MIPS: Add CPU shared FTLB feature detection

Some systems share FTLB RAMs or entries between sibling CPUs (ie.
hardware threads, or VP(E)s, within a core). These properties require
kernel handling in various places. As a start this patch introduces
cpu_has_shared_ftlb_ram & cpu_has_shared_ftlb_entries feature macros
which we set appropriately for I6400 & I6500 CPUs. Further patches will
make use of these macros as appropriate.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16202/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/kernel/cpu-probe.c

@@ -1653,6 +1653,17 @@ static inline void cpu_probe_mips(struct cpuinfo_mips *c, unsigned int cpu)
 	decode_configs(c);
 
 	spram_config();
+
+	switch (__get_cpu_type(c->cputype)) {
+	case CPU_I6500:
+		c->options |= MIPS_CPU_SHARED_FTLB_ENTRIES;
+		/* fall-through */
+	case CPU_I6400:
+		c->options |= MIPS_CPU_SHARED_FTLB_RAM;
+		/* fall-through */
+	default:
+		break;
+	}
 }
 
 static inline void cpu_probe_alchemy(struct cpuinfo_mips *c, unsigned int cpu)