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      1 /*
      2  *  ion.c
      3  *
      4  * Memory Allocator functions for ion
      5  *
      6  *   Copyright 2011 Google, Inc
      7  *
      8  *  Licensed under the Apache License, Version 2.0 (the "License");
      9  *  you may not use this file except in compliance with the License.
     10  *  You may obtain a copy of the License at
     11  *
     12  *      http://www.apache.org/licenses/LICENSE-2.0
     13  *
     14  *  Unless required by applicable law or agreed to in writing, software
     15  *  distributed under the License is distributed on an "AS IS" BASIS,
     16  *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     17  *  See the License for the specific language governing permissions and
     18  *  limitations under the License.
     19  */
     20 #define LOG_TAG "ion"
     21 
     22 #include <cutils/log.h>
     23 #include <errno.h>
     24 #include <fcntl.h>
     25 #include <stdio.h>
     26 #include <sys/ioctl.h>
     27 #include <sys/mman.h>
     28 #include <sys/types.h>
     29 
     30 #include <linux/ion.h>
     31 #include <ion/ion.h>
     32 
     33 int ion_open()
     34 {
     35         int fd = open("/dev/ion", O_RDWR);
     36         if (fd < 0)
     37                 ALOGE("open /dev/ion failed!\n");
     38         return fd;
     39 }
     40 
     41 int ion_close(int fd)
     42 {
     43         return close(fd);
     44 }
     45 
     46 static int ion_ioctl(int fd, int req, void *arg)
     47 {
     48         int ret = ioctl(fd, req, arg);
     49         if (ret < 0) {
     50                 ALOGE("ioctl %x failed with code %d: %s\n", req,
     51                        ret, strerror(errno));
     52                 return -errno;
     53         }
     54         return ret;
     55 }
     56 
     57 int ion_alloc(int fd, size_t len, size_t align, unsigned int flags,
     58               struct ion_handle **handle)
     59 {
     60         int ret;
     61         struct ion_allocation_data data = {
     62                 .len = len,
     63                 .align = align,
     64                 .flags = flags,
     65         };
     66 
     67         ret = ion_ioctl(fd, ION_IOC_ALLOC, &data);
     68         if (ret < 0)
     69                 return ret;
     70         *handle = data.handle;
     71         return ret;
     72 }
     73 
     74 int ion_free(int fd, struct ion_handle *handle)
     75 {
     76         struct ion_handle_data data = {
     77                 .handle = handle,
     78         };
     79         return ion_ioctl(fd, ION_IOC_FREE, &data);
     80 }
     81 
     82 int ion_map(int fd, struct ion_handle *handle, size_t length, int prot,
     83             int flags, off_t offset, unsigned char **ptr, int *map_fd)
     84 {
     85         struct ion_fd_data data = {
     86                 .handle = handle,
     87         };
     88 
     89         int ret = ion_ioctl(fd, ION_IOC_MAP, &data);
     90         if (ret < 0)
     91                 return ret;
     92         *map_fd = data.fd;
     93         if (*map_fd < 0) {
     94                 ALOGE("map ioctl returned negative fd\n");
     95                 return -EINVAL;
     96         }
     97         *ptr = mmap(NULL, length, prot, flags, *map_fd, offset);
     98         if (*ptr == MAP_FAILED) {
     99                 ALOGE("mmap failed: %s\n", strerror(errno));
    100                 return -errno;
    101         }
    102         return ret;
    103 }
    104 
    105 int ion_share(int fd, struct ion_handle *handle, int *share_fd)
    106 {
    107         int map_fd;
    108         struct ion_fd_data data = {
    109                 .handle = handle,
    110         };
    111 
    112         int ret = ion_ioctl(fd, ION_IOC_SHARE, &data);
    113         if (ret < 0)
    114                 return ret;
    115         *share_fd = data.fd;
    116         if (*share_fd < 0) {
    117                 ALOGE("share ioctl returned negative fd\n");
    118                 return -EINVAL;
    119         }
    120         return ret;
    121 }
    122 
    123 int ion_import(int fd, int share_fd, struct ion_handle **handle)
    124 {
    125         struct ion_fd_data data = {
    126                 .fd = share_fd,
    127         };
    128 
    129         int ret = ion_ioctl(fd, ION_IOC_IMPORT, &data);
    130         if (ret < 0)
    131                 return ret;
    132         *handle = data.handle;
    133         return ret;
    134 }
    135