/**
* drm_gem_create_mmap_offset - create a fake mmap offset for an object
* @obj: obj in question
*
* GEM memory mapping works by handing back to userspace a fake mmap offset
* it can use in a subsequent mmap(2) call. The DRM core code then looks
* up the object based on the offset and sets up the various memory mapping
* structures.
*
* This routine allocates and attaches a fake offset for @obj.
*/
int
drm_gem_create_mmap_offset(struct drm_gem_object *obj)
{
struct drm_device *dev = obj->dev;
struct drm_gem_mm *mm = dev->mm_private;
struct drm_map_list *list;
struct drm_local_map *map;
int ret = 0;
/* Set the object up for mmap'ing */
list = &obj->map_list;
list->map = kzalloc(sizeof(struct drm_map_list), GFP_KERNEL);
if (!list->map)
return -ENOMEM;
map = list->map;
map->type = _DRM_GEM;
map->size = obj->size;
map->handle = obj;
/* Get a DRM GEM mmap offset allocated... */
list->file_offset_node = drm_mm_search_free(&mm->offset_manager,
obj->size / PAGE_SIZE, 0, 0);
if (!list->file_offset_node) {
DRM_ERROR("failed to allocate offset for bo %d\n", obj->name);
ret = -ENOSPC;
goto out_free_list;
}
list->file_offset_node = drm_mm_get_block(list->file_offset_node,
obj->size / PAGE_SIZE, 0);
if (!list->file_offset_node) {
ret = -ENOMEM;
goto out_free_list;
}
list->hash.key = list->file_offset_node->start;
ret = drm_ht_insert_item(&mm->offset_hash, &list->hash);
if (ret) {
DRM_ERROR("failed to add to map hash\n");
goto out_free_mm;
}
return 0;
out_free_mm:
drm_mm_put_block(list->file_offset_node);
out_free_list:
kfree(list->map);
list->map = NULL;
return ret;
}
/**
* Inserts the given magic number into the hash table of used magic number
* lists.
*/
static int drm_add_magic(struct drm_device *dev, struct drm_file *priv,
drm_magic_t magic)
{
drm_magic_entry_t *entry;
DRM_DEBUG("%d\n", magic);
entry = kzalloc(sizeof(*entry), GFP_KERNEL);
if (!entry)
return -ENOMEM;
entry->priv = priv;
entry->hash_item.key = (unsigned long)magic;
mutex_lock(&dev->struct_mutex);
drm_ht_insert_item(&dev->magiclist, &entry->hash_item);
list_add_tail(&entry->head, &dev->magicfree);
mutex_unlock(&dev->struct_mutex);
return 0;
}
int
drm_gem_create_mmap_offset(struct drm_gem_object *obj)
{
struct drm_device *dev = obj->dev;
struct drm_gem_mm *mm = dev->mm_private;
int ret;
if (obj->on_map)
return 0;
obj->map_list.key = alloc_unr(mm->idxunr);
ret = drm_ht_insert_item(&mm->offset_hash, &obj->map_list);
if (ret) {
DRM_ERROR("failed to add to map hash\n");
free_unr(mm->idxunr, obj->map_list.key);
return ret;
}
obj->on_map = true;
return 0;
}
/*
* Just insert an item and return any "bits" bit key that hasn't been
* used before.
*/
int drm_ht_just_insert_please(struct drm_open_hash *ht, struct drm_hash_item *item,
unsigned long seed, int bits, int shift,
unsigned long add)
{
int ret;
unsigned long mask = (1 << bits) - 1;
unsigned long first, unshifted_key = 0;
unshifted_key = hash32_buf(&seed, sizeof(seed), unshifted_key);
first = unshifted_key;
do {
item->key = (unshifted_key << shift) + add;
ret = drm_ht_insert_item(ht, item);
if (ret)
unshifted_key = (unshifted_key + 1) & mask;
} while(ret && (unshifted_key != first));
if (ret) {
DRM_ERROR("Available key bit space exhausted\n");
return -EINVAL;
}
return 0;
}