osfmk/kern/ast.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  * 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 <cpus.h>
  61 #include <platforms.h>
  62
  63 #include <kern/assert.h>
  64 #include <kern/cpu_number.h>
  65 #include <kern/macro_help.h>
  66 #include <kern/lock.h>
  67 #include <kern/spl.h>
  68 #include <machine/ast.h>
  69
  70 /*
  71  *      A CPU takes an AST when it is about to return to user code.
  72  *      Instead of going back to user code, it calls ast_taken.
  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
  77 typedef unsigned int ast_t;
  78
  79 /*
  80  *      Bits for reasons
  81  */
  82 #define AST_NONE        0x00
  83 #define AST_HALT        0x01
  84 #define AST_TERMINATE   0x02
  85 #define AST_BLOCK       0x04
  86 #define AST_UNUSED      0x08
  87 #define AST_QUANTUM     0x10
  88 #define AST_APC         0x20    /* migration APC hook */
  89 #define AST_URGENT      0x40
  90
  91 /*
  92  * JMM - This is here temporarily. AST_BSD is used to simulate a
  93  * general purpose mechanism for setting asynchronous procedure calls
  94  * from the outside.
  95  */
  96 #define AST_BSD         0x80
  97 #define AST_BSD_INIT    0x100
  98
  99 #define AST_SWAPOUT     0x20000
 100
 101 #define AST_ALL         (~AST_NONE)
 102
 103 #define AST_SCHEDULING  (AST_HALT | AST_TERMINATE | AST_BLOCK | AST_SWAPOUT)
 104 #define AST_PREEMPT     (AST_BLOCK | AST_QUANTUM | AST_URGENT)
 105
 106 extern volatile ast_t need_ast[NCPUS];
 107
 108 #ifdef  MACHINE_AST
 109 /*
 110  *      machine/ast.h is responsible for defining aston and astoff.
 111  */
 112 #else   /* MACHINE_AST */
 113
 114 #define aston(mycpu)
 115 #define astoff(mycpu)
 116
 117 #endif  /* MACHINE_AST */
 118
 119 /* Initialize module */
 120 extern void     ast_init(void);
 121
 122 /* Handle ASTs */
 123 extern void     ast_taken(
 124                         boolean_t       preemption,
 125                         ast_t           mask,
 126                         boolean_t       interrupt);
 127
 128 /* Check for pending ASTs */
 129 extern void     ast_check(void);
 130
 131 /*
 132  * Per-thread ASTs are reset at context-switch time.
 133  */
 134 #ifndef MACHINE_AST_PER_THREAD
 135 #define MACHINE_AST_PER_THREAD  0
 136 #endif
 137
 138 #define AST_PER_THREAD (MACHINE_AST_PER_THREAD|AST_HALT|AST_TERMINATE|AST_APC|AST_BSD)
 139
 140 /*
 141  *      ast_needed, ast_on, ast_off, ast_context, and ast_propagate
 142  *      assume splsched.
 143  */
 144
 145 #define ast_needed(mycpu)               need_ast[mycpu]
 146
 147 #define ast_on_fast(reasons)                                            \
 148 MACRO_BEGIN                                                             \
 149         int mycpu = cpu_number();                                       \
 150         if ((need_ast[mycpu] |= (reasons)) != AST_NONE)                 \
 151                 { aston(mycpu); }                                       \
 152 MACRO_END
 153
 154 #define ast_off_fast(reasons)                                           \
 155 MACRO_BEGIN                                                             \
 156         int mycpu = cpu_number();                                       \
 157         if ((need_ast[mycpu] &= ~(reasons)) == AST_NONE)                \
 158                 { astoff(mycpu); }                                      \
 159 MACRO_END
 160
 161 #define ast_propagate(reasons)          ast_on(reasons)
 162
 163 #define ast_context(act, mycpu)                                         \
 164 MACRO_BEGIN                                                             \
 165         assert(mycpu == cpu_number());                                  \
 166         if ((need_ast[mycpu] =                                          \
 167              (need_ast[mycpu] &~ AST_PER_THREAD) | (act)->ast)          \
 168                                         != AST_NONE)                    \
 169                 { aston(mycpu); }                                       \
 170         else                                                            \
 171                 { astoff(mycpu); }                                      \
 172 MACRO_END
 173
 174 #define ast_on(reason)                       ast_on_fast(reason)
 175 #define ast_off(reason)                      ast_off_fast(reason)
 176
 177 #define thread_ast_set(act, reason)          (act)->ast |= (reason)
 178 #define thread_ast_clear(act, reason)        (act)->ast &= ~(reason)
 179 #define thread_ast_clear_all(act)            (act)->ast = AST_NONE
 180
 181 /*
 182  *      NOTE: if thread is the current thread, thread_ast_set should
 183  *      be followed by ast_propagate().
 184  */
 185
 186 #ifdef MACH_KERNEL_PRIVATE
 187
 188 #define ast_urgency() (need_ast[cpu_number()] & AST_URGENT)
 189
 190 #endif /* MACH_KERNEL_PRIVATE */
 191
 192 #endif  /* _KERN_AST_H_ */