PCI: Do any VF BAR updates before enabling the BARs (f40ec3c7) · Commits · 戴 / test

Previously we enabled VFs and enable their memory space before calling pcibios_sriov_enable(). But pcibios_sriov_enable() may update the VF BARs: for example, on PPC PowerNV we may change them to manage the association of VFs to PEs. Because 64-bit BARs cannot be updated atomically, it's unsafe to update them while they're enabled. The half-updated state may conflict with other devices in the system. Call pcibios_sriov_enable() before enabling the VFs so any BAR updates happen while the VF BARs are disabled. [bhelgaas: changelog] Tested-by:

Carol Soto <clsoto@us.ibm.com> Signed-off-by:

Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by:

Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/iov.c

+7 −7

Original line number	Diff line number	Diff line
		@@ -306,13 +306,6 @@ static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
		return rc;
		}

		pci_iov_set_numvfs(dev, nr_virtfn);
		iov->ctrl \|= PCI_SRIOV_CTRL_VFE \| PCI_SRIOV_CTRL_MSE;
		pci_cfg_access_lock(dev);
		pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
		msleep(100);
		pci_cfg_access_unlock(dev);

		iov->initial_VFs = initial;
		if (nr_virtfn < initial)
		initial = nr_virtfn;
		@@ -323,6 +316,13 @@ static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
		goto err_pcibios;
		}

		pci_iov_set_numvfs(dev, nr_virtfn);
		iov->ctrl \|= PCI_SRIOV_CTRL_VFE \| PCI_SRIOV_CTRL_MSE;
		pci_cfg_access_lock(dev);
		pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
		msleep(100);
		pci_cfg_access_unlock(dev);

		for (i = 0; i < initial; i++) {
		rc = pci_iov_add_virtfn(dev, i, 0);
		if (rc)

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