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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
44extern int sched_create_sysfs_power_savings_entries(struct sysdev_class *cls);
45
46#ifdef CONFIG_HOTPLUG_CPU
47extern void unregister_cpu(struct cpu *cpu);
48#endif
49struct notifier_block;
50
51#ifdef CONFIG_SMP
52/* Need to know about CPUs going up/down? */
53#ifdef CONFIG_HOTPLUG_CPU
54extern int register_cpu_notifier(struct notifier_block *nb);
55extern void unregister_cpu_notifier(struct notifier_block *nb);
56#else
57
58#ifndef MODULE
59extern int register_cpu_notifier(struct notifier_block *nb);
60#else
61static inline int register_cpu_notifier(struct notifier_block *nb)
62{
63 return 0;
64}
65#endif
66
67static inline void unregister_cpu_notifier(struct notifier_block *nb)
68{
69}
70#endif
71
72int cpu_up(unsigned int cpu);
73
74#else
75
76static inline int register_cpu_notifier(struct notifier_block *nb)
77{
78 return 0;
79}
80static inline void unregister_cpu_notifier(struct notifier_block *nb)
81{
82}
83
84#endif /* CONFIG_SMP */
85extern struct sysdev_class cpu_sysdev_class;
86
87#ifdef CONFIG_HOTPLUG_CPU
88/* Stop CPUs going up and down. */
89
90static inline void cpuhotplug_mutex_lock(struct mutex *cpu_hp_mutex)
91{
92 mutex_lock(cpu_hp_mutex);
93}
94
95static inline void cpuhotplug_mutex_unlock(struct mutex *cpu_hp_mutex)
96{
97 mutex_unlock(cpu_hp_mutex);
98}
99
100extern void lock_cpu_hotplug(void);
101extern void unlock_cpu_hotplug(void);
102#define hotcpu_notifier(fn, pri) { \
103 static struct notifier_block fn##_nb = \
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)
109int cpu_down(unsigned int cpu);
110#define cpu_is_offline(cpu) unlikely(!cpu_online(cpu))
111
112#else /* CONFIG_HOTPLUG_CPU */
113
114static inline void cpuhotplug_mutex_lock(struct mutex *cpu_hp_mutex)
115{ }
116static inline void cpuhotplug_mutex_unlock(struct mutex *cpu_hp_mutex)
117{ }
118
119#define lock_cpu_hotplug() do { } while (0)
120#define unlock_cpu_hotplug() do { } while (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_PM_SLEEP_SMP
130extern int suspend_cpu_hotplug;
131
132extern int disable_nonboot_cpus(void);
133extern void enable_nonboot_cpus(void);
134#else /* !CONFIG_PM_SLEEP_SMP */
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 /* !CONFIG_PM_SLEEP_SMP */
140
141#endif /* _LINUX_CPU_H_ */