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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 41D46C433F5 for ; Wed, 9 Mar 2022 16:34:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date: Message-ID:From:References:Cc:To:Subject:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=A2E/kEdNpouSs7P2t5261d6CWBzjQKXw+LAXbwH67KI=; b=B85aAwy7NGd0p+/n/h8xv52Ypm 6j8Ddo8H9P8b+4npgJA4MCMKRUtcTBwVljHS1NSPGxyVevmg+Dhdq8O4VNU1Ufk2HxAUOxghlw7JX OFETTg5Cbsv3QwvaZ+6xtG135xQo6TRj5yhnup8LgHYFq8UWsf7zzLuR0ABmzwNtU6bflDbjOlPj5 DZTa77U5mONO6hMDpWXN+pWGd/5eB/4m5cq+WQJjpmQPS/+e8aTzkeOFi3i6fa0EzT1dj4w0vwb1H YbPJCIgw8TSUkpoIz9WB6CpbGr4vwWZ+VYNLkQII/IXJ/dCc8TUv0BqgM2NfP8RAMbyMd6ub5Y7+W Gxg+Ii5A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nRzBR-009QFA-VK; Wed, 09 Mar 2022 16:29:06 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nRz4O-009MDf-GA for linux-arm-kernel@lists.infradead.org; Wed, 09 Mar 2022 16:21:50 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 6D154168F; Wed, 9 Mar 2022 08:21:45 -0800 (PST) Received: from [10.1.29.144] (e121487-lin.cambridge.arm.com [10.1.29.144]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 573453F7F5; Wed, 9 Mar 2022 08:21:42 -0800 (PST) Subject: Re: [PATCH 2/2] ARM: remove support for NOMMU ARMv4/v5 To: Arnd Bergmann , Robin Murphy Cc: Russell King , Linus Walleij , Arnd Bergmann , kernel test robot , Thomas Gleixner , Marc Zyngier , Ard Biesheuvel , Andrew Morton , Mark Rutland , Linux ARM , Linux Kernel Mailing List , "Russell King (Oracle)" , Anshuman Khandual References: <20220309144138.360482-1-arnd@kernel.org> <20220309144138.360482-2-arnd@kernel.org> <27250b4e-cf04-0dab-d658-bb472face5ea@arm.com> From: Vladimir Murzin Message-ID: <08232117-7444-55d8-e13c-b49828c8f3e9@arm.com> Date: Wed, 9 Mar 2022 16:21:39 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220309_082148_707084_C40D27CF X-CRM114-Status: GOOD ( 22.83 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 3/9/22 4:17 PM, Arnd Bergmann wrote: > On Wed, Mar 9, 2022 at 4:48 PM Robin Murphy wrote: >> >> On 2022-03-09 14:40, Arnd Bergmann wrote: >>> From: Arnd Bergmann >>> >>> It is possible to build MMU-less kernels for Cortex-M base >>> microcrontrollers as well as a couple of older platforms that >>> have not been converted to CONFIG_ARCH_MULTIPLATFORM, >>> specifically ep93xx, footbridge, dove, sa1100 and s3c24xx. >>> >>> It seems unlikely that anybody has tested those configurations >>> in recent years, as even building them is frequently broken. >>> A patch I submitted caused another build time regression >>> in this configuration. I sent a patch for that, but it seems >>> better to also remove the option entirely, leaving ARMv7-M >>> as the only supported Arm NOMMU target for simplicity. >> >> In that case, it would probably make sense to garbage-collect all the >> configs, setup code and other stuff relating to older MMU-less CPU cores >> like ARM1156, ARM940, etc. at the same time. > > Right, good idea. These are only selected by CONFIG_ARCH_INTEGRATOR, > but that in turn doesn't build for CONFIG_MMU=n because it depends on > ARCH_MULTIPLATFORM. I'll send a patch for these. > > I also went back and forth between removing the #ifdefs in > arch/arm/mm/proc-*.S for this patch, though I did not do that in the end. > We may still want them at least for proc-v7.S because that is a small > chance that someone will want to support Cortex-R. > I'd appreciate if you keep them since I run Cortex-R52... Cheers Vladimir > Arnd > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel