diff --git a/arch/um/include/asm/archparam-i386.h b/arch/um/include/asm/archparam-i386.h
index 49e89b8..93fd723 100644
--- a/arch/um/include/asm/archparam-i386.h
+++ b/arch/um/include/asm/archparam-i386.h
@@ -6,11 +6,11 @@
 #ifndef __UM_ARCHPARAM_I386_H
 #define __UM_ARCHPARAM_I386_H
 
-/********* Nothing for asm-um/hardirq.h **********/
-
-/********* Nothing for asm-um/hw_irq.h **********/
-
-/********* Nothing for asm-um/string.h **********/
+#ifdef CONFIG_X86_PAE
+#define LAST_PKMAP 512
+#else
+#define LAST_PKMAP 1024
+#endif
 
 #endif
 
diff --git a/arch/um/include/asm/fixmap.h b/arch/um/include/asm/fixmap.h
index 9d2be52..69c0252 100644
--- a/arch/um/include/asm/fixmap.h
+++ b/arch/um/include/asm/fixmap.h
@@ -6,6 +6,7 @@
 #include <asm/kmap_types.h>
 #include <asm/archparam.h>
 #include <asm/page.h>
+#include <linux/threads.h>
 
 /*
  * Here we define all the compile-time 'special' virtual
diff --git a/arch/um/include/asm/highmem.h b/arch/um/include/asm/highmem.h
deleted file mode 100644
index 36974cb..0000000
--- a/arch/um/include/asm/highmem.h
+++ /dev/null
@@ -1,12 +0,0 @@
-#ifndef __UM_HIGHMEM_H
-#define __UM_HIGHMEM_H
-
-#include "asm/page.h"
-#include "asm/fixmap.h"
-#include "asm/arch/highmem.h"
-
-#undef PKMAP_BASE
-
-#define PKMAP_BASE ((FIXADDR_START - LAST_PKMAP * PAGE_SIZE) & PMD_MASK)
-
-#endif
diff --git a/arch/um/include/asm/pgtable.h b/arch/um/include/asm/pgtable.h
index 02db81b..58da248 100644
--- a/arch/um/include/asm/pgtable.h
+++ b/arch/um/include/asm/pgtable.h
@@ -47,6 +47,7 @@
 
 #define VMALLOC_OFFSET	(__va_space)
 #define VMALLOC_START ((end_iomem + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))
+#define PKMAP_BASE ((FIXADDR_START - LAST_PKMAP * PAGE_SIZE) & PMD_MASK)
 #ifdef CONFIG_HIGHMEM
 # define VMALLOC_END	(PKMAP_BASE-2*PAGE_SIZE)
 #else
@@ -355,4 +356,11 @@
 
 #include <asm-generic/pgtable.h>
 
+/* Clear a kernel PTE and flush it from the TLB */
+#define kpte_clear_flush(ptep, vaddr)		\
+do {						\
+	pte_clear(&init_mm, (vaddr), (ptep));	\
+	__flush_tlb_one((vaddr));		\
+} while (0)
+
 #endif