[PATCH 6/9] virtio_pci: setup vqs indirectly

From: Michael S. Tsirkin
Date: Mon Dec 08 2014 - 08:08:16 EST


VQ setup is mostly version-specific, add another level of indirection to
split the version-independent code out.

Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
---
drivers/virtio/virtio_pci.c | 69 ++++++++++++++++++++++++++++++---------------
1 file changed, 46 insertions(+), 23 deletions(-)

diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c
index 133978c..68023e5 100644
--- a/drivers/virtio/virtio_pci.c
+++ b/drivers/virtio/virtio_pci.c
@@ -82,6 +82,12 @@ struct virtio_pci_device {
/* Whether we have vector per vq */
bool per_vq_vectors;

+ struct virtqueue *(*setup_vq)(struct virtio_pci_device *vp_dev,
+ struct virtio_pci_vq_info *info,
+ unsigned idx,
+ void (*callback)(struct virtqueue *vq),
+ const char *name,
+ u16 msix_vec);
void (*del_vq)(struct virtio_pci_vq_info *info);
};

@@ -389,15 +395,15 @@ static int vp_request_intx(struct virtio_device *vdev)
return err;
}

-static struct virtqueue *setup_vq(struct virtio_device *vdev, unsigned index,
+static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev,
+ struct virtio_pci_vq_info *info,
+ unsigned index,
void (*callback)(struct virtqueue *vq),
const char *name,
u16 msix_vec)
{
- struct virtio_pci_device *vp_dev = to_vp_device(vdev);
- struct virtio_pci_vq_info *info;
struct virtqueue *vq;
- unsigned long flags, size;
+ unsigned long size;
u16 num;
int err;

@@ -409,28 +415,21 @@ static struct virtqueue *setup_vq(struct virtio_device *vdev, unsigned index,
if (!num || ioread32(vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN))
return ERR_PTR(-ENOENT);

- /* allocate and fill out our structure the represents an active
- * queue */
- info = kmalloc(sizeof(struct virtio_pci_vq_info), GFP_KERNEL);
- if (!info)
- return ERR_PTR(-ENOMEM);
-
info->num = num;
info->msix_vector = msix_vec;

size = PAGE_ALIGN(vring_size(num, VIRTIO_PCI_VRING_ALIGN));
info->queue = alloc_pages_exact(size, GFP_KERNEL|__GFP_ZERO);
- if (info->queue == NULL) {
- err = -ENOMEM;
- goto out_info;
- }
+ if (info->queue == NULL)
+ return ERR_PTR(-ENOMEM);

/* activate the queue */
iowrite32(virt_to_phys(info->queue) >> VIRTIO_PCI_QUEUE_ADDR_SHIFT,
vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);

/* create the vring */
- vq = vring_new_virtqueue(index, info->num, VIRTIO_PCI_VRING_ALIGN, vdev,
+ vq = vring_new_virtqueue(index, info->num,
+ VIRTIO_PCI_VRING_ALIGN, &vp_dev->vdev,
true, info->queue, vp_notify, callback, name);
if (!vq) {
err = -ENOMEM;
@@ -438,7 +437,6 @@ static struct virtqueue *setup_vq(struct virtio_device *vdev, unsigned index,
}

vq->priv = (void __force *)vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NOTIFY;
- info->vq = vq;

if (msix_vec != VIRTIO_MSI_NO_VECTOR) {
iowrite16(msix_vec, vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
@@ -449,6 +447,35 @@ static struct virtqueue *setup_vq(struct virtio_device *vdev, unsigned index,
}
}

+ return vq;
+
+out_assign:
+ vring_del_virtqueue(vq);
+out_activate_queue:
+ iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
+ free_pages_exact(info->queue, size);
+ return ERR_PTR(err);
+}
+
+static struct virtqueue *vp_setup_vq(struct virtio_device *vdev, unsigned index,
+ void (*callback)(struct virtqueue *vq),
+ const char *name,
+ u16 msix_vec)
+{
+ struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+ struct virtio_pci_vq_info *info = kmalloc(sizeof *info, GFP_KERNEL);
+ struct virtqueue *vq;
+ unsigned long flags;
+
+ /* fill out our structure that represents an active queue */
+ if (!info)
+ return ERR_PTR(-ENOMEM);
+
+ vq = vp_dev->setup_vq(vp_dev, info, index, callback, name, msix_vec);
+ if (IS_ERR(vq))
+ goto out_info;
+
+ info->vq = vq;
if (callback) {
spin_lock_irqsave(&vp_dev->lock, flags);
list_add(&info->node, &vp_dev->virtqueues);
@@ -460,14 +487,9 @@ static struct virtqueue *setup_vq(struct virtio_device *vdev, unsigned index,
vp_dev->vqs[index] = info;
return vq;

-out_assign:
- vring_del_virtqueue(vq);
-out_activate_queue:
- iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
- free_pages_exact(info->queue, size);
out_info:
kfree(info);
- return ERR_PTR(err);
+ return vq;
}

static void del_vq(struct virtio_pci_vq_info *info)
@@ -578,7 +600,7 @@ static int vp_try_to_find_vqs(struct virtio_device *vdev, unsigned nvqs,
msix_vec = allocated_vectors++;
else
msix_vec = VP_MSIX_VQ_VECTOR;
- vqs[i] = setup_vq(vdev, i, callbacks[i], names[i], msix_vec);
+ vqs[i] = vp_setup_vq(vdev, i, callbacks[i], names[i], msix_vec);
if (IS_ERR(vqs[i])) {
err = PTR_ERR(vqs[i]);
goto error_find;
@@ -748,6 +770,7 @@ static int virtio_pci_probe(struct pci_dev *pci_dev,
vp_dev->vdev.id.vendor = pci_dev->subsystem_vendor;
vp_dev->vdev.id.device = pci_dev->subsystem_device;

+ vp_dev->setup_vq = setup_vq;
vp_dev->del_vq = del_vq;

/* finally register the virtio device */
--
MST

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