mem: Implement base QoS Policies.

This patch implements a base fixed priority policy and an ideal
turnaround policy for the QoS memory controller.

Change-Id: I38ce16f845fc0ec86d6fc4cc5dc5406f213a465e
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/11972
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>

1 files changed, 101 insertions, 0 deletions

diff --git a/src/mem/qos/policy_fixed_prio.cc b/src/mem/qos/policy_fixed_prio.cc
new file mode 100644
index 000000000..449a25d23
--- /dev/null
+++ b/src/mem/qos/policy_fixed_prio.cc
@@ -0,0 +1,101 @@
+/*
+ * Copyright (c) 2018 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.
+ *
+ * Author: Matteo Andreozzi
+ */
+
+#include "mem/qos/policy_fixed_prio.hh"
+
+#include <algorithm>
+#include <functional>
+
+#include "mem/request.hh"
+
+namespace QoS {
+
+FixedPriorityPolicy::FixedPriorityPolicy(const Params* p)
+  : Policy(p), defaultPriority(p->qos_fixed_prio_default_prio)
+{}
+
+FixedPriorityPolicy::~FixedPriorityPolicy()
+{}
+
+void
+FixedPriorityPolicy::init()
+{
+}
+
+void
+FixedPriorityPolicy::initMasterName(std::string master, uint8_t priority)
+{
+    priorityMap.insert(
+        this->pair<std::string, uint8_t>(master, priority));
+}
+
+void
+FixedPriorityPolicy::initMasterObj(const SimObject* master, uint8_t priority)
+{
+    priorityMap.insert(
+        this->pair<const SimObject*, uint8_t>(master, priority));
+}
+
+uint8_t
+FixedPriorityPolicy::schedule(const MasterID mId, const uint64_t data)
+{
+    // Reads a packet's MasterID contained in its encapsulated request
+    // if a match is found in the configured priority map, returns the
+    // matching priority, else returns zero
+
+    auto ret = priorityMap.find(mId);
+
+    if (ret != priorityMap.end()) {
+        return ret->second;
+    } else {
+        DPRINTF(QOS, "Master %s (MasterID %d) not present in priorityMap, "
+                     "assigning default priority %d\n",
+                      memCtrl->system()->getMasterName(mId),
+                      mId, defaultPriority);
+        return defaultPriority;
+    }
+}
+
+} // namespace QoS
+
+QoS::FixedPriorityPolicy *
+QoSFixedPriorityPolicyParams::create()
+{
+    return new QoS::FixedPriorityPolicy(this);
+}