diff --git a/sys/compat/linuxkpi/common/include/linux/io.h b/sys/compat/linuxkpi/common/include/linux/io.h
--- a/sys/compat/linuxkpi/common/include/linux/io.h
+++ b/sys/compat/linuxkpi/common/include/linux/io.h
@@ -411,8 +411,12 @@
 #define	ioremap(addr, size)						\
     _ioremap_attr((addr), (size), VM_MEMATTR_UNCACHEABLE)
 #endif
+#ifdef VM_MEMATTR_WRITE_COMBINING
 #define	ioremap_wc(addr, size)						\
     _ioremap_attr((addr), (size), VM_MEMATTR_WRITE_COMBINING)
+#else
+#define	ioremap_wc(addr, size)	ioremap_nocache(addr, size)
+#endif
 #define	ioremap_wb(addr, size)						\
     _ioremap_attr((addr), (size), VM_MEMATTR_WRITE_BACK)
 void iounmap(void *addr);
diff --git a/sys/compat/linuxkpi/common/include/linux/page.h b/sys/compat/linuxkpi/common/include/linux/page.h
--- a/sys/compat/linuxkpi/common/include/linux/page.h
+++ b/sys/compat/linuxkpi/common/include/linux/page.h
@@ -83,8 +83,12 @@
 #define	clear_page(page)		memset(page, 0, PAGE_SIZE)
 #define	pgprot_noncached(prot)		\
 	(((prot) & VM_PROT_ALL) | cachemode2protval(VM_MEMATTR_UNCACHEABLE))
+#ifdef VM_MEMATTR_WRITE_COMBINING
 #define	pgprot_writecombine(prot)	\
 	(((prot) & VM_PROT_ALL) | cachemode2protval(VM_MEMATTR_WRITE_COMBINING))
+#else
+#define	pgprot_writecombine(prot)	pgprot_noncached(prot)
+#endif
 
 #undef	PAGE_MASK
 #define	PAGE_MASK	(~(PAGE_SIZE-1))