[mirror_ubuntu-jammy-kernel.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/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);
			if (req)
				blkdev_dequeue_request(req);
		}
		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) {
		printk(KERN_ERR "MMC: killing requests for dead queue\n");
		while ((req = elv_next_request(q)) != NULL) {
			blkdev_dequeue_request(req);
			__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);
	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);
}
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	*/
	12	#include <linux/module.h>
	13	#include <linux/blkdev.h>
83144186	14	#include <linux/freezer.h>
87598a2b	15	#include <linux/kthread.h>
45711f1a	16	#include <linux/scatterlist.h>
1da177e4 LT	17
	18	#include <linux/mmc/card.h>
	19	#include <linux/mmc/host.h>
98ac2162	20	#include "queue.h"
1da177e4	21
98ccf149 PO	22	#define MMC_QUEUE_BOUNCESZ 65536
98ccf149 PO	23
87598a2b	24	#define MMC_QUEUE_SUSPENDED (1 << 0)
1da177e4 LT	25
1da177e4 LT	26	/*
9c9f2d63	27	* Prepare a MMC request. This just filters out odd stuff.
1da177e4 LT	28	*/
	29	static int mmc_prep_request(struct request_queue q, struct request req)
	30	{
9c9f2d63 PO	31	/*
	32	* We only like normal block requests.
	33	*/
d6d8de33	34	if (!blk_fs_request(req)) {
1da177e4	35	blk_dump_rq_flags(req, "MMC bad request");
9c9f2d63	36	return BLKPREP_KILL;
1da177e4 LT	37	}
1da177e4 LT	38
9c9f2d63	39	req->cmd_flags \|= REQ_DONTPREP;
1da177e4	40
9c9f2d63	41	return BLKPREP_OK;
1da177e4 LT	42	}
	43
	44	static int mmc_queue_thread(void *d)
	45	{
	46	struct mmc_queue *mq = d;
	47	struct request_queue *q = mq->queue;
1da177e4	48
83144186	49	current->flags \|= PF_MEMALLOC;
1da177e4	50
1da177e4	51	down(&mq->thread_sem);
1da177e4 LT	52	do {
	53	struct request *req = NULL;
	54
	55	spin_lock_irq(q->queue_lock);
	56	set_current_state(TASK_INTERRUPTIBLE);
296b2f6a	57	if (!blk_queue_plugged(q)) {
c723e08a	58	req = elv_next_request(q);
296b2f6a TH	59	if (req)
	60	blkdev_dequeue_request(req);
	61	}
c723e08a	62	mq->req = req;
1da177e4 LT	63	spin_unlock_irq(q->queue_lock);
	64
	65	if (!req) {
7b30d281 VW	66	if (kthread_should_stop()) {
7b30d281 VW	67	set_current_state(TASK_RUNNING);
1da177e4	68	break;
7b30d281	69	}
1da177e4 LT	70	up(&mq->thread_sem);
	71	schedule();
	72	down(&mq->thread_sem);
	73	continue;
	74	}
	75	set_current_state(TASK_RUNNING);
	76
	77	mq->issue_fn(mq, req);
	78	} while (1);
1da177e4 LT	79	up(&mq->thread_sem);
1da177e4 LT	80
1da177e4 LT	81	return 0;
	82	}
	83
	84	/*
	85	* Generic MMC request handler. This is called for any queue on a
	86	* particular host. When the host is not busy, we look for a request
	87	* on any queue on this host, and attempt to issue it. This may
	88	* not be the queue we were asked to process.
	89	*/
165125e1	90	static void mmc_request(struct request_queue *q)
1da177e4 LT	91	{
1da177e4 LT	92	struct mmc_queue *mq = q->queuedata;
89b4e133	93	struct request *req;
89b4e133 PO	94
	95	if (!mq) {
	96	printk(KERN_ERR "MMC: killing requests for dead queue\n");
	97	while ((req = elv_next_request(q)) != NULL) {
296b2f6a TH	98	blkdev_dequeue_request(req);
296b2f6a TH	99	__blk_end_request_all(req, -EIO);
89b4e133 PO	100	}
	101	return;
	102	}
1da177e4 LT	103
1da177e4 LT	104	if (!mq->req)
87598a2b	105	wake_up_process(mq->thread);
1da177e4 LT	106	}
	107
	108	/**
	109	* mmc_init_queue - initialise a queue structure.
	110	* @mq: mmc queue
	111	* @card: mmc card to attach this queue
	112	* @lock: queue lock
	113	*
	114	* Initialise a MMC card request queue.
	115	*/
	116	int mmc_init_queue(struct mmc_queue mq, struct mmc_card card, spinlock_t *lock)
	117	{
	118	struct mmc_host *host = card->host;
	119	u64 limit = BLK_BOUNCE_HIGH;
	120	int ret;
	121
fcaf71fd GKH	122	if (mmc_dev(host)->dma_mask && *mmc_dev(host)->dma_mask)
fcaf71fd GKH	123	limit = *mmc_dev(host)->dma_mask;
1da177e4 LT	124
	125	mq->card = card;
	126	mq->queue = blk_init_queue(mmc_request, lock);
	127	if (!mq->queue)
	128	return -ENOMEM;
	129
1da177e4 LT	130	mq->queue->queuedata = mq;
	131	mq->req = NULL;
	132
98ccf149	133	blk_queue_prep_rq(mq->queue, mmc_prep_request);
91028954	134	blk_queue_ordered(mq->queue, QUEUE_ORDERED_DRAIN, NULL);
8dddfe19	135	queue_flag_set_unlocked(QUEUE_FLAG_NONROT, mq->queue);
98ccf149 PO	136
	137	#ifdef CONFIG_MMC_BLOCK_BOUNCE
	138	if (host->max_hw_segs == 1) {
aafabfab PO	139	unsigned int bouncesz;
aafabfab PO	140
98ccf149 PO	141	bouncesz = MMC_QUEUE_BOUNCESZ;
	142
	143	if (bouncesz > host->max_req_size)
	144	bouncesz = host->max_req_size;
	145	if (bouncesz > host->max_seg_size)
	146	bouncesz = host->max_seg_size;
f3eb0aaa PO	147	if (bouncesz > (host->max_blk_count * 512))
	148	bouncesz = host->max_blk_count * 512;
	149
	150	if (bouncesz > 512) {
	151	mq->bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
	152	if (!mq->bounce_buf) {
	153	printk(KERN_WARNING "%s: unable to "
	154	"allocate bounce buffer\n",
	155	mmc_card_name(card));
	156	}
	157	}
98ccf149	158
f3eb0aaa	159	if (mq->bounce_buf) {
2ff1fa67	160	blk_queue_bounce_limit(mq->queue, BLK_BOUNCE_ANY);
98ccf149 PO	161	blk_queue_max_sectors(mq->queue, bouncesz / 512);
	162	blk_queue_max_phys_segments(mq->queue, bouncesz / 512);
	163	blk_queue_max_hw_segments(mq->queue, bouncesz / 512);
	164	blk_queue_max_segment_size(mq->queue, bouncesz);
	165
45711f1a	166	mq->sg = kmalloc(sizeof(struct scatterlist),
98ccf149 PO	167	GFP_KERNEL);
	168	if (!mq->sg) {
	169	ret = -ENOMEM;
aafabfab	170	goto cleanup_queue;
98ccf149	171	}
45711f1a	172	sg_init_table(mq->sg, 1);
98ccf149	173
45711f1a	174	mq->bounce_sg = kmalloc(sizeof(struct scatterlist) *
98ccf149 PO	175	bouncesz / 512, GFP_KERNEL);
	176	if (!mq->bounce_sg) {
	177	ret = -ENOMEM;
aafabfab	178	goto cleanup_queue;
98ccf149	179	}
45711f1a	180	sg_init_table(mq->bounce_sg, bouncesz / 512);
98ccf149 PO	181	}
	182	}
	183	#endif
	184
	185	if (!mq->bounce_buf) {
	186	blk_queue_bounce_limit(mq->queue, limit);
f3eb0aaa PO	187	blk_queue_max_sectors(mq->queue,
f3eb0aaa PO	188	min(host->max_blk_count, host->max_req_size / 512));
98ccf149 PO	189	blk_queue_max_phys_segments(mq->queue, host->max_phys_segs);
	190	blk_queue_max_hw_segments(mq->queue, host->max_hw_segs);
	191	blk_queue_max_segment_size(mq->queue, host->max_seg_size);
	192
05e5b136	193	mq->sg = kmalloc(sizeof(struct scatterlist) *
98ccf149 PO	194	host->max_phys_segs, GFP_KERNEL);
	195	if (!mq->sg) {
	196	ret = -ENOMEM;
	197	goto cleanup_queue;
	198	}
05e5b136	199	sg_init_table(mq->sg, host->max_phys_segs);
1da177e4 LT	200	}
1da177e4 LT	201
1da177e4 LT	202	init_MUTEX(&mq->thread_sem);
1da177e4 LT	203
87598a2b CH	204	mq->thread = kthread_run(mmc_queue_thread, mq, "mmcqd");
	205	if (IS_ERR(mq->thread)) {
	206	ret = PTR_ERR(mq->thread);
98ccf149	207	goto free_bounce_sg;
1da177e4 LT	208	}
1da177e4 LT	209
87598a2b	210	return 0;
98ccf149 PO	211	free_bounce_sg:
	212	if (mq->bounce_sg)
	213	kfree(mq->bounce_sg);
	214	mq->bounce_sg = NULL;
aafabfab PO	215	cleanup_queue:
	216	if (mq->sg)
	217	kfree(mq->sg);
1da177e4	218	mq->sg = NULL;
98ccf149 PO	219	if (mq->bounce_buf)
	220	kfree(mq->bounce_buf);
	221	mq->bounce_buf = NULL;
1da177e4	222	blk_cleanup_queue(mq->queue);
1da177e4 LT	223	return ret;
1da177e4 LT	224	}
1da177e4 LT	225
	226	void mmc_cleanup_queue(struct mmc_queue *mq)
	227	{
165125e1	228	struct request_queue *q = mq->queue;
89b4e133 PO	229	unsigned long flags;
	230
	231	/* Mark that we should start throwing out stragglers */
	232	spin_lock_irqsave(q->queue_lock, flags);
	233	q->queuedata = NULL;
	234	spin_unlock_irqrestore(q->queue_lock, flags);
	235
d2b46f66 PO	236	/* Make sure the queue isn't suspended, as that will deadlock */
	237	mmc_queue_resume(mq);
	238
89b4e133	239	/* Then terminate our worker thread */
87598a2b	240	kthread_stop(mq->thread);
1da177e4	241
98ccf149 PO	242	if (mq->bounce_sg)
	243	kfree(mq->bounce_sg);
	244	mq->bounce_sg = NULL;
	245
1da177e4 LT	246	kfree(mq->sg);
	247	mq->sg = NULL;
	248
98ccf149 PO	249	if (mq->bounce_buf)
	250	kfree(mq->bounce_buf);
	251	mq->bounce_buf = NULL;
	252
1da177e4 LT	253	blk_cleanup_queue(mq->queue);
	254
	255	mq->card = NULL;
	256	}
	257	EXPORT_SYMBOL(mmc_cleanup_queue);
	258
	259	/**
	260	* mmc_queue_suspend - suspend a MMC request queue
	261	* @mq: MMC queue to suspend
	262	*
	263	* Stop the block request queue, and wait for our thread to
	264	* complete any outstanding requests. This ensures that we
	265	* won't suspend while a request is being processed.
	266	*/
	267	void mmc_queue_suspend(struct mmc_queue *mq)
	268	{
165125e1	269	struct request_queue *q = mq->queue;
1da177e4 LT	270	unsigned long flags;
	271
	272	if (!(mq->flags & MMC_QUEUE_SUSPENDED)) {
	273	mq->flags \|= MMC_QUEUE_SUSPENDED;
	274
	275	spin_lock_irqsave(q->queue_lock, flags);
	276	blk_stop_queue(q);
	277	spin_unlock_irqrestore(q->queue_lock, flags);
	278
	279	down(&mq->thread_sem);
	280	}
	281	}
1da177e4 LT	282
	283	/**
	284	* mmc_queue_resume - resume a previously suspended MMC request queue
	285	* @mq: MMC queue to resume
	286	*/
	287	void mmc_queue_resume(struct mmc_queue *mq)
	288	{
165125e1	289	struct request_queue *q = mq->queue;
1da177e4 LT	290	unsigned long flags;
	291
	292	if (mq->flags & MMC_QUEUE_SUSPENDED) {
	293	mq->flags &= ~MMC_QUEUE_SUSPENDED;
	294
	295	up(&mq->thread_sem);
	296
	297	spin_lock_irqsave(q->queue_lock, flags);
	298	blk_start_queue(q);
	299	spin_unlock_irqrestore(q->queue_lock, flags);
	300	}
	301	}
98ac2162	302
2ff1fa67 PO	303	/*
	304	* Prepare the sg list(s) to be handed of to the host driver
	305	*/
98ccf149 PO	306	unsigned int mmc_queue_map_sg(struct mmc_queue *mq)
	307	{
	308	unsigned int sg_len;
2ff1fa67 PO	309	size_t buflen;
	310	struct scatterlist *sg;
	311	int i;
98ccf149 PO	312
	313	if (!mq->bounce_buf)
	314	return blk_rq_map_sg(mq->queue, mq->req, mq->sg);
	315
	316	BUG_ON(!mq->bounce_sg);
	317
	318	sg_len = blk_rq_map_sg(mq->queue, mq->req, mq->bounce_sg);
	319
	320	mq->bounce_sg_len = sg_len;
	321
2ff1fa67 PO	322	buflen = 0;
	323	for_each_sg(mq->bounce_sg, sg, sg_len, i)
	324	buflen += sg->length;
98ccf149	325
2ff1fa67	326	sg_init_one(mq->sg, mq->bounce_buf, buflen);
98ccf149 PO	327
	328	return 1;
	329	}
	330
2ff1fa67 PO	331	/*
	332	* If writing, bounce the data to the buffer before the request
	333	* is sent to the host driver
	334	*/
98ccf149 PO	335	void mmc_queue_bounce_pre(struct mmc_queue *mq)
98ccf149 PO	336	{
2ff1fa67 PO	337	unsigned long flags;
2ff1fa67 PO	338
98ccf149 PO	339	if (!mq->bounce_buf)
	340	return;
	341
98ccf149 PO	342	if (rq_data_dir(mq->req) != WRITE)
	343	return;
	344
2ff1fa67 PO	345	local_irq_save(flags);
	346	sg_copy_to_buffer(mq->bounce_sg, mq->bounce_sg_len,
	347	mq->bounce_buf, mq->sg[0].length);
	348	local_irq_restore(flags);
98ccf149 PO	349	}
98ccf149 PO	350
2ff1fa67 PO	351	/*
	352	* If reading, bounce the data from the buffer after the request
	353	* has been handled by the host driver
	354	*/
98ccf149 PO	355	void mmc_queue_bounce_post(struct mmc_queue *mq)
98ccf149 PO	356	{
2ff1fa67 PO	357	unsigned long flags;
2ff1fa67 PO	358
98ccf149 PO	359	if (!mq->bounce_buf)
	360	return;
	361
98ccf149 PO	362	if (rq_data_dir(mq->req) != READ)
	363	return;
	364
2ff1fa67 PO	365	local_irq_save(flags);
	366	sg_copy_from_buffer(mq->bounce_sg, mq->bounce_sg_len,
	367	mq->bounce_buf, mq->sg[0].length);
	368	local_irq_restore(flags);
98ccf149 PO	369	}
98ccf149 PO	370