From 8a016596a56282f1414cf90e575040cffdabe68e Mon Sep 17 00:00:00 2001 From: Chen Gang Date: Tue, 15 Apr 2014 09:21:30 +0800 Subject: arch:unicore32:mm: add devmem_is_allowed() to support STRICT_DEVMEM MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Acked-by: Xuetao Guan Signed-off-by: Xuetao Guan --- arch/unicore32/include/asm/io.h | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) (limited to 'arch/unicore32') diff --git a/arch/unicore32/include/asm/io.h b/arch/unicore32/include/asm/io.h index d6920301465a..cb1d8fd2b16b 100644 --- a/arch/unicore32/include/asm/io.h +++ b/arch/unicore32/include/asm/io.h @@ -48,5 +48,28 @@ 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 +#include + +/* + * 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__ */ -- cgit v1.2.3-59-g8ed1b