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);
62 struct device *cpu_device_create(struct device *parent, void *drvdata,
63 const struct attribute_group **groups,
64 const char *fmt, ...);
65 #ifdef CONFIG_HOTPLUG_CPU
66 extern void unregister_cpu(struct cpu *cpu);
67 extern ssize_t arch_cpu_probe(const char *, size_t);
68 extern ssize_t arch_cpu_release(const char *, size_t);
72 * These states are not related to the core CPU hotplug mechanism. They are
73 * used by various (sub)architectures to track internal state
75 #define CPU_ONLINE 0x0002 /* CPU is up */
76 #define CPU_UP_PREPARE 0x0003 /* CPU coming up */
77 #define CPU_DEAD 0x0007 /* CPU dead */
78 #define CPU_DEAD_FROZEN 0x0008 /* CPU timed out on unplug */
79 #define CPU_POST_DEAD 0x0009 /* CPU successfully unplugged */
80 #define CPU_BROKEN 0x000B /* CPU did not die properly */
83 extern bool cpuhp_tasks_frozen;
84 int cpu_up(unsigned int cpu);
85 void notify_cpu_starting(unsigned int cpu);
86 extern void cpu_maps_update_begin(void);
87 extern void cpu_maps_update_done(void);
89 #else /* CONFIG_SMP */
90 #define cpuhp_tasks_frozen 0
92 static inline void cpu_maps_update_begin(void)
96 static inline void cpu_maps_update_done(void)
100 #endif /* CONFIG_SMP */
101 extern struct bus_type cpu_subsys;
103 #ifdef CONFIG_HOTPLUG_CPU
104 extern void cpus_write_lock(void);
105 extern void cpus_write_unlock(void);
106 extern void cpus_read_lock(void);
107 extern void cpus_read_unlock(void);
108 extern int cpus_read_trylock(void);
109 extern void lockdep_assert_cpus_held(void);
110 extern void cpu_hotplug_disable(void);
111 extern void cpu_hotplug_enable(void);
112 void clear_tasks_mm_cpumask(int cpu);
113 int cpu_down(unsigned int cpu);
115 #else /* CONFIG_HOTPLUG_CPU */
117 static inline void cpus_write_lock(void) { }
118 static inline void cpus_write_unlock(void) { }
119 static inline void cpus_read_lock(void) { }
120 static inline void cpus_read_unlock(void) { }
121 static inline int cpus_read_trylock(void) { return true; }
122 static inline void lockdep_assert_cpus_held(void) { }
123 static inline void cpu_hotplug_disable(void) { }
124 static inline void cpu_hotplug_enable(void) { }
125 #endif /* !CONFIG_HOTPLUG_CPU */
127 /* Wrappers which go away once all code is converted */
128 static inline void cpu_hotplug_begin(void) { cpus_write_lock(); }
129 static inline void cpu_hotplug_done(void) { cpus_write_unlock(); }
130 static inline void get_online_cpus(void) { cpus_read_lock(); }
131 static inline void put_online_cpus(void) { cpus_read_unlock(); }
133 #ifdef CONFIG_PM_SLEEP_SMP
134 extern int freeze_secondary_cpus(int primary);
135 static inline int disable_nonboot_cpus(void)
137 return freeze_secondary_cpus(0);
139 extern void enable_nonboot_cpus(void);
141 static inline int suspend_disable_secondary_cpus(void)
145 if (IS_ENABLED(CONFIG_PM_SLEEP_SMP_NONZERO_CPU))
148 return freeze_secondary_cpus(cpu);
150 static inline void suspend_enable_secondary_cpus(void)
152 return enable_nonboot_cpus();
155 #else /* !CONFIG_PM_SLEEP_SMP */
156 static inline int disable_nonboot_cpus(void) { return 0; }
157 static inline void enable_nonboot_cpus(void) {}
158 static inline int suspend_disable_secondary_cpus(void) { return 0; }
159 static inline void suspend_enable_secondary_cpus(void) { }
160 #endif /* !CONFIG_PM_SLEEP_SMP */
162 void cpu_startup_entry(enum cpuhp_state state);
164 void cpu_idle_poll_ctrl(bool enable);
166 /* Attach to any functions which should be considered cpuidle. */
167 #define __cpuidle __attribute__((__section__(".cpuidle.text")))
169 bool cpu_in_idle(unsigned long pc);
171 void arch_cpu_idle(void);
172 void arch_cpu_idle_prepare(void);
173 void arch_cpu_idle_enter(void);
174 void arch_cpu_idle_exit(void);
175 void arch_cpu_idle_dead(void);
177 int cpu_report_state(int cpu);
178 int cpu_check_up_prepare(int cpu);
179 void cpu_set_state_online(int cpu);
180 void play_idle(unsigned long duration_ms);
182 #ifdef CONFIG_HOTPLUG_CPU
183 bool cpu_wait_death(unsigned int cpu, int seconds);
184 bool cpu_report_death(void);
185 void cpuhp_report_idle_dead(void);
187 static inline void cpuhp_report_idle_dead(void) { }
188 #endif /* #ifdef CONFIG_HOTPLUG_CPU */
190 enum cpuhp_smt_control {
193 CPU_SMT_FORCE_DISABLED,
194 CPU_SMT_NOT_SUPPORTED,
195 CPU_SMT_NOT_IMPLEMENTED,
198 #if defined(CONFIG_SMP) && defined(CONFIG_HOTPLUG_SMT)
199 extern enum cpuhp_smt_control cpu_smt_control;
200 extern void cpu_smt_disable(bool force);
201 extern void cpu_smt_check_topology(void);
203 # define cpu_smt_control (CPU_SMT_NOT_IMPLEMENTED)
204 static inline void cpu_smt_disable(bool force) { }
205 static inline void cpu_smt_check_topology(void) { }
209 * These are used for a global "mitigations=" cmdline option for toggling
210 * optional CPU mitigations.
212 enum cpu_mitigations {
214 CPU_MITIGATIONS_AUTO,
215 CPU_MITIGATIONS_AUTO_NOSMT,
218 extern enum cpu_mitigations cpu_mitigations;
220 /* mitigations=off */
221 static inline bool cpu_mitigations_off(void)
223 return cpu_mitigations == CPU_MITIGATIONS_OFF;
226 /* mitigations=auto,nosmt */
227 static inline bool cpu_mitigations_auto_nosmt(void)
229 return cpu_mitigations == CPU_MITIGATIONS_AUTO_NOSMT;
232 #endif /* _LINUX_CPU_H_ */