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path: root/drivers/gpu/drm/drm_gem.c
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Diffstat (limited to 'drivers/gpu/drm/drm_gem.c')
-rw-r--r--drivers/gpu/drm/drm_gem.c88
1 files changed, 88 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index 186d62eb063b..396e60ce8114 100644
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -285,6 +285,94 @@ again:
}
EXPORT_SYMBOL(drm_gem_handle_create);
+
+/**
+ * drm_gem_free_mmap_offset - release a fake mmap offset for an object
+ * @obj: obj in question
+ *
+ * This routine frees fake offsets allocated by drm_gem_create_mmap_offset().
+ */
+void
+drm_gem_free_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 = &obj->map_list;
+
+ drm_ht_remove_item(&mm->offset_hash, &list->hash);
+ drm_mm_put_block(list->file_offset_node);
+ kfree(list->map);
+ list->map = NULL;
+}
+EXPORT_SYMBOL(drm_gem_free_mmap_offset);
+
+/**
+ * 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;
+}
+EXPORT_SYMBOL(drm_gem_create_mmap_offset);
+
/** Returns a reference to the object named by the handle. */
struct drm_gem_object *
drm_gem_object_lookup(struct drm_device *dev, struct drm_file *filp,