[Intel-gfx] [PATCH 1/2] drm/i915: Whitelist COMMON_SLICE_CHICKEN3 for UMD access

[Matt Roper]

A recommended tuning setting for both gen12 and Xe_HP platforms requires
that we grant userspace r/w access to the COMMON_SLICE_CHICKEN3
register.

Bspec: 73993, 73994, 31870, 68331
Cc: Dongwon Kim <dongwon.kim at intel.com>
Signed-off-by: Matt Roper <matthew.d.roper at intel.com>
---
The bspec update to add COMMON_SLICE_CHICKEN3 to the tuning guide pages
is still pending at the moment, but should be finalized shortly.

 drivers/gpu/drm/i915/gt/intel_workarounds.c | 25 ++++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_workarounds.c b/drivers/gpu/drm/i915/gt/intel_workarounds.c
index 1ef9c9fa2eff..0444c715998a 100644
--- a/drivers/gpu/drm/i915/gt/intel_workarounds.c
+++ b/drivers/gpu/drm/i915/gt/intel_workarounds.c
@@ -2194,6 +2194,10 @@ static void tgl_whitelist_build(struct intel_engine_cs *engine)
 
 		/* Wa_1806527549:tgl */
 		whitelist_reg(w, HIZ_CHICKEN);
+
+		/* Required by recommended tuning setting (not a workaround) */
+		whitelist_reg(w, GEN11_COMMON_SLICE_CHICKEN3);
+
 		break;
 	default:
 		break;
@@ -2227,6 +2231,9 @@ static void dg2_whitelist_build(struct intel_engine_cs *engine)
 					  RING_FORCE_TO_NONPRIV_ACCESS_RD |
 					  RING_FORCE_TO_NONPRIV_RANGE_4);
 
+		/* Required by recommended tuning setting (not a workaround) */
+		whitelist_mcr_reg(w, XEHP_COMMON_SLICE_CHICKEN3);
+
 		break;
 	case COMPUTE_CLASS:
 		/* Wa_16011157294:dg2_g10 */
@@ -2264,6 +2271,22 @@ static void pvc_whitelist_build(struct intel_engine_cs *engine)
 	blacklist_trtt(engine);
 }
 
+static void mtl_whitelist_build(struct intel_engine_cs *engine)
+{
+	struct i915_wa_list *w = &engine->whitelist;
+
+	switch (engine->class) {
+	case RENDER_CLASS:
+		/* Required by recommended tuning setting (not a workaround) */
+		whitelist_mcr_reg(w, XEHP_COMMON_SLICE_CHICKEN3);
+
+		break;
+	default:
+		break;
+	}
+
+}
+
 void intel_engine_init_whitelist(struct intel_engine_cs *engine)
 {
 	struct drm_i915_private *i915 = engine->i915;
@@ -2272,7 +2295,7 @@ void intel_engine_init_whitelist(struct intel_engine_cs *engine)
 	wa_init_start(w, engine->gt, "whitelist", engine->name);
 
 	if (IS_METEORLAKE(i915))
-		; /* noop; none at this time */
+		mtl_whitelist_build(engine);
 	else if (IS_PONTEVECCHIO(i915))
 		pvc_whitelist_build(engine);
 	else if (IS_DG2(i915))
-- 
2.39.1