search for: 0x80_0000_0000

...t scenario needs to set a DMA > mask to be safe. > > Not sure whether that's practical as I suppose you want to make the > DMA mask larger than 32 bits? > Yes. This particular device supports 40 bits (judging from the MMU driver code) of physical address space, and RAM starts at 0x80_0000_0000 on AMD Seattle, so we need all 40 bits. > If you absolutely need to do this in the device, can we move the DMA > mask setting logic in nouveau_ttm into its own function and call it > from the FB driver to make sure the mask is correctly set? Maybe this > could even be made a MMU functi...

The 100c08 scratch page is mapped using dma_map_page() before the TTM layer has had a chance to set the DMA mask. This means we are still running with the default of 32 when this code executes, and this causes problems for platforms with no memory below 4 GB (such as AMD Seattle) So move the dma_map_page() to the .init hook, and set the streaming DMA mask based on the MMU subdev parameters before