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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /tools/testing/selftests/powerpc/pmu/ebb/back_to_back_ebbs_test.c | |
parent | Initial commit. (diff) | |
download | linux-430c2fc249ea5c0536abd21c23382884005c9093.tar.xz linux-430c2fc249ea5c0536abd21c23382884005c9093.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tools/testing/selftests/powerpc/pmu/ebb/back_to_back_ebbs_test.c')
-rw-r--r-- | tools/testing/selftests/powerpc/pmu/ebb/back_to_back_ebbs_test.c | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/tools/testing/selftests/powerpc/pmu/ebb/back_to_back_ebbs_test.c b/tools/testing/selftests/powerpc/pmu/ebb/back_to_back_ebbs_test.c new file mode 100644 index 000000000..a26ac122c --- /dev/null +++ b/tools/testing/selftests/powerpc/pmu/ebb/back_to_back_ebbs_test.c @@ -0,0 +1,106 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright 2014, Michael Ellerman, IBM Corp. + */ + +#include <stdbool.h> +#include <stdio.h> +#include <stdlib.h> + +#include "ebb.h" + + +#define NUMBER_OF_EBBS 50 + +/* + * Test that if we overflow the counter while in the EBB handler, we take + * another EBB on exiting from the handler. + * + * We do this by counting with a stupidly low sample period, causing us to + * overflow the PMU while we're still in the EBB handler, leading to another + * EBB. + * + * We get out of what would otherwise be an infinite loop by leaving the + * counter frozen once we've taken enough EBBs. + */ + +static void ebb_callee(void) +{ + uint64_t siar, val; + + val = mfspr(SPRN_BESCR); + if (!(val & BESCR_PMEO)) { + ebb_state.stats.spurious++; + goto out; + } + + ebb_state.stats.ebb_count++; + trace_log_counter(ebb_state.trace, ebb_state.stats.ebb_count); + + /* Resets the PMC */ + count_pmc(1, sample_period); + +out: + if (ebb_state.stats.ebb_count == NUMBER_OF_EBBS) + /* Reset but leave counters frozen */ + reset_ebb_with_clear_mask(MMCR0_PMAO); + else + /* Unfreezes */ + reset_ebb(); + + /* Do some stuff to chew some cycles and pop the counter */ + siar = mfspr(SPRN_SIAR); + trace_log_reg(ebb_state.trace, SPRN_SIAR, siar); + + val = mfspr(SPRN_PMC1); + trace_log_reg(ebb_state.trace, SPRN_PMC1, val); + + val = mfspr(SPRN_MMCR0); + trace_log_reg(ebb_state.trace, SPRN_MMCR0, val); +} + +int back_to_back_ebbs(void) +{ + struct event event; + + SKIP_IF(!ebb_is_supported()); + + event_init_named(&event, 0x1001e, "cycles"); + 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); + + FAIL_IF(ebb_event_enable(&event)); + + sample_period = 5; + + ebb_freeze_pmcs(); + mtspr(SPRN_PMC1, pmc_sample_period(sample_period)); + ebb_global_enable(); + ebb_unfreeze_pmcs(); + + while (ebb_state.stats.ebb_count < NUMBER_OF_EBBS) + FAIL_IF(core_busy_loop()); + + ebb_global_disable(); + ebb_freeze_pmcs(); + + dump_ebb_state(); + + event_close(&event); + + FAIL_IF(ebb_state.stats.ebb_count != NUMBER_OF_EBBS); + + return 0; +} + +int main(void) +{ + return test_harness(back_to_back_ebbs, "back_to_back_ebbs"); +} |