1 /* SPDX-License-Identifier: GPL-2.0 */
3 * include/linux/cpu.h - generic cpu definition
5 * This is mainly for topological representation. We define the
6 * basic 'struct cpu' here, which can be embedded in per-arch
7 * definitions of processors.
9 * Basic handling of the devices is done in drivers/base/cpu.c
11 * CPUs are exported via sysfs in the devices/system/cpu
17 #include <linux/node.h>
18 #include <linux/compiler.h>
19 #include <linux/cpumask.h>
20 #include <linux/cpuhotplug.h>
24 struct attribute_group;
27 int node_id; /* The node which contains the CPU */
28 int hotpluggable; /* creates sysfs control file if hotpluggable */
32 extern void boot_cpu_init(void);
33 extern void boot_cpu_hotplug_init(void);
34 extern void cpu_init(void);
35 extern void trap_init(void);
37 extern int register_cpu(struct cpu *cpu, int num);
38 extern struct device *get_cpu_device(unsigned cpu);
39 extern bool cpu_is_hotpluggable(unsigned cpu);
40 extern bool arch_match_cpu_phys_id(int cpu, u64 phys_id);
41 extern bool arch_find_n_match_cpu_physical_id(struct device_node *cpun,
42 int cpu, unsigned int *thread);
44 extern int cpu_add_dev_attr(struct device_attribute *attr);
45 extern void cpu_remove_dev_attr(struct device_attribute *attr);
47 extern int cpu_add_dev_attr_group(struct attribute_group *attrs);
48 extern void cpu_remove_dev_attr_group(struct attribute_group *attrs);
50 extern ssize_t cpu_show_meltdown(struct device *dev,
51 struct device_attribute *attr, char *buf);
52 extern ssize_t cpu_show_spectre_v1(struct device *dev,
53 struct device_attribute *attr, char *buf);
54 extern ssize_t cpu_show_spectre_v2(struct device *dev,
55 struct device_attribute *attr, char *buf);
56 extern ssize_t cpu_show_spec_store_bypass(struct device *dev,
57 struct device_attribute *attr, char *buf);
58 extern ssize_t cpu_show_l1tf(struct device *dev,
59 struct device_attribute *attr, char *buf);
60 extern ssize_t cpu_show_mds(struct device *dev,
61 struct device_attribute *attr, char *buf);
62 extern ssize_t cpu_show_tsx_async_abort(struct device *dev,
63 struct device_attribute *attr,
65 extern ssize_t cpu_show_itlb_multihit(struct device *dev,
66 struct device_attribute *attr, char *buf);
67 extern ssize_t cpu_show_srbds(struct device *dev, struct device_attribute *attr, char *buf);
68 extern ssize_t cpu_show_mmio_stale_data(struct device *dev,
69 struct device_attribute *attr,
71 extern ssize_t cpu_show_retbleed(struct device *dev,
72 struct device_attribute *attr, char *buf);
75 struct device *cpu_device_create(struct device *parent, void *drvdata,
76 const struct attribute_group **groups,
77 const char *fmt, ...);
78 #ifdef CONFIG_HOTPLUG_CPU
79 extern void unregister_cpu(struct cpu *cpu);
80 extern ssize_t arch_cpu_probe(const char *, size_t);
81 extern ssize_t arch_cpu_release(const char *, size_t);
85 * These states are not related to the core CPU hotplug mechanism. They are
86 * used by various (sub)architectures to track internal state
88 #define CPU_ONLINE 0x0002 /* CPU is up */
89 #define CPU_UP_PREPARE 0x0003 /* CPU coming up */
90 #define CPU_DEAD 0x0007 /* CPU dead */
91 #define CPU_DEAD_FROZEN 0x0008 /* CPU timed out on unplug */
92 #define CPU_POST_DEAD 0x0009 /* CPU successfully unplugged */
93 #define CPU_BROKEN 0x000B /* CPU did not die properly */
96 extern bool cpuhp_tasks_frozen;
97 int cpu_up(unsigned int cpu);
98 void notify_cpu_starting(unsigned int cpu);
99 extern void cpu_maps_update_begin(void);
100 extern void cpu_maps_update_done(void);
102 #else /* CONFIG_SMP */
103 #define cpuhp_tasks_frozen 0
105 static inline void cpu_maps_update_begin(void)
109 static inline void cpu_maps_update_done(void)
113 #endif /* CONFIG_SMP */
114 extern struct bus_type cpu_subsys;
116 #ifdef CONFIG_HOTPLUG_CPU
117 extern void cpus_write_lock(void);
118 extern void cpus_write_unlock(void);
119 extern void cpus_read_lock(void);
120 extern void cpus_read_unlock(void);
121 extern int cpus_read_trylock(void);
122 extern void lockdep_assert_cpus_held(void);
123 extern void cpu_hotplug_disable(void);
124 extern void cpu_hotplug_enable(void);
125 void clear_tasks_mm_cpumask(int cpu);
126 int cpu_down(unsigned int cpu);
128 #else /* CONFIG_HOTPLUG_CPU */
130 static inline void cpus_write_lock(void) { }
131 static inline void cpus_write_unlock(void) { }
132 static inline void cpus_read_lock(void) { }
133 static inline void cpus_read_unlock(void) { }
134 static inline int cpus_read_trylock(void) { return true; }
135 static inline void lockdep_assert_cpus_held(void) { }
136 static inline void cpu_hotplug_disable(void) { }
137 static inline void cpu_hotplug_enable(void) { }
138 #endif /* !CONFIG_HOTPLUG_CPU */
140 /* Wrappers which go away once all code is converted */
141 static inline void cpu_hotplug_begin(void) { cpus_write_lock(); }
142 static inline void cpu_hotplug_done(void) { cpus_write_unlock(); }
143 static inline void get_online_cpus(void) { cpus_read_lock(); }
144 static inline void put_online_cpus(void) { cpus_read_unlock(); }
146 #ifdef CONFIG_PM_SLEEP_SMP
147 int __freeze_secondary_cpus(int primary, bool suspend);
148 static inline int freeze_secondary_cpus(int primary)
150 return __freeze_secondary_cpus(primary, true);
153 static inline int disable_nonboot_cpus(void)
155 return __freeze_secondary_cpus(0, false);
158 void enable_nonboot_cpus(void);
160 static inline int suspend_disable_secondary_cpus(void)
164 if (IS_ENABLED(CONFIG_PM_SLEEP_SMP_NONZERO_CPU))
167 return freeze_secondary_cpus(cpu);
169 static inline void suspend_enable_secondary_cpus(void)
171 return enable_nonboot_cpus();
174 #else /* !CONFIG_PM_SLEEP_SMP */
175 static inline int disable_nonboot_cpus(void) { return 0; }
176 static inline void enable_nonboot_cpus(void) {}
177 static inline int suspend_disable_secondary_cpus(void) { return 0; }
178 static inline void suspend_enable_secondary_cpus(void) { }
179 #endif /* !CONFIG_PM_SLEEP_SMP */
181 void cpu_startup_entry(enum cpuhp_state state);
183 void cpu_idle_poll_ctrl(bool enable);
185 /* Attach to any functions which should be considered cpuidle. */
186 #define __cpuidle __attribute__((__section__(".cpuidle.text")))
188 bool cpu_in_idle(unsigned long pc);
190 void arch_cpu_idle(void);
191 void arch_cpu_idle_prepare(void);
192 void arch_cpu_idle_enter(void);
193 void arch_cpu_idle_exit(void);
194 void arch_cpu_idle_dead(void);
196 int cpu_report_state(int cpu);
197 int cpu_check_up_prepare(int cpu);
198 void cpu_set_state_online(int cpu);
199 void play_idle(unsigned long duration_us);
201 #ifdef CONFIG_HOTPLUG_CPU
202 bool cpu_wait_death(unsigned int cpu, int seconds);
203 bool cpu_report_death(void);
204 void cpuhp_report_idle_dead(void);
206 static inline void cpuhp_report_idle_dead(void) { }
207 #endif /* #ifdef CONFIG_HOTPLUG_CPU */
209 enum cpuhp_smt_control {
212 CPU_SMT_FORCE_DISABLED,
213 CPU_SMT_NOT_SUPPORTED,
214 CPU_SMT_NOT_IMPLEMENTED,
217 #if defined(CONFIG_SMP) && defined(CONFIG_HOTPLUG_SMT)
218 extern enum cpuhp_smt_control cpu_smt_control;
219 extern void cpu_smt_disable(bool force);
220 extern void cpu_smt_check_topology(void);
221 extern bool cpu_smt_possible(void);
222 extern int cpuhp_smt_enable(void);
223 extern int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval);
225 # define cpu_smt_control (CPU_SMT_NOT_IMPLEMENTED)
226 static inline void cpu_smt_disable(bool force) { }
227 static inline void cpu_smt_check_topology(void) { }
228 static inline bool cpu_smt_possible(void) { return false; }
229 static inline int cpuhp_smt_enable(void) { return 0; }
230 static inline int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval) { return 0; }
233 extern bool cpu_mitigations_off(void);
234 extern bool cpu_mitigations_auto_nosmt(void);
236 #endif /* _LINUX_CPU_H_ */