diff --git a/arch/mips/mm/c-r4k.c b/arch/mips/mm/c-r4k.c
index 726e899..aa830c3 100644
--- a/arch/mips/mm/c-r4k.c
+++ b/arch/mips/mm/c-r4k.c
@@ -1012,8 +1012,10 @@
 	 * with that for us so we don't need to take care ourselves.
 	 */
 	switch (c->cputype) {
+	case CPU_20KC:
 	case CPU_R10000:
 	case CPU_R12000:
+	case CPU_SB1:
 		break;
 	case CPU_24K:
 		if (!(read_c0_config7() & (1 << 16)))