From: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx>
Now that i915 understands the caching modes behind PAT indices, we can
refine the check in vm_fault_gtt() to not reject the uncached PAT if it
was set by userspace on a snoopable platform.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx>
Cc: Fei Yang <fei.yang@xxxxxxxxx>
Cc: Matt Roper <matthew.d.roper@xxxxxxxxx>
---
drivers/gpu/drm/i915/gem/i915_gem_mman.c | 14 +++-----------
1 file changed, 3 insertions(+), 11 deletions(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_mman.c b/drivers/gpu/drm/i915/gem/i915_gem_mman.c
index cd7f8ded0d6f..9aa6ecf68432 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_mman.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_mman.c
@@ -382,17 +382,9 @@ static vm_fault_t vm_fault_gtt(struct vm_fault *vmf)
goto err_reset;
}
- /*
- * For objects created by userspace through GEM_CREATE with pat_index
- * set by set_pat extension, coherency is managed by userspace, make
- * sure we don't fail handling the vm fault by calling
- * i915_gem_object_has_cache_level() which always return true for such
- * objects. Otherwise this helper function would fall back to checking
- * whether the object is un-cached.
- */
- if (!((obj->pat_set_by_user ||
- i915_gem_object_has_cache_mode(obj, I915_CACHE_MODE_UC)) ||
- HAS_LLC(i915))) {
+ /* Access to snoopable pages through the GTT is incoherent. */
+ if (!i915_gem_object_has_cache_mode(obj, I915_CACHE_MODE_UC) &&
+ !HAS_LLC(i915)) {
ret = -EFAULT;
goto err_unpin;
}
--
2.39.2
