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 we can setup an EBB on our child. The child expects this and enables |
19 | * EBBs, which are then delivered to the child, even though the event is |
20 | * created by the parent. |
21 | */ |
22 | |
23 | static int victim_child(union pipe read_pipe, union pipe write_pipe) |
24 | { |
25 | FAIL_IF(wait_for_parent(read_pipe)); |
26 | |
27 | /* Setup our EBB handler, before the EBB event is created */ |
28 | ebb_enable_pmc_counting(pmc: 1); |
29 | setup_ebb_handler(standard_ebb_callee); |
30 | ebb_global_enable(); |
31 | |
32 | FAIL_IF(notify_parent(write_pipe)); |
33 | |
34 | while (ebb_state.stats.ebb_count < 20) { |
35 | FAIL_IF(core_busy_loop()); |
36 | } |
37 | |
38 | ebb_global_disable(); |
39 | ebb_freeze_pmcs(); |
40 | |
41 | dump_ebb_state(); |
42 | |
43 | FAIL_IF(ebb_state.stats.ebb_count == 0); |
44 | |
45 | return 0; |
46 | } |
47 | |
48 | /* Tests we can setup an EBB on our child - if it's expecting it */ |
49 | int ebb_on_willing_child(void) |
50 | { |
51 | union pipe read_pipe, write_pipe; |
52 | struct event event; |
53 | pid_t pid; |
54 | |
55 | SKIP_IF(!ebb_is_supported()); |
56 | |
57 | FAIL_IF(pipe(read_pipe.fds) == -1); |
58 | FAIL_IF(pipe(write_pipe.fds) == -1); |
59 | |
60 | pid = fork(); |
61 | if (pid == 0) { |
62 | /* NB order of pipes looks reversed */ |
63 | exit(victim_child(read_pipe: write_pipe, write_pipe: read_pipe)); |
64 | } |
65 | |
66 | /* Signal the child to setup its EBB handler */ |
67 | FAIL_IF(sync_with_child(read_pipe, write_pipe)); |
68 | |
69 | /* Child is running now */ |
70 | |
71 | event_init_named(e: &event, config: 0x1001e, name: "cycles" ); |
72 | event_leader_ebb_init(e: &event); |
73 | |
74 | event.attr.exclude_kernel = 1; |
75 | event.attr.exclude_hv = 1; |
76 | event.attr.exclude_idle = 1; |
77 | |
78 | FAIL_IF(event_open_with_pid(e: &event, pid)); |
79 | FAIL_IF(ebb_event_enable(e: &event)); |
80 | |
81 | /* Child show now take EBBs and then exit */ |
82 | FAIL_IF(wait_for_child(child_pid: pid)); |
83 | |
84 | event_close(e: &event); |
85 | |
86 | return 0; |
87 | } |
88 | |
89 | int main(void) |
90 | { |
91 | return test_harness(ebb_on_willing_child, "ebb_on_willing_child" ); |
92 | } |
93 | |