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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 /* Initialize module */
111 extern void ast_init(void);
112
113 /* Handle ASTs */
114 extern void ast_taken(
115 ast_t mask,
116 boolean_t enable);
117
118 /* Check for pending ASTs */
119 extern void ast_check(
120 processor_t processor);
121
122 /* Pending ast mask for the current processor */
123 extern ast_t *ast_pending(void);
124
125 /*
126 * Per-thread ASTs are reset at context-switch time.
127 */
128 #ifndef MACHINE_AST_PER_THREAD
129 #define MACHINE_AST_PER_THREAD 0
130 #endif
131
132 #define AST_PER_THREAD (AST_APC | AST_BSD | MACHINE_AST_PER_THREAD)
133 /*
134 * ast_pending(), ast_on(), ast_off(), ast_context(), and ast_propagate()
135 * assume splsched.
136 */
137
138 #define ast_on_fast(reasons) \
139 MACRO_BEGIN \
140 ast_t *myast = ast_pending(); \
141 \
142 if ((*myast |= (reasons)) != AST_NONE) \
143 { aston(myast); } \
144 MACRO_END
145
146 #define ast_off_fast(reasons) \
147 MACRO_BEGIN \
148 ast_t *myast = ast_pending(); \
149 \
150 if ((*myast &= ~(reasons)) == AST_NONE) \
151 { astoff(myast); } \
152 MACRO_END
153
154 #define ast_propagate(reasons) ast_on(reasons)
155
156 #define ast_context(act) \
157 MACRO_BEGIN \
158 ast_t *myast = ast_pending(); \
159 \
160 if ((*myast = ((*myast &~ AST_PER_THREAD) | (act)->ast)) != AST_NONE) \
161 { aston(myast); } \
162 else \
163 { astoff(myast); } \
164 MACRO_END
165
166 #define ast_on(reason) ast_on_fast(reason)
167 #define ast_off(reason) ast_off_fast(reason)
168
169 /*
170 * NOTE: if thread is the current thread, thread_ast_set() should
171 * be followed by ast_propagate().
172 */
173 #define thread_ast_set(act, reason) \
174 (hw_atomic_or(&(act)->ast, (reason)))
175 #define thread_ast_clear(act, reason) \
176 (hw_atomic_and(&(act)->ast, ~(reason)))
177 #define thread_ast_clear_all(act) \
178 (hw_atomic_and(&(act)->ast, AST_NONE))
179
180 #ifdef MACH_BSD
181
182 extern void astbsd_on(void);
183 extern void act_set_astbsd(thread_t);
184 extern void bsd_ast(thread_t);
185
186 #endif /* MACH_BSD */
187
188 #endif /* _KERN_AST_H_ */