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1/*
2 * linux/drivers/acorn/scsi/msgqueue.c
3 *
4 * Copyright (C) 1997-1998 Russell King
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 * message queue handling
11 */
12#include <linux/module.h>
13#include <linux/kernel.h>
14#include <linux/stddef.h>
15#include <linux/init.h>
16
17#include "msgqueue.h"
18
19/*
20 * Function: struct msgqueue_entry *mqe_alloc(MsgQueue_t *msgq)
21 * Purpose : Allocate a message queue entry
22 * Params : msgq - message queue to claim entry for
23 * Returns : message queue entry or NULL.
24 */
25static struct msgqueue_entry *mqe_alloc(MsgQueue_t *msgq)
26{
27 struct msgqueue_entry *mq;
28
29 if ((mq = msgq->free) != NULL)
30 msgq->free = mq->next;
31
32 return mq;
33}
34
35/*
36 * Function: void mqe_free(MsgQueue_t *msgq, struct msgqueue_entry *mq)
37 * Purpose : free a message queue entry
38 * Params : msgq - message queue to free entry from
39 * mq - message queue entry to free
40 */
41static void mqe_free(MsgQueue_t *msgq, struct msgqueue_entry *mq)
42{
43 if (mq) {
44 mq->next = msgq->free;
45 msgq->free = mq;
46 }
47}
48
49/*
50 * Function: void msgqueue_initialise(MsgQueue_t *msgq)
51 * Purpose : initialise a message queue
52 * Params : msgq - queue to initialise
53 */
54void msgqueue_initialise(MsgQueue_t *msgq)
55{
56 int i;
57
58 msgq->qe = NULL;
59 msgq->free = &msgq->entries[0];
60
61 for (i = 0; i < NR_MESSAGES; i++)
62 msgq->entries[i].next = &msgq->entries[i + 1];
63
64 msgq->entries[NR_MESSAGES - 1].next = NULL;
65}
66
67
68/*
69 * Function: void msgqueue_free(MsgQueue_t *msgq)
70 * Purpose : free a queue
71 * Params : msgq - queue to free
72 */
73void msgqueue_free(MsgQueue_t *msgq)
74{
75}
76
77/*
78 * Function: int msgqueue_msglength(MsgQueue_t *msgq)
79 * Purpose : calculate the total length of all messages on the message queue
80 * Params : msgq - queue to examine
81 * Returns : number of bytes of messages in queue
82 */
83int msgqueue_msglength(MsgQueue_t *msgq)
84{
85 struct msgqueue_entry *mq = msgq->qe;
86 int length = 0;
87
88 for (mq = msgq->qe; mq; mq = mq->next)
89 length += mq->msg.length;
90
91 return length;
92}
93
94/*
95 * Function: struct message *msgqueue_getmsg(MsgQueue_t *msgq, int msgno)
96 * Purpose : return a message
97 * Params : msgq - queue to obtain message from
98 * : msgno - message number
99 * Returns : pointer to message string, or NULL
100 */
101struct message *msgqueue_getmsg(MsgQueue_t *msgq, int msgno)
102{
103 struct msgqueue_entry *mq;
104
105 for (mq = msgq->qe; mq && msgno; mq = mq->next, msgno--);
106
107 return mq ? &mq->msg : NULL;
108}
109
110/*
111 * Function: int msgqueue_addmsg(MsgQueue_t *msgq, int length, ...)
112 * Purpose : add a message onto a message queue
113 * Params : msgq - queue to add message on
114 * length - length of message
115 * ... - message bytes
116 * Returns : != 0 if successful
117 */
118int msgqueue_addmsg(MsgQueue_t *msgq, int length, ...)
119{
120 struct msgqueue_entry *mq = mqe_alloc(msgq);
121 va_list ap;
122
123 if (mq) {
124 struct msgqueue_entry **mqp;
125 int i;
126
127 va_start(ap, length);
128 for (i = 0; i < length; i++)
129 mq->msg.msg[i] = va_arg(ap, unsigned int);
130 va_end(ap);
131
132 mq->msg.length = length;
133 mq->msg.fifo = 0;
134 mq->next = NULL;
135
136 mqp = &msgq->qe;
137 while (*mqp)
138 mqp = &(*mqp)->next;
139
140 *mqp = mq;
141 }
142
143 return mq != NULL;
144}
145
146/*
147 * Function: void msgqueue_flush(MsgQueue_t *msgq)
148 * Purpose : flush all messages from message queue
149 * Params : msgq - queue to flush
150 */
151void msgqueue_flush(MsgQueue_t *msgq)
152{
153 struct msgqueue_entry *mq, *mqnext;
154
155 for (mq = msgq->qe; mq; mq = mqnext) {
156 mqnext = mq->next;
157 mqe_free(msgq, mq);
158 }
159 msgq->qe = NULL;
160}
161
162EXPORT_SYMBOL(msgqueue_initialise);
163EXPORT_SYMBOL(msgqueue_free);
164EXPORT_SYMBOL(msgqueue_msglength);
165EXPORT_SYMBOL(msgqueue_getmsg);
166EXPORT_SYMBOL(msgqueue_addmsg);
167EXPORT_SYMBOL(msgqueue_flush);
168
169MODULE_AUTHOR("Russell King");
170MODULE_DESCRIPTION("SCSI message queue handling");
171MODULE_LICENSE("GPL");
1/*
2 * linux/drivers/acorn/scsi/msgqueue.c
3 *
4 * Copyright (C) 1997-1998 Russell King
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 * message queue handling
11 */
12#include <linux/module.h>
13#include <linux/kernel.h>
14#include <linux/stddef.h>
15#include <linux/init.h>
16
17#include "msgqueue.h"
18
19/*
20 * Function: struct msgqueue_entry *mqe_alloc(MsgQueue_t *msgq)
21 * Purpose : Allocate a message queue entry
22 * Params : msgq - message queue to claim entry for
23 * Returns : message queue entry or NULL.
24 */
25static struct msgqueue_entry *mqe_alloc(MsgQueue_t *msgq)
26{
27 struct msgqueue_entry *mq;
28
29 if ((mq = msgq->free) != NULL)
30 msgq->free = mq->next;
31
32 return mq;
33}
34
35/*
36 * Function: void mqe_free(MsgQueue_t *msgq, struct msgqueue_entry *mq)
37 * Purpose : free a message queue entry
38 * Params : msgq - message queue to free entry from
39 * mq - message queue entry to free
40 */
41static void mqe_free(MsgQueue_t *msgq, struct msgqueue_entry *mq)
42{
43 if (mq) {
44 mq->next = msgq->free;
45 msgq->free = mq;
46 }
47}
48
49/*
50 * Function: void msgqueue_initialise(MsgQueue_t *msgq)
51 * Purpose : initialise a message queue
52 * Params : msgq - queue to initialise
53 */
54void msgqueue_initialise(MsgQueue_t *msgq)
55{
56 int i;
57
58 msgq->qe = NULL;
59 msgq->free = &msgq->entries[0];
60
61 for (i = 0; i < NR_MESSAGES; i++)
62 msgq->entries[i].next = &msgq->entries[i + 1];
63
64 msgq->entries[NR_MESSAGES - 1].next = NULL;
65}
66
67
68/*
69 * Function: void msgqueue_free(MsgQueue_t *msgq)
70 * Purpose : free a queue
71 * Params : msgq - queue to free
72 */
73void msgqueue_free(MsgQueue_t *msgq)
74{
75}
76
77/*
78 * Function: int msgqueue_msglength(MsgQueue_t *msgq)
79 * Purpose : calculate the total length of all messages on the message queue
80 * Params : msgq - queue to examine
81 * Returns : number of bytes of messages in queue
82 */
83int msgqueue_msglength(MsgQueue_t *msgq)
84{
85 struct msgqueue_entry *mq = msgq->qe;
86 int length = 0;
87
88 for (mq = msgq->qe; mq; mq = mq->next)
89 length += mq->msg.length;
90
91 return length;
92}
93
94/*
95 * Function: struct message *msgqueue_getmsg(MsgQueue_t *msgq, int msgno)
96 * Purpose : return a message
97 * Params : msgq - queue to obtain message from
98 * : msgno - message number
99 * Returns : pointer to message string, or NULL
100 */
101struct message *msgqueue_getmsg(MsgQueue_t *msgq, int msgno)
102{
103 struct msgqueue_entry *mq;
104
105 for (mq = msgq->qe; mq && msgno; mq = mq->next, msgno--);
106
107 return mq ? &mq->msg : NULL;
108}
109
110/*
111 * Function: int msgqueue_addmsg(MsgQueue_t *msgq, int length, ...)
112 * Purpose : add a message onto a message queue
113 * Params : msgq - queue to add message on
114 * length - length of message
115 * ... - message bytes
116 * Returns : != 0 if successful
117 */
118int msgqueue_addmsg(MsgQueue_t *msgq, int length, ...)
119{
120 struct msgqueue_entry *mq = mqe_alloc(msgq);
121 va_list ap;
122
123 if (mq) {
124 struct msgqueue_entry **mqp;
125 int i;
126
127 va_start(ap, length);
128 for (i = 0; i < length; i++)
129 mq->msg.msg[i] = va_arg(ap, unsigned int);
130 va_end(ap);
131
132 mq->msg.length = length;
133 mq->msg.fifo = 0;
134 mq->next = NULL;
135
136 mqp = &msgq->qe;
137 while (*mqp)
138 mqp = &(*mqp)->next;
139
140 *mqp = mq;
141 }
142
143 return mq != NULL;
144}
145
146/*
147 * Function: void msgqueue_flush(MsgQueue_t *msgq)
148 * Purpose : flush all messages from message queue
149 * Params : msgq - queue to flush
150 */
151void msgqueue_flush(MsgQueue_t *msgq)
152{
153 struct msgqueue_entry *mq, *mqnext;
154
155 for (mq = msgq->qe; mq; mq = mqnext) {
156 mqnext = mq->next;
157 mqe_free(msgq, mq);
158 }
159 msgq->qe = NULL;
160}
161
162EXPORT_SYMBOL(msgqueue_initialise);
163EXPORT_SYMBOL(msgqueue_free);
164EXPORT_SYMBOL(msgqueue_msglength);
165EXPORT_SYMBOL(msgqueue_getmsg);
166EXPORT_SYMBOL(msgqueue_addmsg);
167EXPORT_SYMBOL(msgqueue_flush);
168
169MODULE_AUTHOR("Russell King");
170MODULE_DESCRIPTION("SCSI message queue handling");
171MODULE_LICENSE("GPL");