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Commit	Line	Data
b0d623f7 A	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
b0d623f7 A	59
	60	#include <i386/asm.h>
	61	#include <i386/proc_reg.h>
6d2010ae	62	#include <assym.s>
b0d623f7	63
cb323159 A	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	*/
b0d623f7	73	Entry(Load_context)
cb323159	74	movq %rdi, %rdx /* move thread arg to rdx */
b0d623f7	75
cb323159 A	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 */
b0d623f7	83
cb323159 A	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
b0d623f7	91
cb323159 A	92	xorl %eax, %eax /* set return value to zero (no old thread) */
	93
	94	jmp KSS_RIP(%rcx) / return old thread */
b0d623f7 A	95
	96	/*
	97	* thread_t Switch_context(
cb323159 A	98	* thread_t old, // %rdi
cb323159 A	99	* thread_continue_t continuation, // %rsi
b0d623f7	100	* thread_t new) // %rdx
cb323159 A	101	*
cb323159 A	102	* returns 'old' thread in %rax
b0d623f7 A	103	*/
	104	Entry(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 */
	119	5:
	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 */
6d2010ae	124	lea -IKS_SIZE(%rdx),%rcx
b0d623f7 A	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
cb323159	137	jmp KSS_RIP(%rcx) / return old thread in %rax */
b0d623f7	138
cb323159 A	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	*/
b0d623f7	148	Entry(Thread_continue)
d9a64523	149	movq %rax, %rdi /* this is the old thread from Switch_context */
b0d623f7	150	call %rbx / call real continuation */
cb323159	151	int3 /* (should never return) */
b0d623f7 A	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,
b0d623f7	161	* then runs routine on the interrupt stack.
b0d623f7 A	162	*/
	163	Entry(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)
cb323159 A	171	popq %r8 /* extract return PC */
cb323159 A	172	movq %r8,KSS_RIP(%rcx) /* save return PC */
b0d623f7 A	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
39037602 A	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
cb323159 A	184
	185	pushq %r8 /* set up a call frame on new stack */
	186	pushq %rbp
	187	movq %rsp, %rbp
	188
b0d623f7 A	189	movq %rdx,%rdi /* processor arg to routine */
b0d623f7 A	190	call %rsi / call routine to run */
cb323159	191	int3 /* (should never return) */
b0d623f7	192