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  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#include <i386/asm.h>
61#include <i386/proc_reg.h>
62#include <i386/mp.h>
63#include <assym.s>
64
65Entry(Load_context)
66	movq	TH_KERNEL_STACK(%rdi),%rcx	/* get kernel stack */
67	leaq	-IKS_SIZE(%rcx),%rdx
68	addq	EXT(kernel_stack_size)(%rip),%rdx /* point to stack top */
69	movq	%rcx,%gs:CPU_ACTIVE_STACK	/* store stack address */
70	movq	%rdx,%gs:CPU_KERNEL_STACK	/* store stack top */
71
72	movq	%rdx,%rsp
73	movq	%rdx,%rbp
74
75	xorq	%rdi,%rdi			/* return zero (no old thread) */
76	call	EXT(thread_continue)
77
78
79/*
80 * thread_t Switch_context(
81 *		thread_t old,				// %rsi
82 *		thread_continue_t continuation,		// %rdi
83 *		thread_t new)				// %rdx
84 */
85Entry(Switch_context)
86	popq	%rax				/* pop return PC */
87
88	/* Test for a continuation and skip all state saving if so... */
89	cmpq	$0, %rsi
90	jne 	5f
91	movq	%gs:CPU_KERNEL_STACK,%rcx	/* get old kernel stack top */
92	movq	%rbx,KSS_RBX(%rcx)		/* save registers */
93	movq	%rbp,KSS_RBP(%rcx)
94	movq	%r12,KSS_R12(%rcx)
95	movq	%r13,KSS_R13(%rcx)
96	movq	%r14,KSS_R14(%rcx)
97	movq	%r15,KSS_R15(%rcx)
98	movq	%rax,KSS_RIP(%rcx)		/* save return PC */
99	movq	%rsp,KSS_RSP(%rcx)		/* save SP */
1005:
101	movq	%rdi,%rax			/* return old thread */
102	/* new thread in %rdx */
103	movq    %rdx,%gs:CPU_ACTIVE_THREAD      /* new thread is active */
104	movq	TH_KERNEL_STACK(%rdx),%rdx	/* get its kernel stack */
105	lea	-IKS_SIZE(%rdx),%rcx
106	add	EXT(kernel_stack_size)(%rip),%rcx /* point to stack top */
107
108	movq	%rdx,%gs:CPU_ACTIVE_STACK	/* set current stack */
109	movq	%rcx,%gs:CPU_KERNEL_STACK	/* set stack top */
110
111	movq	KSS_RSP(%rcx),%rsp		/* switch stacks */
112	movq	KSS_RBX(%rcx),%rbx		/* restore registers */
113	movq	KSS_RBP(%rcx),%rbp
114	movq	KSS_R12(%rcx),%r12
115	movq	KSS_R13(%rcx),%r13
116	movq	KSS_R14(%rcx),%r14
117	movq	KSS_R15(%rcx),%r15
118	jmp	*KSS_RIP(%rcx)			/* return old thread */
119
120
121Entry(Thread_continue)
122	movq	%rax, %rdi			/* load thread argument */
123	xorq	%rbp,%rbp			/* zero frame pointer */
124	call	*%rbx				/* call real continuation */
125
126
127/*
128 * thread_t Shutdown_context(
129 *		thread_t thread,		// %rdi
130 *		void (*routine)(processor_t),	// %rsi
131 *		processor_t processor)		// %rdx
132 *
133 * saves the kernel context of the thread,
134 * switches to the interrupt stack,
135 * continues the thread (with thread_continue),
136 * then runs routine on the interrupt stack.
137 *
138 */
139Entry(Shutdown_context)
140	movq	%gs:CPU_KERNEL_STACK,%rcx	/* get old kernel stack top */
141	movq	%rbx,KSS_RBX(%rcx)		/* save registers */
142	movq	%rbp,KSS_RBP(%rcx)
143	movq	%r12,KSS_R12(%rcx)
144	movq	%r13,KSS_R13(%rcx)
145	movq	%r14,KSS_R14(%rcx)
146	movq	%r15,KSS_R15(%rcx)
147	popq	KSS_RIP(%rcx)			/* save return PC */
148	movq	%rsp,KSS_RSP(%rcx)		/* save SP */
149
150	movq	%gs:CPU_ACTIVE_STACK,%rcx	/* get old kernel stack */
151	movq	%rdi,%rax			/* get old thread */
152	movq	%rcx,TH_KERNEL_STACK(%rax)	/* save old stack */
153
154	movq	%gs:CPU_INT_STACK_TOP,%rsp 	/* switch to interrupt stack */
155
156	movq	%rdx,%rdi			/* processor arg to routine */
157	call	*%rsi				/* call routine to run */
158	hlt					/* (should never return) */
159
160