Thanks for you reply.
Here is the diff with the changes you suggested:

Index: cpufunc.h
===================================================================
RCS file: /cvsroot/src/sys/arch/i386/include/cpufunc.h,v
retrieving revision 1.28
diff -u -r1.28 cpufunc.h
--- cpufunc.h	14 Jan 2004 11:31:55 -0000	1.28
+++ cpufunc.h	22 Sep 2004 23:12:48 -0000
@@ -245,6 +245,19 @@
 	return (rv);
 }
 
+static __inline u_int64_t
+rdmsr64(u_int msr)
+{       
+	u_int64_t rv;
+	u_int32_t regs[2];
+        
+	__asm __volatile("rdmsr" : "=A" (regs[0]), "=D" (regs[1]) : "c" (msr));
+	rv = ((u_int64_t) regs[1] << 32) | regs[0];
+
+	return (rv);
+
+} 
+
 static __inline void
 wrmsr(u_int msr, u_int64_t newval)
 {
@@ -252,6 +265,13 @@
 }
 
 static __inline void
+wrmsr64(u_int msr, u_int64_t newval)
+{
+	__asm __volatile("wrmsr" : : "A" (newval >> 32), 
+			 "D" (newval & 0xffffffff), "c" (msr));
+}
+
+static __inline void
 wbinvd(void)
 {
 	__asm __volatile("wbinvd");


Regards.
-- 
Rui Paulo                          "Simplicity is the ultimate sophistication."
                                      -- Leonardo da Vinci