4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Gavin Shan <gws...@linux.vnet.ibm.com>
[ Upstream commit f40ec3c748c6912f6266c56a7f7992de61b255ed ]
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 <cls...@us.ibm.com>
Signed-off-by: Gavin Shan <gws...@linux.vnet.ibm.com>
Signed-off-by: Bjorn Helgaas <bhelg...@google.com>
Signed-off-by: Sasha Levin <alexander.le...@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
drivers/pci/iov.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -306,13 +306,6 @@ static int sriov_enable(struct pci_dev *
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 *
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)
