PCI: Remove redundant validation of SR-IOV offset/stride registers

Previously, we read, validated, and cached PCI_SRIOV_VF_OFFSET and
PCI_SRIOV_VF_STRIDE in sriov_enable().  But sriov_init() now does
that via compute_max_vf_buses(), so we don't need to do it again.

Remove the PCI_SRIOV_VF_OFFSET and PCI_SRIOV_VF_STRIDE config reads from
sriov_enable().  The pci_sriov structure already contains the offset and
stride corresponding to the current NumVFs.

[bhelgaas: split to separate patch for reviewability]
Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Wei Yang <weiyang@linux.vnet.ibm.com>

drivers/pci/iov.c

@@ -235,7 +235,7 @@ static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
 	int rc;
 	int i, j;
 	int nres;
-	u16 offset, stride, initial;
+	u16 initial;
 	struct resource *res;
 	struct pci_dev *pdev;
 	struct pci_sriov *iov = dev->sriov;
@@ -258,11 +258,6 @@ static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
 	    (!(iov->cap & PCI_SRIOV_CAP_VFM) && (nr_virtfn > initial)))
 		return -EINVAL;
 
-	pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_OFFSET, &offset);
-	pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_STRIDE, &stride);
-	if (!offset || (nr_virtfn > 1 && !stride))
-		return -EIO;
-
 	nres = 0;
 	for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 		bars |= (1 << (i + PCI_IOV_RESOURCES));
@@ -275,9 +270,6 @@ static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
 		return -ENOMEM;
 	}
 
-	iov->offset = offset;
-	iov->stride = stride;
-
 	bus = pci_iov_virtfn_bus(dev, nr_virtfn - 1);
 	if (bus > dev->bus->busn_res.end) {
 		dev_err(&dev->dev, "can't enable %d VFs (bus %02x out of range of %pR)\n",