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
17 static int pmc56_overflowed;
18
19 static 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
44 out:
45 reset_ebb();
46 }
47
48 int 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
90 int main(void)
91 {
92 return test_harness(pmc56_overflow, "pmc56_overflow");
93 }
94
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