Date:   Mon, 20 Feb 2023 10:48:08 +0200
From:   Pekka Paalanen <ppaalanen@gmail.com>
To:     Rob Clark <robdclark@gmail.com>
Cc:     dri-devel@lists.freedesktop.org, freedreno@lists.freedesktop.org,
        Daniel Vetter <daniel@ffwll.ch>,
        Christian =?UTF-8?B?S8O2bmln?= <ckoenig.leichtzumerken@gmail.com>,
        Michel =?UTF-8?B?RMOkbnplcg==?= <michel@daenzer.net>,
        Tvrtko Ursulin <tvrtko.ursulin@intel.com>,
        Rodrigo Vivi <rodrigo.vivi@intel.com>,
        Alex Deucher <alexander.deucher@amd.com>,
        Simon Ser <contact@emersion.fr>,
        Rob Clark <robdclark@chromium.org>,
        Sumit Semwal <sumit.semwal@linaro.org>,
        Gustavo Padovan <gustavo@padovan.org>,
        Christian =?UTF-8?B?S8O2bmln?= <christian.koenig@amd.com>,
        linux-media@vger.kernel.org (open list:SYNC FILE FRAMEWORK),
        linaro-mm-sig@lists.linaro.org (moderated list:DMA BUFFER SHARING
        FRAMEWORK), linux-kernel@vger.kernel.org (open list)
Subject: Re: [PATCH v4 05/14] dma-buf/sync_file: Add SET_DEADLINE ioctl
Message-ID: <20230220104808.261acfab@eldfell>
In-Reply-To: <20230218211608.1630586-6-robdclark@gmail.com>
References: <20230218211608.1630586-1-robdclark@gmail.com>
        <20230218211608.1630586-6-robdclark@gmail.com>
MIME-Version: 1.0
Content-Type: multipart/signed; boundary="Sig_/Zs=8tBQ+ROU3tBZ1hRIUE2K";
 protocol="application/pgp-signature"; micalg=pgp-sha256
Precedence: bulk

--Sig_/Zs=8tBQ+ROU3tBZ1hRIUE2K
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: quoted-printable

On Sat, 18 Feb 2023 13:15:48 -0800
Rob Clark <robdclark@gmail.com> wrote:

> From: Rob Clark <robdclark@chromium.org>
>=20
> 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.
>=20
> The igt tests can be found at:
>=20
> https://gitlab.freedesktop.org/robclark/igt-gpu-tools/-/commits/fence-dea=
dline
>=20
> v2: Clarify the timebase, add link to igt tests
>=20
> Signed-off-by: Rob Clark <robdclark@chromium.org>
> ---
>  drivers/dma-buf/sync_file.c    | 19 +++++++++++++++++++
>  include/uapi/linux/sync_file.h | 22 ++++++++++++++++++++++
>  2 files changed, 41 insertions(+)
>=20
> 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_f=
ile *sync_file,
>  	return ret;
>  }
> =20
> +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_nse=
c));
> +
> +	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, unsign=
ed int cmd,
>  	case SYNC_IOC_FILE_INFO:
>  		return sync_file_ioctl_fence_info(sync_file, arg);
> =20
> +	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_fil=
e.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;
>  };
> =20
> +/**
> + * 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

Hi,

should tv_sec,tv_nsec be validated like clock_settime() does?

It requires:
- tv_sec >=3D 0
- tv_nsec >=3D 0
- tv_nsec < 1e9


Thanks,
pq


> + * @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;
> +};
> +
>  #define SYNC_IOC_MAGIC		'>'
> =20
>  /**
> @@ -95,4 +109,12 @@ struct sync_file_info {
>   */
>  #define SYNC_IOC_FILE_INFO	_IOWR(SYNC_IOC_MAGIC, 4, struct sync_file_inf=
o)
> =20
> +
> +/**
> + * DOC: SYNC_IOC_SET_DEADLINE - set a deadline on a fence
> + *
> + * Allows userspace to set a deadline on a fence, see dma_fence_set_dead=
line()
> + */
> +#define SYNC_IOC_SET_DEADLINE	_IOW(SYNC_IOC_MAGIC, 5, struct sync_set_de=
adline)
> +
>  #endif /* _UAPI_LINUX_SYNC_H */


--Sig_/Zs=8tBQ+ROU3tBZ1hRIUE2K
Content-Type: application/pgp-signature
Content-Description: OpenPGP digital signature

-----BEGIN PGP SIGNATURE-----
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=oowF
-----END PGP SIGNATURE-----

--Sig_/Zs=8tBQ+ROU3tBZ1hRIUE2K--