Index: sys/arm64/arm64/gic_v3.c
===================================================================
--- sys/arm64/arm64/gic_v3.c
+++ sys/arm64/arm64/gic_v3.c
@@ -48,6 +48,7 @@
 #include <vm/pmap.h>
 
 #include <machine/bus.h>
+#include <machine/cpu.h>
 #include <machine/intr.h>
 
 #include "pic_if.h"
@@ -230,7 +231,19 @@
 	uint64_t active_irq;
 
 	while (1) {
+		if (CPU_MATCH(CPU_IMPL_MASK | CPU_PART_MASK,
+		    CPU_IMPL_CAVIUM, CPU_PART_THUNDER, 0, 0)) {
+			/*
+			 * Hardware:		Cavium ThunderX
+			 * Chip revision:	Pass 1.0, Pass 1.1
+			 * ERRATUM:		22978, 23154
+			 */
+			__asm __volatile("nop;nop;nop;nop;nop;nop;nop;nop;\n"
+			    "mrs	%0, ICC_IAR1_EL1\n"
+			    "nop;nop;nop;nop;dsb sy;" : "=&r" (active_irq));
+		} else {
 			active_irq = gic_icc_read(IAR1);
+		}
 
 		if (__predict_false(active_irq == ICC_IAR1_EL1_SPUR))
 			break;