Use hardware mechanism to deal with cache aliases in the 24K.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/mm/c-r4k.c

@@ -1011,9 +1011,17 @@ static void __init probe_pcache(void)
 	 * normally they'd suffer from aliases but magic in the hardware deals
 	 * with that for us so we don't need to take care ourselves.
 	 */
-	if (c->cputype != CPU_R10000 && c->cputype != CPU_R12000)
+	switch (c->cputype) {
 		if (c->dcache.waysize > PAGE_SIZE)
-		        c->dcache.flags |= MIPS_CACHE_ALIASES;
+
+	case CPU_R10000:
+	case CPU_R12000:
+		break;
+	case CPU_24K:
+		if (!(read_c0_config7() & (1 << 16)))
+	default:
+			c->dcache.flags |= MIPS_CACHE_ALIASES;
+	}
 
 	switch (c->cputype) {
 	case CPU_20KC: