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kernel/linux-imx6_3.14.28/lib/iovec.c 1.03 KB
6b13f685e   김민수   BSP 최초 추가
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  #include <linux/uaccess.h>
  #include <linux/export.h>
  #include <linux/uio.h>
  
  /*
   *	Copy iovec to kernel. Returns -EFAULT on error.
   *
   *	Note: this modifies the original iovec.
   */
  
  int memcpy_fromiovec(unsigned char *kdata, struct iovec *iov, int len)
  {
  	while (len > 0) {
  		if (iov->iov_len) {
  			int copy = min_t(unsigned int, len, iov->iov_len);
  			if (copy_from_user(kdata, iov->iov_base, copy))
  				return -EFAULT;
  			len -= copy;
  			kdata += copy;
  			iov->iov_base += copy;
  			iov->iov_len -= copy;
  		}
  		iov++;
  	}
  
  	return 0;
  }
  EXPORT_SYMBOL(memcpy_fromiovec);
  
  /*
   *	Copy kernel to iovec. Returns -EFAULT on error.
   *
   *	Note: this modifies the original iovec.
   */
  
  int memcpy_toiovec(struct iovec *iov, unsigned char *kdata, int len)
  {
  	while (len > 0) {
  		if (iov->iov_len) {
  			int copy = min_t(unsigned int, iov->iov_len, len);
  			if (copy_to_user(iov->iov_base, kdata, copy))
  				return -EFAULT;
  			kdata += copy;
  			len -= copy;
  			iov->iov_len -= copy;
  			iov->iov_base += copy;
  		}
  		iov++;
  	}
  
  	return 0;
  }
  EXPORT_SYMBOL(memcpy_toiovec);