1 files changed, 319 insertions, 0 deletions

diff --git a/drivers/scsi/arm/queue.c b/drivers/scsi/arm/queue.c
new file mode 100644
index 000000000000..e6d159270d29
--- /dev/null
+++ b/drivers/scsi/arm/queue.c
@@ -0,0 +1,319 @@
+/*
+ *  linux/drivers/acorn/scsi/queue.c: queue handling primitives
+ *
+ *  Copyright (C) 1997-2000 Russell King
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ *  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.h"
+
+#define DEBUG
+
+typedef struct queue_entry {
+        struct list_head   list;
+        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(sizeof(QE_t) * nqueues, GFP_KERNEL);
+        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);
+        if (queue->alloc)
+                kfree(queue->alloc);
+}
+     
+
+/*
+ * Function: int queue_add_cmd(Queue_t *queue, 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, 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);
+        if (BAD_MAGIC(q, QUEUE_MAGIC_FREE))
+                BUG();
+
+        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 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);
+        if (BAD_MAGIC(q, QUEUE_MAGIC_USED))
+                BUG();
+
+        SET_MAGIC(q, QUEUE_MAGIC_FREE);
+        list_add(ent, &queue->free);
+
+        return q->SCpnt;
+}
+
+/*
+ * Function: 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 : Scsi_Cmnd if successful (and a reference), or NULL if no command available
+ */
+Scsi_Cmnd *queue_remove_exclude(Queue_t *queue, unsigned long *exclude)
+{
+        unsigned long flags;
+        struct list_head *l;
+        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 + q->SCpnt->device->lun, exclude)) {
+                        SCpnt = __queue_remove(queue, l);
+                        break;
+                }
+        }
+        spin_unlock_irqrestore(&queue->queue_lock, flags);
+
+        return SCpnt;
+}
+
+/*
+ * Function: Scsi_Cmnd *queue_remove (queue)
+ * Purpose : removes first SCSI command from a queue
+ * Params  : queue   - queue to remove command from
+ * Returns : Scsi_Cmnd if successful (and a reference), or NULL if no command available
+ */
+Scsi_Cmnd *queue_remove(Queue_t *queue)
+{
+        unsigned long flags;
+        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: 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 : Scsi_Cmnd if successful, or NULL if no command satisfies requirements
+ */
+Scsi_Cmnd *queue_remove_tgtluntag (Queue_t *queue, int target, int lun, int tag)
+{
+        unsigned long flags;
+        struct list_head *l;
+        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 &&
+                    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, 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, 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");