94 lines · c
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 9#include "ebb.h"10 11 12/*13 * Test that PMC5 & 6 are frozen (ie. don't overflow) when they are not being14 * used. Tests the MMCR0_FC56 logic in the kernel.15 */16 17static int pmc56_overflowed;18 19static 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 44out:45 reset_ebb();46}47 48int 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 90int main(void)91{92 return test_harness(pmc56_overflow, "pmc56_overflow");93}94