From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756743AbbLASKY (ORCPT ); Tue, 1 Dec 2015 13:10:24 -0500 Received: from eu-smtp-delivery-143.mimecast.com ([207.82.80.143]:56719 "EHLO eu-smtp-delivery-143.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756364AbbLASKX convert rfc822-to-8bit (ORCPT ); Tue, 1 Dec 2015 13:10:23 -0500 Subject: Re: [PATCH v2 2/6] arm64: Move kill_cpu_early to smp.c To: Mark Rutland References: <1448982731-17182-1-git-send-email-suzuki.poulose@arm.com> <1448982731-17182-3-git-send-email-suzuki.poulose@arm.com> <20151201152826.GA28370@leverpostej> <565DC5DB.7070905@arm.com> <20151201163138.GA29045@leverpostej> <565DDB2E.2010308@arm.com> <20151201175254.GD29045@leverpostej> Cc: linux-arm-kernel@lists.infradead.org, marc.zyngier@arm.com, linux-kernel@vger.kernel.org, will.deacon@arm.com, catalin.marinas@arm.com From: "Suzuki K. Poulose" Message-ID: <565DE289.2000105@arm.com> Date: Tue, 1 Dec 2015 18:10:17 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 MIME-Version: 1.0 In-Reply-To: <20151201175254.GD29045@leverpostej> X-OriginalArrivalTime: 01 Dec 2015 18:10:17.0428 (UTC) FILETIME=[88855940:01D12C63] X-MC-Unique: PzW8vjEaTBWePJUqxWWH8Q-1 Content-Type: text/plain; charset=WINDOWS-1252; format=flowed Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/12/15 17:52, Mark Rutland wrote: > On Tue, Dec 01, 2015 at 05:38:54PM +0000, Suzuki K. Poulose wrote: >> On 01/12/15 16:31, Mark Rutland wrote: > > [...] > >>> We need stuck-in-the-kernel flag to account for CPUs which didn't manage >>> to turn the MMU on (which are either in the spin-table, or failed when >>> they were individually onlined). >> >> Did you mean to say "turn the MMU off" ? > > No, I mean CPUs which were unable to turn the MMU on in the first place. > Perhaps they entered the spin-table but were never individually onlined, > perhaps they didn't support the kernel page size, etc. > > When CPUs exit the kernel via PSCI they never switch the MMU off within > the kernel. OK. So the flag will also be used for CPUs which are stuck-in-the-kernel with MMU turned on. e.g, a CPU (using spin-table) we try to bring down in kill_cpu_early(). Correct ? Thanks Suzuki