mmc: block: Introduce queue semantics
Change from viewing the requests in progress as 'current' and 'previous',
to viewing them as a queue. The current request is allocated to the first
free slot. The presence of incomplete requests is determined from the
count (mq->qcnt) of entries in the queue. Non-read-write requests (i.e.
discards and flushes) are not added to the queue at all and require no
special handling. Also no special handling is needed for the
MMC_BLK_NEW_REQUEST case.
As well as allowing an arbitrarily sized queue, the queue thread function
is significantly simpler.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
index d317e5e..16c313a6 100644
--- a/drivers/mmc/core/block.c
+++ b/drivers/mmc/core/block.c
@@ -129,6 +129,13 @@ static inline int mmc_blk_part_switch(struct mmc_card *card,
struct mmc_blk_data *md);
static int get_card_status(struct mmc_card *card, u32 *status, int retries);
+static void mmc_blk_requeue(struct request_queue *q, struct request *req)
+{
+ spin_lock_irq(q->queue_lock);
+ blk_requeue_request(q, req);
+ spin_unlock_irq(q->queue_lock);
+}
+
static struct mmc_blk_data *mmc_blk_get(struct gendisk *disk)
{
struct mmc_blk_data *md;
@@ -1585,11 +1592,14 @@ static bool mmc_blk_rw_cmd_err(struct mmc_blk_data *md, struct mmc_card *card,
return req_pending;
}
-static void mmc_blk_rw_cmd_abort(struct mmc_card *card, struct request *req)
+static void mmc_blk_rw_cmd_abort(struct mmc_queue *mq, struct mmc_card *card,
+ struct request *req,
+ struct mmc_queue_req *mqrq)
{
if (mmc_card_removed(card))
req->rq_flags |= RQF_QUIET;
while (blk_end_request(req, -EIO, blk_rq_cur_bytes(req)));
+ mmc_queue_req_free(mq, mqrq);
}
/**
@@ -1609,6 +1619,7 @@ static void mmc_blk_rw_try_restart(struct mmc_queue *mq, struct request *req,
if (mmc_card_removed(mq->card)) {
req->rq_flags |= RQF_QUIET;
blk_end_request_all(req, -EIO);
+ mmc_queue_req_free(mq, mqrq);
return;
}
/* Else proceed and try to restart the current async request */
@@ -1623,14 +1634,23 @@ static void mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *new_req)
struct mmc_blk_request *brq;
int disable_multi = 0, retry = 0, type, retune_retry_done = 0;
enum mmc_blk_status status;
- struct mmc_queue_req *mqrq_cur = mq->mqrq_cur;
+ struct mmc_queue_req *mqrq_cur = NULL;
struct mmc_queue_req *mq_rq;
struct request *old_req;
struct mmc_async_req *new_areq;
struct mmc_async_req *old_areq;
bool req_pending = true;
- if (!new_req && !mq->mqrq_prev->req)
+ if (new_req) {
+ mqrq_cur = mmc_queue_req_find(mq, new_req);
+ if (!mqrq_cur) {
+ WARN_ON(1);
+ mmc_blk_requeue(mq->queue, new_req);
+ new_req = NULL;
+ }
+ }
+
+ if (!mq->qcnt)
return;
do {
@@ -1643,7 +1663,7 @@ static void mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *new_req)
!IS_ALIGNED(blk_rq_sectors(new_req), 8)) {
pr_err("%s: Transfer size is not 4KB sector size aligned\n",
new_req->rq_disk->disk_name);
- mmc_blk_rw_cmd_abort(card, new_req);
+ mmc_blk_rw_cmd_abort(mq, card, new_req, mqrq_cur);
return;
}
@@ -1659,8 +1679,6 @@ static void mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *new_req)
* and there is nothing more to do until it is
* complete.
*/
- if (status == MMC_BLK_NEW_REQUEST)
- mq->new_request = true;
return;
}
@@ -1693,7 +1711,7 @@ static void mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *new_req)
pr_err("%s BUG rq_tot %d d_xfer %d\n",
__func__, blk_rq_bytes(old_req),
brq->data.bytes_xfered);
- mmc_blk_rw_cmd_abort(card, old_req);
+ mmc_blk_rw_cmd_abort(mq, card, old_req, mq_rq);
return;
}
break;
@@ -1701,11 +1719,14 @@ static void mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *new_req)
req_pending = mmc_blk_rw_cmd_err(md, card, brq, old_req, req_pending);
if (mmc_blk_reset(md, card->host, type)) {
if (req_pending)
- mmc_blk_rw_cmd_abort(card, old_req);
+ mmc_blk_rw_cmd_abort(mq, card, old_req, mq_rq);
+ else
+ mmc_queue_req_free(mq, mq_rq);
mmc_blk_rw_try_restart(mq, new_req, mqrq_cur);
return;
}
if (!req_pending) {
+ mmc_queue_req_free(mq, mq_rq);
mmc_blk_rw_try_restart(mq, new_req, mqrq_cur);
return;
}
@@ -1718,7 +1739,7 @@ static void mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *new_req)
case MMC_BLK_ABORT:
if (!mmc_blk_reset(md, card->host, type))
break;
- mmc_blk_rw_cmd_abort(card, old_req);
+ mmc_blk_rw_cmd_abort(mq, card, old_req, mq_rq);
mmc_blk_rw_try_restart(mq, new_req, mqrq_cur);
return;
case MMC_BLK_DATA_ERR: {
@@ -1728,7 +1749,7 @@ static void mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *new_req)
if (!err)
break;
if (err == -ENODEV) {
- mmc_blk_rw_cmd_abort(card, old_req);
+ mmc_blk_rw_cmd_abort(mq, card, old_req, mq_rq);
mmc_blk_rw_try_restart(mq, new_req, mqrq_cur);
return;
}
@@ -1750,18 +1771,19 @@ static void mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *new_req)
req_pending = blk_end_request(old_req, -EIO,
brq->data.blksz);
if (!req_pending) {
+ mmc_queue_req_free(mq, mq_rq);
mmc_blk_rw_try_restart(mq, new_req, mqrq_cur);
return;
}
break;
case MMC_BLK_NOMEDIUM:
- mmc_blk_rw_cmd_abort(card, old_req);
+ mmc_blk_rw_cmd_abort(mq, card, old_req, mq_rq);
mmc_blk_rw_try_restart(mq, new_req, mqrq_cur);
return;
default:
pr_err("%s: Unhandled return value (%d)",
old_req->rq_disk->disk_name, status);
- mmc_blk_rw_cmd_abort(card, old_req);
+ mmc_blk_rw_cmd_abort(mq, card, old_req, mq_rq);
mmc_blk_rw_try_restart(mq, new_req, mqrq_cur);
return;
}
@@ -1778,6 +1800,8 @@ static void mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *new_req)
mq_rq->brq.retune_retry_done = retune_retry_done;
}
} while (req_pending);
+
+ mmc_queue_req_free(mq, mq_rq);
}
void mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
@@ -1785,9 +1809,8 @@ void mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
int ret;
struct mmc_blk_data *md = mq->blkdata;
struct mmc_card *card = md->queue.card;
- bool req_is_special = mmc_req_is_special(req);
- if (req && !mq->mqrq_prev->req)
+ if (req && !mq->qcnt)
/* claim host only for the first request */
mmc_get_card(card);
@@ -1799,20 +1822,19 @@ void mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
goto out;
}
- mq->new_request = false;
if (req && req_op(req) == REQ_OP_DISCARD) {
/* complete ongoing async transfer before issuing discard */
- if (card->host->areq)
+ if (mq->qcnt)
mmc_blk_issue_rw_rq(mq, NULL);
mmc_blk_issue_discard_rq(mq, req);
} else if (req && req_op(req) == REQ_OP_SECURE_ERASE) {
/* complete ongoing async transfer before issuing secure erase*/
- if (card->host->areq)
+ if (mq->qcnt)
mmc_blk_issue_rw_rq(mq, NULL);
mmc_blk_issue_secdiscard_rq(mq, req);
} else if (req && req_op(req) == REQ_OP_FLUSH) {
/* complete ongoing async transfer before issuing flush */
- if (card->host->areq)
+ if (mq->qcnt)
mmc_blk_issue_rw_rq(mq, NULL);
mmc_blk_issue_flush(mq, req);
} else {
@@ -1821,13 +1843,7 @@ void mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
}
out:
- if ((!req && !mq->new_request) || req_is_special)
- /*
- * Release host when there are no more requests
- * and after special request(discard, flush) is done.
- * In case sepecial request, there is no reentry to
- * the 'mmc_blk_issue_rq' with 'mqrq_prev->req'.
- */
+ if (!mq->qcnt)
mmc_put_card(card);
}