1 /* SPDX-License-Identifier: GPL-2.0 */
2 
3 /*
4  * If TRACE_SYSTEM is defined, that will be the directory created
5  * in the ftrace directory under /sys/kernel/tracing/events/<system>
6  *
7  * The define_trace.h below will also look for a file name of
8  * TRACE_SYSTEM.h where TRACE_SYSTEM is what is defined here.
9  * In this case, it would look for sample-trace.h
10  *
11  * If the header name will be different than the system name
12  * (as in this case), then you can override the header name that
13  * define_trace.h will look up by defining TRACE_INCLUDE_FILE
14  *
15  * This file is called sample-trace-array.h but we want the system
16  * to be called "sample-subsystem". Therefore we must define the name of this
17  * file:
18  *
19  * #define TRACE_INCLUDE_FILE sample-trace-array
20  *
21  * As we do in the bottom of this file.
22  *
23  * Notice that TRACE_SYSTEM should be defined outside of #if
24  * protection, just like TRACE_INCLUDE_FILE.
25  */
26 #undef TRACE_SYSTEM
27 #define TRACE_SYSTEM sample-subsystem
28 
29 /*
30  * TRACE_SYSTEM is expected to be a C valid variable (alpha-numeric
31  * and underscore), although it may start with numbers. If for some
32  * reason it is not, you need to add the following lines:
33  */
34 #undef TRACE_SYSTEM_VAR
35 #define TRACE_SYSTEM_VAR sample_subsystem
36 
37 /*
38  * But the above is only needed if TRACE_SYSTEM is not alpha-numeric
39  * and underscored. By default, TRACE_SYSTEM_VAR will be equal to
40  * TRACE_SYSTEM. As TRACE_SYSTEM_VAR must be alpha-numeric, if
41  * TRACE_SYSTEM is not, then TRACE_SYSTEM_VAR must be defined with
42  * only alpha-numeric and underscores.
43  *
44  * The TRACE_SYSTEM_VAR is only used internally and not visible to
45  * user space.
46  */
47 
48 /*
49  * Notice that this file is not protected like a normal header.
50  * We also must allow for rereading of this file. The
51  *
52  *  || defined(TRACE_HEADER_MULTI_READ)
53  *
54  * serves this purpose.
55  */
56 #if !defined(_SAMPLE_TRACE_ARRAY_H) || defined(TRACE_HEADER_MULTI_READ)
57 #define _SAMPLE_TRACE_ARRAY_H
58 
59 #include <linux/tracepoint.h>
60 TRACE_EVENT(sample_event,
61 
62 	TP_PROTO(int count, unsigned long time),
63 
64 	TP_ARGS(count, time),
65 
66 	TP_STRUCT__entry(
67 		__field(int, count)
68 		__field(unsigned long, time)
69 	),
70 
71 	TP_fast_assign(
72 		__entry->count = count;
73 		__entry->time = time;
74 	),
75 
76 	TP_printk("count value=%d at jiffies=%lu", __entry->count,
77 		__entry->time)
78 	);
79 #endif
80 
81 #undef TRACE_INCLUDE_PATH
82 #define TRACE_INCLUDE_PATH .
83 #define TRACE_INCLUDE_FILE sample-trace-array
84 #include <trace/define_trace.h>
85