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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/*
50 * CPU notifier priorities.
51 */
52enum {
53 /*
54 * SCHED_ACTIVE marks a cpu which is coming up active during
55 * CPU_ONLINE and CPU_DOWN_FAILED and must be the first
56 * notifier. CPUSET_ACTIVE adjusts cpuset according to
57 * cpu_active mask right after SCHED_ACTIVE. During
58 * CPU_DOWN_PREPARE, SCHED_INACTIVE and CPUSET_INACTIVE are
59 * ordered in the similar way.
60 *
61 * This ordering guarantees consistent cpu_active mask and
62 * migration behavior to all cpu notifiers.
63 */
64 CPU_PRI_SCHED_ACTIVE = INT_MAX,
65 CPU_PRI_CPUSET_ACTIVE = INT_MAX - 1,
66 CPU_PRI_SCHED_INACTIVE = INT_MIN + 1,
67 CPU_PRI_CPUSET_INACTIVE = INT_MIN,
68
69 /* migration should happen before other stuff but after perf */
70 CPU_PRI_PERF = 20,
71 CPU_PRI_MIGRATION = 10,
72 /* bring up workqueues before normal notifiers and down after */
73 CPU_PRI_WORKQUEUE_UP = 5,
74 CPU_PRI_WORKQUEUE_DOWN = -5,
75};
76
77#define CPU_ONLINE 0x0002 /* CPU (unsigned)v is up */
78#define CPU_UP_PREPARE 0x0003 /* CPU (unsigned)v coming up */
79#define CPU_UP_CANCELED 0x0004 /* CPU (unsigned)v NOT coming up */
80#define CPU_DOWN_PREPARE 0x0005 /* CPU (unsigned)v going down */
81#define CPU_DOWN_FAILED 0x0006 /* CPU (unsigned)v NOT going down */
82#define CPU_DEAD 0x0007 /* CPU (unsigned)v dead */
83#define CPU_DYING 0x0008 /* CPU (unsigned)v not running any task,
84 * not handling interrupts, soon dead.
85 * Called on the dying cpu, interrupts
86 * are already disabled. Must not
87 * sleep, must not fail */
88#define CPU_POST_DEAD 0x0009 /* CPU (unsigned)v dead, cpu_hotplug
89 * lock is dropped */
90#define CPU_STARTING 0x000A /* CPU (unsigned)v soon running.
91 * Called on the new cpu, just before
92 * enabling interrupts. Must not sleep,
93 * must not fail */
94
95/* Used for CPU hotplug events occurring while tasks are frozen due to a suspend
96 * operation in progress
97 */
98#define CPU_TASKS_FROZEN 0x0010
99
100#define CPU_ONLINE_FROZEN (CPU_ONLINE | CPU_TASKS_FROZEN)
101#define CPU_UP_PREPARE_FROZEN (CPU_UP_PREPARE | CPU_TASKS_FROZEN)
102#define CPU_UP_CANCELED_FROZEN (CPU_UP_CANCELED | CPU_TASKS_FROZEN)
103#define CPU_DOWN_PREPARE_FROZEN (CPU_DOWN_PREPARE | CPU_TASKS_FROZEN)
104#define CPU_DOWN_FAILED_FROZEN (CPU_DOWN_FAILED | CPU_TASKS_FROZEN)
105#define CPU_DEAD_FROZEN (CPU_DEAD | CPU_TASKS_FROZEN)
106#define CPU_DYING_FROZEN (CPU_DYING | CPU_TASKS_FROZEN)
107#define CPU_STARTING_FROZEN (CPU_STARTING | CPU_TASKS_FROZEN)
108
109
110#ifdef CONFIG_SMP
111/* Need to know about CPUs going up/down? */
112#if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE)
113#define cpu_notifier(fn, pri) { \
114 static struct notifier_block fn##_nb = \
115 { .notifier_call = fn, .priority = pri }; \
116 register_cpu_notifier(&fn##_nb); \
117}
118
119#define __cpu_notifier(fn, pri) { \
120 static struct notifier_block fn##_nb = \
121 { .notifier_call = fn, .priority = pri }; \
122 __register_cpu_notifier(&fn##_nb); \
123}
124#else /* #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
125#define cpu_notifier(fn, pri) do { (void)(fn); } while (0)
126#define __cpu_notifier(fn, pri) do { (void)(fn); } while (0)
127#endif /* #else #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
128
129#ifdef CONFIG_HOTPLUG_CPU
130extern int register_cpu_notifier(struct notifier_block *nb);
131extern int __register_cpu_notifier(struct notifier_block *nb);
132extern void unregister_cpu_notifier(struct notifier_block *nb);
133extern void __unregister_cpu_notifier(struct notifier_block *nb);
134#else
135
136#ifndef MODULE
137extern int register_cpu_notifier(struct notifier_block *nb);
138extern int __register_cpu_notifier(struct notifier_block *nb);
139#else
140static inline int register_cpu_notifier(struct notifier_block *nb)
141{
142 return 0;
143}
144
145static inline int __register_cpu_notifier(struct notifier_block *nb)
146{
147 return 0;
148}
149#endif
150
151static inline void unregister_cpu_notifier(struct notifier_block *nb)
152{
153}
154
155static inline void __unregister_cpu_notifier(struct notifier_block *nb)
156{
157}
158#endif
159
160int cpu_up(unsigned int cpu);
161void notify_cpu_starting(unsigned int cpu);
162extern void cpu_maps_update_begin(void);
163extern void cpu_maps_update_done(void);
164
165#define cpu_notifier_register_begin cpu_maps_update_begin
166#define cpu_notifier_register_done cpu_maps_update_done
167
168#else /* CONFIG_SMP */
169
170#define cpu_notifier(fn, pri) do { (void)(fn); } while (0)
171#define __cpu_notifier(fn, pri) do { (void)(fn); } while (0)
172
173static inline int register_cpu_notifier(struct notifier_block *nb)
174{
175 return 0;
176}
177
178static inline int __register_cpu_notifier(struct notifier_block *nb)
179{
180 return 0;
181}
182
183static inline void unregister_cpu_notifier(struct notifier_block *nb)
184{
185}
186
187static inline void __unregister_cpu_notifier(struct notifier_block *nb)
188{
189}
190
191static inline void cpu_maps_update_begin(void)
192{
193}
194
195static inline void cpu_maps_update_done(void)
196{
197}
198
199static inline void cpu_notifier_register_begin(void)
200{
201}
202
203static inline void cpu_notifier_register_done(void)
204{
205}
206
207#endif /* CONFIG_SMP */
208extern struct bus_type cpu_subsys;
209
210#ifdef CONFIG_HOTPLUG_CPU
211/* Stop CPUs going up and down. */
212
213extern void cpu_hotplug_begin(void);
214extern void cpu_hotplug_done(void);
215extern void get_online_cpus(void);
216extern void put_online_cpus(void);
217extern void cpu_hotplug_disable(void);
218extern void cpu_hotplug_enable(void);
219#define hotcpu_notifier(fn, pri) cpu_notifier(fn, pri)
220#define __hotcpu_notifier(fn, pri) __cpu_notifier(fn, pri)
221#define register_hotcpu_notifier(nb) register_cpu_notifier(nb)
222#define __register_hotcpu_notifier(nb) __register_cpu_notifier(nb)
223#define unregister_hotcpu_notifier(nb) unregister_cpu_notifier(nb)
224#define __unregister_hotcpu_notifier(nb) __unregister_cpu_notifier(nb)
225void clear_tasks_mm_cpumask(int cpu);
226int cpu_down(unsigned int cpu);
227
228#else /* CONFIG_HOTPLUG_CPU */
229
230static inline void cpu_hotplug_begin(void) {}
231static inline void cpu_hotplug_done(void) {}
232#define get_online_cpus() do { } while (0)
233#define put_online_cpus() do { } while (0)
234#define cpu_hotplug_disable() do { } while (0)
235#define cpu_hotplug_enable() do { } while (0)
236#define hotcpu_notifier(fn, pri) do { (void)(fn); } while (0)
237#define __hotcpu_notifier(fn, pri) do { (void)(fn); } while (0)
238/* These aren't inline functions due to a GCC bug. */
239#define register_hotcpu_notifier(nb) ({ (void)(nb); 0; })
240#define __register_hotcpu_notifier(nb) ({ (void)(nb); 0; })
241#define unregister_hotcpu_notifier(nb) ({ (void)(nb); })
242#define __unregister_hotcpu_notifier(nb) ({ (void)(nb); })
243#endif /* CONFIG_HOTPLUG_CPU */
244
245#ifdef CONFIG_PM_SLEEP_SMP
246extern int disable_nonboot_cpus(void);
247extern void enable_nonboot_cpus(void);
248#else /* !CONFIG_PM_SLEEP_SMP */
249static inline int disable_nonboot_cpus(void) { return 0; }
250static inline void enable_nonboot_cpus(void) {}
251#endif /* !CONFIG_PM_SLEEP_SMP */
252
253enum cpuhp_state {
254 CPUHP_OFFLINE,
255 CPUHP_ONLINE,
256};
257
258void cpu_startup_entry(enum cpuhp_state state);
259
260void cpu_idle_poll_ctrl(bool enable);
261
262void arch_cpu_idle(void);
263void arch_cpu_idle_prepare(void);
264void arch_cpu_idle_enter(void);
265void arch_cpu_idle_exit(void);
266void arch_cpu_idle_dead(void);
267
268#endif /* _LINUX_CPU_H_ */