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[v3,2/5] lib: introduce crc_t10dif_update()

Message ID 1429972410-7146-3-git-send-email-akinobu.mita@gmail.com (mailing list archive)
State Not Applicable
Headers show

Commit Message

Akinobu Mita April 25, 2015, 2:33 p.m. UTC 
This introduces crc_t10dif_update() which enables to calculate CRC
for a block which straddles multiple SG elements by calling multiple
times.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-crypto@vger.kernel.org
Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: target-devel@vger.kernel.org
---
* New patch from v3

 include/linux/crc-t10dif.h |  1 +
 lib/crc-t10dif.c           | 23 +++++++++++++++++++++++
 2 files changed, 24 insertions(+)

Comments

Martin K. Petersen April 27, 2015, 11:41 p.m. UTC | #1 
>>>>> "Akinobu" == Akinobu Mita <akinobu.mita@gmail.com> writes:

Akinobu> This introduces crc_t10dif_update() which enables to calculate
Akinobu> CRC for a block which straddles multiple SG elements by calling
Akinobu> multiple times.

Looks good. We need this for the initiator side too.

Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
diff mbox

Patch

diff --git a/include/linux/crc-t10dif.h b/include/linux/crc-t10dif.h
index cf53d07..d81961e 100644
--- a/include/linux/crc-t10dif.h
+++ b/include/linux/crc-t10dif.h
@@ -9,5 +9,6 @@ 
 extern __u16 crc_t10dif_generic(__u16 crc, const unsigned char *buffer,
 				size_t len);
 extern __u16 crc_t10dif(unsigned char const *, size_t);
+extern __u16 crc_t10dif_update(__u16 crc, unsigned char const *, size_t);
 
 #endif
diff --git a/lib/crc-t10dif.c b/lib/crc-t10dif.c
index dfe6ec1..7cdbe2e 100644
--- a/lib/crc-t10dif.c
+++ b/lib/crc-t10dif.c
@@ -19,6 +19,29 @@ 
 static struct crypto_shash *crct10dif_tfm;
 static struct static_key crct10dif_fallback __read_mostly;
 
+__u16 crc_t10dif_update(__u16 crc, const unsigned char *buffer, size_t len)
+{
+	struct {
+		struct shash_desc shash;
+		char ctx[2];
+	} desc;
+	int err;
+
+	if (static_key_false(&crct10dif_fallback))
+		return crc_t10dif_generic(crc, buffer, len);
+
+	desc.shash.tfm = crct10dif_tfm;
+	desc.shash.flags = 0;
+
+	err = crypto_shash_import(&desc.shash, &crc);
+	BUG_ON(err);
+	err = crypto_shash_update(&desc.shash, buffer, len);
+	BUG_ON(err);
+
+	return *(__u16 *)desc.ctx;
+}
+EXPORT_SYMBOL(crc_t10dif_update);
+
 __u16 crc_t10dif(const unsigned char *buffer, size_t len)
 {
 	struct {