diff --git a/sys/compat/linuxkpi/common/include/linux/io-mapping.h b/sys/compat/linuxkpi/common/include/linux/io-mapping.h
--- a/sys/compat/linuxkpi/common/include/linux/io-mapping.h
+++ b/sys/compat/linuxkpi/common/include/linux/io-mapping.h
@@ -37,6 +37,7 @@
 
 #include <linux/types.h>
 #include <linux/io.h>
+#include <linux/mm.h>
 #include <linux/slab.h>
 
 struct io_mapping {
@@ -100,6 +101,17 @@
 	return ((char *)mapping->mem + offset);
 }
 
+int lkpi_io_mapping_map_user(struct io_mapping *iomap,
+    struct vm_area_struct *vma, unsigned long addr, unsigned long pfn,
+    unsigned long size);
+
+static inline int
+io_mapping_map_user(struct io_mapping *iomap, struct vm_area_struct *vma,
+    unsigned long addr, unsigned long pfn, unsigned long size)
+{
+	return (lkpi_io_mapping_map_user(iomap, vma, addr, pfn, size));
+}
+
 static inline void
 io_mapping_unmap(void *vaddr)
 {
diff --git a/sys/compat/linuxkpi/common/include/linux/mm.h b/sys/compat/linuxkpi/common/include/linux/mm.h
--- a/sys/compat/linuxkpi/common/include/linux/mm.h
+++ b/sys/compat/linuxkpi/common/include/linux/mm.h
@@ -218,11 +218,15 @@
 int zap_vma_ptes(struct vm_area_struct *vma, unsigned long address,
     unsigned long size);
 
+int lkpi_remap_pfn_range(struct vm_area_struct *vma,
+    unsigned long start_addr, unsigned long start_pfn, unsigned long size,
+    pgprot_t prot);
+
 static inline int
 remap_pfn_range(struct vm_area_struct *vma, unsigned long addr,
     unsigned long pfn, unsigned long size, pgprot_t prot)
 {
-	return (-ENOTSUP);
+	return (lkpi_remap_pfn_range(vma, addr, pfn, size, prot));
 }
 
 static inline unsigned long
diff --git a/sys/compat/linuxkpi/common/src/linux_page.c b/sys/compat/linuxkpi/common/src/linux_page.c
--- a/sys/compat/linuxkpi/common/src/linux_page.c
+++ b/sys/compat/linuxkpi/common/src/linux_page.c
@@ -67,6 +67,7 @@
 #include <linux/kernel.h>
 #include <linux/idr.h>
 #include <linux/io.h>
+#include <linux/io-mapping.h>
 
 #ifdef __i386__
 DEFINE_IDR(mtrr_idr);
@@ -334,6 +335,63 @@
 	return (VM_FAULT_NOPAGE);
 }
 
+int
+lkpi_remap_pfn_range(struct vm_area_struct *vma, unsigned long start_addr,
+    unsigned long start_pfn, unsigned long size, pgprot_t prot)
+{
+	vm_object_t vm_obj;
+	unsigned long addr, pfn;
+	int err = 0;
+
+	vm_obj = vma->vm_obj;
+
+	VM_OBJECT_WLOCK(vm_obj);
+	for (addr = start_addr, pfn = start_pfn;
+	    addr < start_addr + size;
+	    addr += PAGE_SIZE) {
+		vm_fault_t ret;
+retry:
+		ret = lkpi_vmf_insert_pfn_prot_locked(vma, addr, pfn, prot);
+
+		if ((ret & VM_FAULT_OOM) != 0) {
+			VM_OBJECT_WUNLOCK(vm_obj);
+			vm_wait(NULL);
+			VM_OBJECT_WLOCK(vm_obj);
+			goto retry;
+		}
+
+		if ((ret & VM_FAULT_ERROR) != 0) {
+			err = -EFAULT;
+			break;
+		}
+
+		pfn++;
+	}
+	VM_OBJECT_WUNLOCK(vm_obj);
+
+	if (unlikely(err)) {
+		zap_vma_ptes(vma, start_addr,
+		    (pfn - start_pfn) << PAGE_SHIFT);
+		return (err);
+	}
+
+	return (0);
+}
+
+int
+lkpi_io_mapping_map_user(struct io_mapping *iomap,
+    struct vm_area_struct *vma, unsigned long addr,
+    unsigned long pfn, unsigned long size)
+{
+	pgprot_t prot;
+	int ret;
+
+	prot = cachemode2protval(iomap->attr);
+	ret = lkpi_remap_pfn_range(vma, addr, pfn, size, prot);
+
+	return (ret);
+}
+
 /*
  * Although FreeBSD version of unmap_mapping_range has semantics and types of
  * parameters compatible with Linux version, the values passed in are different