isl: Set MOCS to uncached for Gfx12.0 blitter sources/destinationsHEADmain

We were accidentally leaving XY_BLOCK_COPY_BLT's Source and Destination
MOCS fields set to 0 (Error: Reserved for Non-Use) on Gfx12.0 systems.
This was causing assert fails in debug builds, since we try to ensure
that we don't do that.  In theory, MOCS 0 is supposed to be equivalent
to MOCS 2 (all the caching), but...we probably ought to use MOCS 3
(uncached).  Every Gfx12.5+ platform requires it, so although there
isn't a note about Gfx12.0 needing that, it's possible that it does.
We're currently only using the blitter for DRI PRIME blits on Gfx12.0,
anyway, and I think we're flushing all the caches regardless.

This bug was somewhat obscure to hit:
- You need a hybrid graphics system with Gfx12.0 and some other GPU
- You have to be using "reverse PRIME", i.e. rendering on the integrated
  GPU and displaying on the discrete one.  This is not the common case.
- You have to be using a debug build.

No observable performance delta in GfxBench5 Car Chase (an arbitrary
program) when rendering on Alderlake GT1 and displaying on an Arc A770.

Fixes: 194afe84163 ("anv/iris/blorp: use the right MOCS values for each engine")
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Rohan Garg <rohan.garg@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/28894>

0 files changed, 0 insertions, 0 deletions