until we know all the allocations
       * have succeeded
       */
      temp_pagelist = drm_alloc((dma->page_count + (count << page_order))
                          * sizeof(*dma->pagelist), DRM_MEM_PAGES);
      if (!temp_pagelist) {
            drm_free(entry->buflist,
                   count * sizeof(*entry->buflist), DRM_MEM_BUFS);
            drm_free(entry->seglist,
                   count * sizeof(*entry->seglist), DRM_MEM_SEGS);
            mutex_unlock(&dev->struct_mutex);
            atomic_dec(&dev->buf_alloc);
            return -ENOMEM;
      }
      memcpy(temp_pagelist,
             dma->pagelist, dma->page_count * sizeof(*dma->pagelist));
      DRM_DEBUG("pagelist: %d entries\n",
              dma->page_count + (count << page_order));

      entry->buf_size = size;
      entry->page_order = page_order;
      byte_count = 0;
      page_count = 0;

      while (entry->buf_count < count) {
            
            dmah = drm_pci_alloc(dev, PAGE_SIZE << page_order, 0x1000, 0xfffffffful);
            
            if (!dmah) {
                  /* Set count correctly so we free the proper amount. */
                  entry->buf_count = count;
                  entry->seg_count = count;
                  drm_cleanup_buf_error(dev, entry);
                  drm_free(temp_pagelist,
                         (dma->page_count + (count << page_order))
                         * sizeof(*dma->pagelist), DRM_MEM_PAGES);
                  mutex_unlock(&dev->struct_mutex);
                  atomic_dec(&dev->buf_alloc);
                  return -ENOMEM;
            }
            entry->seglist[entry->seg_count++] = dmah;
            for (i = 0; i < (1 << page_order); i++) {
                  DRM_DEBUG("page %d @ 0x%08lx\n",
                          dma->page_count + page_count,
                          (unsigned long)dmah->vaddr + PAGE_SIZE * i);
                  temp_pagelist[dma->page_count + page_count++]
                        = (unsigned long)dmah->vaddr + PAGE_SIZE * i;
            }
            for (offset = 0;
                 offset + size <= total && entry->buf_count < count;
                 offset += alignment, ++entry->buf_count) {
                  buf = &entry->buflist[entry->buf_count];
                  buf->idx = dma->buf_count + entry->buf_count;
                  buf->total = alignment;
                  buf->order = order;
                  buf->used = 0;
                  buf->offset = (dma->byte_count + byte_count + offset);
                  buf->address = (void *)(dmah->vaddr + offset);
                  buf->bus_address = dmah->busaddr + offset;
                  buf->next = NULL;
                  buf->waiting = 0;
                  buf->pending = 0;
                  init_waitqueue_head(&buf->dma_wait);
                  buf->file_priv = NULL;

                  buf->dev_priv_size = dev->driver->dev_priv_size;
                  buf->dev_private = drm_alloc(buf->dev_priv_size,
                                         DRM_MEM_BUFS);
                  if (!buf->dev_private) {
                        /* Set count correctly so we free the proper amount. */
                        entry->buf_count = count;
                        entry->seg_count = count;
                        drm_cleanup_buf_error(dev, entry);
                        drm_free(temp_pagelist,
                               (dma->page_count +
                                (count << page_order))
                               * sizeof(*dma->pagelist),
                               DRM_MEM_PAGES);
                        mutex_unlock(&dev->struct_mutex);
                        atomic_dec(&dev->buf_alloc);
                        return -ENOMEM;
                  }
                  memset(buf->dev_private, 0, buf->dev_priv_size);

                  DRM_DEBUG("buffer %d @ %p\n",
                          entry->buf_count, buf->address);
            }
            byte_count += PAGE_SIZE << page_order;
      }

      temp_buflist = drm_realloc(dma->buflist,
                           dma->buf_count * sizeof(*dma->buflist),
                           (dma->buf_count + entry->buf_count)
                           * sizeof(*dma->buflist), DRM_MEM_BUFS);
      if (!temp_buflist) {
            /* Free the entry because it isn't valid */
            drm_cleanup_buf_error(dev, entry);
            drm_free(temp_pagelist,
                   (dma->page_count + (count << page_order))
                   * sizeof(*dma->pagelist), DRM_MEM_PAGES);
            mutex_unlock(&dev->struct_mutex);
            atomic_dec(&dev->buf_alloc);
            return -ENOMEM;
      }
      dma->buflist = temp_buflist;

      for (i = 0; i < entry->buf_count; i++) {
            dma->buflist[i + dma->buf_count] = &entry->buflist[i];
      }

      /* No allocations failed, so now we can replace the orginal pagelist
       * with the new one.
       */
      if (dma->page_count) {
            drm_free(dma->pagelist,
                   dma->page_count * sizeof(*dma->pagelist),
                   DRM_MEM_PAGES);
      }
      dma->pagelist = temp_pagelist;

      dma->buf_count += entry->buf_count;
      dma->seg_count += entry->seg_count;
      dma->page_count += entry->seg_count << page_order;
      dma->byte_count += PAGE_SIZE * (entry->seg_count << page_order);

      mutex_unlock(&dev->struct_mutex);

      request->count = entry->buf_count;
      request->size = size;

      if (request->flags & _DRM_PCI_BUFFER_RO)
            dma->flags = _DRM_DMA_USE_PCI_RO;

      atomic_dec(&dev->buf_alloc);
      return 0;

}
EXPORT_SYMBOL(drm_addbufs_pci);

static int drm_addbufs_sg(struct drm_device * dev, struct drm_buf_desc * request)
{
      struct drm_device_dma *dma = dev->dma;
      struct drm_buf_entry *entry;
      struct drm_buf *buf;
      unsigned long offset;
      unsigned long agp_offset;
      int count;
      int order;
      int size;
      int alignment;
      int page_order;
      int total;
      int byte_count;
      int i;
      struct drm_buf **temp_buflist;

      if (!drm_core_check_feature(dev, DRIVER_SG))
            return -EINVAL;

      if (!dma)
            return -EINVAL;

      if (!capable(CAP_SYS_ADMIN))
            return -EPERM;

      count = request->count;
      order = drm_order(request->size);
      size = 1 << order;

      alignment = (request->flags & _DRM_PAGE_ALIGN)
          ? PAGE_ALIGN(size) : size;
      page_order = order - PAGE_SHIFT > 0 ? order - PAGE_SHIFT : 0;
      total = PAGE_SIZE << page_order;

      byte_count = 0;
      agp_offset = request->agp_start;

      DRM_DEBUG("count:      %d\n", count);
      DRM_DEBUG("order:      %d\n", order);
      DRM_DEBUG("size:       %d\n", size);
      DRM_DEBUG("agp_offset: %lu\n", agp_offset);
      DRM_DEBUG("alignment:  %d\n", alignment);
      DRM_DEBUG("page_order: %d\n", page_order);
      DRM_DEBUG("total:      %d\n", total);

      if (order < DRM_MIN_ORDER || order > DRM_MAX_ORDER)
            return -EINVAL;
      if (dev->queue_count)
            return -EBUSY;    /* Not while in use */

      spin_lock(&dev->count_lock);
      if (dev->buf_use) {
            spin_unlock(&dev->count_lock);
            return -EBUSY;
      }
      atomic_inc(&dev->buf_alloc);
      spin_unlock(&dev->count_lock);

      mutex_lock(&dev->struct_mutex);
      entry = &dma->bufs[order];
      if (entry->buf_count) {
            mutex_unlock(&dev->struct_mutex);
            atomic_dec(&dev->buf_alloc);
            return -ENOMEM;   /* May only call once for each order */
      }

      if (count < 0 || count > 4096) {
            mutex_unlock(&dev->struct_mutex);
            atomic_dec(&dev->buf_alloc);
            return -EINVAL;
      }

      entry->buflist = drm_alloc(count * sizeof(*entry->buflist),
                           DRM_MEM_BUFS);
      if (!entry->buflist) {
            mutex_unlock(&dev->struct_mutex);
            atomic_dec(&dev->buf_alloc);
            return -ENOMEM;
      }
      memset(entry->buflist, 0, count * sizeof(*entry->buflist));

      entry->buf_size = size;
      entry->page_order = page_order;

      offset = 0;

      while (entry->buf_count < count) {
            buf = &entry->buflist[entry->buf_count];
            buf->idx = dma->buf_count + entry->buf_count;
            buf->total = alignment;
            buf->order = order;
            buf->used = 0;

            buf->offset = (dma->byte_count + offset);
            buf->bus_address = agp_offset + offset;
            buf->address = (void *)(agp_offset + offset
                              + (unsigned long)dev->sg->virtual);
            buf->next = NULL;
            buf->waiting = 0;
            buf->pending = 0;
            init_waitqueue_head(&buf->dma_wait);
            buf->file_priv = NULL;

            buf->dev_priv_size = dev->driver->dev_priv_size;
            buf->dev_private = drm_alloc(buf->dev_priv_size, DRM_MEM_BUFS);
            if (!buf->dev_private) {
                  /* Set count correctly so we free the proper amount. */
                  entry->buf_count = count;
                  drm_cleanup_buf_error(dev, entry);
                  mutex_unlock(&dev->struct_mutex);
                  atomic_dec(&dev->buf_alloc);
                  return -ENOMEM;
            }

            memset(buf->dev_private, 0, buf->dev_priv_size);

            DRM_DEBUG("buffer %d @ %p\n", entry->buf_count, buf->address);

            offset += alignment;
            entry->buf_count++;
            byte_count += PAGE_SIZE << page_order;
      }

      DRM_DEBUG("byte_count: %d\n", byte_count);

      temp_buflist = drm_realloc(dma->buflist,
                           dma->buf_count * sizeof(*dma->buflist),
                           (dma->buf_count + entry->buf_count)
                           * sizeof(*dma->buflist), DRM_MEM_BUFS);
      if (!temp_buflist) {
            /* Free the entry because it isn't valid */
            drm_cleanup_buf_error(dev, entry);
            mutex_unlock(&dev->struct_mutex);
            atomic_dec(&dev->buf_alloc);
            return -ENOMEM;
      }
      dma->buflist = temp_buflist;

      for (i = 0; i < entry->buf_count; i++) {
            dma->buflist[i + dma->buf_count] = &entry->buflist[i];
      }

      dma->buf_count += entry->buf_count;
      dma->seg_count += entry->seg_count;
      dma->page_count += byte_count >> PAGE_SHIFT;
      dma->byte_count += byte_count;

      DRM_DEBUG("dma->buf_count : %d\n", dma->buf_count);
      DRM_DEBUG("entry->buf_count : %d\n", entry->buf_count);

      mutex_unlock(&dev->struct_mutex);

      request->count = entry->buf_count;
      request->size = size;

      dma->flags = _DRM_DMA_USE_SG;

      atomic_dec(&dev->buf_alloc);
      return 0;
}

static int drm_addbufs_fb(struct drm_device * dev, struct drm_buf_desc * request)
{
      struct drm_device_dma *dma = dev->dma;
      struct drm_buf_entry *entry;
      struct drm_buf *buf;
      unsigned long offset;
      unsigned long agp_offset;
      int count;
      int order;
      int size;
      int alignment;
      int page_order;
      int total;
      int byte_count;
      int i;
      struct drm_buf **temp_buflist;

      if (!drm_core_check_feature(dev, DRIVER_FB_DMA))
            return -EINVAL;

      if (!dma)
            return -EINVAL;

      if (!capable(CAP_SYS_ADMIN))
            return -EPERM;

      count = request->count;
      order = drm_order(request->size);
      size = 1 << order;

      alignment = (request->flags & _DRM_PAGE_ALIGN)
          ? PAGE_ALIGN(size) : size;
      page_order = order - PAGE_SHIFT > 0 ? order - PAGE_SHIFT : 0;
      total = PAGE_SIZE << page_order;

      byte_count = 0;
      agp_offset = request->agp_start;

      DRM_DEBUG("count:      %d\n", count);
      DRM_DEBUG("order:      %d\n", order);
      DRM_DEBUG("size:       %d\n", size);
      DRM_DEBUG("agp_offset: %lu\n", agp_offset);
      DRM_DEBUG("alignment:  %d\n", alignment);
      DRM_DEBUG("page_order: %d\n", page_order);
      DRM_DEBUG("total:      %d\n", total);

      if (order < DRM_MIN_ORDER || order > DRM_MAX_ORDER)
            return -EINVAL;
      if (dev->queue_count)
            return -EBUSY;    /* Not while in use */

      spin_lock(&dev->count_lock);
      if (dev->buf_use) {
            spin_unlock(&dev->count_lock);
            return -EBUSY;
      }
      atomic_inc(&dev->buf_alloc);
      spin_unlock(&dev->count_lock);

      mutex_lock(&dev->struct_mutex);
      entry = &dma->bufs[order];
      if (entry->buf_count) {
            mutex_unlock(&dev->struct_mutex);
            atomic_dec(&dev->buf_alloc);
            return -ENOMEM;   /* May only call once for each order */
      }

      if (count < 0 || count > 4096) {
            mutex_unlock(&dev->struct_mutex);
            atomic_dec(&dev->buf_alloc);
            return -EINVAL;
      }

      entry->buflist = drm_alloc(count * sizeof(*entry->buflist),
                           DRM_MEM_BUFS);
      if (!entry->buflist) {
            mutex_unlock(&dev->struct_mutex);
            atomic_dec(&dev->buf_alloc);
            return -ENOMEM;
      }
      memset(entry->buflist, 0, count * sizeof(*entry->buflist));

      entry->buf_size = size;
      entry->page_order = page_order;

      offset = 0;

      while (entry->buf_count < count) {
            buf = &entry->buflist[entry->buf_count];
            buf->idx = dma->buf_count + entry->buf_count;
            buf->total = alignment;
            buf->order = order;
            buf->used = 0;

            buf->offset = (dma->byte_count + offset);
            buf->bus_address = agp_offset + offset;
            buf->address = (void *)(agp_offset + offset);
            buf->next = NULL;
            buf->waiting = 0;
            buf->pending = 0;
            init_waitqueue_head(&buf->dma_wait);
            buf->file_priv = NULL;

            buf->dev_priv_size = dev->driver->dev_priv_size;
            buf->dev_private = drm_alloc(buf->dev_priv_size, DRM_MEM_BUFS);
            if (!buf->dev_private) {
                  /* Set count correctly so we free the proper amount. */
                  entry->buf_count = count;
                  drm_cleanup_buf_error(dev, entry);
                  mutex_unlock(&dev->struct_mutex);
                  atomic_dec(&dev->buf_alloc);
                  return -ENOMEM;
            }
            memset(buf->dev_private, 0, buf->dev_priv_size);

            DRM_DEBUG("buffer %d @ %p\n", entry->buf_count, buf->address);

            offset += alignment;
            entry->buf_count++;
            byte_count += PAGE_SIZE << page_order;
      }

      DRM_DEBUG("byte_count: %d\n", byte_count);

      temp_buflist = drm_realloc(dma->buflist,
                           dma->buf_count * sizeof(*dma->buflist),
                           (dma->buf_count + entry->buf_count)
                           * sizeof(*dma->buflist), DRM_MEM_BUFS);
      if (!temp_buflist) {
            /* Free the entry because it isn't valid */
            drm_cleanup_buf_error(dev, entry);
            mutex_unlock(&dev->struct_mutex);
            atomic_dec(&dev->buf_alloc);
            return -ENOMEM;
      }
      dma->buflist = temp_buflist;

      for (i = 0; i < entry->buf_count; i++) {
            dma->buflist[i + dma->buf_count] = &entry->buflist[i];
      }

      dma->buf_count += entry->buf_count;
      dma->seg_count += entry->seg_count;
      dma->page_count += byte_count >> PAGE_SHIFT;
      dma->byte_count += byte_count;

      DRM_DEBUG("dma->buf_count : %d\n", dma->buf_count);
      DRM_DEBUG("entry->buf_count : %d\n", entry->buf_count);

      mutex_unlock(&dev->struct_mutex);

      request->count = entry->buf_count;
      request->size = size;

      dma->flags = _DRM_DMA_USE_FB;

      atomic_dec(&dev->buf_alloc);
      return 0;
}


/**
 * Add buffers for DMA transfers (ioctl).
 *
 * \param inode device inode.
 * \param file_priv DRM file private.
 * \param cmd command.
 * \param arg pointer to a struct drm_buf_desc request.
 * \return zero on success or a negative number on failure.
 *
 * According with the memory type specified in drm_buf_desc::flags and the
 * build options, it dispatches the call either to addbufs_agp(),
 * addbufs_sg() or addbufs_pci() for AGP, scatter-gather or consistent
 * PCI memory respectively.
 */
01268 int drm_addbufs(struct drm_device *dev, void *data,
            struct drm_file *file_priv)
{
      struct drm_buf_desc *request = data;
      int ret;

      if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
            return -EINVAL;

#if __OS_HAS_AGP
      if (request->flags & _DRM_AGP_BUFFER)
            ret = drm_addbufs_agp(dev, request);
      else
#endif
      if (request->flags & _DRM_SG_BUFFER)
            ret = drm_addbufs_sg(dev, request);
      else if (request->flags & _DRM_FB_BUFFER)
            ret = drm_addbufs_fb(dev, request);
      else
            ret = drm_addbufs_pci(dev, request);

      return ret;
}

/**
 * Get information about the buffer mappings.
 *
 * This was originally mean for debugging purposes, or by a sophisticated
 * client library to determine how best to use the available buffers (e.g.,
 * large buffers can be used for image transfer).
 *
 * \param inode device inode.
 * \param file_priv DRM file private.
 * \param cmd command.
 * \param arg pointer to a drm_buf_info structure.
 * \return zero on success or a negative number on failure.
 *
 * Increments drm_device::buf_use while holding the drm_device::count_lock
 * lock, preventing of allocating more buffers after this call. Information
 * about each requested buffer is then copied into user space.
 */
01309 int drm_infobufs(struct drm_device *dev, void *data,
             struct drm_file *file_priv)
{
      struct drm_device_dma *dma = dev->dma;
      struct drm_buf_info *request = data;
      int i;
      int count;

      if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
            return -EINVAL;

      if (!dma)
            return -EINVAL;

      spin_lock(&dev->count_lock);
      if (atomic_read(&dev->buf_alloc)) {
            spin_unlock(&dev->count_lock);
            return -EBUSY;
      }
      ++dev->buf_use;         /* Can't allocate more after this call */
      spin_unlock(&dev->count_lock);

      for (i = 0, count = 0; i < DRM_MAX_ORDER + 1; i++) {
            if (dma->bufs[i].buf_count)
                  ++count;
      }

      DRM_DEBUG("count = %d\n", count);

      if (request->count >= count) {
            for (i = 0, count = 0; i < DRM_MAX_ORDER + 1; i++) {
                  if (dma->bufs[i].buf_count) {
                        struct drm_buf_desc __user *to =
                            &request->list[count];
                        struct drm_buf_entry *from = &dma->bufs[i];
                        struct drm_freelist *list = &dma->bufs[i].freelist;
                        if (copy_to_user(&to->count,
                                     &from->buf_count,
                                     sizeof(from->buf_count)) ||
                            copy_to_user(&to->size,
                                     &from->buf_size,
                                     sizeof(from->buf_size)) ||
                            copy_to_user(&to->low_mark,
                                     &list->low_mark,
                                     sizeof(list->low_mark)) ||
                            copy_to_user(&to->high_mark,
                                     &list->high_mark,
                                     sizeof(list->high_mark)))
                              return -EFAULT;

                        DRM_DEBUG("%d %d %d %d %d\n",
                                i,
                                dma->bufs[i].buf_count,
                                dma->bufs[i].buf_size,
                                dma->bufs[i].freelist.low_mark,
                                dma->bufs[i].freelist.high_mark);
                        ++count;
                  }
            }
      }
      request->count = count;

      return 0;
}

/**
 * Specifies a low and high water mark for buffer allocation
 *
 * \param inode device inode.
 * \param file_priv DRM file private.
 * \param cmd command.
 * \param arg a pointer to a drm_buf_desc structure.
 * \return zero on success or a negative number on failure.
 *
 * Verifies that the size order is bounded between the admissible orders and
 * updates the respective drm_device_dma::bufs entry low and high water mark.
 *
 * \note This ioctl is deprecated and mostly never used.
 */
01388 int drm_markbufs(struct drm_device *dev, void *data,
             struct drm_file *file_priv)
{
      struct drm_device_dma *dma = dev->dma;
      struct drm_buf_desc *request = data;
      int order;
      struct drm_buf_entry *entry;

      if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
            return -EINVAL;

      if (!dma)
            return -EINVAL;

      DRM_DEBUG("%d, %d, %d\n",
              request->size, request->low_mark, request->high_mark);
      order = drm_order(request->size);
      if (order < DRM_MIN_ORDER || order > DRM_MAX_ORDER)
            return -EINVAL;
      entry = &dma->bufs[order];

      if (request->low_mark < 0 || request->low_mark > entry->buf_count)
            return -EINVAL;
      if (request->high_mark < 0 || request->high_mark > entry->buf_count)
            return -EINVAL;

      entry->freelist.low_mark = request->low_mark;
      entry->freelist.high_mark = request->high_mark;

      return 0;
}

/**
 * Unreserve the buffers in list, previously reserved using drmDMA.
 *
 * \param inode device inode.
 * \param file_priv DRM file private.
 * \param cmd command.
 * \param arg pointer to a drm_buf_free structure.
 * \return zero on success or a negative number on failure.
 *
 * Calls free_buffer() for each used buffer.
 * This function is primarily used for debugging.
 */
01432 int drm_freebufs(struct drm_device *dev, void *data,
             struct drm_file *file_priv)
{
      struct drm_device_dma *dma = dev->dma;
      struct drm_buf_free *request = data;
      int i;
      int idx;
      struct drm_buf *buf;

      if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
            return -EINVAL;

      if (!dma)
            return -EINVAL;

      DRM_DEBUG("%d\n", request->count);
      for (i = 0; i < request->count; i++) {
            if (copy_from_user(&idx, &request->list[i], sizeof(idx)))
                  return -EFAULT;
            if (idx < 0 || idx >= dma->buf_count) {
                  DRM_ERROR("Index %d (of %d max)\n",
                          idx, dma->buf_count - 1);
                  return -EINVAL;
            }
            buf = dma->buflist[idx];
            if (buf->file_priv != file_priv) {
                  DRM_ERROR("Process %d freeing buffer not owned\n",
                          task_pid_nr(current));
                  return -EINVAL;
            }
            drm_free_buffer(dev, buf);
      }

      return 0;
}

/**
 * Maps all of the DMA buffers into client-virtual space (ioctl).
 *
 * \param inode device inode.
 * \param file_priv DRM file private.
 * \param cmd command.
 * \param arg pointer to a drm_buf_map structure.
 * \return zero on success or a negative number on failure.
 *
 * Maps the AGP, SG or PCI buffer region with do_mmap(), and copies information
 * about each buffer into user space. For PCI buffers, it calls do_mmap() with
 * offset equal to 0, which drm_mmap() interpretes as PCI buffers and calls
 * drm_mmap_dma().
 */
01482 int drm_mapbufs(struct drm_device *dev, void *data,
              struct drm_file *file_priv)
{
      struct drm_device_dma *dma = dev->dma;
      int retcode = 0;
      const int zero = 0;
      unsigned long virtual;
      unsigned long address;
      struct drm_buf_map *request = data;
      int i;

      if (!drm_core_check_feature(dev, DRIVER_HAVE_DMA))
            return -EINVAL;

      if (!dma)
            return -EINVAL;

      spin_lock(&dev->count_lock);
      if (atomic_read(&dev->buf_alloc)) {
            spin_unlock(&dev->count_lock);
            return -EBUSY;
      }
      dev->buf_use++;         /* Can't allocate more after this call */
      spin_unlock(&dev->count_lock);

      if (request->count >= dma->buf_count) {
            if ((drm_core_has_AGP(dev) && (dma->flags & _DRM_DMA_USE_AGP))
                || (drm_core_check_feature(dev, DRIVER_SG)
                  && (dma->flags & _DRM_DMA_USE_SG))
                || (drm_core_check_feature(dev, DRIVER_FB_DMA)
                  && (dma->flags & _DRM_DMA_USE_FB))) {
                  struct drm_map *map = dev->agp_buffer_map;
                  unsigned long token = dev->agp_buffer_token;

                  if (!map) {
                        retcode = -EINVAL;
                        goto done;
                  }
                  down_write(&current->mm->mmap_sem);
                  virtual = do_mmap(file_priv->filp, 0, map->size,
                                PROT_READ | PROT_WRITE,
                                MAP_SHARED,
                                token);
                  up_write(&current->mm->mmap_sem);
            } else {
                  down_write(&current->mm->mmap_sem);
                  virtual = do_mmap(file_priv->filp, 0, dma->byte_count,
                                PROT_READ | PROT_WRITE,
                                MAP_SHARED, 0);
                  up_write(&current->mm->mmap_sem);
            }
            if (virtual > -1024UL) {
                  /* Real error */
                  retcode = (signed long)virtual;
                  goto done;
            }
            request->virtual = (void __user *)virtual;

            for (i = 0; i < dma->buf_count; i++) {
                  if (copy_to_user(&request->list[i].idx,
                               &dma->buflist[i]->idx,
                               sizeof(request->list[0].idx))) {
                        retcode = -EFAULT;
                        goto done;
                  }
                  if (copy_to_user(&request->list[i].total,
                               &dma->buflist[i]->total,
                               sizeof(request->list[0].total))) {
                        retcode = -EFAULT;
                        goto done;
                  }
                  if (copy_to_user(&request->list[i].used,
                               &zero, sizeof(zero))) {
                        retcode = -EFAULT;
                        goto done;
                  }
                  address = virtual + dma->buflist[i]->offset;    /* *** */
                  if (copy_to_user(&request->list[i].address,
                               &address, sizeof(address))) {
                        retcode = -EFAULT;
                        goto done;
                  }
            }
      }
      done:
      request->count = dma->buf_count;
      DRM_DEBUG("%d buffers, retcode = %d\n", request->count, retcode);

      return retcode;
}

/**
 * Compute size order.  Returns the exponent of the smaller power of two which
 * is greater or equal to given number.
 *
 * \param size size.
 * \return order.
 *
 * \todo Can be made faster.
 */
01582 int drm_order(unsigned long size)
{
      int order;
      unsigned long tmp;

      for (order = 0, tmp = size >> 1; tmp; tmp >>= 1, order++) ;

      if (size & (size - 1))
            ++order;

      return order;
}
EXPORT_SYMBOL(drm_order);



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