xref: /linux-6.15/include/linux/cpu.h (revision ebb9a9ae)
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 
97 extern int register_cpu_notifier(struct notifier_block *nb);
98 extern int __register_cpu_notifier(struct notifier_block *nb);
99 extern void unregister_cpu_notifier(struct notifier_block *nb);
100 extern void __unregister_cpu_notifier(struct notifier_block *nb);
101 
102 #else /* #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
103 #define cpu_notifier(fn, pri)	do { (void)(fn); } while (0)
104 #define __cpu_notifier(fn, pri)	do { (void)(fn); } while (0)
105 
106 static inline int register_cpu_notifier(struct notifier_block *nb)
107 {
108 	return 0;
109 }
110 
111 static inline int __register_cpu_notifier(struct notifier_block *nb)
112 {
113 	return 0;
114 }
115 
116 static inline void unregister_cpu_notifier(struct notifier_block *nb)
117 {
118 }
119 
120 static inline void __unregister_cpu_notifier(struct notifier_block *nb)
121 {
122 }
123 #endif
124 
125 int cpu_up(unsigned int cpu);
126 void notify_cpu_starting(unsigned int cpu);
127 extern void cpu_maps_update_begin(void);
128 extern void cpu_maps_update_done(void);
129 
130 #define cpu_notifier_register_begin	cpu_maps_update_begin
131 #define cpu_notifier_register_done	cpu_maps_update_done
132 
133 #else	/* CONFIG_SMP */
134 #define cpuhp_tasks_frozen	0
135 
136 #define cpu_notifier(fn, pri)	do { (void)(fn); } while (0)
137 #define __cpu_notifier(fn, pri)	do { (void)(fn); } while (0)
138 
139 static inline int register_cpu_notifier(struct notifier_block *nb)
140 {
141 	return 0;
142 }
143 
144 static inline int __register_cpu_notifier(struct notifier_block *nb)
145 {
146 	return 0;
147 }
148 
149 static inline void unregister_cpu_notifier(struct notifier_block *nb)
150 {
151 }
152 
153 static inline void __unregister_cpu_notifier(struct notifier_block *nb)
154 {
155 }
156 
157 static inline void cpu_maps_update_begin(void)
158 {
159 }
160 
161 static inline void cpu_maps_update_done(void)
162 {
163 }
164 
165 static inline void cpu_notifier_register_begin(void)
166 {
167 }
168 
169 static inline void cpu_notifier_register_done(void)
170 {
171 }
172 
173 #endif /* CONFIG_SMP */
174 extern struct bus_type cpu_subsys;
175 
176 #ifdef CONFIG_HOTPLUG_CPU
177 /* Stop CPUs going up and down. */
178 
179 extern void cpu_hotplug_begin(void);
180 extern void cpu_hotplug_done(void);
181 extern void get_online_cpus(void);
182 extern void put_online_cpus(void);
183 extern void cpu_hotplug_disable(void);
184 extern void cpu_hotplug_enable(void);
185 #define hotcpu_notifier(fn, pri)	cpu_notifier(fn, pri)
186 #define __hotcpu_notifier(fn, pri)	__cpu_notifier(fn, pri)
187 #define register_hotcpu_notifier(nb)	register_cpu_notifier(nb)
188 #define __register_hotcpu_notifier(nb)	__register_cpu_notifier(nb)
189 #define unregister_hotcpu_notifier(nb)	unregister_cpu_notifier(nb)
190 #define __unregister_hotcpu_notifier(nb)	__unregister_cpu_notifier(nb)
191 void clear_tasks_mm_cpumask(int cpu);
192 int cpu_down(unsigned int cpu);
193 
194 #else		/* CONFIG_HOTPLUG_CPU */
195 
196 static inline void cpu_hotplug_begin(void) {}
197 static inline void cpu_hotplug_done(void) {}
198 #define get_online_cpus()	do { } while (0)
199 #define put_online_cpus()	do { } while (0)
200 #define cpu_hotplug_disable()	do { } while (0)
201 #define cpu_hotplug_enable()	do { } while (0)
202 #define hotcpu_notifier(fn, pri)	do { (void)(fn); } while (0)
203 #define __hotcpu_notifier(fn, pri)	do { (void)(fn); } while (0)
204 /* These aren't inline functions due to a GCC bug. */
205 #define register_hotcpu_notifier(nb)	({ (void)(nb); 0; })
206 #define __register_hotcpu_notifier(nb)	({ (void)(nb); 0; })
207 #define unregister_hotcpu_notifier(nb)	({ (void)(nb); })
208 #define __unregister_hotcpu_notifier(nb)	({ (void)(nb); })
209 #endif		/* CONFIG_HOTPLUG_CPU */
210 
211 #ifdef CONFIG_PM_SLEEP_SMP
212 extern int freeze_secondary_cpus(int primary);
213 static inline int disable_nonboot_cpus(void)
214 {
215 	return freeze_secondary_cpus(0);
216 }
217 extern void enable_nonboot_cpus(void);
218 #else /* !CONFIG_PM_SLEEP_SMP */
219 static inline int disable_nonboot_cpus(void) { return 0; }
220 static inline void enable_nonboot_cpus(void) {}
221 #endif /* !CONFIG_PM_SLEEP_SMP */
222 
223 void cpu_startup_entry(enum cpuhp_state state);
224 
225 void cpu_idle_poll_ctrl(bool enable);
226 
227 /* Attach to any functions which should be considered cpuidle. */
228 #define __cpuidle	__attribute__((__section__(".cpuidle.text")))
229 
230 bool cpu_in_idle(unsigned long pc);
231 
232 void arch_cpu_idle(void);
233 void arch_cpu_idle_prepare(void);
234 void arch_cpu_idle_enter(void);
235 void arch_cpu_idle_exit(void);
236 void arch_cpu_idle_dead(void);
237 
238 int cpu_report_state(int cpu);
239 int cpu_check_up_prepare(int cpu);
240 void cpu_set_state_online(int cpu);
241 void play_idle(unsigned long duration_ms);
242 
243 #ifdef CONFIG_HOTPLUG_CPU
244 bool cpu_wait_death(unsigned int cpu, int seconds);
245 bool cpu_report_death(void);
246 void cpuhp_report_idle_dead(void);
247 #else
248 static inline void cpuhp_report_idle_dead(void) { }
249 #endif /* #ifdef CONFIG_HOTPLUG_CPU */
250 
251 #endif /* _LINUX_CPU_H_ */
252