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 extern ssize_t cpu_show_srbds(struct device *dev, struct device_attribute *attr, char *buf);
68
69 extern __printf(4, 5)
70 struct device *cpu_device_create(struct device *parent, void *drvdata,
71 const struct attribute_group **groups,
72 const char *fmt, ...);
73 #ifdef CONFIG_HOTPLUG_CPU
74 extern void unregister_cpu(struct cpu *cpu);
75 extern ssize_t arch_cpu_probe(const char *, size_t);
76 extern ssize_t arch_cpu_release(const char *, size_t);
77 #endif
78
79 /*
80 * These states are not related to the core CPU hotplug mechanism. They are
81 * used by various (sub)architectures to track internal state
82 */
83 #define CPU_ONLINE 0x0002 /* CPU is up */
84 #define CPU_UP_PREPARE 0x0003 /* CPU coming up */
85 #define CPU_DEAD 0x0007 /* CPU dead */
86 #define CPU_DEAD_FROZEN 0x0008 /* CPU timed out on unplug */
87 #define CPU_POST_DEAD 0x0009 /* CPU successfully unplugged */
88 #define CPU_BROKEN 0x000B /* CPU did not die properly */
89
90 #ifdef CONFIG_SMP
91 extern bool cpuhp_tasks_frozen;
92 int add_cpu(unsigned int cpu);
93 int cpu_device_up(struct device *dev);
94 void notify_cpu_starting(unsigned int cpu);
95 extern void cpu_maps_update_begin(void);
96 extern void cpu_maps_update_done(void);
97 int bringup_hibernate_cpu(unsigned int sleep_cpu);
98 void bringup_nonboot_cpus(unsigned int setup_max_cpus);
99
100 #else /* CONFIG_SMP */
101 #define cpuhp_tasks_frozen 0
102
cpu_maps_update_begin(void)103 static inline void cpu_maps_update_begin(void)
104 {
105 }
106
cpu_maps_update_done(void)107 static inline void cpu_maps_update_done(void)
108 {
109 }
110
add_cpu(unsigned int cpu)111 static inline int add_cpu(unsigned int cpu) { return 0;}
112
113 #endif /* CONFIG_SMP */
114 extern struct bus_type cpu_subsys;
115
116 extern int lockdep_is_cpus_held(void);
117
118 #ifdef CONFIG_HOTPLUG_CPU
119 extern void cpus_write_lock(void);
120 extern void cpus_write_unlock(void);
121 extern void cpus_read_lock(void);
122 extern void cpus_read_unlock(void);
123 extern int cpus_read_trylock(void);
124 extern void lockdep_assert_cpus_held(void);
125 extern void cpu_hotplug_disable(void);
126 extern void cpu_hotplug_enable(void);
127 void clear_tasks_mm_cpumask(int cpu);
128 int remove_cpu(unsigned int cpu);
129 int cpu_device_down(struct device *dev);
130 extern void smp_shutdown_nonboot_cpus(unsigned int primary_cpu);
131
132 #else /* CONFIG_HOTPLUG_CPU */
133
cpus_write_lock(void)134 static inline void cpus_write_lock(void) { }
cpus_write_unlock(void)135 static inline void cpus_write_unlock(void) { }
cpus_read_lock(void)136 static inline void cpus_read_lock(void) { }
cpus_read_unlock(void)137 static inline void cpus_read_unlock(void) { }
cpus_read_trylock(void)138 static inline int cpus_read_trylock(void) { return true; }
lockdep_assert_cpus_held(void)139 static inline void lockdep_assert_cpus_held(void) { }
cpu_hotplug_disable(void)140 static inline void cpu_hotplug_disable(void) { }
cpu_hotplug_enable(void)141 static inline void cpu_hotplug_enable(void) { }
remove_cpu(unsigned int cpu)142 static inline int remove_cpu(unsigned int cpu) { return -EPERM; }
smp_shutdown_nonboot_cpus(unsigned int primary_cpu)143 static inline void smp_shutdown_nonboot_cpus(unsigned int primary_cpu) { }
144 #endif /* !CONFIG_HOTPLUG_CPU */
145
146 /* Wrappers which go away once all code is converted */
cpu_hotplug_begin(void)147 static inline void cpu_hotplug_begin(void) { cpus_write_lock(); }
cpu_hotplug_done(void)148 static inline void cpu_hotplug_done(void) { cpus_write_unlock(); }
get_online_cpus(void)149 static inline void get_online_cpus(void) { cpus_read_lock(); }
put_online_cpus(void)150 static inline void put_online_cpus(void) { cpus_read_unlock(); }
151
152 #ifdef CONFIG_PM_SLEEP_SMP
153 extern int freeze_secondary_cpus(int primary);
154 extern void thaw_secondary_cpus(void);
155
suspend_disable_secondary_cpus(void)156 static inline int suspend_disable_secondary_cpus(void)
157 {
158 int cpu = 0;
159
160 if (IS_ENABLED(CONFIG_PM_SLEEP_SMP_NONZERO_CPU))
161 cpu = -1;
162
163 return freeze_secondary_cpus(cpu);
164 }
suspend_enable_secondary_cpus(void)165 static inline void suspend_enable_secondary_cpus(void)
166 {
167 return thaw_secondary_cpus();
168 }
169
170 #else /* !CONFIG_PM_SLEEP_SMP */
thaw_secondary_cpus(void)171 static inline void thaw_secondary_cpus(void) {}
suspend_disable_secondary_cpus(void)172 static inline int suspend_disable_secondary_cpus(void) { return 0; }
suspend_enable_secondary_cpus(void)173 static inline void suspend_enable_secondary_cpus(void) { }
174 #endif /* !CONFIG_PM_SLEEP_SMP */
175
176 void cpu_startup_entry(enum cpuhp_state state);
177
178 void cpu_idle_poll_ctrl(bool enable);
179
180 /* Attach to any functions which should be considered cpuidle. */
181 #define __cpuidle __section(".cpuidle.text")
182
183 bool cpu_in_idle(unsigned long pc);
184
185 void arch_cpu_idle(void);
186 void arch_cpu_idle_prepare(void);
187 void arch_cpu_idle_enter(void);
188 void arch_cpu_idle_exit(void);
189 void arch_cpu_idle_dead(void);
190
191 int cpu_report_state(int cpu);
192 int cpu_check_up_prepare(int cpu);
193 void cpu_set_state_online(int cpu);
194 void play_idle_precise(u64 duration_ns, u64 latency_ns);
195
play_idle(unsigned long duration_us)196 static inline void play_idle(unsigned long duration_us)
197 {
198 play_idle_precise(duration_us * NSEC_PER_USEC, U64_MAX);
199 }
200
201 #ifdef CONFIG_HOTPLUG_CPU
202 bool cpu_wait_death(unsigned int cpu, int seconds);
203 bool cpu_report_death(void);
204 void cpuhp_report_idle_dead(void);
205 #else
cpuhp_report_idle_dead(void)206 static inline void cpuhp_report_idle_dead(void) { }
207 #endif /* #ifdef CONFIG_HOTPLUG_CPU */
208
209 enum cpuhp_smt_control {
210 CPU_SMT_ENABLED,
211 CPU_SMT_DISABLED,
212 CPU_SMT_FORCE_DISABLED,
213 CPU_SMT_NOT_SUPPORTED,
214 CPU_SMT_NOT_IMPLEMENTED,
215 };
216
217 #if defined(CONFIG_SMP) && defined(CONFIG_HOTPLUG_SMT)
218 extern enum cpuhp_smt_control cpu_smt_control;
219 extern void cpu_smt_disable(bool force);
220 extern void cpu_smt_check_topology(void);
221 extern bool cpu_smt_possible(void);
222 extern int cpuhp_smt_enable(void);
223 extern int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval);
224 #else
225 # define cpu_smt_control (CPU_SMT_NOT_IMPLEMENTED)
cpu_smt_disable(bool force)226 static inline void cpu_smt_disable(bool force) { }
cpu_smt_check_topology(void)227 static inline void cpu_smt_check_topology(void) { }
cpu_smt_possible(void)228 static inline bool cpu_smt_possible(void) { return false; }
cpuhp_smt_enable(void)229 static inline int cpuhp_smt_enable(void) { return 0; }
cpuhp_smt_disable(enum cpuhp_smt_control ctrlval)230 static inline int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval) { return 0; }
231 #endif
232
233 extern bool cpu_mitigations_off(void);
234 extern bool cpu_mitigations_auto_nosmt(void);
235
236 #endif /* _LINUX_CPU_H_ */
237