drm/i915/skl: Implement WaDisableLSQCROPERFforOCL

Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Reviewed-by: Nick Hoath <nicholas.hoath@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_drv.h

@@ -2396,6 +2396,7 @@ struct drm_i915_cmd_table {
 #define SKL_REVID_B0		(0x1)
 #define SKL_REVID_C0		(0x2)
 #define SKL_REVID_D0		(0x3)
+#define SKL_REVID_E0		(0x4)
 
 /*
  * The genX designation typically refers to the render engine, so render

drivers/gpu/drm/i915/i915_reg.h

@@ -5259,6 +5259,9 @@ enum skl_disp_power_wells {
 #define GEN7_L3SQCREG4				0xb034
 #define  L3SQ_URB_READ_CAM_MATCH_DISABLE	(1<<27)
 
+#define GEN8_L3SQCREG4				0xb118
+#define  GEN8_LQSC_RO_PERF_DIS			(1<<27)
+
 /* GEN8 chicken */
 #define HDC_CHICKEN0				0x7300
 #define  HDC_FENCE_DEST_SLM_DISABLE		(1<<14)

drivers/gpu/drm/i915/intel_pm.c

@@ -65,6 +65,11 @@ static void skl_init_clock_gating(struct drm_device *dev)
 			   GEN8_GAPSUNIT_CLOCK_GATE_DISABLE |
 			   GEN8_SDEUNIT_CLOCK_GATE_DISABLE);
 	}
+
+	if (INTEL_REVID(dev) <= SKL_REVID_E0)
+		/* WaDisableLSQCROPERFforOCL:skl */
+		I915_WRITE(GEN8_L3SQCREG4, I915_READ(GEN8_L3SQCREG4) |
+			   GEN8_LQSC_RO_PERF_DIS);
 }
 
 static void i915_pineview_get_mem_freq(struct drm_device *dev)