Commit f6be75d03c88 broke mips64, for no obvious reason.  Reverting it fixes
things.

diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index 1a4dd65..4e00f9b 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -1599,7 +1599,7 @@ void __init trap_init(void)
 		ebase = (unsigned long)
 			__alloc_bootmem(size, 1 << fls(size), 0);
 	} else {
-		ebase = CKSEG0;
+		ebase = CAC_BASE;
 		if (cpu_has_mips_r2)
 			ebase += (read_c0_ebase() & 0x3ffff000);
 	}