MIPS: features: Add initial support for Segmentation Control registers

MIPS32R3 introduced a new set of Segmentation Control registers which
increase the flexibility of the segmented-based memory scheme.

Signed-off-by: Steven J. Hill <Steven.Hill@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Signed-off-by: John Crispin <blogic@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/6131/
diff --git a/arch/mips/include/asm/mipsregs.h b/arch/mips/include/asm/mipsregs.h
index 412fe99..0558f9b 100644
--- a/arch/mips/include/asm/mipsregs.h
+++ b/arch/mips/include/asm/mipsregs.h
@@ -664,6 +664,26 @@
 #define MIPS_FPIR_L		(_ULCAST_(1) << 21)
 #define MIPS_FPIR_F64		(_ULCAST_(1) << 22)
 
+/*
+ * Bits in the MIPS32 Memory Segmentation registers.
+ */
+#define MIPS_SEGCFG_PA_SHIFT	9
+#define MIPS_SEGCFG_PA		(_ULCAST_(127) << MIPS_SEGCFG_PA_SHIFT)
+#define MIPS_SEGCFG_AM_SHIFT	4
+#define MIPS_SEGCFG_AM		(_ULCAST_(7) << MIPS_SEGCFG_AM_SHIFT)
+#define MIPS_SEGCFG_EU_SHIFT	3
+#define MIPS_SEGCFG_EU		(_ULCAST_(1) << MIPS_SEGCFG_EU_SHIFT)
+#define MIPS_SEGCFG_C_SHIFT	0
+#define MIPS_SEGCFG_C		(_ULCAST_(7) << MIPS_SEGCFG_C_SHIFT)
+
+#define MIPS_SEGCFG_UUSK	_ULCAST_(7)
+#define MIPS_SEGCFG_USK		_ULCAST_(5)
+#define MIPS_SEGCFG_MUSUK	_ULCAST_(4)
+#define MIPS_SEGCFG_MUSK	_ULCAST_(3)
+#define MIPS_SEGCFG_MSK		_ULCAST_(2)
+#define MIPS_SEGCFG_MK		_ULCAST_(1)
+#define MIPS_SEGCFG_UK		_ULCAST_(0)
+
 #ifndef __ASSEMBLY__
 
 /*
@@ -1138,6 +1158,15 @@
 #define read_c0_ebase()		__read_32bit_c0_register($15, 1)
 #define write_c0_ebase(val)	__write_32bit_c0_register($15, 1, val)
 
+/* MIPSR3 */
+#define read_c0_segctl0()	__read_32bit_c0_register($5, 2)
+#define write_c0_segctl0(val)	__write_32bit_c0_register($5, 2, val)
+
+#define read_c0_segctl1()	__read_32bit_c0_register($5, 3)
+#define write_c0_segctl1(val)	__write_32bit_c0_register($5, 3, val)
+
+#define read_c0_segctl2()	__read_32bit_c0_register($5, 4)
+#define write_c0_segctl2(val)	__write_32bit_c0_register($5, 4, val)
 
 /* Cavium OCTEON (cnMIPS) */
 #define read_c0_cvmcount()	__read_ulong_c0_register($9, 6)