/*
 * Copyright 2015-2016 NVIDIA Corporation. All rights reserved.
 *
 * Sample to demonstrate use of NVlink CUPTI APIs
 */

 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <cuda.h>
 #include <cupti.h>

 #define CUPTI_CALL(call)                                                      \
 do {                                                                          \
     CUptiResult _status = call;                                               \
     if (_status != CUPTI_SUCCESS) {                                           \
         const char *errstr;                                                   \
         cuptiGetResultString(_status, &errstr);                               \
         fprintf(stderr, "%s:%d: error: function %s failed with error %s.\n",  \
                 __FILE__, __LINE__, #call, errstr);                           \
         exit(-1);                                                             \
     }                                                                         \
 } while (0)

 #define DRIVER_API_CALL(apiFuncCall)                                           \
 do {                                                                           \
     CUresult _status = apiFuncCall;                                            \
     if (_status != CUDA_SUCCESS) {                                             \
         fprintf(stderr, "%s:%d: error: function %s failed with error %d.\n",   \
                 __FILE__, __LINE__, #apiFuncCall, _status);                    \
         exit(-1);                                                              \
     }                                                                          \
 } while (0)

 #define RUNTIME_API_CALL(apiFuncCall)                                          \
 do {                                                                           \
     cudaError_t _status = apiFuncCall;                                         \
     if (_status != cudaSuccess) {                                              \
         fprintf(stderr, "%s:%d: error: function %s failed with error %s.\n",   \
                 __FILE__, __LINE__, #apiFuncCall, cudaGetErrorString(_status));\
         exit(-1);                                                              \
     }                                                                          \
 } while (0)

 #define MEMORY_ALLOCATION_CALL(var)                                            \
 do {                                                                           \
     if (var == NULL) {                                                         \
         fprintf(stderr, "%s:%d: Error: Memory Allocation Failed \n",           \
                 __FILE__, __LINE__);                                           \
         exit(-1);                                                              \
     }                                                                          \
 } while (0)

 #define MAX_DEVICES    (32)
 #define BLOCK_SIZE     (1024)
 #define GRID_SIZE      (512)
 #define BUF_SIZE       (32 * 1024)
 #define ALIGN_SIZE     (8)
 #define SUCCESS        (0)
 #define NUM_METRIC     (4)
 #define NUM_EVENTS     (2)
 #define MAX_SIZE       (64*1024*1024)   // 64 MB
 #define NUM_STREAMS    (6)   // gp100 has 6 physical copy engines

 CUpti_ActivityNvLink *nvlinkRec = NULL;
 int cpuToGpu = 0;
 int gpuToGpu = 0;
 int cpuToGpuAccess = 0;
 int gpuToGpuAccess = 0;

 extern "C" __global__ void test_nvlink_bandwidth(float *src, float *dst)
 {
     int idx = blockIdx.x * blockDim.x + threadIdx.x;
     dst[idx] = src[idx] * 2.0f;
 }

 static void printActivity(CUpti_Activity *record)
 {
     if (record->kind == CUPTI_ACTIVITY_KIND_NVLINK) {
         nvlinkRec = (CUpti_ActivityNvLink *)record;

         printf("typeDev0 %d, typeDev1 %d, sysmem %d, peer %d, physical links %d, portdev0 %d, %d, %d, %d, portDev1 %d, %d, %d, %d, bandwidth %llu\n",
           nvlinkRec->typeDev0,
           nvlinkRec->typeDev1,
           ((nvlinkRec->flag & CUPTI_LINK_FLAG_SYSMEM_ACCESS) ? 1 : 0),
           ((nvlinkRec->flag & CUPTI_LINK_FLAG_PEER_ACCESS) ? 1 : 0),
           nvlinkRec->physicalNvLinkCount,
           nvlinkRec->portDev0[0], nvlinkRec->portDev0[1], nvlinkRec->portDev0[2], nvlinkRec->portDev0[3],
           nvlinkRec->portDev1[0], nvlinkRec->portDev1[1], nvlinkRec->portDev1[2], nvlinkRec->portDev1[3],
           (long long unsigned int)nvlinkRec->bandwidth);
         cpuToGpuAccess |= (nvlinkRec->flag & CUPTI_LINK_FLAG_SYSMEM_ACCESS);
         gpuToGpuAccess |= (nvlinkRec->flag & CUPTI_LINK_FLAG_PEER_ACCESS);
     }
     else {
         printf("Error : Unexpected CUPTI activity kind.\nExpected Activity kind : CUPTI_ACTIVITY_KIND_NVLINK\n");
     }
 }

 static void CUPTIAPI bufferRequested(uint8_t **buffer, size_t *size, size_t *maxNumRecords)

 {
     *size = BUF_SIZE + ALIGN_SIZE;
     *buffer = (uint8_t*) calloc(1, *size);
     MEMORY_ALLOCATION_CALL(*buffer);
     *maxNumRecords = 0;
 }

 static void CUPTIAPI bufferCompleted(CUcontext ctx, uint32_t streamId,
                                 uint8_t *buffer, size_t size,
                                 size_t validSize)
 {
     CUptiResult status;
     CUpti_Activity *record = NULL;
     do {
         status = cuptiActivityGetNextRecord(buffer, validSize, &record);
         if(status == CUPTI_SUCCESS) {
             printActivity(record);
         }
         else if (status == CUPTI_ERROR_MAX_LIMIT_REACHED) {
             break;
         }
         else {
             CUPTI_CALL(status);
         }
     } while (1);

     size_t dropped;
     CUPTI_CALL(cuptiActivityGetNumDroppedRecords(ctx, streamId, &dropped));
     if (dropped != 0) {
         printf("Dropped %u activity records\n", (unsigned int)dropped);
     }
 }

 #define DIM(x) (sizeof(x)/sizeof(*(x)))

 void calculateSize(char *result, uint64_t size)
 {
     int i;

     const char *sizes[]   = { "TB", "GB", "MB", "KB", "B" };
     uint64_t  exbibytes = 1024ULL * 1024ULL * 1024ULL * 1024ULL;

     uint64_t  multiplier = exbibytes;

     for (i = 0; (unsigned)i < DIM(sizes); i++, multiplier /= (uint64_t)1024)
     {
         if (size < multiplier)
             continue;
         sprintf(result, "%.1f %s", (float) size / multiplier, sizes[i]);
         return;
     }
     strcpy(result, "0");
     return;
 }

 void readMetricValue(CUpti_EventGroup eventGroup, uint32_t numEvents,
                     CUdevice dev, CUpti_MetricID *metricId,
                     uint64_t timeDuration,
                     CUpti_MetricValue *metricValue) {

     size_t bufferSizeBytes, numCountersRead;
     uint64_t *eventValueArray = NULL;
     CUpti_EventID *eventIdArray;
     size_t arraySizeBytes = 0;
     size_t numTotalInstancesSize = 0;
     uint64_t numTotalInstances = 0;
     uint64_t *aggrEventValueArray = NULL;
     size_t aggrEventValueArraySize;
     uint32_t i = 0, j = 0;
     CUpti_EventDomainID domainId;
     size_t domainSize;

     domainSize = sizeof(CUpti_EventDomainID);

     CUPTI_CALL(cuptiEventGroupGetAttribute(eventGroup, 
                                            CUPTI_EVENT_GROUP_ATTR_EVENT_DOMAIN_ID, 
                                            &domainSize, 
                                            (void *)&domainId));

     numTotalInstancesSize = sizeof(uint64_t);

     CUPTI_CALL(cuptiDeviceGetEventDomainAttribute(dev, 
                                               domainId, 
                                               CUPTI_EVENT_DOMAIN_ATTR_TOTAL_INSTANCE_COUNT, 
                                               &numTotalInstancesSize, 
                                               (void *)&numTotalInstances));

     arraySizeBytes = sizeof(CUpti_EventID) * numEvents;
     bufferSizeBytes = sizeof(uint64_t) * numEvents * numTotalInstances;

     eventValueArray = (uint64_t *) malloc(bufferSizeBytes);
     MEMORY_ALLOCATION_CALL(eventValueArray);

     eventIdArray = (CUpti_EventID *) malloc(arraySizeBytes);
     MEMORY_ALLOCATION_CALL(eventIdArray);

     aggrEventValueArray = (uint64_t *) calloc(numEvents, sizeof(uint64_t));
     MEMORY_ALLOCATION_CALL(aggrEventValueArray);

     aggrEventValueArraySize = sizeof(uint64_t) * numEvents;

     CUPTI_CALL(cuptiEventGroupReadAllEvents(eventGroup, 
                                                 CUPTI_EVENT_READ_FLAG_NONE,
                                                 &bufferSizeBytes, 
                                                 eventValueArray, 
                                                 &arraySizeBytes, 
                                                 eventIdArray, 
                                                 &numCountersRead));

     for (i = 0; i < numEvents; i++) {
         for (j = 0; j < numTotalInstances; j++) {
             aggrEventValueArray[i] += eventValueArray[i + numEvents * j];
             //printf("For event %d (id %d) instance %d value %ul aggregate %d = %ul\n", i, eventIdArray[i], j,  eventValueArray[i + numEvents * j], i, aggrEventValueArray[i]);
         }
     }

     for (i = 0; i < NUM_METRIC; i++) {
         CUPTI_CALL(cuptiMetricGetValue(dev, metricId[i], arraySizeBytes,
                               eventIdArray, aggrEventValueArraySize,
                               aggrEventValueArray, timeDuration,
                               &metricValue[i]));
     }

     free(eventValueArray);
     free(eventIdArray);
 }

   // Print metric value, we format based on the value kind
 int printMetricValue(CUpti_MetricID metricId, CUpti_MetricValue metricValue, const char *metricName, uint64_t timeDuration) {

     CUpti_MetricValueKind valueKind;
     char str[64];
     size_t valueKindSize = sizeof(valueKind);

     CUPTI_CALL(cuptiMetricGetAttribute(metricId, CUPTI_METRIC_ATTR_VALUE_KIND,
                                        &valueKindSize, &valueKind));
     switch (valueKind) {

     case CUPTI_METRIC_VALUE_KIND_DOUBLE:
         printf("%s = ", metricName);
         calculateSize(str, (uint64_t)metricValue.metricValueDouble);
         // printf("%s   (val %lu  %lu nsec)\n", str, metricValue.metricValueUint64, timeDuration);
         printf("%s\n", str);
         break;

     case CUPTI_METRIC_VALUE_KIND_UINT64:
         printf("%s = ", metricName);
         calculateSize(str, (uint64_t)metricValue.metricValueUint64);
         printf("%s\n", str);
         break;

     case CUPTI_METRIC_VALUE_KIND_INT64:
         printf("%s = ", metricName);
         calculateSize(str, (uint64_t)metricValue.metricValueInt64);
         printf("%s\n", str);
         break;

     case CUPTI_METRIC_VALUE_KIND_THROUGHPUT:
         printf("%s = ", metricName);
         calculateSize(str, (uint64_t)metricValue.metricValueThroughput);
         printf("%s\n", str);
         break;

     default:
         fprintf(stderr, "error: unknown value kind\n");
         return -1;
     }
     return 0;
   }

 void testCpuToGpu(CUpti_EventGroup *eventGroup, CUdeviceptr *pDevBuffer,
                     float** pHostBuffer, size_t bufferSize,
                     cudaStream_t *cudaStreams,
                     uint64_t *timeDuration, int numEventGroup)
 {
     int i;
     uint32_t value = 1;
     uint64_t startTimestamp, endTimestamp;

     for (i = 0; i < numEventGroup; i++) {
             CUPTI_CALL(cuptiEventGroupEnable(eventGroup[i]));
             CUPTI_CALL(cuptiEventGroupSetAttribute(eventGroup[i],
                                 CUPTI_EVENT_GROUP_ATTR_PROFILE_ALL_DOMAIN_INSTANCES,
                                 sizeof(uint32_t), (void*)&value));
     }

     CUPTI_CALL(cuptiGetTimestamp(&startTimestamp));

     //Unidirectional copy H2D
     for (i = 0; i < NUM_STREAMS; i++)
     {
         RUNTIME_API_CALL(cudaMemcpyAsync((void *)pDevBuffer[i], pHostBuffer[i], bufferSize, cudaMemcpyHostToDevice, cudaStreams[i]));
     }
     RUNTIME_API_CALL(cudaDeviceSynchronize());

     //Unidirectional copy D2H
     for (i = 0; i < NUM_STREAMS; i++)
     {
         RUNTIME_API_CALL(cudaMemcpyAsync(pHostBuffer[i], (void *)pDevBuffer[i], bufferSize, cudaMemcpyDeviceToHost, cudaStreams[i]));}

     RUNTIME_API_CALL(cudaDeviceSynchronize());

     //Bidirectional copy
     for (i = 0; i < NUM_STREAMS; i+=2)
     {
         RUNTIME_API_CALL(cudaMemcpyAsync((void *)pDevBuffer[i], pHostBuffer[i], bufferSize, cudaMemcpyHostToDevice, cudaStreams[i]));
         RUNTIME_API_CALL(cudaMemcpyAsync(pHostBuffer[i+1], (void *)pDevBuffer[i+1], bufferSize, cudaMemcpyDeviceToHost, cudaStreams[i+1]));
     }
     RUNTIME_API_CALL(cudaDeviceSynchronize());

     CUPTI_CALL(cuptiGetTimestamp(&endTimestamp));
     *timeDuration = endTimestamp - startTimestamp;
 }

 void testGpuToGpu(CUpti_EventGroup *eventGroup, CUdeviceptr *pDevBuffer0, CUdeviceptr *pDevBuffer1,
                     float** pHostBuffer, size_t bufferSize,
                     cudaStream_t *cudaStreams,
                     uint64_t *timeDuration, int numEventGroup)
 {
     int i;
     uint32_t value = 1;
     uint64_t startTimestamp, endTimestamp;


     RUNTIME_API_CALL(cudaSetDevice(0));
     RUNTIME_API_CALL(cudaDeviceEnablePeerAccess(1, 0));
     RUNTIME_API_CALL(cudaSetDevice(1));
     RUNTIME_API_CALL(cudaDeviceEnablePeerAccess(0, 0));

     //Unidirectional copy H2D
     for (i = 0; i < NUM_STREAMS; i++) {
         RUNTIME_API_CALL(cudaMemcpyAsync((void *)pDevBuffer0[i], pHostBuffer[i], bufferSize, cudaMemcpyHostToDevice, cudaStreams[i]));
     }
     RUNTIME_API_CALL(cudaDeviceSynchronize());

     for (i = 0; i < NUM_STREAMS; i++) {
         RUNTIME_API_CALL(cudaMemcpyAsync((void *)pDevBuffer1[i], pHostBuffer[i], bufferSize, cudaMemcpyHostToDevice, cudaStreams[i]));
     }
     RUNTIME_API_CALL(cudaDeviceSynchronize());


     for (i = 0; i < numEventGroup; i++) {
         printf("cuptiEventGroupEnable(eventGroup[%d])\n", i);
         CUPTI_CALL(cuptiEventGroupEnable(eventGroup[i]));
         CUPTI_CALL(cuptiEventGroupSetAttribute(eventGroup[i],
                             CUPTI_EVENT_GROUP_ATTR_PROFILE_ALL_DOMAIN_INSTANCES,
                             sizeof(uint32_t), (void*)&value));
     }
     CUPTI_CALL(cuptiGetTimestamp(&startTimestamp));

     for (i = 0; i < NUM_STREAMS; i++) {
         RUNTIME_API_CALL(cudaMemcpyAsync((void *)pDevBuffer0[i], (void *)pDevBuffer1[i], bufferSize, cudaMemcpyDeviceToDevice, cudaStreams[i]));
     }
     RUNTIME_API_CALL(cudaDeviceSynchronize());

     for (i = 0; i < NUM_STREAMS; i++) {
         RUNTIME_API_CALL(cudaMemcpyAsync((void *)pDevBuffer1[i], (void *)pDevBuffer0[i], bufferSize, cudaMemcpyDeviceToDevice, cudaStreams[i]));
     }
     RUNTIME_API_CALL(cudaDeviceSynchronize());

     for (i = 0; i < NUM_STREAMS; i++) {
         test_nvlink_bandwidth<<<GRID_SIZE, BLOCK_SIZE>>>((float*)pDevBuffer1[i], (float*)pDevBuffer0[i]);
     }

     CUPTI_CALL(cuptiGetTimestamp(&endTimestamp));
     *timeDuration = endTimestamp - startTimestamp;
 }

 static void printUsage() {
     printf("usage: Demonstrate use of NVlink CUPTI APIs\n");
     printf("       -help           : display help message\n");
     printf("       --cpu-to-gpu    : Show results for data transfer between CPU and GPU \n");
     printf("       --gpu-to-gpu    : Show results for data transfer between two GPUs \n");
 }

 void parseCommandLineArgs(int argc, char *argv[])
 {
     if (argc != 2) {
         printf("Invalid number of options\n");
         exit(0);
     }

     if (strcmp(argv[1], "--cpu-to-gpu") == 0) {
         cpuToGpu = 1;
     }
     else if (strcmp(argv[1], "--gpu-to-gpu") == 0) {
         gpuToGpu = 1;
     }
     else if ((strcmp(argv[1], "--help") == 0) ||
              (strcmp(argv[1], "-help") == 0) ||
              (strcmp(argv[1], "-h") == 0)) {
         printUsage();
         exit(0);
     }
     else {
         cpuToGpu = 1;
     }
 }

 int main(int argc, char *argv[])
 {
     int deviceCount = 0, i = 0, j = 0, numEventGroup = 0;
     size_t bufferSize = 0, freeMemory = 0, totalMemory = 0;
     CUpti_EventGroupSets *passes = NULL;
     CUcontext ctx;
     char str[64];

     CUdeviceptr pDevBuffer0[NUM_STREAMS];
     CUdeviceptr pDevBuffer1[NUM_STREAMS];
     float* pHostBuffer[NUM_STREAMS];

     cudaStream_t cudaStreams[NUM_STREAMS] = {0};

     CUpti_EventGroup eventGroup[32];
     CUpti_MetricID metricId[NUM_METRIC];
     uint32_t numEvents[NUM_METRIC];
     CUpti_MetricValue metricValue[NUM_METRIC];
     cudaDeviceProp prop[MAX_DEVICES];
     uint64_t timeDuration;

     // Adding nvlink Metrics.
     const char *metricName[NUM_METRIC] = {"nvlink_total_data_transmitted",
                                     "nvlink_total_data_received",
                                     "nvlink_transmit_throughput",
                                     "nvlink_receive_throughput"};

     // Parse command line arguments
     parseCommandLineArgs(argc, argv);

     CUPTI_CALL(cuptiActivityEnable(CUPTI_ACTIVITY_KIND_NVLINK));
     CUPTI_CALL(cuptiActivityRegisterCallbacks(bufferRequested, bufferCompleted));

     DRIVER_API_CALL(cuInit(0));

     RUNTIME_API_CALL(cudaGetDeviceCount(&deviceCount));

     printf("There are %d devices.\n", deviceCount);

     if (deviceCount == 0) {
         printf("There is no device supporting CUDA.\n");
         exit(-1);
     }

     for (i = 0; i < deviceCount; i++) {
        RUNTIME_API_CALL(cudaGetDeviceProperties(&prop[i], i));
        printf("CUDA Device %d Name: %s\n", i, prop[i].name);
    }

    // Set memcpy size based on available device memory
    RUNTIME_API_CALL(cudaMemGetInfo(&freeMemory, &totalMemory));
    bufferSize = MAX_SIZE < (freeMemory/4) ? MAX_SIZE : (freeMemory/4);

    printf("Total Device Memory available : ");
    calculateSize(str, (uint64_t)totalMemory);
    printf("%s\n", str);

    printf("Memcpy size is set to %llu B (%llu MB)\n",
    (unsigned long long)bufferSize, (unsigned long long)bufferSize/(1024*1024));

    for(i = 0; i < NUM_STREAMS; i++) {
       RUNTIME_API_CALL(cudaStreamCreate(&cudaStreams[i]));
    }
    RUNTIME_API_CALL(cudaDeviceSynchronize());

    // Nvlink-topology Records are generated even before cudaMemcpy API is called.
    CUPTI_CALL(cuptiActivityFlushAll(0));

    // Transfer Data between Host And Device, if Nvlink is Present
    // Check condition : nvlinkRec->flag & CUPTI_LINK_FLAG_SYSMEM_ACCESS
    // True : Nvlink is present between CPU & GPU
    // False : Nvlink is not present.
    if ((nvlinkRec) && (((cpuToGpu) && (cpuToGpuAccess)) || ((gpuToGpu) && (gpuToGpuAccess)))) {

        for (i = 0; i < NUM_METRIC; i++) {
            CUPTI_CALL(cuptiMetricGetIdFromName(0, metricName[i], &metricId[i]));
            CUPTI_CALL(cuptiMetricGetNumEvents(metricId[i], &numEvents[i]));
        }

        DRIVER_API_CALL(cuCtxCreate(&ctx, 0, 0));

        CUPTI_CALL(cuptiMetricCreateEventGroupSets(ctx, (sizeof metricId) ,metricId, &passes));

        // EventGroups required to profile Nvlink metrics.
        for (i = 0; i < (signed)passes->numSets; i++) {
            for (j = 0; j < (signed)passes->sets[i].numEventGroups; j++) {
                eventGroup[numEventGroup] = passes->sets[i].eventGroups[j];

                if (!eventGroup[numEventGroup]) {
                    printf("\n eventGroup initialization failed \n");
                    exit(-1);
                }

                numEventGroup++;
            }
        }

        CUPTI_CALL(cuptiSetEventCollectionMode(ctx, CUPTI_EVENT_COLLECTION_MODE_CONTINUOUS));

        // ===== Allocate Memory =====================================

        for(i = 0; i < NUM_STREAMS; i++) {
            RUNTIME_API_CALL(cudaMalloc((void**)&pDevBuffer0[i], bufferSize));

            pHostBuffer[i] = (float *)malloc(bufferSize);
            MEMORY_ALLOCATION_CALL(pHostBuffer[i]);
        }

        if (cpuToGpu) {
            testCpuToGpu(eventGroup, pDevBuffer0, pHostBuffer, bufferSize, cudaStreams, &timeDuration, numEventGroup);
            printf("Data tranferred between CPU & Device%d : \n", (int)nvlinkRec->typeDev0);
        }
        else if(gpuToGpu) {
            RUNTIME_API_CALL(cudaSetDevice(1));
            for(i = 0; i < NUM_STREAMS; i++) {
                RUNTIME_API_CALL(cudaMalloc((void**)&pDevBuffer1[i], bufferSize));
            }
            testGpuToGpu(eventGroup, pDevBuffer0, pDevBuffer1,pHostBuffer, bufferSize, cudaStreams, &timeDuration, numEventGroup);
            printf("Data tranferred between Device 0 & Device 1 : \n");
        }

        // Collect Nvlink Metric values for the data transfer via Nvlink for all the eventGroups.
        for (i = 0; i < numEventGroup; i++) {
            readMetricValue(eventGroup[i], NUM_EVENTS, 0, metricId, timeDuration, metricValue);

            CUPTI_CALL(cuptiEventGroupDisable(eventGroup[i]));
            CUPTI_CALL(cuptiEventGroupDestroy(eventGroup[i]));

            for (i = 0; i < NUM_METRIC; i++) {
                if (printMetricValue(metricId[i], metricValue[i], metricName[i], timeDuration) != 0) {
                    printf("\n printMetricValue failed \n");
                    exit(-1);
                }
            }
        }
    }
    else {
        printf("No Nvlink supported device found\n");
    }

    return 0;
}