PCI: Fix devfn for VPD access through function 0

Commit 932c435caba8 ("PCI: Add dev_flags bit to access VPD through function
0") passes PCI_SLOT(devfn) for the devfn parameter of pci_get_slot().
Generally this works because we're fairly well guaranteed that a PCIe
device is at slot address 0, but for the general case, including
conventional PCI, it's incorrect.  We need to get the slot and then convert
it back into a devfn.

Fixes: 932c435caba8 ("PCI: Add dev_flags bit to access VPD through function 0")
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <helgaas@kernel.org>
Acked-by: Myron Stowe <myron.stowe@redhat.com>
Acked-by: Mark Rustad <mark.d.rustad@intel.com>
CC: stable@vger.kernel.org

1 files changed, 6 insertions, 3 deletions

diff --git a/drivers/pci/access.c b/drivers/pci/access.c
index 769f7e35f1a2..5a5f0a7ba801 100644
--- a/drivers/pci/access.c
+++ b/drivers/pci/access.c
@@ -442,7 +442,8 @@ static const struct pci_vpd_ops pci_vpd_pci22_ops = {
 static ssize_t pci_vpd_f0_read(struct pci_dev *dev, loff_t pos, size_t count,
                                void *arg)
 {
-        struct pci_dev *tdev = pci_get_slot(dev->bus, PCI_SLOT(dev->devfn));
+        struct pci_dev *tdev = pci_get_slot(dev->bus,
+                                            PCI_DEVFN(PCI_SLOT(dev->devfn), 0));
         ssize_t ret;
 
         if (!tdev)
@@ -456,7 +457,8 @@ static ssize_t pci_vpd_f0_read(struct pci_dev *dev, loff_t pos, size_t count,
 static ssize_t pci_vpd_f0_write(struct pci_dev *dev, loff_t pos, size_t count,
                                 const void *arg)
 {
-        struct pci_dev *tdev = pci_get_slot(dev->bus, PCI_SLOT(dev->devfn));
+        struct pci_dev *tdev = pci_get_slot(dev->bus,
+                                            PCI_DEVFN(PCI_SLOT(dev->devfn), 0));
         ssize_t ret;
 
         if (!tdev)
@@ -475,7 +477,8 @@ static const struct pci_vpd_ops pci_vpd_f0_ops = {
 
 static int pci_vpd_f0_dev_check(struct pci_dev *dev)
 {
-        struct pci_dev *tdev = pci_get_slot(dev->bus, PCI_SLOT(dev->devfn));
+        struct pci_dev *tdev = pci_get_slot(dev->bus,
+                                            PCI_DEVFN(PCI_SLOT(dev->devfn), 0));
         int ret = 0;
 
         if (!tdev)