mem: Add MemChecker and MemCheckerMonitor

This patch adds the MemChecker and MemCheckerMonitor classes. While
MemChecker can be integrated anywhere in the system and is independent,
the most convenient usage is through the MemCheckerMonitor -- this
however, puts limitations on where the MemChecker is able to observe
read/write transactions.

1 files changed, 374 insertions, 0 deletions

diff --git a/src/mem/mem_checker_monitor.cc b/src/mem/mem_checker_monitor.cc
new file mode 100644
index 000000000..e0f863d99
--- /dev/null
+++ b/src/mem/mem_checker_monitor.cc
@@ -0,0 +1,374 @@
+/*
+ * Copyright (c) 2012-2014 ARM Limited
+ * All rights reserved
+ *
+ * The license below extends only to copyright in the software and shall
+ * not be construed as granting a license to any other intellectual
+ * property including but not limited to intellectual property relating
+ * to a hardware implementation of the functionality of the software
+ * licensed hereunder.  You may use the software subject to the license
+ * terms below provided that you ensure that this notice is replicated
+ * unmodified and in its entirety in all distributions of the software,
+ * modified or unmodified, in source code or in binary form.
+ *
+ * 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.
+ *
+ * Authors: Thomas Grass
+ *          Andreas Hansson
+ *          Marco Elver
+ */
+
+#include <memory>
+
+#include "base/output.hh"
+#include "base/trace.hh"
+#include "debug/MemCheckerMonitor.hh"
+#include "mem/mem_checker_monitor.hh"
+
+using namespace std;
+
+MemCheckerMonitor::MemCheckerMonitor(Params* params)
+    : MemObject(params),
+      masterPort(name() + "-master", *this),
+      slavePort(name() + "-slave", *this),
+      warnOnly(params->warn_only),
+      memchecker(params->memchecker)
+{}
+
+MemCheckerMonitor::~MemCheckerMonitor()
+{}
+
+MemCheckerMonitor*
+MemCheckerMonitorParams::create()
+{
+    return new MemCheckerMonitor(this);
+}
+
+void
+MemCheckerMonitor::init()
+{
+    // make sure both sides of the monitor are connected
+    if (!slavePort.isConnected() || !masterPort.isConnected())
+        fatal("Communication monitor is not connected on both sides.\n");
+}
+
+BaseMasterPort&
+MemCheckerMonitor::getMasterPort(const std::string& if_name, PortID idx)
+{
+    if (if_name == "master" || if_name == "mem_side") {
+        return masterPort;
+    } else {
+        return MemObject::getMasterPort(if_name, idx);
+    }
+}
+
+BaseSlavePort&
+MemCheckerMonitor::getSlavePort(const std::string& if_name, PortID idx)
+{
+    if (if_name == "slave" || if_name == "cpu_side") {
+        return slavePort;
+    } else {
+        return MemObject::getSlavePort(if_name, idx);
+    }
+}
+
+void
+MemCheckerMonitor::recvFunctional(PacketPtr pkt)
+{
+    Addr addr = pkt->getAddr();
+    unsigned size = pkt->getSize();
+
+    // Conservatively reset this address-range. Alternatively we could try to
+    // update the values seen by the memchecker, however, there may be other
+    // reads/writes to these location from other devices we do not see.
+    memchecker->reset(addr, size);
+
+    masterPort.sendFunctional(pkt);
+
+    DPRINTF(MemCheckerMonitor,
+            "Forwarded functional access: addr = %#llx, size = %d\n",
+            addr, size);
+}
+
+void
+MemCheckerMonitor::recvFunctionalSnoop(PacketPtr pkt)
+{
+    Addr addr = pkt->getAddr();
+    unsigned size = pkt->getSize();
+
+    // See above.
+    memchecker->reset(addr, size);
+
+    slavePort.sendFunctionalSnoop(pkt);
+
+    DPRINTF(MemCheckerMonitor,
+            "Received functional snoop: addr = %#llx, size = %d\n",
+            addr, size);
+}
+
+Tick
+MemCheckerMonitor::recvAtomic(PacketPtr pkt)
+{
+    assert(false && "Atomic not supported");
+    return masterPort.sendAtomic(pkt);
+}
+
+Tick
+MemCheckerMonitor::recvAtomicSnoop(PacketPtr pkt)
+{
+    assert(false && "Atomic not supported");
+    return slavePort.sendAtomicSnoop(pkt);
+}
+
+bool
+MemCheckerMonitor::recvTimingReq(PacketPtr pkt)
+{
+    // should always see a request
+    assert(pkt->isRequest());
+
+    // Store relevant fields of packet, because packet may be modified
+    // or even deleted when sendTiming() is called.
+    //
+    // For reads we are only interested in real reads, and not prefetches, as
+    // it is not guaranteed that the prefetch returns any useful data.
+    bool is_read = pkt->isRead() && !pkt->req->isPrefetch();
+    bool is_write = pkt->isWrite();
+    unsigned size = pkt->getSize();
+    Addr addr = pkt->getAddr();
+    bool expects_response = pkt->needsResponse() && !pkt->memInhibitAsserted();
+    std::unique_ptr<uint8_t> pkt_data;
+    MemCheckerMonitorSenderState* state = NULL;
+
+    if (expects_response && is_write) {
+        // On receipt of a request, only need to allocate pkt_data if this is a
+        // write. For reads, we have no data yet, so it doesn't make sense to
+        // allocate.
+        pkt_data.reset(new uint8_t[size]);
+        memcpy(pkt_data.get(), pkt->getConstPtr<uint8_t*>(), size);
+    }
+
+    // If a cache miss is served by a cache, a monitor near the memory
+    // would see a request which needs a response, but this response
+    // would be inhibited and not come back from the memory. Therefore
+    // we additionally have to check the inhibit flag.
+    if (expects_response && (is_read || is_write)) {
+        state = new MemCheckerMonitorSenderState(0);
+        pkt->pushSenderState(state);
+    }
+
+    // Attempt to send the packet (always succeeds for inhibited
+    // packets)
+    bool successful = masterPort.sendTimingReq(pkt);
+
+    // If not successful, restore the sender state
+    if (!successful && expects_response && (is_read || is_write)) {
+        delete pkt->popSenderState();
+    }
+
+    if (successful && expects_response) {
+        if (is_read) {
+            MemChecker::Serial serial = memchecker->startRead(curTick(),
+                                                              addr,
+                                                              size);
+
+            // At the time where we push the sender-state, we do not yet know
+            // the serial the MemChecker class will assign to this request. We
+            // cannot call startRead at the time we push the sender-state, as
+            // the masterPort may not be successful in executing sendTimingReq,
+            // and in case of a failure, we must not modify the state of the
+            // MemChecker.
+            //
+            // Once we know that sendTimingReq was successful, we can set the
+            // serial of the newly constructed sender-state. This is legal, as
+            // we know that nobody else will touch nor is responsible for
+            // deletion of our sender-state.
+            state->serial = serial;
+
+            DPRINTF(MemCheckerMonitor,
+                    "Forwarded read request: serial = %d, addr = %#llx, "
+                    "size = %d\n",
+                    serial, addr, size);
+        } else if (is_write) {
+            MemChecker::Serial serial = memchecker->startWrite(curTick(),
+                                                               addr,
+                                                               size,
+                                                               pkt_data.get());
+
+            state->serial = serial;
+
+            DPRINTF(MemCheckerMonitor,
+                    "Forwarded write request: serial = %d, addr = %#llx, "
+                    "size = %d\n",
+                    serial, addr, size);
+        } else {
+            DPRINTF(MemCheckerMonitor,
+                    "Forwarded non read/write request: addr = %#llx\n", addr);
+        }
+    } else if (successful) {
+        DPRINTF(MemCheckerMonitor,
+                "Forwarded inhibited request: addr = %#llx\n", addr);
+    }
+
+    return successful;
+}
+
+bool
+MemCheckerMonitor::recvTimingResp(PacketPtr pkt)
+{
+    // should always see responses
+    assert(pkt->isResponse());
+
+    // Store relevant fields of packet, because packet may be modified
+    // or even deleted when sendTiming() is called.
+    bool is_read = pkt->isRead() && !pkt->req->isPrefetch();
+    bool is_write = pkt->isWrite();
+    bool is_failed_LLSC = pkt->isLLSC() && pkt->req->getExtraData() == 0;
+    unsigned size = pkt->getSize();
+    Addr addr = pkt->getAddr();
+    std::unique_ptr<uint8_t> pkt_data;
+    MemCheckerMonitorSenderState* received_state = NULL;
+
+    if (is_read) {
+        // On receipt of a response, only need to allocate pkt_data if this is
+        // a read. For writes, we have already given the MemChecker the data on
+        // the request, so it doesn't make sense to allocate on write.
+        pkt_data.reset(new uint8_t[size]);
+        memcpy(pkt_data.get(), pkt->getConstPtr<uint8_t*>(), size);
+    }
+
+    if (is_read || is_write) {
+        received_state =
+            dynamic_cast<MemCheckerMonitorSenderState*>(pkt->senderState);
+
+        // Restore initial sender state
+        panic_if(received_state == NULL,
+                 "Monitor got a response without monitor sender state\n");
+
+        // Restore the state
+        pkt->senderState = received_state->predecessor;
+    }
+
+    // Attempt to send the packet
+    bool successful = slavePort.sendTimingResp(pkt);
+
+    // If packet successfully send, complete transaction in MemChecker
+    // instance, and delete sender state, otherwise restore state.
+    if (successful) {
+        if (is_read) {
+            DPRINTF(MemCheckerMonitor,
+                    "Received read response: serial = %d, addr = %#llx, "
+                    "size = %d\n",
+                    received_state->serial, addr, size);
+
+            bool result = memchecker->completeRead(received_state->serial,
+                                                   curTick(),
+                                                   addr,
+                                                   size,
+                                                   pkt_data.get());
+
+            if (!result) {
+                warn("%s: read of %#llx @ cycle %d failed:\n%s\n",
+                     name(),
+                     addr, curTick(),
+                     memchecker->getErrorMessage().c_str());
+
+                panic_if(!warnOnly, "MemChecker violation!");
+            }
+
+            delete received_state;
+        } else if (is_write) {
+            DPRINTF(MemCheckerMonitor,
+                    "Received write response: serial = %d, addr = %#llx, "
+                    "size = %d\n",
+                    received_state->serial, addr, size);
+
+            if (is_failed_LLSC) {
+                // The write was not successful, let MemChecker know.
+                memchecker->abortWrite(received_state->serial,
+                                       addr,
+                                       size);
+            } else {
+                memchecker->completeWrite(received_state->serial,
+                                          curTick(),
+                                          addr,
+                                          size);
+            }
+
+            delete received_state;
+        } else {
+            DPRINTF(MemCheckerMonitor,
+                    "Received non read/write response: addr = %#llx\n", addr);
+        }
+    } else if (is_read || is_write) {
+        // Don't delete anything and let the packet look like we
+        // did not touch it
+        pkt->senderState = received_state;
+    }
+
+    return successful;
+}
+
+void
+MemCheckerMonitor::recvTimingSnoopReq(PacketPtr pkt)
+{
+    slavePort.sendTimingSnoopReq(pkt);
+}
+
+bool
+MemCheckerMonitor::recvTimingSnoopResp(PacketPtr pkt)
+{
+    return masterPort.sendTimingSnoopResp(pkt);
+}
+
+bool
+MemCheckerMonitor::isSnooping() const
+{
+    // check if the connected master port is snooping
+    return slavePort.isSnooping();
+}
+
+AddrRangeList
+MemCheckerMonitor::getAddrRanges() const
+{
+    // get the address ranges of the connected slave port
+    return masterPort.getAddrRanges();
+}
+
+void
+MemCheckerMonitor::recvRetryMaster()
+{
+    slavePort.sendRetry();
+}
+
+void
+MemCheckerMonitor::recvRetrySlave()
+{
+    masterPort.sendRetry();
+}
+
+void
+MemCheckerMonitor::recvRangeChange()
+{
+    slavePort.sendRangeChange();
+}