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