reactos/ntoskrnl/mm/ncache.c

   1 /* $Id$
   2  *
   3  * COPYRIGHT:       See COPYING in the top level directory
   4  * PROJECT:         ReactOS kernel
   5  * FILE:            ntoskrnl/mm/ncache.c
   6  * PURPOSE:         Manages non-cached memory
   7  *
   8  * PROGRAMMERS:     David Welch (welch@cwcom.net)
   9  */
  10
  11 /* INCLUDES *****************************************************************/
  12
  13 #include <ntoskrnl.h>
  14 #define NDEBUG
  15 #include <internal/debug.h>
  16
  17 /* FUNCTIONS *****************************************************************/
  18
  19
  20 /**********************************************************************
  21  * NAME       EXPORTED
  22  *  MmAllocateNonCachedMemory@4
  23  *
  24  * DESCRIPTION
  25  *  Allocates a virtual address range of noncached and cache
  26  * aligned memory.
  27  *
  28  * ARGUMENTS
  29  * NumberOfBytes
  30  *  Size of region to allocate.
  31  *
  32  * RETURN VALUE
  33  * The base address of the range on success;
  34  * NULL on failure.
  35  *
  36  * NOTE
  37  *  Description taken from include/ddk/mmfuncs.h.
  38  *  Code taken from ntoskrnl/mm/special.c.
  39  *
  40  * REVISIONS
  41  *
  42  * @implemented
  43  */
  44 PVOID STDCALL
  45 MmAllocateNonCachedMemory(IN ULONG NumberOfBytes)
  46 {
  47    PVOID Result;
  48    MEMORY_AREA* marea;
  49    NTSTATUS Status;
  50    ULONG i;
  51    ULONG Attributes;
  52    PHYSICAL_ADDRESS BoundaryAddressMultiple;
  53
  54    BoundaryAddressMultiple.QuadPart = 0;
  55    MmLockAddressSpace(MmGetKernelAddressSpace());
  56    Result = NULL;
  57    Status = MmCreateMemoryArea (NULL,
  58                                 MmGetKernelAddressSpace(),
  59                                 MEMORY_AREA_NO_CACHE,
  60                                 &Result,
  61                                 NumberOfBytes,
  62                                 0,
  63                                 &marea,
  64                                 FALSE,
  65                                 FALSE,
  66                                 BoundaryAddressMultiple);
  67    MmUnlockAddressSpace(MmGetKernelAddressSpace());
  68
  69    if (!NT_SUCCESS(Status))
  70    {
  71       return (NULL);
  72    }
  73    Attributes = PAGE_READWRITE | PAGE_SYSTEM | PAGE_NOCACHE |
  74                 PAGE_WRITETHROUGH;
  75    for (i = 0; i < (PAGE_ROUND_UP(NumberOfBytes) / PAGE_SIZE); i++)
  76    {
  77       PFN_TYPE NPage;
  78
  79       Status = MmRequestPageMemoryConsumer(MC_NPPOOL, TRUE, &NPage);
  80       MmCreateVirtualMapping (NULL,
  81                               (char*)Result + (i * PAGE_SIZE),
  82                               Attributes,
  83                               &NPage,
  84                               1);
  85    }
  86    return ((PVOID)Result);
  87 }
  88
  89 VOID STATIC
  90 MmFreeNonCachedPage(PVOID Context, MEMORY_AREA* MemoryArea, PVOID Address,
  91                     PFN_TYPE Page, SWAPENTRY SwapEntry,
  92                     BOOLEAN Dirty)
  93 {
  94    ASSERT(SwapEntry == 0);
  95    if (Page != 0)
  96    {
  97       MmReleasePageMemoryConsumer(MC_NPPOOL, Page);
  98    }
  99 }
 100
 101 /**********************************************************************
 102  * NAME       EXPORTED
 103  * MmFreeNonCachedMemory@8
 104  *
 105  * DESCRIPTION
 106  * Releases a range of noncached memory allocated with
 107  * MmAllocateNonCachedMemory.
 108  *
 109  * ARGUMENTS
 110  * BaseAddress
 111  *  Virtual address to be freed;
 112  *
 113  * NumberOfBytes
 114  *  Size of the region to be freed.
 115  *
 116  * RETURN VALUE
 117  *  None.
 118  *
 119  * NOTE
 120  *  Description taken from include/ddk/mmfuncs.h.
 121  *  Code taken from ntoskrnl/mm/special.c.
 122  *
 123  * REVISIONS
 124  *
 125  * @implemented
 126  */
 127 VOID STDCALL MmFreeNonCachedMemory (IN PVOID BaseAddress,
 128                                     IN ULONG NumberOfBytes)
 129 {
 130    MmLockAddressSpace(MmGetKernelAddressSpace());
 131    MmFreeMemoryAreaByPtr(MmGetKernelAddressSpace(),
 132                          BaseAddress,
 133                          MmFreeNonCachedPage,
 134                          NULL);
 135    MmUnlockAddressSpace(MmGetKernelAddressSpace());
 136 }
 137
 138 /* EOF */