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 DD5DBC7618D for ; Thu, 6 Apr 2023 21:10:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238304AbjDFVKJ (ORCPT ); Thu, 6 Apr 2023 17:10:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42424 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240464AbjDFVJ4 (ORCPT ); Thu, 6 Apr 2023 17:09:56 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 138E386AC for ; Thu, 6 Apr 2023 14:09:56 -0700 (PDT) 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 A0DC560FD3 for ; Thu, 6 Apr 2023 21:09:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BD712C433D2; Thu, 6 Apr 2023 21:09:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1680815395; bh=QxQh52djmd4QpZTOVeRRXf4csbgTBpjj8+kNAabQFbE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=crpU4TPXjn1qyF/0xzR1oP7iTi9/POyVX+GURM8VAeI49kevnmueHLsScAivxHT9Q AiBbGy/PgWv6N+fk3a/z4ECtuPBd64mgTDEQnBd8QYPclrHCOujs0RS+B4+GzW32Lg 3ddBjXDzPcZXRuoWHdcvDGCi6v5d2CY89TFKfTebCni5j8Ckozmw6MvXhgrmcw/oN8 oS4fdGNlG7e1bRF2fyHyaxsaZq43adtsEVoMJBiO3I6RreAHXk8TgTViU1QBv/0P4A JDTTddRzHY8S16oWQ6bW048pbH8X5qlo3VyRtjcX/tNEuv9kLPGNeEwwqV3VXZfFim J5NTvSHLVle+g== Date: Thu, 6 Apr 2023 14:09:53 -0700 From: Nathan Chancellor To: Jiaxun Yang Cc: Thomas Bogendoerfer , "linux-mips@vger.kernel.org" , llvm@lists.linux.dev, patches@lists.linux.dev Subject: Re: [PATCH] MIPS: generic: Do not select CPUs that are unsupported in clang Message-ID: <20230406210953.GA53516@dev-arch.thelio-3990X> References: <20230406-mips-clang-generic-selects-fix-v1-1-811690c9fb69@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org On Thu, Apr 06, 2023 at 09:59:45PM +0100, Jiaxun Yang wrote: > > > > 2023年4月6日 21:09，Nathan Chancellor 写道： > > > > When building allnoconfig with clang after commit de34007751aa ("MIPS: > > generic: Enable all CPUs supported by virt board in Kconfig"), the > > following error occurs: > > > > error: unknown target CPU 'r4600' > > note: valid target CPU values are: mips1, mips2, mips3, mips4, mips5, mips32, mips32r2, mips32r3, mips32r5, mips32r6, mips64, mips64r2, mips64r3, mips64r5, mips64r6, octeon, octeon+, p5600 > > > > Working around that, there are similar errors for 'loongson2e' and > > 'loongson2f'. > > > > These CPUs are not supported in clang/LLVM, so do not select support for > > them in MIPS_GENERIC_KERNEL when building with clang. > > > > Fixes: de34007751aa ("MIPS: generic: Enable all CPUs supported by virt board in Kconfig") > > Signed-off-by: Nathan Chancellor > > Thanks for the patch. > > Actually there is no need for any special support for those CPUs. > We should be able to build those kernels with -march=mips3. > > I think something like: > > --- a/arch/mips/Makefile > +++ b/arch/mips/Makefile > @@ -150,7 +150,7 @@ cflags-y += $(call cc-option,-Wa$(comma)-mno-fix-loongson3-llsc,) > # > cflags-$(CONFIG_CPU_R3000) += -march=r3000 > cflags-$(CONFIG_CPU_R4300) += -march=r4300 -Wa,--trap > -cflags-$(CONFIG_CPU_R4X00) += -march=r4600 -Wa,--trap > +cflags-$(CONFIG_CPU_R4X00) += $(call cc-option,-march=r4600,-march=mips3) -Wa,--trap > cflags-$(CONFIG_CPU_TX49XX) += -march=r4600 -Wa,--trap > cflags-$(CONFIG_CPU_MIPS32_R1) += -march=mips32 -Wa,--trap > cflags-$(CONFIG_CPU_MIPS32_R2) += -march=mips32r2 -Wa,--trap > @@ -181,8 +181,8 @@ endif > cflags-$(CONFIG_CAVIUM_CN63XXP1) += -Wa,-mfix-cn63xxp1 > cflags-$(CONFIG_CPU_BMIPS) += -march=mips32 -Wa,-mips32 -Wa,--trap > > -cflags-$(CONFIG_CPU_LOONGSON2E) += -march=loongson2e -Wa,--trap > -cflags-$(CONFIG_CPU_LOONGSON2F) += -march=loongson2f -Wa,--trap > +cflags-$(CONFIG_CPU_LOONGSON2E) += $(call cc-option,-march=loongson2e,-march=mips3) -Wa,--trap > +cflags-$(CONFIG_CPU_LOONGSON2F) += $(call cc-option,-march=loongson2f,-march=mips3) -Wa,--trap > # Some -march= flags enable MMI instructions, and GCC complains about that > # support being enabled alongside -msoft-float. Thus explicitly disable MMI. > cflags-$(CONFIG_CPU_LOONGSON2EF) += $(call cc-option,-mno-loongson-mmi) > > Will make them build. Thank you for taking a look and the suggestion! I applied it and tried to build allnoconfig but I get error: ABI 'o32' is not supported on CPU 'mips3' immediately, which could certainly be a bug in clang... Cheers, Nathan