From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752100AbdI1Ezz (ORCPT ); Thu, 28 Sep 2017 00:55:55 -0400 Received: from mail-pg0-f52.google.com ([74.125.83.52]:46480 "EHLO mail-pg0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751591AbdI1Ezx (ORCPT ); Thu, 28 Sep 2017 00:55:53 -0400 X-Google-Smtp-Source: AOwi7QBngCc2KGQCx09qENE46XcAJo3tZ23zlURunjAcELYn81dhQ/GIu5OmBG6uaAxSirV4xaDN6w== Subject: Re: [PATCH] sparc: Provide cmpxchg64 for 32-bit builds To: David Miller Cc: sparclinux@vger.kernel.org, linux-kernel@vger.kernel.org References: <1506274171-28423-1-git-send-email-linux@roeck-us.net> <20170927.213812.1333158312684109871.davem@davemloft.net> From: Guenter Roeck Message-ID: <92d872fa-cdde-3e1d-9e2e-0722c9480bbd@roeck-us.net> Date: Wed, 27 Sep 2017 21:55:50 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.3.0 MIME-Version: 1.0 In-Reply-To: <20170927.213812.1333158312684109871.davem@davemloft.net> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/27/2017 09:38 PM, David Miller wrote: > From: Guenter Roeck > Date: Sun, 24 Sep 2017 10:29:31 -0700 > >> Fix the following build error, seen when building sparc32:allmodconfig. >> >> drivers/net/ethernet/intel/i40e/i40e_ethtool.c: >> In function 'i40e_set_priv_flags': >> drivers/net/ethernet/intel/i40e/i40e_ethtool.c:4150:2: error: >> implicit declaration of function 'cmpxchg64' >> >> Signed-off-by: Guenter Roeck > > That fixes the build: > >> @@ -72,5 +72,6 @@ __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new_, int size) >> ((__typeof__(*(ptr)))__cmpxchg_local_generic((ptr), (unsigned long)(o),\ >> (unsigned long)(n), sizeof(*(ptr)))) >> #define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n)) >> +#define cmpxchg64(ptr, o, n) cmpxchg64_local((ptr), (o), (n)) >> >> #endif /* __ARCH_SPARC_CMPXCHG__ */ > > but it's wrong. cmpxchg64_local() is only atomic on the current cpu > so using it for plain cmpxchg64() is not going to work. > Yeah, I was concerned about that. My bad. Unfortunately I don't know enough about sparc to provide a better solution. Consider this a problem report, then. Guenter