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