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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;
21struct device_node;
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);
32extern bool arch_match_cpu_phys_id(int cpu, u64 phys_id);
33extern bool arch_find_n_match_cpu_physical_id(struct device_node *cpun,
34 int cpu, unsigned int *thread);
35
36extern int cpu_add_dev_attr(struct device_attribute *attr);
37extern void cpu_remove_dev_attr(struct device_attribute *attr);
38
39extern int cpu_add_dev_attr_group(struct attribute_group *attrs);
40extern void cpu_remove_dev_attr_group(struct attribute_group *attrs);
41
42#ifdef CONFIG_HOTPLUG_CPU
43extern void unregister_cpu(struct cpu *cpu);
44extern ssize_t arch_cpu_probe(const char *, size_t);
45extern ssize_t arch_cpu_release(const char *, size_t);
46#endif
47struct notifier_block;
48
49#ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE
50extern int arch_cpu_uevent(struct device *dev, struct kobj_uevent_env *env);
51extern ssize_t arch_print_cpu_modalias(struct device *dev,
52 struct device_attribute *attr,
53 char *bufptr);
54#endif
55
56/*
57 * CPU notifier priorities.
58 */
59enum {
60 /*
61 * SCHED_ACTIVE marks a cpu which is coming up active during
62 * CPU_ONLINE and CPU_DOWN_FAILED and must be the first
63 * notifier. CPUSET_ACTIVE adjusts cpuset according to
64 * cpu_active mask right after SCHED_ACTIVE. During
65 * CPU_DOWN_PREPARE, SCHED_INACTIVE and CPUSET_INACTIVE are
66 * ordered in the similar way.
67 *
68 * This ordering guarantees consistent cpu_active mask and
69 * migration behavior to all cpu notifiers.
70 */
71 CPU_PRI_SCHED_ACTIVE = INT_MAX,
72 CPU_PRI_CPUSET_ACTIVE = INT_MAX - 1,
73 CPU_PRI_SCHED_INACTIVE = INT_MIN + 1,
74 CPU_PRI_CPUSET_INACTIVE = INT_MIN,
75
76 /* migration should happen before other stuff but after perf */
77 CPU_PRI_PERF = 20,
78 CPU_PRI_MIGRATION = 10,
79 /* bring up workqueues before normal notifiers and down after */
80 CPU_PRI_WORKQUEUE_UP = 5,
81 CPU_PRI_WORKQUEUE_DOWN = -5,
82};
83
84#define CPU_ONLINE 0x0002 /* CPU (unsigned)v is up */
85#define CPU_UP_PREPARE 0x0003 /* CPU (unsigned)v coming up */
86#define CPU_UP_CANCELED 0x0004 /* CPU (unsigned)v NOT coming up */
87#define CPU_DOWN_PREPARE 0x0005 /* CPU (unsigned)v going down */
88#define CPU_DOWN_FAILED 0x0006 /* CPU (unsigned)v NOT going down */
89#define CPU_DEAD 0x0007 /* CPU (unsigned)v dead */
90#define CPU_DYING 0x0008 /* CPU (unsigned)v not running any task,
91 * not handling interrupts, soon dead.
92 * Called on the dying cpu, interrupts
93 * are already disabled. Must not
94 * sleep, must not fail */
95#define CPU_POST_DEAD 0x0009 /* CPU (unsigned)v dead, cpu_hotplug
96 * lock is dropped */
97#define CPU_STARTING 0x000A /* CPU (unsigned)v soon running.
98 * Called on the new cpu, just before
99 * enabling interrupts. Must not sleep,
100 * must not fail */
101
102/* Used for CPU hotplug events occurring while tasks are frozen due to a suspend
103 * operation in progress
104 */
105#define CPU_TASKS_FROZEN 0x0010
106
107#define CPU_ONLINE_FROZEN (CPU_ONLINE | CPU_TASKS_FROZEN)
108#define CPU_UP_PREPARE_FROZEN (CPU_UP_PREPARE | CPU_TASKS_FROZEN)
109#define CPU_UP_CANCELED_FROZEN (CPU_UP_CANCELED | CPU_TASKS_FROZEN)
110#define CPU_DOWN_PREPARE_FROZEN (CPU_DOWN_PREPARE | CPU_TASKS_FROZEN)
111#define CPU_DOWN_FAILED_FROZEN (CPU_DOWN_FAILED | CPU_TASKS_FROZEN)
112#define CPU_DEAD_FROZEN (CPU_DEAD | CPU_TASKS_FROZEN)
113#define CPU_DYING_FROZEN (CPU_DYING | CPU_TASKS_FROZEN)
114#define CPU_STARTING_FROZEN (CPU_STARTING | CPU_TASKS_FROZEN)
115
116
117#ifdef CONFIG_SMP
118/* Need to know about CPUs going up/down? */
119#if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE)
120#define cpu_notifier(fn, pri) { \
121 static struct notifier_block fn##_nb = \
122 { .notifier_call = fn, .priority = pri }; \
123 register_cpu_notifier(&fn##_nb); \
124}
125#else /* #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
126#define cpu_notifier(fn, pri) do { (void)(fn); } while (0)
127#endif /* #else #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
128#ifdef CONFIG_HOTPLUG_CPU
129extern int register_cpu_notifier(struct notifier_block *nb);
130extern void unregister_cpu_notifier(struct notifier_block *nb);
131#else
132
133#ifndef MODULE
134extern int register_cpu_notifier(struct notifier_block *nb);
135#else
136static inline int register_cpu_notifier(struct notifier_block *nb)
137{
138 return 0;
139}
140#endif
141
142static inline void unregister_cpu_notifier(struct notifier_block *nb)
143{
144}
145#endif
146
147int cpu_up(unsigned int cpu);
148void notify_cpu_starting(unsigned int cpu);
149extern void cpu_maps_update_begin(void);
150extern void cpu_maps_update_done(void);
151
152#else /* CONFIG_SMP */
153
154#define cpu_notifier(fn, pri) do { (void)(fn); } while (0)
155
156static inline int register_cpu_notifier(struct notifier_block *nb)
157{
158 return 0;
159}
160
161static inline void unregister_cpu_notifier(struct notifier_block *nb)
162{
163}
164
165static inline void cpu_maps_update_begin(void)
166{
167}
168
169static inline void cpu_maps_update_done(void)
170{
171}
172
173#endif /* CONFIG_SMP */
174extern struct bus_type cpu_subsys;
175
176#ifdef CONFIG_HOTPLUG_CPU
177/* Stop CPUs going up and down. */
178
179extern void cpu_hotplug_begin(void);
180extern void cpu_hotplug_done(void);
181extern void get_online_cpus(void);
182extern void put_online_cpus(void);
183extern void cpu_hotplug_disable(void);
184extern void cpu_hotplug_enable(void);
185#define hotcpu_notifier(fn, pri) cpu_notifier(fn, pri)
186#define register_hotcpu_notifier(nb) register_cpu_notifier(nb)
187#define unregister_hotcpu_notifier(nb) unregister_cpu_notifier(nb)
188void clear_tasks_mm_cpumask(int cpu);
189int cpu_down(unsigned int cpu);
190
191#else /* CONFIG_HOTPLUG_CPU */
192
193static inline void cpu_hotplug_begin(void) {}
194static inline void cpu_hotplug_done(void) {}
195#define get_online_cpus() do { } while (0)
196#define put_online_cpus() do { } while (0)
197#define cpu_hotplug_disable() do { } while (0)
198#define cpu_hotplug_enable() do { } while (0)
199#define hotcpu_notifier(fn, pri) do { (void)(fn); } while (0)
200/* These aren't inline functions due to a GCC bug. */
201#define register_hotcpu_notifier(nb) ({ (void)(nb); 0; })
202#define unregister_hotcpu_notifier(nb) ({ (void)(nb); })
203#endif /* CONFIG_HOTPLUG_CPU */
204
205#ifdef CONFIG_PM_SLEEP_SMP
206extern int disable_nonboot_cpus(void);
207extern void enable_nonboot_cpus(void);
208#else /* !CONFIG_PM_SLEEP_SMP */
209static inline int disable_nonboot_cpus(void) { return 0; }
210static inline void enable_nonboot_cpus(void) {}
211#endif /* !CONFIG_PM_SLEEP_SMP */
212
213enum cpuhp_state {
214 CPUHP_OFFLINE,
215 CPUHP_ONLINE,
216};
217
218void cpu_startup_entry(enum cpuhp_state state);
219void cpu_idle(void);
220
221void cpu_idle_poll_ctrl(bool enable);
222
223void arch_cpu_idle(void);
224void arch_cpu_idle_prepare(void);
225void arch_cpu_idle_enter(void);
226void arch_cpu_idle_exit(void);
227void arch_cpu_idle_dead(void);
228
229#endif /* _LINUX_CPU_H_ */