Re: [PATCH v3 05/10] VFIO: platform: add vfio_platform_is_active

From: Christoffer Dall
Date: Wed Sep 02 2015 - 15:28:46 EST


On Mon, Aug 10, 2015 at 03:20:59PM +0200, Eric Auger wrote:
> This function returns whether the IRQ is active at irqchip level or
> VFIO masked. If either is true, it is considered the IRQ is active.
> Currently there is no way to differentiate userspace masked IRQ from
> automasked IRQ. There might be false detection of activity. However
> it is currently acceptable to have false detection.
>
> Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx>
>
> ---
> ---
> drivers/vfio/platform/vfio_platform_irq.c | 17 +++++++++++++++++
> 1 file changed, 17 insertions(+)
>
> diff --git a/drivers/vfio/platform/vfio_platform_irq.c b/drivers/vfio/platform/vfio_platform_irq.c
> index a285384..efaee58 100644
> --- a/drivers/vfio/platform/vfio_platform_irq.c
> +++ b/drivers/vfio/platform/vfio_platform_irq.c
> @@ -205,6 +205,23 @@ static int vfio_platform_set_automasked(struct vfio_platform_irq *irq,
> return 0;
> }
>
> +static int vfio_platform_is_active(struct vfio_platform_irq *irq)
> +{
> + unsigned long flags;
> + bool active, masked, outstanding;
> + int ret;
> +
> + spin_lock_irqsave(&irq->lock, flags);
> +
> + ret = irq_get_irqchip_state(irq->hwirq, IRQCHIP_STATE_ACTIVE, &active);
> + BUG_ON(ret);
> + masked = irq->masked;
> + outstanding = active || masked;

outstanding?

why not just return active || masked ?

-Christoffer

> +
> + spin_unlock_irqrestore(&irq->lock, flags);
> + return outstanding;
> +}
> +
> static void vfio_platform_irq_bypass_stop(struct irq_bypass_producer *prod)
> {
> }
> --
> 1.9.1
>
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