• Mark Nelson's avatar
    powerpc: Update remaining dma_mapping_ops to use map/unmap_page · f9226d57
    Mark Nelson authored
    After the merge of the 32 and 64bit DMA code, dma_direct_ops lost
    their map/unmap_single() functions but gained map/unmap_page().  This
    caused a problem for Cell because Cell's dma_iommu_fixed_ops called
    the dma_direct_ops if the fixed linear mapping was to be used or the
    iommu ops if the dynamic window was to be used.  So in order to fix
    this problem we need to update the 64bit DMA code to use
    map/unmap_page.
    
    First, we update the generic IOMMU code so that iommu_map_single()
    becomes iommu_map_page() and iommu_unmap_single() becomes
    iommu_unmap_page().  Then we propagate these changes up through all
    the callers of these two functions and in the process update all the
    dma_mapping_ops so that they have map/unmap_page rahter than
    map/unmap_single.  We can do this because on 64bit there is no HIGHMEM
    memory so map/unmap_page ends up performing exactly the same function
    as map/unmap_single, just taking different arguments.
    
    This has no affect on drivers because the dma_map_single_attrs() just
    ends up calling the map_page() function of the appropriate
    dma_mapping_ops and similarly the dma_unmap_single_attrs() calls
    unmap_page().
    
    This fixes an oops on Cell blades, which oops on boot without this
    because they call dma_direct_ops.map_single, which is NULL.
    Signed-off-by: default avatarMark Nelson <markn@au1.ibm.com>
    Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
    f9226d57
dma-iommu.c 3.05 KB