dma-buf/sync_file: Surface sync-file uABI

We had all of the internal driver APIs, but not the all important
userspace uABI, in the dma-buf doc.  Fix that.  And re-arrange the
comments slightly as otherwise the comments for the ioctl nr defines
would not show up.

v2: Fix docs build warning coming from newly including the uabi header
    in the docs build
Signed-off-by: Rob Clark <robdclark@chromium.org>
Acked-by: Pekka Paalanen <pekka.paalanen@collabora.com>

Documentation/driver-api/dma-buf.rst

@@ -203,8 +203,8 @@ DMA Fence unwrap
 .. kernel-doc:: include/linux/dma-fence-unwrap.h
    :internal:
 
-DMA Fence uABI/Sync File
-~~~~~~~~~~~~~~~~~~~~~~~~
+DMA Fence Sync File
+~~~~~~~~~~~~~~~~~~~
 
 .. kernel-doc:: drivers/dma-buf/sync_file.c
    :export:
@@ -212,6 +212,12 @@ DMA Fence uABI/Sync File
 .. kernel-doc:: include/linux/sync_file.h
    :internal:
 
+DMA Fence Sync File uABI
+~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. kernel-doc:: include/uapi/linux/sync_file.h
+   :internal:
+
 Indefinite DMA Fences
 ~~~~~~~~~~~~~~~~~~~~~
 

include/uapi/linux/sync_file.h

@@ -16,12 +16,16 @@
 #include <linux/types.h>
 
 /**
- * struct sync_merge_data - data passed to merge ioctl
+ * struct sync_merge_data - SYNC_IOC_MERGE: merge two fences
  * @name:	name of new fence
  * @fd2:	file descriptor of second fence
  * @fence:	returns the fd of the new fence to userspace
  * @flags:	merge_data flags
  * @pad:	padding for 64-bit alignment, should always be zero
+ *
+ * Creates a new fence containing copies of the sync_pts in both
+ * the calling fd and sync_merge_data.fd2.  Returns the new fence's
+ * fd in sync_merge_data.fence
  */
 struct sync_merge_data {
 	char	name[32];
@@ -34,8 +38,8 @@ struct sync_merge_data {
 /**
  * struct sync_fence_info - detailed fence information
  * @obj_name:		name of parent sync_timeline
-* @driver_name:	name of driver implementing the parent
-* @status:		status of the fence 0:active 1:signaled <0:error
+ * @driver_name:	name of driver implementing the parent
+ * @status:		status of the fence 0:active 1:signaled <0:error
  * @flags:		fence_info flags
  * @timestamp_ns:	timestamp of status change in nanoseconds
  */
@@ -48,14 +52,19 @@ struct sync_fence_info {
 };
 
 /**
- * struct sync_file_info - data returned from fence info ioctl
+ * struct sync_file_info - SYNC_IOC_FILE_INFO: get detailed information on a sync_file
  * @name:	name of fence
  * @status:	status of fence. 1: signaled 0:active <0:error
  * @flags:	sync_file_info flags
  * @num_fences	number of fences in the sync_file
  * @pad:	padding for 64-bit alignment, should always be zero
- * @sync_fence_info: pointer to array of structs sync_fence_info with all
+ * @sync_fence_info: pointer to array of struct &sync_fence_info with all
  *		 fences in the sync_file
+ *
+ * Takes a struct sync_file_info. If num_fences is 0, the field is updated
+ * with the actual number of fences. If num_fences is > 0, the system will
+ * use the pointer provided on sync_fence_info to return up to num_fences of
+ * struct sync_fence_info, with detailed fence information.
  */
 struct sync_file_info {
 	char	name[32];
@@ -69,30 +78,14 @@ struct sync_file_info {
 
 #define SYNC_IOC_MAGIC		'>'
 
-/**
+/*
  * Opcodes  0, 1 and 2 were burned during a API change to avoid users of the
  * old API to get weird errors when trying to handling sync_files. The API
  * change happened during the de-stage of the Sync Framework when there was
  * no upstream users available.
  */
 
-/**
- * DOC: SYNC_IOC_MERGE - merge two fences
- *
- * Takes a struct sync_merge_data.  Creates a new fence containing copies of
- * the sync_pts in both the calling fd and sync_merge_data.fd2.  Returns the
- * new fence's fd in sync_merge_data.fence
- */
 #define SYNC_IOC_MERGE		_IOWR(SYNC_IOC_MAGIC, 3, struct sync_merge_data)
-
-/**
- * DOC: SYNC_IOC_FILE_INFO - get detailed information on a sync_file
- *
- * Takes a struct sync_file_info. If num_fences is 0, the field is updated
- * with the actual number of fences. If num_fences is > 0, the system will
- * use the pointer provided on sync_fence_info to return up to num_fences of
- * struct sync_fence_info, with detailed fence information.
- */
 #define SYNC_IOC_FILE_INFO	_IOWR(SYNC_IOC_MAGIC, 4, struct sync_file_info)
 
 #endif /* _UAPI_LINUX_SYNC_H */