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=-1.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, URIBL_BLOCKED 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 8DE40C43381 for ; Sun, 17 Mar 2019 15:44:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5F1F321019 for ; Sun, 17 Mar 2019 15:44:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=agner.ch header.i=@agner.ch header.b="uitkFEjt" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727395AbfCQPor (ORCPT ); Sun, 17 Mar 2019 11:44:47 -0400 Received: from mail.kmu-office.ch ([178.209.48.109]:54922 "EHLO mail.kmu-office.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727043AbfCQPoq (ORCPT ); Sun, 17 Mar 2019 11:44:46 -0400 Received: from webmail.kmu-office.ch (unknown [IPv6:2a02:418:6a02::a3]) by mail.kmu-office.ch (Postfix) with ESMTPSA id 540675C2373; Sun, 17 Mar 2019 16:44:44 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=agner.ch; s=dkim; t=1552837484; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=1Kpro2NFMAD0NxEc2llmKLzygnZGmnEvQNupn985gnY=; b=uitkFEjtDC4ABFjtaYDlGf3AtNpYqPhMuWaQwGswv4XwrpC7eb7VpPIuQRKMOi0S7tSTn+ Pl8449HSu2pGG10ByG8ncWXk+xunPX79YexbSxqvFIpKbCroMicJakAyVfRjIfvihmcUbL T300wdwHpZ7YMyj3uO2PBXnbnPNeH2w= MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Date: Sun, 17 Mar 2019 16:44:44 +0100 From: Stefan Agner To: Nick Desaulniers Cc: Robin Murphy , Russell King , Nicolas Pitre , Mark Rutland , Arnd Bergmann , Ard Biesheuvel , Will Deacon , julien.thierry@arm.com, LKML , Thierry Reding , Nathan Chancellor , Linux ARM , Kristof Beyls , Peter Smith Subject: Re: [PATCH 1/2] ARM: drop unnecessary WASM In-Reply-To: References: <13835555f8ef44b21d1b7ddfe1c4203d0981f77e.1551824161.git.stefan@agner.ch> Message-ID: X-Sender: stefan@agner.ch User-Agent: Roundcube Webmail/1.3.7 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06.03.2019 01:47, Nick Desaulniers wrote: > On Tue, Mar 5, 2019 at 3:39 PM Robin Murphy wrote: >> >> Hi Stefan, >> >> On 2019-03-05 10:18 pm, Stefan Agner wrote: >> > The W macro for generating wide instructions when targeting Thumb-2 >> > is not required for the preload data instructions (pld, pldw) since >> > they are only available as wide instructions. The GNU assembler seems >> > to work with or without the .w appended when compiling an Thumb-2 >> > kernel. However, Clang's integrated assembler does not consider the >> > .w variants as valid instructions: >> > >> > ./arch/arm/include/asm/processor.h:133:5: error: invalid instruction >> > "pldw.w\t%a0 \n" >> > ^ >> > :2:1: note: instantiated into assembly here >> > pldw.w [r0] >> > ^ >> > 1 error generated. >> >> Have you filed a bug against Clang for that? Something like "pldwal.w" > > Yes; please. For each deficiency you find, please file a bug. We're > working on identifying what's missing from Clang's integrated > assembler support. Given the list of issues, it's easier to estimate > how much effort is needed, which helps us allocate resources towards > fixing those issues better. > > It would be good to know if pldw.w is valid under UAL or not. As far as I understand the Arm ARM it is valid under UAL. Reported a bug in LLVM's bug tracker: https://bugs.llvm.org/show_bug.cgi?id=40972 Will send a v2 patch mentioning this is really a work around for LLVM and link to the bug report. > > Hopefully, the ARM kernel team can stress the importance of assembler > support for their ISA to their LLVM team. -- Stefan