Commit bd788c96 authored by Adrian Hunter's avatar Adrian Hunter Committed by Linus Torvalds
Browse files

mmc_block: add discard support 



Enable MMC to service discard requests.  In the case of SD and MMC cards
that do not support trim, discards become erases.  In the case of cards
(MMC) that only allow erases in multiples of erase group size, round to
the nearest completely discarded erase group.

Signed-off-by: default avatarAdrian Hunter <adrian.hunter@nokia.com>
Acked-by: default avatarJens Axboe <axboe@kernel.dk>
Cc: Kyungmin Park <kmpark@infradead.org>
Cc: Madhusudhan Chikkature <madhu.cr@ti.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ben Gardiner <bengardiner@nanometrics.ca>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent dfe86cba

drivers/mmc/card/block.c

+41 −1
Original line number Diff line number Diff line
@@ -247,7 +247,40 @@ static u32 get_card_status(struct mmc_card *card, struct request *req) 
	return cmd.resp[0];

}



static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)

static int mmc_blk_issue_discard_rq(struct mmc_queue *mq, struct request *req)

{

	struct mmc_blk_data *md = mq->data;

	struct mmc_card *card = md->queue.card;

	unsigned int from, nr, arg;

	int err = 0;



	mmc_claim_host(card->host);



	if (!mmc_can_erase(card)) {

		err = -EOPNOTSUPP;

		goto out;

	}



	from = blk_rq_pos(req);

	nr = blk_rq_sectors(req);



	if (mmc_can_trim(card))

		arg = MMC_TRIM_ARG;

	else

		arg = MMC_ERASE_ARG;



	err = mmc_erase(card, from, nr, arg);

out:

	spin_lock_irq(&md->lock);

	__blk_end_request(req, err, blk_rq_bytes(req));

	spin_unlock_irq(&md->lock);



	mmc_release_host(card->host);



	return err ? 0 : 1;

}



static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *req)

{

	struct mmc_blk_data *md = mq->data;

	struct mmc_card *card = md->queue.card;
@@ -475,6 +508,13 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req) 
	return 0;

}



static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)

{

	if (req->cmd_flags & REQ_DISCARD)

		return mmc_blk_issue_discard_rq(mq, req);

	else

		return mmc_blk_issue_rw_rq(mq, req);

}



static inline int mmc_blk_readonly(struct mmc_card *card)

{

drivers/mmc/card/queue.c

+14 −2
Original line number Diff line number Diff line
@@ -30,9 +30,9 @@ 
static int mmc_prep_request(struct request_queue *q, struct request *req)

{

	/*

	 * We only like normal block requests.

	 * We only like normal block requests and discards.

	 */

	if (req->cmd_type != REQ_TYPE_FS) {

	if (req->cmd_type != REQ_TYPE_FS && !(req->cmd_flags & REQ_DISCARD)) {

		blk_dump_rq_flags(req, "MMC bad request");

		return BLKPREP_KILL;

	}
@@ -130,6 +130,18 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card, spinlock_t *lock 
	blk_queue_prep_rq(mq->queue, mmc_prep_request);

	blk_queue_ordered(mq->queue, QUEUE_ORDERED_DRAIN);

	queue_flag_set_unlocked(QUEUE_FLAG_NONROT, mq->queue);

	if (mmc_can_erase(card)) {

		queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mq->queue);

		mq->queue->limits.max_discard_sectors = UINT_MAX;

		if (card->erased_byte == 0)

			mq->queue->limits.discard_zeroes_data = 1;

		if (!mmc_can_trim(card) && is_power_of_2(card->erase_size)) {

			mq->queue->limits.discard_granularity =

							card->erase_size << 9;

			mq->queue->limits.discard_alignment =

							card->erase_size << 9;

		}

	}



#ifdef CONFIG_MMC_BLOCK_BOUNCE

	if (host->max_hw_segs == 1) {

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