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 a pinned per-task event vs an EBB - in that order. The pinned per-task
19 * event should prevent the EBB event from being enabled.
20 */
21
22static int setup_child_event(struct event *event, pid_t child_pid)
23{
24 event_init_named(e: event, config: 0x400FA, name: "PM_RUN_INST_CMPL");
25
26 event->attr.pinned = 1;
27
28 event->attr.exclude_kernel = 1;
29 event->attr.exclude_hv = 1;
30 event->attr.exclude_idle = 1;
31
32 FAIL_IF(event_open_with_pid(e: event, pid: child_pid));
33 FAIL_IF(event_enable(e: event));
34
35 return 0;
36}
37
38int task_event_pinned_vs_ebb(void)
39{
40 union pipe read_pipe, write_pipe;
41 struct event event;
42 pid_t pid;
43 int rc;
44
45 SKIP_IF(!ebb_is_supported());
46
47 FAIL_IF(pipe(read_pipe.fds) == -1);
48 FAIL_IF(pipe(write_pipe.fds) == -1);
49
50 pid = fork();
51 if (pid == 0) {
52 /* NB order of pipes looks reversed */
53 exit(ebb_child(read_pipe: write_pipe, write_pipe: read_pipe));
54 }
55
56 /* We setup the task event first */
57 rc = setup_child_event(event: &event, child_pid: pid);
58 if (rc) {
59 kill_child_and_wait(child_pid: pid);
60 return rc;
61 }
62
63 /* Signal the child to install its EBB event and wait */
64 if (sync_with_child(read_pipe, write_pipe))
65 /* If it fails, wait for it to exit */
66 goto wait;
67
68 /* Signal the child to run */
69 FAIL_IF(sync_with_child(read_pipe, write_pipe));
70
71wait:
72 /* We expect it to fail to read the event */
73 FAIL_IF(wait_for_child(child_pid: pid) != 2);
74 FAIL_IF(event_disable(e: &event));
75 FAIL_IF(event_read(e: &event));
76
77 event_report(e: &event);
78
79 FAIL_IF(event.result.value == 0);
80 /*
81 * For reasons I don't understand enabled is usually just slightly
82 * lower than running. Would be good to confirm why.
83 */
84 FAIL_IF(event.result.enabled == 0);
85 FAIL_IF(event.result.running == 0);
86
87 return 0;
88}
89
90int main(void)
91{
92 return test_harness(task_event_pinned_vs_ebb, "task_event_pinned_vs_ebb");
93}
94

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