2 * include/linux/cpu.h - generic cpu definition
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.
8 * Basic handling of the devices is done in drivers/base/cpu.c
9 * and system devices are handled in drivers/base/sys.c.
11 * CPUs are exported via sysfs in the class/cpu/devices/
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
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>
30 int node_id; /* The node which contains the CPU */
31 int hotpluggable; /* creates sysfs control file if hotpluggable */
32 struct sys_device sysdev;
35 extern int register_cpu(struct cpu *cpu, int num);
36 extern struct sys_device *get_cpu_sysdev(unsigned cpu);
38 extern int cpu_add_sysdev_attr(struct sysdev_attribute *attr);
39 extern void cpu_remove_sysdev_attr(struct sysdev_attribute *attr);
41 extern int cpu_add_sysdev_attr_group(struct attribute_group *attrs);
42 extern void cpu_remove_sysdev_attr_group(struct attribute_group *attrs);
45 #ifdef CONFIG_HOTPLUG_CPU
46 extern void unregister_cpu(struct cpu *cpu);
48 struct notifier_block;
51 /* Need to know about CPUs going up/down? */
52 #ifdef CONFIG_HOTPLUG_CPU
53 extern int register_cpu_notifier(struct notifier_block *nb);
54 extern void unregister_cpu_notifier(struct notifier_block *nb);
58 extern int register_cpu_notifier(struct notifier_block *nb);
60 static inline int register_cpu_notifier(struct notifier_block *nb)
66 static inline void unregister_cpu_notifier(struct notifier_block *nb)
71 int cpu_up(unsigned int cpu);
75 static inline int register_cpu_notifier(struct notifier_block *nb)
79 static inline void unregister_cpu_notifier(struct notifier_block *nb)
83 #endif /* CONFIG_SMP */
84 extern struct sysdev_class cpu_sysdev_class;
86 #ifdef CONFIG_HOTPLUG_CPU
87 /* Stop CPUs going up and down. */
89 static inline void cpuhotplug_mutex_lock(struct mutex *cpu_hp_mutex)
91 mutex_lock(cpu_hp_mutex);
94 static inline void cpuhotplug_mutex_unlock(struct mutex *cpu_hp_mutex)
96 mutex_unlock(cpu_hp_mutex);
99 extern void lock_cpu_hotplug(void);
100 extern void unlock_cpu_hotplug(void);
101 #define hotcpu_notifier(fn, pri) { \
102 static struct notifier_block fn##_nb = \
103 { .notifier_call = fn, .priority = pri }; \
104 register_cpu_notifier(&fn##_nb); \
106 #define register_hotcpu_notifier(nb) register_cpu_notifier(nb)
107 #define unregister_hotcpu_notifier(nb) unregister_cpu_notifier(nb)
108 int cpu_down(unsigned int cpu);
109 #define cpu_is_offline(cpu) unlikely(!cpu_online(cpu))
111 #else /* CONFIG_HOTPLUG_CPU */
113 static inline void cpuhotplug_mutex_lock(struct mutex *cpu_hp_mutex)
115 static inline void cpuhotplug_mutex_unlock(struct mutex *cpu_hp_mutex)
118 #define lock_cpu_hotplug() do { } while (0)
119 #define unlock_cpu_hotplug() do { } while (0)
120 #define lock_cpu_hotplug_interruptible() 0
121 #define hotcpu_notifier(fn, pri) do { (void)(fn); } while (0)
122 #define register_hotcpu_notifier(nb) do { (void)(nb); } while (0)
123 #define unregister_hotcpu_notifier(nb) do { (void)(nb); } while (0)
125 /* CPUs don't go offline once they're online w/o CONFIG_HOTPLUG_CPU */
126 static inline int cpu_is_offline(int cpu) { return 0; }
127 #endif /* CONFIG_HOTPLUG_CPU */
129 #ifdef CONFIG_SUSPEND_SMP
130 extern int suspend_cpu_hotplug;
132 extern int disable_nonboot_cpus(void);
133 extern void enable_nonboot_cpus(void);
135 #define suspend_cpu_hotplug 0
137 static inline int disable_nonboot_cpus(void) { return 0; }
138 static inline void enable_nonboot_cpus(void) {}
141 #endif /* _LINUX_CPU_H_ */