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 #if defined (ALLOC_PRAGMA)
  17 #pragma alloc_text(INIT, MmInitializeKernelAddressSpace)
  18 #endif
  19
  20
  21 /* GLOBALS ******************************************************************/
  22
  23 STATIC MADDRESS_SPACE KernelAddressSpace;
  24
  25 /* FUNCTIONS *****************************************************************/
  26
  27 VOID
  28 NTAPI
  29 MmLockAddressSpace(PMADDRESS_SPACE AddressSpace)
  30 {
  31    /*
  32     * Don't bother with locking if we are the first thread.
  33     */
  34    if (KeGetCurrentThread() == NULL)
  35    {
  36       return;
  37    }
  38    ExEnterCriticalRegionAndAcquireFastMutexUnsafe(&AddressSpace->Lock);
  39 }
  40
  41 VOID
  42 NTAPI
  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    ExReleaseFastMutexUnsafeAndLeaveCriticalRegion(&AddressSpace->Lock);
  53 }
  54
  55 VOID
  56 INIT_FUNCTION
  57 NTAPI
  58 MmInitializeKernelAddressSpace(VOID)
  59 {
  60    MmInitializeAddressSpace(NULL, &KernelAddressSpace);
  61 }
  62
  63 PMADDRESS_SPACE
  64 NTAPI
  65 MmGetCurrentAddressSpace(VOID)
  66 {
  67    return(&PsGetCurrentProcess()->AddressSpace);
  68 }
  69
  70 PMADDRESS_SPACE
  71 NTAPI
  72 MmGetKernelAddressSpace(VOID)
  73 {
  74    return(&KernelAddressSpace);
  75 }
  76
  77 NTSTATUS
  78 NTAPI
  79 MmInitializeAddressSpace(PEPROCESS Process,
  80                          PMADDRESS_SPACE AddressSpace)
  81 {
  82    AddressSpace->MemoryAreaRoot = NULL;
  83    ExInitializeFastMutex(&AddressSpace->Lock);
  84    if (Process != NULL)
  85    {
  86       AddressSpace->LowestAddress = MM_LOWEST_USER_ADDRESS;
  87    }
  88    else
  89    {
  90       AddressSpace->LowestAddress = MmSystemRangeStart;
  91    }
  92    AddressSpace->Process = Process;
  93    if (Process != NULL)
  94    {
  95       ULONG Count;
  96       Count = MiGetUserPageDirectoryCount();
  97       AddressSpace->PageTableRefCountTable =
  98          ExAllocatePoolWithTag(NonPagedPool, Count * sizeof(USHORT),
  99                                TAG_PTRC);
 100       RtlZeroMemory(AddressSpace->PageTableRefCountTable, Count * sizeof(USHORT));
 101       AddressSpace->PageTableRefCountTableSize = Count;
 102    }
 103    else
 104    {
 105       AddressSpace->PageTableRefCountTable = NULL;
 106       AddressSpace->PageTableRefCountTableSize = 0;
 107    }
 108    return(STATUS_SUCCESS);
 109 }
 110
 111 NTSTATUS
 112 NTAPI
 113 MmDestroyAddressSpace(PMADDRESS_SPACE AddressSpace)
 114 {
 115    if (AddressSpace->PageTableRefCountTable != NULL)
 116    {
 117       ExFreePool(AddressSpace->PageTableRefCountTable);
 118    }
 119    return(STATUS_SUCCESS);
 120 }
 121
 122 /* EOF */