xref: /kernel/linux/linux-6.6/Documentation/devicetree/bindings/riscv/extensions.yaml

# SPDX-License-Identifier: (GPL-2.0 OR MIT)
%YAML 1.2
---
$id: http://devicetree.org/schemas/riscv/extensions.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#

title: RISC-V ISA extensions

maintainers:
  - Paul Walmsley <paul.walmsley@sifive.com>
  - Palmer Dabbelt <palmer@sifive.com>
  - Conor Dooley <conor@kernel.org>

description: |
  RISC-V has a large number of extensions, some of which are "standard"
  extensions, meaning they are ratified by RISC-V International, and others
  are "vendor" extensions.
  This document defines properties that indicate whether a hart supports a
  given extension.

  Once a standard extension has been ratified, no changes in behaviour can be
  made without the creation of a new extension.
  The properties for standard extensions therefore map to their originally
  ratified states, with the exception of the I, Zicntr & Zihpm extensions.
  See the "i" property for more information.

select:
  properties:
    compatible:
      contains:
        const: riscv

properties:
  riscv,isa:
    description:
      Identifies the specific RISC-V instruction set architecture
      supported by the hart.  These are documented in the RISC-V
      User-Level ISA document, available from
      https://riscv.org/specifications/

      Due to revisions of the ISA specification, some deviations
      have arisen over time.
      Notably, riscv,isa was defined prior to the creation of the
      Zicntr, Zicsr, Zifencei and Zihpm extensions and thus "i"
      implies "zicntr_zicsr_zifencei_zihpm".

      While the isa strings in ISA specification are case
      insensitive, letters in the riscv,isa string must be all
      lowercase.
    $ref: /schemas/types.yaml#/definitions/string
    pattern: ^rv(?:64|32)imaf?d?q?c?b?k?j?p?v?h?(?:[hsxz](?:[a-z])+)?(?:_[hsxz](?:[a-z])+)*$
    deprecated: true

  riscv,isa-base:
    description:
      The base ISA implemented by this hart, as described by the 20191213
      version of the unprivileged ISA specification.
    enum:
      - rv32i
      - rv64i

  riscv,isa-extensions:
    $ref: /schemas/types.yaml#/definitions/string-array
    minItems: 1
    description: Extensions supported by the hart.
    items:
      anyOf:
        # single letter extensions, in canonical order
        - const: i
          description: |
            The base integer instruction set, as ratified in the 20191213
            version of the unprivileged ISA specification.

            This does not include Chapter 10, "Counters", which was moved into
            the Zicntr and Zihpm extensions after the ratification of the
            20191213 version of the unprivileged specification.

        - const: m
          description:
            The standard M extension for integer multiplication and division, as
            ratified in the 20191213 version of the unprivileged ISA
            specification.

        - const: a
          description:
            The standard A extension for atomic instructions, as ratified in the
            20191213 version of the unprivileged ISA specification.

        - const: f
          description:
            The standard F extension for single-precision floating point, as
            ratified in the 20191213 version of the unprivileged ISA
            specification.

        - const: d
          description:
            The standard D extension for double-precision floating-point, as
            ratified in the 20191213 version of the unprivileged ISA
            specification.

        - const: q
          description:
            The standard Q extension for quad-precision floating-point, as
            ratified in the 20191213 version of the unprivileged ISA
            specification.

        - const: c
          description:
            The standard C extension for compressed instructions, as ratified in
            the 20191213 version of the unprivileged ISA specification.

        - const: v
          description:
            The standard V extension for vector operations, as ratified
            in-and-around commit 7a6c8ae ("Fix text that describes vfmv.v.f
            encoding") of the riscv-v-spec.

        - const: h
          description:
            The standard H extension for hypervisors as ratified in the 20191213
            version of the privileged ISA specification.

        # multi-letter extensions, sorted alphanumerically
        - const: smaia
          description: |
            The standard Smaia supervisor-level extension for the advanced
            interrupt architecture for machine-mode-visible csr and behavioural
            changes to interrupts as frozen at commit ccbddab ("Merge pull
            request #42 from riscv/jhauser-2023-RC4") of riscv-aia.

        - const: ssaia
          description: |
            The standard Ssaia supervisor-level extension for the advanced
            interrupt architecture for supervisor-mode-visible csr and
            behavioural changes to interrupts as frozen at commit ccbddab
            ("Merge pull request #42 from riscv/jhauser-2023-RC4") of riscv-aia.

        - const: sscofpmf
          description: |
            The standard Sscofpmf supervisor-level extension for count overflow
            and mode-based filtering as ratified at commit 01d1df0 ("Add ability
            to manually trigger workflow. (#2)") of riscv-count-overflow.

        - const: sstc
          description: |
            The standard Sstc supervisor-level extension for time compare as
            ratified at commit 3f9ed34 ("Add ability to manually trigger
            workflow. (#2)") of riscv-time-compare.

        - const: svinval
          description:
            The standard Svinval supervisor-level extension for fine-grained
            address-translation cache invalidation as ratified in the 20191213
            version of the privileged ISA specification.

        - const: svnapot
          description:
            The standard Svnapot supervisor-level extensions for napot
            translation contiguity as ratified in the 20191213 version of the
            privileged ISA specification.

        - const: svpbmt
          description:
            The standard Svpbmt supervisor-level extensions for page-based
            memory types as ratified in the 20191213 version of the privileged
            ISA specification.

        - const: zba
          description: |
            The standard Zba bit-manipulation extension for address generation
            acceleration instructions as ratified at commit 6d33919 ("Merge pull
            request #158 from hirooih/clmul-fix-loop-end-condition") of
            riscv-bitmanip.

        - const: zbb
          description: |
            The standard Zbb bit-manipulation extension for basic bit-manipulation
            as ratified at commit 6d33919 ("Merge pull request #158 from
            hirooih/clmul-fix-loop-end-condition") of riscv-bitmanip.

        - const: zbc
          description: |
            The standard Zbc bit-manipulation extension for carry-less
            multiplication as ratified at commit 6d33919 ("Merge pull request
            #158 from hirooih/clmul-fix-loop-end-condition") of riscv-bitmanip.

        - const: zbs
          description: |
            The standard Zbs bit-manipulation extension for single-bit
            instructions as ratified at commit 6d33919 ("Merge pull request #158
            from hirooih/clmul-fix-loop-end-condition") of riscv-bitmanip.

        - const: zicbom
          description:
            The standard Zicbom extension for base cache management operations as
            ratified in commit 3dd606f ("Create cmobase-v1.0.pdf") of riscv-CMOs.

        - const: zicbop
          description:
            The standard Zicbop extension for cache-block prefetch instructions
            as ratified in commit 3dd606f ("Create cmobase-v1.0.pdf") of
            riscv-CMOs.

        - const: zicboz
          description:
            The standard Zicboz extension for cache-block zeroing as ratified
            in commit 3dd606f ("Create cmobase-v1.0.pdf") of riscv-CMOs.

        - const: zicntr
          description:
            The standard Zicntr extension for base counters and timers, as
            ratified in the 20191213 version of the unprivileged ISA
            specification.

        - const: zicsr
          description: |
            The standard Zicsr extension for control and status register
            instructions, as ratified in the 20191213 version of the
            unprivileged ISA specification.

            This does not include Chapter 10, "Counters", which documents
            special case read-only CSRs, that were moved into the Zicntr and
            Zihpm extensions after the ratification of the 20191213 version of
            the unprivileged specification.

        - const: zifencei
          description:
            The standard Zifencei extension for instruction-fetch fence, as
            ratified in the 20191213 version of the unprivileged ISA
            specification.

        - const: zihintpause
          description:
            The standard Zihintpause extension for pause hints, as ratified in
            commit d8ab5c7 ("Zihintpause is ratified") of the riscv-isa-manual.

        - const: zihpm
          description:
            The standard Zihpm extension for hardware performance counters, as
            ratified in the 20191213 version of the unprivileged ISA
            specification.

        - const: ztso
          description:
            The standard Ztso extension for total store ordering, as ratified
            in commit 2e5236 ("Ztso is now ratified.") of the
            riscv-isa-manual.

additionalProperties: true
...