ntoskrnl/ke/i386/context.c

   1 /*
   2  * PROJECT:         ReactOS Kernel
   3  * LICENSE:         BSD - See COPYING.ARM in the top level directory
   4  * FILE:            ntoskrnl/ke/i386/context.c
   5  * PURPOSE:         Context Switching Related Code
   6  * PROGRAMMERS:     ReactOS Portable Systems Group
   7  */
   8
   9 /* INCLUDES *******************************************************************/
  10
  11 #include <ntoskrnl.h>
  12 #define NDEBUG
  13 #include <debug.h>
  14
  15 /* GLOBALS ********************************************************************/
  16
  17 /* FUNCTIONS ******************************************************************/
  18
  19 VOID
  20 NTAPI
  21 KiSwapProcess(IN PKPROCESS NewProcess,
  22               IN PKPROCESS OldProcess)
  23 {
  24     PKIPCR Pcr = (PKIPCR)KeGetPcr();
  25 #ifdef CONFIG_SMP
  26     LONG SetMember;
  27
  28     /* Update active processor mask */
  29     SetMember = (LONG)Pcr->SetMember;
  30     InterlockedXor((PLONG)&NewProcess->ActiveProcessors, SetMember);
  31     InterlockedXor((PLONG)&OldProcess->ActiveProcessors, SetMember);
  32 #endif
  33
  34     /* Check for new LDT */
  35     if (NewProcess->LdtDescriptor.LimitLow != OldProcess->LdtDescriptor.LimitLow)
  36     {
  37         /* Not handled yet */
  38         UNIMPLEMENTED;
  39         ASSERT(FALSE); // while (TRUE);
  40         return;
  41     }
  42
  43     /* Update CR3 */
  44     __writecr3(NewProcess->DirectoryTableBase[0]);
  45
  46     /* Clear GS */
  47     Ke386SetGs(0);
  48
  49     /* Update IOPM offset */
  50     Pcr->TSS->IoMapBase = NewProcess->IopmOffset;
  51 }
  52