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/* Copyright 2008-2012 Freescale Semiconductor, Inc.
*
* 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.
* * Neither the name of Freescale Semiconductor nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
*
* ALTERNATIVELY, this software may be distributed under the terms of the
* GNU General Public License ("GPL") as published by the Free Software
* Foundation, either version 2 of that License or (at your option) any
* later version.
*
* THIS SOFTWARE IS PROVIDED BY Freescale Semiconductor ``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 Freescale Semiconductor 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.
*/
/*
* External prototypes for the circular queue object.
*/
#ifndef __CQ_H
#define __CQ_H
#include <linux/types.h>
#include <linux/mutex.h>
/* Circular queue structure */
struct cq {
int max_items; /* Size of queue */
int item_size; /* Size of each item in the queue */
int items_in_queue; /* Number of items in the queue */
int first; /* Index of first item in queue */
struct mutex cq_lock; /* Circular queue lock */
uint8_t items[0]; /* Holds the elements in the queue -
* fake size */
};
/* Allocate and initialize a new circular queue */
struct cq *cq_new(int max_items, int item_size);
/* Delete a circular queue */
void cq_delete(struct cq *cq);
/* Empty the circular queue (clear all items) */
int cq_flush(struct cq *cq);
/*
* Put a new item in the circular queue
* Return number of items in the queue (including the added item) is successful
* or (-1) if failed to put the item (queue is full)
*/
int cq_put(struct cq *cq, void *item);
/* Put a new 1-byte item in the circular queue
* Return number of items in the queue (including the added item) is successful
* or (-1) if failed to put the item (queue is full)
*/
int cq_put_1byte(struct cq *cq, uint8_t item);
/*
* Put a new 2-byte item in the circular queue
* Return number of items in the queue (including the added item) is successful
* or (-1) if failed to put the item (queue is full)
*/
int cq_put_2bytes(struct cq *cq, uint16_t item);
/*
* Put a new 4-byte item in the circular queue
* Return number of items in the queue (including the added item) is successful
* or (-1) if failed to put the item (queue is full)
*/
int cq_put_4bytes(struct cq *cq, uint32_t item);
/*
* Put a new 8-byte item in the circular queue
* Return number of items in the queue (including the added item) is successful
* or (-1) if failed to put the item (queue is full)
*/
int cq_put_8bytes(struct cq *cq, uint64_t item);
/* Get (and removes) an item from the circular queue
* Return number of items left in the queue if successful or (-1) if failed to
* get an item (queue is empty)
*/
int cq_get(struct cq *cq, void *item);
/*
* Get and removes a 1-byte item from the circular queue
* Return number of items left in the queue if successful or (-1) if failed to
* get an item (queue is empty)
*/
int cq_get_1byte(struct cq *cq, uint8_t *item);
/*
* Get and removes a 2-byte item from the circular queue
* Return number of items left in the queue if successful or (-1) if failed to
* get an item (queue is empty)
*/
int cq_get_2bytes(struct cq *cq, uint16_t *item);
/*
* Get and removes a 4-byte item from the circular queue
* Return number of items left in the queue if successful or (-1) if failed to
* get an item (queue is empty)
*/
int cq_get_4bytes(struct cq *cq, uint32_t *item);
/*
* Get and removes a 8-byte item from the circular queue
* Return number of items left in the queue if successful or (-1) if failed to
* get an item (queue is empty)
*/
int cq_get_8bytes(struct cq *cq, uint64_t *item);
/* Return the number of items that are currently in the queue */
int cq_items_in_queue(struct cq *cq);
/*
* Read an item in the queue. The contents of the queue are not altered.
* Return number of items left in the queue if successful or (-1) if failed to
* read the item (either the queue is empty, or the requested position exceeds
* number of items)
*/
int cq_read(struct cq *cq, void *item, int position);
#endif /* __CQ_H */
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