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
22struct device;
23struct device_node;
24struct attribute_group;
25
26struct cpu {
27 int node_id; /* The node which contains the CPU */
28 int hotpluggable; /* creates sysfs control file if hotpluggable */
29 struct device dev;
30};
31
32extern void boot_cpu_init(void);
33extern void boot_cpu_hotplug_init(void);
34extern void cpu_init(void);
35extern void trap_init(void);
36
37extern int register_cpu(struct cpu *cpu, int num);
38extern struct device *get_cpu_device(unsigned cpu);
39extern bool cpu_is_hotpluggable(unsigned cpu);
40extern bool arch_match_cpu_phys_id(int cpu, u64 phys_id);
41extern bool arch_find_n_match_cpu_physical_id(struct device_node *cpun,
42 int cpu, unsigned int *thread);
43
44extern int cpu_add_dev_attr(struct device_attribute *attr);
45extern void cpu_remove_dev_attr(struct device_attribute *attr);
46
47extern int cpu_add_dev_attr_group(struct attribute_group *attrs);
48extern void cpu_remove_dev_attr_group(struct attribute_group *attrs);
49
50extern ssize_t cpu_show_meltdown(struct device *dev,
51 struct device_attribute *attr, char *buf);
52extern ssize_t cpu_show_spectre_v1(struct device *dev,
53 struct device_attribute *attr, char *buf);
54extern ssize_t cpu_show_spectre_v2(struct device *dev,
55 struct device_attribute *attr, char *buf);
56extern ssize_t cpu_show_spec_store_bypass(struct device *dev,
57 struct device_attribute *attr, char *buf);
58extern ssize_t cpu_show_l1tf(struct device *dev,
59 struct device_attribute *attr, char *buf);
60extern ssize_t cpu_show_mds(struct device *dev,
61 struct device_attribute *attr, char *buf);
62extern ssize_t cpu_show_tsx_async_abort(struct device *dev,
63 struct device_attribute *attr,
64 char *buf);
65extern ssize_t cpu_show_itlb_multihit(struct device *dev,
66 struct device_attribute *attr, char *buf);
67extern ssize_t cpu_show_srbds(struct device *dev, struct device_attribute *attr, char *buf);
68extern ssize_t cpu_show_mmio_stale_data(struct device *dev,
69 struct device_attribute *attr,
70 char *buf);
71extern ssize_t cpu_show_retbleed(struct device *dev,
72 struct device_attribute *attr, char *buf);
73
74extern __printf(4, 5)
75struct device *cpu_device_create(struct device *parent, void *drvdata,
76 const struct attribute_group **groups,
77 const char *fmt, ...);
78#ifdef CONFIG_HOTPLUG_CPU
79extern void unregister_cpu(struct cpu *cpu);
80extern ssize_t arch_cpu_probe(const char *, size_t);
81extern ssize_t arch_cpu_release(const char *, size_t);
82#endif
83
84/*
85 * These states are not related to the core CPU hotplug mechanism. They are
86 * used by various (sub)architectures to track internal state
87 */
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 */
94
95#ifdef CONFIG_SMP
96extern bool cpuhp_tasks_frozen;
97int add_cpu(unsigned int cpu);
98int cpu_device_up(struct device *dev);
99void notify_cpu_starting(unsigned int cpu);
100extern void cpu_maps_update_begin(void);
101extern void cpu_maps_update_done(void);
102int bringup_hibernate_cpu(unsigned int sleep_cpu);
103void bringup_nonboot_cpus(unsigned int setup_max_cpus);
104
105#else /* CONFIG_SMP */
106#define cpuhp_tasks_frozen 0
107
108static inline void cpu_maps_update_begin(void)
109{
110}
111
112static inline void cpu_maps_update_done(void)
113{
114}
115
116static inline int add_cpu(unsigned int cpu) { return 0;}
117
118#endif /* CONFIG_SMP */
119extern struct bus_type cpu_subsys;
120
121extern int lockdep_is_cpus_held(void);
122
123#ifdef CONFIG_HOTPLUG_CPU
124extern void cpus_write_lock(void);
125extern void cpus_write_unlock(void);
126extern void cpus_read_lock(void);
127extern void cpus_read_unlock(void);
128extern int cpus_read_trylock(void);
129extern void lockdep_assert_cpus_held(void);
130extern void cpu_hotplug_disable(void);
131extern void cpu_hotplug_enable(void);
132void clear_tasks_mm_cpumask(int cpu);
133int remove_cpu(unsigned int cpu);
134int cpu_device_down(struct device *dev);
135extern void smp_shutdown_nonboot_cpus(unsigned int primary_cpu);
136
137#else /* CONFIG_HOTPLUG_CPU */
138
139static inline void cpus_write_lock(void) { }
140static inline void cpus_write_unlock(void) { }
141static inline void cpus_read_lock(void) { }
142static inline void cpus_read_unlock(void) { }
143static inline int cpus_read_trylock(void) { return true; }
144static inline void lockdep_assert_cpus_held(void) { }
145static inline void cpu_hotplug_disable(void) { }
146static inline void cpu_hotplug_enable(void) { }
147static inline int remove_cpu(unsigned int cpu) { return -EPERM; }
148static inline void smp_shutdown_nonboot_cpus(unsigned int primary_cpu) { }
149#endif /* !CONFIG_HOTPLUG_CPU */
150
151#ifdef CONFIG_PM_SLEEP_SMP
152extern int freeze_secondary_cpus(int primary);
153extern void thaw_secondary_cpus(void);
154
155static inline int suspend_disable_secondary_cpus(void)
156{
157 int cpu = 0;
158
159 if (IS_ENABLED(CONFIG_PM_SLEEP_SMP_NONZERO_CPU))
160 cpu = -1;
161
162 return freeze_secondary_cpus(cpu);
163}
164static inline void suspend_enable_secondary_cpus(void)
165{
166 return thaw_secondary_cpus();
167}
168
169#else /* !CONFIG_PM_SLEEP_SMP */
170static inline void thaw_secondary_cpus(void) {}
171static inline int suspend_disable_secondary_cpus(void) { return 0; }
172static inline void suspend_enable_secondary_cpus(void) { }
173#endif /* !CONFIG_PM_SLEEP_SMP */
174
175void __noreturn cpu_startup_entry(enum cpuhp_state state);
176
177void cpu_idle_poll_ctrl(bool enable);
178
179/* Attach to any functions which should be considered cpuidle. */
180#define __cpuidle __section(".cpuidle.text")
181
182bool cpu_in_idle(unsigned long pc);
183
184void arch_cpu_idle(void);
185void arch_cpu_idle_prepare(void);
186void arch_cpu_idle_enter(void);
187void arch_cpu_idle_exit(void);
188void arch_cpu_idle_dead(void);
189
190int cpu_report_state(int cpu);
191int cpu_check_up_prepare(int cpu);
192void cpu_set_state_online(int cpu);
193void play_idle_precise(u64 duration_ns, u64 latency_ns);
194
195static inline void play_idle(unsigned long duration_us)
196{
197 play_idle_precise(duration_us * NSEC_PER_USEC, U64_MAX);
198}
199
200#ifdef CONFIG_HOTPLUG_CPU
201bool cpu_wait_death(unsigned int cpu, int seconds);
202bool cpu_report_death(void);
203void cpuhp_report_idle_dead(void);
204#else
205static inline void cpuhp_report_idle_dead(void) { }
206#endif /* #ifdef CONFIG_HOTPLUG_CPU */
207
208enum cpuhp_smt_control {
209 CPU_SMT_ENABLED,
210 CPU_SMT_DISABLED,
211 CPU_SMT_FORCE_DISABLED,
212 CPU_SMT_NOT_SUPPORTED,
213 CPU_SMT_NOT_IMPLEMENTED,
214};
215
216#if defined(CONFIG_SMP) && defined(CONFIG_HOTPLUG_SMT)
217extern enum cpuhp_smt_control cpu_smt_control;
218extern void cpu_smt_disable(bool force);
219extern void cpu_smt_check_topology(void);
220extern bool cpu_smt_possible(void);
221extern int cpuhp_smt_enable(void);
222extern int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval);
223#else
224# define cpu_smt_control (CPU_SMT_NOT_IMPLEMENTED)
225static inline void cpu_smt_disable(bool force) { }
226static inline void cpu_smt_check_topology(void) { }
227static inline bool cpu_smt_possible(void) { return false; }
228static inline int cpuhp_smt_enable(void) { return 0; }
229static inline int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval) { return 0; }
230#endif
231
232extern bool cpu_mitigations_off(void);
233extern bool cpu_mitigations_auto_nosmt(void);
234
235#endif /* _LINUX_CPU_H_ */
236

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