make grade 100/100

kernel/e1000.c

@@ -102,7 +102,23 @@ e1000_transmit(struct mbuf *m)
   // the TX descriptor ring so that the e1000 sends it. Stash
   // a pointer so that it can be freed after sending.
   //
-  
+
+  acquire(&e1000_lock);
+  int tdt = regs[E1000_TDT];
+  if (!(tx_ring[tdt].status & E1000_TXD_STAT_DD)) {
+    release(&e1000_lock);
+    return -1;
+  }
+  if (tx_mbufs[tdt]) {
+    mbuffree(tx_mbufs[tdt]);
+    tx_mbufs[tdt] = 0;
+  }
+  tx_mbufs[tdt] = m;
+  tx_ring[tdt].addr = (uint64)m->head;
+  tx_ring[tdt].length = m->len;
+  tx_ring[tdt].cmd = E1000_TXD_CMD_RS | E1000_TXD_CMD_EOP;
+  regs[E1000_TDT] = (tdt + 1) % TX_RING_SIZE;
+  release(&e1000_lock);
   return 0;
 }
 
@@ -115,6 +131,23 @@ e1000_recv(void)
   // Check for packets that have arrived from the e1000
   // Create and deliver an mbuf for each packet (using net_rx()).
   //
+  acquire(&e1000_lock);
+  int rdt = regs[E1000_RDT];
+  rdt = (rdt + 1) % RX_RING_SIZE;
+  while (rx_ring[rdt].status & E1000_RXD_STAT_DD)
+  {
+    if (!holding(&e1000_lock)) acquire(&e1000_lock);
+    rx_mbufs[rdt]->len = rx_ring[rdt].length;
+    struct mbuf* m = rx_mbufs[rdt];
+    rx_mbufs[rdt] = mbufalloc(0);
+    if (!rx_mbufs[rdt]) panic("e1000 recv");
+    rx_ring[rdt].addr = (uint64)rx_mbufs[rdt]->head;
+    rx_ring[rdt].status = 0;
+    regs[E1000_RDT] = rdt;
+    rdt = (rdt + 1) % RX_RING_SIZE;
+    release(&e1000_lock);
+    net_rx(m);
+  }
 }
 
 void

time.txt

@@ -0,0 +1 @@
+5