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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
27struct cpu {
28 int node_id; /* The node which contains the CPU */
29 int hotpluggable; /* creates sysfs control file if hotpluggable */
30 struct sys_device sysdev;
31};
32
33extern int register_cpu(struct cpu *cpu, int num);
34extern struct sys_device *get_cpu_sysdev(unsigned cpu);
35
36extern int cpu_add_sysdev_attr(struct sysdev_attribute *attr);
37extern void cpu_remove_sysdev_attr(struct sysdev_attribute *attr);
38
39extern int cpu_add_sysdev_attr_group(struct attribute_group *attrs);
40extern void cpu_remove_sysdev_attr_group(struct attribute_group *attrs);
41
42extern int sched_create_sysfs_power_savings_entries(struct sysdev_class *cls);
43
44#ifdef CONFIG_HOTPLUG_CPU
45extern void unregister_cpu(struct cpu *cpu);
46extern ssize_t arch_cpu_probe(const char *, size_t);
47extern ssize_t arch_cpu_release(const char *, size_t);
48#endif
49struct notifier_block;
50
51/*
52 * CPU notifier priorities.
53 */
54enum {
55 /*
56 * SCHED_ACTIVE marks a cpu which is coming up active during
57 * CPU_ONLINE and CPU_DOWN_FAILED and must be the first
58 * notifier. CPUSET_ACTIVE adjusts cpuset according to
59 * cpu_active mask right after SCHED_ACTIVE. During
60 * CPU_DOWN_PREPARE, SCHED_INACTIVE and CPUSET_INACTIVE are
61 * ordered in the similar way.
62 *
63 * This ordering guarantees consistent cpu_active mask and
64 * migration behavior to all cpu notifiers.
65 */
66 CPU_PRI_SCHED_ACTIVE = INT_MAX,
67 CPU_PRI_CPUSET_ACTIVE = INT_MAX - 1,
68 CPU_PRI_SCHED_INACTIVE = INT_MIN + 1,
69 CPU_PRI_CPUSET_INACTIVE = INT_MIN,
70
71 /* migration should happen before other stuff but after perf */
72 CPU_PRI_PERF = 20,
73 CPU_PRI_MIGRATION = 10,
74 /* prepare workqueues for other notifiers */
75 CPU_PRI_WORKQUEUE = 5,
76};
77
78#ifdef CONFIG_SMP
79/* Need to know about CPUs going up/down? */
80#if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE)
81#define cpu_notifier(fn, pri) { \
82 static struct notifier_block fn##_nb __cpuinitdata = \
83 { .notifier_call = fn, .priority = pri }; \
84 register_cpu_notifier(&fn##_nb); \
85}
86#else /* #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
87#define cpu_notifier(fn, pri) do { (void)(fn); } while (0)
88#endif /* #else #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
89#ifdef CONFIG_HOTPLUG_CPU
90extern int register_cpu_notifier(struct notifier_block *nb);
91extern void unregister_cpu_notifier(struct notifier_block *nb);
92#else
93
94#ifndef MODULE
95extern int register_cpu_notifier(struct notifier_block *nb);
96#else
97static inline int register_cpu_notifier(struct notifier_block *nb)
98{
99 return 0;
100}
101#endif
102
103static inline void unregister_cpu_notifier(struct notifier_block *nb)
104{
105}
106#endif
107
108int cpu_up(unsigned int cpu);
109void notify_cpu_starting(unsigned int cpu);
110extern void cpu_maps_update_begin(void);
111extern void cpu_maps_update_done(void);
112
113#else /* CONFIG_SMP */
114
115#define cpu_notifier(fn, pri) do { (void)(fn); } while (0)
116
117static inline int register_cpu_notifier(struct notifier_block *nb)
118{
119 return 0;
120}
121
122static inline void unregister_cpu_notifier(struct notifier_block *nb)
123{
124}
125
126static inline void cpu_maps_update_begin(void)
127{
128}
129
130static inline void cpu_maps_update_done(void)
131{
132}
133
134#endif /* CONFIG_SMP */
135extern struct sysdev_class cpu_sysdev_class;
136
137#ifdef CONFIG_HOTPLUG_CPU
138/* Stop CPUs going up and down. */
139
140extern void get_online_cpus(void);
141extern void put_online_cpus(void);
142#define hotcpu_notifier(fn, pri) cpu_notifier(fn, pri)
143#define register_hotcpu_notifier(nb) register_cpu_notifier(nb)
144#define unregister_hotcpu_notifier(nb) unregister_cpu_notifier(nb)
145int cpu_down(unsigned int cpu);
146
147#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
148extern void cpu_hotplug_driver_lock(void);
149extern void cpu_hotplug_driver_unlock(void);
150#else
151static inline void cpu_hotplug_driver_lock(void)
152{
153}
154
155static inline void cpu_hotplug_driver_unlock(void)
156{
157}
158#endif
159
160#else /* CONFIG_HOTPLUG_CPU */
161
162#define get_online_cpus() do { } while (0)
163#define put_online_cpus() do { } while (0)
164#define hotcpu_notifier(fn, pri) do { (void)(fn); } while (0)
165/* These aren't inline functions due to a GCC bug. */
166#define register_hotcpu_notifier(nb) ({ (void)(nb); 0; })
167#define unregister_hotcpu_notifier(nb) ({ (void)(nb); })
168#endif /* CONFIG_HOTPLUG_CPU */
169
170#ifdef CONFIG_PM_SLEEP_SMP
171extern int suspend_cpu_hotplug;
172
173extern int disable_nonboot_cpus(void);
174extern void enable_nonboot_cpus(void);
175#else /* !CONFIG_PM_SLEEP_SMP */
176#define suspend_cpu_hotplug 0
177
178static inline int disable_nonboot_cpus(void) { return 0; }
179static inline void enable_nonboot_cpus(void) {}
180#endif /* !CONFIG_PM_SLEEP_SMP */
181
182#endif /* _LINUX_CPU_H_ */