Index: linux/arch/x86_64/mm/pageattr.c
===================================================================
--- linux.orig/arch/x86_64/mm/pageattr.c
+++ linux/arch/x86_64/mm/pageattr.c
@@ -176,10 +176,19 @@ __change_page_attr(unsigned long address
  */
 int change_page_attr_addr(unsigned long address, int numpages, pgprot_t prot)
 {
+	unsigned long start = __pa(address);
 	int err = 0; 
 	int i; 
 
 	down_write(&init_mm.mmap_sem);
+	err = mattr_get(start, start + numpages*PAGE_SIZE,prot);
+	if (err) { 
+		printk(KERN_INFO 
+			"%s: change_page_attr: cache conflict %lx-%lx\n",
+			current->comm, start, start+numpages*PAGE_SIZE);
+		up_write(&init_mm.mmap_sem);
+		return err;
+	}
 	for (i = 0; i < numpages; i++, address += PAGE_SIZE) {
 		unsigned long pfn = __pa(address) >> PAGE_SHIFT;
 
@@ -196,6 +205,8 @@ int change_page_attr_addr(unsigned long 
 			err = __change_page_attr(addr2, pfn, prot2, PAGE_KERNEL_EXEC);
 		} 
 	} 	
+	if (err)
+		mattr_put(start, start+numpages*PAGE_SIZE, prot);
 	up_write(&init_mm.mmap_sem); 
 	return err;
 }
Index: linux/include/asm-i386/cacheflush.h
===================================================================
--- linux.orig/include/asm-i386/cacheflush.h
+++ linux/include/asm-i386/cacheflush.h
@@ -26,6 +26,8 @@
 void global_flush_tlb(void); 
 int change_page_attr(struct page *page, int numpages, pgprot_t prot);
 int change_page_attr_pfn(unsigned long pfn, int numpages, pgprot_t prot);
+int mattr_get(unsigned long pfn, unsigned long end, pgprot_t prot);
+void mattr_put(unsigned long pfn, unsigned long end, pgprot_t prot);
 
 #ifdef CONFIG_DEBUG_PAGEALLOC
 /* internal debugging function */
Index: linux/include/asm-x86_64/cacheflush.h
===================================================================
--- linux.orig/include/asm-x86_64/cacheflush.h
+++ linux/include/asm-x86_64/cacheflush.h
@@ -26,6 +26,8 @@
 void global_flush_tlb(void); 
 int change_page_attr(struct page *page, int numpages, pgprot_t prot);
 int change_page_attr_addr(unsigned long addr, int numpages, pgprot_t prot);
+int mattr_get(unsigned long pfn, unsigned long end, pgprot_t prot);
+void mattr_put(unsigned long pfn, unsigned long end, pgprot_t prot);
 
 #ifdef CONFIG_DEBUG_RODATA
 void mark_rodata_ro(void);
Index: linux/arch/i386/pci/i386.c
===================================================================
--- linux.orig/arch/i386/pci/i386.c
+++ linux/arch/i386/pci/i386.c
@@ -288,10 +288,7 @@ int pci_mmap_page_range(struct pci_dev *
 	else
 		vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 
-	if (io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
-			       vma->vm_end - vma->vm_start,
-			       vma->vm_page_prot))
-		return -EAGAIN;
-
-	return 0;
+	return io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
+			    	vma->vm_end - vma->vm_start,
+				vma->vm_page_prot);
 }
Index: linux/include/asm-generic/pgtable.h
===================================================================
--- linux.orig/include/asm-generic/pgtable.h
+++ linux/include/asm-generic/pgtable.h
@@ -230,6 +230,11 @@ static inline int pmd_none_or_clear_bad(
 	}
 	return 0;
 }
+
+#ifndef pte_caching_nonstd 
+#define pte_caching_nonstd 0
+#endif
+
 #endif /* !__ASSEMBLY__ */
 
 #endif /* _ASM_GENERIC_PGTABLE_H */
Index: linux/mm/memory.c
===================================================================
--- linux.orig/mm/memory.c
+++ linux/mm/memory.c
@@ -640,6 +640,11 @@ static unsigned long zap_pte_range(struc
 			struct page *page;
 
 			page = vm_normal_page(vma, addr, ptent);
+			
+			if (pgprot_nonstd(pte_pgprot(ptent)))
+				change_page_attr_pfn(pte_pfn(ptent), 1,
+							PAGE_KERNEL);
+
 			if (unlikely(details) && page) {
 				/*
 				 * unmap_shared_mapping_pages() wants to
Index: linux/include/asm-x86_64/pgtable.h
===================================================================
--- linux.orig/include/asm-x86_64/pgtable.h
+++ linux/include/asm-x86_64/pgtable.h
@@ -445,8 +445,9 @@ void vmalloc_sync_all(void);
 
 extern int kern_addr_valid(unsigned long addr); 
 
-#define io_remap_pfn_range(vma, vaddr, pfn, size, prot)		\
-		remap_pfn_range(vma, vaddr, pfn, size, prot)
+extern int io_remap_page_range(struct vm_area_struct *vma,
+			       unsigned long vaddr, unsigned long pfn,
+			       unsigned long size, pgprot_t prot);
 
 #define MK_IOSPACE_PFN(space, pfn)	(pfn)
 #define GET_IOSPACE(pfn)		0