Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757555AbcC2QST (ORCPT ); Tue, 29 Mar 2016 12:18:19 -0400 Received: from foss.arm.com ([217.140.101.70]:41416 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752575AbcC2QSR (ORCPT ); Tue, 29 Mar 2016 12:18:17 -0400 Date: Tue, 29 Mar 2016 17:18:38 +0100 From: Will Deacon To: Shannon Zhao Cc: linux-arm-kernel@lists.infradead.org, stefano.stabellini@citrix.com, david.vrabel@citrix.com, devicetree@vger.kernel.org, linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org, catalin.marinas@arm.com, julien.grall@arm.com, peter.huangpeng@huawei.com, xen-devel@lists.xen.org, zhaoshenglong@huawei.com, mark.rutland@arm.com Subject: Re: [PATCH v7 12/17] ARM64: ACPI: Check if it runs on Xen to enable or disable ACPI Message-ID: <20160329161837.GH6745@arm.com> References: <1458830676-27075-1-git-send-email-shannon.zhao@linaro.org> <1458830676-27075-13-git-send-email-shannon.zhao@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1458830676-27075-13-git-send-email-shannon.zhao@linaro.org> 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 Content-Length: 1417 Lines: 37 On Thu, Mar 24, 2016 at 10:44:31PM +0800, Shannon Zhao wrote: > When it's a Xen domain0 booting with ACPI, it will supply a /chosen and > a /hypervisor node in DT. So check if it needs to enable ACPI. > > Signed-off-by: Shannon Zhao > Reviewed-by: Stefano Stabellini > Acked-by: Hanjun Guo > --- > arch/arm64/kernel/acpi.c | 12 ++++++++---- > 1 file changed, 8 insertions(+), 4 deletions(-) > > diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c > index d1ce8e2..4e92be0 100644 > --- a/arch/arm64/kernel/acpi.c > +++ b/arch/arm64/kernel/acpi.c > @@ -67,10 +67,13 @@ static int __init dt_scan_depth1_nodes(unsigned long node, > { > /* > * Return 1 as soon as we encounter a node at depth 1 that is > - * not the /chosen node. > + * not the /chosen node, or /hypervisor node when running on Xen. > */ > - if (depth == 1 && (strcmp(uname, "chosen") != 0)) > - return 1; > + if (depth == 1 && (strcmp(uname, "chosen") != 0)) { > + if (!xen_initial_domain() || (strcmp(uname, "hypervisor") != 0)) > + return 1; > + } Hmm, but xen_initial_domain() is false when xen isn't being used at all, so it feels to me like this is a bit too far-reaching and is basically claiming the "/hypervisor" namespace for Xen. Couldn't it be renamed to "xen,hypervisor" or something? Mark, got any thoughts on this? Will