drm/xe/gsc: Implement WA 14018094691

The WA states that we need to keep the primary GT powered up during GSC
load to allow the GSC FW to access its registers. We also need to make
sure that one of the registers is locked before starting the load.

v2: fix location of register def (Matt)

Bspec: 55928
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240326224456.518548-1-daniele.ceraolospurio@intel.com

drivers/gpu/drm/xe/regs/xe_gt_regs.h

@@ -370,6 +370,9 @@
 #define RT_CTRL					XE_REG_MCR(0xe530)
 #define   DIS_NULL_QUERY			REG_BIT(10)
 
+#define EU_SYSTOLIC_LIC_THROTTLE_CTL_WITH_LOCK	XE_REG_MCR(0xe534)
+#define   EU_SYSTOLIC_LIC_THROTTLE_CTL_LOCK_BIT	REG_BIT(31)
+
 #define XEHP_HDC_CHICKEN0					XE_REG_MCR(0xe5f0, XE_REG_OPTION_MASKED)
 #define   LSC_L1_FLUSH_CTL_3D_DATAPORT_FLUSH_EVENTS_MASK	REG_GENMASK(13, 11)
 #define   DIS_ATOMIC_CHAINING_TYPED_WRITES	REG_BIT(3)

drivers/gpu/drm/xe/xe_gsc.c

@@ -17,6 +17,7 @@
 #include "xe_gsc_proxy.h"
 #include "xe_gsc_submit.h"
 #include "xe_gt.h"
+#include "xe_gt_mcr.h"
 #include "xe_gt_printk.h"
 #include "xe_huc.h"
 #include "xe_map.h"
@@ -252,9 +253,30 @@ static int gsc_upload(struct xe_gsc *gsc)
 static int gsc_upload_and_init(struct xe_gsc *gsc)
 {
 	struct xe_gt *gt = gsc_to_gt(gsc);
+	struct xe_tile *tile = gt_to_tile(gt);
 	int ret;
 
+	if (XE_WA(gt, 14018094691)) {
+		ret = xe_force_wake_get(gt_to_fw(tile->primary_gt), XE_FORCEWAKE_ALL);
+
+		/*
+		 * If the forcewake fails we want to keep going, because the worst
+		 * case outcome in failing to apply the WA is that PXP won't work,
+		 * which is not fatal. We still throw a warning so the issue is
+		 * seen if it happens.
+		 */
+		xe_gt_WARN_ON(tile->primary_gt, ret);
+
+		xe_gt_mcr_multicast_write(tile->primary_gt,
+					  EU_SYSTOLIC_LIC_THROTTLE_CTL_WITH_LOCK,
+					  EU_SYSTOLIC_LIC_THROTTLE_CTL_LOCK_BIT);
+	}
+
 	ret = gsc_upload(gsc);
+
+	if (XE_WA(gt, 14018094691))
+		xe_force_wake_put(gt_to_fw(tile->primary_gt), XE_FORCEWAKE_ALL);
+
 	if (ret)
 		return ret;
 

drivers/gpu/drm/xe/xe_wa_oob.rules

@@ -19,3 +19,4 @@
 		GRAPHICS_VERSION_RANGE(1270, 1274)
 		MEDIA_VERSION(1300)
 		PLATFORM(DG2)
+14018094691	GRAPHICS_VERSION(2004)