by Guo Ren

[permalink] [raw]

Subject: Re: [PATCH v6 00/14] riscv: support for Svpbmt and D1 memory types

After trying it on my SMP 4*910 platform, it could boot normally.

Tested-by: Guo Ren <[email protected]>

On Wed, Feb 9, 2022 at 8:38 PM Heiko Stuebner <[email protected]> wrote:
>
> Svpbmt is an extension defining "Supervisor-mode: page-based memory types"
> for things like non-cacheable pages or I/O memory pages.
>
>
> So this is my 2nd try at implementing Svpbmt (and the diverging D1 memory
> types) using the alternatives framework.
>
> This includes a number of changes to the alternatives mechanism itself.
> The biggest one being the move to a more central location, as I expect
> in the future, nearly every chip needing some sort of patching, be it
> either for erratas or for optional features (svpbmt or others).
>
> The dt-binding for svpbmt itself is of course not finished and is still
> using the binding introduced in previous versions, as where to put
> a svpbmt-property in the devicetree is still under dicussion.
> Atish seems to be working on a framework for extensions [0],
>
> The series also introduces support for the memory types of the D1
> which are implemented differently to svpbmt. But when patching anyway
> it's pretty clean to add the D1 variant via ALTERNATIVE_2 to the same
> location.
>
> The only slightly bigger difference is that the "normal" type is not 0
> as with svpbmt, so kernel patches for this PMA type need to be applied
> even before the MMU is brought up, so the series introduces a separate
> stage for that.
>
>
> In theory this series is 3 parts:
> - sbi cache-flush / null-ptr
> - alternatives improvements
> - svpbmt+d1
>
> So expecially patches from the first 2 areas could be applied when
> deemed ready, I just thought to keep it together to show-case where
> the end-goal is and not requiring jumping between different series.
>
>
> The sbi cache-flush patch is based on Atish's sparse-hartid patch [1],
> as it touches a similar area in mm/cacheflush.c
>
>
> I picked the recipient list from the previous version, hopefully
> I didn't forget anybody.
>
> changes in v6:
> - rebase onto 5.17-rc1
> - handle sbi null-ptr differently
> - improve commit messages
> - use riscv,mmu as property name
>
> changes in v5:
> - move to use alternatives for runtime-patching
> - add D1 variant
>
>
> [0] https://lore.kernel.org/r/[email protected]
> [1] https://lore.kernel.org/r/[email protected]
>
>
> Heiko Stuebner (12):
> riscv: prevent null-pointer dereference with sbi_remote_fence_i
> riscv: integrate alternatives better into the main architecture
> riscv: allow different stages with alternatives
> riscv: implement module alternatives
> riscv: implement ALTERNATIVE_2 macro
> riscv: extend concatenated alternatives-lines to the same length
> riscv: prevent compressed instructions in alternatives
> riscv: move boot alternatives to a slightly earlier position
> riscv: Fix accessing pfn bits in PTEs for non-32bit variants
> riscv: add cpufeature handling via alternatives
> riscv: remove FIXMAP_PAGE_IO and fall back to its default value
> riscv: add memory-type errata for T-Head
>
> Wei Fu (2):
> dt-bindings: riscv: add MMU Standard Extensions support for Svpbmt
> riscv: add RISC-V Svpbmt extension support
>
> .../devicetree/bindings/riscv/cpus.yaml | 10 ++
> arch/riscv/Kconfig.erratas | 29 ++--
> arch/riscv/Kconfig.socs | 1 -
> arch/riscv/Makefile | 2 +-
> arch/riscv/errata/Makefile | 2 +-
> arch/riscv/errata/sifive/errata.c | 10 +-
> arch/riscv/errata/thead/Makefile | 1 +
> arch/riscv/errata/thead/errata.c | 85 +++++++++++
> arch/riscv/include/asm/alternative-macros.h | 114 ++++++++-------
> arch/riscv/include/asm/alternative.h | 16 ++-
> arch/riscv/include/asm/errata_list.h | 52 +++++++
> arch/riscv/include/asm/fixmap.h | 2 -
> arch/riscv/include/asm/pgtable-32.h | 17 +++
> arch/riscv/include/asm/pgtable-64.h | 79 +++++++++-
> arch/riscv/include/asm/pgtable-bits.h | 10 --
> arch/riscv/include/asm/pgtable.h | 53 +++++--
> arch/riscv/include/asm/vendorid_list.h | 1 +
> arch/riscv/kernel/Makefile | 1 +
> arch/riscv/{errata => kernel}/alternative.c | 48 ++++++-
> arch/riscv/kernel/cpufeature.c | 136 +++++++++++++++++-
> arch/riscv/kernel/head.S | 2 +
> arch/riscv/kernel/module.c | 29 ++++
> arch/riscv/kernel/sbi.c | 10 +-
> arch/riscv/kernel/smpboot.c | 4 -
> arch/riscv/kernel/traps.c | 2 +-
> arch/riscv/mm/init.c | 1 +
> 26 files changed, 606 insertions(+), 111 deletions(-)
> create mode 100644 arch/riscv/errata/thead/Makefile
> create mode 100644 arch/riscv/errata/thead/errata.c
> rename arch/riscv/{errata => kernel}/alternative.c (59%)
>
> --
> 2.30.2
>

--
Best Regards
Guo Ren

ML: https://lore.kernel.org/linux-csky/