[mirror_ubuntu-artful-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;
		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
	1	/*
	2	* linux/drivers/mmc/card/queue.c
	3	*
	4	* Copyright (C) 2003 Russell King, All Rights Reserved.
	5	* Copyright 2006-2007 Pierre Ossman
	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>
	14	#include <linux/freezer.h>
	15	#include <linux/kthread.h>
	16	#include <linux/scatterlist.h>
	17
	18	#include <linux/mmc/card.h>
	19	#include <linux/mmc/host.h>
	20	#include "queue.h"
	21
	22	#define MMC_QUEUE_BOUNCESZ 65536
	23
	24	#define MMC_QUEUE_SUSPENDED (1 << 0)
	25
	26	/*
	27	* Prepare a MMC request. This just filters out odd stuff.
	28	*/
	29	static int mmc_prep_request(struct request_queue q, struct request req)
	30	{
	31	/*
	32	* We only like normal block requests.
	33	*/
	34	if (!blk_fs_request(req) && !blk_pc_request(req)) {
	35	blk_dump_rq_flags(req, "MMC bad request");
	36	return BLKPREP_KILL;
	37	}
	38
	39	req->cmd_flags \|= REQ_DONTPREP;
	40
	41	return BLKPREP_OK;
	42	}
	43
	44	static int mmc_queue_thread(void *d)
	45	{
	46	struct mmc_queue *mq = d;
	47	struct request_queue *q = mq->queue;
	48
	49	current->flags \|= PF_MEMALLOC;
	50
	51	down(&mq->thread_sem);
	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))
	58	req = elv_next_request(q);
	59	mq->req = req;
	60	spin_unlock_irq(q->queue_lock);
	61
	62	if (!req) {
	63	if (kthread_should_stop()) {
	64	set_current_state(TASK_RUNNING);
	65	break;
	66	}
	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);
	76	up(&mq->thread_sem);
	77
	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	*/
	87	static void mmc_request(struct request_queue *q)
	88	{
	89	struct mmc_queue *mq = q->queuedata;
	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 {
	97	ret = __blk_end_request(req, -EIO,
	98	blk_rq_cur_bytes(req));
	99	} while (ret);
	100	}
	101	return;
	102	}
	103
	104	if (!mq->req)
	105	wake_up_process(mq->thread);
	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
	122	if (mmc_dev(host)->dma_mask && *mmc_dev(host)->dma_mask)
	123	limit = *mmc_dev(host)->dma_mask;
	124
	125	mq->card = card;
	126	mq->queue = blk_init_queue(mmc_request, lock);
	127	if (!mq->queue)
	128	return -ENOMEM;
	129
	130	mq->queue->queuedata = mq;
	131	mq->req = NULL;
	132
	133	blk_queue_prep_rq(mq->queue, mmc_prep_request);
	134
	135	#ifdef CONFIG_MMC_BLOCK_BOUNCE
	136	if (host->max_hw_segs == 1) {
	137	unsigned int bouncesz;
	138
	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	if (bouncesz > (host->max_blk_count * 512))
	146	bouncesz = host->max_blk_count * 512;
	147
	148	if (bouncesz > 512) {
	149	mq->bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
	150	if (!mq->bounce_buf) {
	151	printk(KERN_WARNING "%s: unable to "
	152	"allocate bounce buffer\n",
	153	mmc_card_name(card));
	154	}
	155	}
	156
	157	if (mq->bounce_buf) {
	158	blk_queue_bounce_limit(mq->queue, BLK_BOUNCE_ANY);
	159	blk_queue_max_sectors(mq->queue, bouncesz / 512);
	160	blk_queue_max_phys_segments(mq->queue, bouncesz / 512);
	161	blk_queue_max_hw_segments(mq->queue, bouncesz / 512);
	162	blk_queue_max_segment_size(mq->queue, bouncesz);
	163
	164	mq->sg = kmalloc(sizeof(struct scatterlist),
	165	GFP_KERNEL);
	166	if (!mq->sg) {
	167	ret = -ENOMEM;
	168	goto cleanup_queue;
	169	}
	170	sg_init_table(mq->sg, 1);
	171
	172	mq->bounce_sg = kmalloc(sizeof(struct scatterlist) *
	173	bouncesz / 512, GFP_KERNEL);
	174	if (!mq->bounce_sg) {
	175	ret = -ENOMEM;
	176	goto cleanup_queue;
	177	}
	178	sg_init_table(mq->bounce_sg, bouncesz / 512);
	179	}
	180	}
	181	#endif
	182
	183	if (!mq->bounce_buf) {
	184	blk_queue_bounce_limit(mq->queue, limit);
	185	blk_queue_max_sectors(mq->queue,
	186	min(host->max_blk_count, host->max_req_size / 512));
	187	blk_queue_max_phys_segments(mq->queue, host->max_phys_segs);
	188	blk_queue_max_hw_segments(mq->queue, host->max_hw_segs);
	189	blk_queue_max_segment_size(mq->queue, host->max_seg_size);
	190
	191	mq->sg = kmalloc(sizeof(struct scatterlist) *
	192	host->max_phys_segs, GFP_KERNEL);
	193	if (!mq->sg) {
	194	ret = -ENOMEM;
	195	goto cleanup_queue;
	196	}
	197	sg_init_table(mq->sg, host->max_phys_segs);
	198	}
	199
	200	init_MUTEX(&mq->thread_sem);
	201
	202	mq->thread = kthread_run(mmc_queue_thread, mq, "mmcqd");
	203	if (IS_ERR(mq->thread)) {
	204	ret = PTR_ERR(mq->thread);
	205	goto free_bounce_sg;
	206	}
	207
	208	return 0;
	209	free_bounce_sg:
	210	if (mq->bounce_sg)
	211	kfree(mq->bounce_sg);
	212	mq->bounce_sg = NULL;
	213	cleanup_queue:
	214	if (mq->sg)
	215	kfree(mq->sg);
	216	mq->sg = NULL;
	217	if (mq->bounce_buf)
	218	kfree(mq->bounce_buf);
	219	mq->bounce_buf = NULL;
	220	blk_cleanup_queue(mq->queue);
	221	return ret;
	222	}
	223
	224	void mmc_cleanup_queue(struct mmc_queue *mq)
	225	{
	226	struct request_queue *q = mq->queue;
	227	unsigned long flags;
	228
	229	/* Mark that we should start throwing out stragglers */
	230	spin_lock_irqsave(q->queue_lock, flags);
	231	q->queuedata = NULL;
	232	spin_unlock_irqrestore(q->queue_lock, flags);
	233
	234	/* Make sure the queue isn't suspended, as that will deadlock */
	235	mmc_queue_resume(mq);
	236
	237	/* Then terminate our worker thread */
	238	kthread_stop(mq->thread);
	239
	240	if (mq->bounce_sg)
	241	kfree(mq->bounce_sg);
	242	mq->bounce_sg = NULL;
	243
	244	kfree(mq->sg);
	245	mq->sg = NULL;
	246
	247	if (mq->bounce_buf)
	248	kfree(mq->bounce_buf);
	249	mq->bounce_buf = NULL;
	250
	251	blk_cleanup_queue(mq->queue);
	252
	253	mq->card = NULL;
	254	}
	255	EXPORT_SYMBOL(mmc_cleanup_queue);
	256
	257	/**
	258	* mmc_queue_suspend - suspend a MMC request queue
	259	* @mq: MMC queue to suspend
	260	*
	261	* Stop the block request queue, and wait for our thread to
	262	* complete any outstanding requests. This ensures that we
	263	* won't suspend while a request is being processed.
	264	*/
	265	void mmc_queue_suspend(struct mmc_queue *mq)
	266	{
	267	struct request_queue *q = mq->queue;
	268	unsigned long flags;
	269
	270	if (!(mq->flags & MMC_QUEUE_SUSPENDED)) {
	271	mq->flags \|= MMC_QUEUE_SUSPENDED;
	272
	273	spin_lock_irqsave(q->queue_lock, flags);
	274	blk_stop_queue(q);
	275	spin_unlock_irqrestore(q->queue_lock, flags);
	276
	277	down(&mq->thread_sem);
	278	}
	279	}
	280
	281	/**
	282	* mmc_queue_resume - resume a previously suspended MMC request queue
	283	* @mq: MMC queue to resume
	284	*/
	285	void mmc_queue_resume(struct mmc_queue *mq)
	286	{
	287	struct request_queue *q = mq->queue;
	288	unsigned long flags;
	289
	290	if (mq->flags & MMC_QUEUE_SUSPENDED) {
	291	mq->flags &= ~MMC_QUEUE_SUSPENDED;
	292
	293	up(&mq->thread_sem);
	294
	295	spin_lock_irqsave(q->queue_lock, flags);
	296	blk_start_queue(q);
	297	spin_unlock_irqrestore(q->queue_lock, flags);
	298	}
	299	}
	300
	301	/*
	302	* Prepare the sg list(s) to be handed of to the host driver
	303	*/
	304	unsigned int mmc_queue_map_sg(struct mmc_queue *mq)
	305	{
	306	unsigned int sg_len;
	307	size_t buflen;
	308	struct scatterlist *sg;
	309	int i;
	310
	311	if (!mq->bounce_buf)
	312	return blk_rq_map_sg(mq->queue, mq->req, mq->sg);
	313
	314	BUG_ON(!mq->bounce_sg);
	315
	316	sg_len = blk_rq_map_sg(mq->queue, mq->req, mq->bounce_sg);
	317
	318	mq->bounce_sg_len = sg_len;
	319
	320	buflen = 0;
	321	for_each_sg(mq->bounce_sg, sg, sg_len, i)
	322	buflen += sg->length;
	323
	324	sg_init_one(mq->sg, mq->bounce_buf, buflen);
	325
	326	return 1;
	327	}
	328
	329	/*
	330	* If writing, bounce the data to the buffer before the request
	331	* is sent to the host driver
	332	*/
	333	void mmc_queue_bounce_pre(struct mmc_queue *mq)
	334	{
	335	unsigned long flags;
	336
	337	if (!mq->bounce_buf)
	338	return;
	339
	340	if (rq_data_dir(mq->req) != WRITE)
	341	return;
	342
	343	local_irq_save(flags);
	344	sg_copy_to_buffer(mq->bounce_sg, mq->bounce_sg_len,
	345	mq->bounce_buf, mq->sg[0].length);
	346	local_irq_restore(flags);
	347	}
	348
	349	/*
	350	* If reading, bounce the data from the buffer after the request
	351	* has been handled by the host driver
	352	*/
	353	void mmc_queue_bounce_post(struct mmc_queue *mq)
	354	{
	355	unsigned long flags;
	356
	357	if (!mq->bounce_buf)
	358	return;
	359
	360	if (rq_data_dir(mq->req) != READ)
	361	return;
	362
	363	local_irq_save(flags);
	364	sg_copy_from_buffer(mq->bounce_sg, mq->bounce_sg_len,
	365	mq->bounce_buf, mq->sg[0].length);
	366	local_irq_restore(flags);
	367	}
	368