[PATCH 2/3] virtio_pci: split up vp_interrupt

Michael S. Tsirkin
2009-05-11T22:22:09Z

This reorganizes virtio-pci code in vp_interrupt slightly, so that
it's easier to add per-vq MSI support on top.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
drivers/virtio/virtio_pci.c | 53 +++++++++++++++++++++++++++---------------
1 files changed, 34 insertions(+), 19 deletions(-)

diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c
index d5e030f..a6bebe2 100644
--- a/drivers/virtio/virtio_pci.c
+++ b/drivers/virtio/virtio_pci.c
@@ -164,6 +164,37 @@ static void vp_notify(struct virtqueue *vq)
iowrite16(info->queue_index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NOTIFY);
}

+/* Handle a configuration change: Tell driver if it wants to know. */
+static irqreturn_t vp_config_changed(int irq, void *opaque)
+{
+ struct virtio_pci_device *vp_dev = opaque;
+ struct virtio_driver *drv;
+ drv = container_of(vp_dev->vdev.dev.driver,
+ struct virtio_driver, driver);
+
+ if (drv && drv->config_changed)
+ drv->config_changed(&vp_dev->vdev);
+ return IRQ_HANDLED;
+}
+
+/* Notify all virtqueues on an interrupt. */
+static irqreturn_t vp_vring_interrupt(int irq, void *opaque)
+{
+ struct virtio_pci_device *vp_dev = opaque;
+ struct virtio_pci_vq_info *info;
+ irqreturn_t ret = IRQ_NONE;
+ unsigned long flags;
+
+ spin_lock_irqsave(&vp_dev->lock, flags);
+ list_for_each_entry(info, &vp_dev->virtqueues, node) {
+ if (vring_interrupt(irq, info->vq) == IRQ_HANDLED)
+ ret = IRQ_HANDLED;
+ }
+ spin_unlock_irqrestore(&vp_dev->lock, flags);
+
+ return ret;
+}
+
/* A small wrapper to also acknowledge the interrupt when it's handled.
* I really need an EIO hook for the vring so I can ack the interrupt once we
* know that we'll be handling the IRQ but before we invoke the callback since
@@ -173,9 +204,6 @@ static void vp_notify(struct virtqueue *vq)
static irqreturn_t vp_interrupt(int irq, void *opaque)
{
struct virtio_pci_device *vp_dev = opaque;
- struct virtio_pci_vq_info *info;
- irqreturn_t ret = IRQ_NONE;
- unsigned long flags;
u8 isr;

/* reading the ISR has the effect of also clearing it so it's very
@@ -187,23 +215,10 @@ static irqreturn_t vp_interrupt(int irq, void *opaque)
return IRQ_NONE;

/* Configuration change? Tell driver if it wants to know. */
- if (isr & VIRTIO_PCI_ISR_CONFIG) {
- struct virtio_driver *drv;
- drv = container_of(vp_dev->vdev.dev.driver,
- struct virtio_driver, driver);
-
- if (drv && drv->config_changed)
- drv->config_changed(&vp_dev->vdev);
- }
+ if (isr & VIRTIO_PCI_ISR_CONFIG)
+ vp_config_changed(irq, opaque);

- spin_lock_irqsave(&vp_dev->lock, flags);
- list_for_each_entry(info, &vp_dev->virtqueues, node) {
- if (vring_interrupt(irq, info->vq) == IRQ_HANDLED)
- ret = IRQ_HANDLED;
- }
- spin_unlock_irqrestore(&vp_dev->lock, flags);
-
- return ret;
+ return vp_vring_interrupt(irq, opaque);
}

/* the config->find_vq() implementation */
--
1.6.3.rc3.1.g830204