/*

File:SCSIEmulatorAdapter.cpp

Abstract: Implementation of the core a virtual SCSI HBA based off of

        IOSCSIParallelInterfaceController

Version: 1.0

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*/

#include <IOKit/IOTypes.h>

#include <IOKit/IOMessage.h>

#include <IOKit/scsi/SCSICommandOperationCodes.h>

#include <IOKit/storage/IOStorageProtocolCharacteristics.h>

#include <IOKit/scsi/spi/IOSCSIParallelInterfaceController.h>

#include "SCSIEmulator.h"

#include "SCSIEmulatorAdapter.h"

#include "SCSIEmulatorAdapterNub.h"

#include "SCSIEmulatorIOKitDriver.h"

#include "SCSIEmulatorEventSource.h"

#ifndef MAX_TARGET_ID

#define kMaxTargetID 256

#else

#define kMaxTargetID MAX_TARGET_ID

#endif

#ifndef MAX_LUNS

#define kMaxLUNs 64

#else

#define kMaxLUNs MAX_LUNS

#endif

#ifndef MAX_TASKS

#define kMaxTasks 32 // Arbitrary number.  This sample code will work with anything >= 1

#else

#define kMaxTasks MAX_TASKS

#endif

#ifndef SENSE_BUFFER_LEN

#define kSenseBufferLen 128

#else

#define kSenseBufferLen SENSE_BUFFER_LEN

#endif

#define INITIATOR_IDENTIFIER 0x87654321

// Define superclass

#define super IOSCSIParallelInterfaceController

// REQUIRED! This macro defines the class's constructors, destructors,

// and several other methods I/O Kit requires. Do NOT use super as the

// second parameter. You must use the literal name of the superclass.

OSDefineMetaClassAndStructors(com_apple_dts_SCSIEmulatorAdapter, IOSCSIParallelInterfaceController)

// Only present to provide a debug checkpoint

bool com_apple_dts_SCSIEmulatorAdapter::willTerminate(IOService *provider, IOOptionBits options)

{

    return super::willTerminate(provider, options);

}

// Only present to provide a debug checkpoint

bool com_apple_dts_SCSIEmulatorAdapter::didTerminate(IOService *provider, IOOptionBits options, bool *defer)

{

    return super::didTerminate(provider, options, defer);

}

// Only present to provide a debug checkpoint

bool

com_apple_dts_SCSIEmulatorAdapter::terminate( IOOptionBits options)

{

    bool res = super::terminate(options);

    return res;

}

IOReturn

com_apple_dts_SCSIEmulatorAdapter::message(UInt32 type, IOService *provider, void *argument)

{

    IOReturn ret;

#if 1 // Work-around for bug in IOSCSIParallelFamily.  Radar:4914658

    switch (type) {

        case kIOMessageServiceIsRequestingClose:

        {

            // As the provider is opened by IOSCSIParallelInterfaceController itself, it should

            // be responsible for closing it, not us.  Currently, this is not the case

            ret = super::message(type, provider, argument);

            if (getProvider()->isOpen(this))

                getProvider()->close(this);

            return (getProvider()->isOpen(this) == false) ? ret : kIOReturnError;

            break;

        }

        default:

        {

            break;

        }

    }

#endif

    ret = super::message(type, provider, argument);

    return ret;

}

SCSILogicalUnitNumber

com_apple_dts_SCSIEmulatorAdapter::ReportHBAHighestLogicalUnitNumber ( void )

{

    // Report the highest LUN number devices on this HBA are allowed to have.

    // 0 is a valid response for HBAs that only allow a single LUN per device

    SCSILogicalUnitNumber maxLUN = kMaxLUNs - 1; // Report LUNs for our sample

    return maxLUN;

}

bool

com_apple_dts_SCSIEmulatorAdapter::DoesHBASupportSCSIParallelFeature ( SCSIParallelFeature theFeature )

{

    bool ret = false; // return false for any unimplemented or unknown features

    switch (theFeature) {

        case kSCSIParallelFeature_WideDataTransfer:

            ret = true;

            break;

        case kSCSIParallelFeature_SynchronousDataTransfer:

            ret = true;

            break;

        case kSCSIParallelFeature_QuickArbitrationAndSelection:

            ret = true;

            break;

        case kSCSIParallelFeature_DoubleTransitionDataTransfers:

            ret = true;

            break;

        case kSCSIParallelFeature_InformationUnitTransfers:

            ret = true;

            break;

    }

    return ret;

}

bool

com_apple_dts_SCSIEmulatorAdapter::InitializeTargetForID ( SCSITargetIdentifier targetID )

{   

    bool retVal = false;

    com_apple_dts_SCSIEmulatorAdapterNub *nub = OSDynamicCast(com_apple_dts_SCSIEmulatorAdapterNub, getProvider());

    if (nub) {

        com_apple_dts_SCSIEmulator *emulator = nub->getEmulator(this, targetID);

        if (emulator) {

            if (mTargetsArray)

                mTargetsArray->setObject(targetID, emulator);

            retVal = true;

        }

    }

    return retVal;

}

SCSIServiceResponse

com_apple_dts_SCSIEmulatorAdapter::AbortTaskRequest (   

                            SCSITargetIdentifier        theT,

                            SCSILogicalUnitNumber       theL,

                            SCSITaggedTaskIdentifier    theQ )

{

    // Returning general failure for AbortTaskRequest as this isn't yet supported by our HBA

    return kSCSIServiceResponse_SERVICE_DELIVERY_OR_TARGET_FAILURE;

}

SCSIServiceResponse

com_apple_dts_SCSIEmulatorAdapter::AbortTaskSetRequest (

                            SCSITargetIdentifier        theT,

                            SCSILogicalUnitNumber       theL )

{

    // Returning general failure for AbortTaskSetRequest as this isn't yet supported by our HBA

    return kSCSIServiceResponse_SERVICE_DELIVERY_OR_TARGET_FAILURE;

}

SCSIServiceResponse

com_apple_dts_SCSIEmulatorAdapter::ClearACARequest (

                            SCSITargetIdentifier        theT,

                            SCSILogicalUnitNumber       theL )

{

    // Returning general failure for ClearACARequest as this isn't yet supported by our HBA

    return kSCSIServiceResponse_SERVICE_DELIVERY_OR_TARGET_FAILURE;

}

SCSIServiceResponse

com_apple_dts_SCSIEmulatorAdapter::ClearTaskSetRequest (

                            SCSITargetIdentifier        theT,

                            SCSILogicalUnitNumber       theL )

{

    // Returning general failure for ClearTaskSetRequest as this isn't yet supported by our HBA

    return kSCSIServiceResponse_SERVICE_DELIVERY_OR_TARGET_FAILURE;

}

SCSIServiceResponse

com_apple_dts_SCSIEmulatorAdapter::LogicalUnitResetRequest (

                            SCSITargetIdentifier        theT,

                            SCSILogicalUnitNumber       theL )

{

    // Returning general failure for LogicalUnitResetRequest as this isn't yet supported by our HBA

    return kSCSIServiceResponse_SERVICE_DELIVERY_OR_TARGET_FAILURE;

}

SCSIServiceResponse

com_apple_dts_SCSIEmulatorAdapter::TargetResetRequest (

                            SCSITargetIdentifier        theT )

{

    // Returning general failure for TargetResetRequest as this isn't yet supported by our HBA

    return kSCSIServiceResponse_SERVICE_DELIVERY_OR_TARGET_FAILURE;

}

SCSIInitiatorIdentifier

com_apple_dts_SCSIEmulatorAdapter::ReportInitiatorIdentifier ( void )

{

    // What device ID does our HBA occupy on the bus?

    SCSIInitiatorIdentifier ourIdentity = INITIATOR_IDENTIFIER;

    return ourIdentity;

}

SCSIDeviceIdentifier

com_apple_dts_SCSIEmulatorAdapter::ReportHighestSupportedDeviceID ( void )

{

    // This HBA can handle how many attached devices?  The actual number can be lower

    SCSIDeviceIdentifier highestValidDevice = kMaxTargetID;

    return highestValidDevice;

}

UInt32

com_apple_dts_SCSIEmulatorAdapter::ReportMaximumTaskCount ( void )

{

    // How many concurrent tasks does our HBA support?

    // Given that this is the parallel tasking SCSI family, you'd

    // expect this to be greater than 1, but single task HBAs are

    // supported as well

    UInt32 maxTasks = kMaxTasks;

    return maxTasks;

}

UInt32

com_apple_dts_SCSIEmulatorAdapter::ReportHBASpecificTaskDataSize ( void )

{

    // How much space do we need allocated internally for each task?

    UInt32 taskDataSize = sizeof(SCSIEmulatorRequestBlock);

    return taskDataSize;

}

UInt32

com_apple_dts_SCSIEmulatorAdapter::ReportHBASpecificDeviceDataSize ( void )

{

    // How much space do we need allocated internally for each attached device?

    UInt32 hbaDataSize = sizeof(com_apple_dts_SCSIEmulator *);

    return hbaDataSize;

}

bool

com_apple_dts_SCSIEmulatorAdapter::DoesHBAPerformDeviceManagement ( void )

{

    // Report that we *DO NOT* manage our own devices

    // We will have the system query each possible target during startup

    // and do not expect or handle changes to this list while running

    // If you know that the bus is static and won't change, you can report false here and let the

    // OS handle discovering any attached devices.  If this is a SCSI bus where devices can be

    // dynamically added/removed, then you will need to return true and have a mechanism for

    // detecting, adding and removing devices as needed.

#if 0

    // If you were to do device management yourself, you would have to do something like:

    SCSIDeviceIdentifier index = 0

    CreateTargetForID(index++);

    // Use DestroyTargetForID() to remove targets as they disappear

#endif

    // This HBA does not support a mechanism for device attach/detach 

    // notification, go ahead and create target devices.

    return false;

}

bool

com_apple_dts_SCSIEmulatorAdapter::InitializeController ( void )

{

    com_apple_dts_SCSIEmulatorAdapterNub *nub = NULL;

    IOReturn ret = kIOReturnSuccess;

    nub = OSDynamicCast(com_apple_dts_SCSIEmulatorAdapterNub, getProvider());

    if (!nub) {

        IOLog("InitializeController: failed to cast provider\n");

        goto failed;

    }

    mTargetsArray = OSArray::withCapacity(kMaxTargetID);

    mResponderEventSource = OSTypeAlloc(com_apple_dts_SCSIEmulatorEventSource);

    if (!mResponderEventSource) {

        IOLog("InitializeController: failed to alloc mResponderEventSource\n");

        goto failed;

    }

    if (!mResponderEventSource->init(this,  &com_apple_dts_SCSIEmulatorAdapter::TaskComplete)) {

        IOLog("InitializeController: failed to init mResponderEventSource\n");

        mResponderEventSource->release();

        goto failed;

    }

    ret = GetWorkLoop()->addEventSource(mResponderEventSource);

    if (ret != kIOReturnSuccess) {

        IOLog("InitializeController: failed to add event source.  ret = 0x%X\n", ret);

        mResponderEventSource->release();

        goto failed;

    }

    goto success;

failed:

    return false;

success:

    // The controller is now initialized and ready for operation

    return true;

}

void

com_apple_dts_SCSIEmulatorAdapter::TerminateController ( void )

{

    if (GetWorkLoop()->removeEventSource(mResponderEventSource) != kIOReturnSuccess) {

        IOLog("TerminateController: failed to de-register eventsource?\n");

    }

    if (mResponderEventSource)

        mResponderEventSource->release();

    if (mTargetsArray)

        mTargetsArray->release();

}

bool

com_apple_dts_SCSIEmulatorAdapter::StartController ( void )

{

    // Start providing HBA services.  Re-init anything needed and go

    return true;

}

void

com_apple_dts_SCSIEmulatorAdapter::StopController ( void )

{

    // We've been requested to stop providing HBA services.  Clean up and shut down

}

void

com_apple_dts_SCSIEmulatorAdapter::HandleInterruptRequest ( void )

{

    // OK, odds are, your driver will want to do something here to get info from the HBA.

    // Usually, this will be pulling task completion info, etc. and then calling TaskCompleted().

    //

    // this->TaskCompleted(task, transportSucceeded, scsiStatus, transferredDataLength, senseData, senseDataLength);

    //

    // Since this example operates without using a real primary interrupt, this will never get called

    IOLog("HandleInterruptRequest: captured interrupt?");

}

SCSIServiceResponse

com_apple_dts_SCSIEmulatorAdapter::ProcessParallelTask ( SCSIParallelTaskIdentifier parallelRequest )

{

    // Not all of these may be required.  Unused ones are commented out to avoid compiler warnings

    SCSITargetIdentifier        targetID                = GetTargetIdentifier(parallelRequest);

//  SCSITaskIdentifier          task                    = GetSCSITaskIdentifier(parallelRequest);

//  SCSITaggedTaskIdentifier    taggedTask              = GetTaggedTaskIdentifier(parallelRequest);

    SCSILogicalUnitNumber       lun                     = GetLogicalUnitNumber(parallelRequest);

//  SCSITaskAttribute           taskAttribute           = GetTaskAttribute(parallelRequest);

    UInt8                       transferDir             = GetDataTransferDirection(parallelRequest);

    UInt64                      transferSize            = GetRequestedDataTransferCount(parallelRequest);

    IOMemoryDescriptor *        transferMemDesc         = GetDataBuffer(parallelRequest);

//  UInt64                      transferMemDescOffset   = GetDataBufferOffset(parallelRequest);

    // Get the CDB

    UInt8                       cdbLength               = GetCommandDescriptorBlockSize(parallelRequest);

    SCSICommandDescriptorBlock  cdbData;

    SCSITaskStatus              scsiStatus              = kSCSITaskStatus_GOOD;

    UInt64                      dataLen                 = 0;

    UInt8                       senseBuffer[kSenseBufferLen];

    UInt64                      senseBufferLen          = sizeof(senseBuffer);

    com_apple_dts_SCSIEmulator *emulator = (com_apple_dts_SCSIEmulator *)mTargetsArray->getObject(targetID);

    // Fail if we don't have a SCSI emulator backing this target

    if (!emulator) {

        IOLog("ProcessParallelTask: ABORT - !emulator for targetID = %ud\n", targetID);

        goto failure_exit;

    }

    // Fail if we're supposed to transfer data and don't have a data buffer

    if (!transferMemDesc && (transferDir != kSCSIDataTransfer_NoDataTransfer)) {

        IOLog("ProcessParallelTask: ABORT - !transferMemDesc && (transferDir != kSCSIDataTransfer_NoDataTransfer) - %p and %d\n", transferMemDesc, transferDir);

        goto failure_exit;

    }

    // Fail if we don't have a large enough CDB buffer set aside

    if (cdbLength > sizeof(cdbData)) {

        IOLog("ProcessParallelTask: ABORT - cdbLength > sizeof(cdbData) - %d vs. %d\n", cdbLength, sizeof(cdbData));

        goto failure_exit;

    }

    if (!GetCommandDescriptorBlock(parallelRequest, &cdbData)) {

        IOLog("ProcessParallelTask: ABORT - !GetCommandDescriptorBlock(parallelRequest, &cdbData)\n");

        goto failure_exit;

    }

    if (transferMemDesc && (transferDir != kSCSIDataTransfer_NoDataTransfer)) {

#if 0

        // This block isn't necessary as memory descriptors passed in are always autoprepared for us.

        // Remember: Any memory descriptors allocated and used internally should be prepared before sending

        // or receiving data to/from real hardware

        IOReturn res = transferMemDesc->prepare();

        if (res != kIOReturnSuccess) {

            goto failure_exit;

        }

#endif

        // We are guaranteed that the memory descriptor will always be sized large enough by

        // by SAM/STUC to hold the transfer size requested

        dataLen = transferSize;

    }

    // This is where the "real" work should get done by your hardware.  The individual parameters

    // are being sent instead of just the task reference as the task is opaque by design and

    // the getter/setter methods are protected and available within this class, but not within

    // the emulator itself.

    emulator->sendCommand(cdbData, cdbLength, transferMemDesc, &dataLen, lun, &scsiStatus, senseBuffer, &senseBufferLen);

    // Real hardware should be doing the task processing internally and providing responses

    // via an interrupt mechanism.  IOSCSIParallelInterfaceController expects this and you

    // should always do your task completions from the workloop thread.

    CompleteTaskOnWorkloopThread(parallelRequest, true, scsiStatus, dataLen, senseBuffer, senseBufferLen);

    return kSCSIServiceResponse_Request_In_Process;

failure_exit:

    CompleteTaskOnWorkloopThread(parallelRequest, false, scsiStatus, dataLen, senseBuffer, senseBufferLen);

    return kSCSIServiceResponse_Request_In_Process;

}

void

com_apple_dts_SCSIEmulatorAdapter::CompleteTaskOnWorkloopThread (

    SCSIParallelTaskIdentifier      parallelRequest,

    bool                            transportSuccessful,

    SCSITaskStatus                  scsiStatus,

    UInt64                          actuallyTransferred,

    UInt8*                          senseBuffer,

    int                             senseLength)

{

//  SCSITargetIdentifier        target                  = GetTargetIdentifier(parallelRequest);

    UInt8                       transferDir             = GetDataTransferDirection(parallelRequest);

    UInt64                      transferSizeMax         = GetRequestedDataTransferCount(parallelRequest);

//  IOMemoryDescriptor *        transferMemDesc         = GetDataBuffer(parallelRequest);

    SCSIEmulatorRequestBlock *  srb                     = ( SCSIEmulatorRequestBlock * ) GetHBADataPointer ( parallelRequest );

    if (transportSuccessful && (scsiStatus != kSCSITaskStatus_TASK_SET_FULL)) {

        // set the realized transfer counts

        switch (transferDir) {

            case kSCSIDataTransfer_FromTargetToInitiator:

            {

                if (actuallyTransferred > transferSizeMax) {

                    actuallyTransferred = transferSizeMax;

                }

                if (!SetRealizedDataTransferCount(parallelRequest, actuallyTransferred)) {

                    IOLog("CompleteTaskOnWorkloopThread: SetRealizedDataTransferCount (%d bytes) returned FAIL\n", actuallyTransferred);

                }

                break;

            }

            case kSCSIDataTransfer_FromInitiatorToTarget:

            {

                if (actuallyTransferred > transferSizeMax) {

                    actuallyTransferred = transferSizeMax;

                }

                if (!SetRealizedDataTransferCount(parallelRequest, actuallyTransferred)) {

                    IOLog("CompleteTaskOnWorkloopThread: SetRealizedDataTransferCount (%d bytes) returned FAIL\n", actuallyTransferred);

                }

                break;

            }

            case kSCSIDataTransfer_NoDataTransfer:

            default:

            {

                break;

            }

        }

    }

    // Now, add the completion to the queue to be checked by the workloop thread.  The completion needs

    // to be done on the workloop to allow the stack to unwind itself or you risk running into a panic.

    // The addItemToQueue method in the event source signals the workloop to check the queue after the task

    // is added.

    if (!transportSuccessful) {

        IOLog("CompleteTaskOnWorkloopThread: Failed transport - task = %p, transferDir = %d, transferSize = %lld, scsiStatus = 0x%X\n", parallelRequest, transferDir, transferSizeMax, scsiStatus);

        queue_init(&srb->fQueueChain);

        srb->fTask = parallelRequest;

        srb->fTaskStatus = scsiStatus;

        srb->fServiceResponse = kSCSIServiceResponse_SERVICE_DELIVERY_OR_TARGET_FAILURE;

        mResponderEventSource->addItemToQueue(srb);

    } else {

        // handle sense data in common fashion and complete the task

        if (senseLength > 0) {

            if (!SetAutoSenseData(parallelRequest, (SCSI_Sense_Data*) senseBuffer, senseLength)) {

                IOLog("CompleteTaskOnWorkloopThread: Could not set sense data in parallel task\n");

            }

        }

        queue_init(&srb->fQueueChain);

        srb->fTask = parallelRequest;

        srb->fTaskStatus = scsiStatus;

        srb->fServiceResponse = kSCSIServiceResponse_TASK_COMPLETE;

        mResponderEventSource->addItemToQueue(srb);

    }

}

void

com_apple_dts_SCSIEmulatorAdapter::TaskComplete (com_apple_dts_SCSIEmulatorAdapter *owner, SCSIEmulatorRequestBlock response)

{

    owner->CompleteParallelTask(response.fTask, response.fTaskStatus, response.fServiceResponse);

}