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

[Andi Shyti <andi.shyti@linux.intel.com>]

The hardware is not able to dynamically balance the load between
CCS engines. Wa_16016805146 suggests disabling it for all
platforms.

Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Cc: Chris Wilson <chris.p.wilson@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>
Cc: Tejas Upadhyay <tejas.upadhyay@intel.com>
---
 drivers/gpu/drm/i915/gt/intel_gt_regs.h     | 1 +
 drivers/gpu/drm/i915/gt/intel_workarounds.c | 6 ++++++
 2 files changed, 7 insertions(+)

diff --git a/drivers/gpu/drm/i915/gt/intel_gt_regs.h b/drivers/gpu/drm/i915/gt/intel_gt_regs.h
index 3e558d6d5e89..edaa446abd91 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 3eacbc50caf8..a7718f7d2925 100644
--- a/drivers/gpu/drm/i915/gt/intel_workarounds.c
+++ b/drivers/gpu/drm/i915/gt/intel_workarounds.c
@@ -2978,6 +2978,12 @@ general_render_compute_wa_init(struct intel_engine_cs *engine, struct i915_wa_li
 		wa_mcr_masked_en(wal, GEN8_HALF_SLICE_CHICKEN1,
 				 GEN7_PSD_SINGLE_PORT_DISPATCH_ENABLE);
 	}
+
+	/*
+	 * Wa_16016805146: disable the CCS load balancing
+	 * indiscriminately for all the platforms
+	 */
+	wa_masked_en(wal, GEN12_RCU_MODE, XEHP_RCU_MODE_FIXED_SLICE_CCS_MODE);
 }
 
 static void
-- 
2.43.0