1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright 2013, Michael Ellerman, IBM Corp.
4  */
5 
6 #define _GNU_SOURCE
7 #include <unistd.h>
8 #include <sys/syscall.h>
9 #include <string.h>
10 #include <stdio.h>
11 #include <stdbool.h>
12 #include <sys/ioctl.h>
13 
14 #include "event.h"
15 
16 
17 int perf_event_open(struct perf_event_attr *attr, pid_t pid, int cpu,
18 		int group_fd, unsigned long flags)
19 {
20 	return syscall(__NR_perf_event_open, attr, pid, cpu,
21 			   group_fd, flags);
22 }
23 
24 static void  __event_init_opts(struct event *e, u64 config,
25 			       int type, char *name, bool sampling)
26 {
27 	memset(e, 0, sizeof(*e));
28 
29 	e->name = name;
30 
31 	e->attr.type = type;
32 	e->attr.config = config;
33 	e->attr.size = sizeof(e->attr);
34 	/* This has to match the structure layout in the header */
35 	e->attr.read_format = PERF_FORMAT_TOTAL_TIME_ENABLED | \
36 				  PERF_FORMAT_TOTAL_TIME_RUNNING;
37 	if (sampling) {
38 		e->attr.sample_period = 1000;
39 		e->attr.sample_type = PERF_SAMPLE_REGS_INTR;
40 		e->attr.disabled = 1;
41 	}
42 }
43 
44 void event_init_opts(struct event *e, u64 config, int type, char *name)
45 {
46 	__event_init_opts(e, config, type, name, false);
47 }
48 
49 void event_init_named(struct event *e, u64 config, char *name)
50 {
51 	event_init_opts(e, config, PERF_TYPE_RAW, name);
52 }
53 
54 void event_init(struct event *e, u64 config)
55 {
56 	event_init_opts(e, config, PERF_TYPE_RAW, "event");
57 }
58 
59 void event_init_sampling(struct event *e, u64 config)
60 {
61 	__event_init_opts(e, config, PERF_TYPE_RAW, "event", true);
62 }
63 
64 #define PERF_CURRENT_PID	0
65 #define PERF_NO_PID		-1
66 #define PERF_NO_CPU		-1
67 #define PERF_NO_GROUP		-1
68 
69 int event_open_with_options(struct event *e, pid_t pid, int cpu, int group_fd)
70 {
71 	e->fd = perf_event_open(&e->attr, pid, cpu, group_fd, 0);
72 	if (e->fd == -1) {
73 		perror("perf_event_open");
74 		return -1;
75 	}
76 
77 	return 0;
78 }
79 
80 int event_open_with_group(struct event *e, int group_fd)
81 {
82 	return event_open_with_options(e, PERF_CURRENT_PID, PERF_NO_CPU, group_fd);
83 }
84 
85 int event_open_with_pid(struct event *e, pid_t pid)
86 {
87 	return event_open_with_options(e, pid, PERF_NO_CPU, PERF_NO_GROUP);
88 }
89 
90 int event_open_with_cpu(struct event *e, int cpu)
91 {
92 	return event_open_with_options(e, PERF_NO_PID, cpu, PERF_NO_GROUP);
93 }
94 
95 int event_open(struct event *e)
96 {
97 	return event_open_with_options(e, PERF_CURRENT_PID, PERF_NO_CPU, PERF_NO_GROUP);
98 }
99 
100 void event_close(struct event *e)
101 {
102 	close(e->fd);
103 }
104 
105 int event_enable(struct event *e)
106 {
107 	return ioctl(e->fd, PERF_EVENT_IOC_ENABLE);
108 }
109 
110 int event_disable(struct event *e)
111 {
112 	return ioctl(e->fd, PERF_EVENT_IOC_DISABLE);
113 }
114 
115 int event_reset(struct event *e)
116 {
117 	return ioctl(e->fd, PERF_EVENT_IOC_RESET);
118 }
119 
120 int event_read(struct event *e)
121 {
122 	int rc;
123 
124 	rc = read(e->fd, &e->result, sizeof(e->result));
125 	if (rc != sizeof(e->result)) {
126 		fprintf(stderr, "read error on event %p!\n", e);
127 		return -1;
128 	}
129 
130 	return 0;
131 }
132 
133 void event_report_justified(struct event *e, int name_width, int result_width)
134 {
135 	printf("%*s: result %*llu ", name_width, e->name, result_width,
136 	       e->result.value);
137 
138 	if (e->result.running == e->result.enabled)
139 		printf("running/enabled %llu\n", e->result.running);
140 	else
141 		printf("running %llu enabled %llu\n", e->result.running,
142 			e->result.enabled);
143 }
144 
145 void event_report(struct event *e)
146 {
147 	event_report_justified(e, 0, 0);
148 }
149