MIPS: detect presence of MAARs

Detect the presence of MAAR using the MRP bit in Config5, and record
that presence using a CPU option bit. A cpu_has_maar macro will then
allow code to conditionalise upon the presence of MAARs.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7330/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c
index 66b8fe9..e34b10b 100644
--- a/arch/mips/kernel/cpu-probe.c
+++ b/arch/mips/kernel/cpu-probe.c
@@ -405,6 +405,8 @@
 
 	if (config5 & MIPS_CONF5_EVA)
 		c->options |= MIPS_CPU_EVA;
+	if (config5 & MIPS_CONF5_MRP)
+		c->options |= MIPS_CPU_MAAR;
 
 	return config5 & MIPS_CONF_M;
 }