Re: [PATCH] RISC-V: ACPI: fix early_ioremap to early_memremap

[Sunil V L]

Hi Yunhui,
On Mon, Oct 14, 2024 at 05:47:05PM +0800, Yunhui Cui wrote:
> When SVPBMT is enabled, __acpi_map_table() will directly access the
> data in DDR through the IO attribute, rather than through hardware
> cache consistency, resulting in incorrect data in the obtained ACPI
> table.
> 
> The log: ACPI: [ACPI:0x18] Invalid zero length.
> 
> We do not assume whether the bootloader flushes or not. We should
> access in a cacheable way instead of maintaining cache consistency
> by software.
> 
> Signed-off-by: Yunhui Cui <cuiyunhui@xxxxxxxxxxxxx>
> ---
>  arch/riscv/kernel/acpi.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/riscv/kernel/acpi.c b/arch/riscv/kernel/acpi.c
> index 6e0d333f57e5..3177c9af8764 100644
> --- a/arch/riscv/kernel/acpi.c
> +++ b/arch/riscv/kernel/acpi.c
> @@ -210,7 +210,7 @@ void __init __iomem *__acpi_map_table(unsigned long phys, unsigned long size)
>  	if (!size)
>  		return NULL;
>  
> -	return early_ioremap(phys, size);
> +	return early_memremap(phys, size);
>  }
> 
I think __acpi_unmap_table() also needs similar change. You might need
to typecast to suppress the sparse error [1] then.

[1] - https://lore.kernel.org/oe-kbuild-all/202305201427.I7QhPjNW-lkp@xxxxxxxxx/#r

Thanks,
Sunil