dma.c File Reference

#include <hal.h>
#include <debug.h>

Include dependency graph for dma.c:

Go to the source code of this file.

Macros
#define	NDEBUG
#define	MAX_MAP_REGISTERS   64
#define	TAG_DMA   ' AMD'

Functions
VOID	HalpInitDma (VOID)
HalpGetAdapterMaximumPhysicalAddress
Get the maximum physical address acceptable by the device represented by the passed DMA adapter.
PHYSICAL_ADDRESS NTAPI	HalpGetAdapterMaximumPhysicalAddress (IN PADAPTER_OBJECT AdapterObject)
HalpGrowMapBuffers
Allocate initial, or additional, map buffers for DMA master adapter. Parameters MasterAdapter DMA master adapter to allocate buffers for. SizeOfMapBuffers Size of the map buffers to allocate (not including the size already allocated).
BOOLEAN NTAPI	HalpGrowMapBuffers (IN PADAPTER_OBJECT AdapterObject, IN ULONG SizeOfMapBuffers)
HalpDmaAllocateMasterAdapter
Helper routine to allocate and initialize master adapter object and it's associated map register buffers. See also HalpInitDma
PADAPTER_OBJECT NTAPI	HalpDmaAllocateMasterAdapter (VOID)
HalpDmaAllocateChildAdapter
Helper routine of HalGetAdapter. Allocate child adapter object and fill out some basic fields. See also HalGetAdapter
PADAPTER_OBJECT NTAPI	HalpDmaAllocateChildAdapter (ULONG NumberOfMapRegisters, PDEVICE_DESCRIPTION DeviceDescription)
HalpDmaInitializeEisaAdapter
Setup DMA modes and extended modes for (E)ISA DMA adapter object.
BOOLEAN NTAPI	HalpDmaInitializeEisaAdapter (PADAPTER_OBJECT AdapterObject, PDEVICE_DESCRIPTION DeviceDescription)
HalGetAdapter
Allocate an adapter object for DMA device. Parameters DeviceDescription Structure describing the attributes of the device. NumberOfMapRegisters On return filled with the maximum number of map registers the device driver can allocate for DMA transfer operations. Returns The DMA adapter on success, NULL otherwise. @implemented
PADAPTER_OBJECT NTAPI	HalGetAdapter (PDEVICE_DESCRIPTION DeviceDescription, PULONG NumberOfMapRegisters)
HalpGetDmaAdapter
Internal routine to allocate PnP DMA adapter object. It's exported through HalDispatchTable and used by IoGetDmaAdapter. See also HalGetAdapter
PDMA_ADAPTER NTAPI	HalpGetDmaAdapter (IN PVOID Context, IN PDEVICE_DESCRIPTION DeviceDescription, OUT PULONG NumberOfMapRegisters)
HalPutDmaAdapter
Internal routine to free DMA adapter and resources for reuse. It's exported using the DMA_OPERATIONS interface by HalGetAdapter. See also HalGetAdapter
VOID NTAPI	HalPutDmaAdapter (PADAPTER_OBJECT AdapterObject)
HalAllocateCommonBuffer
Allocates memory that is visible to both the processor(s) and the DMA device. Parameters AdapterObject Adapter object representing the bus master or system dma controller. Length Number of bytes to allocate. LogicalAddress Logical address the driver can use to access the buffer. CacheEnabled Specifies if the memory can be cached. Returns The base virtual address of the memory allocated or NULL on failure. Remarks On real NT x86 systems the CacheEnabled parameter is ignored, we honour it. If it proves to cause problems change it. See also HalFreeCommonBuffer @implemented
PVOID NTAPI	HalAllocateCommonBuffer (PADAPTER_OBJECT AdapterObject, ULONG Length, PPHYSICAL_ADDRESS LogicalAddress, BOOLEAN CacheEnabled)
HalFreeCommonBuffer
Free common buffer allocated with HalAllocateCommonBuffer. See also HalAllocateCommonBuffer @implemented
VOID NTAPI	HalFreeCommonBuffer (PADAPTER_OBJECT AdapterObject, ULONG Length, PHYSICAL_ADDRESS LogicalAddress, PVOID VirtualAddress, BOOLEAN CacheEnabled)
HalpDmaGetDmaAlignment
Internal routine to return the DMA alignment requirement. It's exported using the DMA_OPERATIONS interface by HalGetAdapter. See also HalGetAdapter
ULONG NTAPI	HalpDmaGetDmaAlignment (PADAPTER_OBJECT AdapterObject)
ULONG NTAPI	HalReadDmaCounter (PADAPTER_OBJECT AdapterObject)
HalpGrowMapBufferWorker
Helper routine of HalAllocateAdapterChannel for allocating map registers at PASSIVE_LEVEL in work item.
VOID NTAPI	HalpGrowMapBufferWorker (PVOID DeferredContext)
HalAllocateAdapterChannel
Setup map registers for an adapter object. Parameters AdapterObject Pointer to an ADAPTER_OBJECT to set up. WaitContextBlock Context block to be used with ExecutionRoutine. NumberOfMapRegisters Number of map registers requested. ExecutionRoutine Callback to call when map registers are allocated. Returns If not enough map registers can be allocated then STATUS_INSUFFICIENT_RESOURCES is returned. If the function succeeds or the callback is queued for later delivering then STATUS_SUCCESS is returned. See also IoFreeAdapterChannel @implemented
NTSTATUS NTAPI	HalAllocateAdapterChannel (PADAPTER_OBJECT AdapterObject, PWAIT_CONTEXT_BLOCK WaitContextBlock, ULONG NumberOfMapRegisters, PDRIVER_CONTROL ExecutionRoutine)
IoFreeAdapterChannel
Free DMA resources allocated by IoAllocateAdapterChannel. Parameters AdapterObject Adapter object with resources to free. Remarks This function releases map registers registers assigned to the DMA adapter. After releasing the adapter, it checks the adapter's queue and runs each queued device object in series until the queue is empty. This is the only way the device queue is emptied. See also IoAllocateAdapterChannel @implemented
VOID NTAPI	IoFreeAdapterChannel (PADAPTER_OBJECT AdapterObject)
IoFreeMapRegisters
Free map registers reserved by the system for a DMA. Parameters AdapterObject DMA adapter to free map registers on. MapRegisterBase Handle to map registers to free. NumberOfRegisters Number of map registers to be freed. @implemented
VOID NTAPI	IoFreeMapRegisters (IN PADAPTER_OBJECT AdapterObject, IN PVOID MapRegisterBase, IN ULONG NumberOfMapRegisters)
HalpCopyBufferMap
Helper function for copying data from/to map register buffers. See also IoFlushAdapterBuffers, IoMapTransfer
VOID NTAPI	HalpCopyBufferMap (PMDL Mdl, PROS_MAP_REGISTER_ENTRY MapRegisterBase, PVOID CurrentVa, ULONG Length, BOOLEAN WriteToDevice)
IoFlushAdapterBuffers
Flush any data remaining in the DMA controller's memory into the host memory. Parameters AdapterObject The adapter object to flush. Mdl Original MDL to flush data into. MapRegisterBase Map register base that was just used by IoMapTransfer, etc. CurrentVa Offset into Mdl to be flushed into, same as was passed to IoMapTransfer. Length Length of the buffer to be flushed into. WriteToDevice TRUE if it's a write, FALSE if it's a read. Returns TRUE in all cases. Remarks This copies data from the map register-backed buffer to the user's target buffer. Data are not in the user buffer until this function is called. For slave DMA transfers the controller channel is masked effectively stopping the current transfer. @unimplemented.
BOOLEAN NTAPI	IoFlushAdapterBuffers (PADAPTER_OBJECT AdapterObject, PMDL Mdl, PVOID MapRegisterBase, PVOID CurrentVa, ULONG Length, BOOLEAN WriteToDevice)
IoMapTransfer
Map a DMA for transfer and do the DMA if it's a slave. Parameters AdapterObject Adapter object to do the DMA on. Bus-master may pass NULL. Mdl Locked-down user buffer to DMA in to or out of. MapRegisterBase Handle to map registers to use for this dma. CurrentVa Index into Mdl to transfer into/out of. Length Length of transfer. Number of bytes actually transferred on output. WriteToDevice TRUE if it's an output DMA, FALSE otherwise. Returns A logical address that can be used to program a DMA controller, it's not meaningful for slave DMA device. Remarks This function does a copyover to contiguous memory <16MB represented by the map registers if needed. If the buffer described by MDL can be used as is no copyover is done. If it's a slave transfer, this function actually performs it. @implemented
PHYSICAL_ADDRESS NTAPI	IoMapTransfer (IN PADAPTER_OBJECT AdapterObject, IN PMDL Mdl, IN PVOID MapRegisterBase, IN PVOID CurrentVa, IN OUT PULONG Length, IN BOOLEAN WriteToDevice)
HalFlushCommonBuffer
@implemented
BOOLEAN NTAPI	HalFlushCommonBuffer (IN PADAPTER_OBJECT AdapterObject, IN ULONG Length, IN PHYSICAL_ADDRESS LogicalAddress, IN PVOID VirtualAddress)
PVOID NTAPI	HalAllocateCrashDumpRegisters (IN PADAPTER_OBJECT AdapterObject, IN OUT PULONG NumberOfMapRegisters)

Variables
static KEVENT	HalpDmaLock
static LIST_ENTRY	HalpDmaAdapterList
static PADAPTER_OBJECT	HalpEisaAdapter [8]
static BOOLEAN	HalpEisaDma
static PADAPTER_OBJECT	HalpMasterAdapter
static const ULONG_PTR	HalpEisaPortPage [8]
static DMA_OPERATIONS	HalpDmaOperations

Macro Definition Documentation

MAX_MAP_REGISTERS

#define MAX_MAP_REGISTERS   64

Definition at line 114 of file dma.c.

NDEBUG

#define NDEBUG

Definition at line 74 of file dma.c.

TAG_DMA

#define TAG_DMA   ' AMD'

Definition at line 116 of file dma.c.

Function Documentation

HalAllocateAdapterChannel()

NTSTATUS NTAPI HalAllocateAdapterChannel	(	PADAPTER_OBJECT	AdapterObject,
		PWAIT_CONTEXT_BLOCK	WaitContextBlock,
		ULONG	NumberOfMapRegisters,
		PDRIVER_CONTROL	ExecutionRoutine
	)

Definition at line 1067 of file dma.c.

{
   PADAPTER_OBJECT MasterAdapter;
   PGROW_WORK_ITEM WorkItem;
   ULONG Index = MAXULONG;
   ULONG Result;
   KIRQL OldIrql;

   ASSERT(KeGetCurrentIrql() == DISPATCH_LEVEL);

   /* Set up the wait context block in case we can't run right away. */
   WaitContextBlock->DeviceRoutine = ExecutionRoutine;
   WaitContextBlock->NumberOfMapRegisters = NumberOfMapRegisters;

   /* Returns true if queued, else returns false and sets the queue to busy */
   if (KeInsertDeviceQueue(&AdapterObject->ChannelWaitQueue, &WaitContextBlock->WaitQueueEntry))
      return STATUS_SUCCESS;

   MasterAdapter = AdapterObject->MasterAdapter;

   AdapterObject->NumberOfMapRegisters = NumberOfMapRegisters;
   AdapterObject->CurrentWcb = WaitContextBlock;

   if (NumberOfMapRegisters && AdapterObject->NeedsMapRegisters)
   {
      if (NumberOfMapRegisters > AdapterObject->MapRegistersPerChannel)
      {
         AdapterObject->NumberOfMapRegisters = 0;
         IoFreeAdapterChannel(AdapterObject);
         return STATUS_INSUFFICIENT_RESOURCES;
      }

      /*
       * Get the map registers. This is partly complicated by the fact
       * that new map registers can only be allocated at PASSIVE_LEVEL
       * and we're currently at DISPATCH_LEVEL. The following code has
       * two code paths:
       *
       * - If there is no adapter queued for map register allocation,
       *   try to see if enough contiguous map registers are present.
       *   In case they're we can just get them and proceed further.
       *
       * - If some adapter is already present in the queue we must
       *   respect the order of adapters asking for map registers and
       *   so the fast case described above can't take place.
       *   This case is also entered if not enough coniguous map
       *   registers are present.
       *
       *   A work queue item is allocated and queued, the adapter is
       *   also queued into the master adapter queue. The worker
       *   routine does the job of allocating the map registers at
       *   PASSIVE_LEVEL and calling the ExecutionRoutine.
       */

      OldIrql = KfAcquireSpinLock(&MasterAdapter->SpinLock);

      if (IsListEmpty(&MasterAdapter->AdapterQueue))
      {
         Index = RtlFindClearBitsAndSet(
            MasterAdapter->MapRegisters, NumberOfMapRegisters, 0);
         if (Index != MAXULONG)
         {
            AdapterObject->MapRegisterBase =
               MasterAdapter->MapRegisterBase + Index;
            if (!AdapterObject->ScatterGather)
            {
               AdapterObject->MapRegisterBase =
                  (PROS_MAP_REGISTER_ENTRY)(
                     (ULONG_PTR)AdapterObject->MapRegisterBase |
                     MAP_BASE_SW_SG);
            }
         }
      }

      if (Index == MAXULONG)
      {
         WorkItem = ExAllocatePoolWithTag(
            NonPagedPool, sizeof(GROW_WORK_ITEM), TAG_DMA);
         if (WorkItem == NULL)
         {
            KfReleaseSpinLock(&MasterAdapter->SpinLock, OldIrql);
            AdapterObject->NumberOfMapRegisters = 0;
            IoFreeAdapterChannel(AdapterObject);
            return STATUS_INSUFFICIENT_RESOURCES;
         }

         InsertTailList(&MasterAdapter->AdapterQueue, &AdapterObject->AdapterQueue);

         ExInitializeWorkItem(
            &WorkItem->WorkQueueItem, HalpGrowMapBufferWorker, WorkItem);
         WorkItem->AdapterObject = AdapterObject;
         WorkItem->NumberOfMapRegisters = NumberOfMapRegisters;

         ExQueueWorkItem(&WorkItem->WorkQueueItem, DelayedWorkQueue);

         KfReleaseSpinLock(&MasterAdapter->SpinLock, OldIrql);

         return STATUS_SUCCESS;
      }

      KfReleaseSpinLock(&MasterAdapter->SpinLock, OldIrql);
   }
   else
   {
      AdapterObject->MapRegisterBase = NULL;
      AdapterObject->NumberOfMapRegisters = 0;
   }

   AdapterObject->CurrentWcb = WaitContextBlock;

   Result = ExecutionRoutine(
      WaitContextBlock->DeviceObject, WaitContextBlock->CurrentIrp,
      AdapterObject->MapRegisterBase, WaitContextBlock->DeviceContext);

   /*
    * Possible return values:
    *
    * - KeepObject
    *   Don't free any resources, the ADAPTER_OBJECT is still in use and
    *   the caller will call IoFreeAdapterChannel later.
    *
    * - DeallocateObject
    *   Deallocate the map registers and release the ADAPTER_OBJECT, so
    *   someone else can use it.
    *
    * - DeallocateObjectKeepRegisters
    *   Release the ADAPTER_OBJECT, but hang on to the map registers. The
    *   client will later call IoFreeMapRegisters.
    *
    * NOTE:
    * IoFreeAdapterChannel runs the queue, so it must be called unless
    * the adapter object is not to be freed.
    */

   if (Result == DeallocateObject)
   {
      IoFreeAdapterChannel(AdapterObject);
   }
   else if (Result == DeallocateObjectKeepRegisters)
   {
      AdapterObject->NumberOfMapRegisters = 0;
      IoFreeAdapterChannel(AdapterObject);
   }

   return STATUS_SUCCESS;
}

HalAllocateCommonBuffer()

PVOID NTAPI HalAllocateCommonBuffer	(	PADAPTER_OBJECT	AdapterObject,
		ULONG	Length,
		PPHYSICAL_ADDRESS	LogicalAddress,
		BOOLEAN	CacheEnabled
	)

Definition at line 849 of file dma.c.

{
   PHYSICAL_ADDRESS LowestAcceptableAddress;
   PHYSICAL_ADDRESS HighestAcceptableAddress;
   PHYSICAL_ADDRESS BoundryAddressMultiple;
   PVOID VirtualAddress;

   LowestAcceptableAddress.QuadPart = 0;
   HighestAcceptableAddress =
      HalpGetAdapterMaximumPhysicalAddress(AdapterObject);
   BoundryAddressMultiple.QuadPart = 0;

   /*
    * For bus-master DMA devices the buffer mustn't cross 4Gb boundary. For
    * slave DMA devices the 64Kb boundary mustn't be crossed since the
    * controller wouldn't be able to handle it.
    */

   if (AdapterObject->MasterDevice)
      BoundryAddressMultiple.HighPart = 1;
   else
      BoundryAddressMultiple.LowPart = 0x10000;

   VirtualAddress = MmAllocateContiguousMemorySpecifyCache(
      Length, LowestAcceptableAddress, HighestAcceptableAddress,
      BoundryAddressMultiple, CacheEnabled ? MmCached : MmNonCached);
   if (VirtualAddress == NULL)
      return NULL;

   *LogicalAddress = MmGetPhysicalAddress(VirtualAddress);

   return VirtualAddress;
}

HalAllocateCrashDumpRegisters()

PVOID NTAPI HalAllocateCrashDumpRegisters	(	IN PADAPTER_OBJECT	AdapterObject,
		IN OUT PULONG	NumberOfMapRegisters
	)

Definition at line 1964 of file dma.c.

{
    PADAPTER_OBJECT MasterAdapter = AdapterObject->MasterAdapter;
    ULONG MapRegisterNumber;

    /* Check if it needs map registers */
    if (AdapterObject->NeedsMapRegisters)
    {
        /* Check if we have enough */
        if (*NumberOfMapRegisters > AdapterObject->MapRegistersPerChannel)
        {
            /* We don't, fail */
            AdapterObject->NumberOfMapRegisters = 0;
            return NULL;
        }

        /* Try to find free map registers */
        MapRegisterNumber = RtlFindClearBitsAndSet(MasterAdapter->MapRegisters,
                                                   *NumberOfMapRegisters,
                                                   0);

        /* Check if nothing was found */
        if (MapRegisterNumber == MAXULONG)
        {
            /* No free registers found, so use the base registers */
            RtlSetBits(MasterAdapter->MapRegisters,
                       0,
                       *NumberOfMapRegisters);
            MapRegisterNumber = 0;
        }

        /* Calculate the new base */
        AdapterObject->MapRegisterBase =
            (PROS_MAP_REGISTER_ENTRY)(MasterAdapter->MapRegisterBase +
                                      MapRegisterNumber);

        /* Check if scatter gather isn't supported */
        if (!AdapterObject->ScatterGather)
        {
            /* Set the flag */
            AdapterObject->MapRegisterBase =
                (PROS_MAP_REGISTER_ENTRY)
                ((ULONG_PTR)AdapterObject->MapRegisterBase | MAP_BASE_SW_SG);
        }
    }
    else
    {
        AdapterObject->MapRegisterBase = NULL;
        AdapterObject->NumberOfMapRegisters = 0;
    }

    /* Return the base */
    return AdapterObject->MapRegisterBase;
}

HalFlushCommonBuffer()

BOOLEAN NTAPI HalFlushCommonBuffer	(	IN PADAPTER_OBJECT	AdapterObject,
		IN ULONG	Length,
		IN PHYSICAL_ADDRESS	LogicalAddress,
		IN PVOID	VirtualAddress
	)

Definition at line 1950 of file dma.c.

{
    /* Function always returns true */
    return TRUE;
}

HalFreeCommonBuffer()

VOID NTAPI HalFreeCommonBuffer	(	PADAPTER_OBJECT	AdapterObject,
		ULONG	Length,
		PHYSICAL_ADDRESS	LogicalAddress,
		PVOID	VirtualAddress,
		BOOLEAN	CacheEnabled
	)

Definition at line 898 of file dma.c.

{
   MmFreeContiguousMemory(VirtualAddress);
}

HalGetAdapter()

PADAPTER_OBJECT NTAPI HalGetAdapter	(	PDEVICE_DESCRIPTION	DeviceDescription,
		PULONG	NumberOfMapRegisters
	)

Definition at line 591 of file dma.c.

{
   PADAPTER_OBJECT AdapterObject = NULL;
   PADAPTER_OBJECT MasterAdapter;
   BOOLEAN EisaAdapter;
   ULONG MapRegisters;
   ULONG MaximumLength;

   /* Validate parameters in device description */
   if (DeviceDescription->Version > DEVICE_DESCRIPTION_VERSION2)
      return NULL;

   /*
    * See if we're going to use ISA/EISA DMA adapter. These adapters are
    * special since they're reused.
    *
    * Also note that we check for channel number since there are only 8 DMA
    * channels on ISA, so any request above this requires new adapter.
    */

   if (DeviceDescription->InterfaceType == Isa || !DeviceDescription->Master)
   {
      if (DeviceDescription->InterfaceType == Isa &&
          DeviceDescription->DmaChannel >= 8)
         EisaAdapter = FALSE;
      else
         EisaAdapter = TRUE;
   }
   else
   {
      EisaAdapter = FALSE;
   }

   /*
    * Disallow creating adapter for ISA/EISA DMA channel 4 since it's used
    * for cascading the controllers and it's not available for software use.
    */

   if (EisaAdapter && DeviceDescription->DmaChannel == 4)
      return NULL;

   /*
    * Calculate the number of map registers.
    *
    * - For EISA and PCI scatter/gather no map registers are needed.
    * - For ISA slave scatter/gather one map register is needed.
    * - For all other cases the number of map registers depends on
    *   DeviceDescription->MaximumLength.
    */

   MaximumLength = DeviceDescription->MaximumLength & MAXLONG;
   if (DeviceDescription->ScatterGather &&
       (DeviceDescription->InterfaceType == Eisa ||
        DeviceDescription->InterfaceType == PCIBus))
   {
      MapRegisters = 0;
   }
   else if (DeviceDescription->ScatterGather &&
            !DeviceDescription->Master)
   {
      MapRegisters = 1;
   }
   else
   {
      /*
       * In the equation below the additional map register added by
       * the "+1" accounts for the case when a transfer does not start
       * at a page-aligned address.
       */
      MapRegisters = BYTES_TO_PAGES(MaximumLength) + 1;
      if (MapRegisters > 16)
         MapRegisters = 16;
   }

   /*
    * Acquire the DMA lock that is used to protect adapter lists and
    * EISA adapter array.
    */

   KeWaitForSingleObject(&HalpDmaLock, Executive, KernelMode,
                         FALSE, NULL);

   /*
    * Now we must get ahold of the adapter object. For first eight ISA/EISA
    * channels there are static adapter objects that are reused and updated
    * on succesive HalGetAdapter calls. In other cases a new adapter object
    * is always created and it's to the DMA adapter list (HalpDmaAdapterList).
    */

   if (EisaAdapter)
   {
      AdapterObject = HalpEisaAdapter[DeviceDescription->DmaChannel];
      if (AdapterObject != NULL)
      {
         if (AdapterObject->NeedsMapRegisters &&
             MapRegisters > AdapterObject->MapRegistersPerChannel)
            AdapterObject->MapRegistersPerChannel = MapRegisters;
      }
   }

   if (AdapterObject == NULL)
   {
      AdapterObject = HalpDmaAllocateChildAdapter(
         MapRegisters, DeviceDescription);
      if (AdapterObject == NULL)
      {
         KeSetEvent(&HalpDmaLock, 0, 0);
         return NULL;
      }

      if (EisaAdapter)
      {
         HalpEisaAdapter[DeviceDescription->DmaChannel] = AdapterObject;
      }

      if (MapRegisters > 0)
      {
         AdapterObject->NeedsMapRegisters = TRUE;
         MasterAdapter = HalpMasterAdapter;
         AdapterObject->MapRegistersPerChannel = MapRegisters;

         /*
          * FIXME: Verify that the following makes sense. Actually
          * MasterAdapter->NumberOfMapRegisters contains even the number
          * of gaps, so this will not work correctly all the time. It
          * doesn't matter much since it's only optimization to avoid
          * queuing work items in HalAllocateAdapterChannel.
          */

         MasterAdapter->CommittedMapRegisters += MapRegisters;
         if (MasterAdapter->CommittedMapRegisters > MasterAdapter->NumberOfMapRegisters)
            HalpGrowMapBuffers(MasterAdapter, 0x10000);
      }
      else
      {
         AdapterObject->NeedsMapRegisters = FALSE;
         if (DeviceDescription->Master)
            AdapterObject->MapRegistersPerChannel = BYTES_TO_PAGES(MaximumLength) + 1;
         else
            AdapterObject->MapRegistersPerChannel = 1;
      }
   }

   if (!EisaAdapter)
      InsertTailList(&HalpDmaAdapterList, &AdapterObject->AdapterList);

   /*
    * Release the DMA lock. HalpDmaAdapterList and HalpEisaAdapter will
    * no longer be touched, so we don't need it.
    */

   KeSetEvent(&HalpDmaLock, 0, 0);

   /*
    * Setup the values in the adapter object that are common for all
    * types of buses.
    */

   if (DeviceDescription->Version >= DEVICE_DESCRIPTION_VERSION1)
      AdapterObject->IgnoreCount = DeviceDescription->IgnoreCount;
   else
      AdapterObject->IgnoreCount = 0;

   AdapterObject->Dma32BitAddresses = DeviceDescription->Dma32BitAddresses;
   AdapterObject->Dma64BitAddresses = DeviceDescription->Dma64BitAddresses;
   AdapterObject->ScatterGather = DeviceDescription->ScatterGather;
   AdapterObject->MasterDevice = DeviceDescription->Master;
   *NumberOfMapRegisters = AdapterObject->MapRegistersPerChannel;

   /*
    * For non-(E)ISA adapters we have already done all the work. On the
    * other hand for (E)ISA adapters we must still setup the DMA modes
    * and prepare the controller.
    */

   if (EisaAdapter)
   {
      if (!HalpDmaInitializeEisaAdapter(AdapterObject, DeviceDescription))
      {
         ObDereferenceObject(AdapterObject);
         return NULL;
      }
   }

   return AdapterObject;
}

HalpCopyBufferMap()

VOID NTAPI HalpCopyBufferMap	(	PMDL	Mdl,
		PROS_MAP_REGISTER_ENTRY	MapRegisterBase,
		PVOID	CurrentVa,
		ULONG	Length,
		BOOLEAN	WriteToDevice
	)

Definition at line 1468 of file dma.c.

{
   ULONG CurrentLength;
   ULONG_PTR CurrentAddress;
   ULONG ByteOffset;
   PVOID VirtualAddress;

   VirtualAddress = MmGetSystemAddressForMdlSafe(Mdl, HighPagePriority);
   if (VirtualAddress == NULL)
   {
      /*
       * NOTE: On real NT a mechanism with reserved pages is implemented
       * to handle this case in a slow, but graceful non-fatal way.
       */
      KeBugCheckEx(HAL_MEMORY_ALLOCATION, PAGE_SIZE, 0, (ULONG_PTR)__FILE__, 0);
   }

   CurrentAddress = (ULONG_PTR)VirtualAddress +
                    (ULONG_PTR)CurrentVa -
                    (ULONG_PTR)MmGetMdlVirtualAddress(Mdl);

   while (Length > 0)
   {
      ByteOffset = BYTE_OFFSET(CurrentAddress);
      CurrentLength = PAGE_SIZE - ByteOffset;
      if (CurrentLength > Length)
         CurrentLength = Length;

      if (WriteToDevice)
      {
         RtlCopyMemory(
            (PVOID)((ULONG_PTR)MapRegisterBase->VirtualAddress + ByteOffset),
            (PVOID)CurrentAddress,
            CurrentLength);
      }
      else
      {
         RtlCopyMemory(
            (PVOID)CurrentAddress,
            (PVOID)((ULONG_PTR)MapRegisterBase->VirtualAddress + ByteOffset),
            CurrentLength);
      }

      Length -= CurrentLength;
      CurrentAddress += CurrentLength;
      MapRegisterBase++;
   }
}

Referenced by IoFlushAdapterBuffers(), and IoMapTransfer().

HalpDmaAllocateChildAdapter()

PADAPTER_OBJECT NTAPI HalpDmaAllocateChildAdapter	(	ULONG	NumberOfMapRegisters,
		PDEVICE_DESCRIPTION	DeviceDescription
	)

Definition at line 391 of file dma.c.

{
   PADAPTER_OBJECT AdapterObject;
   OBJECT_ATTRIBUTES ObjectAttributes;
   NTSTATUS Status;
   HANDLE Handle;

   InitializeObjectAttributes(
      &ObjectAttributes,
      NULL,
      OBJ_KERNEL_HANDLE | OBJ_PERMANENT,
      NULL,
      NULL);

   Status = ObCreateObject(
      KernelMode,
      IoAdapterObjectType,
      &ObjectAttributes,
      KernelMode,
      NULL,
      sizeof(ADAPTER_OBJECT),
      0,
      0,
      (PVOID)&AdapterObject);
   if (!NT_SUCCESS(Status))
      return NULL;

   Status = ObReferenceObjectByPointer(
      AdapterObject,
      FILE_READ_DATA | FILE_WRITE_DATA,
      IoAdapterObjectType,
      KernelMode);
   if (!NT_SUCCESS(Status))
      return NULL;

   RtlZeroMemory(AdapterObject, sizeof(ADAPTER_OBJECT));

   Status = ObInsertObject(
      AdapterObject,
      NULL,
      FILE_READ_DATA | FILE_WRITE_DATA,
      0,
      NULL,
      &Handle);
   if (!NT_SUCCESS(Status))
      return NULL;

   ZwClose(Handle);

   AdapterObject->DmaHeader.Version = (USHORT)DeviceDescription->Version;
   AdapterObject->DmaHeader.Size = sizeof(ADAPTER_OBJECT);
   AdapterObject->DmaHeader.DmaOperations = &HalpDmaOperations;
   AdapterObject->MapRegistersPerChannel = 1;
   AdapterObject->Dma32BitAddresses = DeviceDescription->Dma32BitAddresses;
   AdapterObject->ChannelNumber = 0xFF;
   AdapterObject->MasterAdapter = HalpMasterAdapter;
   KeInitializeDeviceQueue(&AdapterObject->ChannelWaitQueue);

   return AdapterObject;
}

Referenced by HalGetAdapter().

HalpDmaAllocateMasterAdapter()

PADAPTER_OBJECT NTAPI HalpDmaAllocateMasterAdapter

(

VOID

)

Definition at line 332 of file dma.c.

{
   PADAPTER_OBJECT MasterAdapter;
   ULONG Size, SizeOfBitmap;

   SizeOfBitmap = MAX_MAP_REGISTERS;
   Size = sizeof(ADAPTER_OBJECT);
   Size += sizeof(RTL_BITMAP);
   Size += (SizeOfBitmap + 7) >> 3;

   MasterAdapter = ExAllocatePoolWithTag(NonPagedPool, Size, TAG_DMA);
   if (MasterAdapter == NULL)
      return NULL;

   RtlZeroMemory(MasterAdapter, Size);

   KeInitializeSpinLock(&MasterAdapter->SpinLock);
   InitializeListHead(&MasterAdapter->AdapterQueue);

   MasterAdapter->MapRegisters = (PVOID)(MasterAdapter + 1);
   RtlInitializeBitMap(
      MasterAdapter->MapRegisters,
      (PULONG)(MasterAdapter->MapRegisters + 1),
      SizeOfBitmap);
   RtlSetAllBits(MasterAdapter->MapRegisters);
   MasterAdapter->NumberOfMapRegisters = 0;
   MasterAdapter->CommittedMapRegisters = 0;

   MasterAdapter->MapRegisterBase = ExAllocatePoolWithTag(
      NonPagedPool,
      SizeOfBitmap * sizeof(ROS_MAP_REGISTER_ENTRY),
      TAG_DMA);
   if (MasterAdapter->MapRegisterBase == NULL)
   {
      ExFreePool(MasterAdapter);
      return NULL;
   }

   RtlZeroMemory(MasterAdapter->MapRegisterBase,
                 SizeOfBitmap * sizeof(ROS_MAP_REGISTER_ENTRY));
   if (!HalpGrowMapBuffers(MasterAdapter, 0x10000))
   {
      ExFreePool(MasterAdapter);
      return NULL;
   }

   return MasterAdapter;
}

Referenced by HalpInitDma().

HalpDmaGetDmaAlignment()

ULONG NTAPI HalpDmaGetDmaAlignment

(

PADAPTER_OBJECT

AdapterObject

)

Definition at line 918 of file dma.c.

{
   return 1;
}

HalpDmaInitializeEisaAdapter()

BOOLEAN NTAPI HalpDmaInitializeEisaAdapter	(	PADAPTER_OBJECT	AdapterObject,
		PDEVICE_DESCRIPTION	DeviceDescription
	)

Definition at line 461 of file dma.c.

{
   UCHAR Controller;
   DMA_MODE DmaMode = {{0 }};
   DMA_EXTENDED_MODE ExtendedMode = {{ 0 }};
   PVOID AdapterBaseVa;

   Controller = (DeviceDescription->DmaChannel & 4) ? 2 : 1;

   if (Controller == 1)
      AdapterBaseVa = (PVOID)FIELD_OFFSET(EISA_CONTROL, DmaController1);
   else
      AdapterBaseVa = (PVOID)FIELD_OFFSET(EISA_CONTROL, DmaController2);

   AdapterObject->AdapterNumber = Controller;
   AdapterObject->ChannelNumber = (UCHAR)(DeviceDescription->DmaChannel & 3);
   AdapterObject->PagePort = (PUCHAR)HalpEisaPortPage[DeviceDescription->DmaChannel];
   AdapterObject->Width16Bits = FALSE;
   AdapterObject->AdapterBaseVa = AdapterBaseVa;

   if (HalpEisaDma)
   {
      ExtendedMode.ChannelNumber = AdapterObject->ChannelNumber;

      switch (DeviceDescription->DmaSpeed)
      {
         case Compatible: ExtendedMode.TimingMode = COMPATIBLE_TIMING; break;
         case TypeA: ExtendedMode.TimingMode = TYPE_A_TIMING; break;
         case TypeB: ExtendedMode.TimingMode = TYPE_B_TIMING; break;
         case TypeC: ExtendedMode.TimingMode = BURST_TIMING; break;
         default:
            return FALSE;
      }

      switch (DeviceDescription->DmaWidth)
      {
         case Width8Bits: ExtendedMode.TransferSize = B_8BITS; break;
         case Width16Bits: ExtendedMode.TransferSize = B_16BITS; break;
         case Width32Bits: ExtendedMode.TransferSize = B_32BITS; break;
         default:
            return FALSE;
      }

      if (Controller == 1)
         WRITE_PORT_UCHAR((PUCHAR)FIELD_OFFSET(EISA_CONTROL, DmaExtendedMode1),
                          ExtendedMode.Byte);
      else
         WRITE_PORT_UCHAR((PUCHAR)FIELD_OFFSET(EISA_CONTROL, DmaExtendedMode2),
                          ExtendedMode.Byte);
   }
   else
   {
      /*
       * Validate setup for non-busmaster DMA adapter. Secondary controller
       * supports only 16-bit transfers and main controller supports only
       * 8-bit transfers. Anything else is invalid.
       */

      if (!DeviceDescription->Master)
      {
         if (Controller == 2 && DeviceDescription->DmaWidth == Width16Bits)
            AdapterObject->Width16Bits = TRUE;
         else if (Controller != 1 || DeviceDescription->DmaWidth != Width8Bits)
            return FALSE;
      }
   }

   DmaMode.Channel = AdapterObject->ChannelNumber;
   DmaMode.AutoInitialize = DeviceDescription->AutoInitialize;

   /*
    * Set the DMA request mode.
    *
    * For (E)ISA bus master devices just unmask (enable) the DMA channel
    * and set it to cascade mode. Otherwise just select the right one
    * bases on the passed device description.
    */

   if (DeviceDescription->Master)
   {
      DmaMode.RequestMode = CASCADE_REQUEST_MODE;
      if (Controller == 1)
      {
         /* Set the Request Data */
         WRITE_PORT_UCHAR(&((PDMA1_CONTROL)AdapterBaseVa)->Mode,
                          DmaMode.Byte);
         /* Unmask DMA Channel */
         WRITE_PORT_UCHAR(&((PDMA1_CONTROL)AdapterBaseVa)->SingleMask,
                          AdapterObject->ChannelNumber | DMA_CLEARMASK);
      } else {
         /* Set the Request Data */
         WRITE_PORT_UCHAR(&((PDMA2_CONTROL)AdapterBaseVa)->Mode,
                          DmaMode.Byte);
         /* Unmask DMA Channel */
         WRITE_PORT_UCHAR(&((PDMA2_CONTROL)AdapterBaseVa)->SingleMask,
                          AdapterObject->ChannelNumber | DMA_CLEARMASK);
      }
   }
   else
   {
      if (DeviceDescription->DemandMode)
         DmaMode.RequestMode = DEMAND_REQUEST_MODE;
      else
         DmaMode.RequestMode = SINGLE_REQUEST_MODE;
   }

   AdapterObject->AdapterMode = DmaMode;

   return TRUE;
}

Referenced by HalGetAdapter().

HalpGetAdapterMaximumPhysicalAddress()

PHYSICAL_ADDRESS NTAPI HalpGetAdapterMaximumPhysicalAddress

(

IN PADAPTER_OBJECT

AdapterObject

)

Definition at line 167 of file dma.c.

{
   PHYSICAL_ADDRESS HighestAddress;

   if (AdapterObject->MasterDevice)
   {
      if (AdapterObject->Dma64BitAddresses)
      {
         HighestAddress.QuadPart = 0xFFFFFFFFFFFFFFFFULL;
         return HighestAddress;
      }
      else if (AdapterObject->Dma32BitAddresses)
      {
         HighestAddress.QuadPart = 0xFFFFFFFF;
         return HighestAddress;
      }
   }

   HighestAddress.QuadPart = 0xFFFFFF;
   return HighestAddress;
}

Referenced by HalAllocateCommonBuffer(), HalpGrowMapBuffers(), IoFlushAdapterBuffers(), and IoMapTransfer().

HalpGetDmaAdapter()

PDMA_ADAPTER NTAPI HalpGetDmaAdapter	(	IN PVOID	Context,
		IN PDEVICE_DESCRIPTION	DeviceDescription,
		OUT PULONG	NumberOfMapRegisters
	)

Definition at line 790 of file dma.c.

{
   return &HalGetAdapter(DeviceDescription, NumberOfMapRegisters)->DmaHeader;
}

Referenced by HalpInitDma().

HalpGrowMapBuffers()

BOOLEAN NTAPI HalpGrowMapBuffers	(	IN PADAPTER_OBJECT	AdapterObject,
		IN ULONG	SizeOfMapBuffers
	)

Definition at line 203 of file dma.c.

{
   PVOID VirtualAddress;
   PHYSICAL_ADDRESS PhysicalAddress;
   PHYSICAL_ADDRESS HighestAcceptableAddress;
   PHYSICAL_ADDRESS LowestAcceptableAddress;
   PHYSICAL_ADDRESS BoundryAddressMultiple;
   KIRQL OldIrql;
   ULONG MapRegisterCount;

   /* FIXME: Check if enough map register slots are available. */

   MapRegisterCount = BYTES_TO_PAGES(SizeOfMapBuffers);

   /*
    * Allocate memory for the new map registers. For 32-bit adapters we use
    * two passes in order not to waste scare resource (low memory).
    */

   HighestAcceptableAddress =
      HalpGetAdapterMaximumPhysicalAddress(AdapterObject);
   LowestAcceptableAddress.HighPart = 0;
   LowestAcceptableAddress.LowPart =
      HighestAcceptableAddress.LowPart == 0xFFFFFFFF ? 0x1000000 : 0;
   BoundryAddressMultiple.QuadPart = 0;

   VirtualAddress = MmAllocateContiguousMemorySpecifyCache(
      MapRegisterCount << PAGE_SHIFT, LowestAcceptableAddress,
      HighestAcceptableAddress, BoundryAddressMultiple, MmNonCached);

   if (VirtualAddress == NULL && LowestAcceptableAddress.LowPart != 0)
   {
      LowestAcceptableAddress.LowPart = 0;
      VirtualAddress = MmAllocateContiguousMemorySpecifyCache(
         MapRegisterCount << PAGE_SHIFT, LowestAcceptableAddress,
         HighestAcceptableAddress, BoundryAddressMultiple, MmNonCached);
   }

   if (VirtualAddress == NULL)
      return FALSE;

   PhysicalAddress = MmGetPhysicalAddress(VirtualAddress);

   /*
    * All the following must be done with the master adapter lock held
    * to prevent corruption.
    */

   OldIrql = KfAcquireSpinLock(&AdapterObject->SpinLock);

   /*
    * Setup map register entries for the buffer allocated. Each entry has
    * a virtual and physical address and corresponds to PAGE_SIZE large
    * buffer.
    */

   if (MapRegisterCount > 0)
   {
      PROS_MAP_REGISTER_ENTRY CurrentEntry, PreviousEntry;

      CurrentEntry = AdapterObject->MapRegisterBase +
                     AdapterObject->NumberOfMapRegisters;
      do
      {
         /*
          * Leave one entry free for every non-contiguous memory region
          * in the map register bitmap. This ensures that we can search
          * using RtlFindClearBits for contiguous map register regions.
          *
          * Also for non-EISA DMA leave one free entry for every 64Kb
          * break, because the DMA controller can handle only coniguous
          * 64Kb regions.
          */

         if (CurrentEntry != AdapterObject->MapRegisterBase)
         {
            PreviousEntry = CurrentEntry - 1;
            if (PreviousEntry->PhysicalAddress.LowPart + PAGE_SIZE ==
                PhysicalAddress.LowPart)
            {
               if (!HalpEisaDma)
               {
                  if ((PreviousEntry->PhysicalAddress.LowPart ^
                       PhysicalAddress.LowPart) & 0xFFFF0000)
                  {
                     CurrentEntry++;
                     AdapterObject->NumberOfMapRegisters++;
                  }
               }
            }
            else
            {
               CurrentEntry++;
               AdapterObject->NumberOfMapRegisters++;
            }
         }

         RtlClearBit(AdapterObject->MapRegisters,
                     CurrentEntry - AdapterObject->MapRegisterBase);
         CurrentEntry->VirtualAddress = VirtualAddress;
         CurrentEntry->PhysicalAddress = PhysicalAddress;

         PhysicalAddress.LowPart += PAGE_SIZE;
         VirtualAddress = (PVOID)((ULONG_PTR)VirtualAddress + PAGE_SIZE);

         CurrentEntry++;
         AdapterObject->NumberOfMapRegisters++;
         MapRegisterCount--;
      }
      while (MapRegisterCount != 0);
   }

   KfReleaseSpinLock(&AdapterObject->SpinLock, OldIrql);

   return TRUE;
}

Referenced by HalGetAdapter(), HalpDmaAllocateMasterAdapter(), and HalpGrowMapBufferWorker().

HalpGrowMapBufferWorker()

VOID NTAPI HalpGrowMapBufferWorker

(

PVOID

DeferredContext

)

Definition at line 1005 of file dma.c.

{
   PGROW_WORK_ITEM WorkItem = (PGROW_WORK_ITEM)DeferredContext;
   KIRQL OldIrql;
   BOOLEAN Succeeded;

   /*
    * Try to allocate new map registers for the adapter.
    *
    * NOTE: The NT implementation actually tries to allocate more map
    * registers than needed as an optimization.
    */

   KeWaitForSingleObject(&HalpDmaLock, Executive, KernelMode,
                         FALSE, NULL);
   Succeeded = HalpGrowMapBuffers(WorkItem->AdapterObject->MasterAdapter,
                                  WorkItem->NumberOfMapRegisters);
   KeSetEvent(&HalpDmaLock, 0, 0);

   if (Succeeded)
   {
      /*
       * Flush the adapter queue now that new map registers are ready. The
       * easiest way to do that is to call IoFreeMapRegisters to not free
       * any registers. Note that we use the magic (PVOID)2 map register
       * base to bypass the parameter checking.
       */

      KeRaiseIrql(DISPATCH_LEVEL, &OldIrql);
      IoFreeMapRegisters(WorkItem->AdapterObject, (PVOID)2, 0);
      KeLowerIrql(OldIrql);
   }

   ExFreePool(WorkItem);
}

Referenced by HalAllocateAdapterChannel().

HalpInitDma()

VOID HalpInitDma

(

VOID

)

Definition at line 121 of file dma.c.

{
   /*
    * Initialize the DMA Operation table
    */
   HalpDmaOperations.AllocateAdapterChannel = (PALLOCATE_ADAPTER_CHANNEL)IoAllocateAdapterChannel;
   HalpDmaOperations.FlushAdapterBuffers = (PFLUSH_ADAPTER_BUFFERS)IoFlushAdapterBuffers;
   HalpDmaOperations.FreeAdapterChannel = (PFREE_ADAPTER_CHANNEL)IoFreeAdapterChannel;
   HalpDmaOperations.FreeMapRegisters = (PFREE_MAP_REGISTERS)IoFreeMapRegisters;
   HalpDmaOperations.MapTransfer = (PMAP_TRANSFER)IoMapTransfer;

   /*
    * Check if Extended DMA is available. We're just going to do a random
    * read and write.
    */

   WRITE_PORT_UCHAR((PUCHAR)FIELD_OFFSET(EISA_CONTROL, DmaController2Pages.Channel2), 0x2A);
   if (READ_PORT_UCHAR((PUCHAR)FIELD_OFFSET(EISA_CONTROL, DmaController2Pages.Channel2)) == 0x2A)
      HalpEisaDma = TRUE;

   /*
    * Intialize all the global variables and allocate master adapter with
    * first map buffers.
    */

   InitializeListHead(&HalpDmaAdapterList);
   KeInitializeEvent(&HalpDmaLock, NotificationEvent, TRUE);

   HalpMasterAdapter = HalpDmaAllocateMasterAdapter();

   /*
    * Setup the HalDispatchTable callback for creating PnP DMA adapters. It's
    * used by IoGetDmaAdapter in the kernel.
    */

   HalGetDmaAdapter = HalpGetDmaAdapter;
}

Referenced by HalInitSystem(), and HalpInitPhase1().

HalPutDmaAdapter()

VOID NTAPI HalPutDmaAdapter

(

PADAPTER_OBJECT

AdapterObject

)

Definition at line 808 of file dma.c.

{
   if (AdapterObject->ChannelNumber == 0xFF)
   {
      KeWaitForSingleObject(&HalpDmaLock, Executive, KernelMode,
                            FALSE, NULL);
      RemoveEntryList(&AdapterObject->AdapterList);
      KeSetEvent(&HalpDmaLock, 0, 0);
   }

   ObDereferenceObject(AdapterObject);
}

HalReadDmaCounter()

ULONG NTAPI HalReadDmaCounter

(

PADAPTER_OBJECT

AdapterObject

)

Definition at line 933 of file dma.c.

{
   KIRQL OldIrql;
   ULONG Count, OldCount;

   ASSERT(!AdapterObject->MasterDevice);

   /*
    * Acquire the master adapter lock since we're going to mess with the
    * system DMA controller registers and we really don't want anyone
    * to do the same at the same time.
    */

   KeAcquireSpinLock(&AdapterObject->MasterAdapter->SpinLock, &OldIrql);

   /* Send the request to the specific controller. */
   if (AdapterObject->AdapterNumber == 1)
   {
      PDMA1_CONTROL DmaControl1 = AdapterObject->AdapterBaseVa;

      Count = 0xffff00;
      do
      {
         OldCount = Count;
         /* Send Reset */
         WRITE_PORT_UCHAR(&DmaControl1->ClearBytePointer, 0);
         /* Read Count */
         Count = READ_PORT_UCHAR(&DmaControl1->DmaAddressCount
                                 [AdapterObject->ChannelNumber].DmaBaseCount);
         Count |= READ_PORT_UCHAR(&DmaControl1->DmaAddressCount
                                  [AdapterObject->ChannelNumber].DmaBaseCount) << 8;
      }
      while (0xffff00 & (OldCount ^ Count));
   }
   else
   {
      PDMA2_CONTROL DmaControl2 = AdapterObject->AdapterBaseVa;

      Count = 0xffff00;
      do
      {
         OldCount = Count;
         /* Send Reset */
         WRITE_PORT_UCHAR(&DmaControl2->ClearBytePointer, 0);
         /* Read Count */
         Count = READ_PORT_UCHAR(&DmaControl2->DmaAddressCount
                                 [AdapterObject->ChannelNumber].DmaBaseCount);
         Count |= READ_PORT_UCHAR(&DmaControl2->DmaAddressCount
                                  [AdapterObject->ChannelNumber].DmaBaseCount) << 8;
      }
      while (0xffff00 & (OldCount ^ Count));
   }

   KeReleaseSpinLock(&AdapterObject->MasterAdapter->SpinLock, OldIrql);

   Count++;
   Count &= 0xffff;
   if (AdapterObject->Width16Bits)
      Count *= 2;

   return Count;
}

IoFlushAdapterBuffers()

BOOLEAN NTAPI IoFlushAdapterBuffers	(	PADAPTER_OBJECT	AdapterObject,
		PMDL	Mdl,
		PVOID	MapRegisterBase,
		PVOID	CurrentVa,
		ULONG	Length,
		BOOLEAN	WriteToDevice
	)

Definition at line 1555 of file dma.c.

{
   BOOLEAN SlaveDma = FALSE;
   PROS_MAP_REGISTER_ENTRY RealMapRegisterBase;
   PHYSICAL_ADDRESS HighestAcceptableAddress;
   PHYSICAL_ADDRESS PhysicalAddress;
   PPFN_NUMBER MdlPagesPtr;

   ASSERT_IRQL_LESS_OR_EQUAL(DISPATCH_LEVEL);

   if (AdapterObject != NULL && !AdapterObject->MasterDevice)
   {
      /* Mask out (disable) the DMA channel. */
      if (AdapterObject->AdapterNumber == 1)
      {
         PDMA1_CONTROL DmaControl1 = AdapterObject->AdapterBaseVa;
         WRITE_PORT_UCHAR(&DmaControl1->SingleMask,
                          AdapterObject->ChannelNumber | DMA_SETMASK);
      }
      else
      {
         PDMA2_CONTROL DmaControl2 = AdapterObject->AdapterBaseVa;
         WRITE_PORT_UCHAR(&DmaControl2->SingleMask,
                          AdapterObject->ChannelNumber | DMA_SETMASK);
      }
      SlaveDma = TRUE;
   }

   /* This can happen if the device supports hardware scatter/gather. */
   if (MapRegisterBase == NULL)
      return TRUE;

   RealMapRegisterBase =
      (PROS_MAP_REGISTER_ENTRY)((ULONG_PTR)MapRegisterBase & ~MAP_BASE_SW_SG);

   if (!WriteToDevice)
   {
      if ((ULONG_PTR)MapRegisterBase & MAP_BASE_SW_SG)
      {
         if (RealMapRegisterBase->Counter != MAXULONG)
         {
            if (SlaveDma && !AdapterObject->IgnoreCount)
               Length -= HalReadDmaCounter(AdapterObject);
         HalpCopyBufferMap(Mdl, RealMapRegisterBase, CurrentVa, Length, FALSE);
      }
      }
      else
      {
         MdlPagesPtr = MmGetMdlPfnArray(Mdl);
         MdlPagesPtr += ((ULONG_PTR)CurrentVa - (ULONG_PTR)Mdl->StartVa) >> PAGE_SHIFT;

         PhysicalAddress.QuadPart = *MdlPagesPtr << PAGE_SHIFT;
         PhysicalAddress.QuadPart += BYTE_OFFSET(CurrentVa);

         HighestAcceptableAddress = HalpGetAdapterMaximumPhysicalAddress(AdapterObject);
         if (PhysicalAddress.QuadPart + Length >
             HighestAcceptableAddress.QuadPart)
         {
            HalpCopyBufferMap(Mdl, RealMapRegisterBase, CurrentVa, Length, FALSE);
      }
   }
   }

   RealMapRegisterBase->Counter = 0;

   return TRUE;
}

IoFreeAdapterChannel()

VOID NTAPI IoFreeAdapterChannel

(

PADAPTER_OBJECT

AdapterObject

)

Definition at line 1238 of file dma.c.

{
   PADAPTER_OBJECT MasterAdapter;
   PKDEVICE_QUEUE_ENTRY DeviceQueueEntry;
   PWAIT_CONTEXT_BLOCK WaitContextBlock;
   ULONG Index = MAXULONG;
   ULONG Result;
   KIRQL OldIrql;

   MasterAdapter = AdapterObject->MasterAdapter;

   for (;;)
   {
      /*
       * To keep map registers, call here with AdapterObject->
       * NumberOfMapRegisters set to zero. This trick is used in
       * HalAllocateAdapterChannel for example.
       */
      if (AdapterObject->NumberOfMapRegisters)
      {
         IoFreeMapRegisters(
            AdapterObject,
            AdapterObject->MapRegisterBase,
            AdapterObject->NumberOfMapRegisters);
      }

      DeviceQueueEntry = KeRemoveDeviceQueue(&AdapterObject->ChannelWaitQueue);
      if (DeviceQueueEntry == NULL)
      {
         break;
      }

      WaitContextBlock = CONTAINING_RECORD(
         DeviceQueueEntry,
         WAIT_CONTEXT_BLOCK,
         WaitQueueEntry);

      AdapterObject->CurrentWcb = WaitContextBlock;
      AdapterObject->NumberOfMapRegisters = WaitContextBlock->NumberOfMapRegisters;

      if (WaitContextBlock->NumberOfMapRegisters &&
          AdapterObject->MasterAdapter)
      {
         OldIrql = KfAcquireSpinLock(&MasterAdapter->SpinLock);

         if (IsListEmpty(&MasterAdapter->AdapterQueue))
         {
            Index = RtlFindClearBitsAndSet(
               MasterAdapter->MapRegisters,
               WaitContextBlock->NumberOfMapRegisters, 0);
            if (Index != MAXULONG)
            {
               AdapterObject->MapRegisterBase =
                  MasterAdapter->MapRegisterBase + Index;
               if (!AdapterObject->ScatterGather)
               {
                  AdapterObject->MapRegisterBase =
                     (PROS_MAP_REGISTER_ENTRY)(
                        (ULONG_PTR)AdapterObject->MapRegisterBase |
                        MAP_BASE_SW_SG);
               }
            }
         }

         if (Index == MAXULONG)
         {
            InsertTailList(&MasterAdapter->AdapterQueue, &AdapterObject->AdapterQueue);
            KfReleaseSpinLock(&MasterAdapter->SpinLock, OldIrql);
            break;
         }

         KfReleaseSpinLock(&MasterAdapter->SpinLock, OldIrql);
      }
      else
      {
         AdapterObject->MapRegisterBase = NULL;
         AdapterObject->NumberOfMapRegisters = 0;
      }

      /* Call the adapter control routine. */
      Result = ((PDRIVER_CONTROL)WaitContextBlock->DeviceRoutine)(
          WaitContextBlock->DeviceObject, WaitContextBlock->CurrentIrp,
          AdapterObject->MapRegisterBase, WaitContextBlock->DeviceContext);

      switch (Result)
      {
         case KeepObject:
            /*
             * We're done until the caller manually calls IoFreeAdapterChannel
             * or IoFreeMapRegisters.
             */
            return;

         case DeallocateObjectKeepRegisters:
            /*
             * Hide the map registers so they aren't deallocated next time
             * around.
             */
            AdapterObject->NumberOfMapRegisters = 0;
            break;

         default:
            break;
      }
   }
}

IoFreeMapRegisters()

VOID NTAPI IoFreeMapRegisters	(	IN PADAPTER_OBJECT	AdapterObject,
		IN PVOID	MapRegisterBase,
		IN ULONG	NumberOfMapRegisters
	)

Definition at line 1362 of file dma.c.

{
   PADAPTER_OBJECT MasterAdapter = AdapterObject->MasterAdapter;
   PLIST_ENTRY ListEntry;
   KIRQL OldIrql;
   ULONG Index;
   ULONG Result;

   ASSERT(KeGetCurrentIrql() == DISPATCH_LEVEL);

   if (MasterAdapter == NULL || MapRegisterBase == NULL)
      return;

   OldIrql = KfAcquireSpinLock(&MasterAdapter->SpinLock);

   if (NumberOfMapRegisters != 0)
   {
      PROS_MAP_REGISTER_ENTRY RealMapRegisterBase;

      RealMapRegisterBase =
         (PROS_MAP_REGISTER_ENTRY)((ULONG_PTR)MapRegisterBase & ~MAP_BASE_SW_SG);
      RtlClearBits(MasterAdapter->MapRegisters,
                   RealMapRegisterBase - MasterAdapter->MapRegisterBase,
                   NumberOfMapRegisters);
   }

   /*
    * Now that we freed few map registers it's time to look at the master
    * adapter queue and see if there is someone waiting for map registers.
    */

   while (!IsListEmpty(&MasterAdapter->AdapterQueue))
   {
      ListEntry = RemoveHeadList(&MasterAdapter->AdapterQueue);
      AdapterObject = CONTAINING_RECORD(
         ListEntry, struct _ADAPTER_OBJECT, AdapterQueue);

      Index = RtlFindClearBitsAndSet(
         MasterAdapter->MapRegisters,
         AdapterObject->NumberOfMapRegisters,
         MasterAdapter->NumberOfMapRegisters);
      if (Index == MAXULONG)
      {
         InsertHeadList(&MasterAdapter->AdapterQueue, ListEntry);
         break;
      }

      KfReleaseSpinLock(&MasterAdapter->SpinLock, OldIrql);

      AdapterObject->MapRegisterBase =
         MasterAdapter->MapRegisterBase + Index;
      if (!AdapterObject->ScatterGather)
      {
         AdapterObject->MapRegisterBase =
            (PROS_MAP_REGISTER_ENTRY)(
               (ULONG_PTR)AdapterObject->MapRegisterBase |
               MAP_BASE_SW_SG);
      }

      Result = ((PDRIVER_CONTROL)AdapterObject->CurrentWcb->DeviceRoutine)(
         AdapterObject->CurrentWcb->DeviceObject,
         AdapterObject->CurrentWcb->CurrentIrp,
         AdapterObject->MapRegisterBase,
         AdapterObject->CurrentWcb->DeviceContext);

      switch (Result)
      {
         case DeallocateObjectKeepRegisters:
            AdapterObject->NumberOfMapRegisters = 0;
            /* fall through */

         case DeallocateObject:
            if (AdapterObject->NumberOfMapRegisters)
            {
               OldIrql = KfAcquireSpinLock(&MasterAdapter->SpinLock);
               RtlClearBits(MasterAdapter->MapRegisters,
                            AdapterObject->MapRegisterBase -
                            MasterAdapter->MapRegisterBase,
                            AdapterObject->NumberOfMapRegisters);
               KfReleaseSpinLock(&MasterAdapter->SpinLock, OldIrql);
            }
            IoFreeAdapterChannel(AdapterObject);
            break;

         default:
            break;
      }

      OldIrql = KfAcquireSpinLock(&MasterAdapter->SpinLock);
   }

   KfReleaseSpinLock(&MasterAdapter->SpinLock, OldIrql);
}

IoMapTransfer()

PHYSICAL_ADDRESS NTAPI IoMapTransfer	(	IN PADAPTER_OBJECT	AdapterObject,
		IN PMDL	Mdl,
		IN PVOID	MapRegisterBase,
		IN PVOID	CurrentVa,
		IN OUT PULONG	Length,
		IN BOOLEAN	WriteToDevice
	)

Definition at line 1662 of file dma.c.

{
   PPFN_NUMBER MdlPagesPtr;
   PFN_NUMBER MdlPage1, MdlPage2;
   ULONG ByteOffset;
   ULONG TransferOffset;
   ULONG TransferLength;
   BOOLEAN UseMapRegisters;
   PROS_MAP_REGISTER_ENTRY RealMapRegisterBase;
   PHYSICAL_ADDRESS PhysicalAddress;
   PHYSICAL_ADDRESS HighestAcceptableAddress;
   ULONG Counter;
   DMA_MODE AdapterMode;
   KIRQL OldIrql;

   /*
    * Precalculate some values that are used in all cases.
    *
    * ByteOffset is offset inside the page at which the transfer starts.
    * MdlPagesPtr is pointer inside the MDL page chain at the page where the
    *             transfer start.
    * PhysicalAddress is physical address corresponding to the transfer
    *                 start page and offset.
    * TransferLength is the initial length of the transfer, which is reminder
    *                of the first page. The actual value is calculated below.
    *
    * Note that all the variables can change during the processing which
    * takes place below. These are just initial values.
    */

   ByteOffset = BYTE_OFFSET(CurrentVa);

   MdlPagesPtr = MmGetMdlPfnArray(Mdl);
   MdlPagesPtr += ((ULONG_PTR)CurrentVa - (ULONG_PTR)Mdl->StartVa) >> PAGE_SHIFT;

   PhysicalAddress.QuadPart = *MdlPagesPtr << PAGE_SHIFT;
   PhysicalAddress.QuadPart += ByteOffset;

   TransferLength = PAGE_SIZE - ByteOffset;

   /*
    * Special case for bus master adapters with S/G support. We can directly
    * use the buffer specified by the MDL, so not much work has to be done.
    *
    * Just return the passed VA's corresponding physical address and update
    * length to the number of physically contiguous bytes found. Also
    * pages crossing the 4Gb boundary aren't considered physically contiguous.
    */

   if (MapRegisterBase == NULL)
   {
      while (TransferLength < *Length)
      {
         MdlPage1 = *MdlPagesPtr;
         MdlPage2 = *(MdlPagesPtr + 1);
         if (MdlPage1 + 1 != MdlPage2)
            break;
         if ((MdlPage1 ^ MdlPage2) & ~0xFFFFF)
            break;
         TransferLength += PAGE_SIZE;
         MdlPagesPtr++;
      }

      if (TransferLength < *Length)
         *Length = TransferLength;

      return PhysicalAddress;
   }

   /*
    * The code below applies to slave DMA adapters and bus master adapters
    * without hardward S/G support.
    */

   RealMapRegisterBase =
      (PROS_MAP_REGISTER_ENTRY)((ULONG_PTR)MapRegisterBase & ~MAP_BASE_SW_SG);

   /*
    * Try to calculate the size of the transfer. We can only transfer
    * pages that are physically contiguous and that don't cross the
    * 64Kb boundary (this limitation applies only for ISA controllers).
    */

   while (TransferLength < *Length)
   {
      MdlPage1 = *MdlPagesPtr;
      MdlPage2 = *(MdlPagesPtr + 1);
      if (MdlPage1 + 1 != MdlPage2)
         break;
      if (!HalpEisaDma && ((MdlPage1 ^ MdlPage2) & ~0xF))
         break;
      TransferLength += PAGE_SIZE;
      MdlPagesPtr++;
   }

   if (TransferLength > *Length)
      TransferLength = *Length;

   /*
    * If we're about to simulate software S/G and not all the pages are
    * physically contiguous then we must use the map registers to store
    * the data and allow the whole transfer to proceed at once.
    */

   if ((ULONG_PTR)MapRegisterBase & MAP_BASE_SW_SG &&
       TransferLength < *Length)
   {
      UseMapRegisters = TRUE;
      PhysicalAddress = RealMapRegisterBase->PhysicalAddress;
      PhysicalAddress.QuadPart += ByteOffset;
      TransferLength = *Length;
      RealMapRegisterBase->Counter = MAXULONG;
      Counter = 0;
   }
   else
   {
      /*
       * This is ordinary DMA transfer, so just update the progress
       * counters. These are used by IoFlushAdapterBuffers to track
       * the transfer progress.
       */

      UseMapRegisters = FALSE;
      Counter = RealMapRegisterBase->Counter;
      RealMapRegisterBase->Counter += BYTES_TO_PAGES(ByteOffset + TransferLength);

      /*
       * Check if the buffer doesn't exceed the highest physical address
       * limit of the device. In that case we must use the map registers to
       * store the data.
       */

      HighestAcceptableAddress = HalpGetAdapterMaximumPhysicalAddress(AdapterObject);
      if (PhysicalAddress.QuadPart + TransferLength >
          HighestAcceptableAddress.QuadPart)
      {
         UseMapRegisters = TRUE;
         PhysicalAddress = RealMapRegisterBase[Counter].PhysicalAddress;
         PhysicalAddress.QuadPart += ByteOffset;
         if ((ULONG_PTR)MapRegisterBase & MAP_BASE_SW_SG)
         {
            RealMapRegisterBase->Counter = MAXULONG;
            Counter = 0;
         }
      }
   }

   /*
    * If we decided to use the map registers (see above) and we're about
    * to transfer data to the device then copy the buffers into the map
    * register memory.
    */

   if (UseMapRegisters && WriteToDevice)
   {
      HalpCopyBufferMap(Mdl, RealMapRegisterBase + Counter,
                        CurrentVa, TransferLength, WriteToDevice);
   }

   /*
    * Return the length of transfer that actually takes place.
    */

   *Length = TransferLength;

   /*
    * If we're doing slave (system) DMA then program the (E)ISA controller
    * to actually start the transfer.
    */

   if (AdapterObject != NULL && !AdapterObject->MasterDevice)
   {
      AdapterMode = AdapterObject->AdapterMode;

      if (WriteToDevice)
      {
         AdapterMode.TransferType = WRITE_TRANSFER;
      }
      else
      {
         AdapterMode.TransferType = READ_TRANSFER;
         if (AdapterObject->IgnoreCount)
         {
            RtlZeroMemory((PUCHAR)RealMapRegisterBase[Counter].VirtualAddress +
                          ByteOffset, TransferLength);
         }
      }

      TransferOffset = PhysicalAddress.LowPart & 0xFFFF;
      if (AdapterObject->Width16Bits)
      {
         TransferLength >>= 1;
         TransferOffset >>= 1;
      }

      OldIrql = KfAcquireSpinLock(&AdapterObject->MasterAdapter->SpinLock);

      if (AdapterObject->AdapterNumber == 1)
      {
         PDMA1_CONTROL DmaControl1 = AdapterObject->AdapterBaseVa;

         /* Reset Register */
         WRITE_PORT_UCHAR(&DmaControl1->ClearBytePointer, 0);
         /* Set the Mode */
         WRITE_PORT_UCHAR(&DmaControl1->Mode, AdapterMode.Byte);
         /* Set the Offset Register */
         WRITE_PORT_UCHAR(&DmaControl1->DmaAddressCount[AdapterObject->ChannelNumber].DmaBaseAddress,
                          (UCHAR)(TransferOffset));
         WRITE_PORT_UCHAR(&DmaControl1->DmaAddressCount[AdapterObject->ChannelNumber].DmaBaseAddress,
                          (UCHAR)(TransferOffset >> 8));
         /* Set the Page Register */
         WRITE_PORT_UCHAR(AdapterObject->PagePort +
                          FIELD_OFFSET(EISA_CONTROL, DmaController1Pages),
                          (UCHAR)(PhysicalAddress.LowPart >> 16));
         if (HalpEisaDma)
         {
            WRITE_PORT_UCHAR(AdapterObject->PagePort +
                             FIELD_OFFSET(EISA_CONTROL, DmaController2Pages),
                             0);
         }
         /* Set the Length */
         WRITE_PORT_UCHAR(&DmaControl1->DmaAddressCount[AdapterObject->ChannelNumber].DmaBaseCount,
                          (UCHAR)(TransferLength - 1));
         WRITE_PORT_UCHAR(&DmaControl1->DmaAddressCount[AdapterObject->ChannelNumber].DmaBaseCount,
                          (UCHAR)((TransferLength - 1) >> 8));
         /* Unmask the Channel */
         WRITE_PORT_UCHAR(&DmaControl1->SingleMask,
                          AdapterObject->ChannelNumber | DMA_CLEARMASK);
      }
      else
      {
         PDMA2_CONTROL DmaControl2 = AdapterObject->AdapterBaseVa;

         /* Reset Register */
         WRITE_PORT_UCHAR(&DmaControl2->ClearBytePointer, 0);
         /* Set the Mode */
         WRITE_PORT_UCHAR(&DmaControl2->Mode, AdapterMode.Byte);
         /* Set the Offset Register */
         WRITE_PORT_UCHAR(&DmaControl2->DmaAddressCount[AdapterObject->ChannelNumber].DmaBaseAddress,
                          (UCHAR)(TransferOffset));
         WRITE_PORT_UCHAR(&DmaControl2->DmaAddressCount[AdapterObject->ChannelNumber].DmaBaseAddress,
                          (UCHAR)(TransferOffset >> 8));
         /* Set the Page Register */
         WRITE_PORT_UCHAR(AdapterObject->PagePort +
                          FIELD_OFFSET(EISA_CONTROL, DmaController1Pages),
                          (UCHAR)(PhysicalAddress.u.LowPart >> 16));
         if (HalpEisaDma)
         {
            WRITE_PORT_UCHAR(AdapterObject->PagePort +
                             FIELD_OFFSET(EISA_CONTROL, DmaController2Pages),
                             0);
         }
         /* Set the Length */
         WRITE_PORT_UCHAR(&DmaControl2->DmaAddressCount[AdapterObject->ChannelNumber].DmaBaseCount,
                          (UCHAR)(TransferLength - 1));
         WRITE_PORT_UCHAR(&DmaControl2->DmaAddressCount[AdapterObject->ChannelNumber].DmaBaseCount,
                          (UCHAR)((TransferLength - 1) >> 8));
         /* Unmask the Channel */
         WRITE_PORT_UCHAR(&DmaControl2->SingleMask,
                          AdapterObject->ChannelNumber | DMA_CLEARMASK);
      }

      KfReleaseSpinLock(&AdapterObject->MasterAdapter->SpinLock, OldIrql);
   }

   /*
    * Return physical address of the buffer with data that is used for the
    * transfer. It can either point inside the Mdl that was passed by the
    * caller or into the map registers if the Mdl buffer can't be used
    * directly.
    */

   return PhysicalAddress;
}

Variable Documentation

HalpDmaAdapterList

LIST_ENTRY HalpDmaAdapterList

static

Definition at line 78 of file dma.c.

Referenced by HalGetAdapter(), and HalpInitDma().

HalpDmaLock

KEVENT HalpDmaLock

static

Definition at line 77 of file dma.c.

Referenced by HalGetAdapter(), HalpGrowMapBufferWorker(), HalpInitDma(), and HalPutDmaAdapter().

HalpDmaOperations

DMA_OPERATIONS HalpDmaOperations

static

Initial value:

= {
   sizeof(DMA_OPERATIONS),
   (PPUT_DMA_ADAPTER)HalPutDmaAdapter,
   (PALLOCATE_COMMON_BUFFER)HalAllocateCommonBuffer,
   (PFREE_COMMON_BUFFER)HalFreeCommonBuffer,
   NULL, 
   NULL, 
   NULL, 
   NULL, 
   NULL, 
   (PGET_DMA_ALIGNMENT)HalpDmaGetDmaAlignment,
   (PREAD_DMA_COUNTER)HalReadDmaCounter,
   
   NULL ,
   NULL ,
   NULL ,
   NULL ,
   NULL 
}

Definition at line 94 of file dma.c.

Referenced by HalpDmaAllocateChildAdapter(), and HalpInitDma().

HalpEisaAdapter

PADAPTER_OBJECT HalpEisaAdapter[8]

static

Definition at line 79 of file dma.c.

Referenced by HalGetAdapter().

HalpEisaDma

BOOLEAN HalpEisaDma

static

Definition at line 80 of file dma.c.

Referenced by HalpDmaInitializeEisaAdapter(), HalpGrowMapBuffers(), HalpInitDma(), and IoMapTransfer().

HalpEisaPortPage

const ULONG_PTR HalpEisaPortPage[8]

static

Initial value:

= {
   FIELD_OFFSET(DMA_PAGE, Channel0),
   FIELD_OFFSET(DMA_PAGE, Channel1),
   FIELD_OFFSET(DMA_PAGE, Channel2),
   FIELD_OFFSET(DMA_PAGE, Channel3),
   0,
   FIELD_OFFSET(DMA_PAGE, Channel5),
   FIELD_OFFSET(DMA_PAGE, Channel6),

}

Definition at line 83 of file dma.c.

Referenced by HalpDmaInitializeEisaAdapter().

HalpMasterAdapter

PADAPTER_OBJECT HalpMasterAdapter

static

Definition at line 81 of file dma.c.

Referenced by HalGetAdapter(), HalpDmaAllocateChildAdapter(), and HalpInitDma().