[v4,0/3] Disable automatic load CCS load balancing

Message

Andi Shyti March 6, 2024, 1:22 a.m. UTC

Hi,

I have to admit that v3 was a lazy attempt. This one should be on
the right path.

this series does basically two things:

1. Disables automatic load balancing as adviced by the hardware
   workaround.

2. Assigns all the CCS slices to one single user engine. The user
   will then be able to query only one CCS engine

I'm using here the "Requires: " tag, but I'm not sure the commit
id will be valid, on the other hand, I don't know what commit id
I should use.

Thanks Tvrtko, Matt, John and Joonas for your reviews!

Andi

Changelog
=========
v3 -> v4
- Reword correctly the comment in the workaround
- Fix a buffer overflow (Thanks Joonas)
- Handle properly the fused engines when setting the CCS mode.

v2 -> v3
- Simplified the algorithm for creating the list of the exported
  uabi engines. (Patch 1) (Thanks, Tvrtko)
- Consider the fused engines when creating the uabi engine list
  (Patch 2) (Thanks, Matt)
- Patch 4 now uses a the refactoring from patch 1, in a cleaner
  outcome.

v1 -> v2
- In Patch 1 use the correct workaround number (thanks Matt).
- In Patch 2 do not add the extra CCS engines to the exposed UABI
  engine list and adapt the engine counting accordingly (thanks
  Tvrtko).
- Reword the commit of Patch 2 (thanks John).


Andi Shyti (3):
  drm/i915/gt: Disable HW load balancing for CCS
  drm/i915/gt: Refactor uabi engine class/instance list creation
  drm/i915/gt: Enable only one CCS for compute workload

 drivers/gpu/drm/i915/gt/intel_engine_user.c | 40 ++++++++++++++-------
 drivers/gpu/drm/i915/gt/intel_gt.c          | 23 ++++++++++++
 drivers/gpu/drm/i915/gt/intel_gt_regs.h     |  6 ++++
 drivers/gpu/drm/i915/gt/intel_workarounds.c |  5 +++
 4 files changed, 62 insertions(+), 12 deletions(-)