ARM: 8872/1: Use common outgoing-CPU-notification code
authorPaul E. McKenney <paulmck@linux.ibm.com>
Wed, 26 Jun 2019 16:39:18 +0000 (17:39 +0100)
committerRussell King <rmk+kernel@armlinux.org.uk>
Fri, 23 Aug 2019 10:38:45 +0000 (11:38 +0100)
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
Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
arch/arm/kernel/smp.c

index aab8ba4..4b0bab2 100644 (file)
@@ -264,15 +264,13 @@ 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;
        }
@@ -319,7 +317,7 @@ 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