This IOCTL provides a mechanism for userspace to trigger a sync object directly. There are other ways that userspace can trigger a syncobj such as submitting a dummy batch somewhere or hanging on to a triggered sync_file and doing an import. This just provides an easy way to manually trigger the sync object without weird hacks.
The motivation for this IOCTL is Vulkan fences. Vulkan lets you create a fence already in the signaled state so that you can wait on it immediatly without stalling. We could also handle this with a new create flag to ask the driver to create a syncobj that is already signaled but the IOCTL seemed a bit cleaner and more generic.
v2: - Take an array of sync objects (Dave Airlie)
Signed-off-by: Jason Ekstrand jason@jlekstrand.net --- drivers/gpu/drm/drm_internal.h | 2 ++ drivers/gpu/drm/drm_ioctl.c | 2 ++ drivers/gpu/drm/drm_syncobj.c | 33 +++++++++++++++++++++++++++++++++ include/uapi/drm/drm.h | 1 + 4 files changed, 38 insertions(+)
diff --git a/drivers/gpu/drm/drm_internal.h b/drivers/gpu/drm/drm_internal.h index 83f1615..fbc3f30 100644 --- a/drivers/gpu/drm/drm_internal.h +++ b/drivers/gpu/drm/drm_internal.h @@ -171,3 +171,5 @@ int drm_syncobj_wait_ioctl(struct drm_device *dev, void *data, struct drm_file *file_private); int drm_syncobj_reset_ioctl(struct drm_device *dev, void *data, struct drm_file *file_private); +int drm_syncobj_signal_ioctl(struct drm_device *dev, void *data, + struct drm_file *file_private); diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c index 16c5d51..a9ae6dd 100644 --- a/drivers/gpu/drm/drm_ioctl.c +++ b/drivers/gpu/drm/drm_ioctl.c @@ -661,6 +661,8 @@ static const struct drm_ioctl_desc drm_ioctls[] = { DRM_UNLOCKED|DRM_RENDER_ALLOW), DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_RESET, drm_syncobj_reset_ioctl, DRM_UNLOCKED|DRM_RENDER_ALLOW), + DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_SIGNAL, drm_syncobj_signal_ioctl, + DRM_UNLOCKED|DRM_RENDER_ALLOW), };
#define DRM_CORE_IOCTL_COUNT ARRAY_SIZE( drm_ioctls ) diff --git a/drivers/gpu/drm/drm_syncobj.c b/drivers/gpu/drm/drm_syncobj.c index 57f8b6c..040ac97 100644 --- a/drivers/gpu/drm/drm_syncobj.c +++ b/drivers/gpu/drm/drm_syncobj.c @@ -915,3 +915,36 @@ drm_syncobj_reset_ioctl(struct drm_device *dev, void *data,
return 0; } + +int +drm_syncobj_signal_ioctl(struct drm_device *dev, void *data, + struct drm_file *file_private) +{ + struct drm_syncobj_array *args = data; + struct drm_syncobj **syncobjs; + uint32_t i; + int ret; + + if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ)) + return -ENODEV; + + if (args->count_handles == 0) + return -EINVAL; + + ret = drm_syncobj_array_find(file_private, + u64_to_user_ptr(args->handles), + args->count_handles, + &syncobjs); + if (ret < 0) + return ret; + + for (i = 0; i < args->count_handles; i++) { + ret = drm_syncobj_assign_null_handle(syncobjs[i]); + if (ret < 0) + break; + } + + drm_syncobj_array_free(syncobjs, args->count_handles); + + return ret; +} diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h index b037fdf..97677cd 100644 --- a/include/uapi/drm/drm.h +++ b/include/uapi/drm/drm.h @@ -861,6 +861,7 @@ extern "C" { #define DRM_IOCTL_SYNCOBJ_FD_TO_HANDLE DRM_IOWR(0xC2, struct drm_syncobj_handle) #define DRM_IOCTL_SYNCOBJ_WAIT DRM_IOWR(0xC3, struct drm_syncobj_wait) #define DRM_IOCTL_SYNCOBJ_RESET DRM_IOWR(0xC4, struct drm_syncobj_array) +#define DRM_IOCTL_SYNCOBJ_SIGNAL DRM_IOWR(0xC5, struct drm_syncobj_array)
/** * Device specific ioctls should only be in their respective headers