1/*
2 * Copyright (c) 2000-2012 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
67#include <kern/assert.h>
68#include <kern/macro_help.h>
69#include <kern/spl.h>
70
71/*
72 * A processor detects an AST when it is about to return from an
73 * interrupt context, and calls ast_taken_kernel or ast_taken_user
74 * depending on whether it was returning from userspace or kernelspace.
75 *
76 * Machine-dependent code is responsible for maintaining
77 * a set of reasons for an AST.
78 */
79typedef uint32_t ast_t;
80
81/*
82 * When returning from interrupt/trap context to kernel mode,
83 * if AST_URGENT is set, then ast_taken_kernel is called, for
84 * instance to effect preemption of a kernel thread by a realtime
85 * thread.
86 *
87 * This is also done when re-enabling preemption or re-enabling
88 * interrupts, since an AST may have been set while preemption
89 * was disabled, and it should take effect as soon as possible.
90 *
91 * When returning from interrupt/trap/syscall context to user
92 * mode, any and all ASTs that are pending should be handled by
93 * calling ast_taken_user.
94 *
95 * If a thread context switches, only ASTs not in AST_PER_THREAD
96 * remain active. The per-thread ASTs are stored in the thread_t
97 * and re-enabled when the thread context switches back.
98 *
99 * Typically the preemption ASTs are set as a result of threads
100 * becoming runnable, threads changing priority, or quantum
101 * expiration. If a thread becomes runnable and is chosen
102 * to run on another processor, cause_ast_check() may be called
103 * to IPI that processor and request csw_check() be run there.
104 */
105
106/*
107 * Bits for reasons
108 * TODO: Split the context switch and return-to-user AST namespaces
109 * NOTE: Some of these are exported as the 'reason' code in scheduler tracepoints
110 */
111#define AST_PREEMPT 0x01
112#define AST_QUANTUM 0x02
113#define AST_URGENT 0x04
114#define AST_HANDOFF 0x08
115#define AST_YIELD 0x10
116#define AST_APC 0x20 /* migration APC hook */
117#define AST_LEDGER 0x40
118#define AST_BSD 0x80
119#define AST_KPERF 0x100 /* kernel profiling */
120#define AST_MACF 0x200 /* MACF user ret pending */
121#define AST_RESET_PCS 0x400 /* restartable ranges */
122#define AST_ARCADE 0x800 /* arcade subsciption support */
123#define AST_GUARD 0x1000
124#define AST_TELEMETRY_USER 0x2000 /* telemetry sample requested on interrupt from userspace */
125#define AST_TELEMETRY_KERNEL 0x4000 /* telemetry sample requested on interrupt from kernel */
126#define AST_TELEMETRY_PMI 0x8000 /* telemetry sample requested on PMI */
127#define AST_SFI 0x10000 /* Evaluate if SFI wait is needed before return to userspace */
128#define AST_DTRACE 0x20000
129#define AST_TELEMETRY_IO 0x40000 /* telemetry sample requested for I/O */
130#define AST_KEVENT 0x80000
131#define AST_REBALANCE 0x100000 /* thread context switched due to rebalancing */
132// was AST_UNQUIESCE 0x200000
133#define AST_PROC_RESOURCE 0x400000 /* port space and/or file descriptor table has reached its limits */
134#define AST_DEBUG_ASSERT 0x800000 /* check debug assertion */
135#define AST_TELEMETRY_MACF 0x1000000 /* telemetry sample requested by MAC framework */
136
137#define AST_NONE 0x00
138#define AST_ALL (~AST_NONE)
139
140#define AST_SCHEDULING (AST_PREEMPTION | AST_YIELD | AST_HANDOFF)
141#define AST_PREEMPTION (AST_PREEMPT | AST_QUANTUM | AST_URGENT)
142
143#define AST_TELEMETRY_ALL (AST_TELEMETRY_USER | AST_TELEMETRY_KERNEL | \
144 AST_TELEMETRY_PMI | AST_TELEMETRY_IO | AST_TELEMETRY_MACF)
145
146/* Per-thread ASTs follow the thread at context-switch time. */
147#define AST_PER_THREAD (AST_APC | AST_BSD | AST_MACF | AST_RESET_PCS | \
148 AST_ARCADE | AST_LEDGER | AST_GUARD | AST_TELEMETRY_ALL | AST_KEVENT | AST_PROC_RESOURCE | AST_DEBUG_ASSERT)
149
150/* Handle AST_URGENT detected while in the kernel */
151extern void ast_taken_kernel(void);
152
153/* Handle an AST flag set while returning to user mode (may continue via thread_exception_return) */
154extern void ast_taken_user(void);
155
156/* Check for pending ASTs */
157extern void ast_check(processor_t processor);
158
159/* Pending ast mask for the current processor */
160extern ast_t *ast_pending(void);
161
162/* Set AST flags on current processor */
163extern void ast_on(ast_t reasons);
164
165/* Clear AST flags on current processor */
166extern void ast_off(ast_t reasons);
167
168/* Consume specified AST flags from current processor */
169extern ast_t ast_consume(ast_t reasons);
170
171/* Read specified AST flags from current processor */
172extern ast_t ast_peek(ast_t reasons);
173
174/* Re-set current processor's per-thread AST flags to those set on thread */
175extern void ast_context(thread_t thread);
176
177/* Propagate ASTs set on a thread to the current processor */
178extern void ast_propagate(thread_t thread);
179
180/*
181 * Set an AST on a thread with thread_ast_set.
182 *
183 * You can then propagate it to the current processor with ast_propagate(),
184 * or tell another processor to act on it with cause_ast_check().
185 *
186 * See act_set_ast() for an example.
187 */
188#define thread_ast_set(act, reason) ((void)os_atomic_or(&(act)->ast, (reason), relaxed))
189#define thread_ast_clear(act, reason) ((void)os_atomic_andnot(&(act)->ast, (reason), relaxed))
190#define thread_ast_peek(act, reason) (os_atomic_load(&(act)->ast, relaxed) & (reason))
191#define thread_ast_get(act) os_atomic_load(&(act)->ast, relaxed)
192
193#ifdef MACH_BSD
194
195extern void act_set_astbsd(thread_t);
196extern void bsd_ast(thread_t);
197extern void proc_filedesc_ast(task_t task);
198
199#endif /* MACH_BSD */
200
201#ifdef CONFIG_DTRACE
202extern void ast_dtrace_on(void);
203extern void dtrace_ast(void);
204#endif /* CONFIG_DTRACE */
205
206/* These are kept in sync with bsd/kern/ast.h */
207#define AST_KEVENT_RETURN_TO_KERNEL 0x0001
208#define AST_KEVENT_REDRIVE_THREADREQ 0x0002
209#define AST_KEVENT_WORKQ_QUANTUM_EXPIRED 0x0004
210
211extern void kevent_ast(thread_t thread, uint16_t bits);
212extern void act_set_astkevent(thread_t thread, uint16_t bits);
213extern uint16_t act_clear_astkevent(thread_t thread, uint16_t bits);
214extern bool act_set_ast_reset_pcs(task_t task, thread_t thread);
215#if CONFIG_PROC_RESOURCE_LIMITS
216extern void task_filedesc_ast(task_t task, int current_size, int soft_limit, int hard_limit);
217extern void task_kqworkloop_ast(task_t task, int current_size, int soft_limit, int hard_limit);
218#endif
219extern void act_set_debug_assert(void);
220
221extern void thread_debug_return_to_user_ast(thread_t thread);
222#endif /* _KERN_AST_H_ */
223