ARM: CPU hotplug: move cpu_killed completion to core code
We always need to wait for the dying CPU to reach a safe state before
taking it down, irrespective of the requirements of the platform.
Move the completion code into the ARM SMP hotplug code rather than
having each platform re-implement this.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index a30c409..8c81ff9 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -24,6 +24,7 @@
#include <linux/irq.h>
#include <linux/percpu.h>
#include <linux/clockchips.h>
+#include <linux/completion.h>
#include <asm/atomic.h>
#include <asm/cacheflush.h>
@@ -238,12 +239,20 @@
return 0;
}
+static DECLARE_COMPLETION(cpu_died);
+
/*
* called on the thread which is asking for a CPU to be shutdown -
* waits until shutdown has completed, or it is timed out.
*/
void __cpu_die(unsigned int cpu)
{
+ if (!wait_for_completion_timeout(&cpu_died, msecs_to_jiffies(5000))) {
+ pr_err("CPU%u: cpu didn't die\n", cpu);
+ return;
+ }
+ printk(KERN_NOTICE "CPU%u: shutdown\n", cpu);
+
if (!platform_cpu_kill(cpu))
printk("CPU%u: unable to kill\n", cpu);
}
@@ -263,9 +272,12 @@
local_irq_disable();
idle_task_exit();
+ /* Tell __cpu_die() that this CPU is now safe to dispose of */
+ complete(&cpu_died);
+
/*
* actual CPU shutdown procedure is at least platform (if not
- * CPU) specific
+ * CPU) specific.
*/
platform_cpu_die(cpu);