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 ssize_t cpu_show_meltdown(struct device *dev,
48 struct device_attribute *attr, char *buf);
49 extern ssize_t cpu_show_spectre_v1(struct device *dev,
50 struct device_attribute *attr, char *buf);
51 extern ssize_t cpu_show_spectre_v2(struct device *dev,
52 struct device_attribute *attr, char *buf);
53
54 extern __printf(4, 5)
55 struct device *cpu_device_create(struct device *parent, void *drvdata,
56 const struct attribute_group **groups,
57 const char *fmt, ...);
58 #ifdef CONFIG_HOTPLUG_CPU
59 extern void unregister_cpu(struct cpu *cpu);
60 extern ssize_t arch_cpu_probe(const char *, size_t);
61 extern ssize_t arch_cpu_release(const char *, size_t);
62 #endif
63 struct notifier_block;
64
65 #define CPU_ONLINE 0x0002 /* CPU (unsigned)v is up */
66 #define CPU_UP_PREPARE 0x0003 /* CPU (unsigned)v coming up */
67 #define CPU_UP_CANCELED 0x0004 /* CPU (unsigned)v NOT coming up */
68 #define CPU_DOWN_PREPARE 0x0005 /* CPU (unsigned)v going down */
69 #define CPU_DOWN_FAILED 0x0006 /* CPU (unsigned)v NOT going down */
70 #define CPU_DEAD 0x0007 /* CPU (unsigned)v dead */
71 #define CPU_POST_DEAD 0x0009 /* CPU (unsigned)v dead, cpu_hotplug
72 * lock is dropped */
73 #define CPU_BROKEN 0x000B /* CPU (unsigned)v did not die properly,
74 * perhaps due to preemption. */
75
76 /* Used for CPU hotplug events occurring while tasks are frozen due to a suspend
77 * operation in progress
78 */
79 #define CPU_TASKS_FROZEN 0x0010
80
81 #define CPU_ONLINE_FROZEN (CPU_ONLINE | CPU_TASKS_FROZEN)
82 #define CPU_UP_PREPARE_FROZEN (CPU_UP_PREPARE | CPU_TASKS_FROZEN)
83 #define CPU_UP_CANCELED_FROZEN (CPU_UP_CANCELED | CPU_TASKS_FROZEN)
84 #define CPU_DOWN_PREPARE_FROZEN (CPU_DOWN_PREPARE | CPU_TASKS_FROZEN)
85 #define CPU_DOWN_FAILED_FROZEN (CPU_DOWN_FAILED | CPU_TASKS_FROZEN)
86 #define CPU_DEAD_FROZEN (CPU_DEAD | CPU_TASKS_FROZEN)
87
88 #ifdef CONFIG_SMP
89 extern bool cpuhp_tasks_frozen;
90 /* Need to know about CPUs going up/down? */
91 #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE)
92 #define cpu_notifier(fn, pri) { \
93 static struct notifier_block fn##_nb = \
94 { .notifier_call = fn, .priority = pri }; \
95 register_cpu_notifier(&fn##_nb); \
96 }
97
98 #define __cpu_notifier(fn, pri) { \
99 static struct notifier_block fn##_nb = \
100 { .notifier_call = fn, .priority = pri }; \
101 __register_cpu_notifier(&fn##_nb); \
102 }
103
104 extern int register_cpu_notifier(struct notifier_block *nb);
105 extern int __register_cpu_notifier(struct notifier_block *nb);
106 extern void unregister_cpu_notifier(struct notifier_block *nb);
107 extern void __unregister_cpu_notifier(struct notifier_block *nb);
108
109 #else /* #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
110 #define cpu_notifier(fn, pri) do { (void)(fn); } while (0)
111 #define __cpu_notifier(fn, pri) do { (void)(fn); } while (0)
112
register_cpu_notifier(struct notifier_block * nb)113 static inline int register_cpu_notifier(struct notifier_block *nb)
114 {
115 return 0;
116 }
117
__register_cpu_notifier(struct notifier_block * nb)118 static inline int __register_cpu_notifier(struct notifier_block *nb)
119 {
120 return 0;
121 }
122
unregister_cpu_notifier(struct notifier_block * nb)123 static inline void unregister_cpu_notifier(struct notifier_block *nb)
124 {
125 }
126
__unregister_cpu_notifier(struct notifier_block * nb)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
register_cpu_notifier(struct notifier_block * nb)146 static inline int register_cpu_notifier(struct notifier_block *nb)
147 {
148 return 0;
149 }
150
__register_cpu_notifier(struct notifier_block * nb)151 static inline int __register_cpu_notifier(struct notifier_block *nb)
152 {
153 return 0;
154 }
155
unregister_cpu_notifier(struct notifier_block * nb)156 static inline void unregister_cpu_notifier(struct notifier_block *nb)
157 {
158 }
159
__unregister_cpu_notifier(struct notifier_block * nb)160 static inline void __unregister_cpu_notifier(struct notifier_block *nb)
161 {
162 }
163
cpu_maps_update_begin(void)164 static inline void cpu_maps_update_begin(void)
165 {
166 }
167
cpu_maps_update_done(void)168 static inline void cpu_maps_update_done(void)
169 {
170 }
171
cpu_notifier_register_begin(void)172 static inline void cpu_notifier_register_begin(void)
173 {
174 }
175
cpu_notifier_register_done(void)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
cpu_hotplug_begin(void)203 static inline void cpu_hotplug_begin(void) {}
cpu_hotplug_done(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);
disable_nonboot_cpus(void)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 */
disable_nonboot_cpus(void)226 static inline int disable_nonboot_cpus(void) { return 0; }
enable_nonboot_cpus(void)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
cpuhp_report_idle_dead(void)253 static inline void cpuhp_report_idle_dead(void) { }
254 #endif /* #ifdef CONFIG_HOTPLUG_CPU */
255
256 #define IDLE_START 1
257 #define IDLE_END 2
258
259 void idle_notifier_register(struct notifier_block *n);
260 void idle_notifier_unregister(struct notifier_block *n);
261 void idle_notifier_call_chain(unsigned long val);
262
263 #endif /* _LINUX_CPU_H_ */
264