/* 
 * Copyright 2010 Stefan Lankes, Chair for Operating Systems,
 *                               RWTH Aachen University
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * This file is part of MetalSVM.
 */

#ifndef __ARCH_ATOMIC_H__
#define __ARCH_ATOMIC_H__

#include <metalsvm/stddef.h>

#ifdef __cplusplus
extern "C" {
#endif

typedef uint32_t atomic_uint32_t;

/*
 * Intel manuals: If a memory operand is referenced, the processor's locking 
 * protocol is automatically implemented for the duration of the exchange 
 * operation, regardless of the presence or absence of the LOCK prefix.
 */
inline static atomic_uint32_t atomic_uint32_test_and_set(atomic_uint32_t* d) {
	atomic_uint32_t ret = 1;

	asm volatile ("xchgl %0, %1" : "=r"(ret) : "m"(*d), "0"(ret) : "memory");

	return ret;
}

inline static void atomic_uint32_inc(atomic_uint32_t* d) {
	asm volatile ("lock addl 1, %0" : "+m"(*d));
}

inline static void atomic_uint32_dec(atomic_uint32_t* d) {
	asm volatile ("lock subl 1, %0" : "+m"(*d));
}

inline static void atomic_uint32_add(atomic_uint32_t *d, int32_t i)
{
        asm volatile("lock addl %1, %0" : "+m" (*d) : "ir" (i));
}

inline static void atomic_uint32_sub(atomic_uint32_t *d, int32_t i)
{
        asm volatile("lock subl %1, %0" : "+m" (*d) : "ir" (i));
}

inline static atomic_uint32_t atomic_uint32_read(atomic_uint32_t *d)
{
	return *d;
}

inline static void atomic_uint32_set(atomic_uint32_t *d, uint32_t v)
{
	*d = v;
}

#define atomic_size_t		atomic_uint32_t
#define atomic_size_read	atomic_uint32_read
#define atomic_size_set		atomic_uint32_set
#define atomic_size_inc		atomic_uint32_inc
#define atomic_size_dec		atomic_uint32_dec
#define atomic_size_add		atomic_uint32_add
#define atomic_size_sub		atomic_uint32_sub

#ifdef __cplusplus
}
#endif

#endif