bulkrwr.c

C8051F320 SOURCE CODE 内容有： * USB Bulk Driver Example * USB Bulk Firmware Example * Host Ap

                        FALSE,
                        FALSE,
                        NULL);

    if(mdl == NULL) {
    
        BulkUsb_DbgPrint(1, ("Failed to alloc mem for mdl\n"));

        ntStatus = STATUS_INSUFFICIENT_RESOURCES;

        ExFreePool(rwContext);

        goto BulkUsb_DispatchReadWrite_Exit;
    }

    //
    // map the portion of user-buffer described by an mdl to another mdl
    //
    IoBuildPartialMdl(Irp->MdlAddress,
                      mdl,
                      (PVOID) virtualAddress,
                      stageLength);

    urb = ExAllocatePool(NonPagedPool,
                         sizeof(struct _URB_BULK_OR_INTERRUPT_TRANSFER));

    if(urb == NULL) {

        BulkUsb_DbgPrint(1, ("Failed to alloc mem for urb\n"));

        ntStatus = STATUS_INSUFFICIENT_RESOURCES;

        ExFreePool(rwContext);
        IoFreeMdl(mdl);

        goto BulkUsb_DispatchReadWrite_Exit;
    }

    UsbBuildInterruptOrBulkTransferRequest(
                            urb,
                            sizeof(struct _URB_BULK_OR_INTERRUPT_TRANSFER),
                            pipeInformation->PipeHandle,
                            NULL,
                            mdl,
                            stageLength,
                            urbFlags,
                            NULL);

    //
    // set BULKUSB_RW_CONTEXT parameters.
    //
    
    rwContext->Urb             = urb;
    rwContext->Mdl             = mdl;
    rwContext->Length          = totalLength - stageLength;
    rwContext->Numxfer         = 0;
    rwContext->VirtualAddress  = virtualAddress + stageLength;
    rwContext->DeviceExtension = deviceExtension;

    //
    // use the original read/write irp as an internal device control irp
    //

    nextStack = IoGetNextIrpStackLocation(Irp);
    nextStack->MajorFunction = IRP_MJ_INTERNAL_DEVICE_CONTROL;
    nextStack->Parameters.Others.Argument1 = (PVOID) urb;
    nextStack->Parameters.DeviceIoControl.IoControlCode = 
                                             IOCTL_INTERNAL_USB_SUBMIT_URB;

    IoSetCompletionRoutine(Irp, 
                           (PIO_COMPLETION_ROUTINE)BulkUsb_ReadWriteCompletion,
                           rwContext,
                           TRUE,
                           TRUE,
                           TRUE);

    //
    // since we return STATUS_PENDING call IoMarkIrpPending.
    // This is the boiler plate code.
    // This may cause extra overhead of an APC for the Irp completion
    // but this is the correct thing to do.
    //

    IoMarkIrpPending(Irp);

    BulkUsb_DbgPrint(3, ("BulkUsb_DispatchReadWrite::"));
    BulkUsb_IoIncrement(deviceExtension);

    ntStatus = IoCallDriver(deviceExtension->TopOfStackDeviceObject,
                            Irp);

    if(!NT_SUCCESS(ntStatus)) {

        BulkUsb_DbgPrint(1, ("IoCallDriver fails with status %X\n", ntStatus));

        //
        // if the device was yanked out, then the pipeInformation 
        // field is invalid.
        // similarly if the request was cancelled, then we need not
        // invoked reset pipe/device.
        //
        if((ntStatus != STATUS_CANCELLED) && 
           (ntStatus != STATUS_DEVICE_NOT_CONNECTED)) {
            
            ntStatus = BulkUsb_ResetPipe(DeviceObject,
                                     pipeInformation);
    
            if(!NT_SUCCESS(ntStatus)) {

                BulkUsb_DbgPrint(1, ("BulkUsb_ResetPipe failed\n"));

                ntStatus = BulkUsb_ResetDevice(DeviceObject);
            }
        }
        else {

            BulkUsb_DbgPrint(3, ("ntStatus is STATUS_CANCELLED or "
                                 "STATUS_DEVICE_NOT_CONNECTED\n"));
        }
    }

    //
    // we return STATUS_PENDING and not the status returned by the lower layer.
    //
    return STATUS_PENDING;

BulkUsb_DispatchReadWrite_Exit:

    Irp->IoStatus.Status = ntStatus;
    Irp->IoStatus.Information = 0;

    IoCompleteRequest(Irp, IO_NO_INCREMENT);

    BulkUsb_DbgPrint(3, ("BulkUsb_DispatchReadWrite - ends\n"));

    return ntStatus;
}

NTSTATUS
BulkUsb_ReadWriteCompletion(
    IN PDEVICE_OBJECT DeviceObject,
    IN PIRP           Irp,
    IN PVOID          Context
    )
/*++
 
Routine Description:

    This is the completion routine for reads/writes
    If the irp completes with success, we check if we
    need to recirculate this irp for another stage of
    transfer. In this case return STATUS_MORE_PROCESSING_REQUIRED.
    if the irp completes in error, free all memory allocs and
    return the status.

Arguments:

    DeviceObject - pointer to device object
    Irp - I/O request packet
    Context - context passed to the completion routine.

Return Value:

    NT status value

--*/
{
    ULONG               stageLength;
    NTSTATUS            ntStatus;
    PIO_STACK_LOCATION  nextStack;
    PBULKUSB_RW_CONTEXT rwContext;

    //
    // initialize variables
    //
    rwContext = (PBULKUSB_RW_CONTEXT) Context;
    ntStatus = Irp->IoStatus.Status;

    UNREFERENCED_PARAMETER(DeviceObject);
    BulkUsb_DbgPrint(3, ("BulkUsb_ReadWriteCompletion - begins\n"));

    //
    // successfully performed a stageLength of transfer.
    // check if we need to recirculate the irp.
    //
    if(NT_SUCCESS(ntStatus)) {

        if(rwContext) {

            rwContext->Numxfer += 
              rwContext->Urb->UrbBulkOrInterruptTransfer.TransferBufferLength;
        
            if(rwContext->Length) {

                //
                // another stage transfer
                //
                BulkUsb_DbgPrint(3, ("Another stage transfer...\n"));

                if(rwContext->Length > BULKUSB_MAX_TRANSFER_SIZE) {
            
                    stageLength = BULKUSB_MAX_TRANSFER_SIZE;
                }
                else {
                
                    stageLength = rwContext->Length;
                }

				
                // the source MDL is not mapped and so when the lower driver
                // calls MmGetSystemAddressForMdl(Safe) on Urb->Mdl (target Mdl), 
                // system PTEs are used.
                // IoFreeMdl calls MmPrepareMdlForReuse to release PTEs (unlock
                // VA address before freeing any Mdl
                // Rather than calling IoFreeMdl and IoAllocateMdl each time,
                // just call MmPrepareMdlForReuse
                // Not calling MmPrepareMdlForReuse will leak system PTEs
                // 
                MmPrepareMdlForReuse(rwContext->Mdl);

                IoBuildPartialMdl(Irp->MdlAddress,
                                  rwContext->Mdl,
                                  (PVOID) rwContext->VirtualAddress,
                                  stageLength);
            
                //
                // reinitialize the urb
                //
                rwContext->Urb->UrbBulkOrInterruptTransfer.TransferBufferLength 
                                                                  = stageLength;
                rwContext->VirtualAddress += stageLength;
                rwContext->Length -= stageLength;

                nextStack = IoGetNextIrpStackLocation(Irp);
                nextStack->MajorFunction = IRP_MJ_INTERNAL_DEVICE_CONTROL;
                nextStack->Parameters.Others.Argument1 = rwContext->Urb;
                nextStack->Parameters.DeviceIoControl.IoControlCode = 
                                            IOCTL_INTERNAL_USB_SUBMIT_URB;

                IoSetCompletionRoutine(Irp,
                                       BulkUsb_ReadWriteCompletion,
                                       rwContext,
                                       TRUE,
                                       TRUE,
                                       TRUE);

                IoCallDriver(rwContext->DeviceExtension->TopOfStackDeviceObject, 
                             Irp);

                return STATUS_MORE_PROCESSING_REQUIRED;
            }
            else {

                //
                // this is the last transfer
                //

                Irp->IoStatus.Information = rwContext->Numxfer;
            }
        }
    }
    else {

        BulkUsb_DbgPrint(1, ("ReadWriteCompletion - failed with status = %X\n", ntStatus));
    }
    
    if(rwContext) {

        //
        // dump rwContext
        //
        BulkUsb_DbgPrint(3, ("rwContext->Urb             = %X\n", 
                             rwContext->Urb));
        BulkUsb_DbgPrint(3, ("rwContext->Mdl             = %X\n", 
                             rwContext->Mdl));
        BulkUsb_DbgPrint(3, ("rwContext->Length          = %d\n", 
                             rwContext->Length));
        BulkUsb_DbgPrint(3, ("rwContext->Numxfer         = %d\n", 
                             rwContext->Numxfer));
        BulkUsb_DbgPrint(3, ("rwContext->VirtualAddress  = %X\n", 
                             rwContext->VirtualAddress));
        BulkUsb_DbgPrint(3, ("rwContext->DeviceExtension = %X\n", 
                             rwContext->DeviceExtension));

        BulkUsb_DbgPrint(3, ("BulkUsb_ReadWriteCompletion::"));
        BulkUsb_IoDecrement(rwContext->DeviceExtension);

        ExFreePool(rwContext->Urb);
        IoFreeMdl(rwContext->Mdl);
        ExFreePool(rwContext);
    }

    BulkUsb_DbgPrint(3, ("BulkUsb_ReadWriteCompletion - ends\n"));

    return ntStatus;
}