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
  34
  35 #include "mem/token_port.hh"
  36
  37 #include "base/trace.hh"
  38 #include "debug/TokenPort.hh"
  39
  40 void
  41 TokenRequestPort::bind(Port &peer)
  42 {
  43     RequestPort::bind(peer);
  44 }
  45
  46 void
  47 TokenRequestPort::recvTokens(int num_tokens)
  48 {
  49     panic_if(!tokenManager, "TokenManager not set for %s.\n", name());
  50
  51     tokenManager->recvTokens(num_tokens);
  52 }
  53
  54 bool
  55 TokenRequestPort::haveTokens(int num_tokens)
  56 {
  57     panic_if(!tokenManager, "TokenManager not set for %s.\n", name());
  58
  59     return tokenManager->haveTokens(num_tokens);
  60 }
  61
  62 void
  63 TokenRequestPort::acquireTokens(int num_tokens)
  64 {
  65     panic_if(!tokenManager, "TokenManager not set for %s.\n", name());
  66
  67     tokenManager->acquireTokens(num_tokens);
  68 }
  69
  70 void
  71 TokenRequestPort::setTokenManager(TokenManager *_tokenManager)
  72 {
  73     tokenManager = _tokenManager;
  74 }
  75
  76 void
  77 TokenResponsePort::sendTokens(int num_tokens)
  78 {
  79     fatal_if(!tokenRequestPort, "Tried sendTokens to non-token requestor!\n");
  80
  81     // Send tokens to a requestor
  82     tokenRequestPort->recvTokens(num_tokens);
  83 }
  84
  85 void
  86 TokenResponsePort::bind(Port& peer)
  87 {
  88     // TokenResponsePort is allowed to bind to either TokenRequestPort or a
  89     // RequestPort as fallback. If the type is a RequestPort, tokenRequestPort
  90     // is set to nullptr to indicate tokens should not be exchanged.
  91     auto *token_request_port = dynamic_cast<TokenRequestPort*>(&peer);
  92     auto *request_port = dynamic_cast<RequestPort*>(&peer);
  93     if (!token_request_port && !request_port) {
  94         fatal("Attempt to bind port %s to unsupported response port %s.",
  95               name(), peer.name());
  96     } else if (token_request_port) {
  97         // response port keeps track of the request port
  98         tokenRequestPort = token_request_port;
  99
 100         // request port also keeps track of response port
 101         tokenRequestPort->bind(*this);
 102     } else if (request_port) {
 103         tokenRequestPort = nullptr;
 104     }
 105 }
 106
 107 void
 108 TokenResponsePort::unbind()
 109 {
 110     ResponsePort::responderUnbind();
 111     tokenRequestPort = nullptr;
 112 }
 113
 114 void
 115 TokenResponsePort::recvRespRetry()
 116 {
 117     // fallback to QueuedResponsePort-like impl for now
 118     panic_if(respQueue.empty(),
 119              "Attempted to retry a response when no retry was queued!\n");
 120
 121     PacketPtr pkt = respQueue.front();
 122     bool success = ResponsePort::sendTimingResp(pkt);
 123
 124     if (success) {
 125         respQueue.pop_front();
 126     }
 127 }
 128
 129 bool
 130 TokenResponsePort::sendTimingResp(PacketPtr pkt)
 131 {
 132     bool success = ResponsePort::sendTimingResp(pkt);
 133
 134     if (!success) {
 135         respQueue.push_back(pkt);
 136     }
 137
 138     return success;
 139 }
 140
 141 TokenManager::TokenManager(int init_tokens)
 142 {
 143     availableTokens = init_tokens;
 144     maxTokens = init_tokens;
 145 }
 146
 147 int
 148 TokenManager::getMaxTokenCount() const
 149 {
 150     return maxTokens;
 151 }
 152
 153 void
 154 TokenManager::recvTokens(int num_tokens)
 155 {
 156     availableTokens += num_tokens;
 157
 158     DPRINTF(TokenPort, "Received %d tokens, have %d\n",
 159                        num_tokens, availableTokens);
 160
 161     panic_if(availableTokens > maxTokens,
 162              "More tokens available than the maximum after recvTokens!\n");
 163 }
 164
 165 bool
 166 TokenManager::haveTokens(int num_tokens)
 167 {
 168     return (availableTokens >= num_tokens);
 169 }
 170
 171 void
 172 TokenManager::acquireTokens(int num_tokens)
 173 {
 174     panic_if(!haveTokens(num_tokens),
 175              "Attempted to acquire more tokens than are available!\n");
 176
 177     availableTokens -= num_tokens;
 178
 179     DPRINTF(TokenPort, "Acquired %d tokens, have %d\n",
 180                        num_tokens, availableTokens);
 181 }