[PATCH v9 05/15] dma-buf/sync_file: Surface sync-file uABI

Rob Clark
2023-03-02T23:54:30Z

From: Rob Clark <robdclark@chromium.org>

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 | 10 ++++++--
include/uapi/linux/sync_file.h | 37 +++++++++++-----------------
2 files changed, 23 insertions(+), 24 deletions(-)

diff --git a/Documentation/driver-api/dma-buf.rst b/Documentation/driver-api/dma-buf.rst
index 183e480d8cea..ff3f8da296af 100644
--- a/Documentation/driver-api/dma-buf.rst
+++ b/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
~~~~~~~~~~~~~~~~~~~~~

diff --git a/include/uapi/linux/sync_file.h b/include/uapi/linux/sync_file.h
index ee2dcfb3d660..7e42a5b7558b 100644
--- a/include/uapi/linux/sync_file.h
+++ b/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 */
--
2.39.1