Index: sys/powerpc/pseries/xics.c
===================================================================
--- sys/powerpc/pseries/xics.c	(revision 338943)
+++ sys/powerpc/pseries/xics.c	(working copy)
@@ -77,6 +77,7 @@
 static void	xicp_mask(device_t, u_int);
 static void	xicp_unmask(device_t, u_int);
 
+
 #ifdef POWERNV
 void	xicp_smp_cpu_startup(void);
 #endif
@@ -248,6 +249,7 @@
 
 		if (sc->xics_emu) {
 			opal_call(OPAL_INT_SET_CPPR, 0xff);
+			powerpc_sync();
 			for (i = 0; i < mp_ncpus; i++) {
 				opal_call(OPAL_INT_SET_MFRR,
 				    pcpu_find(i)->pc_hwref, 0xff);
@@ -385,8 +387,10 @@
 			if (regs)
 				bus_write_1(regs, 4, 0xff);
 #ifdef POWERNV
-			else if (sc->xics_emu)
+			else if (sc->xics_emu) {
 				opal_call(OPAL_INT_SET_CPPR, 0xff);
+				powerpc_sync();
+			}
 #endif
 			else
 				phyp_hcall(H_CPPR, (uint64_t)0xff);
@@ -471,11 +475,12 @@
 
 	if (irq == MAX_XICP_IRQS) /* Remap IPI interrupt to internal value */
 		irq = XICP_IPI;
-	xirr = irq | (XICP_PRIORITY << 24);
+	xirr = irq | (0xff << 24);
 
 #ifdef POWERNV
 	if (mfmsr() & PSL_HV) {
 		sc = device_get_softc(dev);
+		powerpc_sync();
 		if (sc->xics_emu)
 			opal_call(OPAL_INT_EOI, xirr);
 		else
@@ -570,8 +575,10 @@
 	if (mfmsr() & PSL_HV) {
 		sc = device_get_softc(root_pic);
 
-		if (sc->xics_emu)
+		if (sc->xics_emu) {
 			opal_call(OPAL_INT_SET_CPPR, 0xff);
+			powerpc_sync();
+		}
 	}
 }
 #endif