From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753379AbcGLLI1 (ORCPT ); Tue, 12 Jul 2016 07:08:27 -0400 Received: from foss.arm.com ([217.140.101.70]:58420 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751141AbcGLLI0 (ORCPT ); Tue, 12 Jul 2016 07:08:26 -0400 Date: Tue, 12 Jul 2016 12:08:28 +0100 From: Will Deacon To: Suzuki K Poulose Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Steve Capper , Catalin Marinas , Mark Rutland Subject: Re: [PATCH v9] arm64: cpuinfo: Expose MIDR_EL1 and REVIDR_EL1 to sysfs Message-ID: <20160712110827.GB18408@arm.com> References: <1467990073-27462-1-git-send-email-suzuki.poulose@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1467990073-27462-1-git-send-email-suzuki.poulose@arm.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jul 08, 2016 at 04:01:13PM +0100, Suzuki K Poulose wrote: > From: Steve Capper > > It can be useful for JIT software to be aware of MIDR_EL1 and > REVIDR_EL1 to ascertain the presence of any core errata that could > affect code generation. > > This patch exposes these registers through sysfs: > > /sys/devices/system/cpu/cpu$ID/regs/identification/midr_el1 > /sys/devices/system/cpu/cpu$ID/regs/identification/revidr_el1 > > where $ID is the cpu number. For big.LITTLE systems, one can have a > mixture of cores (e.g. Cortex A53 and Cortex A57), thus all CPUs need > to be enumerated. > > If the kernel does not have valid information to populate these entries > with, an empty string is returned to userspace. > > Cc: Catalin Marinas > Cc: Will Deacon > Cc: Mark Rutland > Signed-off-by: Steve Capper > [ ABI documentation updates, hotplug notifiers, kobject changes ] > Signed-off-by: Suzuki K Poulose Looks good to me, thanks for sticking with it: Reviewed-by: Will Deacon Will