patch-2.1.88 linux/drivers/acorn/scsi/msgqueue.c

• Lines: 176
• Date: Sat Feb 7 07:17:46 1998
• Orig file: v2.1.87/linux/drivers/acorn/scsi/msgqueue.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.1.87/linux/drivers/acorn/scsi/msgqueue.c linux/drivers/acorn/scsi/msgqueue.c
@@ -0,0 +1,175 @@
+/*
+ * drivers/acorn/scsi/msgqueue.c: message queue handling
+ *
+ * Copyright (C) 1997,8 Russell King
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/stddef.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->length;
+
+	return length;
+}
+
+/*
+ * Function: char *msgqueue_getnextmsg (MsgQueue_t *msgq, int *length)
+ * Purpose : return a message & its length
+ * Params  : msgq   - queue to obtain message from
+ *	     length - pointer to int for message length
+ * Returns : pointer to message string
+ */
+char *msgqueue_getnextmsg (MsgQueue_t *msgq, int *length)
+{
+	struct msgqueue_entry *mq;
+
+	if ((mq = msgq->qe) != NULL) {
+		msgq->qe = mq->next;
+		mqe_free (msgq, mq);
+		*length = mq->length;
+	}
+
+	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[i] = va_arg (ap, unsigned char);
+		va_end (ap);
+
+		mq->length = length;
+		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_getnextmsg);
+EXPORT_SYMBOL(msgqueue_addmsg);
+EXPORT_SYMBOL(msgqueue_flush);
+
+#ifdef MODULE
+int init_module (void)
+{
+	return 0;
+}
+
+void cleanup_module (void)
+{
+}
+#endif