On Tue, Oct 16, 2018 at 5:01 AM Guo Ren [off-list ref] wrote:

This patch adds files related to memory management and here is our
memory-layout:

   Fixmap       : 0xffc02000 – 0xfffff000       (4 MB - 12KB)
   Pkmap        : 0xff800000 – 0xffc00000       (4 MB)
   Vmalloc      : 0xf0200000 – 0xff000000       (238 MB)
   Lowmem       : 0x80000000 – 0xc0000000       (1GB)

abiv1 CPU (CK610) is VIPT cache and it doesn't support highmem.
abiv2 CPUs are all PIPT cache and they could support highmem.

Lowmem is directly mapped by msa0 & msa1 reg, and we needn't setup
memory page table for it.

Link:https://lore.kernel.org/lkml/20180518215548.GH17671@n2100.armlinux.org.uk/ (local)
Signed-off-by: Guo Ren <redacted>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Arnd Bergmann <arnd@arndb.de>

Reviewed-by: Arnd Bergmann <arnd@arndb.de>

Christoph had all the useful comments on this one, I just checked that I didn't
spot anything beyond that.

      Arnd