diff --git a/sys/dev/pci/pci_host_generic.h b/sys/dev/pci/pci_host_generic.h
--- a/sys/dev/pci/pci_host_generic.h
+++ b/sys/dev/pci/pci_host_generic.h
@@ -64,6 +64,7 @@
 #define	FLAG_TYPE_MEM		0x2
 #define	FLAG_TYPE_PMEM		0x3
 	struct resource *res;
+	int rid;
 };
 
 struct generic_pcie_core_softc {
diff --git a/sys/dev/pci/pci_host_generic.c b/sys/dev/pci/pci_host_generic.c
--- a/sys/dev/pci/pci_host_generic.c
+++ b/sys/dev/pci/pci_host_generic.c
@@ -59,6 +59,12 @@
 #define	PCI_RF_FLAGS	0
 #endif
 
+/*
+ * We allocate "ranges" specified mappings higher up in the rid space to avoid
+ * conflicts with various definitions in the wild that may have other registers
+ * attributed to the controller besides just the config space.
+ */
+#define	RANGE_RID(idx)	((idx) + 100)
 
 /* Forward prototypes */
 
@@ -174,7 +180,7 @@
 		phys_base = sc->ranges[tuple].phys_base;
 		pci_base = sc->ranges[tuple].pci_base;
 		size = sc->ranges[tuple].size;
-		rid = tuple + 1;
+		rid = RANGE_RID(tuple);
 		if (size == 0)
 			continue; /* empty range element */
 		switch (FLAG_TYPE(sc->ranges[tuple].flags)) {
@@ -215,6 +221,7 @@
 			    error);
 			goto err_rman_manage;
 		}
+		sc->ranges[tuple].rid = rid;
 		sc->ranges[tuple].res = bus_alloc_resource_any(dev, type, &rid,
 		    RF_ACTIVE | RF_UNMAPPED | flags);
 		if (sc->ranges[tuple].res == NULL) {
@@ -233,8 +240,13 @@
 
 err_rman_manage:
 	for (tuple = 0; tuple < MAX_RANGES_TUPLES; tuple++) {
-		if (sc->ranges[tuple].size == 0)
+		rid = sc->ranges[tuple].rid;
+		if (sc->ranges[tuple].size == 0) {
+			MPASS(sc->ranges[tuple].res == NULL);
 			continue; /* empty range element */
+		}
+
+		MPASS(rid != -1);
 		switch (FLAG_TYPE(sc->ranges[tuple].flags)) {
 		case FLAG_TYPE_PMEM:
 		case FLAG_TYPE_MEM:
@@ -247,9 +259,9 @@
 			continue;
 		}
 		if (sc->ranges[tuple].res != NULL)
-			bus_release_resource(dev, type, tuple + 1,
+			bus_release_resource(dev, type, rid,
 			    sc->ranges[tuple].res);
-		bus_delete_resource(dev, type, tuple + 1);
+		bus_delete_resource(dev, type, rid);
 	}
 	rman_fini(&sc->io_rman);
 err_io_rman:
@@ -271,7 +283,7 @@
 pci_host_generic_core_detach(device_t dev)
 {
 	struct generic_pcie_core_softc *sc;
-	int error, tuple, type;
+	int error, rid, tuple, type;
 
 	sc = device_get_softc(dev);
 
@@ -280,8 +292,13 @@
 		return (error);
 
 	for (tuple = 0; tuple < MAX_RANGES_TUPLES; tuple++) {
-		if (sc->ranges[tuple].size == 0)
+		rid = sc->ranges[tuple].rid;
+		if (sc->ranges[tuple].size == 0) {
+			MPASS(sc->ranges[tuple].res == NULL);
 			continue; /* empty range element */
+		}
+
+		MPASS(rid != -1);
 		switch (FLAG_TYPE(sc->ranges[tuple].flags)) {
 		case FLAG_TYPE_PMEM:
 		case FLAG_TYPE_MEM:
@@ -294,9 +311,9 @@
 			continue;
 		}
 		if (sc->ranges[tuple].res != NULL)
-			bus_release_resource(dev, type, tuple + 1,
+			bus_release_resource(dev, type, rid,
 			    sc->ranges[tuple].res);
-		bus_delete_resource(dev, type, tuple + 1);
+		bus_delete_resource(dev, type, rid);
 	}
 	rman_fini(&sc->io_rman);
 	rman_fini(&sc->mem_rman);
diff --git a/sys/dev/pci/pci_host_generic_acpi.c b/sys/dev/pci/pci_host_generic_acpi.c
--- a/sys/dev/pci/pci_host_generic_acpi.c
+++ b/sys/dev/pci/pci_host_generic_acpi.c
@@ -183,6 +183,7 @@
 	/* Save detected ranges */
 	if (res->Data.Address.ResourceType == ACPI_MEMORY_RANGE ||
 	    res->Data.Address.ResourceType == ACPI_IO_RANGE) {
+		sc->base.ranges[r].rid = -1;
 		sc->base.ranges[r].pci_base = min;
 		sc->base.ranges[r].phys_base = min + off;
 		sc->base.ranges[r].size = max - min + 1;
diff --git a/sys/dev/pci/pci_host_generic_fdt.c b/sys/dev/pci/pci_host_generic_fdt.c
--- a/sys/dev/pci/pci_host_generic_fdt.c
+++ b/sys/dev/pci/pci_host_generic_fdt.c
@@ -214,6 +214,7 @@
 			sc->ranges[i].flags |= FLAG_TYPE_MEM;
 		}
 
+		sc->ranges[i].rid = -1;
 		sc->ranges[i].pci_base = 0;
 		for (k = 0; k < (pci_addr_cells - 1); k++) {
 			sc->ranges[i].pci_base <<= 32;