Commit | Line | Data |
---|---|---|
f50a7f3d | 1 | // SPDX-License-Identifier: GPL-2.0-only |
3752e453 ME |
2 | /* |
3 | * Copyright 2014, Michael Ellerman, IBM Corp. | |
3752e453 ME |
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 using MMCR0_FC (freeze counters) to only count | |
15 | * parts of the code. This is complicated by the fact that FC is set by the | |
16 | * hardware when the event overflows. We may take the EBB after we have set FC, | |
17 | * so we have to be careful about whether we clear FC at the end of the EBB | |
18 | * handler or not. | |
19 | */ | |
20 | ||
21 | static bool counters_frozen = false; | |
22 | static int ebbs_while_frozen = 0; | |
23 | ||
24 | static void ebb_callee(void) | |
25 | { | |
26 | uint64_t mask, val; | |
27 | ||
28 | mask = MMCR0_PMAO | MMCR0_FC; | |
29 | ||
30 | val = mfspr(SPRN_BESCR); | |
31 | if (!(val & BESCR_PMEO)) { | |
32 | ebb_state.stats.spurious++; | |
33 | goto out; | |
34 | } | |
35 | ||
36 | ebb_state.stats.ebb_count++; | |
37 | trace_log_counter(ebb_state.trace, ebb_state.stats.ebb_count); | |
38 | ||
39 | val = mfspr(SPRN_MMCR0); | |
40 | trace_log_reg(ebb_state.trace, SPRN_MMCR0, val); | |
41 | ||
42 | if (counters_frozen) { | |
43 | trace_log_string(ebb_state.trace, "frozen"); | |
44 | ebbs_while_frozen++; | |
45 | mask &= ~MMCR0_FC; | |
46 | } | |
47 | ||
48 | count_pmc(1, sample_period); | |
49 | out: | |
50 | reset_ebb_with_clear_mask(mask); | |
51 | } | |
52 | ||
53 | int cycles_with_freeze(void) | |
54 | { | |
55 | struct event event; | |
56 | uint64_t val; | |
57 | bool fc_cleared; | |
58 | ||
39fcfb91 DK |
59 | SKIP_IF(!ebb_is_supported()); |
60 | ||
3752e453 ME |
61 | event_init_named(&event, 0x1001e, "cycles"); |
62 | event_leader_ebb_init(&event); | |
63 | ||
64 | event.attr.exclude_kernel = 1; | |
65 | event.attr.exclude_hv = 1; | |
66 | event.attr.exclude_idle = 1; | |
67 | ||
68 | FAIL_IF(event_open(&event)); | |
69 | ||
70 | setup_ebb_handler(ebb_callee); | |
71 | ebb_global_enable(); | |
72 | FAIL_IF(ebb_event_enable(&event)); | |
73 | ||
74 | mtspr(SPRN_PMC1, pmc_sample_period(sample_period)); | |
75 | ||
76 | fc_cleared = false; | |
77 | ||
78 | /* Make sure we loop until we take at least one EBB */ | |
79 | while ((ebb_state.stats.ebb_count < 20 && !fc_cleared) || | |
80 | ebb_state.stats.ebb_count < 1) | |
81 | { | |
82 | counters_frozen = false; | |
83 | mb(); | |
84 | mtspr(SPRN_MMCR0, mfspr(SPRN_MMCR0) & ~MMCR0_FC); | |
85 | ||
86 | FAIL_IF(core_busy_loop()); | |
87 | ||
88 | counters_frozen = true; | |
89 | mb(); | |
90 | mtspr(SPRN_MMCR0, mfspr(SPRN_MMCR0) | MMCR0_FC); | |
91 | ||
92 | val = mfspr(SPRN_MMCR0); | |
93 | if (! (val & MMCR0_FC)) { | |
94 | printf("Outside of loop, FC NOT set MMCR0 0x%lx\n", val); | |
95 | fc_cleared = true; | |
96 | } | |
97 | } | |
98 | ||
99 | ebb_global_disable(); | |
100 | ebb_freeze_pmcs(); | |
101 | ||
102 | count_pmc(1, sample_period); | |
103 | ||
104 | dump_ebb_state(); | |
105 | ||
106 | printf("EBBs while frozen %d\n", ebbs_while_frozen); | |
107 | ||
108 | event_close(&event); | |
109 | ||
110 | FAIL_IF(ebb_state.stats.ebb_count == 0); | |
111 | FAIL_IF(fc_cleared); | |
112 | ||
113 | return 0; | |
114 | } | |
115 | ||
116 | int main(void) | |
117 | { | |
118 | return test_harness(cycles_with_freeze, "cycles_with_freeze"); | |
119 | } |