tools/testing/selftests/powerpc/cache_shape/cache_shape.c

Source file repositories/reference/linux-study-clean/tools/testing/selftests/powerpc/cache_shape/cache_shape.c

File Facts

System
Linux kernel
Corpus path
tools/testing/selftests/powerpc/cache_shape/cache_shape.c
Extension
.c
Size
2380 bytes
Lines
122
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-or-later
/*
 * Copyright 2017, Michael Ellerman, IBM Corp.
 */

#include <elf.h>
#include <errno.h>
#include <fcntl.h>
#include <link.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>

#include "utils.h"

#ifndef AT_L1I_CACHESIZE
#define AT_L1I_CACHESIZE	40
#define AT_L1I_CACHEGEOMETRY	41
#define AT_L1D_CACHESIZE	42
#define AT_L1D_CACHEGEOMETRY	43
#define AT_L2_CACHESIZE		44
#define AT_L2_CACHEGEOMETRY	45
#define AT_L3_CACHESIZE		46
#define AT_L3_CACHEGEOMETRY	47
#endif

static void print_size(const char *label, uint32_t val)
{
	printf("%s cache size: %#10x %10dB %10dK\n", label, val, val, val / 1024);
}

static void print_geo(const char *label, uint32_t val)
{
	uint16_t assoc;

	printf("%s line size:  %#10x       ", label, val & 0xFFFF);

	assoc = val >> 16;
	if (assoc)
		printf("%u-way", assoc);
	else
		printf("fully");

	printf(" associative\n");
}

static int test_cache_shape()
{
	static char buffer[4096];
	ElfW(auxv_t) *p;
	int found;

	FAIL_IF(read_auxv(buffer, sizeof(buffer)));

	found = 0;

	p = find_auxv_entry(AT_L1I_CACHESIZE, buffer);
	if (p) {
		found++;
		print_size("L1I ", (uint32_t)p->a_un.a_val);
	}

	p = find_auxv_entry(AT_L1I_CACHEGEOMETRY, buffer);
	if (p) {
		found++;
		print_geo("L1I ", (uint32_t)p->a_un.a_val);
	}

	p = find_auxv_entry(AT_L1D_CACHESIZE, buffer);
	if (p) {
		found++;
		print_size("L1D ", (uint32_t)p->a_un.a_val);
	}

	p = find_auxv_entry(AT_L1D_CACHEGEOMETRY, buffer);
	if (p) {
		found++;
		print_geo("L1D ", (uint32_t)p->a_un.a_val);
	}

	p = find_auxv_entry(AT_L2_CACHESIZE, buffer);
	if (p) {
		found++;
		print_size("L2  ", (uint32_t)p->a_un.a_val);
	}

Annotation

Implementation Notes