[PATCH 10/20] ARM: hyp-stub: Use r1 for the soft-restart address

[Ard Biesheuvel]

On 17 February 2017 at 15:44, Marc Zyngier <marc.zyngier at arm.com> wrote:
> It is not really obvious why the restart address should be in r3
> when communicated to the hyp-stub. r1 should be perfectly adequate,
> and consistent with the rest of the code.
>
> Signed-off-by: Marc Zyngier <marc.zyngier at arm.com>
> ---
>  arch/arm/kernel/hyp-stub.S | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/arch/arm/kernel/hyp-stub.S b/arch/arm/kernel/hyp-stub.S
> index 8301db963d83..8fa521bd63d2 100644
> --- a/arch/arm/kernel/hyp-stub.S
> +++ b/arch/arm/kernel/hyp-stub.S
> @@ -214,7 +214,7 @@ __hyp_stub_do_trap:
>
>  1:     teq     r0, #HVC_SOFT_RESTART
>         bne     1f
> -       bx      r3
> +       bx      r1
>
>  1:     mov     r0, #-1
>
> @@ -258,10 +258,8 @@ ENTRY(__hyp_set_vectors)
>  ENDPROC(__hyp_set_vectors)
>
>  ENTRY(__hyp_soft_restart)
> -       mov     r3, r0
>         mov     r0, #HVC_SOFT_RESTART
>         __HVC(0)
> -       mov     r0, r3
>         ret     lr
>  ENDPROC(__hyp_soft_restart)
>

/me confused. How does the address end up in r1?