From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754732AbbIPKZb (ORCPT ); Wed, 16 Sep 2015 06:25:31 -0400 Received: from 2.236.17.93.rev.sfr.net ([93.17.236.2]:21142 "EHLO mailhub1.si.c-s.fr" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752678AbbIPKFV (ORCPT ); Wed, 16 Sep 2015 06:05:21 -0400 Message-Id: From: Christophe Leroy Subject: [PATCH v4 0/2] powerpc32: memcpy/memset: only use dcbz once cache is enabled To: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , scottwood@freescale.com, sojkam1@fel.cvut.cz Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Date: Wed, 16 Sep 2015 12:04:48 +0200 (CEST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org memcpy() and memset() use instruction dcbz to speed up copy by not wasting time loading cache lines with data that will be overwritten. Some platform like mpc52xx do no have cache active at startup and can therefore not use memcpy(). Allthough no part of the code explicitly uses memcpy() and memset(), GCC makes calls to them. Christophe Leroy (2): powerpc32: memcpy: only use dcbz once cache is enabled powerpc32: memset: only use dcbz once cache is enabled arch/powerpc/kernel/setup_32.c | 6 ++++++ arch/powerpc/lib/copy_32.S | 11 +++++++++++ 2 files changed, 17 insertions(+) -- 2.1.0