xref: /kernel/linux/linux-5.10/tools/lib/perf/evsel.c (revision 8c2ecf20)
1// SPDX-License-Identifier: GPL-2.0
2#include <errno.h>
3#include <unistd.h>
4#include <sys/syscall.h>
5#include <perf/evsel.h>
6#include <perf/cpumap.h>
7#include <perf/threadmap.h>
8#include <linux/list.h>
9#include <internal/evsel.h>
10#include <linux/zalloc.h>
11#include <stdlib.h>
12#include <internal/xyarray.h>
13#include <internal/cpumap.h>
14#include <internal/threadmap.h>
15#include <internal/lib.h>
16#include <linux/string.h>
17#include <sys/ioctl.h>
18
19void perf_evsel__init(struct perf_evsel *evsel, struct perf_event_attr *attr)
20{
21	INIT_LIST_HEAD(&evsel->node);
22	evsel->attr = *attr;
23}
24
25struct perf_evsel *perf_evsel__new(struct perf_event_attr *attr)
26{
27	struct perf_evsel *evsel = zalloc(sizeof(*evsel));
28
29	if (evsel != NULL)
30		perf_evsel__init(evsel, attr);
31
32	return evsel;
33}
34
35void perf_evsel__delete(struct perf_evsel *evsel)
36{
37	free(evsel);
38}
39
40#define FD(e, x, y) (*(int *) xyarray__entry(e->fd, x, y))
41
42int perf_evsel__alloc_fd(struct perf_evsel *evsel, int ncpus, int nthreads)
43{
44	evsel->fd = xyarray__new(ncpus, nthreads, sizeof(int));
45
46	if (evsel->fd) {
47		int cpu, thread;
48		for (cpu = 0; cpu < ncpus; cpu++) {
49			for (thread = 0; thread < nthreads; thread++) {
50				FD(evsel, cpu, thread) = -1;
51			}
52		}
53	}
54
55	return evsel->fd != NULL ? 0 : -ENOMEM;
56}
57
58static int
59sys_perf_event_open(struct perf_event_attr *attr,
60		    pid_t pid, int cpu, int group_fd,
61		    unsigned long flags)
62{
63	return syscall(__NR_perf_event_open, attr, pid, cpu, group_fd, flags);
64}
65
66int perf_evsel__open(struct perf_evsel *evsel, struct perf_cpu_map *cpus,
67		     struct perf_thread_map *threads)
68{
69	int cpu, thread, err = 0;
70
71	if (cpus == NULL) {
72		static struct perf_cpu_map *empty_cpu_map;
73
74		if (empty_cpu_map == NULL) {
75			empty_cpu_map = perf_cpu_map__dummy_new();
76			if (empty_cpu_map == NULL)
77				return -ENOMEM;
78		}
79
80		cpus = empty_cpu_map;
81	}
82
83	if (threads == NULL) {
84		static struct perf_thread_map *empty_thread_map;
85
86		if (empty_thread_map == NULL) {
87			empty_thread_map = perf_thread_map__new_dummy();
88			if (empty_thread_map == NULL)
89				return -ENOMEM;
90		}
91
92		threads = empty_thread_map;
93	}
94
95	if (evsel->fd == NULL &&
96	    perf_evsel__alloc_fd(evsel, cpus->nr, threads->nr) < 0)
97		return -ENOMEM;
98
99	for (cpu = 0; cpu < cpus->nr; cpu++) {
100		for (thread = 0; thread < threads->nr; thread++) {
101			int fd;
102
103			fd = sys_perf_event_open(&evsel->attr,
104						 threads->map[thread].pid,
105						 cpus->map[cpu], -1, 0);
106
107			if (fd < 0)
108				return -errno;
109
110			FD(evsel, cpu, thread) = fd;
111		}
112	}
113
114	return err;
115}
116
117static void perf_evsel__close_fd_cpu(struct perf_evsel *evsel, int cpu)
118{
119	int thread;
120
121	for (thread = 0; thread < xyarray__max_y(evsel->fd); ++thread) {
122		if (FD(evsel, cpu, thread) >= 0)
123			close(FD(evsel, cpu, thread));
124		FD(evsel, cpu, thread) = -1;
125	}
126}
127
128void perf_evsel__close_fd(struct perf_evsel *evsel)
129{
130	int cpu;
131
132	for (cpu = 0; cpu < xyarray__max_x(evsel->fd); cpu++)
133		perf_evsel__close_fd_cpu(evsel, cpu);
134}
135
136void perf_evsel__free_fd(struct perf_evsel *evsel)
137{
138	xyarray__delete(evsel->fd);
139	evsel->fd = NULL;
140}
141
142void perf_evsel__close(struct perf_evsel *evsel)
143{
144	if (evsel->fd == NULL)
145		return;
146
147	perf_evsel__close_fd(evsel);
148	perf_evsel__free_fd(evsel);
149}
150
151void perf_evsel__close_cpu(struct perf_evsel *evsel, int cpu)
152{
153	if (evsel->fd == NULL)
154		return;
155
156	perf_evsel__close_fd_cpu(evsel, cpu);
157}
158
159int perf_evsel__read_size(struct perf_evsel *evsel)
160{
161	u64 read_format = evsel->attr.read_format;
162	int entry = sizeof(u64); /* value */
163	int size = 0;
164	int nr = 1;
165
166	if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
167		size += sizeof(u64);
168
169	if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
170		size += sizeof(u64);
171
172	if (read_format & PERF_FORMAT_ID)
173		entry += sizeof(u64);
174
175	if (read_format & PERF_FORMAT_GROUP) {
176		nr = evsel->nr_members;
177		size += sizeof(u64);
178	}
179
180	size += entry * nr;
181	return size;
182}
183
184int perf_evsel__read(struct perf_evsel *evsel, int cpu, int thread,
185		     struct perf_counts_values *count)
186{
187	size_t size = perf_evsel__read_size(evsel);
188
189	memset(count, 0, sizeof(*count));
190
191	if (FD(evsel, cpu, thread) < 0)
192		return -EINVAL;
193
194	if (readn(FD(evsel, cpu, thread), count->values, size) <= 0)
195		return -errno;
196
197	return 0;
198}
199
200static int perf_evsel__run_ioctl(struct perf_evsel *evsel,
201				 int ioc,  void *arg,
202				 int cpu)
203{
204	int thread;
205
206	for (thread = 0; thread < xyarray__max_y(evsel->fd); thread++) {
207		int fd = FD(evsel, cpu, thread),
208		    err = ioctl(fd, ioc, arg);
209
210		if (err)
211			return err;
212	}
213
214	return 0;
215}
216
217int perf_evsel__enable_cpu(struct perf_evsel *evsel, int cpu)
218{
219	return perf_evsel__run_ioctl(evsel, PERF_EVENT_IOC_ENABLE, NULL, cpu);
220}
221
222int perf_evsel__enable(struct perf_evsel *evsel)
223{
224	int i;
225	int err = 0;
226
227	for (i = 0; i < xyarray__max_x(evsel->fd) && !err; i++)
228		err = perf_evsel__run_ioctl(evsel, PERF_EVENT_IOC_ENABLE, NULL, i);
229	return err;
230}
231
232int perf_evsel__disable_cpu(struct perf_evsel *evsel, int cpu)
233{
234	return perf_evsel__run_ioctl(evsel, PERF_EVENT_IOC_DISABLE, NULL, cpu);
235}
236
237int perf_evsel__disable(struct perf_evsel *evsel)
238{
239	int i;
240	int err = 0;
241
242	for (i = 0; i < xyarray__max_x(evsel->fd) && !err; i++)
243		err = perf_evsel__run_ioctl(evsel, PERF_EVENT_IOC_DISABLE, NULL, i);
244	return err;
245}
246
247int perf_evsel__apply_filter(struct perf_evsel *evsel, const char *filter)
248{
249	int err = 0, i;
250
251	for (i = 0; i < evsel->cpus->nr && !err; i++)
252		err = perf_evsel__run_ioctl(evsel,
253				     PERF_EVENT_IOC_SET_FILTER,
254				     (void *)filter, i);
255	return err;
256}
257
258struct perf_cpu_map *perf_evsel__cpus(struct perf_evsel *evsel)
259{
260	return evsel->cpus;
261}
262
263struct perf_thread_map *perf_evsel__threads(struct perf_evsel *evsel)
264{
265	return evsel->threads;
266}
267
268struct perf_event_attr *perf_evsel__attr(struct perf_evsel *evsel)
269{
270	return &evsel->attr;
271}
272
273int perf_evsel__alloc_id(struct perf_evsel *evsel, int ncpus, int nthreads)
274{
275	if (ncpus == 0 || nthreads == 0)
276		return 0;
277
278	if (evsel->system_wide)
279		nthreads = 1;
280
281	evsel->sample_id = xyarray__new(ncpus, nthreads, sizeof(struct perf_sample_id));
282	if (evsel->sample_id == NULL)
283		return -ENOMEM;
284
285	evsel->id = zalloc(ncpus * nthreads * sizeof(u64));
286	if (evsel->id == NULL) {
287		xyarray__delete(evsel->sample_id);
288		evsel->sample_id = NULL;
289		return -ENOMEM;
290	}
291
292	return 0;
293}
294
295void perf_evsel__free_id(struct perf_evsel *evsel)
296{
297	xyarray__delete(evsel->sample_id);
298	evsel->sample_id = NULL;
299	zfree(&evsel->id);
300	evsel->ids = 0;
301}
302