reactos/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  *
   8  * PROGRAMMERS:     David Welch (welch@cwcom.net)
   9  */
  10
  11 /* INCLUDES *****************************************************************/
  12
  13 #include <ntoskrnl.h>
  14 #include <internal/debug.h>
  15
  16 /* GLOBALS ******************************************************************/
  17
  18 STATIC MADDRESS_SPACE KernelAddressSpace;
  19
  20 /* FUNCTIONS *****************************************************************/
  21
  22 VOID
  23 MmLockAddressSpace(PMADDRESS_SPACE AddressSpace)
  24 {
  25    /*
  26     * Don't bother with locking if we are the first thread.
  27     */
  28    if (KeGetCurrentThread() == NULL)
  29    {
  30       return;
  31    }
  32    ExAcquireFastMutex(&AddressSpace->Lock);
  33 }
  34
  35 VOID
  36 MmUnlockAddressSpace(PMADDRESS_SPACE AddressSpace)
  37 {
  38    /*
  39     * Don't bother locking if we are the first thread.
  40     */
  41    if (KeGetCurrentThread() == NULL)
  42    {
  43       return;
  44    }
  45    ExReleaseFastMutex(&AddressSpace->Lock);
  46 }
  47
  48 VOID INIT_FUNCTION
  49 MmInitializeKernelAddressSpace(VOID)
  50 {
  51    MmInitializeAddressSpace(NULL, &KernelAddressSpace);
  52 }
  53
  54 PMADDRESS_SPACE MmGetCurrentAddressSpace(VOID)
  55 {
  56    return(&PsGetCurrentProcess()->AddressSpace);
  57 }
  58
  59 PMADDRESS_SPACE MmGetKernelAddressSpace(VOID)
  60 {
  61    return(&KernelAddressSpace);
  62 }
  63
  64 NTSTATUS
  65 MmInitializeAddressSpace(PEPROCESS Process,
  66                          PMADDRESS_SPACE AddressSpace)
  67 {
  68    AddressSpace->MemoryAreaRoot = NULL;
  69    ExInitializeFastMutex(&AddressSpace->Lock);
  70    if (Process != NULL)
  71    {
  72       AddressSpace->LowestAddress = MM_LOWEST_USER_ADDRESS;
  73    }
  74    else
  75    {
  76       AddressSpace->LowestAddress = MmSystemRangeStart;
  77    }
  78    AddressSpace->Process = Process;
  79    if (Process != NULL)
  80    {
  81       ULONG Count;
  82       Count = MiGetUserPageDirectoryCount();
  83       AddressSpace->PageTableRefCountTable =
  84          ExAllocatePoolWithTag(NonPagedPool, Count * sizeof(USHORT),
  85                                TAG_PTRC);
  86       RtlZeroMemory(AddressSpace->PageTableRefCountTable, Count * sizeof(USHORT));
  87       AddressSpace->PageTableRefCountTableSize = Count;
  88    }
  89    else
  90    {
  91       AddressSpace->PageTableRefCountTable = NULL;
  92       AddressSpace->PageTableRefCountTableSize = 0;
  93    }
  94    return(STATUS_SUCCESS);
  95 }
  96
  97 NTSTATUS
  98 MmDestroyAddressSpace(PMADDRESS_SPACE AddressSpace)
  99 {
 100    if (AddressSpace->PageTableRefCountTable != NULL)
 101    {
 102       ExFreePool(AddressSpace->PageTableRefCountTable);
 103    }
 104    return(STATUS_SUCCESS);
 105 }
 106
 107 /* EOF */