Merge tag 'trace-v4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "Some clean ups and small fixes, but the biggest change is the addition
  of the TRACE_DEFINE_ENUM() macro that can be used by tracepoints.

  Tracepoints have helper functions for the TP_printk() called
  __print_symbolic() and __print_flags() that lets a numeric number be
  displayed as a a human comprehensible text.  What is placed in the
  TP_printk() is also shown in the tracepoint format file such that user
  space tools like perf and trace-cmd can parse the binary data and
  express the values too.  Unfortunately, the way the TRACE_EVENT()
  macro works, anything placed in the TP_printk() will be shown pretty
  much exactly as is.  The problem arises when enums are used.  That's
  because unlike macros, enums will not be changed into their values by
  the C pre-processor.  Thus, the enum string is exported to the format
  file, and this makes it useless for user space tools.

  The TRACE_DEFINE_ENUM() solves this by converting the enum strings in
  the TP_printk() format into their number, and that is what is shown to
  user space.  For example, the tracepoint tlb_flush currently has this
  in its format file:

     __print_symbolic(REC->reason,
        { TLB_FLUSH_ON_TASK_SWITCH, "flush on task switch" },
        { TLB_REMOTE_SHOOTDOWN, "remote shootdown" },
        { TLB_LOCAL_SHOOTDOWN, "local shootdown" },
        { TLB_LOCAL_MM_SHOOTDOWN, "local mm shootdown" })

  After adding:

     TRACE_DEFINE_ENUM(TLB_FLUSH_ON_TASK_SWITCH);
     TRACE_DEFINE_ENUM(TLB_REMOTE_SHOOTDOWN);
     TRACE_DEFINE_ENUM(TLB_LOCAL_SHOOTDOWN);
     TRACE_DEFINE_ENUM(TLB_LOCAL_MM_SHOOTDOWN);

  Its format file will contain this:

     __print_symbolic(REC->reason,
        { 0, "flush on task switch" },
        { 1, "remote shootdown" },
        { 2, "local shootdown" },
        { 3, "local mm shootdown" })"

* tag 'trace-v4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (27 commits)
  tracing: Add enum_map file to show enums that have been mapped
  writeback: Export enums used by tracepoint to user space
  v4l: Export enums used by tracepoints to user space
  SUNRPC: Export enums in tracepoints to user space
  mm: tracing: Export enums in tracepoints to user space
  irq/tracing: Export enums in tracepoints to user space
  f2fs: Export the enums in the tracepoints to userspace
  net/9p/tracing: Export enums in tracepoints to userspace
  x86/tlb/trace: Export enums in used by tlb_flush tracepoint
  tracing/samples: Update the trace-event-sample.h with TRACE_DEFINE_ENUM()
  tracing: Allow for modules to convert their enums to values
  tracing: Add TRACE_DEFINE_ENUM() macro to map enums to their values
  tracing: Update trace-event-sample with TRACE_SYSTEM_VAR documentation
  tracing: Give system name a pointer
  brcmsmac: Move each system tracepoints to their own header
  iwlwifi: Move each system tracepoints to their own header
  mac80211: Move message tracepoints to their own header
  tracing: Add TRACE_SYSTEM_VAR to xhci-hcd
  tracing: Add TRACE_SYSTEM_VAR to kvm-s390
  tracing: Add TRACE_SYSTEM_VAR to intel-sst
  ...

1 files changed, 36 insertions, 5 deletions

diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index 41bf65f04dd9..37d4b10b111d 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -18,6 +18,34 @@
 
 #include <linux/ftrace_event.h>
 
+#ifndef TRACE_SYSTEM_VAR
+#define TRACE_SYSTEM_VAR TRACE_SYSTEM
+#endif
+
+#define __app__(x, y) str__##x##y
+#define __app(x, y) __app__(x, y)
+
+#define TRACE_SYSTEM_STRING __app(TRACE_SYSTEM_VAR,__trace_system_name)
+
+#define TRACE_MAKE_SYSTEM_STR()				\
+	static const char TRACE_SYSTEM_STRING[] =	\
+		__stringify(TRACE_SYSTEM)
+
+TRACE_MAKE_SYSTEM_STR();
+
+#undef TRACE_DEFINE_ENUM
+#define TRACE_DEFINE_ENUM(a)				\
+	static struct trace_enum_map __used __initdata	\
+	__##TRACE_SYSTEM##_##a =			\
+	{						\
+		.system = TRACE_SYSTEM_STRING,		\
+		.enum_string = #a,			\
+		.enum_value = a				\
+	};						\
+	static struct trace_enum_map __used		\
+	__attribute__((section("_ftrace_enum_map")))	\
+	*TRACE_SYSTEM##_##a = &__##TRACE_SYSTEM##_##a
+
 /*
  * DECLARE_EVENT_CLASS can be used to add a generic function
  * handlers for events. That is, if all events have the same
@@ -105,7 +133,6 @@
 
 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 
-
 /*
  * Stage 2 of the trace events.
  *
@@ -122,6 +149,9 @@
  * The size of an array is also encoded, in the higher 16 bits of <item>.
  */
 
+#undef TRACE_DEFINE_ENUM
+#define TRACE_DEFINE_ENUM(a)
+
 #undef __field
 #define __field(type, item)
 
@@ -539,7 +569,7 @@ static inline notrace int ftrace_get_offsets_##call(			\
  *	.trace			= ftrace_raw_output_<call>, <-- stage 2
  * };
  *
- * static const char print_fmt_<call>[] = <TP_printk>;
+ * static char print_fmt_<call>[] = <TP_printk>;
  *
  * static struct ftrace_event_class __used event_class_<template> = {
  *	.system			= "<system>",
@@ -690,9 +720,9 @@ static inline void ftrace_test_probe_##call(void)			\
 #undef DECLARE_EVENT_CLASS
 #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print)	\
 _TRACE_PERF_PROTO(call, PARAMS(proto));					\
-static const char print_fmt_##call[] = print;				\
+static char print_fmt_##call[] = print;					\
 static struct ftrace_event_class __used __refdata event_class_##call = { \
-	.system			= __stringify(TRACE_SYSTEM),		\
+	.system			= TRACE_SYSTEM_STRING,			\
 	.define_fields		= ftrace_define_fields_##call,		\
 	.fields			= LIST_HEAD_INIT(event_class_##call.fields),\
 	.raw_init		= trace_event_raw_init,			\
@@ -719,7 +749,7 @@ __attribute__((section("_ftrace_events"))) *__event_##call = &event_##call
 #undef DEFINE_EVENT_PRINT
 #define DEFINE_EVENT_PRINT(template, call, proto, args, print)		\
 									\
-static const char print_fmt_##call[] = print;				\
+static char print_fmt_##call[] = print;					\
 									\
 static struct ftrace_event_call __used event_##call = {			\
 	.class			= &event_class_##template,		\
@@ -735,6 +765,7 @@ __attribute__((section("_ftrace_events"))) *__event_##call = &event_##call
 
 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 
+#undef TRACE_SYSTEM_VAR
 
 #ifdef CONFIG_PERF_EVENTS