1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright 2014, Michael Ellerman, IBM Corp.
4 */
5
6#include <signal.h>
7#include <stdio.h>
8#include <stdlib.h>
9#include <stdbool.h>
10#include <sys/types.h>
11#include <sys/wait.h>
12#include <unistd.h>
13
14#include "ebb.h"
15
16
17/*
18 * Tests an EBB vs a cpu event - in that order. The EBB should force the cpu
19 * event off the PMU.
20 */
21
22static int setup_cpu_event(struct event *event, int cpu)
23{
24 event_init_named(e: event, config: 0x400FA, name: "PM_RUN_INST_CMPL");
25
26 event->attr.exclude_kernel = 1;
27 event->attr.exclude_hv = 1;
28 event->attr.exclude_idle = 1;
29
30 SKIP_IF(require_paranoia_below(level: 1));
31 FAIL_IF(event_open_with_cpu(e: event, cpu));
32 FAIL_IF(event_enable(e: event));
33
34 return 0;
35}
36
37int ebb_vs_cpu_event(void)
38{
39 union pipe read_pipe, write_pipe;
40 struct event event;
41 int cpu, rc;
42 pid_t pid;
43
44 SKIP_IF(!ebb_is_supported());
45
46 cpu = bind_to_cpu(BIND_CPU_ANY);
47 FAIL_IF(cpu < 0);
48
49 FAIL_IF(pipe(read_pipe.fds) == -1);
50 FAIL_IF(pipe(write_pipe.fds) == -1);
51
52 pid = fork();
53 if (pid == 0) {
54 /* NB order of pipes looks reversed */
55 exit(ebb_child(read_pipe: write_pipe, write_pipe: read_pipe));
56 }
57
58 /* Signal the child to install its EBB event and wait */
59 FAIL_IF(sync_with_child(read_pipe, write_pipe));
60
61 /* Now try to install our CPU event */
62 rc = setup_cpu_event(event: &event, cpu);
63 if (rc) {
64 kill_child_and_wait(child_pid: pid);
65 return rc;
66 }
67
68 /* Signal the child to run */
69 FAIL_IF(sync_with_child(read_pipe, write_pipe));
70
71 /* .. and wait for it to complete */
72 FAIL_IF(wait_for_child(child_pid: pid));
73 FAIL_IF(event_disable(e: &event));
74 FAIL_IF(event_read(e: &event));
75
76 event_report(e: &event);
77
78 /* The cpu event may have run, but we don't expect 100% */
79 FAIL_IF(event.result.enabled >= event.result.running);
80
81 return 0;
82}
83
84int main(void)
85{
86 return test_harness(ebb_vs_cpu_event, "ebb_vs_cpu_event");
87}
88

source code of linux/tools/testing/selftests/powerpc/pmu/ebb/ebb_vs_cpu_event_test.c