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/*
* 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;
AddrRangeList getAddrRanges() 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;
/**
* 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 scheduled?
*
* @return true if event is scheduled
*/
bool respondEventScheduled(uint8_t pseudo_channel) const override
{
if (pseudo_channel == 0) {
return MemCtrl::respondEventScheduled(pseudo_channel);
} else {
assert(pseudo_channel == 1);
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;
void recvMemBackdoorReq(const MemBackdoorReq &req,
MemBackdoorPtr &_backdoor) override;
bool recvTimingReq(PacketPtr pkt) override;
};
} // namespace memory
} // namespace gem5
#endif //__HBM_CTRL_HH__