arm: introduce psci_smp_ops

Rename virt_smp_ops to psci_smp_ops and move them to arch/arm/kernel/psci_smp.c.
Remove mach-virt/platsmp.c, now unused.
Compile psci_smp if CONFIG_ARM_PSCI and CONFIG_SMP.

Add a cpu_die smp_op based on psci_ops.cpu_off.

Initialize PSCI before setting smp_ops in setup_arch.

If PSCI is available on the platform, prefer psci_smp_ops over the
platform smp_ops.


Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Will Deacon <will.deacon@arm.com>
CC: arnd@arndb.de
CC: marc.zyngier@arm.com
CC: linux@arm.linux.org.uk
CC: nico@linaro.org
CC: rob.herring@calxeda.com

8 files changed, 106 insertions, 60 deletions

diff --git a/arch/arm/include/asm/psci.h b/arch/arm/include/asm/psci.h
index ce0dbe7c1625..c4ae171850f8 100644
--- a/arch/arm/include/asm/psci.h
+++ b/arch/arm/include/asm/psci.h
@@ -32,5 +32,14 @@ struct psci_operations {
 };
 
 extern struct psci_operations psci_ops;
+extern struct smp_operations psci_smp_ops;
+
+#ifdef CONFIG_ARM_PSCI
+void psci_init(void);
+bool psci_smp_available(void);
+#else
+static inline void psci_init(void) { }
+static inline bool psci_smp_available(void) { return false; }
+#endif
 
 #endif /* __ASM_ARM_PSCI_H */
diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile
index 5f3338eacad2..dd9d90ab65d0 100644
--- a/arch/arm/kernel/Makefile
+++ b/arch/arm/kernel/Makefile
@@ -82,6 +82,9 @@ obj-$(CONFIG_DEBUG_LL)	+= debug.o
 obj-$(CONFIG_EARLY_PRINTK)      += early_printk.o
 
 obj-$(CONFIG_ARM_VIRT_EXT)      += hyp-stub.o
-obj-$(CONFIG_ARM_PSCI)          += psci.o
+ifeq ($(CONFIG_ARM_PSCI),y)
+obj-y                           += psci.o
+obj-$(CONFIG_SMP)               += psci_smp.o
+endif
 
 extra-y := $(head-y) vmlinux.lds
diff --git a/arch/arm/kernel/psci.c b/arch/arm/kernel/psci.c
index 36531643cc2c..46931880093d 100644
--- a/arch/arm/kernel/psci.c
+++ b/arch/arm/kernel/psci.c
@@ -158,7 +158,7 @@ static const struct of_device_id psci_of_match[] __initconst = {
         {},
 };
 
-static int __init psci_init(void)
+void __init psci_init(void)
 {
         struct device_node *np;
         const char *method;
@@ -166,7 +166,7 @@ static int __init psci_init(void)
 
         np = of_find_matching_node(NULL, psci_of_match);
         if (!np)
-                return 0;
+                return;
 
         pr_info("probing function IDs from device-tree\n");
 
@@ -206,6 +206,5 @@ static int __init psci_init(void)
 
 out_put_node:
         of_node_put(np);
-        return 0;
+        return;
 }
-early_initcall(psci_init);
diff --git a/arch/arm/kernel/psci_smp.c b/arch/arm/kernel/psci_smp.c
new file mode 100644
index 000000000000..23a11424c568
--- /dev/null
+++ b/arch/arm/kernel/psci_smp.c
@@ -0,0 +1,84 @@
+/*
+ * 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.
+ *
+ * Copyright (C) 2012 ARM Limited
+ *
+ * Author: Will Deacon <will.deacon@arm.com>
+ */
+
+#include <linux/init.h>
+#include <linux/irqchip/arm-gic.h>
+#include <linux/smp.h>
+#include <linux/of.h>
+
+#include <asm/psci.h>
+#include <asm/smp_plat.h>
+
+/*
+ * psci_smp assumes that the following is true about PSCI:
+ *
+ * cpu_suspend   Suspend the execution on a CPU
+ * @state        we don't currently describe affinity levels, so just pass 0.
+ * @entry_point  the first instruction to be executed on return
+ * returns 0  success, < 0 on failure
+ *
+ * cpu_off       Power down a CPU
+ * @state        we don't currently describe affinity levels, so just pass 0.
+ * no return on successful call
+ *
+ * cpu_on        Power up a CPU
+ * @cpuid        cpuid of target CPU, as from MPIDR
+ * @entry_point  the first instruction to be executed on return
+ * returns 0  success, < 0 on failure
+ *
+ * migrate       Migrate the context to a different CPU
+ * @cpuid        cpuid of target CPU, as from MPIDR
+ * returns 0  success, < 0 on failure
+ *
+ */
+
+extern void secondary_startup(void);
+
+static int __cpuinit psci_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;
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+void __ref psci_cpu_die(unsigned int cpu)
+{
+       const struct psci_power_state ps = {
+               .type = PSCI_POWER_STATE_TYPE_POWER_DOWN,
+       };
+
+       if (psci_ops.cpu_off)
+               psci_ops.cpu_off(ps);
+
+       /* We should never return */
+       panic("psci: cpu %d failed to shutdown\n", cpu);
+}
+#else
+#define psci_cpu_die NULL
+#endif
+
+bool __init psci_smp_available(void)
+{
+        /* is cpu_on available at least? */
+        return (psci_ops.cpu_on != NULL);
+}
+
+struct smp_operations __initdata psci_smp_ops = {
+        .smp_boot_secondary     = psci_boot_secondary,
+        .cpu_die                = psci_cpu_die,
+};
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index 1522c7ae31b0..8f7a6e9926a8 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -37,6 +37,7 @@
 #include <asm/cputype.h>
 #include <asm/elf.h>
 #include <asm/procinfo.h>
+#include <asm/psci.h>
 #include <asm/sections.h>
 #include <asm/setup.h>
 #include <asm/smp_plat.h>
@@ -796,9 +797,13 @@ void __init setup_arch(char **cmdline_p)
         unflatten_device_tree();
 
         arm_dt_init_cpu_maps();
+        psci_init();
 #ifdef CONFIG_SMP
         if (is_smp()) {
-                smp_set_ops(mdesc->smp);
+                if (psci_smp_available())
+                        smp_set_ops(&psci_smp_ops);
+                else if (mdesc->smp)
+                        smp_set_ops(mdesc->smp);
                 smp_init_cpus();
         }
 #endif
diff --git a/arch/arm/mach-virt/Makefile b/arch/arm/mach-virt/Makefile
index 042afc1f8c44..7ddbfa60227f 100644
--- a/arch/arm/mach-virt/Makefile
+++ b/arch/arm/mach-virt/Makefile
@@ -3,4 +3,3 @@
 #
 
 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
deleted file mode 100644
index f4143f5bfa5b..000000000000
--- a/arch/arm/mach-virt/platsmp.c
+++ /dev/null
@@ -1,50 +0,0 @@
-/*
- * 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 <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;
-}
-
-struct smp_operations __initdata virt_smp_ops = {
-        .smp_init_cpus          = virt_smp_init_cpus,
-        .smp_prepare_cpus       = virt_smp_prepare_cpus,
-        .smp_boot_secondary     = virt_boot_secondary,
-};
diff --git a/arch/arm/mach-virt/virt.c b/arch/arm/mach-virt/virt.c
index 061f283f579e..a67d2dd5bb60 100644
--- a/arch/arm/mach-virt/virt.c
+++ b/arch/arm/mach-virt/virt.c
@@ -36,11 +36,8 @@ static const char *virt_dt_match[] = {
         NULL
 };
 
-extern struct smp_operations virt_smp_ops;
-
 DT_MACHINE_START(VIRT, "Dummy Virtual Machine")
         .init_irq       = irqchip_init,
         .init_machine   = virt_init,
-        .smp            = smp_ops(virt_smp_ops),
         .dt_compat      = virt_dt_match,
 MACHINE_END