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>
26 #include <asm/semaphore.h>
29 int node_id; /* The node which contains the CPU */
30 int no_control; /* Should the sysfs control file be created? */
31 struct sys_device sysdev;
34 extern int register_cpu(struct cpu *cpu, int num);
35 extern struct sys_device *get_cpu_sysdev(unsigned cpu);
37 extern int cpu_add_sysdev_attr(struct sysdev_attribute *attr);
38 extern void cpu_remove_sysdev_attr(struct sysdev_attribute *attr);
40 extern int cpu_add_sysdev_attr_group(struct attribute_group *attrs);
41 extern void cpu_remove_sysdev_attr_group(struct attribute_group *attrs);
44 #ifdef CONFIG_HOTPLUG_CPU
45 extern void unregister_cpu(struct cpu *cpu);
47 struct notifier_block;
50 /* Need to know about CPUs going up/down? */
51 extern int register_cpu_notifier(struct notifier_block *nb);
52 #ifdef CONFIG_HOTPLUG_CPU
53 extern void unregister_cpu_notifier(struct notifier_block *nb);
55 static inline void unregister_cpu_notifier(struct notifier_block *nb)
60 int cpu_up(unsigned int cpu);
64 static inline int register_cpu_notifier(struct notifier_block *nb)
68 static inline void unregister_cpu_notifier(struct notifier_block *nb)
72 #endif /* CONFIG_SMP */
73 extern struct sysdev_class cpu_sysdev_class;
75 #ifdef CONFIG_HOTPLUG_CPU
76 /* Stop CPUs going up and down. */
77 extern void lock_cpu_hotplug(void);
78 extern void unlock_cpu_hotplug(void);
79 #define hotcpu_notifier(fn, pri) { \
80 static struct notifier_block fn##_nb = \
81 { .notifier_call = fn, .priority = pri }; \
82 register_cpu_notifier(&fn##_nb); \
84 #define register_hotcpu_notifier(nb) register_cpu_notifier(nb)
85 #define unregister_hotcpu_notifier(nb) unregister_cpu_notifier(nb)
86 int cpu_down(unsigned int cpu);
87 #define cpu_is_offline(cpu) unlikely(!cpu_online(cpu))
89 #define lock_cpu_hotplug() do { } while (0)
90 #define unlock_cpu_hotplug() do { } while (0)
91 #define lock_cpu_hotplug_interruptible() 0
92 #define hotcpu_notifier(fn, pri) do { (void)(fn); } while (0)
93 #define register_hotcpu_notifier(nb) do { (void)(nb); } while (0)
94 #define unregister_hotcpu_notifier(nb) do { (void)(nb); } while (0)
96 /* CPUs don't go offline once they're online w/o CONFIG_HOTPLUG_CPU */
97 static inline int cpu_is_offline(int cpu) { return 0; }
100 #ifdef CONFIG_SUSPEND_SMP
101 extern int disable_nonboot_cpus(void);
102 extern void enable_nonboot_cpus(void);
104 static inline int disable_nonboot_cpus(void) { return 0; }
105 static inline void enable_nonboot_cpus(void) {}
108 #endif /* _LINUX_CPU_H_ */