powerpc: Ensure that swiotlb buffer is allocated from low memory

Some powerpc platforms (e.g. 85xx) limit DMA-able memory way below 4G.
If a system has more physical memory than this limit, the swiotlb
buffer is not addressable because it is allocated from memblock using
top-down mode.

Force memblock to bottom-up mode before calling swiotlb_init() to
ensure that the swiotlb buffer is DMA-able.

Reported-by: Christian Zigotzky <[email protected]>
Signed-off-by: Mike Rapoport <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

0 files changed, 0 insertions, 0 deletions