From: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
To: Hans Verkuil <hans.verkuil@cisco.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>,
Tomasz Figa <tfiga@chromium.org>,
linux-media@vger.kernel.org, linux-kernel@vger.kernel.org,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
Sergey Senozhatsky <senozhatsky@chromium.org>
Subject: [PATCHv5 02/13] videobuf2: add cache management members
Date: Fri, 24 Apr 2020 18:29:09 +0900 [thread overview]
Message-ID: <20200424092920.4801-3-sergey.senozhatsky@gmail.com> (raw)
In-Reply-To: <20200424092920.4801-1-sergey.senozhatsky@gmail.com>
From: Sergey Senozhatsky <senozhatsky@chromium.org>
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 members ->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.
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 9e522bd2acc7..7f39d9fffc8c 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: when set buffer's ->prepare() function
+ * performs cache sync/invalidation.
+ * need_cache_sync_on_finish: when set buffer's ->finish() function
+ * performs cache sync/invalidation.
* 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
@@ -567,6 +576,7 @@ struct vb2_queue {
unsigned int requires_requests:1;
unsigned int uses_qbuf:1;
unsigned int uses_requests:1;
+ unsigned int allow_cache_hints:1;
struct mutex *lock;
void *owner;
--
2.26.2
next prev parent reply other threads:[~2020-04-24 9:30 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-24 9:29 [PATCHv5 00/13] Implement V4L2_BUF_FLAG_NO_CACHE_* flags Sergey Senozhatsky
2020-04-24 9:29 ` [PATCHv5 01/13] videobuf2: use explicit unsigned int in vb2_queue Sergey Senozhatsky
2020-04-24 9:29 ` Sergey Senozhatsky [this message]
2020-04-24 9:29 ` [PATCHv5 03/13] videobuf2: handle V4L2 buffer cache flags Sergey Senozhatsky
2020-04-24 9:29 ` [PATCHv5 04/13] videobuf2: add V4L2_FLAG_MEMORY_NON_CONSISTENT flag Sergey Senozhatsky
2020-04-24 9:29 ` [PATCHv5 05/13] videobuf2: add queue memory consistency parameter Sergey Senozhatsky
2020-04-24 9:29 ` [PATCHv5 06/13] videobuf2: handle V4L2_FLAG_MEMORY_NON_CONSISTENT flag Sergey Senozhatsky
2020-04-24 9:29 ` [PATCHv5 07/13] videobuf2: factor out planes prepare/finish functions Sergey Senozhatsky
2020-04-24 9:29 ` [PATCHv5 08/13] videobuf2: do not sync caches when we are allowed not to Sergey Senozhatsky
2020-04-24 9:29 ` [PATCHv5 09/13] videobuf2: check ->synced flag in prepare() and finish() Sergey Senozhatsky
2020-04-24 9:29 ` [PATCHv5 10/13] videobuf2: add begin/end cpu_access callbacks to dma-contig Sergey Senozhatsky
2020-04-24 9:29 ` [PATCHv5 11/13] videobuf2: add begin/end cpu_access callbacks to dma-sg Sergey Senozhatsky
2020-04-24 9:29 ` [PATCHv5 12/13] videobuf2: don't test db_attach in dma-contig prepare and finish Sergey Senozhatsky
2020-04-24 9:29 ` [PATCHv5 13/13] media: vivid: add cache_hints module param Sergey Senozhatsky
2020-04-28 14:47 ` [PATCHv5 00/13] Implement V4L2_BUF_FLAG_NO_CACHE_* flags Hans Verkuil
2020-05-14 15:36 ` Sergey Senozhatsky
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