virtio_pci: split vp_try_to_find_vqs into INTx and MSI-X variants

There is basically no shared logic between the INTx and MSI-X case in
vp_try_to_find_vqs, so split the function into two and clean them up
a little bit.

Also remove the fairly pointless vp_request_intx wrapper while we're at it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c
index c93739eaeea0a7d969320eee3304413bb43ec275..186cbab327b8f6ac76ce4cc572a03fdd49410f06 100644 (file)
--- a/drivers/virtio/virtio_pci_common.c
+++ b/drivers/virtio/virtio_pci_common.c
@@ -167,18 +167,6 @@ static int vp_request_msix_vectors(struct virtio_device *vdev, int nvectors,
        return err;
 }
 
-static int vp_request_intx(struct virtio_device *vdev)
-{
-       int err;
-       struct virtio_pci_device *vp_dev = to_vp_device(vdev);
-
-       err = request_irq(vp_dev->pci_dev->irq, vp_interrupt,
-                         IRQF_SHARED, dev_name(&vdev->dev), vp_dev);
-       if (!err)
-               vp_dev->intx_enabled = 1;
-       return err;
-}
-
 static struct virtqueue *vp_setup_vq(struct virtio_device *vdev, unsigned index,
                                     void (*callback)(struct virtqueue *vq),
                                     const char *name,
@@ -277,50 +265,44 @@ void vp_del_vqs(struct virtio_device *vdev)
        vp_dev->vqs = NULL;
 }
 
-static int vp_try_to_find_vqs(struct virtio_device *vdev, unsigned nvqs,
+static int vp_find_vqs_msix(struct virtio_device *vdev, unsigned nvqs,
                              struct virtqueue *vqs[],
                              vq_callback_t *callbacks[],
                              const char * const names[],
-                             bool use_msix,
                              bool per_vq_vectors)
 {
        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
        u16 msix_vec;
        int i, err, nvectors, allocated_vectors;
 
-       vp_dev->vqs = kmalloc(nvqs * sizeof *vp_dev->vqs, GFP_KERNEL);
+       vp_dev->vqs = kcalloc(nvqs, sizeof(*vp_dev->vqs), GFP_KERNEL);
        if (!vp_dev->vqs)
                return -ENOMEM;
 
-       if (!use_msix) {
-               /* Old style: one normal interrupt for change and all vqs. */
-               err = vp_request_intx(vdev);
-               if (err)
-                       goto error_find;
+       if (per_vq_vectors) {
+               /* Best option: one for change interrupt, one per vq. */
+               nvectors = 1;
+               for (i = 0; i < nvqs; ++i)
+                       if (callbacks[i])
+                               ++nvectors;
        } else {
-               if (per_vq_vectors) {
-                       /* Best option: one for change interrupt, one per vq. */
-                       nvectors = 1;
-                       for (i = 0; i < nvqs; ++i)
-                               if (callbacks[i])
-                                       ++nvectors;
-               } else {
-                       /* Second best: one for change, shared for all vqs. */
-                       nvectors = 2;
-               }
-
-               err = vp_request_msix_vectors(vdev, nvectors, per_vq_vectors);
-               if (err)
-                       goto error_find;
+               /* Second best: one for change, shared for all vqs. */
+               nvectors = 2;
        }
 
+       err = vp_request_msix_vectors(vdev, nvectors, per_vq_vectors);
+       if (err)
+               goto error_find;
+
        vp_dev->per_vq_vectors = per_vq_vectors;
        allocated_vectors = vp_dev->msix_used_vectors;
        for (i = 0; i < nvqs; ++i) {
                if (!names[i]) {
                        vqs[i] = NULL;
                        continue;
-               } else if (!callbacks[i] || !vp_dev->msix_enabled)
+               }
+
+               if (!callbacks[i])
                        msix_vec = VIRTIO_MSI_NO_VECTOR;
                else if (vp_dev->per_vq_vectors)
                        msix_vec = allocated_vectors++;
@@ -354,6 +336,43 @@ static int vp_try_to_find_vqs(struct virtio_device *vdev, unsigned nvqs,
        return err;
 }
 
+static int vp_find_vqs_intx(struct virtio_device *vdev, unsigned nvqs,
+               struct virtqueue *vqs[], vq_callback_t *callbacks[],
+               const char * const names[])
+{
+       struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+       int i, err;
+
+       vp_dev->vqs = kcalloc(nvqs, sizeof(*vp_dev->vqs), GFP_KERNEL);
+       if (!vp_dev->vqs)
+               return -ENOMEM;
+
+       err = request_irq(vp_dev->pci_dev->irq, vp_interrupt, IRQF_SHARED,
+                       dev_name(&vdev->dev), vp_dev);
+       if (err)
+               goto out_del_vqs;
+
+       vp_dev->intx_enabled = 1;
+       vp_dev->per_vq_vectors = false;
+       for (i = 0; i < nvqs; ++i) {
+               if (!names[i]) {
+                       vqs[i] = NULL;
+                       continue;
+               }
+               vqs[i] = vp_setup_vq(vdev, i, callbacks[i], names[i],
+                               VIRTIO_MSI_NO_VECTOR);
+               if (IS_ERR(vqs[i])) {
+                       err = PTR_ERR(vqs[i]);
+                       goto out_del_vqs;
+               }
+       }
+
+       return 0;
+out_del_vqs:
+       vp_del_vqs(vdev);
+       return err;
+}
+
 /* the config->find_vqs() implementation */
 int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs,
                struct virtqueue *vqs[],
@@ -363,17 +382,15 @@ int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs,
        int err;
 
        /* Try MSI-X with one vector per queue. */
-       err = vp_try_to_find_vqs(vdev, nvqs, vqs, callbacks, names, true, true);
+       err = vp_find_vqs_msix(vdev, nvqs, vqs, callbacks, names, true);
        if (!err)
                return 0;
        /* Fallback: MSI-X with one vector for config, one shared for queues. */
-       err = vp_try_to_find_vqs(vdev, nvqs, vqs, callbacks, names,
-                                true, false);
+       err = vp_find_vqs_msix(vdev, nvqs, vqs, callbacks, names, false);
        if (!err)
                return 0;
        /* Finally fall back to regular interrupts. */
-       return vp_try_to_find_vqs(vdev, nvqs, vqs, callbacks, names,
-                                 false, false);
+       return vp_find_vqs_intx(vdev, nvqs, vqs, callbacks, names);
 }
 
 const char *vp_bus_name(struct virtio_device *vdev)