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 extern void cpu_hotplug_init(void);
  75
  76 #else
  77
  78 static inline int register_cpu_notifier(struct notifier_block *nb)
  79 {
  80         return 0;
  81 }
  82
  83 static inline void unregister_cpu_notifier(struct notifier_block *nb)
  84 {
  85 }
  86
  87 static inline void cpu_hotplug_init(void)
  88 {
  89 }
  90
  91 #endif /* CONFIG_SMP */
  92 extern struct sysdev_class cpu_sysdev_class;
  93 extern void cpu_maps_update_begin(void);
  94 extern void cpu_maps_update_done(void);
  95
  96 #ifdef CONFIG_HOTPLUG_CPU
  97 /* Stop CPUs going up and down. */
  98
  99 static inline void cpuhotplug_mutex_lock(struct mutex *cpu_hp_mutex)
 100 {
 101         mutex_lock(cpu_hp_mutex);
 102 }
 103
 104 static inline void cpuhotplug_mutex_unlock(struct mutex *cpu_hp_mutex)
 105 {
 106         mutex_unlock(cpu_hp_mutex);
 107 }
 108
 109 extern void get_online_cpus(void);
 110 extern void put_online_cpus(void);
 111 #define hotcpu_notifier(fn, pri) {                              \
 112         static struct notifier_block fn##_nb =                  \
 113                 { .notifier_call = fn, .priority = pri };       \
 114         register_cpu_notifier(&fn##_nb);                        \
 115 }
 116 #define register_hotcpu_notifier(nb)    register_cpu_notifier(nb)
 117 #define unregister_hotcpu_notifier(nb)  unregister_cpu_notifier(nb)
 118 int cpu_down(unsigned int cpu);
 119
 120 #else           /* CONFIG_HOTPLUG_CPU */
 121
 122 static inline void cpuhotplug_mutex_lock(struct mutex *cpu_hp_mutex)
 123 { }
 124 static inline void cpuhotplug_mutex_unlock(struct mutex *cpu_hp_mutex)
 125 { }
 126
 127 #define get_online_cpus()       do { } while (0)
 128 #define put_online_cpus()       do { } while (0)
 129 #define hotcpu_notifier(fn, pri)        do { (void)(fn); } while (0)
 130 /* These aren't inline functions due to a GCC bug. */
 131 #define register_hotcpu_notifier(nb)    ({ (void)(nb); 0; })
 132 #define unregister_hotcpu_notifier(nb)  ({ (void)(nb); })
 133 #endif          /* CONFIG_HOTPLUG_CPU */
 134
 135 #ifdef CONFIG_PM_SLEEP_SMP
 136 extern int suspend_cpu_hotplug;
 137
 138 extern int disable_nonboot_cpus(void);
 139 extern void enable_nonboot_cpus(void);
 140 #else /* !CONFIG_PM_SLEEP_SMP */
 141 #define suspend_cpu_hotplug     0
 142
 143 static inline int disable_nonboot_cpus(void) { return 0; }
 144 static inline void enable_nonboot_cpus(void) {}
 145 #endif /* !CONFIG_PM_SLEEP_SMP */
 146
 147 #endif /* _LINUX_CPU_H_ */