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 Protect = PAGE_READWRITE|PAGE_SYSTEM|PAGE_NOCACHE|PAGE_WRITETHROUGH;
  52    PHYSICAL_ADDRESS BoundaryAddressMultiple;
  53
  54    BoundaryAddressMultiple.QuadPart = 0;
  55    MmLockAddressSpace(MmGetKernelAddressSpace());
  56    Result = NULL;
  57    Status = MmCreateMemoryArea (MmGetKernelAddressSpace(),
  58                                 MEMORY_AREA_NO_CACHE,
  59                                 &Result,
  60                                 NumberOfBytes,
  61                                 Protect,
  62                                 &marea,
  63                                 FALSE,
  64                                 0,
  65                                 BoundaryAddressMultiple);
  66    MmUnlockAddressSpace(MmGetKernelAddressSpace());
  67
  68    if (!NT_SUCCESS(Status))
  69    {
  70       return (NULL);
  71    }
  72
  73    for (i = 0; i < (PAGE_ROUND_UP(NumberOfBytes) / PAGE_SIZE); i++)
  74    {
  75       PFN_TYPE NPage;
  76
  77       Status = MmRequestPageMemoryConsumer(MC_NPPOOL, TRUE, &NPage);
  78       MmCreateVirtualMapping (NULL,
  79                               (char*)Result + (i * PAGE_SIZE),
  80                               Protect,
  81                               &NPage,
  82                               1);
  83    }
  84    return ((PVOID)Result);
  85 }
  86
  87 VOID STATIC
  88 MmFreeNonCachedPage(PVOID Context, MEMORY_AREA* MemoryArea, PVOID Address,
  89                     PFN_TYPE Page, SWAPENTRY SwapEntry,
  90                     BOOLEAN Dirty)
  91 {
  92    ASSERT(SwapEntry == 0);
  93    if (Page != 0)
  94    {
  95       MmReleasePageMemoryConsumer(MC_NPPOOL, Page);
  96    }
  97 }
  98
  99 /**********************************************************************
 100  * NAME       EXPORTED
 101  * MmFreeNonCachedMemory@8
 102  *
 103  * DESCRIPTION
 104  * Releases a range of noncached memory allocated with
 105  * MmAllocateNonCachedMemory.
 106  *
 107  * ARGUMENTS
 108  * BaseAddress
 109  *  Virtual address to be freed;
 110  *
 111  * NumberOfBytes
 112  *  Size of the region to be freed.
 113  *
 114  * RETURN VALUE
 115  *  None.
 116  *
 117  * NOTE
 118  *  Description taken from include/ddk/mmfuncs.h.
 119  *  Code taken from ntoskrnl/mm/special.c.
 120  *
 121  * REVISIONS
 122  *
 123  * @implemented
 124  */
 125 VOID STDCALL MmFreeNonCachedMemory (IN PVOID BaseAddress,
 126                                     IN ULONG NumberOfBytes)
 127 {
 128    MmLockAddressSpace(MmGetKernelAddressSpace());
 129    MmFreeMemoryAreaByPtr(MmGetKernelAddressSpace(),
 130                          BaseAddress,
 131                          MmFreeNonCachedPage,
 132                          NULL);
 133    MmUnlockAddressSpace(MmGetKernelAddressSpace());
 134 }
 135
 136 /* EOF */