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#include <linux/mutex.h> 28 29struct cpu { 30 int node_id; /* The node which contains the CPU */ 31 int hotpluggable; /* creates sysfs control file if hotpluggable */ 32 struct sys_device sysdev; 33}; 34 35extern int register_cpu(struct cpu *cpu, int num); 36extern struct sys_device *get_cpu_sysdev(unsigned cpu); 37 38extern int cpu_add_sysdev_attr(struct sysdev_attribute *attr); 39extern void cpu_remove_sysdev_attr(struct sysdev_attribute *attr); 40 41extern int cpu_add_sysdev_attr_group(struct attribute_group *attrs); 42extern void cpu_remove_sysdev_attr_group(struct attribute_group *attrs); 43 44extern int sched_create_sysfs_power_savings_entries(struct sysdev_class *cls); 45 46#ifdef CONFIG_HOTPLUG_CPU 47extern void unregister_cpu(struct cpu *cpu); 48#endif 49struct notifier_block; 50 51#ifdef CONFIG_SMP 52/* Need to know about CPUs going up/down? */ 53#ifdef CONFIG_HOTPLUG_CPU 54extern int register_cpu_notifier(struct notifier_block *nb); 55extern void unregister_cpu_notifier(struct notifier_block *nb); 56#else 57 58#ifndef MODULE 59extern int register_cpu_notifier(struct notifier_block *nb); 60#else 61static inline int register_cpu_notifier(struct notifier_block *nb) 62{ 63 return 0; 64} 65#endif 66 67static inline void unregister_cpu_notifier(struct notifier_block *nb) 68{ 69} 70#endif 71 72int cpu_up(unsigned int cpu); 73 74#else 75 76static inline int register_cpu_notifier(struct notifier_block *nb) 77{ 78 return 0; 79} 80static inline void unregister_cpu_notifier(struct notifier_block *nb) 81{ 82} 83 84#endif /* CONFIG_SMP */ 85extern struct sysdev_class cpu_sysdev_class; 86 87#ifdef CONFIG_HOTPLUG_CPU 88/* Stop CPUs going up and down. */ 89 90static inline void cpuhotplug_mutex_lock(struct mutex *cpu_hp_mutex) 91{ 92 mutex_lock(cpu_hp_mutex); 93} 94 95static inline void cpuhotplug_mutex_unlock(struct mutex *cpu_hp_mutex) 96{ 97 mutex_unlock(cpu_hp_mutex); 98} 99 100extern void lock_cpu_hotplug(void); 101extern void unlock_cpu_hotplug(void); 102#define hotcpu_notifier(fn, pri) { \ 103 static struct notifier_block fn##_nb = \ 104 { .notifier_call = fn, .priority = pri }; \ 105 register_cpu_notifier(&fn##_nb); \ 106} 107#define register_hotcpu_notifier(nb) register_cpu_notifier(nb) 108#define unregister_hotcpu_notifier(nb) unregister_cpu_notifier(nb) 109int cpu_down(unsigned int cpu); 110#define cpu_is_offline(cpu) unlikely(!cpu_online(cpu)) 111 112#else /* CONFIG_HOTPLUG_CPU */ 113 114static inline void cpuhotplug_mutex_lock(struct mutex *cpu_hp_mutex) 115{ } 116static inline void cpuhotplug_mutex_unlock(struct mutex *cpu_hp_mutex) 117{ } 118 119#define lock_cpu_hotplug() do { } while (0) 120#define unlock_cpu_hotplug() do { } while (0) 121#define lock_cpu_hotplug_interruptible() 0 122#define hotcpu_notifier(fn, pri) do { (void)(fn); } while (0) 123#define register_hotcpu_notifier(nb) do { (void)(nb); } while (0) 124#define unregister_hotcpu_notifier(nb) do { (void)(nb); } while (0) 125 126/* CPUs don't go offline once they're online w/o CONFIG_HOTPLUG_CPU */ 127static inline int cpu_is_offline(int cpu) { return 0; } 128#endif /* CONFIG_HOTPLUG_CPU */ 129 130#ifdef CONFIG_SUSPEND_SMP 131extern int suspend_cpu_hotplug; 132 133extern int disable_nonboot_cpus(void); 134extern void enable_nonboot_cpus(void); 135#else 136#define suspend_cpu_hotplug 0 137 138static inline int disable_nonboot_cpus(void) { return 0; } 139static inline void enable_nonboot_cpus(void) {} 140#endif 141 142#endif /* _LINUX_CPU_H_ */ 143