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 <20230919035343.1399389-3-apatel@ventanamicro.com> <20230920-36a5645f766ed9cce75a9e8c@orel>
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From:   Anup Patel <apatel@ventanamicro.com>
Date:   Mon, 25 Sep 2023 19:01:48 +0530
Message-ID: <CAK9=C2XVyN7nkMW+kgELaHCAjLcQ3z-6xVdrGa_UtxfJMdm7Dg@mail.gmail.com>
Subject: Re: [PATCH 2/7] RISC-V: Detect Zicond from ISA string
To:     Andrew Jones <ajones@ventanamicro.com>
Cc:     Paolo Bonzini <pbonzini@redhat.com>,
        Atish Patra <atishp@atishpatra.org>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Conor Dooley <conor@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Shuah Khan <shuah@kernel.org>,
        Mayuresh Chitale <mchitale@ventanamicro.com>,
        devicetree@vger.kernel.org, kvm@vger.kernel.org,
        kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org,
        linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org
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On Wed, Sep 20, 2023 at 1:14=E2=80=AFPM Andrew Jones <ajones@ventanamicro.c=
om> wrote:
>
> On Tue, Sep 19, 2023 at 09:23:38AM +0530, Anup Patel wrote:
> > The RISC-V integer conditional (Zicond) operation extension defines
> > standard conditional arithmetic and conditional-select/move operations
> > which are inspired from the XVentanaCondOps extension. In fact, QEMU
> > RISC-V also has support for emulating Zicond extension.
> >
> > Let us detect Zicond extension from ISA string available through
> > DT or ACPI.
> >
> > Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> > ---
> >  Documentation/devicetree/bindings/riscv/extensions.yaml | 6 ++++++
> >  arch/riscv/include/asm/hwcap.h                          | 1 +
> >  arch/riscv/kernel/cpufeature.c                          | 1 +
> >  3 files changed, 8 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/riscv/extensions.yaml b/=
Documentation/devicetree/bindings/riscv/extensions.yaml
> > index cad8ef68eca7..7ea90e2dbc5b 100644
> > --- a/Documentation/devicetree/bindings/riscv/extensions.yaml
> > +++ b/Documentation/devicetree/bindings/riscv/extensions.yaml
> > @@ -225,6 +225,12 @@ properties:
> >              ratified in the 20191213 version of the unprivileged ISA
> >              specification.
> >
> > +        - const: zicond
> > +          description:
> > +            The standard Zicond extension for conditional arithmetic a=
nd
> > +            conditional-select/move operations as ratified in commit 8=
fb6694
> > +            ("Update Gemfile") of riscv-zicond.
>
> As of yesterday, v1.0 of the spec points at commit 95cf1f9 ("Add changes
> requested by Ved during signoff")

Okay, I will update.

>
> > +
> >          - const: zicsr
> >            description: |
> >              The standard Zicsr extension for control and status regist=
er
> > diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hw=
cap.h
> > index b7efe9e2fa89..15bafc02ffd4 100644
> > --- a/arch/riscv/include/asm/hwcap.h
> > +++ b/arch/riscv/include/asm/hwcap.h
> > @@ -60,6 +60,7 @@
> >  #define RISCV_ISA_EXT_ZIHPM          42
> >  #define RISCV_ISA_EXT_SMSTATEEN              43
> >  #define RISCV_ISA_EXT_XVENTANACONDOPS        44
> > +#define RISCV_ISA_EXT_ZICOND         45
> >
> >  #define RISCV_ISA_EXT_MAX            64
> >
> > diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeat=
ure.c
> > index 3a31d34fe709..49b6551f3347 100644
> > --- a/arch/riscv/kernel/cpufeature.c
> > +++ b/arch/riscv/kernel/cpufeature.c
> > @@ -174,6 +174,7 @@ const struct riscv_isa_ext_data riscv_isa_ext[] =3D=
 {
> >       __RISCV_ISA_EXT_DATA(zba, RISCV_ISA_EXT_ZBA),
> >       __RISCV_ISA_EXT_DATA(zbb, RISCV_ISA_EXT_ZBB),
> >       __RISCV_ISA_EXT_DATA(zbs, RISCV_ISA_EXT_ZBS),
> > +     __RISCV_ISA_EXT_DATA(zicond, RISCV_ISA_EXT_ZICOND),
>
> Zi extensions come before Zb extensions.

Okay, I will update.

>
> >       __RISCV_ISA_EXT_DATA(smaia, RISCV_ISA_EXT_SMAIA),
> >       __RISCV_ISA_EXT_DATA(smstateen, RISCV_ISA_EXT_SMSTATEEN),
> >       __RISCV_ISA_EXT_DATA(ssaia, RISCV_ISA_EXT_SSAIA),
> > --
> > 2.34.1
> >
>
> Thanks,
> drew

Regards,
Anup