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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#include <linux/cpu_smt.h>
22
23struct device;
24struct device_node;
25struct attribute_group;
26
27struct cpu {
28 int node_id; /* The node which contains the CPU */
29 int hotpluggable; /* creates sysfs control file if hotpluggable */
30 struct device dev;
31};
32
33extern void boot_cpu_init(void);
34extern void boot_cpu_hotplug_init(void);
35extern void cpu_init(void);
36extern void trap_init(void);
37
38extern int register_cpu(struct cpu *cpu, int num);
39extern struct device *get_cpu_device(unsigned cpu);
40extern bool cpu_is_hotpluggable(unsigned cpu);
41extern bool arch_match_cpu_phys_id(int cpu, u64 phys_id);
42extern bool arch_find_n_match_cpu_physical_id(struct device_node *cpun,
43 int cpu, unsigned int *thread);
44
45extern int cpu_add_dev_attr(struct device_attribute *attr);
46extern void cpu_remove_dev_attr(struct device_attribute *attr);
47
48extern int cpu_add_dev_attr_group(struct attribute_group *attrs);
49extern void cpu_remove_dev_attr_group(struct attribute_group *attrs);
50
51extern ssize_t cpu_show_meltdown(struct device *dev,
52 struct device_attribute *attr, char *buf);
53extern ssize_t cpu_show_spectre_v1(struct device *dev,
54 struct device_attribute *attr, char *buf);
55extern ssize_t cpu_show_spectre_v2(struct device *dev,
56 struct device_attribute *attr, char *buf);
57extern ssize_t cpu_show_spec_store_bypass(struct device *dev,
58 struct device_attribute *attr, char *buf);
59extern ssize_t cpu_show_l1tf(struct device *dev,
60 struct device_attribute *attr, char *buf);
61extern ssize_t cpu_show_mds(struct device *dev,
62 struct device_attribute *attr, char *buf);
63extern ssize_t cpu_show_tsx_async_abort(struct device *dev,
64 struct device_attribute *attr,
65 char *buf);
66extern ssize_t cpu_show_itlb_multihit(struct device *dev,
67 struct device_attribute *attr, char *buf);
68extern ssize_t cpu_show_srbds(struct device *dev, struct device_attribute *attr, char *buf);
69extern ssize_t cpu_show_mmio_stale_data(struct device *dev,
70 struct device_attribute *attr,
71 char *buf);
72extern ssize_t cpu_show_retbleed(struct device *dev,
73 struct device_attribute *attr, char *buf);
74extern ssize_t cpu_show_spec_rstack_overflow(struct device *dev,
75 struct device_attribute *attr, char *buf);
76extern ssize_t cpu_show_gds(struct device *dev,
77 struct device_attribute *attr, char *buf);
78
79extern __printf(4, 5)
80struct device *cpu_device_create(struct device *parent, void *drvdata,
81 const struct attribute_group **groups,
82 const char *fmt, ...);
83extern bool arch_cpu_is_hotpluggable(int cpu);
84extern int arch_register_cpu(int cpu);
85extern void arch_unregister_cpu(int cpu);
86#ifdef CONFIG_HOTPLUG_CPU
87extern void unregister_cpu(struct cpu *cpu);
88extern ssize_t arch_cpu_probe(const char *, size_t);
89extern ssize_t arch_cpu_release(const char *, size_t);
90#endif
91
92#ifdef CONFIG_GENERIC_CPU_DEVICES
93DECLARE_PER_CPU(struct cpu, cpu_devices);
94#endif
95
96/*
97 * These states are not related to the core CPU hotplug mechanism. They are
98 * used by various (sub)architectures to track internal state
99 */
100#define CPU_ONLINE 0x0002 /* CPU is up */
101#define CPU_UP_PREPARE 0x0003 /* CPU coming up */
102#define CPU_DEAD 0x0007 /* CPU dead */
103#define CPU_DEAD_FROZEN 0x0008 /* CPU timed out on unplug */
104#define CPU_POST_DEAD 0x0009 /* CPU successfully unplugged */
105#define CPU_BROKEN 0x000B /* CPU did not die properly */
106
107#ifdef CONFIG_SMP
108extern bool cpuhp_tasks_frozen;
109int add_cpu(unsigned int cpu);
110int cpu_device_up(struct device *dev);
111void notify_cpu_starting(unsigned int cpu);
112extern void cpu_maps_update_begin(void);
113extern void cpu_maps_update_done(void);
114int bringup_hibernate_cpu(unsigned int sleep_cpu);
115void bringup_nonboot_cpus(unsigned int setup_max_cpus);
116
117#else /* CONFIG_SMP */
118#define cpuhp_tasks_frozen 0
119
120static inline void cpu_maps_update_begin(void)
121{
122}
123
124static inline void cpu_maps_update_done(void)
125{
126}
127
128static inline int add_cpu(unsigned int cpu) { return 0;}
129
130#endif /* CONFIG_SMP */
131extern struct bus_type cpu_subsys;
132
133extern int lockdep_is_cpus_held(void);
134
135#ifdef CONFIG_HOTPLUG_CPU
136extern void cpus_write_lock(void);
137extern void cpus_write_unlock(void);
138extern void cpus_read_lock(void);
139extern void cpus_read_unlock(void);
140extern int cpus_read_trylock(void);
141extern void lockdep_assert_cpus_held(void);
142extern void cpu_hotplug_disable(void);
143extern void cpu_hotplug_enable(void);
144void clear_tasks_mm_cpumask(int cpu);
145int remove_cpu(unsigned int cpu);
146int cpu_device_down(struct device *dev);
147extern void smp_shutdown_nonboot_cpus(unsigned int primary_cpu);
148
149#else /* CONFIG_HOTPLUG_CPU */
150
151static inline void cpus_write_lock(void) { }
152static inline void cpus_write_unlock(void) { }
153static inline void cpus_read_lock(void) { }
154static inline void cpus_read_unlock(void) { }
155static inline int cpus_read_trylock(void) { return true; }
156static inline void lockdep_assert_cpus_held(void) { }
157static inline void cpu_hotplug_disable(void) { }
158static inline void cpu_hotplug_enable(void) { }
159static inline int remove_cpu(unsigned int cpu) { return -EPERM; }
160static inline void smp_shutdown_nonboot_cpus(unsigned int primary_cpu) { }
161#endif /* !CONFIG_HOTPLUG_CPU */
162
163DEFINE_LOCK_GUARD_0(cpus_read_lock, cpus_read_lock(), cpus_read_unlock())
164
165#ifdef CONFIG_PM_SLEEP_SMP
166extern int freeze_secondary_cpus(int primary);
167extern void thaw_secondary_cpus(void);
168
169static inline int suspend_disable_secondary_cpus(void)
170{
171 int cpu = 0;
172
173 if (IS_ENABLED(CONFIG_PM_SLEEP_SMP_NONZERO_CPU))
174 cpu = -1;
175
176 return freeze_secondary_cpus(cpu);
177}
178static inline void suspend_enable_secondary_cpus(void)
179{
180 return thaw_secondary_cpus();
181}
182
183#else /* !CONFIG_PM_SLEEP_SMP */
184static inline void thaw_secondary_cpus(void) {}
185static inline int suspend_disable_secondary_cpus(void) { return 0; }
186static inline void suspend_enable_secondary_cpus(void) { }
187#endif /* !CONFIG_PM_SLEEP_SMP */
188
189void __noreturn cpu_startup_entry(enum cpuhp_state state);
190
191void cpu_idle_poll_ctrl(bool enable);
192
193bool cpu_in_idle(unsigned long pc);
194
195void arch_cpu_idle(void);
196void arch_cpu_idle_prepare(void);
197void arch_cpu_idle_enter(void);
198void arch_cpu_idle_exit(void);
199void __noreturn arch_cpu_idle_dead(void);
200
201#ifdef CONFIG_ARCH_HAS_CPU_FINALIZE_INIT
202void arch_cpu_finalize_init(void);
203#else
204static inline void arch_cpu_finalize_init(void) { }
205#endif
206
207void play_idle_precise(u64 duration_ns, u64 latency_ns);
208
209static inline void play_idle(unsigned long duration_us)
210{
211 play_idle_precise(duration_us * NSEC_PER_USEC, U64_MAX);
212}
213
214#ifdef CONFIG_HOTPLUG_CPU
215void cpuhp_report_idle_dead(void);
216#else
217static inline void cpuhp_report_idle_dead(void) { }
218#endif /* #ifdef CONFIG_HOTPLUG_CPU */
219
220extern bool cpu_mitigations_off(void);
221extern bool cpu_mitigations_auto_nosmt(void);
222
223#endif /* _LINUX_CPU_H_ */