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 #define TAG_PTRC      TAG('P', 'T', 'R', 'C')
  21
  22 /* FUNCTIONS *****************************************************************/
  23
  24 VOID
  25 MmLockAddressSpace(PMADDRESS_SPACE AddressSpace)
  26 {
  27    /*
  28     * Don't bother with locking if we are the first thread.
  29     */
  30    if (KeGetCurrentThread() == NULL)
  31    {
  32       return;
  33    }
  34    ExAcquireFastMutex(&AddressSpace->Lock);
  35 }
  36
  37 VOID
  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    ExReleaseFastMutex(&AddressSpace->Lock);
  48 }
  49
  50 VOID INIT_FUNCTION
  51 MmInitializeKernelAddressSpace(VOID)
  52 {
  53    MmInitializeAddressSpace(NULL, &KernelAddressSpace);
  54 }
  55
  56 PMADDRESS_SPACE MmGetCurrentAddressSpace(VOID)
  57 {
  58    return(&PsGetCurrentProcess()->AddressSpace);
  59 }
  60
  61 PMADDRESS_SPACE MmGetKernelAddressSpace(VOID)
  62 {
  63    return(&KernelAddressSpace);
  64 }
  65
  66 NTSTATUS
  67 MmInitializeAddressSpace(PEPROCESS Process,
  68                          PMADDRESS_SPACE AddressSpace)
  69 {
  70    AddressSpace->MemoryAreaRoot = NULL;
  71    ExInitializeFastMutex(&AddressSpace->Lock);
  72    if (Process != NULL)
  73    {
  74       AddressSpace->LowestAddress = MM_LOWEST_USER_ADDRESS;
  75    }
  76    else
  77    {
  78       AddressSpace->LowestAddress = (PVOID)KERNEL_BASE;
  79    }
  80    AddressSpace->Process = Process;
  81    if (Process != NULL)
  82    {
  83       ULONG Count;
  84       Count = MiGetUserPageDirectoryCount();
  85       AddressSpace->PageTableRefCountTable =
  86          ExAllocatePoolWithTag(NonPagedPool, Count * sizeof(USHORT),
  87                                TAG_PTRC);
  88       RtlZeroMemory(AddressSpace->PageTableRefCountTable, Count * sizeof(USHORT));
  89       AddressSpace->PageTableRefCountTableSize = Count;
  90    }
  91    else
  92    {
  93       AddressSpace->PageTableRefCountTable = NULL;
  94       AddressSpace->PageTableRefCountTableSize = 0;
  95    }
  96    return(STATUS_SUCCESS);
  97 }
  98
  99 NTSTATUS
 100 MmDestroyAddressSpace(PMADDRESS_SPACE AddressSpace)
 101 {
 102    if (AddressSpace->PageTableRefCountTable != NULL)
 103    {
 104       ExFreePool(AddressSpace->PageTableRefCountTable);
 105    }
 106    return(STATUS_SUCCESS);
 107 }
 108
 109 /* EOF */