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 FAST_MUTEX KernelAddressSpaceLock;
  25
  26 /* FUNCTIONS *****************************************************************/
  27
  28 VOID
  29 NTAPI
  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
  40    if (AddressSpace->Process)
  41    {
  42        ExEnterCriticalRegionAndAcquireFastMutexUnsafe(&AddressSpace->Process->AddressCreationLock);
  43    }
  44    else
  45    {
  46        ExEnterCriticalRegionAndAcquireFastMutexUnsafe(&KernelAddressSpaceLock);
  47    }
  48 }
  49
  50 VOID
  51 NTAPI
  52 MmUnlockAddressSpace(PMADDRESS_SPACE AddressSpace)
  53 {
  54    /*
  55     * Don't bother locking if we are the first thread.
  56     */
  57    if (KeGetCurrentThread() == NULL)
  58    {
  59       return;
  60    }
  61    if (AddressSpace->Process)
  62    {
  63         ExReleaseFastMutexUnsafeAndLeaveCriticalRegion(&AddressSpace->Process->AddressCreationLock);
  64    }
  65    else
  66    {
  67         ExReleaseFastMutexUnsafeAndLeaveCriticalRegion(&KernelAddressSpaceLock);
  68    }
  69 }
  70
  71 VOID
  72 INIT_FUNCTION
  73 NTAPI
  74 MmInitializeKernelAddressSpace(VOID)
  75 {
  76    MmInitializeAddressSpace(NULL, &KernelAddressSpace);
  77 }
  78
  79 PMADDRESS_SPACE
  80 NTAPI
  81 MmGetCurrentAddressSpace(VOID)
  82 {
  83    return((PMADDRESS_SPACE)&(PsGetCurrentProcess())->VadRoot);
  84 }
  85
  86 PMADDRESS_SPACE
  87 NTAPI
  88 MmGetKernelAddressSpace(VOID)
  89 {
  90    return(&KernelAddressSpace);
  91 }
  92
  93 NTSTATUS
  94 NTAPI
  95 MmInitializeAddressSpace(PEPROCESS Process,
  96                          PMADDRESS_SPACE AddressSpace)
  97 {
  98    AddressSpace->MemoryAreaRoot = NULL;
  99    if (Process)
 100    {
 101        ExInitializeFastMutex(&Process->AddressCreationLock);
 102    }
 103    else
 104    {
 105         ExInitializeFastMutex(&KernelAddressSpaceLock);
 106    }
 107    if (Process != NULL)
 108    {
 109       AddressSpace->LowestAddress = MM_LOWEST_USER_ADDRESS;
 110    }
 111    else
 112    {
 113       AddressSpace->LowestAddress = MmSystemRangeStart;
 114    }
 115    AddressSpace->Process = Process;
 116    if (Process != NULL)
 117    {
 118       ULONG Count;
 119       Count = MiGetUserPageDirectoryCount();
 120       AddressSpace->PageTableRefCountTable =
 121          ExAllocatePoolWithTag(NonPagedPool, Count * sizeof(USHORT),
 122                                TAG_PTRC);
 123       RtlZeroMemory(AddressSpace->PageTableRefCountTable, Count * sizeof(USHORT));
 124       AddressSpace->PageTableRefCountTableSize = Count;
 125    }
 126    else
 127    {
 128       AddressSpace->PageTableRefCountTable = NULL;
 129       AddressSpace->PageTableRefCountTableSize = 0;
 130    }
 131    return(STATUS_SUCCESS);
 132 }
 133
 134 NTSTATUS
 135 NTAPI
 136 MmDestroyAddressSpace(PMADDRESS_SPACE AddressSpace)
 137 {
 138    if (AddressSpace->PageTableRefCountTable != NULL)
 139    {
 140       ExFreePool(AddressSpace->PageTableRefCountTable);
 141    }
 142    return(STATUS_SUCCESS);
 143 }
 144
 145 /* EOF */