1 files changed, 33 insertions, 0 deletions

diff --git a/arch/arm/kernel/psci_smp.c b/arch/arm/kernel/psci_smp.c
index 570a48cc3d64..28a1db4da704 100644
--- 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
 };