arm: Use common outgoing-CPU-notification code

This commit removes the open-coded CPU-offline notification with new
common code.  In particular, this change avoids calling scheduler code
using RCU from an offline CPU that RCU is ignoring.  This is a minimal
change.  A more intrusive change might invoke the cpu_check_up_prepare()
and cpu_set_state_online() functions at CPU-online time, which would
allow onlining throw an error if the CPU did not go offline properly.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Russell King <linux@arm.linux.org.uk>
[commit rejected in mainline, but needed on Exynos platform to fix
suspicious RCU usage during suspend/resume]
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Change-Id: I26ba637d48fc3264e1b79507cfd0cb82bb5e6390

diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index 5e31c62..80811a4 100644 (file)
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -242,15 +242,13 @@ int __cpu_disable(void)
        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))) {
+       if (!cpu_wait_death(cpu, 5)) {
                pr_err("CPU%u: cpu didn't die\n", cpu);
                return;
        }
@@ -296,7 +294,7 @@ void arch_cpu_idle_dead(void)
         * this returns, power and/or clocks can be removed at any point
         * from this CPU and its cache by platform_cpu_kill().
         */
-       complete(&cpu_died);
+       (void)cpu_report_death();
 
        /*
         * Ensure that the cache lines associated with that completion are