1/*
2 * Copyright (c) 2000-2010 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 */
81typedef 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#define AST_LEDGER		0x40
93
94/*
95 * JMM - This is here temporarily. AST_BSD is used to simulate a
96 * general purpose mechanism for setting asynchronous procedure calls
97 * from the outside.
98 */
99#define AST_BSD			0x80
100#define AST_KPERF		0x100   /* kernel profiling */
101#define	AST_MACF		0x200	/* MACF user ret pending */
102
103#define AST_NONE		0x00
104#define AST_ALL			(~AST_NONE)
105
106#define AST_SCHEDULING	(AST_PREEMPTION | AST_YIELD | AST_HANDOFF)
107#define AST_PREEMPTION	(AST_PREEMPT | AST_QUANTUM | AST_URGENT)
108
109#ifdef  MACHINE_AST
110/*
111 *      machine/ast.h is responsible for defining aston and astoff.
112 */
113#else   /* MACHINE_AST */
114
115#define aston(mycpu)
116#define astoff(mycpu)
117
118#endif  /* MACHINE_AST */
119
120#define AST_CHUD_URGENT     0x800
121#define AST_CHUD            0x400
122
123#define AST_CHUD_ALL        (AST_CHUD_URGENT|AST_CHUD)
124
125/* Initialize module */
126extern void		ast_init(void);
127
128/* Handle ASTs */
129extern void		ast_taken(
130					ast_t		mask,
131					boolean_t	enable);
132
133/* Check for pending ASTs */
134extern void    	ast_check(
135					processor_t		processor);
136
137/* Pending ast mask for the current processor */
138extern ast_t 	*ast_pending(void);
139
140/*
141 * Per-thread ASTs are reset at context-switch time.
142 */
143#ifndef MACHINE_AST_PER_THREAD
144#define MACHINE_AST_PER_THREAD  0
145#endif
146
147#define AST_PER_THREAD	(AST_APC | AST_BSD | AST_MACF | MACHINE_AST_PER_THREAD | AST_LEDGER)
148/*
149 *	ast_pending(), ast_on(), ast_off(), ast_context(), and ast_propagate()
150 *	assume splsched.
151 */
152
153#define ast_on_fast(reasons)					\
154MACRO_BEGIN										\
155	ast_t	*myast = ast_pending();				\
156												\
157	if ((*myast |= (reasons)) != AST_NONE)		\
158		{ aston(myast); }						\
159MACRO_END
160
161#define ast_off_fast(reasons)					\
162MACRO_BEGIN										\
163	ast_t	*myast = ast_pending();				\
164												\
165	if ((*myast &= ~(reasons)) == AST_NONE)		\
166		{ astoff(myast); }						\
167MACRO_END
168
169#define ast_propagate(reasons)		ast_on(reasons)
170
171#define ast_context(act)													\
172MACRO_BEGIN																	\
173	ast_t	*myast = ast_pending();											\
174																			\
175	if ((*myast = ((*myast &~ AST_PER_THREAD) | (act)->ast)) != AST_NONE)	\
176		{ aston(myast);	}													\
177	else																	\
178		{ astoff(myast); }													\
179MACRO_END
180
181#define ast_on(reason)			     ast_on_fast(reason)
182#define ast_off(reason)			     ast_off_fast(reason)
183
184/*
185 *	NOTE: if thread is the current thread, thread_ast_set() should
186 *  be followed by ast_propagate().
187 */
188#define thread_ast_set(act, reason)		\
189						(hw_atomic_or_noret(&(act)->ast, (reason)))
190#define thread_ast_clear(act, reason)	\
191						(hw_atomic_and_noret(&(act)->ast, ~(reason)))
192#define thread_ast_clear_all(act)		\
193						(hw_atomic_and_noret(&(act)->ast, AST_NONE))
194
195#ifdef MACH_BSD
196
197extern void astbsd_on(void);
198extern void act_set_astbsd(thread_t);
199extern void bsd_ast(thread_t);
200
201#endif /* MACH_BSD */
202
203#endif  /* _KERN_AST_H_ */
204