[PATCH V2 09/19] virtio-pci-modern: introduce vp_modern_set_queue_vector()

[Jason Wang]

This patch introduces a helper to set virtqueue MSI vector.

Signed-off-by: Jason Wang <jasow...@redhat.com>
---
 drivers/virtio/virtio_pci_modern.c | 35 ++++++++++++++++++++----------
 1 file changed, 23 insertions(+), 12 deletions(-)

diff --git a/drivers/virtio/virtio_pci_modern.c 
b/drivers/virtio/virtio_pci_modern.c
index a128e5814045..05cd409c0731 100644
--- a/drivers/virtio/virtio_pci_modern.c
+++ b/drivers/virtio/virtio_pci_modern.c
@@ -191,6 +191,25 @@ static void vp_modern_set_features(struct 
virtio_pci_modern_device *mdev,
        vp_iowrite32(features >> 32, &cfg->guest_feature);
 }
 
+/*
+ * vp_modern_queue_vector - set the MSIX vector for a specific virtqueue
+ * @mdev: the modern virtio-pci device
+ * @index: queue index
+ * @vector: the config vector
+ *
+ * Returns the config vector read from the device
+ */
+static u16 vp_modern_queue_vector(struct virtio_pci_modern_device *mdev,
+                                 u16 index, u16 vector)
+{
+       struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
+
+       vp_iowrite16(index, &cfg->queue_select);
+       vp_iowrite16(vector, &cfg->queue_msix_vector);
+       /* Flush the write out to device */
+       return vp_ioread16(&cfg->queue_msix_vector);
+}
+
 /* virtio config->finalize_features() implementation */
 static int vp_finalize_features(struct virtio_device *vdev)
 {
@@ -474,8 +493,7 @@ static struct virtqueue *setup_vq(struct virtio_pci_device 
*vp_dev,
        }
 
        if (msix_vec != VIRTIO_MSI_NO_VECTOR) {
-               vp_iowrite16(msix_vec, &cfg->queue_msix_vector);
-               msix_vec = vp_ioread16(&cfg->queue_msix_vector);
+               msix_vec = vp_modern_queue_vector(mdev, index, msix_vec);
                if (msix_vec == VIRTIO_MSI_NO_VECTOR) {
                        err = -EBUSY;
                        goto err_assign_vector;
@@ -522,17 +540,10 @@ static void del_vq(struct virtio_pci_vq_info *info)
        struct virtqueue *vq = info->vq;
        struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
        struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
-       struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
-
 
-       vp_iowrite16(vq->index, &cfg->queue_select);
-
-       if (vp_dev->msix_enabled) {
-               vp_iowrite16(VIRTIO_MSI_NO_VECTOR,
-                            &cfg->queue_msix_vector);
-               /* Flush the write out to device */
-               vp_ioread16(&cfg->queue_msix_vector);
-       }
+       if (vp_dev->msix_enabled)
+               vp_modern_queue_vector(mdev, vq->index,
+                                      VIRTIO_MSI_NO_VECTOR);
 
        if (!mdev->notify_base)
                pci_iounmap(mdev->pci_dev, (void __force __iomem *)vq->priv);
-- 
2.25.1

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