---
 arch/x86/mm/pat.c |   35 +++++++++++++++--------------------
 1 file changed, 15 insertions(+), 20 deletions(-)

Index: linux-2.6/arch/x86/mm/pat.c
===================================================================
--- linux-2.6.orig/arch/x86/mm/pat.c
+++ linux-2.6/arch/x86/mm/pat.c
@@ -31,7 +31,7 @@
 #ifdef CONFIG_X86_PAT
 int __read_mostly pat_enabled = 1;
 
-void __cpuinit pat_disable(const char *reason)
+static void __cpuinit pat_disable(const char *reason)
 {
 	pat_enabled = 0;
 	printk(KERN_INFO "%s\n", reason);
@@ -176,9 +176,9 @@ static unsigned long pat_x_mtrr_type(u64
 {
 	/*
 	 * Look for MTRR hint to get the effective type in case where PAT
-	 * request is for WB.
+	 * request is for WB or WC.
 	 */
-	if (req_type == _PAGE_CACHE_WB) {
+	if (req_type == _PAGE_CACHE_WB || req_type == _PAGE_CACHE_WC) {
 		u8 mtrr_type;
 
 		mtrr_type = mtrr_type_lookup(start, end);
@@ -191,10 +191,15 @@ static unsigned long pat_x_mtrr_type(u64
 	return req_type;
 }
 
+static unsigned long real_type(struct memtype *entry)
+{
+	return pat_x_mtrr_type(entry->start, entry->end, entry->type);
+}
+
 static int
 chk_conflict(struct memtype *new, struct memtype *entry, unsigned long *type)
 {
-	if (new->type != entry->type) {
+	if (real_type(new) != real_type(entry)) {
 		if (type) {
 			new->type = entry->type;
 			*type = entry->type;
@@ -206,15 +211,16 @@ chk_conflict(struct memtype *new, struct
 	list_for_each_entry_continue(entry, &memtype_list, nd) {
 		if (new->end <= entry->start)
 			break;
-		else if (new->type != entry->type)
+		else if (real_type(new) != real_type(entry))
 			goto conflict;
 	}
 	return 0;
 
  conflict:
 	printk(KERN_INFO "%s:%d conflicting memory types "
-	       "%Lx-%Lx %s<->%s\n", current->comm, current->pid, new->start,
-	       new->end, cattr_name(new->type), cattr_name(entry->type));
+	       "%Lx-%Lx %s <-> %Lx-%Lx%s\n", current->comm, current->pid,
+	       new->start, new->end, cattr_name(new->type),
+	       entry->start, entry->end, cattr_name(entry->type));
 	return -EBUSY;
 }
 
@@ -353,18 +359,7 @@ int reserve_memtype(u64 start, u64 end,
 	}
 
 	if (req_type == -1) {
-		/*
-		 * Call mtrr_lookup to get the type hint. This is an
-		 * optimization for /dev/mem mmap'ers into WB memory (BIOS
-		 * tools and ACPI tools). Use WB request for WB memory and use
-		 * UC_MINUS otherwise.
-		 */
-		u8 mtrr_type = mtrr_type_lookup(start, end);
-
-		if (mtrr_type == MTRR_TYPE_WRBACK)
-			actual_type = _PAGE_CACHE_WB;
-		else
-			actual_type = _PAGE_CACHE_UC_MINUS;
+		actual_type = pat_x_mtrr_type(start, end, _PAGE_CACHE_WB);
 	} else {
 		actual_type = pat_x_mtrr_type(start, end,
 					      req_type & _PAGE_CACHE_MASK);
@@ -386,7 +381,7 @@ int reserve_memtype(u64 start, u64 end,
 
 	new->start	= start;
 	new->end	= end;
-	new->type	= actual_type;
+	new->type	= req_type & _PAGE_CACHE_MASK;
 
 	spin_lock(&memtype_lock);