/*      $NetBSD: atomic_cas_generic.c,v 1.3 2021/03/14 22:56:39 christos Exp $  */

/*-
 * Copyright (c) 2008 The NetBSD Foundation, Inc.
 * 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, 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 NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``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 FOUNDATION OR CONTRIBUTORS
 * 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.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: atomic_cas_generic.c,v 1.3 2021/03/14 22:56:39 christos Exp $");

/*
 * This is basically common/lib/libc/atomic/atomic_init_testset.c
 * which always assumes MP and never uses RAS.  This is used only on
 * some archs.  See Makefile.rumpkern for more information.
 */

#include "atomic_op_namespace.h"

#include <sys/types.h>
#include <sys/atomic.h>
#include <sys/lock.h>

#define I2      __SIMPLELOCK_UNLOCKED, __SIMPLELOCK_UNLOCKED,
#define I16     I2 I2 I2 I2 I2 I2 I2 I2
#define I128    I16 I16 I16 I16 I16 I16 I16 I16

static __cpu_simple_lock_t atomic_locks32[128] = { I128 };

uint32_t
_atomic_cas_32(volatile uint32_t *ptr, uint32_t old, uint32_t new)
{
        __cpu_simple_lock_t *lock;
        uint32_t ret;

        lock = &atomic_locks32[((uintptr_t)ptr >> 3) & 127];
        __cpu_simple_lock(lock);
        ret = *ptr;
        if (__predict_true(ret == old)) {
                *ptr = new;
        }
        __cpu_simple_unlock(lock);

        return ret;
}

#undef atomic_cas_32
atomic_op_alias(atomic_cas_32,_atomic_cas_32)
atomic_op_alias(atomic_cas_32_ni,_atomic_cas_32)
__strong_alias(_atomic_cas_32_ni,_atomic_cas_32)

#ifdef _LP64
static __cpu_simple_lock_t atomic_locks64[128] = { I128 };

uint64_t
_atomic_cas_64(volatile uint64_t *ptr, uint64_t old, uint64_t new)
{
        __cpu_simple_lock_t *lock;
        uint64_t ret;

        lock = &atomic_locks64[((uintptr_t)ptr >> 4) & 127];
        __cpu_simple_lock(lock);
        ret = *ptr;
        if (__predict_true(ret == old)) {
                *ptr = new;
        }
        __cpu_simple_unlock(lock);

        return ret;
}

#undef atomic_cas_64
atomic_op_alias(atomic_cas_64,_atomic_cas_64)
atomic_op_alias(atomic_cas_64_ni,_atomic_cas_64)
__strong_alias(_atomic_cas_64_ni,_atomic_cas_64)

#endif

#undef atomic_cas_uint
#undef atomic_cas_ulong
#undef atomic_cas_ptr

atomic_op_alias(atomic_cas_uint,_atomic_cas_32)
__strong_alias(_atomic_cas_uint,_atomic_cas_32)
atomic_op_alias(atomic_cas_uint_ni,_atomic_cas_32)
__strong_alias(_atomic_cas_uint_ni,_atomic_cas_32)

#ifdef _LP64
atomic_op_alias(atomic_cas_ulong,_atomic_cas_64)
__strong_alias(_atomic_cas_ulong,_atomic_cas_64)
atomic_op_alias(atomic_cas_ulong_ni,_atomic_cas_64)
__strong_alias(_atomic_cas_ulong_ni,_atomic_cas_64)
atomic_op_alias(atomic_cas_ptr,_atomic_cas_64)
__strong_alias(_atomic_cas_ptr,_atomic_cas_64)
atomic_op_alias(atomic_cas_ptr_ni,_atomic_cas_64)
__strong_alias(_atomic_cas_ptr_ni,_atomic_cas_64)
#else
atomic_op_alias(atomic_cas_ulong,_atomic_cas_32)
__strong_alias(_atomic_cas_ulong,_atomic_cas_32)
atomic_op_alias(atomic_cas_ulong_ni,_atomic_cas_32)
__strong_alias(_atomic_cas_ulong_ni,_atomic_cas_32)
atomic_op_alias(atomic_cas_ptr,_atomic_cas_32)
__strong_alias(_atomic_cas_ptr,_atomic_cas_32)
atomic_op_alias(atomic_cas_ptr_ni,_atomic_cas_32)
__strong_alias(_atomic_cas_ptr_ni,_atomic_cas_32)
#endif