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