On 10/22/21 18:48, Matthew Auld wrote:
The scratch page is directly visible in the users address space, and
while this is forced as CACHE_LLC, by the kernel, we still have to
contend with things like "Bypass-LLC" MOCS. So just flush no matter
what.
Signed-off-by: Matthew Auld <matthew.auld@xxxxxxxxx>
Cc: Thomas Hellström <thomas.hellstrom@xxxxxxxxxxxxxxx>
Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Cc: Ramalingam C <ramalingam.c@xxxxxxxxx>
---
drivers/gpu/drm/i915/gt/intel_gtt.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/gpu/drm/i915/gt/intel_gtt.c b/drivers/gpu/drm/i915/gt/intel_gtt.c
index 67d14afa6623..b6c088423319 100644
--- a/drivers/gpu/drm/i915/gt/intel_gtt.c
+++ b/drivers/gpu/drm/i915/gt/intel_gtt.c
@@ -273,6 +273,7 @@ static void poison_scratch_page(struct drm_i915_gem_object *scratch)
val = POISON_FREE;
memset(vaddr, val, scratch->base.size);
+ clflush_cache_range(vaddr, scratch->base.size);
Actually, we should probably use drm_clflush_virt_range() here?
/Thomas
}
int setup_scratch_page(struct i915_address_space *vm)
