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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 *
10 * CPUs are exported via sysfs in the devices/system/cpu
11 * directory.
12 */
13#ifndef _LINUX_CPU_H_
14#define _LINUX_CPU_H_
15
16#include <linux/node.h>
17#include <linux/compiler.h>
18#include <linux/cpumask.h>
19
20struct device;
21
22struct cpu {
23 int node_id; /* The node which contains the CPU */
24 int hotpluggable; /* creates sysfs control file if hotpluggable */
25 struct device dev;
26};
27
28extern int register_cpu(struct cpu *cpu, int num);
29extern struct device *get_cpu_device(unsigned cpu);
30extern bool cpu_is_hotpluggable(unsigned cpu);
31
32extern int cpu_add_dev_attr(struct device_attribute *attr);
33extern void cpu_remove_dev_attr(struct device_attribute *attr);
34
35extern int cpu_add_dev_attr_group(struct attribute_group *attrs);
36extern void cpu_remove_dev_attr_group(struct attribute_group *attrs);
37
38#ifdef CONFIG_HOTPLUG_CPU
39extern void unregister_cpu(struct cpu *cpu);
40extern ssize_t arch_cpu_probe(const char *, size_t);
41extern ssize_t arch_cpu_release(const char *, size_t);
42#endif
43struct notifier_block;
44
45#ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE
46extern int arch_cpu_uevent(struct device *dev, struct kobj_uevent_env *env);
47extern ssize_t arch_print_cpu_modalias(struct device *dev,
48 struct device_attribute *attr,
49 char *bufptr);
50#endif
51
52/*
53 * CPU notifier priorities.
54 */
55enum {
56 /*
57 * SCHED_ACTIVE marks a cpu which is coming up active during
58 * CPU_ONLINE and CPU_DOWN_FAILED and must be the first
59 * notifier. CPUSET_ACTIVE adjusts cpuset according to
60 * cpu_active mask right after SCHED_ACTIVE. During
61 * CPU_DOWN_PREPARE, SCHED_INACTIVE and CPUSET_INACTIVE are
62 * ordered in the similar way.
63 *
64 * This ordering guarantees consistent cpu_active mask and
65 * migration behavior to all cpu notifiers.
66 */
67 CPU_PRI_SCHED_ACTIVE = INT_MAX,
68 CPU_PRI_CPUSET_ACTIVE = INT_MAX - 1,
69 CPU_PRI_SCHED_INACTIVE = INT_MIN + 1,
70 CPU_PRI_CPUSET_INACTIVE = INT_MIN,
71
72 /* migration should happen before other stuff but after perf */
73 CPU_PRI_PERF = 20,
74 CPU_PRI_MIGRATION = 10,
75 /* bring up workqueues before normal notifiers and down after */
76 CPU_PRI_WORKQUEUE_UP = 5,
77 CPU_PRI_WORKQUEUE_DOWN = -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 = \
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);
177extern void cpu_hotplug_disable(void);
178extern void cpu_hotplug_enable(void);
179#define hotcpu_notifier(fn, pri) cpu_notifier(fn, pri)
180#define register_hotcpu_notifier(nb) register_cpu_notifier(nb)
181#define unregister_hotcpu_notifier(nb) unregister_cpu_notifier(nb)
182void clear_tasks_mm_cpumask(int cpu);
183int cpu_down(unsigned int cpu);
184
185#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
186extern void cpu_hotplug_driver_lock(void);
187extern void cpu_hotplug_driver_unlock(void);
188#else
189static inline void cpu_hotplug_driver_lock(void)
190{
191}
192
193static inline void cpu_hotplug_driver_unlock(void)
194{
195}
196#endif
197
198#else /* CONFIG_HOTPLUG_CPU */
199
200#define get_online_cpus() do { } while (0)
201#define put_online_cpus() do { } while (0)
202#define cpu_hotplug_disable() do { } while (0)
203#define cpu_hotplug_enable() do { } while (0)
204#define hotcpu_notifier(fn, pri) do { (void)(fn); } while (0)
205/* These aren't inline functions due to a GCC bug. */
206#define register_hotcpu_notifier(nb) ({ (void)(nb); 0; })
207#define unregister_hotcpu_notifier(nb) ({ (void)(nb); })
208#endif /* CONFIG_HOTPLUG_CPU */
209
210#ifdef CONFIG_PM_SLEEP_SMP
211extern int disable_nonboot_cpus(void);
212extern void enable_nonboot_cpus(void);
213#else /* !CONFIG_PM_SLEEP_SMP */
214static inline int disable_nonboot_cpus(void) { return 0; }
215static inline void enable_nonboot_cpus(void) {}
216#endif /* !CONFIG_PM_SLEEP_SMP */
217
218enum cpuhp_state {
219 CPUHP_OFFLINE,
220 CPUHP_ONLINE,
221};
222
223void cpu_startup_entry(enum cpuhp_state state);
224void cpu_idle(void);
225
226void cpu_idle_poll_ctrl(bool enable);
227
228void arch_cpu_idle(void);
229void arch_cpu_idle_prepare(void);
230void arch_cpu_idle_enter(void);
231void arch_cpu_idle_exit(void);
232void arch_cpu_idle_dead(void);
233
234#endif /* _LINUX_CPU_H_ */