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authorChristoph Hellwig <hch@lst.de>2016-11-17 13:43:16 +0300
committerMichael S. Tsirkin <mst@redhat.com>2016-12-16 01:12:49 +0300
commita3cbec69727c8c149ee2b3652e184818cc269fe6 (patch)
treecbe299e049f0fc919f37210714878e4d659ffa14 /drivers/virtio
parent66f2f55542270c44d67f05533594f75404c1481a (diff)
downloadlinux-a3cbec69727c8c149ee2b3652e184818cc269fe6.tar.xz
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>
Diffstat (limited to 'drivers/virtio')
-rw-r--r--drivers/virtio/virtio_pci_common.c97
1 files changed, 57 insertions, 40 deletions
diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c
index c93739eaeea0..186cbab327b8 100644
--- a/drivers/virtio/virtio_pci_common.c
+++ b/drivers/virtio/virtio_pci_common.c
@@ -167,18 +167,6 @@ error:
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 @@ error_find:
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)