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
  29 struct 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
  35 extern int register_cpu(struct cpu *cpu, int num);
  36 extern struct sys_device *get_cpu_sysdev(unsigned cpu);
  37
  38 extern int cpu_add_sysdev_attr(struct sysdev_attribute *attr);
  39 extern void cpu_remove_sysdev_attr(struct sysdev_attribute *attr);
  40
  41 extern int cpu_add_sysdev_attr_group(struct attribute_group *attrs);
  42 extern void cpu_remove_sysdev_attr_group(struct attribute_group *attrs);
  43
  44 extern int sched_create_sysfs_power_savings_entries(struct sysdev_class *cls);
  45
  46 #ifdef CONFIG_HOTPLUG_CPU
  47 extern void unregister_cpu(struct cpu *cpu);
  48 #endif
  49 struct notifier_block;
  50
  51 #ifdef CONFIG_SMP
  52 /* Need to know about CPUs going up/down? */
  53 #ifdef CONFIG_HOTPLUG_CPU
  54 extern int register_cpu_notifier(struct notifier_block *nb);
  55 extern void unregister_cpu_notifier(struct notifier_block *nb);
  56 #else
  57
  58 #ifndef MODULE
  59 extern int register_cpu_notifier(struct notifier_block *nb);
  60 #else
  61 static inline int register_cpu_notifier(struct notifier_block *nb)
  62 {
  63         return 0;
  64 }
  65 #endif
  66
  67 static inline void unregister_cpu_notifier(struct notifier_block *nb)
  68 {
  69 }
  70 #endif
  71
  72 int cpu_up(unsigned int cpu);
  73
  74 #else
  75
  76 static inline int register_cpu_notifier(struct notifier_block *nb)
  77 {
  78         return 0;
  79 }
  80 static inline void unregister_cpu_notifier(struct notifier_block *nb)
  81 {
  82 }
  83
  84 #endif /* CONFIG_SMP */
  85 extern struct sysdev_class cpu_sysdev_class;
  86
  87 #ifdef CONFIG_HOTPLUG_CPU
  88 /* Stop CPUs going up and down. */
  89
  90 static inline void cpuhotplug_mutex_lock(struct mutex *cpu_hp_mutex)
  91 {
  92         mutex_lock(cpu_hp_mutex);
  93 }
  94
  95 static inline void cpuhotplug_mutex_unlock(struct mutex *cpu_hp_mutex)
  96 {
  97         mutex_unlock(cpu_hp_mutex);
  98 }
  99
 100 extern void lock_cpu_hotplug(void);
 101 extern 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)
 109 int cpu_down(unsigned int cpu);
 110 #define cpu_is_offline(cpu) unlikely(!cpu_online(cpu))
 111
 112 #else           /* CONFIG_HOTPLUG_CPU */
 113
 114 static inline void cpuhotplug_mutex_lock(struct mutex *cpu_hp_mutex)
 115 { }
 116 static 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 hotcpu_notifier(fn, pri)        do { (void)(fn); } while (0)
 122 /* These aren't inline functions due to a GCC bug. */
 123 #define register_hotcpu_notifier(nb)    ({ (void)(nb); 0; })
 124 #define unregister_hotcpu_notifier(nb)  ({ (void)(nb); })
 125
 126 /* CPUs don't go offline once they're online w/o CONFIG_HOTPLUG_CPU */
 127 static inline int cpu_is_offline(int cpu) { return 0; }
 128 #endif          /* CONFIG_HOTPLUG_CPU */
 129
 130 #ifdef CONFIG_PM_SLEEP_SMP
 131 extern int suspend_cpu_hotplug;
 132
 133 extern int disable_nonboot_cpus(void);
 134 extern void enable_nonboot_cpus(void);
 135 #else /* !CONFIG_PM_SLEEP_SMP */
 136 #define suspend_cpu_hotplug     0
 137
 138 static inline int disable_nonboot_cpus(void) { return 0; }
 139 static inline void enable_nonboot_cpus(void) {}
 140 #endif /* !CONFIG_PM_SLEEP_SMP */
 141
 142 #endif /* _LINUX_CPU_H_ */