| /* |
| * Copyright (c) 2016-2020 Advanced Micro Devices, Inc. |
| * All rights reserved. |
| * |
| * 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. |
| */ |
| |
| #ifndef __MEM_TOKEN_PORT_HH__ |
| #define __MEM_TOKEN_PORT_HH__ |
| |
| #include "mem/port.hh" |
| #include "sim/clocked_object.hh" |
| |
| namespace gem5 |
| { |
| |
| class TokenManager; |
| class TokenResponsePort; |
| |
| class TokenRequestPort : public RequestPort |
| { |
| private: |
| /* Manager to track tokens between this token port pair. */ |
| TokenManager *tokenManager; |
| |
| public: |
| TokenRequestPort(const std::string& name, SimObject* owner, |
| PortID id = InvalidPortID) : |
| RequestPort(name, id), tokenManager(nullptr) |
| { } |
| |
| /** |
| * Bind this request port to response port. Called by the response port in |
| * this token implementation. |
| */ |
| void bind(Port &peer) override; |
| |
| /** |
| * Unbind port. Handled by response port in token implementation. |
| */ |
| void unbind() override {} |
| |
| /** |
| * Receive tokens returned by the response port. This increments the number |
| * or available tokens across the port. |
| */ |
| void recvTokens(int num_tokens); |
| |
| /** |
| * Query if there are at least num_tokens tokens available to acquire. |
| */ |
| bool haveTokens(int num_tokens); |
| |
| /** |
| * Acquire tokens by decrementing the number of available tokens across |
| * the port. This does the opposite of recvTokens. |
| */ |
| void acquireTokens(int num_tokens); |
| |
| /** |
| * Specify a token manger, which will handle tracking of tokens for a |
| * TokenRequestPort/ResponseRequestPort pair. |
| */ |
| void setTokenManager(TokenManager *_tokenManager); |
| }; |
| |
| class TokenResponsePort : public ResponsePort |
| { |
| private: |
| TokenRequestPort *tokenRequestPort; |
| |
| std::deque<PacketPtr> respQueue; |
| |
| void recvRespRetry() override; |
| |
| public: |
| TokenResponsePort(const std::string& name, |
| PortID id = InvalidPortID) : |
| ResponsePort(name, id), tokenRequestPort(nullptr) |
| { } |
| ~TokenResponsePort() { } |
| |
| /** |
| * Bind this response port to a request port. This also does the mirror |
| * action and binds the request port to the response port as well as |
| * binding the base class types. |
| */ |
| void bind(Port &peer) override; |
| |
| /** |
| * Unbind this response port and associated request port. |
| */ |
| void unbind() override; |
| |
| /** |
| * Return num_tokens tokens back to the request port. |
| */ |
| void sendTokens(int num_tokens); |
| |
| bool sendTimingResp(PacketPtr pkt); |
| |
| /* There is no storage here so the packet will not be found. */ |
| bool trySatisfyFunctional(PacketPtr) { return false; } |
| }; |
| |
| class TokenManager |
| { |
| protected: |
| /* Maximum tokens possible */ |
| int maxTokens; |
| |
| /* Number of currently available tokens */ |
| int availableTokens; |
| |
| public: |
| TokenManager(int init_tokens); |
| ~TokenManager() { } |
| |
| /** |
| * Return the maximum possible tokens. |
| */ |
| int getMaxTokenCount() const; |
| |
| /** |
| * Increment the number of available tokens by num_tokens. |
| */ |
| void recvTokens(int num_tokens); |
| |
| /** |
| * Query is num_tokens tokens are available. |
| */ |
| bool haveTokens(int num_tokens); |
| |
| /** |
| * Decrement the number of available tokens by num_tokens. |
| */ |
| void acquireTokens(int num_tokens); |
| }; |
| |
| } // namespace gem5 |
| |
| #endif |