pci: Only add special VF handling for direct children in bus methods

For activate/deactivate resource, use a more standard check at the
start of the function since the addition of the PCI_IOV code made this
more complex.  For the three recently added methods, just add the
typical check at the beginning that I missed.

This wasn't always fatal as if your system only had PCI device_t's as
children of PCI bus devices it would happen to work ok, but if you
have a non-PCI child device (e.g. an ATA channel) then dereferencing
ivars for non-direct-children could fault.

Reported by:	Cirrus-CI (via emaste)
Reviewed by:	emaste
Fixes:		871b33ad65 pci: Consistently use pci_vf_* for suballocated VF memory resources
Differential Revision:	https://reviews.freebsd.org/D45499

sys/dev/pci/pci.c

@@ -5695,6 +5695,9 @@ pci_activate_resource(device_t dev, device_t child, struct resource *r)
 	struct pci_devinfo *dinfo;
 	int error, rid, type;
 
+	if (device_get_parent(child) != dev)
+		return (bus_generic_activate_resource(dev, child, r));
+
 	dinfo = device_get_ivars(child);
 #ifdef PCI_IOV
 	if (dinfo->cfg.flags & PCICFG_VF) {
@@ -5716,21 +5719,21 @@ pci_activate_resource(device_t dev, device_t child, struct resource *r)
 	if (error)
 		return (error);
 
-	/* Enable decoding in the command register when activating BARs. */
-	if (device_get_parent(child) == dev) {
-		/* Device ROMs need their decoding explicitly enabled. */
 	rid = rman_get_rid(r);
 	type = rman_get_type(r);
+
+	/* Device ROMs need their decoding explicitly enabled. */
 	if (type == SYS_RES_MEMORY && PCIR_IS_BIOS(&dinfo->cfg, rid))
 		pci_write_bar(child, pci_find_bar(child, rid),
 		    rman_get_start(r) | PCIM_BIOS_ENABLE);
+
+	/* Enable decoding in the command register when activating BARs. */
 	switch (type) {
 	case SYS_RES_IOPORT:
 	case SYS_RES_MEMORY:
 		error = PCI_ENABLE_IO(dev, child, type);
 		break;
 	}
-	}
 	return (error);
 }
 
@@ -5740,6 +5743,9 @@ pci_deactivate_resource(device_t dev, device_t child, struct resource *r)
 	struct pci_devinfo *dinfo;
 	int error, rid, type;
 
+	if (device_get_parent(child) != dev)
+		return (bus_generic_deactivate_resource(dev, child, r));
+
 	dinfo = device_get_ivars(child);
 #ifdef PCI_IOV
 	if (dinfo->cfg.flags & PCICFG_VF) {
@@ -5762,13 +5768,11 @@ pci_deactivate_resource(device_t dev, device_t child, struct resource *r)
 		return (error);
 
 	/* Disable decoding for device ROMs. */
-	if (device_get_parent(child) == dev) {
 	rid = rman_get_rid(r);
 	type = rman_get_type(r);
 	if (type == SYS_RES_MEMORY && PCIR_IS_BIOS(&dinfo->cfg, rid))
 		pci_write_bar(child, pci_find_bar(child, rid),
 		    rman_get_start(r));
-	}
 	return (0);
 }
 
@@ -5779,6 +5783,10 @@ pci_adjust_resource(device_t dev, device_t child, struct resource *r,
 {
 	struct pci_devinfo *dinfo;
 
+	if (device_get_parent(child) != dev)
+		return (bus_generic_adjust_resource(dev, child, r, start,
+		    end));
+
 	dinfo = device_get_ivars(child);
 	if (dinfo->cfg.flags & PCICFG_VF) {
 		switch (rman_get_type(r)) {
@@ -5802,6 +5810,10 @@ pci_map_resource(device_t dev, device_t child, struct resource *r,
 {
 	struct pci_devinfo *dinfo;
 
+	if (device_get_parent(child) != dev)
+		return (bus_generic_map_resource(dev, child, r, argsp,
+		    map));
+
 	dinfo = device_get_ivars(child);
 	if (dinfo->cfg.flags & PCICFG_VF) {
 		switch (rman_get_type(r)) {
@@ -5825,6 +5837,9 @@ pci_unmap_resource(device_t dev, device_t child, struct resource *r,
 {
 	struct pci_devinfo *dinfo;
 
+	if (device_get_parent(child) != dev)
+		return (bus_generic_unmap_resource(dev, child, r, map));
+
 	dinfo = device_get_ivars(child);
 	if (dinfo->cfg.flags & PCICFG_VF) {
 		switch (rman_get_type(r)) {