[S390] cleanup ftrace backend functions

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 7 insertions, 23 deletions

diff --git a/arch/s390/kernel/mcount.S b/arch/s390/kernel/mcount.S
index 4a6e1a575f9e..1e6a55795628 100644
--- a/arch/s390/kernel/mcount.S
+++ b/arch/s390/kernel/mcount.S
@@ -18,22 +18,12 @@ _mcount:
 #ifdef CONFIG_DYNAMIC_FTRACE
         br      %r14
 
-        .data
-        .globl  ftrace_dyn_func
-ftrace_dyn_func:
-        .long   ftrace_stub
-        .previous
-
         .globl ftrace_caller
 ftrace_caller:
 #endif
         stm     %r2,%r5,16(%r15)
         bras    %r1,2f
-#ifdef CONFIG_DYNAMIC_FTRACE
-0:      .long   ftrace_dyn_func
-#else
 0:      .long   ftrace_trace_function
-#endif
 1:      .long   function_trace_stop
 2:      l       %r2,1b-0b(%r1)
         icm     %r2,0xf,0(%r2)
@@ -49,21 +39,15 @@ ftrace_caller:
         l       %r14,0(%r14)
         basr    %r14,%r14
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
-#ifdef CONFIG_DYNAMIC_FTRACE
+        l       %r2,100(%r15)
+        l       %r3,152(%r15)
         .globl  ftrace_graph_caller
 ftrace_graph_caller:
-        # This unconditional branch gets runtime patched. Change only if
-        # you know what you are doing. See ftrace_enable_graph_caller().
-        j       1f
-#endif
-        bras    %r1,0f
-        .long   prepare_ftrace_return
-0:      l       %r2,152(%r15)
-        l       %r4,0(%r1)
-        l       %r3,100(%r15)
-        basr    %r14,%r4
-        st      %r2,100(%r15)
-1:
+# The bras instruction gets runtime patched to call prepare_ftrace_return.
+# See ftrace_enable_ftrace_graph_caller. The patched instruction is:
+#       bras    %r14,prepare_ftrace_return
+        bras    %r14,0f
+0:      st      %r2,100(%r15)
 #endif
         ahi     %r15,96
         l       %r14,56(%r15)