zircon/kernel/tests/cache_tests.cc

// Copyright 2016 The Fuchsia Authors
// Copyright (c) 2014 Travis Geiselbrecht
//
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file or at
// https://opensource.org/licenses/MIT

#include <arch.h>
#include <inttypes.h>
#include <lib/console.h>
#include <platform.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <zircon/types.h>

#include <arch/ops.h>

#include "tests.h"

static void bench_cache(size_t bufsize, uint8_t* buf) {
  zx_time_t t;
  bool do_free;

  printf("cache line size %" PRIu32 "\n", arch_dcache_line_size());

  if (buf == 0) {
    buf = (uint8_t*)memalign(arch_dcache_line_size(), bufsize);
    do_free = true;
  } else {
    do_free = false;
  }

  printf("buf %p, size %zu\n", buf, bufsize);

  if (!buf)
    return;

  t = current_time();
  arch_clean_cache_range((vaddr_t)buf, bufsize);
  zx_duration_t duration = current_time() - t;

  printf("took %" PRIi64 " nsecs to clean %zu bytes (cold)\n", duration, bufsize);

  memset(buf, 0x99, bufsize);

  t = current_time();
  arch_clean_cache_range((vaddr_t)buf, bufsize);
  duration = current_time() - t;

  if (do_free)
    free(buf);

  printf("took %" PRIi64 " nsecs to clean %zu bytes (hot)\n", duration, bufsize);
}

static int cache_tests(int argc, const cmd_args* argv, uint32_t flags) {
  uint8_t* buf;
  buf = (uint8_t*)((argc > 1) ? argv[1].u : 0UL);

  printf("testing cache\n");

  bench_cache(2 * 1024, buf);
  bench_cache(64 * 1024, buf);
  bench_cache(256 * 1024, buf);
  bench_cache(1 * 1024 * 1024, buf);
  bench_cache(8 * 1024 * 1024, buf);
  return 0;
}

STATIC_COMMAND_START
STATIC_COMMAND("cache_tests", "test/bench the cpu cache", &cache_tests)
STATIC_COMMAND_END(cache_tests)