MIPS: No branches in delay slots for huge pages in handle_tlbl

For the case PM_DEFAULT_MASK == 0, we were placing a branch in the
delay slot of another branch.  This leads to undefined behavior.

Signed-off-by: David Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2775/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 2 insertions, 1 deletions

diff --git a/arch/mips/mm/tlbex.c b/arch/mips/mm/tlbex.c
index 46f33c7c1a09..e06370f58ef3 100644
--- a/arch/mips/mm/tlbex.c
+++ b/arch/mips/mm/tlbex.c
@@ -1962,7 +1962,8 @@ static void __cpuinit build_r4000_tlb_load_handler(void)
                         uasm_i_andi(&p, wr.r3, wr.r3, 2);
                         uasm_il_beqz(&p, &r, wr.r3, label_tlbl_goaround2);
                 }
-
+                if (PM_DEFAULT_MASK == 0)
+                        uasm_i_nop(&p);
                 /*
                  * We clobbered C0_PAGEMASK, restore it.  On the other branch
                  * it is restored in build_huge_tlb_write_entry.