drm/xe/guc: Adding steering info support for GuC register lists

The guc_mmio_reg interface supports steering, but it is currently not
implemented. This will allow the GuC to control steering of MMIO
registers after save-restore and avoid reading from fused off MCR
register instances.

Fixes: 9c57bc0 ("drm/xe/lnl: Drop force_probe requirement")
Signed-off-by: Jesus Narvaez <jesus.narvaez@intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241212190100.3768068-1-jesus.narvaez@intel.com

drivers/gpu/drm/xe/xe_gt_mcr.c

@@ -550,9 +550,9 @@ void xe_gt_mcr_set_implicit_defaults(struct xe_gt *gt)
  * Returns true if the caller should steer to the @group/@instance values
  * returned.  Returns false if the caller need not perform any steering
  */
-static bool xe_gt_mcr_get_nonterminated_steering(struct xe_gt *gt,
-						 struct xe_reg_mcr reg_mcr,
-						 u8 *group, u8 *instance)
+bool xe_gt_mcr_get_nonterminated_steering(struct xe_gt *gt,
+					  struct xe_reg_mcr reg_mcr,
+					  u8 *group, u8 *instance)
 {
 	const struct xe_reg reg = to_xe_reg(reg_mcr);
 	const struct xe_mmio_range *implicit_ranges;

drivers/gpu/drm/xe/xe_gt_mcr.h

@@ -26,6 +26,10 @@ void xe_gt_mcr_unicast_write(struct xe_gt *gt, struct xe_reg_mcr mcr_reg,
 void xe_gt_mcr_multicast_write(struct xe_gt *gt, struct xe_reg_mcr mcr_reg,
 			       u32 value);
 
+bool xe_gt_mcr_get_nonterminated_steering(struct xe_gt *gt,
+					  struct xe_reg_mcr reg_mcr,
+					  u8 *group, u8 *instance);
+
 void xe_gt_mcr_steering_dump(struct xe_gt *gt, struct drm_printer *p);
 void xe_gt_mcr_get_dss_steering(struct xe_gt *gt, unsigned int dss, u16 *group, u16 *instance);
 u32 xe_gt_mcr_steering_info_to_dss_id(struct xe_gt *gt, u16 group, u16 instance);

drivers/gpu/drm/xe/xe_guc_ads.c

@@ -29,6 +29,7 @@
 #include "xe_platform_types.h"
 #include "xe_uc_fw.h"
 #include "xe_wa.h"
+#include "xe_gt_mcr.h"
 
 /* Slack of a few additional entries per engine */
 #define ADS_REGSET_EXTRA_MAX	8
@@ -696,6 +697,20 @@ static void guc_mmio_regset_write_one(struct xe_guc_ads *ads,
 		.flags = reg.masked ? GUC_REGSET_MASKED : 0,
 	};
 
+	if (reg.mcr) {
+		struct xe_reg_mcr mcr_reg = XE_REG_MCR(reg.addr);
+		u8 group, instance;
+
+		bool steer = xe_gt_mcr_get_nonterminated_steering(ads_to_gt(ads), mcr_reg,
+								  &group, &instance);
+
+		if (steer) {
+			entry.flags |= FIELD_PREP(GUC_REGSET_STEERING_GROUP, group);
+			entry.flags |= FIELD_PREP(GUC_REGSET_STEERING_INSTANCE, instance);
+			entry.flags |= GUC_REGSET_STEERING_NEEDED;
+		}
+	}
+
 	xe_map_memcpy_to(ads_to_xe(ads), regset_map, n_entry * sizeof(entry),
 			 &entry, sizeof(entry));
 }