[3.16.y-ckt stable] Patch "PCI: Fix devfn for VPD access through function 0" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    PCI: Fix devfn for VPD access through function 0

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue

This patch is scheduled to be released in version 3.19.8-ckt9.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From ebdb663b78bed0e4798f0366d4345674b59b7f88 Mon Sep 17 00:00:00 2001
From: Alex Williamson <alex.williamson at redhat.com>
Date: Tue, 15 Sep 2015 11:17:21 -0600
Subject: PCI: Fix devfn for VPD access through function 0

commit 9d9240756e63dd87d6cbf5da8b98ceb8f8192b55 upstream.

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 at redhat.com>
Signed-off-by: Bjorn Helgaas <helgaas at kernel.org>
Acked-by: Myron Stowe <myron.stowe at redhat.com>
Acked-by: Mark Rustad <mark.d.rustad at intel.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/pci/access.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/access.c b/drivers/pci/access.c
index 7f249b9..2f15e7b 100644
--- a/drivers/pci/access.c
+++ b/drivers/pci/access.c
@@ -355,7 +355,8 @@ 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)
@@ -369,7 +370,8 @@ 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)
@@ -388,7 +390,8 @@ 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)
--
1.9.1