1/* 2 * include/linux/cpu.h - generic cpu definition 3 * 4 * This is mainly for topological representation. We define the 5 * basic 'struct cpu' here, which can be embedded in per-arch 6 * definitions of processors. 7 * 8 * Basic handling of the devices is done in drivers/base/cpu.c 9 * and system devices are handled in drivers/base/sys.c. 10 * 11 * CPUs are exported via sysfs in the class/cpu/devices/ 12 * directory. 13 * 14 * Per-cpu interfaces can be implemented using a struct device_interface. 15 * See the following for how to do this: 16 * - drivers/base/intf.c 17 * - Documentation/driver-model/interface.txt 18 */ 19#ifndef _LINUX_CPU_H_ 20#define _LINUX_CPU_H_ 21 22#include <linux/sysdev.h> 23#include <linux/node.h> 24#include <linux/compiler.h> 25#include <linux/cpumask.h> 26#include <asm/semaphore.h> 27 28struct cpu { 29 int node_id; /* The node which contains the CPU */ 30 int no_control; /* Should the sysfs control file be created? */ 31 struct sys_device sysdev; 32}; 33 34extern int register_cpu(struct cpu *cpu, int num); 35extern struct sys_device *get_cpu_sysdev(unsigned cpu); 36#ifdef CONFIG_HOTPLUG_CPU 37extern void unregister_cpu(struct cpu *cpu); 38#endif 39struct notifier_block; 40 41#ifdef CONFIG_SMP 42/* Need to know about CPUs going up/down? */ 43extern int register_cpu_notifier(struct notifier_block *nb); 44#ifdef CONFIG_HOTPLUG_CPU 45extern void unregister_cpu_notifier(struct notifier_block *nb); 46#else 47static inline void unregister_cpu_notifier(struct notifier_block *nb) 48{ 49} 50#endif 51 52int cpu_up(unsigned int cpu); 53 54#else 55 56static inline int register_cpu_notifier(struct notifier_block *nb) 57{ 58 return 0; 59} 60static inline void unregister_cpu_notifier(struct notifier_block *nb) 61{ 62} 63 64#endif /* CONFIG_SMP */ 65extern struct sysdev_class cpu_sysdev_class; 66 67#ifdef CONFIG_HOTPLUG_CPU 68/* Stop CPUs going up and down. */ 69extern void lock_cpu_hotplug(void); 70extern void unlock_cpu_hotplug(void); 71#define hotcpu_notifier(fn, pri) { \ 72 static struct notifier_block fn##_nb = \ 73 { .notifier_call = fn, .priority = pri }; \ 74 register_cpu_notifier(&fn##_nb); \ 75} 76#define register_hotcpu_notifier(nb) register_cpu_notifier(nb) 77#define unregister_hotcpu_notifier(nb) unregister_cpu_notifier(nb) 78int cpu_down(unsigned int cpu); 79#define cpu_is_offline(cpu) unlikely(!cpu_online(cpu)) 80#else 81#define lock_cpu_hotplug() do { } while (0) 82#define unlock_cpu_hotplug() do { } while (0) 83#define lock_cpu_hotplug_interruptible() 0 84#define hotcpu_notifier(fn, pri) do { } while (0) 85#define register_hotcpu_notifier(nb) do { } while (0) 86#define unregister_hotcpu_notifier(nb) do { } while (0) 87 88/* CPUs don't go offline once they're online w/o CONFIG_HOTPLUG_CPU */ 89static inline int cpu_is_offline(int cpu) { return 0; } 90#endif 91 92#endif /* _LINUX_CPU_H_ */ 93