xbar.hh revision 13892
12381SN/A/* 212780Snikos.nikoleris@arm.com * Copyright (c) 2011-2015, 2018 ARM Limited 38711SN/A * All rights reserved 48711SN/A * 58711SN/A * The license below extends only to copyright in the software and shall 68711SN/A * not be construed as granting a license to any other intellectual 78711SN/A * property including but not limited to intellectual property relating 88711SN/A * to a hardware implementation of the functionality of the software 98711SN/A * licensed hereunder. You may use the software subject to the license 108711SN/A * terms below provided that you ensure that this notice is replicated 118711SN/A * unmodified and in its entirety in all distributions of the software, 128711SN/A * modified or unmodified, in source code or in binary form. 138711SN/A * 142381SN/A * Copyright (c) 2002-2005 The Regents of The University of Michigan 152381SN/A * All rights reserved. 162381SN/A * 172381SN/A * Redistribution and use in source and binary forms, with or without 182381SN/A * modification, are permitted provided that the following conditions are 192381SN/A * met: redistributions of source code must retain the above copyright 202381SN/A * notice, this list of conditions and the following disclaimer; 212381SN/A * redistributions in binary form must reproduce the above copyright 222381SN/A * notice, this list of conditions and the following disclaimer in the 232381SN/A * documentation and/or other materials provided with the distribution; 242381SN/A * neither the name of the copyright holders nor the names of its 252381SN/A * contributors may be used to endorse or promote products derived from 262381SN/A * this software without specific prior written permission. 272381SN/A * 282381SN/A * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 292381SN/A * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 302381SN/A * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 312381SN/A * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 322381SN/A * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 332381SN/A * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 342381SN/A * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 352381SN/A * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 362381SN/A * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 372381SN/A * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 382381SN/A * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 392665SN/A * 402665SN/A * Authors: Ron Dreslinski 412772SN/A * Ali Saidi 428715SN/A * Andreas Hansson 438922SN/A * William Wang 442381SN/A */ 452381SN/A 462381SN/A/** 472982SN/A * @file 4810405Sandreas.hansson@arm.com * Declaration of an abstract crossbar base class. 492381SN/A */ 502381SN/A 5110405Sandreas.hansson@arm.com#ifndef __MEM_XBAR_HH__ 5210405Sandreas.hansson@arm.com#define __MEM_XBAR_HH__ 532381SN/A 549291SN/A#include <deque> 5511168Sandreas.hansson@arm.com#include <unordered_map> 562381SN/A 579235SN/A#include "base/addr_range_map.hh" 586215SN/A#include "base/types.hh" 5910888Sandreas.hansson@arm.com#include "mem/qport.hh" 6010405Sandreas.hansson@arm.com#include "params/BaseXBar.hh" 6113892Sgabeblack@google.com#include "sim/clocked_object.hh" 629712SN/A#include "sim/stats.hh" 632381SN/A 649036SN/A/** 6510405Sandreas.hansson@arm.com * The base crossbar contains the common elements of the non-coherent 6610405Sandreas.hansson@arm.com * and coherent crossbar. It is an abstract class that does not have 6710405Sandreas.hansson@arm.com * any of the functionality relating to the actual reception and 6810405Sandreas.hansson@arm.com * transmission of packets, as this is left for the subclasses. 699036SN/A * 7010405Sandreas.hansson@arm.com * The BaseXBar is responsible for the basic flow control (busy or 719036SN/A * not), the administration of retries, and the address decoding. 729036SN/A */ 7313892Sgabeblack@google.comclass BaseXBar : public ClockedObject 742381SN/A{ 759031SN/A 769036SN/A protected: 772381SN/A 789091SN/A /** 7910405Sandreas.hansson@arm.com * A layer is an internal crossbar arbitration point with its own 8010405Sandreas.hansson@arm.com * flow control. Each layer is a converging multiplexer tree. By 8110405Sandreas.hansson@arm.com * instantiating one layer per destination port (and per packet 8210405Sandreas.hansson@arm.com * type, i.e. request, response, snoop request and snoop 8310405Sandreas.hansson@arm.com * response), we model full crossbar structures like AXI, ACE, 8410405Sandreas.hansson@arm.com * PCIe, etc. 859093SN/A * 869093SN/A * The template parameter, PortClass, indicates the destination 8710405Sandreas.hansson@arm.com * port type for the layer. The retry list holds either master 8810405Sandreas.hansson@arm.com * ports or slave ports, depending on the direction of the 8910405Sandreas.hansson@arm.com * layer. Thus, a request layer has a retry list containing slave 9010405Sandreas.hansson@arm.com * ports, whereas a response layer holds master ports. 919091SN/A */ 929715SN/A template <typename SrcType, typename DstType> 939342SN/A class Layer : public Drainable 949092SN/A { 959091SN/A 969092SN/A public: 979092SN/A 989092SN/A /** 9910405Sandreas.hansson@arm.com * Create a layer and give it a name. The layer uses 10010405Sandreas.hansson@arm.com * the crossbar an event manager. 1019092SN/A * 1029715SN/A * @param _port destination port the layer converges at 10310405Sandreas.hansson@arm.com * @param _xbar the crossbar this layer belongs to 1049092SN/A * @param _name the layer's name 1059092SN/A */ 10610405Sandreas.hansson@arm.com Layer(DstType& _port, BaseXBar& _xbar, const std::string& _name); 1079092SN/A 1089092SN/A /** 10910405Sandreas.hansson@arm.com * Drain according to the normal semantics, so that the crossbar 1109092SN/A * can tell the layer to drain, and pass an event to signal 1119092SN/A * back when drained. 1129092SN/A * 1139092SN/A * @param de drain event to call once drained 1149092SN/A * 1159092SN/A * @return 1 if busy or waiting to retry, or 0 if idle 1169092SN/A */ 11711168Sandreas.hansson@arm.com DrainState drain() override; 1189092SN/A 11910405Sandreas.hansson@arm.com const std::string name() const { return xbar.name() + _name; } 1209092SN/A 1219092SN/A 1229092SN/A /** 12310405Sandreas.hansson@arm.com * Determine if the layer accepts a packet from a specific 1249092SN/A * port. If not, the port in question is also added to the 1259612SN/A * retry list. In either case the state of the layer is 1269714SN/A * updated accordingly. 1279092SN/A * 1289612SN/A * @param port Source port presenting the packet 1299092SN/A * 13010405Sandreas.hansson@arm.com * @return True if the layer accepts the packet 1319092SN/A */ 1329715SN/A bool tryTiming(SrcType* src_port); 1339092SN/A 1349092SN/A /** 1359092SN/A * Deal with a destination port accepting a packet by potentially 1369092SN/A * removing the source port from the retry list (if retrying) and 13710405Sandreas.hansson@arm.com * occupying the layer accordingly. 1389092SN/A * 1399092SN/A * @param busy_time Time to spend as a result of a successful send 1409092SN/A */ 1419092SN/A void succeededTiming(Tick busy_time); 1429092SN/A 1439092SN/A /** 1449092SN/A * Deal with a destination port not accepting a packet by 1459092SN/A * potentially adding the source port to the retry list (if 14610405Sandreas.hansson@arm.com * not already at the front) and occupying the layer 1479092SN/A * accordingly. 1489092SN/A * 1499612SN/A * @param src_port Source port 1509092SN/A * @param busy_time Time to spend as a result of a failed send 1519092SN/A */ 1529715SN/A void failedTiming(SrcType* src_port, Tick busy_time); 1539092SN/A 1549092SN/A void occupyLayer(Tick until); 1559092SN/A 1569092SN/A /** 1579612SN/A * Send a retry to the port at the head of waitingForLayer. The 1589092SN/A * caller must ensure that the list is not empty. 1599092SN/A */ 1609092SN/A void retryWaiting(); 1619092SN/A 1629092SN/A /** 1639612SN/A * Handle a retry from a neighbouring module. This wraps 1649092SN/A * retryWaiting by verifying that there are ports waiting 1659092SN/A * before calling retryWaiting. 1669092SN/A */ 1679715SN/A void recvRetry(); 1689092SN/A 1699712SN/A void regStats(); 1709712SN/A 17110713Sandreas.hansson@arm.com protected: 17210713Sandreas.hansson@arm.com 17310713Sandreas.hansson@arm.com /** 17410713Sandreas.hansson@arm.com * Sending the actual retry, in a manner specific to the 17510713Sandreas.hansson@arm.com * individual layers. Note that for a MasterPort, there is 17610713Sandreas.hansson@arm.com * both a RequestLayer and a SnoopResponseLayer using the same 17710713Sandreas.hansson@arm.com * port, but using different functions for the flow control. 17810713Sandreas.hansson@arm.com */ 17910713Sandreas.hansson@arm.com virtual void sendRetry(SrcType* retry_port) = 0; 18010713Sandreas.hansson@arm.com 1819092SN/A private: 1829092SN/A 1839715SN/A /** The destination port this layer converges at. */ 1849715SN/A DstType& port; 1859715SN/A 18610405Sandreas.hansson@arm.com /** The crossbar this layer is a part of. */ 18710405Sandreas.hansson@arm.com BaseXBar& xbar; 1889092SN/A 1899092SN/A std::string _name; 1909092SN/A 1919092SN/A /** 19210405Sandreas.hansson@arm.com * We declare an enum to track the state of the layer. The 19310405Sandreas.hansson@arm.com * starting point is an idle state where the layer is waiting 19410405Sandreas.hansson@arm.com * for a packet to arrive. Upon arrival, the layer 1959092SN/A * transitions to the busy state, where it remains either 1969092SN/A * until the packet transfer is done, or the header time is 19710405Sandreas.hansson@arm.com * spent. Once the layer leaves the busy state, it can 1989092SN/A * either go back to idle, if no packets have arrived while it 19910405Sandreas.hansson@arm.com * was busy, or the layer goes on to retry the first port 2009612SN/A * in waitingForLayer. A similar transition takes place from 20110405Sandreas.hansson@arm.com * idle to retry if the layer receives a retry from one of 2029092SN/A * its connected ports. The retry state lasts until the port 2039092SN/A * in questions calls sendTiming and returns control to the 20410405Sandreas.hansson@arm.com * layer, or goes to a busy state if the port does not 2059092SN/A * immediately react to the retry by calling sendTiming. 2069092SN/A */ 2079092SN/A enum State { IDLE, BUSY, RETRY }; 2089092SN/A 2099092SN/A State state; 2109092SN/A 2119092SN/A /** 2129612SN/A * A deque of ports that retry should be called on because 2139612SN/A * the original send was delayed due to a busy layer. 2149092SN/A */ 2159715SN/A std::deque<SrcType*> waitingForLayer; 2169092SN/A 2179092SN/A /** 2189715SN/A * Track who is waiting for the retry when receiving it from a 2199715SN/A * peer. If no port is waiting NULL is stored. 2209612SN/A */ 2219715SN/A SrcType* waitingForPeer; 2229612SN/A 2239612SN/A /** 22410405Sandreas.hansson@arm.com * Release the layer after being occupied and return to an 2259092SN/A * idle state where we proceed to send a retry to any 2269092SN/A * potential waiting port, or drain if asked to do so. 2279092SN/A */ 2289092SN/A void releaseLayer(); 22912084Sspwilson2@wisc.edu EventFunctionWrapper releaseEvent; 2309092SN/A 2319712SN/A /** 2329712SN/A * Stats for occupancy and utilization. These stats capture 23310405Sandreas.hansson@arm.com * the time the layer spends in the busy state and are thus only 2349712SN/A * relevant when the memory system is in timing mode. 2359712SN/A */ 2369712SN/A Stats::Scalar occupancy; 2379712SN/A Stats::Formula utilization; 2389712SN/A 2399092SN/A }; 2409091SN/A 24113808Sgabeblack@google.com class ReqLayer : public Layer<SlavePort, MasterPort> 24210713Sandreas.hansson@arm.com { 24310713Sandreas.hansson@arm.com public: 24410713Sandreas.hansson@arm.com /** 24510713Sandreas.hansson@arm.com * Create a request layer and give it a name. 24610713Sandreas.hansson@arm.com * 24710713Sandreas.hansson@arm.com * @param _port destination port the layer converges at 24810713Sandreas.hansson@arm.com * @param _xbar the crossbar this layer belongs to 24910713Sandreas.hansson@arm.com * @param _name the layer's name 25010713Sandreas.hansson@arm.com */ 25110713Sandreas.hansson@arm.com ReqLayer(MasterPort& _port, BaseXBar& _xbar, const std::string& _name) : 25213808Sgabeblack@google.com Layer(_port, _xbar, _name) 25313808Sgabeblack@google.com {} 25410713Sandreas.hansson@arm.com 25510713Sandreas.hansson@arm.com protected: 25613808Sgabeblack@google.com void 25713808Sgabeblack@google.com sendRetry(SlavePort* retry_port) override 25813808Sgabeblack@google.com { 25913808Sgabeblack@google.com retry_port->sendRetryReq(); 26013808Sgabeblack@google.com } 26110713Sandreas.hansson@arm.com }; 26210713Sandreas.hansson@arm.com 26313808Sgabeblack@google.com class RespLayer : public Layer<MasterPort, SlavePort> 26410713Sandreas.hansson@arm.com { 26510713Sandreas.hansson@arm.com public: 26610713Sandreas.hansson@arm.com /** 26710713Sandreas.hansson@arm.com * Create a response layer and give it a name. 26810713Sandreas.hansson@arm.com * 26910713Sandreas.hansson@arm.com * @param _port destination port the layer converges at 27010713Sandreas.hansson@arm.com * @param _xbar the crossbar this layer belongs to 27110713Sandreas.hansson@arm.com * @param _name the layer's name 27210713Sandreas.hansson@arm.com */ 27313808Sgabeblack@google.com RespLayer(SlavePort& _port, BaseXBar& _xbar, 27413808Sgabeblack@google.com const std::string& _name) : 27513808Sgabeblack@google.com Layer(_port, _xbar, _name) 27613808Sgabeblack@google.com {} 27710713Sandreas.hansson@arm.com 27810713Sandreas.hansson@arm.com protected: 27913808Sgabeblack@google.com void 28013808Sgabeblack@google.com sendRetry(MasterPort* retry_port) override 28113808Sgabeblack@google.com { 28213808Sgabeblack@google.com retry_port->sendRetryResp(); 28313808Sgabeblack@google.com } 28410713Sandreas.hansson@arm.com }; 28510713Sandreas.hansson@arm.com 28613808Sgabeblack@google.com class SnoopRespLayer : public Layer<SlavePort, MasterPort> 28710713Sandreas.hansson@arm.com { 28810713Sandreas.hansson@arm.com public: 28910713Sandreas.hansson@arm.com /** 29010713Sandreas.hansson@arm.com * Create a snoop response layer and give it a name. 29110713Sandreas.hansson@arm.com * 29210713Sandreas.hansson@arm.com * @param _port destination port the layer converges at 29310713Sandreas.hansson@arm.com * @param _xbar the crossbar this layer belongs to 29410713Sandreas.hansson@arm.com * @param _name the layer's name 29510713Sandreas.hansson@arm.com */ 29610713Sandreas.hansson@arm.com SnoopRespLayer(MasterPort& _port, BaseXBar& _xbar, 29710713Sandreas.hansson@arm.com const std::string& _name) : 29813808Sgabeblack@google.com Layer(_port, _xbar, _name) 29913808Sgabeblack@google.com {} 30010713Sandreas.hansson@arm.com 30110713Sandreas.hansson@arm.com protected: 30210713Sandreas.hansson@arm.com 30313808Sgabeblack@google.com void 30413808Sgabeblack@google.com sendRetry(SlavePort* retry_port) override 30513808Sgabeblack@google.com { 30613808Sgabeblack@google.com retry_port->sendRetrySnoopResp(); 30713808Sgabeblack@google.com } 30810713Sandreas.hansson@arm.com }; 30910713Sandreas.hansson@arm.com 31010719SMarco.Balboni@ARM.com /** 31110719SMarco.Balboni@ARM.com * Cycles of front-end pipeline including the delay to accept the request 31210719SMarco.Balboni@ARM.com * and to decode the address. 31310719SMarco.Balboni@ARM.com */ 31410719SMarco.Balboni@ARM.com const Cycles frontendLatency; 31510719SMarco.Balboni@ARM.com const Cycles forwardLatency; 31610719SMarco.Balboni@ARM.com const Cycles responseLatency; 31710405Sandreas.hansson@arm.com /** the width of the xbar in bytes */ 3189240SN/A const uint32_t width; 3194475SN/A 32012778Sgabeblack@google.com AddrRangeMap<PortID, 3> portMap; 3214475SN/A 32210656Sandreas.hansson@arm.com /** 32310656Sandreas.hansson@arm.com * Remember where request packets came from so that we can route 32410656Sandreas.hansson@arm.com * responses to the appropriate port. This relies on the fact that 32510656Sandreas.hansson@arm.com * the underlying Request pointer inside the Packet stays 32610656Sandreas.hansson@arm.com * constant. 32710656Sandreas.hansson@arm.com */ 32811168Sandreas.hansson@arm.com std::unordered_map<RequestPtr, PortID> routeTo; 32910656Sandreas.hansson@arm.com 33010405Sandreas.hansson@arm.com /** all contigous ranges seen by this crossbar */ 33110405Sandreas.hansson@arm.com AddrRangeList xbarRanges; 3329564SN/A 3339279SN/A AddrRange defaultRange; 3344475SN/A 3358948SN/A /** 33610405Sandreas.hansson@arm.com * Function called by the port when the crossbar is recieving a 33710405Sandreas.hansson@arm.com * range change. 3389032SN/A * 3399032SN/A * @param master_port_id id of the port that received the change 3409032SN/A */ 34111186Serfan.azarkhish@unibo.it virtual void recvRangeChange(PortID master_port_id); 3424475SN/A 34312780Snikos.nikoleris@arm.com /** 34412780Snikos.nikoleris@arm.com * Find which port connected to this crossbar (if any) should be 34512780Snikos.nikoleris@arm.com * given a packet with this address range. 34610405Sandreas.hansson@arm.com * 34712780Snikos.nikoleris@arm.com * @param addr_range Address range to find port for. 3484894SN/A * @return id of port that the packet should be sent out of. 3494475SN/A */ 35012780Snikos.nikoleris@arm.com PortID findPort(AddrRange addr_range); 3514475SN/A 3528711SN/A /** 35310405Sandreas.hansson@arm.com * Return the address ranges the crossbar is responsible for. 3548711SN/A * 3558711SN/A * @return a list of non-overlapping address ranges 3564475SN/A */ 3579090SN/A AddrRangeList getAddrRanges() const; 3588711SN/A 3599547SN/A /** 3609547SN/A * Calculate the timing parameters for the packet. Updates the 36110694SMarco.Balboni@ARM.com * headerDelay and payloadDelay fields of the packet 3629547SN/A * object with the relative number of ticks required to transmit 36310694SMarco.Balboni@ARM.com * the header and the payload, respectively. 36410719SMarco.Balboni@ARM.com * 36510719SMarco.Balboni@ARM.com * @param pkt Packet to populate with timings 36610719SMarco.Balboni@ARM.com * @param header_delay Header delay to be added 3675354SN/A */ 36810719SMarco.Balboni@ARM.com void calcPacketTiming(PacketPtr pkt, Tick header_delay); 3695354SN/A 3709032SN/A /** 37110405Sandreas.hansson@arm.com * Remember for each of the master ports of the crossbar if we got 37210405Sandreas.hansson@arm.com * an address range from the connected slave. For convenience, 37310405Sandreas.hansson@arm.com * also keep track of if we got ranges from all the slave modules 37410405Sandreas.hansson@arm.com * or not. 3759279SN/A */ 3769279SN/A std::vector<bool> gotAddrRanges; 3779279SN/A bool gotAllAddrRanges; 3783159SN/A 37910405Sandreas.hansson@arm.com /** The master and slave ports of the crossbar */ 38010888Sandreas.hansson@arm.com std::vector<QueuedSlavePort*> slavePorts; 3818966SN/A std::vector<MasterPort*> masterPorts; 3828966SN/A 3832846SN/A /** Port that handles requests that don't match any of the interfaces.*/ 3849031SN/A PortID defaultPortID; 3852846SN/A 3867523SN/A /** If true, use address range provided by default device. Any 3877523SN/A address not handled by another port and not in default device's 3887523SN/A range will cause a fatal error. If false, just send all 3897523SN/A addresses not handled by another port to default device. */ 3909240SN/A const bool useDefaultRange; 3913489SN/A 39210405Sandreas.hansson@arm.com BaseXBar(const BaseXBarParams *p); 3939036SN/A 3949712SN/A /** 3959712SN/A * Stats for transaction distribution and data passing through the 39610405Sandreas.hansson@arm.com * crossbar. The transaction distribution is globally counting 3979712SN/A * different types of commands. The packet count and total packet 39810405Sandreas.hansson@arm.com * size are two-dimensional vectors that are indexed by the 3999712SN/A * slave port and master port id (thus the neighbouring master and 4009712SN/A * neighbouring slave), summing up both directions (request and 4019712SN/A * response). 4029712SN/A */ 4039712SN/A Stats::Vector transDist; 4049712SN/A Stats::Vector2d pktCount; 40510405Sandreas.hansson@arm.com Stats::Vector2d pktSize; 4069712SN/A 4072381SN/A public: 4082381SN/A 40911767Sandreas.sandberg@arm.com virtual ~BaseXBar(); 41011767Sandreas.sandberg@arm.com 41110405Sandreas.hansson@arm.com /** A function used to return the port associated with this object. */ 41213784Sgabeblack@google.com Port &getPort(const std::string &if_name, 41313784Sgabeblack@google.com PortID idx=InvalidPortID) override; 4142568SN/A 41513799SAndrea.Mondelli@ucf.edu void regStats() override; 4162381SN/A}; 4172381SN/A 41810405Sandreas.hansson@arm.com#endif //__MEM_XBAR_HH__ 419