On Wed, Mar 26, 2025 at 7:46 AM Rob Clark robdclark@gmail.com wrote:
On Wed, Mar 26, 2025 at 7:41 AM Christian König christian.koenig@amd.com wrote:
Am 26.03.25 um 15:39 schrieb Rob Clark:
From: Rob Clark robdclark@chromium.org
Add support for exporting a dma_fence fd for a specific point on a timeline.
Looks good on first glance. What's the userspace use case?
Timeline syncobj support for vtest/vpipe[1][2].. since core virglrender and drm native ctx works in terms of fences (since in the VM case, everything is a fence below the guest kernel uabi), we need to be able to turn a point on a timeline back into a fence fd. (Plus it seemed like an odd omission from the existing uabi.)
BR, -R
[1] https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/33433 [2] https://gitlab.freedesktop.org/virgl/virglrenderer/-/merge_requests/805
Regards, Christian.
Signed-off-by: Rob Clark robdclark@chromium.org
drivers/gpu/drm/drm_syncobj.c | 8 ++++++-- include/uapi/drm/drm.h | 2 ++ 2 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/drm_syncobj.c b/drivers/gpu/drm/drm_syncobj.c index 4f2ab8a7b50f..eb7a2dd2e261 100644 --- a/drivers/gpu/drm/drm_syncobj.c +++ b/drivers/gpu/drm/drm_syncobj.c @@ -762,7 +762,7 @@ static int drm_syncobj_import_sync_file_fence(struct drm_file *file_private, }
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 +772,7 @@ 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;@@ -882,8 +882,12 @@ drm_syncobj_handle_to_fd_ioctl(struct drm_device *dev, void *data,
if (args->flags & DRM_SYNCOBJ_HANDLE_TO_FD_FLAGS_EXPORT_SYNC_FILE) return drm_syncobj_export_sync_file(file_private, args->handle,
args->point, &args->fd);
Hmm, maybe I should add DRM_SYNCOBJ_HANDLE_TO_FD_FLAGS_TIMELINE so that userspace gets a clean error on older kernels, rather than having the point param be silently ignored..
BR, -R
if (args->point)return -EINVAL;return drm_syncobj_handle_to_fd(file_private, args->handle, &args->fd);} diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h index 7fba37b94401..c71a8f4439f2 100644 --- a/include/uapi/drm/drm.h +++ b/include/uapi/drm/drm.h @@ -912,6 +912,8 @@ struct drm_syncobj_handle {
__s32 fd; __u32 pad;
__u64 point;};
struct drm_syncobj_transfer {