On Wed, Dec 05, 2018 at 06:43:08AM -0800, Christoph Hellwig wrote: > On Wed, Dec 05, 2018 at 02:40:06PM +0000, Robin Murphy wrote: > > 32-bit Arm doesn't have ZONE_DMA32, but has (or at least had at the time) a > > 2GB ZONE_DMA. Whether we actually need that or not depends on how this all > > interacts with LPAE and highmem, but I'm not sure of those details off-hand. > > Well, arm32 can't address more than 32-bits in the linear kernel > mapping, so GFP_KERNEL should be perfectly fine there if the limit > really is 32-bits and not 31 or smaller because someone stole a bit > or two somewhere. I'm not sure that's necessarily true on the physical side. Wasn't there a keystone SoC with /all/ the coherent memory above 4GB? Will
