[PATCH v2 0/2] Don't use stolen memory or BAR mappings for ring buffers

John.C.Harrison at Intel.com John.C.Harrison at Intel.com
Thu Feb 16 00:22:46 UTC 2023


From: John Harrison <John.C.Harrison at Intel.com>

Instruction from hardware arch is that stolen memory and BAR mappings
are unsafe for use as ring buffers. There can be issues with cache
aliasing due to the CPU access going to memory via the BAR. So, don't
do it.

v2: Dont use BAR mappings either.
Make conditional on LLC so as not to change platforms that don't need
to change (Daniele).
Add 'Fixes' tags (Tvrtko).

Signed-off-by: John Harrison <John.C.Harrison at Intel.com>


Daniele Ceraolo Spurio (1):
  drm/i915: Don't use BAR mappings for ring buffers with LLC

John Harrison (1):
  drm/i915: Don't use stolen memory for ring buffers with LLC

 drivers/gpu/drm/i915/gt/intel_ring.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

-- 
2.39.1



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