device: Implement a bus agnostic dev_num_vf routine

Now that pci_bus_type has num_vf callback set, dev_num_vf can be
implemented in a bus type independent way and the check for whether a
PCI device is being handled in rtnetlink can be dropped.
Signed-off-by: NPhil Sutter <phil@nwl.cc>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include/linux/device.h

@@ -1144,6 +1144,13 @@ extern int device_online(struct device *dev);
 extern void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode);
 extern void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode);
 
+static inline int dev_num_vf(struct device *dev)
+{
+	if (dev->bus && dev->bus->num_vf)
+		return dev->bus->num_vf(dev);
+	return 0;
+}
+
 /*
  * Root device objects for grouping under /sys/devices
  */

include/linux/pci.h

@@ -885,7 +885,6 @@ void pcibios_setup_bridge(struct pci_bus *bus, unsigned long type);
 void pci_sort_breadthfirst(void);
 #define dev_is_pci(d) ((d)->bus == &pci_bus_type)
 #define dev_is_pf(d) ((dev_is_pci(d) ? to_pci_dev(d)->is_physfn : false))
-#define dev_num_vf(d) ((dev_is_pci(d) ? pci_num_vf(to_pci_dev(d)) : 0))
 
 /* Generic PCI functions exported to card drivers */
 
@@ -1630,7 +1629,6 @@ static inline int pci_get_new_domain_nr(void) { return -ENOSYS; }
 
 #define dev_is_pci(d) (false)
 #define dev_is_pf(d) (false)
-#define dev_num_vf(d) (0)
 #endif /* CONFIG_PCI */
 
 /* Include architecture-dependent settings and functions */

net/core/rtnetlink.c

@@ -837,8 +837,7 @@ static void copy_rtnl_link_stats(struct rtnl_link_stats *a,
 static inline int rtnl_vfinfo_size(const struct net_device *dev,
 				   u32 ext_filter_mask)
 {
-	if (dev->dev.parent && dev_is_pci(dev->dev.parent) &&
-	    (ext_filter_mask & RTEXT_FILTER_VF)) {
+	if (dev->dev.parent && (ext_filter_mask & RTEXT_FILTER_VF)) {
 		int num_vfs = dev_num_vf(dev->dev.parent);
 		size_t size = nla_total_size(0);
 		size += num_vfs *