1/*
2 * Copyright (C) 2008 The Android Open Source Project
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *  * Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 *  * Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in
12 *    the documentation and/or other materials provided with the
13 *    distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29#include <unistd.h>
30#include <sys/cachectl.h>
31
32#include "private/libc_logging.h"
33
34// Linux historically defines a cacheflush(3) routine for MIPS
35// with this signature:
36
37//   int cacheflush(char *addr, int nbytes, int cache);
38
39// Android defines an alternate cacheflush routine which exposes the
40// ARM system call interface:
41
42//   int cacheflush (long start, long end, long flags)
43
44// This is an attempt to maintain compatibility between the historical MIPS
45// usage for software previously ported to MIPS and Android specific
46// uses of cacheflush().
47
48int cacheflush(long start, long end, long /*flags*/) {
49  if (end < start) {
50    // It looks like this is really a MIPS-style cacheflush call.
51    static bool warned = false;
52    if (!warned) {
53      __libc_format_log(ANDROID_LOG_WARN, "libc", "cacheflush called with (start,len) instead of (start,end)");
54      warned = true;
55    }
56    end += start;
57  }
58
59  // Use the GCC builtin. This will generate inline synci instructions if available,
60  // or call _flush_cache(start, len, BCACHE) directly.
61  __builtin___clear_cache(reinterpret_cast<char*>(start), reinterpret_cast<char*>(end));
62  return 0;
63}
64