linux-kernel - [PATCH v6 10/14] videobuf2: add begin/end cpu

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: <20200514160153.3646-11-sergey.senozhatsky@gmail.com>
Date:   Fri, 15 May 2020 01:01:49 +0900
From:   Sergey Senozhatsky <sergey.senozhatsky@...il.com>
To:     Hans Verkuil <hans.verkuil@...co.com>
Cc:     Mauro Carvalho Chehab <mchehab@...nel.org>,
        Tomasz Figa <tfiga@...omium.org>, linux-media@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        Sergey Senozhatsky <sergey.senozhatsky@...il.com>,
        Sergey Senozhatsky <senozhatsky@...omium.org>
Subject: [PATCH v6 10/14] videobuf2: add begin/end cpu_access callbacks to dma-contig

From: Sergey Senozhatsky <senozhatsky@...omium.org>

Provide begin_cpu_access() and end_cpu_access() callbacks for
cache synchronisation on exported buffers.

The patch also adds a new helper function - vb2_dc_buffer_consistent(),
which returns true is if the buffer is consistent (DMA_ATTR_NON_CONSISTENT
bit cleared), so then we don't need to sync anything.

Signed-off-by: Sergey Senozhatsky <senozhatsky@...omium.org>
---
 .../common/videobuf2/videobuf2-dma-contig.c   | 35 +++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/drivers/media/common/videobuf2/videobuf2-dma-contig.c b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
index d3a3ee5b597b..6787e2cb905e 100644
--- a/drivers/media/common/videobuf2/videobuf2-dma-contig.c
+++ b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
@@ -42,6 +42,11 @@ struct vb2_dc_buf {
 	struct dma_buf_attachment	*db_attach;
 };
 
+static inline bool vb2_dc_buffer_consistent(unsigned long attr)
+{
+	return !(attr & DMA_ATTR_NON_CONSISTENT);
+}
+
 /*********************************************/
 /*        scatterlist table functions        */
 /*********************************************/
@@ -335,6 +340,34 @@ static void vb2_dc_dmabuf_ops_release(struct dma_buf *dbuf)
 	vb2_dc_put(dbuf->priv);
 }
 
+static int
+vb2_dc_dmabuf_ops_begin_cpu_access(struct dma_buf *dbuf,
+				   enum dma_data_direction direction)
+{
+	struct vb2_dc_buf *buf = dbuf->priv;
+	struct sg_table *sgt = buf->dma_sgt;
+
+	if (vb2_dc_buffer_consistent(buf->attrs))
+		return 0;
+
+	dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
+	return 0;
+}
+
+static int
+vb2_dc_dmabuf_ops_end_cpu_access(struct dma_buf *dbuf,
+				 enum dma_data_direction direction)
+{
+	struct vb2_dc_buf *buf = dbuf->priv;
+	struct sg_table *sgt = buf->dma_sgt;
+
+	if (vb2_dc_buffer_consistent(buf->attrs))
+		return 0;
+
+	dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
+	return 0;
+}
+
 static void *vb2_dc_dmabuf_ops_vmap(struct dma_buf *dbuf)
 {
 	struct vb2_dc_buf *buf = dbuf->priv;
@@ -353,6 +386,8 @@ static const struct dma_buf_ops vb2_dc_dmabuf_ops = {
 	.detach = vb2_dc_dmabuf_ops_detach,
 	.map_dma_buf = vb2_dc_dmabuf_ops_map,
 	.unmap_dma_buf = vb2_dc_dmabuf_ops_unmap,
+	.begin_cpu_access = vb2_dc_dmabuf_ops_begin_cpu_access,
+	.end_cpu_access = vb2_dc_dmabuf_ops_end_cpu_access,
 	.vmap = vb2_dc_dmabuf_ops_vmap,
 	.mmap = vb2_dc_dmabuf_ops_mmap,
 	.release = vb2_dc_dmabuf_ops_release,
-- 
2.26.2