[RFC 0/7] Enable ZONE_DEVICE on POWER

[Anshuman Khandual]

This series enables ZONE_DEVICE support on POWER. The TEST patches are
just example usage of this newly enabled zone. Here are some of the logs
from the example device driver. This demonstrates how struct pages can
be allocated inside the device memory range itself and how usable memory
will be less than the total memory mapped in this way.

[    0.462493] RMEM: Driver loaded
[    0.462502] RMEM: Reserved memory sections
[    0.462504] RMEM: Base b10000000 Size: 10000000 Node: 0
[    0.462507] RMEM: Base b20000000 Size: 10000000 Node: 0
[    0.462510] RMEM: Base b30000000 Size: 10000000 Node: 0
[    0.462512] RMEM: Base b40000000 Size: 10000000 Node: 0
[    0.462515] RMEM: Base b50000000 Size: 10000000 Node: 0
[    0.462517] RMEM: Base b60000000 Size: 10000000 Node: 0
[    0.462520] RMEM: Base b70000000 Size: 10000000 Node: 0
[    0.462522] RMEM: Base b80000000 Size: 10000000 Node: 0
[    0.462525] RMEM: Base b90000000 Size: 10000000 Node: 0
[    0.462527] RMEM: Base ba0000000 Size: 10000000 Node: 0
[    0.462530] RMEM: Base bb0000000 Size: 10000000 Node: 0
[    0.462532] RMEM: Base bc0000000 Size: 10000000 Node: 0
[    0.462535] RMEM: Base bd0000000 Size: 10000000 Node: 0
[    0.462537] RMEM: Base be0000000 Size: 10000000 Node: 0
[    0.462540] RMEM: Base bf0000000 Size: 10000000 Node: 0
[    0.462611] RMEM: vmemmap backing (f000000001000000 40b000000)
[    0.462617] RMEM: vmemmap backing (f000000000000000 40c000000)
[    0.462800] RMEM: vmemmap backing (f000000002000000 b10000000)
[    0.462804] RMEM: vmemmap backing (f000000001000000 40b000000)
[    0.462807] RMEM: vmemmap backing (f000000000000000 40c000000)
[    0.462810] RMEM: Read access complete (c000000b10000000 8000000)
[    0.462813] RMEM: altmap->base_pfn 724992
[    0.462815] RMEM: altmap->reserve 0
[    0.462817] RMEM: altmap->free 256
[    0.462818] RMEM: altmap->align 0
[    0.462820] RMEM: altmap->alloc 256
[    0.462822] RMEM: pagemap            (c000000002060018)
[    0.462824] RMEM: dev_pagemap        (c000000002060060)
[    0.462827] RMEM: pfn range (b1100 b1800)
[    1.264550] RMEM: Driver now owns PFN(b1100....b1800)
[    1.264552] RMEM: Data integrity test successful

Thoughts, suggestions, inputs and comments welcome. Thank you.

Anshuman Khandual (5):
  powerpc/mm: Make vmemmap_populate accommodate ZONE_DEVICE memory
  powerpc/mm: Enable support for ZONE_DEVICE on PPC_BOOK3S_64 platforms
  mm/memremap: Export pfn_first, pfn_end, find_pagemap functions
  TEST: Reserve system memory to be emulated as device memory
  TEST: Driver to test device memory through ZONE_DEVICE

Oliver O'Halloran (2):
  powerpc/mm: Define TOP_ZONE as a constant
  powerpc/mm: Set MAX_ZONE_PFN to 0 for all zones beyond TOP_ZONE

 arch/powerpc/Kconfig                    |   4 +
 arch/powerpc/include/asm/prom.h         |  15 +++
 arch/powerpc/kernel/prom.c              |  11 ++
 arch/powerpc/mm/init_64.c               |  18 +++-
 arch/powerpc/mm/mem.c                   |  28 ++---
 arch/powerpc/platforms/pseries/Makefile |   2 +-
 arch/powerpc/platforms/pseries/rmem.c   | 186 ++++++++++++++++++++++++++++++++
 include/linux/memremap.h                |  18 ++++
 kernel/memremap.c                       |  15 ++-
 mm/Kconfig                              |   2 +-
 10 files changed, 280 insertions(+), 19 deletions(-)
 create mode 100644 arch/powerpc/platforms/pseries/rmem.c

-- 
1.8.3.1