/* *  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/slab.h>#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){	struct mmc_queue *mq = q->queuedata; 	/*	 * We only like normal block requests and discards.	 */	if (req->cmd_type != REQ_TYPE_FS && !(req->cmd_flags & REQ_DISCARD)) {		blk_dump_rq_flags(req, "MMC bad request");		return BLKPREP_KILL;	} 	if (mq && mmc_card_removed(mq->card))		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;		struct mmc_queue_req *tmp; 		spin_lock_irq(q->queue_lock);		set_current_state(TASK_INTERRUPTIBLE);		req = blk_fetch_request(q);		mq->mqrq_cur->req = req;		spin_unlock_irq(q->queue_lock); 		if (req || mq->mqrq_prev->req) {			set_current_state(TASK_RUNNING);			mq->issue_fn(mq, req);		} else {			if (kthread_should_stop()) {				set_current_state(TASK_RUNNING);				break;			}			up(&mq->thread_sem);			schedule();			down(&mq->thread_sem);		} 		/* Current request becomes previous request and vice versa. */		mq->mqrq_prev->brq.mrq.data = NULL;		mq->mqrq_prev->req = NULL;		tmp = mq->mqrq_prev;		mq->mqrq_prev = mq->mqrq_cur;		mq->mqrq_cur = tmp;	} 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; 	if (!mq) {		while ((req = blk_fetch_request(q)) != NULL) {			req->cmd_flags |= REQ_QUIET;			__blk_end_request_all(req, -EIO);		}		return;	} 	if (!mq->mqrq_cur->req && !mq->mqrq_prev->req)		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);	q->limits.max_discard_sectors = 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) || mmc_can_sanitize(card))		queue_flag_set_unlocked(QUEUE_FLAG_SECDISCARD, q);} /** * 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;	int ret;	struct mmc_queue_req *mqrq_cur = &mq->mqrq[0];	struct mmc_queue_req *mqrq_prev = &mq->mqrq[1]; 	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_fn, lock);	if (!mq->queue)		return -ENOMEM; 	mq->mqrq_cur = mqrq_cur;	mq->mqrq_prev = mqrq_prev;	mq->queue->queuedata = mq; 	blk_queue_prep_rq(mq->queue, mmc_prep_request);	queue_flag_set_unlocked(QUEUE_FLAG_NONROT, 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) {			mqrq_cur->bounce_buf = kmalloc(bouncesz, GFP_KERNEL);			if (!mqrq_cur->bounce_buf) {				pr_warning("%s: unable to "					"allocate bounce cur buffer\n",					mmc_card_name(card));			}			mqrq_prev->bounce_buf = kmalloc(bouncesz, GFP_KERNEL);			if (!mqrq_prev->bounce_buf) {				pr_warning("%s: unable to "					"allocate bounce prev buffer\n",					mmc_card_name(card));				kfree(mqrq_cur->bounce_buf);				mqrq_cur->bounce_buf = NULL;			}		} 		if (mqrq_cur->bounce_buf && mqrq_prev->bounce_buf) {			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); 			mqrq_cur->sg = mmc_alloc_sg(1, &ret);			if (ret)				goto cleanup_queue; 			mqrq_cur->bounce_sg =				mmc_alloc_sg(bouncesz / 512, &ret);			if (ret)				goto cleanup_queue; 			mqrq_prev->sg = mmc_alloc_sg(1, &ret);			if (ret)				goto cleanup_queue; 			mqrq_prev->bounce_sg =				mmc_alloc_sg(bouncesz / 512, &ret);			if (ret)				goto cleanup_queue;		}	}#endif 	if (!mqrq_cur->bounce_buf && !mqrq_prev->bounce_buf) {		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); 		mqrq_cur->sg = mmc_alloc_sg(host->max_segs, &ret);		if (ret)			goto cleanup_queue;  		mqrq_prev->sg = mmc_alloc_sg(host->max_segs, &ret);		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 free_bounce_sg;	} 	return 0; free_bounce_sg:	kfree(mqrq_cur->bounce_sg);	mqrq_cur->bounce_sg = NULL;	kfree(mqrq_prev->bounce_sg);	mqrq_prev->bounce_sg = NULL;  cleanup_queue:	kfree(mqrq_cur->sg);	mqrq_cur->sg = NULL;	kfree(mqrq_cur->bounce_buf);	mqrq_cur->bounce_buf = NULL; 	kfree(mqrq_prev->sg);	mqrq_prev->sg = NULL;	kfree(mqrq_prev->bounce_buf);	mqrq_prev->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;	struct mmc_queue_req *mqrq_cur = mq->mqrq_cur;	struct mmc_queue_req *mqrq_prev = mq->mqrq_prev; 	/* 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); 	kfree(mqrq_cur->bounce_sg);	mqrq_cur->bounce_sg = NULL; 	kfree(mqrq_cur->sg);	mqrq_cur->sg = NULL; 	kfree(mqrq_cur->bounce_buf);	mqrq_cur->bounce_buf = NULL; 	kfree(mqrq_prev->bounce_sg);	mqrq_prev->bounce_sg = NULL; 	kfree(mqrq_prev->sg);	mqrq_prev->sg = NULL; 	kfree(mqrq_prev->bounce_buf);	mqrq_prev->bounce_buf = 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); 	BUG_ON(!mqrq->bounce_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);}