diff mbox series

[PATCHv4,05/11] videobuf2: handle V4L2_FLAG_MEMORY_NON_CONSISTENT flag

Message ID 20200302041213.27662-6-senozhatsky@chromium.org (mailing list archive)
State Changes Requested, archived
Delegated to: Hans Verkuil
Headers
Series Implement V4L2_BUF_FLAG_NO_CACHE_* flags |

Commit Message

Sergey Senozhatsky March 2, 2020, 4:12 a.m. UTC 
  This patch lets user-space to request a non-consistent 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.

= 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/uapi/v4l/vidioc-create-bufs.rst     |  7 ++++-
 .../media/uapi/v4l/vidioc-reqbufs.rst         | 11 +++++--
 .../media/common/videobuf2/videobuf2-v4l2.c   | 31 +++++++++++++++++--
 drivers/media/v4l2-core/v4l2-ioctl.c          |  5 +--
 include/uapi/linux/videodev2.h                |  8 +++--
 5 files changed, 50 insertions(+), 12 deletions(-)

Comments

Hans Verkuil March 6, 2020, 3:30 p.m. UTC | #1 
On 02/03/2020 05:12, Sergey Senozhatsky wrote:
> This patch lets user-space to request a non-consistent 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.
> 
> = 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/uapi/v4l/vidioc-create-bufs.rst     |  7 ++++-
>  .../media/uapi/v4l/vidioc-reqbufs.rst         | 11 +++++--
>  .../media/common/videobuf2/videobuf2-v4l2.c   | 31 +++++++++++++++++--
>  drivers/media/v4l2-core/v4l2-ioctl.c          |  5 +--
>  include/uapi/linux/videodev2.h                |  8 +++--
>  5 files changed, 50 insertions(+), 12 deletions(-)
> 
> diff --git a/Documentation/media/uapi/v4l/vidioc-create-bufs.rst b/Documentation/media/uapi/v4l/vidioc-create-bufs.rst
> index bd08e4f77ae4..a9c6c89f5098 100644
> --- a/Documentation/media/uapi/v4l/vidioc-create-bufs.rst
> +++ b/Documentation/media/uapi/v4l/vidioc-create-bufs.rst
> @@ -121,7 +121,12 @@ than the number requested.
>  	other changes, then set ``count`` to 0, ``memory`` to
>  	``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/media/uapi/v4l/vidioc-reqbufs.rst b/Documentation/media/uapi/v4l/vidioc-reqbufs.rst
> index 21ecacc72487..faf0df4f9bb6 100644
> --- a/Documentation/media/uapi/v4l/vidioc-reqbufs.rst
> +++ b/Documentation/media/uapi/v4l/vidioc-reqbufs.rst
> @@ -112,10 +112,17 @@ 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-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
> index 6111d74f68c9..b4b379f3bf98 100644
> --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
> +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
> @@ -722,9 +722,18 @@ static void fill_buf_caps(struct vb2_queue *q, u32 *caps)
>  int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
>  {
>  	int ret = vb2_verify_memory_type(q, req->memory, req->type);
> +	bool consistent = true;
> +
> +	if (!vb2_queue_allows_cache_hints(q))
> +		req->flags &= ~V4L2_FLAG_MEMORY_NON_CONSISTENT;
> +
> +	if (req->flags & V4L2_FLAG_MEMORY_NON_CONSISTENT)
> +		consistent = false;
>  
>  	fill_buf_caps(q, &req->capabilities);
> -	return ret ? ret : vb2_core_reqbufs(q, req->memory, true, &req->count);
> +	if (ret)
> +		return ret;
> +	return vb2_core_reqbufs(q, req->memory, consistent, &req->count);
>  }
>  EXPORT_SYMBOL_GPL(vb2_reqbufs);
>  
> @@ -753,6 +762,7 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
>  	unsigned requested_sizes[VIDEO_MAX_PLANES];
>  	struct v4l2_format *f = &create->format;
>  	int ret = vb2_verify_memory_type(q, create->memory, f->type);
> +	bool consistent = true;
>  	unsigned i;
>  
>  	fill_buf_caps(q, &create->capabilities);
> @@ -798,7 +808,14 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
>  	for (i = 0; i < requested_planes; i++)
>  		if (requested_sizes[i] == 0)
>  			return -EINVAL;
> -	return ret ? ret : vb2_core_create_bufs(q, create->memory, true,
> +
> +	if (!vb2_queue_allows_cache_hints(q))
> +		create->flags &= ~V4L2_FLAG_MEMORY_NON_CONSISTENT;
> +
> +	if (create->flags & V4L2_FLAG_MEMORY_NON_CONSISTENT)
> +		consistent = false;
> +
> +	return ret ? ret : vb2_core_create_bufs(q, create->memory, consistent,
>  		&create->count, requested_planes, requested_sizes);
>  }
>  EXPORT_SYMBOL_GPL(vb2_create_bufs);
> @@ -968,13 +985,21 @@ int vb2_ioctl_reqbufs(struct file *file, void *priv,
>  {
>  	struct video_device *vdev = video_devdata(file);
>  	int res = vb2_verify_memory_type(vdev->queue, p->memory, p->type);
> +	bool consistent = true;
>  
>  	fill_buf_caps(vdev->queue, &p->capabilities);
>  	if (res)
>  		return res;
>  	if (vb2_queue_is_busy(vdev, file))
>  		return -EBUSY;
> -	res = vb2_core_reqbufs(vdev->queue, p->memory, true, &p->count);
> +
> +	if (!vb2_queue_allows_cache_hints(vdev->queue))
> +		p->flags &= ~V4L2_FLAG_MEMORY_NON_CONSISTENT;
> +
> +	if (p->flags & V4L2_FLAG_MEMORY_NON_CONSISTENT)
> +		consistent = false;
> +
> +	res = vb2_core_reqbufs(vdev->queue, p->memory, consistent, &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)
> diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
> index fbcc7a20eedf..53b87bfd50d7 100644
> --- a/drivers/media/v4l2-core/v4l2-ioctl.c
> +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
> @@ -1973,9 +1973,6 @@ 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);
>  }
>  
> @@ -2015,7 +2012,7 @@ 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 e92c29864730..12b1bd220347 100644
> --- a/include/uapi/linux/videodev2.h
> +++ b/include/uapi/linux/videodev2.h
> @@ -938,7 +938,10 @@ 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];
> +	};
>  };
>  
>  /* capabilities for struct v4l2_requestbuffers and v4l2_create_buffers */
> @@ -2446,7 +2449,8 @@ struct v4l2_create_buffers {
>  	__u32			memory;
>  	struct v4l2_format	format;
>  	__u32			capabilities;
> -	__u32			reserved[7];
> +	__u32			flags;

The new flags argument needs to be documented in the command for struct v4l2_create_buffers.

Regards,

	Hans

> +	__u32			reserved[6];
>  };
>  
>  /*
>
Sergey Senozhatsky March 7, 2020, 7:51 a.m. UTC | #2 
On (20/03/06 16:30), Hans Verkuil wrote:
[..]
> >  
> >  /* capabilities for struct v4l2_requestbuffers and v4l2_create_buffers */
> > @@ -2446,7 +2449,8 @@ struct v4l2_create_buffers {
> >  	__u32			memory;
> >  	struct v4l2_format	format;
> >  	__u32			capabilities;
> > -	__u32			reserved[7];
> > +	__u32			flags;
> 
> The new flags argument needs to be documented in the command for struct v4l2_create_buffers.
> 

Will add.

	-ss
Sergey Senozhatsky March 7, 2020, 9:38 a.m. UTC | #3 
On (20/03/07 16:51), Sergey Senozhatsky wrote:
> On (20/03/06 16:30), Hans Verkuil wrote:
> [..]
> > >  
> > >  /* capabilities for struct v4l2_requestbuffers and v4l2_create_buffers */
> > > @@ -2446,7 +2449,8 @@ struct v4l2_create_buffers {
> > >  	__u32			memory;
> > >  	struct v4l2_format	format;
> > >  	__u32			capabilities;
> > > -	__u32			reserved[7];
> > > +	__u32			flags;
> > 
> > The new flags argument needs to be documented in the command for struct v4l2_create_buffers.
> > 

Hans, what does "command for struct v4l2_create_buffers" mean?

BTW, I added v4l2_create_buffers::flags comment:

---

diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index 12b1bd220347..c6c1cccbb5c1 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -2441,6 +2441,8 @@ 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 if queue
+ *		does not have V4L2_BUF_CAP_SUPPORTS_CACHE_HINTS capability).
  * @reserved:	future extensions
  */
 struct v4l2_create_buffers {
Hans Verkuil March 7, 2020, 10:05 a.m. UTC | #4 
On 07/03/2020 10:38, Sergey Senozhatsky wrote:
> On (20/03/07 16:51), Sergey Senozhatsky wrote:
>> On (20/03/06 16:30), Hans Verkuil wrote:
>> [..]
>>>>  
>>>>  /* capabilities for struct v4l2_requestbuffers and v4l2_create_buffers */
>>>> @@ -2446,7 +2449,8 @@ struct v4l2_create_buffers {
>>>>  	__u32			memory;
>>>>  	struct v4l2_format	format;
>>>>  	__u32			capabilities;
>>>> -	__u32			reserved[7];
>>>> +	__u32			flags;
>>>
>>> The new flags argument needs to be documented in the command for struct v4l2_create_buffers.
>>>
> 
> Hans, what does "command for struct v4l2_create_buffers" mean?

Oops: command -> comment

> 
> BTW, I added v4l2_create_buffers::flags comment:

Good, that's what I meant :-)

Regards,

	Hans

> 
> ---
> 
> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> index 12b1bd220347..c6c1cccbb5c1 100644
> --- a/include/uapi/linux/videodev2.h
> +++ b/include/uapi/linux/videodev2.h
> @@ -2441,6 +2441,8 @@ 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 if queue
> + *		does not have V4L2_BUF_CAP_SUPPORTS_CACHE_HINTS capability).
>   * @reserved:	future extensions
>   */
>  struct v4l2_create_buffers {
>
diff mbox series

Patch

diff --git a/Documentation/media/uapi/v4l/vidioc-create-bufs.rst b/Documentation/media/uapi/v4l/vidioc-create-bufs.rst
index bd08e4f77ae4..a9c6c89f5098 100644
--- a/Documentation/media/uapi/v4l/vidioc-create-bufs.rst
+++ b/Documentation/media/uapi/v4l/vidioc-create-bufs.rst
@@ -121,7 +121,12 @@  than the number requested.
 	other changes, then set ``count`` to 0, ``memory`` to
 	``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/media/uapi/v4l/vidioc-reqbufs.rst b/Documentation/media/uapi/v4l/vidioc-reqbufs.rst
index 21ecacc72487..faf0df4f9bb6 100644
--- a/Documentation/media/uapi/v4l/vidioc-reqbufs.rst
+++ b/Documentation/media/uapi/v4l/vidioc-reqbufs.rst
@@ -112,10 +112,17 @@  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-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
index 6111d74f68c9..b4b379f3bf98 100644
--- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
+++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
@@ -722,9 +722,18 @@  static void fill_buf_caps(struct vb2_queue *q, u32 *caps)
 int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
 {
 	int ret = vb2_verify_memory_type(q, req->memory, req->type);
+	bool consistent = true;
+
+	if (!vb2_queue_allows_cache_hints(q))
+		req->flags &= ~V4L2_FLAG_MEMORY_NON_CONSISTENT;
+
+	if (req->flags & V4L2_FLAG_MEMORY_NON_CONSISTENT)
+		consistent = false;
 
 	fill_buf_caps(q, &req->capabilities);
-	return ret ? ret : vb2_core_reqbufs(q, req->memory, true, &req->count);
+	if (ret)
+		return ret;
+	return vb2_core_reqbufs(q, req->memory, consistent, &req->count);
 }
 EXPORT_SYMBOL_GPL(vb2_reqbufs);
 
@@ -753,6 +762,7 @@  int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
 	unsigned requested_sizes[VIDEO_MAX_PLANES];
 	struct v4l2_format *f = &create->format;
 	int ret = vb2_verify_memory_type(q, create->memory, f->type);
+	bool consistent = true;
 	unsigned i;
 
 	fill_buf_caps(q, &create->capabilities);
@@ -798,7 +808,14 @@  int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
 	for (i = 0; i < requested_planes; i++)
 		if (requested_sizes[i] == 0)
 			return -EINVAL;
-	return ret ? ret : vb2_core_create_bufs(q, create->memory, true,
+
+	if (!vb2_queue_allows_cache_hints(q))
+		create->flags &= ~V4L2_FLAG_MEMORY_NON_CONSISTENT;
+
+	if (create->flags & V4L2_FLAG_MEMORY_NON_CONSISTENT)
+		consistent = false;
+
+	return ret ? ret : vb2_core_create_bufs(q, create->memory, consistent,
 		&create->count, requested_planes, requested_sizes);
 }
 EXPORT_SYMBOL_GPL(vb2_create_bufs);
@@ -968,13 +985,21 @@  int vb2_ioctl_reqbufs(struct file *file, void *priv,
 {
 	struct video_device *vdev = video_devdata(file);
 	int res = vb2_verify_memory_type(vdev->queue, p->memory, p->type);
+	bool consistent = true;
 
 	fill_buf_caps(vdev->queue, &p->capabilities);
 	if (res)
 		return res;
 	if (vb2_queue_is_busy(vdev, file))
 		return -EBUSY;
-	res = vb2_core_reqbufs(vdev->queue, p->memory, true, &p->count);
+
+	if (!vb2_queue_allows_cache_hints(vdev->queue))
+		p->flags &= ~V4L2_FLAG_MEMORY_NON_CONSISTENT;
+
+	if (p->flags & V4L2_FLAG_MEMORY_NON_CONSISTENT)
+		consistent = false;
+
+	res = vb2_core_reqbufs(vdev->queue, p->memory, consistent, &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)
diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
index fbcc7a20eedf..53b87bfd50d7 100644
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -1973,9 +1973,6 @@  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);
 }
 
@@ -2015,7 +2012,7 @@  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 e92c29864730..12b1bd220347 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -938,7 +938,10 @@  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];
+	};
 };
 
 /* capabilities for struct v4l2_requestbuffers and v4l2_create_buffers */
@@ -2446,7 +2449,8 @@  struct v4l2_create_buffers {
 	__u32			memory;
 	struct v4l2_format	format;
 	__u32			capabilities;
-	__u32			reserved[7];
+	__u32			flags;
+	__u32			reserved[6];
 };
 
 /*