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From: Sergey Senozhatsky <senozhatsky@chromium.org>
To: Tomasz Figa <tfiga@chromium.org>,
	Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: Christoph Hellwig <hch@lst.de>,
	Mauro Carvalho Chehab <mchehab@kernel.org>,
	linux-media@vger.kernel.org, linux-kernel@vger.kernel.org,
	Sergey Senozhatsky <senozhatsky@chromium.org>
Subject: [PATCH 7/8] videobuf2: handle V4L2_FLAG_MEMORY_NON_COHERENT flag
Date: Tue,  2 Mar 2021 09:46:23 +0900	[thread overview]
Message-ID: <20210302004624.31294-8-senozhatsky@chromium.org> (raw)
In-Reply-To: <20210302004624.31294-1-senozhatsky@chromium.org>

This patch lets user-space to request a non-coherent memory
allocation during CREATE_BUFS and REQBUFS ioctl calls.

= CREATE_BUFS

  struct v4l2_create_buffers has seven 4-byte reserved areas,
  so reserved[0] is renamed to ->flags. The struct, thus, now
  has six reserved 4-byte regions.

= CREATE_BUFS32

  struct v4l2_create_buffers32 has seven 4-byte reserved areas,
  so reserved[0] is renamed to ->flags. The struct, thus, now
  has six reserved 4-byte regions.

= REQBUFS

 We use one bit of a ->reserved[1] member of struct v4l2_requestbuffers,
 which is now renamed to ->flags. Unlike v4l2_create_buffers, struct
 v4l2_requestbuffers does not have enough reserved room. Therefore for
 backward compatibility  ->reserved and ->flags were put into anonymous
 union.

Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
---
 .../media/v4l/vidioc-create-bufs.rst          |  7 ++++++-
 .../media/v4l/vidioc-reqbufs.rst              | 11 +++++++++--
 .../media/common/videobuf2/videobuf2-core.c   |  6 ++++++
 .../media/common/videobuf2/videobuf2-v4l2.c   | 19 ++++++++++++++++---
 drivers/media/v4l2-core/v4l2-compat-ioctl32.c |  9 ++++++++-
 drivers/media/v4l2-core/v4l2-ioctl.c          |  5 +----
 include/uapi/linux/videodev2.h                | 11 +++++++++--
 7 files changed, 55 insertions(+), 13 deletions(-)

diff --git a/Documentation/userspace-api/media/v4l/vidioc-create-bufs.rst b/Documentation/userspace-api/media/v4l/vidioc-create-bufs.rst
index b06e5b528e11..132c8b612a94 100644
--- a/Documentation/userspace-api/media/v4l/vidioc-create-bufs.rst
+++ b/Documentation/userspace-api/media/v4l/vidioc-create-bufs.rst
@@ -113,7 +113,12 @@ than the number requested.
 	``V4L2_MEMORY_MMAP`` and ``format.type`` to the buffer type.
 
     * - __u32
-      - ``reserved``\ [7]
+      - ``flags``
+      - Specifies additional buffer management attributes.
+	See :ref:`memory-flags`.
+
+    * - __u32
+      - ``reserved``\ [6]
       - A place holder for future extensions. Drivers and applications
 	must set the array to zero.
 
diff --git a/Documentation/userspace-api/media/v4l/vidioc-reqbufs.rst b/Documentation/userspace-api/media/v4l/vidioc-reqbufs.rst
index 950e7ec1aac5..80ea48acea84 100644
--- a/Documentation/userspace-api/media/v4l/vidioc-reqbufs.rst
+++ b/Documentation/userspace-api/media/v4l/vidioc-reqbufs.rst
@@ -104,10 +104,17 @@ aborting or finishing any DMA in progress, an implicit
 	``V4L2_MEMORY_MMAP`` and ``type`` set to the buffer type. This will
 	free any previously allocated buffers, so this is typically something
 	that will be done at the start of the application.
+    * - union {
+      - (anonymous)
+    * - __u32
+      - ``flags``
+      - Specifies additional buffer management attributes.
+	See :ref:`memory-flags`.
     * - __u32
       - ``reserved``\ [1]
-      - A place holder for future extensions. Drivers and applications
-	must set the array to zero.
+      - Kept for backwards compatibility. Use ``flags`` instead.
+    * - }
+      -
 
 .. tabularcolumns:: |p{6.1cm}|p{2.2cm}|p{8.7cm}|
 
diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
index 7040b7f47133..5906a48e7757 100644
--- a/drivers/media/common/videobuf2/videobuf2-core.c
+++ b/drivers/media/common/videobuf2/videobuf2-core.c
@@ -768,6 +768,9 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
 	unsigned int i;
 	int ret;
 
+	if (flags & V4L2_FLAG_MEMORY_NON_COHERENT)
+		coherent_mem = false;
+
 	if (q->streaming) {
 		dprintk(q, 1, "streaming active\n");
 		return -EBUSY;
@@ -911,6 +914,9 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
 	bool coherent_mem = true;
 	int ret;
 
+	if (flags & V4L2_FLAG_MEMORY_NON_COHERENT)
+		coherent_mem = false;
+
 	if (q->num_buffers == VB2_MAX_FRAME) {
 		dprintk(q, 1, "maximum number of buffers already allocated\n");
 		return -ENOBUFS;
diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
index 1166d5a9291a..f6a8dcc1b5c6 100644
--- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
+++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
@@ -692,12 +692,22 @@ static void fill_buf_caps(struct vb2_queue *q, u32 *caps)
 #endif
 }
 
+static void validate_coherency_flags(struct vb2_queue *q,
+				     int memory,
+				     unsigned int *flags)
+{
+	if (!q->allow_cache_hints || memory != V4L2_MEMORY_MMAP)
+		*flags &= ~V4L2_FLAG_MEMORY_NON_COHERENT;
+}
+
 int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
 {
 	int ret = vb2_verify_memory_type(q, req->memory, req->type);
 
 	fill_buf_caps(q, &req->capabilities);
-	return ret ? ret : vb2_core_reqbufs(q, req->memory, 0, &req->count);
+	validate_coherency_flags(q, req->memory, &req->flags);
+	return ret ? ret : vb2_core_reqbufs(q, req->memory,
+					    req->flags, &req->count);
 }
 EXPORT_SYMBOL_GPL(vb2_reqbufs);
 
@@ -729,6 +739,7 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
 	unsigned i;
 
 	fill_buf_caps(q, &create->capabilities);
+	validate_coherency_flags(q, create->memory, &create->flags);
 	create->index = q->num_buffers;
 	if (create->count == 0)
 		return ret != -EBUSY ? ret : 0;
@@ -772,7 +783,7 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
 		if (requested_sizes[i] == 0)
 			return -EINVAL;
 	return ret ? ret : vb2_core_create_bufs(q, create->memory,
-						0,
+						create->flags,
 						&create->count,
 						requested_planes,
 						requested_sizes);
@@ -957,11 +968,12 @@ int vb2_ioctl_reqbufs(struct file *file, void *priv,
 	int res = vb2_verify_memory_type(vdev->queue, p->memory, p->type);
 
 	fill_buf_caps(vdev->queue, &p->capabilities);
+	validate_coherency_flags(vdev->queue, p->memory, &p->flags);
 	if (res)
 		return res;
 	if (vb2_queue_is_busy(vdev, file))
 		return -EBUSY;
-	res = vb2_core_reqbufs(vdev->queue, p->memory, 0, &p->count);
+	res = vb2_core_reqbufs(vdev->queue, p->memory, p->flags, &p->count);
 	/* If count == 0, then the owner has released all buffers and he
 	   is no longer owner of the queue. Otherwise we have a new owner. */
 	if (res == 0)
@@ -979,6 +991,7 @@ int vb2_ioctl_create_bufs(struct file *file, void *priv,
 
 	p->index = vdev->queue->num_buffers;
 	fill_buf_caps(vdev->queue, &p->capabilities);
+	validate_coherency_flags(vdev->queue, p->memory, &p->flags);
 	/*
 	 * If count == 0, then just check if memory and type are valid.
 	 * Any -EBUSY result from vb2_verify_memory_type can be mapped to 0.
diff --git a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
index 0ca75f6784c5..1aa9ca3b6ca4 100644
--- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
+++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
@@ -126,6 +126,9 @@ struct v4l2_format32 {
  * @memory:	buffer memory type
  * @format:	frame format, for which buffers are requested
  * @capabilities: capabilities of this buffer type.
+ * @flags:	additional buffer management attributes (ignored unless the
+ *		queue has V4L2_BUF_CAP_SUPPORTS_MMAP_CACHE_HINTS capability and
+ *		configured for MMAP streaming I/O).
  * @reserved:	future extensions
  */
 struct v4l2_create_buffers32 {
@@ -134,7 +137,8 @@ struct v4l2_create_buffers32 {
 	__u32			memory;	/* enum v4l2_memory */
 	struct v4l2_format32	format;
 	__u32			capabilities;
-	__u32			reserved[7];
+	__u32			flags;
+	__u32			reserved[6];
 };
 
 static int get_v4l2_format32(struct v4l2_format *p64,
@@ -182,6 +186,8 @@ static int get_v4l2_create32(struct v4l2_create_buffers *p64,
 	if (copy_from_user(p64, p32,
 			   offsetof(struct v4l2_create_buffers32, format)))
 		return -EFAULT;
+	if (copy_from_user(&p64->flags, &p32->flags, sizeof(p32->flags)))
+		return -EFAULT;
 	return get_v4l2_format32(&p64->format, &p32->format);
 }
 
@@ -227,6 +233,7 @@ static int put_v4l2_create32(struct v4l2_create_buffers *p64,
 	if (copy_to_user(p32, p64,
 			 offsetof(struct v4l2_create_buffers32, format)) ||
 	    put_user(p64->capabilities, &p32->capabilities) ||
+	    put_user(p64->flags, &p32->flags) ||
 	    copy_to_user(p32->reserved, p64->reserved, sizeof(p64->reserved)))
 		return -EFAULT;
 	return put_v4l2_format32(&p64->format, &p32->format);
diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
index 31d1342e61e8..f8d38a3cd1e0 100644
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -2045,9 +2045,6 @@ static int v4l_reqbufs(const struct v4l2_ioctl_ops *ops,
 
 	if (ret)
 		return ret;
-
-	CLEAR_AFTER_FIELD(p, capabilities);
-
 	return ops->vidioc_reqbufs(file, fh, p);
 }
 
@@ -2087,7 +2084,7 @@ static int v4l_create_bufs(const struct v4l2_ioctl_ops *ops,
 	if (ret)
 		return ret;
 
-	CLEAR_AFTER_FIELD(create, capabilities);
+	CLEAR_AFTER_FIELD(create, flags);
 
 	v4l_sanitize_format(&create->format);
 
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index b1d4171fe50b..85d2681e73b6 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -951,7 +951,10 @@ struct v4l2_requestbuffers {
 	__u32			type;		/* enum v4l2_buf_type */
 	__u32			memory;		/* enum v4l2_memory */
 	__u32			capabilities;
-	__u32			reserved[1];
+	union {
+		__u32		flags;
+		__u32		reserved[1];
+	};
 };
 
 #define V4L2_FLAG_MEMORY_NON_COHERENT			(1 << 0)
@@ -2473,6 +2476,9 @@ struct v4l2_dbg_chip_info {
  * @memory:	enum v4l2_memory; buffer memory type
  * @format:	frame format, for which buffers are requested
  * @capabilities: capabilities of this buffer type.
+ * @flags:	additional buffer management attributes (ignored unless the
+ *		queue has V4L2_BUF_CAP_SUPPORTS_MMAP_CACHE_HINTS capability
+ *		and configured for MMAP streaming I/O).
  * @reserved:	future extensions
  */
 struct v4l2_create_buffers {
@@ -2481,7 +2487,8 @@ struct v4l2_create_buffers {
 	__u32			memory;
 	struct v4l2_format	format;
 	__u32			capabilities;
-	__u32			reserved[7];
+	__u32			flags;
+	__u32			reserved[6];
 };
 
 /*
-- 
2.30.1.766.gb4fecdf3b7-goog


  parent reply	other threads:[~2021-03-02  7:46 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-02  0:46 [PATCH 0/8] videobuf2: support new noncontiguous DMA API Sergey Senozhatsky
2021-03-02  0:46 ` [PATCH 1/8] videobuf2: rework vb2_mem_ops API Sergey Senozhatsky
2021-03-02  0:46 ` [PATCH 2/8] videobuf2: inverse buffer cache_hints flags Sergey Senozhatsky
2021-03-02  0:46 ` [PATCH 3/8] videobuf2: split buffer cache_hints initialisation Sergey Senozhatsky
2021-03-02  0:46 ` [PATCH 4/8] videobuf2: move cache_hints handling to allocators Sergey Senozhatsky
2021-03-02  0:46 ` [PATCH 5/8] videobuf2: add V4L2_FLAG_MEMORY_NON_COHERENT flag Sergey Senozhatsky
2021-03-22  7:02   ` Hans Verkuil
2021-03-02  0:46 ` [PATCH 6/8] videobuf2: add queue memory coherency parameter Sergey Senozhatsky
2021-03-02  0:46 ` Sergey Senozhatsky [this message]
2021-03-22  7:16   ` [PATCH 7/8] videobuf2: handle V4L2_FLAG_MEMORY_NON_COHERENT flag Hans Verkuil
2021-03-22  7:18   ` Hans Verkuil
2021-03-02  0:46 ` [PATCH 8/8] videobuf2: handle non-contiguous DMA allocations Sergey Senozhatsky
2021-03-22  7:40   ` Hans Verkuil
2021-03-24 12:07   ` Tomasz Figa
2023-07-04 10:50   ` Hsia-Jun Li
2023-07-05 10:45     ` Tomasz Figa
2023-07-17  9:21       ` Hsia-Jun Li
2023-07-28  8:19         ` Tomasz Figa
2021-03-02  0:49 ` [PATCH] v4l-compliance: re-introduce NON_COHERENT and cache hints tests Sergey Senozhatsky
2021-03-02  0:50   ` Sergey Senozhatsky
2021-03-24 12:09 ` [PATCH 0/8] videobuf2: support new noncontiguous DMA API Tomasz Figa

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