Initial import of modified Linux 2.6.28 tree

Original upstream URL:
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git | branch linux-2.6.28.y

1 files changed, 370 insertions, 0 deletions

diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c
new file mode 100644
index 0000000..7a72e75
--- /dev/null
+++ b/drivers/mmc/card/queue.c
@@ -0,0 +1,370 @@
+/*
+ *  linux/drivers/mmc/card/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/freezer.h>
+#include <linux/kthread.h>
+#include <linux/scatterlist.h>
+
+#include <linux/mmc/card.h>
+#include <linux/mmc/host.h>
+#include "queue.h"
+
+#define MMC_QUEUE_BOUNCESZ	65536
+
+#define MMC_QUEUE_SUSPENDED	(1 << 0)
+
+/*
+ * Prepare a MMC request. This just filters out odd stuff.
+ */
+static int mmc_prep_request(struct request_queue *q, struct request *req)
+{
+	/*
+	 * We only like normal block requests.
+	 */
+	if (!blk_fs_request(req)) {
+		blk_dump_rq_flags(req, "MMC bad request");
+		return BLKPREP_KILL;
+	}
+
+	req->cmd_flags |= REQ_DONTPREP;
+
+	return BLKPREP_OK;
+}
+
+static int mmc_queue_thread(void *d)
+{
+	struct mmc_queue *mq = d;
+	struct request_queue *q = mq->queue;
+
+	current->flags |= PF_MEMALLOC;
+
+	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(struct request_queue *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 = __blk_end_request(req, -EIO,
+							blk_rq_cur_bytes(req));
+			} 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;
+
+	mq->queue->queuedata = mq;
+	mq->req = NULL;
+
+	blk_queue_prep_rq(mq->queue, mmc_prep_request);
+	blk_queue_ordered(mq->queue, QUEUE_ORDERED_DRAIN, NULL);
+	queue_flag_set_unlocked(QUEUE_FLAG_NONROT, mq->queue);
+
+#ifdef CONFIG_MMC_BLOCK_BOUNCE
+	if (host->max_hw_segs == 1) {
+		unsigned int bouncesz;
+
+		bouncesz = MMC_QUEUE_BOUNCESZ;
+
+		if (bouncesz > host->max_req_size)
+			bouncesz = host->max_req_size;
+		if (bouncesz > host->max_seg_size)
+			bouncesz = host->max_seg_size;
+		if (bouncesz > (host->max_blk_count * 512))
+			bouncesz = host->max_blk_count * 512;
+
+		if (bouncesz > 512) {
+			mq->bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
+			if (!mq->bounce_buf) {
+				printk(KERN_WARNING "%s: unable to "
+					"allocate bounce buffer\n",
+					mmc_card_name(card));
+			}
+		}
+
+		if (mq->bounce_buf) {
+			blk_queue_bounce_limit(mq->queue, BLK_BOUNCE_ANY);
+			blk_queue_max_sectors(mq->queue, bouncesz / 512);
+			blk_queue_max_phys_segments(mq->queue, bouncesz / 512);
+			blk_queue_max_hw_segments(mq->queue, bouncesz / 512);
+			blk_queue_max_segment_size(mq->queue, bouncesz);
+
+			mq->sg = kmalloc(sizeof(struct scatterlist),
+				GFP_KERNEL);
+			if (!mq->sg) {
+				ret = -ENOMEM;
+				goto cleanup_queue;
+			}
+			sg_init_table(mq->sg, 1);
+
+			mq->bounce_sg = kmalloc(sizeof(struct scatterlist) *
+				bouncesz / 512, GFP_KERNEL);
+			if (!mq->bounce_sg) {
+				ret = -ENOMEM;
+				goto cleanup_queue;
+			}
+			sg_init_table(mq->bounce_sg, bouncesz / 512);
+		}
+	}
+#endif
+
+	if (!mq->bounce_buf) {
+		blk_queue_bounce_limit(mq->queue, limit);
+		blk_queue_max_sectors(mq->queue,
+			min(host->max_blk_count, 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->sg = kmalloc(sizeof(struct scatterlist) *
+			host->max_phys_segs, GFP_KERNEL);
+		if (!mq->sg) {
+			ret = -ENOMEM;
+			goto cleanup_queue;
+		}
+		sg_init_table(mq->sg, host->max_phys_segs);
+	}
+
+	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_bounce_sg;
+	}
+
+	return 0;
+ free_bounce_sg:
+ 	if (mq->bounce_sg)
+ 		kfree(mq->bounce_sg);
+ 	mq->bounce_sg = NULL;
+ cleanup_queue:
+ 	if (mq->sg)
+		kfree(mq->sg);
+	mq->sg = NULL;
+	if (mq->bounce_buf)
+		kfree(mq->bounce_buf);
+	mq->bounce_buf = NULL;
+	blk_cleanup_queue(mq->queue);
+	return ret;
+}
+
+void mmc_cleanup_queue(struct mmc_queue *mq)
+{
+	struct request_queue *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);
+
+ 	if (mq->bounce_sg)
+ 		kfree(mq->bounce_sg);
+ 	mq->bounce_sg = NULL;
+
+	kfree(mq->sg);
+	mq->sg = NULL;
+
+	if (mq->bounce_buf)
+		kfree(mq->bounce_buf);
+	mq->bounce_buf = 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)
+{
+	struct request_queue *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)
+{
+	struct request_queue *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);
+	}
+}
+
+/*
+ * Prepare the sg list(s) to be handed of to the host driver
+ */
+unsigned int mmc_queue_map_sg(struct mmc_queue *mq)
+{
+	unsigned int sg_len;
+	size_t buflen;
+	struct scatterlist *sg;
+	int i;
+
+	if (!mq->bounce_buf)
+		return blk_rq_map_sg(mq->queue, mq->req, mq->sg);
+
+	BUG_ON(!mq->bounce_sg);
+
+	sg_len = blk_rq_map_sg(mq->queue, mq->req, mq->bounce_sg);
+
+	mq->bounce_sg_len = sg_len;
+
+	buflen = 0;
+	for_each_sg(mq->bounce_sg, sg, sg_len, i)
+		buflen += sg->length;
+
+	sg_init_one(mq->sg, mq->bounce_buf, buflen);
+
+	return 1;
+}
+
+/*
+ * If writing, bounce the data to the buffer before the request
+ * is sent to the host driver
+ */
+void mmc_queue_bounce_pre(struct mmc_queue *mq)
+{
+	unsigned long flags;
+
+	if (!mq->bounce_buf)
+		return;
+
+	if (rq_data_dir(mq->req) != WRITE)
+		return;
+
+	local_irq_save(flags);
+	sg_copy_to_buffer(mq->bounce_sg, mq->bounce_sg_len,
+		mq->bounce_buf, mq->sg[0].length);
+	local_irq_restore(flags);
+}
+
+/*
+ * If reading, bounce the data from the buffer after the request
+ * has been handled by the host driver
+ */
+void mmc_queue_bounce_post(struct mmc_queue *mq)
+{
+	unsigned long flags;
+
+	if (!mq->bounce_buf)
+		return;
+
+	if (rq_data_dir(mq->req) != READ)
+		return;
+
+	local_irq_save(flags);
+	sg_copy_from_buffer(mq->bounce_sg, mq->bounce_sg_len,
+		mq->bounce_buf, mq->sg[0].length);
+	local_irq_restore(flags);
+}
+