/*

 * Copyright (c) 2001-2020 Mellanox Technologies, Ltd. All rights reserved.

 *

 * This software is available to you under a choice of one of two

 * licenses.  You may choose to be licensed under the terms of the GNU

 * General Public License (GPL) Version 2, available from the file

 * COPYING in the main directory of this source tree, or the

 * BSD license below:

 *

 *     Redistribution and use in source and binary forms, with or

 *     without modification, are permitted provided that the following

 *     conditions are met:

 *

 *      - Redistributions of source code must retain the above

 *        copyright notice, this list of conditions and the following

 *        disclaimer.

 *

 *      - 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.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,

 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF

 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND

 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS

 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN

 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN

 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE

 * SOFTWARE.

 */

#ifndef ATOMIC_H_

#define ATOMIC_H_

#include "asm.h"

#include "utils/bullseye.h"

struct atomic_t {

	__volatile__ int counter;

};

#define ATOMIC_INIT(i)  { (i) }

/**

 * Read atomic variable.

 * @param v pointer of type atomic_t

 * @return Value of the atomic.

 *

 * Atomically reads the value of @v.

 */

#define atomic_read(v) ((v)->counter)

/**

 * Set atomic variable.

 * @param v pointer of type atomic_t.

 * @param i required value.

 */

#define atomic_set(v,i) (((v)->counter) = (i))

#if 0

#if _BullseyeCoverage

    #pragma BullseyeCoverage off

#endif

/**

 *  Returns current contents of addr and replaces contents with value.

 *  @param value Values to set.

 *  @param addr Address to set.

 *  @return Previous value of *addr.

 */

template<typename T>

static inline T atomic_swap(T new_value, T *addr)

{

	return (T)xchg((unsigned long)new_value, (void*)addr);

}

/**

 *  Replaces *addr with new_value if it equals old_value.

 *  @param old_value Expected value.

 *  @param new_value Value to set.

 *  @param addr Address to set.

 *  @return true if was set, false if not.

 */

template<typename T>

static bool atomic_cas(T old_value, T new_value, T *addr)

{

	return cmpxchg((unsigned long)old_value, (unsigned long)new_value, (void*)addr);

}

#if _BullseyeCoverage

    #pragma BullseyeCoverage on

#endif

#endif

/**

 * Add to the atomic variable.

 * @param i integer value to add.

 * @param v pointer of type atomic_t.

 * @return Value before add.

 */

static inline int atomic_fetch_and_inc(atomic_t *v)

{

	return atomic_fetch_and_add(1, &v->counter);

}

/**

 * Add to the atomic variable.

 * @param i integer value to add.

 * @param v pointer of type atomic_t.

 * @return Value before add.

 */

static inline int atomic_fetch_and_dec(atomic_t *v)

{

	return atomic_fetch_and_add(-1, &v->counter);

}

#endif /* ATOMIC_H_ */