[4/5] mmc: block: move single ioctl() commands to block requests

Message ID 20170510082418.10513-5-linus.walleij@linaro.org
State New
Headers show
Series
  • mmc: core: modernize ioctl() requests
Related show

Commit Message

Linus Walleij May 10, 2017, 8:24 a.m.
This wraps single ioctl() commands into block requests using
the custom block layer request types REQ_OP_DRV_IN and
REQ_OP_DRV_OUT.

By doing this we are loosening the grip on the big host lock,
since two calls to mmc_get_card()/mmc_put_card() are removed.

We are storing the ioctl() in/out argument as a pointer in
the per-request struct mmc_blk_request container. Since we
now let the block layer allocate this data, blk_get_request()
will allocate it for us and we can immediately dereference
it and use it to pass the argument into the block layer.

Tested on the ux500 with the userspace:
mmc extcsd read /dev/mmcblk3
resulting in a successful EXTCSD info dump back to the
console.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

---
 drivers/mmc/core/block.c | 56 ++++++++++++++++++++++++++++++++++++++----------
 drivers/mmc/core/queue.h |  3 +++
 2 files changed, 48 insertions(+), 11 deletions(-)

-- 
2.9.3

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Comments

Ulf Hansson May 16, 2017, 9:15 a.m. | #1
On 10 May 2017 at 10:24, Linus Walleij <linus.walleij@linaro.org> wrote:
> This wraps single ioctl() commands into block requests using

> the custom block layer request types REQ_OP_DRV_IN and

> REQ_OP_DRV_OUT.

>

> By doing this we are loosening the grip on the big host lock,

> since two calls to mmc_get_card()/mmc_put_card() are removed.

>

> We are storing the ioctl() in/out argument as a pointer in

> the per-request struct mmc_blk_request container. Since we

> now let the block layer allocate this data, blk_get_request()

> will allocate it for us and we can immediately dereference

> it and use it to pass the argument into the block layer.

>

> Tested on the ux500 with the userspace:

> mmc extcsd read /dev/mmcblk3

> resulting in a successful EXTCSD info dump back to the

> console.

>

> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

> ---

>  drivers/mmc/core/block.c | 56 ++++++++++++++++++++++++++++++++++++++----------


[...]

> @@ -1854,7 +1882,13 @@ void mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)

>                 goto out;

>         }

>

> -       if (req && req_op(req) == REQ_OP_DISCARD) {

> +       if (req &&

> +           (req_op(req) == REQ_OP_DRV_IN || req_op(req) == REQ_OP_DRV_OUT)) {

> +               /* complete ongoing async transfer before issuing ioctl()s */

> +               if (mq->qcnt)

> +                       mmc_blk_issue_rw_rq(mq, NULL);

> +               mmc_blk_ioctl_cmd_issue(mq, req);

> +       } else if (req && req_op(req) == REQ_OP_DISCARD) {


While you are at it, would you mind converting this if-else-if to a
switch clause instead?

[...]

Kind regards
Uffe
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Avri Altman May 23, 2017, 8:14 a.m. | #2
> -----Original Message-----

> From: linux-mmc-owner@vger.kernel.org [mailto:linux-mmc-

> owner@vger.kernel.org] On Behalf Of Linus Walleij

> Sent: Wednesday, May 10, 2017 11:24 AM

> To: linux-mmc@vger.kernel.org; Ulf Hansson <ulf.hansson@linaro.org>;

> Adrian Hunter <adrian.hunter@intel.com>

> Cc: linux-block@vger.kernel.org; Jens Axboe <axboe@kernel.dk>; Christoph

> Hellwig <hch@lst.de>; Arnd Bergmann <arnd@arndb.de>; Bartlomiej

> Zolnierkiewicz <b.zolnierkie@samsung.com>; Paolo Valente

> <paolo.valente@linaro.org>; Linus Walleij <linus.walleij@linaro.org>

> Subject: [PATCH 4/5] mmc: block: move single ioctl() commands to block

> requests

> 

> This wraps single ioctl() commands into block requests using the custom

> block layer request types REQ_OP_DRV_IN and REQ_OP_DRV_OUT.

> 

> By doing this we are loosening the grip on the big host lock, since two calls to

> mmc_get_card()/mmc_put_card() are removed.

> 

> We are storing the ioctl() in/out argument as a pointer in the per-request

> struct mmc_blk_request container. Since we now let the block layer allocate

> this data, blk_get_request() will allocate it for us and we can immediately

> dereference it and use it to pass the argument into the block layer.

> 

> Tested on the ux500 with the userspace:

> mmc extcsd read /dev/mmcblk3

> resulting in a successful EXTCSD info dump back to the console.

> 

> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

tested-by: Avri Altman <Avri.Altman@sandisk.com>

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Patch hide | download patch | download mbox

diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
index 323f3790b629..640db4f57a31 100644
--- a/drivers/mmc/core/block.c
+++ b/drivers/mmc/core/block.c
@@ -564,8 +564,10 @@  static int mmc_blk_ioctl_cmd(struct block_device *bdev,
 {
 	struct mmc_blk_ioc_data *idata;
 	struct mmc_blk_data *md;
+	struct mmc_queue *mq;
 	struct mmc_card *card;
 	int err = 0, ioc_err = 0;
+	struct request *req;
 
 	/*
 	 * The caller must have CAP_SYS_RAWIO, and must be calling this on the
@@ -591,17 +593,18 @@  static int mmc_blk_ioctl_cmd(struct block_device *bdev,
 		goto cmd_done;
 	}
 
-	mmc_get_card(card);
-
-	ioc_err = __mmc_blk_ioctl_cmd(card, md, idata);
-
-	/* Always switch back to main area after RPMB access */
-	if (md->area_type & MMC_BLK_DATA_AREA_RPMB)
-		mmc_blk_part_switch(card, dev_get_drvdata(&card->dev));
-
-	mmc_put_card(card);
-
+	/*
+	 * Dispatch the ioctl() into the block request queue.
+	 */
+	mq = &md->queue;
+	req = blk_get_request(mq->queue,
+		idata->ic.write_flag ? REQ_OP_DRV_OUT : REQ_OP_DRV_IN,
+		__GFP_RECLAIM);
+	req_to_mq_rq(req)->idata = idata;
+	blk_execute_rq(mq->queue, NULL, req, 0);
+	ioc_err = req_to_mq_rq(req)->ioc_result;
 	err = mmc_blk_ioctl_copy_to_user(ic_ptr, idata);
+	blk_put_request(req);
 
 cmd_done:
 	mmc_blk_put(md);
@@ -611,6 +614,31 @@  static int mmc_blk_ioctl_cmd(struct block_device *bdev,
 	return ioc_err ? ioc_err : err;
 }
 
+/*
+ * The ioctl commands come back from the block layer after it queued it and
+ * processed it with all other requests and then they get issued in this
+ * function.
+ */
+static void mmc_blk_ioctl_cmd_issue(struct mmc_queue *mq, struct request *req)
+{
+	struct mmc_queue_req *mq_rq;
+	struct mmc_blk_ioc_data *idata;
+	struct mmc_card *card = mq->card;
+	struct mmc_blk_data *md = mq->blkdata;
+	int ioc_err;
+
+	mq_rq = req_to_mq_rq(req);
+	idata = mq_rq->idata;
+	ioc_err = __mmc_blk_ioctl_cmd(card, md, idata);
+	mq_rq->ioc_result = ioc_err;
+
+	/* Always switch back to main area after RPMB access */
+	if (md->area_type & MMC_BLK_DATA_AREA_RPMB)
+		mmc_blk_part_switch(card, dev_get_drvdata(&card->dev));
+
+	blk_end_request_all(req, ioc_err);
+}
+
 static int mmc_blk_ioctl_multi_cmd(struct block_device *bdev,
 				   struct mmc_ioc_multi_cmd __user *user)
 {
@@ -1854,7 +1882,13 @@  void mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
 		goto out;
 	}
 
-	if (req && req_op(req) == REQ_OP_DISCARD) {
+	if (req &&
+	    (req_op(req) == REQ_OP_DRV_IN || req_op(req) == REQ_OP_DRV_OUT)) {
+		/* complete ongoing async transfer before issuing ioctl()s */
+		if (mq->qcnt)
+			mmc_blk_issue_rw_rq(mq, NULL);
+		mmc_blk_ioctl_cmd_issue(mq, req);
+	} else if (req && req_op(req) == REQ_OP_DISCARD) {
 		/* complete ongoing async transfer before issuing discard */
 		if (mq->qcnt)
 			mmc_blk_issue_rw_rq(mq, NULL);
diff --git a/drivers/mmc/core/queue.h b/drivers/mmc/core/queue.h
index 8aa10ffdf622..aeb3408dc85e 100644
--- a/drivers/mmc/core/queue.h
+++ b/drivers/mmc/core/queue.h
@@ -22,6 +22,7 @@  static inline bool mmc_req_is_special(struct request *req)
 
 struct task_struct;
 struct mmc_blk_data;
+struct mmc_blk_ioc_data;
 
 struct mmc_blk_request {
 	struct mmc_request	mrq;
@@ -40,6 +41,8 @@  struct mmc_queue_req {
 	struct scatterlist	*bounce_sg;
 	unsigned int		bounce_sg_len;
 	struct mmc_async_req	areq;
+	int			ioc_result;
+	struct mmc_blk_ioc_data	*idata;
 };
 
 struct mmc_queue {