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authorHerbert Xu <herbert@gondor.apana.org.au>2005-07-06 13:51:31 -0700
committerDavid S. Miller <davem@davemloft.net>2005-07-06 13:51:31 -0700
commitc774e93e2152d0be2612739418689e6e6400f4eb (patch)
treeabe25ec0577bd95128adb3f38609a09f0a3e2469 /crypto/scatterwalk.c
parent8279dd748f9704b811e528b31304e2fab026abc5 (diff)
downloadlwn-c774e93e2152d0be2612739418689e6e6400f4eb.tar.gz
lwn-c774e93e2152d0be2612739418689e6e6400f4eb.zip
[CRYPTO] Add plumbing for multi-block operations
The VIA Padlock device is able to perform much better when multiple blocks are fed to it at once. As this device offers an exceptional throughput rate it is worthwhile to optimise the infrastructure specifically for it. We shift the existing page-sized fast path down to the CBC/ECB functions. We can then replace the CBC/ECB functions with functions provided by the underlying algorithm that performs the multi-block operations. As a side-effect this improves the performance of large cipher operations for all existing algorithm implementations. I've measured the gain to be around 5% for 3DES and 15% for AES. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'crypto/scatterwalk.c')
-rw-r--r--crypto/scatterwalk.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/crypto/scatterwalk.c b/crypto/scatterwalk.c
index 50c9461e8cc6..47ac90e615f4 100644
--- a/crypto/scatterwalk.c
+++ b/crypto/scatterwalk.c
@@ -100,7 +100,7 @@ void scatterwalk_done(struct scatter_walk *walk, int out, int more)
int scatterwalk_copychunks(void *buf, struct scatter_walk *walk,
size_t nbytes, int out)
{
- do {
+ while (nbytes > walk->len_this_page) {
memcpy_dir(buf, walk->data, walk->len_this_page, out);
buf += walk->len_this_page;
nbytes -= walk->len_this_page;
@@ -108,7 +108,7 @@ int scatterwalk_copychunks(void *buf, struct scatter_walk *walk,
scatterwalk_unmap(walk, out);
scatterwalk_pagedone(walk, out, 1);
scatterwalk_map(walk, out);
- } while (nbytes > walk->len_this_page);
+ }
memcpy_dir(buf, walk->data, nbytes, out);
return nbytes;