diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu index a703b9e9aeb..d868a11c94a 100644 --- a/Documentation/ABI/testing/sysfs-devices-system-cpu +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu @@ -62,6 +62,21 @@ Description: CPU topology files that describe kernel limits related to See Documentation/cputopology.txt for more information. +What: /sys/devices/system/cpu/probe + /sys/devices/system/cpu/release +Date: November 2009 +Contact: Linux kernel mailing list +Description: Dynamic addition and removal of CPU's. This is not hotplug + removal, this is meant complete removal/addition of the CPU + from the system. + + probe: writes to this file will dynamically add a CPU to the + system. Information written to the file to add CPU's is + architecture specific. + + release: writes to this file dynamically remove a CPU from + the system. Information writtento the file to remove CPU's + is architecture specific. What: /sys/devices/system/cpu/cpu#/node Date: October 2009 diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 5dbd375a3f2..0df57466e78 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -320,6 +320,10 @@ config HOTPLUG_CPU Say N if you are unsure. +config ARCH_CPU_PROBE_RELEASE + def_bool y + depends on HOTPLUG_CPU + config ARCH_ENABLE_MEMORY_HOTPLUG def_bool y diff --git a/arch/powerpc/include/asm/machdep.h b/arch/powerpc/include/asm/machdep.h index 9efa2be7833..9f0fc9e6ce0 100644 --- a/arch/powerpc/include/asm/machdep.h +++ b/arch/powerpc/include/asm/machdep.h @@ -266,6 +266,11 @@ struct machdep_calls { void (*suspend_disable_irqs)(void); void (*suspend_enable_irqs)(void); #endif + +#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE + ssize_t (*cpu_probe)(const char *, size_t); + ssize_t (*cpu_release)(const char *, size_t); +#endif }; extern void e500_idle(void); diff --git a/arch/powerpc/kernel/sysfs.c b/arch/powerpc/kernel/sysfs.c index 956ab33fd73..e235e52dc4f 100644 --- a/arch/powerpc/kernel/sysfs.c +++ b/arch/powerpc/kernel/sysfs.c @@ -461,6 +461,25 @@ static void unregister_cpu_online(unsigned int cpu) cacheinfo_cpu_offline(cpu); } + +#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE +ssize_t arch_cpu_probe(const char *buf, size_t count) +{ + if (ppc_md.cpu_probe) + return ppc_md.cpu_probe(buf, count); + + return -EINVAL; +} + +ssize_t arch_cpu_release(const char *buf, size_t count) +{ + if (ppc_md.cpu_release) + return ppc_md.cpu_release(buf, count); + + return -EINVAL; +} +#endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */ + #endif /* CONFIG_HOTPLUG_CPU */ static int __cpuinit sysfs_cpu_notify(struct notifier_block *self, diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c index e62a4ccea54..7c03af7b84a 100644 --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -72,6 +72,38 @@ void unregister_cpu(struct cpu *cpu) per_cpu(cpu_sys_devices, logical_cpu) = NULL; return; } + +#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE +static ssize_t cpu_probe_store(struct class *class, const char *buf, + size_t count) +{ + return arch_cpu_probe(buf, count); +} + +static ssize_t cpu_release_store(struct class *class, const char *buf, + size_t count) +{ + return arch_cpu_release(buf, count); +} + +static CLASS_ATTR(probe, S_IWUSR, NULL, cpu_probe_store); +static CLASS_ATTR(release, S_IWUSR, NULL, cpu_release_store); + +int __init cpu_probe_release_init(void) +{ + int rc; + + rc = sysfs_create_file(&cpu_sysdev_class.kset.kobj, + &class_attr_probe.attr); + if (!rc) + rc = sysfs_create_file(&cpu_sysdev_class.kset.kobj, + &class_attr_release.attr); + + return rc; +} +device_initcall(cpu_probe_release_init); +#endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */ + #else /* ... !CONFIG_HOTPLUG_CPU */ static inline void register_cpu_control(struct cpu *cpu) { diff --git a/include/linux/cpu.h b/include/linux/cpu.h index 47536197ffd..c972f7ccb7d 100644 --- a/include/linux/cpu.h +++ b/include/linux/cpu.h @@ -43,6 +43,8 @@ extern int sched_create_sysfs_power_savings_entries(struct sysdev_class *cls); #ifdef CONFIG_HOTPLUG_CPU extern void unregister_cpu(struct cpu *cpu); +extern ssize_t arch_cpu_probe(const char *, size_t); +extern ssize_t arch_cpu_release(const char *, size_t); #endif struct notifier_block;