2 * include/linux/cpu.h - generic cpu definition
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.
8 * Basic handling of the devices is done in drivers/base/cpu.c
9 * and system devices are handled in drivers/base/sys.c.
11 * CPUs are exported via sysfs in the class/cpu/devices/
14 * Per-cpu interfaces can be implemented using a struct device_interface.
15 * See the following for how to do this:
16 * - drivers/base/intf.c
17 * - Documentation/driver-model/interface.txt
22 #include <linux/sysdev.h>
23 #include <linux/node.h>
24 #include <linux/compiler.h>
25 #include <linux/cpumask.h>
28 int node_id; /* The node which contains the CPU */
29 int hotpluggable; /* creates sysfs control file if hotpluggable */
30 struct sys_device sysdev;
33 extern int register_cpu(struct cpu *cpu, int num);
34 extern struct sys_device *get_cpu_sysdev(unsigned cpu);
36 extern int cpu_add_sysdev_attr(struct sysdev_attribute *attr);
37 extern void cpu_remove_sysdev_attr(struct sysdev_attribute *attr);
39 extern int cpu_add_sysdev_attr_group(struct attribute_group *attrs);
40 extern void cpu_remove_sysdev_attr_group(struct attribute_group *attrs);
42 extern int sched_create_sysfs_power_savings_entries(struct sysdev_class *cls);
44 #ifdef CONFIG_HOTPLUG_CPU
45 extern void unregister_cpu(struct cpu *cpu);
46 extern ssize_t arch_cpu_probe(const char *, size_t);
47 extern ssize_t arch_cpu_release(const char *, size_t);
49 struct notifier_block;
52 * CPU notifier priorities.
56 * SCHED_ACTIVE marks a cpu which is coming up active during
57 * CPU_ONLINE and CPU_DOWN_FAILED and must be the first
58 * notifier. CPUSET_ACTIVE adjusts cpuset according to
59 * cpu_active mask right after SCHED_ACTIVE. During
60 * CPU_DOWN_PREPARE, SCHED_INACTIVE and CPUSET_INACTIVE are
61 * ordered in the similar way.
63 * This ordering guarantees consistent cpu_active mask and
64 * migration behavior to all cpu notifiers.
66 CPU_PRI_SCHED_ACTIVE = INT_MAX,
67 CPU_PRI_CPUSET_ACTIVE = INT_MAX - 1,
68 CPU_PRI_SCHED_INACTIVE = INT_MIN + 1,
69 CPU_PRI_CPUSET_INACTIVE = INT_MIN,
71 /* migration should happen before other stuff but after perf */
73 CPU_PRI_MIGRATION = 10,
77 /* Need to know about CPUs going up/down? */
78 #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE)
79 #define cpu_notifier(fn, pri) { \
80 static struct notifier_block fn##_nb __cpuinitdata = \
81 { .notifier_call = fn, .priority = pri }; \
82 register_cpu_notifier(&fn##_nb); \
84 #else /* #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
85 #define cpu_notifier(fn, pri) do { (void)(fn); } while (0)
86 #endif /* #else #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
87 #ifdef CONFIG_HOTPLUG_CPU
88 extern int register_cpu_notifier(struct notifier_block *nb);
89 extern void unregister_cpu_notifier(struct notifier_block *nb);
93 extern int register_cpu_notifier(struct notifier_block *nb);
95 static inline int register_cpu_notifier(struct notifier_block *nb)
101 static inline void unregister_cpu_notifier(struct notifier_block *nb)
106 int cpu_up(unsigned int cpu);
107 void notify_cpu_starting(unsigned int cpu);
108 extern void cpu_maps_update_begin(void);
109 extern void cpu_maps_update_done(void);
111 #else /* CONFIG_SMP */
113 #define cpu_notifier(fn, pri) do { (void)(fn); } while (0)
115 static inline int register_cpu_notifier(struct notifier_block *nb)
120 static inline void unregister_cpu_notifier(struct notifier_block *nb)
124 static inline void cpu_maps_update_begin(void)
128 static inline void cpu_maps_update_done(void)
132 #endif /* CONFIG_SMP */
133 extern struct sysdev_class cpu_sysdev_class;
135 #ifdef CONFIG_HOTPLUG_CPU
136 /* Stop CPUs going up and down. */
138 extern void get_online_cpus(void);
139 extern void put_online_cpus(void);
140 #define hotcpu_notifier(fn, pri) cpu_notifier(fn, pri)
141 #define register_hotcpu_notifier(nb) register_cpu_notifier(nb)
142 #define unregister_hotcpu_notifier(nb) unregister_cpu_notifier(nb)
143 int cpu_down(unsigned int cpu);
145 #ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
146 extern void cpu_hotplug_driver_lock(void);
147 extern void cpu_hotplug_driver_unlock(void);
149 static inline void cpu_hotplug_driver_lock(void)
153 static inline void cpu_hotplug_driver_unlock(void)
158 #else /* CONFIG_HOTPLUG_CPU */
160 #define get_online_cpus() do { } while (0)
161 #define put_online_cpus() do { } while (0)
162 #define hotcpu_notifier(fn, pri) do { (void)(fn); } while (0)
163 /* These aren't inline functions due to a GCC bug. */
164 #define register_hotcpu_notifier(nb) ({ (void)(nb); 0; })
165 #define unregister_hotcpu_notifier(nb) ({ (void)(nb); })
166 #endif /* CONFIG_HOTPLUG_CPU */
168 #ifdef CONFIG_PM_SLEEP_SMP
169 extern int suspend_cpu_hotplug;
171 extern int disable_nonboot_cpus(void);
172 extern void enable_nonboot_cpus(void);
173 #else /* !CONFIG_PM_SLEEP_SMP */
174 #define suspend_cpu_hotplug 0
176 static inline int disable_nonboot_cpus(void) { return 0; }
177 static inline void enable_nonboot_cpus(void) {}
178 #endif /* !CONFIG_PM_SLEEP_SMP */
180 #endif /* _LINUX_CPU_H_ */