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);
69 struct device *cpu_device_create(struct device *parent, void *drvdata,
70 const struct attribute_group **groups,
71 const char *fmt, ...);
72 #ifdef CONFIG_HOTPLUG_CPU
73 extern void unregister_cpu(struct cpu *cpu);
74 extern ssize_t arch_cpu_probe(const char *, size_t);
75 extern ssize_t arch_cpu_release(const char *, size_t);
79 * These states are not related to the core CPU hotplug mechanism. They are
80 * used by various (sub)architectures to track internal state
82 #define CPU_ONLINE 0x0002 /* CPU is up */
83 #define CPU_UP_PREPARE 0x0003 /* CPU coming up */
84 #define CPU_DEAD 0x0007 /* CPU dead */
85 #define CPU_DEAD_FROZEN 0x0008 /* CPU timed out on unplug */
86 #define CPU_POST_DEAD 0x0009 /* CPU successfully unplugged */
87 #define CPU_BROKEN 0x000B /* CPU did not die properly */
90 extern bool cpuhp_tasks_frozen;
91 int cpu_up(unsigned int cpu);
92 void notify_cpu_starting(unsigned int cpu);
93 extern void cpu_maps_update_begin(void);
94 extern void cpu_maps_update_done(void);
96 #else /* CONFIG_SMP */
97 #define cpuhp_tasks_frozen 0
99 static inline void cpu_maps_update_begin(void)
103 static inline void cpu_maps_update_done(void)
107 #endif /* CONFIG_SMP */
108 extern struct bus_type cpu_subsys;
110 #ifdef CONFIG_HOTPLUG_CPU
111 extern void cpus_write_lock(void);
112 extern void cpus_write_unlock(void);
113 extern void cpus_read_lock(void);
114 extern void cpus_read_unlock(void);
115 extern int cpus_read_trylock(void);
116 extern void lockdep_assert_cpus_held(void);
117 extern void cpu_hotplug_disable(void);
118 extern void cpu_hotplug_enable(void);
119 void clear_tasks_mm_cpumask(int cpu);
120 int cpu_down(unsigned int cpu);
122 #else /* CONFIG_HOTPLUG_CPU */
124 static inline void cpus_write_lock(void) { }
125 static inline void cpus_write_unlock(void) { }
126 static inline void cpus_read_lock(void) { }
127 static inline void cpus_read_unlock(void) { }
128 static inline int cpus_read_trylock(void) { return true; }
129 static inline void lockdep_assert_cpus_held(void) { }
130 static inline void cpu_hotplug_disable(void) { }
131 static inline void cpu_hotplug_enable(void) { }
132 #endif /* !CONFIG_HOTPLUG_CPU */
134 /* Wrappers which go away once all code is converted */
135 static inline void cpu_hotplug_begin(void) { cpus_write_lock(); }
136 static inline void cpu_hotplug_done(void) { cpus_write_unlock(); }
137 static inline void get_online_cpus(void) { cpus_read_lock(); }
138 static inline void put_online_cpus(void) { cpus_read_unlock(); }
140 #ifdef CONFIG_PM_SLEEP_SMP
141 extern int freeze_secondary_cpus(int primary);
142 static inline int disable_nonboot_cpus(void)
144 return freeze_secondary_cpus(0);
146 extern void enable_nonboot_cpus(void);
147 #else /* !CONFIG_PM_SLEEP_SMP */
148 static inline int disable_nonboot_cpus(void) { return 0; }
149 static inline void enable_nonboot_cpus(void) {}
150 #endif /* !CONFIG_PM_SLEEP_SMP */
152 void cpu_startup_entry(enum cpuhp_state state);
154 void cpu_idle_poll_ctrl(bool enable);
156 /* Attach to any functions which should be considered cpuidle. */
157 #define __cpuidle __attribute__((__section__(".cpuidle.text")))
159 bool cpu_in_idle(unsigned long pc);
161 void arch_cpu_idle(void);
162 void arch_cpu_idle_prepare(void);
163 void arch_cpu_idle_enter(void);
164 void arch_cpu_idle_exit(void);
165 void arch_cpu_idle_dead(void);
167 int cpu_report_state(int cpu);
168 int cpu_check_up_prepare(int cpu);
169 void cpu_set_state_online(int cpu);
170 void play_idle(unsigned long duration_ms);
172 #ifdef CONFIG_HOTPLUG_CPU
173 bool cpu_wait_death(unsigned int cpu, int seconds);
174 bool cpu_report_death(void);
175 void cpuhp_report_idle_dead(void);
177 static inline void cpuhp_report_idle_dead(void) { }
178 #endif /* #ifdef CONFIG_HOTPLUG_CPU */
180 enum cpuhp_smt_control {
183 CPU_SMT_FORCE_DISABLED,
184 CPU_SMT_NOT_SUPPORTED,
187 #if defined(CONFIG_SMP) && defined(CONFIG_HOTPLUG_SMT)
188 extern enum cpuhp_smt_control cpu_smt_control;
189 extern void cpu_smt_disable(bool force);
190 extern void cpu_smt_check_topology(void);
191 extern int cpuhp_smt_enable(void);
192 extern int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval);
194 # define cpu_smt_control (CPU_SMT_ENABLED)
195 static inline void cpu_smt_disable(bool force) { }
196 static inline void cpu_smt_check_topology(void) { }
197 static inline int cpuhp_smt_enable(void) { return 0; }
198 static inline int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval) { return 0; }
201 extern bool cpu_mitigations_off(void);
202 extern bool cpu_mitigations_auto_nosmt(void);
204 #endif /* _LINUX_CPU_H_ */