Merge tag 'trace-3.16' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux...

[firefly-linux-kernel-4.4.55.git] / arch / arm / kernel / psci_smp.c

diff --git a/arch/arm/kernel/psci_smp.c b/arch/arm/kernel/psci_smp.c
index 570a48cc3d64b1714bd711c4b4cc4a6d1ab1358c..28a1db4da70428cbc286f80359eeae5bbdcd8057 100644 (file)
--- a/arch/arm/kernel/psci_smp.c
+++ b/arch/arm/kernel/psci_smp.c
@@ -16,6 +16,8 @@
 #include <linux/init.h>
 #include <linux/smp.h>
 #include <linux/of.h>
+#include <linux/delay.h>
+#include <uapi/linux/psci.h>
 
 #include <asm/psci.h>
 #include <asm/smp_plat.h>
@@ -66,6 +68,36 @@ void __ref psci_cpu_die(unsigned int cpu)
        /* We should never return */
        panic("psci: cpu %d failed to shutdown\n", cpu);
 }
+
+int __ref psci_cpu_kill(unsigned int cpu)
+{
+       int err, i;
+
+       if (!psci_ops.affinity_info)
+               return 1;
+       /*
+        * cpu_kill could race with cpu_die and we can
+        * potentially end up declaring this cpu undead
+        * while it is dying. So, try again a few times.
+        */
+
+       for (i = 0; i < 10; i++) {
+               err = psci_ops.affinity_info(cpu_logical_map(cpu), 0);
+               if (err == PSCI_0_2_AFFINITY_LEVEL_OFF) {
+                       pr_info("CPU%d killed.\n", cpu);
+                       return 1;
+               }
+
+               msleep(10);
+               pr_info("Retrying again to check for CPU kill\n");
+       }
+
+       pr_warn("CPU%d may not have shut down cleanly (AFFINITY_INFO reports %d)\n",
+                       cpu, err);
+       /* Make platform_cpu_kill() fail. */
+       return 0;
+}
+
 #endif
 
 bool __init psci_smp_available(void)
@@ -78,5 +110,6 @@ struct smp_operations __initdata psci_smp_ops = {
        .smp_boot_secondary     = psci_boot_secondary,
 #ifdef CONFIG_HOTPLUG_CPU
        .cpu_die                = psci_cpu_die,
+       .cpu_kill               = psci_cpu_kill,
 #endif
 };