1/*
2 * Copyright 2008 The Android Open Source Project
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8/*
9 * Implementation of the user-space ashmem API for devices, which have our
10 * ashmem-enabled kernel. See ashmem-sim.c for the "fake" tmp-based version,
11 * used by the simulator.
12 */
13
14#include <android/ashmem.h>
15
16#include <unistd.h>
17#include <string.h>
18#include <sys/types.h>
19#include <sys/stat.h>
20#include <sys/ioctl.h>
21#include <fcntl.h>
22
23#include <linux/ashmem.h>
24
25#define ASHMEM_DEVICE   "/dev/ashmem"
26
27/*
28 * ashmem_create_region - creates a new ashmem region and returns the file
29 * descriptor, or <0 on error
30 *
31 * `name' is an optional label to give the region (visible in /proc/pid/maps)
32 * `size' is the size of the region, in page-aligned bytes
33 */
34int ashmem_create_region(const char *name, size_t size)
35{
36    int fd, ret;
37
38    fd = open(ASHMEM_DEVICE, O_RDWR);
39    if (fd < 0)
40        return fd;
41
42    if (name) {
43        char buf[ASHMEM_NAME_LEN];
44
45        strlcpy(buf, name, sizeof(buf));
46        ret = ioctl(fd, ASHMEM_SET_NAME, buf);
47        if (ret < 0)
48            goto error;
49    }
50
51    ret = ioctl(fd, ASHMEM_SET_SIZE, size);
52    if (ret < 0)
53        goto error;
54
55    return fd;
56
57error:
58    close(fd);
59    return ret;
60}
61
62int ashmem_set_prot_region(int fd, int prot)
63{
64    return ioctl(fd, ASHMEM_SET_PROT_MASK, prot);
65}
66
67int ashmem_pin_region(int fd, size_t offset, size_t len)
68{
69    struct ashmem_pin pin = { offset, len };
70    return ioctl(fd, ASHMEM_PIN, &pin);
71}
72
73int ashmem_unpin_region(int fd, size_t offset, size_t len)
74{
75    struct ashmem_pin pin = { offset, len };
76    return ioctl(fd, ASHMEM_UNPIN, &pin);
77}
78
79int ashmem_get_size_region(int fd)
80{
81  return ioctl(fd, ASHMEM_GET_SIZE, NULL);
82}
83