diff options
| author | Simon Ser <contact@emersion.fr> | 2023-07-14 11:13:03 +0000 |
|---|---|---|
| committer | Simon Ser <contact@emersion.fr> | 2023-07-20 12:01:03 +0200 |
| commit | c7a472297169156252a50d76965eb36b081186e2 (patch) | |
| tree | 64c78cdf142d8061fa834af9c07e28e5f8b7706b /include/uapi/drm/drm.h | |
| parent | 4f66feeab173bd73e71028b8c2e1dcea07e32dd5 (diff) | |
drm/syncobj: add IOCTL to register an eventfd
Introduce a new DRM_IOCTL_SYNCOBJ_EVENTFD IOCTL which signals an
eventfd from a syncobj.
This is useful for Wayland compositors to handle wait-before-submit.
Wayland clients can send a timeline point to the compositor
before the point has materialized yet, then compositors can wait
for the point to materialize via this new IOCTL.
The existing DRM_IOCTL_SYNCOBJ_TIMELINE_WAIT IOCTL is not suitable
because it blocks. Compositors want to integrate the wait with
their poll(2)-based event loop.
Requirements for new uAPI:
- User-space patch: https://gitlab.freedesktop.org/wlroots/wlroots/-/merge_requests/4262
- IGT: https://lists.freedesktop.org/archives/igt-dev/2023-July/057893.html
v2:
- Wait for fence when flags is zero
- Improve documentation (Pekka)
- Rename IOCTL (Christian)
- Fix typo in drm_syncobj_add_eventfd() (Christian)
v3:
- Link user-space + IGT patches
- Add reference from overview docs
v4: fix IOCTL number conflict with GETFB2 (Nicholas Choi, Vitaly Prosyak)
Signed-off-by: Simon Ser <contact@emersion.fr>
Reviewed-by: Christian König <christian.koenig@amd.com>
Acked-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Cc: Jason Ekstrand <jason@jlekstrand.net>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Cc: Daniel Stone <daniel@fooishbar.org>
Cc: James Jones <jajones@nvidia.com>
Cc: Austin Shafer <ashafer@nvidia.com>
Cc: Vitaly Prosyak <vprosyak@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230714111257.11940-1-contact@emersion.fr
Diffstat (limited to 'include/uapi/drm/drm.h')
| -rw-r--r-- | include/uapi/drm/drm.h | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h index a87bbbbca2d4..863e47200911 100644 --- a/include/uapi/drm/drm.h +++ b/include/uapi/drm/drm.h @@ -909,6 +909,27 @@ struct drm_syncobj_timeline_wait { __u32 pad; }; +/** + * struct drm_syncobj_eventfd + * @handle: syncobj handle. + * @flags: Zero to wait for the point to be signalled, or + * &DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE to wait for a fence to be + * available for the point. + * @point: syncobj timeline point (set to zero for binary syncobjs). + * @fd: Existing eventfd to sent events to. + * @pad: Must be zero. + * + * Register an eventfd to be signalled by a syncobj. The eventfd counter will + * be incremented by one. + */ +struct drm_syncobj_eventfd { + __u32 handle; + __u32 flags; + __u64 point; + __s32 fd; + __u32 pad; +}; + struct drm_syncobj_array { __u64 handles; @@ -1169,6 +1190,8 @@ extern "C" { */ #define DRM_IOCTL_MODE_GETFB2 DRM_IOWR(0xCE, struct drm_mode_fb_cmd2) +#define DRM_IOCTL_SYNCOBJ_EVENTFD DRM_IOWR(0xCF, struct drm_syncobj_eventfd) + /* * Device specific ioctls should only be in their respective headers * The device specific ioctl range is from 0x40 to 0x9f. |