Re: [Linaro-mm-sig] [PATCH v5] drm/syncobj: Extend EXPORT_SYNC_FILE for timeline syncobjs

["Christian König" <ckoenig.leichtzumerken@gmail.com>]

Am 31.03.25 um 23:23 schrieb Rob Clark:
> From: Rob Clark <robdclark@chromium.org>
>
> Add support for exporting a dma_fence fd for a specific point on a
> timeline.  This is needed for vtest/vpipe[1][2] to implement timeline
> syncobj support, as it needs a way to turn a point on a timeline back
> into a dma_fence fd.  It also closes an odd omission from the syncobj
> UAPI.
>
> [1] https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/33433
> [2] https://gitlab.freedesktop.org/virgl/virglrenderer/-/merge_requests/805
>
> v2: Add DRM_SYNCOBJ_HANDLE_TO_FD_FLAGS_TIMELINE
> v3: Add unstaged uabi header hunk
> v4: Also handle IMPORT_SYNC_FILE case
> v5: Address comments from Dmitry
>
> Signed-off-by: Rob Clark <robdclark@chromium.org>
> ---
>  drivers/gpu/drm/drm_syncobj.c | 45 +++++++++++++++++++++++++++--------
>  include/uapi/drm/drm.h        |  4 ++++
>  2 files changed, 39 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_syncobj.c b/drivers/gpu/drm/drm_syncobj.c
> index 4f2ab8a7b50f..b0a4c58fe726 100644
> --- a/drivers/gpu/drm/drm_syncobj.c
> +++ b/drivers/gpu/drm/drm_syncobj.c
> @@ -741,7 +741,7 @@ static int drm_syncobj_fd_to_handle(struct drm_file *file_private,
>  }
>  
>  static int drm_syncobj_import_sync_file_fence(struct drm_file *file_private,
> -					      int fd, int handle)
> +					      int fd, int handle, u64 point)
>  {
>  	struct dma_fence *fence = sync_file_get_fence(fd);
>  	struct drm_syncobj *syncobj;
> @@ -755,14 +755,22 @@ static int drm_syncobj_import_sync_file_fence(struct drm_file *file_private,
>  		return -ENOENT;
>  	}
>  
> -	drm_syncobj_replace_fence(syncobj, fence);
> +	if (point) {
> +		struct dma_fence_chain *chain = dma_fence_chain_alloc();
> +		if (!chain)
> +			return -ENOMEM;
> +		drm_syncobj_add_point(syncobj, chain, fence, point);

Just a nit pick but checkpatch.pl will complain about it: Empty line between declaration and code please.

Maybe double check if checpatch.pl is otherwise happy with the patch.

With that done feel free to add Reviewed-by: Christian König <christian.koenig@amd.com>.

Let me know if I should push it to drm-misc-next.

Regards,
Christian.

> +	} else {
> +		drm_syncobj_replace_fence(syncobj, fence);
> +	}
> +
>  	dma_fence_put(fence);
>  	drm_syncobj_put(syncobj);
>  	return 0;
>  }
>  
>  static int drm_syncobj_export_sync_file(struct drm_file *file_private,
> -					int handle, int *p_fd)
> +					int handle, u64 point, int *p_fd)
>  {
>  	int ret;
>  	struct dma_fence *fence;
> @@ -772,7 +780,7 @@ static int drm_syncobj_export_sync_file(struct drm_file *file_private,
>  	if (fd < 0)
>  		return fd;
>  
> -	ret = drm_syncobj_find_fence(file_private, handle, 0, 0, &fence);
> +	ret = drm_syncobj_find_fence(file_private, handle, point, 0, &fence);
>  	if (ret)
>  		goto err_put_fd;
>  
> @@ -869,6 +877,9 @@ drm_syncobj_handle_to_fd_ioctl(struct drm_device *dev, void *data,
>  				   struct drm_file *file_private)
>  {
>  	struct drm_syncobj_handle *args = data;
> +	unsigned valid_flags = DRM_SYNCOBJ_HANDLE_TO_FD_FLAGS_TIMELINE |
> +			       DRM_SYNCOBJ_HANDLE_TO_FD_FLAGS_EXPORT_SYNC_FILE;
> +	u64 point = 0;
>  
>  	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
>  		return -EOPNOTSUPP;
> @@ -876,13 +887,18 @@ drm_syncobj_handle_to_fd_ioctl(struct drm_device *dev, void *data,
>  	if (args->pad)
>  		return -EINVAL;
>  
> -	if (args->flags != 0 &&
> -	    args->flags != DRM_SYNCOBJ_HANDLE_TO_FD_FLAGS_EXPORT_SYNC_FILE)
> +	if (args->flags & ~valid_flags)
>  		return -EINVAL;
>  
> +	if (args->flags & DRM_SYNCOBJ_HANDLE_TO_FD_FLAGS_TIMELINE)
> +		point = args->point;
> +
>  	if (args->flags & DRM_SYNCOBJ_HANDLE_TO_FD_FLAGS_EXPORT_SYNC_FILE)
>  		return drm_syncobj_export_sync_file(file_private, args->handle,
> -						    &args->fd);
> +						    point, &args->fd);
> +
> +	if (args->point)
> +		return -EINVAL;
>  
>  	return drm_syncobj_handle_to_fd(file_private, args->handle,
>  					&args->fd);
> @@ -893,6 +909,9 @@ drm_syncobj_fd_to_handle_ioctl(struct drm_device *dev, void *data,
>  				   struct drm_file *file_private)
>  {
>  	struct drm_syncobj_handle *args = data;
> +	unsigned valid_flags = DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_TIMELINE |
> +			       DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_IMPORT_SYNC_FILE;
> +	u64 point = 0;
>  
>  	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
>  		return -EOPNOTSUPP;
> @@ -900,14 +919,20 @@ drm_syncobj_fd_to_handle_ioctl(struct drm_device *dev, void *data,
>  	if (args->pad)
>  		return -EINVAL;
>  
> -	if (args->flags != 0 &&
> -	    args->flags != DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_IMPORT_SYNC_FILE)
> +	if (args->flags & ~valid_flags)
>  		return -EINVAL;
>  
> +	if (args->flags & DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_TIMELINE)
> +		point = args->point;
> +
>  	if (args->flags & DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_IMPORT_SYNC_FILE)
>  		return drm_syncobj_import_sync_file_fence(file_private,
>  							  args->fd,
> -							  args->handle);
> +							  args->handle,
> +							  point);
> +
> +	if (args->point)
> +		return -EINVAL;
>  
>  	return drm_syncobj_fd_to_handle(file_private, args->fd,
>  					&args->handle);
> diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h
> index 7fba37b94401..e63a71d3c607 100644
> --- a/include/uapi/drm/drm.h
> +++ b/include/uapi/drm/drm.h
> @@ -905,13 +905,17 @@ struct drm_syncobj_destroy {
>  };
>  
>  #define DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_IMPORT_SYNC_FILE (1 << 0)
> +#define DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_TIMELINE         (1 << 1)
>  #define DRM_SYNCOBJ_HANDLE_TO_FD_FLAGS_EXPORT_SYNC_FILE (1 << 0)
> +#define DRM_SYNCOBJ_HANDLE_TO_FD_FLAGS_TIMELINE         (1 << 1)
>  struct drm_syncobj_handle {
>  	__u32 handle;
>  	__u32 flags;
>  
>  	__s32 fd;
>  	__u32 pad;
> +
> +	__u64 point;
>  };
>  
>  struct drm_syncobj_transfer {