• Muli Ben-Yehuda's avatar
    [PATCH] x86_64: Use function pointers to call DMA mapping functions · 17a941d8
    Muli Ben-Yehuda authored
    AK: I hacked Muli's original patch a lot and there were a lot
    of changes - all bugs are probably to blame on me now.
    There were also some changes in the fall back behaviour
    for swiotlb - in particular it doesn't try to use GFP_DMA
    now anymore. Also all DMA mapping operations use the
    same core dma_alloc_coherent code with proper fallbacks now.
    And various other changes and cleanups.
    Known problems: iommu=force swiotlb=force together breaks
                    needs more testing.
    This patch cleans up x86_64's DMA mapping dispatching code. Right now
    we have three possible IOMMU types: AGP GART, swiotlb and nommu, and
    in the future we will also have Xen's x86_64 swiotlb and other HW
    IOMMUs for x86_64. In order to support all of them cleanly, this
    - introduces a struct dma_mapping_ops with function pointers for each
      of the DMA mapping operations of gart (AMD HW IOMMU), swiotlb
      (software IOMMU) and nommu (no IOMMU).
    - gets rid of:
      if (swiotlb)
          return swiotlb_xxx();
    - PCI_DMA_BUS_IS_PHYS is now checked against the dma_ops being set
    This makes swiotlb faster by avoiding double copying in some cases.
    Signed-Off-By: default avatarMuli Ben-Yehuda <mulix@mulix.org>
    Signed-Off-By: default avatarJon D. Mason <jdmason@us.ibm.com>
    Signed-off-by: default avatarAndi Kleen <ak@suse.de>
    Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
swiotlb.c 22.7 KB