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, unsigned long *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: queue_remove_all_target(queue, target) 78 * Purpose : remove all SCSI commands from the queue for a specified target 79 * Params : queue - queue to remove command from 80 * target - target device id 81 * Returns : nothing 82 */ 83 extern void queue_remove_all_target(Queue_t *queue, int target); 84 85 /* 86 * Function: int queue_probetgtlun (queue, target, lun) 87 * Purpose : check to see if we have a command in the queue for the specified 88 * target/lun. 89 * Params : queue - queue to look in 90 * target - target we want to probe 91 * lun - lun on target 92 * Returns : 0 if not found, != 0 if found 93 */ 94 extern int queue_probetgtlun (Queue_t *queue, int target, int lun); 95 96 /* 97 * Function: int queue_remove_cmd (Queue_t *queue, Scsi_Cmnd *SCpnt) 98 * Purpose : remove a specific command from the queues 99 * Params : queue - queue to look in 100 * SCpnt - command to find 101 * Returns : 0 if not found 102 */ 103 int queue_remove_cmd(Queue_t *queue, Scsi_Cmnd *SCpnt); 104 105 #endif /* QUEUE_H */ 106