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