From 924fe8df7fcfa508729b5a1591df41c0bafed429 Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Thu, 14 Dec 2017 21:30:52 +0100 Subject: [PATCH] drm/syncobj: some kerneldoc polish Complete a few missing bits, fix up the existing xcross-references and add a bunch more. v2: Fix typos (Alex). Cc: Dave Airlie via lists.freedesktop.org Reviewed-by: Alex Deucher Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20171214203054.20141-4-daniel.vetter@ffwll.ch --- drivers/gpu/drm/drm_syncobj.c | 45 +++++++++++++++++++++++++++++++---- include/drm/drm_syncobj.h | 34 +++++++++++++++----------- 2 files changed, 61 insertions(+), 18 deletions(-) diff --git a/drivers/gpu/drm/drm_syncobj.c b/drivers/gpu/drm/drm_syncobj.c index 9b733c510cbf..131695915acd 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) @@ -229,6 +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) @@ -269,6 +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) @@ -302,6 +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) @@ -388,6 +416,15 @@ static int drm_syncobj_alloc_file(struct drm_syncobj *syncobj) 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; diff --git a/include/drm/drm_syncobj.h b/include/drm/drm_syncobj.h index 9e8ba90c6784..3980602472c0 100644 --- a/include/drm/drm_syncobj.h +++ b/include/drm/drm_syncobj.h @@ -33,36 +33,31 @@ struct drm_syncobj_cb; /** * struct drm_syncobj - sync object. * - * This structure defines a generic sync object which wraps a dma fence. + * This structure defines a generic sync object which wraps a &dma_fence. */ struct drm_syncobj { /** - * @refcount: - * - * Reference count of this object. + * @refcount: Reference count of this object. */ struct kref refcount; /** * @fence: * NULL or a pointer to the fence bound to this object. * - * This field should not be used directly. Use drm_syncobj_fence_get - * and drm_syncobj_replace_fence instead. + * This field should not be used directly. Use drm_syncobj_fence_get() + * and drm_syncobj_replace_fence() instead. */ struct dma_fence __rcu *fence; /** - * @cb_list: - * List of callbacks to call when the fence gets replaced + * @cb_list: List of callbacks to call when the &fence gets replaced. */ struct list_head cb_list; /** - * @lock: - * locks cb_list and write-locks fence. + * @lock: Protects &cb_list and write-locks &fence. */ spinlock_t lock; /** - * @file: - * a file backing for this syncobj. + * @file: A file backing for this syncobj. */ struct file *file; }; @@ -73,7 +68,7 @@ typedef void (*drm_syncobj_func_t)(struct drm_syncobj *syncobj, /** * struct drm_syncobj_cb - callback for drm_syncobj_add_callback * @node: used by drm_syncob_add_callback to append this struct to - * syncobj::cb_list + * &drm_syncobj.cb_list * @func: drm_syncobj_func_t to call * * This struct will be initialized by drm_syncobj_add_callback, additional @@ -92,7 +87,7 @@ void drm_syncobj_free(struct kref *kref); * drm_syncobj_get - acquire a syncobj reference * @obj: sync object * - * This acquires additional reference to @obj. It is illegal to call this + * This acquires an additional reference to @obj. It is illegal to call this * without already holding a reference. No locks required. */ static inline void @@ -111,6 +106,17 @@ drm_syncobj_put(struct drm_syncobj *obj) kref_put(&obj->refcount, drm_syncobj_free); } +/** + * drm_syncobj_fence_get - get a reference to a fence in a sync object + * @syncobj: sync object. + * + * This acquires additional reference to &drm_syncobj.fence contained in @obj, + * if not NULL. It is illegal to call this without already holding a reference. + * No locks required. + * + * Returns: + * Either the fence of @obj or NULL if there's none. + */ static inline struct dma_fence * drm_syncobj_fence_get(struct drm_syncobj *syncobj) {