1/*
2 *  linux/drivers/acorn/scsi/queue.h: queue handling
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#ifndef QUEUE_H
11#define QUEUE_H
12
13typedef struct {
14	struct list_head head;
15	struct list_head free;
16	spinlock_t queue_lock;
17	void *alloc;			/* start of allocated mem */
18} Queue_t;
19
20/*
21 * Function: void queue_initialise (Queue_t *queue)
22 * Purpose : initialise a queue
23 * Params  : queue - queue to initialise
24 */
25extern int queue_initialise (Queue_t *queue);
26
27/*
28 * Function: void queue_free (Queue_t *queue)
29 * Purpose : free a queue
30 * Params  : queue - queue to free
31 */
32extern void queue_free (Queue_t *queue);
33
34/*
35 * Function: struct scsi_cmnd *queue_remove (queue)
36 * Purpose : removes first SCSI command from a queue
37 * Params  : queue   - queue to remove command from
38 * Returns : struct scsi_cmnd if successful (and a reference), or NULL if no command available
39 */
40extern struct scsi_cmnd *queue_remove (Queue_t *queue);
41
42/*
43 * Function: struct scsi_cmnd *queue_remove_exclude_ref (queue, exclude)
44 * Purpose : remove a SCSI command from a queue
45 * Params  : queue   - queue to remove command from
46 *	     exclude - array of busy LUNs
47 * Returns : struct scsi_cmnd if successful (and a reference), or NULL if no command available
48 */
49extern struct scsi_cmnd *queue_remove_exclude(Queue_t *queue,
50					      unsigned long *exclude);
51
52#define queue_add_cmd_ordered(queue,SCpnt) \
53	__queue_add(queue,SCpnt,(SCpnt)->cmnd[0] == REQUEST_SENSE)
54#define queue_add_cmd_tail(queue,SCpnt) \
55	__queue_add(queue,SCpnt,0)
56/*
57 * Function: int __queue_add(Queue_t *queue, struct scsi_cmnd *SCpnt, int head)
58 * Purpose : Add a new command onto a queue
59 * Params  : queue - destination queue
60 *	     SCpnt - command to add
61 *	     head  - add command to head of queue
62 * Returns : 0 on error, !0 on success
63 */
64extern int __queue_add(Queue_t *queue, struct scsi_cmnd *SCpnt, int head);
65
66/*
67 * Function: struct scsi_cmnd *queue_remove_tgtluntag (queue, target, lun, tag)
68 * Purpose : remove a SCSI command from the queue for a specified target/lun/tag
69 * Params  : queue  - queue to remove command from
70 *	     target - target that we want
71 *	     lun    - lun on device
72 *	     tag    - tag on device
73 * Returns : struct scsi_cmnd if successful, or NULL if no command satisfies requirements
74 */
75extern struct scsi_cmnd *queue_remove_tgtluntag(Queue_t *queue, int target,
76						int lun, int tag);
77
78/*
79 * Function: queue_remove_all_target(queue, target)
80 * Purpose : remove all SCSI commands from the queue for a specified target
81 * Params  : queue  - queue to remove command from
82 *           target - target device id
83 * Returns : nothing
84 */
85extern void queue_remove_all_target(Queue_t *queue, int target);
86
87/*
88 * Function: int queue_probetgtlun (queue, target, lun)
89 * Purpose : check to see if we have a command in the queue for the specified
90 *	     target/lun.
91 * Params  : queue  - queue to look in
92 *	     target - target we want to probe
93 *	     lun    - lun on target
94 * Returns : 0 if not found, != 0 if found
95 */
96extern int queue_probetgtlun (Queue_t *queue, int target, int lun);
97
98/*
99 * Function: int queue_remove_cmd (Queue_t *queue, struct scsi_cmnd *SCpnt)
100 * Purpose : remove a specific command from the queues
101 * Params  : queue - queue to look in
102 *	     SCpnt - command to find
103 * Returns : 0 if not found
104 */
105int queue_remove_cmd(Queue_t *queue, struct scsi_cmnd *SCpnt);
106
107#endif /* QUEUE_H */
108