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
23 struct device;
24 struct device_node;
25 struct attribute_group;
26
27 struct 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
33 extern void boot_cpu_init(void);
34 extern void boot_cpu_hotplug_init(void);
35 extern void cpu_init(void);
36 extern void trap_init(void);
37
38 extern int register_cpu(struct cpu *cpu, int num);
39 extern struct device *get_cpu_device(unsigned cpu);
40 extern bool cpu_is_hotpluggable(unsigned cpu);
41 extern bool arch_match_cpu_phys_id(int cpu, u64 phys_id);
42 extern bool arch_find_n_match_cpu_physical_id(struct device_node *cpun,
43 int cpu, unsigned int *thread);
44
45 extern int cpu_add_dev_attr(struct device_attribute *attr);
46 extern void cpu_remove_dev_attr(struct device_attribute *attr);
47
48 extern int cpu_add_dev_attr_group(struct attribute_group *attrs);
49 extern void cpu_remove_dev_attr_group(struct attribute_group *attrs);
50
51 extern ssize_t cpu_show_meltdown(struct device *dev,
52 struct device_attribute *attr, char *buf);
53 extern ssize_t cpu_show_spectre_v1(struct device *dev,
54 struct device_attribute *attr, char *buf);
55 extern ssize_t cpu_show_spectre_v2(struct device *dev,
56 struct device_attribute *attr, char *buf);
57 extern ssize_t cpu_show_spec_store_bypass(struct device *dev,
58 struct device_attribute *attr, char *buf);
59 extern ssize_t cpu_show_l1tf(struct device *dev,
60 struct device_attribute *attr, char *buf);
61 extern ssize_t cpu_show_mds(struct device *dev,
62 struct device_attribute *attr, char *buf);
63 extern ssize_t cpu_show_tsx_async_abort(struct device *dev,
64 struct device_attribute *attr,
65 char *buf);
66 extern ssize_t cpu_show_itlb_multihit(struct device *dev,
67 struct device_attribute *attr, char *buf);
68 extern ssize_t cpu_show_srbds(struct device *dev, struct device_attribute *attr, char *buf);
69 extern ssize_t cpu_show_mmio_stale_data(struct device *dev,
70 struct device_attribute *attr,
71 char *buf);
72 extern ssize_t cpu_show_retbleed(struct device *dev,
73 struct device_attribute *attr, char *buf);
74 extern ssize_t cpu_show_spec_rstack_overflow(struct device *dev,
75 struct device_attribute *attr, char *buf);
76 extern ssize_t cpu_show_gds(struct device *dev,
77 struct device_attribute *attr, char *buf);
78 extern ssize_t cpu_show_reg_file_data_sampling(struct device *dev,
79 struct device_attribute *attr, char *buf);
80
81 extern __printf(4, 5)
82 struct device *cpu_device_create(struct device *parent, void *drvdata,
83 const struct attribute_group **groups,
84 const char *fmt, ...);
85 extern bool arch_cpu_is_hotpluggable(int cpu);
86 extern int arch_register_cpu(int cpu);
87 extern void arch_unregister_cpu(int cpu);
88 #ifdef CONFIG_HOTPLUG_CPU
89 extern void unregister_cpu(struct cpu *cpu);
90 extern ssize_t arch_cpu_probe(const char *, size_t);
91 extern ssize_t arch_cpu_release(const char *, size_t);
92 #endif
93
94 #ifdef CONFIG_GENERIC_CPU_DEVICES
95 DECLARE_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
110 extern bool cpuhp_tasks_frozen;
111 int add_cpu(unsigned int cpu);
112 int cpu_device_up(struct device *dev);
113 void notify_cpu_starting(unsigned int cpu);
114 extern void cpu_maps_update_begin(void);
115 extern void cpu_maps_update_done(void);
116 int bringup_hibernate_cpu(unsigned int sleep_cpu);
117 void bringup_nonboot_cpus(unsigned int max_cpus);
118
119 #else /* CONFIG_SMP */
120 #define cpuhp_tasks_frozen 0
121
122 static inline void cpu_maps_update_begin(void)
123 {
124 }
125
126 static inline void cpu_maps_update_done(void)
127 {
128 }
129
130 static inline int add_cpu(unsigned int cpu) { return 0;}
131
132 #endif /* CONFIG_SMP */
133 extern const struct bus_type cpu_subsys;
134
135 #ifdef CONFIG_PM_SLEEP_SMP
136 extern int freeze_secondary_cpus(int primary);
137 extern void thaw_secondary_cpus(void);
138
139 static inline int suspend_disable_secondary_cpus(void)
140 {
141 int cpu = 0;
142
143 if (IS_ENABLED(CONFIG_PM_SLEEP_SMP_NONZERO_CPU))
144 cpu = -1;
145
146 return freeze_secondary_cpus(cpu);
147 }
148 static inline void suspend_enable_secondary_cpus(void)
149 {
150 return thaw_secondary_cpus();
151 }
152
153 #else /* !CONFIG_PM_SLEEP_SMP */
154 static inline void thaw_secondary_cpus(void) {}
155 static inline int suspend_disable_secondary_cpus(void) { return 0; }
156 static inline void suspend_enable_secondary_cpus(void) { }
157 #endif /* !CONFIG_PM_SLEEP_SMP */
158
159 void __noreturn cpu_startup_entry(enum cpuhp_state state);
160
161 void cpu_idle_poll_ctrl(bool enable);
162
163 bool cpu_in_idle(unsigned long pc);
164
165 void arch_cpu_idle(void);
166 void arch_cpu_idle_prepare(void);
167 void arch_cpu_idle_enter(void);
168 void arch_cpu_idle_exit(void);
169 void arch_tick_broadcast_enter(void);
170 void arch_tick_broadcast_exit(void);
171 void __noreturn arch_cpu_idle_dead(void);
172
173 #ifdef CONFIG_ARCH_HAS_CPU_FINALIZE_INIT
174 void arch_cpu_finalize_init(void);
175 #else
176 static inline void arch_cpu_finalize_init(void) { }
177 #endif
178
179 void play_idle_precise(u64 duration_ns, u64 latency_ns);
180
181 static inline void play_idle(unsigned long duration_us)
182 {
183 play_idle_precise(duration_us * NSEC_PER_USEC, U64_MAX);
184 }
185
186 #ifdef CONFIG_HOTPLUG_CPU
187 void cpuhp_report_idle_dead(void);
188 #else
189 static inline void cpuhp_report_idle_dead(void) { }
190 #endif /* #ifdef CONFIG_HOTPLUG_CPU */
191
192 #ifdef CONFIG_CPU_MITIGATIONS
193 extern bool cpu_mitigations_off(void);
194 extern bool cpu_mitigations_auto_nosmt(void);
195 #else
196 static inline bool cpu_mitigations_off(void)
197 {
198 return true;
199 }
200 static inline bool cpu_mitigations_auto_nosmt(void)
201 {
202 return false;
203 }
204 #endif
205
206 #endif /* _LINUX_CPU_H_ */
207
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