1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * include/linux/cpu.h - generic cpu definition
4 *
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.
8 *
9 * Basic handling of the devices is done in drivers/base/cpu.c
10 *
11 * CPUs are exported via sysfs in the devices/system/cpu
12 * directory.
13 */
14#ifndef _LINUX_CPU_H_
15#define _LINUX_CPU_H_
16
17#include <linux/node.h>
18#include <linux/compiler.h>
19#include <linux/cpumask.h>
20#include <linux/cpuhotplug.h>
21#include <linux/cpu_smt.h>
22
23struct device;
24struct device_node;
25struct attribute_group;
26
27struct cpu {
28 int node_id; /* The node which contains the CPU */
29 int hotpluggable; /* creates sysfs control file if hotpluggable */
30 struct device dev;
31};
32
33extern void boot_cpu_init(void);
34extern void boot_cpu_hotplug_init(void);
35extern void cpu_init(void);
36extern void trap_init(void);
37
38extern int register_cpu(struct cpu *cpu, int num);
39extern struct device *get_cpu_device(unsigned cpu);
40extern bool cpu_is_hotpluggable(unsigned cpu);
41extern bool arch_match_cpu_phys_id(int cpu, u64 phys_id);
42extern bool arch_find_n_match_cpu_physical_id(struct device_node *cpun,
43 int cpu, unsigned int *thread);
44
45extern int cpu_add_dev_attr(struct device_attribute *attr);
46extern void cpu_remove_dev_attr(struct device_attribute *attr);
47
48extern int cpu_add_dev_attr_group(struct attribute_group *attrs);
49extern void cpu_remove_dev_attr_group(struct attribute_group *attrs);
50
51extern ssize_t cpu_show_meltdown(struct device *dev,
52 struct device_attribute *attr, char *buf);
53extern ssize_t cpu_show_spectre_v1(struct device *dev,
54 struct device_attribute *attr, char *buf);
55extern ssize_t cpu_show_spectre_v2(struct device *dev,
56 struct device_attribute *attr, char *buf);
57extern ssize_t cpu_show_spec_store_bypass(struct device *dev,
58 struct device_attribute *attr, char *buf);
59extern ssize_t cpu_show_l1tf(struct device *dev,
60 struct device_attribute *attr, char *buf);
61extern ssize_t cpu_show_mds(struct device *dev,
62 struct device_attribute *attr, char *buf);
63extern ssize_t cpu_show_tsx_async_abort(struct device *dev,
64 struct device_attribute *attr,
65 char *buf);
66extern ssize_t cpu_show_itlb_multihit(struct device *dev,
67 struct device_attribute *attr, char *buf);
68extern ssize_t cpu_show_srbds(struct device *dev, struct device_attribute *attr, char *buf);
69extern ssize_t cpu_show_mmio_stale_data(struct device *dev,
70 struct device_attribute *attr,
71 char *buf);
72extern ssize_t cpu_show_retbleed(struct device *dev,
73 struct device_attribute *attr, char *buf);
74extern ssize_t cpu_show_spec_rstack_overflow(struct device *dev,
75 struct device_attribute *attr, char *buf);
76extern ssize_t cpu_show_gds(struct device *dev,
77 struct device_attribute *attr, char *buf);
78
79extern __printf(4, 5)
80struct device *cpu_device_create(struct device *parent, void *drvdata,
81 const struct attribute_group **groups,
82 const char *fmt, ...);
83extern int arch_register_cpu(int cpu);
84extern void arch_unregister_cpu(int cpu);
85#ifdef CONFIG_HOTPLUG_CPU
86extern void unregister_cpu(struct cpu *cpu);
87extern ssize_t arch_cpu_probe(const char *, size_t);
88extern ssize_t arch_cpu_release(const char *, size_t);
89#endif
90
91/*
92 * These states are not related to the core CPU hotplug mechanism. They are
93 * used by various (sub)architectures to track internal state
94 */
95#define CPU_ONLINE 0x0002 /* CPU is up */
96#define CPU_UP_PREPARE 0x0003 /* CPU coming up */
97#define CPU_DEAD 0x0007 /* CPU dead */
98#define CPU_DEAD_FROZEN 0x0008 /* CPU timed out on unplug */
99#define CPU_POST_DEAD 0x0009 /* CPU successfully unplugged */
100#define CPU_BROKEN 0x000B /* CPU did not die properly */
101
102#ifdef CONFIG_SMP
103extern bool cpuhp_tasks_frozen;
104int add_cpu(unsigned int cpu);
105int cpu_device_up(struct device *dev);
106void notify_cpu_starting(unsigned int cpu);
107extern void cpu_maps_update_begin(void);
108extern void cpu_maps_update_done(void);
109int bringup_hibernate_cpu(unsigned int sleep_cpu);
110void bringup_nonboot_cpus(unsigned int setup_max_cpus);
111
112#else /* CONFIG_SMP */
113#define cpuhp_tasks_frozen 0
114
115static inline void cpu_maps_update_begin(void)
116{
117}
118
119static inline void cpu_maps_update_done(void)
120{
121}
122
123static inline int add_cpu(unsigned int cpu) { return 0;}
124
125#endif /* CONFIG_SMP */
126extern struct bus_type cpu_subsys;
127
128extern int lockdep_is_cpus_held(void);
129
130#ifdef CONFIG_HOTPLUG_CPU
131extern void cpus_write_lock(void);
132extern void cpus_write_unlock(void);
133extern void cpus_read_lock(void);
134extern void cpus_read_unlock(void);
135extern int cpus_read_trylock(void);
136extern void lockdep_assert_cpus_held(void);
137extern void cpu_hotplug_disable(void);
138extern void cpu_hotplug_enable(void);
139void clear_tasks_mm_cpumask(int cpu);
140int remove_cpu(unsigned int cpu);
141int cpu_device_down(struct device *dev);
142extern void smp_shutdown_nonboot_cpus(unsigned int primary_cpu);
143
144#else /* CONFIG_HOTPLUG_CPU */
145
146static inline void cpus_write_lock(void) { }
147static inline void cpus_write_unlock(void) { }
148static inline void cpus_read_lock(void) { }
149static inline void cpus_read_unlock(void) { }
150static inline int cpus_read_trylock(void) { return true; }
151static inline void lockdep_assert_cpus_held(void) { }
152static inline void cpu_hotplug_disable(void) { }
153static inline void cpu_hotplug_enable(void) { }
154static inline int remove_cpu(unsigned int cpu) { return -EPERM; }
155static inline void smp_shutdown_nonboot_cpus(unsigned int primary_cpu) { }
156#endif /* !CONFIG_HOTPLUG_CPU */
157
158DEFINE_LOCK_GUARD_0(cpus_read_lock, cpus_read_lock(), cpus_read_unlock())
159
160#ifdef CONFIG_PM_SLEEP_SMP
161extern int freeze_secondary_cpus(int primary);
162extern void thaw_secondary_cpus(void);
163
164static inline int suspend_disable_secondary_cpus(void)
165{
166 int cpu = 0;
167
168 if (IS_ENABLED(CONFIG_PM_SLEEP_SMP_NONZERO_CPU))
169 cpu = -1;
170
171 return freeze_secondary_cpus(primary: cpu);
172}
173static inline void suspend_enable_secondary_cpus(void)
174{
175 return thaw_secondary_cpus();
176}
177
178#else /* !CONFIG_PM_SLEEP_SMP */
179static inline void thaw_secondary_cpus(void) {}
180static inline int suspend_disable_secondary_cpus(void) { return 0; }
181static inline void suspend_enable_secondary_cpus(void) { }
182#endif /* !CONFIG_PM_SLEEP_SMP */
183
184void __noreturn cpu_startup_entry(enum cpuhp_state state);
185
186void cpu_idle_poll_ctrl(bool enable);
187
188bool cpu_in_idle(unsigned long pc);
189
190void arch_cpu_idle(void);
191void arch_cpu_idle_prepare(void);
192void arch_cpu_idle_enter(void);
193void arch_cpu_idle_exit(void);
194void __noreturn arch_cpu_idle_dead(void);
195
196#ifdef CONFIG_ARCH_HAS_CPU_FINALIZE_INIT
197void arch_cpu_finalize_init(void);
198#else
199static inline void arch_cpu_finalize_init(void) { }
200#endif
201
202void play_idle_precise(u64 duration_ns, u64 latency_ns);
203
204static inline void play_idle(unsigned long duration_us)
205{
206 play_idle_precise(duration_ns: duration_us * NSEC_PER_USEC, U64_MAX);
207}
208
209#ifdef CONFIG_HOTPLUG_CPU
210void cpuhp_report_idle_dead(void);
211#else
212static inline void cpuhp_report_idle_dead(void) { }
213#endif /* #ifdef CONFIG_HOTPLUG_CPU */
214
215extern bool cpu_mitigations_off(void);
216extern bool cpu_mitigations_auto_nosmt(void);
217
218#endif /* _LINUX_CPU_H_ */
219

source code of linux/include/linux/cpu.h