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
243
244
245
246
247
248
249
250
|
/*
* Copyright (c) 2008 Princeton University
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
* 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;
* neither the name of the copyright holders 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
* OWNER 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.
*
* Authors: Niket Agarwal
*/
#include "mem/ruby/network/garnet/fixed-pipeline/GarnetNetwork_d.hh"
#include "mem/ruby/network/garnet/fixed-pipeline/InputUnit_d.hh"
#include "mem/ruby/network/garnet/fixed-pipeline/OutputUnit_d.hh"
#include "mem/ruby/network/garnet/fixed-pipeline/Router_d.hh"
#include "mem/ruby/network/garnet/fixed-pipeline/SWallocator_d.hh"
SWallocator_d::SWallocator_d(Router_d *router)
: Consumer(router)
{
m_router = router;
m_num_vcs = m_router->get_num_vcs();
m_vc_per_vnet = m_router->get_vc_per_vnet();
m_local_arbiter_activity = 0;
m_global_arbiter_activity = 0;
}
void
SWallocator_d::init()
{
m_input_unit = m_router->get_inputUnit_ref();
m_output_unit = m_router->get_outputUnit_ref();
m_num_inports = m_router->get_num_inports();
m_num_outports = m_router->get_num_outports();
m_round_robin_outport.resize(m_num_outports);
m_round_robin_inport.resize(m_num_inports);
m_port_req.resize(m_num_outports);
m_vc_winners.resize(m_num_outports);
for (int i = 0; i < m_num_inports; i++) {
m_round_robin_inport[i] = 0;
}
for (int i = 0; i < m_num_outports; i++) {
m_port_req[i].resize(m_num_inports);
m_vc_winners[i].resize(m_num_inports);
m_round_robin_outport[i] = 0;
for (int j = 0; j < m_num_inports; j++) {
m_port_req[i][j] = false; // [outport][inport]
}
}
}
void
SWallocator_d::wakeup()
{
arbitrate_inports(); // First stage of allocation
arbitrate_outports(); // Second stage of allocation
clear_request_vector();
check_for_wakeup();
m_router->call_switch();
}
void
SWallocator_d::arbitrate_inports()
{
// First do round robin arbitration on a set of input vc requests
for (int inport = 0; inport < m_num_inports; inport++) {
int invc = m_round_robin_inport[inport];
// Select next round robin vc candidate within valid vnet
int next_round_robin_invc = invc;
do {
next_round_robin_invc++;
if (next_round_robin_invc >= m_num_vcs)
next_round_robin_invc = 0;
} while (!((m_router->get_net_ptr())->validVirtualNetwork(
get_vnet(next_round_robin_invc))));
m_round_robin_inport[inport] = next_round_robin_invc;
for (int invc_iter = 0; invc_iter < m_num_vcs; invc_iter++) {
invc++;
if (invc >= m_num_vcs)
invc = 0;
if (!((m_router->get_net_ptr())->validVirtualNetwork(
get_vnet(invc))))
continue;
if (m_input_unit[inport]->need_stage(invc, ACTIVE_, SA_,
m_router->curCycle()) &&
m_input_unit[inport]->has_credits(invc)) {
if (is_candidate_inport(inport, invc)) {
int outport = m_input_unit[inport]->get_route(invc);
m_local_arbiter_activity++;
m_port_req[outport][inport] = true;
m_vc_winners[outport][inport]= invc;
break; // got one vc winner for this port
}
}
}
}
}
bool
SWallocator_d::is_candidate_inport(int inport, int invc)
{
int outport = m_input_unit[inport]->get_route(invc);
Cycles t_enqueue_time = m_input_unit[inport]->get_enqueue_time(invc);
int t_vnet = get_vnet(invc);
int vc_base = t_vnet*m_vc_per_vnet;
if ((m_router->get_net_ptr())->isVNetOrdered(t_vnet)) {
for (int vc_offset = 0; vc_offset < m_vc_per_vnet; vc_offset++) {
int temp_vc = vc_base + vc_offset;
if (m_input_unit[inport]->need_stage(temp_vc, ACTIVE_, SA_,
m_router->curCycle()) &&
(m_input_unit[inport]->get_route(temp_vc) == outport) &&
(m_input_unit[inport]->get_enqueue_time(temp_vc) <
t_enqueue_time)) {
return false;
break;
}
}
}
return true;
}
void
SWallocator_d::arbitrate_outports()
{
// Now there are a set of input vc requests for output vcs.
// Again do round robin arbitration on these requests
for (int outport = 0; outport < m_num_outports; outport++) {
int inport = m_round_robin_outport[outport];
m_round_robin_outport[outport]++;
if (m_round_robin_outport[outport] >= m_num_outports)
m_round_robin_outport[outport] = 0;
for (int inport_iter = 0; inport_iter < m_num_inports; inport_iter++) {
inport++;
if (inport >= m_num_inports)
inport = 0;
// inport has a request this cycle for outport:
if (m_port_req[outport][inport]) {
m_port_req[outport][inport] = false;
int invc = m_vc_winners[outport][inport];
int outvc = m_input_unit[inport]->get_outvc(invc);
// remove flit from Input Unit
flit_d *t_flit = m_input_unit[inport]->getTopFlit(invc);
t_flit->advance_stage(ST_, m_router->curCycle());
t_flit->set_vc(outvc);
t_flit->set_outport(outport);
t_flit->set_time(m_router->curCycle());
m_output_unit[outport]->decrement_credit(outvc);
m_router->update_sw_winner(inport, t_flit);
m_global_arbiter_activity++;
if ((t_flit->get_type() == TAIL_) ||
t_flit->get_type() == HEAD_TAIL_) {
// Send a credit back
// along with the information that this VC is now idle
m_input_unit[inport]->increment_credit(invc, true,
m_router->curCycle());
// This Input VC should now be empty
assert(m_input_unit[inport]->isReady(invc,
m_router->curCycle()) == false);
m_input_unit[inport]->set_vc_state(IDLE_, invc,
m_router->curCycle());
m_input_unit[inport]->set_enqueue_time(invc,
Cycles(INFINITE_));
} else {
// Send a credit back
// but do not indicate that the VC is idle
m_input_unit[inport]->increment_credit(invc, false,
m_router->curCycle());
}
break; // got a in request for this outport
}
}
}
}
void
SWallocator_d::check_for_wakeup()
{
Cycles nextCycle = m_router->curCycle() + Cycles(1);
for (int i = 0; i < m_num_inports; i++) {
for (int j = 0; j < m_num_vcs; j++) {
if (m_input_unit[i]->need_stage(j, ACTIVE_, SA_, nextCycle)) {
m_router->vcarb_req();
return;
}
}
}
}
int
SWallocator_d::get_vnet(int invc)
{
int vnet = invc/m_vc_per_vnet;
assert(vnet < m_router->get_num_vnets());
return vnet;
}
void
SWallocator_d::clear_request_vector()
{
for (int i = 0; i < m_num_outports; i++) {
for (int j = 0; j < m_num_inports; j++) {
m_port_req[i][j] = false;
}
}
}
|
