osfmk/x86_64/cswitch.s

   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
  65 Entry(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  */
  85 Entry(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 */
 100 5:
 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
 121 Entry(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  */
 139 Entry(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