From aefe9cc624902fe26535028f86ba3a45f555bcf0 Mon Sep 17 00:00:00 2001
From: Giacomo Gabrielli <Giacomo.Gabrielli@arm.com>
Date: Fri, 24 Jan 2014 15:29:30 -0600
Subject: mem: Add support for a security bit in the memory system

This patch adds the basic building blocks required to support e.g. ARM
TrustZone by discerning secure and non-secure memory accesses.
---
 src/mem/cache/prefetch/base.cc | 33 +++++++++++++++++++++------------
 1 file changed, 21 insertions(+), 12 deletions(-)

(limited to 'src/mem/cache/prefetch/base.cc')

diff --git a/src/mem/cache/prefetch/base.cc b/src/mem/cache/prefetch/base.cc
index ed7b63f82..c440978e6 100644
--- a/src/mem/cache/prefetch/base.cc
+++ b/src/mem/cache/prefetch/base.cc
@@ -122,9 +122,9 @@ BasePrefetcher::regStats()
 }
 
 inline bool
-BasePrefetcher::inCache(Addr addr)
+BasePrefetcher::inCache(Addr addr, bool is_secure)
 {
-    if (cache->inCache(addr)) {
+    if (cache->inCache(addr, is_secure)) {
         pfCacheHit++;
         return true;
     }
@@ -132,9 +132,9 @@ BasePrefetcher::inCache(Addr addr)
 }
 
 inline bool
-BasePrefetcher::inMissQueue(Addr addr)
+BasePrefetcher::inMissQueue(Addr addr, bool is_secure)
 {
-    if (cache->inMissQueue(addr)) {
+    if (cache->inMissQueue(addr, is_secure)) {
         pfMSHRHit++;
         return true;
     }
@@ -157,12 +157,14 @@ BasePrefetcher::getPacket()
         pf.pop_front();
 
         Addr blk_addr = pkt->getAddr() & ~(Addr)(blkSize-1);
+        bool is_secure = pkt->isSecure();
 
-        if (!inCache(blk_addr) && !inMissQueue(blk_addr))
+        if (!inCache(blk_addr, is_secure) && !inMissQueue(blk_addr, is_secure))
             // we found a prefetch, return it
             break;
 
-        DPRINTF(HWPrefetch, "addr 0x%x in cache, skipping\n", pkt->getAddr());
+        DPRINTF(HWPrefetch, "addr 0x%x (%s) in cache, skipping\n",
+                pkt->getAddr(), is_secure ? "s" : "ns");
         delete pkt->req;
         delete pkt;
 
@@ -174,7 +176,8 @@ BasePrefetcher::getPacket()
 
     pfIssued++;
     assert(pkt != NULL);
-    DPRINTF(HWPrefetch, "returning 0x%x\n", pkt->getAddr());
+    DPRINTF(HWPrefetch, "returning 0x%x (%s)\n", pkt->getAddr(),
+            pkt->isSecure() ? "s" : "ns");
     return pkt;
 }
 
@@ -185,12 +188,15 @@ BasePrefetcher::notify(PacketPtr &pkt, Tick tick)
     if (!pkt->req->isUncacheable() && !(pkt->req->isInstFetch() && onlyData)) {
         // Calculate the blk address
         Addr blk_addr = pkt->getAddr() & ~(Addr)(blkSize-1);
+        bool is_secure = pkt->isSecure();
 
         // Check if miss is in pfq, if so remove it
-        std::list<DeferredPacket>::iterator iter = inPrefetch(blk_addr);
+        std::list<DeferredPacket>::iterator iter = inPrefetch(blk_addr,
+                                                              is_secure);
         if (iter != pf.end()) {
             DPRINTF(HWPrefetch, "Saw a miss to a queued prefetch addr: "
-                    "0x%x, removing it\n", blk_addr);
+                    "0x%x (%s), removing it\n", blk_addr,
+                    is_secure ? "s" : "ns");
             pfRemovedMSHR++;
             delete iter->pkt->req;
             delete iter->pkt;
@@ -239,7 +245,7 @@ BasePrefetcher::notify(PacketPtr &pkt, Tick tick)
                     addr, *delayIter, time);
 
             // Check if it is already in the pf buffer
-            if (inPrefetch(addr) != pf.end()) {
+            if (inPrefetch(addr, is_secure) != pf.end()) {
                 pfBufferHit++;
                 DPRINTF(HWPrefetch, "Prefetch addr already in pf buffer\n");
                 continue;
@@ -247,6 +253,8 @@ BasePrefetcher::notify(PacketPtr &pkt, Tick tick)
 
             // create a prefetch memreq
             Request *prefetchReq = new Request(*addrIter, blkSize, 0, masterId);
+            if (is_secure)
+                prefetchReq->setFlags(Request::SECURE);
             prefetchReq->taskId(ContextSwitchTaskId::Prefetcher);
             PacketPtr prefetch =
                 new Packet(prefetchReq, MemCmd::HardPFReq);
@@ -274,12 +282,13 @@ BasePrefetcher::notify(PacketPtr &pkt, Tick tick)
 }
 
 std::list<BasePrefetcher::DeferredPacket>::iterator
-BasePrefetcher::inPrefetch(Addr address)
+BasePrefetcher::inPrefetch(Addr address, bool is_secure)
 {
     // Guaranteed to only be one match, we always check before inserting
     std::list<DeferredPacket>::iterator iter;
     for (iter = pf.begin(); iter != pf.end(); iter++) {
-        if ((iter->pkt->getAddr() & ~(Addr)(blkSize-1)) == address) {
+        if (((*iter).pkt->getAddr() & ~(Addr)(blkSize-1)) == address &&
+            (*iter).pkt->isSecure() == is_secure) {
             return iter;
         }
     }
-- 
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