MIPS: Move RIXI exception enabling after vendor-specific cpu_probe

Some processors may not have the RIXI bit advertised in the Config3 register,
not being a MIPS32R2 or R6 core, yet, they might be supporting it through a
different way, which is overriden during vendor-specific cpu_probe().

Move the RIXI exceptions enabling after the vendor-specific cpu_probe()
function has had a change to run and override the current CPU's options with
MIPS_CPU_RIXI.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Cc: john@phrozen.org
Cc: cernekee@gmail.com
Cc: jon.fraser@broadcom.com
Cc: pgynther@google.com
Cc: paul.burton@imgtec.com
Cc: ddaney.cavm@gmail.com
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12506/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/kernel/cpu-probe.c

@@ -862,15 +862,6 @@ static void decode_configs(struct cpuinfo_mips *c)
 
 	mips_probe_watch_registers(c);
 
-	if (cpu_has_rixi) {
-		/* Enable the RIXI exceptions */
-		set_c0_pagegrain(PG_IEC);
-		back_to_back_c0_hazard();
-		/* Verify the IEC bit is set */
-		if (read_c0_pagegrain() & PG_IEC)
-			c->options |= MIPS_CPU_RIXIEX;
-	}
-
 #ifndef CONFIG_MIPS_CPS
 	if (cpu_has_mips_r2_r6) {
 		c->core = get_ebase_cpunum();
@@ -1733,6 +1724,15 @@ void cpu_probe(void)
 	 */
 	BUG_ON(current_cpu_type() != c->cputype);
 
+	if (cpu_has_rixi) {
+		/* Enable the RIXI exceptions */
+		set_c0_pagegrain(PG_IEC);
+		back_to_back_c0_hazard();
+		/* Verify the IEC bit is set */
+		if (read_c0_pagegrain() & PG_IEC)
+			c->options |= MIPS_CPU_RIXIEX;
+	}
+
 	if (mips_fpu_disabled)
 		c->options &= ~MIPS_CPU_FPU;