2 * include/linux/cpu.h - generic cpu definition
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.
8 * Basic handling of the devices is done in drivers/base/cpu.c
10 * CPUs are exported via sysfs in the devices/system/cpu
16 #include <linux/node.h>
17 #include <linux/compiler.h>
18 #include <linux/cpumask.h>
19 #include <linux/cpuhotplug.h>
23 struct attribute_group;
26 int node_id; /* The node which contains the CPU */
27 int hotpluggable; /* creates sysfs control file if hotpluggable */
31 extern void boot_cpu_init(void);
32 extern void boot_cpu_hotplug_init(void);
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);
41 extern int cpu_add_dev_attr(struct device_attribute *attr);
42 extern void cpu_remove_dev_attr(struct device_attribute *attr);
44 extern int cpu_add_dev_attr_group(struct attribute_group *attrs);
45 extern void cpu_remove_dev_attr_group(struct attribute_group *attrs);
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 extern ssize_t cpu_show_spec_store_bypass(struct device *dev,
54 struct device_attribute *attr, char *buf);
55 extern ssize_t cpu_show_l1tf(struct device *dev,
56 struct device_attribute *attr, char *buf);
57 extern ssize_t cpu_show_mds(struct device *dev,
58 struct device_attribute *attr, char *buf);
59 extern ssize_t cpu_show_tsx_async_abort(struct device *dev,
60 struct device_attribute *attr,
62 extern ssize_t cpu_show_itlb_multihit(struct device *dev,
63 struct device_attribute *attr, char *buf);
64 extern ssize_t cpu_show_srbds(struct device *dev, struct device_attribute *attr, char *buf);
65 extern ssize_t cpu_show_mmio_stale_data(struct device *dev,
66 struct device_attribute *attr,
70 struct device *cpu_device_create(struct device *parent, void *drvdata,
71 const struct attribute_group **groups,
72 const char *fmt, ...);
73 #ifdef CONFIG_HOTPLUG_CPU
74 extern void unregister_cpu(struct cpu *cpu);
75 extern ssize_t arch_cpu_probe(const char *, size_t);
76 extern ssize_t arch_cpu_release(const char *, size_t);
78 struct notifier_block;
80 #define CPU_ONLINE 0x0002 /* CPU (unsigned)v is up */
81 #define CPU_UP_PREPARE 0x0003 /* CPU (unsigned)v coming up */
82 #define CPU_UP_CANCELED 0x0004 /* CPU (unsigned)v NOT coming up */
83 #define CPU_DOWN_PREPARE 0x0005 /* CPU (unsigned)v going down */
84 #define CPU_DOWN_FAILED 0x0006 /* CPU (unsigned)v NOT going down */
85 #define CPU_DEAD 0x0007 /* CPU (unsigned)v dead */
86 #define CPU_POST_DEAD 0x0009 /* CPU (unsigned)v dead, cpu_hotplug
88 #define CPU_BROKEN 0x000B /* CPU (unsigned)v did not die properly,
89 * perhaps due to preemption. */
91 /* Used for CPU hotplug events occurring while tasks are frozen due to a suspend
92 * operation in progress
94 #define CPU_TASKS_FROZEN 0x0010
96 #define CPU_ONLINE_FROZEN (CPU_ONLINE | CPU_TASKS_FROZEN)
97 #define CPU_UP_PREPARE_FROZEN (CPU_UP_PREPARE | CPU_TASKS_FROZEN)
98 #define CPU_UP_CANCELED_FROZEN (CPU_UP_CANCELED | CPU_TASKS_FROZEN)
99 #define CPU_DOWN_PREPARE_FROZEN (CPU_DOWN_PREPARE | CPU_TASKS_FROZEN)
100 #define CPU_DOWN_FAILED_FROZEN (CPU_DOWN_FAILED | CPU_TASKS_FROZEN)
101 #define CPU_DEAD_FROZEN (CPU_DEAD | CPU_TASKS_FROZEN)
104 extern bool cpuhp_tasks_frozen;
105 /* Need to know about CPUs going up/down? */
106 #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE)
107 #define cpu_notifier(fn, pri) { \
108 static struct notifier_block fn##_nb = \
109 { .notifier_call = fn, .priority = pri }; \
110 register_cpu_notifier(&fn##_nb); \
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); \
119 extern int register_cpu_notifier(struct notifier_block *nb);
120 extern int __register_cpu_notifier(struct notifier_block *nb);
121 extern void unregister_cpu_notifier(struct notifier_block *nb);
122 extern void __unregister_cpu_notifier(struct notifier_block *nb);
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)
128 static inline int register_cpu_notifier(struct notifier_block *nb)
133 static inline int __register_cpu_notifier(struct notifier_block *nb)
138 static inline void unregister_cpu_notifier(struct notifier_block *nb)
142 static inline void __unregister_cpu_notifier(struct notifier_block *nb)
147 int cpu_up(unsigned int cpu);
148 void notify_cpu_starting(unsigned int cpu);
149 extern void cpu_maps_update_begin(void);
150 extern void cpu_maps_update_done(void);
152 #define cpu_notifier_register_begin cpu_maps_update_begin
153 #define cpu_notifier_register_done cpu_maps_update_done
155 #else /* CONFIG_SMP */
156 #define cpuhp_tasks_frozen 0
158 #define cpu_notifier(fn, pri) do { (void)(fn); } while (0)
159 #define __cpu_notifier(fn, pri) do { (void)(fn); } while (0)
161 static inline int register_cpu_notifier(struct notifier_block *nb)
166 static inline int __register_cpu_notifier(struct notifier_block *nb)
171 static inline void unregister_cpu_notifier(struct notifier_block *nb)
175 static inline void __unregister_cpu_notifier(struct notifier_block *nb)
179 static inline void cpu_maps_update_begin(void)
183 static inline void cpu_maps_update_done(void)
187 static inline void cpu_notifier_register_begin(void)
191 static inline void cpu_notifier_register_done(void)
195 #endif /* CONFIG_SMP */
196 extern struct bus_type cpu_subsys;
198 #ifdef CONFIG_HOTPLUG_CPU
199 /* Stop CPUs going up and down. */
201 extern void cpu_hotplug_begin(void);
202 extern void cpu_hotplug_done(void);
203 extern void get_online_cpus(void);
204 extern void put_online_cpus(void);
205 extern void cpu_hotplug_disable(void);
206 extern void cpu_hotplug_enable(void);
207 #define hotcpu_notifier(fn, pri) cpu_notifier(fn, pri)
208 #define __hotcpu_notifier(fn, pri) __cpu_notifier(fn, pri)
209 #define register_hotcpu_notifier(nb) register_cpu_notifier(nb)
210 #define __register_hotcpu_notifier(nb) __register_cpu_notifier(nb)
211 #define unregister_hotcpu_notifier(nb) unregister_cpu_notifier(nb)
212 #define __unregister_hotcpu_notifier(nb) __unregister_cpu_notifier(nb)
213 void clear_tasks_mm_cpumask(int cpu);
214 int cpu_down(unsigned int cpu);
216 #else /* CONFIG_HOTPLUG_CPU */
218 static inline void cpu_hotplug_begin(void) {}
219 static inline void cpu_hotplug_done(void) {}
220 #define get_online_cpus() do { } while (0)
221 #define put_online_cpus() do { } while (0)
222 #define cpu_hotplug_disable() do { } while (0)
223 #define cpu_hotplug_enable() do { } while (0)
224 #define hotcpu_notifier(fn, pri) do { (void)(fn); } while (0)
225 #define __hotcpu_notifier(fn, pri) do { (void)(fn); } while (0)
226 /* These aren't inline functions due to a GCC bug. */
227 #define register_hotcpu_notifier(nb) ({ (void)(nb); 0; })
228 #define __register_hotcpu_notifier(nb) ({ (void)(nb); 0; })
229 #define unregister_hotcpu_notifier(nb) ({ (void)(nb); })
230 #define __unregister_hotcpu_notifier(nb) ({ (void)(nb); })
231 #endif /* CONFIG_HOTPLUG_CPU */
233 #ifdef CONFIG_PM_SLEEP_SMP
234 extern int freeze_secondary_cpus(int primary);
235 static inline int disable_nonboot_cpus(void)
237 return freeze_secondary_cpus(0);
239 extern void enable_nonboot_cpus(void);
240 #else /* !CONFIG_PM_SLEEP_SMP */
241 static inline int disable_nonboot_cpus(void) { return 0; }
242 static inline void enable_nonboot_cpus(void) {}
243 #endif /* !CONFIG_PM_SLEEP_SMP */
245 void cpu_startup_entry(enum cpuhp_state state);
247 void cpu_idle_poll_ctrl(bool enable);
249 /* Attach to any functions which should be considered cpuidle. */
250 #define __cpuidle __attribute__((__section__(".cpuidle.text")))
252 bool cpu_in_idle(unsigned long pc);
254 void arch_cpu_idle(void);
255 void arch_cpu_idle_prepare(void);
256 void arch_cpu_idle_enter(void);
257 void arch_cpu_idle_exit(void);
258 void arch_cpu_idle_dead(void);
260 int cpu_report_state(int cpu);
261 int cpu_check_up_prepare(int cpu);
262 void cpu_set_state_online(int cpu);
263 #ifdef CONFIG_HOTPLUG_CPU
264 bool cpu_wait_death(unsigned int cpu, int seconds);
265 bool cpu_report_death(void);
266 void cpuhp_report_idle_dead(void);
268 static inline void cpuhp_report_idle_dead(void) { }
269 #endif /* #ifdef CONFIG_HOTPLUG_CPU */
271 enum cpuhp_smt_control {
274 CPU_SMT_FORCE_DISABLED,
275 CPU_SMT_NOT_SUPPORTED,
278 #if defined(CONFIG_SMP) && defined(CONFIG_HOTPLUG_SMT)
279 extern enum cpuhp_smt_control cpu_smt_control;
280 extern void cpu_smt_disable(bool force);
281 extern void cpu_smt_check_topology_early(void);
282 extern void cpu_smt_check_topology(void);
283 extern int cpuhp_smt_enable(void);
284 extern int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval);
286 # define cpu_smt_control (CPU_SMT_ENABLED)
287 static inline void cpu_smt_disable(bool force) { }
288 static inline void cpu_smt_check_topology_early(void) { }
289 static inline void cpu_smt_check_topology(void) { }
290 static inline int cpuhp_smt_enable(void) { return 0; }
291 static inline int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval) { return 0; }
294 extern bool cpu_mitigations_off(void);
295 extern bool cpu_mitigations_auto_nosmt(void);
297 #endif /* _LINUX_CPU_H_ */