1 /* 2 * Copyright (C) 2008 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 /* 18 * Implementation of the user-space ashmem API for devices, which have our 19 * ashmem-enabled kernel. See ashmem-sim.c for the "fake" tmp-based version, 20 * used by the simulator. 21 */ 22 23 #include <unistd.h> 24 #include <string.h> 25 #include <sys/types.h> 26 #include <sys/stat.h> 27 #include <sys/ioctl.h> 28 #include <fcntl.h> 29 30 #include <linux/ashmem.h> 31 #include "ashmem.h" 32 33 #define ASHMEM_DEVICE "/dev/ashmem" 34 35 /* 36 * ashmem_create_region - creates a new ashmem region and returns the file 37 * descriptor, or <0 on error 38 * 39 * `name' is an optional label to give the region (visible in /proc/pid/maps) 40 * `size' is the size of the region, in page-aligned bytes 41 */ 42 int ashmem_create_region(const char *name, size_t size) 43 { 44 int fd, ret; 45 46 fd = open(ASHMEM_DEVICE, O_RDWR); 47 if (fd < 0) 48 return fd; 49 50 if (name) { 51 char buf[ASHMEM_NAME_LEN]; 52 53 strlcpy(buf, name, sizeof(buf)); 54 ret = ioctl(fd, ASHMEM_SET_NAME, buf); 55 if (ret < 0) 56 goto error; 57 } 58 59 ret = ioctl(fd, ASHMEM_SET_SIZE, size); 60 if (ret < 0) 61 goto error; 62 63 return fd; 64 65 error: 66 close(fd); 67 return ret; 68 } 69 70 int ashmem_set_prot_region(int fd, int prot) 71 { 72 return ioctl(fd, ASHMEM_SET_PROT_MASK, prot); 73 } 74 75 int ashmem_pin_region(int fd, size_t offset, size_t len) 76 { 77 struct ashmem_pin pin = { offset, len }; 78 return ioctl(fd, ASHMEM_PIN, &pin); 79 } 80 81 int ashmem_unpin_region(int fd, size_t offset, size_t len) 82 { 83 struct ashmem_pin pin = { offset, len }; 84 return ioctl(fd, ASHMEM_UNPIN, &pin); 85 } 86 87 int ashmem_get_size_region(int fd) 88 { 89 return ioctl(fd, ASHMEM_GET_SIZE, NULL); 90 } 91 92 int ashmem_purge_all(void) 93 { 94 const int fd = open(ASHMEM_DEVICE, O_RDWR); 95 if (fd < 0) 96 return fd; 97 const int ret = ioctl(fd, ASHMEM_PURGE_ALL_CACHES, 0); 98 close(fd); 99 return ret; 100 } 101
