[PATCH v5 0/4] riscv, mm: detect svnapot cpu support at runtime

[Qinglin Pan]

Sorry for missing below information.

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
Changes in v5:
   - modify code according to @Conor and @Heiko's suggestions.
     Thanks @Conor @Heiko


On 10/3/22 9:47 PM, panqinglin2020 at iscas.ac.cn wrote:
> 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 extension 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.
> 
> 
> 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                   |  17 +-
>   arch/riscv/include/asm/errata_list.h |  23 ++-
>   arch/riscv/include/asm/hugetlb.h     |  30 +++-
>   arch/riscv/include/asm/hwcap.h       |   3 +-
>   arch/riscv/include/asm/page.h        |   2 +-
>   arch/riscv/include/asm/pgtable-64.h  |  13 ++
>   arch/riscv/include/asm/pgtable.h     |  68 +++++++-
>   arch/riscv/include/asm/vmalloc.h     |  28 +++
>   arch/riscv/kernel/cpu.c              |   1 +
>   arch/riscv/kernel/cpufeature.c       |  18 ++
>   arch/riscv/mm/hugetlbpage.c          | 250 ++++++++++++++++++++++++++-
>   arch/riscv/mm/init.c                 |  28 ++-
>   12 files changed, 467 insertions(+), 14 deletions(-)
>