From: Akinobu Mita Subject: [PATCH v3 2/5] lib: introduce crc_t10dif_update() Date: Sat, 25 Apr 2015 23:33:27 +0900 Message-ID: <1429972410-7146-3-git-send-email-akinobu.mita@gmail.com> References: <1429972410-7146-1-git-send-email-akinobu.mita@gmail.com> Cc: Akinobu Mita , Tim Chen , Herbert Xu , "David S. Miller" , linux-crypto@vger.kernel.org, Nicholas Bellinger , Sagi Grimberg , "Martin K. Petersen" , Christoph Hellwig , "James E.J. Bottomley" To: target-devel@vger.kernel.org Return-path: In-Reply-To: <1429972410-7146-1-git-send-email-akinobu.mita@gmail.com> Sender: target-devel-owner@vger.kernel.org List-Id: linux-crypto.vger.kernel.org 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 Cc: Tim Chen Cc: Herbert Xu Cc: "David S. Miller" Cc: linux-crypto@vger.kernel.org Cc: Nicholas Bellinger Cc: Sagi Grimberg Cc: "Martin K. Petersen" Cc: Christoph Hellwig Cc: "James E.J. Bottomley" 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(+) 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 { -- 1.9.1