On Tue, May 13, 2014 at 04:19:42PM -0700, Tim Chen wrote: > For x86_64, it is not necessary to incur the additional overhead in > kmap_atomic to map the scatter gather buffer to a linear address. > Mapping the address directly will allow in x86_64 allows multi-buffer > crypto hash alogrithms to have several unfinished buffers with their > address stored in job context before switching out of the crypto daemon. > > Signed-off-by: Tim Chen <tim.c.chen@xxxxxxxxxxxxxxx> > --- > crypto/ahash.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/crypto/ahash.c b/crypto/ahash.c > index a92dc38..556f1fa 100644 > --- a/crypto/ahash.c > +++ b/crypto/ahash.c > @@ -46,7 +46,11 @@ static int hash_walk_next(struct crypto_hash_walk *walk) > unsigned int nbytes = min(walk->entrylen, > ((unsigned int)(PAGE_SIZE)) - offset); > > +#ifdef CONFIG_X86_64 > + walk->data = page_address(walk->pg); > +#else > walk->data = kmap_atomic(walk->pg); > +#endif Why do we need this patch since kmap_atomic is equivalent to page_address plus preempt_disable on x86-64? Cheers, -- Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
