text: /*
   *  ion.c
   *
   * Memory Allocator functions for ion
   *
   *   Copyright 2011 Google, Inc
   *
   *  Licensed under the Apache License, Version 2.0 (the "License");
   *  you may not use this file except in compliance with the License.
   *  You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   *  Unless required by applicable law or agreed to in writing, software
   *  distributed under the License is distributed on an "AS IS" BASIS,
   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   *  See the License for the specific language governing permissions and
   *  limitations under the License.
   */
  #define LOG_TAG "ion"
  
  #include <cutils/log.h>
  #include <errno.h>
  #include <fcntl.h>
  #include <stdio.h>
  #include <string.h>
  #include <sys/ioctl.h>
  #include <sys/mman.h>
  #include <sys/types.h>
  
  #include <linux/ion.h>
  #include <ion/ion.h>
  
  int ion_open()
  {
      int fd = open("/dev/ion", O_RDWR);
      if (fd < 0)
          ALOGE("open /dev/ion failed!\n");
      return fd;
  }
  
  int ion_close(int fd)
  {
      int ret = close(fd);
      if (ret < 0)
          return -errno;
      return ret;
  }
  
  static int ion_ioctl(int fd, int req, void *arg)
  {
      int ret = ioctl(fd, req, arg);
      if (ret < 0) {
          ALOGE("ioctl %x failed with code %d: %s\n", req,
                ret, strerror(errno));
          return -errno;
      }
      return ret;
  }
  
  int ion_alloc(int fd, size_t len, size_t align, unsigned int heap_mask,
                unsigned int flags, ion_user_handle_t *handle)
  {
      int ret;
      struct ion_allocation_data data = {
          .len = len,
          .align = align,
          .heap_id_mask = heap_mask,
          .flags = flags,
      };
  
      if (handle == NULL)
          return -EINVAL;
  
      ret = ion_ioctl(fd, ION_IOC_ALLOC, &data);
      if (ret < 0)
          return ret;
      *handle = data.handle;
      return ret;
  }
  
  int ion_free(int fd, ion_user_handle_t handle)
  {
      struct ion_handle_data data = {
          .handle = handle,
      };
      return ion_ioctl(fd, ION_IOC_FREE, &data);
  }
  
  int ion_map(int fd, ion_user_handle_t handle, size_t length, int prot,
              int flags, off_t offset, unsigned char **ptr, int *map_fd)
  {
      int ret;
      unsigned char *tmp_ptr;
      struct ion_fd_data data = {
          .handle = handle,
      };
  
      if (map_fd == NULL)
          return -EINVAL;
      if (ptr == NULL)
          return -EINVAL;
  
      ret = ion_ioctl(fd, ION_IOC_MAP, &data);
      if (ret < 0)
          return ret;
      if (data.fd < 0) {
          ALOGE("map ioctl returned negative fd\n");
          return -EINVAL;
      }
      tmp_ptr = mmap(NULL, length, prot, flags, data.fd, offset);
      if (tmp_ptr == MAP_FAILED) {
          ALOGE("mmap failed: %s\n", strerror(errno));
          return -errno;
      }
      *map_fd = data.fd;
      *ptr = tmp_ptr;
      return ret;
  }
  
  int ion_share(int fd, ion_user_handle_t handle, int *share_fd)
  {
      int ret;
      struct ion_fd_data data = {
          .handle = handle,
      };
  
      if (share_fd == NULL)
          return -EINVAL;
  
      ret = ion_ioctl(fd, ION_IOC_SHARE, &data);
      if (ret < 0)
          return ret;
      if (data.fd < 0) {
          ALOGE("share ioctl returned negative fd\n");
          return -EINVAL;
      }
      *share_fd = data.fd;
      return ret;
  }
  
  int ion_alloc_fd(int fd, size_t len, size_t align, unsigned int heap_mask,
                   unsigned int flags, int *handle_fd) {
      ion_user_handle_t handle;
      int ret;
  
      ret = ion_alloc(fd, len, align, heap_mask, flags, &handle);
      if (ret < 0)
          return ret;
      ret = ion_share(fd, handle, handle_fd);
      ion_free(fd, handle);
      return ret;
  }
  
  int ion_import(int fd, int share_fd, ion_user_handle_t *handle)
  {
      int ret;
      struct ion_fd_data data = {
          .fd = share_fd,
      };
  
      if (handle == NULL)
          return -EINVAL;
  
      ret = ion_ioctl(fd, ION_IOC_IMPORT, &data);
      if (ret < 0)
          return ret;
      *handle = data.handle;
      return ret;
  }
  
  int ion_sync_fd(int fd, int handle_fd)
  {
      struct ion_fd_data data = {
          .fd = handle_fd,
      };
      return ion_ioctl(fd, ION_IOC_SYNC, &data);
  }
  