From f5e36d156dc33a6c01c69c19efc2b5b0450496f6 Mon Sep 17 00:00:00 2001
From: Ali Saidi <saidi@eecs.umich.edu>
Date: Tue, 20 May 2008 16:06:56 -0400
Subject: [PATCH] IGbE: Implement sending packet that is contained in more than
 2 descriptors.

--HG--
extra : convert_revision : 8fb7d5fad5cb840f69c31aa8b331dbe09e46ee9d
---
 src/dev/i8254xGBe.cc | 19 ++++++++++++-------
 src/dev/i8254xGBe.hh |  9 +++++++++
 2 files changed, 21 insertions(+), 7 deletions(-)

diff --git a/src/dev/i8254xGBe.cc b/src/dev/i8254xGBe.cc
index 44e056fc3..ff255d5f7 100644
--- a/src/dev/i8254xGBe.cc
+++ b/src/dev/i8254xGBe.cc
@@ -919,7 +919,7 @@ IGbE::TxDescCache::getPacketData(EthPacketPtr p)
 
     pktWaiting = true;
 
-    DPRINTF(EthernetDesc, "Starting DMA of packet\n");
+    DPRINTF(EthernetDesc, "Starting DMA of packet at offset %d\n", p->length);
     igbe->dmaRead(igbe->platform->pciToDma(TxdOp::getBuf(desc)),
             TxdOp::getLen(desc), &pktEvent, p->data + p->length);
 
@@ -943,20 +943,22 @@ IGbE::TxDescCache::pktComplete()
     DPRINTF(EthernetDesc, "TxDescriptor data d1: %#llx d2: %#llx\n", desc->d1, desc->d2);
 
     if (!TxdOp::eop(desc)) {
-        // This only supports two descriptors per tx packet
-        assert(pktPtr->length == 0);
-        pktPtr->length = TxdOp::getLen(desc);
+        pktPtr->length += TxdOp::getLen(desc);
         unusedCache.pop_front();
         usedCache.push_back(desc);
         pktDone = true;
         pktWaiting = false;
+        pktMultiDesc = true;
+
+        DPRINTF(EthernetDesc, "Partial Packet Descriptor of %d bytes Done\n",
+                pktPtr->length);
         pktPtr = NULL;
 
-        DPRINTF(EthernetDesc, "Partial Packet Descriptor Done\n");
         enableSm();
         igbe->checkDrain();
         return;
     }
+    pktMultiDesc = false;
 
     // Set the length of the data in the EtherPacket
     pktPtr->length += TxdOp::getLen(desc);
@@ -988,7 +990,7 @@ IGbE::TxDescCache::pktComplete()
     if (TxdOp::isData(desc) && ( TxdOp::ixsm(desc) || TxdOp::txsm(desc)) ) {
         DPRINTF(EthernetDesc, "Calculating checksums for packet\n");
         IpPtr ip(pktPtr);
-
+        assert(ip);
         if (TxdOp::ixsm(desc)) {
             ip->sum(0);
             ip->sum(cksum(ip));
@@ -1058,6 +1060,7 @@ IGbE::TxDescCache::serialize(std::ostream &os)
     SERIALIZE_SCALAR(pktDone);
     SERIALIZE_SCALAR(isTcp);
     SERIALIZE_SCALAR(pktWaiting);
+    SERIALIZE_SCALAR(pktMultiDesc);
 }
 
 void
@@ -1067,6 +1070,7 @@ IGbE::TxDescCache::unserialize(Checkpoint *cp, const std::string &section)
     UNSERIALIZE_SCALAR(pktDone);
     UNSERIALIZE_SCALAR(isTcp);
     UNSERIALIZE_SCALAR(pktWaiting);
+    UNSERIALIZE_SCALAR(pktMultiDesc);
 }
 
 bool
@@ -1172,7 +1176,8 @@ IGbE::txStateMachine()
     // If we have a packet available and it's length is not 0 (meaning it's not
     // a multidescriptor packet) put it in the fifo, otherwise an the next
     // iteration we'll get the rest of the data
-    if (txPacket && txDescCache.packetAvailable() && txPacket->length) {
+    if (txPacket && txDescCache.packetAvailable()
+                 && !txDescCache.packetMultiDesc() && txPacket->length) {
         bool success;
 
         DPRINTF(EthernetSM, "TXS: packet placed in TX FIFO\n");
diff --git a/src/dev/i8254xGBe.hh b/src/dev/i8254xGBe.hh
index 9403c87b6..0daf094c1 100644
--- a/src/dev/i8254xGBe.hh
+++ b/src/dev/i8254xGBe.hh
@@ -564,6 +564,7 @@ class IGbE : public EtherDevice
         bool pktDone;
         bool isTcp;
         bool pktWaiting;
+        bool pktMultiDesc;
 
       public:
         TxDescCache(IGbE *i, std::string n, int s);
@@ -586,6 +587,14 @@ class IGbE : public EtherDevice
          */
         bool packetWaiting() { return pktWaiting; }
 
+        /** Ask if this packet is composed of multiple descriptors
+         * so even if we've got data, we need to wait for more before
+         * we can send it out.
+         * @return packet can't be sent out because it's a multi-descriptor
+         * packet
+         */
+        bool packetMultiDesc() { return pktMultiDesc;}
+
         /** Called by event when dma to write packet is completed
          */
         void pktComplete();
-- 
2.30.2