Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751831Ab3FZIFj (ORCPT ); Wed, 26 Jun 2013 04:05:39 -0400 Received: from b.ns.miles-group.at ([95.130.255.144]:1660 "EHLO radon.swed.at" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751530Ab3FZIFd (ORCPT ); Wed, 26 Jun 2013 04:05:33 -0400 Message-ID: <51CAA0C6.60007@nod.at> Date: Wed, 26 Jun 2013 10:05:26 +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> In-Reply-To: <51CA9E92.4000107@asianux.com> X-Enigmail-Version: 1.5.1 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3808 Lines: 98 Hi! Am 26.06.2013 09:56, schrieb Chen Gang: > On 06/26/2013 02:54 PM, Richard Weinberger wrote: >> Hi! >> >> Am 26.06.2013 08:31, schrieb Chen Gang: >>> For "User Mode Linux", it may enable 'MMU', but not need implement >>> ioremap and iounmap, so "include/asm-generic/io.h" need notice this >>> case to keep itself 'generic'. >>> >>> The related error (with allmodconfig, without pcap): >>> >>> CC [M] drivers/ptp/ptp_pch.o >>> drivers/ptp/ptp_pch.c: In function �pch_remove�: >>> drivers/ptp/ptp_pch.c:571:3: error: implicit declaration of function �iounmap� [-Werror=implicit-function-declaration] >>> drivers/ptp/ptp_pch.c: In function �pch_probe�: >>> drivers/ptp/ptp_pch.c:621:2: error: implicit declaration of function �ioremap� [-Werror=implicit-function-declaration] >>> drivers/ptp/ptp_pch.c:621:13: warning: assignment makes pointer from integer without a cast [enabled by default] >>> cc1: some warnings being treated as errors >>> >>> >>> Signed-off-by: Chen Gang >>> --- >>> arch/um/include/asm/Kbuild | 1 + >>> include/asm-generic/io.h | 6 +++--- >>> 2 files changed, 4 insertions(+), 3 deletions(-) >>> >>> diff --git a/arch/um/include/asm/Kbuild b/arch/um/include/asm/Kbuild >>> index b30f34a..a34ea5d 100644 >>> --- a/arch/um/include/asm/Kbuild >>> +++ b/arch/um/include/asm/Kbuild >>> @@ -3,3 +3,4 @@ generic-y += hw_irq.h irq_regs.h kdebug.h percpu.h sections.h topology.h xor.h >>> generic-y += ftrace.h pci.h io.h param.h delay.h mutex.h current.h exec.h >>> generic-y += switch_to.h clkdev.h >>> generic-y += trace_clock.h >>> +generic-y += io.h >> >> We include that file already. See three lines above. >> > > Oh, really it is, thanks. > >>> 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. > 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 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/