[PATCH 3/3] arm64: acpi: Enable ACPI CCEL support

[Will Deacon]

On Fri, Jun 13, 2025 at 12:11:53PM +0100, Suzuki K Poulose wrote:
> ACPI CCEL memory area is reported as Non-Volatile storage area. Map it as
> PAGE_KERNEL.

It would be helpful to have a citation for that. I've tried digging it
out of the ACPI spec, but that pointed me to the Intel TDX site and I
got lost in whitepapers :/

> Cc: Sami Mujawar <sami.mujawar at arm.com>
> Cc: Will Deacon <will at kernel.org>
> Cc: Catalin Marinas <catalin.marinas at arm.com>
> Cc: "Aneesh Kumar K.V" <aneesh.kumar at kernel.org>
> Cc: Steven Price <steven.price at arm.com>
> Cc: Sudeep Holla <sudeep.holla at arm.com>
> Signed-off-by: Suzuki K Poulose <suzuki.poulose at arm.com>
> ---
>  arch/arm64/kernel/acpi.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
> index b9a66fc146c9..f52439d411a0 100644
> --- a/arch/arm64/kernel/acpi.c
> +++ b/arch/arm64/kernel/acpi.c
> @@ -356,6 +356,11 @@ void __iomem *acpi_os_ioremap(acpi_physical_address phys, acpi_size size)
>  			prot = PAGE_KERNEL_RO;
>  			break;
>  
> +		case EFI_ACPI_MEMORY_NVS:
> +			/* Non-volatile storage, required for CCEL */
> +			prot = PAGE_KERNEL;

By "storage" you just mean memory, right?

Will