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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320// SPDX-License-Identifier: GPL-2.0-only/* * linux/drivers/acorn/scsi/queue.c: queue handling primitives * * Copyright (C) 1997-2000 Russell King * * Changelog: * 15-Sep-1997 RMK Created. * 11-Oct-1997 RMK Corrected problem with queue_remove_exclude * not updating internal linked list properly * (was causing commands to go missing). * 30-Aug-2000 RMK Use Linux list handling and spinlocks */#include <linux/module.h>#include <linux/blkdev.h>#include <linux/kernel.h>#include <linux/string.h>#include <linux/slab.h>#include <linux/spinlock.h>#include <linux/list.h>#include <linux/init.h>
#include <scsi/scsi.h>#include <scsi/scsi_cmnd.h>#include <scsi/scsi_device.h>#include <scsi/scsi_eh.h>#include <scsi/scsi_tcq.h>
#define DEBUG
typedef struct queue_entry { struct list_head list; struct scsi_cmnd *SCpnt;#ifdef DEBUG unsigned long magic;#endif} QE_t;
#ifdef DEBUG#define QUEUE_MAGIC_FREE 0xf7e1c9a3#define QUEUE_MAGIC_USED 0xf7e1cc33
#define SET_MAGIC(q,m) ((q)->magic = (m))#define BAD_MAGIC(q,m) ((q)->magic != (m))#else#define SET_MAGIC(q,m) do { } while (0)#define BAD_MAGIC(q,m) (0)#endif
#include "queue.h"
#define NR_QE 32
/* * Function: void queue_initialise (Queue_t *queue) * Purpose : initialise a queue * Params : queue - queue to initialise */int queue_initialise (Queue_t *queue){ unsigned int nqueues = NR_QE; QE_t *q;
spin_lock_init(&queue->queue_lock); INIT_LIST_HEAD(&queue->head); INIT_LIST_HEAD(&queue->free);
/* * If life was easier, then SCpnt would have a * host-available list head, and we wouldn't * need to keep free lists or allocate this * memory. */ queue->alloc = q = kmalloc_objs(QE_t, nqueues); if (q) { for (; nqueues; q++, nqueues--) { SET_MAGIC(q, QUEUE_MAGIC_FREE); q->SCpnt = NULL; list_add(&q->list, &queue->free); } }
return queue->alloc != NULL;}
/* * Function: void queue_free (Queue_t *queue) * Purpose : free a queue * Params : queue - queue to free */void queue_free (Queue_t *queue){ if (!list_empty(&queue->head)) printk(KERN_WARNING "freeing non-empty queue %p\n", queue); kfree(queue->alloc);}
/* * Function: int __queue_add(Queue_t *queue, struct scsi_cmnd *SCpnt, int head) * Purpose : Add a new command onto a queue, adding REQUEST_SENSE to head. * Params : queue - destination queue * SCpnt - command to add * head - add command to head of queue * Returns : 0 on error, !0 on success */int __queue_add(Queue_t *queue, struct scsi_cmnd *SCpnt, int head){ unsigned long flags; struct list_head *l; QE_t *q; int ret = 0;
spin_lock_irqsave(&queue->queue_lock, flags); if (list_empty(&queue->free)) goto empty;
l = queue->free.next; list_del(l);
q = list_entry(l, QE_t, list); BUG_ON(BAD_MAGIC(q, QUEUE_MAGIC_FREE));
SET_MAGIC(q, QUEUE_MAGIC_USED); q->SCpnt = SCpnt;
if (head) list_add(l, &queue->head); else list_add_tail(l, &queue->head);
ret = 1;empty: spin_unlock_irqrestore(&queue->queue_lock, flags); return ret;}
static struct scsi_cmnd *__queue_remove(Queue_t *queue, struct list_head *ent){ QE_t *q;
/* * Move the entry from the "used" list onto the "free" list */ list_del(ent); q = list_entry(ent, QE_t, list); BUG_ON(BAD_MAGIC(q, QUEUE_MAGIC_USED));
SET_MAGIC(q, QUEUE_MAGIC_FREE); list_add(ent, &queue->free);
return q->SCpnt;}
/* * Function: struct scsi_cmnd *queue_remove_exclude (queue, exclude) * Purpose : remove a SCSI command from a queue * Params : queue - queue to remove command from * exclude - bit array of target&lun which is busy * Returns : struct scsi_cmnd if successful (and a reference), or NULL if no command available */struct scsi_cmnd *queue_remove_exclude(Queue_t *queue, unsigned long *exclude){ unsigned long flags; struct list_head *l; struct scsi_cmnd *SCpnt = NULL;
spin_lock_irqsave(&queue->queue_lock, flags); list_for_each(l, &queue->head) { QE_t *q = list_entry(l, QE_t, list); if (!test_bit(q->SCpnt->device->id * 8 + (u8)(q->SCpnt->device->lun & 0x7), exclude)) { SCpnt = __queue_remove(queue, l); break; } } spin_unlock_irqrestore(&queue->queue_lock, flags);
return SCpnt;}
/* * Function: struct scsi_cmnd *queue_remove (queue) * Purpose : removes first SCSI command from a queue * Params : queue - queue to remove command from * Returns : struct scsi_cmnd if successful (and a reference), or NULL if no command available */struct scsi_cmnd *queue_remove(Queue_t *queue){ unsigned long flags; struct scsi_cmnd *SCpnt = NULL;
spin_lock_irqsave(&queue->queue_lock, flags); if (!list_empty(&queue->head)) SCpnt = __queue_remove(queue, queue->head.next); spin_unlock_irqrestore(&queue->queue_lock, flags);
return SCpnt;}
/* * Function: struct scsi_cmnd *queue_remove_tgtluntag (queue, target, lun, tag) * Purpose : remove a SCSI command from the queue for a specified target/lun/tag * Params : queue - queue to remove command from * target - target that we want * lun - lun on device * tag - tag on device * Returns : struct scsi_cmnd if successful, or NULL if no command satisfies requirements */struct scsi_cmnd *queue_remove_tgtluntag(Queue_t *queue, int target, int lun, int tag){ unsigned long flags; struct list_head *l; struct scsi_cmnd *SCpnt = NULL;
spin_lock_irqsave(&queue->queue_lock, flags); list_for_each(l, &queue->head) { QE_t *q = list_entry(l, QE_t, list); if (q->SCpnt->device->id == target && q->SCpnt->device->lun == lun && scsi_cmd_to_rq(q->SCpnt)->tag == tag) { SCpnt = __queue_remove(queue, l); break; } } spin_unlock_irqrestore(&queue->queue_lock, flags);
return SCpnt;}
/* * Function: queue_remove_all_target(queue, target) * Purpose : remove all SCSI commands from the queue for a specified target * Params : queue - queue to remove command from * target - target device id * Returns : nothing */void queue_remove_all_target(Queue_t *queue, int target){ unsigned long flags; struct list_head *l;
spin_lock_irqsave(&queue->queue_lock, flags); list_for_each(l, &queue->head) { QE_t *q = list_entry(l, QE_t, list); if (q->SCpnt->device->id == target) __queue_remove(queue, l); } spin_unlock_irqrestore(&queue->queue_lock, flags);}
/* * Function: int queue_probetgtlun (queue, target, lun) * Purpose : check to see if we have a command in the queue for the specified * target/lun. * Params : queue - queue to look in * target - target we want to probe * lun - lun on target * Returns : 0 if not found, != 0 if found */int queue_probetgtlun (Queue_t *queue, int target, int lun){ unsigned long flags; struct list_head *l; int found = 0;
spin_lock_irqsave(&queue->queue_lock, flags); list_for_each(l, &queue->head) { QE_t *q = list_entry(l, QE_t, list); if (q->SCpnt->device->id == target && q->SCpnt->device->lun == lun) { found = 1; break; } } spin_unlock_irqrestore(&queue->queue_lock, flags);
return found;}
/* * Function: int queue_remove_cmd(Queue_t *queue, struct scsi_cmnd *SCpnt) * Purpose : remove a specific command from the queues * Params : queue - queue to look in * SCpnt - command to find * Returns : 0 if not found */int queue_remove_cmd(Queue_t *queue, struct scsi_cmnd *SCpnt){ unsigned long flags; struct list_head *l; int found = 0;
spin_lock_irqsave(&queue->queue_lock, flags); list_for_each(l, &queue->head) { QE_t *q = list_entry(l, QE_t, list); if (q->SCpnt == SCpnt) { __queue_remove(queue, l); found = 1; break; } } spin_unlock_irqrestore(&queue->queue_lock, flags);
return found;}
EXPORT_SYMBOL(queue_initialise);EXPORT_SYMBOL(queue_free);EXPORT_SYMBOL(__queue_add);EXPORT_SYMBOL(queue_remove);EXPORT_SYMBOL(queue_remove_exclude);EXPORT_SYMBOL(queue_remove_tgtluntag);EXPORT_SYMBOL(queue_remove_cmd);EXPORT_SYMBOL(queue_remove_all_target);EXPORT_SYMBOL(queue_probetgtlun);
MODULE_AUTHOR("Russell King");MODULE_DESCRIPTION("SCSI command queueing");MODULE_LICENSE("GPL");