ntoskrnl/mm/aspace.c

   1 /* $Id$
   2  *
   3  * COPYRIGHT:       See COPYING in the top level directory
   4  * PROJECT:         ReactOS kernel
   5  * FILE:            ntoskrnl/mm/aspace.c
   6  * PURPOSE:         Manages address spaces
   7  * PROGRAMMER:      David Welch (welch@cwcom.net)
   8  * UPDATE HISTORY:
   9  *                  Created 22/05/98
  10  */
  11
  12 /* INCLUDES *****************************************************************/
  13
  14 #include <ddk/ntddk.h>
  15 #include <internal/mm.h>
  16 #include <internal/ps.h>
  17 #include <internal/pool.h>
  18
  19 #include <internal/debug.h>
  20
  21 /* GLOBALS ******************************************************************/
  22
  23 STATIC MADDRESS_SPACE KernelAddressSpace;
  24
  25 #define TAG_PTRC      TAG('P', 'T', 'R', 'C')
  26
  27 /* FUNCTIONS *****************************************************************/
  28
  29 VOID
  30 MmLockAddressSpace(PMADDRESS_SPACE AddressSpace)
  31 {
  32   /*
  33    * Don't bother with locking if we are the first thread.
  34    */
  35   if (KeGetCurrentThread() == NULL)
  36     {
  37       return;
  38     }
  39   ExAcquireFastMutex(&AddressSpace->Lock);
  40 }
  41
  42 VOID
  43 MmUnlockAddressSpace(PMADDRESS_SPACE AddressSpace)
  44 {
  45   /*
  46    * Don't bother locking if we are the first thread.
  47    */
  48   if (KeGetCurrentThread() == NULL)
  49     {
  50       return;
  51     }
  52   ExReleaseFastMutex(&AddressSpace->Lock);
  53 }
  54
  55 VOID
  56 MmInitializeKernelAddressSpace(VOID)
  57 {
  58    MmInitializeAddressSpace(NULL, &KernelAddressSpace);
  59 }
  60
  61 PMADDRESS_SPACE MmGetCurrentAddressSpace(VOID)
  62 {
  63    return(&PsGetCurrentProcess()->AddressSpace);
  64 }
  65
  66 PMADDRESS_SPACE MmGetKernelAddressSpace(VOID)
  67 {
  68    return(&KernelAddressSpace);
  69 }
  70
  71 NTSTATUS
  72 MmInitializeAddressSpace(PEPROCESS Process,
  73                          PMADDRESS_SPACE AddressSpace)
  74 {
  75    InitializeListHead(&AddressSpace->MAreaListHead);
  76    ExInitializeFastMutex(&AddressSpace->Lock);
  77    if (Process != NULL)
  78      {
  79         AddressSpace->LowestAddress = MM_LOWEST_USER_ADDRESS;
  80      }
  81    else
  82      {
  83         AddressSpace->LowestAddress = KERNEL_BASE;
  84      }
  85    AddressSpace->Process = Process;
  86    if (Process != NULL)
  87      {
  88         AddressSpace->PageTableRefCountTable =
  89           ExAllocatePoolWithTag(NonPagedPool, 768 * sizeof(USHORT),
  90                                 TAG_PTRC);
  91         AddressSpace->PageTableRefCountTableSize = 768;
  92      }
  93    else
  94      {
  95         AddressSpace->PageTableRefCountTable = NULL;
  96         AddressSpace->PageTableRefCountTableSize = 0;
  97      }
  98    return(STATUS_SUCCESS);
  99 }
 100
 101 NTSTATUS
 102 MmDestroyAddressSpace(PMADDRESS_SPACE AddressSpace)
 103 {
 104   if (AddressSpace->PageTableRefCountTable != NULL)
 105     {
 106       ExFreePool(AddressSpace->PageTableRefCountTable);
 107     }
 108    return(STATUS_SUCCESS);
 109 }