From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BF8EFC4332F for ; Thu, 15 Dec 2022 20:42:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229830AbiLOUmM (ORCPT ); Thu, 15 Dec 2022 15:42:12 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40076 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229484AbiLOUmI (ORCPT ); Thu, 15 Dec 2022 15:42:08 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E594545EDE for ; Thu, 15 Dec 2022 12:42:06 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 7F55D61EFF for ; Thu, 15 Dec 2022 20:42:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C0694C433EF; Thu, 15 Dec 2022 20:42:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1671136925; bh=d/a7C/PBOg8rdq9nwXwUdpRZ5tsLNSdSY3Squ2imeAs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=E3xlF6bUMRnZWvVutOYkDDYPoagnHMfAjHcWy839UzoWE65h0njzkehIWK3rHiMFl pFFVxTqJqLwGMWEH4DVNlk4yVHvfz6tvKF/Y6uIoo1y8pYyIy9DIkd1p5b7LzigHg7 n6EPWk3n6woOvhhKmT0M8USBykiEonQ9P0U8InbXyqZHSyLd5wurBcdSm8pKgCqXpF 5PTeCaHzp+F+wr844bzYtcdsKRBC9uOkObwyCxE2AwhpSmp4bpyNxEKMY/jUgjsrXz 872QztzTey9jImak0Ss0J4YGmhBBZQ1380yW6dMV3svniT6bDiz0YQDOjcShFbpfdT ieAmiZVdYfVZg== Received: by pali.im (Postfix) id 6DA4A5CD; Thu, 15 Dec 2022 21:42:02 +0100 (CET) Date: Thu, 15 Dec 2022 21:42:02 +0100 From: Pali =?utf-8?B?Um9ow6Fy?= To: Christophe Leroy Cc: Michael Ellerman , Nicholas Piggin , linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH v1] powerpc/64: Set default CPU in Kconfig Message-ID: <20221215204202.mbw2ij4ou7t2ttpv@pali> References: <3fd60c2d8a28668a42b766b18362a526ef47e757.1670420281.git.christophe.leroy@csgroup.eu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3fd60c2d8a28668a42b766b18362a526ef47e757.1670420281.git.christophe.leroy@csgroup.eu> User-Agent: NeoMutt/20180716 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello! On Wednesday 07 December 2022 14:38:40 Christophe Leroy wrote: > diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile ... > @@ -166,11 +153,12 @@ CC_FLAGS_FTRACE += -mprofile-kernel > endif > endif > > -CFLAGS-$(CONFIG_TARGET_CPU_BOOL) += $(call cc-option,-mcpu=$(CONFIG_TARGET_CPU)) > -AFLAGS-$(CONFIG_TARGET_CPU_BOOL) += $(call cc-option,-mcpu=$(CONFIG_TARGET_CPU)) > +CFLAGS-$(CONFIG_TARGET_CPU_BOOL) += -mcpu=$(CONFIG_TARGET_CPU) > +AFLAGS-$(CONFIG_TARGET_CPU_BOOL) += -mcpu=$(CONFIG_TARGET_CPU) > > -CFLAGS-$(CONFIG_E5500_CPU) += $(call cc-option,-mcpu=e500mc64,-mcpu=powerpc64) > -CFLAGS-$(CONFIG_E6500_CPU) += $(call cc-option,-mcpu=e6500,$(E5500_CPU)) > +CFLAGS-$(CONFIG_POWERPC64_CPU) += $(call cc-option,-mtune=power10, \ > + $(call cc-option,-mtune=power9, \ > + $(call cc-option,-mtune=power8))) > > asinstr := $(call as-instr,lis 9$(comma)foo@high,-DHAVE_AS_ATHIGH=1) > > diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype ... > @@ -251,6 +249,10 @@ config TARGET_CPU > default "power8" if POWER8_CPU > default "power9" if POWER9_CPU > default "power10" if POWER10_CPU > + default "e500mc64" if E5500_CPU Now I'm looking at this change again... and should not E5500_CPU rather enforce -mcpu=e5500 flag? I know that your patch moves e500mc64 flag from the Makefile to Kconfig, but maybe it could be changed in some other followup patch... Anyway, do you know what is e500mc64 core? I was trying to find some information about it, but it looks like some unreleased freescale core which predates e5500 core. ISA (without extensions like altivec) seems to be same for e500mc64, e5500 and e6500 cores and difference is only pipeline definitions in gcc config files. So if my understanding is correct then kernel binary compiled with any of these -mcpu= flag should work on any of those cores. Just for mismatches core binary will not be optimized for speed. > + default "e6500" if E6500_CPU > + default "power4" if POWERPC64_CPU && !CPU_LITTLE_ENDIAN > + default "power8" if POWERPC64_CPU && CPU_LITTLE_ENDIAN > default "405" if 405_CPU > default "440" if 440_CPU > default "464" if 464_CPU > -- > 2.38.1 >