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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#ifndef _LINUX_CPU_H_
15#define _LINUX_CPU_H_
16
17#include <linux/node.h>
18#include <linux/compiler.h>
19#include <linux/cpumask.h>
20
21struct device;
22
23struct cpu {
24 int node_id; /* The node which contains the CPU */
25 int hotpluggable; /* creates sysfs control file if hotpluggable */
26 struct device dev;
27};
28
29extern int register_cpu(struct cpu *cpu, int num);
30extern struct device *get_cpu_device(unsigned cpu);
31extern bool cpu_is_hotpluggable(unsigned cpu);
32
33extern int cpu_add_dev_attr(struct device_attribute *attr);
34extern void cpu_remove_dev_attr(struct device_attribute *attr);
35
36extern int cpu_add_dev_attr_group(struct attribute_group *attrs);
37extern void cpu_remove_dev_attr_group(struct attribute_group *attrs);
38
39#ifdef CONFIG_HOTPLUG_CPU
40extern void unregister_cpu(struct cpu *cpu);
41extern ssize_t arch_cpu_probe(const char *, size_t);
42extern ssize_t arch_cpu_release(const char *, size_t);
43#endif
44struct notifier_block;
45
46#ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE
47extern int arch_cpu_uevent(struct device *dev, struct kobj_uevent_env *env);
48extern ssize_t arch_print_cpu_modalias(struct device *dev,
49 struct device_attribute *attr,
50 char *bufptr);
51#endif
52
53/*
54 * CPU notifier priorities.
55 */
56enum {
57 /*
58 * SCHED_ACTIVE marks a cpu which is coming up active during
59 * CPU_ONLINE and CPU_DOWN_FAILED and must be the first
60 * notifier. CPUSET_ACTIVE adjusts cpuset according to
61 * cpu_active mask right after SCHED_ACTIVE. During
62 * CPU_DOWN_PREPARE, SCHED_INACTIVE and CPUSET_INACTIVE are
63 * ordered in the similar way.
64 *
65 * This ordering guarantees consistent cpu_active mask and
66 * migration behavior to all cpu notifiers.
67 */
68 CPU_PRI_SCHED_ACTIVE = INT_MAX,
69 CPU_PRI_CPUSET_ACTIVE = INT_MAX - 1,
70 CPU_PRI_SCHED_INACTIVE = INT_MIN + 1,
71 CPU_PRI_CPUSET_INACTIVE = INT_MIN,
72
73 /* migration should happen before other stuff but after perf */
74 CPU_PRI_PERF = 20,
75 CPU_PRI_MIGRATION = 10,
76 /* prepare workqueues for other notifiers */
77 CPU_PRI_WORKQUEUE = 5,
78};
79
80#define CPU_ONLINE 0x0002 /* CPU (unsigned)v is up */
81#define CPU_UP_PREPARE 0x0003 /* CPU (unsigned)v coming up */
82#define CPU_UP_CANCELED 0x0004 /* CPU (unsigned)v NOT coming up */
83#define CPU_DOWN_PREPARE 0x0005 /* CPU (unsigned)v going down */
84#define CPU_DOWN_FAILED 0x0006 /* CPU (unsigned)v NOT going down */
85#define CPU_DEAD 0x0007 /* CPU (unsigned)v dead */
86#define CPU_DYING 0x0008 /* CPU (unsigned)v not running any task,
87 * not handling interrupts, soon dead.
88 * Called on the dying cpu, interrupts
89 * are already disabled. Must not
90 * sleep, must not fail */
91#define CPU_POST_DEAD 0x0009 /* CPU (unsigned)v dead, cpu_hotplug
92 * lock is dropped */
93#define CPU_STARTING 0x000A /* CPU (unsigned)v soon running.
94 * Called on the new cpu, just before
95 * enabling interrupts. Must not sleep,
96 * must not fail */
97
98/* Used for CPU hotplug events occurring while tasks are frozen due to a suspend
99 * operation in progress
100 */
101#define CPU_TASKS_FROZEN 0x0010
102
103#define CPU_ONLINE_FROZEN (CPU_ONLINE | CPU_TASKS_FROZEN)
104#define CPU_UP_PREPARE_FROZEN (CPU_UP_PREPARE | CPU_TASKS_FROZEN)
105#define CPU_UP_CANCELED_FROZEN (CPU_UP_CANCELED | CPU_TASKS_FROZEN)
106#define CPU_DOWN_PREPARE_FROZEN (CPU_DOWN_PREPARE | CPU_TASKS_FROZEN)
107#define CPU_DOWN_FAILED_FROZEN (CPU_DOWN_FAILED | CPU_TASKS_FROZEN)
108#define CPU_DEAD_FROZEN (CPU_DEAD | CPU_TASKS_FROZEN)
109#define CPU_DYING_FROZEN (CPU_DYING | CPU_TASKS_FROZEN)
110#define CPU_STARTING_FROZEN (CPU_STARTING | CPU_TASKS_FROZEN)
111
112
113#ifdef CONFIG_SMP
114/* Need to know about CPUs going up/down? */
115#if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE)
116#define cpu_notifier(fn, pri) { \
117 static struct notifier_block fn##_nb __cpuinitdata = \
118 { .notifier_call = fn, .priority = pri }; \
119 register_cpu_notifier(&fn##_nb); \
120}
121#else /* #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
122#define cpu_notifier(fn, pri) do { (void)(fn); } while (0)
123#endif /* #else #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
124#ifdef CONFIG_HOTPLUG_CPU
125extern int register_cpu_notifier(struct notifier_block *nb);
126extern void unregister_cpu_notifier(struct notifier_block *nb);
127#else
128
129#ifndef MODULE
130extern int register_cpu_notifier(struct notifier_block *nb);
131#else
132static inline int register_cpu_notifier(struct notifier_block *nb)
133{
134 return 0;
135}
136#endif
137
138static inline void unregister_cpu_notifier(struct notifier_block *nb)
139{
140}
141#endif
142
143int cpu_up(unsigned int cpu);
144void notify_cpu_starting(unsigned int cpu);
145extern void cpu_maps_update_begin(void);
146extern void cpu_maps_update_done(void);
147
148#else /* CONFIG_SMP */
149
150#define cpu_notifier(fn, pri) do { (void)(fn); } while (0)
151
152static inline int register_cpu_notifier(struct notifier_block *nb)
153{
154 return 0;
155}
156
157static inline void unregister_cpu_notifier(struct notifier_block *nb)
158{
159}
160
161static inline void cpu_maps_update_begin(void)
162{
163}
164
165static inline void cpu_maps_update_done(void)
166{
167}
168
169#endif /* CONFIG_SMP */
170extern struct bus_type cpu_subsys;
171
172#ifdef CONFIG_HOTPLUG_CPU
173/* Stop CPUs going up and down. */
174
175extern void get_online_cpus(void);
176extern void put_online_cpus(void);
177#define hotcpu_notifier(fn, pri) cpu_notifier(fn, pri)
178#define register_hotcpu_notifier(nb) register_cpu_notifier(nb)
179#define unregister_hotcpu_notifier(nb) unregister_cpu_notifier(nb)
180void clear_tasks_mm_cpumask(int cpu);
181int cpu_down(unsigned int cpu);
182
183#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
184extern void cpu_hotplug_driver_lock(void);
185extern void cpu_hotplug_driver_unlock(void);
186#else
187static inline void cpu_hotplug_driver_lock(void)
188{
189}
190
191static inline void cpu_hotplug_driver_unlock(void)
192{
193}
194#endif
195
196#else /* CONFIG_HOTPLUG_CPU */
197
198#define get_online_cpus() do { } while (0)
199#define put_online_cpus() do { } while (0)
200#define hotcpu_notifier(fn, pri) do { (void)(fn); } while (0)
201/* These aren't inline functions due to a GCC bug. */
202#define register_hotcpu_notifier(nb) ({ (void)(nb); 0; })
203#define unregister_hotcpu_notifier(nb) ({ (void)(nb); })
204#endif /* CONFIG_HOTPLUG_CPU */
205
206#ifdef CONFIG_PM_SLEEP_SMP
207extern int disable_nonboot_cpus(void);
208extern void enable_nonboot_cpus(void);
209#else /* !CONFIG_PM_SLEEP_SMP */
210static inline int disable_nonboot_cpus(void) { return 0; }
211static inline void enable_nonboot_cpus(void) {}
212#endif /* !CONFIG_PM_SLEEP_SMP */
213
214#endif /* _LINUX_CPU_H_ */