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 #ifdef CONFIG_HOTPLUG_CPU
  52 extern int register_cpu_notifier(struct notifier_block *nb);
  53 extern void unregister_cpu_notifier(struct notifier_block *nb);
  54 #else
  55
  56 #ifndef MODULE
  57 extern int register_cpu_notifier(struct notifier_block *nb);
  58 #else
  59 static inline int register_cpu_notifier(struct notifier_block *nb)
  60 {
  61         return 0;
  62 }
  63 #endif
  64
  65 static inline void unregister_cpu_notifier(struct notifier_block *nb)
  66 {
  67 }
  68 #endif
  69
  70 int cpu_up(unsigned int cpu);
  71 void notify_cpu_starting(unsigned int cpu);
  72 extern void cpu_maps_update_begin(void);
  73 extern void cpu_maps_update_done(void);
  74
  75 #else   /* CONFIG_SMP */
  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_maps_update_begin(void)
  87 {
  88 }
  89
  90 static inline void cpu_maps_update_done(void)
  91 {
  92 }
  93
  94 #endif /* CONFIG_SMP */
  95 extern struct sysdev_class cpu_sysdev_class;
  96
  97 #ifdef CONFIG_HOTPLUG_CPU
  98 /* Stop CPUs going up and down. */
  99
 100 extern void get_online_cpus(void);
 101 extern void put_online_cpus(void);
 102 #define hotcpu_notifier(fn, pri) {                              \
 103         static struct notifier_block fn##_nb __cpuinitdata =    \
 104                 { .notifier_call = fn, .priority = pri };       \
 105         register_cpu_notifier(&fn##_nb);                        \
 106 }
 107 #define register_hotcpu_notifier(nb)    register_cpu_notifier(nb)
 108 #define unregister_hotcpu_notifier(nb)  unregister_cpu_notifier(nb)
 109 int cpu_down(unsigned int cpu);
 110
 111 #else           /* CONFIG_HOTPLUG_CPU */
 112
 113 #define get_online_cpus()       do { } while (0)
 114 #define put_online_cpus()       do { } while (0)
 115 #define hotcpu_notifier(fn, pri)        do { (void)(fn); } while (0)
 116 /* These aren't inline functions due to a GCC bug. */
 117 #define register_hotcpu_notifier(nb)    ({ (void)(nb); 0; })
 118 #define unregister_hotcpu_notifier(nb)  ({ (void)(nb); })
 119 #endif          /* CONFIG_HOTPLUG_CPU */
 120
 121 #ifdef CONFIG_PM_SLEEP_SMP
 122 extern int suspend_cpu_hotplug;
 123
 124 extern int disable_nonboot_cpus(void);
 125 extern void enable_nonboot_cpus(void);
 126 #else /* !CONFIG_PM_SLEEP_SMP */
 127 #define suspend_cpu_hotplug     0
 128
 129 static inline int disable_nonboot_cpus(void) { return 0; }
 130 static inline void enable_nonboot_cpus(void) {}
 131 #endif /* !CONFIG_PM_SLEEP_SMP */
 132
 133 #endif /* _LINUX_CPU_H_ */