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 E8369C433F5 for ; Thu, 26 May 2022 02:40:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231135AbiEZCkp (ORCPT ); Wed, 25 May 2022 22:40:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56338 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229928AbiEZCko (ORCPT ); Wed, 25 May 2022 22:40:44 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9878D6621A for ; Wed, 25 May 2022 19:40:42 -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 ams.source.kernel.org (Postfix) with ESMTPS id 0C4F2B81E6C for ; Thu, 26 May 2022 02:40:41 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2BCD5C385B8; Thu, 26 May 2022 02:40:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1653532839; bh=Nekco3mEdzmOoGYbr+l5+JxZcWOSAqhdgYQ+UjDVSz8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=MR5z7y1ZVGstMnPmq97lSE3kBPaVat/Rm/kjPHJ4cU3joo6Ufz6DNkHJr1g64XVu2 zyMzVlnsk/GqSqPnX3+l5tQ2d/Pax4ByeTLrbEWnYIRYPvsCMJXmvZUpeB16tyRUB1 Qm7oYRFUhP2q30+ivW2xBMrH+hyyNRM+nrxrxiztWNkqVJx7X8d2pw8EgUXUAPsEQ8 m3654klQQlJun3gVn2B4T+4Pf0BqKqdEoB1f5L+21up5imWq07E7AKxQQDAXIvCrdv ut+72EmMGbqJd6/vEhNDb8yQZi37K1eaLVzToiPIuwbAWcKz6B5IuGmE8LvIdIw5mw 7hkUX90Wmipkg== Date: Wed, 25 May 2022 19:40:37 -0700 From: Nathan Chancellor To: Paul Walmsley , Palmer Dabbelt , Albert Ou Cc: Nick Desaulniers , Heiko Stuebner , linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev, patches@lists.linux.dev, Jessica Clarke Subject: Re: [PATCH] riscv: Fix ALT_THEAD_PMA's asm parameters Message-ID: References: <20220518184529.454008-1-nathan@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220518184529.454008-1-nathan@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Small ping on this and https://lore.kernel.org/20220516214520.3252074-1-nathan@kernel.org/. Our builds on -next have been broken for a week now. Hopefully these can make the first RISC-V pull request to avoid mainline being broken in the same fashion. Cheers, Nathan On Wed, May 18, 2022 at 11:45:29AM -0700, Nathan Chancellor wrote: > After commit a35707c3d850 ("riscv: add memory-type errata for T-Head"), > builds with LLVM's integrated assembler fail like: > > In file included from arch/riscv/kernel/asm-offsets.c:10: > In file included from ./include/linux/mm.h:29: > In file included from ./include/linux/pgtable.h:6: > In file included from ./arch/riscv/include/asm/pgtable.h:114: > ./arch/riscv/include/asm/pgtable-64.h:210:2: error: invalid input constraint '0' in asm > ALT_THEAD_PMA(prot_val); > ^ > ./arch/riscv/include/asm/errata_list.h:88:4: note: expanded from macro 'ALT_THEAD_PMA' > : "0"(_val), \ > ^ > > This was reported upstream to LLVM where Jessica pointed out a couple of > issues with the existing implementation of ALT_THEAD_PMA: > > * t3 is modified but not listed in the clobbers list. > > * "+r"(_val) marks _val as both an input and output of the asm but then > "0"(_val) marks _val as an input matching constraint, which does not > make much sense in this situation, as %1 is not actually used in the > asm and matching constraints are designed to be used for different > inputs that need to use the same register. > > Drop the matching contraint and shift all the operands by one, as %1 is > unused, and mark t3 as clobbered. This resolves the build error and goes > not cause any problems with GNU as. > > Fixes: a35707c3d850 ("riscv: add memory-type errata for T-Head") > Link: https://github.com/ClangBuiltLinux/linux/issues/1641 > Link: https://github.com/llvm/llvm-project/issues/55514 > Link: https://gcc.gnu.org/onlinedocs/gcc/Simple-Constraints.html > Suggested-by: Jessica Clarke > Signed-off-by: Nathan Chancellor > --- > arch/riscv/include/asm/errata_list.h | 14 +++++++------- > 1 file changed, 7 insertions(+), 7 deletions(-) > > diff --git a/arch/riscv/include/asm/errata_list.h b/arch/riscv/include/asm/errata_list.h > index 9e2888dbb5b1..416ead0f9a65 100644 > --- a/arch/riscv/include/asm/errata_list.h > +++ b/arch/riscv/include/asm/errata_list.h > @@ -75,20 +75,20 @@ asm volatile(ALTERNATIVE( \ > "nop\n\t" \ > "nop\n\t" \ > "nop", \ > - "li t3, %2\n\t" \ > - "slli t3, t3, %4\n\t" \ > + "li t3, %1\n\t" \ > + "slli t3, t3, %3\n\t" \ > "and t3, %0, t3\n\t" \ > "bne t3, zero, 2f\n\t" \ > - "li t3, %3\n\t" \ > - "slli t3, t3, %4\n\t" \ > + "li t3, %2\n\t" \ > + "slli t3, t3, %3\n\t" \ > "or %0, %0, t3\n\t" \ > "2:", THEAD_VENDOR_ID, \ > ERRATA_THEAD_PBMT, CONFIG_ERRATA_THEAD_PBMT) \ > : "+r"(_val) \ > - : "0"(_val), \ > - "I"(_PAGE_MTMASK_THEAD >> ALT_THEAD_PBMT_SHIFT), \ > + : "I"(_PAGE_MTMASK_THEAD >> ALT_THEAD_PBMT_SHIFT), \ > "I"(_PAGE_PMA_THEAD >> ALT_THEAD_PBMT_SHIFT), \ > - "I"(ALT_THEAD_PBMT_SHIFT)) > + "I"(ALT_THEAD_PBMT_SHIFT) \ > + : "t3") > #else > #define ALT_THEAD_PMA(_val) > #endif > > base-commit: 93c0651617a62a69717299f1464dda798af8bebb > -- > 2.36.1 > > > _______________________________________________ > linux-riscv mailing list > linux-riscv@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-riscv