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 X-Spam-Level: X-Spam-Status: No, score=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 143BDC433ED for ; Fri, 23 Apr 2021 12:22:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C7C3561459 for ; Fri, 23 Apr 2021 12:22:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231312AbhDWMXL (ORCPT ); Fri, 23 Apr 2021 08:23:11 -0400 Received: from elvis.franken.de ([193.175.24.41]:38486 "EHLO elvis.franken.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229479AbhDWMXK (ORCPT ); Fri, 23 Apr 2021 08:23:10 -0400 Received: from uucp (helo=alpha) by elvis.franken.de with local-bsmtp (Exim 3.36 #1) id 1lZupM-00019R-03; Fri, 23 Apr 2021 14:22:32 +0200 Received: by alpha.franken.de (Postfix, from userid 1000) id D1468C0B3B; Fri, 23 Apr 2021 13:51:40 +0200 (CEST) Date: Fri, 23 Apr 2021 13:51:40 +0200 From: Thomas Bogendoerfer To: Sudip Mukherjee Cc: linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org, Romain Naour Subject: Re: [PATCH v4] mips: Do not include hi and lo in clobber list for R6 Message-ID: <20210423115140.GD8582@alpha.franken.de> References: <20210420211210.702980-1-sudipm.mukherjee@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20210420211210.702980-1-sudipm.mukherjee@gmail.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org On Tue, Apr 20, 2021 at 10:12:10PM +0100, Sudip Mukherjee wrote: > From: Romain Naour > > >From [1] > "GCC 10 (PR 91233) won't silently allow registers that are not > architecturally available to be present in the clobber list anymore, > resulting in build failure for mips*r6 targets in form of: > ... > .../sysdep.h:146:2: error: the register ‘lo’ cannot be clobbered in ‘asm’ for the current target > 146 | __asm__ volatile ( \ > | ^~~~~~~ > > This is because base R6 ISA doesn't define hi and lo registers w/o DSP > extension. This patch provides the alternative clobber list for r6 targets > that won't include those registers." > > Since kernel 5.4 and mips support for generic vDSO [2], the kernel fail to > build for mips r6 cpus with gcc 10 for the same reason as glibc. > > [1] https://sourceware.org/git/?p=glibc.git;a=commit;h=020b2a97bb15f807c0482f0faee2184ed05bcad8 > [2] '24640f233b46 ("mips: Add support for generic vDSO")' > > Signed-off-by: Romain Naour > Signed-off-by: Sudip Mukherjee > --- > > v4: [sudip] added macro VDSO_SYSCALL_CLOBBERS and fix checkpatch errors with commit message. > v3 Avoid duplicate code (Maciej W. Rozycki) > v2 use MIPS_ISA_REV instead of __mips_isa_rev (Alexander Lobakin) > > I have reused the original patch by Romain and have retained his s-o-b > and author name as he is the original author of this patch. I have just > added the macro. Build tested with gcc-10.3.1 and gcc-9.3.0. > > arch/mips/include/asm/vdso/gettimeofday.h | 26 ++++++++++++++++++----- > 1 file changed, 21 insertions(+), 5 deletions(-) applied to mips-next. Thomas. -- Crap can work. Given enough thrust pigs will fly, but it's not necessarily a good idea. [ RFC1925, 2.3 ]