From: Hans Verkuil <hverkuil@xs4all.nl>
To: Sergey Senozhatsky <senozhatsky@chromium.org>,
Hans Verkuil <hans.verkuil@cisco.com>,
Tomasz Figa <tfiga@chromium.org>,
Mauro Carvalho Chehab <mchehab@kernel.org>,
Kyungmin Park <kyungmin.park@samsung.com>,
Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Sakari Ailus <sakari.ailus@iki.fi>,
Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
Pawel Osciak <posciak@chromium.org>,
linux-media@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [RFC][PATCHv2 01/12] videobuf2: add cache management members
Date: Wed, 19 Feb 2020 09:05:35 +0100 [thread overview]
Message-ID: <964aeb73-1474-032f-b2a6-b317cc15f7cb@xs4all.nl> (raw)
In-Reply-To: <20200204025641.218376-2-senozhatsky@chromium.org>
On 2/4/20 3:56 AM, Sergey Senozhatsky wrote:
> Extend vb2_buffer and vb2_queue structs with cache management
> members.
>
> V4L2 UAPI already contains two buffer flags which user-space,
> supposedly, can use to control buffer cache sync:
>
> - V4L2_BUF_FLAG_NO_CACHE_INVALIDATE
> - V4L2_BUF_FLAG_NO_CACHE_CLEAN
>
> None of these, however, do anything at the moment. This patch
> set is intended to change it.
>
> Since user-space cache management hints are supposed to be
> implemented on a per-buffer basis we need to extend vb2_buffer
> struct with two new memebers ->need_cache_sync_on_prepare and
> ->need_cache_sync_on_finish, which will store corresponding
> user-space hints.
>
> In order to preserve the existing behaviour, user-space cache
> managements flags will be handled only by those drivers that
> permit user-space cache hints. That's the purpose of vb2_queue
> ->allow_cache_hints member. Driver must set ->allow_cache_hints
> during queue initialisation to enable cache management hints
> mechanism.
>
> Only drivers that set ->allow_cache_hints during queue initialisation
> will handle user-space cache management hints. Otherwise hints
> will be ignored.
>
> Change-Id: I52beec2a0d021b7a3715b4f6ae4bfd9dc5e94f0d
> Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
> ---
> include/media/videobuf2-core.h | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
> index a2b2208b02da..026004180440 100644
> --- a/include/media/videobuf2-core.h
> +++ b/include/media/videobuf2-core.h
> @@ -263,6 +263,10 @@ struct vb2_buffer {
> * after the 'buf_finish' op is called.
> * copied_timestamp: the timestamp of this capture buffer was copied
> * from an output buffer.
> + * need_cache_sync_on_prepare: do not sync/invalidate cache from
> + * buffer's ->prepare() callback.
> + * need_cache_sync_on_finish: do not sync/invalidate cache from buffer's
> + * ->finish() callback.
Shouldn't 'do not' be deleted from the flag descriptions? If the flag is set,
then you need to sync/validate, right?
Regards,
Hans
> * queued_entry: entry on the queued buffers list, which holds
> * all buffers queued from userspace
> * done_entry: entry on the list that stores all buffers ready
> @@ -273,6 +277,8 @@ struct vb2_buffer {
> unsigned int synced:1;
> unsigned int prepared:1;
> unsigned int copied_timestamp:1;
> + unsigned int need_cache_sync_on_prepare:1;
> + unsigned int need_cache_sync_on_finish:1;
>
> struct vb2_plane planes[VB2_MAX_PLANES];
> struct list_head queued_entry;
> @@ -491,6 +497,9 @@ struct vb2_buf_ops {
> * @uses_requests: requests are used for this queue. Set to 1 the first time
> * a request is queued. Set to 0 when the queue is canceled.
> * If this is 1, then you cannot queue buffers directly.
> + * @allow_cache_hints: when set user-space can pass cache management hints in
> + * order to skip cache flush/invalidation on ->prepare() or/and
> + * ->finish().
> * @lock: pointer to a mutex that protects the &struct vb2_queue. The
> * driver can set this to a mutex to let the v4l2 core serialize
> * the queuing ioctls. If the driver wants to handle locking
> @@ -564,6 +573,7 @@ struct vb2_queue {
> unsigned requires_requests:1;
> unsigned uses_qbuf:1;
> unsigned uses_requests:1;
> + unsigned allow_cache_hints:1;
>
> struct mutex *lock;
> void *owner;
>
next prev parent reply other threads:[~2020-02-19 8:05 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-04 2:56 [RFC][PATCHv2 00/12] Implement V4L2_BUF_FLAG_NO_CACHE_* flags Sergey Senozhatsky
2020-02-04 2:56 ` [RFC][PATCHv2 01/12] videobuf2: add cache management members Sergey Senozhatsky
2020-02-19 8:05 ` Hans Verkuil [this message]
2020-02-19 8:16 ` Sergey Senozhatsky
2020-02-19 8:27 ` Hans Verkuil
2020-02-04 2:56 ` [RFC][PATCHv2 02/12] videobuf2: handle V4L2 buffer cache flags Sergey Senozhatsky
2020-02-05 8:13 ` Sergey Senozhatsky
2020-02-19 8:07 ` Hans Verkuil
2020-02-19 8:13 ` Sergey Senozhatsky
2020-02-19 8:25 ` Hans Verkuil
2020-02-19 8:46 ` Hans Verkuil
2020-02-04 2:56 ` [RFC][PATCHv2 03/12] videobuf2: add V4L2_FLAG_MEMORY_NON_CONSISTENT flag Sergey Senozhatsky
2020-02-13 7:08 ` Tomasz Figa
2020-02-19 8:19 ` Hans Verkuil
2020-02-19 8:56 ` Hans Verkuil
2020-02-25 7:45 ` Sergey Senozhatsky
2020-02-04 2:56 ` [RFC][PATCHv2 04/12] videobuf2: add queue memory consistency parameter Sergey Senozhatsky
2020-02-04 2:56 ` [RFC][PATCHv2 05/12] videobuf2: handle V4L2_FLAG_MEMORY_NON_CONSISTENT flag Sergey Senozhatsky
2020-02-19 8:25 ` Hans Verkuil
2020-02-19 8:59 ` Sergey Senozhatsky
2020-02-19 9:04 ` Hans Verkuil
2020-02-19 8:48 ` Hans Verkuil
2020-02-19 9:05 ` Sergey Senozhatsky
2020-02-19 9:11 ` Hans Verkuil
2020-02-04 2:56 ` [RFC][PATCHv2 06/12] videobuf2: factor out planes prepare/finish functions Sergey Senozhatsky
2020-02-04 2:56 ` [RFC][PATCHv2 07/12] videobuf2: do not sync caches when we are allowed not to Sergey Senozhatsky
2020-02-04 2:56 ` [RFC][PATCHv2 08/12] videobuf2: check ->synced flag in prepare() and finish() Sergey Senozhatsky
2020-02-04 2:56 ` [RFC][PATCHv2 09/12] videobuf2: let user-space know if driver supports cache hints Sergey Senozhatsky
2020-02-19 8:33 ` Hans Verkuil
2020-02-19 8:45 ` Sergey Senozhatsky
2020-02-19 8:56 ` Hans Verkuil
2020-02-04 2:56 ` [RFC][PATCHv2 10/12] videobuf2: add begin/end cpu_access callbacks to dma-contig Sergey Senozhatsky
2020-02-04 2:56 ` [RFC][PATCHv2 11/12] videobuf2: add begin/end cpu_access callbacks to dma-sg Sergey Senozhatsky
2020-02-19 8:35 ` Hans Verkuil
2020-02-19 8:42 ` Sergey Senozhatsky
2020-02-04 2:56 ` [RFC][PATCHv2 12/12] videobuf2: don't test db_attach in dma-contig prepare and finish Sergey Senozhatsky
2020-02-19 8:53 ` [RFC][PATCHv2 00/12] Implement V4L2_BUF_FLAG_NO_CACHE_* flags Hans Verkuil
2020-02-26 11:20 ` Sergey Senozhatsky
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