[ARM SMP] Add hotplug CPU infrastructure

This patch adds the infrastructure to support hotplug CPU on ARM
platforms.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 9 insertions, 0 deletions

diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 409db6d5ec99..ba298277becd 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -26,6 +26,7 @@
 #include <linux/interrupt.h>
 #include <linux/kallsyms.h>
 #include <linux/init.h>
+#include <linux/cpu.h>
 
 #include <asm/system.h>
 #include <asm/io.h>
@@ -105,6 +106,14 @@ void cpu_idle(void)
         /* endless idle loop with no priority at all */
         while (1) {
                 void (*idle)(void) = pm_idle;
+
+#ifdef CONFIG_HOTPLUG_CPU
+                if (cpu_is_offline(smp_processor_id())) {
+                        leds_event(led_idle_start);
+                        cpu_die();
+                }
+#endif
+
                 if (!idle)
                         idle = default_idle;
                 preempt_disable();