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 NTAPI
  24 MmLockAddressSpace(PMADDRESS_SPACE AddressSpace)
  25 {
  26    /*
  27     * Don't bother with locking if we are the first thread.
  28     */
  29    if (KeGetCurrentThread() == NULL)
  30    {
  31       return;
  32    }
  33    ExEnterCriticalRegionAndAcquireFastMutexUnsafe(&AddressSpace->Lock);
  34 }
  35
  36 VOID
  37 NTAPI
  38 MmUnlockAddressSpace(PMADDRESS_SPACE AddressSpace)
  39 {
  40    /*
  41     * Don't bother locking if we are the first thread.
  42     */
  43    if (KeGetCurrentThread() == NULL)
  44    {
  45       return;
  46    }
  47    ExReleaseFastMutexUnsafeAndLeaveCriticalRegion(&AddressSpace->Lock);
  48 }
  49
  50 VOID
  51 INIT_FUNCTION
  52 NTAPI
  53 MmInitializeKernelAddressSpace(VOID)
  54 {
  55    MmInitializeAddressSpace(NULL, &KernelAddressSpace);
  56 }
  57
  58 PMADDRESS_SPACE
  59 NTAPI
  60 MmGetCurrentAddressSpace(VOID)
  61 {
  62    return(&PsGetCurrentProcess()->AddressSpace);
  63 }
  64
  65 PMADDRESS_SPACE
  66 NTAPI
  67 MmGetKernelAddressSpace(VOID)
  68 {
  69    return(&KernelAddressSpace);
  70 }
  71
  72 NTSTATUS
  73 NTAPI
  74 MmInitializeAddressSpace(PEPROCESS Process,
  75                          PMADDRESS_SPACE AddressSpace)
  76 {
  77    AddressSpace->MemoryAreaRoot = NULL;
  78    ExInitializeFastMutex(&AddressSpace->Lock);
  79    if (Process != NULL)
  80    {
  81       AddressSpace->LowestAddress = MM_LOWEST_USER_ADDRESS;
  82    }
  83    else
  84    {
  85       AddressSpace->LowestAddress = MmSystemRangeStart;
  86    }
  87    AddressSpace->Process = Process;
  88    if (Process != NULL)
  89    {
  90       ULONG Count;
  91       Count = MiGetUserPageDirectoryCount();
  92       AddressSpace->PageTableRefCountTable =
  93          ExAllocatePoolWithTag(NonPagedPool, Count * sizeof(USHORT),
  94                                TAG_PTRC);
  95       RtlZeroMemory(AddressSpace->PageTableRefCountTable, Count * sizeof(USHORT));
  96       AddressSpace->PageTableRefCountTableSize = Count;
  97    }
  98    else
  99    {
 100       AddressSpace->PageTableRefCountTable = NULL;
 101       AddressSpace->PageTableRefCountTableSize = 0;
 102    }
 103    return(STATUS_SUCCESS);
 104 }
 105
 106 NTSTATUS
 107 NTAPI
 108 MmDestroyAddressSpace(PMADDRESS_SPACE AddressSpace)
 109 {
 110    if (AddressSpace->PageTableRefCountTable != NULL)
 111    {
 112       ExFreePool(AddressSpace->PageTableRefCountTable);
 113    }
 114    return(STATUS_SUCCESS);
 115 }
 116
 117 /* EOF */