[PATCH v3 02/10] riscv: Define arch_apei_get_mem_attribute for RISC-V

[Sunil V L]

Hi Himanshu,

On Fri, Jan 9, 2026 at 2:32 PM Himanshu Chauhan
<himanshu.chauhan at oss.qualcomm.com> wrote:
>
> ghes_map function uses arch_apei_get_mem_attribute to get the
> protection bits for a given physical address. These protection
> bits are then used to map the physical address.
>
> Signed-off-by: Himanshu Chauhan <himanshu.chauhan at oss.qualcomm.com>
> ---
>  arch/riscv/include/asm/acpi.h | 20 ++++++++++++++++++++
>  1 file changed, 20 insertions(+)
>
> diff --git a/arch/riscv/include/asm/acpi.h b/arch/riscv/include/asm/acpi.h
> index 6e13695120bc..0c599452ef48 100644
> --- a/arch/riscv/include/asm/acpi.h
> +++ b/arch/riscv/include/asm/acpi.h
> @@ -27,6 +27,26 @@ extern int acpi_disabled;
>  extern int acpi_noirq;
>  extern int acpi_pci_disabled;
>
> +#ifdef CONFIG_ACPI_APEI
> +/*
> + * acpi_disable_cmcff is used in drivers/acpi/apei/hest.c for disabling
> + * IA-32 Architecture Corrected Machine Check (CMC) Firmware-First mode
> + * with a kernel command line parameter "acpi=nocmcoff". But we don't
> + * have this IA-32 specific feature on ARM64, this definition is only
> + * for compatibility.
> + */
This comment needs to be updated.

> +#define acpi_disable_cmcff 1
> +static inline pgprot_t arch_apei_get_mem_attribute(phys_addr_t addr)
> +{
> +       /*
> +        * Until we have a way to look for EFI memory attributes.
> +        */
I am not sure I understand this comment. We should be able to get the
attributes of the EFI memory regions. Do you mean the memory region
attribute will be the same and currently don't support non-cacheable?

> +       return PAGE_KERNEL;
> +}
> +#else /* CONFIG_ACPI_APEI */
> +#define acpi_disable_cmcff 0
Why is this change required?

Regards,
Sunil