[PATCH v5 0/7] riscv: Add support for xmipsexectl

[Aleksa Paunovic via B4 Relay]

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@xxxxxxxxxxxxx>
---
Changes in v5:
- Add MIPS.IHB and MIPS.EHB instructions
- Rebase on alex-for-next
- Address other smaller comments pointed out by Alexandre
- Link to v4: https://lore.kernel.org/r/20250625-p8700-pause-v4-0-6c7dd7f85756@xxxxxxxxxxxxx

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@xxxxxxxxx/

---
Aleksa Paunovic (6):
      dt-bindings: riscv: Add xmipsexectl ISA extension description
      riscv: Add xmipsexectl as a vendor extension
      riscv: Add xmipsexectl instructions
      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               | 13 ++++-
 arch/riscv/include/asm/errata_list_vendors.h       |  5 ++
 arch/riscv/include/asm/hwprobe.h                   |  3 +-
 arch/riscv/include/asm/vdso/processor.h            |  3 +-
 arch/riscv/include/asm/vendor_extensions/mips.h    | 37 ++++++++++++
 .../include/asm/vendor_extensions/mips_hwprobe.h   | 22 +++++++
 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/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 | 23 ++++++++
 arch/riscv/mm/init.c                               |  1 +
 tools/arch/riscv/include/asm/vdso/processor.h      | 27 +++++----
 26 files changed, 298 insertions(+), 14 deletions(-)
---
base-commit: b6a4bae2f16162876842127d7507dad84e404f8f
change-id: 20250424-p8700-pause-dcb649968e24

Best regards,
-- 
Aleksa Paunovic <aleksa.paunovic@xxxxxxxxxxxxx>