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/*
* include/linux/cpu.h - generic cpu definition
*
* This is mainly for topological representation. We define the
* basic 'struct cpu' here, which can be embedded in per-arch
* definitions of processors.
*
* Basic handling of the devices is done in drivers/base/cpu.c
* and system devices are handled in drivers/base/sys.c.
*
* CPUs are exported via sysfs in the class/cpu/devices/
* directory.
*
* Per-cpu interfaces can be implemented using a struct device_interface.
* See the following for how to do this:
* - drivers/base/intf.c
* - Documentation/driver-model/interface.txt
*/
#ifndef _LINUX_CPU_H_
#define _LINUX_CPU_H_
#include <linux/sysdev.h>
#include <linux/node.h>
#include <linux/compiler.h>
#include <linux/cpumask.h>
#include <asm/semaphore.h>
struct cpu {
int node_id; /* The node which contains the CPU */
int no_control; /* Should the sysfs control file be created? */
struct sys_device sysdev;
};
extern int register_cpu(struct cpu *, int, struct node *);
extern struct sys_device *get_cpu_sysdev(int cpu);
#ifdef CONFIG_HOTPLUG_CPU
extern void unregister_cpu(struct cpu *, struct node *);
#endif
struct notifier_block;
#ifdef CONFIG_SMP
/* Need to know about CPUs going up/down? */
extern int register_cpu_notifier(struct notifier_block *nb);
extern void unregister_cpu_notifier(struct notifier_block *nb);
int cpu_up(unsigned int cpu);
#else
static inline int register_cpu_notifier(struct notifier_block *nb)
{
return 0;
}
static inline void unregister_cpu_notifier(struct notifier_block *nb)
{
}
#endif /* CONFIG_SMP */
extern struct sysdev_class cpu_sysdev_class;
#ifdef CONFIG_HOTPLUG_CPU
/* Stop CPUs going up and down. */
extern struct semaphore cpucontrol;
#define lock_cpu_hotplug() down(&cpucontrol)
#define unlock_cpu_hotplug() up(&cpucontrol)
#define lock_cpu_hotplug_interruptible() down_interruptible(&cpucontrol)
#define hotcpu_notifier(fn, pri) { \
static struct notifier_block fn##_nb = \
{ .notifier_call = fn, .priority = pri }; \
register_cpu_notifier(&fn##_nb); \
}
int cpu_down(unsigned int cpu);
extern int __attribute__((weak)) smp_prepare_cpu(int cpu);
#define cpu_is_offline(cpu) unlikely(!cpu_online(cpu))
#else
#define lock_cpu_hotplug() do { } while (0)
#define unlock_cpu_hotplug() do { } while (0)
#define lock_cpu_hotplug_interruptible() 0
#define hotcpu_notifier(fn, pri)
/* CPUs don't go offline once they're online w/o CONFIG_HOTPLUG_CPU */
static inline int cpu_is_offline(int cpu) { return 0; }
#endif
#endif /* _LINUX_CPU_H_ */
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