Re: [PATCH] irqchip/riscv-intc: Fix no-SMP boot with ACPI

[Anup Patel]

On Mon, Oct 14, 2024 at 12:27 PM Sunil V L <sunilvl@xxxxxxxxxxxxxxxx> wrote:
>
> When CONFIG_SMP is disabled, the static array rintc_acpi_data with size
> NR_CPUS will not be sufficient to hold all RINTC structures passed from
> the firmware. All RINTC structures are required to configure
> IMSIC/APLIC/PLIC properly irrespective of SMP in the OS. So, allocate
> dynamic memory based on the number of RINTC structures in MADT to fix
> this issue.
>
> Fixes: f8619b66bdb1 ("irqchip/riscv-intc: Add ACPI support for AIA")
> Reported-by: Björn Töpel <bjorn@xxxxxxxxxx>
> Closes: https://github.com/linux-riscv/linux-riscv/actions/runs/11280997511/job/31375229012
> Signed-off-by: Sunil V L <sunilvl@xxxxxxxxxxxxxxxx>

LGTM.

Reviewed-by: Anup Patel <anup@xxxxxxxxxxxxxx>

Regards,
Anup

> ---
>  drivers/irqchip/irq-riscv-intc.c | 19 ++++++++++++++++++-
>  1 file changed, 18 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/irqchip/irq-riscv-intc.c b/drivers/irqchip/irq-riscv-intc.c
> index 8c5411386220..f653c13de62b 100644
> --- a/drivers/irqchip/irq-riscv-intc.c
> +++ b/drivers/irqchip/irq-riscv-intc.c
> @@ -265,7 +265,7 @@ struct rintc_data {
>  };
>
>  static u32 nr_rintc;
> -static struct rintc_data *rintc_acpi_data[NR_CPUS];
> +static struct rintc_data **rintc_acpi_data;
>
>  #define for_each_matching_plic(_plic_id)                               \
>         unsigned int _plic;                                             \
> @@ -329,13 +329,30 @@ int acpi_rintc_get_imsic_mmio_info(u32 index, struct resource *res)
>         return 0;
>  }
>
> +static int __init riscv_intc_acpi_match(union acpi_subtable_headers *header,
> +                                       const unsigned long end)
> +{
> +       return 0;
> +}
> +
>  static int __init riscv_intc_acpi_init(union acpi_subtable_headers *header,
>                                        const unsigned long end)
>  {
>         struct acpi_madt_rintc *rintc;
>         struct fwnode_handle *fn;
> +       int count;
>         int rc;
>
> +       if (!rintc_acpi_data) {
> +               count = acpi_table_parse_madt(ACPI_MADT_TYPE_RINTC, riscv_intc_acpi_match, 0);
> +               if (count <= 0)
> +                       return -EINVAL;
> +
> +               rintc_acpi_data = kcalloc(count, sizeof(*rintc_acpi_data), GFP_KERNEL);
> +               if (!rintc_acpi_data)
> +                       return -ENOMEM;
> +       }
> +
>         rintc = (struct acpi_madt_rintc *)header;
>         rintc_acpi_data[nr_rintc] = kzalloc(sizeof(*rintc_acpi_data[0]), GFP_KERNEL);
>         if (!rintc_acpi_data[nr_rintc])
> --
> 2.43.0
>