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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);
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);
73extern ssize_t cpu_show_spec_rstack_overflow(struct device *dev,
74 struct device_attribute *attr, char *buf);
75extern ssize_t cpu_show_gds(struct device *dev,
76 struct device_attribute *attr, char *buf);
77
78extern __printf(4, 5)
79struct device *cpu_device_create(struct device *parent, void *drvdata,
80 const struct attribute_group **groups,
81 const char *fmt, ...);
82#ifdef CONFIG_HOTPLUG_CPU
83extern void unregister_cpu(struct cpu *cpu);
84extern ssize_t arch_cpu_probe(const char *, size_t);
85extern ssize_t arch_cpu_release(const char *, size_t);
86#endif
87
88/*
89 * These states are not related to the core CPU hotplug mechanism. They are
90 * used by various (sub)architectures to track internal state
91 */
92#define CPU_ONLINE 0x0002 /* CPU is up */
93#define CPU_UP_PREPARE 0x0003 /* CPU coming up */
94#define CPU_DEAD 0x0007 /* CPU dead */
95#define CPU_DEAD_FROZEN 0x0008 /* CPU timed out on unplug */
96#define CPU_POST_DEAD 0x0009 /* CPU successfully unplugged */
97#define CPU_BROKEN 0x000B /* CPU did not die properly */
98
99#ifdef CONFIG_SMP
100extern bool cpuhp_tasks_frozen;
101int add_cpu(unsigned int cpu);
102int cpu_device_up(struct device *dev);
103void notify_cpu_starting(unsigned int cpu);
104extern void cpu_maps_update_begin(void);
105extern void cpu_maps_update_done(void);
106int bringup_hibernate_cpu(unsigned int sleep_cpu);
107void bringup_nonboot_cpus(unsigned int setup_max_cpus);
108
109#else /* CONFIG_SMP */
110#define cpuhp_tasks_frozen 0
111
112static inline void cpu_maps_update_begin(void)
113{
114}
115
116static inline void cpu_maps_update_done(void)
117{
118}
119
120static inline int add_cpu(unsigned int cpu) { return 0;}
121
122#endif /* CONFIG_SMP */
123extern struct bus_type cpu_subsys;
124
125extern int lockdep_is_cpus_held(void);
126
127#ifdef CONFIG_HOTPLUG_CPU
128extern void cpus_write_lock(void);
129extern void cpus_write_unlock(void);
130extern void cpus_read_lock(void);
131extern void cpus_read_unlock(void);
132extern int cpus_read_trylock(void);
133extern void lockdep_assert_cpus_held(void);
134extern void cpu_hotplug_disable(void);
135extern void cpu_hotplug_enable(void);
136void clear_tasks_mm_cpumask(int cpu);
137int remove_cpu(unsigned int cpu);
138int cpu_device_down(struct device *dev);
139extern void smp_shutdown_nonboot_cpus(unsigned int primary_cpu);
140
141#else /* CONFIG_HOTPLUG_CPU */
142
143static inline void cpus_write_lock(void) { }
144static inline void cpus_write_unlock(void) { }
145static inline void cpus_read_lock(void) { }
146static inline void cpus_read_unlock(void) { }
147static inline int cpus_read_trylock(void) { return true; }
148static inline void lockdep_assert_cpus_held(void) { }
149static inline void cpu_hotplug_disable(void) { }
150static inline void cpu_hotplug_enable(void) { }
151static inline int remove_cpu(unsigned int cpu) { return -EPERM; }
152static inline void smp_shutdown_nonboot_cpus(unsigned int primary_cpu) { }
153#endif /* !CONFIG_HOTPLUG_CPU */
154
155#ifdef CONFIG_PM_SLEEP_SMP
156extern int freeze_secondary_cpus(int primary);
157extern void thaw_secondary_cpus(void);
158
159static inline int suspend_disable_secondary_cpus(void)
160{
161 int cpu = 0;
162
163 if (IS_ENABLED(CONFIG_PM_SLEEP_SMP_NONZERO_CPU))
164 cpu = -1;
165
166 return freeze_secondary_cpus(cpu);
167}
168static inline void suspend_enable_secondary_cpus(void)
169{
170 return thaw_secondary_cpus();
171}
172
173#else /* !CONFIG_PM_SLEEP_SMP */
174static inline void thaw_secondary_cpus(void) {}
175static inline int suspend_disable_secondary_cpus(void) { return 0; }
176static inline void suspend_enable_secondary_cpus(void) { }
177#endif /* !CONFIG_PM_SLEEP_SMP */
178
179void __noreturn cpu_startup_entry(enum cpuhp_state state);
180
181void cpu_idle_poll_ctrl(bool enable);
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 __noreturn arch_cpu_idle_dead(void);
190
191#ifdef CONFIG_ARCH_HAS_CPU_FINALIZE_INIT
192void arch_cpu_finalize_init(void);
193#else
194static inline void arch_cpu_finalize_init(void) { }
195#endif
196
197void cpu_set_state_online(int cpu);
198void play_idle_precise(u64 duration_ns, u64 latency_ns);
199
200static inline void play_idle(unsigned long duration_us)
201{
202 play_idle_precise(duration_us * NSEC_PER_USEC, U64_MAX);
203}
204
205#ifdef CONFIG_HOTPLUG_CPU
206void cpuhp_report_idle_dead(void);
207#else
208static inline void cpuhp_report_idle_dead(void) { }
209#endif /* #ifdef CONFIG_HOTPLUG_CPU */
210
211enum cpuhp_smt_control {
212 CPU_SMT_ENABLED,
213 CPU_SMT_DISABLED,
214 CPU_SMT_FORCE_DISABLED,
215 CPU_SMT_NOT_SUPPORTED,
216 CPU_SMT_NOT_IMPLEMENTED,
217};
218
219#if defined(CONFIG_SMP) && defined(CONFIG_HOTPLUG_SMT)
220extern enum cpuhp_smt_control cpu_smt_control;
221extern void cpu_smt_disable(bool force);
222extern void cpu_smt_check_topology(void);
223extern bool cpu_smt_possible(void);
224extern int cpuhp_smt_enable(void);
225extern int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval);
226#else
227# define cpu_smt_control (CPU_SMT_NOT_IMPLEMENTED)
228static inline void cpu_smt_disable(bool force) { }
229static inline void cpu_smt_check_topology(void) { }
230static inline bool cpu_smt_possible(void) { return false; }
231static inline int cpuhp_smt_enable(void) { return 0; }
232static inline int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval) { return 0; }
233#endif
234
235extern bool cpu_mitigations_off(void);
236extern bool cpu_mitigations_auto_nosmt(void);
237
238#endif /* _LINUX_CPU_H_ */