This series is in order to enable sparse-vmemmap for LoongArch. But
LoongArch cannot use generic helpers directly because MIPS&LoongArch
need to call pgd_init()/pud_init()/pmd_init() when populating page
tables. So we adjust the prototypes of p?d_init() to make generic
helpers can call them, then enable sparse-vmemmap with generic helpers,
and to be further, generalise vmemmap_populate_hugepages() for ARM64,
X86 and LoongArch.

V1 -> V2:
Split ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP to a separate patch.

V2 -> V3:
1, Change the Signed-off-by order of author and committer;
2, Update commit message about the build error on LoongArch.

V3 -> V4:
Change pmd to pmdp for ARM64 for consistency.

V4 -> V5:
Add a detailed comment for no-fallback in the altmap case.

V5 -> V6:
1, Fix build error for NIOS2;
2, Fix build error for allnoconfig;
3, Update comment for no-fallback in the altmap case.

V6 -> V7:
Fix build warnings of "no previous prototype".

V7 -> V8:
Fix build error for MIPS pud_init().

Huacai Chen and Feiyang Chen(4):
 MIPS&LoongArch&NIOS2: Adjust prototypes of p?d_init().
 LoongArch: Add sparse memory vmemmap support.
 mm/sparse-vmemmap: Generalise vmemmap_populate_hugepages().
 LoongArch: Enable ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP.

Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Feiyang Chen <chenfeiyang@loongson.cn> 
---
 arch/arm64/mm/mmu.c                    | 53 ++++++--------------
 arch/loongarch/Kconfig                 |  2 +
 arch/loongarch/include/asm/pgalloc.h   | 13 +----
 arch/loongarch/include/asm/pgtable.h   | 13 +++--
 arch/loongarch/include/asm/sparsemem.h |  8 +++
 arch/loongarch/kernel/numa.c           |  4 +-
 arch/loongarch/mm/init.c               | 44 +++++++++++++++-
 arch/loongarch/mm/pgtable.c            | 23 +++++----
 arch/mips/include/asm/pgalloc.h        |  8 +--
 arch/mips/include/asm/pgtable-64.h     |  8 +--
 arch/mips/kvm/mmu.c                    |  3 +-
 arch/mips/mm/pgtable-32.c              | 10 ++--
 arch/mips/mm/pgtable-64.c              | 18 ++++---
 arch/mips/mm/pgtable.c                 |  2 +-
 arch/x86/mm/init_64.c                  | 92 ++++++++++++----------------------
 include/linux/mm.h                     |  8 +++
 include/linux/page-flags.h             |  1 +
 mm/sparse-vmemmap.c                    | 64 +++++++++++++++++++++++
 18 files changed, 222 insertions(+), 152 deletions(-)
--
2.27.0