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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);
67extern ssize_t cpu_show_srbds(struct device *dev, struct device_attribute *attr, char *buf);
68
69extern __printf(4, 5)
70struct device *cpu_device_create(struct device *parent, void *drvdata,
71 const struct attribute_group **groups,
72 const char *fmt, ...);
73#ifdef CONFIG_HOTPLUG_CPU
74extern void unregister_cpu(struct cpu *cpu);
75extern ssize_t arch_cpu_probe(const char *, size_t);
76extern ssize_t arch_cpu_release(const char *, size_t);
77#endif
78
79/*
80 * These states are not related to the core CPU hotplug mechanism. They are
81 * used by various (sub)architectures to track internal state
82 */
83#define CPU_ONLINE 0x0002 /* CPU is up */
84#define CPU_UP_PREPARE 0x0003 /* CPU coming up */
85#define CPU_DEAD 0x0007 /* CPU dead */
86#define CPU_DEAD_FROZEN 0x0008 /* CPU timed out on unplug */
87#define CPU_POST_DEAD 0x0009 /* CPU successfully unplugged */
88#define CPU_BROKEN 0x000B /* CPU did not die properly */
89
90#ifdef CONFIG_SMP
91extern bool cpuhp_tasks_frozen;
92int add_cpu(unsigned int cpu);
93int cpu_device_up(struct device *dev);
94void notify_cpu_starting(unsigned int cpu);
95extern void cpu_maps_update_begin(void);
96extern void cpu_maps_update_done(void);
97int bringup_hibernate_cpu(unsigned int sleep_cpu);
98void bringup_nonboot_cpus(unsigned int setup_max_cpus);
99
100#else /* CONFIG_SMP */
101#define cpuhp_tasks_frozen 0
102
103static inline void cpu_maps_update_begin(void)
104{
105}
106
107static inline void cpu_maps_update_done(void)
108{
109}
110
111static inline int add_cpu(unsigned int cpu) { return 0;}
112
113#endif /* CONFIG_SMP */
114extern struct bus_type cpu_subsys;
115
116extern int lockdep_is_cpus_held(void);
117
118#ifdef CONFIG_HOTPLUG_CPU
119extern void cpus_write_lock(void);
120extern void cpus_write_unlock(void);
121extern void cpus_read_lock(void);
122extern void cpus_read_unlock(void);
123extern int cpus_read_trylock(void);
124extern void lockdep_assert_cpus_held(void);
125extern void cpu_hotplug_disable(void);
126extern void cpu_hotplug_enable(void);
127void clear_tasks_mm_cpumask(int cpu);
128int remove_cpu(unsigned int cpu);
129int cpu_device_down(struct device *dev);
130extern void smp_shutdown_nonboot_cpus(unsigned int primary_cpu);
131
132#else /* CONFIG_HOTPLUG_CPU */
133
134static inline void cpus_write_lock(void) { }
135static inline void cpus_write_unlock(void) { }
136static inline void cpus_read_lock(void) { }
137static inline void cpus_read_unlock(void) { }
138static inline int cpus_read_trylock(void) { return true; }
139static inline void lockdep_assert_cpus_held(void) { }
140static inline void cpu_hotplug_disable(void) { }
141static inline void cpu_hotplug_enable(void) { }
142static inline int remove_cpu(unsigned int cpu) { return -EPERM; }
143static inline void smp_shutdown_nonboot_cpus(unsigned int primary_cpu) { }
144#endif /* !CONFIG_HOTPLUG_CPU */
145
146/* Wrappers which go away once all code is converted */
147static inline void cpu_hotplug_begin(void) { cpus_write_lock(); }
148static inline void cpu_hotplug_done(void) { cpus_write_unlock(); }
149static inline void get_online_cpus(void) { cpus_read_lock(); }
150static inline void put_online_cpus(void) { cpus_read_unlock(); }
151
152#ifdef CONFIG_PM_SLEEP_SMP
153extern int freeze_secondary_cpus(int primary);
154extern void thaw_secondary_cpus(void);
155
156static inline int suspend_disable_secondary_cpus(void)
157{
158 int cpu = 0;
159
160 if (IS_ENABLED(CONFIG_PM_SLEEP_SMP_NONZERO_CPU))
161 cpu = -1;
162
163 return freeze_secondary_cpus(cpu);
164}
165static inline void suspend_enable_secondary_cpus(void)
166{
167 return thaw_secondary_cpus();
168}
169
170#else /* !CONFIG_PM_SLEEP_SMP */
171static inline void thaw_secondary_cpus(void) {}
172static inline int suspend_disable_secondary_cpus(void) { return 0; }
173static inline void suspend_enable_secondary_cpus(void) { }
174#endif /* !CONFIG_PM_SLEEP_SMP */
175
176void cpu_startup_entry(enum cpuhp_state state);
177
178void cpu_idle_poll_ctrl(bool enable);
179
180/* Attach to any functions which should be considered cpuidle. */
181#define __cpuidle __section(".cpuidle.text")
182
183bool cpu_in_idle(unsigned long pc);
184
185void arch_cpu_idle(void);
186void arch_cpu_idle_prepare(void);
187void arch_cpu_idle_enter(void);
188void arch_cpu_idle_exit(void);
189void arch_cpu_idle_dead(void);
190
191int cpu_report_state(int cpu);
192int cpu_check_up_prepare(int cpu);
193void cpu_set_state_online(int cpu);
194void play_idle_precise(u64 duration_ns, u64 latency_ns);
195
196static inline void play_idle(unsigned long duration_us)
197{
198 play_idle_precise(duration_us * NSEC_PER_USEC, U64_MAX);
199}
200
201#ifdef CONFIG_HOTPLUG_CPU
202bool cpu_wait_death(unsigned int cpu, int seconds);
203bool cpu_report_death(void);
204void cpuhp_report_idle_dead(void);
205#else
206static inline void cpuhp_report_idle_dead(void) { }
207#endif /* #ifdef CONFIG_HOTPLUG_CPU */
208
209enum cpuhp_smt_control {
210 CPU_SMT_ENABLED,
211 CPU_SMT_DISABLED,
212 CPU_SMT_FORCE_DISABLED,
213 CPU_SMT_NOT_SUPPORTED,
214 CPU_SMT_NOT_IMPLEMENTED,
215};
216
217#if defined(CONFIG_SMP) && defined(CONFIG_HOTPLUG_SMT)
218extern enum cpuhp_smt_control cpu_smt_control;
219extern void cpu_smt_disable(bool force);
220extern void cpu_smt_check_topology(void);
221extern bool cpu_smt_possible(void);
222extern int cpuhp_smt_enable(void);
223extern int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval);
224#else
225# define cpu_smt_control (CPU_SMT_NOT_IMPLEMENTED)
226static inline void cpu_smt_disable(bool force) { }
227static inline void cpu_smt_check_topology(void) { }
228static inline bool cpu_smt_possible(void) { return false; }
229static inline int cpuhp_smt_enable(void) { return 0; }
230static inline int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval) { return 0; }
231#endif
232
233extern bool cpu_mitigations_off(void);
234extern bool cpu_mitigations_auto_nosmt(void);
235
236#endif /* _LINUX_CPU_H_ */