linux-stable/include/linux/cpu.h
Satyam Sharma 761bb43190 Redefine {un}register_hotcpu_notifier() !HOTPLUG_CPU stubs
The return of the present "do {} while" based stub definition of
register_hotcpu_notifier() cannot be checked.  This makes the stub
asymmetric w.r.t.  the real HOTPLUG_CPU=y implementation that is
int-returning.  So let us redefine this to be consistent with the full
version.  Also do the same for unregister_hotcpu_notifier().

We cannot define these as static inline functions due to an existing GCC
bug (#33172).  So define as macros that return appropriately instead (int
'0' for the register_hotcpu_notifier case and void for
unregister_hotcpu_notifier).

Signed-off-by: Satyam Sharma <satyam@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-18 14:37:28 -07:00

142 lines
4 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>
#include <linux/mutex.h>
struct cpu {
int node_id; /* The node which contains the CPU */
int hotpluggable; /* creates sysfs control file if hotpluggable */
struct sys_device sysdev;
};
extern int register_cpu(struct cpu *cpu, int num);
extern struct sys_device *get_cpu_sysdev(unsigned cpu);
extern int cpu_add_sysdev_attr(struct sysdev_attribute *attr);
extern void cpu_remove_sysdev_attr(struct sysdev_attribute *attr);
extern int cpu_add_sysdev_attr_group(struct attribute_group *attrs);
extern void cpu_remove_sysdev_attr_group(struct attribute_group *attrs);
extern int sched_create_sysfs_power_savings_entries(struct sysdev_class *cls);
#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? */
#ifdef CONFIG_HOTPLUG_CPU
extern int register_cpu_notifier(struct notifier_block *nb);
extern void unregister_cpu_notifier(struct notifier_block *nb);
#else
#ifndef MODULE
extern int register_cpu_notifier(struct notifier_block *nb);
#else
static inline int register_cpu_notifier(struct notifier_block *nb)
{
return 0;
}
#endif
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. */
static inline void cpuhotplug_mutex_lock(struct mutex *cpu_hp_mutex)
{
mutex_lock(cpu_hp_mutex);
}
static inline void cpuhotplug_mutex_unlock(struct mutex *cpu_hp_mutex)
{
mutex_unlock(cpu_hp_mutex);
}
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 /* CONFIG_HOTPLUG_CPU */
static inline void cpuhotplug_mutex_lock(struct mutex *cpu_hp_mutex)
{ }
static inline void cpuhotplug_mutex_unlock(struct mutex *cpu_hp_mutex)
{ }
#define lock_cpu_hotplug() do { } while (0)
#define unlock_cpu_hotplug() do { } while (0)
#define hotcpu_notifier(fn, pri) do { (void)(fn); } while (0)
/* These aren't inline functions due to a GCC bug. */
#define register_hotcpu_notifier(nb) ({ (void)(nb); 0; })
#define unregister_hotcpu_notifier(nb) ({ (void)(nb); })
/* 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 /* CONFIG_HOTPLUG_CPU */
#ifdef CONFIG_PM_SLEEP_SMP
extern int suspend_cpu_hotplug;
extern int disable_nonboot_cpus(void);
extern void enable_nonboot_cpus(void);
#else /* !CONFIG_PM_SLEEP_SMP */
#define suspend_cpu_hotplug 0
static inline int disable_nonboot_cpus(void) { return 0; }
static inline void enable_nonboot_cpus(void) {}
#endif /* !CONFIG_PM_SLEEP_SMP */
#endif /* _LINUX_CPU_H_ */