MIPS: Add accessor & bit definitions for GlobalNumber

MIPSr6 introduces a GlobalNumber register, which is required when VPs
are implemented (ie. when multi-threading is supported) but otherwise
optional. The register contains sufficient information to uniquely
identify a VP within a system using its cluster number, core number & VP
ID.

In preparation for using this register & its fields, introduce an
accessor macro for it & define its various bits with the typical style
preprocessor macros.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/17007/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/include/asm/mipsregs.h

@@ -48,6 +48,7 @@
 #define CP0_ENTRYLO0 $2
 #define CP0_ENTRYLO1 $3
 #define CP0_CONF $3
+#define CP0_GLOBALNUMBER $3, 1
 #define CP0_CONTEXT $4
 #define CP0_PAGEMASK $5
 #define CP0_SEGCTL0 $5, 2
@@ -147,6 +148,16 @@
 #define MIPS_ENTRYLO_XI		(_ULCAST_(1) << (BITS_PER_LONG - 2))
 #define MIPS_ENTRYLO_RI		(_ULCAST_(1) << (BITS_PER_LONG - 1))
 
+/*
+ * MIPSr6+ GlobalNumber register definitions
+ */
+#define MIPS_GLOBALNUMBER_VP_SHF	0
+#define MIPS_GLOBALNUMBER_VP		(_ULCAST_(0xff) << MIPS_GLOBALNUMBER_VP_SHF)
+#define MIPS_GLOBALNUMBER_CORE_SHF	8
+#define MIPS_GLOBALNUMBER_CORE		(_ULCAST_(0xff) << MIPS_GLOBALNUMBER_CORE_SHF)
+#define MIPS_GLOBALNUMBER_CLUSTER_SHF	16
+#define MIPS_GLOBALNUMBER_CLUSTER	(_ULCAST_(0xf) << MIPS_GLOBALNUMBER_CLUSTER_SHF)
+
 /*
  * Values for PageMask register
  */
@@ -1446,6 +1457,8 @@ do {									\
 #define read_c0_conf()		__read_32bit_c0_register($3, 0)
 #define write_c0_conf(val)	__write_32bit_c0_register($3, 0, val)
 
+#define read_c0_globalnumber()	__read_32bit_c0_register($3, 1)
+
 #define read_c0_context()	__read_ulong_c0_register($4, 0)
 #define write_c0_context(val)	__write_ulong_c0_register($4, 0, val)