--- src/mesa/drivers/dri/sis/sis_context.h.orig	Tue Apr 11 13:41:11 2006
+++ src/mesa/drivers/dri/sis/sis_context.h	Wed Dec 20 18:32:46 2006
@@ -401,8 +401,20 @@
 #define MMIO_READ(reg) *(volatile GLint *)(smesa->IOBase + (reg))
 #define MMIO_READf(reg) *(volatile GLfloat *)(smesa->IOBase + (reg))
 
-#if defined(__i386__) || defined(__amd64__)
+#if defined(__alpha__)
+#define MMIO_WMB()	__asm __volatile("wmb" : : : "memory")
+#elif defined(__amd64__) || defined(__i386__)
 #define MMIO_WMB()	__asm __volatile("" : : : "memory")
+#elif defined(__ia64__)
+#define MMIO_WMB()	__asm __volatile("mf" : : : "memory")
+#elif defined(__powerpc__)
+#define MMIO_WMB()	__asm __volatile("eieio" : : : "memory")
+#elif defined(__sparc64__)
+/*
+ * #StoreStore probably would be sufficient for this driver at the
+ * time of this writing but we use #Sync for safety.
+ */
+#define MMIO_WMB()	__asm __volatile("membar #Sync" : : : "memory")
 #else
 #error platform needs WMB
 #endif