c6x: add ret_from_kernel_thread(), simplify kernel_thread()

Signed-off-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 20 insertions, 0 deletions

diff --git a/arch/c6x/kernel/entry.S b/arch/c6x/kernel/entry.S
index 30b37e5f4a61..6e6bd9d3d9cc 100644
--- a/arch/c6x/kernel/entry.S
+++ b/arch/c6x/kernel/entry.S
@@ -400,6 +400,26 @@ ret_from_fork_2:
         STW     .D2T2   B0,*+SP(REGS_A4+8)
 ENDPROC(ret_from_fork)
 
+ENTRY(ret_from_kernel_thread)
+#ifdef CONFIG_C6X_BIG_KERNEL
+        MVKL    .S1     schedule_tail,A0
+        MVKH    .S1     schedule_tail,A0
+        B       .S2X    A0
+#else
+        B       .S2     schedule_tail
+#endif
+        LDW     .D2T2   *+SP(REGS_A0+8),B10 /* get fn  */
+        ADDKPC  .S2     0f,B3,3
+0:
+        B       .S2     B10                /* call fn */
+        LDW     .D2T1   *+SP(REGS_A1+8),A4 /* get arg */
+        MVKL    .S2     sys_exit,B11
+        MVKH    .S2     sys_exit,B11
+        ADDKPC  .S2     0f,B3,1
+0:
+        BNOP    .S2     B11,5   /* jump to sys_exit */
+ENDPROC(ret_from_kernel_thread)
+
         ;;
         ;; These are the interrupt handlers, responsible for calling __do_IRQ()
         ;; int6 is used for syscalls (see _system_call entry)