On 10/31/2014 08:36 PM, Alex Williamson wrote:
> On Mon, 2014-10-27 at 19:07 +0100, Antonios Motakis wrote:
>> Level sensitive interrupts are exposed as maskable and automasked
>> interrupts and are masked and disabled automatically when they fire.
>>
>> Signed-off-by: Antonios Motakis <a.motakis@xxxxxxxxxxxxxxxxxxxxxx>
>> ---
>> drivers/vfio/platform/vfio_platform_irq.c | 102 +++++++++++++++++++++++++-
>> drivers/vfio/platform/vfio_platform_private.h | 2 +
>> 2 files changed, 100 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/vfio/platform/vfio_platform_irq.c b/drivers/vfio/platform/vfio_platform_irq.c
>> index 2ac8ed7..563abf6 100644
>> --- a/drivers/vfio/platform/vfio_platform_irq.c
>> +++ b/drivers/vfio/platform/vfio_platform_irq.c
>> @@ -31,18 +31,108 @@
>>
>> #include "vfio_platform_private.h"
>>
>> +static void vfio_platform_mask(struct vfio_platform_irq *irq_ctx)
>> +{
>> + unsigned long flags;
>> +
>> + spin_lock_irqsave(&irq_ctx->lock, flags);
>> +
>> + if (!irq_ctx->masked) {
>> + disable_irq(irq_ctx->hwirq);
>> + irq_ctx->masked = true;
>> + }
>> +
>> + spin_unlock_irqrestore(&irq_ctx->lock, flags);
>> +}
>> +
>> static int vfio_platform_set_irq_mask(struct vfio_platform_device *vdev,
>> unsigned index, unsigned start,
>> unsigned count, uint32_t flags, void *data)
>> {
>> - return -EINVAL;
>> + if (start != 0 || count != 1)
>> + return -EINVAL;
>> +
>> + if (!(vdev->irqs[index].flags & VFIO_IRQ_INFO_MASKABLE))
>> + return -EINVAL;
>> +
>> + if (flags & VFIO_IRQ_SET_DATA_EVENTFD)
>> + return -EINVAL; /* not implemented yet */
>> +
>> + if (flags & VFIO_IRQ_SET_DATA_NONE) {
>> + vfio_platform_mask(&vdev->irqs[index]);
>> +
>> + } else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
>> + uint8_t mask = *(uint8_t *)data;
>> +
>> + if (mask)
>> + vfio_platform_mask(&vdev->irqs[index]);
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static void vfio_platform_unmask(struct vfio_platform_irq *irq_ctx)
>> +{
>> + unsigned long flags;
>> +
>> + spin_lock_irqsave(&irq_ctx->lock, flags);
>> +
>> + if (irq_ctx->masked) {
>> + enable_irq(irq_ctx->hwirq);
>> + irq_ctx->masked = false;
>> + }
>> +
>> + spin_unlock_irqrestore(&irq_ctx->lock, flags);
>> }
>>
>> static int vfio_platform_set_irq_unmask(struct vfio_platform_device *vdev,
>> unsigned index, unsigned start,
>> unsigned count, uint32_t flags, void *data)
>> {
>> - return -EINVAL;
>> + if (start != 0 || count != 1)
>> + return -EINVAL;
>> +
>> + if (!(vdev->irqs[index].flags & VFIO_IRQ_INFO_MASKABLE))
>> + return -EINVAL;
>> +
>> + if (flags & VFIO_IRQ_SET_DATA_EVENTFD)
>> + return -EINVAL; /* not implemented yet */
>> +
>> + if (flags & VFIO_IRQ_SET_DATA_NONE) {
>> + vfio_platform_unmask(&vdev->irqs[index]);
>> +
>> + } else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
>> + uint8_t unmask = *(uint8_t *)data;
>> +
>> + if (unmask)
>> + vfio_platform_unmask(&vdev->irqs[index]);
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static irqreturn_t vfio_maskable_irq_handler(int irq, void *dev_id)
>> +{
>> + struct vfio_platform_irq *irq_ctx = dev_id;
>> + unsigned long flags;
>> + int ret = IRQ_NONE;
>> +
>> + spin_lock_irqsave(&irq_ctx->lock, flags);
>> +
>> + if (!irq_ctx->masked) {
>> + ret = IRQ_HANDLED;
>> +
>> + /* automask maskable interrupts */
>> + disable_irq_nosync(irq_ctx->hwirq);
>> + irq_ctx->masked = true;
>> + }
>> +
>> + spin_unlock_irqrestore(&irq_ctx->lock, flags);
>> +
>> + if (ret == IRQ_HANDLED)
>> + eventfd_signal(irq_ctx->trigger, 1);
>> +
>> + return ret;
>
> This is not just a maskable irq handler, but specifically a level (aka
> automasked) handler. So this should only be used for AUTOMASKED irqs.
>
>> }
Antonios, Alex,
When turning forwarded IRQ modality on/off, I guess I now should the
swap the handlers (free_irq, request_irq) adding some extra complexity
in the driver compared to the previous implementation. Do you confirm
this is the prefered way?
Thanks
Eric
>>
>> static irqreturn_t vfio_irq_handler(int irq, void *dev_id)
>> @@ -103,7 +193,7 @@ static int vfio_platform_set_irq_trigger(struct vfio_platform_device *vdev,
>> irq_handler_t handler;
>>
>> if (vdev->irqs[index].flags & VFIO_IRQ_INFO_MASKABLE)
>> - return -EINVAL; /* not implemented */
>> + handler = vfio_maskable_irq_handler;
>
> As noted in the previous patch, this should be a test for AUTOMASKED,
> not just MASKABLE.
>
>> else
>> handler = vfio_irq_handler;
>>
>> @@ -175,13 +265,17 @@ int vfio_platform_irq_init(struct vfio_platform_device *vdev)
>> if (hwirq < 0)
>> goto err;
>>
>> + spin_lock_init(&vdev->irqs[i].lock);
>> +
>> vdev->irqs[i].flags = VFIO_IRQ_INFO_EVENTFD;
>>
>> if (irq_get_trigger_type(hwirq) & IRQ_TYPE_LEVEL_MASK)
>> - vdev->irqs[i].flags |= VFIO_IRQ_INFO_MASKABLE;
>> + vdev->irqs[i].flags |= VFIO_IRQ_INFO_MASKABLE
>> + | VFIO_IRQ_INFO_AUTOMASKED;
>>
>> vdev->irqs[i].count = 1;
>> vdev->irqs[i].hwirq = hwirq;
>> + vdev->irqs[i].masked = false;
>> }
>>
>> vdev->num_irqs = cnt;
>> diff --git a/drivers/vfio/platform/vfio_platform_private.h b/drivers/vfio/platform/vfio_platform_private.h
>> index a3f2411..d25c4cd 100644
>> --- a/drivers/vfio/platform/vfio_platform_private.h
>> +++ b/drivers/vfio/platform/vfio_platform_private.h
>> @@ -30,6 +30,8 @@ struct vfio_platform_irq {
>> int hwirq;
>> char *name;
>> struct eventfd_ctx *trigger;
>> + bool masked;
>> + spinlock_t lock;
>> };
>>
>> struct vfio_platform_region {
>
>
>
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