msvc6/ntoskrnl/ke_i386_tskswitch.c

   1 /*
   2  *  ReactOS kernel
   3  *  Copyright (C) 2000 David Welch <welch@cwcom.net>
   4  *
   5  *  Moved to MSVC-compatible inline assembler by Mike Nordell, 2003-12-26
   6  *
   7  *  This program is free software; you can redistribute it and/or modify
   8  *  it under the terms of the GNU General Public License as published by
   9  *  the Free Software Foundation; either version 2 of the License, or
  10  *  (at your option) any later version.
  11  *
  12  *  This program is distributed in the hope that it will be useful,
  13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *  GNU General Public License for more details.
  16  *
  17  *  You should have received a copy of the GNU General Public License
  18  *  along with this program; if not, write to the Free Software
  19  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20  */
  21 /*
  22  * FILE:            ntoskrnl/ke/i386/vm86_sup.S
  23  * PURPOSE:         V86 mode support
  24  * PROGRAMMER:      David Welch (welch@cwcom.net)
  25  * UPDATE HISTORY:
  26  *                  Created 09/10/00
  27  */
  28
  29 /* INCLUDES ******************************************************************/
  30
  31 #pragma hdrstop
  32
  33 #include <ddk/ntddk.h>
  34 #include <ddk/status.h>
  35 #include <internal/i386/segment.h>
  36 #include <internal/i386/fpu.h>
  37 #include <internal/ps.h>
  38 #include <ddk/defines.h>
  39 #include <internal/v86m.h>
  40 #include <ntos/tss.h>
  41 //#include <ntos/service.h>
  42 #include <internal/trap.h>
  43 #include <internal/ps.h>
  44
  45 #include <roscfg.h>
  46 #include <internal/ntoskrnl.h>
  47 #include <internal/i386/segment.h>
  48
  49
  50 extern KSPIN_LOCK PiThreadListLock;
  51 extern ULONG PiNrThreadsAwaitingReaping;
  52 extern ULONG MmGlobalKernelPageDirectory[1024];
  53
  54 VOID STDCALL PiWakeupReaperThread(VOID);
  55 VOID         KeSetBaseGdtSelector(ULONG Entry, PVOID Base);
  56
  57
  58 /*
  59  * FUNCTIONS: Switches to another thread's context
  60  * ARGUMENTS:
  61  *        Thread = Thread to switch to
  62  *        OldThread = Thread to switch from
  63  */
  64 __declspec(naked)
  65 VOID
  66 Ki386ContextSwitch(struct _KTHREAD* NewThread,  struct _KTHREAD* OldThread)
  67 {
  68         __asm
  69         {
  70                 push    ebp
  71                 mov             ebp, esp
  72
  73                 /* Save callee save registers. */
  74                 push    ebx
  75                 push    esi
  76                 push    edi
  77
  78                 cli     /* This is a critical section for this processor. */
  79
  80         /* Get the pointer to the new thread. */
  81                 mov             ebx, NewThread
  82
  83                 /*
  84                  * Set the base of the TEB selector to the base of the TEB for
  85                  * this thread.
  86                  */
  87                 push    ebx
  88                 push    KTHREAD_TEB[ebx]
  89                 push    TEB_SELECTOR
  90                 call    KeSetBaseGdtSelector
  91                 add             esp, 8
  92                 pop             ebx
  93
  94                 /*
  95                  * Load the PCR selector.
  96                  */
  97                 mov             eax, PCR_SELECTOR
  98                 mov             fs, ax
  99
 100                 /*
 101                  * Set the current thread information in the PCR.
 102                  */
 103                 mov             fs:KPCR_CURRENT_THREAD, ebx
 104
 105                 /*
 106                  * Set the current LDT
 107                  */
 108                 xor             eax, eax
 109                 mov             edi, ETHREAD_THREADS_PROCESS[ebx]
 110                 test    word ptr KPROCESS_LDT_DESCRIPTOR0[edi], 0xFFFF
 111                 jz      L4
 112
 113                 push    KPROCESS_LDT_DESCRIPTOR1[edi]
 114                 push    KPROCESS_LDT_DESCRIPTOR0[edi]
 115                 push    LDT_SELECTOR
 116                 call    KeSetGdtSelector
 117                 add             esp, 12
 118
 119                 mov             eax, LDT_SELECTOR
 120
 121 L4:
 122                 lldt            ax
 123
 124                 /*
 125                  * Load up the iomap offset for this thread in
 126                  * preparation for setting it below.
 127                  */
 128                 mov             eax, KPROCESS_IOPM_OFFSET[edi]
 129
 130                 /*
 131                  * FIXME: Save debugging state.
 132                  */
 133
 134                 /*
 135                  * FIXME: Save floating point state.
 136                  */
 137
 138                 /*
 139                  * Switch stacks
 140                  */
 141                 mov             ebx, 12[ebp]
 142                 mov             KTHREAD_KERNEL_STACK[ebx], esp
 143                 mov             ebx, 8[ebp]
 144                 mov             esp, KTHREAD_KERNEL_STACK[ebx]
 145                 mov             edi, KTHREAD_STACK_LIMIT[ebx]
 146
 147                 /*
 148                  * Set the stack pointer in this processors TSS
 149                  */
 150                 mov             esi, fs:KPCR_TSS
 151
 152                 /*
 153                  * Set current IOPM offset in the TSS
 154                  */
 155                 mov             KTSS_IOMAPBASE[esi], ax
 156
 157                 mov             eax, KTHREAD_INITIAL_STACK[ebx]
 158                 mov             KTSS_ESP0[esi], eax
 159
 160                 /*
 161                  * Change the address space
 162                  */
 163                 mov             ebx, ETHREAD_THREADS_PROCESS[ebx]
 164                 mov             eax, KPROCESS_DIRECTORY_TABLE_BASE[ebx]
 165                 mov             cr3, eax
 166
 167                 /*
 168                  * Set up the PDE for the top of the new stack.
 169                  */
 170                 mov             ebx, 0
 171 L2:
 172                 mov             esi, edi
 173                 shr             esi, 22
 174                 mov             eax, 0xF03C0000[esi*4]
 175                 cmp             eax, 0
 176                 jne             L1
 177                 mov             eax, MmGlobalKernelPageDirectory[esi*4]
 178                 mov             0xF03C0000[esi*4], eax
 179 L1:
 180                 add             edi, 4096
 181                 inc             ebx
 182                 cmp             ebx, (MM_STACK_SIZE / 4096)
 183                 jl              L2
 184
 185                 /*
 186                  * FIXME: Restore floating point state
 187                  */
 188
 189                 /*
 190                  * FIXME: Restore debugging state
 191                  */
 192
 193                 /*
 194                  * Exit the critical section
 195                  */
 196                 sti
 197         }
 198
 199         KeReleaseSpinLockFromDpcLevel(&PiThreadListLock);
 200
 201         if (PiNrThreadsAwaitingReaping) {
 202                 PiWakeupReaperThread();
 203         }
 204
 205         __asm
 206         {
 207                 /*
 208                  * Restore the saved register and exit
 209                  */
 210                 pop             edi
 211                 pop             esi
 212                 pop             ebx
 213
 214                 pop             ebp
 215                 ret
 216         }
 217 }