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
9#include "ebb.h"
10
11
12/*
13 * Test that PMC5 & 6 are frozen (ie. don't overflow) when they are not being
14 * used. Tests the MMCR0_FC56 logic in the kernel.
15 */
16
17static int pmc56_overflowed;
18
19static void ebb_callee(void)
20{
21	uint64_t val;
22
23	val = mfspr(SPRN_BESCR);
24	if (!(val & BESCR_PMEO)) {
25		ebb_state.stats.spurious++;
26		goto out;
27	}
28
29	ebb_state.stats.ebb_count++;
30	count_pmc(2, sample_period);
31
32	val = mfspr(SPRN_PMC5);
33	if (val >= COUNTER_OVERFLOW)
34		pmc56_overflowed++;
35
36	count_pmc(5, COUNTER_OVERFLOW);
37
38	val = mfspr(SPRN_PMC6);
39	if (val >= COUNTER_OVERFLOW)
40		pmc56_overflowed++;
41
42	count_pmc(6, COUNTER_OVERFLOW);
43
44out:
45	reset_ebb();
46}
47
48int pmc56_overflow(void)
49{
50	struct event event;
51
52	SKIP_IF(!ebb_is_supported());
53
54	/* Use PMC2 so we set PMCjCE, which enables PMC5/6 */
55	event_init(&event, 0x2001e);
56	event_leader_ebb_init(&event);
57
58	event.attr.exclude_kernel = 1;
59	event.attr.exclude_hv = 1;
60	event.attr.exclude_idle = 1;
61
62	FAIL_IF(event_open(&event));
63
64	setup_ebb_handler(ebb_callee);
65	ebb_global_enable();
66
67	FAIL_IF(ebb_event_enable(&event));
68
69	mtspr(SPRN_PMC2, pmc_sample_period(sample_period));
70	mtspr(SPRN_PMC5, 0);
71	mtspr(SPRN_PMC6, 0);
72
73	while (ebb_state.stats.ebb_count < 10)
74		FAIL_IF(core_busy_loop());
75
76	ebb_global_disable();
77	ebb_freeze_pmcs();
78
79	dump_ebb_state();
80
81	printf("PMC5/6 overflow %d\n", pmc56_overflowed);
82
83	event_close(&event);
84
85	FAIL_IF(ebb_state.stats.ebb_count == 0 || pmc56_overflowed != 0);
86
87	return 0;
88}
89
90int main(void)
91{
92	return test_harness(pmc56_overflow, "pmc56_overflow");
93}
94