[PATCH 5/7] virtio_pci: add a helper to request MSI-X interrupts

[Christoph Hellwig]

Factor out some duplicated code to format that MSI-X vector name and
request the interrupt for it.

Signed-off-by: Christoph Hellwig <h...@lst.de>
---
 drivers/virtio/virtio_pci_common.c | 38 +++++++++++++++-----------------------
 1 file changed, 15 insertions(+), 23 deletions(-)

diff --git a/drivers/virtio/virtio_pci_common.c 
b/drivers/virtio/virtio_pci_common.c
index 644bd80..7c44891 100644
--- a/drivers/virtio/virtio_pci_common.c
+++ b/drivers/virtio/virtio_pci_common.c
@@ -102,11 +102,19 @@ static irqreturn_t vp_interrupt(int irq, void *opaque)
        return vp_vring_interrupt(irq, opaque);
 }
 
+static int vp_request_msix_vector(struct virtio_pci_device *vp_dev, int vec,
+               irq_handler_t handler, const char *name, void *dev_id)
+{
+       snprintf(vp_dev->msix_names[vec], sizeof(vp_dev->msix_names[vec]),
+                       "%s-%s", dev_name(&vp_dev->vdev.dev), name);
+       return request_irq(pci_irq_vector(vp_dev->pci_dev, vec), handler, 0,
+                       vp_dev->msix_names[vec], dev_id);
+}
+
 static int vp_request_msix_vectors(struct virtio_device *vdev, int nvectors,
                                   bool per_vq_vectors)
 {
        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
-       const char *name = dev_name(&vp_dev->vdev.dev);
        unsigned i, v;
        int err = -ENOMEM;
 
@@ -133,15 +141,10 @@ static int vp_request_msix_vectors(struct virtio_device 
*vdev, int nvectors,
        vp_dev->msix_enabled = 1;
 
        /* Set the vector used for configuration */
-       v = vp_dev->msix_used_vectors;
-       snprintf(vp_dev->msix_names[v], sizeof *vp_dev->msix_names,
-                "%s-config", name);
-       err = request_irq(pci_irq_vector(vp_dev->pci_dev, v),
-                         vp_config_changed, 0, vp_dev->msix_names[v],
-                         vp_dev);
+       err = vp_request_msix_vector(vp_dev, vp_dev->msix_used_vectors++,
+                       vp_config_changed, "config", vp_dev);
        if (err)
                goto error;
-       ++vp_dev->msix_used_vectors;
 
        v = vp_dev->config_vector(vp_dev, v);
        /* Verify we had enough resources to assign the vector */
@@ -152,15 +155,10 @@ static int vp_request_msix_vectors(struct virtio_device 
*vdev, int nvectors,
 
        if (!per_vq_vectors) {
                /* Shared vector for all VQs */
-               v = vp_dev->msix_used_vectors;
-               snprintf(vp_dev->msix_names[v], sizeof *vp_dev->msix_names,
-                        "%s-virtqueues", name);
-               err = request_irq(pci_irq_vector(vp_dev->pci_dev, v),
-                                 vp_vring_interrupt, 0, vp_dev->msix_names[v],
-                                 vp_dev);
+               err = vp_request_msix_vector(vp_dev, 
vp_dev->msix_used_vectors++,
+                               vp_vring_interrupt, "virtqueues", vp_dev);
                if (err)
                        goto error;
-               ++vp_dev->msix_used_vectors;
        }
        return 0;
 error:
@@ -316,14 +314,8 @@ static int vp_try_to_find_vqs(struct virtio_device *vdev, 
unsigned nvqs,
                        continue;
 
                /* allocate per-vq irq if available and necessary */
-               snprintf(vp_dev->msix_names[msix_vec],
-                        sizeof *vp_dev->msix_names,
-                        "%s-%s",
-                        dev_name(&vp_dev->vdev.dev), names[i]);
-               err = request_irq(pci_irq_vector(vp_dev->pci_dev, msix_vec),
-                                 vring_interrupt, 0,
-                                 vp_dev->msix_names[msix_vec],
-                                 vqs[i]);
+               err = vp_request_msix_vector(vp_dev, msix_vec, vring_interrupt,
+                               names[i], vqs[i]);
                if (err) {
                        vp_del_vq(vqs[i]);
                        goto error_find;
-- 
2.1.4