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

/*
 *  linux/drivers/mmc/mmc_queue.c
 *
 *  Copyright (C) 2003 Russell King, All Rights Reserved.
 *
 * 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/mmc/card.h>
#include <linux/mmc/host.h>
#include "mmc_queue.h"

#define MMC_QUEUE_EXIT		(1 << 0)
#define MMC_QUEUE_SUSPENDED	(1 << 1)

/*
 * Prepare a MMC request.  Essentially, this means passing the
 * preparation off to the media driver.  The media driver will
 * create a mmc_io_request in req->special.
 */
static int mmc_prep_request(struct request_queue *q, struct request *req)
{
	struct mmc_queue *mq = q->queuedata;
	int ret = BLKPREP_KILL;

	if (blk_special_request(req)) {
		/*
		 * Special commands already have the command
		 * blocks already setup in req->special.
		 */
		BUG_ON(!req->special);

		ret = BLKPREP_OK;
	} else if (blk_fs_request(req) || blk_pc_request(req)) {
		/*
		 * Block I/O requests need translating according
		 * to the protocol.
		 */
		ret = mq->prep_fn(mq, req);
	} else {
		/*
		 * Everything else is invalid.
		 */
		blk_dump_rq_flags(req, "MMC bad request");
	}

	if (ret == BLKPREP_OK)
		req->cmd_flags |= REQ_DONTPREP;

	return ret;
}

static int mmc_queue_thread(void *d)
{
	struct mmc_queue *mq = d;
	struct request_queue *q = mq->queue;
	DECLARE_WAITQUEUE(wait, current);

	/*
	 * Set iothread to ensure that we aren't put to sleep by
	 * the process freezing.  We handle suspension ourselves.
	 */
	current->flags |= PF_MEMALLOC|PF_NOFREEZE;

	daemonize("mmcqd");

	complete(&mq->thread_complete);

	down(&mq->thread_sem);
	add_wait_queue(&mq->thread_wq, &wait);
	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 (mq->flags & MMC_QUEUE_EXIT)
				break;
			up(&mq->thread_sem);
			schedule();
			down(&mq->thread_sem);
			continue;
		}
		set_current_state(TASK_RUNNING);

		mq->issue_fn(mq, req);
	} while (1);
	remove_wait_queue(&mq->thread_wq, &wait);
	up(&mq->thread_sem);

	complete_and_exit(&mq->thread_complete, 0);
	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(request_queue_t *q)
{
	struct mmc_queue *mq = q->queuedata;

	if (!mq->req)
		wake_up(&mq->thread_wq);
}

/**
 * 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 (host->dev->dma_mask && *host->dev->dma_mask)
		limit = *host->dev->dma_mask;

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

	blk_queue_prep_rq(mq->queue, mmc_prep_request);
	blk_queue_bounce_limit(mq->queue, limit);
	blk_queue_max_sectors(mq->queue, host->max_sectors);
	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->queue->queuedata = mq;
	mq->req = NULL;

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

	init_completion(&mq->thread_complete);
	init_waitqueue_head(&mq->thread_wq);
	init_MUTEX(&mq->thread_sem);

	ret = kernel_thread(mmc_queue_thread, mq, CLONE_KERNEL);
	if (ret >= 0) {
		wait_for_completion(&mq->thread_complete);
		init_completion(&mq->thread_complete);
		ret = 0;
		goto out;
	}

 cleanup:
	kfree(mq->sg);
	mq->sg = NULL;

	blk_cleanup_queue(mq->queue);
 out:
	return ret;
}
EXPORT_SYMBOL(mmc_init_queue);

void mmc_cleanup_queue(struct mmc_queue *mq)
{
	mq->flags |= MMC_QUEUE_EXIT;
	wake_up(&mq->thread_wq);
	wait_for_completion(&mq->thread_complete);

	kfree(mq->sg);
	mq->sg = 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)
{
	request_queue_t *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);
	}
}
EXPORT_SYMBOL(mmc_queue_suspend);

/**
 * mmc_queue_resume - resume a previously suspended MMC request queue
 * @mq: MMC queue to resume
 */
void mmc_queue_resume(struct mmc_queue *mq)
{
	request_queue_t *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);
	}
}
EXPORT_SYMBOL(mmc_queue_resume);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/drivers/mmc/mmc_queue.c
	3	*
	4	* Copyright (C) 2003 Russell King, All Rights Reserved.
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
	9	*
	10	*/
	11	#include <linux/module.h>
	12	#include <linux/blkdev.h>
	13
	14	#include <linux/mmc/card.h>
	15	#include <linux/mmc/host.h>
	16	#include "mmc_queue.h"
	17
	18	#define MMC_QUEUE_EXIT (1 << 0)
	19	#define MMC_QUEUE_SUSPENDED (1 << 1)
	20
	21	/*
	22	* Prepare a MMC request. Essentially, this means passing the
	23	* preparation off to the media driver. The media driver will
	24	* create a mmc_io_request in req->special.
	25	*/
	26	static int mmc_prep_request(struct request_queue q, struct request req)
	27	{
	28	struct mmc_queue *mq = q->queuedata;
	29	int ret = BLKPREP_KILL;
	30
4aff5e23	31	if (blk_special_request(req)) {
1da177e4 LT	32	/*
	33	* Special commands already have the command
	34	* blocks already setup in req->special.
	35	*/
	36	BUG_ON(!req->special);
	37
	38	ret = BLKPREP_OK;
4aff5e23	39	} else if (blk_fs_request(req) \|\| blk_pc_request(req)) {
1da177e4 LT	40	/*
	41	* Block I/O requests need translating according
	42	* to the protocol.
	43	*/
	44	ret = mq->prep_fn(mq, req);
	45	} else {
	46	/*
	47	* Everything else is invalid.
	48	*/
	49	blk_dump_rq_flags(req, "MMC bad request");
	50	}
	51
	52	if (ret == BLKPREP_OK)
4aff5e23	53	req->cmd_flags \|= REQ_DONTPREP;
1da177e4 LT	54
	55	return ret;
	56	}
	57
	58	static int mmc_queue_thread(void *d)
	59	{
	60	struct mmc_queue *mq = d;
	61	struct request_queue *q = mq->queue;
	62	DECLARE_WAITQUEUE(wait, current);
	63
	64	/*
	65	* Set iothread to ensure that we aren't put to sleep by
	66	* the process freezing. We handle suspension ourselves.
	67	*/
	68	current->flags \|= PF_MEMALLOC\|PF_NOFREEZE;
	69
	70	daemonize("mmcqd");
	71
	72	complete(&mq->thread_complete);
	73
	74	down(&mq->thread_sem);
	75	add_wait_queue(&mq->thread_wq, &wait);
	76	do {
	77	struct request *req = NULL;
	78
	79	spin_lock_irq(q->queue_lock);
	80	set_current_state(TASK_INTERRUPTIBLE);
	81	if (!blk_queue_plugged(q))
c723e08a JY	82	req = elv_next_request(q);
c723e08a JY	83	mq->req = req;
1da177e4 LT	84	spin_unlock_irq(q->queue_lock);
	85
	86	if (!req) {
	87	if (mq->flags & MMC_QUEUE_EXIT)
	88	break;
	89	up(&mq->thread_sem);
	90	schedule();
	91	down(&mq->thread_sem);
	92	continue;
	93	}
	94	set_current_state(TASK_RUNNING);
	95
	96	mq->issue_fn(mq, req);
	97	} while (1);
	98	remove_wait_queue(&mq->thread_wq, &wait);
	99	up(&mq->thread_sem);
	100
	101	complete_and_exit(&mq->thread_complete, 0);
	102	return 0;
	103	}
	104
	105	/*
	106	* Generic MMC request handler. This is called for any queue on a
	107	* particular host. When the host is not busy, we look for a request
	108	* on any queue on this host, and attempt to issue it. This may
	109	* not be the queue we were asked to process.
	110	*/
	111	static void mmc_request(request_queue_t *q)
	112	{
	113	struct mmc_queue *mq = q->queuedata;
	114
	115	if (!mq->req)
	116	wake_up(&mq->thread_wq);
	117	}
	118
	119	/**
	120	* mmc_init_queue - initialise a queue structure.
	121	* @mq: mmc queue
	122	* @card: mmc card to attach this queue
	123	* @lock: queue lock
	124	*
	125	* Initialise a MMC card request queue.
	126	*/
	127	int mmc_init_queue(struct mmc_queue mq, struct mmc_card card, spinlock_t *lock)
	128	{
	129	struct mmc_host *host = card->host;
	130	u64 limit = BLK_BOUNCE_HIGH;
	131	int ret;
	132
	133	if (host->dev->dma_mask && *host->dev->dma_mask)
	134	limit = *host->dev->dma_mask;
	135
	136	mq->card = card;
	137	mq->queue = blk_init_queue(mmc_request, lock);
	138	if (!mq->queue)
	139	return -ENOMEM;
	140
	141	blk_queue_prep_rq(mq->queue, mmc_prep_request);
	142	blk_queue_bounce_limit(mq->queue, limit);
	143	blk_queue_max_sectors(mq->queue, host->max_sectors);
	144	blk_queue_max_phys_segments(mq->queue, host->max_phys_segs);
	145	blk_queue_max_hw_segments(mq->queue, host->max_hw_segs);
	146	blk_queue_max_segment_size(mq->queue, host->max_seg_size);
	147
148	mq->queue->queuedata = mq;
149	mq->req = NULL;
150
151	mq->sg = kmalloc(sizeof(struct scatterlist) * host->max_phys_segs,
152	GFP_KERNEL);
153	if (!mq->sg) {
154	ret = -ENOMEM;
155	goto cleanup;
156	}
157
158	init_completion(&mq->thread_complete);
159	init_waitqueue_head(&mq->thread_wq);
160	init_MUTEX(&mq->thread_sem);
161
162	ret = kernel_thread(mmc_queue_thread, mq, CLONE_KERNEL);
163	if (ret >= 0) {
164	wait_for_completion(&mq->thread_complete);
165	init_completion(&mq->thread_complete);
166	ret = 0;
167	goto out;
168	}
169
170	cleanup:
171	kfree(mq->sg);
172	mq->sg = NULL;
173
174	blk_cleanup_queue(mq->queue);
175	out:
176	return ret;
177	}
178	EXPORT_SYMBOL(mmc_init_queue);
179
180	void mmc_cleanup_queue(struct mmc_queue *mq)
181	{
182	mq->flags \|= MMC_QUEUE_EXIT;
183	wake_up(&mq->thread_wq);
184	wait_for_completion(&mq->thread_complete);
185
186	kfree(mq->sg);
187	mq->sg = NULL;
188
189	blk_cleanup_queue(mq->queue);
190
191	mq->card = NULL;
192	}
193	EXPORT_SYMBOL(mmc_cleanup_queue);
194
195	/**
196	* mmc_queue_suspend - suspend a MMC request queue
197	* @mq: MMC queue to suspend
198	*
199	* Stop the block request queue, and wait for our thread to
200	* complete any outstanding requests. This ensures that we
201	* won't suspend while a request is being processed.
202	*/
203	void mmc_queue_suspend(struct mmc_queue *mq)
204	{
205	request_queue_t *q = mq->queue;
206	unsigned long flags;
207
208	if (!(mq->flags & MMC_QUEUE_SUSPENDED)) {
209	mq->flags \|= MMC_QUEUE_SUSPENDED;
210
211	spin_lock_irqsave(q->queue_lock, flags);
212	blk_stop_queue(q);
213	spin_unlock_irqrestore(q->queue_lock, flags);
214
215	down(&mq->thread_sem);
216	}
217	}
218	EXPORT_SYMBOL(mmc_queue_suspend);
219
220	/**
221	* mmc_queue_resume - resume a previously suspended MMC request queue
222	* @mq: MMC queue to resume
223	*/
224	void mmc_queue_resume(struct mmc_queue *mq)
225	{
226	request_queue_t *q = mq->queue;
227	unsigned long flags;
228
229	if (mq->flags & MMC_QUEUE_SUSPENDED) {
230	mq->flags &= ~MMC_QUEUE_SUSPENDED;
231
232	up(&mq->thread_sem);
233
234	spin_lock_irqsave(q->queue_lock, flags);
235	blk_start_queue(q);
236	spin_unlock_irqrestore(q->queue_lock, flags);
237	}
238	}
239	EXPORT_SYMBOL(mmc_queue_resume);