text: /*
   * Copyright (c) 2000-2008 Apple Inc. All rights reserved.
   *
   * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   * 
   * This file contains Original Code and/or Modifications of Original Code
   * as defined in and that are subject to the Apple Public Source License
   * Version 2.0 (the 'License'). You may not use this file except in
   * compliance with the License. The rights granted to you under the License
   * may not be used to create, or enable the creation or redistribution of,
   * unlawful or unlicensed copies of an Apple operating system, or to
   * circumvent, violate, or enable the circumvention or violation of, any
   * terms of an Apple operating system software license agreement.
   * 
   * Please obtain a copy of the License at
   * http://www.opensource.apple.com/apsl/ and read it before using this file.
   * 
   * The Original Code and all software distributed under the License are
   * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
   * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
   * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
   * Please see the License for the specific language governing rights and
   * limitations under the License.
   * 
   * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
   */
  /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
  /*
   * Copyright (c) 1982, 1986, 1993, 1994
   *	The Regents of the University of California.  All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   * 3. All advertising materials mentioning features or use of this software
   *    must display the following acknowledgement:
   *	This product includes software developed by the University of
   *	California, Berkeley and its contributors.
   * 4. Neither the name of the University nor the names of its contributors
   *    may be used to endorse or promote products derived from this software
   *    without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   *
   *	@(#)uio.h	8.5 (Berkeley) 2/22/94
   */
  
  #ifndef _SYS_UIO_H_
  #define	_SYS_UIO_H_
  
  #include <sys/cdefs.h>
  #include <sys/_types.h>
  
  /*
   * [XSI] The ssize_t and size_t types shall be defined as described
   * in <sys/types.h>.
   */
  #include <sys/_types/_size_t.h>
  #include <sys/_types/_ssize_t.h>
  
  /*
   * [XSI] Structure whose address is passed as the second parameter to the
   * readv() and writev() functions.
   */
  #include <sys/_types/_iovec_t.h>
  
  
  #if !defined(_POSIX_C_SOURCE) || defined(_DARWIN_C_SOURCE)
  /*
   * IO direction for uio_t.
   *	UIO_READ - data moves into iovec(s) associated with uio_t
   *	UIO_WRITE - data moves out of iovec(s) associated with uio_t
   */
  enum uio_rw { UIO_READ, UIO_WRITE };
  #endif
  
  
  /*
   * XXX This all really wants a uio_internal.h
   */
  
  #include <sys/kernel_types.h>
  
  
  /*
   * user / kernel address space type flags.
   * WARNING - make sure to check when adding flags!  Be sure new flags
   * don't overlap the definitions in uio_internal.h
   * NOTES - 
   *	UIO_USERSPACE is equivalent to UIO_USERSPACE32, but UIO_USERSPACE32
   *		is preferred.  UIO_USERSPACE remains for backwards compatibility.
   *	UIO_SYSSPACE is equivalent to UIO_SYSSPACE32, but UIO_SYSSPACE
   *		is preferred.
   */
  enum uio_seg {
  	UIO_USERSPACE 		= 0,	/* kernel address is virtual,  to/from user virtual */
  	UIO_SYSSPACE 		= 2,	/* kernel address is virtual,  to/from system virtual */
  	UIO_USERSPACE32 	= 5,	/* kernel address is virtual,  to/from user 32-bit virtual */
  	UIO_USERSPACE64 	= 8,	/* kernel address is virtual,  to/from user 64-bit virtual */
  	UIO_SYSSPACE32 		= 11	/* deprecated */
  };
  
  #define UIO_SEG_IS_USER_SPACE( a_uio_seg )  \
  	( (a_uio_seg) == UIO_USERSPACE64 || (a_uio_seg) == UIO_USERSPACE32 || \
  	  (a_uio_seg) == UIO_USERSPACE )
  
  
  __BEGIN_DECLS
  
  /*
   * uio_create - create an uio_t.
   * 	Space is allocated to hold up to a_iovcount number of iovecs.  The uio_t
   *	is not fully initialized until all iovecs are added using uio_addiov calls.
   *	a_iovcount is the maximum number of iovecs you may add.
   */
  uio_t uio_create( int a_iovcount,		/* max number of iovecs */
  				  off_t a_offset,		/* current offset */
  				  int a_spacetype,		/* type of address space */
  				  int a_iodirection );	/* read or write flag */
  
  /*
   * uio_reset - reset an uio_t.
   * 	Reset the given uio_t to initial values.  The uio_t is not fully initialized
   * 	until all iovecs are added using uio_add_ov calls.
   *	The a_iovcount value passed in the uio_create is the maximum number of 
   *	iovecs you may add.
   */
  void uio_reset( uio_t a_uio,
  				off_t a_offset,			/* current offset */
  				int a_spacetype,		/* type of address space */
  				int a_iodirection );	/* read or write flag */
  
  /*
   * uio_duplicate - allocate a new uio and make a copy of the given uio_t.
   *	may return NULL.
   */
  uio_t uio_duplicate( uio_t a_uio );
  
  
  /*
   * uio_free - free a uio_t allocated via uio_create. 
   */
  void uio_free( uio_t a_uio );
  
  /*
   * uio_addiov - add an iovec to the given uio_t.  You may call this up to
   * 	the a_iovcount number that was passed to uio_create. 
   *	returns 0 if add was successful else non zero.
   */
  int uio_addiov( uio_t a_uio, user_addr_t a_baseaddr, user_size_t a_length );
  
  /*
   * uio_getiov - get iovec data associated with the given uio_t.  Use
   *  a_index to iterate over each iovec (0 to (uio_iovcnt(uio_t) - 1)).
   *  a_baseaddr_p and a_length_p may be NULL.
   * 	returns -1 when a_index is out of range or invalid uio_t.
   *	returns 0 when data is returned.
   */
  int uio_getiov( uio_t a_uio, 
                   int a_index, 
                   user_addr_t * a_baseaddr_p, 
                   user_size_t * a_length_p );
  
  /*
   * uio_update - update the given uio_t for a_count of completed IO.
   *	This call adjusts decrements the current iovec length and residual IO,
   *	and increments the current iovec base address and offset value. 
   */
  void uio_update( uio_t a_uio, user_size_t a_count );
  
  /*
   * uio_resid - return the residual IO value for the given uio_t
   */
  user_ssize_t uio_resid( uio_t a_uio );
  
  /*
   * uio_setresid - set the residual IO value for the given uio_t
   */
  void uio_setresid( uio_t a_uio, user_ssize_t a_value );
  
  /*
   * uio_iovcnt - return count of active iovecs for the given uio_t
   */
  int uio_iovcnt( uio_t a_uio );
  
  /*
   * uio_offset - return the current offset value for the given uio_t
   */
  off_t uio_offset( uio_t a_uio );
  
  /*
   * uio_setoffset - set the current offset value for the given uio_t
   */
  void uio_setoffset( uio_t a_uio, off_t a_offset );
  
  /*
   * uio_rw - return the read / write flag for the given uio_t
   */
  int uio_rw( uio_t a_uio );
  
  /*
   * uio_setrw - set the read / write flag for the given uio_t
   */
  void uio_setrw( uio_t a_uio, int a_value );
  
  /*
   * uio_isuserspace - return non zero value if the address space 
   * flag is for a user address space (could be 32 or 64 bit).
   */
  int uio_isuserspace( uio_t a_uio );
  
  /*
   * uio_curriovbase - return the base address of the current iovec associated 
   *	with the given uio_t.  May return 0.
   */
  user_addr_t uio_curriovbase( uio_t a_uio );
  
  /*
   * uio_curriovlen - return the length value of the current iovec associated 
   *	with the given uio_t.
   */
  user_size_t uio_curriovlen( uio_t a_uio );
  
  /*
   * Limits
   */
  #define UIO_MAXIOV	1024		/* max 1K of iov's */
  #define UIO_SMALLIOV	8		/* 8 on stack, else malloc */
  
  extern int uiomove(const char * cp, int n, struct uio *uio);
  extern int uiomove64(const __uint64_t cp, int n, struct uio *uio);
  __END_DECLS
  
  
  
  #endif /* !_SYS_UIO_H_ */
  