[PATCH 5.9 46/46] drm/i915/gt: Fixup tgl mocs for PTE tracking

[Greg Kroah-Hartman]

From: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>

commit be33805c65297611971003d72e7f9235e23ec84d upstream.

Forcing mocs:1 [used for our winsys follows-pte mode] to be cached
caused display glitches. Though it is documented as deprecated (and so
likely behaves as uncached) use the follow-pte bit and force it out of
L3 cache.

Testcase: igt/kms_frontbuffer_tracking
Testcase: igt/kms_big_fb
Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Cc: Ayaz A Siddiqui <ayaz.siddiqui@xxxxxxxxx>
Cc: Lucas De Marchi <lucas.demarchi@xxxxxxxxx>
Cc: Matt Roper <matthew.d.roper@xxxxxxxxx>
Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Cc: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx>
Reviewed-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20201015122138.30161-4-chris@xxxxxxxxxxxxxxxxxx
(cherry picked from commit a04ac827366594c7244f60e9be79fcb404af69f0)
Fixes: 849c0fe9e831 ("drm/i915/gt: Initialize reserved and unspecified MOCS indices")
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
[Rodrigo: Updated Fixes tag]
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/gpu/drm/i915/gt/intel_mocs.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

--- a/drivers/gpu/drm/i915/gt/intel_mocs.c
+++ b/drivers/gpu/drm/i915/gt/intel_mocs.c
@@ -243,8 +243,9 @@ static const struct drm_i915_mocs_entry
 	 * only, __init_mocs_table() take care to program unused index with
 	 * this entry.
 	 */
-	MOCS_ENTRY(1, LE_3_WB | LE_TC_1_LLC | LE_LRUM(3),
-		   L3_3_WB),
+	MOCS_ENTRY(I915_MOCS_PTE,
+		   LE_0_PAGETABLE | LE_TC_0_PAGETABLE,
+		   L3_1_UC),
 	GEN11_MOCS_ENTRIES,
 
 	/* Implicitly enable L1 - HDC:L1 + L3 + LLC */