/*
Copyright (c) 2015-2016 Advanced Micro Devices, Inc. All rights reserved.
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANNTY OF ANY KIND, EXPRESS OR
IMPLIED, INNCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANNY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER INN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR INN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/

#include <hc_am.hpp>

#include "hip_runtime.h"
#include "hcc_detail/hip_hcc.h"
#include "hcc_detail/trace_helper.h"

/**
 * HCC returns 0 in *canAccessPeer ; Need to update this function when RT supports P2P
 */
//---
hipError_t hipDeviceCanAccessPeer (int* canAccessPeer, int  deviceId, int peerDeviceId)
{
    HIP_INIT_API(canAccessPeer, deviceId, peerDeviceId);

    hipError_t err = hipSuccess;

    auto thisDevice = ihipGetDevice(deviceId);
    auto peerDevice = ihipGetDevice(peerDeviceId);

    if ((thisDevice != NULL) && (peerDevice != NULL)) {
        if (deviceId == peerDeviceId) {
            *canAccessPeer = 0;
        } else {
#if USE_PEER_TO_PEER>=2
             *canAccessPeer = peerDevice->_acc.get_is_peer(thisDevice->_acc);
#else
            *canAccessPeer = 0;
#endif
        }

    } else {
        *canAccessPeer = 0;
        err = hipErrorInvalidDevice;
    }


    return ihipLogStatus(err);
}


//---
// Disable visibility of this device into memory allocated on peer device.
// Remove this device from peer device peerlist.
hipError_t hipDeviceDisablePeerAccess (int peerDeviceId)
{
    HIP_INIT_API(peerDeviceId);

    hipError_t err = hipSuccess;

    auto thisDevice = ihipGetTlsDefaultDevice();
    auto peerDevice = ihipGetDevice(peerDeviceId);
    if ((thisDevice != NULL) && (peerDevice != NULL)) {
#if USE_PEER_TO_PEER>=2
        // Return true if thisDevice can access peerDevice's memory:
        bool canAccessPeer =  peerDevice->_acc.get_is_peer(thisDevice->_acc);
#else
        bool canAccessPeer = 0;
#endif

        if (! canAccessPeer) {
            err = hipErrorInvalidDevice;  // P2P not allowed between these devices.
        } else if (thisDevice == peerDevice)  {
            err = hipErrorInvalidDevice;  // Can't disable peer access to self.
        } else {
            LockedAccessor_DeviceCrit_t peerCrit(peerDevice->criticalData());
            bool changed = peerCrit->removePeer(thisDevice);
            if (changed) {
#if USE_PEER_TO_PEER>=3
                // Update the peers for all memory already saved in the tracker:
                am_memtracker_update_peers(peerDevice->_acc, peerCrit->peerCnt(), peerCrit->peerAgents());
#endif
            } else {
                err = hipErrorPeerAccessNotEnabled; // never enabled P2P access.
            }
        } 
    } else {
        err = hipErrorInvalidDevice;
    }

    return ihipLogStatus(err);
};


//---
// Allow the current device to see all memory allocated on peerDevice.
// This should add this device to the peer-device peer list.
hipError_t hipDeviceEnablePeerAccess (int peerDeviceId, unsigned int flags)
{
    HIP_INIT_API(peerDeviceId, flags);

    hipError_t err = hipSuccess;
    if (flags != 0) {
        err = hipErrorInvalidValue;
    } else {
        auto thisDevice = ihipGetTlsDefaultDevice();
        auto peerDevice = ihipGetDevice(peerDeviceId);
        if (thisDevice == peerDevice)  {
            err = hipErrorInvalidDevice;  // Can't enable peer access to self.
        } else if ((thisDevice != NULL) && (peerDevice != NULL)) {
            LockedAccessor_DeviceCrit_t peerCrit(peerDevice->criticalData());
            bool isNewPeer = peerCrit->addPeer(thisDevice);
            if (isNewPeer) {
#if USE_PEER_TO_PEER>=3
                am_memtracker_update_peers(peerDevice->_acc, peerCrit->peerCnt(), peerCrit->peerAgents());
#endif
            } else {
                err = hipErrorPeerAccessAlreadyEnabled;
            }
        } else {
            err = hipErrorInvalidDevice;
        }
    }

    return ihipLogStatus(err);
}


//---
hipError_t hipMemcpyPeer (void* dst, int  dstDevice, const void* src, int  srcDevice, size_t sizeBytes)
{
    HIP_INIT_API(dst, dstDevice, src, srcDevice, sizeBytes);

    // HCC has a unified memory architecture so device specifiers are not required.
    return hipMemcpy(dst, src, sizeBytes, hipMemcpyDefault);
};


/**
 * This function uses a synchronous copy
 */
//---
hipError_t hipMemcpyPeerAsync (void* dst, int  dstDevice, const void* src, int  srcDevice, size_t sizeBytes, hipStream_t stream)
{
    HIP_INIT_API(dst, dstDevice, src, srcDevice, sizeBytes, stream);
    // HCC has a unified memory architecture so device specifiers are not required.
    return hipMemcpyAsync(dst, src, sizeBytes, hipMemcpyDefault, stream);
};


/**
 * @return #hipSuccess
 */
//---
hipError_t hipDriverGetVersion(int *driverVersion)
{
    HIP_INIT_API(driverVersion);

    if (driverVersion) {
        *driverVersion = 4;
    }

    return ihipLogStatus(hipSuccess);
}