PCI: Disable VF decoding before pcibios_sriov_disable() updates resources

A struct resource represents the address space consumed by a device.  We
should not modify that resource while the device is actively using the
address space.  For VFs, pci_iov_update_resource() enforces this by
printing a warning and doing nothing if the VFE (VF Enable) and MSE (VF
Memory Space Enable) bits are set.

Previously, both sriov_enable() and sriov_disable() called the
pcibios_sriov_disable() arch hook, which may update the struct resource,
while VFE and MSE were enabled.  This effectively dropped the resource
update pcibios_sriov_disable() intended to do.

Disable VF memory decoding before calling pcibios_sriov_disable().

Reported-by: Carol L Soto <clsoto@us.ibm.com>
Tested-by: Carol L Soto <clsoto@us.ibm.com>
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
[bhelgaas: changelog]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: shan.gavin@gmail.com
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>

diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index 120485d..ac41c8b 100644 (file)
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -331,7 +331,6 @@ failed:
        while (i--)
                pci_iov_remove_virtfn(dev, i, 0);
 
-       pcibios_sriov_disable(dev);
 err_pcibios:
        iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
        pci_cfg_access_lock(dev);
@@ -339,6 +338,8 @@ err_pcibios:
        ssleep(1);
        pci_cfg_access_unlock(dev);
 
+       pcibios_sriov_disable(dev);
+
        if (iov->link != dev->devfn)
                sysfs_remove_link(&dev->dev.kobj, "dep_link");
 
@@ -357,14 +358,14 @@ static void sriov_disable(struct pci_dev *dev)
        for (i = 0; i < iov->num_VFs; i++)
                pci_iov_remove_virtfn(dev, i, 0);
 
-       pcibios_sriov_disable(dev);
-
        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);
        ssleep(1);
        pci_cfg_access_unlock(dev);
 
+       pcibios_sriov_disable(dev);
+
        if (iov->link != dev->devfn)
                sysfs_remove_link(&dev->dev.kobj, "dep_link");