diff options
Diffstat (limited to '')
-rw-r--r-- | tools/testing/selftests/powerpc/pmu/ebb/pmc56_overflow_test.c | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/tools/testing/selftests/powerpc/pmu/ebb/pmc56_overflow_test.c b/tools/testing/selftests/powerpc/pmu/ebb/pmc56_overflow_test.c new file mode 100644 index 000000000..b29f8ba22 --- /dev/null +++ b/tools/testing/selftests/powerpc/pmu/ebb/pmc56_overflow_test.c @@ -0,0 +1,93 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright 2014, Michael Ellerman, IBM Corp. + */ + +#include <stdio.h> +#include <stdlib.h> + +#include "ebb.h" + + +/* + * Test that PMC5 & 6 are frozen (ie. don't overflow) when they are not being + * used. Tests the MMCR0_FC56 logic in the kernel. + */ + +static int pmc56_overflowed; + +static void ebb_callee(void) +{ + uint64_t val; + + val = mfspr(SPRN_BESCR); + if (!(val & BESCR_PMEO)) { + ebb_state.stats.spurious++; + goto out; + } + + ebb_state.stats.ebb_count++; + count_pmc(2, sample_period); + + val = mfspr(SPRN_PMC5); + if (val >= COUNTER_OVERFLOW) + pmc56_overflowed++; + + count_pmc(5, COUNTER_OVERFLOW); + + val = mfspr(SPRN_PMC6); + if (val >= COUNTER_OVERFLOW) + pmc56_overflowed++; + + count_pmc(6, COUNTER_OVERFLOW); + +out: + reset_ebb(); +} + +int pmc56_overflow(void) +{ + struct event event; + + SKIP_IF(!ebb_is_supported()); + + /* Use PMC2 so we set PMCjCE, which enables PMC5/6 */ + event_init(&event, 0x2001e); + event_leader_ebb_init(&event); + + event.attr.exclude_kernel = 1; + event.attr.exclude_hv = 1; + event.attr.exclude_idle = 1; + + FAIL_IF(event_open(&event)); + + setup_ebb_handler(ebb_callee); + ebb_global_enable(); + + FAIL_IF(ebb_event_enable(&event)); + + mtspr(SPRN_PMC2, pmc_sample_period(sample_period)); + mtspr(SPRN_PMC5, 0); + mtspr(SPRN_PMC6, 0); + + while (ebb_state.stats.ebb_count < 10) + FAIL_IF(core_busy_loop()); + + ebb_global_disable(); + ebb_freeze_pmcs(); + + dump_ebb_state(); + + printf("PMC5/6 overflow %d\n", pmc56_overflowed); + + event_close(&event); + + FAIL_IF(ebb_state.stats.ebb_count == 0 || pmc56_overflowed != 0); + + return 0; +} + +int main(void) +{ + return test_harness(pmc56_overflow, "pmc56_overflow"); +} |