#define PL_64M         26
 #define PL_256M                28
 
+/*
+ * PageGrain bits
+ */
+#define PG_RIE         (_ULCAST_(1) <<  31)
+#define PG_XIE         (_ULCAST_(1) <<  30)
+#define PG_ELPA                (_ULCAST_(1) <<  29)
+#define PG_ESP         (_ULCAST_(1) <<  28)
+
 /*
  * R4x00 interrupt enable / cause bits
  */
 #define read_c0_pagemask()     __read_32bit_c0_register($5, 0)
 #define write_c0_pagemask(val) __write_32bit_c0_register($5, 0, val)
 
+#define read_c0_pagegrain()    __read_32bit_c0_register($5, 1)
+#define write_c0_pagegrain(val)        __write_32bit_c0_register($5, 1, val)
+
 #define read_c0_wired()                __read_32bit_c0_register($6, 0)
 #define write_c0_wired(val)    __write_32bit_c0_register($6, 0, val)