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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);
67
68extern __printf(4, 5)
69struct device *cpu_device_create(struct device *parent, void *drvdata,
70 const struct attribute_group **groups,
71 const char *fmt, ...);
72#ifdef CONFIG_HOTPLUG_CPU
73extern void unregister_cpu(struct cpu *cpu);
74extern ssize_t arch_cpu_probe(const char *, size_t);
75extern ssize_t arch_cpu_release(const char *, size_t);
76#endif
77
78/*
79 * These states are not related to the core CPU hotplug mechanism. They are
80 * used by various (sub)architectures to track internal state
81 */
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 */
88
89#ifdef CONFIG_SMP
90extern bool cpuhp_tasks_frozen;
91int cpu_up(unsigned int cpu);
92void notify_cpu_starting(unsigned int cpu);
93extern void cpu_maps_update_begin(void);
94extern void cpu_maps_update_done(void);
95
96#else /* CONFIG_SMP */
97#define cpuhp_tasks_frozen 0
98
99static inline void cpu_maps_update_begin(void)
100{
101}
102
103static inline void cpu_maps_update_done(void)
104{
105}
106
107#endif /* CONFIG_SMP */
108extern struct bus_type cpu_subsys;
109
110#ifdef CONFIG_HOTPLUG_CPU
111extern void cpus_write_lock(void);
112extern void cpus_write_unlock(void);
113extern void cpus_read_lock(void);
114extern void cpus_read_unlock(void);
115extern int cpus_read_trylock(void);
116extern void lockdep_assert_cpus_held(void);
117extern void cpu_hotplug_disable(void);
118extern void cpu_hotplug_enable(void);
119void clear_tasks_mm_cpumask(int cpu);
120int cpu_down(unsigned int cpu);
121
122#else /* CONFIG_HOTPLUG_CPU */
123
124static inline void cpus_write_lock(void) { }
125static inline void cpus_write_unlock(void) { }
126static inline void cpus_read_lock(void) { }
127static inline void cpus_read_unlock(void) { }
128static inline int cpus_read_trylock(void) { return true; }
129static inline void lockdep_assert_cpus_held(void) { }
130static inline void cpu_hotplug_disable(void) { }
131static inline void cpu_hotplug_enable(void) { }
132#endif /* !CONFIG_HOTPLUG_CPU */
133
134/* Wrappers which go away once all code is converted */
135static inline void cpu_hotplug_begin(void) { cpus_write_lock(); }
136static inline void cpu_hotplug_done(void) { cpus_write_unlock(); }
137static inline void get_online_cpus(void) { cpus_read_lock(); }
138static inline void put_online_cpus(void) { cpus_read_unlock(); }
139
140#ifdef CONFIG_PM_SLEEP_SMP
141extern int freeze_secondary_cpus(int primary);
142static inline int disable_nonboot_cpus(void)
143{
144 return freeze_secondary_cpus(0);
145}
146extern void enable_nonboot_cpus(void);
147
148static inline int suspend_disable_secondary_cpus(void)
149{
150 int cpu = 0;
151
152 if (IS_ENABLED(CONFIG_PM_SLEEP_SMP_NONZERO_CPU))
153 cpu = -1;
154
155 return freeze_secondary_cpus(cpu);
156}
157static inline void suspend_enable_secondary_cpus(void)
158{
159 return enable_nonboot_cpus();
160}
161
162#else /* !CONFIG_PM_SLEEP_SMP */
163static inline int disable_nonboot_cpus(void) { return 0; }
164static inline void enable_nonboot_cpus(void) {}
165static inline int suspend_disable_secondary_cpus(void) { return 0; }
166static inline void suspend_enable_secondary_cpus(void) { }
167#endif /* !CONFIG_PM_SLEEP_SMP */
168
169void cpu_startup_entry(enum cpuhp_state state);
170
171void cpu_idle_poll_ctrl(bool enable);
172
173/* Attach to any functions which should be considered cpuidle. */
174#define __cpuidle __attribute__((__section__(".cpuidle.text")))
175
176bool cpu_in_idle(unsigned long pc);
177
178void arch_cpu_idle(void);
179void arch_cpu_idle_prepare(void);
180void arch_cpu_idle_enter(void);
181void arch_cpu_idle_exit(void);
182void arch_cpu_idle_dead(void);
183
184int cpu_report_state(int cpu);
185int cpu_check_up_prepare(int cpu);
186void cpu_set_state_online(int cpu);
187void play_idle_precise(u64 duration_ns, u64 latency_ns);
188
189static inline void play_idle(unsigned long duration_us)
190{
191 play_idle_precise(duration_us * NSEC_PER_USEC, U64_MAX);
192}
193
194#ifdef CONFIG_HOTPLUG_CPU
195bool cpu_wait_death(unsigned int cpu, int seconds);
196bool cpu_report_death(void);
197void cpuhp_report_idle_dead(void);
198#else
199static inline void cpuhp_report_idle_dead(void) { }
200#endif /* #ifdef CONFIG_HOTPLUG_CPU */
201
202enum cpuhp_smt_control {
203 CPU_SMT_ENABLED,
204 CPU_SMT_DISABLED,
205 CPU_SMT_FORCE_DISABLED,
206 CPU_SMT_NOT_SUPPORTED,
207 CPU_SMT_NOT_IMPLEMENTED,
208};
209
210#if defined(CONFIG_SMP) && defined(CONFIG_HOTPLUG_SMT)
211extern enum cpuhp_smt_control cpu_smt_control;
212extern void cpu_smt_disable(bool force);
213extern void cpu_smt_check_topology(void);
214extern bool cpu_smt_possible(void);
215extern int cpuhp_smt_enable(void);
216extern int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval);
217#else
218# define cpu_smt_control (CPU_SMT_NOT_IMPLEMENTED)
219static inline void cpu_smt_disable(bool force) { }
220static inline void cpu_smt_check_topology(void) { }
221static inline bool cpu_smt_possible(void) { return false; }
222static inline int cpuhp_smt_enable(void) { return 0; }
223static inline int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval) { return 0; }
224#endif
225
226extern bool cpu_mitigations_off(void);
227extern bool cpu_mitigations_auto_nosmt(void);
228
229#endif /* _LINUX_CPU_H_ */