Re: [PATCH] ARCv2: intc: Use kflag if STATUS32.IE must be reset

From: Vineet Gupta
Date: Fri Sep 30 2016 - 17:18:48 EST


On 09/12/2016 08:55 AM, Yuriy Kolerov wrote:
> In the end of "arc_init_IRQ" STATUS32.IE flag is going to be affected by
> "flag" instruction but "flag" never touches IE flag on ARCv2. So "kflag"
> instruction must be used instead of "flag".
>
> Signed-off-by: Yuriy Kolerov <yuriy.kolerov@xxxxxxxxxxxx>
> ---
> arch/arc/kernel/intc-arcv2.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/arc/kernel/intc-arcv2.c b/arch/arc/kernel/intc-arcv2.c
> index 6c24faf..62b59409 100644
> --- a/arch/arc/kernel/intc-arcv2.c
> +++ b/arch/arc/kernel/intc-arcv2.c
> @@ -74,7 +74,7 @@ void arc_init_IRQ(void)
> tmp = read_aux_reg(0xa);
> tmp |= STATUS_AD_MASK | (irq_prio << 1);
> tmp &= ~STATUS_IE_MASK;
> - asm volatile("flag %0 \n"::"r"(tmp));
> + asm volatile("kflag %0 \n"::"r"(tmp));

Revisiting this in light of ongoing 2 priority interrupt support for HS38 cores.

It seems there is no need to fiddle with interrupt bits here at all.

init/main.c now has well known checkpoints where it explicitly disables the
interrupts in early boot code and enables them when time is right. So when we land
in arc_init_IRQ() interrupts have already been disabled.

So I'm dropping this patch and instead adding another one which removes the intr
bits touching part !

OK ?

-Vineet