osfmk/i386/hw_lock_types.h

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * @OSF_COPYRIGHT@
  24  */
  25
  26 /*
  27  * Mach Operating System
  28  * Copyright (c) 1991,1990 Carnegie Mellon University
  29  * All Rights Reserved.
  30  *
  31  * Permission to use, copy, modify and distribute this software and its
  32  * documentation is hereby granted, provided that both the copyright
  33  * notice and this permission notice appear in all copies of the
  34  * software, derivative works or modified versions, and any portions
  35  * thereof, and that both notices appear in supporting documentation.
  36  *
  37  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  38  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  39  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  40  *
  41  * Carnegie Mellon requests users of this software to return to
  42  *
  43  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  44  *  School of Computer Science
  45  *  Carnegie Mellon University
  46  *  Pittsburgh PA 15213-3890
  47  *
  48  * any improvements or extensions that they make and grant Carnegie Mellon
  49  * the rights to redistribute these changes.
  50  */
  51
  52 /*
  53  * Machine-dependent simple locks for the i386.
  54  */
  55
  56 #ifndef _I386_HW_LOCK_TYPES_H_
  57 #define _I386_HW_LOCK_TYPES_H_
  58
  59 /*
  60  *      The "hardware lock".  Low-level locking primitives that
  61  *      MUST be exported by machine-dependent code; this abstraction
  62  *      must provide atomic, non-blocking mutual exclusion that
  63  *      is invulnerable to uniprocessor or SMP races, interrupts,
  64  *      traps or any other events.
  65  *
  66  *              hw_lock_data_t          machine-specific lock data structure
  67  *              hw_lock_t               pointer to hw_lock_data_t
  68  *
  69  *      An implementation must export these data types and must
  70  *      also provide routines to manipulate them (see prototypes,
  71  *      below).  These routines may be external, inlined, optimized,
  72  *      or whatever, based on the kernel configuration.  In the event
  73  *      that the implementation wishes to define its own prototypes,
  74  *      macros, or inline functions, it may define LOCK_HW_PROTOS
  75  *      to disable the definitions below.
  76  *
  77  *      Mach does not expect these locks to support statistics,
  78  *      debugging, tracing or any other complexity.  In certain
  79  *      configurations, Mach will build other locking constructs
  80  *      on top of this one.  A correctly functioning Mach port need
  81  *      only implement these locks to be successful.  However,
  82  *      greater efficiency may be gained with additional machine-
  83  *      dependent optimizations for the locking constructs defined
  84  *      later in kern/lock.h..
  85  */
  86 typedef volatile char   hw_lock_data_t;
  87 typedef hw_lock_data_t  *hw_lock_t;
  88 #define hw_lock_addr(hwl)       (&(hwl))
  89
  90
  91 #endif  /* _I386_HW_LOCK_TYPES_H_ */
  92