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#include <machine/ast.h> 71 72/* 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. 78 */ 79typedef uint32_t ast_t; 80 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 */ 103 104/* 105 * Bits for reasons 106 */ 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 112#define AST_APC 0x20 /* migration APC hook */ 113#define AST_LEDGER 0x40 114 115/* 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 */ 120#define AST_BSD 0x80 121#define AST_KPERF 0x100 /* kernel profiling */ 122#define AST_MACF 0x200 /* MACF user ret pending */ 123#define AST_CHUD 0x400 124#define AST_CHUD_URGENT 0x800 125#define AST_GUARD 0x1000 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 */ 131 132#define AST_NONE 0x00 133#define AST_ALL (~AST_NONE) 134 135#define AST_SCHEDULING (AST_PREEMPTION | AST_YIELD | AST_HANDOFF) 136#define AST_PREEMPTION (AST_PREEMPT | AST_QUANTUM | AST_URGENT) 137 138#define AST_CHUD_ALL (AST_CHUD_URGENT|AST_CHUD) 139#define AST_TELEMETRY_ALL (AST_TELEMETRY_USER | AST_TELEMETRY_KERNEL | AST_TELEMETRY_WINDOWED) 140 141#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 */ 153extern void ast_init(void); 154 155/* Handle ASTs */ 156extern void ast_taken( 157 ast_t mask, 158 boolean_t enable); 159 160/* Check for pending ASTs */ 161extern void ast_check( 162 processor_t processor); 163 164/* Pending ast mask for the current processor */ 165extern ast_t *ast_pending(void); 166 167/* 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 173 174#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) 175/* 176 * ast_pending(), ast_on(), ast_off(), ast_context(), and ast_propagate() 177 * assume splsched. 178 */ 179 180#define ast_on_fast(reasons) \ 181MACRO_BEGIN \ 182 ast_t *_ast_myast = ast_pending(); \ 183 \ 184 if ((*_ast_myast |= (reasons)) != AST_NONE) \ 185 { aston(_ast_myast); } \ 186MACRO_END 187 188#define ast_off_fast(reasons) \ 189MACRO_BEGIN \ 190 ast_t *_ast_myast = ast_pending(); \ 191 \ 192 if ((*_ast_myast &= ~(reasons)) == AST_NONE) \ 193 { astoff(_ast_myast); } \ 194MACRO_END 195 196#define ast_propagate(reasons) ast_on(reasons) 197 198#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); } \ 206MACRO_END 207 208#define ast_on(reason) ast_on_fast(reason) 209#define ast_off(reason) ast_off_fast(reason) 210 211/* 212 * NOTE: if thread is the current thread, thread_ast_set() should 213 * be followed by ast_propagate(). 214 */ 215#define thread_ast_set(act, reason) \ 216 (hw_atomic_or_noret(&(act)->ast, (reason))) 217#define thread_ast_clear(act, reason) \ 218 (hw_atomic_and_noret(&(act)->ast, ~(reason))) 219#define thread_ast_clear_all(act) \ 220 (hw_atomic_and_noret(&(act)->ast, AST_NONE)) 221 222#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 */ 229 230#endif /* _KERN_AST_H_ */ 231