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 * and system devices are handled in drivers/base/sys.c.
10 *
11 * CPUs are exported via sysfs in the class/cpu/devices/
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
21 struct device;
22
23 struct cpu {
24 int node_id; /* The node which contains the CPU */
25 int hotpluggable; /* creates sysfs control file if hotpluggable */
26 struct device dev;
27 };
28
29 extern int register_cpu(struct cpu *cpu, int num);
30 extern struct device *get_cpu_device(unsigned cpu);
31 extern bool cpu_is_hotpluggable(unsigned cpu);
32
33 extern int cpu_add_dev_attr(struct device_attribute *attr);
34 extern void cpu_remove_dev_attr(struct device_attribute *attr);
35
36 extern int cpu_add_dev_attr_group(struct attribute_group *attrs);
37 extern void cpu_remove_dev_attr_group(struct attribute_group *attrs);
38
39 extern int sched_create_sysfs_power_savings_entries(struct device *dev);
40
41 #ifdef CONFIG_HOTPLUG_CPU
42 extern void unregister_cpu(struct cpu *cpu);
43 extern ssize_t arch_cpu_probe(const char *, size_t);
44 extern ssize_t arch_cpu_release(const char *, size_t);
45 #endif
46 struct notifier_block;
47
48 #ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE
49 extern int arch_cpu_uevent(struct device *dev, struct kobj_uevent_env *env);
50 extern ssize_t arch_print_cpu_modalias(struct device *dev,
51 struct device_attribute *attr,
52 char *bufptr);
53 #endif
54
55 /*
56 * CPU notifier priorities.
57 */
58 enum {
59 /*
60 * SCHED_ACTIVE marks a cpu which is coming up active during
61 * CPU_ONLINE and CPU_DOWN_FAILED and must be the first
62 * notifier. CPUSET_ACTIVE adjusts cpuset according to
63 * cpu_active mask right after SCHED_ACTIVE. During
64 * CPU_DOWN_PREPARE, SCHED_INACTIVE and CPUSET_INACTIVE are
65 * ordered in the similar way.
66 *
67 * This ordering guarantees consistent cpu_active mask and
68 * migration behavior to all cpu notifiers.
69 */
70 CPU_PRI_SCHED_ACTIVE = INT_MAX,
71 CPU_PRI_CPUSET_ACTIVE = INT_MAX - 1,
72 CPU_PRI_SCHED_INACTIVE = INT_MIN + 1,
73 CPU_PRI_CPUSET_INACTIVE = INT_MIN,
74
75 /* migration should happen before other stuff but after perf */
76 CPU_PRI_PERF = 20,
77 CPU_PRI_MIGRATION = 10,
78 /* bring up workqueues before normal notifiers and down after */
79 CPU_PRI_WORKQUEUE_UP = 5,
80 CPU_PRI_WORKQUEUE_DOWN = -5,
81 };
82
83 #define CPU_ONLINE 0x0002 /* CPU (unsigned)v is up */
84 #define CPU_UP_PREPARE 0x0003 /* CPU (unsigned)v coming up */
85 #define CPU_UP_CANCELED 0x0004 /* CPU (unsigned)v NOT coming up */
86 #define CPU_DOWN_PREPARE 0x0005 /* CPU (unsigned)v going down */
87 #define CPU_DOWN_FAILED 0x0006 /* CPU (unsigned)v NOT going down */
88 #define CPU_DEAD 0x0007 /* CPU (unsigned)v dead */
89 #define CPU_DYING 0x0008 /* CPU (unsigned)v not running any task,
90 * not handling interrupts, soon dead.
91 * Called on the dying cpu, interrupts
92 * are already disabled. Must not
93 * sleep, must not fail */
94 #define CPU_POST_DEAD 0x0009 /* CPU (unsigned)v dead, cpu_hotplug
95 * lock is dropped */
96 #define CPU_STARTING 0x000A /* CPU (unsigned)v soon running.
97 * Called on the new cpu, just before
98 * enabling interrupts. Must not sleep,
99 * must not fail */
100
101 /* Used for CPU hotplug events occurring while tasks are frozen due to a suspend
102 * operation in progress
103 */
104 #define CPU_TASKS_FROZEN 0x0010
105
106 #define CPU_ONLINE_FROZEN (CPU_ONLINE | CPU_TASKS_FROZEN)
107 #define CPU_UP_PREPARE_FROZEN (CPU_UP_PREPARE | CPU_TASKS_FROZEN)
108 #define CPU_UP_CANCELED_FROZEN (CPU_UP_CANCELED | CPU_TASKS_FROZEN)
109 #define CPU_DOWN_PREPARE_FROZEN (CPU_DOWN_PREPARE | CPU_TASKS_FROZEN)
110 #define CPU_DOWN_FAILED_FROZEN (CPU_DOWN_FAILED | CPU_TASKS_FROZEN)
111 #define CPU_DEAD_FROZEN (CPU_DEAD | CPU_TASKS_FROZEN)
112 #define CPU_DYING_FROZEN (CPU_DYING | CPU_TASKS_FROZEN)
113 #define CPU_STARTING_FROZEN (CPU_STARTING | CPU_TASKS_FROZEN)
114
115
116 #ifdef CONFIG_SMP
117 /* Need to know about CPUs going up/down? */
118 #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE)
119 #define cpu_notifier(fn, pri) { \
120 static struct notifier_block fn##_nb __cpuinitdata = \
121 { .notifier_call = fn, .priority = pri }; \
122 register_cpu_notifier(&fn##_nb); \
123 }
124 #else /* #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
125 #define cpu_notifier(fn, pri) do { (void)(fn); } while (0)
126 #endif /* #else #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
127 #ifdef CONFIG_HOTPLUG_CPU
128 extern int register_cpu_notifier(struct notifier_block *nb);
129 extern void unregister_cpu_notifier(struct notifier_block *nb);
130 #else
131
132 #ifndef MODULE
133 extern int register_cpu_notifier(struct notifier_block *nb);
134 #else
register_cpu_notifier(struct notifier_block * nb)135 static inline int register_cpu_notifier(struct notifier_block *nb)
136 {
137 return 0;
138 }
139 #endif
140
unregister_cpu_notifier(struct notifier_block * nb)141 static inline void unregister_cpu_notifier(struct notifier_block *nb)
142 {
143 }
144 #endif
145
146 int cpu_up(unsigned int cpu);
147 void notify_cpu_starting(unsigned int cpu);
148 extern void cpu_maps_update_begin(void);
149 extern void cpu_maps_update_done(void);
150
151 #else /* CONFIG_SMP */
152
153 #define cpu_notifier(fn, pri) do { (void)(fn); } while (0)
154
register_cpu_notifier(struct notifier_block * nb)155 static inline int register_cpu_notifier(struct notifier_block *nb)
156 {
157 return 0;
158 }
159
unregister_cpu_notifier(struct notifier_block * nb)160 static inline void unregister_cpu_notifier(struct notifier_block *nb)
161 {
162 }
163
cpu_maps_update_begin(void)164 static inline void cpu_maps_update_begin(void)
165 {
166 }
167
cpu_maps_update_done(void)168 static inline void cpu_maps_update_done(void)
169 {
170 }
171
172 #endif /* CONFIG_SMP */
173 extern struct bus_type cpu_subsys;
174
175 #ifdef CONFIG_HOTPLUG_CPU
176 /* Stop CPUs going up and down. */
177
178 extern void get_online_cpus(void);
179 extern void put_online_cpus(void);
180 extern void cpu_hotplug_disable(void);
181 extern void cpu_hotplug_enable(void);
182 #define hotcpu_notifier(fn, pri) cpu_notifier(fn, pri)
183 #define register_hotcpu_notifier(nb) register_cpu_notifier(nb)
184 #define unregister_hotcpu_notifier(nb) unregister_cpu_notifier(nb)
185 int cpu_down(unsigned int cpu);
186
187 #ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
188 extern void cpu_hotplug_driver_lock(void);
189 extern void cpu_hotplug_driver_unlock(void);
190 #else
cpu_hotplug_driver_lock(void)191 static inline void cpu_hotplug_driver_lock(void)
192 {
193 }
194
cpu_hotplug_driver_unlock(void)195 static inline void cpu_hotplug_driver_unlock(void)
196 {
197 }
198 #endif
199
200 #else /* CONFIG_HOTPLUG_CPU */
201
202 #define get_online_cpus() do { } while (0)
203 #define put_online_cpus() do { } while (0)
204 #define cpu_hotplug_disable() do { } while (0)
205 #define cpu_hotplug_enable() do { } while (0)
206 #define hotcpu_notifier(fn, pri) do { (void)(fn); } while (0)
207 /* These aren't inline functions due to a GCC bug. */
208 #define register_hotcpu_notifier(nb) ({ (void)(nb); 0; })
209 #define unregister_hotcpu_notifier(nb) ({ (void)(nb); })
210 #endif /* CONFIG_HOTPLUG_CPU */
211
212 #ifdef CONFIG_PM_SLEEP_SMP
213 extern int disable_nonboot_cpus(void);
214 extern void enable_nonboot_cpus(void);
215 #else /* !CONFIG_PM_SLEEP_SMP */
disable_nonboot_cpus(void)216 static inline int disable_nonboot_cpus(void) { return 0; }
enable_nonboot_cpus(void)217 static inline void enable_nonboot_cpus(void) {}
218 #endif /* !CONFIG_PM_SLEEP_SMP */
219
220 #endif /* _LINUX_CPU_H_ */
221