[PATCH v4 0/4] riscv, mm: detect svnapot cpu support at runtime

[panqinglin2020 at iscas.ac.cn]

From: Qinglin Pan <panqinglin2020 at iscas.ac.cn>

Svnapot is a RISC-V extension for marking contiguous 4K pages as a non-4K
page. This patch set is for using Svnapot in Linux Kernel's boot process
and hugetlb fs.

This patchset adds a Kconfig item for using Svnapot in
"Platform type"->"Svnapot support". Its default value is off, and people can set
it on if they allow kernel to detect Svnapot hardware support and leverage it.

Tested on:
  - qemu rv64 with "Svnapot support" off and svnapot=true.
  - qemu rv64 with "Svnapot support" on and svnapot=true.
  - qemu rv64 with "Svnapot support" off and svnapot=false.
  - qemu rv64 with "Svnapot support" on and svnapot=false.

Changes in v2:
  - detect Svnapot hardware support at boot time.
Changes in v3:
  - do linear mapping again if has_svnapot
Changes in v4:
  - fix some errors/warns reported by checkpatch.pl, thanks @Conor

Qinglin Pan (4):
  mm: modify pte format for Svnapot
  mm: support Svnapot in physical page linear-mapping
  mm: support Svnapot in hugetlb page
  mm: support Svnapot in huge vmap

 arch/riscv/Kconfig                   |  10 +-
 arch/riscv/include/asm/errata_list.h |  24 ++-
 arch/riscv/include/asm/hugetlb.h     |  30 +++-
 arch/riscv/include/asm/hwcap.h       |   1 +
 arch/riscv/include/asm/mmu.h         |   1 +
 arch/riscv/include/asm/page.h        |   2 +-
 arch/riscv/include/asm/pgtable-64.h  |  14 ++
 arch/riscv/include/asm/pgtable.h     |  70 +++++++-
 arch/riscv/include/asm/vmalloc.h     |  22 +++
 arch/riscv/kernel/cpu.c              |   1 +
 arch/riscv/kernel/cpufeature.c       |  18 ++
 arch/riscv/kernel/setup.c            |  11 +-
 arch/riscv/mm/hugetlbpage.c          | 250 ++++++++++++++++++++++++++-
 arch/riscv/mm/init.c                 |  47 +++--
 14 files changed, 477 insertions(+), 24 deletions(-)

-- 
2.35.1