Commit be2830b1 authored by Eric Biggers's avatar Eric Biggers Committed by Herbert Xu
Browse files

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: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent aa762409

arch/arm/crypto/chacha20-neon-glue.c

+3 −3
Original line number Diff line number Diff line
@@ -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;

}