dev: Distributed Ethernet link for distributed gem5 simulations

Distributed gem5 (abbreviated dist-gem5) is the result of the
convergence effort between multi-gem5 and pd-gem5 (from Univ. of
Wisconsin). It relies on the base multi-gem5 infrastructure for packet
forwarding, synchronisation and checkpointing but combines those with
the elaborated network switch model from pd-gem5.

--HG--
rename : src/dev/net/multi_etherlink.cc => src/dev/net/dist_etherlink.cc
rename : src/dev/net/multi_etherlink.hh => src/dev/net/dist_etherlink.hh
rename : src/dev/net/multi_iface.cc => src/dev/net/dist_iface.cc
rename : src/dev/net/multi_iface.hh => src/dev/net/dist_iface.hh
rename : src/dev/net/multi_packet.hh => src/dev/net/dist_packet.hh

3 files changed, 88 insertions, 9 deletions

diff --git a/src/sim/global_event.hh b/src/sim/global_event.hh
index 88981b52a..1aab4a233 100644
--- a/src/sim/global_event.hh
+++ b/src/sim/global_event.hh
@@ -219,7 +219,7 @@ class GlobalSyncEvent : public BaseGlobalEventTemplate<GlobalSyncEvent>
     };
 
     GlobalSyncEvent(Priority p, Flags f)
-        : Base(p, f)
+        : Base(p, f), repeat(0)
     { }
 
     GlobalSyncEvent(Tick when, Tick _repeat, Priority p, Flags f)
diff --git a/src/sim/initparam_keys.hh b/src/sim/initparam_keys.hh
new file mode 100644
index 000000000..3ea68ddfe
--- /dev/null
+++ b/src/sim/initparam_keys.hh
@@ -0,0 +1,70 @@
+/*
+ * Copyright (c) 2015 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: Gabor Dozsa
+ */
+
+/* @file
+ * Magic key definitions for the InitParam pseudo inst
+ */
+#ifndef ___SIM_INITPARAM_KEYS_HH__
+#define ___SIM_INITPARAM_KEYS_HH__
+
+namespace PseudoInst {
+/**
+ * Unique keys to retrieve various params by the initParam pseudo inst.
+ *
+ * @note Each key must be shorter than 16 characters (because we use
+ * two 64-bit registers two pass in the key to the initparam function)
+ */
+struct InitParamKey
+{
+    /**
+     *  The default key (empty string)
+     */
+    static constexpr const char *DEFAULT = "";
+    /**
+     *  Unique key for "rank" param (distributed gem5 runs)
+     */
+    static constexpr const char *DIST_RANK = "dist-rank";
+    /**
+     *  Unique key for "size" param (distributed gem5 runs)
+     */
+    static constexpr const char *DIST_SIZE = "dist-size";
+};
+} // namespace PseudoInst
+
+#endif
diff --git a/src/sim/pseudo_inst.cc b/src/sim/pseudo_inst.cc
index 0f7de0c3a..67c47ce77 100644
--- a/src/sim/pseudo_inst.cc
+++ b/src/sim/pseudo_inst.cc
@@ -63,8 +63,10 @@
 #include "debug/PseudoInst.hh"
 #include "debug/Quiesce.hh"
 #include "debug/WorkItems.hh"
+#include "dev/net/dist_iface.hh"
 #include "params/BaseCPU.hh"
 #include "sim/full_system.hh"
+#include "sim/initparam_keys.hh"
 #include "sim/process.hh"
 #include "sim/pseudo_inst.hh"
 #include "sim/serialize.hh"
@@ -357,8 +359,10 @@ void
 m5exit(ThreadContext *tc, Tick delay)
 {
     DPRINTF(PseudoInst, "PseudoInst::m5exit(%i)\n", delay);
-    Tick when = curTick() + delay * SimClock::Int::ns;
-    exitSimLoop("m5_exit instruction encountered", 0, when, 0, true);
+    if (DistIface::readyToExit(delay)) {
+        Tick when = curTick() + delay * SimClock::Int::ns;
+        exitSimLoop("m5_exit instruction encountered", 0, when, 0, true);
+    }
 }
 
 void
@@ -471,10 +475,14 @@ initParam(ThreadContext *tc, uint64_t key_str1, uint64_t key_str2)
     // Compare the key parameter with the known values to select the return
     // value
     uint64_t val;
-    if (strlen(key_str) == 0) {
+    if (strcmp(key_str, InitParamKey::DEFAULT) == 0) {
         val = tc->getCpuPtr()->system->init_param;
+    } else if (strcmp(key_str, InitParamKey::DIST_RANK) == 0) {
+        val = DistIface::rankParam();
+    } else if (strcmp(key_str, InitParamKey::DIST_SIZE) == 0) {
+        val = DistIface::sizeParam();
     } else {
-        panic("Unknown key for initparam pseudo instruction");
+        panic("Unknown key for initparam pseudo instruction:\"%s\"", key_str);
     }
     return val;
 }
@@ -529,10 +537,11 @@ m5checkpoint(ThreadContext *tc, Tick delay, Tick period)
     if (!tc->getCpuPtr()->params()->do_checkpoint_insts)
         return;
 
-    Tick when = curTick() + delay * SimClock::Int::ns;
-    Tick repeat = period * SimClock::Int::ns;
-
-    exitSimLoop("checkpoint", 0, when, repeat);
+    if (DistIface::readyToCkpt(delay, period)) {
+        Tick when = curTick() + delay * SimClock::Int::ns;
+        Tick repeat = period * SimClock::Int::ns;
+        exitSimLoop("checkpoint", 0, when, repeat);
+    }
 }
 
 uint64_t