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 extern ssize_t arch_cpu_probe(const char *, size_t);
  47 extern ssize_t arch_cpu_release(const char *, size_t);
  48 #endif
  49 struct notifier_block;
  50
  51 #ifdef CONFIG_SMP
  52 /* Need to know about CPUs going up/down? */
  53 #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE)
  54 #define cpu_notifier(fn, pri) {                                 \
  55         static struct notifier_block fn##_nb __cpuinitdata =    \
  56                 { .notifier_call = fn, .priority = pri };       \
  57         register_cpu_notifier(&fn##_nb);                        \
  58 }
  59 #else /* #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
  60 #define cpu_notifier(fn, pri)   do { (void)(fn); } while (0)
  61 #endif /* #else #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
  62 #ifdef CONFIG_HOTPLUG_CPU
  63 extern int register_cpu_notifier(struct notifier_block *nb);
  64 extern void unregister_cpu_notifier(struct notifier_block *nb);
  65 #else
  66
  67 #ifndef MODULE
  68 extern int register_cpu_notifier(struct notifier_block *nb);
  69 #else
  70 static inline int register_cpu_notifier(struct notifier_block *nb)
  71 {
  72         return 0;
  73 }
  74 #endif
  75
  76 static inline void unregister_cpu_notifier(struct notifier_block *nb)
  77 {
  78 }
  79 #endif
  80
  81 int cpu_up(unsigned int cpu);
  82 void notify_cpu_starting(unsigned int cpu);
  83 extern void cpu_maps_update_begin(void);
  84 extern void cpu_maps_update_done(void);
  85
  86 #else   /* CONFIG_SMP */
  87
  88 #define cpu_notifier(fn, pri)   do { (void)(fn); } while (0)
  89
  90 static inline int register_cpu_notifier(struct notifier_block *nb)
  91 {
  92         return 0;
  93 }
  94
  95 static inline void unregister_cpu_notifier(struct notifier_block *nb)
  96 {
  97 }
  98
  99 static inline void cpu_maps_update_begin(void)
 100 {
 101 }
 102
 103 static inline void cpu_maps_update_done(void)
 104 {
 105 }
 106
 107 #endif /* CONFIG_SMP */
 108 extern struct sysdev_class cpu_sysdev_class;
 109
 110 #ifdef CONFIG_HOTPLUG_CPU
 111 /* Stop CPUs going up and down. */
 112
 113 extern void get_online_cpus(void);
 114 extern void put_online_cpus(void);
 115 #define hotcpu_notifier(fn, pri)        cpu_notifier(fn, pri)
 116 #define register_hotcpu_notifier(nb)    register_cpu_notifier(nb)
 117 #define unregister_hotcpu_notifier(nb)  unregister_cpu_notifier(nb)
 118 int cpu_down(unsigned int cpu);
 119
 120 #ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
 121 extern void cpu_hotplug_driver_lock(void);
 122 extern void cpu_hotplug_driver_unlock(void);
 123 #else
 124 static inline void cpu_hotplug_driver_lock(void)
 125 {
 126 }
 127
 128 static inline void cpu_hotplug_driver_unlock(void)
 129 {
 130 }
 131 #endif
 132
 133 #else           /* CONFIG_HOTPLUG_CPU */
 134
 135 #define get_online_cpus()       do { } while (0)
 136 #define put_online_cpus()       do { } while (0)
 137 #define hotcpu_notifier(fn, pri)        do { (void)(fn); } while (0)
 138 /* These aren't inline functions due to a GCC bug. */
 139 #define register_hotcpu_notifier(nb)    ({ (void)(nb); 0; })
 140 #define unregister_hotcpu_notifier(nb)  ({ (void)(nb); })
 141 #endif          /* CONFIG_HOTPLUG_CPU */
 142
 143 #ifdef CONFIG_PM_SLEEP_SMP
 144 extern int suspend_cpu_hotplug;
 145
 146 extern int disable_nonboot_cpus(void);
 147 extern void enable_nonboot_cpus(void);
 148 #else /* !CONFIG_PM_SLEEP_SMP */
 149 #define suspend_cpu_hotplug     0
 150
 151 static inline int disable_nonboot_cpus(void) { return 0; }
 152 static inline void enable_nonboot_cpus(void) {}
 153 #endif /* !CONFIG_PM_SLEEP_SMP */
 154
 155 #endif /* _LINUX_CPU_H_ */