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);
73 extern ssize_t cpu_show_spec_rstack_overflow(struct device *dev,
74 struct device_attribute *attr, char *buf);
75 extern ssize_t cpu_show_gds(struct device *dev,
76 struct device_attribute *attr, char *buf);
79 struct device *cpu_device_create(struct device *parent, void *drvdata,
80 const struct attribute_group **groups,
81 const char *fmt, ...);
82 #ifdef CONFIG_HOTPLUG_CPU
83 extern void unregister_cpu(struct cpu *cpu);
84 extern ssize_t arch_cpu_probe(const char *, size_t);
85 extern ssize_t arch_cpu_release(const char *, size_t);
89 * These states are not related to the core CPU hotplug mechanism. They are
90 * used by various (sub)architectures to track internal state
92 #define CPU_ONLINE 0x0002 /* CPU is up */
93 #define CPU_UP_PREPARE 0x0003 /* CPU coming up */
94 #define CPU_DEAD 0x0007 /* CPU dead */
95 #define CPU_DEAD_FROZEN 0x0008 /* CPU timed out on unplug */
96 #define CPU_POST_DEAD 0x0009 /* CPU successfully unplugged */
97 #define CPU_BROKEN 0x000B /* CPU did not die properly */
100 extern bool cpuhp_tasks_frozen;
101 int add_cpu(unsigned int cpu);
102 int cpu_device_up(struct device *dev);
103 void notify_cpu_starting(unsigned int cpu);
104 extern void cpu_maps_update_begin(void);
105 extern void cpu_maps_update_done(void);
106 int bringup_hibernate_cpu(unsigned int sleep_cpu);
107 void bringup_nonboot_cpus(unsigned int setup_max_cpus);
109 #else /* CONFIG_SMP */
110 #define cpuhp_tasks_frozen 0
112 static inline void cpu_maps_update_begin(void)
116 static inline void cpu_maps_update_done(void)
120 static inline int add_cpu(unsigned int cpu) { return 0;}
122 #endif /* CONFIG_SMP */
123 extern struct bus_type cpu_subsys;
125 extern int lockdep_is_cpus_held(void);
127 #ifdef CONFIG_HOTPLUG_CPU
128 extern void cpus_write_lock(void);
129 extern void cpus_write_unlock(void);
130 extern void cpus_read_lock(void);
131 extern void cpus_read_unlock(void);
132 extern int cpus_read_trylock(void);
133 extern void lockdep_assert_cpus_held(void);
134 extern void cpu_hotplug_disable(void);
135 extern void cpu_hotplug_enable(void);
136 void clear_tasks_mm_cpumask(int cpu);
137 int remove_cpu(unsigned int cpu);
138 int cpu_device_down(struct device *dev);
139 extern void smp_shutdown_nonboot_cpus(unsigned int primary_cpu);
141 #else /* CONFIG_HOTPLUG_CPU */
143 static inline void cpus_write_lock(void) { }
144 static inline void cpus_write_unlock(void) { }
145 static inline void cpus_read_lock(void) { }
146 static inline void cpus_read_unlock(void) { }
147 static inline int cpus_read_trylock(void) { return true; }
148 static inline void lockdep_assert_cpus_held(void) { }
149 static inline void cpu_hotplug_disable(void) { }
150 static inline void cpu_hotplug_enable(void) { }
151 static inline int remove_cpu(unsigned int cpu) { return -EPERM; }
152 static inline void smp_shutdown_nonboot_cpus(unsigned int primary_cpu) { }
153 #endif /* !CONFIG_HOTPLUG_CPU */
155 #ifdef CONFIG_PM_SLEEP_SMP
156 extern int freeze_secondary_cpus(int primary);
157 extern void thaw_secondary_cpus(void);
159 static inline int suspend_disable_secondary_cpus(void)
163 if (IS_ENABLED(CONFIG_PM_SLEEP_SMP_NONZERO_CPU))
166 return freeze_secondary_cpus(cpu);
168 static inline void suspend_enable_secondary_cpus(void)
170 return thaw_secondary_cpus();
173 #else /* !CONFIG_PM_SLEEP_SMP */
174 static inline void thaw_secondary_cpus(void) {}
175 static inline int suspend_disable_secondary_cpus(void) { return 0; }
176 static inline void suspend_enable_secondary_cpus(void) { }
177 #endif /* !CONFIG_PM_SLEEP_SMP */
179 void __noreturn cpu_startup_entry(enum cpuhp_state state);
181 void cpu_idle_poll_ctrl(bool enable);
183 bool cpu_in_idle(unsigned long pc);
185 void arch_cpu_idle(void);
186 void arch_cpu_idle_prepare(void);
187 void arch_cpu_idle_enter(void);
188 void arch_cpu_idle_exit(void);
189 void __noreturn arch_cpu_idle_dead(void);
191 #ifdef CONFIG_ARCH_HAS_CPU_FINALIZE_INIT
192 void arch_cpu_finalize_init(void);
194 static inline void arch_cpu_finalize_init(void) { }
197 void cpu_set_state_online(int cpu);
198 void play_idle_precise(u64 duration_ns, u64 latency_ns);
200 static inline void play_idle(unsigned long duration_us)
202 play_idle_precise(duration_us * NSEC_PER_USEC, U64_MAX);
205 #ifdef CONFIG_HOTPLUG_CPU
206 void cpuhp_report_idle_dead(void);
208 static inline void cpuhp_report_idle_dead(void) { }
209 #endif /* #ifdef CONFIG_HOTPLUG_CPU */
211 enum cpuhp_smt_control {
214 CPU_SMT_FORCE_DISABLED,
215 CPU_SMT_NOT_SUPPORTED,
216 CPU_SMT_NOT_IMPLEMENTED,
219 #if defined(CONFIG_SMP) && defined(CONFIG_HOTPLUG_SMT)
220 extern enum cpuhp_smt_control cpu_smt_control;
221 extern void cpu_smt_disable(bool force);
222 extern void cpu_smt_check_topology(void);
223 extern bool cpu_smt_possible(void);
224 extern int cpuhp_smt_enable(void);
225 extern int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval);
227 # define cpu_smt_control (CPU_SMT_NOT_IMPLEMENTED)
228 static inline void cpu_smt_disable(bool force) { }
229 static inline void cpu_smt_check_topology(void) { }
230 static inline bool cpu_smt_possible(void) { return false; }
231 static inline int cpuhp_smt_enable(void) { return 0; }
232 static inline int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval) { return 0; }
235 extern bool cpu_mitigations_off(void);
236 extern bool cpu_mitigations_auto_nosmt(void);
238 #endif /* _LINUX_CPU_H_ */