1 files changed, 51 insertions, 2 deletions

diff --git a/arch/arm/mach-mvebu/platsmp-a9.c b/arch/arm/mach-mvebu/platsmp-a9.c
index 47a71a924b9..2ec1a42b432 100644
--- a/arch/arm/mach-mvebu/platsmp-a9.c
+++ b/arch/arm/mach-mvebu/platsmp-a9.c
@@ -43,21 +43,70 @@ static int __cpuinit mvebu_cortex_a9_boot_secondary(unsigned int cpu,
 	else
 		mvebu_pmsu_set_cpu_boot_addr(hw_cpu, mvebu_cortex_a9_secondary_startup);
 	smp_wmb();
+
+	/*
+	 * Doing this before deasserting the CPUs is needed to wake up CPUs
+	 * in the offline state after using CPU hotplug.
+	 */
+	arch_send_wakeup_ipi_mask(cpumask_of(cpu));
+
 	ret = mvebu_cpu_reset_deassert(hw_cpu);
 	if (ret) {
 		pr_err("Could not start the secondary CPU: %d\n", ret);
 		return ret;
 	}
-	arch_send_wakeup_ipi_mask(cpumask_of(cpu));
 
 	return 0;
 }
+/*
+ * When a CPU is brought back online, either through CPU hotplug, or
+ * because of the boot of a kexec'ed kernel, the PMSU configuration
+ * for this CPU might be in the deep idle state, preventing this CPU
+ * from receiving interrupts. Here, we therefore take out the current
+ * CPU from this state, which was entered by armada_38x_cpu_die()
+ * below.
+ */
+static void armada_38x_secondary_init(unsigned int cpu)
+{
+	mvebu_v7_pmsu_idle_exit();
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+static void armada_38x_cpu_die(unsigned int cpu)
+{
+	/*
+	 * CPU hotplug is implemented by putting offline CPUs into the
+	 * deep idle sleep state.
+	 */
+	armada_38x_do_cpu_suspend(true);
+}
+
+/*
+ * We need a dummy function, so that platform_can_cpu_hotplug() knows
+ * we support CPU hotplug. However, the function does not need to do
+ * anything, because CPUs going offline can enter the deep idle state
+ * by themselves, without any help from a still alive CPU.
+ */
+static int armada_38x_cpu_kill(unsigned int cpu)
+{
+	return 1;
+}
+#endif
 
 static struct smp_operations mvebu_cortex_a9_smp_ops __initdata = {
 	.smp_boot_secondary	= mvebu_cortex_a9_boot_secondary,
 };
 
+static struct smp_operations armada_38x_smp_ops __initdata = {
+	.smp_boot_secondary	= mvebu_cortex_a9_boot_secondary,
+	.smp_secondary_init     = armada_38x_secondary_init,
+#ifdef CONFIG_HOTPLUG_CPU
+	.cpu_die		= armada_38x_cpu_die,
+	.cpu_kill               = armada_38x_cpu_kill,
+#endif
+};
+
 CPU_METHOD_OF_DECLARE(mvebu_armada_375_smp, "marvell,armada-375-smp",
 		      &mvebu_cortex_a9_smp_ops);
 CPU_METHOD_OF_DECLARE(mvebu_armada_380_smp, "marvell,armada-380-smp",
-		      &mvebu_cortex_a9_smp_ops);
+		      &armada_38x_smp_ops);