From 95477377995aefa2ec1654a9a3777bd57ea99146 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Wed, 6 Jul 2005 13:52:09 -0700 Subject: [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 Signed-off-by: David S. Miller --- crypto/scatterwalk.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'crypto/scatterwalk.h') diff --git a/crypto/scatterwalk.h b/crypto/scatterwalk.h index 5495bb97081..e79925c474a 100644 --- a/crypto/scatterwalk.h +++ b/crypto/scatterwalk.h @@ -55,6 +55,12 @@ static inline void scatterwalk_advance(struct scatter_walk *walk, walk->len_this_segment -= nbytes; } +static inline unsigned int scatterwalk_aligned(struct scatter_walk *walk, + unsigned int alignmask) +{ + return !(walk->offset & alignmask); +} + void scatterwalk_start(struct scatter_walk *walk, struct scatterlist *sg); int scatterwalk_copychunks(void *buf, struct scatter_walk *walk, size_t nbytes, int out); void scatterwalk_map(struct scatter_walk *walk, int out); -- cgit v1.2.3