Re: [PATCH v5 3/7] media: videobuf2: Expose helpers to implement the _ext_fmt and _ext_buf hooks

Tomasz Figa
2020-12-14T08:53:28Z

Hi Helen,

On Tue, Aug 04, 2020 at 04:29:35PM -0300, Helen Koike wrote:
> The VB2 layer is used by a lot of drivers. Patch it to support the
> _EXT_PIX_FMT and _EXT_BUF ioctls in order to ease conversion of existing
> drivers to these new APIs.
>
> Note that internally, the VB2 core is now only using ext structs and old
> APIs are supported through conversion wrappers.

We decided to only support V4L2_BUF_TYPE_VIDEO* for the ext structs. Still,
existing drivers may use vb2 with the other, legacy, buf types. How would
they be handled with this change?

>
> Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
> Signed-off-by: Helen Koike <helen.koike@collabora.com>
> ---
> Changes in v5:
> - Update with new format and buffer structs
> - Updated commit message with the uAPI prefix
>
> Changes in v4:
> - Update with new format and buffer structs
> - Fix some bugs caught by v4l2-compliance
> - Rebased on top of media/master (post 5.8-rc1)
>
> Changes in v3:
> - Rebased on top of media/master (post 5.4-rc1)
>
> Changes in v2:
> - New patch
> ---
> .../media/common/videobuf2/videobuf2-core.c | 2 +
> .../media/common/videobuf2/videobuf2-v4l2.c | 560 ++++++++++--------
> include/media/videobuf2-core.h | 6 +-
> include/media/videobuf2-v4l2.h | 21 +-
> 4 files changed, 345 insertions(+), 244 deletions(-)
>
> diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
> index f544d3393e9d6..d719b1e9c148b 100644
> --- a/drivers/media/common/videobuf2/videobuf2-core.c
> +++ b/drivers/media/common/videobuf2/videobuf2-core.c
> @@ -1270,6 +1270,7 @@ static int __prepare_dmabuf(struct vb2_buffer *vb)
> vb->planes[plane].length = 0;
> vb->planes[plane].m.fd = 0;
> vb->planes[plane].data_offset = 0;
> + vb->planes[plane].dbuf_offset = 0;
>
> /* Acquire each plane's memory */
> mem_priv = call_ptr_memop(vb, attach_dmabuf,
> @@ -1313,6 +1314,7 @@ static int __prepare_dmabuf(struct vb2_buffer *vb)
> vb->planes[plane].length = planes[plane].length;
> vb->planes[plane].m.fd = planes[plane].m.fd;
> vb->planes[plane].data_offset = planes[plane].data_offset;
> + vb->planes[plane].dbuf_offset = planes[plane].dbuf_offset;
> }
>
> if (reacquired) {
> diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
> index 30caad27281e1..911681d24b3ae 100644
> --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
> +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
> @@ -29,6 +29,7 @@
> #include <media/v4l2-fh.h>
> #include <media/v4l2-event.h>
> #include <media/v4l2-common.h>
> +#include <media/v4l2-ioctl.h>
>
> #include <media/videobuf2-v4l2.h>
>
> @@ -56,72 +57,39 @@ module_param(debug, int, 0644);
> V4L2_BUF_FLAG_TIMECODE | \
> V4L2_BUF_FLAG_M2M_HOLD_CAPTURE_BUF)
>
> -/*
> - * __verify_planes_array() - verify that the planes array passed in struct
> - * v4l2_buffer from userspace can be safely used
> - */
> -static int __verify_planes_array(struct vb2_buffer *vb, const struct v4l2_buffer *b)
> -{
> - if (!V4L2_TYPE_IS_MULTIPLANAR(b->type))
> - return 0;
> -
> - /* Is memory for copying plane information present? */
> - if (b->m.planes == NULL) {
> - dprintk(vb->vb2_queue, 1,
> - "multi-planar buffer passed but planes array not provided\n");
> - return -EINVAL;
> - }
> -
> - if (b->length < vb->num_planes || b->length > VB2_MAX_PLANES) {
> - dprintk(vb->vb2_queue, 1,
> - "incorrect planes array length, expected %d, got %d\n",
> - vb->num_planes, b->length);
> - return -EINVAL;
> - }
> -
> - return 0;
> -}
> -
> static int __verify_planes_array_core(struct vb2_buffer *vb, const void *pb)
> {
> - return __verify_planes_array(vb, pb);
> + return 0;
> }
>
> /*
> * __verify_length() - Verify that the bytesused value for each plane fits in
> * the plane length and that the data offset doesn't exceed the bytesused value.
> */
> -static int __verify_length(struct vb2_buffer *vb, const struct v4l2_buffer *b)
> +static int __verify_length(struct vb2_buffer *vb,
> + const struct v4l2_ext_buffer *b)
> {
> unsigned int length;
> unsigned int bytesused;
> - unsigned int plane;
> + unsigned int i;
>
> if (V4L2_TYPE_IS_CAPTURE(b->type))
> return 0;
>
> - if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
> - for (plane = 0; plane < vb->num_planes; ++plane) {
> - length = (b->memory == VB2_MEMORY_USERPTR ||
> - b->memory == VB2_MEMORY_DMABUF)
> - ? b->m.planes[plane].length
> - : vb->planes[plane].length;
> - bytesused = b->m.planes[plane].bytesused
> - ? b->m.planes[plane].bytesused : length;
> -
> - if (b->m.planes[plane].bytesused > length)
> - return -EINVAL;
> -
> - if (b->m.planes[plane].data_offset > 0 &&
> - b->m.planes[plane].data_offset >= bytesused)
> - return -EINVAL;
> - }
> - } else {
> - length = (b->memory == VB2_MEMORY_USERPTR ||
> - b->memory == VB2_MEMORY_DMABUF)
> - ? b->length : vb->planes[0].length;
> + for (i = 0; i < vb->num_planes; ++i) {
> + const struct v4l2_ext_plane *plane = &b->planes[i];
>
> - if (b->bytesused > length)
> + length = (plane->memory == VB2_MEMORY_USERPTR ||
> + plane->memory == VB2_MEMORY_DMABUF) ?
> + plane->buffer_length :
> + vb->planes[i].length;
> + bytesused = plane->plane_length ?
> + plane->plane_length : length;
> +
> + if (bytesused > length)
> + return -EINVAL;
> +
> + if (plane->offset + bytesused > length)
> return -EINVAL;
> }
>
> @@ -140,21 +108,12 @@ static void __init_vb2_v4l2_buffer(struct vb2_buffer *vb)
>
> static void __copy_timestamp(struct vb2_buffer *vb, const void *pb)
> {
> - const struct v4l2_buffer *b = pb;
> - struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
> + const struct v4l2_ext_buffer *b = pb;
> struct vb2_queue *q = vb->vb2_queue;
>
> - if (q->is_output) {
> - /*
> - * For output buffers copy the timestamp if needed,
> - * and the timecode field and flag if needed.
> - */
> - if (q->copy_timestamp)
> - vb->timestamp = v4l2_buffer_get_timestamp(b);
> - vbuf->flags |= b->flags & V4L2_BUF_FLAG_TIMECODE;
> - if (b->flags & V4L2_BUF_FLAG_TIMECODE)
> - vbuf->timecode = b->timecode;

Is it okay to remove the timecode copying functionality?

> - }
> + /* For output buffers copy the timestamp if needed. */
> + if (q->is_output && q->copy_timestamp)
> + vb->timestamp = b->timestamp;
> };
>
> static void vb2_warn_zero_bytesused(struct vb2_buffer *vb)
> @@ -173,7 +132,8 @@ static void vb2_warn_zero_bytesused(struct vb2_buffer *vb)
> pr_warn("use the actual size instead.\n");
> }
>
> -static int vb2_fill_vb2_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b)
> +static int vb2_fill_vb2_v4l2_buffer(struct vb2_buffer *vb,
> + struct v4l2_ext_buffer *b)
> {
> struct vb2_queue *q = vb->vb2_queue;
> struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
> @@ -203,110 +163,67 @@ static int vb2_fill_vb2_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b
> vbuf->request_fd = -1;
> vbuf->is_held = false;
>
> - if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
> - switch (b->memory) {
> - case VB2_MEMORY_USERPTR:
> - for (plane = 0; plane < vb->num_planes; ++plane) {
> - planes[plane].m.userptr =
> - b->m.planes[plane].m.userptr;
> - planes[plane].length =
> - b->m.planes[plane].length;
> - }
> - break;
> - case VB2_MEMORY_DMABUF:
> - for (plane = 0; plane < vb->num_planes; ++plane) {
> - planes[plane].m.fd =
> - b->m.planes[plane].m.fd;
> - planes[plane].length =
> - b->m.planes[plane].length;
> - }
> - break;
> - default:
> - for (plane = 0; plane < vb->num_planes; ++plane) {
> - planes[plane].m.offset =
> - vb->planes[plane].m.offset;
> - planes[plane].length =
> - vb->planes[plane].length;
> - }
> - break;
> + for (plane = 0; plane < vb->num_planes; ++plane) {
> + if (b->planes[0].memory != b->planes[plane].memory) {
> + dprintk(q, 1, "planes should have the same memory type\n");
> + return -EINVAL;
> }
> + }
>
> - /* Fill in driver-provided information for OUTPUT types */
> - if (V4L2_TYPE_IS_OUTPUT(b->type)) {
> - /*
> - * Will have to go up to b->length when API starts
> - * accepting variable number of planes.
> - *
> - * If bytesused == 0 for the output buffer, then fall
> - * back to the full buffer size. In that case
> - * userspace clearly never bothered to set it and
> - * it's a safe assumption that they really meant to
> - * use the full plane sizes.
> - *
> - * Some drivers, e.g. old codec drivers, use bytesused == 0
> - * as a way to indicate that streaming is finished.
> - * In that case, the driver should use the
> - * allow_zero_bytesused flag to keep old userspace
> - * applications working.
> - */
> - for (plane = 0; plane < vb->num_planes; ++plane) {
> - struct vb2_plane *pdst = &planes[plane];
> - struct v4l2_plane *psrc = &b->m.planes[plane];
> -
> - if (psrc->bytesused == 0)
> - vb2_warn_zero_bytesused(vb);
> -
> - if (vb->vb2_queue->allow_zero_bytesused)
> - pdst->bytesused = psrc->bytesused;
> - else
> - pdst->bytesused = psrc->bytesused ?
> - psrc->bytesused : pdst->length;
> - pdst->data_offset = psrc->data_offset;
> - }
> + switch (b->planes[0].memory) {
> + case VB2_MEMORY_USERPTR:
> + for (plane = 0; plane < vb->num_planes; ++plane) {
> + planes[plane].m.userptr = b->planes[plane].m.userptr;
> + planes[plane].length = b->planes[plane].buffer_length;
> }
> - } else {
> + break;
> + case VB2_MEMORY_DMABUF:
> + for (plane = 0; plane < vb->num_planes; ++plane) {
> + planes[plane].m.fd = b->planes[plane].m.dmabuf_fd;
> + planes[plane].dbuf_offset = b->planes[plane].offset;
> + planes[plane].length = b->planes[plane].buffer_length;
> + }
> + break;
> + default:
> + for (plane = 0; plane < vb->num_planes; ++plane) {
> + planes[plane].m.offset = vb->planes[plane].m.offset;
> + planes[plane].length = vb->planes[plane].length;
> + }
> + break;
> + }
> +
> + /* Fill in driver-provided information for OUTPUT types */
> + if (V4L2_TYPE_IS_OUTPUT(b->type)) {
> /*
> - * Single-planar buffers do not use planes array,
> - * so fill in relevant v4l2_buffer struct fields instead.
> - * In videobuf we use our internal V4l2_planes struct for
> - * single-planar buffers as well, for simplicity.
> + * Will have to go up to b->length when API starts
> + * accepting variable number of planes.
> *
> - * If bytesused == 0 for the output buffer, then fall back
> - * to the full buffer size as that's a sensible default.
> + * If bytesused == 0 for the output buffer, then fall

Should this be updated with the new field name?

> + * back to the full buffer size. In that case
> + * userspace clearly never bothered to set it and
> + * it's a safe assumption that they really meant to
> + * use the full plane sizes.
> *
> - * Some drivers, e.g. old codec drivers, use bytesused == 0 as
> - * a way to indicate that streaming is finished. In that case,
> - * the driver should use the allow_zero_bytesused flag to keep
> - * old userspace applications working.
> + * Some drivers, e.g. old codec drivers, use bytesused == 0
> + * as a way to indicate that streaming is finished.
> + * In that case, the driver should use the
> + * allow_zero_bytesused flag to keep old userspace
> + * applications working.

Do we retain this behavior in the new API? If no, I guess we need to check
if this was old or new API and react appropriately.

> */
> - switch (b->memory) {
> - case VB2_MEMORY_USERPTR:
> - planes[0].m.userptr = b->m.userptr;
> - planes[0].length = b->length;
> - break;
> - case VB2_MEMORY_DMABUF:
> - planes[0].m.fd = b->m.fd;
> - planes[0].length = b->length;
> - break;
> - default:
> - planes[0].m.offset = vb->planes[0].m.offset;
> - planes[0].length = vb->planes[0].length;
> - break;
> - }
> + for (plane = 0; plane < vb->num_planes; ++plane) {
> + struct vb2_plane *pdst = &planes[plane];
> + struct v4l2_ext_plane *psrc = &b->planes[plane];
>
> - planes[0].data_offset = 0;
> - if (V4L2_TYPE_IS_OUTPUT(b->type)) {
> - if (b->bytesused == 0)
> + if (psrc->plane_length == 0)
> vb2_warn_zero_bytesused(vb);
>
> if (vb->vb2_queue->allow_zero_bytesused)
> - planes[0].bytesused = b->bytesused;
> + pdst->bytesused = psrc->plane_length;
> else
> - planes[0].bytesused = b->bytesused ?
> - b->bytesused : planes[0].length;
> - } else
> - planes[0].bytesused = 0;
> -
> + pdst->bytesused = psrc->plane_length ?
> + psrc->plane_length :
> + pdst->length;
> + }
> }
>
> /* Zero flags that we handle */
> @@ -343,7 +260,7 @@ static int vb2_fill_vb2_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b
>
> static void set_buffer_cache_hints(struct vb2_queue *q,
> struct vb2_buffer *vb,
> - struct v4l2_buffer *b)
> + struct v4l2_ext_buffer *b)
> {
> /*
> * DMA exporter should take care of cache syncs, so we can avoid
> @@ -388,17 +305,44 @@ static void set_buffer_cache_hints(struct vb2_queue *q,
> vb->need_cache_sync_on_prepare = 0;
> }
>
> +static enum v4l2_buf_type vb2_ext_qtype(struct vb2_queue *q)
> +{
> + if (!q->is_multiplanar)
> + return q->type;

Do we need this explicit check? Wouldn't the code below would return
the right thing anyway?

> +
> + if (q->type == V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE)
> + return V4L2_BUF_TYPE_VIDEO_CAPTURE;
> + else if (q->type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE)
> + return V4L2_BUF_TYPE_VIDEO_OUTPUT;
> +
> + return q->type;
> +}
> +
> +static enum v4l2_buf_type vb2_ext_type(unsigned int type, bool is_multiplanar)
> +{
> + if (!is_multiplanar)
> + return type;

Ditto.

> +
> + if (type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
> + return V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
> + else if (type == V4L2_BUF_TYPE_VIDEO_OUTPUT)
> + return V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE;
> +
> + return type;
> +}
> +
> static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct media_device *mdev,
> - struct v4l2_buffer *b, bool is_prepare,
> + struct v4l2_ext_buffer *b, bool is_prepare,
> struct media_request **p_req)
> {
> const char *opname = is_prepare ? "prepare_buf" : "qbuf";
> struct media_request *req;
> struct vb2_v4l2_buffer *vbuf;
> struct vb2_buffer *vb;
> + unsigned int i;
> int ret;
>
> - if (b->type != q->type) {
> + if (b->type != vb2_ext_qtype(q)) {
> dprintk(q, 1, "%s: invalid buffer type\n", opname);
> return -EINVAL;
> }
> @@ -414,16 +358,14 @@ static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct media_device *md
> return -EINVAL;
> }
>
> - if (b->memory != q->memory) {
> + for (i = 0; i < VIDEO_MAX_PLANES && b->planes[i].buffer_length; i++)
> + if (b->planes[i].memory != q->memory) {
> dprintk(q, 1, "%s: invalid memory type\n", opname);
> return -EINVAL;
> }
>
> vb = q->bufs[b->index];
> vbuf = to_vb2_v4l2_buffer(vb);
> - ret = __verify_planes_array(vb, b);
> - if (ret)
> - return ret;
>
> if (!is_prepare && (b->flags & V4L2_BUF_FLAG_REQUEST_FD) &&
> vb->state != VB2_BUF_STATE_DEQUEUED) {
> @@ -487,11 +429,6 @@ static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct media_device *md
> !q->ops->buf_out_validate))
> return -EINVAL;
>
> - if (b->request_fd < 0) {
> - dprintk(q, 1, "%s: request_fd < 0\n", opname);
> - return -EINVAL;
> - }
> -

I guess this code was useless already, because the call below would
validate the FD, but should it be perhaps removed in a separate patch?

> req = media_request_get_by_fd(mdev, b->request_fd);
> if (IS_ERR(req)) {
> dprintk(q, 1, "%s: invalid request_fd\n", opname);
> @@ -516,64 +453,46 @@ static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct media_device *md
> }
>
> /*
> - * __fill_v4l2_buffer() - fill in a struct v4l2_buffer with information to be
> - * returned to userspace
> + * __fill_v4l2_buffer() - fill in a struct v4l2_ext_buffer with information to
> + * be returned to userspace
> */
> static void __fill_v4l2_buffer(struct vb2_buffer *vb, void *pb)
> {
> - struct v4l2_buffer *b = pb;
> + struct v4l2_ext_buffer *b = pb;
> struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
> struct vb2_queue *q = vb->vb2_queue;
> unsigned int plane;
>
> /* Copy back data such as timestamp, flags, etc. */
> b->index = vb->index;
> - b->type = vb->type;
> - b->memory = vb->memory;
> - b->bytesused = 0;
> + b->type = vb2_ext_qtype(q);
>
> b->flags = vbuf->flags;
> b->field = vbuf->field;
> - v4l2_buffer_set_timestamp(b, vb->timestamp);
> - b->timecode = vbuf->timecode;
> + b->timestamp = vb->timestamp;
> b->sequence = vbuf->sequence;
> - b->reserved2 = 0;
> b->request_fd = 0;
> + memset(b->reserved, 0, sizeof(b->reserved));
>
> - if (q->is_multiplanar) {
> - /*
> - * Fill in plane-related data if userspace provided an array
> - * for it. The caller has already verified memory and size.
> - */
> - b->length = vb->num_planes;
> - for (plane = 0; plane < vb->num_planes; ++plane) {
> - struct v4l2_plane *pdst = &b->m.planes[plane];
> - struct vb2_plane *psrc = &vb->planes[plane];
> -
> - pdst->bytesused = psrc->bytesused;
> - pdst->length = psrc->length;
> - if (q->memory == VB2_MEMORY_MMAP)
> - pdst->m.mem_offset = psrc->m.offset;
> - else if (q->memory == VB2_MEMORY_USERPTR)
> - pdst->m.userptr = psrc->m.userptr;
> - else if (q->memory == VB2_MEMORY_DMABUF)
> - pdst->m.fd = psrc->m.fd;
> - pdst->data_offset = psrc->data_offset;
> - memset(pdst->reserved, 0, sizeof(pdst->reserved));
> - }
> - } else {
> - /*
> - * We use length and offset in v4l2_planes array even for
> - * single-planar buffers, but userspace does not.
> - */
> - b->length = vb->planes[0].length;
> - b->bytesused = vb->planes[0].bytesused;
> + /*
> + * Fill in plane-related data if userspace provided an array
> + * for it. The caller has already verified memory and size.
> + */
> + for (plane = 0; plane < vb->num_planes; ++plane) {
> + struct v4l2_ext_plane *pdst = &b->planes[plane];
> + struct vb2_plane *psrc = &vb->planes[plane];
> +
> + pdst->memory = vb->memory;
> + pdst->plane_length = psrc->bytesused;
> + pdst->buffer_length = psrc->length;
> + pdst->offset = psrc->dbuf_offset;
> if (q->memory == VB2_MEMORY_MMAP)
> - b->m.offset = vb->planes[0].m.offset;
> + pdst->m.mem_offset = psrc->m.offset;
> else if (q->memory == VB2_MEMORY_USERPTR)
> - b->m.userptr = vb->planes[0].m.userptr;
> + pdst->m.userptr = psrc->m.userptr;
> else if (q->memory == VB2_MEMORY_DMABUF)
> - b->m.fd = vb->planes[0].m.fd;
> + pdst->m.dmabuf_fd = psrc->m.fd;
> + memset(pdst->reserved, 0, sizeof(pdst->reserved));
> }
>
> /*
> @@ -668,6 +587,35 @@ int vb2_find_timestamp(const struct vb2_queue *q, u64 timestamp,
> }
> EXPORT_SYMBOL_GPL(vb2_find_timestamp);
>
> +#define vb2_buf_to_ext_buf_op(_name, ...) \
> +({ \
> + int ret; \
> + \
> + ret = v4l2_buffer_to_ext_buffer(b, &eb); \
> + if (!ret) \
> + ret = _name(__VA_ARGS__); \
> + if (!ret) \
> + ret = v4l2_ext_buffer_to_buffer(&eb, b, \
> + q->is_multiplanar); \

I'm not very happy with this macro implicitly relying on existence of some
specific variables with predefined names in the scope of the caller.

That said, I don't have a good idea on how this could be fixed, other than
just repeating this code manually in each function.

If we don't find anything better, I think at least a comment here
explaining the assumptions would make it a bit better.

> + ret; \
> +})
> +
> +int vb2_ext_querybuf(struct vb2_queue *q, struct v4l2_ext_buffer *b)
> +{
> + if (b->type != vb2_ext_qtype(q)) {
> + dprintk(q, 1, "wrong buffer type\n");
> + return -EINVAL;
> + }
> +
> + if (b->index >= q->num_buffers) {
> + dprintk(q, 1, "buffer index out of range\n");
> + return -EINVAL;
> + }
> + vb2_core_querybuf(q, b->index, b);
> + return 0;
> +}
> +EXPORT_SYMBOL(vb2_ext_querybuf);
> +
> /*
> * vb2_querybuf() - query video buffer information
> * @q: videobuf queue
> @@ -683,23 +631,9 @@ EXPORT_SYMBOL_GPL(vb2_find_timestamp);
> */
> int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b)
> {
> - struct vb2_buffer *vb;
> - int ret;
> -
> - if (b->type != q->type) {
> - dprintk(q, 1, "wrong buffer type\n");
> - return -EINVAL;
> - }
> + struct v4l2_ext_buffer eb;
>
> - if (b->index >= q->num_buffers) {
> - dprintk(q, 1, "buffer index out of range\n");
> - return -EINVAL;
> - }
> - vb = q->bufs[b->index];
> - ret = __verify_planes_array(vb, b);
> - if (!ret)
> - vb2_core_querybuf(q, b->index, b);
> - return ret;
> + return vb2_buf_to_ext_buf_op(vb2_ext_querybuf, q, &eb);
> }
> EXPORT_SYMBOL(vb2_querybuf);
>
> @@ -741,8 +675,8 @@ int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
> }
> EXPORT_SYMBOL_GPL(vb2_reqbufs);
>
> -int vb2_prepare_buf(struct vb2_queue *q, struct media_device *mdev,
> - struct v4l2_buffer *b)
> +int vb2_ext_prepare_buf(struct vb2_queue *q, struct media_device *mdev,
> + struct v4l2_ext_buffer *b)
> {
> int ret;
>
> @@ -758,16 +692,59 @@ int vb2_prepare_buf(struct vb2_queue *q, struct media_device *mdev,
>
> return ret ? ret : vb2_core_prepare_buf(q, b->index, b);
> }
> +EXPORT_SYMBOL_GPL(vb2_ext_prepare_buf);
> +
> +int vb2_prepare_buf(struct vb2_queue *q, struct media_device *mdev,
> + struct v4l2_buffer *b)
> +{
> + struct v4l2_ext_buffer eb;
> +
> + return vb2_buf_to_ext_buf_op(vb2_ext_prepare_buf, q, mdev, &eb);
> +}
> EXPORT_SYMBOL_GPL(vb2_prepare_buf);
>
> +int vb2_ext_create_bufs(struct vb2_queue *q,
> + struct v4l2_ext_create_buffers *create)
> +{
> + unsigned int requested_sizes[VIDEO_MAX_PLANES];
> + struct v4l2_ext_pix_format *f = &create->format;
> + int ret = vb2_verify_memory_type(q, create->memory,
> + vb2_ext_type(f->type, q->is_multiplanar));
> + unsigned i;
> +
> + if (create->format.type != V4L2_BUF_TYPE_VIDEO_CAPTURE &&
> + create->format.type != V4L2_BUF_TYPE_VIDEO_OUTPUT)
> + return -EINVAL;
> +
> + fill_buf_caps(q, &create->capabilities);
> + clear_consistency_attr(q, create->memory, &create->flags);
> + create->index = q->num_buffers;
> + if (create->count == 0)
> + return ret != -EBUSY ? ret : 0;
> +
> + if (!f->plane_fmt[0].sizeimage)
> + return -EINVAL;
> + for (i = 0; i < VIDEO_MAX_PLANES &&
> + f->plane_fmt[i].sizeimage; i++)
> + requested_sizes[i] = f->plane_fmt[i].sizeimage;
> +
> + return ret ? ret : vb2_core_create_bufs(q, create->memory,
> + create->flags,
> + &create->count,
> + i,
> + requested_sizes);
> +}
> +EXPORT_SYMBOL_GPL(vb2_ext_create_bufs);
> +
> int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
> {
> + struct v4l2_format *f = &create->format;
> unsigned requested_planes = 1;
> unsigned requested_sizes[VIDEO_MAX_PLANES];
> - struct v4l2_format *f = &create->format;
> int ret = vb2_verify_memory_type(q, create->memory, f->type);
> unsigned i;
>
> +
> fill_buf_caps(q, &create->capabilities);
> clear_consistency_attr(q, create->memory, &create->flags);
> create->index = q->num_buffers;
> @@ -777,18 +754,29 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
> switch (f->type) {
> case V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE:
> case V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE:
> - requested_planes = f->fmt.pix_mp.num_planes;
> - if (requested_planes == 0 ||
> - requested_planes > VIDEO_MAX_PLANES)
> - return -EINVAL;
> - for (i = 0; i < requested_planes; i++)
> - requested_sizes[i] =
> - f->fmt.pix_mp.plane_fmt[i].sizeimage;
> - break;
> case V4L2_BUF_TYPE_VIDEO_CAPTURE:
> - case V4L2_BUF_TYPE_VIDEO_OUTPUT:
> - requested_sizes[0] = f->fmt.pix.sizeimage;
> - break;
> + case V4L2_BUF_TYPE_VIDEO_OUTPUT: {
> + struct v4l2_ext_create_buffers ecreate = {
> + .count = create->count,
> + .memory = create->memory,
> + .flags = create->flags,
> + };
> +
> + ret = v4l2_format_to_ext_pix_format(&create->format,
> + &ecreate.format, true);
> + if (ret)
> + return ret;
> +
> + ret = vb2_ext_create_bufs(q, &ecreate);
> + if (ret)
> + return ret;
> +
> + create->index = ecreate.index;
> + create->count = ecreate.count;
> + create->flags = ecreate.flags;
> + create->capabilities = ecreate.capabilities;
> + return 0;
> + }
> case V4L2_BUF_TYPE_VBI_CAPTURE:
> case V4L2_BUF_TYPE_VBI_OUTPUT:
> requested_sizes[0] = f->fmt.vbi.samples_per_line *
> @@ -820,8 +808,8 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
> }
> EXPORT_SYMBOL_GPL(vb2_create_bufs);
>
> -int vb2_qbuf(struct vb2_queue *q, struct media_device *mdev,
> - struct v4l2_buffer *b)
> +int vb2_ext_qbuf(struct vb2_queue *q, struct media_device *mdev,
> + struct v4l2_ext_buffer *b)
> {
> struct media_request *req = NULL;
> int ret;
> @@ -839,9 +827,19 @@ int vb2_qbuf(struct vb2_queue *q, struct media_device *mdev,
> media_request_put(req);
> return ret;
> }
> +EXPORT_SYMBOL_GPL(vb2_ext_qbuf);
> +
> +int vb2_qbuf(struct vb2_queue *q, struct media_device *mdev,
> + struct v4l2_buffer *b)
> +{
> + struct v4l2_ext_buffer eb;
> +
> + return vb2_buf_to_ext_buf_op(vb2_ext_qbuf, q, mdev, &eb);
> +}
> EXPORT_SYMBOL_GPL(vb2_qbuf);
>
> -int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)
> +int vb2_ext_dqbuf(struct vb2_queue *q, struct v4l2_ext_buffer *b,
> + bool nonblocking)
> {
> int ret;
>
> @@ -850,7 +848,7 @@ int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)
> return -EBUSY;
> }
>
> - if (b->type != q->type) {
> + if (b->type != vb2_ext_qtype(q)) {
> dprintk(q, 1, "invalid buffer type\n");
> return -EINVAL;
> }
> @@ -870,6 +868,14 @@ int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)
>
> return ret;
> }
> +EXPORT_SYMBOL_GPL(vb2_ext_dqbuf);
> +
> +int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)
> +{
> + struct v4l2_ext_buffer eb;
> +
> + return vb2_buf_to_ext_buf_op(vb2_ext_dqbuf, q, &eb, nonblocking);
> +}
> EXPORT_SYMBOL_GPL(vb2_dqbuf);
>
> int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
> @@ -1040,6 +1046,33 @@ int vb2_ioctl_create_bufs(struct file *file, void *priv,
> }
> EXPORT_SYMBOL_GPL(vb2_ioctl_create_bufs);
>
> +int vb2_ioctl_ext_create_bufs(struct file *file, void *priv,
> + struct v4l2_ext_create_buffers *p)
> +{
> + struct video_device *vdev = video_devdata(file);
> + int res = vb2_verify_memory_type(vdev->queue, p->memory,
> + vb2_ext_type(p->format.type, vdev->queue->is_multiplanar));
> +
> + p->index = vdev->queue->num_buffers;
> + fill_buf_caps(vdev->queue, &p->capabilities);
> + /*
> + * 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.
> + */
> + if (p->count == 0)
> + return res != -EBUSY ? res : 0;
> + if (res)
> + return res;
> + if (vb2_queue_is_busy(vdev, file))
> + return -EBUSY;
> +
> + res = vb2_ext_create_bufs(vdev->queue, p);
> + if (res == 0)
> + vdev->queue->owner = file->private_data;
> + return res;
> +}
> +EXPORT_SYMBOL_GPL(vb2_ioctl_ext_create_bufs);
> +
> int vb2_ioctl_prepare_buf(struct file *file, void *priv,
> struct v4l2_buffer *p)
> {
> @@ -1051,6 +1084,17 @@ int vb2_ioctl_prepare_buf(struct file *file, void *priv,
> }
> EXPORT_SYMBOL_GPL(vb2_ioctl_prepare_buf);
>
> +int vb2_ioctl_ext_prepare_buf(struct file *file, void *priv,
> + struct v4l2_ext_buffer *p)
> +{
> + struct video_device *vdev = video_devdata(file);
> +
> + if (vb2_queue_is_busy(vdev, file))
> + return -EBUSY;
> + return vb2_ext_prepare_buf(vdev->queue, vdev->v4l2_dev->mdev, p);
> +}
> +EXPORT_SYMBOL_GPL(vb2_ioctl_ext_prepare_buf);
> +
> int vb2_ioctl_querybuf(struct file *file, void *priv, struct v4l2_buffer *p)
> {
> struct video_device *vdev = video_devdata(file);
> @@ -1060,6 +1104,16 @@ int vb2_ioctl_querybuf(struct file *file, void *priv, struct v4l2_buffer *p)
> }
> EXPORT_SYMBOL_GPL(vb2_ioctl_querybuf);
>
> +int vb2_ioctl_ext_querybuf(struct file *file, void *priv,
> + struct v4l2_ext_buffer *p)
> +{
> + struct video_device *vdev = video_devdata(file);
> +
> + /* No need to call vb2_queue_is_busy(), anyone can query buffers. */
> + return vb2_ext_querybuf(vdev->queue, p);
> +}
> +EXPORT_SYMBOL_GPL(vb2_ioctl_ext_querybuf);
> +
> int vb2_ioctl_qbuf(struct file *file, void *priv, struct v4l2_buffer *p)
> {
> struct video_device *vdev = video_devdata(file);
> @@ -1070,6 +1124,17 @@ int vb2_ioctl_qbuf(struct file *file, void *priv, struct v4l2_buffer *p)
> }
> EXPORT_SYMBOL_GPL(vb2_ioctl_qbuf);
>
> +int vb2_ioctl_ext_qbuf(struct file *file, void *priv,
> + struct v4l2_ext_buffer *p)
> +{
> + struct video_device *vdev = video_devdata(file);
> +
> + if (vb2_queue_is_busy(vdev, file))
> + return -EBUSY;
> + return vb2_ext_qbuf(vdev->queue, vdev->v4l2_dev->mdev, p);
> +}
> +EXPORT_SYMBOL_GPL(vb2_ioctl_ext_qbuf);
> +
> int vb2_ioctl_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p)
> {
> struct video_device *vdev = video_devdata(file);
> @@ -1080,6 +1145,17 @@ int vb2_ioctl_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p)
> }
> EXPORT_SYMBOL_GPL(vb2_ioctl_dqbuf);
>
> +int vb2_ioctl_ext_dqbuf(struct file *file, void *priv,
> + struct v4l2_ext_buffer *p)
> +{
> + struct video_device *vdev = video_devdata(file);
> +
> + if (vb2_queue_is_busy(vdev, file))
> + return -EBUSY;
> + return vb2_ext_dqbuf(vdev->queue, p, file->f_flags & O_NONBLOCK);
> +}
> +EXPORT_SYMBOL_GPL(vb2_ioctl_ext_dqbuf);
> +
> int vb2_ioctl_streamon(struct file *file, void *priv, enum v4l2_buf_type i)
> {
> struct video_device *vdev = video_devdata(file);
> diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
> index 52ef92049073e..f334767785bd9 100644
> --- a/include/media/videobuf2-core.h
> +++ b/include/media/videobuf2-core.h
> @@ -152,6 +152,8 @@ struct vb2_mem_ops {
> * @mem_priv: private data with this plane.
> * @dbuf: dma_buf - shared buffer object.
> * @dbuf_mapped: flag to show whether dbuf is mapped or not
> + * @dbuf_offset: offset where the plane starts. Usually 0, unless the buffer
> + * is shared by all planes of a multi-planar format.

The comment kind of implies that non-zero is a special case, but I wouldn't
want driver authors to come to incorrect conclusions based on that. Do we
actually need the last sentence at all?

> * @bytesused: number of bytes occupied by data in the plane (payload).
> * @length: size of this plane (NOT the payload) in bytes.
> * @min_length: minimum required size of this plane (NOT the payload) in bytes.
> @@ -175,6 +177,7 @@ struct vb2_plane {
> void *mem_priv;
> struct dma_buf *dbuf;
> unsigned int dbuf_mapped;
> + unsigned int dbuf_offset;
> unsigned int bytesused;
> unsigned int length;
> unsigned int min_length;
> @@ -446,7 +449,8 @@ struct vb2_ops {
> * struct vb2_buffer.
> * For V4L2 this is a &struct vb2_v4l2_buffer.
> * @fill_user_buffer: given a &vb2_buffer fill in the userspace structure.
> - * For V4L2 this is a &struct v4l2_buffer.
> + * For V4L2 this is a &struct v4l2_buffer or
> + * &struct v4l2_ext_buffer.

Isn't it always v4l2_ext_buffer with current code?

Best regards,
Tomasz