From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752096AbbCWBit (ORCPT ); Sun, 22 Mar 2015 21:38:49 -0400 Received: from szxga02-in.huawei.com ([119.145.14.65]:57975 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751914AbbCWBir (ORCPT ); Sun, 22 Mar 2015 21:38:47 -0400 Message-ID: <550F6E48.4080406@huawei.com> Date: Mon, 23 Mar 2015 09:37:12 +0800 From: Hanjun Guo User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:24.0) Gecko/20100101 Thunderbird/24.0.1 MIME-Version: 1.0 To: "Rafael J. Wysocki" , Julien Grall CC: 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 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> In-Reply-To: <5749112.zNnbMCHVxZ@vostro.rjw.lan> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.17.188] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. Thanks Hanjun