Oh, sorry, it is my careless, it even can not pass compiling, I will/should send patch v3. Thanks. On 04/15/2014 08:28 AM, Chen Gang wrote: > unicore32 supports STRICT_DEVMEM, so it needs devmem_is_allowed(), like > some of other architectures have done (e.g. arm, powerpc, x86 ...). > > The related error with allmodconfig: > > CC drivers/char/mem.o > drivers/char/mem.c: In function ‘range_is_allowed’: > drivers/char/mem.c:69: error: implicit declaration of function ‘devmem_is_allowed’ > make[2]: *** [drivers/char/mem.o] Error 1 > make[1]: *** [drivers/char] Error 2 > make: *** [drivers] Error 2 > > > Signed-off-by: Chen Gang <gang.chen.5i5j@xxxxxxxxx> > --- > arch/unicore32/include/asm/io.h | 18 ++++++++++++++++++ > 1 file changed, 18 insertions(+) > > diff --git a/arch/unicore32/include/asm/io.h b/arch/unicore32/include/asm/io.h > index 39decb6..839c2ea 100644 > --- a/arch/unicore32/include/asm/io.h > +++ b/arch/unicore32/include/asm/io.h > @@ -44,5 +44,23 @@ extern void __uc32_iounmap(volatile void __iomem *addr); > #define PIO_MASK (unsigned int)(IO_SPACE_LIMIT) > #define PIO_RESERVED (PIO_OFFSET + PIO_MASK + 1) > > +#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 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 */ > + > #endif /* __KERNEL__ */ > #endif /* __UNICORE_IO_H__ */ > -- 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 majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/