gem5/src/mem/ruby/system/Sequencer.cc

/*
 * Copyright (c) 1999-2008 Mark D. Hill and David A. Wood
 * 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.
 */

#include "base/str.hh"
#include "cpu/rubytest/RubyTester.hh"
#include "mem/gems_common/Map.hh"
#include "mem/protocol/CacheMsg.hh"
#include "mem/protocol/Protocol.hh"
#include "mem/protocol/Protocol.hh"
#include "mem/ruby/buffers/MessageBuffer.hh"
#include "mem/ruby/common/Global.hh"
#include "mem/ruby/common/SubBlock.hh"
#include "mem/ruby/libruby.hh"
#include "mem/ruby/profiler/Profiler.hh"
#include "mem/ruby/recorder/Tracer.hh"
#include "mem/ruby/slicc_interface/AbstractController.hh"
#include "mem/ruby/system/CacheMemory.hh"
#include "mem/ruby/system/Sequencer.hh"
#include "mem/ruby/system/System.hh"
#include "params/RubySequencer.hh"

using namespace std;

Sequencer *
RubySequencerParams::create()
{
    return new Sequencer(this);
}

Sequencer::Sequencer(const Params *p)
    : RubyPort(p), deadlockCheckEvent(this)
{
    m_store_waiting_on_load_cycles = 0;
    m_store_waiting_on_store_cycles = 0;
    m_load_waiting_on_store_cycles = 0;
    m_load_waiting_on_load_cycles = 0;

    m_outstanding_count = 0;

    m_max_outstanding_requests = 0;
    m_deadlock_threshold = 0;
    m_instCache_ptr = NULL;
    m_dataCache_ptr = NULL;

    m_instCache_ptr = p->icache;
    m_dataCache_ptr = p->dcache;
    m_max_outstanding_requests = p->max_outstanding_requests;
    m_deadlock_threshold = p->deadlock_threshold;
    m_usingRubyTester = p->using_ruby_tester;

    assert(m_max_outstanding_requests > 0);
    assert(m_deadlock_threshold > 0);
    assert(m_instCache_ptr != NULL);
    assert(m_dataCache_ptr != NULL);
}

Sequencer::~Sequencer()
{
}

void
Sequencer::wakeup()
{
    // Check for deadlock of any of the requests
    Time current_time = g_eventQueue_ptr->getTime();

    // Check across all outstanding requests
    int total_outstanding = 0;

    std::vector<Address> keys = m_readRequestTable.keys();
    for (int i = 0; i < keys.size(); i++) {
        SequencerRequest* request = m_readRequestTable.lookup(keys[i]);
        if (current_time - request->issue_time >= m_deadlock_threshold) {
            WARN_MSG("Possible Deadlock detected");
            WARN_EXPR(request);
            WARN_EXPR(m_version);
            WARN_EXPR(request->ruby_request.paddr);
            WARN_EXPR(keys.size());
            WARN_EXPR(current_time);
            WARN_EXPR(request->issue_time);
            WARN_EXPR(current_time - request->issue_time);
            ERROR_MSG("Aborting");
        }
    }

    keys = m_writeRequestTable.keys();
    for (int i = 0; i < keys.size(); i++) {
        SequencerRequest* request = m_writeRequestTable.lookup(keys[i]);
        if (current_time - request->issue_time >= m_deadlock_threshold) {
            WARN_MSG("Possible Deadlock detected");
            WARN_EXPR(request);
            WARN_EXPR(m_version);
            WARN_EXPR(current_time);
            WARN_EXPR(request->issue_time);
            WARN_EXPR(current_time - request->issue_time);
            WARN_EXPR(keys.size());
            ERROR_MSG("Aborting");
        }
    }

    total_outstanding += m_writeRequestTable.size();
    total_outstanding += m_readRequestTable.size();

    assert(m_outstanding_count == total_outstanding);

    if (m_outstanding_count > 0) {
        // If there are still outstanding requests, keep checking
        schedule(deadlockCheckEvent,
                 m_deadlock_threshold * g_eventQueue_ptr->getClock() +
                 curTick);
    }
}

void
Sequencer::printStats(ostream & out) const
{
    out << "Sequencer: " << m_name << endl
        << "  store_waiting_on_load_cycles: "
        << m_store_waiting_on_load_cycles << endl
        << "  store_waiting_on_store_cycles: "
        << m_store_waiting_on_store_cycles << endl
        << "  load_waiting_on_load_cycles: "
        << m_load_waiting_on_load_cycles << endl
        << "  load_waiting_on_store_cycles: "
        << m_load_waiting_on_store_cycles << endl;
}

void
Sequencer::printProgress(ostream& out) const
{
#if 0
    int total_demand = 0;
    out << "Sequencer Stats Version " << m_version << endl;
    out << "Current time = " << g_eventQueue_ptr->getTime() << endl;
    out << "---------------" << endl;
    out << "outstanding requests" << endl;

    std::vector<Address> rkeys = m_readRequestTable.keys();
    int read_size = rkeys.size();
    out << "proc " << m_version << " Read Requests = " << read_size << endl;

    // print the request table
    for (int i = 0; i < read_size; ++i) {
        SequencerRequest *request = m_readRequestTable.lookup(rkeys[i]);
        out << "\tRequest[ " << i << " ] = " << request->type
            << " Address " << rkeys[i]
            << " Posted " << request->issue_time
            << " PF " << PrefetchBit_No << endl;
        total_demand++;
    }

    std::vector<Address> wkeys = m_writeRequestTable.keys();
    int write_size = wkeys.size();
    out << "proc " << m_version << " Write Requests = " << write_size << endl;

    // print the request table
    for (int i = 0; i < write_size; ++i){
        CacheMsg &request = m_writeRequestTable.lookup(wkeys[i]);
        out << "\tRequest[ " << i << " ] = " << request.getType()
            << " Address " << wkeys[i]
            << " Posted " << request.getTime()
            << " PF " << request.getPrefetch() << endl;
        if (request.getPrefetch() == PrefetchBit_No) {
            total_demand++;
        }
    }

    out << endl;

    out << "Total Number Outstanding: " << m_outstanding_count << endl
        << "Total Number Demand     : " << total_demand << endl
        << "Total Number Prefetches : " << m_outstanding_count - total_demand
        << endl << endl << endl;
#endif
}

void
Sequencer::printConfig(ostream& out) const
{
    out << "Seqeuncer config: " << m_name << endl
        << "  controller: " << m_controller->getName() << endl
        << "  version: " << m_version << endl
        << "  max_outstanding_requests: " << m_max_outstanding_requests << endl
        << "  deadlock_threshold: " << m_deadlock_threshold << endl;
}

// Insert the request on the correct request table.  Return true if
// the entry was already present.
bool
Sequencer::insertRequest(SequencerRequest* request)
{
    int total_outstanding =
        m_writeRequestTable.size() + m_readRequestTable.size();

    assert(m_outstanding_count == total_outstanding);

    // See if we should schedule a deadlock check
    if (deadlockCheckEvent.scheduled() == false) {
        schedule(deadlockCheckEvent, m_deadlock_threshold + curTick);
    }

    Address line_addr(request->ruby_request.paddr);
    line_addr.makeLineAddress();
    if ((request->ruby_request.type == RubyRequestType_ST) ||
        (request->ruby_request.type == RubyRequestType_RMW_Read) ||
        (request->ruby_request.type == RubyRequestType_RMW_Write) ||
        (request->ruby_request.type == RubyRequestType_Locked_Read) ||
        (request->ruby_request.type == RubyRequestType_Locked_Write)) {
        if (m_writeRequestTable.exist(line_addr)) {
            m_writeRequestTable.lookup(line_addr) = request;
            // return true;

            // drh5: isn't this an error?  do you lose the initial request?
            assert(0);
        }
        m_writeRequestTable.allocate(line_addr);
        m_writeRequestTable.lookup(line_addr) = request;
        m_outstanding_count++;
    } else {
        if (m_readRequestTable.exist(line_addr)) {
            m_readRequestTable.lookup(line_addr) = request;
            // return true;

            // drh5: isn't this an error?  do you lose the initial request?
            assert(0);
        }
        m_readRequestTable.allocate(line_addr);
        m_readRequestTable.lookup(line_addr) = request;
        m_outstanding_count++;
    }

    g_system_ptr->getProfiler()->sequencerRequests(m_outstanding_count);

    total_outstanding = m_writeRequestTable.size() + m_readRequestTable.size();
    assert(m_outstanding_count == total_outstanding);

    return false;
}

void
Sequencer::removeRequest(SequencerRequest* srequest)
{
    assert(m_outstanding_count ==
           m_writeRequestTable.size() + m_readRequestTable.size());

    const RubyRequest & ruby_request = srequest->ruby_request;
    Address line_addr(ruby_request.paddr);
    line_addr.makeLineAddress();
    if ((ruby_request.type == RubyRequestType_ST) ||
        (ruby_request.type == RubyRequestType_RMW_Read) ||
        (ruby_request.type == RubyRequestType_RMW_Write) ||
        (ruby_request.type == RubyRequestType_Locked_Read) ||
        (ruby_request.type == RubyRequestType_Locked_Write)) {
        m_writeRequestTable.deallocate(line_addr);
    } else {
        m_readRequestTable.deallocate(line_addr);
    }
    m_outstanding_count--;

    assert(m_outstanding_count == m_writeRequestTable.size() + m_readRequestTable.size());
}

void
Sequencer::writeCallback(const Address& address, DataBlock& data)
{
    assert(address == line_address(address));
    assert(m_writeRequestTable.exist(line_address(address)));

    SequencerRequest* request = m_writeRequestTable.lookup(address);

    removeRequest(request);

    assert((request->ruby_request.type == RubyRequestType_ST) ||
           (request->ruby_request.type == RubyRequestType_RMW_Read) ||
           (request->ruby_request.type == RubyRequestType_RMW_Write) ||
           (request->ruby_request.type == RubyRequestType_Locked_Read) ||
           (request->ruby_request.type == RubyRequestType_Locked_Write));

    if (request->ruby_request.type == RubyRequestType_Locked_Read) {
        m_dataCache_ptr->setLocked(address, m_version);
    } else if (request->ruby_request.type == RubyRequestType_RMW_Read) {
        m_controller->blockOnQueue(address, m_mandatory_q_ptr);
    } else if (request->ruby_request.type == RubyRequestType_RMW_Write) {
        m_controller->unblock(address);
    }

    hitCallback(request, data);
}

void
Sequencer::readCallback(const Address& address, DataBlock& data)
{
    assert(address == line_address(address));
    assert(m_readRequestTable.exist(line_address(address)));

    SequencerRequest* request = m_readRequestTable.lookup(address);
    removeRequest(request);

    assert((request->ruby_request.type == RubyRequestType_LD) ||
           (request->ruby_request.type == RubyRequestType_RMW_Read) ||
           (request->ruby_request.type == RubyRequestType_IFETCH));

    hitCallback(request, data);
}

void
Sequencer::hitCallback(SequencerRequest* srequest, DataBlock& data)
{
    const RubyRequest & ruby_request = srequest->ruby_request;
    Address request_address(ruby_request.paddr);
    Address request_line_address(ruby_request.paddr);
    request_line_address.makeLineAddress();
    RubyRequestType type = ruby_request.type;
    Time issued_time = srequest->issue_time;

    // Set this cache entry to the most recently used
    if (type == RubyRequestType_IFETCH) {
        if (m_instCache_ptr->isTagPresent(request_line_address))
            m_instCache_ptr->setMRU(request_line_address);
    } else {
        if (m_dataCache_ptr->isTagPresent(request_line_address))
            m_dataCache_ptr->setMRU(request_line_address);
    }

    assert(g_eventQueue_ptr->getTime() >= issued_time);
    Time miss_latency = g_eventQueue_ptr->getTime() - issued_time;

    // Profile the miss latency for all non-zero demand misses
    if (miss_latency != 0) {
        g_system_ptr->getProfiler()->missLatency(miss_latency, type);

        if (Debug::getProtocolTrace()) {
            g_system_ptr->getProfiler()->
                profileTransition("Seq", m_version,
                                  Address(ruby_request.paddr), "", "Done", "",
                                  csprintf("%d cycles", miss_latency));
        }
    }
#if 0
    if (request.getPrefetch() == PrefetchBit_Yes) {
        return; // Ignore the prefetch
    }
#endif

    // update the data
    if (ruby_request.data != NULL) {
        if ((type == RubyRequestType_LD) ||
            (type == RubyRequestType_IFETCH) ||
            (type == RubyRequestType_RMW_Read) ||
            (type == RubyRequestType_Locked_Read)) {

            memcpy(ruby_request.data,
                   data.getData(request_address.getOffset(), ruby_request.len),
                   ruby_request.len);
        } else {
            data.setData(ruby_request.data, request_address.getOffset(),
                         ruby_request.len);
        }
    } else {
        DPRINTF(MemoryAccess,
                "WARNING.  Data not transfered from Ruby to M5 for type %s\n",
                RubyRequestType_to_string(type));
    }

    // If using the RubyTester, update the RubyTester sender state's
    // subBlock with the recieved data.  The tester will later access
    // this state.
    // Note: RubyPort will access it's sender state before the
    // RubyTester.
    if (m_usingRubyTester) {
        RubyPort::SenderState *requestSenderState =
            safe_cast<RubyPort::SenderState*>(ruby_request.pkt->senderState);
        RubyTester::SenderState* testerSenderState =
            safe_cast<RubyTester::SenderState*>(requestSenderState->saved);
        testerSenderState->subBlock->mergeFrom(data);
    }

    ruby_hit_callback(ruby_request.pkt);
    delete srequest;
}

// Returns true if the sequencer already has a load or store outstanding
RequestStatus
Sequencer::getRequestStatus(const RubyRequest& request)
{
    bool is_outstanding_store =
        m_writeRequestTable.exist(line_address(Address(request.paddr)));
    bool is_outstanding_load =
        m_readRequestTable.exist(line_address(Address(request.paddr)));
    if (is_outstanding_store) {
        if ((request.type == RubyRequestType_LD) ||
            (request.type == RubyRequestType_IFETCH) ||
            (request.type == RubyRequestType_RMW_Read)) {
            m_store_waiting_on_load_cycles++;
        } else {
            m_store_waiting_on_store_cycles++;
        }
        return RequestStatus_Aliased;
    } else if (is_outstanding_load) {
        if ((request.type == RubyRequestType_ST) ||
            (request.type == RubyRequestType_RMW_Write)) {
            m_load_waiting_on_store_cycles++;
        } else {
            m_load_waiting_on_load_cycles++;
        }
        return RequestStatus_Aliased;
    }

    if (m_outstanding_count >= m_max_outstanding_requests) {
        return RequestStatus_BufferFull;
    }

    return RequestStatus_Ready;
}

bool
Sequencer::empty() const
{
    return m_writeRequestTable.size() == 0 && m_readRequestTable.size() == 0;
}

RequestStatus
Sequencer::makeRequest(const RubyRequest &request)
{
    assert(Address(request.paddr).getOffset() + request.len <=
           RubySystem::getBlockSizeBytes());
    RequestStatus status = getRequestStatus(request);
    if (status != RequestStatus_Ready)
        return status;

    SequencerRequest *srequest =
        new SequencerRequest(request, g_eventQueue_ptr->getTime());
    bool found = insertRequest(srequest);
    if (found) {
        panic("Sequencer::makeRequest should never be called if the "
              "request is already outstanding\n");
        return RequestStatus_NULL;
    }

    if (request.type == RubyRequestType_Locked_Write) {
        // NOTE: it is OK to check the locked flag here as the
        // mandatory queue will be checked first ensuring that nothing
        // comes between checking the flag and servicing the store.

        Address line_addr = line_address(Address(request.paddr));
        if (!m_dataCache_ptr->isLocked(line_addr, m_version)) {
            removeRequest(srequest);
            if (Debug::getProtocolTrace()) {
                g_system_ptr->getProfiler()->
                    profileTransition("Seq", m_version,
                                      Address(request.paddr),
                                      "", "SC Fail", "",
                                      RubyRequestType_to_string(request.type));
            }
            return RequestStatus_LlscFailed;
        } else {
            m_dataCache_ptr->clearLocked(line_addr);
        }
    }
    issueRequest(request);

    // TODO: issue hardware prefetches here
    return RequestStatus_Issued;
}

void
Sequencer::issueRequest(const RubyRequest& request)
{
    // TODO: get rid of CacheMsg, CacheRequestType, and
    // AccessModeTYpe, & have SLICC use RubyRequest and subtypes
    // natively
    CacheRequestType ctype;
    switch(request.type) {
      case RubyRequestType_IFETCH:
        ctype = CacheRequestType_IFETCH;
        break;
      case RubyRequestType_LD:
        ctype = CacheRequestType_LD;
        break;
      case RubyRequestType_ST:
        ctype = CacheRequestType_ST;
        break;
      case RubyRequestType_Locked_Read:
      case RubyRequestType_Locked_Write:
        ctype = CacheRequestType_ATOMIC;
        break;
      case RubyRequestType_RMW_Read:
        ctype = CacheRequestType_ATOMIC;
        break;
      case RubyRequestType_RMW_Write:
        ctype = CacheRequestType_ATOMIC;
        break;
      default:
        assert(0);
    }

    AccessModeType amtype;
    switch(request.access_mode){
      case RubyAccessMode_User:
        amtype = AccessModeType_UserMode;
        break;
      case RubyAccessMode_Supervisor:
        amtype = AccessModeType_SupervisorMode;
        break;
      case RubyAccessMode_Device:
        amtype = AccessModeType_UserMode;
        break;
      default:
        assert(0);
    }

    Address line_addr(request.paddr);
    line_addr.makeLineAddress();
    CacheMsg *msg = new CacheMsg(line_addr, Address(request.paddr), ctype,
        Address(request.pc), amtype, request.len, PrefetchBit_No,
        request.proc_id);

    if (Debug::getProtocolTrace()) {
        g_system_ptr->getProfiler()->
            profileTransition("Seq", m_version, Address(request.paddr),
                              "", "Begin", "",
                              RubyRequestType_to_string(request.type));
    }

    if (g_system_ptr->getTracer()->traceEnabled()) {
        g_system_ptr->getTracer()->
            traceRequest(this, line_addr, Address(request.pc),
                         request.type, g_eventQueue_ptr->getTime());
    }

    Time latency = 0;  // initialzed to an null value

    if (request.type == RubyRequestType_IFETCH)
        latency = m_instCache_ptr->getLatency();
    else
        latency = m_dataCache_ptr->getLatency();

    // Send the message to the cache controller
    assert(latency > 0);

    assert(m_mandatory_q_ptr != NULL);
    m_mandatory_q_ptr->enqueue(msg, latency);
}

#if 0
bool
Sequencer::tryCacheAccess(const Address& addr, CacheRequestType type,
                          AccessModeType access_mode,
                          int size, DataBlock*& data_ptr)
{
    CacheMemory *cache =
        (type == CacheRequestType_IFETCH) ? m_instCache_ptr : m_dataCache_ptr;

    return cache->tryCacheAccess(line_address(addr), type, data_ptr);
}
#endif

void
Sequencer::print(ostream& out) const
{
    out << "[Sequencer: " << m_version
        << ", outstanding requests: " << m_outstanding_count
        << ", read request table: " << m_readRequestTable
        << ", write request table: " << m_writeRequestTable
        << "]";
}

// this can be called from setState whenever coherence permissions are
// upgraded when invoked, coherence violations will be checked for the
// given block
void
Sequencer::checkCoherence(const Address& addr)
{
#ifdef CHECK_COHERENCE
    g_system_ptr->checkGlobalCoherenceInvariant(addr);
#endif
}