/* * include/linux/cpu.h - generic cpu definition * * This is mainly for topological representation. We define the * basic 'struct cpu' here, which can be embedded in per-arch * definitions of processors. * * Basic handling of the devices is done in drivers/base/cpu.c * and system devices are handled in drivers/base/sys.c. * * CPUs are exported via sysfs in the class/cpu/devices/ * directory. * * Per-cpu interfaces can be implemented using a struct device_interface. * See the following for how to do this: * - drivers/base/intf.c * - Documentation/driver-model/interface.txt */ #ifndef _LINUX_CPU_H_ #define _LINUX_CPU_H_ #include <linux/sysdev.h> #include <linux/node.h> #include <linux/compiler.h> #include <linux/cpumask.h> #include <asm/semaphore.h> struct cpu { int node_id; /* The node which contains the CPU */ int no_control; /* Should the sysfs control file be created? */ struct sys_device sysdev; }; extern int register_cpu(struct cpu *, int, struct node *); extern struct sys_device *get_cpu_sysdev(unsigned cpu); #ifdef CONFIG_HOTPLUG_CPU extern void unregister_cpu(struct cpu *, struct node *); #endif struct notifier_block; #ifdef CONFIG_SMP /* Need to know about CPUs going up/down? */ extern int register_cpu_notifier(struct notifier_block *nb); extern void unregister_cpu_notifier(struct notifier_block *nb); extern int current_in_cpu_hotplug(void); int cpu_up(unsigned int cpu); #else static inline int register_cpu_notifier(struct notifier_block *nb) { return 0; } static inline void unregister_cpu_notifier(struct notifier_block *nb) { } static inline int current_in_cpu_hotplug(void) { return 0; } #endif /* CONFIG_SMP */ extern struct sysdev_class cpu_sysdev_class; #ifdef CONFIG_HOTPLUG_CPU /* Stop CPUs going up and down. */ extern void lock_cpu_hotplug(void); extern void unlock_cpu_hotplug(void); extern int lock_cpu_hotplug_interruptible(void); #define hotcpu_notifier(fn, pri) { \ static struct notifier_block fn##_nb = \ { .notifier_call = fn, .priority = pri }; \ register_cpu_notifier(&fn##_nb); \ } int cpu_down(unsigned int cpu); #define cpu_is_offline(cpu) unlikely(!cpu_online(cpu)) #else #define lock_cpu_hotplug() do { } while (0) #define unlock_cpu_hotplug() do { } while (0) #define lock_cpu_hotplug_interruptible() 0 #define hotcpu_notifier(fn, pri) /* CPUs don't go offline once they're online w/o CONFIG_HOTPLUG_CPU */ static inline int cpu_is_offline(int cpu) { return 0; } #endif #endif /* _LINUX_CPU_H_ */