Add DELETE_BUF ioctl

Unlike when resolution change on keyframes, dynamic resolution change
on inter frames doesn't allow to do a stream off/on sequence because
it is need to keep all previous references alive to decode inter frames.
This constraint have two main problems:
- more memory consumption.
- more buffers in use.
To solve these issue this series introduce DELETE_BUFS ioctl and remove
the 32 buffers limit per queue.

VP9 conformance tests using fluster give a score of 210/305.
The 24 resize inter tests (vp90-2-21-resize_inter_* files) are ok
but require to use postprocessor.

Kernel branch is available here:
https://gitlab.collabora.com/benjamin.gaignard/for-upstre...

GStreamer branch to use DELETE_BUF ioctl and testing dynamic resolution
change is here:
https://gitlab.freedesktop.org/benjamin.gaignard1/gstream...

changes in version 4:
- Stop using Xarray, instead let queues decide about their own maximum
  number of buffer and allocate bufs array given that value.
- Rework offset cookie encoding pattern.
- Change DELETE_BUF to DELETE_BUFS because it now usable for
  range of buffer to be symetrical of CREATE_BUFS.
- Add fixes tags on couple of Verisilicon related patches.
- Be smarter in Verisilicon postprocessor buffers management.
- Rebase on top of v6.4

changes in version 3:
- Use Xarray API to store allocated video buffers.
- No module parameter to limit the number of buffer per queue.
- Use Xarray inside Verisilicon driver to store postprocessor buffers
  and remove VB2_MAX_FRAME limit.
- Allow Versilicon driver to change of resolution while streaming
- Various fixes the Verisilicon VP9 code to improve fluster score.
 
changes in version 2:
- Use a dynamic array and not a list to keep trace of allocated buffers.
  Not use IDR interface because it is marked as deprecated in kernel
  documentation.
- Add a module parameter to limit the number of buffer per queue.
- Add DELETE_BUF ioctl and m2m helpers.
 
Benjamin Gaignard (10):
  media: videobuf2: Access vb2_queue bufs array through helper functions
  media: videobuf2: Be more flexible on the number of queue stored
    buffers
  media: videobuf2: Rework offset 'cookie' encoding pattern
  media: verisilicon: Refactor postprocessor to store more buffers
  media: verisilicon: Store chroma and motion vectors offset
  media: verisilicon: vp9: Use destination buffer height to compute
    chroma offset
  media: verisilicon: postproc: Fix down scale test
  media: verisilicon: vp9: Allow to change resolution while streaming
  media: v4l2: Add DELETE_BUFS ioctl
  media: v4l2: Add mem2mem helpers for DELETE_BUFS ioctl

 .../userspace-api/media/v4l/user-func.rst     |   1 +
 .../media/v4l/vidioc-delete-bufs.rst          |  73 +++++
 .../media/common/videobuf2/videobuf2-core.c   | 304 +++++++++++++-----
 .../media/common/videobuf2/videobuf2-v4l2.c   |  44 ++-
 drivers/media/platform/amphion/vpu_dbg.c      |  22 +-
 .../platform/mediatek/jpeg/mtk_jpeg_core.c    |   6 +-
 .../vcodec/vdec/vdec_vp9_req_lat_if.c         |   2 +-
 drivers/media/platform/st/sti/hva/hva-v4l2.c  |   4 +
 drivers/media/platform/verisilicon/hantro.h   |   9 +-
 .../media/platform/verisilicon/hantro_drv.c   |   4 +-
 .../platform/verisilicon/hantro_g2_vp9_dec.c  |  10 +-
 .../media/platform/verisilicon/hantro_hw.h    |   2 +-
 .../platform/verisilicon/hantro_postproc.c    | 105 ++++--
 .../media/platform/verisilicon/hantro_v4l2.c  |  27 +-
 drivers/media/test-drivers/vim2m.c            |   1 +
 drivers/media/test-drivers/visl/visl-dec.c    |  28 +-
 drivers/media/v4l2-core/v4l2-dev.c            |   1 +
 drivers/media/v4l2-core/v4l2-ioctl.c          |  17 +
 drivers/media/v4l2-core/v4l2-mem2mem.c        |  20 ++
 .../staging/media/atomisp/pci/atomisp_ioctl.c |   2 +-
 include/media/v4l2-ioctl.h                    |   4 +
 include/media/v4l2-mem2mem.h                  |  12 +
 include/media/videobuf2-core.h                |  13 +-
 include/media/videobuf2-v4l2.h                |  11 +
 include/uapi/linux/videodev2.h                |  17 +
 25 files changed, 592 insertions(+), 147 deletions(-)
 create mode 100644 Documentation/userspace-api/media/v4l/vidioc-delete-bufs.rst

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2.39.2