crypto: arm/chacha20 - limit the preemption-disabled section

To improve responsivesess, disable preemption for each step of the walk
(which is at most PAGE_SIZE) rather than for the entire
encryption/decryption operation.

Suggested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Eric Biggers 2018-11-16 17:26:23 -08:00 committed by Herbert Xu
parent aa7624093c
commit be2830b15b

View File

@ -68,22 +68,22 @@ static int chacha20_neon(struct skcipher_request *req)
if (req->cryptlen <= CHACHA_BLOCK_SIZE || !may_use_simd())
return crypto_chacha_crypt(req);
err = skcipher_walk_virt(&walk, req, true);
err = skcipher_walk_virt(&walk, req, false);
crypto_chacha_init(state, ctx, walk.iv);
kernel_neon_begin();
while (walk.nbytes > 0) {
unsigned int nbytes = walk.nbytes;
if (nbytes < walk.total)
nbytes = round_down(nbytes, walk.stride);
kernel_neon_begin();
chacha20_doneon(state, walk.dst.virt.addr, walk.src.virt.addr,
nbytes);
kernel_neon_end();
err = skcipher_walk_done(&walk, walk.nbytes - nbytes);
}
kernel_neon_end();
return err;
}