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1.1 root 1: /*
2: * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
3: *
4: * @APPLE_LICENSE_HEADER_START@
5: *
6: * The contents of this file constitute Original Code as defined in and
7: * are subject to the Apple Public Source License Version 1.1 (the
8: * "License"). You may not use this file except in compliance with the
9: * License. Please obtain a copy of the License at
10: * http://www.apple.com/publicsource and read it before using this file.
11: *
12: * This Original Code and all software distributed under the License are
13: * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
14: * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
15: * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
16: * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
17: * License for the specific language governing rights and limitations
18: * under the License.
19: *
20: * @APPLE_LICENSE_HEADER_END@
21: */
22: /*
23: * @OSF_COPYRIGHT@
24: */
25: /*
26: * Mach Operating System
27: * Copyright (c) 1991,1990 Carnegie Mellon University
28: * All Rights Reserved.
29: *
30: * Permission to use, copy, modify and distribute this software and its
31: * documentation is hereby granted, provided that both the copyright
32: * notice and this permission notice appear in all copies of the
33: * software, derivative works or modified versions, and any portions
34: * thereof, and that both notices appear in supporting documentation.
35: *
36: * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
37: * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
38: * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
39: *
40: * Carnegie Mellon requests users of this software to return to
41: *
42: * Software Distribution Coordinator or [email protected]
43: * School of Computer Science
44: * Carnegie Mellon University
45: * Pittsburgh PA 15213-3890
46: *
47: * any improvements or extensions that they make and grant Carnegie Mellon
48: * the rights to redistribute these changes.
49: */
50: /*
51: */
52:
53: #include <cpus.h>
54: #include <platforms.h>
55:
56: #include <i386/asm.h>
57: #include <i386/proc_reg.h>
58: #include <assym.s>
59:
60: #if NCPUS > 1
61:
62: #ifdef SYMMETRY
63: #include <sqt/asm_macros.h>
64: #endif
65:
66: #if AT386
67: #include <i386/AT386/mp/mp.h>
68: #endif /* AT386 */
69:
70: #define CX(addr, reg) addr(,reg,4)
71:
72: #else /* NCPUS == 1 */
73:
74: #define CPU_NUMBER(reg)
75: #define CX(addr,reg) addr
76:
77: #endif /* NCPUS == 1 */
78:
79: /*
80: * Context switch routines for i386.
81: */
82:
83: Entry(Load_context)
84: movl S_ARG0,%ecx /* get thread */
85: movl TH_KERNEL_STACK(%ecx),%ecx /* get kernel stack */
86: lea KERNEL_STACK_SIZE-IKS_SIZE-IEL_SIZE(%ecx),%edx
87: /* point to stack top */
88: CPU_NUMBER(%eax)
89: movl %ecx,CX(EXT(active_stacks),%eax) /* store stack address */
90: movl %edx,CX(EXT(kernel_stack),%eax) /* store stack top */
91:
92: movl KSS_ESP(%ecx),%esp /* switch stacks */
93: movl KSS_ESI(%ecx),%esi /* restore registers */
94: movl KSS_EDI(%ecx),%edi
95: movl KSS_EBP(%ecx),%ebp
96: movl KSS_EBX(%ecx),%ebx
97: xorl %eax,%eax /* return zero (no old thread) */
98: jmp *KSS_EIP(%ecx) /* resume thread */
99:
100: /*
101: * This really only has to save registers
102: * when there is no explicit continuation.
103: */
104:
105: Entry(Switch_context)
106: CPU_NUMBER(%edx)
107: movl CX(EXT(active_stacks),%edx),%ecx /* get old kernel stack */
108:
109: movl %ebx,KSS_EBX(%ecx) /* save registers */
110: movl %ebp,KSS_EBP(%ecx)
111: movl %edi,KSS_EDI(%ecx)
112: movl %esi,KSS_ESI(%ecx)
113: popl KSS_EIP(%ecx) /* save return PC */
114: movl %esp,KSS_ESP(%ecx) /* save SP */
115:
116: movl 0(%esp),%eax /* get old thread */
117: movl 4(%esp),%ebx /* get continuation */
118: movl %ebx,TH_CONTINUATION(%eax) /* save continuation */
119: movl %ecx,TH_KERNEL_STACK(%eax) /* save kernel stack */
120:
121: movl 8(%esp),%esi /* get new thread */
122: movl $CPD_ACTIVE_THREAD,%ecx
123: movl %esi,%gs:(%ecx) /* new thread is active */
124: movl TH_KERNEL_STACK(%esi),%ecx /* get its kernel stack */
125: lea KERNEL_STACK_SIZE-IKS_SIZE-IEL_SIZE(%ecx),%ebx
126: /* point to stack top */
127:
128: movl %ecx,CX(EXT(active_stacks),%edx) /* set current stack */
129: movl %ebx,CX(EXT(kernel_stack),%edx) /* set stack top */
130:
131: movl TH_TOP_ACT(%esi),%esi /* get new_thread->top_act */
132: cmpl $0,ACT_KLOADED(%esi) /* check kernel-loaded flag */
133: je 0f
134: movl %esi,CX(EXT(active_kloaded),%edx)
135: jmp 1f
136: 0:
137: movl $0,CX(EXT(active_kloaded),%edx)
138: 1:
139: movl KSS_ESP(%ecx),%esp /* switch stacks */
140: movl KSS_ESI(%ecx),%esi /* restore registers */
141: movl KSS_EDI(%ecx),%edi
142: movl KSS_EBP(%ecx),%ebp
143: movl KSS_EBX(%ecx),%ebx
144: jmp *KSS_EIP(%ecx) /* return old thread */
145:
146: Entry(Thread_continue)
147: pushl %eax /* push the thread argument */
148: xorl %ebp,%ebp /* zero frame pointer */
149: call *%ebx /* call real continuation */
150:
151: #if NCPUS > 1
152: /*
153: * void switch_to_shutdown_context(thread_t thread,
154: * void (*routine)(processor_t),
155: * processor_t processor)
156: *
157: * saves the kernel context of the thread,
158: * switches to the interrupt stack,
159: * continues the thread (with thread_continue),
160: * then runs routine on the interrupt stack.
161: *
162: * Assumes that the thread is a kernel thread (thus
163: * has no FPU state)
164: */
165: Entry(switch_to_shutdown_context)
166: CPU_NUMBER(%edx)
167: movl EXT(active_stacks)(,%edx,4),%ecx /* get old kernel stack */
168: movl %ebx,KSS_EBX(%ecx) /* save registers */
169: movl %ebp,KSS_EBP(%ecx)
170: movl %edi,KSS_EDI(%ecx)
171: movl %esi,KSS_ESI(%ecx)
172: popl KSS_EIP(%ecx) /* save return PC */
173: movl %esp,KSS_ESP(%ecx) /* save SP */
174:
175: movl 0(%esp),%eax /* get old thread */
176: movl $0,TH_CONTINUATION(%eax) /* clear continuation */
177: movl %ecx,TH_KERNEL_STACK(%eax) /* save old stack */
178: movl 4(%esp),%ebx /* get routine to run next */
179: movl 8(%esp),%esi /* get its argument */
180:
181: movl CX(EXT(interrupt_stack),%edx),%ecx /* point to its intr stack */
182: lea INTSTACK_SIZE(%ecx),%esp /* switch to it (top) */
183:
184: pushl %eax /* push thread */
185: call EXT(thread_dispatch) /* reschedule thread */
186: addl $4,%esp /* clean stack */
187:
188: pushl %esi /* push argument */
189: call *%ebx /* call routine to run */
190: hlt /* (should never return) */
191:
192: #endif /* NCPUS > 1 */
193:
194: .text
195:
196: .globl EXT(locore_end)
197: LEXT(locore_end)
198:
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