[PATCH v4 1/3] drm/i915/gt: Disable HW load balancing for CCS

[Andi Shyti]

The hardware should not dynamically balance the load between CCS
engines. Wa_14019159160 recommends disabling it across all
platforms.

Fixes: d2eae8e98d59 ("drm/i915/dg2: Drop force_probe requirement")
Signed-off-by: Andi Shyti <andi.shyti at linux.intel.com>
Cc: Chris Wilson <chris.p.wilson at linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
Cc: Matt Roper <matthew.d.roper at intel.com>
Cc: <stable at vger.kernel.org> # v6.2+
---
 drivers/gpu/drm/i915/gt/intel_gt_regs.h     | 1 +
 drivers/gpu/drm/i915/gt/intel_workarounds.c | 5 +++++
 2 files changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/i915/gt/intel_gt_regs.h b/drivers/gpu/drm/i915/gt/intel_gt_regs.h
index 50962cfd1353..cf709f6c05ae 100644
--- a/drivers/gpu/drm/i915/gt/intel_gt_regs.h
+++ b/drivers/gpu/drm/i915/gt/intel_gt_regs.h
@@ -1478,6 +1478,7 @@
 
 #define GEN12_RCU_MODE				_MMIO(0x14800)
 #define   GEN12_RCU_MODE_CCS_ENABLE		REG_BIT(0)
+#define   XEHP_RCU_MODE_FIXED_SLICE_CCS_MODE	REG_BIT(1)
 
 #define CHV_FUSE_GT				_MMIO(VLV_GUNIT_BASE + 0x2168)
 #define   CHV_FGT_DISABLE_SS0			(1 << 10)
diff --git a/drivers/gpu/drm/i915/gt/intel_workarounds.c b/drivers/gpu/drm/i915/gt/intel_workarounds.c
index d67d44611c28..a2e78cf0b5f5 100644
--- a/drivers/gpu/drm/i915/gt/intel_workarounds.c
+++ b/drivers/gpu/drm/i915/gt/intel_workarounds.c
@@ -2945,6 +2945,11 @@ general_render_compute_wa_init(struct intel_engine_cs *engine, struct i915_wa_li
 
 		/* Wa_18028616096 */
 		wa_mcr_write_or(wal, LSC_CHICKEN_BIT_0_UDW, UGM_FRAGMENT_THRESHOLD_TO_3);
+
+		/*
+		 * Wa_14019159160: disable the automatic CCS load balancing
+		 */
+		wa_masked_en(wal, GEN12_RCU_MODE, XEHP_RCU_MODE_FIXED_SLICE_CCS_MODE);
 	}
 
 	if (IS_DG2_G11(i915)) {
-- 
2.43.0