block: ioctl support for sanitize in eMMC 4.5

Adding a new ioctl to support sanitize operation in eMMC
cards version 4.5.
The sanitize ioctl support helps performing this operation
via user application.

Change-Id: I79aa4163e7753a75bed5a26a9a92de902b4b9c21
Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>
Signed-off-by: Maya Erez <merez@codeaurora.org>
diff --git a/block/blk-lib.c b/block/blk-lib.c
index 78e627e..39a7f25 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -112,6 +112,57 @@
 EXPORT_SYMBOL(blkdev_issue_discard);
 
 /**
+ * blkdev_issue_sanitize - queue a sanitize request
+ * @bdev:	blockdev to issue sanitize for
+ * @gfp_mask:	memory allocation flags (for bio_alloc)
+ *
+ * Description:
+ *    Issue a sanitize request for the specified block device
+ */
+int blkdev_issue_sanitize(struct block_device *bdev, gfp_t gfp_mask)
+{
+	DECLARE_COMPLETION_ONSTACK(wait);
+	struct request_queue *q = bdev_get_queue(bdev);
+	int type = REQ_WRITE | REQ_SANITIZE;
+	struct bio_batch bb;
+	struct bio *bio;
+	int ret = 0;
+
+	if (!q)
+		return -ENXIO;
+
+	if (!blk_queue_sanitize(q)) {
+		pr_err("%s - card doesn't support sanitize", __func__);
+		return -EOPNOTSUPP;
+	}
+
+	bio = bio_alloc(gfp_mask, 1);
+	if (!bio)
+		return -ENOMEM;
+
+	atomic_set(&bb.done, 1);
+	bb.flags = 1 << BIO_UPTODATE;
+	bb.wait = &wait;
+
+	bio->bi_end_io = bio_batch_end_io;
+	bio->bi_bdev = bdev;
+	bio->bi_private = &bb;
+
+	atomic_inc(&bb.done);
+	submit_bio(type, bio);
+
+	/* Wait for bios in-flight */
+	if (!atomic_dec_and_test(&bb.done))
+		wait_for_completion(&wait);
+
+	if (!test_bit(BIO_UPTODATE, &bb.flags))
+		ret = -EIO;
+
+	return ret;
+}
+EXPORT_SYMBOL(blkdev_issue_sanitize);
+
+/**
  * blkdev_issue_zeroout - generate number of zero filed write bios
  * @bdev:	blockdev to issue
  * @sector:	start sector