When implementing the SR-IOV on PowerNV platform, some resource reservation is
needed for VFs which don't exist at the bootup stage. To do the match between
resources and VFs, the code need to get the VF's BDF in advance.

In this patch, it exports the interface to retrieve VF's BDF:
   * Make the virtfn_bus as an interface
   * Make the virtfn_devfn as an interface
   * Rename them with more specific name
   * Code cleanup in pci_sriov_resource_alignment()

Signed-off-by: Wei Yang <redacted>
---
 drivers/pci/iov.c   |   22 +++++++++++++---------
 include/linux/pci.h |   11 +++++++++++
 2 files changed, 24 insertions(+), 9 deletions(-)

diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index 4d109c0..5e8091b 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c

@@ -19,14 +19,18 @@
 
 #define VIRTFN_ID_LEN	16
 
-static inline u8 virtfn_bus(struct pci_dev *dev, int id)
+int pci_iov_virtfn_bus(struct pci_dev *dev, int id)
 {
+	if (!dev->is_physfn)
+		return -EINVAL;
 	return dev->bus->number + ((dev->devfn + dev->sriov->offset +
 				    dev->sriov->stride * id) >> 8);
 }
 
-static inline u8 virtfn_devfn(struct pci_dev *dev, int id)
+int pci_iov_virtfn_devfn(struct pci_dev *dev, int id)
 {
+	if (!dev->is_physfn)
+		return -EINVAL;
 	return (dev->devfn + dev->sriov->offset +
 		dev->sriov->stride * id) & 0xff;
 }