From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753240AbbCWSlG (ORCPT ); Mon, 23 Mar 2015 14:41:06 -0400 Received: from smtp.citrix.com ([66.165.176.89]:52266 "EHLO SMTP.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752551AbbCWSlC (ORCPT ); Mon, 23 Mar 2015 14:41:02 -0400 X-IronPort-AV: E=Sophos;i="5.11,453,1422921600"; d="scan'208";a="245924151" Date: Mon, 23 Mar 2015 18:39:47 +0000 From: Stefano Stabellini X-X-Sender: sstabellini@kaball.uk.xensource.com To: Hanjun Guo CC: "Rafael J. Wysocki" , Julien Grall , Naresh Bhat , Hanjun Guo , Jon Fraser , Parth Dixit , Stefano Stabellini , Catalin Marinas , Olof Johansson , "grant.likely@linaro.org" , Lorenzo Pieralisi , Arnd Bergmann , Mark Rutland , "graeme.gregory@linaro.org" , Sudeep Holla , "jcm@redhat.com" , Marc Zyngier , "Mark Brown" , Robert Richter , Timur Tabi , Ashwin Chaugule , "suravee.suthikulpanit@amd.com" , "linux-acpi@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernelorg" , "linaro-acpi@lists.linaro.org" , Ian Campbell Subject: Re: [PATCH v10 00/21] Introduce ACPI for ARM64 based on ACPI 5.1 In-Reply-To: <550F6E48.4080406@huawei.com> Message-ID: References: <1426077587-1561-1-git-send-email-hanjun.guo@linaro.org> <2189259.UNlTC1BNmt@vostro.rjw.lan> <550F3500.1040608@linaro.org> <5749112.zNnbMCHVxZ@vostro.rjw.lan> <550F6E48.4080406@huawei.com> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" X-DLP: MIA2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 23 Mar 2015, Hanjun Guo wrote: > On 2015/3/23 6:11, Rafael J. Wysocki wrote: > > On Sunday, March 22, 2015 09:32:48 PM Julien Grall wrote: > >> On 22/03/2015 21:49, Rafael J. Wysocki wrote: > >>> On Sunday, March 22, 2015 09:05:21 PM Julien Grall wrote: > >>>> Hello, > >>>> > >>>> On 21/03/2015 12:09, Naresh Bhat wrote: > >>>>> From 268dcdafa34a690e2f99c0784ca33a6d2352ecf5 Mon Sep 17 00:00:00 2001 > >>>>> From: Hanjun Guo > > >>>>> Date: Sat, 21 Mar 2015 14:43:54 +0800 > >>>>> Subject: [PATCH] XEN / ACPI: Make XEN ACPI depend on X86 > >>>>> > >>>>> When ACPI is enabled on ARM64, XEN ACPI will also compiled > >>>>> into the kernel, but XEN ACPI is x86 dependent, so introduce > >>>>> CONFIG_XEN_ACPI to make it depend on x86 before XEN ACPI is > >>>>> functional on ARM64. > >>>>> > >>>>> Signed-off-by: Hanjun Guo >>>>> > > >>>>> --- > >>>>> drivers/xen/Kconfig | 4 ++++ > >>>>> drivers/xen/Makefile | 2 +- > >>>>> 2 files changed, 5 insertions(+), 1 deletion(-) > >>>>> > >>>>> diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig > >>>>> index b812462..a31cd29 100644 > >>>>> --- a/drivers/xen/Kconfig > >>>>> +++ b/drivers/xen/Kconfig > >>>>> @@ -253,4 +253,8 @@ config XEN_EFI > >>>>> def_bool y > >>>>> depends on X86_64 && EFI > >>>>> > >>>>> +config XEN_ACPI > >>>>> + def_bool y > >>>>> + depends on X86 && ACPI > >>>>> + > >>>>> endmenu > >>>>> diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile > >>>>> index 2ccd359..f4622ab 100644 > >>>>> --- a/drivers/xen/Makefile > >>>>> +++ b/drivers/xen/Makefile > >>>>> @@ -13,7 +13,7 @@ CFLAGS_efi.o += -fshort-wchar > >>>>> > >>>>> dom0-$(CONFIG_PCI) += pci.o > >>>>> dom0-$(CONFIG_USB_SUPPORT) += dbgp.o > >>>>> -dom0-$(CONFIG_ACPI) += acpi.o $(xen-pad-y) > >>>>> +dom0-$(CONFIG_XEN_ACPI) += acpi.o $(xen-pad-y) > >>>>> xen-pad-$(CONFIG_X86) += xen-acpi-pad.o > >>>>> dom0-$(CONFIG_X86) += pcpu.o > >>>>> obj-$(CONFIG_XEN_DOM0) += $(dom0-y) > >>>> [..] > >>>> > >>>>> AFAIK, There is already a kernel patch exists to fix this issue. I > >>>>> think Julien or Parth is a right person to ask. Hence I am CCed Julien > >>>>> Grall too. > >>>> The ACPI support for Xen is not ready. So I think avoiding to compile > >>>> drivers/xen/acpi.c on ARM64/ARM seems the better solution for now. > >>>> > >>>> Although, rather than introducing a new CONFIG option, I would use the > >>>> same trick we use within the Makefile to avoid hotplug.c on ARM/ARM64. > >>>> > >>>> ifeq ($(filter y, $(CONFIG_ARM) $(CONFIG_ARM64)), ) > >>>> dom0-$(CONFIG_ACPI) += acpi.o $(xen-pad-y) > >>>> endif > >>> Well, is avoiding an extra CONFIG_ option worth the ugliness of this? > >> When the support of ACPI for Xen will come, the CONFIG_ option will be > >> an alias to CONFIG_XEN. > >> > >> In this case the CONFIG_ option won't bring much improvement to the code > >> and add an extra indirection. > >> > >> The "ugliness" option has, at least, the advantage to be tiny and > >> self-contained. > > Oh well, not really. You're moving a config-time check to compile time > > which means that it will be done every time this Makefile is executed > > and for all architectures that execute it. Not nice. > > > > Also I think that ia64 is missing from the list, but I may be wrong. > > In commit d52eefb47d (ia64/xen: Remove Xen support for ia64), XEN is > not supported anymore on ia64 now. > > > > > Not to mention the fact that the dependency will be rather difficult to find > > for tools like xconfig ... > > I also think introducing a CONFIG_ option is a better idea. Me too