diff options
| author | Herbert Xu <herbert@gondor.apana.org.au> | 2005-07-07 00:52:09 +0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2005-07-07 00:52:09 +0400 |
| commit | 95477377995aefa2ec1654a9a3777bd57ea99146 (patch) | |
| tree | 7aa4d6173de13c81c2fa0e4d2f9e0de22e141b6a /crypto/scatterwalk.h | |
| parent | 40725181b74be6b0e3bdc8c05bd1e0b9873ec5cc (diff) | |
| download | linux-95477377995aefa2ec1654a9a3777bd57ea99146.tar.xz | |
[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>
Diffstat (limited to 'crypto/scatterwalk.h')
| -rw-r--r-- | crypto/scatterwalk.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/crypto/scatterwalk.h b/crypto/scatterwalk.h index 5495bb970816..e79925c474a3 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); |