[PATCH v2] riscv: Allow to downgrade paging mode from the command line

[Björn Töpel]

Alexandre Ghiti <alexghiti at rivosinc.com> writes:

> Add 2 early command line parameters called "no5lvl" and "no4lvl" (using
> the same naming as x86) to allow a user to downgrade from sv57 (the
> default mode if the hardware supports it) to sv48 or sv39.
>
> Note that going through the device tree to get the kernel command line
> works with ACPI too since the efi stub creates a device tree anyway with
> the command line.
>
> Also, as those params are treated very early in the boot process and we
> use standard device tree functions that may be kasan instrumented, we
> only enable them for !KASAN configurations.
>
> Signed-off-by: Alexandre Ghiti <alexghiti at rivosinc.com>

Reviewed-by: Björn Töpel <bjorn at kernel.org>