Commit | Line | Data |
---|---|---|
d2912cb1 | 1 | /* SPDX-License-Identifier: GPL-2.0-only */ |
1da177e4 LT |
2 | /* |
3 | * linux/drivers/acorn/scsi/msgqueue.h | |
4 | * | |
5 | * Copyright (C) 1997 Russell King | |
6 | * | |
1da177e4 LT |
7 | * message queue handling |
8 | */ | |
9 | #ifndef MSGQUEUE_H | |
10 | #define MSGQUEUE_H | |
11 | ||
12 | struct message { | |
13 | char msg[8]; | |
14 | int length; | |
15 | int fifo; | |
16 | }; | |
17 | ||
18 | struct msgqueue_entry { | |
19 | struct message msg; | |
20 | struct msgqueue_entry *next; | |
21 | }; | |
22 | ||
23 | #define NR_MESSAGES 4 | |
24 | ||
25 | typedef struct { | |
26 | struct msgqueue_entry *qe; | |
27 | struct msgqueue_entry *free; | |
28 | struct msgqueue_entry entries[NR_MESSAGES]; | |
29 | } MsgQueue_t; | |
30 | ||
31 | /* | |
32 | * Function: void msgqueue_initialise(MsgQueue_t *msgq) | |
33 | * Purpose : initialise a message queue | |
34 | * Params : msgq - queue to initialise | |
35 | */ | |
36 | extern void msgqueue_initialise(MsgQueue_t *msgq); | |
37 | ||
38 | /* | |
39 | * Function: void msgqueue_free(MsgQueue_t *msgq) | |
40 | * Purpose : free a queue | |
41 | * Params : msgq - queue to free | |
42 | */ | |
43 | extern void msgqueue_free(MsgQueue_t *msgq); | |
44 | ||
45 | /* | |
46 | * Function: int msgqueue_msglength(MsgQueue_t *msgq) | |
47 | * Purpose : calculate the total length of all messages on the message queue | |
48 | * Params : msgq - queue to examine | |
49 | * Returns : number of bytes of messages in queue | |
50 | */ | |
51 | extern int msgqueue_msglength(MsgQueue_t *msgq); | |
52 | ||
53 | /* | |
54 | * Function: struct message *msgqueue_getmsg(MsgQueue_t *msgq, int msgno) | |
55 | * Purpose : return a message & its length | |
56 | * Params : msgq - queue to obtain message from | |
57 | * : msgno - message number | |
58 | * Returns : pointer to message string, or NULL | |
59 | */ | |
60 | extern struct message *msgqueue_getmsg(MsgQueue_t *msgq, int msgno); | |
61 | ||
62 | /* | |
63 | * Function: int msgqueue_addmsg(MsgQueue_t *msgq, int length, ...) | |
64 | * Purpose : add a message onto a message queue | |
65 | * Params : msgq - queue to add message on | |
66 | * length - length of message | |
67 | * ... - message bytes | |
68 | * Returns : != 0 if successful | |
69 | */ | |
70 | extern int msgqueue_addmsg(MsgQueue_t *msgq, int length, ...); | |
71 | ||
72 | /* | |
73 | * Function: void msgqueue_flush(MsgQueue_t *msgq) | |
74 | * Purpose : flush all messages from message queue | |
75 | * Params : msgq - queue to flush | |
76 | */ | |
77 | extern void msgqueue_flush(MsgQueue_t *msgq); | |
78 | ||
79 | #endif |