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);
78extern ssize_t cpu_show_reg_file_data_sampling(struct device *dev,
79					       struct device_attribute *attr, char *buf);
80
81extern __printf(4, 5)
82struct device *cpu_device_create(struct device *parent, void *drvdata,
83				 const struct attribute_group **groups,
84				 const char *fmt, ...);
85extern bool arch_cpu_is_hotpluggable(int cpu);
86extern int arch_register_cpu(int cpu);
87extern void arch_unregister_cpu(int cpu);
88#ifdef CONFIG_HOTPLUG_CPU
89extern void unregister_cpu(struct cpu *cpu);
90extern ssize_t arch_cpu_probe(const char *, size_t);
91extern ssize_t arch_cpu_release(const char *, size_t);
92#endif
93
94#ifdef CONFIG_GENERIC_CPU_DEVICES
95DECLARE_PER_CPU(struct cpu, cpu_devices);
96#endif
97
98/*
99 * These states are not related to the core CPU hotplug mechanism. They are
100 * used by various (sub)architectures to track internal state
101 */
102#define CPU_ONLINE		0x0002 /* CPU is up */
103#define CPU_UP_PREPARE		0x0003 /* CPU coming up */
104#define CPU_DEAD		0x0007 /* CPU dead */
105#define CPU_DEAD_FROZEN		0x0008 /* CPU timed out on unplug */
106#define CPU_POST_DEAD		0x0009 /* CPU successfully unplugged */
107#define CPU_BROKEN		0x000B /* CPU did not die properly */
108
109#ifdef CONFIG_SMP
110extern bool cpuhp_tasks_frozen;
111int add_cpu(unsigned int cpu);
112int cpu_device_up(struct device *dev);
113void notify_cpu_starting(unsigned int cpu);
114extern void cpu_maps_update_begin(void);
115extern void cpu_maps_update_done(void);
116int bringup_hibernate_cpu(unsigned int sleep_cpu);
117void bringup_nonboot_cpus(unsigned int max_cpus);
118
119#else	/* CONFIG_SMP */
120#define cpuhp_tasks_frozen	0
121
122static inline void cpu_maps_update_begin(void)
123{
124}
125
126static inline void cpu_maps_update_done(void)
127{
128}
129
130static inline int add_cpu(unsigned int cpu) { return 0;}
131
132#endif /* CONFIG_SMP */
133extern const struct bus_type cpu_subsys;
134
135extern int lockdep_is_cpus_held(void);
136
137#ifdef CONFIG_HOTPLUG_CPU
138extern void cpus_write_lock(void);
139extern void cpus_write_unlock(void);
140extern void cpus_read_lock(void);
141extern void cpus_read_unlock(void);
142extern int  cpus_read_trylock(void);
143extern void lockdep_assert_cpus_held(void);
144extern void cpu_hotplug_disable(void);
145extern void cpu_hotplug_enable(void);
146void clear_tasks_mm_cpumask(int cpu);
147int remove_cpu(unsigned int cpu);
148int cpu_device_down(struct device *dev);
149extern void smp_shutdown_nonboot_cpus(unsigned int primary_cpu);
150
151#else /* CONFIG_HOTPLUG_CPU */
152
153static inline void cpus_write_lock(void) { }
154static inline void cpus_write_unlock(void) { }
155static inline void cpus_read_lock(void) { }
156static inline void cpus_read_unlock(void) { }
157static inline int  cpus_read_trylock(void) { return true; }
158static inline void lockdep_assert_cpus_held(void) { }
159static inline void cpu_hotplug_disable(void) { }
160static inline void cpu_hotplug_enable(void) { }
161static inline int remove_cpu(unsigned int cpu) { return -EPERM; }
162static inline void smp_shutdown_nonboot_cpus(unsigned int primary_cpu) { }
163#endif	/* !CONFIG_HOTPLUG_CPU */
164
165DEFINE_LOCK_GUARD_0(cpus_read_lock, cpus_read_lock(), cpus_read_unlock())
166
167#ifdef CONFIG_PM_SLEEP_SMP
168extern int freeze_secondary_cpus(int primary);
169extern void thaw_secondary_cpus(void);
170
171static inline int suspend_disable_secondary_cpus(void)
172{
173	int cpu = 0;
174
175	if (IS_ENABLED(CONFIG_PM_SLEEP_SMP_NONZERO_CPU))
176		cpu = -1;
177
178	return freeze_secondary_cpus(cpu);
179}
180static inline void suspend_enable_secondary_cpus(void)
181{
182	return thaw_secondary_cpus();
183}
184
185#else /* !CONFIG_PM_SLEEP_SMP */
186static inline void thaw_secondary_cpus(void) {}
187static inline int suspend_disable_secondary_cpus(void) { return 0; }
188static inline void suspend_enable_secondary_cpus(void) { }
189#endif /* !CONFIG_PM_SLEEP_SMP */
190
191void __noreturn cpu_startup_entry(enum cpuhp_state state);
192
193void cpu_idle_poll_ctrl(bool enable);
194
195bool cpu_in_idle(unsigned long pc);
196
197void arch_cpu_idle(void);
198void arch_cpu_idle_prepare(void);
199void arch_cpu_idle_enter(void);
200void arch_cpu_idle_exit(void);
201void arch_tick_broadcast_enter(void);
202void arch_tick_broadcast_exit(void);
203void __noreturn arch_cpu_idle_dead(void);
204
205#ifdef CONFIG_ARCH_HAS_CPU_FINALIZE_INIT
206void arch_cpu_finalize_init(void);
207#else
208static inline void arch_cpu_finalize_init(void) { }
209#endif
210
211void play_idle_precise(u64 duration_ns, u64 latency_ns);
212
213static inline void play_idle(unsigned long duration_us)
214{
215	play_idle_precise(duration_us * NSEC_PER_USEC, U64_MAX);
216}
217
218#ifdef CONFIG_HOTPLUG_CPU
219void cpuhp_report_idle_dead(void);
220#else
221static inline void cpuhp_report_idle_dead(void) { }
222#endif /* #ifdef CONFIG_HOTPLUG_CPU */
223
224extern bool cpu_mitigations_off(void);
225extern bool cpu_mitigations_auto_nosmt(void);
226
227#endif /* _LINUX_CPU_H_ */
228