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 #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
81 extern __printf(4, 5)
82 struct device *cpu_device_create(struct device *parent, void *drvdata,
83 const struct attribute_group **groups,
84 const char *fmt, ...);
85 extern int arch_register_cpu(int cpu);
86 extern void arch_unregister_cpu(int cpu);
87 #ifdef CONFIG_HOTPLUG_CPU
88 extern void unregister_cpu(struct cpu *cpu);
89 extern ssize_t arch_cpu_probe(const char *, size_t);
90 extern ssize_t arch_cpu_release(const char *, size_t);
91 #endif
92
93 /*
94 * These states are not related to the core CPU hotplug mechanism. They are
95 * used by various (sub)architectures to track internal state
96 */
97 #define CPU_ONLINE 0x0002 /* CPU is up */
98 #define CPU_UP_PREPARE 0x0003 /* CPU coming up */
99 #define CPU_DEAD 0x0007 /* CPU dead */
100 #define CPU_DEAD_FROZEN 0x0008 /* CPU timed out on unplug */
101 #define CPU_POST_DEAD 0x0009 /* CPU successfully unplugged */
102 #define CPU_BROKEN 0x000B /* CPU did not die properly */
103
104 #ifdef CONFIG_SMP
105 extern bool cpuhp_tasks_frozen;
106 int add_cpu(unsigned int cpu);
107 int cpu_device_up(struct device *dev);
108 void notify_cpu_starting(unsigned int cpu);
109 extern void cpu_maps_update_begin(void);
110 extern void cpu_maps_update_done(void);
111 int bringup_hibernate_cpu(unsigned int sleep_cpu);
112 void bringup_nonboot_cpus(unsigned int setup_max_cpus);
113
114 #else /* CONFIG_SMP */
115 #define cpuhp_tasks_frozen 0
116
cpu_maps_update_begin(void)117 static inline void cpu_maps_update_begin(void)
118 {
119 }
120
cpu_maps_update_done(void)121 static inline void cpu_maps_update_done(void)
122 {
123 }
124
add_cpu(unsigned int cpu)125 static inline int add_cpu(unsigned int cpu) { return 0;}
126
127 #endif /* CONFIG_SMP */
128 extern struct bus_type cpu_subsys;
129
130 extern int lockdep_is_cpus_held(void);
131
132 #ifdef CONFIG_HOTPLUG_CPU
133 extern void cpus_write_lock(void);
134 extern void cpus_write_unlock(void);
135 extern void cpus_read_lock(void);
136 extern void cpus_read_unlock(void);
137 extern int cpus_read_trylock(void);
138 extern void lockdep_assert_cpus_held(void);
139 extern void cpu_hotplug_disable(void);
140 extern void cpu_hotplug_enable(void);
141 void clear_tasks_mm_cpumask(int cpu);
142 int remove_cpu(unsigned int cpu);
143 int cpu_device_down(struct device *dev);
144 extern void smp_shutdown_nonboot_cpus(unsigned int primary_cpu);
145
146 #else /* CONFIG_HOTPLUG_CPU */
147
cpus_write_lock(void)148 static inline void cpus_write_lock(void) { }
cpus_write_unlock(void)149 static inline void cpus_write_unlock(void) { }
cpus_read_lock(void)150 static inline void cpus_read_lock(void) { }
cpus_read_unlock(void)151 static inline void cpus_read_unlock(void) { }
cpus_read_trylock(void)152 static inline int cpus_read_trylock(void) { return true; }
lockdep_assert_cpus_held(void)153 static inline void lockdep_assert_cpus_held(void) { }
cpu_hotplug_disable(void)154 static inline void cpu_hotplug_disable(void) { }
cpu_hotplug_enable(void)155 static inline void cpu_hotplug_enable(void) { }
remove_cpu(unsigned int cpu)156 static inline int remove_cpu(unsigned int cpu) { return -EPERM; }
smp_shutdown_nonboot_cpus(unsigned int primary_cpu)157 static inline void smp_shutdown_nonboot_cpus(unsigned int primary_cpu) { }
158 #endif /* !CONFIG_HOTPLUG_CPU */
159
160 DEFINE_LOCK_GUARD_0(cpus_read_lock, cpus_read_lock(), cpus_read_unlock())
161
162 #ifdef CONFIG_PM_SLEEP_SMP
163 extern int freeze_secondary_cpus(int primary);
164 extern void thaw_secondary_cpus(void);
165
suspend_disable_secondary_cpus(void)166 static inline int suspend_disable_secondary_cpus(void)
167 {
168 int cpu = 0;
169
170 if (IS_ENABLED(CONFIG_PM_SLEEP_SMP_NONZERO_CPU))
171 cpu = -1;
172
173 return freeze_secondary_cpus(cpu);
174 }
suspend_enable_secondary_cpus(void)175 static inline void suspend_enable_secondary_cpus(void)
176 {
177 return thaw_secondary_cpus();
178 }
179
180 #else /* !CONFIG_PM_SLEEP_SMP */
181 static inline void thaw_secondary_cpus(void) {}
182 static inline int suspend_disable_secondary_cpus(void) { return 0; }
183 static inline void suspend_enable_secondary_cpus(void) { }
184 #endif /* !CONFIG_PM_SLEEP_SMP */
185
186 void __noreturn cpu_startup_entry(enum cpuhp_state state);
187
188 void cpu_idle_poll_ctrl(bool enable);
189
190 bool cpu_in_idle(unsigned long pc);
191
192 void arch_cpu_idle(void);
193 void arch_cpu_idle_prepare(void);
194 void arch_cpu_idle_enter(void);
195 void arch_cpu_idle_exit(void);
196 void __noreturn arch_cpu_idle_dead(void);
197
198 #ifdef CONFIG_ARCH_HAS_CPU_FINALIZE_INIT
199 void arch_cpu_finalize_init(void);
200 #else
arch_cpu_finalize_init(void)201 static inline void arch_cpu_finalize_init(void) { }
202 #endif
203
204 void play_idle_precise(u64 duration_ns, u64 latency_ns);
205
play_idle(unsigned long duration_us)206 static inline void play_idle(unsigned long duration_us)
207 {
208 play_idle_precise(duration_us * NSEC_PER_USEC, U64_MAX);
209 }
210
211 #ifdef CONFIG_HOTPLUG_CPU
212 void cpuhp_report_idle_dead(void);
213 #else
cpuhp_report_idle_dead(void)214 static inline void cpuhp_report_idle_dead(void) { }
215 #endif /* #ifdef CONFIG_HOTPLUG_CPU */
216
217 #ifdef CONFIG_CPU_MITIGATIONS
218 extern bool cpu_mitigations_off(void);
219 extern bool cpu_mitigations_auto_nosmt(void);
220 #else
cpu_mitigations_off(void)221 static inline bool cpu_mitigations_off(void)
222 {
223 return true;
224 }
cpu_mitigations_auto_nosmt(void)225 static inline bool cpu_mitigations_auto_nosmt(void)
226 {
227 return false;
228 }
229 #endif
230
231 #endif /* _LINUX_CPU_H_ */
232