On 04/08/2014 11:20 AM, 管雪涛 wrote: > I'd like to put the code into asm/io.h, and make it static. >
It sounds OK to me, but I don't know why the other architectures (e.g. arm, powerpc, x86) put them into ".c". iomem_is_exclusive() and page_is_ram() are all extern functions, so for me, devmem_is_allowed() is shot enough to be as inline function. >> +#ifdef CONFIG_STRICT_DEVMEM >> +/* >> + * devmem_is_allowed() checks to see if /dev/mem access to a certain >> + * address is valid. The argument is a physical page number. >> + * We mimic x86 here by disallowing access to system RAM as well as >> + * device-exclusive MMIO regions. This effectively disable read()/write() >> + * on /dev/mem. >> + */ >> +static int devmem_is_allowed(unsigned long pfn) How about "static inline int devmem_is_allowed(unsigned long pfn)"? >> +{ >> + if (iomem_is_exclusive(pfn << PAGE_SHIFT)) >> + return 0; >> + if (!page_is_ram(pfn)) >> + return 1; >> + return 0; >> +} >> +#endif /* CONFIG_STRICT_DEVMEM */ > > Thanks, > > Acked-by: Xuetao Guan <g...@mprc.pku.edu.cn> > [...] Thanks. -- Chen Gang Open, share, and attitude like air, water, and life which God blessed -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/