1/* 2 * Copyright (c) 2000-2006 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 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 [email protected] 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#include <i386/asm.h> 61#include <i386/proc_reg.h> 62#include <assym.s> 63 64/* 65 * void Load_context( 66 * thread_t thread) // %rdi 67 * 68 * Loads the first thread context to run on a CPU, 69 * i.e. without switching from a previous thread. 70 * 71 * returns 'old' thread in %rax (which is always NULL) 72 */ 73Entry(Load_context) 74 movq %rdi, %rdx /* move thread arg to rdx */ 75 76 movq %rdx,%gs:CPU_ACTIVE_THREAD /* new thread is active */ 77 movq TH_KERNEL_STACK(%rdx),%rdx /* get its kernel stack */ 78 lea -IKS_SIZE(%rdx),%rcx 79 add EXT(kernel_stack_size)(%rip),%rcx /* point to stack top */ 80 81 movq %rdx,%gs:CPU_ACTIVE_STACK /* set current stack */ 82 movq %rcx,%gs:CPU_KERNEL_STACK /* set stack top */ 83 84 movq KSS_RSP(%rcx),%rsp /* switch stacks */ 85 movq KSS_RBX(%rcx),%rbx /* restore registers */ 86 movq KSS_RBP(%rcx),%rbp 87 movq KSS_R12(%rcx),%r12 88 movq KSS_R13(%rcx),%r13 89 movq KSS_R14(%rcx),%r14 90 movq KSS_R15(%rcx),%r15 91 92 xorl %eax, %eax /* set return value to zero (no old thread) */ 93 94 jmp *KSS_RIP(%rcx) /* return old thread */ 95 96/* 97 * thread_t Switch_context( 98 * thread_t old, // %rdi 99 * thread_continue_t continuation, // %rsi 100 * thread_t new) // %rdx 101 * 102 * returns 'old' thread in %rax 103 */ 104Entry(Switch_context) 105 popq %rax /* pop return PC */ 106 107 /* Test for a continuation and skip all state saving if so... */ 108 cmpq $0, %rsi 109 jne 5f 110 movq %gs:CPU_KERNEL_STACK,%rcx /* get old kernel stack top */ 111 movq %rbx,KSS_RBX(%rcx) /* save registers */ 112 movq %rbp,KSS_RBP(%rcx) 113 movq %r12,KSS_R12(%rcx) 114 movq %r13,KSS_R13(%rcx) 115 movq %r14,KSS_R14(%rcx) 116 movq %r15,KSS_R15(%rcx) 117 movq %rax,KSS_RIP(%rcx) /* save return PC */ 118 movq %rsp,KSS_RSP(%rcx) /* save SP */ 1195: 120 movq %rdi,%rax /* return old thread */ 121 /* new thread in %rdx */ 122 movq %rdx,%gs:CPU_ACTIVE_THREAD /* new thread is active */ 123 movq TH_KERNEL_STACK(%rdx),%rdx /* get its kernel stack */ 124 lea -IKS_SIZE(%rdx),%rcx 125 add EXT(kernel_stack_size)(%rip),%rcx /* point to stack top */ 126 127 movq %rdx,%gs:CPU_ACTIVE_STACK /* set current stack */ 128 movq %rcx,%gs:CPU_KERNEL_STACK /* set stack top */ 129 130 movq KSS_RSP(%rcx),%rsp /* switch stacks */ 131 movq KSS_RBX(%rcx),%rbx /* restore registers */ 132 movq KSS_RBP(%rcx),%rbp 133 movq KSS_R12(%rcx),%r12 134 movq KSS_R13(%rcx),%r13 135 movq KSS_R14(%rcx),%r14 136 movq KSS_R15(%rcx),%r15 137 jmp *KSS_RIP(%rcx) /* return old thread in %rax */ 138 139/* 140 * machine_stack_attach sets this as the RIP of newly-attached stacks 141 * %rbx is the C routine to call 142 * %rax is the parameter to pass to the C routine 143 * 144 * This stub is needed to convert the return value of the old thread from Switch_context 145 * in %rax into a parameter to thread_continue passed in %rdi, because using the 146 * same register for the first argument and first retval makes too much sense for the SysV ABI. 147 */ 148Entry(Thread_continue) 149 movq %rax, %rdi /* this is the old thread from Switch_context */ 150 call *%rbx /* call real continuation */ 151 int3 /* (should never return) */ 152 153/* 154 * thread_t Shutdown_context( 155 * thread_t thread, // %rdi 156 * void (*routine)(processor_t), // %rsi 157 * processor_t processor) // %rdx 158 * 159 * saves the kernel context of the thread, 160 * switches to the interrupt stack, 161 * then runs routine on the interrupt stack. 162 */ 163Entry(Shutdown_context) 164 movq %gs:CPU_KERNEL_STACK,%rcx /* get old kernel stack top */ 165 movq %rbx,KSS_RBX(%rcx) /* save registers */ 166 movq %rbp,KSS_RBP(%rcx) 167 movq %r12,KSS_R12(%rcx) 168 movq %r13,KSS_R13(%rcx) 169 movq %r14,KSS_R14(%rcx) 170 movq %r15,KSS_R15(%rcx) 171 popq %r8 /* extract return PC */ 172 movq %r8,KSS_RIP(%rcx) /* save return PC */ 173 movq %rsp,KSS_RSP(%rcx) /* save SP */ 174 175 movq %gs:CPU_ACTIVE_STACK,%rcx /* get old kernel stack */ 176 movq %rdi,%rax /* get old thread */ 177 movq %rcx,TH_KERNEL_STACK(%rax) /* save old stack */ 178 179 movq %gs:CPU_INT_STACK_TOP,%rsp /* switch to interrupt stack */ 180 181 movq %rsp, %gs:CPU_ACTIVE_STACK 182 movq EXT(kernel_stack_size)(%rip),%rcx /* point to stack top */ 183 subq %rcx, %gs:CPU_ACTIVE_STACK 184 185 pushq %r8 /* set up a call frame on new stack */ 186 pushq %rbp 187 movq %rsp, %rbp 188 189 movq %rdx,%rdi /* processor arg to routine */ 190 call *%rsi /* call routine to run */ 191 int3 /* (should never return) */ 192 193