On Tue, 11 May 2021 at 12:05, Mike Rapoport [off-list ref] wrote:

From: Mike Rapoport <redacted>

Hi,

These patches aim to remove CONFIG_HOLES_IN_ZONE and essentially hardwire
pfn_valid_within() to 1.

The idea is to mark NOMAP pages as reserved in the memory map and restore
the intended semantics of pfn_valid() to designate availability of struct
page for a pfn.

With this the core mm will be able to cope with the fact that it cannot use
NOMAP pages and the holes created by NOMAP ranges within MAX_ORDER blocks
will be treated correctly even without the need for pfn_valid_within.

The patches are boot tested on qemu-system-aarch64.

Did you use EFI boot when testing this? The memory map is much more
fragmented in that case, so this would be a good data point.

I beleive it would be best to route these via mmotm tree.

v4:
* rebase on v5.13-rc1

v3: Link: https://lore.kernel.org/lkml/20210422061902.21614-1-rppt@kernel.org (local)
* Fix minor issues found by Anshuman
* Freshen up the declaration of pfn_valid() to make it consistent with
  pfn_is_map_memory()
* Add more Acked-by and Reviewed-by tags, thanks Anshuman and David

v2: Link: https://lore.kernel.org/lkml/20210421065108.1987-1-rppt@kernel.org (local)
* Add check for PFN overflow in pfn_is_map_memory()
* Add Acked-by and Reviewed-by tags, thanks David.

v1: Link: https://lore.kernel.org/lkml/20210420090925.7457-1-rppt@kernel.org (local)
* Add comment about the semantics of pfn_valid() as Anshuman suggested
* Extend comments about MEMBLOCK_NOMAP, per Anshuman
* Use pfn_is_map_memory() name for the exported wrapper for
  memblock_is_map_memory(). It is still local to arch/arm64 in the end
  because of header dependency issues.

rfc: Link: https://lore.kernel.org/lkml/20210407172607.8812-1-rppt@kernel.org (local)

Mike Rapoport (4):
  include/linux/mmzone.h: add documentation for pfn_valid()
  memblock: update initialization of reserved pages
  arm64: decouple check whether pfn is in linear map from pfn_valid()
  arm64: drop pfn_valid_within() and simplify pfn_valid()

 arch/arm64/Kconfig              |  3 ---
 arch/arm64/include/asm/memory.h |  2 +-
 arch/arm64/include/asm/page.h   |  3 ++-
 arch/arm64/kvm/mmu.c            |  2 +-
 arch/arm64/mm/init.c            | 14 +++++++++++++-
 arch/arm64/mm/ioremap.c         |  4 ++--
 arch/arm64/mm/mmu.c             |  2 +-
 include/linux/memblock.h        |  4 +++-
 include/linux/mmzone.h          | 11 +++++++++++
 mm/memblock.c                   | 28 ++++++++++++++++++++++++++--
 10 files changed, 60 insertions(+), 13 deletions(-)


base-commit: 6efb943b8616ec53a5e444193dccf1af9ad627b5
--
2.28.0