Messages in this thread Patch in this message | | | From | "john.liuli" <> | Subject | [RFC PATCH 2/2] Assign a new irq handler while irqfd enabled | Date | Sat, 25 Oct 2014 16:24:54 +0800 |
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From: Li Liu <john.liuli@huawei.com>
This irq handler will get the interrupt reason from a shared memory. And will be assigned only while irqfd enabled.
Signed-off-by: Li Liu <john.liuli@huawei.com> --- drivers/virtio/virtio_mmio.c | 34 ++++++++++++++++++++++++++++++++-- 1 file changed, 32 insertions(+), 2 deletions(-)
diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c index 28ddb55..7229605 100644 --- a/drivers/virtio/virtio_mmio.c +++ b/drivers/virtio/virtio_mmio.c @@ -259,7 +259,31 @@ static irqreturn_t vm_interrupt(int irq, void *opaque) return ret; } +/* Notify all virtqueues on an interrupt. */ +static irqreturn_t vm_interrupt_irqfd(int irq, void *opaque) +{ + struct virtio_mmio_device *vm_dev = opaque; + struct virtio_mmio_vq_info *info; + unsigned long status; + unsigned long flags; + irqreturn_t ret = IRQ_NONE; + /* Read the interrupt reason and reset it */ + status = *vm_dev->isr_mem; + *vm_dev->isr_mem = 0x0; + + if (unlikely(status & VIRTIO_MMIO_INT_CONFIG)) { + virtio_config_changed(&vm_dev->vdev); + ret = IRQ_HANDLED; + } + + spin_lock_irqsave(&vm_dev->lock, flags); + list_for_each_entry(info, &vm_dev->virtqueues, node) + ret |= vring_interrupt(irq, info->vq); + spin_unlock_irqrestore(&vm_dev->lock, flags); + + return ret; +} static void vm_del_vq(struct virtqueue *vq) { @@ -391,6 +415,7 @@ error_available: return ERR_PTR(err); } +#define VIRTIO_MMIO_F_IRQFD (1 << 7) static int vm_find_vqs(struct virtio_device *vdev, unsigned nvqs, struct virtqueue *vqs[], vq_callback_t *callbacks[], @@ -400,8 +425,13 @@ static int vm_find_vqs(struct virtio_device *vdev, unsigned nvqs, unsigned int irq = platform_get_irq(vm_dev->pdev, 0); int i, err; - err = request_irq(irq, vm_interrupt, IRQF_SHARED, - dev_name(&vdev->dev), vm_dev); + if (*vm_dev->isr_mem & VIRTIO_MMIO_F_IRQFD) { + err = request_irq(irq, vm_interrupt_irqfd, IRQF_SHARED, + dev_name(&vdev->dev), vm_dev); + } else { + err = request_irq(irq, vm_interrupt, IRQF_SHARED, + dev_name(&vdev->dev), vm_dev); + } if (err) return err; -- 1.7.9.5
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