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/*
* Copyright 2014, Michael Ellerman, IBM Corp.
* Licensed under GPLv2.
*/
#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();
count_pmc(2, sample_period);
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");
}
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