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authorAdrian Hunter2010-08-11 14:17:47 -0700
committerLinus Torvalds2010-08-12 08:43:30 -0700
commitbd788c9665fb7c543aac21317059375632343337 (patch)
tree8d4a2a629cafefa2e0f2a9a44a558d10d3c7bddd
parentdfe86cba7676d58db8de7e623f5e72f1b0d3ca35 (diff)
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: Adrian Hunter <adrian.hunter@nokia.com> Acked-by: Jens 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: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--drivers/mmc/card/block.c42
-rw-r--r--drivers/mmc/card/queue.c16
2 files changed, 55 insertions, 3 deletions
diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index 8433cde29c8b..03f96e975fe5 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -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)
{
diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c
index c77eb49eda0e..3b15884e435c 100644
--- a/drivers/mmc/card/queue.c
+++ b/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, 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) {