zfs/include/sys/atomic.h

155 lines
3.5 KiB
C

/*
* This file is part of the SPL: Solaris Porting Layer.
*
* Copyright (c) 2008 Lawrence Livermore National Security, LLC.
* Produced at Lawrence Livermore National Laboratory
* Written by:
* Brian Behlendorf <behlendorf1@llnl.gov>,
* Herb Wartens <wartens2@llnl.gov>,
* Jim Garlick <garlick@llnl.gov>
* UCRL-CODE-235197
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef _SPL_ATOMIC_H
#define _SPL_ATOMIC_H
#ifdef __cplusplus
extern "C" {
#endif
#include <linux/module.h>
#include <linux/spinlock.h>
/* XXX: Serialize everything through global locks. This is
* going to be bad for performance, but for now it's the easiest
* way to ensure correct behavior. I don't like it at all.
* It would be nicer to make these function to the atomic linux
* functions, but the normal uint64_t type complicates this.
*/
extern spinlock_t atomic64_lock;
extern spinlock_t atomic32_lock;
static __inline__ uint32_t
atomic_add_32(volatile uint32_t *target, int32_t delta)
{
uint32_t rc;
spin_lock(&atomic32_lock);
rc = *target;
*target += delta;
spin_unlock(&atomic32_lock);
return rc;
}
static __inline__ void
atomic_inc_64(volatile uint64_t *target)
{
spin_lock(&atomic64_lock);
(*target)++;
spin_unlock(&atomic64_lock);
}
static __inline__ void
atomic_dec_64(volatile uint64_t *target)
{
spin_lock(&atomic64_lock);
(*target)--;
spin_unlock(&atomic64_lock);
}
static __inline__ uint64_t
atomic_add_64(volatile uint64_t *target, uint64_t delta)
{
uint64_t rc;
spin_lock(&atomic64_lock);
rc = *target;
*target += delta;
spin_unlock(&atomic64_lock);
return rc;
}
static __inline__ uint64_t
atomic_sub_64(volatile uint64_t *target, uint64_t delta)
{
uint64_t rc;
spin_lock(&atomic64_lock);
rc = *target;
*target -= delta;
spin_unlock(&atomic64_lock);
return rc;
}
static __inline__ uint64_t
atomic_add_64_nv(volatile uint64_t *target, uint64_t delta)
{
spin_lock(&atomic64_lock);
*target += delta;
spin_unlock(&atomic64_lock);
return *target;
}
static __inline__ uint64_t
atomic_sub_64_nv(volatile uint64_t *target, uint64_t delta)
{
spin_lock(&atomic64_lock);
*target -= delta;
spin_unlock(&atomic64_lock);
return *target;
}
static __inline__ uint64_t
atomic_cas_64(volatile uint64_t *target, uint64_t cmp,
uint64_t newval)
{
uint64_t rc;
spin_lock(&atomic64_lock);
rc = *target;
if (*target == cmp)
*target = newval;
spin_unlock(&atomic64_lock);
return rc;
}
#if defined(__x86_64__)
/* XXX: Implement atomic_cas_ptr() in terms of uint64'ts. This
* is of course only safe and correct for 64 bit arches... but
* for now I'm OK with that.
*/
static __inline__ void *
atomic_cas_ptr(volatile void *target, void *cmp, void *newval)
{
return (void *)atomic_cas_64((volatile uint64_t *)target,
(uint64_t)cmp, (uint64_t)newval);
}
#endif
#ifdef __cplusplus
}
#endif
#endif /* _SPL_ATOMIC_H */