osfmk/kern/ast.h

   1 /*
   2  * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_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. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 /*
  24  * @OSF_COPYRIGHT@
  25  */
  26 /*
  27  * Mach Operating System
  28  * Copyright (c) 1991,1990,1989 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
  54 /*
  55  *      kern/ast.h: Definitions for Asynchronous System Traps.
  56  */
  57
  58 #ifndef _KERN_AST_H_
  59 #define _KERN_AST_H_
  60
  61 #include <platforms.h>
  62
  63 #include <kern/assert.h>
  64 #include <kern/macro_help.h>
  65 #include <kern/lock.h>
  66 #include <kern/spl.h>
  67 #include <machine/ast.h>
  68
  69 /*
  70  * A processor takes an AST when it is about to return from an
  71  * interrupt context, and calls ast_taken.
  72  *
  73  * Machine-dependent code is responsible for maintaining
  74  * a set of reasons for an AST, and passing this set to ast_taken.
  75  */
  76 typedef uint32_t                ast_t;
  77
  78 /*
  79  *      Bits for reasons
  80  */
  81 #define AST_PREEMPT             0x01
  82 #define AST_QUANTUM             0x02
  83 #define AST_URGENT              0x04
  84 #define AST_HANDOFF             0x08
  85 #define AST_YIELD               0x10
  86 #define AST_APC                 0x20    /* migration APC hook */
  87 /*
  88  * JMM - This is here temporarily. AST_BSD is used to simulate a
  89  * general purpose mechanism for setting asynchronous procedure calls
  90  * from the outside.
  91  */
  92 #define AST_BSD                 0x80
  93
  94 #define AST_NONE                0x00
  95 #define AST_ALL                 (~AST_NONE)
  96
  97 #define AST_SCHEDULING  (AST_PREEMPTION | AST_YIELD | AST_HANDOFF)
  98 #define AST_PREEMPTION  (AST_PREEMPT | AST_QUANTUM | AST_URGENT)
  99
 100 #ifdef  MACHINE_AST
 101 /*
 102  *      machine/ast.h is responsible for defining aston and astoff.
 103  */
 104 #else   /* MACHINE_AST */
 105
 106 #define aston(mycpu)
 107 #define astoff(mycpu)
 108
 109 #endif  /* MACHINE_AST */
 110
 111 /* Initialize module */
 112 extern void             ast_init(void);
 113
 114 /* Handle ASTs */
 115 extern void             ast_taken(
 116                                         ast_t           mask,
 117                                         boolean_t       enable);
 118
 119 /* Check for pending ASTs */
 120 extern void     ast_check(
 121                                         processor_t             processor);
 122
 123 /* Pending ast mask for the current processor */
 124 extern ast_t    *ast_pending(void);
 125
 126 /*
 127  * Per-thread ASTs are reset at context-switch time.
 128  */
 129 #ifndef MACHINE_AST_PER_THREAD
 130 #define MACHINE_AST_PER_THREAD  0
 131 #endif
 132
 133 #define AST_PER_THREAD  (AST_APC | AST_BSD | MACHINE_AST_PER_THREAD)
 134 /*
 135  *      ast_pending(), ast_on(), ast_off(), ast_context(), and ast_propagate()
 136  *      assume splsched.
 137  */
 138
 139 #define ast_on_fast(reasons)                                    \
 140 MACRO_BEGIN                                                                             \
 141         ast_t   *myast = ast_pending();                         \
 142                                                                                                 \
 143         if ((*myast |= (reasons)) != AST_NONE)          \
 144                 { aston(myast); }                                               \
 145 MACRO_END
 146
 147 #define ast_off_fast(reasons)                                   \
 148 MACRO_BEGIN                                                                             \
 149         ast_t   *myast = ast_pending();                         \
 150                                                                                                 \
 151         if ((*myast &= ~(reasons)) == AST_NONE)         \
 152                 { astoff(myast); }                                              \
 153 MACRO_END
 154
 155 #define ast_propagate(reasons)          ast_on(reasons)
 156
 157 #define ast_context(act)                                                                                                        \
 158 MACRO_BEGIN                                                                                                                                     \
 159         ast_t   *myast = ast_pending();                                                                                 \
 160                                                                                                                                                         \
 161         if ((*myast = ((*myast &~ AST_PER_THREAD) | (act)->ast)) != AST_NONE)   \
 162                 { aston(myast); }                                                                                                       \
 163         else                                                                                                                                    \
 164                 { astoff(myast); }                                                                                                      \
 165 MACRO_END
 166
 167 #define ast_on(reason)                       ast_on_fast(reason)
 168 #define ast_off(reason)                      ast_off_fast(reason)
 169
 170 /*
 171  *      NOTE: if thread is the current thread, thread_ast_set() should
 172  *  be followed by ast_propagate().
 173  */
 174 #define thread_ast_set(act, reason)             \
 175                                                 (hw_atomic_or(&(act)->ast, (reason)))
 176 #define thread_ast_clear(act, reason)   \
 177                                                 (hw_atomic_and(&(act)->ast, ~(reason)))
 178 #define thread_ast_clear_all(act)               \
 179                                                 (hw_atomic_and(&(act)->ast, AST_NONE))
 180
 181 #ifdef MACH_BSD
 182
 183 extern void astbsd_on(void);
 184 extern void act_set_astbsd(thread_t);
 185 extern void bsd_ast(thread_t);
 186
 187 #endif /* MACH_BSD */
 188
 189 #endif  /* _KERN_AST_H_ */