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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no 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 44437C73C42 for ; Tue, 9 Jul 2019 12:18:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0E80C2082A for ; Tue, 9 Jul 2019 12:18:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="f4xWJs1r" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726284AbfGIMSL (ORCPT ); Tue, 9 Jul 2019 08:18:11 -0400 Received: from mail-lj1-f194.google.com ([209.85.208.194]:44097 "EHLO mail-lj1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726025AbfGIMSL (ORCPT ); Tue, 9 Jul 2019 08:18:11 -0400 Received: by mail-lj1-f194.google.com with SMTP id k18so19326918ljc.11 for ; Tue, 09 Jul 2019 05:18:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=TYUZq7v6hg9F7A7hhMPEbsURdusM+toQNt32J9GD77k=; b=f4xWJs1rkxhdZh6VKdTdoooCK03zPhYeu+utI5sLkxuMNNpq6JFZhCp6qlUvf2anbR bnD9Q16qqv4Dm6uP/sjy7HzUwVXVlXoVh5/xKv+25+7zR0BYqnxeW8uOzgshPKsIQvOF Mjtc5D/3WIRJy38LPeT9tu8iyOvc7OBDwEMukvnU3H2/czGHc8iId4gxHDRSwFZCU+2h KsDrxHQju99B34OL34vf21WFKzZ3D2AjR6FZXoyTwPxt4rFfTHvu3HA3oinCcy3Rvbhj vjfLPUH/gcYvmOpCnAmdNLX3i+9t7aI0sJJdllF/IqXMETEQhgSlmnvmWjKANEgCW2Xa r3rw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=TYUZq7v6hg9F7A7hhMPEbsURdusM+toQNt32J9GD77k=; b=lDWIaxIiVWl83C3PBb98DTP7l9oqdsQeil7pmqt48SfOmkbWbsISArWR0u2o9ftq07 e96HWp2ZnODjhN8nNuDsmpPQY92ArqEEvpPB/GUNPRXCFwke7z99+d/Z5JktTa8vpsKr sr99Kz/m9NRd+vA3tlgNYdsFBNmZje0TBrTKPs658JL2G8wqjWOXv6qqOzeiiC8PxiJs 9qJvmfB4LXoiy0mrsl9OVLscdLT+W00JauUtFBa0mVEq+ePyoQP6WKzP5JqZZc7E+e/+ eTvbrofLkfHovcy9+3Cm8+6ArerNXCS7SrKc1NGdd/Wx4ntnWaiVZz5WsXfjwhmgLKX3 U3HA== X-Gm-Message-State: APjAAAVNS2ir6PBLk+3IkexmNqh208189Hq4tdf8mOa0H/hr3Gz6ELLc SQXqv56du2FPLTfOaMGAoUys03tN3AR2TBNK/1ondvupfRM= X-Google-Smtp-Source: APXvYqy1qu2+l+YL5DOsxvjmzznPXi+BVdOsWmKyCR6/5tRMWSNFkxo+m/lnuvORd/QmhWM+XBF+DRoi2gMuPj5dv8E= X-Received: by 2002:a2e:9593:: with SMTP id w19mr10559143ljh.69.1562674690149; Tue, 09 Jul 2019 05:18:10 -0700 (PDT) MIME-Version: 1.0 References: <20190708203049.3484750-1-arnd@arndb.de> In-Reply-To: <20190708203049.3484750-1-arnd@arndb.de> From: Linus Walleij Date: Tue, 9 Jul 2019 14:17:58 +0200 Message-ID: Subject: Re: [PATCH] ARM: mtd-xip: work around clang/llvm bug To: Arnd Bergmann Cc: Russell King , Linux ARM , "linux-kernel@vger.kernel.org" , clang-built-linux@googlegroups.com Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 8, 2019 at 10:31 PM Arnd Bergmann wrote: > -#define xip_iprefetch() do { asm volatile (".rep 8; nop; .endr"); } while (0) > +#define xip_iprefetch() do { \ > + asm volatile ("nop; nop; nop; nop; nop; nop; nop; nop;"); \ > +} while (0) \ This is certainly an OK fix since we use a row of inline nop at other places. However after Russell explained the other nops I didn't understand I located these in boot/compressed/head.S as this in __start: .rept 7 __nop .endr #ifndef CONFIG_THUMB2_KERNEL mov r0, r0 #else And certainly this gets compiled, right? So does .rept/.endr work better than .rep/.endr, is it simply mis-spelled? I.e. s/.rep/.rept/g ? In that case we should explain in the commit that .rep doesn't work but .rept does. Yours, Linus Walleij