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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);
62
63extern __printf(4, 5)
64struct device *cpu_device_create(struct device *parent, void *drvdata,
65 const struct attribute_group **groups,
66 const char *fmt, ...);
67#ifdef CONFIG_HOTPLUG_CPU
68extern void unregister_cpu(struct cpu *cpu);
69extern ssize_t arch_cpu_probe(const char *, size_t);
70extern ssize_t arch_cpu_release(const char *, size_t);
71#endif
72
73/*
74 * These states are not related to the core CPU hotplug mechanism. They are
75 * used by various (sub)architectures to track internal state
76 */
77#define CPU_ONLINE 0x0002 /* CPU is up */
78#define CPU_UP_PREPARE 0x0003 /* CPU coming up */
79#define CPU_DEAD 0x0007 /* CPU dead */
80#define CPU_DEAD_FROZEN 0x0008 /* CPU timed out on unplug */
81#define CPU_POST_DEAD 0x0009 /* CPU successfully unplugged */
82#define CPU_BROKEN 0x000B /* CPU did not die properly */
83
84#ifdef CONFIG_SMP
85extern bool cpuhp_tasks_frozen;
86int cpu_up(unsigned int cpu);
87void notify_cpu_starting(unsigned int cpu);
88extern void cpu_maps_update_begin(void);
89extern void cpu_maps_update_done(void);
90
91#else /* CONFIG_SMP */
92#define cpuhp_tasks_frozen 0
93
94static inline void cpu_maps_update_begin(void)
95{
96}
97
98static inline void cpu_maps_update_done(void)
99{
100}
101
102#endif /* CONFIG_SMP */
103extern struct bus_type cpu_subsys;
104
105#ifdef CONFIG_HOTPLUG_CPU
106extern void cpus_write_lock(void);
107extern void cpus_write_unlock(void);
108extern void cpus_read_lock(void);
109extern void cpus_read_unlock(void);
110extern int cpus_read_trylock(void);
111extern void lockdep_assert_cpus_held(void);
112extern void cpu_hotplug_disable(void);
113extern void cpu_hotplug_enable(void);
114void clear_tasks_mm_cpumask(int cpu);
115int cpu_down(unsigned int cpu);
116
117#else /* CONFIG_HOTPLUG_CPU */
118
119static inline void cpus_write_lock(void) { }
120static inline void cpus_write_unlock(void) { }
121static inline void cpus_read_lock(void) { }
122static inline void cpus_read_unlock(void) { }
123static inline int cpus_read_trylock(void) { return true; }
124static inline void lockdep_assert_cpus_held(void) { }
125static inline void cpu_hotplug_disable(void) { }
126static inline void cpu_hotplug_enable(void) { }
127#endif /* !CONFIG_HOTPLUG_CPU */
128
129/* Wrappers which go away once all code is converted */
130static inline void cpu_hotplug_begin(void) { cpus_write_lock(); }
131static inline void cpu_hotplug_done(void) { cpus_write_unlock(); }
132static inline void get_online_cpus(void) { cpus_read_lock(); }
133static inline void put_online_cpus(void) { cpus_read_unlock(); }
134
135#ifdef CONFIG_PM_SLEEP_SMP
136extern int freeze_secondary_cpus(int primary);
137static inline int disable_nonboot_cpus(void)
138{
139 return freeze_secondary_cpus(0);
140}
141extern void enable_nonboot_cpus(void);
142
143static inline int suspend_disable_secondary_cpus(void)
144{
145 int cpu = 0;
146
147 if (IS_ENABLED(CONFIG_PM_SLEEP_SMP_NONZERO_CPU))
148 cpu = -1;
149
150 return freeze_secondary_cpus(cpu);
151}
152static inline void suspend_enable_secondary_cpus(void)
153{
154 return enable_nonboot_cpus();
155}
156
157#else /* !CONFIG_PM_SLEEP_SMP */
158static inline int disable_nonboot_cpus(void) { return 0; }
159static inline void enable_nonboot_cpus(void) {}
160static inline int suspend_disable_secondary_cpus(void) { return 0; }
161static inline void suspend_enable_secondary_cpus(void) { }
162#endif /* !CONFIG_PM_SLEEP_SMP */
163
164void cpu_startup_entry(enum cpuhp_state state);
165
166void cpu_idle_poll_ctrl(bool enable);
167
168/* Attach to any functions which should be considered cpuidle. */
169#define __cpuidle __attribute__((__section__(".cpuidle.text")))
170
171bool cpu_in_idle(unsigned long pc);
172
173void arch_cpu_idle(void);
174void arch_cpu_idle_prepare(void);
175void arch_cpu_idle_enter(void);
176void arch_cpu_idle_exit(void);
177void arch_cpu_idle_dead(void);
178
179int cpu_report_state(int cpu);
180int cpu_check_up_prepare(int cpu);
181void cpu_set_state_online(int cpu);
182void play_idle(unsigned long duration_us);
183
184#ifdef CONFIG_HOTPLUG_CPU
185bool cpu_wait_death(unsigned int cpu, int seconds);
186bool cpu_report_death(void);
187void cpuhp_report_idle_dead(void);
188#else
189static inline void cpuhp_report_idle_dead(void) { }
190#endif /* #ifdef CONFIG_HOTPLUG_CPU */
191
192enum cpuhp_smt_control {
193 CPU_SMT_ENABLED,
194 CPU_SMT_DISABLED,
195 CPU_SMT_FORCE_DISABLED,
196 CPU_SMT_NOT_SUPPORTED,
197 CPU_SMT_NOT_IMPLEMENTED,
198};
199
200#if defined(CONFIG_SMP) && defined(CONFIG_HOTPLUG_SMT)
201extern enum cpuhp_smt_control cpu_smt_control;
202extern void cpu_smt_disable(bool force);
203extern void cpu_smt_check_topology(void);
204extern bool cpu_smt_possible(void);
205extern int cpuhp_smt_enable(void);
206extern int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval);
207#else
208# define cpu_smt_control (CPU_SMT_NOT_IMPLEMENTED)
209static inline void cpu_smt_disable(bool force) { }
210static inline void cpu_smt_check_topology(void) { }
211static inline bool cpu_smt_possible(void) { return false; }
212static inline int cpuhp_smt_enable(void) { return 0; }
213static inline int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval) { return 0; }
214#endif
215
216/*
217 * These are used for a global "mitigations=" cmdline option for toggling
218 * optional CPU mitigations.
219 */
220enum cpu_mitigations {
221 CPU_MITIGATIONS_OFF,
222 CPU_MITIGATIONS_AUTO,
223 CPU_MITIGATIONS_AUTO_NOSMT,
224};
225
226extern enum cpu_mitigations cpu_mitigations;
227
228/* mitigations=off */
229static inline bool cpu_mitigations_off(void)
230{
231 return cpu_mitigations == CPU_MITIGATIONS_OFF;
232}
233
234/* mitigations=auto,nosmt */
235static inline bool cpu_mitigations_auto_nosmt(void)
236{
237 return cpu_mitigations == CPU_MITIGATIONS_AUTO_NOSMT;
238}
239
240#endif /* _LINUX_CPU_H_ */