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linux-next/include/linux/cpu.h
Rafael J. Wysocki e3920fb42c [PATCH] Disable CPU hotplug during suspend
The current suspend code has to be run on one CPU, so we use the CPU
hotplug to take the non-boot CPUs offline on SMP machines.  However, we
should also make sure that these CPUs will not be enabled by someone else
after we have disabled them.

The functions disable_nonboot_cpus() and enable_nonboot_cpus() are moved to
kernel/cpu.c, because they now refer to some stuff in there that should
better be static.  Also it's better if disable_nonboot_cpus() returns an
error instead of panicking if something goes wrong, and
enable_nonboot_cpus() has no reason to panic(), because the CPUs may have
been enabled by the userland before it tries to take them online.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26 08:48:59 -07:00

101 lines
2.9 KiB
C

/*
* 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 *cpu, int num);
extern struct sys_device *get_cpu_sysdev(unsigned cpu);
#ifdef CONFIG_HOTPLUG_CPU
extern void unregister_cpu(struct cpu *cpu);
#endif
struct notifier_block;
#ifdef CONFIG_SMP
/* Need to know about CPUs going up/down? */
extern int register_cpu_notifier(struct notifier_block *nb);
#ifdef CONFIG_HOTPLUG_CPU
extern void unregister_cpu_notifier(struct notifier_block *nb);
#else
static inline void unregister_cpu_notifier(struct notifier_block *nb)
{
}
#endif
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 void lock_cpu_hotplug(void);
extern void unlock_cpu_hotplug(void);
#define hotcpu_notifier(fn, pri) { \
static struct notifier_block fn##_nb = \
{ .notifier_call = fn, .priority = pri }; \
register_cpu_notifier(&fn##_nb); \
}
#define register_hotcpu_notifier(nb) register_cpu_notifier(nb)
#define unregister_hotcpu_notifier(nb) unregister_cpu_notifier(nb)
int cpu_down(unsigned 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) do { } while (0)
#define register_hotcpu_notifier(nb) do { } while (0)
#define unregister_hotcpu_notifier(nb) do { } while (0)
/* 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
#ifdef CONFIG_SUSPEND_SMP
extern int disable_nonboot_cpus(void);
extern void enable_nonboot_cpus(void);
#else
static inline int disable_nonboot_cpus(void) { return 0; }
static inline void enable_nonboot_cpus(void) {}
#endif
#endif /* _LINUX_CPU_H_ */