On 06/26/2013 06:22 PM, Chen Gang wrote: > On 06/26/2013 06:17 PM, Richard Weinberger wrote: >> Am 26.06.2013 12:01, schrieb Chen Gang: >>>> On 06/26/2013 05:48 PM, Geert Uytterhoeven wrote: >>>>>> On Wed, Jun 26, 2013 at 11:38 AM, Richard Weinberger <rich...@nod.at> >>>>>> wrote: >>>>>>>>>>>>>> Since the API itself already contents the meaning: "return NULL >>>>>>>>>>>>>> means >>>>>>>>>>>>>> the arch has no related io memory", >>>>>> No, NULL means it could not map the I/O memory. >>>>>> >>>> >>>> "it could not map the I/O memory" includes "has no related io memory". >>>> So it is enough for our case. >>>> >>>>>>>>>>>>>> Why not define a generic dummy one in "include/asm-generic/io.h" >>>>>>>>>>>>>> instead >>>>>>>>>>>>>> of "HAS_IOMEM" (which has already spread many various places, >>>>>>>>>>>>>> and also, >>>>>>>>>>>>>> most of new drivers have to know about it). >>>>>>>>>>>>>> >>>>>>>>>>>>>> e.g: in "include/asm-generic/io.h", if "CONFIG_HAS_IOMEM=n", >>>>>>>>>>>>>> define a >>>>>>>>>>>>>> dummy ioremap() which return NULL ... (also need consider more >>>>>>>>>>>>>> details). >>>>>>>>>> >>>>>>>>>> Because we don't even want to build these drivers and not make them >>>>>>>>>> fail while >>>>>>>>>> executing io memory related functions. >>>>>> Indeed, it doesn't make sense to build drivers that cannot work. >>>>>> And they may fail in a very bad way. >>>> >>>> That is our 'platform' guys feeling, not the 'module' guys, as >>>> 'platform' guys, it is better to provide the choice to 'module' guys, >>>> and let them decide by themselves, not forced by us. >> FYI, this is my last reply to this thread. >> >> As Geert and I said, drivers which need io memory have to depend on >> HAS_IOMEM=y. >> If an arch does not have io memory these drivers cannot work and therefore >> we don't >> want them built. >
Hmm, if the modules select 'COMPILE_TEST', it is better to let asm-generic support this features (at least, not forbid it) So how about the diff below ? ;-) ---------------------------diff begin----------------------------------- diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h index d5afe96..ede3775 100644 --- a/include/asm-generic/io.h +++ b/include/asm-generic/io.h @@ -303,13 +303,17 @@ 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 - * you'll need to provide your own definitions. + * This for the no-MMU, or no-IOMEM but still try to COMPILE_TEST cases. + * if you have an MMU and IOMEM, you'll need to provide your own definitions. */ -#ifndef CONFIG_MMU +#if !defined(CONFIG_MMU) || \ + (!defined(CONFIG_HAS_IOMEM) && defined(COMPILE_TEST)) static inline void __iomem *ioremap(phys_addr_t offset, unsigned long size) { +#if !defined(CONFIG_MMU) return (void __iomem*) (unsigned long)offset; +#else + return NULL; } #define __ioremap(offset, size, flags) ioremap(offset, size) @@ -325,7 +329,7 @@ static inline void __iomem *ioremap(phys_addr_t offset, unsigned long size) static inline void iounmap(void __iomem *addr) { } -#endif /* CONFIG_MMU */ +#endif /* !MMU || (!HAS_IOMEM && COMPILE_TEST) */ #ifdef CONFIG_HAS_IOPORT #ifndef CONFIG_GENERIC_IOMAP ---------------------------diff end------------------------------------- > It is really the time for stopping discussion, and thank you all for > spending your time resources on this discussion. > > Next, I will send related patch for it (also cc to you all). > > > Thanks. > -- Chen Gang ------------------------------------------------------------------------------ This SF.net email is sponsored by Windows: Build for Windows Store. http://p.sf.net/sfu/windows-dev2dev _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel