tools/testing/selftests/powerpc/pmu/sampling_tests/mmcr2_fcs_fch_test.c

Source file repositories/reference/linux-study-clean/tools/testing/selftests/powerpc/pmu/sampling_tests/mmcr2_fcs_fch_test.c

File Facts

System
Linux kernel
Corpus path
tools/testing/selftests/powerpc/pmu/sampling_tests/mmcr2_fcs_fch_test.c
Extension
.c
Size
1882 bytes
Lines
86
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: implementation source
Status
source implementation candidate

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright 2022, Madhavan Srinivasan, IBM Corp.
 */

#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>

#include "../event.h"
#include "misc.h"
#include "utils.h"

extern void thirty_two_instruction_loop(int loops);

static bool is_hv;

static void sig_usr2_handler(int signum, siginfo_t *info, void *data)
{
	ucontext_t *uctx = data;

	is_hv = !!(uctx->uc_mcontext.gp_regs[PT_MSR] & MSR_HV);
}

/*
 * A perf sampling test for mmcr2
 * fields : fcs, fch.
 */
static int mmcr2_fcs_fch(void)
{
	struct sigaction sigact = {
		.sa_sigaction = sig_usr2_handler,
		.sa_flags = SA_SIGINFO
	};
	struct event event;
	u64 *intr_regs;

	FAIL_IF(sigaction(SIGUSR2, &sigact, NULL));
	FAIL_IF(kill(getpid(), SIGUSR2));

	/* 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, 0x1001e);
	event.attr.sample_regs_intr = platform_extended_mask;
	event.attr.exclude_kernel = 1;
	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 fcs and fch field of MMCR2 match
	 * with corresponding modifier fields.
	 */
	if (is_hv)
		FAIL_IF(event.attr.exclude_kernel !=
			get_mmcr2_fch(get_reg_value(intr_regs, "MMCR2"), 1));
	else
		FAIL_IF(event.attr.exclude_kernel !=
			get_mmcr2_fcs(get_reg_value(intr_regs, "MMCR2"), 1));

	event_close(&event);
	return 0;
}

int main(void)
{
	return test_harness(mmcr2_fcs_fch, "mmcr2_fcs_fch");
}

Annotation

Implementation Notes