[MIPS] ret_from_irq adjustment

Make sure that RA on top of interrupt stack is an address of ret_from_irq,
so that dump_stack etc. can trace info interrupted context.

Also this patch fixes except_vec_vi_handler and __smtc_ipi_vector which
seems broken.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 3 insertions, 6 deletions

diff --git a/arch/mips/kernel/smtc-asm.S b/arch/mips/kernel/smtc-asm.S
index 76cb31d57482..1cb9441f1474 100644
--- a/arch/mips/kernel/smtc-asm.S
+++ b/arch/mips/kernel/smtc-asm.S
@@ -97,15 +97,12 @@ FEXPORT(__smtc_ipi_vector)
         SAVE_ALL
         CLI
         TRACE_IRQS_OFF
-        move    a0,sp
         /* Function to be invoked passed stack pad slot 5 */
         lw      t0,PT_PADSLOT5(sp)
         /* Argument from sender passed in stack pad slot 4 */
-        lw      a1,PT_PADSLOT4(sp)
-        jalr    t0
-        nop
-        j       ret_from_irq
-        nop
+        lw      a0,PT_PADSLOT4(sp)
+        PTR_LA  ra, _ret_from_irq
+        jr      t0
 
 /*
  * Called from idle loop to provoke processing of queued IPIs