• Kai Jiang's avatar
    uio: Support physical addresses >32 bits on 32-bit systems · 27a90700
    Kai Jiang authored
    
    
    To support >32-bit physical addresses for UIO_MEM_PHYS type we need to
    extend the width of 'addr' in struct uio_mem.  Numerous platforms like
    embedded PPC, ARM, and X86 have support for systems with larger physical
    address than logical.
    
    Since 'addr' may contain a physical, logical, or virtual address the
    easiest solution is to just change the type to 'phys_addr_t' which
    should always be greater than or equal to the sizeof(void *) such that
    it can properly hold any of the address types.
    
    For physical address we can support up to a 44-bit physical address on a
    typical 32-bit system as we utilize remap_pfn_range() for the mapping of
    the memory region and pfn's are represnted by shifting the address by
    the page size (typically 4k).
    Signed-off-by: default avatarKai Jiang <Kai.Jiang@freescale.com>
    Signed-off-by: default avatarMinghuan Lian <Minghuan.Lian@freescale.com>
    Signed-off-by: default avatarKumar Gala <galak@kernel.crashing.org>
    Signed-off-by: default avatarHans J. Koch <hjk@hansjkoch.de>
    Signed-off...
    27a90700
uio.c 19.5 KB