MIPS: Avoid potential hazard on Context register

set_saved_sp reads Context register. Avoid reading stale value from
earlier incomplete write.

Issue found and fixed for head.S by Chris Dearman <chris@mips.com>.

Signed-off-by: Chris Dearman <chris@mips.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/arch/mips/kernel/head.S b/arch/mips/kernel/head.S
index 531ce7b16124..ea695d9605e9 100644
--- a/arch/mips/kernel/head.S
+++ b/arch/mips/kernel/head.S
@@ -191,6 +191,7 @@ NESTED(kernel_entry, 16, sp)			# kernel entry point
         /* Set the SP after an empty pt_regs.  */
         PTR_LI          sp, _THREAD_SIZE - 32 - PT_SIZE
         PTR_ADDU        sp, $28
+        back_to_back_c0_hazard
         set_saved_sp    sp, t0, t1
         PTR_SUBU        sp, 4 * SZREG           # init stack pointer