gpu_mem_helpers.hh

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/*
 * Copyright (c) 2018 Advanced Micro Devices, Inc.
 * All rights reserved.
 *
 * For use for simulation and test purposes only
 *
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 * modification, are permitted provided that the following conditions are met:
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 * 1. Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
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 * software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
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 * Authors: Matt Sinclair
 */
 
#ifndef __ARCH_GCN3_GPU_MEM_HELPERS_HH__
#define __ARCH_GCN3_GPU_MEM_HELPERS_HH__
 
#include "arch/gcn3/insts/gpu_static_inst.hh"
#include "arch/gcn3/insts/op_encodings.hh"
#include "debug/GPUMem.hh"
#include "gpu-compute/gpu_dyn_inst.hh"
 
template<typename T, int N>
inline void
initMemReqHelper(GPUDynInstPtr gpuDynInst, MemCmd mem_req_type,
                 bool is_atomic=false)
{
    // local variables
    int req_size = N * sizeof(T);
    int block_size = gpuDynInst->computeUnit()->cacheLineSize();
    Addr vaddr = 0, split_addr = 0;
    bool misaligned_acc = false;
    RequestPtr req = nullptr, req1 = nullptr, req2 = nullptr;
    PacketPtr pkt = nullptr, pkt1 = nullptr, pkt2 = nullptr;
 
    gpuDynInst->resetEntireStatusVector();
    for (int lane = 0; lane < Gcn3ISA::NumVecElemPerVecReg; ++lane) {
        if (gpuDynInst->exec_mask[lane]) {
            vaddr = gpuDynInst->addr[lane];
 
            split_addr = roundDown(vaddr + req_size - 1, block_size);
 
            assert(split_addr <= vaddr || split_addr - vaddr < block_size);
            misaligned_acc = split_addr > vaddr;
 
            if (is_atomic) {
                // make sure request is word aligned
                assert((vaddr & 0x3) == 0);
 
                // a given lane's atomic can't cross cache lines
                assert(!misaligned_acc);
 
                req = std::make_shared<Request>(vaddr, sizeof(T), 0,
                    gpuDynInst->computeUnit()->requestorId(), 0,
                    gpuDynInst->wfDynId,
                    gpuDynInst->makeAtomicOpFunctor<T>(
                        &(reinterpret_cast<T*>(gpuDynInst->a_data))[lane],
                        &(reinterpret_cast<T*>(gpuDynInst->x_data))[lane]));
            } else {
                req = std::make_shared<Request>(vaddr, req_size, 0,
                                  gpuDynInst->computeUnit()->requestorId(), 0,
                                  gpuDynInst->wfDynId);
            }
 
            if (misaligned_acc) {
                gpuDynInst->setStatusVector(lane, 2);
                req->splitOnVaddr(split_addr, req1, req2);
                gpuDynInst->setRequestFlags(req1);
                gpuDynInst->setRequestFlags(req2);
                pkt1 = new Packet(req1, mem_req_type);
                pkt2 = new Packet(req2, mem_req_type);
                pkt1->dataStatic(&(reinterpret_cast<T*>(
                    gpuDynInst->d_data))[lane * N]);
                pkt2->dataStatic(&(reinterpret_cast<T*>(
                    gpuDynInst->d_data))[lane * N + req1->getSize()]);
                DPRINTF(GPUMem, "CU%d: WF[%d][%d]: index: %d unaligned memory "
                        "request for %#x\n", gpuDynInst->cu_id,
                        gpuDynInst->simdId, gpuDynInst->wfSlotId, lane,
                        split_addr);
                gpuDynInst->computeUnit()->sendRequest(gpuDynInst, lane, pkt1);
                gpuDynInst->computeUnit()->sendRequest(gpuDynInst, lane, pkt2);
            } else {
                gpuDynInst->setStatusVector(lane, 1);
                gpuDynInst->setRequestFlags(req);
                pkt = new Packet(req, mem_req_type);
                pkt->dataStatic(&(reinterpret_cast<T*>(
                    gpuDynInst->d_data))[lane * N]);
                gpuDynInst->computeUnit()->sendRequest(gpuDynInst, lane, pkt);
            }
        } else { // if lane is not active, then no pending requests
            gpuDynInst->setStatusVector(lane, 0);
        }
    }
}
 
template<typename T, int N>
inline void
initMemReqScalarHelper(GPUDynInstPtr gpuDynInst, MemCmd mem_req_type)
{
    int req_size = N * sizeof(T);
    int block_size = gpuDynInst->computeUnit()->cacheLineSize();
    Addr vaddr = gpuDynInst->scalarAddr;
 
    Addr split_addr = roundDown(vaddr + req_size - 1, block_size);
 
    assert(split_addr <= vaddr || split_addr - vaddr < block_size);
    bool misaligned_acc = split_addr > vaddr;
 
    RequestPtr req = std::make_shared<Request>(vaddr, req_size, 0,
                                 gpuDynInst->computeUnit()->requestorId(), 0,
                                 gpuDynInst->wfDynId);
 
    if (misaligned_acc) {
        RequestPtr req1, req2;
        req->splitOnVaddr(split_addr, req1, req2);
        gpuDynInst->numScalarReqs = 2;
        gpuDynInst->setRequestFlags(req1);
        gpuDynInst->setRequestFlags(req2);
        PacketPtr pkt1 = new Packet(req1, mem_req_type);
        PacketPtr pkt2 = new Packet(req2, mem_req_type);
        pkt1->dataStatic(gpuDynInst->scalar_data);
        pkt2->dataStatic(gpuDynInst->scalar_data + req1->getSize());
        DPRINTF(GPUMem, "CU%d: WF[%d][%d]: unaligned scalar memory request for"
                " %#x\n", gpuDynInst->cu_id, gpuDynInst->simdId,
                gpuDynInst->wfSlotId, split_addr);
        gpuDynInst->computeUnit()->sendScalarRequest(gpuDynInst, pkt1);
        gpuDynInst->computeUnit()->sendScalarRequest(gpuDynInst, pkt2);
    } else {
        gpuDynInst->numScalarReqs = 1;
        gpuDynInst->setRequestFlags(req);
        PacketPtr pkt = new Packet(req, mem_req_type);
        pkt->dataStatic(gpuDynInst->scalar_data);
        gpuDynInst->computeUnit()->sendScalarRequest(gpuDynInst, pkt);
    }
}
 
#endif // __ARCH_GCN3_GPU_MEM_HELPERS_HH__