From mboxrd@z Thu Jan 1 00:00:00 1970 From: Richard Weinberger Subject: Re: [PATCH] include/asm-generic/io.h: add 'UML' case just like 'no-MMU' Date: Wed, 26 Jun 2013 10:05:26 +0200 Message-ID: <51CAA0C6.60007@nod.at> References: <51CA8AB8.7080504@asianux.com> <51CA900E.9020407@nod.at> <51CA9E92.4000107@asianux.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: 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 S1751731Ab3FZIFd (ORCPT ); Wed, 26 Jun 2013 04:05:33 -0400 In-Reply-To: <51CA9E92.4000107@asianux.com> Sender: linux-arch-owner@vger.kernel.org List-ID: 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 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 =EF=BF=BDpch_remove=EF=BF=BD: >>> drivers/ptp/ptp_pch.c:571:3: error: implicit declaration of funct= ion =EF=BF=BDiounmap=EF=BF=BD [-Werror=3Dimplicit-function-declaration] >>> drivers/ptp/ptp_pch.c: In function =EF=BF=BDpch_probe=EF=BF=BD: >>> drivers/ptp/ptp_pch.c:621:2: error: implicit declaration of funct= ion =EF=BF=BDioremap=EF=BF=BD [-Werror=3Dimplicit-function-declaration] >>> drivers/ptp/ptp_pch.c:621:13: warning: assignment makes pointer f= rom 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/Kbuil= d >>> index b30f34a..a34ea5d 100644 >>> --- a/arch/um/include/asm/Kbuild >>> +++ b/arch/um/include/asm/Kbuild >>> @@ -3,3 +3,4 @@ generic-y +=3D hw_irq.h irq_regs.h kdebug.h percpu.= h sections.h topology.h xor.h >>> generic-y +=3D ftrace.h pci.h io.h param.h delay.h mutex.h current= =2Eh exec.h >>> generic-y +=3D switch_to.h clkdev.h >>> generic-y +=3D trace_clock.h >>> +generic-y +=3D io.h >> >> We include that file already. See three lines above. >> >=20 > Oh, really it is, thanks. >=20 >>> 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 lon= g 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 yo= u 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 l= ong 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 */ >>> =20 >>> #ifdef CONFIG_HAS_IOPORT >>> #ifndef CONFIG_GENERIC_IOMAP >>> >> >> UML has no io memory but a MMU, so I'd argue that you better fix dri= vers/ptp/ptp_pch.c dependencies. >> _If_ ptp_pch.c really works without real io memory, you can look wha= t I did in my GENERIC_IO series[1] >> to make nandsim work on UML. Maybe this helps. >> >=20 > 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=3Dn Thanks, //richard