[16/24] mmc_block: add discard support

Commit Message

Andrew Morton Aug. 11, 2010, 9:17 p.m. UTC

None

Patch

diff -puN drivers/mmc/card/block.c~mmc_block-add-discard-support drivers/mmc/card/block.c
--- a/drivers/mmc/card/block.c~mmc_block-add-discard-support
+++ a/drivers/mmc/card/block.c
@@ -247,7 +247,40 @@  static u32 get_card_status(struct mmc_ca
 	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_q
 	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)
 {
diff -puN drivers/mmc/card/queue.c~mmc_block-add-discard-support drivers/mmc/card/queue.c
--- a/drivers/mmc/card/queue.c~mmc_block-add-discard-support
+++ a/drivers/mmc/card/queue.c
@@ -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,
 	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) {