• Russell King's avatar
    ARM: DMA-API: better handing of DMA masks for coherent allocations · 4dcfa600
    Russell King authored
    We need to start treating DMA masks as something which is specific to
    the bus that the device resides on, otherwise we're going to hit all
    sorts of nasty issues with LPAE and 32-bit DMA controllers in >32-bit
    systems, where memory is offset from PFN 0.
    
    In order to start doing this, we convert the DMA mask to a PFN using
    the device specific dma_to_pfn() macro.  This is the reverse of the
    pfn_to_dma() macro which is used to get the DMA address for the device.
    
    This gives us a PFN mask, which we can then check against the PFN
    limit of the DMA zone.
    Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
    4dcfa600
dma-mapping.c 52.4 KB