[Intel-gfx] [RFC PATCH 0/4] drm/i915: implement NOA mux reprogramming at ctx-switch

[Lionel Landwerlin]

I forgot to mentioned this was tested on SKL GT4 using 2 OA/NOA 
configurations that exposes :

      1. signals of the state of power on each slice/subslice
      2. signals of the number of sampler cache misses on each slice

We verified that the counters incrementing on those signals return to 
normal values when you switch between 2 different context with 2 
different RPCS configurations (as opposed to running the same 
configurations without this series).
We used Chris's series to expose RPCS configuration to userspace : 
https://github.com/djdeath/linux/commit/b2ea9b16ef1377f808be4d4c60f5f23596517f49
You can pull the branch with those changes here : 
https://github.com/djdeath/linux/commits/wip/djdeath/oa-next-slice-control

Cheers,

-
Lionel

On 30/08/17 19:20, Lionel Landwerlin wrote:
> Hi all,
>
> This little series implements NOA muxes reprogramming on context
> switch through the per context batch buffer.
>
> NOA muxes resides in slices & subslices, which makes their
> configuration subject to loss when a slice or subslice is shutdown.
> The goal of this series is to restore the configuration on context
> switch. It currently reloads all configurations on context switch but
> we may be able to be a bit more clever by copying the last RPCS
> configuration in memory and compare the current configuration before
> executing all the MI_LRIs using a MI_PREDICATE.
>
> Looking forward to comments!
>
> Cheers,
>
> Lionel Landwerlin (4):
>    drm/i915: use same define size for wa_bb pin/allocation
>    drm/i915: extract per-ctx/indirect bb programming
>    drm/i915: pass wa_ctx as argument
>    drm/i915: reprogram NOA muxes on context switch when using perf
>
>   drivers/gpu/drm/i915/i915_drv.h  |   2 +
>   drivers/gpu/drm/i915/i915_perf.c |  77 +++++++++++++++++++++++++++
>   drivers/gpu/drm/i915/intel_lrc.c | 110 ++++++++++++++++++++++++++++++---------
>   drivers/gpu/drm/i915/intel_lrc.h |   1 +
>   4 files changed, 166 insertions(+), 24 deletions(-)
>
> --
> 2.14.1
>