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=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 6B17FC43460 for ; Fri, 21 May 2021 10:42:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4A265613D8 for ; Fri, 21 May 2021 10:42:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231493AbhEUKnZ (ORCPT ); Fri, 21 May 2021 06:43:25 -0400 Received: from mail.kernel.org ([198.145.29.99]:37268 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230480AbhEUKnY (ORCPT ); Fri, 21 May 2021 06:43:24 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9B4FD6008E; Fri, 21 May 2021 10:41:58 +0000 (UTC) Date: Fri, 21 May 2021 11:41:56 +0100 From: Catalin Marinas To: Will Deacon Cc: linux-arm-kernel@lists.infradead.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, Marc Zyngier , Greg Kroah-Hartman , Peter Zijlstra , Morten Rasmussen , Qais Yousef , Suren Baghdasaryan , Quentin Perret , Tejun Heo , Li Zefan , Johannes Weiner , Ingo Molnar , Juri Lelli , Vincent Guittot , "Rafael J. Wysocki" , kernel-team@android.com Subject: Re: [PATCH v6 02/21] arm64: Allow mismatched 32-bit EL0 support Message-ID: <20210521104155.GC6675@arm.com> References: <20210518094725.7701-1-will@kernel.org> <20210518094725.7701-3-will@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210518094725.7701-3-will@kernel.org> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 18, 2021 at 10:47:06AM +0100, Will Deacon wrote: > +static int enable_mismatched_32bit_el0(unsigned int cpu) > +{ > + struct cpuinfo_arm64 *info = &per_cpu(cpu_data, cpu); > + bool cpu_32bit = id_aa64pfr0_32bit_el0(info->reg_id_aa64pfr0); > + > + if (cpu_32bit) { > + cpumask_set_cpu(cpu, cpu_32bit_el0_mask); > + static_branch_enable_cpuslocked(&arm64_mismatched_32bit_el0); It may be worth only calling static_branch_enable_cpuslocked() if not already set, in case you try this on a system with lots of CPUs. -- Catalin 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=-5.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 5F7ACC433B4 for ; Fri, 21 May 2021 10:43:42 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 2AF276008E for ; Fri, 21 May 2021 10:43:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2AF276008E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=desiato.20200630; h=Sender:Content-Transfer-Encoding :Content-Type:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=lUP8rVJp0xECPwTqdHrKGrZynyyY7NtEqxDZLhcomFw=; b=fvl9dLOiti+hAk1s1L6H+Mdc8F axMTT6mGtZHoIgoLbVA0Tm8v64Uu80UpoNXgObOSAe8PWfZUnZ7EgWGR3DUFxiFdqWLsMYvbulia4 J+97QpOpYUOsyRvslegOXvYxTOBFZodyrVj8FnB11l71X5cbH7h1qo2iNvyn4TrK3VlYbixnefZV9 vfWHABMwoneavrqvFEokPaSK5JCZN6GGD//xVjKAcG6bjJ39sa19cynxkni24JhiMWfHWVs27d897 ZddrmZfg0rqLybLOcGYrRXPdgv0QkF1hJXMFM/PXRYZ7ReYFocM1+/CRCWOJI380i0gYKGQ3NtGyB TWJArg9Q==; Received: from localhost ([::1] helo=desiato.infradead.org) by desiato.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1lk2bX-004ymO-RM; Fri, 21 May 2021 10:42:08 +0000 Received: from bombadil.infradead.org ([2607:7c80:54:e::133]) by desiato.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1lk2bV-004ylw-Eb for linux-arm-kernel@desiato.infradead.org; Fri, 21 May 2021 10:42:05 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=fhXOCZ+K4t0KstlUHCJRDT6dGSnzKHHd+KC5/a3/tnc=; b=dtE2OS7TYpoqodJAwO7Faz7Jyi QuS4ueDqIi0+D/spJYFzQOElY3ghx6dg+eTeNYTydjoORq+5WN7UXzSgYrlixsOTnc1pEL9K7cgUq fiOfdFgB+l0eEni/1r4LqGEI3fbTWGr10eJM++nG6wMOnJ8GamsJ+rpSLTlOouHasH/ofBY01s5gr ZRNcUMawZOyZLZsc7qz8GayzKDp0jQQU7npnvY8Tsj9J8d2lY5hQwO/mKL80uBMBwZDYi6OxtF/zY rUj3hl+SZuXAqoJih+iGwJpE1gUsk5/0UhtmwUclxIf5B5ywYcIdjAnkZSRbuH09PLmlukN4zqU0C QnG2Hqtw==; Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lk2bS-00H2rt-QV for linux-arm-kernel@lists.infradead.org; Fri, 21 May 2021 10:42:04 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9B4FD6008E; Fri, 21 May 2021 10:41:58 +0000 (UTC) Date: Fri, 21 May 2021 11:41:56 +0100 From: Catalin Marinas To: Will Deacon Cc: linux-arm-kernel@lists.infradead.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, Marc Zyngier , Greg Kroah-Hartman , Peter Zijlstra , Morten Rasmussen , Qais Yousef , Suren Baghdasaryan , Quentin Perret , Tejun Heo , Li Zefan , Johannes Weiner , Ingo Molnar , Juri Lelli , Vincent Guittot , "Rafael J. Wysocki" , kernel-team@android.com Subject: Re: [PATCH v6 02/21] arm64: Allow mismatched 32-bit EL0 support Message-ID: <20210521104155.GC6675@arm.com> References: <20210518094725.7701-1-will@kernel.org> <20210518094725.7701-3-will@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210518094725.7701-3-will@kernel.org> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210521_034202_901622_D26BAACC X-CRM114-Status: GOOD ( 10.65 ) 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 Tue, May 18, 2021 at 10:47:06AM +0100, Will Deacon wrote: > +static int enable_mismatched_32bit_el0(unsigned int cpu) > +{ > + struct cpuinfo_arm64 *info = &per_cpu(cpu_data, cpu); > + bool cpu_32bit = id_aa64pfr0_32bit_el0(info->reg_id_aa64pfr0); > + > + if (cpu_32bit) { > + cpumask_set_cpu(cpu, cpu_32bit_el0_mask); > + static_branch_enable_cpuslocked(&arm64_mismatched_32bit_el0); It may be worth only calling static_branch_enable_cpuslocked() if not already set, in case you try this on a system with lots of CPUs. -- Catalin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel