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 per-task event vs an EBB - in that order. The EBB should push the
19 * per-task event off the PMU.
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.exclude_kernel = 1;
27 event->attr.exclude_hv = 1;
28 event->attr.exclude_idle = 1;
29
30 FAIL_IF(event_open_with_pid(e: event, pid: child_pid));
31 FAIL_IF(event_enable(e: event));
32
33 return 0;
34}
35
36int task_event_vs_ebb(void)
37{
38 union pipe read_pipe, write_pipe;
39 struct event event;
40 pid_t pid;
41 int rc;
42
43 SKIP_IF(!ebb_is_supported());
44
45 FAIL_IF(pipe(read_pipe.fds) == -1);
46 FAIL_IF(pipe(write_pipe.fds) == -1);
47
48 pid = fork();
49 if (pid == 0) {
50 /* NB order of pipes looks reversed */
51 exit(ebb_child(read_pipe: write_pipe, write_pipe: read_pipe));
52 }
53
54 /* We setup the task event first */
55 rc = setup_child_event(event: &event, child_pid: pid);
56 if (rc) {
57 kill_child_and_wait(child_pid: pid);
58 return rc;
59 }
60
61 /* Signal the child to install its EBB event and wait */
62 if (sync_with_child(read_pipe, write_pipe))
63 /* If it fails, wait for it to exit */
64 goto wait;
65
66 /* Signal the child to run */
67 FAIL_IF(sync_with_child(read_pipe, write_pipe));
68
69wait:
70 /* The EBB event should push the task event off so the child should succeed */
71 FAIL_IF(wait_for_child(child_pid: pid));
72 FAIL_IF(event_disable(e: &event));
73 FAIL_IF(event_read(e: &event));
74
75 event_report(e: &event);
76
77 /* The task event may have run, or not so we can't assert anything about it */
78
79 return 0;
80}
81
82int main(void)
83{
84 return test_harness(task_event_vs_ebb, "task_event_vs_ebb");
85}
86

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