xref: /linux/include/linux/cpu.h (revision 223ba8ee0a3986718c874b66ed24e7f87f6b8124)
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/cpuhotplug.h>
20 #include <linux/cpuhplock.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 extern ssize_t cpu_show_ghostwrite(struct device *dev, struct device_attribute *attr, char *buf);
81 extern ssize_t cpu_show_old_microcode(struct device *dev,
82 				      struct device_attribute *attr, char *buf);
83 extern ssize_t cpu_show_indirect_target_selection(struct device *dev,
84 						  struct device_attribute *attr, char *buf);
85 extern ssize_t cpu_show_tsa(struct device *dev, struct device_attribute *attr, char *buf);
86 extern ssize_t cpu_show_vmscape(struct device *dev, struct device_attribute *attr, char *buf);
87 
88 extern __printf(4, 5)
89 struct device *cpu_device_create(struct device *parent, void *drvdata,
90 				 const struct attribute_group **groups,
91 				 const char *fmt, ...);
92 extern bool arch_cpu_is_hotpluggable(int cpu);
93 extern int arch_register_cpu(int cpu);
94 extern void arch_unregister_cpu(int cpu);
95 #ifdef CONFIG_HOTPLUG_CPU
96 extern void unregister_cpu(struct cpu *cpu);
97 extern ssize_t arch_cpu_probe(const char *, size_t);
98 extern ssize_t arch_cpu_release(const char *, size_t);
99 #endif
100 
101 #ifdef CONFIG_GENERIC_CPU_DEVICES
102 DECLARE_PER_CPU(struct cpu, cpu_devices);
103 #endif
104 
105 /*
106  * These states are not related to the core CPU hotplug mechanism. They are
107  * used by various (sub)architectures to track internal state
108  */
109 #define CPU_ONLINE		0x0002 /* CPU is up */
110 #define CPU_UP_PREPARE		0x0003 /* CPU coming up */
111 #define CPU_DEAD		0x0007 /* CPU dead */
112 #define CPU_DEAD_FROZEN		0x0008 /* CPU timed out on unplug */
113 #define CPU_POST_DEAD		0x0009 /* CPU successfully unplugged */
114 #define CPU_BROKEN		0x000B /* CPU did not die properly */
115 
116 #ifdef CONFIG_SMP
117 extern bool cpuhp_tasks_frozen;
118 int add_cpu(unsigned int cpu);
119 int cpu_device_up(struct device *dev);
120 void notify_cpu_starting(unsigned int cpu);
121 extern void cpu_maps_update_begin(void);
122 extern void cpu_maps_update_done(void);
123 int bringup_hibernate_cpu(unsigned int sleep_cpu);
124 void bringup_nonboot_cpus(unsigned int max_cpus);
125 int arch_cpu_rescan_dead_smt_siblings(void);
126 
127 #else	/* CONFIG_SMP */
128 #define cpuhp_tasks_frozen	0
129 
cpu_maps_update_begin(void)130 static inline void cpu_maps_update_begin(void)
131 {
132 }
133 
cpu_maps_update_done(void)134 static inline void cpu_maps_update_done(void)
135 {
136 }
137 
add_cpu(unsigned int cpu)138 static inline int add_cpu(unsigned int cpu) { return 0;}
139 
arch_cpu_rescan_dead_smt_siblings(void)140 static inline int arch_cpu_rescan_dead_smt_siblings(void) { return 0; }
141 
142 #endif /* CONFIG_SMP */
143 extern const struct bus_type cpu_subsys;
144 
145 #ifdef CONFIG_PM_SLEEP_SMP
146 extern int freeze_secondary_cpus(int primary);
147 extern void thaw_secondary_cpus(void);
148 
suspend_disable_secondary_cpus(void)149 static inline int suspend_disable_secondary_cpus(void)
150 {
151 	int cpu = 0;
152 
153 	if (IS_ENABLED(CONFIG_PM_SLEEP_SMP_NONZERO_CPU))
154 		cpu = -1;
155 
156 	return freeze_secondary_cpus(cpu);
157 }
suspend_enable_secondary_cpus(void)158 static inline void suspend_enable_secondary_cpus(void)
159 {
160 	thaw_secondary_cpus();
161 }
162 
163 #else /* !CONFIG_PM_SLEEP_SMP */
thaw_secondary_cpus(void)164 static inline void thaw_secondary_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 __noreturn cpu_startup_entry(enum cpuhp_state state);
170 
171 void cpu_idle_poll_ctrl(bool enable);
172 
173 bool cpu_in_idle(unsigned long pc);
174 
175 void arch_cpu_idle(void);
176 void arch_cpu_idle_prepare(void);
177 void arch_cpu_idle_enter(void);
178 void arch_cpu_idle_exit(void);
179 void arch_tick_broadcast_enter(void);
180 void arch_tick_broadcast_exit(void);
181 void __noreturn arch_cpu_idle_dead(void);
182 
183 #ifdef CONFIG_ARCH_HAS_CPU_FINALIZE_INIT
184 void arch_cpu_finalize_init(void);
185 #else
arch_cpu_finalize_init(void)186 static inline void arch_cpu_finalize_init(void) { }
187 #endif
188 
189 void play_idle_precise(u64 duration_ns, u64 latency_ns);
190 
191 #ifdef CONFIG_HOTPLUG_CPU
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 cpu_attack_vectors {
198 	CPU_MITIGATE_USER_KERNEL,
199 	CPU_MITIGATE_USER_USER,
200 	CPU_MITIGATE_GUEST_HOST,
201 	CPU_MITIGATE_GUEST_GUEST,
202 	NR_CPU_ATTACK_VECTORS,
203 };
204 
205 enum smt_mitigations {
206 	SMT_MITIGATIONS_OFF,
207 	SMT_MITIGATIONS_AUTO,
208 	SMT_MITIGATIONS_ON,
209 };
210 
211 #ifdef CONFIG_CPU_MITIGATIONS
212 extern bool cpu_mitigations_off(void);
213 extern bool cpu_mitigations_auto_nosmt(void);
214 extern bool cpu_attack_vector_mitigated(enum cpu_attack_vectors v);
215 extern enum smt_mitigations smt_mitigations;
216 #else
cpu_mitigations_off(void)217 static inline bool cpu_mitigations_off(void)
218 {
219 	return true;
220 }
cpu_mitigations_auto_nosmt(void)221 static inline bool cpu_mitigations_auto_nosmt(void)
222 {
223 	return false;
224 }
cpu_attack_vector_mitigated(enum cpu_attack_vectors v)225 static inline bool cpu_attack_vector_mitigated(enum cpu_attack_vectors v)
226 {
227 	return false;
228 }
229 #define smt_mitigations SMT_MITIGATIONS_OFF
230 #endif
231 
232 #endif /* _LINUX_CPU_H_ */
233