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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 hotpluggable; /* creates sysfs control file if hotpluggable */
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? */
52#ifdef CONFIG_HOTPLUG_CPU
53extern int register_cpu_notifier(struct notifier_block *nb);
54extern void unregister_cpu_notifier(struct notifier_block *nb);
55#else
56
57#ifndef MODULE
58extern int register_cpu_notifier(struct notifier_block *nb);
59#else
60static inline int register_cpu_notifier(struct notifier_block *nb)
61{
62 return 0;
63}
64#endif
65
66static inline void unregister_cpu_notifier(struct notifier_block *nb)
67{
68}
69#endif
70
71int cpu_up(unsigned int cpu);
72
73#else
74
75static inline int register_cpu_notifier(struct notifier_block *nb)
76{
77 return 0;
78}
79static inline void unregister_cpu_notifier(struct notifier_block *nb)
80{
81}
82
83#endif /* CONFIG_SMP */
84extern struct sysdev_class cpu_sysdev_class;
85
86#ifdef CONFIG_HOTPLUG_CPU
87/* Stop CPUs going up and down. */
88
89static inline void cpuhotplug_mutex_lock(struct mutex *cpu_hp_mutex)
90{
91 mutex_lock(cpu_hp_mutex);
92}
93
94static inline void cpuhotplug_mutex_unlock(struct mutex *cpu_hp_mutex)
95{
96 mutex_unlock(cpu_hp_mutex);
97}
98
99extern void lock_cpu_hotplug(void);
100extern 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); \
105}
106#define register_hotcpu_notifier(nb) register_cpu_notifier(nb)
107#define unregister_hotcpu_notifier(nb) unregister_cpu_notifier(nb)
108int cpu_down(unsigned int cpu);
109#define cpu_is_offline(cpu) unlikely(!cpu_online(cpu))
110
111#else /* CONFIG_HOTPLUG_CPU */
112
113static inline void cpuhotplug_mutex_lock(struct mutex *cpu_hp_mutex)
114{ }
115static inline void cpuhotplug_mutex_unlock(struct mutex *cpu_hp_mutex)
116{ }
117
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)
124
125/* CPUs don't go offline once they're online w/o CONFIG_HOTPLUG_CPU */
126static inline int cpu_is_offline(int cpu) { return 0; }
127#endif /* CONFIG_HOTPLUG_CPU */
128
129#ifdef CONFIG_SUSPEND_SMP
130extern int suspend_cpu_hotplug;
131
132extern int disable_nonboot_cpus(void);
133extern void enable_nonboot_cpus(void);
134#else
135#define suspend_cpu_hotplug 0
136
137static inline int disable_nonboot_cpus(void) { return 0; }
138static inline void enable_nonboot_cpus(void) {}
139#endif
140
141#endif /* _LINUX_CPU_H_ */