Hello,
This is the last missing piece to let us efficiently use large DMA buffers on systems with lots of memory, which have support for himem enabled. The first patch adds support for CMA regions placed in high memory zones, the second one also enables allocations of individual pages from high memory zone for IOMMU-mapped devices. Those two changes let us to significantly save low memory for other tasks.
Best regards Marek Szyprowski Samsung Poland R&D Center
Patch summary:
Marek Szyprowski (2): ARM: dma-mapping: add support for CMA regions placed in highmem zone ARM: dma-mapping: use himem for DMA buffers for IOMMU-mapped devices
arch/arm/mm/dma-mapping.c | 70 +++++++++++++++++++++++++++++++++------------ 1 file changed, 52 insertions(+), 18 deletions(-)