[net-next-2.6.git] / drivers / mmc / card / queue.c

/*
 *  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/slab.h>
#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 and discards.
	 */
	if (req->cmd_type != REQ_TYPE_FS && !(req->cmd_flags & REQ_DISCARD)) {
		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 = blk_fetch_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;

	if (!mq) {
		while ((req = blk_fetch_request(q)) != NULL) {
			req->cmd_flags |= REQ_QUIET;
			__blk_end_request_all(req, -EIO);
		}
		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);
	queue_flag_set_unlocked(QUEUE_FLAG_NONROT, mq->queue);
	if (mmc_can_erase(card)) {
		queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mq->queue);
		mq->queue->limits.max_discard_sectors = UINT_MAX;
		if (card->erased_byte == 0)
			mq->queue->limits.discard_zeroes_data = 1;
		if (!mmc_can_trim(card) && is_power_of_2(card->erase_size)) {
			mq->queue->limits.discard_granularity =
							card->erase_size << 9;
			mq->queue->limits.discard_alignment =
							card->erase_size << 9;
		}
		if (mmc_can_secure_erase_trim(card))
			queue_flag_set_unlocked(QUEUE_FLAG_SECDISCARD,
						mq->queue);
	}

#ifdef CONFIG_MMC_BLOCK_BOUNCE
	if (host->max_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_hw_sectors(mq->queue, bouncesz / 512);
			blk_queue_max_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_hw_sectors(mq->queue,
			min(host->max_blk_count, host->max_req_size / 512));
		blk_queue_max_segments(mq->queue, host->max_segs);
		blk_queue_max_segment_size(mq->queue, host->max_seg_size);

		mq->sg = kmalloc(sizeof(struct scatterlist) *
			host->max_segs, GFP_KERNEL);
		if (!mq->sg) {
			ret = -ENOMEM;
			goto cleanup_queue;
		}
		sg_init_table(mq->sg, host->max_segs);
	}

	sema_init(&mq->thread_sem, 1);

	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;

	/* Make sure the queue isn't suspended, as that will deadlock */
	mmc_queue_resume(mq);

	/* Then terminate our worker thread */
	kthread_stop(mq->thread);

	/* Empty the queue */
	spin_lock_irqsave(q->queue_lock, flags);
	q->queuedata = NULL;
	blk_start_queue(q);
	spin_unlock_irqrestore(q->queue_lock, flags);

 	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;

	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);
}
Commit	Line	Data
1da177e4	1	/*
70f10482	2	* linux/drivers/mmc/card/queue.c
1da177e4 LT	3	*
1da177e4 LT	4	* Copyright (C) 2003 Russell King, All Rights Reserved.
98ac2162	5	* Copyright 2006-2007 Pierre Ossman
1da177e4 LT	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License version 2 as
	9	* published by the Free Software Foundation.
	10	*
	11	*/
5a0e3ad6	12	#include <linux/slab.h>
1da177e4 LT	13	#include <linux/module.h>
1da177e4 LT	14	#include <linux/blkdev.h>
83144186	15	#include <linux/freezer.h>
87598a2b	16	#include <linux/kthread.h>
45711f1a	17	#include <linux/scatterlist.h>
1da177e4 LT	18
	19	#include <linux/mmc/card.h>
	20	#include <linux/mmc/host.h>
98ac2162	21	#include "queue.h"
1da177e4	22
98ccf149 PO	23	#define MMC_QUEUE_BOUNCESZ 65536
98ccf149 PO	24
87598a2b	25	#define MMC_QUEUE_SUSPENDED (1 << 0)
1da177e4 LT	26
1da177e4 LT	27	/*
9c9f2d63	28	* Prepare a MMC request. This just filters out odd stuff.
1da177e4 LT	29	*/
	30	static int mmc_prep_request(struct request_queue q, struct request req)
	31	{
9c9f2d63	32	/*
bd788c96	33	* We only like normal block requests and discards.
9c9f2d63	34	*/
bd788c96	35	if (req->cmd_type != REQ_TYPE_FS && !(req->cmd_flags & REQ_DISCARD)) {
1da177e4	36	blk_dump_rq_flags(req, "MMC bad request");
9c9f2d63	37	return BLKPREP_KILL;
1da177e4 LT	38	}
1da177e4 LT	39
9c9f2d63	40	req->cmd_flags \|= REQ_DONTPREP;
1da177e4	41
9c9f2d63	42	return BLKPREP_OK;
1da177e4 LT	43	}
	44
	45	static int mmc_queue_thread(void *d)
	46	{
	47	struct mmc_queue *mq = d;
	48	struct request_queue *q = mq->queue;
1da177e4	49
83144186	50	current->flags \|= PF_MEMALLOC;
1da177e4	51
1da177e4	52	down(&mq->thread_sem);
1da177e4 LT	53	do {
	54	struct request *req = NULL;
	55
	56	spin_lock_irq(q->queue_lock);
	57	set_current_state(TASK_INTERRUPTIBLE);
9934c8c0 TH	58	if (!blk_queue_plugged(q))
9934c8c0 TH	59	req = blk_fetch_request(q);
c723e08a	60	mq->req = req;
1da177e4 LT	61	spin_unlock_irq(q->queue_lock);
	62
	63	if (!req) {
7b30d281 VW	64	if (kthread_should_stop()) {
7b30d281 VW	65	set_current_state(TASK_RUNNING);
1da177e4	66	break;
7b30d281	67	}
1da177e4 LT	68	up(&mq->thread_sem);
	69	schedule();
	70	down(&mq->thread_sem);
	71	continue;
	72	}
	73	set_current_state(TASK_RUNNING);
	74
	75	mq->issue_fn(mq, req);
	76	} while (1);
1da177e4 LT	77	up(&mq->thread_sem);
1da177e4 LT	78
1da177e4 LT	79	return 0;
	80	}
	81
	82	/*
	83	* Generic MMC request handler. This is called for any queue on a
	84	* particular host. When the host is not busy, we look for a request
	85	* on any queue on this host, and attempt to issue it. This may
	86	* not be the queue we were asked to process.
	87	*/
165125e1	88	static void mmc_request(struct request_queue *q)
1da177e4 LT	89	{
1da177e4 LT	90	struct mmc_queue *mq = q->queuedata;
89b4e133	91	struct request *req;
89b4e133 PO	92
89b4e133 PO	93	if (!mq) {
5fa83ce2 AH	94	while ((req = blk_fetch_request(q)) != NULL) {
5fa83ce2 AH	95	req->cmd_flags \|= REQ_QUIET;
296b2f6a	96	__blk_end_request_all(req, -EIO);
5fa83ce2	97	}
89b4e133 PO	98	return;
89b4e133 PO	99	}
1da177e4 LT	100
1da177e4 LT	101	if (!mq->req)
87598a2b	102	wake_up_process(mq->thread);
1da177e4 LT	103	}
	104
	105	/**
	106	* mmc_init_queue - initialise a queue structure.
	107	* @mq: mmc queue
	108	* @card: mmc card to attach this queue
	109	* @lock: queue lock
	110	*
	111	* Initialise a MMC card request queue.
	112	*/
	113	int mmc_init_queue(struct mmc_queue mq, struct mmc_card card, spinlock_t *lock)
	114	{
	115	struct mmc_host *host = card->host;
	116	u64 limit = BLK_BOUNCE_HIGH;
	117	int ret;
	118
fcaf71fd GKH	119	if (mmc_dev(host)->dma_mask && *mmc_dev(host)->dma_mask)
fcaf71fd GKH	120	limit = *mmc_dev(host)->dma_mask;
1da177e4 LT	121
	122	mq->card = card;
	123	mq->queue = blk_init_queue(mmc_request, lock);
	124	if (!mq->queue)
	125	return -ENOMEM;
	126
1da177e4 LT	127	mq->queue->queuedata = mq;
	128	mq->req = NULL;
	129
98ccf149	130	blk_queue_prep_rq(mq->queue, mmc_prep_request);
8dddfe19	131	queue_flag_set_unlocked(QUEUE_FLAG_NONROT, mq->queue);
bd788c96 AH	132	if (mmc_can_erase(card)) {
	133	queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mq->queue);
	134	mq->queue->limits.max_discard_sectors = UINT_MAX;
	135	if (card->erased_byte == 0)
	136	mq->queue->limits.discard_zeroes_data = 1;
	137	if (!mmc_can_trim(card) && is_power_of_2(card->erase_size)) {
	138	mq->queue->limits.discard_granularity =
	139	card->erase_size << 9;
	140	mq->queue->limits.discard_alignment =
	141	card->erase_size << 9;
	142	}
49804548 AH	143	if (mmc_can_secure_erase_trim(card))
	144	queue_flag_set_unlocked(QUEUE_FLAG_SECDISCARD,
	145	mq->queue);
bd788c96	146	}
98ccf149 PO	147
98ccf149 PO	148	#ifdef CONFIG_MMC_BLOCK_BOUNCE
a36274e0	149	if (host->max_segs == 1) {
aafabfab PO	150	unsigned int bouncesz;
aafabfab PO	151
98ccf149 PO	152	bouncesz = MMC_QUEUE_BOUNCESZ;
	153
	154	if (bouncesz > host->max_req_size)
	155	bouncesz = host->max_req_size;
	156	if (bouncesz > host->max_seg_size)
	157	bouncesz = host->max_seg_size;
f3eb0aaa PO	158	if (bouncesz > (host->max_blk_count * 512))
	159	bouncesz = host->max_blk_count * 512;
	160
	161	if (bouncesz > 512) {
	162	mq->bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
	163	if (!mq->bounce_buf) {
	164	printk(KERN_WARNING "%s: unable to "
	165	"allocate bounce buffer\n",
	166	mmc_card_name(card));
	167	}
	168	}
98ccf149	169
f3eb0aaa	170	if (mq->bounce_buf) {
2ff1fa67	171	blk_queue_bounce_limit(mq->queue, BLK_BOUNCE_ANY);
086fa5ff	172	blk_queue_max_hw_sectors(mq->queue, bouncesz / 512);
8a78362c	173	blk_queue_max_segments(mq->queue, bouncesz / 512);
98ccf149 PO	174	blk_queue_max_segment_size(mq->queue, bouncesz);
98ccf149 PO	175
45711f1a	176	mq->sg = kmalloc(sizeof(struct scatterlist),
98ccf149 PO	177	GFP_KERNEL);
	178	if (!mq->sg) {
	179	ret = -ENOMEM;
aafabfab	180	goto cleanup_queue;
98ccf149	181	}
45711f1a	182	sg_init_table(mq->sg, 1);
98ccf149	183
45711f1a	184	mq->bounce_sg = kmalloc(sizeof(struct scatterlist) *
98ccf149 PO	185	bouncesz / 512, GFP_KERNEL);
	186	if (!mq->bounce_sg) {
	187	ret = -ENOMEM;
aafabfab	188	goto cleanup_queue;
98ccf149	189	}
45711f1a	190	sg_init_table(mq->bounce_sg, bouncesz / 512);
98ccf149 PO	191	}
	192	}
	193	#endif
	194
	195	if (!mq->bounce_buf) {
	196	blk_queue_bounce_limit(mq->queue, limit);
086fa5ff	197	blk_queue_max_hw_sectors(mq->queue,
f3eb0aaa	198	min(host->max_blk_count, host->max_req_size / 512));
a36274e0	199	blk_queue_max_segments(mq->queue, host->max_segs);
98ccf149 PO	200	blk_queue_max_segment_size(mq->queue, host->max_seg_size);
98ccf149 PO	201
05e5b136	202	mq->sg = kmalloc(sizeof(struct scatterlist) *
a36274e0	203	host->max_segs, GFP_KERNEL);
98ccf149 PO	204	if (!mq->sg) {
	205	ret = -ENOMEM;
	206	goto cleanup_queue;
	207	}
a36274e0	208	sg_init_table(mq->sg, host->max_segs);
1da177e4 LT	209	}
1da177e4 LT	210
632cf92a	211	sema_init(&mq->thread_sem, 1);
1da177e4	212
87598a2b CH	213	mq->thread = kthread_run(mmc_queue_thread, mq, "mmcqd");
	214	if (IS_ERR(mq->thread)) {
	215	ret = PTR_ERR(mq->thread);
98ccf149	216	goto free_bounce_sg;
1da177e4 LT	217	}
1da177e4 LT	218
87598a2b	219	return 0;
98ccf149 PO	220	free_bounce_sg:
	221	if (mq->bounce_sg)
	222	kfree(mq->bounce_sg);
	223	mq->bounce_sg = NULL;
aafabfab PO	224	cleanup_queue:
	225	if (mq->sg)
	226	kfree(mq->sg);
1da177e4	227	mq->sg = NULL;
98ccf149 PO	228	if (mq->bounce_buf)
	229	kfree(mq->bounce_buf);
	230	mq->bounce_buf = NULL;
1da177e4	231	blk_cleanup_queue(mq->queue);
1da177e4 LT	232	return ret;
1da177e4 LT	233	}
1da177e4 LT	234
	235	void mmc_cleanup_queue(struct mmc_queue *mq)
	236	{
165125e1	237	struct request_queue *q = mq->queue;
89b4e133 PO	238	unsigned long flags;
89b4e133 PO	239
d2b46f66 PO	240	/* Make sure the queue isn't suspended, as that will deadlock */
	241	mmc_queue_resume(mq);
	242
89b4e133	243	/* Then terminate our worker thread */
87598a2b	244	kthread_stop(mq->thread);
1da177e4	245
5fa83ce2 AH	246	/* Empty the queue */
	247	spin_lock_irqsave(q->queue_lock, flags);
	248	q->queuedata = NULL;
	249	blk_start_queue(q);
	250	spin_unlock_irqrestore(q->queue_lock, flags);
	251
98ccf149 PO	252	if (mq->bounce_sg)
	253	kfree(mq->bounce_sg);
	254	mq->bounce_sg = NULL;
	255
1da177e4 LT	256	kfree(mq->sg);
	257	mq->sg = NULL;
	258
98ccf149 PO	259	if (mq->bounce_buf)
	260	kfree(mq->bounce_buf);
	261	mq->bounce_buf = NULL;
	262
1da177e4 LT	263	mq->card = NULL;
	264	}
	265	EXPORT_SYMBOL(mmc_cleanup_queue);
	266
	267	/**
	268	* mmc_queue_suspend - suspend a MMC request queue
	269	* @mq: MMC queue to suspend
	270	*
	271	* Stop the block request queue, and wait for our thread to
	272	* complete any outstanding requests. This ensures that we
	273	* won't suspend while a request is being processed.
	274	*/
	275	void mmc_queue_suspend(struct mmc_queue *mq)
	276	{
165125e1	277	struct request_queue *q = mq->queue;
1da177e4 LT	278	unsigned long flags;
	279
	280	if (!(mq->flags & MMC_QUEUE_SUSPENDED)) {
	281	mq->flags \|= MMC_QUEUE_SUSPENDED;
	282
	283	spin_lock_irqsave(q->queue_lock, flags);
	284	blk_stop_queue(q);
	285	spin_unlock_irqrestore(q->queue_lock, flags);
	286
	287	down(&mq->thread_sem);
	288	}
	289	}
1da177e4 LT	290
	291	/**
	292	* mmc_queue_resume - resume a previously suspended MMC request queue
	293	* @mq: MMC queue to resume
	294	*/
	295	void mmc_queue_resume(struct mmc_queue *mq)
	296	{
165125e1	297	struct request_queue *q = mq->queue;
1da177e4 LT	298	unsigned long flags;
	299
	300	if (mq->flags & MMC_QUEUE_SUSPENDED) {
	301	mq->flags &= ~MMC_QUEUE_SUSPENDED;
	302
	303	up(&mq->thread_sem);
	304
	305	spin_lock_irqsave(q->queue_lock, flags);
	306	blk_start_queue(q);
	307	spin_unlock_irqrestore(q->queue_lock, flags);
	308	}
	309	}
98ac2162	310
2ff1fa67 PO	311	/*
	312	* Prepare the sg list(s) to be handed of to the host driver
	313	*/
98ccf149 PO	314	unsigned int mmc_queue_map_sg(struct mmc_queue *mq)
	315	{
	316	unsigned int sg_len;
2ff1fa67 PO	317	size_t buflen;
	318	struct scatterlist *sg;
	319	int i;
98ccf149 PO	320
	321	if (!mq->bounce_buf)
	322	return blk_rq_map_sg(mq->queue, mq->req, mq->sg);
	323
	324	BUG_ON(!mq->bounce_sg);
	325
	326	sg_len = blk_rq_map_sg(mq->queue, mq->req, mq->bounce_sg);
	327
	328	mq->bounce_sg_len = sg_len;
	329
2ff1fa67 PO	330	buflen = 0;
	331	for_each_sg(mq->bounce_sg, sg, sg_len, i)
	332	buflen += sg->length;
98ccf149	333
2ff1fa67	334	sg_init_one(mq->sg, mq->bounce_buf, buflen);
98ccf149 PO	335
	336	return 1;
	337	}
	338
2ff1fa67 PO	339	/*
	340	* If writing, bounce the data to the buffer before the request
	341	* is sent to the host driver
	342	*/
98ccf149 PO	343	void mmc_queue_bounce_pre(struct mmc_queue *mq)
98ccf149 PO	344	{
2ff1fa67 PO	345	unsigned long flags;
2ff1fa67 PO	346
98ccf149 PO	347	if (!mq->bounce_buf)
	348	return;
	349
98ccf149 PO	350	if (rq_data_dir(mq->req) != WRITE)
	351	return;
	352
2ff1fa67 PO	353	local_irq_save(flags);
	354	sg_copy_to_buffer(mq->bounce_sg, mq->bounce_sg_len,
	355	mq->bounce_buf, mq->sg[0].length);
	356	local_irq_restore(flags);
98ccf149 PO	357	}
98ccf149 PO	358
2ff1fa67 PO	359	/*
	360	* If reading, bounce the data from the buffer after the request
	361	* has been handled by the host driver
	362	*/
98ccf149 PO	363	void mmc_queue_bounce_post(struct mmc_queue *mq)
98ccf149 PO	364	{
2ff1fa67 PO	365	unsigned long flags;
2ff1fa67 PO	366
98ccf149 PO	367	if (!mq->bounce_buf)
	368	return;
	369
98ccf149 PO	370	if (rq_data_dir(mq->req) != READ)
	371	return;
	372
2ff1fa67 PO	373	local_irq_save(flags);
	374	sg_copy_from_buffer(mq->bounce_sg, mq->bounce_sg_len,
	375	mq->bounce_buf, mq->sg[0].length);
	376	local_irq_restore(flags);
98ccf149 PO	377	}
98ccf149 PO	378