Read the Multiprocessing Extensions bit from the Multiprocessor Affinity

register.

Sponsored by:	ABT Systems Ltd
X-Differential Revision:	https://reviews.freebsd.org/D8092

sys/arm/arm/cpuinfo.c

@@ -131,6 +131,8 @@ cpuinfo_init(void)
 	cpuinfo.generic_timer_ext = (cpuinfo.id_pfr1 >> 16) & 0xF;
 	cpuinfo.virtualization_ext = (cpuinfo.id_pfr1 >> 12) & 0xF;
 	cpuinfo.security_ext = (cpuinfo.id_pfr1 >> 4) & 0xF;
+	/* mpidr */
+	cpuinfo.mp_ext = (cpuinfo.mpidr >> 31u) & 0x1;
 
 	/* L1 Cache sizes */
 	if (CPU_CT_FORMAT(cpuinfo.ctr) == CPU_CT_ARMV7) {

sys/arm/include/cpuinfo.h

@@ -105,6 +105,9 @@ struct cpuinfo {
 	int dcache_line_mask;
 	int icache_line_size;
 	int icache_line_mask;
+
+	/* mpidr */
+	int mp_ext;
 };
 
 extern struct cpuinfo cpuinfo;