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1c79356b 1/*
39236c6e 2 * Copyright (c) 2000-2012 Apple Computer, Inc. All rights reserved.
1c79356b 3 *
2d21ac55 4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
1c79356b 5 *
2d21ac55
A
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.
8f6c56a5 14 *
2d21ac55
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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
8f6c56a5
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20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
2d21ac55
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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.
8f6c56a5 25 *
2d21ac55 26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
1c79356b
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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
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66
67#include <kern/assert.h>
1c79356b 68#include <kern/macro_help.h>
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69#include <kern/spl.h>
70#include <machine/ast.h>
71
72/*
9bccf70c
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73 * A processor takes an AST when it is about to return from an
74 * interrupt context, and calls ast_taken.
75 *
76 * Machine-dependent code is responsible for maintaining
77 * a set of reasons for an AST, and passing this set to ast_taken.
1c79356b 78 */
9bccf70c 79typedef uint32_t ast_t;
1c79356b 80
fe8ab488
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81/*
82 * When returning from interrupt/trap context to kernel mode,
83 * the pending ASTs are masked with AST_URGENT to determine if
84 * ast_taken(AST_PREEMPTION) should be called, for instance to
85 * effect preemption of a kernel thread by a realtime thread.
86 * This is also done when re-enabling preemption or re-enabling
87 * interrupts, since an AST may have been set while preemption
88 * was disabled, and it should take effect as soon as possible.
89 *
90 * When returning from interrupt/trap/syscall context to user
91 * mode, any and all ASTs that are pending should be handled.
92 *
93 * If a thread context switches, only ASTs not in AST_PER_THREAD
94 * remain active. The per-thread ASTs are stored in the thread_t
95 * and re-enabled when the thread context switches back.
96 *
97 * Typically the preemption ASTs are set as a result of threads
98 * becoming runnable, threads changing priority, or quantum
99 * expiration. If a thread becomes runnable and is chosen
100 * to run on another processor, cause_ast_check() may be called
101 * to IPI that processor and request csw_check() be run there.
102 */
103
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104/*
105 * Bits for reasons
106 */
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107#define AST_PREEMPT 0x01
108#define AST_QUANTUM 0x02
109#define AST_URGENT 0x04
110#define AST_HANDOFF 0x08
111#define AST_YIELD 0x10
0b4e3aa0 112#define AST_APC 0x20 /* migration APC hook */
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113#define AST_LEDGER 0x40
114
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115/*
116 * JMM - This is here temporarily. AST_BSD is used to simulate a
117 * general purpose mechanism for setting asynchronous procedure calls
118 * from the outside.
119 */
55e303ae 120#define AST_BSD 0x80
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121#define AST_KPERF 0x100 /* kernel profiling */
122#define AST_MACF 0x200 /* MACF user ret pending */
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123#define AST_CHUD 0x400
124#define AST_CHUD_URGENT 0x800
125#define AST_GUARD 0x1000
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126#define AST_TELEMETRY_USER 0x2000 /* telemetry sample requested on interrupt from userspace */
127#define AST_TELEMETRY_KERNEL 0x4000 /* telemetry sample requested on interrupt from kernel */
128#define AST_TELEMETRY_WINDOWED 0x8000 /* telemetry sample meant for the window buffer */
129
130#define AST_SFI 0x10000 /* Evaluate if SFI wait is needed before return to userspace */
1c79356b 131
0b4e3aa0 132#define AST_NONE 0x00
55e303ae 133#define AST_ALL (~AST_NONE)
1c79356b 134
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135#define AST_SCHEDULING (AST_PREEMPTION | AST_YIELD | AST_HANDOFF)
136#define AST_PREEMPTION (AST_PREEMPT | AST_QUANTUM | AST_URGENT)
1c79356b 137
39236c6e 138#define AST_CHUD_ALL (AST_CHUD_URGENT|AST_CHUD)
fe8ab488 139#define AST_TELEMETRY_ALL (AST_TELEMETRY_USER | AST_TELEMETRY_KERNEL | AST_TELEMETRY_WINDOWED)
39236c6e 140
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141#ifdef MACHINE_AST
142/*
143 * machine/ast.h is responsible for defining aston and astoff.
144 */
145#else /* MACHINE_AST */
146
147#define aston(mycpu)
148#define astoff(mycpu)
149
150#endif /* MACHINE_AST */
151
152/* Initialize module */
0b4e3aa0 153extern void ast_init(void);
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154
155/* Handle ASTs */
0b4e3aa0
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156extern void ast_taken(
157 ast_t mask,
158 boolean_t enable);
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159
160/* Check for pending ASTs */
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161extern void ast_check(
162 processor_t processor);
1c79356b 163
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164/* Pending ast mask for the current processor */
165extern ast_t *ast_pending(void);
166
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167/*
168 * Per-thread ASTs are reset at context-switch time.
169 */
170#ifndef MACHINE_AST_PER_THREAD
171#define MACHINE_AST_PER_THREAD 0
172#endif
173
fe8ab488 174#define AST_PER_THREAD (AST_APC | AST_BSD | AST_MACF | MACHINE_AST_PER_THREAD | AST_LEDGER | AST_GUARD | AST_TELEMETRY_USER | AST_TELEMETRY_KERNEL | AST_TELEMETRY_WINDOWED)
1c79356b 175/*
91447636 176 * ast_pending(), ast_on(), ast_off(), ast_context(), and ast_propagate()
0b4e3aa0 177 * assume splsched.
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178 */
179
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180#define ast_on_fast(reasons) \
181MACRO_BEGIN \
39236c6e 182 ast_t *_ast_myast = ast_pending(); \
91447636 183 \
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184 if ((*_ast_myast |= (reasons)) != AST_NONE) \
185 { aston(_ast_myast); } \
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186MACRO_END
187
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188#define ast_off_fast(reasons) \
189MACRO_BEGIN \
39236c6e 190 ast_t *_ast_myast = ast_pending(); \
91447636 191 \
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192 if ((*_ast_myast &= ~(reasons)) == AST_NONE) \
193 { astoff(_ast_myast); } \
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194MACRO_END
195
196#define ast_propagate(reasons) ast_on(reasons)
197
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198#define ast_context(act) \
199MACRO_BEGIN \
200 ast_t *myast = ast_pending(); \
201 \
202 if ((*myast = ((*myast &~ AST_PER_THREAD) | (act)->ast)) != AST_NONE) \
203 { aston(myast); } \
204 else \
205 { astoff(myast); } \
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206MACRO_END
207
208#define ast_on(reason) ast_on_fast(reason)
209#define ast_off(reason) ast_off_fast(reason)
210
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211/*
212 * NOTE: if thread is the current thread, thread_ast_set() should
213 * be followed by ast_propagate().
214 */
9bccf70c 215#define thread_ast_set(act, reason) \
b0d623f7 216 (hw_atomic_or_noret(&(act)->ast, (reason)))
9bccf70c 217#define thread_ast_clear(act, reason) \
b0d623f7 218 (hw_atomic_and_noret(&(act)->ast, ~(reason)))
9bccf70c 219#define thread_ast_clear_all(act) \
b0d623f7 220 (hw_atomic_and_noret(&(act)->ast, AST_NONE))
1c79356b 221
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222#ifdef MACH_BSD
223
224extern void astbsd_on(void);
225extern void act_set_astbsd(thread_t);
226extern void bsd_ast(thread_t);
227
228#endif /* MACH_BSD */
1c79356b 229
1c79356b 230#endif /* _KERN_AST_H_ */