ARM: mcpm: generic SMP secondary bringup and hotplug support

Now that the cluster power API is in place, we can use it for SMP secondary
bringup and CPU hotplug in a generic fashion.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>

2 files changed, 88 insertions, 1 deletions

diff --git a/arch/arm/common/Makefile b/arch/arm/common/Makefile
index 9ec273188ccb..48c0ee578174 100644
--- a/arch/arm/common/Makefile
+++ b/arch/arm/common/Makefile
@@ -11,4 +11,4 @@ obj-$(CONFIG_SHARP_PARAM)	+= sharpsl_param.o
 obj-$(CONFIG_SHARP_SCOOP)       += scoop.o
 obj-$(CONFIG_PCI_HOST_ITE8152)  += it8152.o
 obj-$(CONFIG_ARM_TIMER_SP804)   += timer-sp.o
-obj-$(CONFIG_MCPM)              += mcpm_head.o mcpm_entry.o vlock.o
+obj-$(CONFIG_MCPM)              += mcpm_head.o mcpm_entry.o mcpm_platsmp.o vlock.o
diff --git a/arch/arm/common/mcpm_platsmp.c b/arch/arm/common/mcpm_platsmp.c
new file mode 100644
index 000000000000..e7e3235b8b64
--- /dev/null
+++ b/arch/arm/common/mcpm_platsmp.c
@@ -0,0 +1,87 @@
+/*
+ * linux/arch/arm/mach-vexpress/mcpm_platsmp.c
+ *
+ * Created by:  Nicolas Pitre, November 2012
+ * Copyright:   (C) 2012-2013  Linaro Limited
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Code to handle secondary CPU bringup and hotplug for the cluster power API.
+ */
+
+#include <linux/init.h>
+#include <linux/smp.h>
+#include <linux/spinlock.h>
+
+#include <linux/irqchip/arm-gic.h>
+
+#include <asm/mcpm.h>
+#include <asm/smp.h>
+#include <asm/smp_plat.h>
+
+static void __init simple_smp_init_cpus(void)
+{
+}
+
+static int __cpuinit mcpm_boot_secondary(unsigned int cpu, struct task_struct *idle)
+{
+        unsigned int mpidr, pcpu, pcluster, ret;
+        extern void secondary_startup(void);
+
+        mpidr = cpu_logical_map(cpu);
+        pcpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
+        pcluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
+        pr_debug("%s: logical CPU %d is physical CPU %d cluster %d\n",
+                 __func__, cpu, pcpu, pcluster);
+
+        mcpm_set_entry_vector(pcpu, pcluster, NULL);
+        ret = mcpm_cpu_power_up(pcpu, pcluster);
+        if (ret)
+                return ret;
+        mcpm_set_entry_vector(pcpu, pcluster, secondary_startup);
+        arch_send_wakeup_ipi_mask(cpumask_of(cpu));
+        dsb_sev();
+        return 0;
+}
+
+static void __cpuinit mcpm_secondary_init(unsigned int cpu)
+{
+        mcpm_cpu_powered_up();
+        gic_secondary_init(0);
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+
+static int mcpm_cpu_disable(unsigned int cpu)
+{
+        /*
+         * We assume all CPUs may be shut down.
+         * This would be the hook to use for eventual Secure
+         * OS migration requests as described in the PSCI spec.
+         */
+        return 0;
+}
+
+static void mcpm_cpu_die(unsigned int cpu)
+{
+        unsigned int mpidr, pcpu, pcluster;
+        mpidr = read_cpuid_mpidr();
+        pcpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
+        pcluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
+        mcpm_set_entry_vector(pcpu, pcluster, NULL);
+        mcpm_cpu_power_down();
+}
+
+#endif
+
+struct smp_operations __initdata mcpm_smp_ops = {
+        .smp_init_cpus          = simple_smp_init_cpus,
+        .smp_boot_secondary     = mcpm_boot_secondary,
+        .smp_secondary_init     = mcpm_secondary_init,
+#ifdef CONFIG_HOTPLUG_CPU
+        .cpu_disable            = mcpm_cpu_disable,
+        .cpu_die                = mcpm_cpu_die,
+#endif
+};