mirror of
https://github.com/adulau/aha.git
synced 2024-12-28 03:36:19 +00:00
96f1050d3d
Bill Gatliff & David Brownell pointed out we were missing some copyrights, and licensing terms in some of the files in ./arch/blackfin, so this fixes things, and cleans them up. It also removes: - verbose GPL text(refer to the top level ./COPYING file) - file names (you are looking at the file) - bug url (it's in the ./MAINTAINERS file) - "or later" on GPL-2, when we did not have that right It also allows some Blackfin-specific assembly files to be under a BSD like license (for people to use them outside of Linux). Signed-off-by: Robin Getz <robin.getz@analog.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
76 lines
1.7 KiB
C
76 lines
1.7 KiB
C
/*
|
|
* Pull in the generic implementation for the mutex fastpath.
|
|
*
|
|
* TODO: implement optimized primitives instead, or leave the generic
|
|
* implementation in place, or pick the atomic_xchg() based generic
|
|
* implementation. (see asm-generic/mutex-xchg.h for details)
|
|
*
|
|
* Copyright 2006-2009 Analog Devices Inc.
|
|
*
|
|
* Licensed under the GPL-2 or later.
|
|
*/
|
|
|
|
#ifndef _ASM_MUTEX_H
|
|
#define _ASM_MUTEX_H
|
|
|
|
#ifndef CONFIG_SMP
|
|
#include <asm-generic/mutex.h>
|
|
#else
|
|
|
|
static inline void
|
|
__mutex_fastpath_lock(atomic_t *count, void (*fail_fn)(atomic_t *))
|
|
{
|
|
if (unlikely(atomic_dec_return(count) < 0))
|
|
fail_fn(count);
|
|
else
|
|
smp_mb();
|
|
}
|
|
|
|
static inline int
|
|
__mutex_fastpath_lock_retval(atomic_t *count, int (*fail_fn)(atomic_t *))
|
|
{
|
|
if (unlikely(atomic_dec_return(count) < 0))
|
|
return fail_fn(count);
|
|
else {
|
|
smp_mb();
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
static inline void
|
|
__mutex_fastpath_unlock(atomic_t *count, void (*fail_fn)(atomic_t *))
|
|
{
|
|
smp_mb();
|
|
if (unlikely(atomic_inc_return(count) <= 0))
|
|
fail_fn(count);
|
|
}
|
|
|
|
#define __mutex_slowpath_needs_to_unlock() 1
|
|
|
|
static inline int
|
|
__mutex_fastpath_trylock(atomic_t *count, int (*fail_fn)(atomic_t *))
|
|
{
|
|
/*
|
|
* We have two variants here. The cmpxchg based one is the best one
|
|
* because it never induce a false contention state. It is included
|
|
* here because architectures using the inc/dec algorithms over the
|
|
* xchg ones are much more likely to support cmpxchg natively.
|
|
*
|
|
* If not we fall back to the spinlock based variant - that is
|
|
* just as efficient (and simpler) as a 'destructive' probing of
|
|
* the mutex state would be.
|
|
*/
|
|
#ifdef __HAVE_ARCH_CMPXCHG
|
|
if (likely(atomic_cmpxchg(count, 1, 0) == 1)) {
|
|
smp_mb();
|
|
return 1;
|
|
}
|
|
return 0;
|
|
#else
|
|
return fail_fn(count);
|
|
#endif
|
|
}
|
|
|
|
#endif
|
|
|
|
#endif
|