diff -ru orig/kernel/nv-pat.c work/kernel/nv-pat.c
--- orig/kernel/nv-pat.c	2015-06-24 20:01:46.434898721 -0500
+++ work/kernel/nv-pat.c	2015-06-24 20:00:56.856901342 -0500
@@ -35,8 +35,13 @@
     unsigned long cr0 = read_cr0();
     write_cr0(((cr0 & (0xdfffffff)) | 0x40000000));
     wbinvd();
+#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 20, 0)
     *cr4 = read_cr4();
     if (*cr4 & 0x80) write_cr4(*cr4 & ~0x80);
+#else
+    *cr4 = __read_cr4();
+    if (*cr4 & 0x80) __write_cr4(*cr4 & ~0x80);
+#endif
     __flush_tlb();
 }
 
@@ -46,7 +51,11 @@
     wbinvd();
     __flush_tlb();
     write_cr0((cr0 & 0x9fffffff));
+#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 20, 0)
     if (cr4 & 0x80) write_cr4(cr4);
+#else
+    if (cr4 & 0x80) __write_cr4(cr4);
+#endif   
 }
 
 static int nv_determine_pat_mode(void)