* @filp: drm file-private structure to use for the handle look up
* @handle: userspace handle to delete
*
- * Removes the GEM handle from the @filp lookup table and if this is the last
- * handle also cleans up linked resources like GEM names.
+ * Removes the GEM handle from the @filp lookup table which has been added with
+ * drm_gem_handle_create(). If this is the last handle also cleans up linked
+ * resources like GEM names.
*/
int
drm_gem_handle_delete(struct drm_file *filp, u32 handle)
* This expects the dev->object_name_lock to be held already and will drop it
* before returning. Used to avoid races in establishing new handles when
* importing an object from either an flink name or a dma-buf.
+ *
+ * Handles must be release again through drm_gem_handle_delete(). This is done
+ * when userspace closes @file_priv for all attached handles, or through the
+ * GEM_CLOSE ioctl for individual handles.
*/
int
drm_gem_handle_create_tail(struct drm_file *file_priv,
}
EXPORT_SYMBOL(drm_gem_put_pages);
-/** Returns a reference to the object named by the handle. */
+/**
+ * drm_gem_object_lookup - look up a GEM object from it's handle
+ * @dev: DRM device
+ * @filp: DRM file private date
+ * @handle: userspace handle
+ *
+ * Returns:
+ *
+ * A reference to the object named by the handle if such exists on @filp, NULL
+ * otherwise.
+ */
struct drm_gem_object *
drm_gem_object_lookup(struct drm_device *dev, struct drm_file *filp,
u32 handle)
void
drm_gem_object_free(struct kref *kref)
{
- struct drm_gem_object *obj = (struct drm_gem_object *) kref;
+ struct drm_gem_object *obj =
+ container_of(kref, struct drm_gem_object, refcount);
struct drm_device *dev = obj->dev;
WARN_ON(!mutex_is_locked(&dev->struct_mutex));
}
EXPORT_SYMBOL(drm_gem_object_free);
+/**
+ * drm_gem_vm_open - vma->ops->open implementation for GEM
+ * @vma: VM area structure
+ *
+ * This function implements the #vm_operations_struct open() callback for GEM
+ * drivers. This must be used together with drm_gem_vm_close().
+ */
void drm_gem_vm_open(struct vm_area_struct *vma)
{
struct drm_gem_object *obj = vma->vm_private_data;
}
EXPORT_SYMBOL(drm_gem_vm_open);
+/**
+ * drm_gem_vm_close - vma->ops->close implementation for GEM
+ * @vma: VM area structure
+ *
+ * This function implements the #vm_operations_struct close() callback for GEM
+ * drivers. This must be used together with drm_gem_vm_open().
+ */
void drm_gem_vm_close(struct vm_area_struct *vma)
{
struct drm_gem_object *obj = vma->vm_private_data;
* drm_gem_mmap() prevents unprivileged users from mapping random objects. So
* callers must verify access restrictions before calling this helper.
*
- * NOTE: This function has to be protected with dev->struct_mutex
- *
* Return 0 or success or -EINVAL if the object size is smaller than the VMA
* size, or if no gem_vm_ops are provided.
*/
{
struct drm_device *dev = obj->dev;
- lockdep_assert_held(&dev->struct_mutex);
-
/* Check for valid size. */
if (obj_size < vma->vm_end - vma->vm_start)
return -EINVAL;
{
struct drm_file *priv = filp->private_data;
struct drm_device *dev = priv->minor->dev;
- struct drm_gem_object *obj;
+ struct drm_gem_object *obj = NULL;
struct drm_vma_offset_node *node;
int ret;
if (drm_device_is_unplugged(dev))
return -ENODEV;
- mutex_lock(&dev->struct_mutex);
+ drm_vma_offset_lock_lookup(dev->vma_offset_manager);
+ node = drm_vma_offset_exact_lookup_locked(dev->vma_offset_manager,
+ vma->vm_pgoff,
+ vma_pages(vma));
+ if (likely(node)) {
+ obj = container_of(node, struct drm_gem_object, vma_node);
+ /*
+ * When the object is being freed, after it hits 0-refcnt it
+ * proceeds to tear down the object. In the process it will
+ * attempt to remove the VMA offset and so acquire this
+ * mgr->vm_lock. Therefore if we find an object with a 0-refcnt
+ * that matches our range, we know it is in the process of being
+ * destroyed and will be freed as soon as we release the lock -
+ * so we have to check for the 0-refcnted object and treat it as
+ * invalid.
+ */
+ if (!kref_get_unless_zero(&obj->refcount))
+ obj = NULL;
+ }
+ drm_vma_offset_unlock_lookup(dev->vma_offset_manager);
- node = drm_vma_offset_exact_lookup(dev->vma_offset_manager,
- vma->vm_pgoff,
- vma_pages(vma));
- if (!node) {
- mutex_unlock(&dev->struct_mutex);
+ if (!obj)
return -EINVAL;
- } else if (!drm_vma_node_is_allowed(node, filp)) {
- mutex_unlock(&dev->struct_mutex);
+
+ if (!drm_vma_node_is_allowed(node, filp)) {
+ drm_gem_object_unreference_unlocked(obj);
return -EACCES;
}
- obj = container_of(node, struct drm_gem_object, vma_node);
- ret = drm_gem_mmap_obj(obj, drm_vma_node_size(node) << PAGE_SHIFT, vma);
+ ret = drm_gem_mmap_obj(obj, drm_vma_node_size(node) << PAGE_SHIFT,
+ vma);
- mutex_unlock(&dev->struct_mutex);
+ drm_gem_object_unreference_unlocked(obj);
return ret;
}
projects / karo-tx-linux.git / blobdiff