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
78 /*
79 * These states are not related to the core CPU hotplug mechanism. They are
80 * used by various (sub)architectures to track internal state
81 */
82 #define CPU_ONLINE 0x0002 /* CPU is up */
83 #define CPU_UP_PREPARE 0x0003 /* CPU coming up */
84 #define CPU_DEAD 0x0007 /* CPU dead */
85 #define CPU_DEAD_FROZEN 0x0008 /* CPU timed out on unplug */
86 #define CPU_POST_DEAD 0x0009 /* CPU successfully unplugged */
87 #define CPU_BROKEN 0x000B /* CPU did not die properly */
88
89 #ifdef CONFIG_SMP
90 extern bool cpuhp_tasks_frozen;
91 int cpu_up(unsigned int cpu);
92 void notify_cpu_starting(unsigned int cpu);
93 extern void cpu_maps_update_begin(void);
94 extern void cpu_maps_update_done(void);
95
96 #else /* CONFIG_SMP */
97 #define cpuhp_tasks_frozen 0
98
cpu_maps_update_begin(void)99 static inline void cpu_maps_update_begin(void)
100 {
101 }
102
cpu_maps_update_done(void)103 static inline void cpu_maps_update_done(void)
104 {
105 }
106
107 #endif /* CONFIG_SMP */
108 extern struct bus_type cpu_subsys;
109
110 #ifdef CONFIG_HOTPLUG_CPU
111 extern void cpus_write_lock(void);
112 extern void cpus_write_unlock(void);
113 extern void cpus_read_lock(void);
114 extern void cpus_read_unlock(void);
115 extern int cpus_read_trylock(void);
116 extern void lockdep_assert_cpus_held(void);
117 extern void cpu_hotplug_disable(void);
118 extern void cpu_hotplug_enable(void);
119 void clear_tasks_mm_cpumask(int cpu);
120 int cpu_down(unsigned int cpu);
121
122 #else /* CONFIG_HOTPLUG_CPU */
123
cpus_write_lock(void)124 static inline void cpus_write_lock(void) { }
cpus_write_unlock(void)125 static inline void cpus_write_unlock(void) { }
cpus_read_lock(void)126 static inline void cpus_read_lock(void) { }
cpus_read_unlock(void)127 static inline void cpus_read_unlock(void) { }
cpus_read_trylock(void)128 static inline int cpus_read_trylock(void) { return true; }
lockdep_assert_cpus_held(void)129 static inline void lockdep_assert_cpus_held(void) { }
cpu_hotplug_disable(void)130 static inline void cpu_hotplug_disable(void) { }
cpu_hotplug_enable(void)131 static inline void cpu_hotplug_enable(void) { }
132 #endif /* !CONFIG_HOTPLUG_CPU */
133
134 /* Wrappers which go away once all code is converted */
cpu_hotplug_begin(void)135 static inline void cpu_hotplug_begin(void) { cpus_write_lock(); }
cpu_hotplug_done(void)136 static inline void cpu_hotplug_done(void) { cpus_write_unlock(); }
get_online_cpus(void)137 static inline void get_online_cpus(void) { cpus_read_lock(); }
put_online_cpus(void)138 static inline void put_online_cpus(void) { cpus_read_unlock(); }
139
140 #ifdef CONFIG_PM_SLEEP_SMP
141 extern int freeze_secondary_cpus(int primary);
disable_nonboot_cpus(void)142 static inline int disable_nonboot_cpus(void)
143 {
144 return freeze_secondary_cpus(0);
145 }
146 extern void enable_nonboot_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 return enable_nonboot_cpus();
160 }
161
162 #else /* !CONFIG_PM_SLEEP_SMP */
disable_nonboot_cpus(void)163 static inline int disable_nonboot_cpus(void) { return 0; }
enable_nonboot_cpus(void)164 static inline void enable_nonboot_cpus(void) {}
suspend_disable_secondary_cpus(void)165 static inline int suspend_disable_secondary_cpus(void) { return 0; }
suspend_enable_secondary_cpus(void)166 static inline void suspend_enable_secondary_cpus(void) { }
167 #endif /* !CONFIG_PM_SLEEP_SMP */
168
169 void cpu_startup_entry(enum cpuhp_state state);
170
171 void cpu_idle_poll_ctrl(bool enable);
172
173 /* Attach to any functions which should be considered cpuidle. */
174 #define __cpuidle __attribute__((__section__(".cpuidle.text")))
175
176 bool cpu_in_idle(unsigned long pc);
177
178 void arch_cpu_idle(void);
179 void arch_cpu_idle_prepare(void);
180 void arch_cpu_idle_enter(void);
181 void arch_cpu_idle_exit(void);
182 void arch_cpu_idle_dead(void);
183
184 int cpu_report_state(int cpu);
185 int cpu_check_up_prepare(int cpu);
186 void cpu_set_state_online(int cpu);
187 void play_idle(unsigned long duration_us);
188
189 #ifdef CONFIG_HOTPLUG_CPU
190 bool cpu_wait_death(unsigned int cpu, int seconds);
191 bool cpu_report_death(void);
192 void cpuhp_report_idle_dead(void);
193 #else
cpuhp_report_idle_dead(void)194 static inline void cpuhp_report_idle_dead(void) { }
195 #endif /* #ifdef CONFIG_HOTPLUG_CPU */
196
197 enum cpuhp_smt_control {
198 CPU_SMT_ENABLED,
199 CPU_SMT_DISABLED,
200 CPU_SMT_FORCE_DISABLED,
201 CPU_SMT_NOT_SUPPORTED,
202 CPU_SMT_NOT_IMPLEMENTED,
203 };
204
205 #if defined(CONFIG_SMP) && defined(CONFIG_HOTPLUG_SMT)
206 extern enum cpuhp_smt_control cpu_smt_control;
207 extern void cpu_smt_disable(bool force);
208 extern void cpu_smt_check_topology(void);
209 extern bool cpu_smt_possible(void);
210 extern int cpuhp_smt_enable(void);
211 extern int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval);
212 #else
213 # define cpu_smt_control (CPU_SMT_NOT_IMPLEMENTED)
cpu_smt_disable(bool force)214 static inline void cpu_smt_disable(bool force) { }
cpu_smt_check_topology(void)215 static inline void cpu_smt_check_topology(void) { }
cpu_smt_possible(void)216 static inline bool cpu_smt_possible(void) { return false; }
cpuhp_smt_enable(void)217 static inline int cpuhp_smt_enable(void) { return 0; }
cpuhp_smt_disable(enum cpuhp_smt_control ctrlval)218 static inline int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval) { return 0; }
219 #endif
220
221 extern bool cpu_mitigations_off(void);
222 extern bool cpu_mitigations_auto_nosmt(void);
223
224 #endif /* _LINUX_CPU_H_ */
225
