Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754090AbaATOO1 (ORCPT ); Mon, 20 Jan 2014 09:14:27 -0500 Received: from mail-pb0-f49.google.com ([209.85.160.49]:48497 "EHLO mail-pb0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751898AbaATOOV (ORCPT ); Mon, 20 Jan 2014 09:14:21 -0500 Message-ID: <52DD2F23.2010109@linaro.org> Date: Mon, 20 Jan 2014 22:13:55 +0800 From: Hanjun Guo User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130623 Thunderbird/17.0.7 MIME-Version: 1.0 To: Arnd Bergmann CC: linaro-kernel@lists.linaro.org, Mark Rutland , Matthew Garrett , Russell King - ARM Linux , Rob Herring , Catalin Marinas , Olof Johansson , "Rafael J. Wysocki" , linux-kernel@vger.kernel.org, linaro-acpi@lists.linaro.org, linux-acpi@vger.kernel.org, patches@linaro.org, Grant Likely , Bjorn Helgaas , linux-arm-kernel@lists.infradead.org, Charles.Garcia-Tobin@arm.com Subject: Re: [PATCH 06/20] ARM64 / ACPI: Introduce some PCI functions when PCI is enabled References: <1389961514-13562-1-git-send-email-hanjun.guo@linaro.org> <201401171504.24525.arnd@arndb.de> <52DCD961.70303@linaro.org> <4387274.ri38HmFxAV@wuerfel> In-Reply-To: <4387274.ri38HmFxAV@wuerfel> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2014年01月20日 16:20, Arnd Bergmann wrote: > On Monday 20 January 2014 16:08:01 Hanjun Guo wrote: >>>> diff --git a/drivers/acpi/plat/arm-core.c b/drivers/acpi/plat/arm-core.c >>>> index 3c8521d..1835b21 100644 >>>> --- a/drivers/acpi/plat/arm-core.c >>>> +++ b/drivers/acpi/plat/arm-core.c >>>> @@ -100,6 +100,25 @@ int acpi_gsi_to_irq(u32 gsi, unsigned int *irq) >>>> } >>>> EXPORT_SYMBOL_GPL(acpi_gsi_to_irq); >>>> >>>> +int acpi_isa_irq_to_gsi(unsigned isa_irq, u32 *gsi) >>>> +{ >>>> + return -1; >>>> +} >>>> + >>>> +int acpi_register_ioapic(acpi_handle handle, u64 phys_addr, u32 gsi_base) >>>> +{ >>>> + /* TBD */ >>>> + return -EINVAL; >>>> +} >>>> +EXPORT_SYMBOL(acpi_register_ioapic); >>>> + >>>> +int acpi_unregister_ioapic(acpi_handle handle, u32 gsi_base) >>>> +{ >>>> + /* TBD */ >>>> + return -EINVAL; >>>> +} >>>> +EXPORT_SYMBOL(acpi_unregister_ioapic); >>>> + >>> My feeling is that these are better handled in the ACPI code by not >>> calling them on architectures that have no ISA or no IOAPIC support. >>> >>> We have configuration symbols for both, so you don't have to make >>> it depend on CONFIG_ARM64 or CONFIG_X86. >> Do you mean introduce a stub function when there is no ISA support? > Do you anticipate ISA devices on ARM64? I hope not ;-) me too :) > > My guess is that whatever code calls this function should be disabled > in reduced hw mode. ok, that would be make sense, will update it in next version. > >> acpi_register_ioapic()/acpi_unregister_ioapic() will be used for IOAPIC >> hotplug and GIC distributor is something like IOAPIC on x86, so I think >> these two functions can be reserved for future use. > But GIC is not hotplugged, is it? It still sounds x86 specific to me. Well, if we want to do physical CPU hotplug on ARM/ARM64 (maybe years later?), then GIC add/remove is needed because we have to remove GIC on the SoC too when we remove the physical CPU. Thanks Hanjun -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/