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 A5590C433F5 for ; Fri, 3 Dec 2021 17:02:55 +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=mIY5hP7XuujY4E79T9OnGoOpw+ZQZX4rg/xkyKmxBZQ=; b=giHwwEzuo4QOq8Hmx+Amo73aPq 7Psp0Eqvqupn9VzmEKIpfR6OwRJjGrm2oah4tM4btiW2xvCbg9MdNlOkZVgAkQqOgtqOpcI88t5Im +ZdWVtwYV/CEmfgts6gwF7K1io0BKiQ7NoRh6n1y0odVgBsBje+AMalabVPpuDthqxBeuERuF5aQU ENnaFqZI6FQyLvwcAcLlNNfx1w8FazM1zZjN74KyMDGV94vPfATK9oqNJCrgWj3iWSJPXhQkZiauv 0rbJ2DuaV7Xj57ifjVjuOHwrJatulQV+rnr8pmCqMBkIN/HenWJTdGDPIuKvDwanE6kZxeUkhWzji dpjym7Cw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mtBvt-00GchY-NW; Fri, 03 Dec 2021 17:01:13 +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 1mtBvp-00GcgU-Lp for linux-arm-kernel@lists.infradead.org; Fri, 03 Dec 2021 17:01:11 +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 71C801435; Fri, 3 Dec 2021 09:01:06 -0800 (PST) Received: from [10.57.0.218] (unknown [10.57.0.218]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 4B0203F73B; Fri, 3 Dec 2021 09:01:04 -0800 (PST) Subject: Re: [PATCH] ARM: Kconfig: improve ARM_SINGLE_ARMV7M description with Cortex M7 To: Giulio Benetti , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: Russell King , Arnd Bergmann , Linus Walleij , Andrew Morton , "Russell King (Oracle)" , Ard Biesheuvel , Mark Rutland , Anshuman Khandual , Geert Uytterhoeven , Mike Rapoport , =?UTF-8?Q?Uwe_Kleine-K=c3=b6nig?= , Lukas Bulwahn References: <20211202222002.33456-1-giulio.benetti@benettiengineering.com> <170aea55-44f3-9cf0-fd88-adf8c66efeb4@benettiengineering.com> From: Vladimir Murzin Message-ID: Date: Fri, 3 Dec 2021 17:01:05 +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: <170aea55-44f3-9cf0-fd88-adf8c66efeb4@benettiengineering.com> Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211203_090109_820970_00E52ABE X-CRM114-Status: GOOD ( 22.54 ) 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 12/3/21 4:41 PM, Giulio Benetti wrote: > Hi Vladimir, > > On 03/12/21 10:30, Vladimir Murzin wrote: >> On 12/2/21 10:20 PM, Giulio Benetti wrote: >>> ARM_SINGLE_ARMV7M implies Arm Cortex M7 too, so let's add it to >>> description with M0/M3/M4. >> >> Well it also implies M33 and M55. I'd suggest drop specific implementations >> from description - so we do not need to update it each time new compatible >> core is released. To account newest cores like M33 and M55 you can rephrase >> to: >> - ARMv7-M/v8-M > > This ^^^ is ok for me. Also, I don't see any M0 used at the moment so no ARMv6-M makes sense, if any in the future we can update. I see M3,M4,M7 for the moment, so ARMv7-M. But at the moment no ARMv8-M, or am I wrong? We already support PMSAv8 which is ARMv8-M, M33/M55 is in flight [1]. > Maybe it would be better to add ARMv8-M when there will really be the support, considering also that ARM_SINGLE_ARMV7M is a bit ambiguous to be used with ARMv8-M. So maybe that could be modified too when an ARMv8-M is added. > > What do you think about this? Well, I prefer to touch this as rare as possible, and if we touch it then ensure we do not need to touch it for a long time ;) Look at A-class cores, config ARCH_MULTI_V7 bool "ARMv7 based platforms (Cortex-A, PJ4, Scorpion, Krait)" it doesn't mention ARMv8, yet it is pretty much possible to run it on some cores either bare-metal or as a guest (just look under arch/arm/include/asm/cputype.h) These are just config options, not a legal deeds... [1] https://lore.kernel.org/linux-arm-kernel/20211201132908.106711-1-vladimir.murzin@arm.com/T/ Cheers Vladimir > > Best regards _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel