gem5  v21.1.0.2
coherent_xbar.hh
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40 
46 #ifndef __MEM_COHERENT_XBAR_HH__
47 #define __MEM_COHERENT_XBAR_HH__
48 
49 #include <unordered_map>
50 #include <unordered_set>
51 
52 #include "mem/snoop_filter.hh"
53 #include "mem/xbar.hh"
54 #include "params/CoherentXBar.hh"
55 
56 namespace gem5
57 {
58 
70 class CoherentXBar : public BaseXBar
71 {
72 
73  protected:
74 
82 
89  {
90 
91  private:
92 
95 
98 
99  public:
100 
101  CoherentXBarResponsePort(const std::string &_name,
102  CoherentXBar &_xbar, PortID _id)
103  : QueuedResponsePort(_name, &_xbar, queue, _id), xbar(_xbar),
104  queue(_xbar, *this)
105  { }
106 
107  protected:
108 
109  bool
110  recvTimingReq(PacketPtr pkt) override
111  {
112  return xbar.recvTimingReq(pkt, id);
113  }
114 
115  bool
117  {
118  return xbar.recvTimingSnoopResp(pkt, id);
119  }
120 
121  Tick
122  recvAtomic(PacketPtr pkt) override
123  {
124  return xbar.recvAtomicBackdoor(pkt, id);
125  }
126 
127  Tick
128  recvAtomicBackdoor(PacketPtr pkt, MemBackdoorPtr &backdoor) override
129  {
130  return xbar.recvAtomicBackdoor(pkt, id, &backdoor);
131  }
132 
133  void
134  recvFunctional(PacketPtr pkt) override
135  {
136  xbar.recvFunctional(pkt, id);
137  }
138 
140  getAddrRanges() const override
141  {
142  return xbar.getAddrRanges();
143  }
144 
145  };
146 
153  {
154  private:
157 
158  public:
159 
160  CoherentXBarRequestPort(const std::string &_name,
161  CoherentXBar &_xbar, PortID _id)
162  : RequestPort(_name, &_xbar, _id), xbar(_xbar)
163  { }
164 
165  protected:
166 
173  bool isSnooping() const override { return true; }
174 
175  bool
176  recvTimingResp(PacketPtr pkt) override
177  {
178  return xbar.recvTimingResp(pkt, id);
179  }
180 
181  void
183  {
184  return xbar.recvTimingSnoopReq(pkt, id);
185  }
186 
187  Tick
189  {
190  return xbar.recvAtomicSnoop(pkt, id);
191  }
192 
193  void
195  {
196  xbar.recvFunctionalSnoop(pkt, id);
197  }
198 
199  void recvRangeChange() override { xbar.recvRangeChange(id); }
200  void recvReqRetry() override { xbar.recvReqRetry(id); }
201 
202  };
203 
209  class SnoopRespPort : public RequestPort
210  {
211 
212  private:
213 
216 
217  public:
218 
223  CoherentXBar& _xbar) :
224  RequestPort(cpu_side_port.name() + ".snoopRespPort", &_xbar),
225  cpuSidePort(cpu_side_port) { }
226 
231  void
232  sendRetryResp() override
233  {
234  // forward it as a snoop response retry
236  }
237 
238  void
239  recvReqRetry() override
240  {
241  panic("SnoopRespPort should never see retry");
242  }
243 
244  bool
245  recvTimingResp(PacketPtr pkt) override
246  {
247  panic("SnoopRespPort should never see timing response");
248  }
249 
250  };
251 
253 
255 
261  std::unordered_set<RequestPtr> outstandingSnoop;
262 
268  std::unordered_map<PacketId, PacketPtr> outstandingCMO;
269 
275 
279 
282 
284  const unsigned int maxOutstandingSnoopCheck;
285 
287  const unsigned int maxRoutingTableSizeCheck;
288 
290  const bool pointOfCoherency;
291 
293  const bool pointOfUnification;
294 
299  std::unique_ptr<Packet> pendingDelete;
300 
301  bool recvTimingReq(PacketPtr pkt, PortID cpu_side_port_id);
302  bool recvTimingResp(PacketPtr pkt, PortID mem_side_port_id);
303  void recvTimingSnoopReq(PacketPtr pkt, PortID mem_side_port_id);
304  bool recvTimingSnoopResp(PacketPtr pkt, PortID cpu_side_port_id);
305  void recvReqRetry(PortID mem_side_port_id);
306 
315  void
316  forwardTiming(PacketPtr pkt, PortID exclude_cpu_side_port_id)
317  {
318  forwardTiming(pkt, exclude_cpu_side_port_id, snoopPorts);
319  }
320 
330  void forwardTiming(PacketPtr pkt, PortID exclude_cpu_side_port_id,
331  const std::vector<QueuedResponsePort*>& dests);
332 
333  Tick recvAtomicBackdoor(PacketPtr pkt, PortID cpu_side_port_id,
334  MemBackdoorPtr *backdoor=nullptr);
335  Tick recvAtomicSnoop(PacketPtr pkt, PortID mem_side_port_id);
336 
348  forwardAtomic(PacketPtr pkt, PortID exclude_cpu_side_port_id)
349  {
350  return forwardAtomic(pkt, exclude_cpu_side_port_id, InvalidPortID,
351  snoopPorts);
352  }
353 
368  PortID exclude_cpu_side_port_id,
369  PortID source_mem_side_port_id,
371  dests);
372 
375  void recvFunctional(PacketPtr pkt, PortID cpu_side_port_id);
376 
379  void recvFunctionalSnoop(PacketPtr pkt, PortID mem_side_port_id);
380 
389  void forwardFunctional(PacketPtr pkt, PortID exclude_cpu_side_port_id);
390 
395  bool sinkPacket(const PacketPtr pkt) const;
396 
401  bool forwardPacket(const PacketPtr pkt);
402 
414  bool
415  isDestination(const PacketPtr pkt) const
416  {
417  return (pkt->req->isToPOC() && pointOfCoherency) ||
418  (pkt->req->isToPOU() && pointOfUnification);
419  }
420 
424 
425  public:
426 
427  virtual void init();
428 
429  CoherentXBar(const CoherentXBarParams &p);
430 
431  virtual ~CoherentXBar();
432 
433  virtual void regStats();
434 };
435 
436 } // namespace gem5
437 
438 #endif //__MEM_COHERENT_XBAR_HH__
gem5::statistics::Scalar
This is a simple scalar statistic, like a counter.
Definition: statistics.hh:1927
gem5::PortID
int16_t PortID
Port index/ID type, and a symbolic name for an invalid port id.
Definition: types.hh:252
gem5::BaseXBar
The base crossbar contains the common elements of the non-coherent and coherent crossbar.
Definition: xbar.hh:71
gem5::CoherentXBar::SnoopRespPort::sendRetryResp
void sendRetryResp() override
Override the sending of retries and pass them on through the mirrored CPU-side port.
Definition: coherent_xbar.hh:232
gem5::Port::name
const std::string name() const
Return port name (for DPRINTF).
Definition: port.hh:111
gem5::CoherentXBar::SnoopRespPort::SnoopRespPort
SnoopRespPort(QueuedResponsePort &cpu_side_port, CoherentXBar &_xbar)
Create a snoop response port that mirrors a given CPU-side port.
Definition: coherent_xbar.hh:222
gem5::statistics::Distribution
A simple distribution stat.
Definition: statistics.hh:2081
gem5::RespPacketQueue
Definition: packet_queue.hh:300
gem5::CoherentXBar::snoopPorts
std::vector< QueuedResponsePort * > snoopPorts
Definition: coherent_xbar.hh:254
xbar.hh
gem5::SnoopFilter
This snoop filter keeps track of which connected port has a particular line of data.
Definition: snoop_filter.hh:89
gem5::ResponsePort::sendRetrySnoopResp
void sendRetrySnoopResp()
Send a retry to the request port that previously attempted a sendTimingSnoopResp to this response por...
Definition: port.hh:415
gem5::CoherentXBar::CoherentXBarRequestPort::CoherentXBarRequestPort
CoherentXBarRequestPort(const std::string &_name, CoherentXBar &_xbar, PortID _id)
Definition: coherent_xbar.hh:160
gem5::CoherentXBar::snoopLayers
std::vector< SnoopRespLayer * > snoopLayers
Definition: coherent_xbar.hh:81
gem5::CoherentXBar::system
System * system
Keep a pointer to the system to be allow to querying memory system properties.
Definition: coherent_xbar.hh:274
gem5::Packet::req
RequestPtr req
A pointer to the original request.
Definition: packet.hh:366
gem5::CoherentXBar::CoherentXBarResponsePort::recvTimingReq
bool recvTimingReq(PacketPtr pkt) override
Receive a timing request from the peer.
Definition: coherent_xbar.hh:110
gem5::CoherentXBar::forwardPacket
bool forwardPacket(const PacketPtr pkt)
Determine if the crossbar should forward the packet, as opposed to responding to it.
Definition: coherent_xbar.cc:1104
gem5::CoherentXBar::CoherentXBar
CoherentXBar(const CoherentXBarParams &p)
Definition: coherent_xbar.cc:58
gem5::CoherentXBar::CoherentXBarResponsePort
Declaration of the coherent crossbar CPU-side port type, one will be instantiated for each of the mem...
Definition: coherent_xbar.hh:88
gem5::CoherentXBar::sinkPacket
bool sinkPacket(const PacketPtr pkt) const
Determine if the crossbar should sink the packet, as opposed to forwarding it, or responding.
Definition: coherent_xbar.cc:1080
gem5::CoherentXBar::CoherentXBarResponsePort::getAddrRanges
AddrRangeList getAddrRanges() const override
Get a list of the non-overlapping address ranges the owner is responsible for.
Definition: coherent_xbar.hh:140
std::vector< ReqLayer * >
gem5::CoherentXBar::snoopTraffic
statistics::Scalar snoopTraffic
Definition: coherent_xbar.hh:422
gem5::CoherentXBar::CoherentXBarRequestPort::xbar
CoherentXBar & xbar
A reference to the crossbar to which this port belongs.
Definition: coherent_xbar.hh:156
gem5::CoherentXBar::recvFunctionalSnoop
void recvFunctionalSnoop(PacketPtr pkt, PortID mem_side_port_id)
Function called by the port when the crossbar is receiving a functional snoop transaction.
Definition: coherent_xbar.cc:1037
gem5::InvalidPortID
const PortID InvalidPortID
Definition: types.hh:253
gem5::CoherentXBar::recvAtomicBackdoor
Tick recvAtomicBackdoor(PacketPtr pkt, PortID cpu_side_port_id, MemBackdoorPtr *backdoor=nullptr)
Definition: coherent_xbar.cc:737
gem5::CoherentXBar::CoherentXBarRequestPort
Declaration of the coherent crossbar memory-side port type, one will be instantiated for each of the ...
Definition: coherent_xbar.hh:152
gem5::CoherentXBar::CoherentXBarResponsePort::recvAtomicBackdoor
Tick recvAtomicBackdoor(PacketPtr pkt, MemBackdoorPtr &backdoor) override
Receive an atomic request packet from the peer, and optionally provide a backdoor to the data being a...
Definition: coherent_xbar.hh:128
gem5::RequestPort
A RequestPort is a specialisation of a Port, which implements the default protocol for the three diff...
Definition: port.hh:77
gem5::Cycles
Cycles is a wrapper class for representing cycle counts, i.e.
Definition: types.hh:78
gem5::CoherentXBar::respLayers
std::vector< RespLayer * > respLayers
Definition: coherent_xbar.hh:80
gem5::CoherentXBar::reqLayers
std::vector< ReqLayer * > reqLayers
Declare the layers of this crossbar, one vector for requests, one for responses, and one for snoop re...
Definition: coherent_xbar.hh:79
gem5::CoherentXBar::CoherentXBarRequestPort::recvFunctionalSnoop
void recvFunctionalSnoop(PacketPtr pkt) override
Receive a functional snoop request packet from the peer.
Definition: coherent_xbar.hh:194
gem5::System
Definition: system.hh:77
gem5::CoherentXBar::SnoopRespPort::recvTimingResp
bool recvTimingResp(PacketPtr pkt) override
Receive a timing response from the peer.
Definition: coherent_xbar.hh:245
gem5::CoherentXBar::forwardAtomic
std::pair< MemCmd, Tick > forwardAtomic(PacketPtr pkt, PortID exclude_cpu_side_port_id)
Forward an atomic packet to our snoopers, potentially excluding one of the connected coherent request...
Definition: coherent_xbar.hh:348
gem5::CoherentXBar::isDestination
bool isDestination(const PacketPtr pkt) const
Determine if the packet's destination is the memory below.
Definition: coherent_xbar.hh:415
gem5::QueuedResponsePort
A queued port is a port that has an infinite queue for outgoing packets and thus decouples the module...
Definition: qport.hh:61
gem5::Packet
A Packet is used to encapsulate a transfer between two objects in the memory system (e....
Definition: packet.hh:283
gem5::CoherentXBar::recvReqRetry
void recvReqRetry(PortID mem_side_port_id)
Definition: coherent_xbar.cc:728
gem5::MipsISA::p
Bitfield< 0 > p
Definition: pra_constants.hh:326
gem5::Tick
uint64_t Tick
Tick count type.
Definition: types.hh:58
gem5::CoherentXBar::CoherentXBarResponsePort::xbar
CoherentXBar & xbar
A reference to the crossbar to which this port belongs.
Definition: coherent_xbar.hh:94
gem5::CoherentXBar::recvFunctional
void recvFunctional(PacketPtr pkt, PortID cpu_side_port_id)
Function called by the port when the crossbar is receiving a Functional transaction.
Definition: coherent_xbar.cc:1001
gem5::CoherentXBar::CoherentXBarRequestPort::recvTimingSnoopReq
void recvTimingSnoopReq(PacketPtr pkt) override
Receive a timing snoop request from the peer.
Definition: coherent_xbar.hh:182
gem5::BaseXBar::recvRangeChange
virtual void recvRangeChange(PortID mem_side_port_id)
Function called by the port when the crossbar is recieving a range change.
Definition: xbar.cc:364
gem5::CoherentXBar::recvTimingReq
bool recvTimingReq(PacketPtr pkt, PortID cpu_side_port_id)
Definition: coherent_xbar.cc:149
gem5::CoherentXBar::CoherentXBarResponsePort::recvAtomic
Tick recvAtomic(PacketPtr pkt) override
Receive an atomic request packet from the peer.
Definition: coherent_xbar.hh:122
gem5::BaseXBar::getAddrRanges
AddrRangeList getAddrRanges() const
Return the address ranges the crossbar is responsible for.
Definition: xbar.cc:526
gem5::CoherentXBar::snoopFanout
statistics::Distribution snoopFanout
Definition: coherent_xbar.hh:423
gem5::CoherentXBar::~CoherentXBar
virtual ~CoherentXBar()
Definition: coherent_xbar.cc:111
gem5::CoherentXBar::pointOfCoherency
const bool pointOfCoherency
Is this crossbar the point of coherency?
Definition: coherent_xbar.hh:290
gem5::CoherentXBar::CoherentXBarResponsePort::recvFunctional
void recvFunctional(PacketPtr pkt) override
Receive a functional request packet from the peer.
Definition: coherent_xbar.hh:134
std::pair
STL pair class.
Definition: stl.hh:58
gem5::CoherentXBar::outstandingSnoop
std::unordered_set< RequestPtr > outstandingSnoop
Store the outstanding requests that we are expecting snoop responses from so we can determine which s...
Definition: coherent_xbar.hh:261
gem5::CoherentXBar::recvTimingSnoopReq
void recvTimingSnoopReq(PacketPtr pkt, PortID mem_side_port_id)
Definition: coherent_xbar.cc:510
gem5::CoherentXBar::SnoopRespPort::cpuSidePort
QueuedResponsePort & cpuSidePort
The port which we mirror internally.
Definition: coherent_xbar.hh:215
gem5::CoherentXBar::snoops
statistics::Scalar snoops
Definition: coherent_xbar.hh:421
gem5::CoherentXBar::snoopFilter
SnoopFilter * snoopFilter
A snoop filter that tracks cache line residency and can restrict the broadcast needed for probes.
Definition: coherent_xbar.hh:278
gem5::CoherentXBar::CoherentXBarResponsePort::CoherentXBarResponsePort
CoherentXBarResponsePort(const std::string &_name, CoherentXBar &_xbar, PortID _id)
Definition: coherent_xbar.hh:101
gem5::MemBackdoor
Definition: backdoor.hh:41
gem5::CoherentXBar
A coherent crossbar connects a number of (potentially) snooping requestors and responders,...
Definition: coherent_xbar.hh:70
gem5::CoherentXBar::init
virtual void init()
init() is called after all C++ SimObjects have been created and all ports are connected.
Definition: coherent_xbar.cc:124
gem5::CoherentXBar::outstandingCMO
std::unordered_map< PacketId, PacketPtr > outstandingCMO
Store the outstanding cache maintenance that we are expecting snoop responses from so we can determin...
Definition: coherent_xbar.hh:268
gem5::CoherentXBar::maxOutstandingSnoopCheck
const unsigned int maxOutstandingSnoopCheck
Maximum number of outstading snoops sanity check.
Definition: coherent_xbar.hh:284
gem5::CoherentXBar::CoherentXBarRequestPort::recvAtomicSnoop
Tick recvAtomicSnoop(PacketPtr pkt) override
Receive an atomic snoop request packet from our peer.
Definition: coherent_xbar.hh:188
gem5::CoherentXBar::pointOfUnification
const bool pointOfUnification
Is this crossbar the point of unification?
Definition: coherent_xbar.hh:293
gem5::CoherentXBar::CoherentXBarRequestPort::recvTimingResp
bool recvTimingResp(PacketPtr pkt) override
Receive a timing response from the peer.
Definition: coherent_xbar.hh:176
gem5::CoherentXBar::snoopResponseLatency
const Cycles snoopResponseLatency
Cycles of snoop response latency.
Definition: coherent_xbar.hh:281
gem5::CoherentXBar::regStats
virtual void regStats()
Callback to set stat parameters.
Definition: coherent_xbar.cc:1119
gem5::CoherentXBar::CoherentXBarResponsePort::recvTimingSnoopResp
bool recvTimingSnoopResp(PacketPtr pkt) override
Receive a timing snoop response from the peer.
Definition: coherent_xbar.hh:116
gem5::CoherentXBar::forwardFunctional
void forwardFunctional(PacketPtr pkt, PortID exclude_cpu_side_port_id)
Forward a functional packet to our snoopers, potentially excluding one of the connected coherent requ...
Definition: coherent_xbar.cc:1058
gem5::CoherentXBar::recvAtomicSnoop
Tick recvAtomicSnoop(PacketPtr pkt, PortID mem_side_port_id)
Definition: coherent_xbar.cc:889
gem5::CoherentXBar::SnoopRespPort::recvReqRetry
void recvReqRetry() override
Called by the peer if sendTimingReq was called on this peer (causing recvTimingReq to be called on th...
Definition: coherent_xbar.hh:239
gem5::CoherentXBar::SnoopRespPort
Internal class to bridge between an incoming snoop response from a CPU-side port and forwarding it th...
Definition: coherent_xbar.hh:209
gem5::CoherentXBar::pendingDelete
std::unique_ptr< Packet > pendingDelete
Upstream caches need this packet until true is returned, so hold it for deletion until a subsequent c...
Definition: coherent_xbar.hh:299
gem5::CoherentXBar::forwardTiming
void forwardTiming(PacketPtr pkt, PortID exclude_cpu_side_port_id)
Forward a timing packet to our snoopers, potentially excluding one of the connected coherent requesto...
Definition: coherent_xbar.hh:316
gem5::CoherentXBar::recvTimingSnoopResp
bool recvTimingSnoopResp(PacketPtr pkt, PortID cpu_side_port_id)
Definition: coherent_xbar.cc:570
std::list< AddrRange >
snoop_filter.hh
gem5::CoherentXBar::recvTimingResp
bool recvTimingResp(PacketPtr pkt, PortID mem_side_port_id)
Definition: coherent_xbar.cc:447
gem5::CoherentXBar::snoopRespPorts
std::vector< SnoopRespPort * > snoopRespPorts
Definition: coherent_xbar.hh:252
gem5
Reference material can be found at the JEDEC website: UFS standard http://www.jedec....
Definition: decoder.cc:40
gem5::CoherentXBar::CoherentXBarRequestPort::recvReqRetry
void recvReqRetry() override
Called by the peer if sendTimingReq was called on this peer (causing recvTimingReq to be called on th...
Definition: coherent_xbar.hh:200
gem5::CoherentXBar::CoherentXBarRequestPort::isSnooping
bool isSnooping() const override
Determine if this port should be considered a snooper.
Definition: coherent_xbar.hh:173
gem5::Named::_name
const std::string _name
Definition: named.hh:41
gem5::CoherentXBar::maxRoutingTableSizeCheck
const unsigned int maxRoutingTableSizeCheck
Maximum routing table size sanity check.
Definition: coherent_xbar.hh:287
gem5::CoherentXBar::CoherentXBarResponsePort::queue
RespPacketQueue queue
A normal packet queue used to store responses.
Definition: coherent_xbar.hh:97
gem5::CoherentXBar::CoherentXBarRequestPort::recvRangeChange
void recvRangeChange() override
Called to receive an address range change from the peer response port.
Definition: coherent_xbar.hh:199
panic
#define panic(...)
This implements a cprintf based panic() function.
Definition: logging.hh:177

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