mbox series

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

Message ID 20230216002248.1851966-1-John.C.Harrison@Intel.com (mailing list archive)
Headers show
Series Don't use stolen memory or BAR mappings for ring buffers | expand

Message

John Harrison Feb. 16, 2023, 12:22 a.m. UTC 
From: John Harrison <John.C.Harrison@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@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(-)