Clean up transmit buffer realignment.

Many thanks to Mr. Kolja Waschk for identifying the problem.

c/src/lib/libbsp/m68k/uC5282/ChangeLog

@@ -1,3 +1,8 @@
+2005-06-20  Eric Norum <norume@aps.anl.gov>
+
+	* network/network.c: Clean up transmit buffer realignment.  Many thanks to
+                         Mr. Kolja Waschk for identifying the problem.
+
 2005-05-26	Ralf Corsepius <ralf.corsepius@rtems.org>
 
 	* include/bsp.h: New header guard.

c/src/lib/libbsp/m68k/uC5282/README

@@ -87,7 +87,7 @@ port into RAM then executed or programmed into flash memory.
 4) Run 'tftp' on your host machine:
         tftp> binary
         tftp> connect www.xxx.yyy.zzz   (Your ucDIMM's address)
-            tftp> put someFile.exe
+        tftp> put someFile.exe          (someFile.boot for the EPICS build system)
 
 5) When the file has downloaded press the <ESC> key to terminate
    the uCDIMM tftp command.

c/src/lib/libbsp/m68k/uC5282/network/network.c

@@ -1,10 +1,5 @@
 /*
  * RTEMS/TCPIP driver for MCF5282 Fast Ethernet Controller
- *
- * TO DO: Check network stack code -- Is it possible force longword alignment
- *                                    of all tx mbufs?  If so, the stupid 
- *                                    realignment code in the output routine
- *                                    could be removed.
  */
 
 #include <bsp.h>
@@ -103,7 +98,7 @@ struct mcf5282_enet_struct {
     unsigned long   txInterrupts;
     unsigned long   txRawWait;
     unsigned long   txRealign;
-    unsigned long   txRealignBytes;
+    unsigned long   txRealignDrop;
 };
 static struct mcf5282_enet_struct enet_driver[NIFACES];
 
@@ -320,11 +315,14 @@ static void
 fec_retire_tx_bd(volatile struct mcf5282_enet_struct *sc )
 {
     struct mbuf *m, *n;
+    uint16_t status;
 
     while ((sc->txBdActiveCount != 0)
-        && ((sc->txBdBase[sc->txBdTail].status & MCF5282_FEC_TxBD_R) == 0)) {
+        && (((status = sc->txBdBase[sc->txBdTail].status) & MCF5282_FEC_TxBD_R) == 0)) {
+        if ((status & MCF5282_FEC_TxBD_TO1) == 0) {
             m = sc->txMbuf[sc->txBdTail];
             MFREE(m, n);
+        }
         if (++sc->txBdTail == sc->txBdCount)
             sc->txBdTail = 0;
         sc->txBdActiveCount--;
@@ -337,7 +335,7 @@ fec_rxDaemon (void *arg)
     volatile struct mcf5282_enet_struct *sc = (volatile struct mcf5282_enet_struct *)arg;
     struct ifnet *ifp = (struct ifnet* )&sc->arpcom.ac_if;
     struct mbuf *m;
-    volatile uint16_t status;
+    uint16_t status;
     volatile mcf5282BufferDescriptor_t *rxBd;
     int rxBdIndex;
 
@@ -454,6 +452,7 @@ fec_sendpacket(struct ifnet *ifp, struct mbuf *m)
     struct mcf5282_enet_struct *sc = ifp->if_softc;
     volatile mcf5282BufferDescriptor_t *firstTxBd, *txBd;
     uint16_t status;
+    int offset;
     int nAdded;
 
    /*
@@ -471,7 +470,7 @@ fec_sendpacket(struct ifnet *ifp, struct mbuf *m)
     nAdded = 0;
     firstTxBd = sc->txBdBase + sc->txBdHead;
     
-    for (;;) {
+    while (m != NULL) {
         /* 
          * Wait for buffer descriptor to become available
          */
@@ -517,43 +516,53 @@ fec_sendpacket(struct ifnet *ifp, struct mbuf *m)
         txBd = sc->txBdBase + sc->txBdHead;
         if (m->m_len) {
             char *p = mtod(m, char *);
-            /*
+            if ((offset = (int)p & 0x3) == 0) {
-             * Stupid FEC can't handle misaligned data!
-             * Given the way that mbuf's are layed out it should be
-             * safe to shuffle the data down like this.....
-             * Perhaps this code could be improved with a "Duff's Device".
-             */
-            if ((int)p & 0x3) {
-                int l = m->m_len;
-                char *dest = p - ((int)p & 0x3);
-                uint16_t *o = (uint16_t *)dest, *i = (uint16_t *)p;
-                while (l > 0) {
-                    *o++ = *i++;
-                    l -= sizeof(uint16_t);
-                }
-                p = dest;
-                sc->txRealign++;
-                sc->txRealignBytes += m->m_len;
-            }
                 txBd->buffer = p;
                 txBd->length = m->m_len;
                 sc->txMbuf[sc->txBdHead] = m;
+                m = m->m_next;
+            }
+            else {
+                /*
+                 * Stupid FEC can't handle misaligned data!
+                 * Move offending bytes to a local buffer.
+                 * Use buffer descriptor TO1 bit to indicate this.
+                 */
+                int nmove = 4 - offset;
+                char *d = (char *)&sc->txMbuf[sc->txBdHead];
+                status |= MCF5282_FEC_TxBD_TO1;
+                sc->txRealign++;
+                if (nmove > m->m_len)
+                    nmove = m->m_len;
+                m->m_data += nmove;
+                m->m_len -= nmove;
+                txBd->buffer = d;
+                txBd->length = nmove;
+                while (nmove--)
+                    *d++ = *p++;
+                if (m->m_len == 0) {
+                    struct mbuf *n;
+                    sc->txRealignDrop++;
+                    MFREE(m, n);
+                    m = n;
+                }
+            }
             nAdded++;
             if (++sc->txBdHead == sc->txBdCount) {
                 status |= MCF5282_FEC_TxBD_W;
                 sc->txBdHead = 0;
             }
-            m = m->m_next;
+            txBd->status = status;
         }
         else {
             /*
-             * Just toss empty mbufs
+             * Toss empty mbufs.
              */
             struct mbuf *n;
             MFREE(m, n);
             m = n;
         }
-        if (m == NULL) {
+    }
     if (nAdded) {
         txBd->status = status | MCF5282_FEC_TxBD_R
                               | MCF5282_FEC_TxBD_L
@@ -563,10 +572,6 @@ fec_sendpacket(struct ifnet *ifp, struct mbuf *m)
         MCF5282_FEC_TDAR = 0;
         sc->txBdActiveCount += nAdded;
       }
-          break;
-        }
-        txBd->status = status;
-    }
 }
 
 void
@@ -699,8 +704,8 @@ enet_stats(struct mcf5282_enet_struct *sc)
     printf("   Rx Octets OK:%-10lu\n", MCF5282_FEC_IEEE_R_OCTETS_OK);
     printf("  Tx Interrupts:%-10lu",   sc->txInterrupts);
     printf("Tx Output Waits:%-10lu",   sc->txRawWait);
-    printf("Tx Realignments:%-10lu\n",   sc->txRealign);
+    printf("Tx mbuf realign:%-10lu\n", sc->txRealign);
-    printf(" Tx RealignByte:%-10lu", sc->txRealignBytes);
+    printf("Tx realign drop:%-10lu",   sc->txRealignDrop);
     printf(" Tx Unaccounted:%-10lu",   MCF5282_FEC_RMON_T_DROP);
     printf("Tx Packet Count:%-10lu\n", MCF5282_FEC_RMON_T_PACKETS);
     printf("   Tx Broadcast:%-10lu",   MCF5282_FEC_RMON_T_BC_PKT);
@@ -746,7 +751,7 @@ enet_stats(struct mcf5282_enet_struct *sc)
          * Yes, there are races here with adding and retiring descriptors,
          * but this diagnostic is more for when things have backed up.
          */
-        printf("Transmit Buffer Descriptors (Tail %d, Head %d, Active %d):\n",
+        printf("Transmit Buffer Descriptors (Tail %d, Head %d, Unretired %d):\n",
                                                     sc->txBdTail,
                                                     sc->txBdHead,
                                                     sc->txBdActiveCount);