CORE/SERVICES/COMMON/adf/adf_os_atomic.h

/*
 * Copyright (c) 2011,2015 The Linux Foundation. All rights reserved.
 *
 * Previously licensed under the ISC license by Qualcomm Atheros, Inc.
 *
 *
 * Permission to use, copy, modify, and/or distribute this software for
 * any purpose with or without fee is hereby granted, provided that the
 * above copyright notice and this permission notice appear in all
 * copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
 * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
 * AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */

/*
 * This file was originally distributed by Qualcomm Atheros, Inc.
 * under proprietary terms before Copyright ownership was assigned
 * to the Linux Foundation.
 */



/**
 * @ingroup adf_os_public
 * @file adf_os_atomic.h
 * This file abstracts an atomic counter.
 */

#ifndef _ADF_OS_ATOMIC_H
#define _ADF_OS_ATOMIC_H

#include <adf_os_atomic_pvt.h>
/**
 * @brief Atomic type of variable.
 * Use this when you want a simple resource counter etc. which is atomic
 * across multiple CPU's. These maybe slower than usual counters on some
 * platforms/OS'es, so use them with caution.
 */
typedef __adf_os_atomic_t    adf_os_atomic_t;

/**
 * @brief Initialize an atomic type variable
 * @param[in] v a pointer to an opaque atomic variable
 */
static inline void
adf_os_atomic_init(adf_os_atomic_t *v)
{
    __adf_os_atomic_init(v);
}

/**
 * @brief Read the value of an atomic variable.
 * @param[in] v a pointer to an opaque atomic variable
 *
 * @return the current value of the variable
 */
static inline int32_t
adf_os_atomic_read(adf_os_atomic_t *v)
{
    return (__adf_os_atomic_read(v));
}

/**
 * @brief Increment the value of an atomic variable.
 * @param[in] v a pointer to an opaque atomic variable
 */
static inline void
adf_os_atomic_inc(adf_os_atomic_t *v)
{
    __adf_os_atomic_inc(v);
}

/**
 * @brief Decrement the value of an atomic variable.
 * @param v a pointer to an opaque atomic variable
 */
static inline void
adf_os_atomic_dec(adf_os_atomic_t *v)
{
    __adf_os_atomic_dec(v);
}

/**
 * @brief Add a value to the value of an atomic variable.
 * @param v a pointer to an opaque atomic variable
 * @param i the amount by which to increase the atomic counter
 */
static inline void
adf_os_atomic_add(int i, adf_os_atomic_t *v)
{
    __adf_os_atomic_add(i, v);
}

/**
 * adf_os_atomic_sub() - Subtract a value from an atomic variable.
 * @v: a pointer to an opaque atomic variable
 * @i: the amount by which to decrease the atomic counter
 *
 * Return: none
 */
static inline void
adf_os_atomic_sub(int i, adf_os_atomic_t *v)
{
	__adf_os_atomic_sub(i, v);
}

/**
 * @brief Decrement an atomic variable and check if the new value is zero.
 * @param v a pointer to an opaque atomic variable
 * @return
 *      true (non-zero) if the new value is zero,
 *      or false (0) if the new value is non-zero
 */
static inline int32_t
adf_os_atomic_dec_and_test(adf_os_atomic_t *v)
{
    return __adf_os_atomic_dec_and_test(v);
}

/**
 * adf_os_atomic_inc_return() - Increment and return an atomic variable
 * @v a pointer to an opaque atomic variable
 *
 * good for eliminating race conditions between multiple increments and reads
 *
 * @return
 *      the new value stored int the atomic type.
 */
static inline int32_t
adf_os_atomic_inc_return(adf_os_atomic_t *v)
{
	return __adf_os_atomic_inc_return(v);
}

/**
 * @brief Set a value to the value of an atomic variable.
 * @param v a pointer to an opaque atomic variable
 * @param i the amount by which to increase the atomic counter
 */
static inline void
adf_os_atomic_set(adf_os_atomic_t *v, int i)
{
    __adf_os_atomic_set(v, i);
}
#endif