[PATCH v8 0/3] media: qcom: iris: add multi slice support

[Sachin Kumar Garg]

This series adds support for multi-slice encoding in the Qualcomm Iris
driver.

Multi-slice mode allows encoding a single frame into multiple slices,
which can improve error resilience and enable parallel processing.
The feature supports two slice modes:
- MAX_MB mode: slices are created based on macroblock count, controlled
  via V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MAX_MB
- MAX_BYTES mode: slices are created based on byte size, controlled via
  V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MAX_BYTES

Clients can enable slice mode using the V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MODE
control.

Patch 1 is a prerequisite fix: iris_set_stage() computes a work_mode
but never caches it back into inst->fw_caps[STAGE].value, leaving
buffer-size and clock-frequency calculations based on a stale value.

Patch 2 is another prerequisite fix: iris_set_stage() currently always
selects STAGE_2 work mode for encoder sessions, but CBR rate control
requires STAGE_1. This is fixed by forcing STAGE_1 when BITRATE_MODE is
set to CBR.

Patch 3 adds the multi-slice support itself for Iris HFI Gen2 based
targets (qcm2290, sc7280, qcs8300, sm8550 and other SM8550-derived targets).
Support for HFI Gen1 targets will be added in a follow-up series.

This series has been verified with GST level testing.
Command used:
gst-launch-1.0 -v videotestsrc ! video/x-raw,format=NV12, \
width=1280,height=720,framerate=30/1 ! v4l2h264enc output-io-mode=4 |
capture-io-mode=4 extra-controls="controls,video_bitrate_mode=1, \
slice_partitioning_method=1,number_of_mbs_in_a_slice=460;" \
! filesink location=/opt/test_enc.h264

Depends-on: message-id: 20260709-iris-ar50lt-v7-0-76af9dd4d1f6@xxxxxxxxxxxxxxxx

Changes in v8:
- Rebased on top of AR50_LT enablement series
  (https://lore.kernel.org/all/20260709-iris-ar50lt-v7-0-76af9dd4d1f6@xxxxxxxxxxxxxxxx/)
- Extend multi-slice support to VPU2 (sc7280) and AR50LT (qcm2290)
  platforms, in addition to the existing VPU3x platforms.
- Rename the shared slice_caps instance from slice_caps_vpu3x to
  iris_vpu2_vpu3x_slice_caps to reflect that it is now shared across
  VPU2 and VPU3x platforms, and wire it into sc7280_data.
- Add a new iris_ar50lt_slice_caps instance for the AR50LT platform,
  and wire it into qcm2290_data.
- Link to v7: https://lore.kernel.org/r/20260725-iris_multi_slice-v7-0-b4365c4930fe@xxxxxxxxxxxxxxxx

Changes in v7:
- Moved slice_caps_vpu3x from a static const in iris_platform_vpu3x.c
  to a real definition in iris_hfi_gen2.c, extern-declared in
  iris_platform_common.h (same pattern as iris_hfi_gen2_data), so it
  no longer has to sit between #include lines to satisfy ordering.
- Link to v6: https://lore.kernel.org/r/20260724-iris_multi_slice-v6-0-a99d160cb42a@xxxxxxxxxxxxxxxx

Changes in v6:
- Reordered local variable declarations in iris_set_slice_count() to
  follow reverse Christmas tree style.
- Renamed default_slice_caps_vpu3x to slice_caps_vpu3x.
- Link to v5: https://lore.kernel.org/r/20260724-iris_multi_slice-v5-0-4fb593d29b44@xxxxxxxxxxxxxxxx

Changes in v5:
- Fixed unbounded slice count under RC_OFF in iris_set_slice_count()
  for the MAX_BYTES use case.
- Addressed remaining coding-style review comments.
- Link to v4: https://lore.kernel.org/r/20260723-iris_multi_slice-v4-0-45f0a3fe7fce@xxxxxxxxxxxxxxxx

Changes in v4:
- Split out a new prerequisite patch (patch 1) to cache the computed
  work_mode into inst->fw_caps[STAGE].value in iris_set_stage(), since
  this fixes a pre-existing bug independent of the CBR change and
  needed its own Fixes tag.
- Deduplicated the per-target slice capability limits that were
  previously repeated identically across platform_inst_cap_qcs8300 and
  platform_inst_cap_sm8550. Introduced struct platform_inst_slice_caps
  and moved it to iris_platform_data (one level up from
  platform_inst_caps), since all Iris HFI Gen2 targets share the same
  encoder capability table and hence the same slice limits; a single
  default_slice_caps_vpu3x instance is now referenced by all Gen2
  platforms.
- Link to v3: https://lore.kernel.org/r/20260721-iris_multi_slice-v3-0-adc61a687e7e@xxxxxxxxxxxxxxxx

hanges in v3:
- Patch 1 (force stage 1 work mode for CBR RC): cache the computed
  work_mode into inst->fw_caps[STAGE].value so buffer-size and
  clock-frequency calculations stay consistent with what is actually
  configured on firmware.
- Patch 2 (multi-slice support):
  - Use inst->hfi_rc_type instead of the raw V4L2 BITRATE_MODE value
    when validating/deriving slice parameters, avoiding a mismatch
    between V4L2 and firmware rate-control enums.
  - Round up (instead of truncate) when computing the minimum
    MAX_MB and MAX_BYTES slice size floors, so the hardware's
    max-slices-per-frame limit is never exceeded.

Changes in v2:
- Added a prerequisite patch to force STAGE_1 work mode for CBR rate
  control on the encoder, required for multi-slice encoding to work
  correctly.
- Addressed review comments on the multi-slice patch (updated commit
  subject and description).

Signed-off-by: Sachin Kumar Garg <sachin.garg@xxxxxxxxxxxxxxxx>
---
Sachin Kumar Garg (3):
      media: iris: cache work mode after computing it in iris_set_stage
      media: iris: force stage 1 work mode for CBR RC on encoder
      media: iris: add support for multi_slice in iris encoder

 drivers/media/platform/qcom/iris/iris_ctrls.c      | 91 ++++++++++++++++++++++
 drivers/media/platform/qcom/iris/iris_ctrls.h      |  1 +
 drivers/media/platform/qcom/iris/iris_hfi_gen2.c   | 86 ++++++++++++++++++++
 .../platform/qcom/iris/iris_hfi_gen2_defines.h     |  2 +
 .../platform/qcom/iris/iris_platform_common.h      | 18 +++++
 .../media/platform/qcom/iris/iris_platform_vpu2.c  |  1 +
 .../media/platform/qcom/iris/iris_platform_vpu3x.c |  5 ++
 .../platform/qcom/iris/iris_platform_vpu_ar50lt.c  |  1 +
 8 files changed, 205 insertions(+)
---
base-commit: 2ba8bf550753c4ca46c708a5038a6e1690762d0f
change-id: 20260716-iris_multi_slice-5647287a9563
prerequisite-message-id: <20260709-iris-ar50lt-v7-0-76af9dd4d1f6@xxxxxxxxxxxxxxxx>
prerequisite-patch-id: 8b5a1be5778fb4c7feb069452ecb60e8b8dfc3f8
prerequisite-patch-id: e669517302297a7b315c9aa4f4189e4928091e0c
prerequisite-patch-id: 922bc325dbd9a499a3a209d2f8dbbce6a4166e60
prerequisite-patch-id: a5a49cda4e21d835558fa84f2f6bd25b8f7e72b4
prerequisite-patch-id: e62e8285bcbddade64c026379f23a8c5ae70fe52
prerequisite-patch-id: cac29b25348e2e791638a0286283109f2546f9a7
prerequisite-patch-id: 4dfaff2f9644d7a168b1b35fe947660b8f464af6
prerequisite-patch-id: a26fa49eefecf2b5ba6cf964be9327eb5ba5929a
prerequisite-patch-id: d97c79463fe1487fa7bc9eebd4cfb4610713f44a
prerequisite-patch-id: 76eafea8230160a3b5e6503c68a5c9c3c2d1497e
prerequisite-patch-id: ea9cd9a8e6561321cd9cf338a76da1382ff47e13
prerequisite-patch-id: 26e9083b709cc8f2f1184edf6b39fb89f365a9f1
prerequisite-patch-id: ce4576bd3d20880939a97a1cda9bb8678808ea65
prerequisite-patch-id: 8c94bec467b385c373bd98eb9ee5a5805fc4e6a6
prerequisite-patch-id: 6e258cd475b77927d6476704cbf91bf48a63aa0d
prerequisite-patch-id: 54c8855d0721ba8667d095e6ad6556c2021f89e9
prerequisite-patch-id: f5479d2ca6b850c0c750944a8e0b05a7df2cc5a8
prerequisite-patch-id: 96dfec1c2df69f748c1a4bd741628e946cb7bec1

Best regards,
-- 
Sachin Kumar Garg <sachin.garg@xxxxxxxxxxxxxxxx>