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 
setup_child_event(struct event * event,pid_t child_pid)22 static int setup_child_event(struct event *event, pid_t child_pid)
23 {
24 	event_init_named(event, 0x400FA, "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(event, child_pid));
31 	FAIL_IF(event_enable(event));
32 
33 	return 0;
34 }
35 
task_event_vs_ebb(void)36 int 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(write_pipe, read_pipe));
52 	}
53 
54 	/* We setup the task event first */
55 	rc = setup_child_event(&event, pid);
56 	if (rc) {
57 		kill_child_and_wait(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 
69 wait:
70 	/* The EBB event should push the task event off so the child should succeed */
71 	FAIL_IF(wait_for_child(pid));
72 	FAIL_IF(event_disable(&event));
73 	FAIL_IF(event_read(&event));
74 
75 	event_report(&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 
main(void)82 int main(void)
83 {
84 	return test_harness(task_event_vs_ebb, "task_event_vs_ebb");
85 }
86