Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751817Ab3FZIj6 (ORCPT ); Wed, 26 Jun 2013 04:39:58 -0400 Received: from b.ns.miles-group.at ([95.130.255.144]:1661 "EHLO radon.swed.at" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751401Ab3FZIjz (ORCPT ); Wed, 26 Jun 2013 04:39:55 -0400 Message-ID: <51CAA8D6.9000505@nod.at> Date: Wed, 26 Jun 2013 10:39:50 +0200 From: Richard Weinberger User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130510 Thunderbird/17.0.6 MIME-Version: 1.0 To: Chen Gang CC: Jeff Dike , Arnd Bergmann , dhsharp@google.com, Mark Brown , "sfr@canb.auug.org.au" , Steven Rostedt , Ingo Molnar , uml-devel , uml-user , "linux-kernel@vger.kernel.org" , Linux-Arch Subject: Re: [PATCH] include/asm-generic/io.h: add 'UML' case just like 'no-MMU' References: <51CA8AB8.7080504@asianux.com> <51CA900E.9020407@nod.at> <51CA9E92.4000107@asianux.com> <51CAA0C6.60007@nod.at> <51CAA78C.5040900@asianux.com> In-Reply-To: <51CAA78C.5040900@asianux.com> X-Enigmail-Version: 1.5.1 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2960 Lines: 72 Am 26.06.2013 10:34, schrieb Chen Gang: > On 06/26/2013 04:05 PM, Richard Weinberger wrote: >>>>>>>> diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h >>>>>>>> index d5afe96..e80331d 100644 >>>>>>>> --- a/include/asm-generic/io.h >>>>>>>> +++ b/include/asm-generic/io.h >>>>>>>> @@ -303,10 +303,10 @@ static inline void *phys_to_virt(unsigned long address) >>>>>>>> /* >>>>>>>> * Change "struct page" to physical address. >>>>>>>> * >>>>>>>> - * This implementation is for the no-MMU case only... if you have an MMU >>>>>>>> + * This implementation is for the no-MMU or UML case only... if you have an MMU >>>>>>>> * you'll need to provide your own definitions. >>>>>>>> */ >>>>>>>> -#ifndef CONFIG_MMU >>>>>>>> +#if !CONFIG_MMU || CONFIG_UML >>>>>>>> static inline void __iomem *ioremap(phys_addr_t offset, unsigned long size) >>>>>>>> { >>>>>>>> return (void __iomem*) (unsigned long)offset; >>>>>>>> @@ -325,7 +325,7 @@ static inline void __iomem *ioremap(phys_addr_t offset, unsigned long size) >>>>>>>> static inline void iounmap(void __iomem *addr) >>>>>>>> { >>>>>>>> } >>>>>>>> -#endif /* CONFIG_MMU */ >>>>>>>> +#endif /* !CONFIG_MMU || CONFIG_UML */ >>>>>>>> >>>>>>>> #ifdef CONFIG_HAS_IOPORT >>>>>>>> #ifndef CONFIG_GENERIC_IOMAP >>>>>>>> >>>>>> >>>>>> UML has no io memory but a MMU, so I'd argue that you better fix drivers/ptp/ptp_pch.c dependencies. >>>>>> _If_ ptp_pch.c really works without real io memory, you can look what I did in my GENERIC_IO series[1] >>>>>> to make nandsim work on UML. Maybe this helps. >>>>>> >>>> >>>> But "no io memory" is not the excuse to not define the related dummy >>>> function. >> UML has no io memory, period. >> Same applies for s390, it also includes asm-generic/io.h in the !CONFIG_PCI >> case. >> UML and s390 are very special here. >> > > Oh, yes, really the same. > >>>> The drivers internal code has already check the related return value, >>>> so it is the architecture's duty to 'tell' the driver whether support >>>> io memory (e.g. define ioremap, but return NULL). >> It does so already by setting CONFIG_HAS_IOMEM=n > > Excuse me, I use "grep -rn ioremap *" under "include/" and "arch/um/" > directory, but can not find the related definition for 'ioremap'. > > Is there another declaration or definition way which I don't know ? > (maybe it is). Both UML and s390 (in the !CONFIG_PCI) do not define ioremap() because without io memory you cannot have a ioremap(). > For our case, the ".config" file does not define 'CONFIG_HAS_IOMEM', can > I assume it means "CONFIG_HAS_IOMEM=n" ? If I'm not mistaken it works the other way around. All archs except UML and s390 set CONFIG_HAS_IOMEM=y. Thanks, //richard -- 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/