xref: /linux-6.15/include/linux/cpu.h (revision 071bf69a)
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_DYING		0x0008 /* CPU (unsigned)v not running any task,
65 					* not handling interrupts, soon dead.
66 					* Called on the dying cpu, interrupts
67 					* are already disabled. Must not
68 					* sleep, must not fail */
69 #define CPU_POST_DEAD		0x0009 /* CPU (unsigned)v dead, cpu_hotplug
70 					* lock is dropped */
71 #define CPU_STARTING		0x000A /* CPU (unsigned)v soon running.
72 					* Called on the new cpu, just before
73 					* enabling interrupts. Must not sleep,
74 					* must not fail */
75 #define CPU_BROKEN		0x000B /* CPU (unsigned)v did not die properly,
76 					* perhaps due to preemption. */
77 
78 /* Used for CPU hotplug events occurring while tasks are frozen due to a suspend
79  * operation in progress
80  */
81 #define CPU_TASKS_FROZEN	0x0010
82 
83 #define CPU_ONLINE_FROZEN	(CPU_ONLINE | CPU_TASKS_FROZEN)
84 #define CPU_UP_PREPARE_FROZEN	(CPU_UP_PREPARE | CPU_TASKS_FROZEN)
85 #define CPU_UP_CANCELED_FROZEN	(CPU_UP_CANCELED | CPU_TASKS_FROZEN)
86 #define CPU_DOWN_PREPARE_FROZEN	(CPU_DOWN_PREPARE | CPU_TASKS_FROZEN)
87 #define CPU_DOWN_FAILED_FROZEN	(CPU_DOWN_FAILED | CPU_TASKS_FROZEN)
88 #define CPU_DEAD_FROZEN		(CPU_DEAD | CPU_TASKS_FROZEN)
89 #define CPU_DYING_FROZEN	(CPU_DYING | CPU_TASKS_FROZEN)
90 #define CPU_STARTING_FROZEN	(CPU_STARTING | CPU_TASKS_FROZEN)
91 
92 
93 #ifdef CONFIG_SMP
94 extern bool cpuhp_tasks_frozen;
95 /* Need to know about CPUs going up/down? */
96 #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE)
97 #define cpu_notifier(fn, pri) {					\
98 	static struct notifier_block fn##_nb =			\
99 		{ .notifier_call = fn, .priority = pri };	\
100 	register_cpu_notifier(&fn##_nb);			\
101 }
102 
103 #define __cpu_notifier(fn, pri) {				\
104 	static struct notifier_block fn##_nb =			\
105 		{ .notifier_call = fn, .priority = pri };	\
106 	__register_cpu_notifier(&fn##_nb);			\
107 }
108 #else /* #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
109 #define cpu_notifier(fn, pri)	do { (void)(fn); } while (0)
110 #define __cpu_notifier(fn, pri)	do { (void)(fn); } while (0)
111 #endif /* #else #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
112 
113 #ifdef CONFIG_HOTPLUG_CPU
114 extern int register_cpu_notifier(struct notifier_block *nb);
115 extern int __register_cpu_notifier(struct notifier_block *nb);
116 extern void unregister_cpu_notifier(struct notifier_block *nb);
117 extern void __unregister_cpu_notifier(struct notifier_block *nb);
118 #else
119 
120 #ifndef MODULE
121 extern int register_cpu_notifier(struct notifier_block *nb);
122 extern int __register_cpu_notifier(struct notifier_block *nb);
123 #else
124 static inline int register_cpu_notifier(struct notifier_block *nb)
125 {
126 	return 0;
127 }
128 
129 static inline int __register_cpu_notifier(struct notifier_block *nb)
130 {
131 	return 0;
132 }
133 #endif
134 
135 static inline void unregister_cpu_notifier(struct notifier_block *nb)
136 {
137 }
138 
139 static inline void __unregister_cpu_notifier(struct notifier_block *nb)
140 {
141 }
142 #endif
143 
144 int cpu_up(unsigned int cpu);
145 void notify_cpu_starting(unsigned int cpu);
146 extern void cpu_maps_update_begin(void);
147 extern void cpu_maps_update_done(void);
148 
149 #define cpu_notifier_register_begin	cpu_maps_update_begin
150 #define cpu_notifier_register_done	cpu_maps_update_done
151 
152 #else	/* CONFIG_SMP */
153 #define cpuhp_tasks_frozen	0
154 
155 #define cpu_notifier(fn, pri)	do { (void)(fn); } while (0)
156 #define __cpu_notifier(fn, pri)	do { (void)(fn); } while (0)
157 
158 static inline int register_cpu_notifier(struct notifier_block *nb)
159 {
160 	return 0;
161 }
162 
163 static inline int __register_cpu_notifier(struct notifier_block *nb)
164 {
165 	return 0;
166 }
167 
168 static inline void unregister_cpu_notifier(struct notifier_block *nb)
169 {
170 }
171 
172 static inline void __unregister_cpu_notifier(struct notifier_block *nb)
173 {
174 }
175 
176 static inline void cpu_maps_update_begin(void)
177 {
178 }
179 
180 static inline void cpu_maps_update_done(void)
181 {
182 }
183 
184 static inline void cpu_notifier_register_begin(void)
185 {
186 }
187 
188 static inline void cpu_notifier_register_done(void)
189 {
190 }
191 
192 #endif /* CONFIG_SMP */
193 extern struct bus_type cpu_subsys;
194 
195 #ifdef CONFIG_HOTPLUG_CPU
196 /* Stop CPUs going up and down. */
197 
198 extern void cpu_hotplug_begin(void);
199 extern void cpu_hotplug_done(void);
200 extern void get_online_cpus(void);
201 extern void put_online_cpus(void);
202 extern void cpu_hotplug_disable(void);
203 extern void cpu_hotplug_enable(void);
204 #define hotcpu_notifier(fn, pri)	cpu_notifier(fn, pri)
205 #define __hotcpu_notifier(fn, pri)	__cpu_notifier(fn, pri)
206 #define register_hotcpu_notifier(nb)	register_cpu_notifier(nb)
207 #define __register_hotcpu_notifier(nb)	__register_cpu_notifier(nb)
208 #define unregister_hotcpu_notifier(nb)	unregister_cpu_notifier(nb)
209 #define __unregister_hotcpu_notifier(nb)	__unregister_cpu_notifier(nb)
210 void clear_tasks_mm_cpumask(int cpu);
211 int cpu_down(unsigned int cpu);
212 
213 #else		/* CONFIG_HOTPLUG_CPU */
214 
215 static inline void cpu_hotplug_begin(void) {}
216 static inline void cpu_hotplug_done(void) {}
217 #define get_online_cpus()	do { } while (0)
218 #define put_online_cpus()	do { } while (0)
219 #define cpu_hotplug_disable()	do { } while (0)
220 #define cpu_hotplug_enable()	do { } while (0)
221 #define hotcpu_notifier(fn, pri)	do { (void)(fn); } while (0)
222 #define __hotcpu_notifier(fn, pri)	do { (void)(fn); } while (0)
223 /* These aren't inline functions due to a GCC bug. */
224 #define register_hotcpu_notifier(nb)	({ (void)(nb); 0; })
225 #define __register_hotcpu_notifier(nb)	({ (void)(nb); 0; })
226 #define unregister_hotcpu_notifier(nb)	({ (void)(nb); })
227 #define __unregister_hotcpu_notifier(nb)	({ (void)(nb); })
228 #endif		/* CONFIG_HOTPLUG_CPU */
229 
230 #ifdef CONFIG_PM_SLEEP_SMP
231 extern int disable_nonboot_cpus(void);
232 extern void enable_nonboot_cpus(void);
233 #else /* !CONFIG_PM_SLEEP_SMP */
234 static inline int disable_nonboot_cpus(void) { return 0; }
235 static inline void enable_nonboot_cpus(void) {}
236 #endif /* !CONFIG_PM_SLEEP_SMP */
237 
238 void cpu_startup_entry(enum cpuhp_state state);
239 
240 void cpu_idle_poll_ctrl(bool enable);
241 
242 void arch_cpu_idle(void);
243 void arch_cpu_idle_prepare(void);
244 void arch_cpu_idle_enter(void);
245 void arch_cpu_idle_exit(void);
246 void arch_cpu_idle_dead(void);
247 
248 int cpu_report_state(int cpu);
249 int cpu_check_up_prepare(int cpu);
250 void cpu_set_state_online(int cpu);
251 #ifdef CONFIG_HOTPLUG_CPU
252 bool cpu_wait_death(unsigned int cpu, int seconds);
253 bool cpu_report_death(void);
254 void cpuhp_report_idle_dead(void);
255 #else
256 static inline void cpuhp_report_idle_dead(void) { }
257 #endif /* #ifdef CONFIG_HOTPLUG_CPU */
258 
259 #endif /* _LINUX_CPU_H_ */
260