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@xxxxxxxxx>
Cc: Tim Chen <tim.c.chen@xxxxxxxxxxxxxxx>
Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: linux-crypto@xxxxxxxxxxxxxxx
Cc: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
Cc: Sagi Grimberg <sagig@xxxxxxxxxxxx>
Cc: "Martin K. Petersen" <martin.petersen@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: "James E.J. Bottomley" <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx>
Cc: target-devel@xxxxxxxxxxxxxxx
---
* 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
--
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