From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:49558 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727382AbeK1Rry (ORCPT ); Wed, 28 Nov 2018 12:47:54 -0500 From: Eric Biggers To: linux-crypto@vger.kernel.org Cc: Paul Crowley , Martin Willi , Milan Broz , "Jason A . Donenfeld" , linux-kernel@vger.kernel.org Subject: [PATCH 3/6] crypto: x86/chacha20 - limit the preemption-disabled section Date: Tue, 27 Nov 2018 22:44:42 -0800 Message-Id: <20181128064445.3813-4-ebiggers@kernel.org> In-Reply-To: <20181128064445.3813-1-ebiggers@kernel.org> References: <20181128064445.3813-1-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 responsiveness, disable preemption for each step of the walk (which is at most PAGE_SIZE) rather than for the entire encryption/decryption operation. Signed-off-by: Eric Biggers --- arch/x86/crypto/chacha20_glue.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) diff --git a/arch/x86/crypto/chacha20_glue.c b/arch/x86/crypto/chacha20_glue.c index 1e9e665092264..5928fee7acdd4 100644 --- a/arch/x86/crypto/chacha20_glue.c +++ b/arch/x86/crypto/chacha20_glue.c @@ -100,26 +100,24 @@ static int chacha20_simd(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_fpu_begin(); - while (walk.nbytes > 0) { unsigned int nbytes = walk.nbytes; if (nbytes < walk.total) nbytes = round_down(nbytes, walk.stride); + kernel_fpu_begin(); chacha20_dosimd(state, walk.dst.virt.addr, walk.src.virt.addr, nbytes); + kernel_fpu_end(); err = skcipher_walk_done(&walk, walk.nbytes - nbytes); } - kernel_fpu_end(); - return err; } -- 2.19.2