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
22 struct device;
23 struct device_node;
24 struct attribute_group;
25
26 struct cpu {
27 int node_id; /* The node which contains the CPU */
28 int hotpluggable; /* creates sysfs control file if hotpluggable */
29 struct device dev;
30 };
31
32 extern void boot_cpu_init(void);
33 extern void boot_cpu_hotplug_init(void);
34 extern void cpu_init(void);
35 extern void trap_init(void);
36
37 extern int register_cpu(struct cpu *cpu, int num);
38 extern struct device *get_cpu_device(unsigned cpu);
39 extern bool cpu_is_hotpluggable(unsigned cpu);
40 extern bool arch_match_cpu_phys_id(int cpu, u64 phys_id);
41 extern bool arch_find_n_match_cpu_physical_id(struct device_node *cpun,
42 int cpu, unsigned int *thread);
43
44 extern int cpu_add_dev_attr(struct device_attribute *attr);
45 extern void cpu_remove_dev_attr(struct device_attribute *attr);
46
47 extern int cpu_add_dev_attr_group(struct attribute_group *attrs);
48 extern void cpu_remove_dev_attr_group(struct attribute_group *attrs);
49
50 extern ssize_t cpu_show_meltdown(struct device *dev,
51 struct device_attribute *attr, char *buf);
52 extern ssize_t cpu_show_spectre_v1(struct device *dev,
53 struct device_attribute *attr, char *buf);
54 extern ssize_t cpu_show_spectre_v2(struct device *dev,
55 struct device_attribute *attr, char *buf);
56 extern ssize_t cpu_show_spec_store_bypass(struct device *dev,
57 struct device_attribute *attr, char *buf);
58 extern ssize_t cpu_show_l1tf(struct device *dev,
59 struct device_attribute *attr, char *buf);
60 extern ssize_t cpu_show_mds(struct device *dev,
61 struct device_attribute *attr, char *buf);
62 extern ssize_t cpu_show_tsx_async_abort(struct device *dev,
63 struct device_attribute *attr,
64 char *buf);
65 extern ssize_t cpu_show_itlb_multihit(struct device *dev,
66 struct device_attribute *attr, char *buf);
67
68 extern __printf(4, 5)
69 struct device *cpu_device_create(struct device *parent, void *drvdata,
70 const struct attribute_group **groups,
71 const char *fmt, ...);
72 #ifdef CONFIG_HOTPLUG_CPU
73 extern void unregister_cpu(struct cpu *cpu);
74 extern ssize_t arch_cpu_probe(const char *, size_t);
75 extern ssize_t arch_cpu_release(const char *, size_t);
76 #endif
77 struct notifier_block;
78
79 #define CPU_ONLINE 0x0002 /* CPU (unsigned)v is up */
80 #define CPU_UP_PREPARE 0x0003 /* CPU (unsigned)v coming up */
81 #define CPU_DEAD 0x0007 /* CPU (unsigned)v dead */
82 #define CPU_POST_DEAD 0x0009 /* CPU (unsigned)v dead, cpu_hotplug
83 * lock is dropped */
84 #define CPU_BROKEN 0x000B /* CPU (unsigned)v did not die properly,
85 * perhaps due to preemption. */
86
87 /* Used for CPU hotplug events occurring while tasks are frozen due to a suspend
88 * operation in progress
89 */
90 #define CPU_TASKS_FROZEN 0x0010
91
92 #define CPU_ONLINE_FROZEN (CPU_ONLINE | CPU_TASKS_FROZEN)
93 #define CPU_UP_PREPARE_FROZEN (CPU_UP_PREPARE | CPU_TASKS_FROZEN)
94 #define CPU_UP_CANCELED_FROZEN (CPU_UP_CANCELED | CPU_TASKS_FROZEN)
95 #define CPU_DOWN_PREPARE_FROZEN (CPU_DOWN_PREPARE | CPU_TASKS_FROZEN)
96 #define CPU_DOWN_FAILED_FROZEN (CPU_DOWN_FAILED | CPU_TASKS_FROZEN)
97 #define CPU_DEAD_FROZEN (CPU_DEAD | CPU_TASKS_FROZEN)
98
99 #ifdef CONFIG_SMP
100 extern bool cpuhp_tasks_frozen;
101 int cpu_up(unsigned int cpu);
102 void notify_cpu_starting(unsigned int cpu);
103 extern void cpu_maps_update_begin(void);
104 extern void cpu_maps_update_done(void);
105
106 #else /* CONFIG_SMP */
107 #define cpuhp_tasks_frozen 0
108
cpu_maps_update_begin(void)109 static inline void cpu_maps_update_begin(void)
110 {
111 }
112
cpu_maps_update_done(void)113 static inline void cpu_maps_update_done(void)
114 {
115 }
116
117 #endif /* CONFIG_SMP */
118 extern struct bus_type cpu_subsys;
119
120 #ifdef CONFIG_HOTPLUG_CPU
121 extern void cpus_write_lock(void);
122 extern void cpus_write_unlock(void);
123 extern void cpus_read_lock(void);
124 extern void cpus_read_unlock(void);
125 extern void lockdep_assert_cpus_held(void);
126 extern void cpu_hotplug_disable(void);
127 extern void cpu_hotplug_enable(void);
128 void clear_tasks_mm_cpumask(int cpu);
129 int cpu_down(unsigned int cpu);
130
131 #else /* CONFIG_HOTPLUG_CPU */
132
cpus_write_lock(void)133 static inline void cpus_write_lock(void) { }
cpus_write_unlock(void)134 static inline void cpus_write_unlock(void) { }
cpus_read_lock(void)135 static inline void cpus_read_lock(void) { }
cpus_read_unlock(void)136 static inline void cpus_read_unlock(void) { }
lockdep_assert_cpus_held(void)137 static inline void lockdep_assert_cpus_held(void) { }
cpu_hotplug_disable(void)138 static inline void cpu_hotplug_disable(void) { }
cpu_hotplug_enable(void)139 static inline void cpu_hotplug_enable(void) { }
140 #endif /* !CONFIG_HOTPLUG_CPU */
141
142 /* Wrappers which go away once all code is converted */
cpu_hotplug_begin(void)143 static inline void cpu_hotplug_begin(void) { cpus_write_lock(); }
cpu_hotplug_done(void)144 static inline void cpu_hotplug_done(void) { cpus_write_unlock(); }
get_online_cpus(void)145 static inline void get_online_cpus(void) { cpus_read_lock(); }
put_online_cpus(void)146 static inline void put_online_cpus(void) { cpus_read_unlock(); }
147
148 #ifdef CONFIG_PM_SLEEP_SMP
149 extern int freeze_secondary_cpus(int primary);
disable_nonboot_cpus(void)150 static inline int disable_nonboot_cpus(void)
151 {
152 return freeze_secondary_cpus(0);
153 }
154 extern void enable_nonboot_cpus(void);
155 #else /* !CONFIG_PM_SLEEP_SMP */
disable_nonboot_cpus(void)156 static inline int disable_nonboot_cpus(void) { return 0; }
enable_nonboot_cpus(void)157 static inline void enable_nonboot_cpus(void) {}
158 #endif /* !CONFIG_PM_SLEEP_SMP */
159
160 void cpu_startup_entry(enum cpuhp_state state);
161
162 void cpu_idle_poll_ctrl(bool enable);
163
164 /* Attach to any functions which should be considered cpuidle. */
165 #define __cpuidle __attribute__((__section__(".cpuidle.text")))
166
167 bool cpu_in_idle(unsigned long pc);
168
169 void arch_cpu_idle(void);
170 void arch_cpu_idle_prepare(void);
171 void arch_cpu_idle_enter(void);
172 void arch_cpu_idle_exit(void);
173 void arch_cpu_idle_dead(void);
174
175 int cpu_report_state(int cpu);
176 int cpu_check_up_prepare(int cpu);
177 void cpu_set_state_online(int cpu);
178 void play_idle(unsigned long duration_ms);
179
180 #ifdef CONFIG_HOTPLUG_CPU
181 bool cpu_wait_death(unsigned int cpu, int seconds);
182 bool cpu_report_death(void);
183 void cpuhp_report_idle_dead(void);
184 #else
cpuhp_report_idle_dead(void)185 static inline void cpuhp_report_idle_dead(void) { }
186 #endif /* #ifdef CONFIG_HOTPLUG_CPU */
187
188 enum cpuhp_smt_control {
189 CPU_SMT_ENABLED,
190 CPU_SMT_DISABLED,
191 CPU_SMT_FORCE_DISABLED,
192 CPU_SMT_NOT_SUPPORTED,
193 };
194
195 #if defined(CONFIG_SMP) && defined(CONFIG_HOTPLUG_SMT)
196 extern enum cpuhp_smt_control cpu_smt_control;
197 extern void cpu_smt_disable(bool force);
198 extern void cpu_smt_check_topology(void);
199 extern int cpuhp_smt_enable(void);
200 extern int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval);
201 #else
202 # define cpu_smt_control (CPU_SMT_ENABLED)
cpu_smt_disable(bool force)203 static inline void cpu_smt_disable(bool force) { }
cpu_smt_check_topology(void)204 static inline void cpu_smt_check_topology(void) { }
cpuhp_smt_enable(void)205 static inline int cpuhp_smt_enable(void) { return 0; }
cpuhp_smt_disable(enum cpuhp_smt_control ctrlval)206 static inline int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval) { return 0; }
207 #endif
208
209 extern bool cpu_mitigations_off(void);
210 extern bool cpu_mitigations_auto_nosmt(void);
211
212 #endif /* _LINUX_CPU_H_ */
213