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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 struct sysdev_attribute attr_sched_mc_power_savings;
45extern struct sysdev_attribute attr_sched_smt_power_savings;
46extern int sched_create_sysfs_power_savings_entries(struct sysdev_class *cls);
47
48#ifdef CONFIG_HOTPLUG_CPU
49extern void unregister_cpu(struct cpu *cpu);
50#endif
51struct notifier_block;
52
53#ifdef CONFIG_SMP
54/* Need to know about CPUs going up/down? */
55#ifdef CONFIG_HOTPLUG_CPU
56extern int register_cpu_notifier(struct notifier_block *nb);
57extern void unregister_cpu_notifier(struct notifier_block *nb);
58#else
59
60#ifndef MODULE
61extern int register_cpu_notifier(struct notifier_block *nb);
62#else
63static inline int register_cpu_notifier(struct notifier_block *nb)
64{
65 return 0;
66}
67#endif
68
69static inline void unregister_cpu_notifier(struct notifier_block *nb)
70{
71}
72#endif
73
74int cpu_up(unsigned int cpu);
75
76#else
77
78static inline int register_cpu_notifier(struct notifier_block *nb)
79{
80 return 0;
81}
82static inline void unregister_cpu_notifier(struct notifier_block *nb)
83{
84}
85
86#endif /* CONFIG_SMP */
87extern struct sysdev_class cpu_sysdev_class;
88
89#ifdef CONFIG_HOTPLUG_CPU
90/* Stop CPUs going up and down. */
91
92static inline void cpuhotplug_mutex_lock(struct mutex *cpu_hp_mutex)
93{
94 mutex_lock(cpu_hp_mutex);
95}
96
97static inline void cpuhotplug_mutex_unlock(struct mutex *cpu_hp_mutex)
98{
99 mutex_unlock(cpu_hp_mutex);
100}
101
102extern void lock_cpu_hotplug(void);
103extern void unlock_cpu_hotplug(void);
104#define hotcpu_notifier(fn, pri) { \
105 static struct notifier_block fn##_nb = \
106 { .notifier_call = fn, .priority = pri }; \
107 register_cpu_notifier(&fn##_nb); \
108}
109#define register_hotcpu_notifier(nb) register_cpu_notifier(nb)
110#define unregister_hotcpu_notifier(nb) unregister_cpu_notifier(nb)
111int cpu_down(unsigned int cpu);
112#define cpu_is_offline(cpu) unlikely(!cpu_online(cpu))
113
114#else /* CONFIG_HOTPLUG_CPU */
115
116static inline void cpuhotplug_mutex_lock(struct mutex *cpu_hp_mutex)
117{ }
118static inline void cpuhotplug_mutex_unlock(struct mutex *cpu_hp_mutex)
119{ }
120
121#define lock_cpu_hotplug() do { } while (0)
122#define unlock_cpu_hotplug() do { } while (0)
123#define lock_cpu_hotplug_interruptible() 0
124#define hotcpu_notifier(fn, pri) do { (void)(fn); } while (0)
125#define register_hotcpu_notifier(nb) do { (void)(nb); } while (0)
126#define unregister_hotcpu_notifier(nb) do { (void)(nb); } while (0)
127
128/* CPUs don't go offline once they're online w/o CONFIG_HOTPLUG_CPU */
129static inline int cpu_is_offline(int cpu) { return 0; }
130#endif /* CONFIG_HOTPLUG_CPU */
131
132#ifdef CONFIG_SUSPEND_SMP
133extern int suspend_cpu_hotplug;
134
135extern int disable_nonboot_cpus(void);
136extern void enable_nonboot_cpus(void);
137#else
138#define suspend_cpu_hotplug 0
139
140static inline int disable_nonboot_cpus(void) { return 0; }
141static inline void enable_nonboot_cpus(void) {}
142#endif
143
144#endif /* _LINUX_CPU_H_ */