LXR linux/include/linux/cpu.h

   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 struct sysdev_attribute attr_sched_mc_power_savings;
  45extern struct sysdev_attribute attr_sched_smt_power_savings;
  46extern int sched_create_sysfs_power_savings_entries(struct sysdev_class *cls);
  47
  48#ifdef CONFIG_HOTPLUG_CPU
  49extern void unregister_cpu(struct cpu *cpu);
  50#endif
  51struct notifier_block;
  52
  53#ifdef CONFIG_SMP
  54/* Need to know about CPUs going up/down? */
  55#ifdef CONFIG_HOTPLUG_CPU
  56extern int register_cpu_notifier(struct notifier_block *nb);
  57extern void unregister_cpu_notifier(struct notifier_block *nb);
  58#else
  59
  60#ifndef MODULE
  61extern int register_cpu_notifier(struct notifier_block *nb);
  62#else
  63static inline int register_cpu_notifier(struct notifier_block *nb)
  64{
  65        return 0;
  66}
  67#endif
  68
  69static inline void unregister_cpu_notifier(struct notifier_block *nb)
  70{
  71}
  72#endif
  73
  74int cpu_up(unsigned int cpu);
  75
  76#else
  77
  78static inline int register_cpu_notifier(struct notifier_block *nb)
  79{
  80        return 0;
  81}
  82static inline void unregister_cpu_notifier(struct notifier_block *nb)
  83{
  84}
  85
  86#endif /* CONFIG_SMP */
  87extern struct sysdev_class cpu_sysdev_class;
  88
  89#ifdef CONFIG_HOTPLUG_CPU
  90/* Stop CPUs going up and down. */
  91
  92static inline void cpuhotplug_mutex_lock(struct mutex *cpu_hp_mutex)
  93{
  94        mutex_lock(cpu_hp_mutex);
  95}
  96
  97static inline void cpuhotplug_mutex_unlock(struct mutex *cpu_hp_mutex)
  98{
  99        mutex_unlock(cpu_hp_mutex);
 100}
 101
 102extern void lock_cpu_hotplug(void);
 103extern void unlock_cpu_hotplug(void);
 104#define hotcpu_notifier(fn, pri) {                              \
 105        static struct notifier_block fn##_nb =                  \
 106                { .notifier_call = fn, .priority = pri };       \
 107        register_cpu_notifier(&fn##_nb);                        \
 108}
 109#define register_hotcpu_notifier(nb)    register_cpu_notifier(nb)
 110#define unregister_hotcpu_notifier(nb)  unregister_cpu_notifier(nb)
 111int cpu_down(unsigned int cpu);
 112#define cpu_is_offline(cpu) unlikely(!cpu_online(cpu))
 113
 114#else           /* CONFIG_HOTPLUG_CPU */
 115
 116static inline void cpuhotplug_mutex_lock(struct mutex *cpu_hp_mutex)
 117{ }
 118static inline void cpuhotplug_mutex_unlock(struct mutex *cpu_hp_mutex)
 119{ }
 120
 121#define lock_cpu_hotplug()      do { } while (0)
 122#define unlock_cpu_hotplug()    do { } while (0)
 123#define lock_cpu_hotplug_interruptible() 0
 124#define hotcpu_notifier(fn, pri)        do { (void)(fn); } while (0)
 125#define register_hotcpu_notifier(nb)    do { (void)(nb); } while (0)
 126#define unregister_hotcpu_notifier(nb)  do { (void)(nb); } while (0)
 127
 128/* CPUs don't go offline once they're online w/o CONFIG_HOTPLUG_CPU */
 129static inline int cpu_is_offline(int cpu) { return 0; }
 130#endif          /* CONFIG_HOTPLUG_CPU */
 131
 132#ifdef CONFIG_SUSPEND_SMP
 133extern int suspend_cpu_hotplug;
 134
 135extern int disable_nonboot_cpus(void);
 136extern void enable_nonboot_cpus(void);
 137#else
 138#define suspend_cpu_hotplug     0
 139
 140static inline int disable_nonboot_cpus(void) { return 0; }
 141static inline void enable_nonboot_cpus(void) {}
 142#endif
 143
 144#endif /* _LINUX_CPU_H_ */
 145