kernel-ark/include/linux/spinlock_up.h
Viresh Kumar 0a0fca9d83 sched: Rename sched.c as sched/core.c in comments and Documentation
Most of the stuff from kernel/sched.c was moved to kernel/sched/core.c long time
back and the comments/Documentation never got updated.

I figured it out when I was going through sched-domains.txt and so thought of
fixing it globally.

I haven't crossed check if the stuff that is referenced in sched/core.c by all
these files is still present and hasn't changed as that wasn't the motive behind
this patch.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/cdff76a265326ab8d71922a1db5be599f20aad45.1370329560.git.viresh.kumar@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-19 12:58:42 +02:00

86 lines
2.5 KiB
C

#ifndef __LINUX_SPINLOCK_UP_H
#define __LINUX_SPINLOCK_UP_H
#ifndef __LINUX_SPINLOCK_H
# error "please don't include this file directly"
#endif
#include <asm/processor.h> /* for cpu_relax() */
/*
* include/linux/spinlock_up.h - UP-debug version of spinlocks.
*
* portions Copyright 2005, Red Hat, Inc., Ingo Molnar
* Released under the General Public License (GPL).
*
* In the debug case, 1 means unlocked, 0 means locked. (the values
* are inverted, to catch initialization bugs)
*
* No atomicity anywhere, we are on UP. However, we still need
* the compiler barriers, because we do not want the compiler to
* move potentially faulting instructions (notably user accesses)
* into the locked sequence, resulting in non-atomic execution.
*/
#ifdef CONFIG_DEBUG_SPINLOCK
#define arch_spin_is_locked(x) ((x)->slock == 0)
static inline void arch_spin_lock(arch_spinlock_t *lock)
{
lock->slock = 0;
barrier();
}
static inline void
arch_spin_lock_flags(arch_spinlock_t *lock, unsigned long flags)
{
local_irq_save(flags);
lock->slock = 0;
barrier();
}
static inline int arch_spin_trylock(arch_spinlock_t *lock)
{
char oldval = lock->slock;
lock->slock = 0;
barrier();
return oldval > 0;
}
static inline void arch_spin_unlock(arch_spinlock_t *lock)
{
barrier();
lock->slock = 1;
}
/*
* Read-write spinlocks. No debug version.
*/
#define arch_read_lock(lock) do { barrier(); (void)(lock); } while (0)
#define arch_write_lock(lock) do { barrier(); (void)(lock); } while (0)
#define arch_read_trylock(lock) ({ barrier(); (void)(lock); 1; })
#define arch_write_trylock(lock) ({ barrier(); (void)(lock); 1; })
#define arch_read_unlock(lock) do { barrier(); (void)(lock); } while (0)
#define arch_write_unlock(lock) do { barrier(); (void)(lock); } while (0)
#else /* DEBUG_SPINLOCK */
#define arch_spin_is_locked(lock) ((void)(lock), 0)
/* for sched/core.c and kernel_lock.c: */
# define arch_spin_lock(lock) do { barrier(); (void)(lock); } while (0)
# define arch_spin_lock_flags(lock, flags) do { barrier(); (void)(lock); } while (0)
# define arch_spin_unlock(lock) do { barrier(); (void)(lock); } while (0)
# define arch_spin_trylock(lock) ({ barrier(); (void)(lock); 1; })
#endif /* DEBUG_SPINLOCK */
#define arch_spin_is_contended(lock) (((void)(lock), 0))
#define arch_read_can_lock(lock) (((void)(lock), 1))
#define arch_write_can_lock(lock) (((void)(lock), 1))
#define arch_spin_unlock_wait(lock) \
do { cpu_relax(); } while (arch_spin_is_locked(lock))
#endif /* __LINUX_SPINLOCK_UP_H */