[GIT PULL] dma-mapping fixes for 4.20

[Christoph Hellwig]

The following changes since commit c8ce94b8fe5324aca4c10baeb53dea2d5775a170:

  Merge tag 'mips_fixes_4.20_3' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux (2018-11-20 14:31:00 -0800)

are available in the Git repository at:

  git://git.infradead.org/users/hch/dma-mapping.git tags/dma-mapping-4.20-3

for you to fetch changes up to cb216b84d6ea24fa10f1e7aac35de77246841041:

  swiotlb: Skip cache maintenance on map error (2018-11-21 18:47:58 +0100)

----------------------------------------------------------------
Two dma-direct / swiotlb regressions fixes

 - 0 is a valid physical address on some arm boards, we can't use
   0 as the error value
 - don't try to cache flush the error return value (no matter what it is)

----------------------------------------------------------------
Robin Murphy (2):
      dma-direct: Make DIRECT_MAPPING_ERROR viable for SWIOTLB
      swiotlb: Skip cache maintenance on map error

 include/linux/dma-direct.h | 2 +-
 kernel/dma/swiotlb.c       | 3 ++-
 2 files changed, 3 insertions(+), 2 deletions(-)