1 /*
2 * include/linux/cpu.h - generic cpu definition
3 *
4 * This is mainly for topological representation. We define the
5 * basic 'struct cpu' here, which can be embedded in per-arch
6 * definitions of processors.
7 *
8 * Basic handling of the devices is done in drivers/base/cpu.c
9 *
10 * CPUs are exported via sysfs in the devices/system/cpu
11 * directory.
12 */
13 #ifndef _LINUX_CPU_H_
14 #define _LINUX_CPU_H_
15
16 #include <linux/node.h>
17 #include <linux/compiler.h>
18 #include <linux/cpumask.h>
19
20 struct device;
21 struct device_node;
22 struct attribute_group;
23
24 struct cpu {
25 int node_id; /* The node which contains the CPU */
26 int hotpluggable; /* creates sysfs control file if hotpluggable */
27 struct device dev;
28 };
29
30 extern int register_cpu(struct cpu *cpu, int num);
31 extern struct device *get_cpu_device(unsigned cpu);
32 extern bool cpu_is_hotpluggable(unsigned cpu);
33 extern bool arch_match_cpu_phys_id(int cpu, u64 phys_id);
34 extern bool arch_find_n_match_cpu_physical_id(struct device_node *cpun,
35 int cpu, unsigned int *thread);
36
37 extern int cpu_add_dev_attr(struct device_attribute *attr);
38 extern void cpu_remove_dev_attr(struct device_attribute *attr);
39
40 extern int cpu_add_dev_attr_group(struct attribute_group *attrs);
41 extern void cpu_remove_dev_attr_group(struct attribute_group *attrs);
42
43 extern ssize_t cpu_show_meltdown(struct device *dev,
44 struct device_attribute *attr, char *buf);
45 extern ssize_t cpu_show_spectre_v1(struct device *dev,
46 struct device_attribute *attr, char *buf);
47 extern ssize_t cpu_show_spectre_v2(struct device *dev,
48 struct device_attribute *attr, char *buf);
49 extern ssize_t cpu_show_spec_store_bypass(struct device *dev,
50 struct device_attribute *attr, char *buf);
51 extern ssize_t cpu_show_l1tf(struct device *dev,
52 struct device_attribute *attr, char *buf);
53 extern ssize_t cpu_show_mds(struct device *dev,
54 struct device_attribute *attr, char *buf);
55 extern ssize_t cpu_show_tsx_async_abort(struct device *dev,
56 struct device_attribute *attr,
57 char *buf);
58 extern ssize_t cpu_show_itlb_multihit(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 struct notifier_block;
71
72 /*
73 * CPU notifier priorities.
74 */
75 enum {
76 /*
77 * SCHED_ACTIVE marks a cpu which is coming up active during
78 * CPU_ONLINE and CPU_DOWN_FAILED and must be the first
79 * notifier. CPUSET_ACTIVE adjusts cpuset according to
80 * cpu_active mask right after SCHED_ACTIVE. During
81 * CPU_DOWN_PREPARE, SCHED_INACTIVE and CPUSET_INACTIVE are
82 * ordered in the similar way.
83 *
84 * This ordering guarantees consistent cpu_active mask and
85 * migration behavior to all cpu notifiers.
86 */
87 CPU_PRI_SCHED_ACTIVE = INT_MAX,
88 CPU_PRI_CPUSET_ACTIVE = INT_MAX - 1,
89 CPU_PRI_SCHED_INACTIVE = INT_MIN + 1,
90 CPU_PRI_CPUSET_INACTIVE = INT_MIN,
91
92 /* migration should happen before other stuff but after perf */
93 CPU_PRI_PERF = 20,
94 CPU_PRI_MIGRATION = 10,
95 CPU_PRI_SMPBOOT = 9,
96 /* bring up workqueues before normal notifiers and down after */
97 CPU_PRI_WORKQUEUE_UP = 5,
98 CPU_PRI_WORKQUEUE_DOWN = -5,
99 };
100
101 #define CPU_ONLINE 0x0002 /* CPU (unsigned)v is up */
102 #define CPU_UP_PREPARE 0x0003 /* CPU (unsigned)v coming up */
103 #define CPU_UP_CANCELED 0x0004 /* CPU (unsigned)v NOT coming up */
104 #define CPU_DOWN_PREPARE 0x0005 /* CPU (unsigned)v going down */
105 #define CPU_DOWN_FAILED 0x0006 /* CPU (unsigned)v NOT going down */
106 #define CPU_DEAD 0x0007 /* CPU (unsigned)v dead */
107 #define CPU_DYING 0x0008 /* CPU (unsigned)v not running any task,
108 * not handling interrupts, soon dead.
109 * Called on the dying cpu, interrupts
110 * are already disabled. Must not
111 * sleep, must not fail */
112 #define CPU_POST_DEAD 0x0009 /* CPU (unsigned)v dead, cpu_hotplug
113 * lock is dropped */
114 #define CPU_STARTING 0x000A /* CPU (unsigned)v soon running.
115 * Called on the new cpu, just before
116 * enabling interrupts. Must not sleep,
117 * must not fail */
118 #define CPU_DYING_IDLE 0x000B /* CPU (unsigned)v dying, reached
119 * idle loop. */
120 #define CPU_BROKEN 0x000C /* CPU (unsigned)v did not die properly,
121 * perhaps due to preemption. */
122
123 /* Used for CPU hotplug events occurring while tasks are frozen due to a suspend
124 * operation in progress
125 */
126 #define CPU_TASKS_FROZEN 0x0010
127
128 #define CPU_ONLINE_FROZEN (CPU_ONLINE | CPU_TASKS_FROZEN)
129 #define CPU_UP_PREPARE_FROZEN (CPU_UP_PREPARE | CPU_TASKS_FROZEN)
130 #define CPU_UP_CANCELED_FROZEN (CPU_UP_CANCELED | CPU_TASKS_FROZEN)
131 #define CPU_DOWN_PREPARE_FROZEN (CPU_DOWN_PREPARE | CPU_TASKS_FROZEN)
132 #define CPU_DOWN_FAILED_FROZEN (CPU_DOWN_FAILED | CPU_TASKS_FROZEN)
133 #define CPU_DEAD_FROZEN (CPU_DEAD | CPU_TASKS_FROZEN)
134 #define CPU_DYING_FROZEN (CPU_DYING | CPU_TASKS_FROZEN)
135 #define CPU_STARTING_FROZEN (CPU_STARTING | CPU_TASKS_FROZEN)
136
137
138 #ifdef CONFIG_SMP
139 /* Need to know about CPUs going up/down? */
140 #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE)
141 #define cpu_notifier(fn, pri) { \
142 static struct notifier_block fn##_nb = \
143 { .notifier_call = fn, .priority = pri }; \
144 register_cpu_notifier(&fn##_nb); \
145 }
146
147 #define __cpu_notifier(fn, pri) { \
148 static struct notifier_block fn##_nb = \
149 { .notifier_call = fn, .priority = pri }; \
150 __register_cpu_notifier(&fn##_nb); \
151 }
152
153 extern int register_cpu_notifier(struct notifier_block *nb);
154 extern int __register_cpu_notifier(struct notifier_block *nb);
155 extern void unregister_cpu_notifier(struct notifier_block *nb);
156 extern void __unregister_cpu_notifier(struct notifier_block *nb);
157
158 #else /* #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
159 #define cpu_notifier(fn, pri) do { (void)(fn); } while (0)
160 #define __cpu_notifier(fn, pri) do { (void)(fn); } while (0)
161
register_cpu_notifier(struct notifier_block * nb)162 static inline int register_cpu_notifier(struct notifier_block *nb)
163 {
164 return 0;
165 }
166
__register_cpu_notifier(struct notifier_block * nb)167 static inline int __register_cpu_notifier(struct notifier_block *nb)
168 {
169 return 0;
170 }
171
unregister_cpu_notifier(struct notifier_block * nb)172 static inline void unregister_cpu_notifier(struct notifier_block *nb)
173 {
174 }
175
__unregister_cpu_notifier(struct notifier_block * nb)176 static inline void __unregister_cpu_notifier(struct notifier_block *nb)
177 {
178 }
179 #endif
180
181 void smpboot_thread_init(void);
182 int cpu_up(unsigned int cpu);
183 void notify_cpu_starting(unsigned int cpu);
184 extern void cpu_maps_update_begin(void);
185 extern void cpu_maps_update_done(void);
186
187 #define cpu_notifier_register_begin cpu_maps_update_begin
188 #define cpu_notifier_register_done cpu_maps_update_done
189
190 #else /* CONFIG_SMP */
191
192 #define cpu_notifier(fn, pri) do { (void)(fn); } while (0)
193 #define __cpu_notifier(fn, pri) do { (void)(fn); } while (0)
194
register_cpu_notifier(struct notifier_block * nb)195 static inline int register_cpu_notifier(struct notifier_block *nb)
196 {
197 return 0;
198 }
199
__register_cpu_notifier(struct notifier_block * nb)200 static inline int __register_cpu_notifier(struct notifier_block *nb)
201 {
202 return 0;
203 }
204
unregister_cpu_notifier(struct notifier_block * nb)205 static inline void unregister_cpu_notifier(struct notifier_block *nb)
206 {
207 }
208
__unregister_cpu_notifier(struct notifier_block * nb)209 static inline void __unregister_cpu_notifier(struct notifier_block *nb)
210 {
211 }
212
cpu_maps_update_begin(void)213 static inline void cpu_maps_update_begin(void)
214 {
215 }
216
cpu_maps_update_done(void)217 static inline void cpu_maps_update_done(void)
218 {
219 }
220
cpu_notifier_register_begin(void)221 static inline void cpu_notifier_register_begin(void)
222 {
223 }
224
cpu_notifier_register_done(void)225 static inline void cpu_notifier_register_done(void)
226 {
227 }
228
smpboot_thread_init(void)229 static inline void smpboot_thread_init(void)
230 {
231 }
232
233 #endif /* CONFIG_SMP */
234 extern struct bus_type cpu_subsys;
235
236 #ifdef CONFIG_HOTPLUG_CPU
237 /* Stop CPUs going up and down. */
238
239 extern void cpu_hotplug_begin(void);
240 extern void cpu_hotplug_done(void);
241 extern void get_online_cpus(void);
242 extern void put_online_cpus(void);
243 extern void cpu_hotplug_disable(void);
244 extern void cpu_hotplug_enable(void);
245 #define hotcpu_notifier(fn, pri) cpu_notifier(fn, pri)
246 #define __hotcpu_notifier(fn, pri) __cpu_notifier(fn, pri)
247 #define register_hotcpu_notifier(nb) register_cpu_notifier(nb)
248 #define __register_hotcpu_notifier(nb) __register_cpu_notifier(nb)
249 #define unregister_hotcpu_notifier(nb) unregister_cpu_notifier(nb)
250 #define __unregister_hotcpu_notifier(nb) __unregister_cpu_notifier(nb)
251 void clear_tasks_mm_cpumask(int cpu);
252 int cpu_down(unsigned int cpu);
253
254 #else /* CONFIG_HOTPLUG_CPU */
255
cpu_hotplug_begin(void)256 static inline void cpu_hotplug_begin(void) {}
cpu_hotplug_done(void)257 static inline void cpu_hotplug_done(void) {}
258 #define get_online_cpus() do { } while (0)
259 #define put_online_cpus() do { } while (0)
260 #define cpu_hotplug_disable() do { } while (0)
261 #define cpu_hotplug_enable() do { } while (0)
262 #define hotcpu_notifier(fn, pri) do { (void)(fn); } while (0)
263 #define __hotcpu_notifier(fn, pri) do { (void)(fn); } while (0)
264 /* These aren't inline functions due to a GCC bug. */
265 #define register_hotcpu_notifier(nb) ({ (void)(nb); 0; })
266 #define __register_hotcpu_notifier(nb) ({ (void)(nb); 0; })
267 #define unregister_hotcpu_notifier(nb) ({ (void)(nb); })
268 #define __unregister_hotcpu_notifier(nb) ({ (void)(nb); })
269 #endif /* CONFIG_HOTPLUG_CPU */
270
271 #ifdef CONFIG_PM_SLEEP_SMP
272 extern int disable_nonboot_cpus(void);
273 extern void enable_nonboot_cpus(void);
274 #else /* !CONFIG_PM_SLEEP_SMP */
disable_nonboot_cpus(void)275 static inline int disable_nonboot_cpus(void) { return 0; }
enable_nonboot_cpus(void)276 static inline void enable_nonboot_cpus(void) {}
277 #endif /* !CONFIG_PM_SLEEP_SMP */
278
279 enum cpuhp_state {
280 CPUHP_OFFLINE,
281 CPUHP_ONLINE,
282 };
283
284 void cpu_startup_entry(enum cpuhp_state state);
285
286 void cpu_idle_poll_ctrl(bool enable);
287
288 void arch_cpu_idle(void);
289 void arch_cpu_idle_prepare(void);
290 void arch_cpu_idle_enter(void);
291 void arch_cpu_idle_exit(void);
292 void arch_cpu_idle_dead(void);
293
294 DECLARE_PER_CPU(bool, cpu_dead_idle);
295
296 int cpu_report_state(int cpu);
297 int cpu_check_up_prepare(int cpu);
298 void cpu_set_state_online(int cpu);
299 #ifdef CONFIG_HOTPLUG_CPU
300 bool cpu_wait_death(unsigned int cpu, int seconds);
301 bool cpu_report_death(void);
302 #endif /* #ifdef CONFIG_HOTPLUG_CPU */
303
304 /*
305 * These are used for a global "mitigations=" cmdline option for toggling
306 * optional CPU mitigations.
307 */
308 enum cpu_mitigations {
309 CPU_MITIGATIONS_OFF,
310 CPU_MITIGATIONS_AUTO,
311 };
312
313 extern enum cpu_mitigations cpu_mitigations;
314
315 /* mitigations=off */
cpu_mitigations_off(void)316 static inline bool cpu_mitigations_off(void)
317 {
318 return cpu_mitigations == CPU_MITIGATIONS_OFF;
319 }
320
321 #define IDLE_START 1
322 #define IDLE_END 2
323
324 void idle_notifier_register(struct notifier_block *n);
325 void idle_notifier_unregister(struct notifier_block *n);
326 void idle_notifier_call_chain(unsigned long val);
327
328 #endif /* _LINUX_CPU_H_ */
329