diff options
Diffstat (limited to 'arch/unicore32')
| -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__ */ |