MIPS: microMIPS: Add support for exception handling.

All exceptions must be taken in microMIPS mode, never in classic
MIPS mode or the kernel falls apart. A few NOP instructions are
used to maintain the correct alignment of microMIPS versions of
the exception vectors.

Signed-off-by: Steven J. Hill <Steven.Hill@imgtec.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/arch/mips/kernel/scall32-o32.S b/arch/mips/kernel/scall32-o32.S
index 9ea29649fc28..9b36424b03c5 100644
--- a/arch/mips/kernel/scall32-o32.S
+++ b/arch/mips/kernel/scall32-o32.S
@@ -138,9 +138,18 @@ stackargs:
 5:      jr      t1
          sw     t5, 16(sp)              # argument #5 to ksp
 
+#ifdef CONFIG_CPU_MICROMIPS
         sw      t8, 28(sp)              # argument #8 to ksp
+        nop
         sw      t7, 24(sp)              # argument #7 to ksp
+        nop
         sw      t6, 20(sp)              # argument #6 to ksp
+        nop
+#else
+        sw      t8, 28(sp)              # argument #8 to ksp
+        sw      t7, 24(sp)              # argument #7 to ksp
+        sw      t6, 20(sp)              # argument #6 to ksp
+#endif
 6:      j       stack_done              # go back
          nop
         .set    pop