ARM: mach-virt: add SMP support using PSCI

This patch adds support for SMP to mach-virt using the PSCI
infrastructure.

Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>

arch/arm/mach-virt/Kconfig

@@ -3,6 +3,7 @@ config ARCH_VIRT
 	select ARCH_WANT_OPTIONAL_GPIOLIB
 	select ARM_GIC
 	select ARM_ARCH_TIMER
+	select ARM_PSCI
 	select HAVE_SMP
 	select CPU_V7
 	select SPARSE_IRQ

arch/arm/mach-virt/Makefile

@@ -3,3 +3,4 @@
 #
 
 obj-y					:= virt.o
+obj-$(CONFIG_SMP)			+= platsmp.o

arch/arm/mach-virt/platsmp.c

@@ -0,0 +1,58 @@
+/*
+ * Dummy Virtual Machine - does what it says on the tin.
+ *
+ * Copyright (C) 2012 ARM Ltd
+ * Author: Will Deacon <will.deacon@arm.com>
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/init.h>
+#include <linux/smp.h>
+#include <linux/of.h>
+
+#include <linux/irqchip/arm-gic.h>
+
+#include <asm/psci.h>
+#include <asm/smp_plat.h>
+
+extern void secondary_startup(void);
+
+static void __init virt_smp_init_cpus(void)
+{
+}
+
+static void __init virt_smp_prepare_cpus(unsigned int max_cpus)
+{
+}
+
+static int __cpuinit virt_boot_secondary(unsigned int cpu,
+					 struct task_struct *idle)
+{
+	if (psci_ops.cpu_on)
+		return psci_ops.cpu_on(cpu_logical_map(cpu),
+				       __pa(secondary_startup));
+	return -ENODEV;
+}
+
+static void __cpuinit virt_secondary_init(unsigned int cpu)
+{
+	gic_secondary_init(0);
+}
+
+struct smp_operations __initdata virt_smp_ops = {
+	.smp_init_cpus		= virt_smp_init_cpus,
+	.smp_prepare_cpus	= virt_smp_prepare_cpus,
+	.smp_secondary_init	= virt_secondary_init,
+	.smp_boot_secondary	= virt_boot_secondary,
+};

arch/arm/mach-virt/virt.c

@@ -21,6 +21,7 @@
 #include <linux/irqchip.h>
 #include <linux/of_irq.h>
 #include <linux/of_platform.h>
+#include <linux/smp.h>
 
 #include <asm/arch_timer.h>
 #include <asm/mach/arch.h>
@@ -46,9 +47,12 @@ static struct sys_timer virt_timer = {
 	.init = virt_timer_init,
 };
 
+extern struct smp_operations virt_smp_ops;
+
 DT_MACHINE_START(VIRT, "Dummy Virtual Machine")
 	.init_irq	= irqchip_init,
 	.timer		= &virt_timer,
 	.init_machine	= virt_init,
+	.smp		= smp_ops(virt_smp_ops),
 	.dt_compat	= virt_dt_match,
 MACHINE_END