MIPS: Cavium: Add CPU hotplugging code.

Thanks to Cavium Inc. for the code contribution and help.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/include/asm/smp.h

@@ -41,7 +41,7 @@ extern int __cpu_logical_map[NR_CPUS];
 /* Octeon - Tell another core to flush its icache */
 #define SMP_ICACHE_FLUSH	0x4
 
-extern cpumask_t cpu_callin_map;
+extern volatile cpumask_t cpu_callin_map;
 
 extern void asmlinkage smp_bootstrap(void);