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References: <20230912174928.528414-1-apatel@ventanamicro.com> <20230912174928.528414-2-apatel@ventanamicro.com>
In-Reply-To: <20230912174928.528414-2-apatel@ventanamicro.com>
From:   Atish Patra <atishp@atishpatra.org>
Date:   Tue, 19 Sep 2023 17:11:58 -0700
Message-ID: <CAOnJCU+0iUR+ziwkPnEykoS+Ym8zkG-Afs_XyyCSD4fi8wjP6w@mail.gmail.com>
Subject: Re: [PATCH v8 01/16] RISC-V: Don't fail in riscv_of_parent_hartid()
 for disabled HARTs
To:     Anup Patel <apatel@ventanamicro.com>
Cc:     Palmer Dabbelt <palmer@dabbelt.com>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Marc Zyngier <maz@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Frank Rowand <frowand.list@gmail.com>,
        Conor Dooley <conor+dt@kernel.org>,
        Andrew Jones <ajones@ventanamicro.com>,
        Sunil V L <sunilvl@ventanamicro.com>,
        Saravana Kannan <saravanak@google.com>,
        Anup Patel <anup@brainfault.org>,
        linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
        devicetree@vger.kernel.org
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On Tue, Sep 12, 2023 at 10:50=E2=80=AFAM Anup Patel <apatel@ventanamicro.co=
m> wrote:
>
> The riscv_of_processor_hartid() used by riscv_of_parent_hartid() fails
> for HARTs disabled in the DT. This results in the following warning
> thrown by the RISC-V INTC driver for the E-core on SiFive boards:
>
> [    0.000000] riscv-intc: unable to find hart id for /cpus/cpu@0/interru=
pt-controller
>
> The riscv_of_parent_hartid() is only expected to read the hartid from
> the DT so we should directly call of_get_cpu_hwid() instead of calling
> riscv_of_processor_hartid().
>
> Fixes: ad635e723e17 ("riscv: cpu: Add 64bit hartid support on RV64")
> Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> ---
>  arch/riscv/kernel/cpu.c | 11 ++++++-----
>  1 file changed, 6 insertions(+), 5 deletions(-)
>
> diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
> index c17dacb1141c..157ace8b262c 100644
> --- a/arch/riscv/kernel/cpu.c
> +++ b/arch/riscv/kernel/cpu.c
> @@ -125,13 +125,14 @@ int __init riscv_early_of_processor_hartid(struct d=
evice_node *node, unsigned lo
>   */
>  int riscv_of_parent_hartid(struct device_node *node, unsigned long *hart=
id)
>  {
> -       int rc;
> -
>         for (; node; node =3D node->parent) {
>                 if (of_device_is_compatible(node, "riscv")) {
> -                       rc =3D riscv_of_processor_hartid(node, hartid);
> -                       if (!rc)
> -                               return 0;
> +                       *hartid =3D (unsigned long)of_get_cpu_hwid(node, =
0);
> +                       if (*hartid =3D=3D ~0UL) {
> +                               pr_warn("Found CPU without hart ID\n");
> +                               return -ENODEV;
> +                       }
> +                       return 0;
>                 }
>         }
>
> --
> 2.34.1
>

LGTM.

Reviewed-by: Atish Patra <atishp@rivosinc.com>

--=20
Regards,
Atish