ftrace: document function and function graph implementation

While implementing function tracer and function tracer graph support,
I found the exact arch implementation details to be a bit lacking
(and my x86 foo ain't great).  So after pounding out support for
the Blackfin arch, start documenting the requirements/details.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
LKML-Reference: <1252973415-21264-1-git-send-email-vapier@gentoo.org>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 13 insertions, 3 deletions

diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index aa002cef924c..e71634604400 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -11,12 +11,18 @@ config NOP_TRACER
 
 config HAVE_FTRACE_NMI_ENTER
         bool
+        help
+          See Documentation/trace/ftrace-implementation.txt
 
 config HAVE_FUNCTION_TRACER
         bool
+        help
+          See Documentation/trace/ftrace-implementation.txt
 
 config HAVE_FUNCTION_GRAPH_TRACER
         bool
+        help
+          See Documentation/trace/ftrace-implementation.txt
 
 config HAVE_FUNCTION_GRAPH_FP_TEST
         bool
@@ -28,21 +34,25 @@ config HAVE_FUNCTION_GRAPH_FP_TEST
 config HAVE_FUNCTION_TRACE_MCOUNT_TEST
         bool
         help
-         This gets selected when the arch tests the function_trace_stop
-         variable at the mcount call site. Otherwise, this variable
-         is tested by the called function.
+          See Documentation/trace/ftrace-implementation.txt
 
 config HAVE_DYNAMIC_FTRACE
         bool
+        help
+          See Documentation/trace/ftrace-implementation.txt
 
 config HAVE_FTRACE_MCOUNT_RECORD
         bool
+        help
+          See Documentation/trace/ftrace-implementation.txt
 
 config HAVE_HW_BRANCH_TRACER
         bool
 
 config HAVE_SYSCALL_TRACEPOINTS
         bool
+        help
+          See Documentation/trace/ftrace-implementation.txt
 
 config TRACER_MAX_TRACE
         bool