osfmk/kern/ast.h

   1 /*
   2  * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_OSREFERENCE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License.  The rights granted to you under the
  10  * License may not be used to create, or enable the creation or
  11  * redistribution of, unlawful or unlicensed copies of an Apple operating
  12  * system, or to circumvent, violate, or enable the circumvention or
  13  * violation of, any terms of an Apple operating system software license
  14  * agreement.
  15  *
  16  * Please obtain a copy of the License at
  17  * http://www.opensource.apple.com/apsl/ and read it before using this
  18  * file.
  19  *
  20  * The Original Code and all software distributed under the License are
  21  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  22  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  23  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  25  * Please see the License for the specific language governing rights and
  26  * limitations under the License.
  27  *
  28  * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
  29  */
  30 /*
  31  * @OSF_COPYRIGHT@
  32  */
  33 /*
  34  * Mach Operating System
  35  * Copyright (c) 1991,1990,1989 Carnegie Mellon University
  36  * All Rights Reserved.
  37  *
  38  * Permission to use, copy, modify and distribute this software and its
  39  * documentation is hereby granted, provided that both the copyright
  40  * notice and this permission notice appear in all copies of the
  41  * software, derivative works or modified versions, and any portions
  42  * thereof, and that both notices appear in supporting documentation.
  43  *
  44  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  45  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  46  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  47  *
  48  * Carnegie Mellon requests users of this software to return to
  49  *
  50  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  51  *  School of Computer Science
  52  *  Carnegie Mellon University
  53  *  Pittsburgh PA 15213-3890
  54  *
  55  * any improvements or extensions that they make and grant Carnegie Mellon
  56  * the rights to redistribute these changes.
  57  */
  58 /*
  59  */
  60
  61 /*
  62  *      kern/ast.h: Definitions for Asynchronous System Traps.
  63  */
  64
  65 #ifndef _KERN_AST_H_
  66 #define _KERN_AST_H_
  67
  68 #include <platforms.h>
  69
  70 #include <kern/assert.h>
  71 #include <kern/macro_help.h>
  72 #include <kern/lock.h>
  73 #include <kern/spl.h>
  74 #include <machine/ast.h>
  75
  76 /*
  77  * A processor takes an AST when it is about to return from an
  78  * interrupt context, and calls ast_taken.
  79  *
  80  * Machine-dependent code is responsible for maintaining
  81  * a set of reasons for an AST, and passing this set to ast_taken.
  82  */
  83 typedef uint32_t                ast_t;
  84
  85 /*
  86  *      Bits for reasons
  87  */
  88 #define AST_PREEMPT             0x01
  89 #define AST_QUANTUM             0x02
  90 #define AST_URGENT              0x04
  91 #define AST_HANDOFF             0x08
  92 #define AST_YIELD               0x10
  93 #define AST_APC                 0x20    /* migration APC hook */
  94 /*
  95  * JMM - This is here temporarily. AST_BSD is used to simulate a
  96  * general purpose mechanism for setting asynchronous procedure calls
  97  * from the outside.
  98  */
  99 #define AST_BSD                 0x80
 100
 101 #define AST_NONE                0x00
 102 #define AST_ALL                 (~AST_NONE)
 103
 104 #define AST_SCHEDULING  (AST_PREEMPTION | AST_YIELD | AST_HANDOFF)
 105 #define AST_PREEMPTION  (AST_PREEMPT | AST_QUANTUM | AST_URGENT)
 106
 107 #ifdef  MACHINE_AST
 108 /*
 109  *      machine/ast.h is responsible for defining aston and astoff.
 110  */
 111 #else   /* MACHINE_AST */
 112
 113 #define aston(mycpu)
 114 #define astoff(mycpu)
 115
 116 #endif  /* MACHINE_AST */
 117
 118 /* Initialize module */
 119 extern void             ast_init(void);
 120
 121 /* Handle ASTs */
 122 extern void             ast_taken(
 123                                         ast_t           mask,
 124                                         boolean_t       enable);
 125
 126 /* Check for pending ASTs */
 127 extern void     ast_check(
 128                                         processor_t             processor);
 129
 130 /* Pending ast mask for the current processor */
 131 extern ast_t    *ast_pending(void);
 132
 133 /*
 134  * Per-thread ASTs are reset at context-switch time.
 135  */
 136 #ifndef MACHINE_AST_PER_THREAD
 137 #define MACHINE_AST_PER_THREAD  0
 138 #endif
 139
 140 #define AST_PER_THREAD  (AST_APC | AST_BSD | MACHINE_AST_PER_THREAD)
 141 /*
 142  *      ast_pending(), ast_on(), ast_off(), ast_context(), and ast_propagate()
 143  *      assume splsched.
 144  */
 145
 146 #define ast_on_fast(reasons)                                    \
 147 MACRO_BEGIN                                                                             \
 148         ast_t   *myast = ast_pending();                         \
 149                                                                                                 \
 150         if ((*myast |= (reasons)) != AST_NONE)          \
 151                 { aston(myast); }                                               \
 152 MACRO_END
 153
 154 #define ast_off_fast(reasons)                                   \
 155 MACRO_BEGIN                                                                             \
 156         ast_t   *myast = ast_pending();                         \
 157                                                                                                 \
 158         if ((*myast &= ~(reasons)) == AST_NONE)         \
 159                 { astoff(myast); }                                              \
 160 MACRO_END
 161
 162 #define ast_propagate(reasons)          ast_on(reasons)
 163
 164 #define ast_context(act)                                                                                                        \
 165 MACRO_BEGIN                                                                                                                                     \
 166         ast_t   *myast = ast_pending();                                                                                 \
 167                                                                                                                                                         \
 168         if ((*myast = ((*myast &~ AST_PER_THREAD) | (act)->ast)) != AST_NONE)   \
 169                 { aston(myast); }                                                                                                       \
 170         else                                                                                                                                    \
 171                 { astoff(myast); }                                                                                                      \
 172 MACRO_END
 173
 174 #define ast_on(reason)                       ast_on_fast(reason)
 175 #define ast_off(reason)                      ast_off_fast(reason)
 176
 177 /*
 178  *      NOTE: if thread is the current thread, thread_ast_set() should
 179  *  be followed by ast_propagate().
 180  */
 181 #define thread_ast_set(act, reason)             \
 182                                                 (hw_atomic_or(&(act)->ast, (reason)))
 183 #define thread_ast_clear(act, reason)   \
 184                                                 (hw_atomic_and(&(act)->ast, ~(reason)))
 185 #define thread_ast_clear_all(act)               \
 186                                                 (hw_atomic_and(&(act)->ast, AST_NONE))
 187
 188 #ifdef MACH_BSD
 189
 190 extern void astbsd_on(void);
 191 extern void act_set_astbsd(thread_t);
 192 extern void bsd_ast(thread_t);
 193
 194 #endif /* MACH_BSD */
 195
 196 #endif  /* _KERN_AST_H_ */