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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Copyright 2014, Michael Ellerman, IBM Corp.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 count15 * parts of the code. This is complicated by the fact that FC is set by the16 * 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 EBB18 * handler or not.19 */20 21static bool counters_frozen = false;22static int ebbs_while_frozen = 0;23 24static 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);49out:50 reset_ebb_with_clear_mask(mask);51}52 53int 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 dump_ebb_state();103 104 printf("EBBs while frozen %d\n", ebbs_while_frozen);105 106 event_close(&event);107 108 FAIL_IF(ebb_state.stats.ebb_count == 0);109 FAIL_IF(fc_cleared);110 111 return 0;112}113 114int main(void)115{116 return test_harness(cycles_with_freeze, "cycles_with_freeze");117}118