diff options
Diffstat (limited to 'drivers/scsi/arm/msgqueue.h')
-rw-r--r-- | drivers/scsi/arm/msgqueue.h | 82 |
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 000000000..41c7333df --- /dev/null +++ b/drivers/scsi/arm/msgqueue.h @@ -0,0 +1,82 @@ +/* + * linux/drivers/acorn/scsi/msgqueue.h + * + * Copyright (C) 1997 Russell King + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * message queue handling + */ +#ifndef MSGQUEUE_H +#define MSGQUEUE_H + +struct message { + char msg[8]; + int length; + int fifo; +}; + +struct msgqueue_entry { + struct message msg; + struct msgqueue_entry *next; +}; + +#define NR_MESSAGES 4 + +typedef struct { + struct msgqueue_entry *qe; + struct msgqueue_entry *free; + struct msgqueue_entry entries[NR_MESSAGES]; +} MsgQueue_t; + +/* + * Function: void msgqueue_initialise(MsgQueue_t *msgq) + * Purpose : initialise a message queue + * Params : msgq - queue to initialise + */ +extern void msgqueue_initialise(MsgQueue_t *msgq); + +/* + * Function: void msgqueue_free(MsgQueue_t *msgq) + * Purpose : free a queue + * Params : msgq - queue to free + */ +extern 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 + */ +extern int msgqueue_msglength(MsgQueue_t *msgq); + +/* + * Function: struct message *msgqueue_getmsg(MsgQueue_t *msgq, int msgno) + * Purpose : return a message & its length + * Params : msgq - queue to obtain message from + * : msgno - message number + * Returns : pointer to message string, or NULL + */ +extern struct message *msgqueue_getmsg(MsgQueue_t *msgq, int msgno); + +/* + * 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 + */ +extern int msgqueue_addmsg(MsgQueue_t *msgq, int length, ...); + +/* + * Function: void msgqueue_flush(MsgQueue_t *msgq) + * Purpose : flush all messages from message queue + * Params : msgq - queue to flush + */ +extern void msgqueue_flush(MsgQueue_t *msgq); + +#endif |