reactos/ntoskrnl/mm/mdl.c

   1 /* $Id: mdl.c,v 1.44 2002/09/08 10:23:34 chorns Exp $
   2  *
   3  * COPYRIGHT:    See COPYING in the top level directory
   4  * PROJECT:      ReactOS kernel
   5  * FILE:         ntoskrnl/mm/mdl.c
   6  * PURPOSE:      Manipulates MDLs
   7  * PROGRAMMER:   David Welch (welch@cwcom.net)
   8  * UPDATE HISTORY:
   9  *               27/05/98: Created
  10  */
  11
  12 /* INCLUDES ****************************************************************/
  13
  14 #include <ddk/ntddk.h>
  15 #include <internal/mm.h>
  16 #include <internal/ps.h>
  17 #include <internal/pool.h>
  18
  19 #define NDEBUG
  20 #include <internal/debug.h>
  21
  22 /* GLOBALS *******************************************************************/
  23
  24 #define TAG_MDL    TAG('M', 'M', 'D', 'L')
  25
  26 #define MI_MDL_MAPPING_REGION_SIZE       (256*1024*1024)
  27
  28 static PVOID MiMdlMappingRegionBase = NULL;
  29 static PULONG MiMdlMappingRegionAllocMap = NULL;
  30 static ULONG MiMdlMappingRegionHighWaterMark = 0;
  31 static KSPIN_LOCK MiMdlMappingRegionLock;
  32
  33 /* FUNCTIONS *****************************************************************/
  34
  35 VOID
  36 MmInitializeMdlImplementation(VOID)
  37 {
  38   MEMORY_AREA* Result;
  39   NTSTATUS Status;
  40
  41   MiMdlMappingRegionBase = NULL;
  42
  43   MmLockAddressSpace(MmGetKernelAddressSpace());
  44   Status = MmCreateMemoryArea(NULL,
  45                               MmGetKernelAddressSpace(),
  46                               MEMORY_AREA_MDL_MAPPING,
  47                               &MiMdlMappingRegionBase,
  48                               MI_MDL_MAPPING_REGION_SIZE,
  49                               0,
  50                               &Result,
  51                               FALSE);
  52   if (!NT_SUCCESS(Status))
  53     {
  54       MmUnlockAddressSpace(MmGetKernelAddressSpace());
  55       KeBugCheck(0);
  56     }
  57   MmUnlockAddressSpace(MmGetKernelAddressSpace());
  58
  59   MiMdlMappingRegionAllocMap =
  60     ExAllocatePool(NonPagedPool,
  61                    MI_MDL_MAPPING_REGION_SIZE / (PAGESIZE * 32));
  62   MiMdlMappingRegionHighWaterMark = 0;
  63   KeInitializeSpinLock(&MiMdlMappingRegionLock);
  64 }
  65
  66 PVOID
  67 MmGetMdlPageAddress(PMDL Mdl, PVOID Offset)
  68 {
  69    PULONG MdlPages;
  70
  71    MdlPages = (PULONG)(Mdl + 1);
  72
  73    return((PVOID)MdlPages[((ULONG)Offset) / PAGESIZE]);
  74 }
  75
  76 VOID STDCALL
  77 MmUnlockPages(PMDL Mdl)
  78 /*
  79  * FUNCTION: Unlocks the physical pages described by a given MDL
  80  * ARGUMENTS:
  81  *      MemoryDescriptorList = MDL describing the buffer to be unlocked
  82  * NOTES: The memory described by the specified MDL must have been locked
  83  * previously by a call to MmProbeAndLockPages. As the pages unlocked, the
  84  * MDL is updated
  85  */
  86 {
  87    ULONG i;
  88    PULONG MdlPages;
  89
  90    /*
  91     * FIXME: I don't know whether this right, but it looks sensible
  92     */
  93    if ((Mdl->MdlFlags & MDL_SOURCE_IS_NONPAGED_POOL) ||
  94        (Mdl->MdlFlags & MDL_IO_PAGE_READ))
  95      {
  96         return;
  97      }
  98
  99    /*
 100     * FIXME: Seems sensible
 101     */
 102    if (!(Mdl->MdlFlags & MDL_PAGES_LOCKED))
 103      {
 104         return;
 105      }
 106
 107    MdlPages = (PULONG)(Mdl + 1);
 108    for (i=0; i<(PAGE_ROUND_UP(Mdl->ByteCount+Mdl->ByteOffset)/PAGESIZE); i++)
 109      {
 110         MmUnlockPage((LARGE_INTEGER)(LONGLONG)MdlPages[i]);
 111         MmDereferencePage((LARGE_INTEGER)(LONGLONG)MdlPages[i]);
 112      }
 113    Mdl->MdlFlags = Mdl->MdlFlags & (~MDL_PAGES_LOCKED);
 114 }
 115
 116 PVOID STDCALL
 117 MmMapLockedPages(PMDL Mdl, KPROCESSOR_MODE AccessMode)
 118 /*
 119  * FUNCTION: Maps the physical pages described by a given MDL
 120  * ARGUMENTS:
 121  *       Mdl = Points to an MDL updated by MmProbeAndLockPages
 122  *       AccessMode = Specifies the portion of the address space to map the
 123  *                    pages.
 124  * RETURNS: The base virtual address that maps the locked pages for the
 125  * range described by the MDL
 126  */
 127 {
 128    PVOID Base;
 129    ULONG i;
 130    PULONG MdlPages;
 131    KIRQL oldIrql;
 132    ULONG RegionSize;
 133
 134    DPRINT("MmMapLockedPages(Mdl %x, AccessMode %x)\n", Mdl, AccessMode);
 135
 136    if (Mdl->MdlFlags & MDL_SOURCE_IS_NONPAGED_POOL)
 137      {
 138        return(Mdl->MappedSystemVa);
 139      }
 140
 141    if (AccessMode == UserMode)
 142      {
 143        DPRINT1("MDL mapping to user-mode not yet handled.\n");
 144        KeBugCheck(0);
 145      }
 146
 147    /* Calculate the number of pages required. */
 148    RegionSize = PAGE_ROUND_UP(Mdl->ByteCount + Mdl->ByteOffset) / PAGESIZE;
 149
 150    /* Allocate that number of pages from the mdl mapping region. */
 151    KeAcquireSpinLock(&MiMdlMappingRegionLock, &oldIrql);
 152    Base = MiMdlMappingRegionBase + MiMdlMappingRegionHighWaterMark * PAGESIZE;
 153    for (i = 0; i < RegionSize; i++)
 154      {
 155        ULONG Offset = MiMdlMappingRegionHighWaterMark + i;
 156        MiMdlMappingRegionAllocMap[Offset / 32] |= (1 << (Offset % 32));
 157      }
 158    MiMdlMappingRegionHighWaterMark += RegionSize;
 159    KeReleaseSpinLock(&MiMdlMappingRegionLock, oldIrql);
 160
 161    /* Set the virtual mappings for the MDL pages. */
 162    MdlPages = (PULONG)(Mdl + 1);
 163    for (i = 0; i < RegionSize; i++)
 164      {
 165        NTSTATUS Status;
 166        Status = MmCreateVirtualMapping(NULL,
 167                                        (PVOID)((ULONG)Base+(i*PAGESIZE)),
 168                                        PAGE_READWRITE,
 169                                        (LARGE_INTEGER)(LONGLONG)MdlPages[i],
 170                                        FALSE);
 171        if (!NT_SUCCESS(Status))
 172          {
 173            DbgPrint("Unable to create virtual mapping\n");
 174            KeBugCheck(0);
 175          }
 176      }
 177
 178    /* Mark the MDL has having being mapped. */
 179    Mdl->MdlFlags = Mdl->MdlFlags | MDL_MAPPED_TO_SYSTEM_VA;
 180    Mdl->MappedSystemVa = Base + Mdl->ByteOffset;
 181    return(Base + Mdl->ByteOffset);
 182 }
 183
 184 VOID STDCALL
 185 MmUnmapLockedPages(PVOID BaseAddress, PMDL Mdl)
 186 /*
 187  * FUNCTION: Releases a mapping set up by a preceding call to MmMapLockedPages
 188  * ARGUMENTS:
 189  *         BaseAddress = Base virtual address to which the pages were mapped
 190  *         MemoryDescriptorList = MDL describing the mapped pages
 191  */
 192 {
 193   KIRQL oldIrql;
 194   ULONG i;
 195   ULONG RegionSize;
 196   ULONG Base;
 197
 198   DPRINT("MmUnmapLockedPages(BaseAddress %x, Mdl %x)\n", Mdl, BaseAddress);
 199
 200   /*
 201    * In this case, the MDL has the same system address as the base address
 202    * so there is no need to free it
 203    */
 204   if (Mdl->MdlFlags & MDL_SOURCE_IS_NONPAGED_POOL)
 205     {
 206       return;
 207     }
 208
 209   /* Calculate the number of pages we mapped. */
 210   RegionSize = PAGE_ROUND_UP(Mdl->ByteCount + Mdl->ByteOffset) / PAGESIZE;
 211
 212   /* Unmap all the pages. */
 213   for (i = 0; i < RegionSize; i++)
 214     {
 215       MmDeleteVirtualMapping(NULL,
 216                              BaseAddress + (i * PAGESIZE),
 217                              FALSE,
 218                              NULL,
 219                              NULL);
 220     }
 221
 222   KeAcquireSpinLock(&MiMdlMappingRegionLock, &oldIrql);
 223   /* Deallocate all the pages used. */
 224   Base = (ULONG)(BaseAddress - MiMdlMappingRegionBase - Mdl->ByteOffset);
 225   Base = Base / PAGESIZE;
 226   for (i = 0; i < RegionSize; i++)
 227     {
 228       ULONG Offset = Base + i;
 229       MiMdlMappingRegionAllocMap[Offset / 32] &= ~(1 << (Offset % 32));
 230     }
 231   /* If all the pages below the high-water mark are free then move it down. */
 232   if ((Base + RegionSize) == MiMdlMappingRegionHighWaterMark)
 233     {
 234       MiMdlMappingRegionHighWaterMark = Base;
 235     }
 236   KeReleaseSpinLock(&MiMdlMappingRegionLock, oldIrql);
 237
 238   /* Reset the MDL state. */
 239   Mdl->MdlFlags = Mdl->MdlFlags & ~MDL_MAPPED_TO_SYSTEM_VA;
 240   Mdl->MappedSystemVa = NULL;
 241 }
 242
 243
 244 VOID
 245 MmBuildMdlFromPages(PMDL Mdl, PULONG Pages)
 246 {
 247    ULONG i;
 248    PULONG MdlPages;
 249
 250    Mdl->MdlFlags = Mdl->MdlFlags |
 251      (MDL_PAGES_LOCKED | MDL_IO_PAGE_READ);
 252
 253    MdlPages = (PULONG)(Mdl + 1);
 254
 255    for (i=0;i<(PAGE_ROUND_UP(Mdl->ByteOffset+Mdl->ByteCount)/PAGESIZE);i++)
 256      {
 257         MdlPages[i] = Pages[i];
 258      }
 259 }
 260
 261 VOID STDCALL MmProbeAndLockPages (PMDL Mdl,
 262                                   KPROCESSOR_MODE AccessMode,
 263                                   LOCK_OPERATION Operation)
 264 /*
 265  * FUNCTION: Probes the specified pages, makes them resident and locks them
 266  * ARGUMENTS:
 267  *          Mdl = MDL to probe
 268  *          AccessMode = Access at which to probe the buffer
 269  *          Operation = Operation to probe for
 270  */
 271 {
 272    PULONG MdlPages;
 273    ULONG i, j;
 274    ULONG NrPages;
 275    NTSTATUS Status;
 276    KPROCESSOR_MODE Mode;
 277    PEPROCESS CurrentProcess;
 278
 279    DPRINT("MmProbeAndLockPages(Mdl %x)\n", Mdl);
 280
 281    /*
 282     * FIXME: Check behaviour against NT
 283     */
 284    if (Mdl->MdlFlags & MDL_PAGES_LOCKED)
 285      {
 286         return;
 287      }
 288
 289    CurrentProcess = PsGetCurrentProcess();
 290
 291    if (Mdl->Process != CurrentProcess)
 292      {
 293        KeAttachProcess(Mdl->Process);
 294      }
 295
 296    if (Mdl->StartVa >= (PVOID)KERNEL_BASE)
 297      {
 298        Mode = KernelMode;
 299      }
 300    else
 301      {
 302        Mode = UserMode;
 303      }
 304
 305    /*
 306     * Lock the pages
 307     */
 308
 309    MmLockAddressSpace(&Mdl->Process->AddressSpace);
 310    MdlPages = (ULONG *)(Mdl + 1);
 311    NrPages = PAGE_ROUND_UP(Mdl->ByteOffset + Mdl->ByteCount) / PAGESIZE;
 312    for (i = 0; i < NrPages; i++)
 313      {
 314         PVOID Address;
 315
 316         Address = Mdl->StartVa + (i*PAGESIZE);
 317
 318         if (!MmIsPagePresent(NULL, Address))
 319           {
 320             Status = MmNotPresentFault(Mode, (ULONG)Address, TRUE);
 321             if (!NT_SUCCESS(Status))
 322               {
 323                 for (j = 0; j < i; j++)
 324                   {
 325                     MmUnlockPage((LARGE_INTEGER)(LONGLONG)MdlPages[j]);
 326                     MmDereferencePage((LARGE_INTEGER)(LONGLONG)MdlPages[j]);
 327                   }
 328                 ExRaiseStatus(Status);
 329               }
 330           }
 331         else
 332           {
 333             MmLockPage(MmGetPhysicalAddressForProcess(NULL, Address));
 334           }
 335         if ((Operation == IoWriteAccess || Operation == IoModifyAccess) &&
 336             (!(MmGetPageProtect(NULL, (PVOID)Address) & PAGE_READWRITE)))
 337           {
 338             Status = MmAccessFault(Mode, (ULONG)Address, TRUE);
 339             if (!NT_SUCCESS(Status))
 340               {
 341                 for (j = 0; j < i; j++)
 342                   {
 343                         MmUnlockPage((LARGE_INTEGER)(LONGLONG)MdlPages[j]);
 344                         MmDereferencePage(
 345                                          (LARGE_INTEGER)(LONGLONG)MdlPages[j]);
 346                   }
 347                 ExRaiseStatus(Status);
 348               }
 349           }
 350         MdlPages[i] = MmGetPhysicalAddressForProcess(NULL, Address).u.LowPart;
 351         MmReferencePage((LARGE_INTEGER)(LONGLONG)MdlPages[i]);
 352      }
 353    MmUnlockAddressSpace(&Mdl->Process->AddressSpace);
 354    if (Mdl->Process != CurrentProcess)
 355      {
 356        KeDetachProcess();
 357      }
 358    Mdl->MdlFlags = Mdl->MdlFlags | MDL_PAGES_LOCKED;
 359 }
 360
 361
 362 ULONG STDCALL MmSizeOfMdl (PVOID        Base,
 363                            ULONG        Length)
 364 /*
 365  * FUNCTION: Returns the number of bytes to allocate for an MDL describing
 366  * the given address range
 367  * ARGUMENTS:
 368  *         Base = base virtual address
 369  *         Length = number of bytes to map
 370  */
 371 {
 372    ULONG len;
 373
 374    len = ADDRESS_AND_SIZE_TO_SPAN_PAGES(Base,Length);
 375
 376    return(sizeof(MDL)+(len*sizeof(ULONG)));
 377 }
 378
 379
 380 VOID STDCALL
 381 MmBuildMdlForNonPagedPool (PMDL Mdl)
 382 /*
 383  * FUNCTION: Fills in the corresponding physical page array of a given
 384  * MDL for a buffer in nonpaged system space
 385  * ARGUMENTS:
 386  *        Mdl = Points to an MDL that supplies a virtual address,
 387  *              byte offset and length
 388  */
 389 {
 390    int va;
 391    Mdl->MdlFlags = Mdl->MdlFlags |
 392      (MDL_SOURCE_IS_NONPAGED_POOL | MDL_PAGES_LOCKED);
 393    for (va=0; va < ((Mdl->Size - sizeof(MDL)) / sizeof(ULONG)); va++)
 394      {
 395         ((PULONG)(Mdl + 1))[va] =
 396             (MmGetPhysicalAddress(Mdl->StartVa + (va * PAGESIZE))).u.LowPart;
 397      }
 398    Mdl->MappedSystemVa = Mdl->StartVa + Mdl->ByteOffset;
 399 }
 400
 401
 402 PMDL STDCALL
 403 MmCreateMdl (PMDL       MemoryDescriptorList,
 404              PVOID      Base,
 405              ULONG      Length)
 406 /*
 407  * FUNCTION: Allocates and initalizes an MDL
 408  * ARGUMENTS:
 409  *          MemoryDescriptorList = Points to MDL to initalize. If this is
 410  *                                 NULL then one is allocated
 411  *          Base = Base virtual address of the buffer
 412  *          Length = Length in bytes of the buffer
 413  * RETURNS: A pointer to initalized MDL
 414  */
 415 {
 416    if (MemoryDescriptorList == NULL)
 417      {
 418         ULONG Size;
 419
 420         Size = MmSizeOfMdl(Base,Length);
 421         MemoryDescriptorList =
 422           (PMDL)ExAllocatePoolWithTag(NonPagedPool, Size, TAG_MDL);
 423         if (MemoryDescriptorList == NULL)
 424           {
 425              return(NULL);
 426           }
 427      }
 428
 429    MmInitializeMdl(MemoryDescriptorList,Base,Length);
 430
 431    return(MemoryDescriptorList);
 432 }
 433
 434 VOID STDCALL
 435 MmMapMemoryDumpMdl (PVOID       Unknown0)
 436 /*
 437  * FIXME: Has something to do with crash dumps. Do we want to implement
 438  * this?
 439  */
 440 {
 441    UNIMPLEMENTED;
 442 }
 443
 444 /* EOF */
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