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Date:   Thu, 14 Sep 2023 15:48:07 +0100
From:   Jonathan Cameron <Jonathan.Cameron@Huawei.com>
To:     James Morse <james.morse@arm.com>
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        Jean-Philippe Brucker <jean-philippe@linaro.org>,
        <jianyong.wu@arm.com>, <justin.he@arm.com>
Subject: Re: [RFC PATCH v2 27/35] ACPICA: Add new MADT GICC flags fields
 [code first?]
Message-ID: <20230914154807.0000710d@Huawei.com>
In-Reply-To: <20230913163823.7880-28-james.morse@arm.com>
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        <20230913163823.7880-28-james.morse@arm.com>
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On Wed, 13 Sep 2023 16:38:15 +0000
James Morse <james.morse@arm.com> 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@arm.com>
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) */
>