MIPS: Add accessor functions and bit definitions for c0_PageGrain

Signed-off-by: NDavid Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/950/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

arch/mips/include/asm/mipsregs.h

@@ -250,6 +250,14 @@
 #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
  */
@@ -830,6 +838,9 @@ do {									\
 #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)