Index: sys/arm64/cavium/thunder_pcie_common.h
===================================================================
--- sys/arm64/cavium/thunder_pcie_common.h
+++ sys/arm64/cavium/thunder_pcie_common.h
@@ -39,5 +39,9 @@
 uint64_t range_addr_pci_to_phys(struct pcie_range *, uint64_t);
 
 int thunder_pcie_identify_ecam(device_t, int *);
+#ifdef THUNDERX_PASS_1_1_ERRATA
+struct resource *thunder_pcie_alloc_resource(device_t,
+    device_t, int, int *, rman_res_t, rman_res_t, rman_res_t, u_int);
+#endif
 
 #endif /* _CAVIUM_THUNDER_PCIE_COMMON_H_ */
Index: sys/arm64/cavium/thunder_pcie_common.c
===================================================================
--- sys/arm64/cavium/thunder_pcie_common.c
+++ sys/arm64/cavium/thunder_pcie_common.c
@@ -33,6 +33,7 @@
 __FBSDID("$FreeBSD$");
 
 #include "opt_platform.h"
+#include "opt_bus.h"
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -52,10 +53,16 @@
 #include <dev/ofw/ofw_pci.h>
 #endif
 
-#include <dev/pci/pcivar.h>
+#include <sys/pciio.h>
 #include <dev/pci/pcireg.h>
+#include <dev/pci/pcivar.h>
+#include <dev/pci/pci_private.h>
 #include <dev/pci/pcib_private.h>
 #include <dev/pci/pci_host_generic.h>
+#ifdef PCI_IOV
+#include <sys/nv.h>
+#include <dev/pci/pci_iov_private.h>
+#endif
 
 #include "thunder_pcie_common.h"
 
@@ -142,3 +149,67 @@
 
 	return (0);
 }
+
+#ifdef THUNDERX_PASS_1_1_ERRATA
+struct resource *
+thunder_pcie_alloc_resource(device_t dev, device_t child, int type, int *rid,
+    rman_res_t start, rman_res_t end, rman_res_t count, u_int flags)
+{
+	pci_addr_t map, testval;
+#ifdef PCI_IOV
+	struct pci_devinfo *dinfo;
+	struct pcicfg_iov *iov;
+#endif
+	int iov_cnt;
+
+	iov_cnt = 1;
+#ifdef PCI_IOV
+	dinfo = device_get_ivars(child);
+	iov = dinfo->cfg.iov;
+	if (iov != NULL)
+		iov_cnt = iov->iov_num_vfs;
+#endif
+
+	/*
+	 * If Enhanced Allocation is not used, we can't allocate any random
+	 * range. All internal devices have hardcoded place where they can
+	 * be located within PCI address space. Fortunately, we can read
+	 * this value from BAR.
+	 */
+	if (((type == SYS_RES_IOPORT) || (type == SYS_RES_MEMORY)) &&
+	    RMAN_IS_DEFAULT_RANGE(start, end)) {
+#ifdef FDT
+		if ((int)ofw_bus_get_node(child) > 0)
+			return (pci_host_generic_alloc_resource(dev, child,
+			    type, rid, start, end, count, flags));
+#endif
+
+		/* Read BAR manually to get resource address and size */
+		pci_read_bar(child, *rid, &map, &testval, NULL);
+
+		/* Mask the information bits */
+		if (PCI_BAR_MEM(map))
+			map &= PCIM_BAR_MEM_BASE;
+		else
+			map &= PCIM_BAR_IO_BASE;
+
+		if (PCI_BAR_MEM(testval))
+			testval &= PCIM_BAR_MEM_BASE;
+		else
+			testval &= PCIM_BAR_IO_BASE;
+
+		/*
+		 * If the upper layer wants us to allocate VF-BAR, reserve
+		 * a bigger slice to make a room for other VFs adjacent
+		 * to this one.
+		 */
+		start = map;
+		count = (~testval) + 1;
+		count = count * iov_cnt;
+		end = start + count - 1;
+	}
+
+	return (pci_host_generic_alloc_resource(dev, child, type, rid, start,
+	    end, count, flags));
+}
+#endif
Index: sys/arm64/cavium/thunder_pcie_fdt.c
===================================================================
--- sys/arm64/cavium/thunder_pcie_fdt.c
+++ sys/arm64/cavium/thunder_pcie_fdt.c
@@ -25,11 +25,13 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */
-#include "opt_platform.h"
 
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
+#include "opt_platform.h"
+#include "opt_bus.h"
+
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/malloc.h>
@@ -41,10 +43,15 @@
 #include <sys/bus.h>
 #include <sys/endian.h>
 #include <sys/cpuset.h>
+#include <machine/bus.h>
 
 #include <dev/ofw/openfirm.h>
 #include <dev/ofw/ofw_bus.h>
 #include <dev/ofw/ofw_bus_subr.h>
+
+#include <sys/pciio.h>
+#include <dev/pci/pcireg.h>
+#include <dev/pci/pcivar.h>
 #include <dev/pci/pci_host_generic.h>
 
 #include "thunder_pcie_common.h"
@@ -56,6 +63,9 @@
 	/* Device interface */
 	DEVMETHOD(device_probe,		thunder_pcie_fdt_probe),
 	DEVMETHOD(device_attach,	thunder_pcie_fdt_attach),
+#ifdef THUNDERX_PASS_1_1_ERRATA
+	DEVMETHOD(bus_alloc_resource,	thunder_pcie_alloc_resource),
+#endif
 
 	/* End */
 	DEVMETHOD_END
Index: sys/dev/pci/pci_host_generic.h
===================================================================
--- sys/dev/pci/pci_host_generic.h
+++ sys/dev/pci/pci_host_generic.h
@@ -66,6 +66,8 @@
 extern devclass_t generic_pcie_devclass;
 DECLARE_CLASS(generic_pcie_driver);
 
+struct resource *pci_host_generic_alloc_resource(device_t,
+    device_t, int, int *, rman_res_t, rman_res_t, rman_res_t, u_int);
 int pci_host_generic_attach(device_t);
 
 #endif /* __PCI_HOST_GENERIC_H_ */
Index: sys/dev/pci/pci_host_generic.c
===================================================================
--- sys/dev/pci/pci_host_generic.c
+++ sys/dev/pci/pci_host_generic.c
@@ -104,9 +104,6 @@
     uintptr_t *result);
 static int generic_pcie_write_ivar(device_t dev, device_t child, int index,
     uintptr_t value);
-static struct resource *generic_pcie_alloc_resource(device_t dev,
-    device_t child, int type, int *rid, rman_res_t start, rman_res_t end,
-    rman_res_t count, u_int flags);
 static struct resource *generic_pcie_alloc_resource_ofw(device_t, device_t,
     int, int *, rman_res_t, rman_res_t, rman_res_t, u_int);
 static struct resource *generic_pcie_alloc_resource_pcie(device_t dev,
@@ -508,8 +505,8 @@
 	    child, type, rid, res));
 }
 
-static struct resource *
-generic_pcie_alloc_resource(device_t dev, device_t child, int type, int *rid,
+struct resource *
+pci_host_generic_alloc_resource(device_t dev, device_t child, int type, int *rid,
     rman_res_t start, rman_res_t end, rman_res_t count, u_int flags)
 {
 
@@ -661,7 +658,7 @@
 	DEVMETHOD(device_attach,		pci_host_generic_attach),
 	DEVMETHOD(bus_read_ivar,		generic_pcie_read_ivar),
 	DEVMETHOD(bus_write_ivar,		generic_pcie_write_ivar),
-	DEVMETHOD(bus_alloc_resource,		generic_pcie_alloc_resource),
+	DEVMETHOD(bus_alloc_resource,		pci_host_generic_alloc_resource),
 	DEVMETHOD(bus_adjust_resource,		generic_pcie_adjust_resource),
 	DEVMETHOD(bus_release_resource,		generic_pcie_release_resource),
 	DEVMETHOD(bus_activate_resource,	generic_pcie_activate_resource),