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
61 extern __printf(4, 5)
62 struct device *cpu_device_create(struct device *parent, void *drvdata,
63 const struct attribute_group **groups,
64 const char *fmt, ...);
65 #ifdef CONFIG_HOTPLUG_CPU
66 extern void unregister_cpu(struct cpu *cpu);
67 extern ssize_t arch_cpu_probe(const char *, size_t);
68 extern ssize_t arch_cpu_release(const char *, size_t);
69 #endif
70
71 /*
72 * These states are not related to the core CPU hotplug mechanism. They are
73 * used by various (sub)architectures to track internal state
74 */
75 #define CPU_ONLINE 0x0002 /* CPU is up */
76 #define CPU_UP_PREPARE 0x0003 /* CPU coming up */
77 #define CPU_DEAD 0x0007 /* CPU dead */
78 #define CPU_DEAD_FROZEN 0x0008 /* CPU timed out on unplug */
79 #define CPU_POST_DEAD 0x0009 /* CPU successfully unplugged */
80 #define CPU_BROKEN 0x000B /* CPU did not die properly */
81
82 #ifdef CONFIG_SMP
83 extern bool cpuhp_tasks_frozen;
84 int cpu_up(unsigned int cpu);
85 void notify_cpu_starting(unsigned int cpu);
86 extern void cpu_maps_update_begin(void);
87 extern void cpu_maps_update_done(void);
88
89 #else /* CONFIG_SMP */
90 #define cpuhp_tasks_frozen 0
91
cpu_maps_update_begin(void)92 static inline void cpu_maps_update_begin(void)
93 {
94 }
95
cpu_maps_update_done(void)96 static inline void cpu_maps_update_done(void)
97 {
98 }
99
100 #endif /* CONFIG_SMP */
101 extern struct bus_type cpu_subsys;
102
103 #ifdef CONFIG_HOTPLUG_CPU
104 extern void cpus_write_lock(void);
105 extern void cpus_write_unlock(void);
106 extern void cpus_read_lock(void);
107 extern void cpus_read_unlock(void);
108 extern int cpus_read_trylock(void);
109 extern void lockdep_assert_cpus_held(void);
110 extern void cpu_hotplug_disable(void);
111 extern void cpu_hotplug_enable(void);
112 void clear_tasks_mm_cpumask(int cpu);
113 int cpu_down(unsigned int cpu);
114
115 #else /* CONFIG_HOTPLUG_CPU */
116
cpus_write_lock(void)117 static inline void cpus_write_lock(void) { }
cpus_write_unlock(void)118 static inline void cpus_write_unlock(void) { }
cpus_read_lock(void)119 static inline void cpus_read_lock(void) { }
cpus_read_unlock(void)120 static inline void cpus_read_unlock(void) { }
cpus_read_trylock(void)121 static inline int cpus_read_trylock(void) { return true; }
lockdep_assert_cpus_held(void)122 static inline void lockdep_assert_cpus_held(void) { }
cpu_hotplug_disable(void)123 static inline void cpu_hotplug_disable(void) { }
cpu_hotplug_enable(void)124 static inline void cpu_hotplug_enable(void) { }
125 #endif /* !CONFIG_HOTPLUG_CPU */
126
127 /* Wrappers which go away once all code is converted */
cpu_hotplug_begin(void)128 static inline void cpu_hotplug_begin(void) { cpus_write_lock(); }
cpu_hotplug_done(void)129 static inline void cpu_hotplug_done(void) { cpus_write_unlock(); }
get_online_cpus(void)130 static inline void get_online_cpus(void) { cpus_read_lock(); }
put_online_cpus(void)131 static inline void put_online_cpus(void) { cpus_read_unlock(); }
132
133 #ifdef CONFIG_PM_SLEEP_SMP
134 extern int freeze_secondary_cpus(int primary);
disable_nonboot_cpus(void)135 static inline int disable_nonboot_cpus(void)
136 {
137 return freeze_secondary_cpus(0);
138 }
139 extern void enable_nonboot_cpus(void);
140 #else /* !CONFIG_PM_SLEEP_SMP */
disable_nonboot_cpus(void)141 static inline int disable_nonboot_cpus(void) { return 0; }
enable_nonboot_cpus(void)142 static inline void enable_nonboot_cpus(void) {}
143 #endif /* !CONFIG_PM_SLEEP_SMP */
144
145 void cpu_startup_entry(enum cpuhp_state state);
146
147 void cpu_idle_poll_ctrl(bool enable);
148
149 /* Attach to any functions which should be considered cpuidle. */
150 #define __cpuidle __attribute__((__section__(".cpuidle.text")))
151
152 bool cpu_in_idle(unsigned long pc);
153
154 void arch_cpu_idle(void);
155 void arch_cpu_idle_prepare(void);
156 void arch_cpu_idle_enter(void);
157 void arch_cpu_idle_exit(void);
158 void arch_cpu_idle_dead(void);
159
160 int cpu_report_state(int cpu);
161 int cpu_check_up_prepare(int cpu);
162 void cpu_set_state_online(int cpu);
163 void play_idle(unsigned long duration_ms);
164
165 #ifdef CONFIG_HOTPLUG_CPU
166 bool cpu_wait_death(unsigned int cpu, int seconds);
167 bool cpu_report_death(void);
168 void cpuhp_report_idle_dead(void);
169 #else
cpuhp_report_idle_dead(void)170 static inline void cpuhp_report_idle_dead(void) { }
171 #endif /* #ifdef CONFIG_HOTPLUG_CPU */
172
173 enum cpuhp_smt_control {
174 CPU_SMT_ENABLED,
175 CPU_SMT_DISABLED,
176 CPU_SMT_FORCE_DISABLED,
177 CPU_SMT_NOT_SUPPORTED,
178 };
179
180 #if defined(CONFIG_SMP) && defined(CONFIG_HOTPLUG_SMT)
181 extern enum cpuhp_smt_control cpu_smt_control;
182 extern void cpu_smt_disable(bool force);
183 extern void cpu_smt_check_topology_early(void);
184 extern void cpu_smt_check_topology(void);
185 #else
186 # define cpu_smt_control (CPU_SMT_ENABLED)
cpu_smt_disable(bool force)187 static inline void cpu_smt_disable(bool force) { }
cpu_smt_check_topology_early(void)188 static inline void cpu_smt_check_topology_early(void) { }
cpu_smt_check_topology(void)189 static inline void cpu_smt_check_topology(void) { }
190 #endif
191
192 #endif /* _LINUX_CPU_H_ */
193
