powerpc/vmemmap: Add altmap support
authorOliver O'Halloran <oohall@gmail.com>
Wed, 28 Jun 2017 01:32:33 +0000 (11:32 +1000)
committerMichael Ellerman <mpe@ellerman.id.au>
Sun, 2 Jul 2017 10:40:27 +0000 (20:40 +1000)
commitb584c2544041707ea041748dbfbb1081289c6cf5
treed3b0f56dbf44a9194740c402a4f648feb5844cca
parentd7d9b612f1b0ac154071bafc02bc9b7b879d7363
powerpc/vmemmap: Add altmap support

Adds support to powerpc for the altmap feature of ZONE_DEVICE memory. An
altmap is a driver provided region that is used to provide the backing
storage for the struct pages of ZONE_DEVICE memory. In situations where
large amount of ZONE_DEVICE memory is being added to the system the
altmap reduces pressure on main system memory by allowing the mm/
metadata to be stored on the device itself rather in main memory.

Reviewed-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
arch/powerpc/mm/init_64.c
arch/powerpc/mm/mem.c