linux-stable/include/linux/spinlock_up.h
Stephen Rothwell d974d905cb spinlock_up.h: include asm/processor.h in for cpu_relax
Commit e66eed651f ("list: remove prefetching from regular list
iterators") removed the include of prefetch.h from list.h and this was a
path to including asm/processor.h.  We need to include it excplicitly
now.

Fixes this build error on sparc32 (at least):

  In file included from include/linux/seqlock.h:29,
                   from include/linux/time.h:8,
                   from include/linux/timex.h:56,
                   from include/linux/sched.h:57,
                   from arch/sparc/kernel/asm-offsets.c:13:
  include/linux/spinlock.h: In function 'spin_unlock_wait':
  include/linux/spinlock.h:360: error: implicit declaration of function 'cpu_relax

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-20 12:51:07 -07:00

78 lines
2.1 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.
*/
#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;
}
static inline void
arch_spin_lock_flags(arch_spinlock_t *lock, unsigned long flags)
{
local_irq_save(flags);
lock->slock = 0;
}
static inline int arch_spin_trylock(arch_spinlock_t *lock)
{
char oldval = lock->slock;
lock->slock = 0;
return oldval > 0;
}
static inline void arch_spin_unlock(arch_spinlock_t *lock)
{
lock->slock = 1;
}
/*
* Read-write spinlocks. No debug version.
*/
#define arch_read_lock(lock) do { (void)(lock); } while (0)
#define arch_write_lock(lock) do { (void)(lock); } while (0)
#define arch_read_trylock(lock) ({ (void)(lock); 1; })
#define arch_write_trylock(lock) ({ (void)(lock); 1; })
#define arch_read_unlock(lock) do { (void)(lock); } while (0)
#define arch_write_unlock(lock) do { (void)(lock); } while (0)
#else /* DEBUG_SPINLOCK */
#define arch_spin_is_locked(lock) ((void)(lock), 0)
/* for sched.c and kernel_lock.c: */
# define arch_spin_lock(lock) do { (void)(lock); } while (0)
# define arch_spin_lock_flags(lock, flags) do { (void)(lock); } while (0)
# define arch_spin_unlock(lock) do { (void)(lock); } while (0)
# define arch_spin_trylock(lock) ({ (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 */