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);
60
61extern __printf(4, 5)
62struct device *cpu_device_create(struct device *parent, void *drvdata,
63 const struct attribute_group **groups,
64 const char *fmt, ...);
65#ifdef CONFIG_HOTPLUG_CPU
66extern void unregister_cpu(struct cpu *cpu);
67extern ssize_t arch_cpu_probe(const char *, size_t);
68extern ssize_t arch_cpu_release(const char *, size_t);
69#endif
70
71/*
72 * These states are not related to the core CPU hotplug mechanism. They are
73 * used by various (sub)architectures to track internal state
74 */
75#define CPU_ONLINE 0x0002 /* CPU is up */
76#define CPU_UP_PREPARE 0x0003 /* CPU coming up */
77#define CPU_DEAD 0x0007 /* CPU dead */
78#define CPU_DEAD_FROZEN 0x0008 /* CPU timed out on unplug */
79#define CPU_POST_DEAD 0x0009 /* CPU successfully unplugged */
80#define CPU_BROKEN 0x000B /* CPU did not die properly */
81
82#ifdef CONFIG_SMP
83extern bool cpuhp_tasks_frozen;
84int cpu_up(unsigned int cpu);
85void notify_cpu_starting(unsigned int cpu);
86extern void cpu_maps_update_begin(void);
87extern void cpu_maps_update_done(void);
88
89#else /* CONFIG_SMP */
90#define cpuhp_tasks_frozen 0
91
92static inline void cpu_maps_update_begin(void)
93{
94}
95
96static inline void cpu_maps_update_done(void)
97{
98}
99
100#endif /* CONFIG_SMP */
101extern struct bus_type cpu_subsys;
102
103#ifdef CONFIG_HOTPLUG_CPU
104extern void cpus_write_lock(void);
105extern void cpus_write_unlock(void);
106extern void cpus_read_lock(void);
107extern void cpus_read_unlock(void);
108extern int cpus_read_trylock(void);
109extern void lockdep_assert_cpus_held(void);
110extern void cpu_hotplug_disable(void);
111extern void cpu_hotplug_enable(void);
112void clear_tasks_mm_cpumask(int cpu);
113int cpu_down(unsigned int cpu);
114
115#else /* CONFIG_HOTPLUG_CPU */
116
117static inline void cpus_write_lock(void) { }
118static inline void cpus_write_unlock(void) { }
119static inline void cpus_read_lock(void) { }
120static inline void cpus_read_unlock(void) { }
121static inline int cpus_read_trylock(void) { return true; }
122static inline void lockdep_assert_cpus_held(void) { }
123static inline void cpu_hotplug_disable(void) { }
124static inline void cpu_hotplug_enable(void) { }
125#endif /* !CONFIG_HOTPLUG_CPU */
126
127/* Wrappers which go away once all code is converted */
128static inline void cpu_hotplug_begin(void) { cpus_write_lock(); }
129static inline void cpu_hotplug_done(void) { cpus_write_unlock(); }
130static inline void get_online_cpus(void) { cpus_read_lock(); }
131static inline void put_online_cpus(void) { cpus_read_unlock(); }
132
133#ifdef CONFIG_PM_SLEEP_SMP
134extern int freeze_secondary_cpus(int primary);
135static inline int disable_nonboot_cpus(void)
136{
137 return freeze_secondary_cpus(0);
138}
139extern void enable_nonboot_cpus(void);
140#else /* !CONFIG_PM_SLEEP_SMP */
141static inline int disable_nonboot_cpus(void) { return 0; }
142static inline void enable_nonboot_cpus(void) {}
143#endif /* !CONFIG_PM_SLEEP_SMP */
144
145void cpu_startup_entry(enum cpuhp_state state);
146
147void cpu_idle_poll_ctrl(bool enable);
148
149/* Attach to any functions which should be considered cpuidle. */
150#define __cpuidle __attribute__((__section__(".cpuidle.text")))
151
152bool cpu_in_idle(unsigned long pc);
153
154void arch_cpu_idle(void);
155void arch_cpu_idle_prepare(void);
156void arch_cpu_idle_enter(void);
157void arch_cpu_idle_exit(void);
158void arch_cpu_idle_dead(void);
159
160int cpu_report_state(int cpu);
161int cpu_check_up_prepare(int cpu);
162void cpu_set_state_online(int cpu);
163void play_idle(unsigned long duration_ms);
164
165#ifdef CONFIG_HOTPLUG_CPU
166bool cpu_wait_death(unsigned int cpu, int seconds);
167bool cpu_report_death(void);
168void cpuhp_report_idle_dead(void);
169#else
170static inline void cpuhp_report_idle_dead(void) { }
171#endif /* #ifdef CONFIG_HOTPLUG_CPU */
172
173enum cpuhp_smt_control {
174 CPU_SMT_ENABLED,
175 CPU_SMT_DISABLED,
176 CPU_SMT_FORCE_DISABLED,
177 CPU_SMT_NOT_SUPPORTED,
178};
179
180#if defined(CONFIG_SMP) && defined(CONFIG_HOTPLUG_SMT)
181extern enum cpuhp_smt_control cpu_smt_control;
182extern void cpu_smt_disable(bool force);
183extern void cpu_smt_check_topology_early(void);
184extern void cpu_smt_check_topology(void);
185#else
186# define cpu_smt_control (CPU_SMT_ENABLED)
187static inline void cpu_smt_disable(bool force) { }
188static inline void cpu_smt_check_topology_early(void) { }
189static inline void cpu_smt_check_topology(void) { }
190#endif
191
192#endif /* _LINUX_CPU_H_ */
193