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
  28 struct cpu {
  29         int node_id;            /* The node which contains the CPU */
  30         int no_control;         /* Should the sysfs control file be created? */
  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
  44 #ifdef CONFIG_HOTPLUG_CPU
  45 extern void unregister_cpu(struct cpu *cpu);
  46 #endif
  47 struct notifier_block;
  48
  49 #ifdef CONFIG_SMP
  50 /* Need to know about CPUs going up/down? */
  51 extern int register_cpu_notifier(struct notifier_block *nb);
  52 #ifdef CONFIG_HOTPLUG_CPU
  53 extern void unregister_cpu_notifier(struct notifier_block *nb);
  54 #else
  55 static inline void unregister_cpu_notifier(struct notifier_block *nb)
  56 {
  57 }
  58 #endif
  59
  60 int cpu_up(unsigned int cpu);
  61
  62 #else
  63
  64 static inline int register_cpu_notifier(struct notifier_block *nb)
  65 {
  66         return 0;
  67 }
  68 static inline void unregister_cpu_notifier(struct notifier_block *nb)
  69 {
  70 }
  71
  72 #endif /* CONFIG_SMP */
  73 extern struct sysdev_class cpu_sysdev_class;
  74
  75 #ifdef CONFIG_HOTPLUG_CPU
  76 /* Stop CPUs going up and down. */
  77 extern void lock_cpu_hotplug(void);
  78 extern void unlock_cpu_hotplug(void);
  79 #define hotcpu_notifier(fn, pri) {                              \
  80         static struct notifier_block fn##_nb =                  \
  81                 { .notifier_call = fn, .priority = pri };       \
  82         register_cpu_notifier(&fn##_nb);                        \
  83 }
  84 #define register_hotcpu_notifier(nb)    register_cpu_notifier(nb)
  85 #define unregister_hotcpu_notifier(nb)  unregister_cpu_notifier(nb)
  86 int cpu_down(unsigned int cpu);
  87 #define cpu_is_offline(cpu) unlikely(!cpu_online(cpu))
  88 #else
  89 #define lock_cpu_hotplug()      do { } while (0)
  90 #define unlock_cpu_hotplug()    do { } while (0)
  91 #define lock_cpu_hotplug_interruptible() 0
  92 #define hotcpu_notifier(fn, pri)        do { } while (0)
  93 #define register_hotcpu_notifier(nb)    do { } while (0)
  94 #define unregister_hotcpu_notifier(nb)  do { } while (0)
  95
  96 /* CPUs don't go offline once they're online w/o CONFIG_HOTPLUG_CPU */
  97 static inline int cpu_is_offline(int cpu) { return 0; }
  98 #endif
  99
 100 #ifdef CONFIG_SUSPEND_SMP
 101 extern int disable_nonboot_cpus(void);
 102 extern void enable_nonboot_cpus(void);
 103 #else
 104 static inline int disable_nonboot_cpus(void) { return 0; }
 105 static inline void enable_nonboot_cpus(void) {}
 106 #endif
 107
 108 #endif /* _LINUX_CPU_H_ */