hw/iov.c

   1 /*
   2  * Helpers for getting linearized buffers from iov / filling buffers into iovs
   3  *
   4  * Copyright IBM, Corp. 2007, 2008
   5  * Copyright (C) 2010 Red Hat, Inc.
   6  *
   7  * Author(s):
   8  *  Anthony Liguori <aliguori@us.ibm.com>
   9  *  Amit Shah <amit.shah@redhat.com>
  10  *
  11  * This work is licensed under the terms of the GNU GPL, version 2.  See
  12  * the COPYING file in the top-level directory.
  13  */
  14
  15 #include "iov.h"
  16
  17 size_t iov_from_buf(struct iovec *iov, unsigned int iovcnt,
  18                     const void *buf, size_t size)
  19 {
  20     size_t offset;
  21     unsigned int i;
  22
  23     offset = 0;
  24     for (i = 0; offset < size && i < iovcnt; i++) {
  25         size_t len;
  26
  27         len = MIN(iov[i].iov_len, size - offset);
  28
  29         memcpy(iov[i].iov_base, buf + offset, len);
  30         offset += len;
  31     }
  32     return offset;
  33 }