microblaze: ftrace: Add dynamic function graph tracer

This patch add support for dynamic function graph tracer.

There is one my expactation that I can do flush_icache after
all code modification. On microblaze is this safer than do
flush for every entry. For icache is used name flush but
correct should be invalidation - this will be fix in upcomming
new cache implementaion and WB support.

Signed-off-by: Michal Simek <monstr@monstr.eu>
diff --git a/arch/microblaze/kernel/mcount.S b/arch/microblaze/kernel/mcount.S
index 84a1945..e7eaa7a 100644
--- a/arch/microblaze/kernel/mcount.S
+++ b/arch/microblaze/kernel/mcount.S
@@ -97,6 +97,7 @@
 	nop;
 	/* MS: HAVE_FUNCTION_TRACE_MCOUNT_TEST end of checking */
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
+#ifndef CONFIG_DYNAMIC_FTRACE
 	lwi	r5, r0, ftrace_graph_return;
 	addik	r6, r0, ftrace_stub; /* asm implementation */
 	cmpu	r5, r5, r6; /* ftrace_graph_return != ftrace_stub */
@@ -108,6 +109,11 @@
 	cmpu	r5, r5, r6; /* ftrace_graph_entry != ftrace_graph_entry_stub */
 	beqid	r5, end_graph_tracer;
 	nop;
+#else /* CONFIG_DYNAMIC_FTRACE */
+NOALIGN_ENTRY(ftrace_call_graph)
+	/* MS: jump over graph function - replaced from C code */
+	bri	end_graph_tracer
+#endif /* CONFIG_DYNAMIC_FTRACE */
 	addik	r5, r1, 120; /* MS: load parent addr */
 	addik	r6, r15, 0; /* MS: load current function addr */
 	bralid	r15, prepare_ftrace_return;