drm/i915/guc: Enable the timer expired interrupt for GuC

The GuC can implement execution qunatums, detect hung contexts and
other such things but it requires the timer expired interrupt to do so.
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
CC: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210727002348.97202-15-matthew.brost@intel.com

drivers/gpu/drm/i915/gt/intel_rps.c

@@ -1877,6 +1877,10 @@ void intel_rps_init(struct intel_rps *rps)
 
 	if (GRAPHICS_VER(i915) >= 8 && GRAPHICS_VER(i915) < 11)
 		rps->pm_intrmsk_mbz |= GEN8_PMINTR_DISABLE_REDIRECT_TO_GUC;
+
+	/* GuC needs ARAT expired interrupt unmasked */
+	if (intel_uc_uses_guc_submission(&rps_to_gt(rps)->uc))
+		rps->pm_intrmsk_mbz |= ARAT_EXPIRED_INTRMSK;
 }
 
 void intel_rps_sanitize(struct intel_rps *rps)