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(pmc: 2, sample_period); |
31 | |
32 | val = mfspr(SPRN_PMC5); |
33 | if (val >= COUNTER_OVERFLOW) |
34 | pmc56_overflowed++; |
35 | |
36 | count_pmc(pmc: 5, COUNTER_OVERFLOW); |
37 | |
38 | val = mfspr(SPRN_PMC6); |
39 | if (val >= COUNTER_OVERFLOW) |
40 | pmc56_overflowed++; |
41 | |
42 | count_pmc(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(e: &event, config: 0x2001e); |
56 | event_leader_ebb_init(e: &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(e: &event)); |
63 | |
64 | setup_ebb_handler(ebb_callee); |
65 | ebb_global_enable(); |
66 | |
67 | FAIL_IF(ebb_event_enable(e: &event)); |
68 | |
69 | mtspr(SPRN_PMC2, pmc_sample_period(value: 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(e: &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 | |