selftests/powerpc: Add cycles test with MMCR2 handling

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Michael Ellerman 2014-07-23 17:31:38 +10:00 committed by Benjamin Herrenschmidt
parent c418a67872
commit 985ac68eba
2 changed files with 93 additions and 1 deletions

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@ -13,7 +13,8 @@ PROGS := reg_access_test event_attributes_test cycles_test \
close_clears_pmcc_test instruction_count_test \
fork_cleanup_test ebb_on_child_test \
ebb_on_willing_child_test back_to_back_ebbs_test \
lost_exception_test no_handler_test
lost_exception_test no_handler_test \
cycles_with_mmcr2_test
all: $(PROGS)

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@ -0,0 +1,91 @@
/*
* Copyright 2014, Michael Ellerman, IBM Corp.
* Licensed under GPLv2.
*/
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include "ebb.h"
/*
* Test of counting cycles while manipulating the user accessible bits in MMCR2.
*/
/* We use two values because the first freezes PMC1 and so we would get no EBBs */
#define MMCR2_EXPECTED_1 0x4020100804020000UL /* (FC1P|FC2P|FC3P|FC4P|FC5P|FC6P) */
#define MMCR2_EXPECTED_2 0x0020100804020000UL /* ( FC2P|FC3P|FC4P|FC5P|FC6P) */
int cycles_with_mmcr2(void)
{
struct event event;
uint64_t val, expected[2], actual;
int i;
bool bad_mmcr2;
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));
ebb_enable_pmc_counting(1);
setup_ebb_handler(standard_ebb_callee);
ebb_global_enable();
FAIL_IF(ebb_event_enable(&event));
mtspr(SPRN_PMC1, pmc_sample_period(sample_period));
/* XXX Set of MMCR2 must be after enable */
expected[0] = MMCR2_EXPECTED_1;
expected[1] = MMCR2_EXPECTED_2;
i = 0;
bad_mmcr2 = false;
/* Make sure we loop until we take at least one EBB */
while ((ebb_state.stats.ebb_count < 20 && !bad_mmcr2) ||
ebb_state.stats.ebb_count < 1)
{
mtspr(SPRN_MMCR2, expected[i % 2]);
FAIL_IF(core_busy_loop());
val = mfspr(SPRN_MMCR2);
if (val != expected[i % 2]) {
bad_mmcr2 = true;
actual = val;
}
i++;
}
ebb_global_disable();
ebb_freeze_pmcs();
count_pmc(1, sample_period);
dump_ebb_state();
event_close(&event);
FAIL_IF(ebb_state.stats.ebb_count == 0);
if (bad_mmcr2)
printf("Bad MMCR2 value seen is 0x%lx\n", actual);
FAIL_IF(bad_mmcr2);
return 0;
}
int main(void)
{
return test_harness(cycles_with_mmcr2, "cycles_with_mmcr2");
}