aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/scsi/arm/msgqueue.h
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/scsi/arm/msgqueue.h')
-rw-r--r--drivers/scsi/arm/msgqueue.h82
1 files changed, 82 insertions, 0 deletions
diff --git a/drivers/scsi/arm/msgqueue.h b/drivers/scsi/arm/msgqueue.h
new file mode 100644
index 000000000000..41c7333df3e3
--- /dev/null
+++ b/drivers/scsi/arm/msgqueue.h
@@ -0,0 +1,82 @@
1/*
2 * linux/drivers/acorn/scsi/msgqueue.h
3 *
4 * Copyright (C) 1997 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#ifndef MSGQUEUE_H
13#define MSGQUEUE_H
14
15struct message {
16 char msg[8];
17 int length;
18 int fifo;
19};
20
21struct msgqueue_entry {
22 struct message msg;
23 struct msgqueue_entry *next;
24};
25
26#define NR_MESSAGES 4
27
28typedef struct {
29 struct msgqueue_entry *qe;
30 struct msgqueue_entry *free;
31 struct msgqueue_entry entries[NR_MESSAGES];
32} MsgQueue_t;
33
34/*
35 * Function: void msgqueue_initialise(MsgQueue_t *msgq)
36 * Purpose : initialise a message queue
37 * Params : msgq - queue to initialise
38 */
39extern void msgqueue_initialise(MsgQueue_t *msgq);
40
41/*
42 * Function: void msgqueue_free(MsgQueue_t *msgq)
43 * Purpose : free a queue
44 * Params : msgq - queue to free
45 */
46extern void msgqueue_free(MsgQueue_t *msgq);
47
48/*
49 * Function: int msgqueue_msglength(MsgQueue_t *msgq)
50 * Purpose : calculate the total length of all messages on the message queue
51 * Params : msgq - queue to examine
52 * Returns : number of bytes of messages in queue
53 */
54extern int msgqueue_msglength(MsgQueue_t *msgq);
55
56/*
57 * Function: struct message *msgqueue_getmsg(MsgQueue_t *msgq, int msgno)
58 * Purpose : return a message & its length
59 * Params : msgq - queue to obtain message from
60 * : msgno - message number
61 * Returns : pointer to message string, or NULL
62 */
63extern struct message *msgqueue_getmsg(MsgQueue_t *msgq, int msgno);
64
65/*
66 * Function: int msgqueue_addmsg(MsgQueue_t *msgq, int length, ...)
67 * Purpose : add a message onto a message queue
68 * Params : msgq - queue to add message on
69 * length - length of message
70 * ... - message bytes
71 * Returns : != 0 if successful
72 */
73extern int msgqueue_addmsg(MsgQueue_t *msgq, int length, ...);
74
75/*
76 * Function: void msgqueue_flush(MsgQueue_t *msgq)
77 * Purpose : flush all messages from message queue
78 * Params : msgq - queue to flush
79 */
80extern void msgqueue_flush(MsgQueue_t *msgq);
81
82#endif