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From:   Anup Patel <apatel@ventanamicro.com>
Date:   Tue, 26 Sep 2023 16:06:31 +0530
Message-ID: <CAK9=C2UiBNQtv0Q2yJMKqc5pMX_jam+ZmfRz3Rme0ZYuqN68HA@mail.gmail.com>
Subject: Re: [PATCH] irqchip/riscv-intc: Mark INTC nodes for secondary CPUs as initialized.
To:     Dmitry Dunaev <dunaev@tecon.ru>
Cc:     dunaich@mail.ru, Thomas Gleixner <tglx@linutronix.de>,
        Marc Zyngier <maz@kernel.org>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Albert Ou <aou@eecs.berkeley.edu>,
        linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org
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On Tue, Sep 26, 2023 at 3:59=E2=80=AFPM Dmitry Dunaev <dunaev@tecon.ru> wro=
te:
>
> The current Linux driver irq-riscv-intc initialize IRQ domain only once,
> when init function called on primary hart. In other cases no IRQ domain i=
s
> created and no operation on interrupt-controller node is performed.
> This is cause of that no common Linux driver can use per-cpu interrupts
> mapped to several CPUs because fwnode of secondary cores INTC is not
> marked as initialized. This device is always will be marked as deferred.
> For example the system with devicetree
>
>     cpu0: cpu@0 {
>         cpu0_intc: interrupt-controller {
>             interrupt-controller;
>             compatible =3D riscv,cpu-intc;
>         };
>     };
>
>     cpu1: cpu@1 {
>         cpu1_intc: interrupt-controller {
>             interrupt-controller;
>             compatible =3D riscv,cpu-intc;
>         };
>     };
>
>     buserr {
>         compatible =3D riscv,buserr;
>         interrupts-extended =3D <&cpu0_intc 16 &cpu1_intc 16>;
>     };
>
> will always report 'buserr' node as deferred without calling any
> bus probe function.
>
> This patch will mark all secondary nodes passed to irq-riscv-intc
> driver init function as initialized to be able to act as correct
> IRQ phandle node.
>
> Signed-off-by: Dmitry Dunaev <dunaev@tecon.ru>
> ---
>  drivers/irqchip/irq-riscv-intc.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/irqchip/irq-riscv-intc.c b/drivers/irqchip/irq-riscv=
-intc.c
> index 4adeee1bc391..c01a4e8d4983 100644
> --- a/drivers/irqchip/irq-riscv-intc.c
> +++ b/drivers/irqchip/irq-riscv-intc.c
> @@ -155,8 +155,10 @@ static int __init riscv_intc_init(struct device_node=
 *node,
>          * for each INTC DT node. We only need to do INTC initialization
>          * for the INTC DT node belonging to boot CPU (or boot HART).
>          */
> -       if (riscv_hartid_to_cpuid(hartid) !=3D smp_processor_id())
> +       if (riscv_hartid_to_cpuid(hartid) !=3D smp_processor_id()) {
> +               fwnode_dev_initialized(of_node_to_fwnode(node), true);

There is already a patch on LKML to address this.
https://www.spinics.net/lists/kernel/msg4929886.html

>                 return 0;
> +       }
>
>         return riscv_intc_init_common(of_node_to_fwnode(node));
>  }
> @@ -179,8 +181,10 @@ static int __init riscv_intc_acpi_init(union acpi_su=
btable_headers *header,
>          * for each INTC. We only do INTC initialization
>          * for the INTC belonging to the boot CPU (or boot HART).
>          */
> -       if (riscv_hartid_to_cpuid(rintc->hart_id) !=3D smp_processor_id()=
)
> +       if (riscv_hartid_to_cpuid(rintc->hart_id) !=3D smp_processor_id()=
) {
> +               fwnode_dev_initialized(of_node_to_fwnode(node), true);
>                 return 0;
> +       }

We don't need this change for ACPI because we don't have devlink
dependency between devices and INTC.

Regards,
Anup

>
>         fn =3D irq_domain_alloc_named_fwnode("RISCV-INTC");
>         if (!fn) {
> --
> 2.34.1
>
>
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