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