[mirror_ubuntu-artful-kernel.git] / drivers / mmc / core / 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/dma-mapping.h>

#include <linux/mmc/card.h>
#include <linux/mmc/host.h>

#include "queue.h"
#include "block.h"

#define MMC_QUEUE_BOUNCESZ	65536

/*
 * Prepare a MMC request. This just filters out odd stuff.
 */
static int mmc_prep_request(struct request_queue *q, struct request *req)
{
	struct mmc_queue *mq = q->queuedata;

	if (mq && (mmc_card_removed(mq->card) || mmc_access_rpmb(mq)))
		return BLKPREP_KILL;

	req->rq_flags |= RQF_DONTPREP;

	return BLKPREP_OK;
}

static int mmc_queue_thread(void *d)
{
	struct mmc_queue *mq = d;
	struct request_queue *q = mq->queue;
	struct mmc_context_info *cntx = &mq->card->host->context_info;

	current->flags |= PF_MEMALLOC;

	down(&mq->thread_sem);
	do {
		struct request *req = NULL;

		spin_lock_irq(q->queue_lock);
		set_current_state(TASK_INTERRUPTIBLE);
		req = blk_fetch_request(q);
		mq->asleep = false;
		cntx->is_waiting_last_req = false;
		cntx->is_new_req = false;
		if (!req) {
			/*
			 * Dispatch queue is empty so set flags for
			 * mmc_request_fn() to wake us up.
			 */
			if (mq->mqrq_prev->req)
				cntx->is_waiting_last_req = true;
			else
				mq->asleep = true;
		}
		mq->mqrq_cur->req = req;
		spin_unlock_irq(q->queue_lock);

		if (req || mq->mqrq_prev->req) {
			bool req_is_special = mmc_req_is_special(req);

			set_current_state(TASK_RUNNING);
			mmc_blk_issue_rq(mq, req);
			cond_resched();
			if (mq->flags & MMC_QUEUE_NEW_REQUEST) {
				mq->flags &= ~MMC_QUEUE_NEW_REQUEST;
				continue; /* fetch again */
			}

			/*
			 * Current request becomes previous request
			 * and vice versa.
			 * In case of special requests, current request
			 * has been finished. Do not assign it to previous
			 * request.
			 */
			if (req_is_special)
				mq->mqrq_cur->req = NULL;

			mq->mqrq_prev->brq.mrq.data = NULL;
			mq->mqrq_prev->req = NULL;
			swap(mq->mqrq_prev, mq->mqrq_cur);
		} else {
			if (kthread_should_stop()) {
				set_current_state(TASK_RUNNING);
				break;
			}
			up(&mq->thread_sem);
			schedule();
			down(&mq->thread_sem);
		}
	} 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_fn(struct request_queue *q)
{
	struct mmc_queue *mq = q->queuedata;
	struct request *req;
	struct mmc_context_info *cntx;

	if (!mq) {
		while ((req = blk_fetch_request(q)) != NULL) {
			req->rq_flags |= RQF_QUIET;
			__blk_end_request_all(req, -EIO);
		}
		return;
	}

	cntx = &mq->card->host->context_info;

	if (cntx->is_waiting_last_req) {
		cntx->is_new_req = true;
		wake_up_interruptible(&cntx->wait);
	}

	if (mq->asleep)
		wake_up_process(mq->thread);
}

static struct scatterlist *mmc_alloc_sg(int sg_len, int *err)
{
	struct scatterlist *sg;

	sg = kmalloc(sizeof(struct scatterlist)*sg_len, GFP_KERNEL);
	if (!sg)
		*err = -ENOMEM;
	else {
		*err = 0;
		sg_init_table(sg, sg_len);
	}

	return sg;
}

static void mmc_queue_setup_discard(struct request_queue *q,
				    struct mmc_card *card)
{
	unsigned max_discard;

	max_discard = mmc_calc_max_discard(card);
	if (!max_discard)
		return;

	queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
	blk_queue_max_discard_sectors(q, max_discard);
	if (card->erased_byte == 0 && !mmc_can_discard(card))
		q->limits.discard_zeroes_data = 1;
	q->limits.discard_granularity = card->pref_erase << 9;
	/* granularity must not be greater than max. discard */
	if (card->pref_erase > max_discard)
		q->limits.discard_granularity = 0;
	if (mmc_can_secure_erase_trim(card))
		queue_flag_set_unlocked(QUEUE_FLAG_SECERASE, q);
}

#ifdef CONFIG_MMC_BLOCK_BOUNCE
static bool mmc_queue_alloc_bounce_bufs(struct mmc_queue *mq,
					unsigned int bouncesz)
{
	int i;

	for (i = 0; i < mq->qdepth; i++) {
		mq->mqrq[i].bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
		if (!mq->mqrq[i].bounce_buf)
			goto out_err;
	}

	return true;

out_err:
	while (--i >= 0) {
		kfree(mq->mqrq[i].bounce_buf);
		mq->mqrq[i].bounce_buf = NULL;
	}
	pr_warn("%s: unable to allocate bounce buffers\n",
		mmc_card_name(mq->card));
	return false;
}

static int mmc_queue_alloc_bounce_sgs(struct mmc_queue *mq,
				      unsigned int bouncesz)
{
	int i, ret;

	for (i = 0; i < mq->qdepth; i++) {
		mq->mqrq[i].sg = mmc_alloc_sg(1, &ret);
		if (ret)
			return ret;

		mq->mqrq[i].bounce_sg = mmc_alloc_sg(bouncesz / 512, &ret);
		if (ret)
			return ret;
	}

	return 0;
}
#endif

static int mmc_queue_alloc_sgs(struct mmc_queue *mq, int max_segs)
{
	int i, ret;

	for (i = 0; i < mq->qdepth; i++) {
		mq->mqrq[i].sg = mmc_alloc_sg(max_segs, &ret);
		if (ret)
			return ret;
	}

	return 0;
}

static void mmc_queue_req_free_bufs(struct mmc_queue_req *mqrq)
{
	kfree(mqrq->bounce_sg);
	mqrq->bounce_sg = NULL;

	kfree(mqrq->sg);
	mqrq->sg = NULL;

	kfree(mqrq->bounce_buf);
	mqrq->bounce_buf = NULL;
}

static void mmc_queue_reqs_free_bufs(struct mmc_queue *mq)
{
	int i;

	for (i = 0; i < mq->qdepth; i++)
		mmc_queue_req_free_bufs(&mq->mqrq[i]);
}

/**
 * mmc_init_queue - initialise a queue structure.
 * @mq: mmc queue
 * @card: mmc card to attach this queue
 * @lock: queue lock
 * @subname: partition subname
 *
 * Initialise a MMC card request queue.
 */
int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
		   spinlock_t *lock, const char *subname)
{
	struct mmc_host *host = card->host;
	u64 limit = BLK_BOUNCE_HIGH;
	bool bounce = false;
	int ret = -ENOMEM;

	if (mmc_dev(host)->dma_mask && *mmc_dev(host)->dma_mask)
		limit = (u64)dma_max_pfn(mmc_dev(host)) << PAGE_SHIFT;

	mq->card = card;
	mq->queue = blk_init_queue(mmc_request_fn, lock);
	if (!mq->queue)
		return -ENOMEM;

	mq->qdepth = 2;
	mq->mqrq = kcalloc(mq->qdepth, sizeof(struct mmc_queue_req),
			   GFP_KERNEL);
	if (!mq->mqrq)
		goto blk_cleanup;
	mq->mqrq_cur = &mq->mqrq[0];
	mq->mqrq_prev = &mq->mqrq[1];
	mq->queue->queuedata = mq;

	blk_queue_prep_rq(mq->queue, mmc_prep_request);
	queue_flag_set_unlocked(QUEUE_FLAG_NONROT, mq->queue);
	queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, mq->queue);
	if (mmc_can_erase(card))
		mmc_queue_setup_discard(mq->queue, card);

#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 &&
		    mmc_queue_alloc_bounce_bufs(mq, bouncesz)) {
			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);

			ret = mmc_queue_alloc_bounce_sgs(mq, bouncesz);
			if (ret)
				goto cleanup_queue;
			bounce = true;
		}
	}
#endif

	if (!bounce) {
		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);

		ret = mmc_queue_alloc_sgs(mq, host->max_segs);
		if (ret)
			goto cleanup_queue;
	}

	sema_init(&mq->thread_sem, 1);

	mq->thread = kthread_run(mmc_queue_thread, mq, "mmcqd/%d%s",
		host->index, subname ? subname : "");

	if (IS_ERR(mq->thread)) {
		ret = PTR_ERR(mq->thread);
		goto cleanup_queue;
	}

	return 0;

 cleanup_queue:
	mmc_queue_reqs_free_bufs(mq);
	kfree(mq->mqrq);
	mq->mqrq = NULL;
blk_cleanup:
	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);

	mmc_queue_reqs_free_bufs(mq);
	kfree(mq->mqrq);
	mq->mqrq = 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, struct mmc_queue_req *mqrq)
{
	unsigned int sg_len;
	size_t buflen;
	struct scatterlist *sg;
	int i;

	if (!mqrq->bounce_buf)
		return blk_rq_map_sg(mq->queue, mqrq->req, mqrq->sg);

	sg_len = blk_rq_map_sg(mq->queue, mqrq->req, mqrq->bounce_sg);

	mqrq->bounce_sg_len = sg_len;

	buflen = 0;
	for_each_sg(mqrq->bounce_sg, sg, sg_len, i)
		buflen += sg->length;

	sg_init_one(mqrq->sg, mqrq->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_req *mqrq)
{
	if (!mqrq->bounce_buf)
		return;

	if (rq_data_dir(mqrq->req) != WRITE)
		return;

	sg_copy_to_buffer(mqrq->bounce_sg, mqrq->bounce_sg_len,
		mqrq->bounce_buf, mqrq->sg[0].length);
}

/*
 * 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_req *mqrq)
{
	if (!mqrq->bounce_buf)
		return;

	if (rq_data_dir(mqrq->req) != READ)
		return;

	sg_copy_from_buffer(mqrq->bounce_sg, mqrq->bounce_sg_len,
		mqrq->bounce_buf, mqrq->sg[0].length);
}
Commit	Line	Data
1da177e4	1	/*
1da177e4	2	* Copyright (C) 2003 Russell King, All Rights Reserved.
98ac2162	3	* Copyright 2006-2007 Pierre Ossman
1da177e4 LT	4	*
	5	* This program is free software; you can redistribute it and/or modify
	6	* it under the terms of the GNU General Public License version 2 as
	7	* published by the Free Software Foundation.
	8	*
	9	*/
5a0e3ad6	10	#include <linux/slab.h>
1da177e4 LT	11	#include <linux/module.h>
1da177e4 LT	12	#include <linux/blkdev.h>
83144186	13	#include <linux/freezer.h>
87598a2b	14	#include <linux/kthread.h>
45711f1a	15	#include <linux/scatterlist.h>
8e0cb8a1	16	#include <linux/dma-mapping.h>
1da177e4 LT	17
	18	#include <linux/mmc/card.h>
	19	#include <linux/mmc/host.h>
29eb7bd0	20
98ac2162	21	#include "queue.h"
29eb7bd0	22	#include "block.h"
1da177e4	23
98ccf149 PO	24	#define MMC_QUEUE_BOUNCESZ 65536
98ccf149 PO	25
1da177e4	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	{
a8ad82cc SRT	31	struct mmc_queue *mq = q->queuedata;
a8ad82cc SRT	32
4e93b9a6	33	if (mq && (mmc_card_removed(mq->card) \|\| mmc_access_rpmb(mq)))
a8ad82cc SRT	34	return BLKPREP_KILL;
a8ad82cc SRT	35
e8064021	36	req->rq_flags \|= RQF_DONTPREP;
1da177e4	37
9c9f2d63	38	return BLKPREP_OK;
1da177e4 LT	39	}
	40
	41	static int mmc_queue_thread(void *d)
	42	{
	43	struct mmc_queue *mq = d;
	44	struct request_queue *q = mq->queue;
e0097cf5	45	struct mmc_context_info *cntx = &mq->card->host->context_info;
1da177e4	46
83144186	47	current->flags \|= PF_MEMALLOC;
1da177e4	48
1da177e4	49	down(&mq->thread_sem);
1da177e4 LT	50	do {
	51	struct request *req = NULL;
	52
	53	spin_lock_irq(q->queue_lock);
	54	set_current_state(TASK_INTERRUPTIBLE);
7eaceacc	55	req = blk_fetch_request(q);
e0097cf5 AH	56	mq->asleep = false;
	57	cntx->is_waiting_last_req = false;
	58	cntx->is_new_req = false;
	59	if (!req) {
	60	/*
	61	* Dispatch queue is empty so set flags for
	62	* mmc_request_fn() to wake us up.
	63	*/
	64	if (mq->mqrq_prev->req)
	65	cntx->is_waiting_last_req = true;
	66	else
	67	mq->asleep = true;
	68	}
97868a2b	69	mq->mqrq_cur->req = req;
1da177e4 LT	70	spin_unlock_irq(q->queue_lock);
1da177e4 LT	71
ee8a43a5	72	if (req \|\| mq->mqrq_prev->req) {
869c5548 AH	73	bool req_is_special = mmc_req_is_special(req);
869c5548 AH	74
ee8a43a5	75	set_current_state(TASK_RUNNING);
29eb7bd0	76	mmc_blk_issue_rq(mq, req);
a8c27c0b	77	cond_resched();
2220eedf KD	78	if (mq->flags & MMC_QUEUE_NEW_REQUEST) {
	79	mq->flags &= ~MMC_QUEUE_NEW_REQUEST;
	80	continue; /* fetch again */
	81	}
45c5a914 SJ	82
	83	/*
	84	* Current request becomes previous request
	85	* and vice versa.
369d321e SJ	86	* In case of special requests, current request
	87	* has been finished. Do not assign it to previous
	88	* request.
45c5a914	89	*/
869c5548	90	if (req_is_special)
369d321e SJ	91	mq->mqrq_cur->req = NULL;
369d321e SJ	92
45c5a914 SJ	93	mq->mqrq_prev->brq.mrq.data = NULL;
45c5a914 SJ	94	mq->mqrq_prev->req = NULL;
7551847c	95	swap(mq->mqrq_prev, mq->mqrq_cur);
ee8a43a5	96	} else {
7b30d281 VW	97	if (kthread_should_stop()) {
7b30d281 VW	98	set_current_state(TASK_RUNNING);
1da177e4	99	break;
7b30d281	100	}
1da177e4 LT	101	up(&mq->thread_sem);
	102	schedule();
	103	down(&mq->thread_sem);
1da177e4	104	}
1da177e4	105	} while (1);
1da177e4 LT	106	up(&mq->thread_sem);
1da177e4 LT	107
1da177e4 LT	108	return 0;
	109	}
	110
	111	/*
	112	* Generic MMC request handler. This is called for any queue on a
	113	* particular host. When the host is not busy, we look for a request
	114	* on any queue on this host, and attempt to issue it. This may
	115	* not be the queue we were asked to process.
	116	*/
1b50f5f3	117	static void mmc_request_fn(struct request_queue *q)
1da177e4 LT	118	{
1da177e4 LT	119	struct mmc_queue *mq = q->queuedata;
89b4e133	120	struct request *req;
2220eedf	121	struct mmc_context_info *cntx;
89b4e133 PO	122
89b4e133 PO	123	if (!mq) {
5fa83ce2	124	while ((req = blk_fetch_request(q)) != NULL) {
e8064021	125	req->rq_flags \|= RQF_QUIET;
296b2f6a	126	__blk_end_request_all(req, -EIO);
5fa83ce2	127	}
89b4e133 PO	128	return;
89b4e133 PO	129	}
1da177e4	130
2220eedf	131	cntx = &mq->card->host->context_info;
e0097cf5 AH	132
	133	if (cntx->is_waiting_last_req) {
	134	cntx->is_new_req = true;
	135	wake_up_interruptible(&cntx->wait);
	136	}
	137
	138	if (mq->asleep)
87598a2b	139	wake_up_process(mq->thread);
1da177e4 LT	140	}
1da177e4 LT	141
7513cd7a	142	static struct scatterlist mmc_alloc_sg(int sg_len, int err)
97868a2b PF	143	{
	144	struct scatterlist *sg;
	145
	146	sg = kmalloc(sizeof(struct scatterlist)*sg_len, GFP_KERNEL);
	147	if (!sg)
	148	*err = -ENOMEM;
	149	else {
	150	*err = 0;
	151	sg_init_table(sg, sg_len);
	152	}
	153
	154	return sg;
	155	}
	156
e056a1b5 AH	157	static void mmc_queue_setup_discard(struct request_queue *q,
	158	struct mmc_card *card)
	159	{
	160	unsigned max_discard;
	161
	162	max_discard = mmc_calc_max_discard(card);
	163	if (!max_discard)
	164	return;
	165
	166	queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
2bb4cd5c	167	blk_queue_max_discard_sectors(q, max_discard);
7194efb8	168	if (card->erased_byte == 0 && !mmc_can_discard(card))
e056a1b5 AH	169	q->limits.discard_zeroes_data = 1;
	170	q->limits.discard_granularity = card->pref_erase << 9;
	171	/* granularity must not be greater than max. discard */
	172	if (card->pref_erase > max_discard)
	173	q->limits.discard_granularity = 0;
775a9362	174	if (mmc_can_secure_erase_trim(card))
288dab8a	175	queue_flag_set_unlocked(QUEUE_FLAG_SECERASE, q);
e056a1b5 AH	176	}
e056a1b5 AH	177
c853982e AH	178	#ifdef CONFIG_MMC_BLOCK_BOUNCE
	179	static bool mmc_queue_alloc_bounce_bufs(struct mmc_queue *mq,
	180	unsigned int bouncesz)
	181	{
c5bda0ca	182	int i;
c853982e	183
c5bda0ca AH	184	for (i = 0; i < mq->qdepth; i++) {
	185	mq->mqrq[i].bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
	186	if (!mq->mqrq[i].bounce_buf)
	187	goto out_err;
c853982e AH	188	}
	189
	190	return true;
c5bda0ca AH	191
	192	out_err:
	193	while (--i >= 0) {
	194	kfree(mq->mqrq[i].bounce_buf);
	195	mq->mqrq[i].bounce_buf = NULL;
	196	}
	197	pr_warn("%s: unable to allocate bounce buffers\n",
	198	mmc_card_name(mq->card));
	199	return false;
c853982e	200	}
f2b8b522 AH	201
	202	static int mmc_queue_alloc_bounce_sgs(struct mmc_queue *mq,
	203	unsigned int bouncesz)
	204	{
c5bda0ca	205	int i, ret;
f2b8b522	206
c5bda0ca AH	207	for (i = 0; i < mq->qdepth; i++) {
	208	mq->mqrq[i].sg = mmc_alloc_sg(1, &ret);
	209	if (ret)
	210	return ret;
f2b8b522	211
c5bda0ca AH	212	mq->mqrq[i].bounce_sg = mmc_alloc_sg(bouncesz / 512, &ret);
	213	if (ret)
	214	return ret;
	215	}
f2b8b522	216
c5bda0ca	217	return 0;
f2b8b522	218	}
c853982e AH	219	#endif
c853982e AH	220
64e29e42 AH	221	static int mmc_queue_alloc_sgs(struct mmc_queue *mq, int max_segs)
64e29e42 AH	222	{
c5bda0ca	223	int i, ret;
64e29e42	224
c5bda0ca AH	225	for (i = 0; i < mq->qdepth; i++) {
	226	mq->mqrq[i].sg = mmc_alloc_sg(max_segs, &ret);
	227	if (ret)
	228	return ret;
	229	}
64e29e42	230
c5bda0ca AH	231	return 0;
c5bda0ca AH	232	}
64e29e42	233
c5bda0ca AH	234	static void mmc_queue_req_free_bufs(struct mmc_queue_req *mqrq)
	235	{
	236	kfree(mqrq->bounce_sg);
	237	mqrq->bounce_sg = NULL;
	238
	239	kfree(mqrq->sg);
	240	mqrq->sg = NULL;
	241
	242	kfree(mqrq->bounce_buf);
	243	mqrq->bounce_buf = NULL;
64e29e42 AH	244	}
64e29e42 AH	245
c09949cf AH	246	static void mmc_queue_reqs_free_bufs(struct mmc_queue *mq)
c09949cf AH	247	{
c5bda0ca AH	248	int i;
	249
	250	for (i = 0; i < mq->qdepth; i++)
	251	mmc_queue_req_free_bufs(&mq->mqrq[i]);
c09949cf AH	252	}
c09949cf AH	253
1da177e4 LT	254	/**
	255	* mmc_init_queue - initialise a queue structure.
	256	* @mq: mmc queue
	257	* @card: mmc card to attach this queue
	258	* @lock: queue lock
d09408ad	259	* @subname: partition subname
1da177e4 LT	260	*
	261	* Initialise a MMC card request queue.
	262	*/
d09408ad AH	263	int mmc_init_queue(struct mmc_queue mq, struct mmc_card card,
d09408ad AH	264	spinlock_t lock, const char subname)
1da177e4 LT	265	{
	266	struct mmc_host *host = card->host;
	267	u64 limit = BLK_BOUNCE_HIGH;
f2b8b522	268	bool bounce = false;
c5bda0ca	269	int ret = -ENOMEM;
1da177e4	270
fcaf71fd	271	if (mmc_dev(host)->dma_mask && *mmc_dev(host)->dma_mask)
e83b3664	272	limit = (u64)dma_max_pfn(mmc_dev(host)) << PAGE_SHIFT;
1da177e4 LT	273
1da177e4 LT	274	mq->card = card;
1b50f5f3	275	mq->queue = blk_init_queue(mmc_request_fn, lock);
1da177e4 LT	276	if (!mq->queue)
	277	return -ENOMEM;
	278
c5bda0ca AH	279	mq->qdepth = 2;
	280	mq->mqrq = kcalloc(mq->qdepth, sizeof(struct mmc_queue_req),
	281	GFP_KERNEL);
	282	if (!mq->mqrq)
	283	goto blk_cleanup;
c09949cf AH	284	mq->mqrq_cur = &mq->mqrq[0];
c09949cf AH	285	mq->mqrq_prev = &mq->mqrq[1];
1da177e4	286	mq->queue->queuedata = mq;
1da177e4	287
98ccf149	288	blk_queue_prep_rq(mq->queue, mmc_prep_request);
8dddfe19	289	queue_flag_set_unlocked(QUEUE_FLAG_NONROT, mq->queue);
b277da0a	290	queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, mq->queue);
e056a1b5 AH	291	if (mmc_can_erase(card))
e056a1b5 AH	292	mmc_queue_setup_discard(mq->queue, card);
98ccf149 PO	293
98ccf149 PO	294	#ifdef CONFIG_MMC_BLOCK_BOUNCE
a36274e0	295	if (host->max_segs == 1) {
aafabfab PO	296	unsigned int bouncesz;
aafabfab PO	297
98ccf149 PO	298	bouncesz = MMC_QUEUE_BOUNCESZ;
	299
	300	if (bouncesz > host->max_req_size)
	301	bouncesz = host->max_req_size;
	302	if (bouncesz > host->max_seg_size)
	303	bouncesz = host->max_seg_size;
f3eb0aaa PO	304	if (bouncesz > (host->max_blk_count * 512))
	305	bouncesz = host->max_blk_count * 512;
	306
c853982e AH	307	if (bouncesz > 512 &&
c853982e AH	308	mmc_queue_alloc_bounce_bufs(mq, bouncesz)) {
2ff1fa67	309	blk_queue_bounce_limit(mq->queue, BLK_BOUNCE_ANY);
086fa5ff	310	blk_queue_max_hw_sectors(mq->queue, bouncesz / 512);
8a78362c	311	blk_queue_max_segments(mq->queue, bouncesz / 512);
98ccf149 PO	312	blk_queue_max_segment_size(mq->queue, bouncesz);
98ccf149 PO	313
f2b8b522	314	ret = mmc_queue_alloc_bounce_sgs(mq, bouncesz);
04296b7b PF	315	if (ret)
04296b7b PF	316	goto cleanup_queue;
f2b8b522	317	bounce = true;
98ccf149 PO	318	}
	319	}
	320	#endif
	321
f2b8b522	322	if (!bounce) {
98ccf149	323	blk_queue_bounce_limit(mq->queue, limit);
086fa5ff	324	blk_queue_max_hw_sectors(mq->queue,
f3eb0aaa	325	min(host->max_blk_count, host->max_req_size / 512));
a36274e0	326	blk_queue_max_segments(mq->queue, host->max_segs);
98ccf149 PO	327	blk_queue_max_segment_size(mq->queue, host->max_seg_size);
98ccf149 PO	328
64e29e42	329	ret = mmc_queue_alloc_sgs(mq, host->max_segs);
04296b7b PF	330	if (ret)
04296b7b PF	331	goto cleanup_queue;
1da177e4 LT	332	}
1da177e4 LT	333
632cf92a	334	sema_init(&mq->thread_sem, 1);
1da177e4	335
d09408ad AH	336	mq->thread = kthread_run(mmc_queue_thread, mq, "mmcqd/%d%s",
d09408ad AH	337	host->index, subname ? subname : "");
de528fa3	338
87598a2b CH	339	if (IS_ERR(mq->thread)) {
87598a2b CH	340	ret = PTR_ERR(mq->thread);
c09949cf	341	goto cleanup_queue;
1da177e4 LT	342	}
1da177e4 LT	343
87598a2b	344	return 0;
97868a2b	345
aafabfab	346	cleanup_queue:
c09949cf	347	mmc_queue_reqs_free_bufs(mq);
c5bda0ca AH	348	kfree(mq->mqrq);
	349	mq->mqrq = NULL;
	350	blk_cleanup:
1da177e4	351	blk_cleanup_queue(mq->queue);
1da177e4 LT	352	return ret;
1da177e4 LT	353	}
1da177e4 LT	354
	355	void mmc_cleanup_queue(struct mmc_queue *mq)
	356	{
165125e1	357	struct request_queue *q = mq->queue;
89b4e133 PO	358	unsigned long flags;
89b4e133 PO	359
d2b46f66 PO	360	/* Make sure the queue isn't suspended, as that will deadlock */
	361	mmc_queue_resume(mq);
	362
89b4e133	363	/* Then terminate our worker thread */
87598a2b	364	kthread_stop(mq->thread);
1da177e4	365
5fa83ce2 AH	366	/* Empty the queue */
	367	spin_lock_irqsave(q->queue_lock, flags);
	368	q->queuedata = NULL;
	369	blk_start_queue(q);
	370	spin_unlock_irqrestore(q->queue_lock, flags);
	371
c09949cf	372	mmc_queue_reqs_free_bufs(mq);
c5bda0ca AH	373	kfree(mq->mqrq);
c5bda0ca AH	374	mq->mqrq = NULL;
04296b7b	375
1da177e4 LT	376	mq->card = NULL;
	377	}
	378	EXPORT_SYMBOL(mmc_cleanup_queue);
	379
	380	/**
	381	* mmc_queue_suspend - suspend a MMC request queue
	382	* @mq: MMC queue to suspend
	383	*
	384	* Stop the block request queue, and wait for our thread to
	385	* complete any outstanding requests. This ensures that we
	386	* won't suspend while a request is being processed.
	387	*/
	388	void mmc_queue_suspend(struct mmc_queue *mq)
	389	{
165125e1	390	struct request_queue *q = mq->queue;
1da177e4 LT	391	unsigned long flags;
	392
	393	if (!(mq->flags & MMC_QUEUE_SUSPENDED)) {
	394	mq->flags \|= MMC_QUEUE_SUSPENDED;
	395
	396	spin_lock_irqsave(q->queue_lock, flags);
	397	blk_stop_queue(q);
	398	spin_unlock_irqrestore(q->queue_lock, flags);
	399
	400	down(&mq->thread_sem);
	401	}
	402	}
1da177e4 LT	403
	404	/**
	405	* mmc_queue_resume - resume a previously suspended MMC request queue
	406	* @mq: MMC queue to resume
	407	*/
	408	void mmc_queue_resume(struct mmc_queue *mq)
	409	{
165125e1	410	struct request_queue *q = mq->queue;
1da177e4 LT	411	unsigned long flags;
	412
	413	if (mq->flags & MMC_QUEUE_SUSPENDED) {
	414	mq->flags &= ~MMC_QUEUE_SUSPENDED;
	415
	416	up(&mq->thread_sem);
	417
	418	spin_lock_irqsave(q->queue_lock, flags);
	419	blk_start_queue(q);
	420	spin_unlock_irqrestore(q->queue_lock, flags);
	421	}
	422	}
98ac2162	423
2ff1fa67 PO	424	/*
	425	* Prepare the sg list(s) to be handed of to the host driver
	426	*/
97868a2b	427	unsigned int mmc_queue_map_sg(struct mmc_queue mq, struct mmc_queue_req mqrq)
98ccf149 PO	428	{
98ccf149 PO	429	unsigned int sg_len;
2ff1fa67 PO	430	size_t buflen;
	431	struct scatterlist *sg;
	432	int i;
98ccf149	433
03d640ae LW	434	if (!mqrq->bounce_buf)
03d640ae LW	435	return blk_rq_map_sg(mq->queue, mqrq->req, mqrq->sg);
98ccf149	436
03d640ae	437	sg_len = blk_rq_map_sg(mq->queue, mqrq->req, mqrq->bounce_sg);
98ccf149	438
97868a2b	439	mqrq->bounce_sg_len = sg_len;
98ccf149	440
2ff1fa67	441	buflen = 0;
97868a2b	442	for_each_sg(mqrq->bounce_sg, sg, sg_len, i)
2ff1fa67	443	buflen += sg->length;
98ccf149	444
97868a2b	445	sg_init_one(mqrq->sg, mqrq->bounce_buf, buflen);
98ccf149 PO	446
	447	return 1;
	448	}
	449
2ff1fa67 PO	450	/*
	451	* If writing, bounce the data to the buffer before the request
	452	* is sent to the host driver
	453	*/
97868a2b	454	void mmc_queue_bounce_pre(struct mmc_queue_req *mqrq)
98ccf149	455	{
97868a2b	456	if (!mqrq->bounce_buf)
98ccf149 PO	457	return;
98ccf149 PO	458
97868a2b	459	if (rq_data_dir(mqrq->req) != WRITE)
98ccf149 PO	460	return;
98ccf149 PO	461
97868a2b PF	462	sg_copy_to_buffer(mqrq->bounce_sg, mqrq->bounce_sg_len,
97868a2b PF	463	mqrq->bounce_buf, mqrq->sg[0].length);
98ccf149 PO	464	}
98ccf149 PO	465
2ff1fa67 PO	466	/*
	467	* If reading, bounce the data from the buffer after the request
	468	* has been handled by the host driver
	469	*/
97868a2b	470	void mmc_queue_bounce_post(struct mmc_queue_req *mqrq)
98ccf149	471	{
97868a2b	472	if (!mqrq->bounce_buf)
98ccf149 PO	473	return;
98ccf149 PO	474
97868a2b	475	if (rq_data_dir(mqrq->req) != READ)
98ccf149 PO	476	return;
98ccf149 PO	477
97868a2b PF	478	sg_copy_from_buffer(mqrq->bounce_sg, mqrq->bounce_sg_len,
97868a2b PF	479	mqrq->bounce_buf, mqrq->sg[0].length);
98ccf149	480	}