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);
61 struct device *cpu_device_create(struct device *parent, void *drvdata,
62 const struct attribute_group **groups,
63 const char *fmt, ...);
64 #ifdef CONFIG_HOTPLUG_CPU
65 extern void unregister_cpu(struct cpu *cpu);
66 extern ssize_t arch_cpu_probe(const char *, size_t);
67 extern ssize_t arch_cpu_release(const char *, size_t);
69 struct notifier_block;
71 #define CPU_ONLINE 0x0002 /* CPU (unsigned)v is up */
72 #define CPU_UP_PREPARE 0x0003 /* CPU (unsigned)v coming up */
73 #define CPU_UP_CANCELED 0x0004 /* CPU (unsigned)v NOT coming up */
74 #define CPU_DOWN_PREPARE 0x0005 /* CPU (unsigned)v going down */
75 #define CPU_DOWN_FAILED 0x0006 /* CPU (unsigned)v NOT going down */
76 #define CPU_DEAD 0x0007 /* CPU (unsigned)v dead */
77 #define CPU_POST_DEAD 0x0009 /* CPU (unsigned)v dead, cpu_hotplug
79 #define CPU_BROKEN 0x000B /* CPU (unsigned)v did not die properly,
80 * perhaps due to preemption. */
82 /* Used for CPU hotplug events occurring while tasks are frozen due to a suspend
83 * operation in progress
85 #define CPU_TASKS_FROZEN 0x0010
87 #define CPU_ONLINE_FROZEN (CPU_ONLINE | CPU_TASKS_FROZEN)
88 #define CPU_UP_PREPARE_FROZEN (CPU_UP_PREPARE | CPU_TASKS_FROZEN)
89 #define CPU_UP_CANCELED_FROZEN (CPU_UP_CANCELED | CPU_TASKS_FROZEN)
90 #define CPU_DOWN_PREPARE_FROZEN (CPU_DOWN_PREPARE | CPU_TASKS_FROZEN)
91 #define CPU_DOWN_FAILED_FROZEN (CPU_DOWN_FAILED | CPU_TASKS_FROZEN)
92 #define CPU_DEAD_FROZEN (CPU_DEAD | CPU_TASKS_FROZEN)
95 extern bool cpuhp_tasks_frozen;
96 /* Need to know about CPUs going up/down? */
97 #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE)
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); \
104 #define __cpu_notifier(fn, pri) { \
105 static struct notifier_block fn##_nb = \
106 { .notifier_call = fn, .priority = pri }; \
107 __register_cpu_notifier(&fn##_nb); \
110 extern int register_cpu_notifier(struct notifier_block *nb);
111 extern int __register_cpu_notifier(struct notifier_block *nb);
112 extern void unregister_cpu_notifier(struct notifier_block *nb);
113 extern void __unregister_cpu_notifier(struct notifier_block *nb);
115 #else /* #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
116 #define cpu_notifier(fn, pri) do { (void)(fn); } while (0)
117 #define __cpu_notifier(fn, pri) do { (void)(fn); } while (0)
119 static inline int register_cpu_notifier(struct notifier_block *nb)
124 static inline int __register_cpu_notifier(struct notifier_block *nb)
129 static inline void unregister_cpu_notifier(struct notifier_block *nb)
133 static inline void __unregister_cpu_notifier(struct notifier_block *nb)
138 int cpu_up(unsigned int cpu);
139 void notify_cpu_starting(unsigned int cpu);
140 extern void cpu_maps_update_begin(void);
141 extern void cpu_maps_update_done(void);
143 #define cpu_notifier_register_begin cpu_maps_update_begin
144 #define cpu_notifier_register_done cpu_maps_update_done
146 #else /* CONFIG_SMP */
147 #define cpuhp_tasks_frozen 0
149 #define cpu_notifier(fn, pri) do { (void)(fn); } while (0)
150 #define __cpu_notifier(fn, pri) do { (void)(fn); } while (0)
152 static inline int register_cpu_notifier(struct notifier_block *nb)
157 static inline int __register_cpu_notifier(struct notifier_block *nb)
162 static inline void unregister_cpu_notifier(struct notifier_block *nb)
166 static inline void __unregister_cpu_notifier(struct notifier_block *nb)
170 static inline void cpu_maps_update_begin(void)
174 static inline void cpu_maps_update_done(void)
178 static inline void cpu_notifier_register_begin(void)
182 static inline void cpu_notifier_register_done(void)
186 #endif /* CONFIG_SMP */
187 extern struct bus_type cpu_subsys;
189 #ifdef CONFIG_HOTPLUG_CPU
190 /* Stop CPUs going up and down. */
192 extern void cpu_hotplug_begin(void);
193 extern void cpu_hotplug_done(void);
194 extern void get_online_cpus(void);
195 extern void put_online_cpus(void);
196 extern void cpu_hotplug_disable(void);
197 extern void cpu_hotplug_enable(void);
198 #define hotcpu_notifier(fn, pri) cpu_notifier(fn, pri)
199 #define __hotcpu_notifier(fn, pri) __cpu_notifier(fn, pri)
200 #define register_hotcpu_notifier(nb) register_cpu_notifier(nb)
201 #define __register_hotcpu_notifier(nb) __register_cpu_notifier(nb)
202 #define unregister_hotcpu_notifier(nb) unregister_cpu_notifier(nb)
203 #define __unregister_hotcpu_notifier(nb) __unregister_cpu_notifier(nb)
204 void clear_tasks_mm_cpumask(int cpu);
205 int cpu_down(unsigned int cpu);
207 #else /* CONFIG_HOTPLUG_CPU */
209 static inline void cpu_hotplug_begin(void) {}
210 static inline void cpu_hotplug_done(void) {}
211 #define get_online_cpus() do { } while (0)
212 #define put_online_cpus() do { } while (0)
213 #define cpu_hotplug_disable() do { } while (0)
214 #define cpu_hotplug_enable() do { } while (0)
215 #define hotcpu_notifier(fn, pri) do { (void)(fn); } while (0)
216 #define __hotcpu_notifier(fn, pri) do { (void)(fn); } while (0)
217 /* These aren't inline functions due to a GCC bug. */
218 #define register_hotcpu_notifier(nb) ({ (void)(nb); 0; })
219 #define __register_hotcpu_notifier(nb) ({ (void)(nb); 0; })
220 #define unregister_hotcpu_notifier(nb) ({ (void)(nb); })
221 #define __unregister_hotcpu_notifier(nb) ({ (void)(nb); })
222 #endif /* CONFIG_HOTPLUG_CPU */
224 #ifdef CONFIG_PM_SLEEP_SMP
225 extern int freeze_secondary_cpus(int primary);
226 static inline int disable_nonboot_cpus(void)
228 return freeze_secondary_cpus(0);
230 extern void enable_nonboot_cpus(void);
231 #else /* !CONFIG_PM_SLEEP_SMP */
232 static inline int disable_nonboot_cpus(void) { return 0; }
233 static inline void enable_nonboot_cpus(void) {}
234 #endif /* !CONFIG_PM_SLEEP_SMP */
236 void cpu_startup_entry(enum cpuhp_state state);
238 void cpu_idle_poll_ctrl(bool enable);
240 /* Attach to any functions which should be considered cpuidle. */
241 #define __cpuidle __attribute__((__section__(".cpuidle.text")))
243 bool cpu_in_idle(unsigned long pc);
245 void arch_cpu_idle(void);
246 void arch_cpu_idle_prepare(void);
247 void arch_cpu_idle_enter(void);
248 void arch_cpu_idle_exit(void);
249 void arch_cpu_idle_dead(void);
251 int cpu_report_state(int cpu);
252 int cpu_check_up_prepare(int cpu);
253 void cpu_set_state_online(int cpu);
254 #ifdef CONFIG_HOTPLUG_CPU
255 bool cpu_wait_death(unsigned int cpu, int seconds);
256 bool cpu_report_death(void);
257 void cpuhp_report_idle_dead(void);
259 static inline void cpuhp_report_idle_dead(void) { }
260 #endif /* #ifdef CONFIG_HOTPLUG_CPU */
262 enum cpuhp_smt_control {
265 CPU_SMT_FORCE_DISABLED,
266 CPU_SMT_NOT_SUPPORTED,
269 #if defined(CONFIG_SMP) && defined(CONFIG_HOTPLUG_SMT)
270 extern enum cpuhp_smt_control cpu_smt_control;
271 extern void cpu_smt_disable(bool force);
272 extern void cpu_smt_check_topology_early(void);
273 extern void cpu_smt_check_topology(void);
274 extern int cpuhp_smt_enable(void);
275 extern int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval);
277 # define cpu_smt_control (CPU_SMT_ENABLED)
278 static inline void cpu_smt_disable(bool force) { }
279 static inline void cpu_smt_check_topology_early(void) { }
280 static inline void cpu_smt_check_topology(void) { }
281 static inline int cpuhp_smt_enable(void) { return 0; }
282 static inline int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval) { return 0; }
286 * These are used for a global "mitigations=" cmdline option for toggling
287 * optional CPU mitigations.
289 enum cpu_mitigations {
291 CPU_MITIGATIONS_AUTO,
292 CPU_MITIGATIONS_AUTO_NOSMT,
295 extern enum cpu_mitigations cpu_mitigations;
297 /* mitigations=off */
298 static inline bool cpu_mitigations_off(void)
300 return cpu_mitigations == CPU_MITIGATIONS_OFF;
303 /* mitigations=auto,nosmt */
304 static inline bool cpu_mitigations_auto_nosmt(void)
306 return cpu_mitigations == CPU_MITIGATIONS_AUTO_NOSMT;
309 #endif /* _LINUX_CPU_H_ */