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-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html