circ_buf.h

/******************************************************************************
 *
 * Copyright(c) 2007 - 2017 Realtek Corporation.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
 * more details.
 *
 *****************************************************************************/
#ifndef __CIRC_BUF_H_
#define __CIRC_BUF_H_ 1

#define CIRC_CNT(head,tail,size) (((head) - (tail)) & ((size)-1))

#define CIRC_SPACE(head,tail,size) CIRC_CNT((tail),((head)+1),(size))

#endif //_CIRC_BUF_H_