diff options
Diffstat (limited to 'drivers/gpu/drm/drm_syncobj.c')
| -rw-r--r-- | drivers/gpu/drm/drm_syncobj.c | 133 |
1 files changed, 77 insertions, 56 deletions
diff --git a/drivers/gpu/drm/drm_syncobj.c b/drivers/gpu/drm/drm_syncobj.c index f776fc1cc543..0b7b0d1ad2d5 100644 --- a/drivers/gpu/drm/drm_syncobj.c +++ b/drivers/gpu/drm/drm_syncobj.c @@ -29,9 +29,9 @@ /** * DOC: Overview * - * DRM synchronisation objects (syncobj) are a persistent objects, - * that contain an optional fence. The fence can be updated with a new - * fence, or be NULL. + * DRM synchronisation objects (syncobj, see struct &drm_syncobj) are + * persistent objects that contain an optional fence. The fence can be updated + * with a new fence, or be NULL. * * syncobj's can be waited upon, where it will wait for the underlying * fence. @@ -61,7 +61,8 @@ * @file_private: drm file private pointer * @handle: sync object handle to lookup. * - * Returns a reference to the syncobj pointed to by handle or NULL. + * Returns a reference to the syncobj pointed to by handle or NULL. The + * reference must be released by calling drm_syncobj_put(). */ struct drm_syncobj *drm_syncobj_find(struct drm_file *file_private, u32 handle) @@ -106,7 +107,8 @@ static int drm_syncobj_fence_get_or_add_callback(struct drm_syncobj *syncobj, * callback when a fence has already been set. */ if (syncobj->fence) { - *fence = dma_fence_get(syncobj->fence); + *fence = dma_fence_get(rcu_dereference_protected(syncobj->fence, + lockdep_is_held(&syncobj->lock))); ret = 1; } else { *fence = NULL; @@ -168,8 +170,9 @@ void drm_syncobj_replace_fence(struct drm_syncobj *syncobj, spin_lock(&syncobj->lock); - old_fence = syncobj->fence; - syncobj->fence = fence; + old_fence = rcu_dereference_protected(syncobj->fence, + lockdep_is_held(&syncobj->lock)); + rcu_assign_pointer(syncobj->fence, fence); if (fence != old_fence) { list_for_each_entry_safe(cur, tmp, &syncobj->cb_list, node) { @@ -227,6 +230,19 @@ static int drm_syncobj_assign_null_handle(struct drm_syncobj *syncobj) return 0; } +/** + * drm_syncobj_find_fence - lookup and reference the fence in a sync object + * @file_private: drm file private pointer + * @handle: sync object handle to lookup. + * @fence: out parameter for the fence + * + * This is just a convenience function that combines drm_syncobj_find() and + * drm_syncobj_fence_get(). + * + * Returns 0 on success or a negative error value on failure. On success @fence + * contains a reference to the fence, which must be released by calling + * dma_fence_put(). + */ int drm_syncobj_find_fence(struct drm_file *file_private, u32 handle, struct dma_fence **fence) @@ -267,6 +283,12 @@ EXPORT_SYMBOL(drm_syncobj_free); * @out_syncobj: returned syncobj * @flags: DRM_SYNCOBJ_* flags * @fence: if non-NULL, the syncobj will represent this fence + * + * This is the first function to create a sync object. After creating, drivers + * probably want to make it available to userspace, either through + * drm_syncobj_get_handle() or drm_syncobj_get_fd(). + * + * Returns 0 on success or a negative error value on failure. */ int drm_syncobj_create(struct drm_syncobj **out_syncobj, uint32_t flags, struct dma_fence *fence) @@ -300,6 +322,14 @@ EXPORT_SYMBOL(drm_syncobj_create); /** * drm_syncobj_get_handle - get a handle from a syncobj + * @file_private: drm file private pointer + * @syncobj: Sync object to export + * @handle: out parameter with the new handle + * + * Exports a sync object created with drm_syncobj_create() as a handle on + * @file_private to userspace. + * + * Returns 0 on success or a negative error value on failure. */ int drm_syncobj_get_handle(struct drm_file *file_private, struct drm_syncobj *syncobj, u32 *handle) @@ -369,40 +399,35 @@ static const struct file_operations drm_syncobj_file_fops = { .release = drm_syncobj_file_release, }; -static int drm_syncobj_alloc_file(struct drm_syncobj *syncobj) -{ - struct file *file = anon_inode_getfile("syncobj_file", - &drm_syncobj_file_fops, - syncobj, 0); - if (IS_ERR(file)) - return PTR_ERR(file); - - drm_syncobj_get(syncobj); - if (cmpxchg(&syncobj->file, NULL, file)) { - /* lost the race */ - fput(file); - } - - return 0; -} - +/** + * drm_syncobj_get_fd - get a file descriptor from a syncobj + * @syncobj: Sync object to export + * @p_fd: out parameter with the new file descriptor + * + * Exports a sync object created with drm_syncobj_create() as a file descriptor. + * + * Returns 0 on success or a negative error value on failure. + */ int drm_syncobj_get_fd(struct drm_syncobj *syncobj, int *p_fd) { - int ret; + struct file *file; int fd; fd = get_unused_fd_flags(O_CLOEXEC); if (fd < 0) return fd; - if (!syncobj->file) { - ret = drm_syncobj_alloc_file(syncobj); - if (ret) { - put_unused_fd(fd); - return ret; - } + file = anon_inode_getfile("syncobj_file", + &drm_syncobj_file_fops, + syncobj, 0); + if (IS_ERR(file)) { + put_unused_fd(fd); + return PTR_ERR(file); } - fd_install(fd, syncobj->file); + + drm_syncobj_get(syncobj); + fd_install(fd, file); + *p_fd = fd; return 0; } @@ -422,31 +447,24 @@ static int drm_syncobj_handle_to_fd(struct drm_file *file_private, return ret; } -static struct drm_syncobj *drm_syncobj_fdget(int fd) -{ - struct file *file = fget(fd); - - if (!file) - return NULL; - if (file->f_op != &drm_syncobj_file_fops) - goto err; - - return file->private_data; -err: - fput(file); - return NULL; -}; - static int drm_syncobj_fd_to_handle(struct drm_file *file_private, int fd, u32 *handle) { - struct drm_syncobj *syncobj = drm_syncobj_fdget(fd); + struct drm_syncobj *syncobj; + struct file *file; int ret; - if (!syncobj) + file = fget(fd); + if (!file) return -EINVAL; + if (file->f_op != &drm_syncobj_file_fops) { + fput(file); + return -EINVAL; + } + /* take a reference to put in the idr */ + syncobj = file->private_data; drm_syncobj_get(syncobj); idr_preload(GFP_KERNEL); @@ -455,12 +473,14 @@ static int drm_syncobj_fd_to_handle(struct drm_file *file_private, spin_unlock(&file_private->syncobj_table_lock); idr_preload_end(); - if (ret < 0) { - fput(syncobj->file); - return ret; - } - *handle = ret; - return 0; + if (ret > 0) { + *handle = ret; + ret = 0; + } else + drm_syncobj_put(syncobj); + + fput(file); + return ret; } static int drm_syncobj_import_sync_file_fence(struct drm_file *file_private, @@ -659,7 +679,8 @@ static void syncobj_wait_syncobj_func(struct drm_syncobj *syncobj, container_of(cb, struct syncobj_wait_entry, syncobj_cb); /* This happens inside the syncobj lock */ - wait->fence = dma_fence_get(syncobj->fence); + wait->fence = dma_fence_get(rcu_dereference_protected(syncobj->fence, + lockdep_is_held(&syncobj->lock))); wake_up_process(wait->task); } |