linux-kernel - [RFC][PATCHv2 09/12] videobuf2: let user-space know if driver supports cache hints

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20200204025641.218376-10-senozhatsky@chromium.org>
Date:   Tue,  4 Feb 2020 11:56:38 +0900
From:   Sergey Senozhatsky <senozhatsky@...omium.org>
To:     Hans Verkuil <hans.verkuil@...co.com>,
        Tomasz Figa <tfiga@...omium.org>,
        Mauro Carvalho Chehab <mchehab@...nel.org>,
        Kyungmin Park <kyungmin.park@...sung.com>,
        Marek Szyprowski <m.szyprowski@...sung.com>
Cc:     Sakari Ailus <sakari.ailus@....fi>,
        Laurent Pinchart <laurent.pinchart@...asonboard.com>,
        Pawel Osciak <posciak@...omium.org>,
        linux-media@...r.kernel.org, linux-kernel@...r.kernel.org,
        Sergey Senozhatsky <senozhatsky@...omium.org>
Subject: [RFC][PATCHv2 09/12] videobuf2: let user-space know if driver supports cache hints

Add V4L2_BUF_CAP_SUPPORTS_CACHE_HINTS to fill_buf_caps(), which
is set when queue supports user-space cache management hints.

Change-Id: Ieac93f3726c61fd3b88e02c36980c1f3c7a82ecc
Signed-off-by: Sergey Senozhatsky <senozhatsky@...omium.org>
---
 Documentation/media/uapi/v4l/vidioc-reqbufs.rst | 7 +++++++
 drivers/media/common/videobuf2/videobuf2-v4l2.c | 2 ++
 include/uapi/linux/videodev2.h                  | 1 +
 3 files changed, 10 insertions(+)

diff --git a/Documentation/media/uapi/v4l/vidioc-reqbufs.rst b/Documentation/media/uapi/v4l/vidioc-reqbufs.rst
index 9741dac0d5b3..80603f57eb8a 100644
--- a/Documentation/media/uapi/v4l/vidioc-reqbufs.rst
+++ b/Documentation/media/uapi/v4l/vidioc-reqbufs.rst
@@ -165,6 +165,13 @@ aborting or finishing any DMA in progress, an implicit
       - Only valid for stateless decoders. If set, then userspace can set the
         ``V4L2_BUF_FLAG_M2M_HOLD_CAPTURE_BUF`` flag to hold off on returning the
 	capture buffer until the OUTPUT timestamp changes.
+    * - ``V4L2_BUF_CAP_SUPPORTS_CACHE_HINTS``
+      - 0x00000040
+      - Set when the queue/buffer support memory consistency and cache
+        management hints. See :ref:`V4L2_FLAG_MEMORY_NON_CONSISTENT`,
+        :ref:`V4L2_BUF_FLAG_NO_CACHE_INVALIDATE` and
+        :ref:`V4L2_BUF_FLAG_NO_CACHE_CLEAN`.
+
 
 Return Value
 ============
diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
index eb5d1306cb03..22ae0ff64684 100644
--- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
+++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
@@ -698,6 +698,8 @@ static void fill_buf_caps(struct vb2_queue *q, u32 *caps)
 		*caps |= V4L2_BUF_CAP_SUPPORTS_DMABUF;
 	if (q->subsystem_flags & VB2_V4L2_FL_SUPPORTS_M2M_HOLD_CAPTURE_BUF)
 		*caps |= V4L2_BUF_CAP_SUPPORTS_M2M_HOLD_CAPTURE_BUF;
+	if (q->allow_cache_hints)
+		*caps |= V4L2_BUF_CAP_SUPPORTS_CACHE_HINTS;
 #ifdef CONFIG_MEDIA_CONTROLLER_REQUEST_API
 	if (q->supports_requests)
 		*caps |= V4L2_BUF_CAP_SUPPORTS_REQUESTS;
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index 169a8cf345ed..12b1bd220347 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -951,6 +951,7 @@ struct v4l2_requestbuffers {
 #define V4L2_BUF_CAP_SUPPORTS_REQUESTS			(1 << 3)
 #define V4L2_BUF_CAP_SUPPORTS_ORPHANED_BUFS		(1 << 4)
 #define V4L2_BUF_CAP_SUPPORTS_M2M_HOLD_CAPTURE_BUF	(1 << 5)
+#define V4L2_BUF_CAP_SUPPORTS_CACHE_HINTS		(1 << 6)
 
 /**
  * struct v4l2_plane - plane info for multi-planar buffers
-- 
2.25.0.341.g760bfbb309-goog