Commit 0fc690a7 authored Aug 11, 2017 by Gavin Shan Committed by Bjorn Helgaas Aug 29, 2017

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>

parent a0418aa2

drivers/pci/iov.c

+4 −3

Original line number	Diff line number	Diff line
		@@ -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");

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