Re: [PATCH v4 02/21] arm64: Fix outdated TCR setup comment

Catalin Marinas
2021-01-20T18:42:12Z

On Mon, Jan 18, 2021 at 09:45:14AM +0000, Marc Zyngier wrote:
> The arm64 kernel has long be able to use more than 39bit VAs.
> Since day one, actually. Let's rewrite the offending comment.
>
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---
> arch/arm64/mm/proc.S | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S
> index 1f7ee8c8b7b8..ece785477bdc 100644
> --- a/arch/arm64/mm/proc.S
> +++ b/arch/arm64/mm/proc.S
> @@ -464,8 +464,8 @@ SYM_FUNC_START(__cpu_setup)
> #endif
> msr mair_el1, x5
> /*
> - * Set/prepare TCR and TTBR. We use 512GB (39-bit) address range for
> - * both user and kernel.
> + * Set/prepare TCR and TTBR. TCR_EL1.T1SZ gets further
> + * adjusted if the kernel is compiled with 52bit VA support.

I think both T0SZ and T1SZ get updated based on a mismatch between the
kernel configuration and the hardware support. Anyway, I'm not asking
for a detailed comment here, so:

Acked-by: Catalin Marinas <catalin.marinas@arm.com>