PCI: Add pci_upstream_bridge()
This adds a pci_upstream_bridge() interface to find the PCI-to-PCI bridge
upstream from a device. This is typically just "dev->bus->self", but in
the case of a VF on a virtual bus, we have to start from the corresponding
PF. Returns NULL if there is no upstream PCI bridge, i.e., if the device
is on a root bus.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
diff --git a/include/linux/pci.h b/include/linux/pci.h
index d3a888a..835ec7b 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -480,6 +480,15 @@
return !(pbus->parent);
}
+static inline struct pci_dev *pci_upstream_bridge(struct pci_dev *dev)
+{
+ dev = pci_physfn(dev);
+ if (pci_is_root_bus(dev->bus))
+ return NULL;
+
+ return dev->bus->self;
+}
+
#ifdef CONFIG_PCI_MSI
static inline bool pci_dev_msi_enabled(struct pci_dev *pci_dev)
{