Commit eb7aa044 authored by Athira Rajeev's avatar Athira Rajeev Committed by Michael Ellerman
Browse files

selftests/powerpc/pmu/: Add interface test for mmcr0 exception bits 



The testcase uses "instructions" event to verify two bits(PMAE and PMAO)
in Monitor Mode Control Register 0 (MMCR0). At the time of interrupt,
pmae bit ( which enables performance monitor exception ) is expected to
be cleared and pmao (which indicates performance monitor alert) bit is
expected to be set in MMCR0. And testcases handles these checks.

Signed-off-by: default avatarAthira Rajeev <atrajeev@linux.vnet.ibm.com>
[mpe: Add error checking, drop GET_MMCR_FIELD, add to .gitignore]
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220127072012.662451-10-kjain@linux.ibm.com
parent 13307f95

tools/testing/selftests/powerpc/pmu/sampling_tests/.gitignore

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mmcr0_exceptionbits_test

tools/testing/selftests/powerpc/pmu/sampling_tests/Makefile

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# SPDX-License-Identifier: GPL-2.0

CFLAGS += -m64



TEST_GEN_PROGS := mmcr0_exceptionbits_test



top_srcdir = ../../../../../..

include ../../../lib.mk



$(TEST_GEN_PROGS): ../../harness.c ../../utils.c ../event.c ../lib.c misc.c misc.h
 
$(TEST_GEN_PROGS): ../../harness.c ../../utils.c ../event.c ../lib.c misc.c misc.h ../loop.S

tools/testing/selftests/powerpc/pmu/sampling_tests/mmcr0_exceptionbits_test.c

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// SPDX-License-Identifier: GPL-2.0-only

/*

 * Copyright 2022, Athira Rajeev, IBM Corp.

 */



#include <stdio.h>

#include <stdlib.h>



#include "../event.h"

#include "misc.h"

#include "utils.h"



extern void thirty_two_instruction_loop(int loops);



/*

 * A perf sampling test for mmcr0

 * fields : pmae, pmao.

 */

static int mmcr0_exceptionbits(void)

{

	struct event event;

	u64 *intr_regs;



	/* Check for platform support for the test */

	SKIP_IF(check_pvr_for_sampling_tests());



	/* Init the event for the sampling test */

	event_init_sampling(&event, 0x500fa);

	event.attr.sample_regs_intr = platform_extended_mask;

	FAIL_IF(event_open(&event));

	event.mmap_buffer = event_sample_buf_mmap(event.fd, 1);



	FAIL_IF(event_enable(&event));



	/* workload to make the event overflow */

	thirty_two_instruction_loop(10000);



	FAIL_IF(event_disable(&event));



	/* Check for sample count */

	FAIL_IF(!collect_samples(event.mmap_buffer));



	intr_regs = get_intr_regs(&event, event.mmap_buffer);



	/* Check for intr_regs */

	FAIL_IF(!intr_regs);



	/* Verify that pmae is cleared and pmao is set in MMCR0 */

	FAIL_IF(get_mmcr0_pmae(get_reg_value(intr_regs, "MMCR0"), 5));

	FAIL_IF(!get_mmcr0_pmao(get_reg_value(intr_regs, "MMCR0"), 5));



	event_close(&event);

	return 0;

}



int main(void)

{

	return test_harness(mmcr0_exceptionbits, "mmcr0_exceptionbits");

}