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