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

From: Eric Auger
Date: Mon Aug 17 2015 - 11:40:46 EST


On 08/12/2015 08:56 PM, Alex Williamson wrote:
> On Mon, 2015-08-10 at 15:20 +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)
>
> vfio_platform_irq_is_active()?
OK
>
>> +{
>> + 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);
>
> Why can't we propagate this error to the caller and let them decide?
sure

Eric
>
>> + masked = irq->masked;
>> + outstanding = active || masked;
>> +
>> + spin_unlock_irqrestore(&irq->lock, flags);
>> + return outstanding;
>> +}
>> +
>> static void vfio_platform_irq_bypass_stop(struct irq_bypass_producer *prod)
>> {
>> }
>
>
>

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