Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751916Ab3FZIfg (ORCPT ); Wed, 26 Jun 2013 04:35:36 -0400 Received: from intranet.asianux.com ([58.214.24.6]:64828 "EHLO intranet.asianux.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751396Ab3FZIfN (ORCPT ); Wed, 26 Jun 2013 04:35:13 -0400 X-Spam-Score: -100.8 Message-ID: <51CAA78C.5040900@asianux.com> Date: Wed, 26 Jun 2013 16:34:20 +0800 From: Chen Gang User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130110 Thunderbird/17.0.2 MIME-Version: 1.0 To: Richard Weinberger 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> In-Reply-To: <51CAA0C6.60007@nod.at> 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: 2692 Lines: 69 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). For our case, the ".config" file does not define 'CONFIG_HAS_IOMEM', can I assume it means "CONFIG_HAS_IOMEM=n" ? Thanks -- Chen Gang Asianux Corporation -- 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/