[PATCH v2 6/6] ARM: mach-virt: add SMP support using PSCI
Will Deacon
will.deacon at arm.com
Mon Dec 17 11:35:41 EST 2012
This patch adds support for SMP to mach-virt using the PSCI
infrastructure.
Signed-off-by: Will Deacon <will.deacon at arm.com>
---
arch/arm/mach-virt/Kconfig | 1 +
arch/arm/mach-virt/Makefile | 1 +
arch/arm/mach-virt/platsmp.c | 76 ++++++++++++++++++++++++++++++++++++++++++++
arch/arm/mach-virt/virt.c | 6 ++++
4 files changed, 84 insertions(+)
create mode 100644 arch/arm/mach-virt/platsmp.c
diff --git a/arch/arm/mach-virt/Kconfig b/arch/arm/mach-virt/Kconfig
index a568a2a..8958f0d 100644
--- a/arch/arm/mach-virt/Kconfig
+++ b/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
diff --git a/arch/arm/mach-virt/Makefile b/arch/arm/mach-virt/Makefile
index 7ddbfa6..042afc1 100644
--- a/arch/arm/mach-virt/Makefile
+++ b/arch/arm/mach-virt/Makefile
@@ -3,3 +3,4 @@
#
obj-y := virt.o
+obj-$(CONFIG_SMP) += platsmp.o
diff --git a/arch/arm/mach-virt/platsmp.c b/arch/arm/mach-virt/platsmp.c
new file mode 100644
index 0000000..930362b
--- /dev/null
+++ b/arch/arm/mach-virt/platsmp.c
@@ -0,0 +1,76 @@
+/*
+ * Dummy Virtual Machine - does what it says on the tin.
+ *
+ * Copyright (C) 2012 ARM Ltd
+ * Author: Will Deacon <will.deacon at 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 <asm/psci.h>
+#include <asm/smp_plat.h>
+#include <asm/hardware/gic.h>
+
+extern void secondary_startup(void);
+
+/*
+ * Enumerate the possible CPU set from the device tree.
+ */
+static void __init virt_smp_init_cpus(void)
+{
+ struct device_node *dn = NULL;
+ int cpu = 0;
+
+ while ((dn = of_find_node_by_type(dn, "cpu"))) {
+ if (cpu < NR_CPUS)
+ set_cpu_possible(cpu, true);
+ cpu++;
+ }
+
+ /* sanity check */
+ if (cpu > NR_CPUS)
+ pr_warning("no. of cores (%d) greater than configured maximum "
+ "of %d - clipping\n",
+ cpu, NR_CPUS);
+
+ set_smp_cross_call(gic_raise_softirq);
+}
+
+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,
+};
diff --git a/arch/arm/mach-virt/virt.c b/arch/arm/mach-virt/virt.c
index 174b9da..d764835 100644
--- a/arch/arm/mach-virt/virt.c
+++ b/arch/arm/mach-virt/virt.c
@@ -20,6 +20,7 @@
#include <linux/of_irq.h>
#include <linux/of_platform.h>
+#include <linux/smp.h>
#include <asm/arch_timer.h>
#include <asm/hardware/gic.h>
@@ -56,10 +57,15 @@ static struct sys_timer virt_timer = {
.init = virt_timer_init,
};
+#ifdef CONFIG_SMP
+extern struct smp_operations virt_smp_ops;
+#endif
+
DT_MACHINE_START(VIRT, "Dummy Virtual Machine")
.init_irq = gic_init_irq,
.handle_irq = gic_handle_irq,
.timer = &virt_timer,
.init_machine = virt_init,
+ .smp = smp_ops(virt_smp_ops),
.dt_compat = virt_dt_match,
MACHINE_END
--
1.8.0
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