src/mem/token_port.cc

   1 /*
   2  * Copyright (c) 2016-2020 Advanced Micro Devices, Inc.
   3  * All rights reserved.
   4  *
   5  * For use for simulation and test purposes only
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright notice,
  11  * this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright notice,
  14  * this list of conditions and the following disclaimer in the documentation
  15  * and/or other materials provided with the distribution.
  16  *
  17  * 3. Neither the name of the copyright holder nor the names of its
  18  * contributors may be used to endorse or promote products derived from this
  19  * software without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  22  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
  25  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  26  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  27  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  28  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  29  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  30  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  31  * POSSIBILITY OF SUCH DAMAGE.
  32  *
  33  * Authors: Matthew Poremba
  34  */
  35
  36
  37 #include "mem/token_port.hh"
  38
  39 #include "base/trace.hh"
  40 #include "debug/TokenPort.hh"
  41
  42 void
  43 TokenRequestPort::bind(Port &peer)
  44 {
  45     RequestPort::bind(peer);
  46 }
  47
  48 void
  49 TokenRequestPort::recvTokens(int num_tokens)
  50 {
  51     panic_if(!tokenManager, "TokenManager not set for %s.\n", name());
  52
  53     tokenManager->recvTokens(num_tokens);
  54 }
  55
  56 bool
  57 TokenRequestPort::haveTokens(int num_tokens)
  58 {
  59     panic_if(!tokenManager, "TokenManager not set for %s.\n", name());
  60
  61     return tokenManager->haveTokens(num_tokens);
  62 }
  63
  64 void
  65 TokenRequestPort::acquireTokens(int num_tokens)
  66 {
  67     panic_if(!tokenManager, "TokenManager not set for %s.\n", name());
  68
  69     tokenManager->acquireTokens(num_tokens);
  70 }
  71
  72 void
  73 TokenRequestPort::setTokenManager(TokenManager *_tokenManager)
  74 {
  75     tokenManager = _tokenManager;
  76 }
  77
  78 void
  79 TokenResponsePort::sendTokens(int num_tokens)
  80 {
  81     fatal_if(!tokenRequestPort, "Tried sendTokens to non-token requestor!\n");
  82
  83     // Send tokens to a requestor
  84     tokenRequestPort->recvTokens(num_tokens);
  85 }
  86
  87 void
  88 TokenResponsePort::bind(Port& peer)
  89 {
  90     // TokenResponsePort is allowed to bind to either TokenRequestPort or a
  91     // RequestPort as fallback. If the type is a RequestPort, tokenRequestPort
  92     // is set to nullptr to indicate tokens should not be exchanged.
  93     auto *token_request_port = dynamic_cast<TokenRequestPort*>(&peer);
  94     auto *request_port = dynamic_cast<RequestPort*>(&peer);
  95     if (!token_request_port && !request_port) {
  96         fatal("Attempt to bind port %s to unsupported response port %s.",
  97               name(), peer.name());
  98     } else if (token_request_port) {
  99         // response port keeps track of the request port
 100         tokenRequestPort = token_request_port;
 101
 102         // request port also keeps track of response port
 103         tokenRequestPort->bind(*this);
 104     } else if (request_port) {
 105         tokenRequestPort = nullptr;
 106     }
 107 }
 108
 109 void
 110 TokenResponsePort::unbind()
 111 {
 112     ResponsePort::responderUnbind();
 113     tokenRequestPort = nullptr;
 114 }
 115
 116 void
 117 TokenResponsePort::recvRespRetry()
 118 {
 119     // fallback to QueuedResponsePort-like impl for now
 120     panic_if(respQueue.empty(),
 121              "Attempted to retry a response when no retry was queued!\n");
 122
 123     PacketPtr pkt = respQueue.front();
 124     bool success = ResponsePort::sendTimingResp(pkt);
 125
 126     if (success) {
 127         respQueue.pop_front();
 128     }
 129 }
 130
 131 bool
 132 TokenResponsePort::sendTimingResp(PacketPtr pkt)
 133 {
 134     bool success = ResponsePort::sendTimingResp(pkt);
 135
 136     if (!success) {
 137         respQueue.push_back(pkt);
 138     }
 139
 140     return success;
 141 }
 142
 143 TokenManager::TokenManager(int init_tokens)
 144 {
 145     availableTokens = init_tokens;
 146     maxTokens = init_tokens;
 147 }
 148
 149 int
 150 TokenManager::getMaxTokenCount() const
 151 {
 152     return maxTokens;
 153 }
 154
 155 void
 156 TokenManager::recvTokens(int num_tokens)
 157 {
 158     availableTokens += num_tokens;
 159
 160     DPRINTF(TokenPort, "Received %d tokens, have %d\n",
 161                        num_tokens, availableTokens);
 162
 163     panic_if(availableTokens > maxTokens,
 164              "More tokens available than the maximum after recvTokens!\n");
 165 }
 166
 167 bool
 168 TokenManager::haveTokens(int num_tokens)
 169 {
 170     return (availableTokens >= num_tokens);
 171 }
 172
 173 void
 174 TokenManager::acquireTokens(int num_tokens)
 175 {
 176     panic_if(!haveTokens(num_tokens),
 177              "Attempted to acquire more tokens than are available!\n");
 178
 179     availableTokens -= num_tokens;
 180
 181     DPRINTF(TokenPort, "Acquired %d tokens, have %d\n",
 182                        num_tokens, availableTokens);
 183 }