Pawel Osciak wrote:
> Current V4L2 API assumes that each video buffer contains exactly one,
> contiguous memory buffer for video data. Even in case of planar video
> formats, e.g. YCbCr with each component residing in a separate area
> of memory, it is specified that each of those planes immediately follows
> the previous one in memory.
>
> There exist hardware video devices that handle, or even require, each of
> the planes to reside in a separate, arbitrary memory area. Some even
> require different planes to be placed in different, physical memory banks.
>
> This patch introduces a backward-compatible extension of V4L2 API, which
> allows passing additional, per-plane info in the video buffer structure.
>
> Signed-off-by: Pawel Osciak <p.osciak@xxxxxxxxxxx>
> Reviewed-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
> Reviewed-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
> ---
> drivers/media/video/v4l2-ioctl.c | 97 ++++++++++++++++++++++++++-----------
> include/linux/videodev2.h | 33 ++++++++++++-
> 2 files changed, 99 insertions(+), 31 deletions(-)
>
> diff --git a/drivers/media/video/v4l2-ioctl.c b/drivers/media/video/v4l2-ioctl.c
> index 4b11257..b89b73f 100644
> --- a/drivers/media/video/v4l2-ioctl.c
> +++ b/drivers/media/video/v4l2-ioctl.c
> @@ -172,6 +172,8 @@ static const char *v4l2_memory_names[] = {
> [V4L2_MEMORY_MMAP] = "mmap",
> [V4L2_MEMORY_USERPTR] = "userptr",
> [V4L2_MEMORY_OVERLAY] = "overlay",
> + [V4L2_MEMORY_MULTI_USERPTR] = "multi-userptr",
> + [V4L2_MEMORY_MULTI_MMAP] = "multi-mmap",
> };
>
> #define prt_names(a, arr) ((((a) >= 0) && ((a) < ARRAY_SIZE(arr))) ? \
> @@ -1975,7 +1977,7 @@ static unsigned long cmd_input_size(unsigned int cmd)
> switch (cmd) {
> CMDINSIZE(ENUM_FMT, fmtdesc, type);
> CMDINSIZE(G_FMT, format, type);
> - CMDINSIZE(QUERYBUF, buffer, type);
> + CMDINSIZE(QUERYBUF, buffer, length);
> CMDINSIZE(G_PARM, streamparm, type);
> CMDINSIZE(ENUMSTD, standard, index);
> CMDINSIZE(ENUMINPUT, input, index);
> @@ -2000,6 +2002,46 @@ static unsigned long cmd_input_size(unsigned int cmd)
> }
> }
>
> +static int check_array_args(unsigned int cmd, void *parg, size_t *array_size,
> + void * __user *user_ptr, void ***kernel_ptr)
> +{
> + int ret = 0;
> +
> + switch(cmd) {
> + case VIDIOC_QUERYBUF:
> + case VIDIOC_QBUF:
> + case VIDIOC_DQBUF: {
> + struct v4l2_buffer *buf = parg;
> +
> + if ((buf->memory == V4L2_MEMORY_MULTI_USERPTR
> + || buf->memory == V4L2_MEMORY_MULTI_MMAP)) {
> + *user_ptr = (void __user *)buf->m.planes;
> + *kernel_ptr = (void **)&buf->m.planes;
> + *array_size = sizeof(struct v4l2_plane) * buf->length;
> + ret = 1;
> + }
> + break;
> + }
> +
> + case VIDIOC_S_EXT_CTRLS:
> + case VIDIOC_G_EXT_CTRLS:
> + case VIDIOC_TRY_EXT_CTRLS: {
> + struct v4l2_ext_controls *ctrls = parg;
> +
> + if (ctrls->count != 0) {
> + *user_ptr = (void __user *)ctrls->controls;
> + *kernel_ptr = (void **)&ctrls->controls;
> + *array_size = sizeof(struct v4l2_ext_control)
> + * ctrls->count;
> + ret = 1;
> + }
> + break;
> + }
> + }
> +
> + return ret;
> +}
> +
> long video_ioctl2(struct file *file,
> unsigned int cmd, unsigned long arg)
> {
> @@ -2007,15 +2049,16 @@ long video_ioctl2(struct file *file,
> void *mbuf = NULL;
> void *parg = NULL;
> long err = -EINVAL;
> - int is_ext_ctrl;
> - size_t ctrls_size = 0;
> + int has_array_args;
> + size_t array_size = 0;
> void __user *user_ptr = NULL;
> + void **kernel_ptr = NULL;
>
> #ifdef __OLD_VIDIOC_
> cmd = video_fix_command(cmd);
> #endif
> - is_ext_ctrl = (cmd == VIDIOC_S_EXT_CTRLS || cmd == VIDIOC_G_EXT_CTRLS ||
> - cmd == VIDIOC_TRY_EXT_CTRLS);
> + /*is_ext_ctrl = (cmd == VIDIOC_S_EXT_CTRLS || cmd == VIDIOC_G_EXT_CTRLS ||
> + cmd == VIDIOC_TRY_EXT_CTRLS);*/
Just drop it if not used anymore.
>
> /* Copy arguments into temp kernel buffer */
> if (_IOC_DIR(cmd) != _IOC_NONE) {
> @@ -2045,43 +2088,39 @@ long video_ioctl2(struct file *file,
> }
> }
>
> - if (is_ext_ctrl) {
> - struct v4l2_ext_controls *p = parg;
> + has_array_args = check_array_args(cmd, parg, &array_size,
> + &user_ptr, &kernel_ptr);
>
> - /* In case of an error, tell the caller that it wasn't
> - a specific control that caused it. */
> - p->error_idx = p->count;
> - user_ptr = (void __user *)p->controls;
> - if (p->count) {
> - ctrls_size = sizeof(struct v4l2_ext_control) * p->count;
> - /* Note: v4l2_ext_controls fits in sbuf[] so mbuf is still NULL. */
> - mbuf = kmalloc(ctrls_size, GFP_KERNEL);
> - err = -ENOMEM;
> - if (NULL == mbuf)
> - goto out_ext_ctrl;
> - err = -EFAULT;
> - if (copy_from_user(mbuf, user_ptr, ctrls_size))
> - goto out_ext_ctrl;
> - p->controls = mbuf;
> - }
> + if (has_array_args) {
> + /* When adding new types of array args, make sure that the
> + * parent argument to ioctl, which contains the array, fits into
> + * sbuf (so that mbuf will still remain unused up to here).
> + */
> + mbuf = kmalloc(array_size, GFP_KERNEL);
> + err = -ENOMEM;
> + if (NULL == mbuf)
> + goto out_array_args;
> + err = -EFAULT;
> + if (copy_from_user(mbuf, user_ptr, array_size))
> + goto out_array_args;
> + *kernel_ptr = mbuf;
You probably need something similar to this at v4l2-compat-ioctl32.c.
> }
>
> /* Handles IOCTL */
> err = __video_do_ioctl(file, cmd, parg);
> if (err == -ENOIOCTLCMD)
> err = -EINVAL;
> - if (is_ext_ctrl) {
> - struct v4l2_ext_controls *p = parg;
>
> - p->controls = (void *)user_ptr;
> - if (p->count && err == 0 && copy_to_user(user_ptr, mbuf, ctrls_size))
> + if (has_array_args) {
> + *kernel_ptr = user_ptr;
> + if (copy_to_user(user_ptr, mbuf, array_size))
> err = -EFAULT;
> - goto out_ext_ctrl;
> + goto out_array_args;
> }
> if (err < 0)
> goto out;
>
> -out_ext_ctrl:
> +out_array_args:
> /* Copy results into user buffer */
> switch (_IOC_DIR(cmd)) {
> case _IOC_READ:
> diff --git a/include/linux/videodev2.h b/include/linux/videodev2.h
> index d4962a7..bf3f33d 100644
> --- a/include/linux/videodev2.h
> +++ b/include/linux/videodev2.h
> @@ -70,6 +70,7 @@
> * Moved from videodev.h
> */
> #define VIDEO_MAX_FRAME 32
> +#define VIDEO_MAX_PLANES 3
>
> #ifndef __KERNEL__
>
> @@ -180,6 +181,10 @@ enum v4l2_memory {
> V4L2_MEMORY_MMAP = 1,
> V4L2_MEMORY_USERPTR = 2,
> V4L2_MEMORY_OVERLAY = 3,
> +
> + /* Discontiguous buffer types */
> + V4L2_MEMORY_MULTI_USERPTR = 4,
> + V4L2_MEMORY_MULTI_MMAP = 5,
> };
>
> /* see also http://vektor.theorem.ca/graphics/ycbcr/ */
> @@ -519,6 +524,29 @@ struct v4l2_requestbuffers {
> __u32 reserved[2];
> };
>
> +/* struct v4l2_plane - a multi-plane buffer plane.
> + *
> + * Multi-plane buffers consist of two or more planes, e.g. an YCbCr buffer
> + * with two planes has one plane for Y, and another for interleaved CbCr
> + * components. Each plane can reside in a separate memory buffer, or in
> + * a completely separate memory chip even (e.g. in embedded devices).
> + */
> +struct v4l2_plane {
> + __u32 bytesused;
> +
> + union {
> + __u32 offset;
> + unsigned long userptr;
> + } m;
> + __u32 length;
> + __u32 reserved[5];
> +};
> +
> +/* struct v4l2_buffer - a video buffer (frame)
> + * @length: size of the buffer (not its payload) for single-plane buffers,
> + * number of planes (and number of elements in planes array)
> + * for multi-plane
> + */
> struct v4l2_buffer {
> __u32 index;
> enum v4l2_buf_type type;
> @@ -532,8 +560,9 @@ struct v4l2_buffer {
> /* memory location */
> enum v4l2_memory memory;
> union {
> - __u32 offset;
> - unsigned long userptr;
> + __u32 offset;
> + unsigned long userptr;
> + struct v4l2_plane *planes;
> } m;
> __u32 length;
> __u32 input;
--
Cheers,
Mauro
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