osfmk/kern/ast.h

   1 /*
   2  * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_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. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 /*
  29  * @OSF_COPYRIGHT@
  30  */
  31 /*
  32  * Mach Operating System
  33  * Copyright (c) 1991,1990,1989 Carnegie Mellon University
  34  * All Rights Reserved.
  35  *
  36  * Permission to use, copy, modify and distribute this software and its
  37  * documentation is hereby granted, provided that both the copyright
  38  * notice and this permission notice appear in all copies of the
  39  * software, derivative works or modified versions, and any portions
  40  * thereof, and that both notices appear in supporting documentation.
  41  *
  42  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  43  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  44  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  45  *
  46  * Carnegie Mellon requests users of this software to return to
  47  *
  48  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  49  *  School of Computer Science
  50  *  Carnegie Mellon University
  51  *  Pittsburgh PA 15213-3890
  52  *
  53  * any improvements or extensions that they make and grant Carnegie Mellon
  54  * the rights to redistribute these changes.
  55  */
  56 /*
  57  */
  58
  59 /*
  60  *      kern/ast.h: Definitions for Asynchronous System Traps.
  61  */
  62
  63 #ifndef _KERN_AST_H_
  64 #define _KERN_AST_H_
  65
  66 #include <platforms.h>
  67
  68 #include <kern/assert.h>
  69 #include <kern/macro_help.h>
  70 #include <kern/lock.h>
  71 #include <kern/spl.h>
  72 #include <machine/ast.h>
  73
  74 /*
  75  * A processor takes an AST when it is about to return from an
  76  * interrupt context, and calls ast_taken.
  77  *
  78  * Machine-dependent code is responsible for maintaining
  79  * a set of reasons for an AST, and passing this set to ast_taken.
  80  */
  81 typedef uint32_t                ast_t;
  82
  83 /*
  84  *      Bits for reasons
  85  */
  86 #define AST_PREEMPT             0x01
  87 #define AST_QUANTUM             0x02
  88 #define AST_URGENT              0x04
  89 #define AST_HANDOFF             0x08
  90 #define AST_YIELD               0x10
  91 #define AST_APC                 0x20    /* migration APC hook */
  92 /*
  93  * JMM - This is here temporarily. AST_BSD is used to simulate a
  94  * general purpose mechanism for setting asynchronous procedure calls
  95  * from the outside.
  96  */
  97 #define AST_BSD                 0x80
  98
  99 #define AST_NONE                0x00
 100 #define AST_ALL                 (~AST_NONE)
 101
 102 #define AST_SCHEDULING  (AST_PREEMPTION | AST_YIELD | AST_HANDOFF)
 103 #define AST_PREEMPTION  (AST_PREEMPT | AST_QUANTUM | AST_URGENT)
 104
 105 #ifdef  MACHINE_AST
 106 /*
 107  *      machine/ast.h is responsible for defining aston and astoff.
 108  */
 109 #else   /* MACHINE_AST */
 110
 111 #define aston(mycpu)
 112 #define astoff(mycpu)
 113
 114 #endif  /* MACHINE_AST */
 115
 116 #define AST_CHUD_URGENT     0x800
 117 #define AST_CHUD            0x400
 118
 119 #define AST_CHUD_ALL        (AST_CHUD_URGENT|AST_CHUD)
 120
 121 /* Initialize module */
 122 extern void             ast_init(void);
 123
 124 /* Handle ASTs */
 125 extern void             ast_taken(
 126                                         ast_t           mask,
 127                                         boolean_t       enable);
 128
 129 /* Check for pending ASTs */
 130 extern void     ast_check(
 131                                         processor_t             processor);
 132
 133 /* Pending ast mask for the current processor */
 134 extern ast_t    *ast_pending(void);
 135
 136 /*
 137  * Per-thread ASTs are reset at context-switch time.
 138  */
 139 #ifndef MACHINE_AST_PER_THREAD
 140 #define MACHINE_AST_PER_THREAD  0
 141 #endif
 142
 143 #define AST_PER_THREAD  (AST_APC | AST_BSD | MACHINE_AST_PER_THREAD)
 144 /*
 145  *      ast_pending(), ast_on(), ast_off(), ast_context(), and ast_propagate()
 146  *      assume splsched.
 147  */
 148
 149 #define ast_on_fast(reasons)                                    \
 150 MACRO_BEGIN                                                                             \
 151         ast_t   *myast = ast_pending();                         \
 152                                                                                                 \
 153         if ((*myast |= (reasons)) != AST_NONE)          \
 154                 { aston(myast); }                                               \
 155 MACRO_END
 156
 157 #define ast_off_fast(reasons)                                   \
 158 MACRO_BEGIN                                                                             \
 159         ast_t   *myast = ast_pending();                         \
 160                                                                                                 \
 161         if ((*myast &= ~(reasons)) == AST_NONE)         \
 162                 { astoff(myast); }                                              \
 163 MACRO_END
 164
 165 #define ast_propagate(reasons)          ast_on(reasons)
 166
 167 #define ast_context(act)                                                                                                        \
 168 MACRO_BEGIN                                                                                                                                     \
 169         ast_t   *myast = ast_pending();                                                                                 \
 170                                                                                                                                                         \
 171         if ((*myast = ((*myast &~ AST_PER_THREAD) | (act)->ast)) != AST_NONE)   \
 172                 { aston(myast); }                                                                                                       \
 173         else                                                                                                                                    \
 174                 { astoff(myast); }                                                                                                      \
 175 MACRO_END
 176
 177 #define ast_on(reason)                       ast_on_fast(reason)
 178 #define ast_off(reason)                      ast_off_fast(reason)
 179
 180 /*
 181  *      NOTE: if thread is the current thread, thread_ast_set() should
 182  *  be followed by ast_propagate().
 183  */
 184 #define thread_ast_set(act, reason)             \
 185                                                 ((void)hw_atomic_or(&(act)->ast, (reason)))
 186 #define thread_ast_clear(act, reason)   \
 187                                                 ((void)hw_atomic_and(&(act)->ast, ~(reason)))
 188 #define thread_ast_clear_all(act)               \
 189                                                 ((void)hw_atomic_and(&(act)->ast, AST_NONE))
 190
 191 #ifdef MACH_BSD
 192
 193 extern void astbsd_on(void);
 194 extern void act_set_astbsd(thread_t);
 195 extern void bsd_ast(thread_t);
 196
 197 #endif /* MACH_BSD */
 198
 199 #endif  /* _KERN_AST_H_ */