/*-
* Copyright (c) 2010 Isilon Systems, Inc.
* Copyright (c) 2010 iX Systems, Inc.
* Copyright (c) 2010 Panasas, Inc.
* Copyright (c) 2013-2017 Mellanox Technologies, Ltd.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice unmodified, this list of conditions, and the following
* disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef _LINUX_MUTEX_H_
#define _LINUX_MUTEX_H_
#include <sys/param.h>
#include <sys/proc.h>
#include <sys/lock.h>
#include <sys/sx.h>
#include <linux/spinlock.h>
#include <asm/atomic.h>
typedef struct mutex {
struct sx sx;
} mutex_t;
/*
* By defining CONFIG_NO_MUTEX_SKIP LinuxKPI mutexes and asserts will
* not be skipped during panic().
*/
#ifdef CONFIG_NO_MUTEX_SKIP
#define MUTEX_SKIP(void) 0
#else
#define MUTEX_SKIP(void) unlikely(SCHEDULER_STOPPED() || kdb_active)
#endif
#define mutex_lock(_m) do { \
if (MUTEX_SKIP()) \
break; \
sx_xlock(&(_m)->sx); \
} while (0)
#define mutex_lock_nested(_m, _s) mutex_lock(_m)
#define mutex_lock_nest_lock(_m, _s) mutex_lock(_m)
#define mutex_lock_interruptible(_m) ({ \
MUTEX_SKIP() ? 0 : \
linux_mutex_lock_interruptible(_m); \
})
#define mutex_lock_interruptible_nested(m, c) mutex_lock_interruptible(m)
/*
* Reuse the interruptable method since the SX
* lock handles both signals and interrupts:
*/
#define mutex_lock_killable(_m) ({ \
MUTEX_SKIP() ? 0 : \
linux_mutex_lock_interruptible(_m); \
})
#define mutex_lock_killable_nested(_m, _sub) \
mutex_lock_killable(_m)
#define mutex_unlock(_m) do { \
if (MUTEX_SKIP()) \
break; \
sx_xunlock(&(_m)->sx); \
} while (0)
#define mutex_trylock(_m) ({ \
MUTEX_SKIP() ? 1 : \
!!sx_try_xlock(&(_m)->sx); \
})
enum mutex_trylock_recursive_enum {
MUTEX_TRYLOCK_FAILED = 0,
MUTEX_TRYLOCK_SUCCESS = 1,
MUTEX_TRYLOCK_RECURSIVE = 2,
};
static inline __must_check enum mutex_trylock_recursive_enum
mutex_trylock_recursive(struct mutex *lock)
{
if (unlikely(sx_xholder(&lock->sx) == curthread))
return (MUTEX_TRYLOCK_RECURSIVE);
return (mutex_trylock(lock));
}
#define mutex_init(_m) \
linux_mutex_init(_m, mutex_name(#_m), SX_NOWITNESS)
#define __mutex_init(_m, _n, _l) \
linux_mutex_init(_m, _n, SX_NOWITNESS)
#define mutex_init_witness(_m) \
linux_mutex_init(_m, mutex_name(#_m), SX_DUPOK)
#define mutex_destroy(_m) \
linux_mutex_destroy(_m)
static inline bool
mutex_is_locked(mutex_t *m)
{
return ((struct thread *)SX_OWNER(m->sx.sx_lock) != NULL);
}
static inline bool
mutex_is_owned(mutex_t *m)
{
return (sx_xlocked(&m->sx));
}
static inline int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *m)
{
if (atomic_dec_and_test(cnt)) {
mutex_lock(m);
return (1);
}
return (0);
}
#ifdef WITNESS_ALL
/* NOTE: the maximum WITNESS name is 64 chars */
#define __mutex_name(name, file, line) \
(((const char *){file ":" #line "-" name}) + \
(sizeof(file) > 16 ? sizeof(file) - 16 : 0))
#else
#define __mutex_name(name, file, line) name
#endif
#define _mutex_name(...) __mutex_name(__VA_ARGS__)
#define mutex_name(name) _mutex_name(name, __FILE__, __LINE__)
#define DEFINE_MUTEX(lock) \
mutex_t lock; \
SX_SYSINIT_FLAGS(lock, &(lock).sx, mutex_name(#lock), SX_DUPOK)
static inline void
linux_mutex_init(mutex_t *m, const char *name, int flags)
{
memset(m, 0, sizeof(*m));
sx_init_flags(&m->sx, name, flags);
}
static inline void
linux_mutex_destroy(mutex_t *m)
{
if (mutex_is_owned(m))
mutex_unlock(m);
sx_destroy(&m->sx);
}
extern int linux_mutex_lock_interruptible(mutex_t *m);
#endif /* _LINUX_MUTEX_H_ */
