On Mon, Feb 20, 2023 at 12:27 AM Christian König <christian.koenig@xxxxxxx> wrote: > > Am 18.02.23 um 22:15 schrieb Rob Clark: > > From: Rob Clark <robdclark@xxxxxxxxxxxx> > > > > The initial purpose is for igt tests, but this would also be useful for > > compositors that wait until close to vblank deadline to make decisions > > about which frame to show. > > > > The igt tests can be found at: > > > > https://gitlab.freedesktop.org/robclark/igt-gpu-tools/-/commits/fence-deadline > > > > v2: Clarify the timebase, add link to igt tests > > > > Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx> > > --- > > drivers/dma-buf/sync_file.c | 19 +++++++++++++++++++ > > include/uapi/linux/sync_file.h | 22 ++++++++++++++++++++++ > > 2 files changed, 41 insertions(+) > > > > diff --git a/drivers/dma-buf/sync_file.c b/drivers/dma-buf/sync_file.c > > index af57799c86ce..fb6ca1032885 100644 > > --- a/drivers/dma-buf/sync_file.c > > +++ b/drivers/dma-buf/sync_file.c > > @@ -350,6 +350,22 @@ static long sync_file_ioctl_fence_info(struct sync_file *sync_file, > > return ret; > > } > > > > +static int sync_file_ioctl_set_deadline(struct sync_file *sync_file, > > + unsigned long arg) > > +{ > > + struct sync_set_deadline ts; > > + > > + if (copy_from_user(&ts, (void __user *)arg, sizeof(ts))) > > + return -EFAULT; > > + > > + if (ts.pad) > > + return -EINVAL; > > + > > + dma_fence_set_deadline(sync_file->fence, ktime_set(ts.tv_sec, ts.tv_nsec)); > > + > > + return 0; > > +} > > + > > static long sync_file_ioctl(struct file *file, unsigned int cmd, > > unsigned long arg) > > { > > @@ -362,6 +378,9 @@ static long sync_file_ioctl(struct file *file, unsigned int cmd, > > case SYNC_IOC_FILE_INFO: > > return sync_file_ioctl_fence_info(sync_file, arg); > > > > + case SYNC_IOC_SET_DEADLINE: > > + return sync_file_ioctl_set_deadline(sync_file, arg); > > + > > default: > > return -ENOTTY; > > } > > diff --git a/include/uapi/linux/sync_file.h b/include/uapi/linux/sync_file.h > > index ee2dcfb3d660..c8666580816f 100644 > > --- a/include/uapi/linux/sync_file.h > > +++ b/include/uapi/linux/sync_file.h > > @@ -67,6 +67,20 @@ struct sync_file_info { > > __u64 sync_fence_info; > > }; > > > > +/** > > + * struct sync_set_deadline - set a deadline on a fence > > + * @tv_sec: seconds elapsed since epoch > > + * @tv_nsec: nanoseconds elapsed since the time given by the tv_sec > > + * @pad: must be zero > > + * > > + * The timebase for the deadline is CLOCK_MONOTONIC (same as vblank) > > + */ > > +struct sync_set_deadline { > > + __s64 tv_sec; > > + __s32 tv_nsec; > > + __u32 pad; > > IIRC struct timespec defined this as time_t/long (which is horrible for > an UAPI because of the sizeof(long) dependency), one possible > alternative is to use 64bit nanoseconds from CLOCK_MONOTONIC (which is > essentially ktime). > > Not 100% sure if there is any preferences documented, but I think the > later might be better. The original thought is that this maps directly to clock_gettime() without extra conversion needed, and is similar to other pre-ktime_t UAPI. But OTOH if userspace wants to add an offset, it is maybe better to convert completely to ns in userspace and use a u64 (as that is what ns_to_ktime() uses).. (and OFC whatever decision here also applies to the syncobj wait ioctls) I'm leaning towards u64 CLOCK_MONOTONIC ns if no one has a good argument against that. BR, -R > Either way the patch is Acked-by: Christian König > <christian.koenig@xxxxxxx> for this patch. > > Regards, > Christian. > > > +}; > > + > > #define SYNC_IOC_MAGIC '>' > > > > /** > > @@ -95,4 +109,12 @@ struct sync_file_info { > > */ > > #define SYNC_IOC_FILE_INFO _IOWR(SYNC_IOC_MAGIC, 4, struct sync_file_info) > > > > + > > +/** > > + * DOC: SYNC_IOC_SET_DEADLINE - set a deadline on a fence > > + * > > + * Allows userspace to set a deadline on a fence, see dma_fence_set_deadline() > > + */ > > +#define SYNC_IOC_SET_DEADLINE _IOW(SYNC_IOC_MAGIC, 5, struct sync_set_deadline) > > + > > #endif /* _UAPI_LINUX_SYNC_H */ >
