[Intel-gfx] [PATCH 00/13] Forcewake binary search & code shrink

[Jani Nikula]

On Thu, 29 Sep 2016, Tvrtko Ursulin <tursulin at ursulin.net> wrote:
> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
>
> A bunch of cleaned up patches from one of my old branches. Just an idea I had
> been toying about and probably more a RFC at this point. But it amazingly
> passed trybot on (almost) the first try so I got tempted to post it.
>
> Basically main motivation was to replace linear search comparison ladders in
> all mmio accessors with something smarter - a binary search in this case.
>
> Main enabler is moving the comparison ladders from the code into the data
> tables. Then gradually, patch by patch, I was able to reduce the code and
> end up with a total saving of approximately 14KiB for the series.
>
> That is kind of nice, but whether the churn is worth it I leave open for
> dicussion. It is slightly less code so perhaps more maintainable. Although
> tastes will probably differ.

Glanced through it quickly, I think the new stuff looks prettier and
more manageable. I'm not opposed.

BR,
Jani.


>
> And I haven't been able to do any benchmarking to see if any performance
> differece is at all detectable.
>
> Tvrtko Ursulin (13):
>   drm/i915: Remove redundant hsw_write* mmio functions
>   drm/i915: Keep track of active forcewake domains in a bitmask
>   drm/i915: Do not inline forcewake taking in mmio accessors
>   drm/i915: Data driven register to forcewake domains lookup
>   drm/i915: Sort forcewake mapping tables
>   drm/i915: Use binary search when looking up forcewake domains
>   drm/i915: Eliminate Gen9 special case
>   drm/i915: Store the active forcewake range table pointer
>   drm/i915: Remove identical macros
>   drm/i915: Remove identical mmio read functions
>   drm/i915: Remove identical write mmmio functions
>   drm/i915: Sort the shadow register table
>   drm/i915: Use binary search when looking for shadowed registers
>
>  drivers/gpu/drm/i915/i915_drv.h     |  13 +
>  drivers/gpu/drm/i915/intel_uncore.c | 525 ++++++++++++++++--------------------
>  2 files changed, 247 insertions(+), 291 deletions(-)

-- 
Jani Nikula, Intel Open Source Technology Center