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168 lines
3.6 KiB
168 lines
3.6 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* linux/drivers/acorn/scsi/msgqueue.c |
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* |
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* Copyright (C) 1997-1998 Russell King |
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* |
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* message queue handling |
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*/ |
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#include <linux/module.h> |
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#include <linux/kernel.h> |
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#include <linux/stddef.h> |
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#include <linux/init.h> |
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#include "msgqueue.h" |
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/* |
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* Function: struct msgqueue_entry *mqe_alloc(MsgQueue_t *msgq) |
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* Purpose : Allocate a message queue entry |
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* Params : msgq - message queue to claim entry for |
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* Returns : message queue entry or NULL. |
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*/ |
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static struct msgqueue_entry *mqe_alloc(MsgQueue_t *msgq) |
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{ |
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struct msgqueue_entry *mq; |
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if ((mq = msgq->free) != NULL) |
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msgq->free = mq->next; |
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return mq; |
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} |
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/* |
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* Function: void mqe_free(MsgQueue_t *msgq, struct msgqueue_entry *mq) |
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* Purpose : free a message queue entry |
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* Params : msgq - message queue to free entry from |
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* mq - message queue entry to free |
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*/ |
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static void mqe_free(MsgQueue_t *msgq, struct msgqueue_entry *mq) |
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{ |
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if (mq) { |
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mq->next = msgq->free; |
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msgq->free = mq; |
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} |
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} |
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/* |
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* Function: void msgqueue_initialise(MsgQueue_t *msgq) |
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* Purpose : initialise a message queue |
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* Params : msgq - queue to initialise |
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*/ |
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void msgqueue_initialise(MsgQueue_t *msgq) |
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{ |
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int i; |
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msgq->qe = NULL; |
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msgq->free = &msgq->entries[0]; |
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for (i = 0; i < NR_MESSAGES; i++) |
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msgq->entries[i].next = &msgq->entries[i + 1]; |
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msgq->entries[NR_MESSAGES - 1].next = NULL; |
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} |
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/* |
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* Function: void msgqueue_free(MsgQueue_t *msgq) |
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* Purpose : free a queue |
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* Params : msgq - queue to free |
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*/ |
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void msgqueue_free(MsgQueue_t *msgq) |
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{ |
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} |
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/* |
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* Function: int msgqueue_msglength(MsgQueue_t *msgq) |
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* Purpose : calculate the total length of all messages on the message queue |
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* Params : msgq - queue to examine |
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* Returns : number of bytes of messages in queue |
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*/ |
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int msgqueue_msglength(MsgQueue_t *msgq) |
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{ |
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struct msgqueue_entry *mq = msgq->qe; |
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int length = 0; |
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for (mq = msgq->qe; mq; mq = mq->next) |
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length += mq->msg.length; |
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return length; |
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} |
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/* |
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* Function: struct message *msgqueue_getmsg(MsgQueue_t *msgq, int msgno) |
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* Purpose : return a message |
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* Params : msgq - queue to obtain message from |
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* : msgno - message number |
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* Returns : pointer to message string, or NULL |
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*/ |
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struct message *msgqueue_getmsg(MsgQueue_t *msgq, int msgno) |
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{ |
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struct msgqueue_entry *mq; |
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for (mq = msgq->qe; mq && msgno; mq = mq->next, msgno--); |
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return mq ? &mq->msg : NULL; |
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} |
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/* |
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* Function: int msgqueue_addmsg(MsgQueue_t *msgq, int length, ...) |
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* Purpose : add a message onto a message queue |
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* Params : msgq - queue to add message on |
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* length - length of message |
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* ... - message bytes |
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* Returns : != 0 if successful |
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*/ |
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int msgqueue_addmsg(MsgQueue_t *msgq, int length, ...) |
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{ |
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struct msgqueue_entry *mq = mqe_alloc(msgq); |
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va_list ap; |
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if (mq) { |
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struct msgqueue_entry **mqp; |
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int i; |
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va_start(ap, length); |
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for (i = 0; i < length; i++) |
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mq->msg.msg[i] = va_arg(ap, unsigned int); |
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va_end(ap); |
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mq->msg.length = length; |
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mq->msg.fifo = 0; |
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mq->next = NULL; |
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mqp = &msgq->qe; |
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while (*mqp) |
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mqp = &(*mqp)->next; |
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*mqp = mq; |
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} |
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return mq != NULL; |
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} |
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/* |
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* Function: void msgqueue_flush(MsgQueue_t *msgq) |
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* Purpose : flush all messages from message queue |
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* Params : msgq - queue to flush |
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*/ |
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void msgqueue_flush(MsgQueue_t *msgq) |
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{ |
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struct msgqueue_entry *mq, *mqnext; |
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for (mq = msgq->qe; mq; mq = mqnext) { |
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mqnext = mq->next; |
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mqe_free(msgq, mq); |
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} |
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msgq->qe = NULL; |
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} |
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EXPORT_SYMBOL(msgqueue_initialise); |
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EXPORT_SYMBOL(msgqueue_free); |
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EXPORT_SYMBOL(msgqueue_msglength); |
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EXPORT_SYMBOL(msgqueue_getmsg); |
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EXPORT_SYMBOL(msgqueue_addmsg); |
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EXPORT_SYMBOL(msgqueue_flush); |
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MODULE_AUTHOR("Russell King"); |
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MODULE_DESCRIPTION("SCSI message queue handling"); |
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MODULE_LICENSE("GPL");
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