[PATCH v4 06/15] ARM: mcpm: generic SMP secondary bringup and hotplug support

[Nicolas Pitre]

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 at linaro.org>
Reviewed-by: Santosh Shilimkar <santosh.shilimkar at ti.com>
Reviewed-by: Will Deacon <will.deacon at arm.com>
---
 arch/arm/common/Makefile       |  2 +-
 arch/arm/common/mcpm_platsmp.c | 86 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 87 insertions(+), 1 deletion(-)
 create mode 100644 arch/arm/common/mcpm_platsmp.c

diff --git a/arch/arm/common/Makefile b/arch/arm/common/Makefile
index c901a38c59..e1c9db45de 100644
--- a/arch/arm/common/Makefile
+++ b/arch/arm/common/Makefile
@@ -13,4 +13,4 @@ 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-$(CONFIG_CLUSTER_PM)	+= mcpm_head.o mcpm_entry.o vlock.o
+obj-$(CONFIG_CLUSTER_PM)	+= 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 0000000000..e81e73d0f8
--- /dev/null
+++ b/arch/arm/common/mcpm_platsmp.c
@@ -0,0 +1,86 @@
+/*
+ * 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 <asm/mcpm_entry.h>
+#include <asm/smp.h>
+#include <asm/smp_plat.h>
+#include <asm/hardware/gic.h>
+
+static void __init simple_smp_init_cpus(void)
+{
+	set_smp_cross_call(gic_raise_softirq);
+}
+
+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
+};
-- 
1.8.1.2