Return-Path: Received: from mail.kernel.org ([198.145.29.99]:54536 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727560AbeKFItM (ORCPT ); Tue, 6 Nov 2018 03:49:12 -0500 From: Eric Biggers To: linux-crypto@vger.kernel.org Cc: linux-fscrypt@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Herbert Xu , Paul Crowley , Greg Kaiser , "Jason A . Donenfeld" , Samuel Neves , Tomer Ashur Subject: [RFC PATCH v3 06/15] crypto: arm/chacha20 - limit the preemption-disabled section Date: Mon, 5 Nov 2018 15:25:17 -0800 Message-Id: <20181105232526.173947-7-ebiggers@kernel.org> In-Reply-To: <20181105232526.173947-1-ebiggers@kernel.org> References: <20181105232526.173947-1-ebiggers@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-crypto-owner@vger.kernel.org List-ID: From: Eric Biggers 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 Signed-off-by: Eric Biggers --- arch/arm/crypto/chacha20-neon-glue.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/arm/crypto/chacha20-neon-glue.c b/arch/arm/crypto/chacha20-neon-glue.c index 7386eb1c1889..2bc035cb8f23 100644 --- a/arch/arm/crypto/chacha20-neon-glue.c +++ b/arch/arm/crypto/chacha20-neon-glue.c @@ -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; } -- 2.19.1.930.g4563a0d9d0-goog