Commit 8a016596 authored by Chen Gang's avatar Chen Gang Committed by Guan Xuetao

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 ‘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: default avatarChen Gang <gang.chen.5i5j@gmail.com>
Acked-by: default avatarXuetao Guan <gxt@mprc.pku.edu.cn>
Signed-off-by: default avatarXuetao Guan <gxt@mprc.pku.edu.cn>
parent aaad6183
......@@ -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__ */
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