From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753791AbdK1MT3 (ORCPT ); Tue, 28 Nov 2017 07:19:29 -0500 Received: from mx2.suse.de ([195.135.220.15]:44753 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753007AbdK1KaU (ORCPT ); Tue, 28 Nov 2017 05:30:20 -0500 Subject: Re: [Xen-devel] [PATCH 2/3] x86/acpi: take rsdp address for boot params if available To: =?UTF-8?Q?Roger_Pau_Monn=c3=a9?= Cc: linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org, x86@kernel.org, corbet@lwn.net, rjw@rjwysocki.net, linux-acpi@vger.kernel.org, mingo@redhat.com, hpa@zytor.com, boris.ostrovsky@oracle.com, tglx@linutronix.de, lenb@kernel.org References: <20171128094400.25955-1-jgross@suse.com> <20171128094400.25955-3-jgross@suse.com> <20171128101834.fmiqygqpfh6wxrvv@MacBook-Pro-de-Roger.local> From: Juergen Gross Message-ID: <072e88ef-dd61-8b7d-026a-5966b13ffed9@suse.com> Date: Tue, 28 Nov 2017 11:30:15 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.4.0 MIME-Version: 1.0 In-Reply-To: <20171128101834.fmiqygqpfh6wxrvv@MacBook-Pro-de-Roger.local> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 28/11/17 11:18, Roger Pau Monné wrote: > On Tue, Nov 28, 2017 at 10:43:59AM +0100, Juergen Gross wrote: >> In case the rsdp address in struct boot_params is specified don't try >> to find the table by searching, but take the address directly as set >> by the boot loader. >> >> Signed-off-by: Juergen Gross >> --- >> drivers/acpi/osl.c | 8 ++++++++ >> 1 file changed, 8 insertions(+) >> >> diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c >> index 3bb46cb24a99..3b25e2ad7d75 100644 >> --- a/drivers/acpi/osl.c >> +++ b/drivers/acpi/osl.c >> @@ -45,6 +45,10 @@ >> #include >> #include >> >> +#ifdef CONFIG_X86 >> +#include >> +#endif >> + >> #include "internal.h" >> >> #define _COMPONENT ACPI_OS_SERVICES >> @@ -195,6 +199,10 @@ acpi_physical_address __init acpi_os_get_root_pointer(void) >> if (acpi_rsdp) >> return acpi_rsdp; >> #endif >> +#ifdef CONFIG_X86 >> + if (boot_params.hdr.acpi_rsdp_addr) >> + return boot_params.hdr.acpi_rsdp_addr; >> +#endif > > I'm struggling to figure out how was PVH getting the RSDP previously, > because that should be removed now that it's in the zero-page. I don't think it should be removed, because this was the legacy case (searching through memory). It was pure luck that Xen put it at the right location. Juergen