1 files changed, 252 insertions, 0 deletions

diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c
new file mode 100644
index 000000000000..2e77963db334
--- /dev/null
+++ b/drivers/mmc/card/queue.c
@@ -0,0 +1,252 @@
+/*
+ *  linux/drivers/mmc/queue.c
+ *
+ *  Copyright (C) 2003 Russell King, All Rights Reserved.
+ *  Copyright 2006-2007 Pierre Ossman
+ *
+ * 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.
+ *
+ */
+#include <linux/module.h>
+#include <linux/blkdev.h>
+#include <linux/kthread.h>
+
+#include <linux/mmc/card.h>
+#include <linux/mmc/host.h>
+#include "queue.h"
+
+#define MMC_QUEUE_SUSPENDED     (1 << 0)
+
+/*
+ * Prepare a MMC request.  Essentially, this means passing the
+ * preparation off to the media driver.  The media driver will
+ * create a mmc_io_request in req->special.
+ */
+static int mmc_prep_request(struct request_queue *q, struct request *req)
+{
+        struct mmc_queue *mq = q->queuedata;
+        int ret = BLKPREP_KILL;
+
+        if (blk_special_request(req)) {
+                /*
+                 * Special commands already have the command
+                 * blocks already setup in req->special.
+                 */
+                BUG_ON(!req->special);
+
+                ret = BLKPREP_OK;
+        } else if (blk_fs_request(req) || blk_pc_request(req)) {
+                /*
+                 * Block I/O requests need translating according
+                 * to the protocol.
+                 */
+                ret = mq->prep_fn(mq, req);
+        } else {
+                /*
+                 * Everything else is invalid.
+                 */
+                blk_dump_rq_flags(req, "MMC bad request");
+        }
+
+        if (ret == BLKPREP_OK)
+                req->cmd_flags |= REQ_DONTPREP;
+
+        return ret;
+}
+
+static int mmc_queue_thread(void *d)
+{
+        struct mmc_queue *mq = d;
+        struct request_queue *q = mq->queue;
+
+        /*
+         * Set iothread to ensure that we aren't put to sleep by
+         * the process freezing.  We handle suspension ourselves.
+         */
+        current->flags |= PF_MEMALLOC|PF_NOFREEZE;
+
+        down(&mq->thread_sem);
+        do {
+                struct request *req = NULL;
+
+                spin_lock_irq(q->queue_lock);
+                set_current_state(TASK_INTERRUPTIBLE);
+                if (!blk_queue_plugged(q))
+                        req = elv_next_request(q);
+                mq->req = req;
+                spin_unlock_irq(q->queue_lock);
+
+                if (!req) {
+                        if (kthread_should_stop()) {
+                                set_current_state(TASK_RUNNING);
+                                break;
+                        }
+                        up(&mq->thread_sem);
+                        schedule();
+                        down(&mq->thread_sem);
+                        continue;
+                }
+                set_current_state(TASK_RUNNING);
+
+                mq->issue_fn(mq, req);
+        } while (1);
+        up(&mq->thread_sem);
+
+        return 0;
+}
+
+/*
+ * Generic MMC request handler.  This is called for any queue on a
+ * particular host.  When the host is not busy, we look for a request
+ * on any queue on this host, and attempt to issue it.  This may
+ * not be the queue we were asked to process.
+ */
+static void mmc_request(request_queue_t *q)
+{
+        struct mmc_queue *mq = q->queuedata;
+        struct request *req;
+        int ret;
+
+        if (!mq) {
+                printk(KERN_ERR "MMC: killing requests for dead queue\n");
+                while ((req = elv_next_request(q)) != NULL) {
+                        do {
+                                ret = end_that_request_chunk(req, 0,
+                                        req->current_nr_sectors << 9);
+                        } while (ret);
+                }
+                return;
+        }
+
+        if (!mq->req)
+                wake_up_process(mq->thread);
+}
+
+/**
+ * mmc_init_queue - initialise a queue structure.
+ * @mq: mmc queue
+ * @card: mmc card to attach this queue
+ * @lock: queue lock
+ *
+ * Initialise a MMC card request queue.
+ */
+int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card, spinlock_t *lock)
+{
+        struct mmc_host *host = card->host;
+        u64 limit = BLK_BOUNCE_HIGH;
+        int ret;
+
+        if (mmc_dev(host)->dma_mask && *mmc_dev(host)->dma_mask)
+                limit = *mmc_dev(host)->dma_mask;
+
+        mq->card = card;
+        mq->queue = blk_init_queue(mmc_request, lock);
+        if (!mq->queue)
+                return -ENOMEM;
+
+        blk_queue_prep_rq(mq->queue, mmc_prep_request);
+        blk_queue_bounce_limit(mq->queue, limit);
+        blk_queue_max_sectors(mq->queue, host->max_req_size / 512);
+        blk_queue_max_phys_segments(mq->queue, host->max_phys_segs);
+        blk_queue_max_hw_segments(mq->queue, host->max_hw_segs);
+        blk_queue_max_segment_size(mq->queue, host->max_seg_size);
+
+        mq->queue->queuedata = mq;
+        mq->req = NULL;
+
+        mq->sg = kmalloc(sizeof(struct scatterlist) * host->max_phys_segs,
+                         GFP_KERNEL);
+        if (!mq->sg) {
+                ret = -ENOMEM;
+                goto cleanup_queue;
+        }
+
+        init_MUTEX(&mq->thread_sem);
+
+        mq->thread = kthread_run(mmc_queue_thread, mq, "mmcqd");
+        if (IS_ERR(mq->thread)) {
+                ret = PTR_ERR(mq->thread);
+                goto free_sg;
+        }
+
+        return 0;
+
+ free_sg:
+        kfree(mq->sg);
+        mq->sg = NULL;
+ cleanup_queue:
+        blk_cleanup_queue(mq->queue);
+        return ret;
+}
+
+void mmc_cleanup_queue(struct mmc_queue *mq)
+{
+        request_queue_t *q = mq->queue;
+        unsigned long flags;
+
+        /* Mark that we should start throwing out stragglers */
+        spin_lock_irqsave(q->queue_lock, flags);
+        q->queuedata = NULL;
+        spin_unlock_irqrestore(q->queue_lock, flags);
+
+        /* Make sure the queue isn't suspended, as that will deadlock */
+        mmc_queue_resume(mq);
+
+        /* Then terminate our worker thread */
+        kthread_stop(mq->thread);
+
+        kfree(mq->sg);
+        mq->sg = NULL;
+
+        blk_cleanup_queue(mq->queue);
+
+        mq->card = NULL;
+}
+EXPORT_SYMBOL(mmc_cleanup_queue);
+
+/**
+ * mmc_queue_suspend - suspend a MMC request queue
+ * @mq: MMC queue to suspend
+ *
+ * Stop the block request queue, and wait for our thread to
+ * complete any outstanding requests.  This ensures that we
+ * won't suspend while a request is being processed.
+ */
+void mmc_queue_suspend(struct mmc_queue *mq)
+{
+        request_queue_t *q = mq->queue;
+        unsigned long flags;
+
+        if (!(mq->flags & MMC_QUEUE_SUSPENDED)) {
+                mq->flags |= MMC_QUEUE_SUSPENDED;
+
+                spin_lock_irqsave(q->queue_lock, flags);
+                blk_stop_queue(q);
+                spin_unlock_irqrestore(q->queue_lock, flags);
+
+                down(&mq->thread_sem);
+        }
+}
+
+/**
+ * mmc_queue_resume - resume a previously suspended MMC request queue
+ * @mq: MMC queue to resume
+ */
+void mmc_queue_resume(struct mmc_queue *mq)
+{
+        request_queue_t *q = mq->queue;
+        unsigned long flags;
+
+        if (mq->flags & MMC_QUEUE_SUSPENDED) {
+                mq->flags &= ~MMC_QUEUE_SUSPENDED;
+
+                up(&mq->thread_sem);
+
+                spin_lock_irqsave(q->queue_lock, flags);
+                blk_start_queue(q);
+                spin_unlock_irqrestore(q->queue_lock, flags);
+        }
+}
+