src/mem/hbm_ctrl.hh - public/gem5 - Git at Google

 /*
  * Copyright (c) 2022 The Regents of the University of California
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met: redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer;
  * 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;
  * neither the name of the copyright holders 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
  * OWNER 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.
  */

 /**
  * @file
  * HBMCtrl declaration
  */

 #ifndef __HBM_CTRL_HH__
 #define __HBM_CTRL_HH__

 #include <deque>
 #include <string>
 #include <unordered_set>
 #include <utility>
 #include <vector>

 #include "mem/mem_ctrl.hh"
 #include "params/HBMCtrl.hh"

 namespace gem5
 {

 namespace memory
 {

 class MemInterface;
 class DRAMInterface;


 /**
  * HBM2 is divided into two pseudo channels which have independent data buses
  * but share a command bus (separate row and column command bus). Therefore,
  * the HBM memory controller should be able to control both pseudo channels.
  * This HBM memory controller inherits from gem5's default
  * memory controller (pseudo channel 0) and manages the additional HBM pseudo
  * channel (pseudo channel 1).
  */
 class HBMCtrl : public MemCtrl
 {

   protected:

     bool respQEmpty() override
     {
         return (respQueue.empty() && respQueuePC1.empty());
     }

   private:

     /**
      * Remember if we have to retry a request for second pseudo channel.
      */
     bool retryRdReqPC1;
     bool retryWrReqPC1;

     /**
      * Remove commands that have already issued from rowBurstTicks
      * and colBurstTicks
      */
     void pruneBurstTick() override;

   public:
     HBMCtrl(const HBMCtrlParams &p);

     void pruneRowBurstTick();
     void pruneColBurstTick();

     /**
      * Check for command bus contention for single cycle command.
      * If there is contention, shift command to next burst.
      * Check verifies that the commands issued per burst is less
      * than a defined max number, maxCommandsPerWindow.
      * Therefore, contention per cycle is not verified and instead
      * is done based on a burst window.
      *
      * @param cmd_tick Initial tick of command, to be verified
      * @param max_cmds_per_burst Number of commands that can issue
      *                           in a burst window
      * @return tick for command issue without contention
      */
     Tick verifySingleCmd(Tick cmd_tick, Tick max_cmds_per_burst,
                         bool row_cmd) override;

     /**
      * Check for command bus contention for multi-cycle (2 currently)
      * command. If there is contention, shift command(s) to next burst.
      * Check verifies that the commands issued per burst is less
      * than a defined max number, maxCommandsPerWindow.
      * Therefore, contention per cycle is not verified and instead
      * is done based on a burst window.
      * For HBM2, only row cmds (activate) can be multi-cycle
      *
      * @param cmd_tick Initial tick of command, to be verified
      * @param max_multi_cmd_split Maximum delay between commands
      * @param max_cmds_per_burst Number of commands that can issue
      *                           in a burst window
      * @return tick for command issue without contention
      */
     Tick verifyMultiCmd(Tick cmd_tick, Tick max_cmds_per_burst,
                         Tick max_multi_cmd_split = 0) override;

     /**
      * NextReq and Respond events for second pseudo channel
      *
      */
     EventFunctionWrapper nextReqEventPC1;
     EventFunctionWrapper respondEventPC1;

     /**
      * Check if the read queue partition of both pseudo
      * channels has room for more entries. This is used when the HBM ctrl
      * is run with partitioned queues
      *
      * @param pkt_count The number of entries needed in the read queue
      * @return true if read queue partition is full, false otherwise
      */
     bool readQueueFullPC0(unsigned int pkt_count) const;
     bool readQueueFullPC1(unsigned int pkt_count) const;
     bool readQueueFull(unsigned int pkt_count) const;

     /**
      * Check if the write queue partition of both pseudo
      * channels has room for more entries. This is used when the HBM ctrl
      * is run with partitioned queues
      *
      * @param pkt_count The number of entries needed in the write queue
      * @return true if write queue is full, false otherwise
      */
     bool writeQueueFullPC0(unsigned int pkt_count) const;
     bool writeQueueFullPC1(unsigned int pkt_count) const;

     /**
      * Following counters are used to keep track of the entries in read/write
      * queue for each pseudo channel (useful when the partitioned queues are
      * used)
      */
     uint64_t readQueueSizePC0 = 0;
     uint64_t readQueueSizePC1 = 0;
     uint64_t writeQueueSizePC0 = 0;
     uint64_t writeQueueSizePC1 = 0;

     /**
      * Response queue for pkts sent to second pseudo channel
      * The first pseudo channel uses MemCtrl::respQueue
      */
     std::deque<MemPacket*> respQueuePC1;

     /**
      * Holds count of row commands issued in burst window starting at
      * defined Tick. This is used to ensure that the row command bandwidth
      * does not exceed the allowable media constraints.
      */
     std::unordered_multiset<Tick> rowBurstTicks;

     /**
      * This is used to ensure that the column command bandwidth
      * does not exceed the allowable media constraints. HBM2 has separate
      * command bus for row and column commands
      */
     std::unordered_multiset<Tick> colBurstTicks;

     /**
      * Pointers to interfaces of the two pseudo channels
      * pc0Int is same as MemCtrl::dram (it will be pointing to
      * the DRAM interface defined in base MemCtrl)
      */
     DRAMInterface* pc0Int;
     DRAMInterface* pc1Int;

     /**
      * This indicates if the R/W queues will be partitioned among
      * pseudo channels
      */
     bool partitionedQ;

   public:

     /**
      * Is there a respondEvent for pseudo channel 1 scheduled?
      *
      * @return true if event is scheduled
      */
     bool respondEventPC1Scheduled() const
     {
         return respondEventPC1.scheduled();
     }

     /**
      * Is there a read/write burst Event scheduled?
      *
      * @return true if event is scheduled
      */
     bool requestEventScheduled(uint8_t pseudo_channel) const override
     {
         if (pseudo_channel == 0) {
             return MemCtrl::requestEventScheduled(pseudo_channel);
         } else {
             assert(pseudo_channel == 1);
             return nextReqEventPC1.scheduled();
         }
     }

     /**
      * restart the controller scheduler
      *
      * @param Tick to schedule next event
      * @param pseudo_channel pseudo channel number for which scheduler
      * needs to restart
      */
     void restartScheduler(Tick tick, uint8_t pseudo_channel) override
     {
         if (pseudo_channel == 0) {
             MemCtrl::restartScheduler(tick);
         } else {
             schedule(nextReqEventPC1, tick);
         }
     }


     virtual void init() override;
     virtual void startup() override;
     virtual void drainResume() override;


   protected:
     Tick recvAtomic(PacketPtr pkt) override;
     Tick recvAtomicBackdoor(PacketPtr pkt, MemBackdoorPtr &backdoor) override;
     void recvFunctional(PacketPtr pkt) override;
     bool recvTimingReq(PacketPtr pkt) override;

 };

 } // namespace memory
 } // namespace gem5

 #endif //__HBM_CTRL_HH__
	/*
	* Copyright (c) 2022 The Regents of the University of California
	* All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions are
	* met: redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer;
	* 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;
	* neither the name of the copyright holders 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
	* OWNER 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.
	*/

	/**
	* @file
	* HBMCtrl declaration
	*/

	#ifndef __HBM_CTRL_HH__
	#define __HBM_CTRL_HH__

	#include <deque>
	#include <string>
	#include <unordered_set>
	#include <utility>
	#include <vector>

	#include "mem/mem_ctrl.hh"
	#include "params/HBMCtrl.hh"

	namespace gem5
	{

	namespace memory
	{

	class MemInterface;
	class DRAMInterface;


	/**
	* HBM2 is divided into two pseudo channels which have independent data buses
	* but share a command bus (separate row and column command bus). Therefore,
	* the HBM memory controller should be able to control both pseudo channels.
	* This HBM memory controller inherits from gem5's default
	* memory controller (pseudo channel 0) and manages the additional HBM pseudo
	* channel (pseudo channel 1).
	*/
	class HBMCtrl : public MemCtrl
	{

	protected:

	bool respQEmpty() override
	{
	return (respQueue.empty() && respQueuePC1.empty());
	}

	private:

	/**
	* Remember if we have to retry a request for second pseudo channel.
	*/
	bool retryRdReqPC1;
	bool retryWrReqPC1;

	/**
	* Remove commands that have already issued from rowBurstTicks
	* and colBurstTicks
	*/
	void pruneBurstTick() override;

	public:
	HBMCtrl(const HBMCtrlParams &p);

	void pruneRowBurstTick();
	void pruneColBurstTick();

	/**
	* Check for command bus contention for single cycle command.
	* If there is contention, shift command to next burst.
	* Check verifies that the commands issued per burst is less
	* than a defined max number, maxCommandsPerWindow.
	* Therefore, contention per cycle is not verified and instead
	* is done based on a burst window.
	*
	* @param cmd_tick Initial tick of command, to be verified
	* @param max_cmds_per_burst Number of commands that can issue
	* in a burst window
	* @return tick for command issue without contention
	*/
	Tick verifySingleCmd(Tick cmd_tick, Tick max_cmds_per_burst,
	bool row_cmd) override;

	/**
	* Check for command bus contention for multi-cycle (2 currently)
	* command. If there is contention, shift command(s) to next burst.
	* Check verifies that the commands issued per burst is less
	* than a defined max number, maxCommandsPerWindow.
	* Therefore, contention per cycle is not verified and instead
	* is done based on a burst window.
	* For HBM2, only row cmds (activate) can be multi-cycle
	*
	* @param cmd_tick Initial tick of command, to be verified
	* @param max_multi_cmd_split Maximum delay between commands
	* @param max_cmds_per_burst Number of commands that can issue
	* in a burst window
	* @return tick for command issue without contention
	*/
	Tick verifyMultiCmd(Tick cmd_tick, Tick max_cmds_per_burst,
	Tick max_multi_cmd_split = 0) override;

	/**
	* NextReq and Respond events for second pseudo channel
	*
	*/
	EventFunctionWrapper nextReqEventPC1;
	EventFunctionWrapper respondEventPC1;

	/**
	* Check if the read queue partition of both pseudo
	* channels has room for more entries. This is used when the HBM ctrl
	* is run with partitioned queues
	*
	* @param pkt_count The number of entries needed in the read queue
	* @return true if read queue partition is full, false otherwise
	*/
	bool readQueueFullPC0(unsigned int pkt_count) const;
	bool readQueueFullPC1(unsigned int pkt_count) const;
	bool readQueueFull(unsigned int pkt_count) const;

	/**
	* Check if the write queue partition of both pseudo
	* channels has room for more entries. This is used when the HBM ctrl
	* is run with partitioned queues
	*
	* @param pkt_count The number of entries needed in the write queue
	* @return true if write queue is full, false otherwise
	*/
	bool writeQueueFullPC0(unsigned int pkt_count) const;
	bool writeQueueFullPC1(unsigned int pkt_count) const;

	/**
	* Following counters are used to keep track of the entries in read/write
	* queue for each pseudo channel (useful when the partitioned queues are
	* used)
	*/
	uint64_t readQueueSizePC0 = 0;
	uint64_t readQueueSizePC1 = 0;
	uint64_t writeQueueSizePC0 = 0;
	uint64_t writeQueueSizePC1 = 0;

	/**
	* Response queue for pkts sent to second pseudo channel
	* The first pseudo channel uses MemCtrl::respQueue
	*/
	std::deque<MemPacket*> respQueuePC1;

	/**
	* Holds count of row commands issued in burst window starting at
	* defined Tick. This is used to ensure that the row command bandwidth
	* does not exceed the allowable media constraints.
	*/
	std::unordered_multiset<Tick> rowBurstTicks;

	/**
	* This is used to ensure that the column command bandwidth
	* does not exceed the allowable media constraints. HBM2 has separate
	* command bus for row and column commands
	*/
	std::unordered_multiset<Tick> colBurstTicks;

	/**
	* Pointers to interfaces of the two pseudo channels
	* pc0Int is same as MemCtrl::dram (it will be pointing to
	* the DRAM interface defined in base MemCtrl)
	*/
	DRAMInterface* pc0Int;
	DRAMInterface* pc1Int;

	/**
	* This indicates if the R/W queues will be partitioned among
	* pseudo channels
	*/
	bool partitionedQ;

	public:

	/**
	* Is there a respondEvent for pseudo channel 1 scheduled?
	*
	* @return true if event is scheduled
	*/
	bool respondEventPC1Scheduled() const
	{
	return respondEventPC1.scheduled();
	}

	/**
	* Is there a read/write burst Event scheduled?
	*
	* @return true if event is scheduled
	*/
	bool requestEventScheduled(uint8_t pseudo_channel) const override
	{
	if (pseudo_channel == 0) {
	return MemCtrl::requestEventScheduled(pseudo_channel);
	} else {
	assert(pseudo_channel == 1);
	return nextReqEventPC1.scheduled();
	}
	}

	/**
	* restart the controller scheduler
	*
	* @param Tick to schedule next event
	* @param pseudo_channel pseudo channel number for which scheduler
	* needs to restart
	*/
	void restartScheduler(Tick tick, uint8_t pseudo_channel) override
	{
	if (pseudo_channel == 0) {
	MemCtrl::restartScheduler(tick);
	} else {
	schedule(nextReqEventPC1, tick);
	}
	}


	virtual void init() override;
	virtual void startup() override;
	virtual void drainResume() override;


	protected:
	Tick recvAtomic(PacketPtr pkt) override;
	Tick recvAtomicBackdoor(PacketPtr pkt, MemBackdoorPtr &backdoor) override;
	void recvFunctional(PacketPtr pkt) override;
	bool recvTimingReq(PacketPtr pkt) override;

	};

	} // namespace memory
	} // namespace gem5

	#endif //__HBM_CTRL_HH__