osfmk/kern/ast.h

   1 /*
   2  * Copyright (c) 2000-2004 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  * Mach Operating System
  27  * Copyright (c) 1991,1990,1989 Carnegie Mellon University
  28  * All Rights Reserved.
  29  *
  30  * Permission to use, copy, modify and distribute this software and its
  31  * documentation is hereby granted, provided that both the copyright
  32  * notice and this permission notice appear in all copies of the
  33  * software, derivative works or modified versions, and any portions
  34  * thereof, and that both notices appear in supporting documentation.
  35  *
  36  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  37  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  38  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  39  *
  40  * Carnegie Mellon requests users of this software to return to
  41  *
  42  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  43  *  School of Computer Science
  44  *  Carnegie Mellon University
  45  *  Pittsburgh PA 15213-3890
  46  *
  47  * any improvements or extensions that they make and grant Carnegie Mellon
  48  * the rights to redistribute these changes.
  49  */
  50 /*
  51  */
  52
  53 /*
  54  *      kern/ast.h: Definitions for Asynchronous System Traps.
  55  */
  56
  57 #ifndef _KERN_AST_H_
  58 #define _KERN_AST_H_
  59
  60 #include <platforms.h>
  61
  62 #include <kern/assert.h>
  63 #include <kern/macro_help.h>
  64 #include <kern/lock.h>
  65 #include <kern/spl.h>
  66 #include <machine/ast.h>
  67
  68 /*
  69  * A processor takes an AST when it is about to return from an
  70  * interrupt context, and calls ast_taken.
  71  *
  72  * Machine-dependent code is responsible for maintaining
  73  * a set of reasons for an AST, and passing this set to ast_taken.
  74  */
  75 typedef uint32_t                ast_t;
  76
  77 /*
  78  *      Bits for reasons
  79  */
  80 #define AST_PREEMPT             0x01
  81 #define AST_QUANTUM             0x02
  82 #define AST_URGENT              0x04
  83 #define AST_HANDOFF             0x08
  84 #define AST_YIELD               0x10
  85 #define AST_APC                 0x20    /* migration APC hook */
  86 /*
  87  * JMM - This is here temporarily. AST_BSD is used to simulate a
  88  * general purpose mechanism for setting asynchronous procedure calls
  89  * from the outside.
  90  */
  91 #define AST_BSD                 0x80
  92
  93 #define AST_NONE                0x00
  94 #define AST_ALL                 (~AST_NONE)
  95
  96 #define AST_SCHEDULING  (AST_PREEMPTION | AST_YIELD | AST_HANDOFF)
  97 #define AST_PREEMPTION  (AST_PREEMPT | AST_QUANTUM | AST_URGENT)
  98
  99 #ifdef  MACHINE_AST
 100 /*
 101  *      machine/ast.h is responsible for defining aston and astoff.
 102  */
 103 #else   /* MACHINE_AST */
 104
 105 #define aston(mycpu)
 106 #define astoff(mycpu)
 107
 108 #endif  /* MACHINE_AST */
 109
 110 #define AST_CHUD_URGENT     0x800
 111 #define AST_CHUD            0x400
 112
 113 #define AST_CHUD_ALL        (AST_CHUD_URGENT|AST_CHUD)
 114
 115 /* Initialize module */
 116 extern void             ast_init(void);
 117
 118 /* Handle ASTs */
 119 extern void             ast_taken(
 120                                         ast_t           mask,
 121                                         boolean_t       enable);
 122
 123 /* Check for pending ASTs */
 124 extern void     ast_check(
 125                                         processor_t             processor);
 126
 127 /* Pending ast mask for the current processor */
 128 extern ast_t    *ast_pending(void);
 129
 130 /*
 131  * Per-thread ASTs are reset at context-switch time.
 132  */
 133 #ifndef MACHINE_AST_PER_THREAD
 134 #define MACHINE_AST_PER_THREAD  0
 135 #endif
 136
 137 #define AST_PER_THREAD  (AST_APC | AST_BSD | MACHINE_AST_PER_THREAD)
 138 /*
 139  *      ast_pending(), ast_on(), ast_off(), ast_context(), and ast_propagate()
 140  *      assume splsched.
 141  */
 142
 143 #define ast_on_fast(reasons)                                    \
 144 MACRO_BEGIN                                                                             \
 145         ast_t   *myast = ast_pending();                         \
 146                                                                                                 \
 147         if ((*myast |= (reasons)) != AST_NONE)          \
 148                 { aston(myast); }                                               \
 149 MACRO_END
 150
 151 #define ast_off_fast(reasons)                                   \
 152 MACRO_BEGIN                                                                             \
 153         ast_t   *myast = ast_pending();                         \
 154                                                                                                 \
 155         if ((*myast &= ~(reasons)) == AST_NONE)         \
 156                 { astoff(myast); }                                              \
 157 MACRO_END
 158
 159 #define ast_propagate(reasons)          ast_on(reasons)
 160
 161 #define ast_context(act)                                                                                                        \
 162 MACRO_BEGIN                                                                                                                                     \
 163         ast_t   *myast = ast_pending();                                                                                 \
 164                                                                                                                                                         \
 165         if ((*myast = ((*myast &~ AST_PER_THREAD) | (act)->ast)) != AST_NONE)   \
 166                 { aston(myast); }                                                                                                       \
 167         else                                                                                                                                    \
 168                 { astoff(myast); }                                                                                                      \
 169 MACRO_END
 170
 171 #define ast_on(reason)                       ast_on_fast(reason)
 172 #define ast_off(reason)                      ast_off_fast(reason)
 173
 174 /*
 175  *      NOTE: if thread is the current thread, thread_ast_set() should
 176  *  be followed by ast_propagate().
 177  */
 178 #define thread_ast_set(act, reason)             \
 179                                                 (hw_atomic_or(&(act)->ast, (reason)))
 180 #define thread_ast_clear(act, reason)   \
 181                                                 (hw_atomic_and(&(act)->ast, ~(reason)))
 182 #define thread_ast_clear_all(act)               \
 183                                                 (hw_atomic_and(&(act)->ast, AST_NONE))
 184
 185 #ifdef MACH_BSD
 186
 187 extern void astbsd_on(void);
 188 extern void act_set_astbsd(thread_t);
 189 extern void bsd_ast(thread_t);
 190
 191 #endif /* MACH_BSD */
 192
 193 #endif  /* _KERN_AST_H_ */