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/*-
* 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.
*/
#ifndef _LINUXKPI_LINUX_SPINLOCK_H_
#define _LINUXKPI_LINUX_SPINLOCK_H_
#include <asm/atomic.h>
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/kdb.h>
#include <linux/compiler.h>
#include <linux/rwlock.h>
#include <linux/bottom_half.h>
#include <linux/lockdep.h>
typedef struct {
struct mtx m;
} spinlock_t;
/*
* By defining CONFIG_SPIN_SKIP LinuxKPI spinlocks and asserts will be
* skipped during panic(). By default it is disabled due to
* performance reasons.
*/
#ifdef CONFIG_SPIN_SKIP
#define SPIN_SKIP(void) unlikely(SCHEDULER_STOPPED() || kdb_active)
#else
#define SPIN_SKIP(void) 0
#endif
#define spin_lock(_l) do { \
if (SPIN_SKIP()) \
break; \
mtx_lock(&(_l)->m); \
local_bh_disable(); \
} while (0)
#define spin_lock_bh(_l) do { \
spin_lock(_l); \
local_bh_disable(); \
} while (0)
#define spin_lock_irq(_l) do { \
spin_lock(_l); \
} while (0)
#define spin_unlock(_l) do { \
if (SPIN_SKIP()) \
break; \
local_bh_enable(); \
mtx_unlock(&(_l)->m); \
} while (0)
#define spin_unlock_bh(_l) do { \
local_bh_enable(); \
spin_unlock(_l); \
} while (0)
#define spin_unlock_irq(_l) do { \
spin_unlock(_l); \
} while (0)
#define spin_trylock(_l) ({ \
int __ret; \
if (SPIN_SKIP()) { \
__ret = 1; \
} else { \
__ret = mtx_trylock(&(_l)->m); \
if (likely(__ret != 0)) \
local_bh_disable(); \
} \
__ret; \
})
#define spin_trylock_irq(_l) \
spin_trylock(_l)
#define spin_trylock_irqsave(_l, flags) ({ \
(flags) = 0; \
spin_trylock(_l); \
})
#define spin_lock_nested(_l, _n) do { \
if (SPIN_SKIP()) \
break; \
mtx_lock_flags(&(_l)->m, MTX_DUPOK); \
local_bh_disable(); \
} while (0)
#define spin_lock_irqsave(_l, flags) do { \
(flags) = 0; \
spin_lock(_l); \
} while (0)
#define spin_lock_irqsave_nested(_l, flags, _n) do { \
(flags) = 0; \
spin_lock_nested(_l, _n); \
} while (0)
#define spin_unlock_irqrestore(_l, flags) do { \
(void)(flags); \
spin_unlock(_l); \
} while (0)
#ifdef WITNESS_ALL
/* NOTE: the maximum WITNESS name is 64 chars */
#define __spin_lock_name(name, file, line) \
(((const char *){file ":" #line "-" name}) + \
(sizeof(file) > 16 ? sizeof(file) - 16 : 0))
#else
#define __spin_lock_name(name, file, line) name
#endif
#define _spin_lock_name(...) __spin_lock_name(__VA_ARGS__)
#define spin_lock_name(name) _spin_lock_name(name, __FILE__, __LINE__)
#define spin_lock_init(lock) linux_spin_lock_init(lock, spin_lock_name("lnxspin"))
static inline void
linux_spin_lock_init(spinlock_t *lock, const char *name)
{
memset(lock, 0, sizeof(*lock));
mtx_init(&lock->m, name, NULL, MTX_DEF | MTX_NOWITNESS);
}
static inline void
spin_lock_destroy(spinlock_t *lock)
{
mtx_destroy(&lock->m);
}
#define DEFINE_SPINLOCK(lock) \
spinlock_t lock; \
MTX_SYSINIT(lock, &(lock).m, spin_lock_name("lnxspin"), MTX_DEF)
#define assert_spin_locked(_l) do { \
if (SPIN_SKIP()) \
break; \
mtx_assert(&(_l)->m, MA_OWNED); \
} while (0)
#define atomic_dec_and_lock_irqsave(cnt, lock, flags) \
_atomic_dec_and_lock_irqsave(cnt, lock, &(flags))
static inline int
_atomic_dec_and_lock_irqsave(atomic_t *cnt, spinlock_t *lock,
unsigned long *flags)
{
if (atomic_add_unless(cnt, -1, 1))
return (0);
spin_lock_irqsave(lock, *flags);
if (atomic_dec_and_test(cnt))
return (1);
spin_unlock_irqrestore(lock, *flags);
return (0);
}
#endif /* _LINUXKPI_LINUX_SPINLOCK_H_ */
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