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 */ 108