172 lines
3.8 KiB
C
172 lines
3.8 KiB
C
|
/*
|
||
|
|
* linux/drivers/acorn/scsi/msgqueue.c
|
||
|
|
*
|
||
|
|
* Copyright (C) 1997-1998 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.
|
||
|
|
*
|
||
|
|
* message queue handling
|
||
|
|
*/
|
||
|
|
#include <linux/module.h>
|
||
|
|
#include <linux/kernel.h>
|
||
|
|
#include <linux/stddef.h>
|
||
|
|
#include <linux/init.h>
|
||
|
|
|
||
|
|
#include "msgqueue.h"
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Function: struct msgqueue_entry *mqe_alloc(MsgQueue_t *msgq)
|
||
|
|
* Purpose : Allocate a message queue entry
|
||
|
|
* Params : msgq - message queue to claim entry for
|
||
|
|
* Returns : message queue entry or NULL.
|
||
|
|
*/
|
||
|
|
static struct msgqueue_entry *mqe_alloc(MsgQueue_t *msgq)
|
||
|
|
{
|
||
|
|
struct msgqueue_entry *mq;
|
||
|
|
|
||
|
|
if ((mq = msgq->free) != NULL)
|
||
|
|
msgq->free = mq->next;
|
||
|
|
|
||
|
|
return mq;
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Function: void mqe_free(MsgQueue_t *msgq, struct msgqueue_entry *mq)
|
||
|
|
* Purpose : free a message queue entry
|
||
|
|
* Params : msgq - message queue to free entry from
|
||
|
|
* mq - message queue entry to free
|
||
|
|
*/
|
||
|
|
static void mqe_free(MsgQueue_t *msgq, struct msgqueue_entry *mq)
|
||
|
|
{
|
||
|
|
if (mq) {
|
||
|
|
mq->next = msgq->free;
|
||
|
|
msgq->free = mq;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Function: void msgqueue_initialise(MsgQueue_t *msgq)
|
||
|
|
* Purpose : initialise a message queue
|
||
|
|
* Params : msgq - queue to initialise
|
||
|
|
*/
|
||
|
|
void msgqueue_initialise(MsgQueue_t *msgq)
|
||
|
|
{
|
||
|
|
int i;
|
||
|
|
|
||
|
|
msgq->qe = NULL;
|
||
|
|
msgq->free = &msgq->entries[0];
|
||
|
|
|
||
|
|
for (i = 0; i < NR_MESSAGES; i++)
|
||
|
|
msgq->entries[i].next = &msgq->entries[i + 1];
|
||
|
|
|
||
|
|
msgq->entries[NR_MESSAGES - 1].next = NULL;
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Function: void msgqueue_free(MsgQueue_t *msgq)
|
||
|
|
* Purpose : free a queue
|
||
|
|
* Params : msgq - queue to free
|
||
|
|
*/
|
||
|
|
void msgqueue_free(MsgQueue_t *msgq)
|
||
|
|
{
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Function: int msgqueue_msglength(MsgQueue_t *msgq)
|
||
|
|
* Purpose : calculate the total length of all messages on the message queue
|
||
|
|
* Params : msgq - queue to examine
|
||
|
|
* Returns : number of bytes of messages in queue
|
||
|
|
*/
|
||
|
|
int msgqueue_msglength(MsgQueue_t *msgq)
|
||
|
|
{
|
||
|
|
struct msgqueue_entry *mq = msgq->qe;
|
||
|
|
int length = 0;
|
||
|
|
|
||
|
|
for (mq = msgq->qe; mq; mq = mq->next)
|
||
|
|
length += mq->msg.length;
|
||
|
|
|
||
|
|
return length;
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Function: struct message *msgqueue_getmsg(MsgQueue_t *msgq, int msgno)
|
||
|
|
* Purpose : return a message
|
||
|
|
* Params : msgq - queue to obtain message from
|
||
|
|
* : msgno - message number
|
||
|
|
* Returns : pointer to message string, or NULL
|
||
|
|
*/
|
||
|
|
struct message *msgqueue_getmsg(MsgQueue_t *msgq, int msgno)
|
||
|
|
{
|
||
|
|
struct msgqueue_entry *mq;
|
||
|
|
|
||
|
|
for (mq = msgq->qe; mq && msgno; mq = mq->next, msgno--);
|
||
|
|
|
||
|
|
return mq ? &mq->msg : NULL;
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Function: int msgqueue_addmsg(MsgQueue_t *msgq, int length, ...)
|
||
|
|
* Purpose : add a message onto a message queue
|
||
|
|
* Params : msgq - queue to add message on
|
||
|
|
* length - length of message
|
||
|
|
* ... - message bytes
|
||
|
|
* Returns : != 0 if successful
|
||
|
|
*/
|
||
|
|
int msgqueue_addmsg(MsgQueue_t *msgq, int length, ...)
|
||
|
|
{
|
||
|
|
struct msgqueue_entry *mq = mqe_alloc(msgq);
|
||
|
|
va_list ap;
|
||
|
|
|
||
|
|
if (mq) {
|
||
|
|
struct msgqueue_entry **mqp;
|
||
|
|
int i;
|
||
|
|
|
||
|
|
va_start(ap, length);
|
||
|
|
for (i = 0; i < length; i++)
|
||
|
|
mq->msg.msg[i] = va_arg(ap, unsigned int);
|
||
|
|
va_end(ap);
|
||
|
|
|
||
|
|
mq->msg.length = length;
|
||
|
|
mq->msg.fifo = 0;
|
||
|
|
mq->next = NULL;
|
||
|
|
|
||
|
|
mqp = &msgq->qe;
|
||
|
|
while (*mqp)
|
||
|
|
mqp = &(*mqp)->next;
|
||
|
|
|
||
|
|
*mqp = mq;
|
||
|
|
}
|
||
|
|
|
||
|
|
return mq != NULL;
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Function: void msgqueue_flush(MsgQueue_t *msgq)
|
||
|
|
* Purpose : flush all messages from message queue
|
||
|
|
* Params : msgq - queue to flush
|
||
|
|
*/
|
||
|
|
void msgqueue_flush(MsgQueue_t *msgq)
|
||
|
|
{
|
||
|
|
struct msgqueue_entry *mq, *mqnext;
|
||
|
|
|
||
|
|
for (mq = msgq->qe; mq; mq = mqnext) {
|
||
|
|
mqnext = mq->next;
|
||
|
|
mqe_free(msgq, mq);
|
||
|
|
}
|
||
|
|
msgq->qe = NULL;
|
||
|
|
}
|
||
|
|
|
||
|
|
EXPORT_SYMBOL(msgqueue_initialise);
|
||
|
|
EXPORT_SYMBOL(msgqueue_free);
|
||
|
|
EXPORT_SYMBOL(msgqueue_msglength);
|
||
|
|
EXPORT_SYMBOL(msgqueue_getmsg);
|
||
|
|
EXPORT_SYMBOL(msgqueue_addmsg);
|
||
|
|
EXPORT_SYMBOL(msgqueue_flush);
|
||
|
|
|
||
|
|
MODULE_AUTHOR("Russell King");
|
||
|
|
MODULE_DESCRIPTION("SCSI message queue handling");
|
||
|
|
MODULE_LICENSE("GPL");
|