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=-12.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 A2983C433B4 for ; Tue, 6 Apr 2021 10:09:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 75592613C4 for ; Tue, 6 Apr 2021 10:09:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233995AbhDFKJn (ORCPT ); Tue, 6 Apr 2021 06:09:43 -0400 Received: from mout.gmx.net ([212.227.15.15]:42401 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233604AbhDFKJm (ORCPT ); Tue, 6 Apr 2021 06:09:42 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1617703768; bh=8BFgwwQsCdpZB3KEkBauG0JI1pthdfTr1AMrrHOMCU4=; h=X-UI-Sender-Class:Subject:To:Cc:References:From:Date:In-Reply-To; b=Pb/LIDXHOkmFGq19jLe5HlMh4Rp+H7shmdi4SwxwRYrv5TonK6vhDB1Uj3EPKCbIY Ik+bI3d5MmYAM8/eQCQ6nOCRx3BqVkCvNN/Q76Hj2XsKubHBnRz2n9OtxBEmIp66UE 12ZBv8o9uiLfNZQQyVHk8/+rlXQb2jl+aVFfVp50= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from [192.168.20.60] ([92.116.164.142]) by mail.gmx.net (mrgmx004 [212.227.17.190]) with ESMTPSA (Nemesis) id 1MMGN2-1lBdni2wQY-00JLiy; Tue, 06 Apr 2021 12:09:28 +0200 Subject: Re: [PATCH] parisc: avoid a warning on u8 cast for cmpxchg on u8 pointers To: Gao Xiang , linux-parisc@vger.kernel.org Cc: Liam Beguin , linux-kernel@vger.kernel.org, Gao Xiang References: <20210406045929.30331-1-xiang@kernel.org> From: Helge Deller Message-ID: Date: Tue, 6 Apr 2021 12:08:55 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: <20210406045929.30331-1-xiang@kernel.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:IMq8tYVDnfb+yXN9zYAV2GpvJp5AfJb1AhkxL3SLvTL2UXobw24 SpowhBscXc5LnCcamG0aBWy9F8LWm8uD2losKI0lhiPHMevQowWdy9UUrcof0Hn11yUGSU2 QMPCoIwuSWRijTqCtyyd9hGHC3kw2lMLvEYmmBMzQxntoWW1kal0ZxidlpsUXVALPrmmaPO id4xE9WGQVeNfJscJWyZg== X-UI-Out-Filterresults: notjunk:1;V03:K0:BX+CrpIVLRo=:zjNdnI96rrhSeSK3OIhLvY we5WvufCqUS/e6KD3GTuD1JNDG8s+7DnSDvy7PTyzwcoyVxaGPcFvsl050hXxV3k0hSqT8gGL NAJ3iP/L/+8meSIut3LNiWAEWDN9uWrB4BMen6LSpYfDFyOGOcQxcRxu7sHb42612rpFZmiT5 MpO3HeA8mgTKemzS/CZFFRe9B3/Q6NK9Peo46RrENYvUaYAX+VPzhwgHF3VQBDlvMSCObDvZd BSMipQAWPX+FNbA4Wfzp1ImFW1k5+7jhkrrM/EYDH2ttJxA8z0xFkmQVkIyqx+zeUB15jSzbp 2mgos34G+egHKyivFlQGGbZWM5wlQuNhYOiEivjLbG9oMBZAe8yFX6CjEu/GFs0G3epaQhkYM DGndoNQpEs5RYaeIpEEUa/NYS8wOKZxfjLEwlFOZurSvR5r+E2z7VnMbgIL17L4HQ7uXbTOpy TvSiBYt6is0eQfiqAIb2uu6mCE/oLCINM9XAiurj+1zQ6DZJoZLVt5GwWbi0rQQny6t1Y+9lD 6l65rNMHAXGiwZXd0L0aLsDLSA9B9TCLYuCqur5D5c1hDg9LYnPs+J89JGzFYfJTHIGLxgHwX KlBb0A3swwsx7jdZCJXGf4shq7dVLobfAqUnl4xrUlzjz2yzGOzKo5X5sQQFKVawDn92qiI1O ftO+r7Gd1hNpzAqLXADGBxshk9AJlV5Cxkw9/eSYJUNIPdjjcZK/Y6I4QII3naiRwDoXdCeBk R27EEHOAUkN2H3rusvABkYBC83+fr7fsdm+dhZx38wwzqyXIkiox7pJ/ebShzmidFHtkGHTHv gFya6uq2t7OsmXXzIP6NWWtvruLIaXAu07HrEagHcMQ4KkunYHe9O/ZTLUAZ5eOpbpmKO6OXe lnkUtv19/WXWLoT/p20sXJqYSlj1mQ3DqblvrME4sPf6B0V6/fzJkTNISWrrtgFAm67s9QMCq KbJgQ+n57R9GuSDnGivNsuwVWC8oRNm69B62p+GBbzNbZanAXDJ0bYYXkrAl3BuyHOac1nixv 885puCHz7N/+abjTBeDCQ8aDe/U5/aUUnotN9ROojviU2Gm8Mc9TsGkRaAebPO2rsog8z1fUG 9T+aw/UVK+XG6QTICQcwKcZz8sCgRbe+lXwZxFtCqlYowymS7UNb4MrREq59JZ7BA55lBvoql 0i6hyxOVZI/07eMcT4910J62a9Jp/Mu+G0+uOHnhfdUSlg4XNBL+6ucJZfRjND0sgAhC4= Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 4/6/21 6:59 AM, Gao Xiang wrote: > From: Gao Xiang > > commit b344d6a83d01 ("parisc: add support for cmpxchg on u8 pointers") > can generate a sparse warningi ("cast truncates bits from constant > value"), which has been reported several times [1] [2] [3]. > > The original code worked as expected, but anyway, let silence such > sparse warning as what others did [4]. > > [1] https://lore.kernel.org/r/202104061220.nRMBwCXw-lkp@intel.com > [2] https://lore.kernel.org/r/202012291914.T5Agcn99-lkp@intel.com > [3] https://lore.kernel.org/r/202008210829.KVwn7Xeh%25lkp@intel.com > [4] https://lore.kernel.org/r/20210315131512.133720-2-jacopo+renesas@jmo= ndi.org > Cc: Liam Beguin > Cc: Helge Deller > Signed-off-by: Gao Xiang applied to the parisc for-next git tree. (I fixed up the typo above too) Thanks! Helge > --- > arch/parisc/include/asm/cmpxchg.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/parisc/include/asm/cmpxchg.h b/arch/parisc/include/asm= /cmpxchg.h > index cf5ee9b0b393..84ee232278a6 100644 > --- a/arch/parisc/include/asm/cmpxchg.h > +++ b/arch/parisc/include/asm/cmpxchg.h > @@ -72,7 +72,7 @@ __cmpxchg(volatile void *ptr, unsigned long old, unsig= ned long new_, int size) > #endif > case 4: return __cmpxchg_u32((unsigned int *)ptr, > (unsigned int)old, (unsigned int)new_); > - case 1: return __cmpxchg_u8((u8 *)ptr, (u8)old, (u8)new_); > + case 1: return __cmpxchg_u8((u8 *)ptr, old & 0xff, new_ & 0xff); > } > __cmpxchg_called_with_bad_pointer(); > return old; >