[PATCHv8 01/26] v4l: Add DMABUF as a memory type

[Hans Verkuil]

On Tue August 14 2012 17:34:31 Tomasz Stanislawski wrote:
> From: Sumit Semwal <sumit.semwal at ti.com>
> 
> Adds DMABUF memory type to v4l framework. Also adds the related file
> descriptor in v4l2_plane and v4l2_buffer.
> 
> Signed-off-by: Tomasz Stanislawski <t.stanislaws at samsung.com>
>    [original work in the PoC for buffer sharing]
> Signed-off-by: Sumit Semwal <sumit.semwal at ti.com>
> Signed-off-by: Sumit Semwal <sumit.semwal at linaro.org>
> Acked-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> ---
>  drivers/media/video/v4l2-compat-ioctl32.c |   18 ++++++++++++++++++
>  drivers/media/video/v4l2-ioctl.c          |    1 +
>  include/linux/videodev2.h                 |    7 +++++++
>  3 files changed, 26 insertions(+)
> 
> diff --git a/drivers/media/video/v4l2-compat-ioctl32.c b/drivers/media/video/v4l2-compat-ioctl32.c
> index 9ebd5c5..a2e0549 100644
> --- a/drivers/media/video/v4l2-compat-ioctl32.c
> +++ b/drivers/media/video/v4l2-compat-ioctl32.c
> @@ -304,6 +304,7 @@ struct v4l2_plane32 {
>  	union {
>  		__u32		mem_offset;
>  		compat_long_t	userptr;
> +		__u32		fd;

Shouldn't this be int?

>  	} m;
>  	__u32			data_offset;
>  	__u32			reserved[11];
> @@ -325,6 +326,7 @@ struct v4l2_buffer32 {
>  		__u32           offset;
>  		compat_long_t   userptr;
>  		compat_caddr_t  planes;
> +		__u32		fd;

Ditto.

>  	} m;
>  	__u32			length;
>  	__u32			reserved2;
> @@ -348,6 +350,9 @@ static int get_v4l2_plane32(struct v4l2_plane *up, struct v4l2_plane32 *up32,
>  		up_pln = compat_ptr(p);
>  		if (put_user((unsigned long)up_pln, &up->m.userptr))
>  			return -EFAULT;
> +	} else if (memory == V4L2_MEMORY_DMABUF) {
> +		if (copy_in_user(&up->m.fd, &up32->m.fd, sizeof(int)))
> +			return -EFAULT;
>  	} else {
>  		if (copy_in_user(&up->m.mem_offset, &up32->m.mem_offset,
>  					sizeof(__u32)))
> @@ -371,6 +376,11 @@ static int put_v4l2_plane32(struct v4l2_plane *up, struct v4l2_plane32 *up32,
>  		if (copy_in_user(&up32->m.mem_offset, &up->m.mem_offset,
>  					sizeof(__u32)))
>  			return -EFAULT;
> +	/* For DMABUF, driver might've set up the fd, so copy it back. */
> +	if (memory == V4L2_MEMORY_DMABUF)
> +		if (copy_in_user(&up32->m.fd, &up->m.fd,
> +					sizeof(int)))
> +			return -EFAULT;
>  
>  	return 0;
>  }
> @@ -453,6 +463,10 @@ static int get_v4l2_buffer32(struct v4l2_buffer *kp, struct v4l2_buffer32 __user
>  			if (get_user(kp->m.offset, &up->m.offset))
>  				return -EFAULT;
>  			break;
> +		case V4L2_MEMORY_DMABUF:
> +			if (get_user(kp->m.fd, &up->m.fd))
> +				return -EFAULT;
> +			break;
>  		}
>  	}
>  
> @@ -517,6 +531,10 @@ static int put_v4l2_buffer32(struct v4l2_buffer *kp, struct v4l2_buffer32 __user
>  			if (put_user(kp->m.offset, &up->m.offset))
>  				return -EFAULT;
>  			break;
> +		case V4L2_MEMORY_DMABUF:
> +			if (put_user(kp->m.fd, &up->m.fd))
> +				return -EFAULT;
> +			break;
>  		}
>  	}
>  
> diff --git a/drivers/media/video/v4l2-ioctl.c b/drivers/media/video/v4l2-ioctl.c
> index 6bc47fc..dffd3c9 100644
> --- a/drivers/media/video/v4l2-ioctl.c
> +++ b/drivers/media/video/v4l2-ioctl.c
> @@ -155,6 +155,7 @@ static const char *v4l2_memory_names[] = {
>  	[V4L2_MEMORY_MMAP]    = "mmap",
>  	[V4L2_MEMORY_USERPTR] = "userptr",
>  	[V4L2_MEMORY_OVERLAY] = "overlay",
> +	[V4L2_MEMORY_DMABUF] = "dmabuf",
>  };
>  
>  #define prt_names(a, arr) ((((a) >= 0) && ((a) < ARRAY_SIZE(arr))) ? \
> diff --git a/include/linux/videodev2.h b/include/linux/videodev2.h
> index 7a147c8..7f918dc 100644
> --- a/include/linux/videodev2.h
> +++ b/include/linux/videodev2.h
> @@ -186,6 +186,7 @@ enum v4l2_memory {
>  	V4L2_MEMORY_MMAP             = 1,
>  	V4L2_MEMORY_USERPTR          = 2,
>  	V4L2_MEMORY_OVERLAY          = 3,
> +	V4L2_MEMORY_DMABUF           = 4,
>  };
>  
>  /* see also http://vektor.theorem.ca/graphics/ycbcr/ */
> @@ -596,6 +597,8 @@ struct v4l2_requestbuffers {
>   *			should be passed to mmap() called on the video node)
>   * @userptr:		when memory is V4L2_MEMORY_USERPTR, a userspace pointer
>   *			pointing to this plane
> + * @fd:			when memory is V4L2_MEMORY_DMABUF, a userspace file
> + *			descriptor associated with this plane
>   * @data_offset:	offset in the plane to the start of data; usually 0,
>   *			unless there is a header in front of the data
>   *
> @@ -610,6 +613,7 @@ struct v4l2_plane {
>  	union {
>  		__u32		mem_offset;
>  		unsigned long	userptr;
> +		int		fd;
>  	} m;
>  	__u32			data_offset;
>  	__u32			reserved[11];
> @@ -634,6 +638,8 @@ struct v4l2_plane {
>   *		(or a "cookie" that should be passed to mmap() as offset)
>   * @userptr:	for non-multiplanar buffers with memory == V4L2_MEMORY_USERPTR;
>   *		a userspace pointer pointing to this buffer
> + * @fd:		for non-multiplanar buffers with memory == V4L2_MEMORY_DMABUF;
> + *		a userspace file descriptor associated with this buffer
>   * @planes:	for multiplanar buffers; userspace pointer to the array of plane
>   *		info structs for this buffer
>   * @length:	size in bytes of the buffer (NOT its payload) for single-plane
> @@ -660,6 +666,7 @@ struct v4l2_buffer {
>  		__u32           offset;
>  		unsigned long   userptr;
>  		struct v4l2_plane *planes;
> +		int		fd;
>  	} m;
>  	__u32			length;
>  	__u32			reserved2;
> 

Regards,

	Hans