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author | Chen Gang <gang.chen.5i5j@gmail.com> | 2014-04-15 09:21:30 +0800 |
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committer | Guan Xuetao <gxt@mprc.pku.edu.cn> | 2014-06-20 08:22:40 +0800 |
commit | 8a016596a56282f1414cf90e575040cffdabe68e (patch) | |
tree | 7c64c581f6728435c5220bdc940ac3628f15715b /arch | |
parent | aaad61838242469b0f9724a6057ea74ab4e87369 (diff) | |
download | linux-8a016596a56282f1414cf90e575040cffdabe68e.tar.gz linux-8a016596a56282f1414cf90e575040cffdabe68e.tar.bz2 linux-8a016596a56282f1414cf90e575040cffdabe68e.zip |
arch:unicore32:mm: add devmem_is_allowed() to support STRICT_DEVMEM
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 ârange_is_allowedâ:
drivers/char/mem.c:69: error: implicit declaration of function âdevmem_is_allowedâ
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@gmail.com>
Acked-by: Xuetao Guan <gxt@mprc.pku.edu.cn>
Signed-off-by: Xuetao Guan <gxt@mprc.pku.edu.cn>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/unicore32/include/asm/io.h | 23 |
1 files changed, 23 insertions, 0 deletions
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 <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__ */ |