summaryrefslogtreecommitdiff
path: root/src/gpu-compute/global_memory_pipeline.cc
blob: 102905ec848cac24987c9d48b6c60887d13289b3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
/*
 * Copyright (c) 2014-2015 Advanced Micro Devices, Inc.
 * All rights reserved.
 *
 * For use for simulation and test purposes only
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 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
 * and/or other materials provided with the distribution.
 *
 * 3. Neither the name of the copyright holder nor the names of its contributors
 * may be used to endorse or promote products derived from this 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
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 * Author: John Kalamatianos, Sooraj Puthoor
 */

#include "gpu-compute/global_memory_pipeline.hh"

#include "debug/GPUMem.hh"
#include "debug/GPUReg.hh"
#include "gpu-compute/compute_unit.hh"
#include "gpu-compute/gpu_dyn_inst.hh"
#include "gpu-compute/shader.hh"
#include "gpu-compute/vector_register_file.hh"
#include "gpu-compute/wavefront.hh"

GlobalMemPipeline::GlobalMemPipeline(const ComputeUnitParams* p) :
    computeUnit(nullptr), gmQueueSize(p->global_mem_queue_size),
    inflightStores(0), inflightLoads(0)
{
}

void
GlobalMemPipeline::init(ComputeUnit *cu)
{
    computeUnit = cu;
    globalMemSize = computeUnit->shader->globalMemSize;
    _name = computeUnit->name() + ".GlobalMemPipeline";
}

void
GlobalMemPipeline::exec()
{
    // apply any returned global memory operations
    GPUDynInstPtr m = !gmReturnedLoads.empty() ? gmReturnedLoads.front() :
        !gmReturnedStores.empty() ? gmReturnedStores.front() : nullptr;

    bool accessVrf = true;
    // check the VRF to see if the operands of a load (or load component
    // of an atomic) are accessible
    if ((m) && (m->m_op==Enums::MO_LD || MO_A(m->m_op))) {
        Wavefront *w = computeUnit->wfList[m->simdId][m->wfSlotId];

        accessVrf =
            w->computeUnit->vrf[m->simdId]->
            vrfOperandAccessReady(m->seqNum(), w, m,
                                  VrfAccessType::WRITE);
    }

    if ((!gmReturnedStores.empty() || !gmReturnedLoads.empty()) &&
        m->latency.rdy() && computeUnit->glbMemToVrfBus.rdy() &&
        accessVrf && m->statusBitVector == VectorMask(0) &&
        (computeUnit->shader->coissue_return ||
         computeUnit->wfWait.at(m->pipeId).rdy())) {

        if (m->v_type == VT_32 && m->m_type == Enums::M_U8)
            doGmReturn<uint32_t, uint8_t>(m);
        else if (m->v_type == VT_32 && m->m_type == Enums::M_U16)
            doGmReturn<uint32_t, uint16_t>(m);
        else if (m->v_type == VT_32 && m->m_type == Enums::M_U32)
            doGmReturn<uint32_t, uint32_t>(m);
        else if (m->v_type == VT_32 && m->m_type == Enums::M_S8)
            doGmReturn<int32_t, int8_t>(m);
        else if (m->v_type == VT_32 && m->m_type == Enums::M_S16)
            doGmReturn<int32_t, int16_t>(m);
        else if (m->v_type == VT_32 && m->m_type == Enums::M_S32)
            doGmReturn<int32_t, int32_t>(m);
        else if (m->v_type == VT_32 && m->m_type == Enums::M_F16)
            doGmReturn<float, Float16>(m);
        else if (m->v_type == VT_32 && m->m_type == Enums::M_F32)
            doGmReturn<float, float>(m);
        else if (m->v_type == VT_64 && m->m_type == Enums::M_U8)
            doGmReturn<uint64_t, uint8_t>(m);
        else if (m->v_type == VT_64 && m->m_type == Enums::M_U16)
            doGmReturn<uint64_t, uint16_t>(m);
        else if (m->v_type == VT_64 && m->m_type == Enums::M_U32)
            doGmReturn<uint64_t, uint32_t>(m);
        else if (m->v_type == VT_64 && m->m_type == Enums::M_U64)
            doGmReturn<uint64_t, uint64_t>(m);
        else if (m->v_type == VT_64 && m->m_type == Enums::M_S8)
            doGmReturn<int64_t, int8_t>(m);
        else if (m->v_type == VT_64 && m->m_type == Enums::M_S16)
            doGmReturn<int64_t, int16_t>(m);
        else if (m->v_type == VT_64 && m->m_type == Enums::M_S32)
            doGmReturn<int64_t, int32_t>(m);
        else if (m->v_type == VT_64 && m->m_type == Enums::M_S64)
            doGmReturn<int64_t, int64_t>(m);
        else if (m->v_type == VT_64 && m->m_type == Enums::M_F16)
            doGmReturn<double, Float16>(m);
        else if (m->v_type == VT_64 && m->m_type == Enums::M_F32)
            doGmReturn<double, float>(m);
        else if (m->v_type == VT_64 && m->m_type == Enums::M_F64)
            doGmReturn<double, double>(m);
    }

    // If pipeline has executed a global memory instruction
    // execute global memory packets and issue global
    // memory packets to DTLB
    if (!gmIssuedRequests.empty()) {
        GPUDynInstPtr mp = gmIssuedRequests.front();
        if (mp->m_op == Enums::MO_LD ||
            (mp->m_op >= Enums::MO_AAND && mp->m_op <= Enums::MO_AMIN) ||
            (mp->m_op >= Enums::MO_ANRAND && mp->m_op <= Enums::MO_ANRMIN)) {

            if (inflightLoads >= gmQueueSize) {
                return;
            } else {
                ++inflightLoads;
            }
        } else {
            if (inflightStores >= gmQueueSize) {
                return;
            } else if (mp->m_op == Enums::MO_ST) {
                ++inflightStores;
            }
        }

        mp->initiateAcc(mp);
        gmIssuedRequests.pop();

        DPRINTF(GPUMem, "CU%d: WF[%d][%d] Popping 0 mem_op = %s\n",
                computeUnit->cu_id, mp->simdId, mp->wfSlotId,
                Enums::MemOpTypeStrings[mp->m_op]);
    }
}

template<typename c0, typename c1>
void
GlobalMemPipeline::doGmReturn(GPUDynInstPtr m)
{
    Wavefront *w = computeUnit->wfList[m->simdId][m->wfSlotId];

    // Return data to registers
    if (m->m_op == Enums::MO_LD || MO_A(m->m_op) || MO_ANR(m->m_op)) {
        gmReturnedLoads.pop();
        assert(inflightLoads > 0);
        --inflightLoads;

        if (m->m_op == Enums::MO_LD || MO_A(m->m_op)) {
            std::vector<uint32_t> regVec;
            // iterate over number of destination register operands since
            // this is a load or atomic operation
            for (int k = 0; k < m->n_reg; ++k) {
                assert((sizeof(c1) * m->n_reg) <= MAX_WIDTH_FOR_MEM_INST);
                int dst = m->dst_reg + k;

                if (m->n_reg > MAX_REGS_FOR_NON_VEC_MEM_INST)
                    dst = m->dst_reg_vec[k];
                // virtual->physical VGPR mapping
                int physVgpr = w->remap(dst, sizeof(c0), 1);
                // save the physical VGPR index
                regVec.push_back(physVgpr);
                c1 *p1 = &((c1 *)m->d_data)[k * w->computeUnit->wfSize()];

                for (int i = 0; i < w->computeUnit->wfSize(); ++i) {
                    if (m->exec_mask[i]) {
                        DPRINTF(GPUReg, "CU%d, WF[%d][%d], lane %d: "
                                "$%s%d <- %d global ld done (src = wavefront "
                                "ld inst)\n", w->computeUnit->cu_id, w->simdId,
                                w->wfSlotId, i, sizeof(c0) == 4 ? "s" : "d",
                                dst, *p1);
                        // write the value into the physical VGPR. This is a
                        // purely functional operation. No timing is modeled.
                        w->computeUnit->vrf[w->simdId]->write<c0>(physVgpr,
                                                                    *p1, i);
                    }
                    ++p1;
                }
            }

            // Schedule the write operation of the load data on the VRF.
            // This simply models the timing aspect of the VRF write operation.
            // It does not modify the physical VGPR.
            loadVrfBankConflictCycles +=
                w->computeUnit->vrf[w->simdId]->exec(m->seqNum(),
                                                     w, regVec, sizeof(c0),
                                                     m->time);
        }
    } else {
        gmReturnedStores.pop();
        assert(inflightStores > 0);
        --inflightStores;
    }

    // Decrement outstanding register count
    computeUnit->shader->ScheduleAdd(&w->outstandingReqs, m->time, -1);

    if (m->m_op == Enums::MO_ST || MO_A(m->m_op) || MO_ANR(m->m_op) ||
        MO_H(m->m_op)) {
        computeUnit->shader->ScheduleAdd(&w->outstandingReqsWrGm, m->time,
                                         -1);
    }

    if (m->m_op == Enums::MO_LD || MO_A(m->m_op) || MO_ANR(m->m_op)) {
        computeUnit->shader->ScheduleAdd(&w->outstandingReqsRdGm, m->time,
                                         -1);
    }

    // Mark write bus busy for appropriate amount of time
    computeUnit->glbMemToVrfBus.set(m->time);
    if (!computeUnit->shader->coissue_return)
        w->computeUnit->wfWait.at(m->pipeId).set(m->time);
}

void
GlobalMemPipeline::regStats()
{
    loadVrfBankConflictCycles
        .name(name() + ".load_vrf_bank_conflict_cycles")
        .desc("total number of cycles GM data are delayed before updating "
              "the VRF")
        ;
}