Commit c0acf9cf authored by Sergey Senozhatsky's avatar Sergey Senozhatsky Committed by Mauro Carvalho Chehab
Browse files

media: videobuf2: handle V4L2_MEMORY_FLAG_NON_COHERENT flag 



This patch lets user-space 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 byte of a 4 byte ->reserved[1] member of struct
 v4l2_requestbuffers. The struct, thus, now has reserved 3 bytes.

Signed-off-by: default avatarSergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: default avatarHans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab+huawei@kernel.org>
parent b00a9e59

Documentation/userspace-api/media/v4l/vidioc-create-bufs.rst

+6 −1
Original line number Diff line number Diff line
@@ -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.

Documentation/userspace-api/media/v4l/vidioc-reqbufs.rst

+7 −4
Original line number Diff line number Diff line
@@ -104,10 +104,13 @@ 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.

    * - __u32

      - ``reserved``\ [1]

      - A place holder for future extensions. Drivers and applications

	must set the array to zero.

    * - __u8

      - ``flags``

      - Specifies additional buffer management attributes.

	See :ref:`memory-flags`.

    * - __u8

      - ``reserved``\ [3]

      - Reserved for future extensions.



.. _v4l2-buf-capabilities:

.. _V4L2-BUF-CAP-SUPPORTS-MMAP:

drivers/media/common/videobuf2/videobuf2-core.c

+2 −2
Original line number Diff line number Diff line
@@ -761,7 +761,7 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory, 
{

	unsigned int num_buffers, allocated_buffers, num_planes = 0;

	unsigned plane_sizes[VB2_MAX_PLANES] = { };

	bool non_coherent_mem = false;

	bool non_coherent_mem = flags & V4L2_MEMORY_FLAG_NON_COHERENT;

	unsigned int i;

	int ret;
@@ -905,7 +905,7 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory, 
{

	unsigned int num_planes = 0, num_buffers, allocated_buffers;

	unsigned plane_sizes[VB2_MAX_PLANES] = { };

	bool non_coherent_mem = false;

	bool non_coherent_mem = flags & V4L2_MEMORY_FLAG_NON_COHERENT;

	int ret;



	if (q->num_buffers == VB2_MAX_FRAME) {

drivers/media/common/videobuf2/videobuf2-v4l2.c

+28 −3
Original line number Diff line number Diff line
@@ -692,12 +692,32 @@ static void fill_buf_caps(struct vb2_queue *q, u32 *caps) 
#endif

}



static void validate_memory_flags(struct vb2_queue *q,

				  int memory,

				  u32 *flags)

{

	if (!q->allow_cache_hints || memory != V4L2_MEMORY_MMAP) {

		/*

		 * This needs to clear V4L2_MEMORY_FLAG_NON_COHERENT only,

		 * but in order to avoid bugs we zero out all bits.

		 */

		*flags = 0;

	} else {

		/* Clear all unknown flags. */

		*flags &= V4L2_MEMORY_FLAG_NON_COHERENT;

	}

}



int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)

{

	int ret = vb2_verify_memory_type(q, req->memory, req->type);

	u32 flags = req->flags;



	fill_buf_caps(q, &req->capabilities);

	return ret ? ret : vb2_core_reqbufs(q, req->memory, 0, &req->count);

	validate_memory_flags(q, req->memory, &flags);

	req->flags = flags;

	return ret ? ret : vb2_core_reqbufs(q, req->memory,

					    req->flags, &req->count);

}

EXPORT_SYMBOL_GPL(vb2_reqbufs);
@@ -729,6 +749,7 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create) 
	unsigned i;



	fill_buf_caps(q, &create->capabilities);

	validate_memory_flags(q, create->memory, &create->flags);

	create->index = q->num_buffers;

	if (create->count == 0)

		return ret != -EBUSY ? ret : 0;
@@ -772,7 +793,7 @@ 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);
@@ -969,13 +990,16 @@ 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);

	u32 flags = p->flags;



	fill_buf_caps(vdev->queue, &p->capabilities);

	validate_memory_flags(vdev->queue, p->memory, &flags);

	p->flags = 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)
@@ -993,6 +1017,7 @@ int vb2_ioctl_create_bufs(struct file *file, void *priv, 


	p->index = vdev->queue->num_buffers;

	fill_buf_caps(vdev->queue, &p->capabilities);

	validate_memory_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.

drivers/media/v4l2-core/v4l2-compat-ioctl32.c

+8 −1
Original line number Diff line number Diff line
@@ -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);