sh: ftrace support.

This adds support for ftrace to SH. This only includes CONFIG_FTRACE,
and does not handle dynamic ftrace presently.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 44 insertions, 0 deletions

diff --git a/arch/sh/kernel/entry-common.S b/arch/sh/kernel/entry-common.S
index efbb4268875e..1a5cf9dd82de 100644
--- a/arch/sh/kernel/entry-common.S
+++ b/arch/sh/kernel/entry-common.S
@@ -371,3 +371,47 @@ syscall_exit:
 #endif
 7:      .long   do_syscall_trace_enter
 8:      .long   do_syscall_trace_leave
+
+#ifdef CONFIG_FTRACE
+        .align 2
+        .globl  _mcount
+        .type   _mcount,@function
+        .globl  mcount
+        .type   mcount,@function
+_mcount:
+mcount:
+        mov.l   r4, @-r15
+        mov.l   r5, @-r15
+        mov.l   r6, @-r15
+        mov.l   r7, @-r15
+        sts.l   pr, @-r15
+
+        mov.l   @(20,r15),r4
+        sts     pr, r5
+
+        mov.l   1f, r6
+        mov.l   ftrace_stub, r7 
+        cmp/eq  r6, r7
+        bt      skip_trace
+
+        mov.l   @r6, r6
+        jsr     @r6
+         nop
+
+skip_trace:
+
+        lds.l   @r15+, pr
+        mov.l   @r15+, r7
+        mov.l   @r15+, r6
+        mov.l   @r15+, r5
+        rts
+         mov.l  @r15+, r4
+
+        .align 2
+1:      .long   ftrace_trace_function
+
+        .globl  ftrace_stub
+ftrace_stub:
+        rts
+         nop
+#endif /* CONFIG_FTRACE */