[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_pc_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);

#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;

		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));
		} else {
			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, 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	*/
	34	if (!blk_fs_request(req) && !blk_pc_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);
	57	if (!blk_queue_plugged(q))
c723e08a JY	58	req = elv_next_request(q);
c723e08a JY	59	mq->req = req;
1da177e4 LT	60	spin_unlock_irq(q->queue_lock);
	61
	62	if (!req) {
7b30d281 VW	63	if (kthread_should_stop()) {
7b30d281 VW	64	set_current_state(TASK_RUNNING);
1da177e4	65	break;
7b30d281	66	}
1da177e4 LT	67	up(&mq->thread_sem);
	68	schedule();
	69	down(&mq->thread_sem);
	70	continue;
	71	}
	72	set_current_state(TASK_RUNNING);
	73
	74	mq->issue_fn(mq, req);
	75	} while (1);
1da177e4 LT	76	up(&mq->thread_sem);
1da177e4 LT	77
1da177e4 LT	78	return 0;
	79	}
	80
	81	/*
	82	* Generic MMC request handler. This is called for any queue on a
	83	* particular host. When the host is not busy, we look for a request
	84	* on any queue on this host, and attempt to issue it. This may
	85	* not be the queue we were asked to process.
	86	*/
165125e1	87	static void mmc_request(struct request_queue *q)
1da177e4 LT	88	{
1da177e4 LT	89	struct mmc_queue *mq = q->queuedata;
89b4e133 PO	90	struct request *req;
	91	int ret;
	92
	93	if (!mq) {
	94	printk(KERN_ERR "MMC: killing requests for dead queue\n");
	95	while ((req = elv_next_request(q)) != NULL) {
	96	do {
fd539832 KU	97	ret = __blk_end_request(req, -EIO,
fd539832 KU	98	blk_rq_cur_bytes(req));
89b4e133 PO	99	} while (ret);
	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 PO	133	blk_queue_prep_rq(mq->queue, mmc_prep_request);
	134
	135	#ifdef CONFIG_MMC_BLOCK_BOUNCE
	136	if (host->max_hw_segs == 1) {
aafabfab PO	137	unsigned int bouncesz;
aafabfab PO	138
98ccf149 PO	139	bouncesz = MMC_QUEUE_BOUNCESZ;
	140
	141	if (bouncesz > host->max_req_size)
	142	bouncesz = host->max_req_size;
	143	if (bouncesz > host->max_seg_size)
	144	bouncesz = host->max_seg_size;
	145
	146	mq->bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
	147	if (!mq->bounce_buf) {
	148	printk(KERN_WARNING "%s: unable to allocate "
	149	"bounce buffer\n", mmc_card_name(card));
	150	} else {
2ff1fa67	151	blk_queue_bounce_limit(mq->queue, BLK_BOUNCE_ANY);
98ccf149 PO	152	blk_queue_max_sectors(mq->queue, bouncesz / 512);
	153	blk_queue_max_phys_segments(mq->queue, bouncesz / 512);
	154	blk_queue_max_hw_segments(mq->queue, bouncesz / 512);
	155	blk_queue_max_segment_size(mq->queue, bouncesz);
	156
45711f1a	157	mq->sg = kmalloc(sizeof(struct scatterlist),
98ccf149 PO	158	GFP_KERNEL);
	159	if (!mq->sg) {
	160	ret = -ENOMEM;
aafabfab	161	goto cleanup_queue;
98ccf149	162	}
45711f1a	163	sg_init_table(mq->sg, 1);
98ccf149	164
45711f1a	165	mq->bounce_sg = kmalloc(sizeof(struct scatterlist) *
98ccf149 PO	166	bouncesz / 512, GFP_KERNEL);
	167	if (!mq->bounce_sg) {
	168	ret = -ENOMEM;
aafabfab	169	goto cleanup_queue;
98ccf149	170	}
45711f1a	171	sg_init_table(mq->bounce_sg, bouncesz / 512);
98ccf149 PO	172	}
	173	}
	174	#endif
	175
	176	if (!mq->bounce_buf) {
	177	blk_queue_bounce_limit(mq->queue, limit);
	178	blk_queue_max_sectors(mq->queue, host->max_req_size / 512);
	179	blk_queue_max_phys_segments(mq->queue, host->max_phys_segs);
	180	blk_queue_max_hw_segments(mq->queue, host->max_hw_segs);
	181	blk_queue_max_segment_size(mq->queue, host->max_seg_size);
	182
05e5b136	183	mq->sg = kmalloc(sizeof(struct scatterlist) *
98ccf149 PO	184	host->max_phys_segs, GFP_KERNEL);
	185	if (!mq->sg) {
	186	ret = -ENOMEM;
	187	goto cleanup_queue;
	188	}
05e5b136	189	sg_init_table(mq->sg, host->max_phys_segs);
1da177e4 LT	190	}
1da177e4 LT	191
1da177e4 LT	192	init_MUTEX(&mq->thread_sem);
1da177e4 LT	193
87598a2b CH	194	mq->thread = kthread_run(mmc_queue_thread, mq, "mmcqd");
	195	if (IS_ERR(mq->thread)) {
	196	ret = PTR_ERR(mq->thread);
98ccf149	197	goto free_bounce_sg;
1da177e4 LT	198	}
1da177e4 LT	199
87598a2b	200	return 0;
98ccf149 PO	201	free_bounce_sg:
	202	if (mq->bounce_sg)
	203	kfree(mq->bounce_sg);
	204	mq->bounce_sg = NULL;
aafabfab PO	205	cleanup_queue:
	206	if (mq->sg)
	207	kfree(mq->sg);
1da177e4	208	mq->sg = NULL;
98ccf149 PO	209	if (mq->bounce_buf)
	210	kfree(mq->bounce_buf);
	211	mq->bounce_buf = NULL;
1da177e4	212	blk_cleanup_queue(mq->queue);
1da177e4 LT	213	return ret;
1da177e4 LT	214	}
1da177e4 LT	215
	216	void mmc_cleanup_queue(struct mmc_queue *mq)
	217	{
165125e1	218	struct request_queue *q = mq->queue;
89b4e133 PO	219	unsigned long flags;
	220
	221	/* Mark that we should start throwing out stragglers */
	222	spin_lock_irqsave(q->queue_lock, flags);
	223	q->queuedata = NULL;
	224	spin_unlock_irqrestore(q->queue_lock, flags);
	225
d2b46f66 PO	226	/* Make sure the queue isn't suspended, as that will deadlock */
	227	mmc_queue_resume(mq);
	228
89b4e133	229	/* Then terminate our worker thread */
87598a2b	230	kthread_stop(mq->thread);
1da177e4	231
98ccf149 PO	232	if (mq->bounce_sg)
	233	kfree(mq->bounce_sg);
	234	mq->bounce_sg = NULL;
	235
1da177e4 LT	236	kfree(mq->sg);
	237	mq->sg = NULL;
	238
98ccf149 PO	239	if (mq->bounce_buf)
	240	kfree(mq->bounce_buf);
	241	mq->bounce_buf = NULL;
	242
1da177e4 LT	243	blk_cleanup_queue(mq->queue);
	244
	245	mq->card = NULL;
	246	}
	247	EXPORT_SYMBOL(mmc_cleanup_queue);
	248
	249	/**
	250	* mmc_queue_suspend - suspend a MMC request queue
	251	* @mq: MMC queue to suspend
	252	*
	253	* Stop the block request queue, and wait for our thread to
	254	* complete any outstanding requests. This ensures that we
	255	* won't suspend while a request is being processed.
	256	*/
	257	void mmc_queue_suspend(struct mmc_queue *mq)
	258	{
165125e1	259	struct request_queue *q = mq->queue;
1da177e4 LT	260	unsigned long flags;
	261
	262	if (!(mq->flags & MMC_QUEUE_SUSPENDED)) {
	263	mq->flags \|= MMC_QUEUE_SUSPENDED;
	264
	265	spin_lock_irqsave(q->queue_lock, flags);
	266	blk_stop_queue(q);
	267	spin_unlock_irqrestore(q->queue_lock, flags);
	268
	269	down(&mq->thread_sem);
	270	}
	271	}
1da177e4 LT	272
	273	/**
	274	* mmc_queue_resume - resume a previously suspended MMC request queue
	275	* @mq: MMC queue to resume
	276	*/
	277	void mmc_queue_resume(struct mmc_queue *mq)
	278	{
165125e1	279	struct request_queue *q = mq->queue;
1da177e4 LT	280	unsigned long flags;
	281
	282	if (mq->flags & MMC_QUEUE_SUSPENDED) {
	283	mq->flags &= ~MMC_QUEUE_SUSPENDED;
	284
	285	up(&mq->thread_sem);
	286
	287	spin_lock_irqsave(q->queue_lock, flags);
	288	blk_start_queue(q);
	289	spin_unlock_irqrestore(q->queue_lock, flags);
	290	}
	291	}
98ac2162	292
2ff1fa67 PO	293	/*
	294	* Prepare the sg list(s) to be handed of to the host driver
	295	*/
98ccf149 PO	296	unsigned int mmc_queue_map_sg(struct mmc_queue *mq)
	297	{
	298	unsigned int sg_len;
2ff1fa67 PO	299	size_t buflen;
	300	struct scatterlist *sg;
	301	int i;
98ccf149 PO	302
	303	if (!mq->bounce_buf)
	304	return blk_rq_map_sg(mq->queue, mq->req, mq->sg);
	305
	306	BUG_ON(!mq->bounce_sg);
	307
	308	sg_len = blk_rq_map_sg(mq->queue, mq->req, mq->bounce_sg);
	309
	310	mq->bounce_sg_len = sg_len;
	311
2ff1fa67 PO	312	buflen = 0;
	313	for_each_sg(mq->bounce_sg, sg, sg_len, i)
	314	buflen += sg->length;
98ccf149	315
2ff1fa67	316	sg_init_one(mq->sg, mq->bounce_buf, buflen);
98ccf149 PO	317
	318	return 1;
	319	}
	320
2ff1fa67 PO	321	/*
	322	* If writing, bounce the data to the buffer before the request
	323	* is sent to the host driver
	324	*/
98ccf149 PO	325	void mmc_queue_bounce_pre(struct mmc_queue *mq)
98ccf149 PO	326	{
2ff1fa67 PO	327	unsigned long flags;
2ff1fa67 PO	328
98ccf149 PO	329	if (!mq->bounce_buf)
	330	return;
	331
98ccf149 PO	332	if (rq_data_dir(mq->req) != WRITE)
	333	return;
	334
2ff1fa67 PO	335	local_irq_save(flags);
	336	sg_copy_to_buffer(mq->bounce_sg, mq->bounce_sg_len,
	337	mq->bounce_buf, mq->sg[0].length);
	338	local_irq_restore(flags);
98ccf149 PO	339	}
98ccf149 PO	340
2ff1fa67 PO	341	/*
	342	* If reading, bounce the data from the buffer after the request
	343	* has been handled by the host driver
	344	*/
98ccf149 PO	345	void mmc_queue_bounce_post(struct mmc_queue *mq)
98ccf149 PO	346	{
2ff1fa67 PO	347	unsigned long flags;
2ff1fa67 PO	348
98ccf149 PO	349	if (!mq->bounce_buf)
	350	return;
	351
98ccf149 PO	352	if (rq_data_dir(mq->req) != READ)
	353	return;
	354
2ff1fa67 PO	355	local_irq_save(flags);
	356	sg_copy_from_buffer(mq->bounce_sg, mq->bounce_sg_len,
	357	mq->bounce_buf, mq->sg[0].length);
	358	local_irq_restore(flags);
98ccf149 PO	359	}
98ccf149 PO	360