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Subject[PATCH 4.9 59/93] PCI: Ignore BAR updates on virtual functions
Date
4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Bjorn Helgaas <bhelgaas@google.com>

[ Upstream commit 63880b230a4af502c56dde3d4588634c70c66006 ]

VF BARs are read-only zero, so updating VF BARs will not have any effect.
See the SR-IOV spec r1.1, sec 3.4.1.11.

We already ignore these updates because of 70675e0b6a1a ("PCI: Don't try to
restore VF BARs"); this merely restructures it slightly to make it easier
to split updates for standard and SR-IOV BARs.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/pci/pci.c | 4 ----
drivers/pci/setup-res.c | 5 ++---
2 files changed, 2 insertions(+), 7 deletions(-)

--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -564,10 +564,6 @@ static void pci_restore_bars(struct pci_
{
int i;

- /* Per SR-IOV spec 3.4.1.11, VF BARs are RO zero */
- if (dev->is_virtfn)
- return;
-
for (i = 0; i < PCI_BRIDGE_RESOURCES; i++)
pci_update_resource(dev, i);
}
--- a/drivers/pci/setup-res.c
+++ b/drivers/pci/setup-res.c
@@ -34,10 +34,9 @@ static void pci_std_update_resource(stru
int reg;
struct resource *res = dev->resource + resno;

- if (dev->is_virtfn) {
- dev_warn(&dev->dev, "can't update VF BAR%d\n", resno);
+ /* Per SR-IOV spec 3.4.1.11, VF BARs are RO zero */
+ if (dev->is_virtfn)
return;
- }

/*
* Ignore resources for unimplemented BARs and unused resource slots

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