[PATCH v4 2/7] PCI: Ignore BAR updates on virtual functions

Bjorn Helgaas bhelgaas at google.com
Tue Nov 29 15:14:29 AEDT 2016


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 at google.com>
CC: Wei Yang <richard.weiyang at gmail.com>
---
 drivers/pci/pci.c       |    4 ----
 drivers/pci/setup-res.c |    5 ++---
 2 files changed, 2 insertions(+), 7 deletions(-)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index ba34907..631eac2 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -564,10 +564,6 @@ static void pci_restore_bars(struct pci_dev *dev)
 {
 	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);
 }
diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c
index 66c4d8f..d2a32d8 100644
--- a/drivers/pci/setup-res.c
+++ b/drivers/pci/setup-res.c
@@ -36,10 +36,9 @@ void pci_update_resource(struct pci_dev *dev, int resno)
 	enum pci_bar_type type;
 	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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