drivers/scsi/arm/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: 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  */
  40 extern 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  */
  49 extern 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  */
  64 extern 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  */
  75 extern 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  */
  85 extern 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  */
  96 extern 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  */
 105 int queue_remove_cmd(Queue_t *queue, struct scsi_cmnd *SCpnt);
 106
 107 #endif /* QUEUE_H */