1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * linux/drivers/acorn/scsi/queue.h: queue handling
4 *
5 * Copyright (C) 1997 Russell King
6 */
7 #ifndef QUEUE_H
8 #define QUEUE_H
9
10 typedef struct {
11 struct list_head head;
12 struct list_head free;
13 spinlock_t queue_lock;
14 void *alloc; /* start of allocated mem */
15 } Queue_t;
16
17 /*
18 * Function: void queue_initialise (Queue_t *queue)
19 * Purpose : initialise a queue
20 * Params : queue - queue to initialise
21 */
22 extern int queue_initialise (Queue_t *queue);
23
24 /*
25 * Function: void queue_free (Queue_t *queue)
26 * Purpose : free a queue
27 * Params : queue - queue to free
28 */
29 extern void queue_free (Queue_t *queue);
30
31 /*
32 * Function: struct scsi_cmnd *queue_remove (queue)
33 * Purpose : removes first SCSI command from a queue
34 * Params : queue - queue to remove command from
35 * Returns : struct scsi_cmnd if successful (and a reference), or NULL if no command available
36 */
37 extern struct scsi_cmnd *queue_remove (Queue_t *queue);
38
39 /*
40 * Function: struct scsi_cmnd *queue_remove_exclude_ref (queue, exclude)
41 * Purpose : remove a SCSI command from a queue
42 * Params : queue - queue to remove command from
43 * exclude - array of busy LUNs
44 * Returns : struct scsi_cmnd if successful (and a reference), or NULL if no command available
45 */
46 extern struct scsi_cmnd *queue_remove_exclude(Queue_t *queue,
47 unsigned long *exclude);
48
49 #define queue_add_cmd_ordered(queue,SCpnt) \
50 __queue_add(queue,SCpnt,(SCpnt)->cmnd[0] == REQUEST_SENSE)
51 #define queue_add_cmd_tail(queue,SCpnt) \
52 __queue_add(queue,SCpnt,0)
53 /*
54 * Function: int __queue_add(Queue_t *queue, struct scsi_cmnd *SCpnt, int head)
55 * Purpose : Add a new command onto a queue
56 * Params : queue - destination queue
57 * SCpnt - command to add
58 * head - add command to head of queue
59 * Returns : 0 on error, !0 on success
60 */
61 extern int __queue_add(Queue_t *queue, struct scsi_cmnd *SCpnt, int head);
62
63 /*
64 * Function: struct scsi_cmnd *queue_remove_tgtluntag (queue, target, lun, tag)
65 * Purpose : remove a SCSI command from the queue for a specified target/lun/tag
66 * Params : queue - queue to remove command from
67 * target - target that we want
68 * lun - lun on device
69 * tag - tag on device
70 * Returns : struct scsi_cmnd if successful, or NULL if no command satisfies requirements
71 */
72 extern struct scsi_cmnd *queue_remove_tgtluntag(Queue_t *queue, int target,
73 int lun, int tag);
74
75 /*
76 * Function: queue_remove_all_target(queue, target)
77 * Purpose : remove all SCSI commands from the queue for a specified target
78 * Params : queue - queue to remove command from
79 * target - target device id
80 * Returns : nothing
81 */
82 extern void queue_remove_all_target(Queue_t *queue, int target);
83
84 /*
85 * Function: int queue_probetgtlun (queue, target, lun)
86 * Purpose : check to see if we have a command in the queue for the specified
87 * target/lun.
88 * Params : queue - queue to look in
89 * target - target we want to probe
90 * lun - lun on target
91 * Returns : 0 if not found, != 0 if found
92 */
93 extern int queue_probetgtlun (Queue_t *queue, int target, int lun);
94
95 /*
96 * Function: int queue_remove_cmd (Queue_t *queue, struct scsi_cmnd *SCpnt)
97 * Purpose : remove a specific command from the queues
98 * Params : queue - queue to look in
99 * SCpnt - command to find
100 * Returns : 0 if not found
101 */
102 int queue_remove_cmd(Queue_t *queue, struct scsi_cmnd *SCpnt);
103
104 #endif /* QUEUE_H */