• Christoph Hellwig's avatar
    dma-mapping: consolidate the dma mmap implementations · 58b04406
    Christoph Hellwig authored
    The only functional differences (modulo a few missing fixes in the arch
    code) is that architectures without coherent caches need a hook to
    convert a virtual or dma address into a pfn, given that we don't have
    the kernel linear mapping available for the otherwise easy virt_to_page
    call.  As a side effect we can support mmap of the per-device coherent
    area even on architectures not providing the callback, and we make
    previous dangerous default methods dma_common_mmap actually save for
    non-coherent architectures by rejecting it without the right helper.
    
    In addition to that we need a hook so that some architectures can
    override the protection bits when mmaping a dma coherent allocations.
    Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
    Acked-by: Paul Burton <paul.burton@mips.com> # MIPS parts
    58b04406
dma-mapping.h 25.3 KB