Re: [PATCH net-next v6] page_pool: disable dma mapping support for 32-bit arch with 64-bit DMA

[Christoph Hellwig]

This is just popping out of nowhere on lkml, but yes ARM LPAE
uses a 64-bit dma_addr_t, as a 64-bit phys_addr_t implies that.
Same for x86-32 PAE and similar cases on MIPS and probably a few
other architectures.

But what is the actual problem with a 32-bit virtual and 64-bit
pysical/dma address?  That is a pretty common setup and absolutely
needs to be deal with in drivers and inrastructure.