Re: [RFC PATCH v2 27/35] ACPICA: Add new MADT GICC flags fields [code first?]

From: Jonathan Cameron
Date: Thu Sep 14 2023 - 10:48:19 EST


On Wed, 13 Sep 2023 16:38:15 +0000
James Morse <james.morse@xxxxxxx> wrote:

> Add the new flag field to the MADT's GICC structure.
>
> 'Online Capable' indicates a disabled CPU can be enabled later.
>
> Signed-off-by: James Morse <james.morse@xxxxxxx>
Why [code first?] it's in ACPI 6.5
https://uefi.org/sites/default/files/resources/ACPI_Spec_6_5_Aug29.pdf

Spec reference would be good though. It's 6.5 Tabel 5.37: GICC CPU Interface Flags
I think

> ---
> This patch probably needs to go via the upstream acpica project,
> but is included here so the feature can be testd.
tested

> ---
> include/acpi/actbl2.h | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/include/acpi/actbl2.h b/include/acpi/actbl2.h
> index 3751ae69432f..c433a079d8e1 100644
> --- a/include/acpi/actbl2.h
> +++ b/include/acpi/actbl2.h
> @@ -1046,6 +1046,7 @@ struct acpi_madt_generic_interrupt {
> /* ACPI_MADT_ENABLED (1) Processor is usable if set */
> #define ACPI_MADT_PERFORMANCE_IRQ_MODE (1<<1) /* 01: Performance Interrupt Mode */
> #define ACPI_MADT_VGIC_IRQ_MODE (1<<2) /* 02: VGIC Maintenance Interrupt mode */
> +#define ACPI_MADT_GICC_CPU_CAPABLE (1<<3) /* 03: CPU is online capable */
bikeshed colour time....

It's capable of being a CPU?

ACPI_MADT_GICC_ONLINE_CAPABLE

GICC already tells us it's a CPU (last C) despite the table in ACPI being labeled
Table 5.37: GICC CPU Interface table



>
> /* 12: Generic Distributor (ACPI 5.0 + ACPI 6.0 changes) */
>