linux-imx

/*

 *  linux/drivers/acorn/scsi/queue.c: queue handling primitives

 *

 *  Copyright (C) 1997-2000 Russell King

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation.

 *

 *  Changelog:

 *   15-Sep-1997 RMK    Created.

 *   11-Oct-1997 RMK    Corrected problem with queue_remove_exclude

 *          not updating internal linked list properly

 *          (was causing commands to go missing).

 *   30-Aug-2000 RMK    Use Linux list handling and spinlocks

 */

#include <linux/module.h>

#include <linux/blkdev.h>

#include <linux/kernel.h>

#include <linux/string.h>

#include <linux/slab.h>

#include <linux/spinlock.h>

#include <linux/list.h>

#include <linux/init.h>

​

#include "../scsi.h"

​

#define DEBUG

​

typedef struct queue_entry {

    struct list_head   list;

    struct scsi_cmnd   *SCpnt;

#ifdef DEBUG

    unsigned long      magic;

#endif

} QE_t;

​

#ifdef DEBUG

#define QUEUE_MAGIC_FREE    0xf7e1c9a3

#define QUEUE_MAGIC_USED    0xf7e1cc33

​

#define SET_MAGIC(q,m)  ((q)->magic = (m))

#define BAD_MAGIC(q,m)  ((q)->magic != (m))

#else

#define SET_MAGIC(q,m)  do { } while (0)

#define BAD_MAGIC(q,m)  (0)

#endif

​

#include "queue.h"

​

#define NR_QE   32

​

/*

 * Function: void queue_initialise (Queue_t *queue)

 * Purpose : initialise a queue

 * Params  : queue - queue to initialise

 */

int queue_initialise (Queue_t *queue)

{

    unsigned int nqueues = NR_QE;

    QE_t *q;

​

    spin_lock_init(&queue->queue_lock);

    INIT_LIST_HEAD(&queue->head);

    INIT_LIST_HEAD(&queue->free);

​

    /*

     * If life was easier, then SCpnt would have a

     * host-available list head, and we wouldn't

     * need to keep free lists or allocate this

     * memory.

     */

    queue->alloc = q = kmalloc_array(nqueues, sizeof(QE_t), GFP_KERNEL);

    if (q) {

        for (; nqueues; q++, nqueues--) {

            SET_MAGIC(q, QUEUE_MAGIC_FREE);

            q->SCpnt = NULL;

            list_add(&q->list, &queue->free);

        }

    }

​

    return queue->alloc != NULL;

}

​

/*

 * Function: void queue_free (Queue_t *queue)

 * Purpose : free a queue

 * Params  : queue - queue to free

 */

void queue_free (Queue_t *queue)

{

    if (!list_empty(&queue->head))