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
  27 struct cpu {
  28         int node_id;            /* The node which contains the CPU */
  29         int hotpluggable;       /* creates sysfs control file if hotpluggable */
  30         struct sys_device sysdev;
  31 };
  32
  33 extern int register_cpu(struct cpu *cpu, int num);
  34 extern struct sys_device *get_cpu_sysdev(unsigned cpu);
  35
  36 extern int cpu_add_sysdev_attr(struct sysdev_attribute *attr);
  37 extern void cpu_remove_sysdev_attr(struct sysdev_attribute *attr);
  38
  39 extern int cpu_add_sysdev_attr_group(struct attribute_group *attrs);
  40 extern void cpu_remove_sysdev_attr_group(struct attribute_group *attrs);
  41
  42 extern int sched_create_sysfs_power_savings_entries(struct sysdev_class *cls);
  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 #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE)
  52 #define cpu_notifier(fn, pri) {                                 \
  53         static struct notifier_block fn##_nb __cpuinitdata =    \
  54                 { .notifier_call = fn, .priority = pri };       \
  55         register_cpu_notifier(&fn##_nb);                        \
  56 }
  57 #else /* #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
  58 #define cpu_notifier(fn, pri)   do { (void)(fn); } while (0)
  59 #endif /* #else #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
  60 #ifdef CONFIG_HOTPLUG_CPU
  61 extern int register_cpu_notifier(struct notifier_block *nb);
  62 extern void unregister_cpu_notifier(struct notifier_block *nb);
  63 #else
  64
  65 #ifndef MODULE
  66 extern int register_cpu_notifier(struct notifier_block *nb);
  67 #else
  68 static inline int register_cpu_notifier(struct notifier_block *nb)
  69 {
  70         return 0;
  71 }
  72 #endif
  73
  74 static inline void unregister_cpu_notifier(struct notifier_block *nb)
  75 {
  76 }
  77 #endif
  78
  79 int cpu_up(unsigned int cpu);
  80 void notify_cpu_starting(unsigned int cpu);
  81 extern void cpu_maps_update_begin(void);
  82 extern void cpu_maps_update_done(void);
  83
  84 #else   /* CONFIG_SMP */
  85
  86 #define cpu_notifier(fn, pri)   do { (void)(fn); } while (0)
  87
  88 static inline int register_cpu_notifier(struct notifier_block *nb)
  89 {
  90         return 0;
  91 }
  92
  93 static inline void unregister_cpu_notifier(struct notifier_block *nb)
  94 {
  95 }
  96
  97 static inline void cpu_maps_update_begin(void)
  98 {
  99 }
 100
 101 static inline void cpu_maps_update_done(void)
 102 {
 103 }
 104
 105 #endif /* CONFIG_SMP */
 106 extern struct sysdev_class cpu_sysdev_class;
 107
 108 #ifdef CONFIG_HOTPLUG_CPU
 109 /* Stop CPUs going up and down. */
 110
 111 extern void get_online_cpus(void);
 112 extern void put_online_cpus(void);
 113 #define hotcpu_notifier(fn, pri)        cpu_notifier(fn, pri)
 114 #define register_hotcpu_notifier(nb)    register_cpu_notifier(nb)
 115 #define unregister_hotcpu_notifier(nb)  unregister_cpu_notifier(nb)
 116 int cpu_down(unsigned int cpu);
 117
 118 #else           /* CONFIG_HOTPLUG_CPU */
 119
 120 #define get_online_cpus()       do { } while (0)
 121 #define put_online_cpus()       do { } while (0)
 122 #define hotcpu_notifier(fn, pri)        do { (void)(fn); } while (0)
 123 /* These aren't inline functions due to a GCC bug. */
 124 #define register_hotcpu_notifier(nb)    ({ (void)(nb); 0; })
 125 #define unregister_hotcpu_notifier(nb)  ({ (void)(nb); })
 126 #endif          /* CONFIG_HOTPLUG_CPU */
 127
 128 #ifdef CONFIG_PM_SLEEP_SMP
 129 extern int suspend_cpu_hotplug;
 130
 131 extern int disable_nonboot_cpus(void);
 132 extern void enable_nonboot_cpus(void);
 133 #else /* !CONFIG_PM_SLEEP_SMP */
 134 #define suspend_cpu_hotplug     0
 135
 136 static inline int disable_nonboot_cpus(void) { return 0; }
 137 static inline void enable_nonboot_cpus(void) {}
 138 #endif /* !CONFIG_PM_SLEEP_SMP */
 139
 140 #endif /* _LINUX_CPU_H_ */