| 1 | /* |
| 2 | * Copyright 2014, Michael Ellerman, IBM Corp. |
| 3 | * Licensed under GPLv2. |
| 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 | |
| 59 | SKIP_IF(!ebb_is_supported()); |
| 60 | |
| 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 | } |