[PATCH v4 0/7] riscv: Add support for xmipsexectl

[Alexandre Ghiti]

On 6/25/25 16:20, Aleksa Paunovic via B4 Relay wrote:
> This patch series adds support for the xmipsexectl vendor extension.
> A new hardware probe key has also been added to allow userspace to probe for MIPS vendor extensions.
>
> Additionally, since the standard Zihintpause PAUSE instruction encoding is not supported on some MIPS CPUs,
> an errata was implemented for replacing this instruction with the xmipsexectl MIPS.PAUSE alternative encoding.
>
> Signed-off-by: Aleksa Paunovic <aleksa.paunovic at htecgroup.com>
> ---
> This is a continuation of a previous series, which did not implement the full
> xmipsexectl vendor extension. The title was updated accordingly.
>
> Changes in v4:
> - Add support for the xmipsexectl vendor extension
> - Remove the ifdef/else from errata_list.h
> - Replace the ifdef/else with a hwprobe call in the userspace code.
>
> Link to v3:
> https://lore.kernel.org/linux-riscv/20250129131703.733098-1-arikalo@gmail.com/
>
> ---
> Aleksa Paunovic (6):
>        dt-bindings: riscv: Add xmipsexectl ISA extension description
>        riscv: Add xmipsexectl as a vendor extension
>        riscv: Add xmipsexectl PAUSE instruction
>        riscv: hwprobe: Add MIPS vendor extension probing
>        riscv: hwprobe: Document MIPS xmipsexectl vendor extension
>        riscv: Add tools support for xmipsexectl
>
> Djordje Todorovic (1):
>        riscv: errata: Fix the PAUSE Opcode for MIPS P8700
>
>   Documentation/arch/riscv/hwprobe.rst               |  9 +++
>   .../devicetree/bindings/riscv/extensions.yaml      |  6 ++
>   arch/riscv/Kconfig.errata                          | 23 ++++++++
>   arch/riscv/Kconfig.vendor                          | 13 +++++
>   arch/riscv/errata/Makefile                         |  1 +
>   arch/riscv/errata/mips/Makefile                    |  5 ++
>   arch/riscv/errata/mips/errata.c                    | 67 ++++++++++++++++++++++
>   arch/riscv/include/asm/alternative.h               |  3 +
>   arch/riscv/include/asm/cmpxchg.h                   |  3 +-
>   arch/riscv/include/asm/errata_list.h               | 17 +++++-
>   arch/riscv/include/asm/hwprobe.h                   |  3 +-
>   arch/riscv/include/asm/vdso/processor.h            |  4 +-
>   arch/riscv/include/asm/vendor_extensions/mips.h    | 23 ++++++++
>   .../include/asm/vendor_extensions/mips_hwprobe.h   | 23 ++++++++
>   arch/riscv/include/asm/vendorid_list.h             |  1 +
>   arch/riscv/include/uapi/asm/hwprobe.h              |  1 +
>   arch/riscv/include/uapi/asm/vendor/mips.h          |  3 +
>   arch/riscv/kernel/alternative.c                    |  5 ++
>   arch/riscv/kernel/entry.S                          |  2 +
>   arch/riscv/kernel/sys_hwprobe.c                    |  4 ++
>   arch/riscv/kernel/vendor_extensions.c              | 10 ++++
>   arch/riscv/kernel/vendor_extensions/Makefile       |  2 +
>   arch/riscv/kernel/vendor_extensions/mips.c         | 22 +++++++
>   arch/riscv/kernel/vendor_extensions/mips_hwprobe.c | 22 +++++++
>   arch/riscv/mm/init.c                               |  1 +
>   tools/arch/riscv/include/asm/vdso/processor.h      | 27 +++++----
>   26 files changed, 286 insertions(+), 14 deletions(-)
> ---
> base-commit: 19272b37aa4f83ca52bdf9c16d5d81bdd1354494
> change-id: 20250424-p8700-pause-dcb649968e24
>
> Best regards,


I tried to fix all the small comments I added, but there are quite a few 
(and using MIPS_PAUSE triggered a new header nightmare) so can you send 
another version rebased on top of this branch 
https://git.kernel.org/pub/scm/linux/kernel/git/alexghiti/linux.git/log/?h=alex-for-next 
?

Thanks,

Alex