cpu.h revision f7dff2b12654149c9cac8d8c79b6588759edd5a9 
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#include <linux/mutex.h>
28
29struct cpu {
30	int node_id;		/* The node which contains the CPU */
31	int no_control;		/* Should the sysfs control file be created? */
32	struct sys_device sysdev;
33};
34
35extern int register_cpu(struct cpu *cpu, int num);
36extern struct sys_device *get_cpu_sysdev(unsigned cpu);
37
38extern int cpu_add_sysdev_attr(struct sysdev_attribute *attr);
39extern void cpu_remove_sysdev_attr(struct sysdev_attribute *attr);
40
41extern int cpu_add_sysdev_attr_group(struct attribute_group *attrs);
42extern void cpu_remove_sysdev_attr_group(struct attribute_group *attrs);
43
44
45#ifdef CONFIG_HOTPLUG_CPU
46extern void unregister_cpu(struct cpu *cpu);
47#endif
48struct notifier_block;
49
50#ifdef CONFIG_SMP
51/* Need to know about CPUs going up/down? */
52extern int register_cpu_notifier(struct notifier_block *nb);
53#ifdef CONFIG_HOTPLUG_CPU
54extern void unregister_cpu_notifier(struct notifier_block *nb);
55#else
56static inline void unregister_cpu_notifier(struct notifier_block *nb)
57{
58}
59#endif
60
61int cpu_up(unsigned int cpu);
62
63#else
64
65static inline int register_cpu_notifier(struct notifier_block *nb)
66{
67	return 0;
68}
69static inline void unregister_cpu_notifier(struct notifier_block *nb)
70{
71}
72
73#endif /* CONFIG_SMP */
74extern struct sysdev_class cpu_sysdev_class;
75
76#ifdef CONFIG_HOTPLUG_CPU
77/* Stop CPUs going up and down. */
78
79static inline void cpuhotplug_mutex_lock(struct mutex *cpu_hp_mutex)
80{
81	mutex_lock(cpu_hp_mutex);
82}
83
84static inline void cpuhotplug_mutex_unlock(struct mutex *cpu_hp_mutex)
85{
86	mutex_unlock(cpu_hp_mutex);
87}
88
89extern void lock_cpu_hotplug(void);
90extern void unlock_cpu_hotplug(void);
91#define hotcpu_notifier(fn, pri) {				\
92	static struct notifier_block fn##_nb =			\
93		{ .notifier_call = fn, .priority = pri };	\
94	register_cpu_notifier(&fn##_nb);			\
95}
96#define register_hotcpu_notifier(nb)	register_cpu_notifier(nb)
97#define unregister_hotcpu_notifier(nb)	unregister_cpu_notifier(nb)
98int cpu_down(unsigned int cpu);
99#define cpu_is_offline(cpu) unlikely(!cpu_online(cpu))
100
101#else		/* CONFIG_HOTPLUG_CPU */
102
103static inline void cpuhotplug_mutex_lock(struct mutex *cpu_hp_mutex)
104{ }
105static inline void cpuhotplug_mutex_unlock(struct mutex *cpu_hp_mutex)
106{ }
107
108#define lock_cpu_hotplug()	do { } while (0)
109#define unlock_cpu_hotplug()	do { } while (0)
110#define lock_cpu_hotplug_interruptible() 0
111#define hotcpu_notifier(fn, pri)	do { (void)(fn); } while (0)
112#define register_hotcpu_notifier(nb)	do { (void)(nb); } while (0)
113#define unregister_hotcpu_notifier(nb)	do { (void)(nb); } while (0)
114
115/* CPUs don't go offline once they're online w/o CONFIG_HOTPLUG_CPU */
116static inline int cpu_is_offline(int cpu) { return 0; }
117#endif		/* CONFIG_HOTPLUG_CPU */
118
119#ifdef CONFIG_SUSPEND_SMP
120extern int disable_nonboot_cpus(void);
121extern void enable_nonboot_cpus(void);
122#else
123static inline int disable_nonboot_cpus(void) { return 0; }
124static inline void enable_nonboot_cpus(void) {}
125#endif
126
127#endif /* _LINUX_CPU_H_ */
128