Re: [kvm-unit-tests PATCH 15/17] arm: gic: Provide FIQ handler

[Alexandru Elisei <alexandru.elisei@arm.com>]

Hi,

On 11/8/19 2:42 PM, Andre Przywara wrote:
> When configuring an interrupt as Group 0, we can ask the GIC to deliver
> them as a FIQ. For this we need a separate exception handler.
>
> Provide this to be used later.
>
> Signed-off-by: Andre Przywara <andre.przywara@arm.com>
> ---
>  arm/gic.c | 24 ++++++++++++++++++++++++
>  1 file changed, 24 insertions(+)
>
> diff --git a/arm/gic.c b/arm/gic.c
> index c68b5b5..6756850 100644
> --- a/arm/gic.c
> +++ b/arm/gic.c
> @@ -178,6 +178,30 @@ static void irq_handler(struct pt_regs *regs __unused)
>  	smp_wmb(); /* pairs with rmb in check_acked */
>  }
>  
> +static inline void fiq_handler(struct pt_regs *regs __unused)
> +{
> +	u32 irqstat = gic_read_iar(0);
> +	u32 irqnr = gic_iar_irqnr(irqstat);
> +
> +	if (irqnr == GICC_INT_SPURIOUS) {
> +		++spurious[smp_processor_id()];
> +		smp_wmb();
> +		return;
> +	}
> +
> +	gic_write_eoir(irqstat, 0);
> +
> +	smp_rmb(); /* pairs with wmb in stats_reset */
> +	++acked[smp_processor_id()];
> +	if (irqnr < GIC_NR_PRIVATE_IRQS) {
> +		check_ipi_sender(irqstat);
> +		check_irqnr(irqnr, IPI_IRQ);
> +	} else {
> +		check_irqnr(irqnr, SPI_IRQ);
> +	}
> +	smp_wmb(); /* pairs with rmb in check_acked */
> +}

If I'm not mistaken, this is identical to irq_handler, with the exception that
gic_read_iar and gic_write_eoir take group 0 as argument here. Maybe we can
abstract the common code into a function that takes the group as the argument?
What do you think?

Thanks,
Alex
> +
>  static void gicv2_ipi_send_self(void)
>  {
>  	writel(2 << 24 | IPI_IRQ, gicv2_dist_base() + GICD_SGIR);

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