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 struct device *cpu_device_create(struct device *parent, void *drvdata,
44 const struct attribute_group **groups,
45 const char *fmt, ...);
46 #ifdef CONFIG_HOTPLUG_CPU
47 extern void unregister_cpu(struct cpu *cpu);
48 extern ssize_t arch_cpu_probe(const char *, size_t);
49 extern ssize_t arch_cpu_release(const char *, size_t);
50 #endif
51 struct notifier_block;
52
53 /*
54 * CPU notifier priorities.
55 */
56 enum {
57 /*
58 * SCHED_ACTIVE marks a cpu which is coming up active during
59 * CPU_ONLINE and CPU_DOWN_FAILED and must be the first
60 * notifier. CPUSET_ACTIVE adjusts cpuset according to
61 * cpu_active mask right after SCHED_ACTIVE. During
62 * CPU_DOWN_PREPARE, SCHED_INACTIVE and CPUSET_INACTIVE are
63 * ordered in the similar way.
64 *
65 * This ordering guarantees consistent cpu_active mask and
66 * migration behavior to all cpu notifiers.
67 */
68 CPU_PRI_SCHED_ACTIVE = INT_MAX,
69 CPU_PRI_CPUSET_ACTIVE = INT_MAX - 1,
70 CPU_PRI_SCHED_INACTIVE = INT_MIN + 1,
71 CPU_PRI_CPUSET_INACTIVE = INT_MIN,
72
73 /* migration should happen before other stuff but after perf */
74 CPU_PRI_PERF = 20,
75 CPU_PRI_MIGRATION = 10,
76 CPU_PRI_SMPBOOT = 9,
77 /* bring up workqueues before normal notifiers and down after */
78 CPU_PRI_WORKQUEUE_UP = 5,
79 CPU_PRI_WORKQUEUE_DOWN = -5,
80 };
81
82 #define CPU_ONLINE 0x0002 /* CPU (unsigned)v is up */
83 #define CPU_UP_PREPARE 0x0003 /* CPU (unsigned)v coming up */
84 #define CPU_UP_CANCELED 0x0004 /* CPU (unsigned)v NOT coming up */
85 #define CPU_DOWN_PREPARE 0x0005 /* CPU (unsigned)v going down */
86 #define CPU_DOWN_FAILED 0x0006 /* CPU (unsigned)v NOT going down */
87 #define CPU_DEAD 0x0007 /* CPU (unsigned)v dead */
88 #define CPU_DYING 0x0008 /* CPU (unsigned)v not running any task,
89 * not handling interrupts, soon dead.
90 * Called on the dying cpu, interrupts
91 * are already disabled. Must not
92 * sleep, must not fail */
93 #define CPU_POST_DEAD 0x0009 /* CPU (unsigned)v dead, cpu_hotplug
94 * lock is dropped */
95 #define CPU_STARTING 0x000A /* CPU (unsigned)v soon running.
96 * Called on the new cpu, just before
97 * enabling interrupts. Must not sleep,
98 * must not fail */
99 #define CPU_DYING_IDLE 0x000B /* CPU (unsigned)v dying, reached
100 * idle loop. */
101 #define CPU_BROKEN 0x000C /* CPU (unsigned)v did not die properly,
102 * perhaps due to preemption. */
103
104 /* Used for CPU hotplug events occurring while tasks are frozen due to a suspend
105 * operation in progress
106 */
107 #define CPU_TASKS_FROZEN 0x0010
108
109 #define CPU_ONLINE_FROZEN (CPU_ONLINE | CPU_TASKS_FROZEN)
110 #define CPU_UP_PREPARE_FROZEN (CPU_UP_PREPARE | CPU_TASKS_FROZEN)
111 #define CPU_UP_CANCELED_FROZEN (CPU_UP_CANCELED | CPU_TASKS_FROZEN)
112 #define CPU_DOWN_PREPARE_FROZEN (CPU_DOWN_PREPARE | CPU_TASKS_FROZEN)
113 #define CPU_DOWN_FAILED_FROZEN (CPU_DOWN_FAILED | CPU_TASKS_FROZEN)
114 #define CPU_DEAD_FROZEN (CPU_DEAD | CPU_TASKS_FROZEN)
115 #define CPU_DYING_FROZEN (CPU_DYING | CPU_TASKS_FROZEN)
116 #define CPU_STARTING_FROZEN (CPU_STARTING | CPU_TASKS_FROZEN)
117
118
119 #ifdef CONFIG_SMP
120 /* Need to know about CPUs going up/down? */
121 #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE)
122 #define cpu_notifier(fn, pri) { \
123 static struct notifier_block fn##_nb = \
124 { .notifier_call = fn, .priority = pri }; \
125 register_cpu_notifier(&fn##_nb); \
126 }
127
128 #define __cpu_notifier(fn, pri) { \
129 static struct notifier_block fn##_nb = \
130 { .notifier_call = fn, .priority = pri }; \
131 __register_cpu_notifier(&fn##_nb); \
132 }
133 #else /* #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
134 #define cpu_notifier(fn, pri) do { (void)(fn); } while (0)
135 #define __cpu_notifier(fn, pri) do { (void)(fn); } while (0)
136 #endif /* #else #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
137
138 #ifdef CONFIG_HOTPLUG_CPU
139 extern int register_cpu_notifier(struct notifier_block *nb);
140 extern int __register_cpu_notifier(struct notifier_block *nb);
141 extern void unregister_cpu_notifier(struct notifier_block *nb);
142 extern void __unregister_cpu_notifier(struct notifier_block *nb);
143 #else
144
145 #ifndef MODULE
146 extern int register_cpu_notifier(struct notifier_block *nb);
147 extern int __register_cpu_notifier(struct notifier_block *nb);
148 #else
register_cpu_notifier(struct notifier_block * nb)149 static inline int register_cpu_notifier(struct notifier_block *nb)
150 {
151 return 0;
152 }
153
__register_cpu_notifier(struct notifier_block * nb)154 static inline int __register_cpu_notifier(struct notifier_block *nb)
155 {
156 return 0;
157 }
158 #endif
159
unregister_cpu_notifier(struct notifier_block * nb)160 static inline void unregister_cpu_notifier(struct notifier_block *nb)
161 {
162 }
163
__unregister_cpu_notifier(struct notifier_block * nb)164 static inline void __unregister_cpu_notifier(struct notifier_block *nb)
165 {
166 }
167 #endif
168
169 void smpboot_thread_init(void);
170 int cpu_up(unsigned int cpu);
171 void notify_cpu_starting(unsigned int cpu);
172 extern void cpu_maps_update_begin(void);
173 extern void cpu_maps_update_done(void);
174
175 #define cpu_notifier_register_begin cpu_maps_update_begin
176 #define cpu_notifier_register_done cpu_maps_update_done
177
178 #else /* CONFIG_SMP */
179
180 #define cpu_notifier(fn, pri) do { (void)(fn); } while (0)
181 #define __cpu_notifier(fn, pri) do { (void)(fn); } while (0)
182
register_cpu_notifier(struct notifier_block * nb)183 static inline int register_cpu_notifier(struct notifier_block *nb)
184 {
185 return 0;
186 }
187
__register_cpu_notifier(struct notifier_block * nb)188 static inline int __register_cpu_notifier(struct notifier_block *nb)
189 {
190 return 0;
191 }
192
unregister_cpu_notifier(struct notifier_block * nb)193 static inline void unregister_cpu_notifier(struct notifier_block *nb)
194 {
195 }
196
__unregister_cpu_notifier(struct notifier_block * nb)197 static inline void __unregister_cpu_notifier(struct notifier_block *nb)
198 {
199 }
200
cpu_maps_update_begin(void)201 static inline void cpu_maps_update_begin(void)
202 {
203 }
204
cpu_maps_update_done(void)205 static inline void cpu_maps_update_done(void)
206 {
207 }
208
cpu_notifier_register_begin(void)209 static inline void cpu_notifier_register_begin(void)
210 {
211 }
212
cpu_notifier_register_done(void)213 static inline void cpu_notifier_register_done(void)
214 {
215 }
216
smpboot_thread_init(void)217 static inline void smpboot_thread_init(void)
218 {
219 }
220
221 #endif /* CONFIG_SMP */
222 extern struct bus_type cpu_subsys;
223
224 #ifdef CONFIG_HOTPLUG_CPU
225 /* Stop CPUs going up and down. */
226
227 extern void cpu_hotplug_begin(void);
228 extern void cpu_hotplug_done(void);
229 extern void get_online_cpus(void);
230 extern bool try_get_online_cpus(void);
231 extern void put_online_cpus(void);
232 extern void cpu_hotplug_disable(void);
233 extern void cpu_hotplug_enable(void);
234 #define hotcpu_notifier(fn, pri) cpu_notifier(fn, pri)
235 #define __hotcpu_notifier(fn, pri) __cpu_notifier(fn, pri)
236 #define register_hotcpu_notifier(nb) register_cpu_notifier(nb)
237 #define __register_hotcpu_notifier(nb) __register_cpu_notifier(nb)
238 #define unregister_hotcpu_notifier(nb) unregister_cpu_notifier(nb)
239 #define __unregister_hotcpu_notifier(nb) __unregister_cpu_notifier(nb)
240 void clear_tasks_mm_cpumask(int cpu);
241 int cpu_down(unsigned int cpu);
242
243 #else /* CONFIG_HOTPLUG_CPU */
244
cpu_hotplug_begin(void)245 static inline void cpu_hotplug_begin(void) {}
cpu_hotplug_done(void)246 static inline void cpu_hotplug_done(void) {}
247 #define get_online_cpus() do { } while (0)
248 #define try_get_online_cpus() true
249 #define put_online_cpus() do { } while (0)
250 #define cpu_hotplug_disable() do { } while (0)
251 #define cpu_hotplug_enable() do { } while (0)
252 #define hotcpu_notifier(fn, pri) do { (void)(fn); } while (0)
253 #define __hotcpu_notifier(fn, pri) do { (void)(fn); } while (0)
254 /* These aren't inline functions due to a GCC bug. */
255 #define register_hotcpu_notifier(nb) ({ (void)(nb); 0; })
256 #define __register_hotcpu_notifier(nb) ({ (void)(nb); 0; })
257 #define unregister_hotcpu_notifier(nb) ({ (void)(nb); })
258 #define __unregister_hotcpu_notifier(nb) ({ (void)(nb); })
259 #endif /* CONFIG_HOTPLUG_CPU */
260
261 #ifdef CONFIG_PM_SLEEP_SMP
262 extern int disable_nonboot_cpus(void);
263 extern void enable_nonboot_cpus(void);
264 #else /* !CONFIG_PM_SLEEP_SMP */
disable_nonboot_cpus(void)265 static inline int disable_nonboot_cpus(void) { return 0; }
enable_nonboot_cpus(void)266 static inline void enable_nonboot_cpus(void) {}
267 #endif /* !CONFIG_PM_SLEEP_SMP */
268
269 enum cpuhp_state {
270 CPUHP_OFFLINE,
271 CPUHP_ONLINE,
272 };
273
274 void cpu_startup_entry(enum cpuhp_state state);
275
276 void cpu_idle_poll_ctrl(bool enable);
277
278 void arch_cpu_idle(void);
279 void arch_cpu_idle_prepare(void);
280 void arch_cpu_idle_enter(void);
281 void arch_cpu_idle_exit(void);
282 void arch_cpu_idle_dead(void);
283
284 DECLARE_PER_CPU(bool, cpu_dead_idle);
285
286 int cpu_report_state(int cpu);
287 int cpu_check_up_prepare(int cpu);
288 void cpu_set_state_online(int cpu);
289 #ifdef CONFIG_HOTPLUG_CPU
290 bool cpu_wait_death(unsigned int cpu, int seconds);
291 bool cpu_report_death(void);
292 #endif /* #ifdef CONFIG_HOTPLUG_CPU */
293
294 #endif /* _LINUX_CPU_H_ */
295