From: Adrian Hunter on
From 548ec42c86a88092b92597ff2774691e5498974f Mon Sep 17 00:00:00 2001
From: Adrian Hunter <adrian.hunter(a)nokia.com>
Date: Wed, 23 Jun 2010 15:55:50 +0300
Subject: [PATCH 5/5] mmc_block: Add support for secure discard

Secure discard is implemented by Secure Trim if the discard
is unaligned or Secure Erase otherwise.

Signed-off-by: Adrian Hunter <adrian.hunter(a)nokia.com>
---
drivers/mmc/card/block.c | 46 +++++++++++++++++++++++++++++++++++++++++++---
drivers/mmc/card/queue.c | 3 +++
2 files changed, 46 insertions(+), 3 deletions(-)

diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index adb8314..0265712 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -275,6 +275,42 @@ out:
return err ? 0 : 1;
}

+static int mmc_blk_issue_secdiscard_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_secure_erase_trim(card)) {
+ err = -EOPNOTSUPP;
+ goto out;
+ }
+
+ 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;
+
+ err = mmc_erase(card, from, nr, arg);
+ if (!err && arg == MMC_SECURE_TRIM1_ARG)
+ err = mmc_erase(card, from, nr, MMC_SECURE_TRIM2_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;
@@ -505,10 +541,14 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *req)

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
+ if (req->cmd_flags & REQ_DISCARD) {
+ if (req->cmd_flags & REQ_SECURE)
+ return mmc_blk_issue_secdiscard_rq(mq, req);
+ else
+ 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 0add067..a7876d5 100644
--- a/drivers/mmc/card/queue.c
+++ b/drivers/mmc/card/queue.c
@@ -141,6 +141,9 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card, spinlock_t *lock
mq->queue->limits.discard_alignment =
card->erase_size << 9;
}
+ if (mmc_can_secure_erase_trim(card))
+ queue_flag_set_unlocked(QUEUE_FLAG_SECDISCARD,
+ mq->queue);
}

#ifdef CONFIG_MMC_BLOCK_BOUNCE
--
1.6.3.3

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