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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169// SPDX-License-Identifier: GPL-2.0-only/* * linux/drivers/acorn/scsi/msgqueue.c * * Copyright (C) 1997-1998 Russell King * * 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");