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: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
[mpe: Add error checking, drop GET_MMCR_FIELD, add to .gitignore]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220127072012.662451-10-kjain@linux.ibm.com
This commit is contained in:
Athira Rajeev 2022-01-27 12:50:01 +05:30 committed by Michael Ellerman
parent 13307f9584
commit eb7aa044df
3 changed files with 63 additions and 1 deletions

View File

@ -0,0 +1 @@
mmcr0_exceptionbits_test

View File

@ -1,7 +1,9 @@
# 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

View File

@ -0,0 +1,59 @@
// 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");
}