xref: /linux-6.15/include/linux/cpu.h (revision 91e040a7)
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 #include <linux/cpuhotplug.h>
20 
21 struct device;
22 struct device_node;
23 struct attribute_group;
24 
25 struct cpu {
26 	int node_id;		/* The node which contains the CPU */
27 	int hotpluggable;	/* creates sysfs control file if hotpluggable */
28 	struct device dev;
29 };
30 
31 extern void boot_cpu_init(void);
32 extern void boot_cpu_state_init(void);
33 
34 extern int register_cpu(struct cpu *cpu, int num);
35 extern struct device *get_cpu_device(unsigned cpu);
36 extern bool cpu_is_hotpluggable(unsigned cpu);
37 extern bool arch_match_cpu_phys_id(int cpu, u64 phys_id);
38 extern bool arch_find_n_match_cpu_physical_id(struct device_node *cpun,
39 					      int cpu, unsigned int *thread);
40 
41 extern int cpu_add_dev_attr(struct device_attribute *attr);
42 extern void cpu_remove_dev_attr(struct device_attribute *attr);
43 
44 extern int cpu_add_dev_attr_group(struct attribute_group *attrs);
45 extern void cpu_remove_dev_attr_group(struct attribute_group *attrs);
46 
47 extern __printf(4, 5)
48 struct device *cpu_device_create(struct device *parent, void *drvdata,
49 				 const struct attribute_group **groups,
50 				 const char *fmt, ...);
51 #ifdef CONFIG_HOTPLUG_CPU
52 extern void unregister_cpu(struct cpu *cpu);
53 extern ssize_t arch_cpu_probe(const char *, size_t);
54 extern ssize_t arch_cpu_release(const char *, size_t);
55 #endif
56 struct notifier_block;
57 
58 #define CPU_ONLINE		0x0002 /* CPU (unsigned)v is up */
59 #define CPU_UP_PREPARE		0x0003 /* CPU (unsigned)v coming up */
60 #define CPU_UP_CANCELED		0x0004 /* CPU (unsigned)v NOT coming up */
61 #define CPU_DOWN_PREPARE	0x0005 /* CPU (unsigned)v going down */
62 #define CPU_DOWN_FAILED		0x0006 /* CPU (unsigned)v NOT going down */
63 #define CPU_DEAD		0x0007 /* CPU (unsigned)v dead */
64 #define CPU_POST_DEAD		0x0009 /* CPU (unsigned)v dead, cpu_hotplug
65 					* lock is dropped */
66 #define CPU_BROKEN		0x000B /* CPU (unsigned)v did not die properly,
67 					* perhaps due to preemption. */
68 
69 /* Used for CPU hotplug events occurring while tasks are frozen due to a suspend
70  * operation in progress
71  */
72 #define CPU_TASKS_FROZEN	0x0010
73 
74 #define CPU_ONLINE_FROZEN	(CPU_ONLINE | CPU_TASKS_FROZEN)
75 #define CPU_UP_PREPARE_FROZEN	(CPU_UP_PREPARE | CPU_TASKS_FROZEN)
76 #define CPU_UP_CANCELED_FROZEN	(CPU_UP_CANCELED | CPU_TASKS_FROZEN)
77 #define CPU_DOWN_PREPARE_FROZEN	(CPU_DOWN_PREPARE | CPU_TASKS_FROZEN)
78 #define CPU_DOWN_FAILED_FROZEN	(CPU_DOWN_FAILED | CPU_TASKS_FROZEN)
79 #define CPU_DEAD_FROZEN		(CPU_DEAD | CPU_TASKS_FROZEN)
80 
81 #ifdef CONFIG_SMP
82 extern bool cpuhp_tasks_frozen;
83 /* Need to know about CPUs going up/down? */
84 #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE)
85 #define cpu_notifier(fn, pri) {					\
86 	static struct notifier_block fn##_nb =			\
87 		{ .notifier_call = fn, .priority = pri };	\
88 	register_cpu_notifier(&fn##_nb);			\
89 }
90 
91 #define __cpu_notifier(fn, pri) {				\
92 	static struct notifier_block fn##_nb =			\
93 		{ .notifier_call = fn, .priority = pri };	\
94 	__register_cpu_notifier(&fn##_nb);			\
95 }
96 #else /* #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
97 #define cpu_notifier(fn, pri)	do { (void)(fn); } while (0)
98 #define __cpu_notifier(fn, pri)	do { (void)(fn); } while (0)
99 #endif /* #else #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
100 
101 #ifdef CONFIG_HOTPLUG_CPU
102 extern int register_cpu_notifier(struct notifier_block *nb);
103 extern int __register_cpu_notifier(struct notifier_block *nb);
104 extern void unregister_cpu_notifier(struct notifier_block *nb);
105 extern void __unregister_cpu_notifier(struct notifier_block *nb);
106 #else
107 
108 #ifndef MODULE
109 extern int register_cpu_notifier(struct notifier_block *nb);
110 extern int __register_cpu_notifier(struct notifier_block *nb);
111 #else
112 static inline int register_cpu_notifier(struct notifier_block *nb)
113 {
114 	return 0;
115 }
116 
117 static inline int __register_cpu_notifier(struct notifier_block *nb)
118 {
119 	return 0;
120 }
121 #endif
122 
123 static inline void unregister_cpu_notifier(struct notifier_block *nb)
124 {
125 }
126 
127 static inline void __unregister_cpu_notifier(struct notifier_block *nb)
128 {
129 }
130 #endif
131 
132 int cpu_up(unsigned int cpu);
133 void notify_cpu_starting(unsigned int cpu);
134 extern void cpu_maps_update_begin(void);
135 extern void cpu_maps_update_done(void);
136 
137 #define cpu_notifier_register_begin	cpu_maps_update_begin
138 #define cpu_notifier_register_done	cpu_maps_update_done
139 
140 #else	/* CONFIG_SMP */
141 #define cpuhp_tasks_frozen	0
142 
143 #define cpu_notifier(fn, pri)	do { (void)(fn); } while (0)
144 #define __cpu_notifier(fn, pri)	do { (void)(fn); } while (0)
145 
146 static inline int register_cpu_notifier(struct notifier_block *nb)
147 {
148 	return 0;
149 }
150 
151 static inline int __register_cpu_notifier(struct notifier_block *nb)
152 {
153 	return 0;
154 }
155 
156 static inline void unregister_cpu_notifier(struct notifier_block *nb)
157 {
158 }
159 
160 static inline void __unregister_cpu_notifier(struct notifier_block *nb)
161 {
162 }
163 
164 static inline void cpu_maps_update_begin(void)
165 {
166 }
167 
168 static inline void cpu_maps_update_done(void)
169 {
170 }
171 
172 static inline void cpu_notifier_register_begin(void)
173 {
174 }
175 
176 static inline void cpu_notifier_register_done(void)
177 {
178 }
179 
180 #endif /* CONFIG_SMP */
181 extern struct bus_type cpu_subsys;
182 
183 #ifdef CONFIG_HOTPLUG_CPU
184 /* Stop CPUs going up and down. */
185 
186 extern void cpu_hotplug_begin(void);
187 extern void cpu_hotplug_done(void);
188 extern void get_online_cpus(void);
189 extern void put_online_cpus(void);
190 extern void cpu_hotplug_disable(void);
191 extern void cpu_hotplug_enable(void);
192 #define hotcpu_notifier(fn, pri)	cpu_notifier(fn, pri)
193 #define __hotcpu_notifier(fn, pri)	__cpu_notifier(fn, pri)
194 #define register_hotcpu_notifier(nb)	register_cpu_notifier(nb)
195 #define __register_hotcpu_notifier(nb)	__register_cpu_notifier(nb)
196 #define unregister_hotcpu_notifier(nb)	unregister_cpu_notifier(nb)
197 #define __unregister_hotcpu_notifier(nb)	__unregister_cpu_notifier(nb)
198 void clear_tasks_mm_cpumask(int cpu);
199 int cpu_down(unsigned int cpu);
200 
201 #else		/* CONFIG_HOTPLUG_CPU */
202 
203 static inline void cpu_hotplug_begin(void) {}
204 static inline void cpu_hotplug_done(void) {}
205 #define get_online_cpus()	do { } while (0)
206 #define put_online_cpus()	do { } while (0)
207 #define cpu_hotplug_disable()	do { } while (0)
208 #define cpu_hotplug_enable()	do { } while (0)
209 #define hotcpu_notifier(fn, pri)	do { (void)(fn); } while (0)
210 #define __hotcpu_notifier(fn, pri)	do { (void)(fn); } while (0)
211 /* These aren't inline functions due to a GCC bug. */
212 #define register_hotcpu_notifier(nb)	({ (void)(nb); 0; })
213 #define __register_hotcpu_notifier(nb)	({ (void)(nb); 0; })
214 #define unregister_hotcpu_notifier(nb)	({ (void)(nb); })
215 #define __unregister_hotcpu_notifier(nb)	({ (void)(nb); })
216 #endif		/* CONFIG_HOTPLUG_CPU */
217 
218 #ifdef CONFIG_PM_SLEEP_SMP
219 extern int freeze_secondary_cpus(int primary);
220 static inline int disable_nonboot_cpus(void)
221 {
222 	return freeze_secondary_cpus(0);
223 }
224 extern void enable_nonboot_cpus(void);
225 #else /* !CONFIG_PM_SLEEP_SMP */
226 static inline int disable_nonboot_cpus(void) { return 0; }
227 static inline void enable_nonboot_cpus(void) {}
228 #endif /* !CONFIG_PM_SLEEP_SMP */
229 
230 void cpu_startup_entry(enum cpuhp_state state);
231 
232 void cpu_idle_poll_ctrl(bool enable);
233 
234 /* Attach to any functions which should be considered cpuidle. */
235 #define __cpuidle	__attribute__((__section__(".cpuidle.text")))
236 
237 bool cpu_in_idle(unsigned long pc);
238 
239 void arch_cpu_idle(void);
240 void arch_cpu_idle_prepare(void);
241 void arch_cpu_idle_enter(void);
242 void arch_cpu_idle_exit(void);
243 void arch_cpu_idle_dead(void);
244 
245 int cpu_report_state(int cpu);
246 int cpu_check_up_prepare(int cpu);
247 void cpu_set_state_online(int cpu);
248 #ifdef CONFIG_HOTPLUG_CPU
249 bool cpu_wait_death(unsigned int cpu, int seconds);
250 bool cpu_report_death(void);
251 void cpuhp_report_idle_dead(void);
252 #else
253 static inline void cpuhp_report_idle_dead(void) { }
254 #endif /* #ifdef CONFIG_HOTPLUG_CPU */
255 
256 #endif /* _LINUX_CPU_H_ */
257