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  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /*
  26  * @OSF_COPYRIGHT@
  27  */
  28
  29 /*
  30  * Mach Operating System
  31  * Copyright (c) 1991,1990 Carnegie Mellon University
  32  * All Rights Reserved.
  33  *
  34  * Permission to use, copy, modify and distribute this software and its
  35  * documentation is hereby granted, provided that both the copyright
  36  * notice and this permission notice appear in all copies of the
  37  * software, derivative works or modified versions, and any portions
  38  * thereof, and that both notices appear in supporting documentation.
  39  *
  40  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  41  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  42  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  43  *
  44  * Carnegie Mellon requests users of this software to return to
  45  *
  46  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  47  *  School of Computer Science
  48  *  Carnegie Mellon University
  49  *  Pittsburgh PA 15213-3890
  50  *
  51  * any improvements or extensions that they make and grant Carnegie Mellon
  52  * the rights to redistribute these changes.
  53  */
  54
  55 /*
  56  * Machine-dependent simple locks for the i386.
  57  */
  58
  59 #ifndef _I386_HW_LOCK_TYPES_H_
  60 #define _I386_HW_LOCK_TYPES_H_
  61
  62 /*
  63  *      The "hardware lock".  Low-level locking primitives that
  64  *      MUST be exported by machine-dependent code; this abstraction
  65  *      must provide atomic, non-blocking mutual exclusion that
  66  *      is invulnerable to uniprocessor or SMP races, interrupts,
  67  *      traps or any other events.
  68  *
  69  *              hw_lock_data_t          machine-specific lock data structure
  70  *              hw_lock_t               pointer to hw_lock_data_t
  71  *
  72  *      An implementation must export these data types and must
  73  *      also provide routines to manipulate them (see prototypes,
  74  *      below).  These routines may be external, inlined, optimized,
  75  *      or whatever, based on the kernel configuration.  In the event
  76  *      that the implementation wishes to define its own prototypes,
  77  *      macros, or inline functions, it may define LOCK_HW_PROTOS
  78  *      to disable the definitions below.
  79  *
  80  *      Mach does not expect these locks to support statistics,
  81  *      debugging, tracing or any other complexity.  In certain
  82  *      configurations, Mach will build other locking constructs
  83  *      on top of this one.  A correctly functioning Mach port need
  84  *      only implement these locks to be successful.  However,
  85  *      greater efficiency may be gained with additional machine-
  86  *      dependent optimizations for the locking constructs defined
  87  *      later in kern/lock.h..
  88  */
  89 typedef volatile int    hw_lock_data_t;
  90 typedef hw_lock_data_t  *hw_lock_t;
  91 #define hw_lock_addr(hwl)       (&(hwl))
  92
  93
  94 #endif  /* _I386_HW_LOCK_TYPES_H_ */
  95