On 04/16/2014 01:15 PM, 管雪涛 wrote:
> Acked-by: Xuetao Guan <g...@mprc.pku.edu.cn>
>
OK, thanks.
> ----- Chen Gang <gang.chen.5...@gmail.com> 写道：
>> 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.5...@gmail.com>
>> ---
>> arch/unicore32/include/asm/io.h | 23 +++++++++++++++++++++++
>> 1 file changed, 23 insertions(+)
>>
>> diff --git a/arch/unicore32/include/asm/io.h
>> b/arch/unicore32/include/asm/io.h
>> index 39decb6..ae327e4 100644
>> --- a/arch/unicore32/include/asm/io.h
>> +++ b/arch/unicore32/include/asm/io.h
>> @@ -44,5 +44,28 @@ 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
>> +
>> +#include <linux/ioport.h>
>> +#include <linux/mm.h>
>> +
>> +/*
>> + * 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__ */
>> --
>> 1.7.9.5
>>
>
--
Chen Gang
Open, share, and attitude like air, water, and life which God blessed
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