release/src-rt-6.x/linux/linux-2.6/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 struct sysdev_attribute attr_sched_mc_power_savings;
  45 extern struct sysdev_attribute attr_sched_smt_power_savings;
  46 extern int sched_create_sysfs_power_savings_entries(struct sysdev_class *cls);
  47
  48 #ifdef CONFIG_HOTPLUG_CPU
  49 extern void unregister_cpu(struct cpu *cpu);
  50 #endif
  51 struct notifier_block;
  52
  53 #ifdef CONFIG_SMP
  54 /* Need to know about CPUs going up/down? */
  55 #ifdef CONFIG_HOTPLUG_CPU
  56 extern int register_cpu_notifier(struct notifier_block *nb);
  57 extern void unregister_cpu_notifier(struct notifier_block *nb);
  58 #else
  59
  60 #ifndef MODULE
  61 extern int register_cpu_notifier(struct notifier_block *nb);
  62 #else
  63 static inline int register_cpu_notifier(struct notifier_block *nb)
  64 {
  65         return 0;
  66 }
  67 #endif
  68
  69 static inline void unregister_cpu_notifier(struct notifier_block *nb)
  70 {
  71 }
  72 #endif
  73
  74 int cpu_up(unsigned int cpu);
  75
  76 #else
  77
  78 static inline int register_cpu_notifier(struct notifier_block *nb)
  79 {
  80         return 0;
  81 }
  82 static inline void unregister_cpu_notifier(struct notifier_block *nb)
  83 {
  84 }
  85
  86 #endif /* CONFIG_SMP */
  87 extern struct sysdev_class cpu_sysdev_class;
  88
  89 #ifdef CONFIG_HOTPLUG_CPU
  90 /* Stop CPUs going up and down. */
  91
  92 static inline void cpuhotplug_mutex_lock(struct mutex *cpu_hp_mutex)
  93 {
  94         mutex_lock(cpu_hp_mutex);
  95 }
  96
  97 static inline void cpuhotplug_mutex_unlock(struct mutex *cpu_hp_mutex)
  98 {
  99         mutex_unlock(cpu_hp_mutex);
 100 }
 101
 102 extern void lock_cpu_hotplug(void);
 103 extern void unlock_cpu_hotplug(void);
 104 #define hotcpu_notifier(fn, pri) {                              \
 105         static struct notifier_block fn##_nb =                  \
 106                 { .notifier_call = fn, .priority = pri };       \
 107         register_cpu_notifier(&fn##_nb);                        \
 108 }
 109 #define register_hotcpu_notifier(nb)    register_cpu_notifier(nb)
 110 #define unregister_hotcpu_notifier(nb)  unregister_cpu_notifier(nb)
 111 int cpu_down(unsigned int cpu);
 112 #define cpu_is_offline(cpu) unlikely(!cpu_online(cpu))
 113
 114 #else           /* CONFIG_HOTPLUG_CPU */
 115
 116 static inline void cpuhotplug_mutex_lock(struct mutex *cpu_hp_mutex)
 117 { }
 118 static inline void cpuhotplug_mutex_unlock(struct mutex *cpu_hp_mutex)
 119 { }
 120
 121 #define lock_cpu_hotplug()      do { } while (0)
 122 #define unlock_cpu_hotplug()    do { } while (0)
 123 #define lock_cpu_hotplug_interruptible() 0
 124 #define hotcpu_notifier(fn, pri)        do { (void)(fn); } while (0)
 125 #define register_hotcpu_notifier(nb)    do { (void)(nb); } while (0)
 126 #define unregister_hotcpu_notifier(nb)  do { (void)(nb); } while (0)
 127
 128 /* CPUs don't go offline once they're online w/o CONFIG_HOTPLUG_CPU */
 129 static inline int cpu_is_offline(int cpu) { return 0; }
 130 #endif          /* CONFIG_HOTPLUG_CPU */
 131
 132 #ifdef CONFIG_SUSPEND_SMP
 133 extern int suspend_cpu_hotplug;
 134
 135 extern int disable_nonboot_cpus(void);
 136 extern void enable_nonboot_cpus(void);
 137 #else
 138 #define suspend_cpu_hotplug     0
 139
 140 static inline int disable_nonboot_cpus(void) { return 0; }
 141 static inline void enable_nonboot_cpus(void) {}
 142 #endif
 143
 144 #endif /* _LINUX_CPU_H_ */