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 <linux/mutex.h>
  27
  28 struct cpu {
  29         int node_id;            /* The node which contains the CPU */
  30         int hotpluggable;       /* creates sysfs control file if hotpluggable */
  31         struct sys_device sysdev;
  32 };
  33
  34 extern int register_cpu(struct cpu *cpu, int num);
  35 extern struct sys_device *get_cpu_sysdev(unsigned cpu);
  36
  37 extern int cpu_add_sysdev_attr(struct sysdev_attribute *attr);
  38 extern void cpu_remove_sysdev_attr(struct sysdev_attribute *attr);
  39
  40 extern int cpu_add_sysdev_attr_group(struct attribute_group *attrs);
  41 extern void cpu_remove_sysdev_attr_group(struct attribute_group *attrs);
  42
  43 extern int sched_create_sysfs_power_savings_entries(struct sysdev_class *cls);
  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 extern void cpu_hotplug_init(void);
  74
  75 #else
  76
  77 static inline int register_cpu_notifier(struct notifier_block *nb)
  78 {
  79         return 0;
  80 }
  81
  82 static inline void unregister_cpu_notifier(struct notifier_block *nb)
  83 {
  84 }
  85
  86 static inline void cpu_hotplug_init(void)
  87 {
  88 }
  89
  90 #endif /* CONFIG_SMP */
  91 extern struct sysdev_class cpu_sysdev_class;
  92 extern void cpu_maps_update_begin(void);
  93 extern void cpu_maps_update_done(void);
  94
  95 #ifdef CONFIG_HOTPLUG_CPU
  96 /* Stop CPUs going up and down. */
  97
  98 static inline void cpuhotplug_mutex_lock(struct mutex *cpu_hp_mutex)
  99 {
 100         mutex_lock(cpu_hp_mutex);
 101 }
 102
 103 static inline void cpuhotplug_mutex_unlock(struct mutex *cpu_hp_mutex)
 104 {
 105         mutex_unlock(cpu_hp_mutex);
 106 }
 107
 108 extern void get_online_cpus(void);
 109 extern void put_online_cpus(void);
 110 #define hotcpu_notifier(fn, pri) {                              \
 111         static struct notifier_block fn##_nb __cpuinitdata =    \
 112                 { .notifier_call = fn, .priority = pri };       \
 113         register_cpu_notifier(&fn##_nb);                        \
 114 }
 115 #define register_hotcpu_notifier(nb)    register_cpu_notifier(nb)
 116 #define unregister_hotcpu_notifier(nb)  unregister_cpu_notifier(nb)
 117 int cpu_down(unsigned int cpu);
 118
 119 #else           /* CONFIG_HOTPLUG_CPU */
 120
 121 static inline void cpuhotplug_mutex_lock(struct mutex *cpu_hp_mutex)
 122 { }
 123 static inline void cpuhotplug_mutex_unlock(struct mutex *cpu_hp_mutex)
 124 { }
 125
 126 #define get_online_cpus()       do { } while (0)
 127 #define put_online_cpus()       do { } while (0)
 128 #define hotcpu_notifier(fn, pri)        do { (void)(fn); } while (0)
 129 /* These aren't inline functions due to a GCC bug. */
 130 #define register_hotcpu_notifier(nb)    ({ (void)(nb); 0; })
 131 #define unregister_hotcpu_notifier(nb)  ({ (void)(nb); })
 132 #endif          /* CONFIG_HOTPLUG_CPU */
 133
 134 #ifdef CONFIG_PM_SLEEP_SMP
 135 extern int suspend_cpu_hotplug;
 136
 137 extern int disable_nonboot_cpus(void);
 138 extern void enable_nonboot_cpus(void);
 139 #else /* !CONFIG_PM_SLEEP_SMP */
 140 #define suspend_cpu_hotplug     0
 141
 142 static inline int disable_nonboot_cpus(void) { return 0; }
 143 static inline void enable_nonboot_cpus(void) {}
 144 #endif /* !CONFIG_PM_SLEEP_SMP */
 145
 146 #endif /* _LINUX_CPU_H_ */