[PATCH v3 1/1] PCI: Fix BAR resizing when VF BARs are assigned

["Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>]

__resource_resize_store() attempts to release all resources of the
device before attempting the resize. The loop, however, only covers
standard BARs (< PCI_STD_NUM_BARS). If a device has VF BARs that are
assigned, pci_reassign_bridge_resources() finds the bridge window still
has some assigned child resources and returns -NOENT which makes
pci_resize_resource() to detect an error and abort the resize.

Change the release loop to cover all resources up to VF BARs which
allows the resize operation to release the bridge windows and attempt
to assigned them again with the different size.

If SR-IOV is enabled, disallow resize as it requires releasing also IOV
resources.

Fixes: 91fa127794ac ("PCI: Expose PCIe Resizable BAR support via sysfs")
Reported-by: Michał Winiarski <michal.winiarski@intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
---

v3:
- Check that SR-IOV is not enabled before resizing

v2:
- Removed language about expansion ROMs

 drivers/pci/pci-sysfs.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index b46ce1a2c554..0e7eb2a42d88 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -1556,7 +1556,7 @@ static ssize_t __resource_resize_store(struct device *dev, int n,
 		return -EINVAL;
 
 	device_lock(dev);
-	if (dev->driver) {
+	if (dev->driver || pci_num_vf(pdev)) {
 		ret = -EBUSY;
 		goto unlock;
 	}
@@ -1578,7 +1578,7 @@ static ssize_t __resource_resize_store(struct device *dev, int n,
 
 	pci_remove_resource_files(pdev);
 
-	for (i = 0; i < PCI_STD_NUM_BARS; i++) {
+	for (i = 0; i < PCI_BRIDGE_RESOURCES; i++) {
 		if (pci_resource_len(pdev, i) &&
 		    pci_resource_flags(pdev, i) == flags)
 			pci_release_resource(pdev, i);

base-commit: 2014c95afecee3e76ca4a56956a936e23283f05b
-- 
2.39.5