Impact: clean up

Neil Horman (et. al.) criticized the way the trace events were broken up
into two files. The reason for that was that ftrace needed to separate out
the declarations from where the #include <linux/tracepoint.h> was used.
It then dawned on me that the tracepoint.h header only needs to define the
TRACE_EVENT macro if it is not already defined.

The solution is simply to test if TRACE_EVENT is defined, and if it is not
then the linux/tracepoint.h header can define it. This change consolidates
all the <traces>.h and <traces>_event_types.h into the <traces>.h file.
Reported-by: NNeil Horman <nhorman@tuxdriver.com>
Reported-by: NTheodore Tso <tytso@mit.edu>
Reported-by: NJiaying Zhang <jiayingz@google.com>
Cc: Zhaolei <zhaolei@cn.fujitsu.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

TRACE_EVENT is a more generic way to define a tracepoint.
Doing so adds these new capabilities to this tracepoint:

  - zero-copy and per-cpu splice() tracing
  - binary tracing without printf overhead
  - structured logging records exposed under /debug/tracing/events
  - trace events embedded in function tracer output and other plugins
  - user-defined, per tracepoint filter expressions
Signed-off-by: NZhao Lei <zhaolei@cn.fujitsu.com>
Acked-by: NNeil Horman <nhorman@tuxdriver.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: "Steven Rostedt ;" <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <49DD90D2.5020604@cn.fujitsu.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Today's linux-next build (powerpc ppc64_defconfig) failed like this:

 In file included from net/core/skbuff.c:69:
 include/trace/skb.h:4: error: expected ')' before '(' token
 include/trace/skb.h:4: error: expected ')' before '(' token
 [...]

Caused by commit 2939b046 ("tracing:
replace TP<var> with TP_<var>") from the tracing tree interacting with
commit 4893d39e ("Network Drop Monitor:
Add trace declaration for skb frees") from the net tree.
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The tracing header needs to include definitions for the macros used and
the types referenced.  This lets automated tracing tools like SystemTap
make use of the tracepoint without any specific knowledge of its
meaning (leaving that to the user).
Signed-off-by: NJosh Stone <jistone@redhat.com>
CC: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NNeil Horman <nhorman@tuxdriver.com>

 include/trace/skb.h   |    8 ++++++++
 net/core/Makefile     |    2 ++
 net/core/net-traces.c |   29 +++++++++++++++++++++++++++++
 3 files changed, 39 insertions(+)
Signed-off-by: NDavid S. Miller <davem@davemloft.net>