[CRYPTO] Add alignmask for low-level cipher implementations
The VIA Padlock device requires the input and output buffers to
be aligned on 16-byte boundaries. This patch adds the alignmask
attribute for low-level cipher implementations to indicate their
alignment requirements.
The mid-level crypt() function will copy the input/output buffers
if they are not aligned correctly before they are passed to the
low-level implementation.
Strictly speaking, some of the software implementations require
the buffers to be aligned on 4-byte boundaries as they do 32-bit
loads. However, it is not clear whether it is better to copy
the buffers or pay the penalty for unaligned loads/stores.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/crypto.h b/include/linux/crypto.h
index 26ce01c..ac9d49b 100644
--- a/include/linux/crypto.h
+++ b/include/linux/crypto.h
@@ -124,6 +124,7 @@
u32 cra_flags;
unsigned int cra_blocksize;
unsigned int cra_ctxsize;
+ unsigned int cra_alignmask;
const char cra_name[CRYPTO_MAX_ALG_NAME];
union {