1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright 2014, Michael Ellerman, IBM Corp.
4 */
5
6#include <stdio.h>
7#include <stdlib.h>
8#include <stdbool.h>
9
10#include "ebb.h"
11
12
13/*
14 * Test of counting cycles while manipulating the user accessible bits in MMCR2.
15 */
16
17/* We use two values because the first freezes PMC1 and so we would get no EBBs */
18#define MMCR2_EXPECTED_1 0x4020100804020000UL /* (FC1P|FC2P|FC3P|FC4P|FC5P|FC6P) */
19#define MMCR2_EXPECTED_2 0x0020100804020000UL /* ( FC2P|FC3P|FC4P|FC5P|FC6P) */
20
21
22int cycles_with_mmcr2(void)
23{
24 struct event event;
25 uint64_t val, expected[2], actual;
26 int i;
27 bool bad_mmcr2;
28
29 SKIP_IF(!ebb_is_supported());
30
31 event_init_named(e: &event, config: 0x1001e, name: "cycles");
32 event_leader_ebb_init(e: &event);
33
34 event.attr.exclude_kernel = 1;
35 event.attr.exclude_hv = 1;
36 event.attr.exclude_idle = 1;
37
38 FAIL_IF(event_open(e: &event));
39
40 ebb_enable_pmc_counting(pmc: 1);
41 setup_ebb_handler(standard_ebb_callee);
42 ebb_global_enable();
43
44 FAIL_IF(ebb_event_enable(e: &event));
45
46 mtspr(SPRN_PMC1, pmc_sample_period(value: sample_period));
47
48 /* XXX Set of MMCR2 must be after enable */
49 expected[0] = MMCR2_EXPECTED_1;
50 expected[1] = MMCR2_EXPECTED_2;
51 i = 0;
52 bad_mmcr2 = false;
53 actual = 0;
54
55 /* Make sure we loop until we take at least one EBB */
56 while ((ebb_state.stats.ebb_count < 20 && !bad_mmcr2) ||
57 ebb_state.stats.ebb_count < 1)
58 {
59 mtspr(SPRN_MMCR2, expected[i % 2]);
60
61 FAIL_IF(core_busy_loop());
62
63 val = mfspr(SPRN_MMCR2);
64 if (val != expected[i % 2]) {
65 bad_mmcr2 = true;
66 actual = val;
67 }
68
69 i++;
70 }
71
72 ebb_global_disable();
73 ebb_freeze_pmcs();
74
75 dump_ebb_state();
76
77 event_close(e: &event);
78
79 FAIL_IF(ebb_state.stats.ebb_count == 0);
80
81 if (bad_mmcr2)
82 printf("Bad MMCR2 value seen is 0x%lx\n", actual);
83
84 FAIL_IF(bad_mmcr2);
85
86 return 0;
87}
88
89int main(void)
90{
91 return test_harness(cycles_with_mmcr2, "cycles_with_mmcr2");
92}
93

source code of linux/tools/testing/selftests/powerpc/pmu/ebb/cycles_with_mmcr2_test.c