1/*
2 * Copyright (c) 2012-2013 ARM Limited
3 * All rights reserved
4 *
5 * The license below extends only to copyright in the software and shall
6 * not be construed as granting a license to any other intellectual
7 * property including but not limited to intellectual property relating
8 * to a hardware implementation of the functionality of the software
9 * licensed hereunder.  You may use the software subject to the license
10 * terms below provided that you ensure that this notice is replicated
11 * unmodified and in its entirety in all distributions of the software,
12 * modified or unmodified, in source code or in binary form.
13 *
14 * Copyright (c) 2006 The Regents of The University of Michigan
15 * All rights reserved.
16 *
17 * Redistribution and use in source and binary forms, with or without
18 * modification, are permitted provided that the following conditions are
19 * met: redistributions of source code must retain the above copyright
20 * notice, this list of conditions and the following disclaimer;
21 * redistributions in binary form must reproduce the above copyright
22 * notice, this list of conditions and the following disclaimer in the
23 * documentation and/or other materials provided with the distribution;
24 * neither the name of the copyright holders nor the names of its
25 * contributors may be used to endorse or promote products derived from
26 * this software without specific prior written permission.
27 *
28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
29 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
30 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
31 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
32 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
33 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
34 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
35 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
36 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
37 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
38 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
39 *
40 * Authors: Kevin Lim
41 */
42
43#include "cpu/o3/fu_pool.hh"
44
45#include <sstream>
46
47#include "cpu/func_unit.hh"
48
49using namespace std;
50
51////////////////////////////////////////////////////////////////////////////
52//
53//  A pool of function units
54//
55
56inline void
57FUPool::FUIdxQueue::addFU(int fu_idx)
58{
59    funcUnitsIdx.push_back(fu_idx);
60    ++size;
61}
62
63inline int
64FUPool::FUIdxQueue::getFU()
65{
66    int retval = funcUnitsIdx[idx++];
67
68    if (idx == size)
69        idx = 0;
70
71    return retval;
72}
73
74FUPool::~FUPool()
75{
76    fuListIterator i = funcUnits.begin();
77    fuListIterator end = funcUnits.end();
78    for (; i != end; ++i)
79        delete *i;
80}
81
82
83// Constructor
84FUPool::FUPool(const Params *p)
85    : SimObject(p)
86{
87    numFU = 0;
88
89    funcUnits.clear();
90
91    maxOpLatencies.fill(Cycles(0));
92    pipelined.fill(true);
93
94    //
95    //  Iterate through the list of FUDescData structures
96    //
97    const vector<FUDesc *> &paramList =  p->FUList;
98    for (FUDDiterator i = paramList.begin(); i != paramList.end(); ++i) {
99
100        //
101        //  Don't bother with this if we're not going to create any FU's
102        //
103        if ((*i)->number) {
104            //
105            //  Create the FuncUnit object from this structure
106            //   - add the capabilities listed in the FU's operation
107            //     description
108            //
109            //  We create the first unit, then duplicate it as needed
110            //
111            FuncUnit *fu = new FuncUnit;
112
113            OPDDiterator j = (*i)->opDescList.begin();
114            OPDDiterator end = (*i)->opDescList.end();
115            for (; j != end; ++j) {
116                // indicate that this pool has this capability
117                capabilityList.set((*j)->opClass);
118
119                // Add each of the FU's that will have this capability to the
120                // appropriate queue.
121                for (int k = 0; k < (*i)->number; ++k)
122                    fuPerCapList[(*j)->opClass].addFU(numFU + k);
123
124                // indicate that this FU has the capability
125                fu->addCapability((*j)->opClass, (*j)->opLat, (*j)->pipelined);
126
127                if ((*j)->opLat > maxOpLatencies[(*j)->opClass])
128                    maxOpLatencies[(*j)->opClass] = (*j)->opLat;
129
130                if (!(*j)->pipelined)
131                    pipelined[(*j)->opClass] = false;
132            }
133
134            numFU++;
135
136            //  Add the appropriate number of copies of this FU to the list
137            fu->name = (*i)->name() + "(0)";
138            funcUnits.push_back(fu);
139
140            for (int c = 1; c < (*i)->number; ++c) {
141                ostringstream s;
142                numFU++;
143                FuncUnit *fu2 = new FuncUnit(*fu);
144
145                s << (*i)->name() << "(" << c << ")";
146                fu2->name = s.str();
147                funcUnits.push_back(fu2);
148            }
149        }
150    }
151
152    unitBusy.resize(numFU);
153
154    for (int i = 0; i < numFU; i++) {
155        unitBusy[i] = false;
156    }
157}
158
159int
160FUPool::getUnit(OpClass capability)
161{
162    //  If this pool doesn't have the specified capability,
163    //  return this information to the caller
164    if (!capabilityList[capability])
165        return -2;
166
167    int fu_idx = fuPerCapList[capability].getFU();
168    int start_idx = fu_idx;
169
170    // Iterate through the circular queue if needed, stopping if we've reached
171    // the first element again.
172    while (unitBusy[fu_idx]) {
173        fu_idx = fuPerCapList[capability].getFU();
174        if (fu_idx == start_idx) {
175            // No FU available
176            return -1;
177        }
178    }
179
180    assert(fu_idx < numFU);
181
182    unitBusy[fu_idx] = true;
183
184    return fu_idx;
185}
186
187void
188FUPool::freeUnitNextCycle(int fu_idx)
189{
190    assert(unitBusy[fu_idx]);
191    unitsToBeFreed.push_back(fu_idx);
192}
193
194void
195FUPool::processFreeUnits()
196{
197    while (!unitsToBeFreed.empty()) {
198        int fu_idx = unitsToBeFreed.back();
199        unitsToBeFreed.pop_back();
200
201        assert(unitBusy[fu_idx]);
202
203        unitBusy[fu_idx] = false;
204    }
205}
206
207void
208FUPool::dump()
209{
210    cout << "Function Unit Pool (" << name() << ")\n";
211    cout << "======================================\n";
212    cout << "Free List:\n";
213
214    for (int i = 0; i < numFU; ++i) {
215        if (unitBusy[i]) {
216            continue;
217        }
218
219        cout << "  [" << i << "] : ";
220
221        cout << funcUnits[i]->name << " ";
222
223        cout << "\n";
224    }
225
226    cout << "======================================\n";
227    cout << "Busy List:\n";
228    for (int i = 0; i < numFU; ++i) {
229        if (!unitBusy[i]) {
230            continue;
231        }
232
233        cout << "  [" << i << "] : ";
234
235        cout << funcUnits[i]->name << " ";
236
237        cout << "\n";
238    }
239}
240
241bool
242FUPool::isDrained() const
243{
244    bool is_drained = true;
245    for (int i = 0; i < numFU; i++)
246        is_drained = is_drained && !unitBusy[i];
247
248    return is_drained;
249}
250
251//
252
253////////////////////////////////////////////////////////////////////////////
254//
255//  The SimObjects we use to get the FU information into the simulator
256//
257////////////////////////////////////////////////////////////////////////////
258
259//
260//    FUPool - Contails a list of FUDesc objects to make available
261//
262
263//
264//  The FuPool object
265//
266FUPool *
267FUPoolParams::create()
268{
269    return new FUPool(this);
270}
271