[PATCH 2/2] mmc: fixes for eMMC v4.5 sanitize operation

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

eMMC v4.5 sanitize operation erases all copies of unmapped
data.  However trim or erase operations must be used first
to unmap the required sectors.  That was not being done.

Fixes apply to linux 3.2 on.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: <stable@vger.kernel.org>
---
 drivers/mmc/card/block.c |   54 ++++++++++++++++++++++++++++++++-------------
 drivers/mmc/core/core.c  |    2 +
 2 files changed, 40 insertions(+), 16 deletions(-)

diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index b180965..4232bc4 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -873,7 +873,7 @@ static int mmc_blk_issue_secdiscard_rq(struct mmc_queue *mq,
 {
 	struct mmc_blk_data *md = mq->data;
 	struct mmc_card *card = md->queue.card;
-	unsigned int from, nr, arg;
+	unsigned int from, nr, arg, trim_arg, erase_arg;
 	int err = 0, type = MMC_BLK_SECDISCARD;
 
 	if (!(mmc_can_secure_erase_trim(card) || mmc_can_sanitize(card))) {
@@ -881,20 +881,26 @@ static int mmc_blk_issue_secdiscard_rq(struct mmc_queue *mq,
 		goto out;
 	}
 
+	from = blk_rq_pos(req);
+	nr = blk_rq_sectors(req);
+
 	/* The sanitize operation is supported at v4.5 only */
 	if (mmc_can_sanitize(card)) {
-		err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
-				EXT_CSD_SANITIZE_START, 1, 0);
-		goto out;
+		erase_arg = MMC_ERASE_ARG;
+		trim_arg = MMC_TRIM_ARG;
+	} else {
+		erase_arg = MMC_SECURE_ERASE_ARG;
+		trim_arg = MMC_SECURE_TRIM1_ARG;
 	}
 
-	from = blk_rq_pos(req);
-	nr = blk_rq_sectors(req);
-
-	if (mmc_can_trim(card) && !mmc_erase_group_aligned(card, from, nr))
-		arg = MMC_SECURE_TRIM1_ARG;
-	else
-		arg = MMC_SECURE_ERASE_ARG;
+	if (mmc_erase_group_aligned(card, from, nr))
+		arg = erase_arg;
+	else if (mmc_can_trim(card))
+		arg = trim_arg;
+	else {
+		err = -EINVAL;
+		goto out;
+	}
 retry:
 	if (card->quirks & MMC_QUIRK_INAND_CMD38) {
 		err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
@@ -904,25 +910,41 @@ retry:
 				 INAND_CMD38_ARG_SECERASE,
 				 0);
 		if (err)
-			goto out;
+			goto out_retry;
 	}
+
 	err = mmc_erase(card, from, nr, arg);
-	if (!err && arg == MMC_SECURE_TRIM1_ARG) {
+	if (err == -EIO)
+		goto out_retry;
+	if (err)
+		goto out;
+
+	if (arg == MMC_SECURE_TRIM1_ARG) {
 		if (card->quirks & MMC_QUIRK_INAND_CMD38) {
 			err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
 					 INAND_CMD38_ARG_EXT_CSD,
 					 INAND_CMD38_ARG_SECTRIM2,
 					 0);
 			if (err)
-				goto out;
+				goto out_retry;
 		}
+
 		err = mmc_erase(card, from, nr, MMC_SECURE_TRIM2_ARG);
+		if (err == -EIO)
+			goto out_retry;
+		if (err)
+			goto out;
 	}
-out:
-	if (err == -EIO && !mmc_blk_reset(md, card->host, type))
+
+	if (mmc_can_sanitize(card))
+		err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
+				 EXT_CSD_SANITIZE_START, 1, 0);
+out_retry:
+	if (err && !mmc_blk_reset(md, card->host, type))
 		goto retry;
 	if (!err)
 		mmc_blk_reset_success(md, type);
+out:
 	spin_lock_irq(&md->lock);
 	__blk_end_request(req, err, blk_rq_bytes(req));
 	spin_unlock_irq(&md->lock);
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 8a9f286..50eb323 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -1698,6 +1698,8 @@ EXPORT_SYMBOL(mmc_can_discard);
 
 int mmc_can_sanitize(struct mmc_card *card)
 {
+	if (!mmc_can_trim(card) && !mmc_can_erase(card))
+		return 0;
 	if (card->ext_csd.sec_feature_support & EXT_CSD_SEC_SANITIZE)
 		return 1;
 	return 0;
-- 
1.7.6.5