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39fcfb911c
EBB (Event Based Branches) are currently only available on POWER8, so we should skip them on other CPUs. I've found that at least one test loops forever on 970MP (cycles_with_freeze_test). Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org> [mpe: Minor change log editing, add skip to cpu_event_vs_ebb_test] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
96 lines
1.6 KiB
C
96 lines
1.6 KiB
C
/*
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* Copyright 2014, Michael Ellerman, IBM Corp.
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* Licensed under GPLv2.
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include "ebb.h"
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/*
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* Test that PMC5 & 6 are frozen (ie. don't overflow) when they are not being
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* used. Tests the MMCR0_FC56 logic in the kernel.
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*/
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static int pmc56_overflowed;
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static void ebb_callee(void)
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{
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uint64_t val;
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val = mfspr(SPRN_BESCR);
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if (!(val & BESCR_PMEO)) {
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ebb_state.stats.spurious++;
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goto out;
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}
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ebb_state.stats.ebb_count++;
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count_pmc(2, sample_period);
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val = mfspr(SPRN_PMC5);
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if (val >= COUNTER_OVERFLOW)
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pmc56_overflowed++;
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count_pmc(5, COUNTER_OVERFLOW);
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val = mfspr(SPRN_PMC6);
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if (val >= COUNTER_OVERFLOW)
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pmc56_overflowed++;
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count_pmc(6, COUNTER_OVERFLOW);
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out:
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reset_ebb();
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}
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int pmc56_overflow(void)
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{
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struct event event;
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SKIP_IF(!ebb_is_supported());
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/* Use PMC2 so we set PMCjCE, which enables PMC5/6 */
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event_init(&event, 0x2001e);
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event_leader_ebb_init(&event);
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event.attr.exclude_kernel = 1;
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event.attr.exclude_hv = 1;
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event.attr.exclude_idle = 1;
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FAIL_IF(event_open(&event));
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setup_ebb_handler(ebb_callee);
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ebb_global_enable();
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FAIL_IF(ebb_event_enable(&event));
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mtspr(SPRN_PMC1, pmc_sample_period(sample_period));
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mtspr(SPRN_PMC5, 0);
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mtspr(SPRN_PMC6, 0);
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while (ebb_state.stats.ebb_count < 10)
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FAIL_IF(core_busy_loop());
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ebb_global_disable();
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ebb_freeze_pmcs();
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count_pmc(2, sample_period);
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dump_ebb_state();
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printf("PMC5/6 overflow %d\n", pmc56_overflowed);
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event_close(&event);
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FAIL_IF(ebb_state.stats.ebb_count == 0 || pmc56_overflowed != 0);
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return 0;
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}
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int main(void)
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{
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return test_harness(pmc56_overflow, "pmc56_overflow");
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}
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