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302b88e6ab
These functions didn't exist for all archs prior to 2.6.24. This
patch addes an autoconf test to detect this and add them when needed.
The autoconf check is needed instead of just an #ifndef because in
the most modern kernels atomic64_{cmp}xchg are implemented as in
inline function and not a #define.
228 lines
6.0 KiB
C
228 lines
6.0 KiB
C
/*
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* This file is part of the SPL: Solaris Porting Layer.
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*
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* Copyright (c) 2008 Lawrence Livermore National Security, LLC.
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* Produced at Lawrence Livermore National Laboratory
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* Written by:
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* Brian Behlendorf <behlendorf1@llnl.gov>,
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* Herb Wartens <wartens2@llnl.gov>,
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* Jim Garlick <garlick@llnl.gov>
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* UCRL-CODE-235197
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*
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* This is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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#ifndef _SPL_ATOMIC_H
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#define _SPL_ATOMIC_H
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#include <linux/module.h>
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#include <linux/spinlock.h>
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#include <sys/types.h>
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#include <asm/atomic_compat.h>
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/*
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* Two approaches to atomic operations are implemented each with its
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* own benefits are drawbacks imposed by the Solaris API. Neither
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* approach handles the issue of word breaking when using a 64-bit
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* atomic variable on a 32-bit arch. The Solaris API would need to
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* add an atomic read call to correctly support this.
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*
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* When ATOMIC_SPINLOCK is defined all atomic operations will be
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* serialized through global spin locks. This is bad for performance
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* but it does allow a simple generic implementation.
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*
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* When ATOMIC_SPINLOCK is not defined the Linux atomic operations
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* are used. This is safe as long as the core Linux implementation
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* doesn't change because we are relying on the fact that an atomic
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* type is really just a uint32 or uint64. If this changes at some
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* point in the future we need to fall-back to the spin approach.
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*/
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#ifdef ATOMIC_SPINLOCK
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extern spinlock_t atomic32_lock;
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extern spinlock_t atomic64_lock;
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static __inline__ void
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atomic_inc_32(volatile uint32_t *target)
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{
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spin_lock(&atomic32_lock);
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(*target)++;
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spin_unlock(&atomic32_lock);
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}
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static __inline__ void
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atomic_dec_32(volatile uint32_t *target)
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{
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spin_lock(&atomic32_lock);
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(*target)--;
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spin_unlock(&atomic32_lock);
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}
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static __inline__ void
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atomic_add_32(volatile uint32_t *target, int32_t delta)
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{
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spin_lock(&atomic32_lock);
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*target += delta;
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spin_unlock(&atomic32_lock);
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}
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static __inline__ void
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atomic_sub_32(volatile uint32_t *target, int32_t delta)
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{
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spin_lock(&atomic32_lock);
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*target -= delta;
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spin_unlock(&atomic32_lock);
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}
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static __inline__ uint32_t
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atomic_add_32_nv(volatile uint32_t *target, uint32_t delta)
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{
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spin_lock(&atomic32_lock);
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*target += delta;
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spin_unlock(&atomic32_lock);
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return *target;
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}
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static __inline__ uint32_t
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atomic_sub_32_nv(volatile uint32_t *target, uint32_t delta)
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{
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spin_lock(&atomic32_lock);
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*target -= delta;
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spin_unlock(&atomic32_lock);
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return *target;
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}
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static __inline__ uint32_t
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atomic_cas_32(volatile uint32_t *target, uint32_t cmp,
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uint32_t newval)
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{
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uint32_t rc;
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spin_lock(&atomic32_lock);
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rc = *target;
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if (*target == cmp)
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*target = newval;
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spin_unlock(&atomic32_lock);
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return rc;
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}
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static __inline__ void
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atomic_inc_64(volatile uint64_t *target)
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{
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spin_lock(&atomic64_lock);
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(*target)++;
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spin_unlock(&atomic64_lock);
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}
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static __inline__ void
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atomic_dec_64(volatile uint64_t *target)
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{
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spin_lock(&atomic64_lock);
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(*target)--;
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spin_unlock(&atomic64_lock);
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}
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static __inline__ void
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atomic_add_64(volatile uint64_t *target, uint64_t delta)
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{
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spin_lock(&atomic64_lock);
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*target += delta;
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spin_unlock(&atomic64_lock);
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}
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static __inline__ void
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atomic_sub_64(volatile uint64_t *target, uint64_t delta)
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{
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spin_lock(&atomic64_lock);
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*target -= delta;
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spin_unlock(&atomic64_lock);
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}
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static __inline__ uint64_t
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atomic_add_64_nv(volatile uint64_t *target, uint64_t delta)
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{
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spin_lock(&atomic64_lock);
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*target += delta;
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spin_unlock(&atomic64_lock);
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return *target;
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}
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static __inline__ uint64_t
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atomic_sub_64_nv(volatile uint64_t *target, uint64_t delta)
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{
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spin_lock(&atomic64_lock);
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*target -= delta;
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spin_unlock(&atomic64_lock);
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return *target;
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}
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static __inline__ uint64_t
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atomic_cas_64(volatile uint64_t *target, uint64_t cmp,
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uint64_t newval)
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{
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uint64_t rc;
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spin_lock(&atomic64_lock);
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rc = *target;
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if (*target == cmp)
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*target = newval;
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spin_unlock(&atomic64_lock);
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return rc;
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}
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#else /* ATOMIC_SPINLOCK */
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#define atomic_inc_32(v) atomic_inc((atomic_t *)(v))
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#define atomic_dec_32(v) atomic_dec((atomic_t *)(v))
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#define atomic_add_32(v, i) atomic_add((i), (atomic_t *)(v))
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#define atomic_sub_32(v, i) atomic_sub((i), (atomic_t *)(v))
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#define atomic_add_32_nv(v, i) atomic_add_return((i), (atomic_t *)(v))
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#define atomic_sub_32_nv(v, i) atomic_sub_return((i), (atomic_t *)(v))
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#define atomic_cas_32(v, x, y) atomic_cmpxchg((atomic_t *)(v), x, y)
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#define atomic_inc_64(v) atomic64_inc((atomic64_t *)(v))
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#define atomic_dec_64(v) atomic64_dec((atomic64_t *)(v))
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#define atomic_add_64(v, i) atomic64_add((i), (atomic64_t *)(v))
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#define atomic_sub_64(v, i) atomic64_sub((i), (atomic64_t *)(v))
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#define atomic_add_64_nv(v, i) atomic64_add_return((i), (atomic64_t *)(v))
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#define atomic_sub_64_nv(v, i) atomic64_sub_return((i), (atomic64_t *)(v))
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#define atomic_cas_64(v, x, y) atomic64_cmpxchg((atomic64_t *)(v), x, y)
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#endif /* ATOMIC_SPINLOCK */
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#ifdef _LP64
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static __inline__ void *
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atomic_cas_ptr(volatile void *target, void *cmp, void *newval)
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{
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return (void *)atomic_cas_64((volatile uint64_t *)target,
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(uint64_t)cmp, (uint64_t)newval);
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}
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#else /* _LP64 */
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static __inline__ void *
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atomic_cas_ptr(volatile void *target, void *cmp, void *newval)
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{
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return (void *)atomic_cas_32((volatile uint32_t *)target,
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(uint32_t)cmp, (uint32_t)newval);
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}
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#endif /* _LP64 */
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#endif /* _SPL_ATOMIC_H */
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