[RFC] arm: use PSCI if available

Check for the presence of PSCI before setting smp_ops, use PSCI if it is
available.

This is useful because at least when running on Xen it's possible to have a
PSCI node for example on a Versatile Express or an Exynos5 machine. In these
cases the PSCI SMP calls should be the ones to be called.

Remove virt_smp_ops and platsmp.c from mach-virt because they aren't needed
anymore.

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

diff --git a/arch/arm/include/asm/psci.h b/arch/arm/include/asm/psci.h
index ce0dbe7c1625d296b165794ab75165a7452ecbfe..e64ea8428258173d3165ec147d8906e55d44c719 100644 (file)
--- a/arch/arm/include/asm/psci.h
+++ b/arch/arm/include/asm/psci.h
@@ -32,5 +32,6 @@ struct psci_operations {
 };
 
 extern struct psci_operations psci_ops;
+int psci_init(struct smp_operations *ops);
 
 #endif /* __ASM_ARM_PSCI_H */

diff --git a/arch/arm/kernel/psci.c b/arch/arm/kernel/psci.c
index 36531643cc2c01e3d8e997e32e2ffaa9a8b9ce12..6f66d93171f0e9ac15654480432d7a428a7a25f9 100644 (file)
--- a/arch/arm/kernel/psci.c
+++ b/arch/arm/kernel/psci.c
@@ -16,6 +16,7 @@
 #define pr_fmt(fmt) "psci: " fmt
 
 #include <linux/init.h>
+#include <linux/irqchip/arm-gic.h>
 #include <linux/of.h>
 
 #include <asm/compiler.h>
@@ -23,7 +24,9 @@
 #include <asm/opcodes-sec.h>
 #include <asm/opcodes-virt.h>
 #include <asm/psci.h>
+#include <asm/smp_plat.h>
 
+extern void secondary_startup(void);
 struct psci_operations psci_ops;
 
 static int (*invoke_psci_fn)(u32, u32, u32, u32);
@@ -153,20 +156,50 @@ static int psci_migrate(unsigned long cpuid)
        return psci_to_linux_errno(err);
 }
 
+static void __init psci_smp_init_cpus(void)
+{
+}
+
+static void __init psci_smp_prepare_cpus(unsigned int max_cpus)
+{
+}
+
+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;
+}
+
+static void __cpuinit psci_secondary_init(unsigned int cpu)
+{
+       gic_secondary_init(0);
+}
+
+struct smp_operations __initdata psci_smp_ops = {
+       .smp_init_cpus          = psci_smp_init_cpus,
+       .smp_prepare_cpus       = psci_smp_prepare_cpus,
+       .smp_secondary_init     = psci_secondary_init,
+       .smp_boot_secondary     = psci_boot_secondary,
+};
+
 static const struct of_device_id psci_of_match[] __initconst = {
        { .compatible = "arm,psci",     },
        {},
 };
 
-static int __init psci_init(void)
+int __init psci_init(struct smp_operations *ops)
 {
        struct device_node *np;
        const char *method;
        u32 id;
+       int rc = -EINVAL;
 
        np = of_find_matching_node(NULL, psci_of_match);
        if (!np)
-               return 0;
+               return -ENODEV;
 
        pr_info("probing function IDs from device-tree\n");
 
@@ -203,9 +236,10 @@ static int __init psci_init(void)
                psci_function_id[PSCI_FN_MIGRATE] = id;
                psci_ops.migrate = psci_migrate;
        }
+       *ops = psci_smp_ops;
+       rc = 0;
 
 out_put_node:
        of_node_put(np);
-       return 0;
+       return rc;
 }
-early_initcall(psci_init);

diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index 31644f1978d56d8e6fad053804ed8d730bff9003..09eda3cc1a9f73b437ee4694339bbf8fdd9e1973 100644 (file)
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -38,6 +38,7 @@
 #include <asm/pgtable.h>
 #include <asm/pgalloc.h>
 #include <asm/processor.h>
+#include <asm/psci.h>
 #include <asm/sections.h>
 #include <asm/tlbflush.h>
 #include <asm/ptrace.h>
@@ -74,7 +75,11 @@ static struct smp_operations smp_ops;
 
 void __init smp_set_ops(struct smp_operations *ops)
 {
-       if (ops)
+       int rc = -ENODEV;
+#ifdef CONFIG_ARM_PSCI
+       rc = psci_init(&smp_ops);
+#endif
+       if (rc && ops)
                smp_ops = *ops;
 };
 

diff --git a/arch/arm/mach-virt/Makefile b/arch/arm/mach-virt/Makefile
index 042afc1f8c4425f4ce887910dd4a5daddb4e8615..7ddbfa60227f8e267acc58bca381428fdb99e294 100644 (file)
--- 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 (file)
index 8badaab..0000000
--- a/arch/arm/mach-virt/platsmp.c
+++ /dev/null
@@ -1,58 +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 <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,
-};

diff --git a/arch/arm/mach-virt/virt.c b/arch/arm/mach-virt/virt.c
index 528c05eab3a7bcdc0a353f1675cefaeea9f16e73..c41775294e0da3452f5b7fd5b3ba70267257430a 100644 (file)
--- a/arch/arm/mach-virt/virt.c
+++ b/arch/arm/mach-virt/virt.c
@@ -44,12 +44,9 @@ 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_time      = virt_timer_init,
        .init_machine   = virt_init,
-       .smp            = smp_ops(virt_smp_ops),
        .dt_compat      = virt_dt_match,
 MACHINE_END