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 lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 4A0FBCDB482 for ; Mon, 16 Oct 2023 16:36:25 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.617879.960954 (Exim 4.92) (envelope-from ) id 1qsQZe-0005ge-Jx; Mon, 16 Oct 2023 16:36:10 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 617879.960954; Mon, 16 Oct 2023 16:36:10 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1qsQZe-0005gX-HL; Mon, 16 Oct 2023 16:36:10 +0000 Received: by outflank-mailman (input) for mailman id 617879; Mon, 16 Oct 2023 16:36:09 +0000 Received: from se1-gles-sth1-in.inumbo.com ([159.253.27.254] helo=se1-gles-sth1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1qsQZd-0005gR-Ks for xen-devel@lists.xenproject.org; Mon, 16 Oct 2023 16:36:09 +0000 Received: from support.bugseng.com (mail.bugseng.com [162.55.131.47]) by se1-gles-sth1.inumbo.com (Halon) with ESMTPS id 183239b9-6c42-11ee-98d4-6d05b1d4d9a1; Mon, 16 Oct 2023 18:36:02 +0200 (CEST) Received: from support.bugseng.com (support.bugseng.com [162.55.131.47]) by support.bugseng.com (Postfix) with ESMTPA id 202D34EE0737; Mon, 16 Oct 2023 18:36:02 +0200 (CEST) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 183239b9-6c42-11ee-98d4-6d05b1d4d9a1 MIME-Version: 1.0 Date: Mon, 16 Oct 2023 18:36:02 +0200 From: Nicola Vetrini To: Jan Beulich Cc: sstabellini@kernel.org, michal.orzel@amd.com, xenia.ragiadakou@amd.com, ayan.kumar.halder@amd.com, consulting@bugseng.com, andrew.cooper3@citrix.com, roger.pau@citrix.com, Wei Liu , xen-devel@lists.xenproject.org Subject: Re: [XEN PATCH][for-next v2 5/8] x86/io_apic: address violation of MISRA C:2012 Rule 10.1 In-Reply-To: <262b878b-578f-451a-6e7d-18af4a826848@suse.com> References: <1fe7602b48cabb7710025f6b4e32e9b99a1faacd.1697123806.git.nicola.vetrini@bugseng.com> <262b878b-578f-451a-6e7d-18af4a826848@suse.com> User-Agent: Roundcube Webmail/1.4.3 Message-ID: X-Sender: nicola.vetrini@bugseng.com Organization: BUGSENG s.r.l. Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit On 16/10/2023 17:42, Jan Beulich wrote: > On 12.10.2023 17:28, Nicola Vetrini wrote: >> The definition of IO_APIC_BASE contains a sum of an essentially enum >> value (FIX_IO_APIC_BASE_0) that is positive with an index that, in all >> instances, is unsigned, therefore the former is cast to unsigned, so >> that >> the operands are of the same essential type. >> >> No functional change. >> --- >> xen/arch/x86/include/asm/io_apic.h | 7 ++++--- >> 1 file changed, 4 insertions(+), 3 deletions(-) >> >> diff --git a/xen/arch/x86/include/asm/io_apic.h >> b/xen/arch/x86/include/asm/io_apic.h >> index a7e4c9e146de..a0fc50d601fe 100644 >> --- a/xen/arch/x86/include/asm/io_apic.h >> +++ b/xen/arch/x86/include/asm/io_apic.h >> @@ -14,9 +14,10 @@ >> * Copyright (C) 1997, 1998, 1999, 2000 Ingo Molnar >> */ >> >> -#define IO_APIC_BASE(idx) >> \ >> - ((volatile uint32_t *)(__fix_to_virt(FIX_IO_APIC_BASE_0 + (idx)) >> \ >> - + (mp_ioapics[idx].mpc_apicaddr & >> ~PAGE_MASK))) >> +#define IO_APIC_BASE(idx) \ >> + ((volatile uint32_t *) \ >> + (__fix_to_virt((unsigned int)FIX_IO_APIC_BASE_0 + (idx)) \ >> + + (mp_ioapics[idx].mpc_apicaddr & ~PAGE_MASK))) > > Let's assume that down the road we want to make __fix_to_virt() an > inline > function (which perhaps it really ought to be already): Won't this > trade > one violation for another then? I don't think so: the violation is in the argument to the macro (i.e., the fact that idx is unsigned and FIX_IO_APIC_BASE_0 is a constant from a named enum). Do you see a way in which a MISRA rule is violated if __fix_to_virt becomes a function with an unsigned int argument? > I wonder whether the better course of > action wouldn't be to switch the two enums to be "anonymous", even if > that > means adjusting __set_fixmap() and __set_fixmap_x(). > I don't know. It certainly would help from a violation count perspective, though that's more of a code style decision in my opinion. > As an aside, since you touch the entire construct, it would be nice if > the > + was also moved to the end of the earlier line. > Sure -- Nicola Vetrini, BSc Software Engineer, BUGSENG srl (https://bugseng.com)