File: /usr/src/linux/drivers/acorn/scsi/queue.h
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
13 typedef 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 */
25 extern 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 */
32 extern void queue_free (Queue_t *queue);
33
34 /*
35 * Function: Scsi_Cmnd *queue_remove (queue)
36 * Purpose : removes first SCSI command from a queue
37 * Params : queue - queue to remove command from
38 * Returns : Scsi_Cmnd if successful (and a reference), or NULL if no command available
39 */
40 extern Scsi_Cmnd *queue_remove (Queue_t *queue);
41
42 /*
43 * Function: 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 : Scsi_Cmnd if successful (and a reference), or NULL if no command available
48 */
49 extern Scsi_Cmnd *queue_remove_exclude (Queue_t *queue, void *exclude);
50
51 #define queue_add_cmd_ordered(queue,SCpnt) \
52 __queue_add(queue,SCpnt,(SCpnt)->cmnd[0] == REQUEST_SENSE)
53 #define queue_add_cmd_tail(queue,SCpnt) \
54 __queue_add(queue,SCpnt,0)
55 /*
56 * Function: int __queue_add(Queue_t *queue, Scsi_Cmnd *SCpnt, int head)
57 * Purpose : Add a new command onto a queue
58 * Params : queue - destination queue
59 * SCpnt - command to add
60 * head - add command to head of queue
61 * Returns : 0 on error, !0 on success
62 */
63 extern int __queue_add(Queue_t *queue, Scsi_Cmnd *SCpnt, int head);
64
65 /*
66 * Function: Scsi_Cmnd *queue_remove_tgtluntag (queue, target, lun, tag)
67 * Purpose : remove a SCSI command from the queue for a specified target/lun/tag
68 * Params : queue - queue to remove command from
69 * target - target that we want
70 * lun - lun on device
71 * tag - tag on device
72 * Returns : Scsi_Cmnd if successful, or NULL if no command satisfies requirements
73 */
74 extern Scsi_Cmnd *queue_remove_tgtluntag (Queue_t *queue, int target, int lun, int tag);
75
76 /*
77 * Function: int queue_probetgtlun (queue, target, lun)
78 * Purpose : check to see if we have a command in the queue for the specified
79 * target/lun.
80 * Params : queue - queue to look in
81 * target - target we want to probe
82 * lun - lun on target
83 * Returns : 0 if not found, != 0 if found
84 */
85 extern int queue_probetgtlun (Queue_t *queue, int target, int lun);
86
87 /*
88 * Function: int queue_remove_cmd (Queue_t *queue, Scsi_Cmnd *SCpnt)
89 * Purpose : remove a specific command from the queues
90 * Params : queue - queue to look in
91 * SCpnt - command to find
92 * Returns : 0 if not found
93 */
94 int queue_remove_cmd(Queue_t *queue, Scsi_Cmnd *SCpnt);
95
96 #endif /* QUEUE_H */
97