xilinx-ethlite: Simplify byteswapping to/from brams

Signed-off-by: Edgar E. Iglesias <edgar.iglesias@petalogix.com>
diff --git a/hw/xilinx_ethlite.c b/hw/xilinx_ethlite.c
index 54b57d7..f35ba84 100644
--- a/hw/xilinx_ethlite.c
+++ b/hw/xilinx_ethlite.c
@@ -90,13 +90,8 @@
             D(qemu_log("%s %x=%x\n", __func__, addr * 4, r));
             break;
 
-        /* Rx packet data is endian fixed at the way into the rx rams. This
-         * speeds things up because the ethlite MAC does not have a len
-         * register. That means the CPU will issue MMIO reads for the entire
-         * 2k rx buffer even for small packets.
-         */
         default:
-            r = s->regs[addr];
+            r = tswap32(s->regs[addr]);
             break;
     }
     return r;
@@ -145,9 +140,8 @@
             s->regs[addr] = value;
             break;
 
-        /* Packet data, make sure it stays BE.  */
         default:
-            s->regs[addr] = cpu_to_be32(value);
+            s->regs[addr] = tswap32(value);
             break;
     }
 }
@@ -172,7 +166,6 @@
 {
     struct xlx_ethlite *s = DO_UPCAST(NICState, nc, nc)->opaque;
     unsigned int rxbase = s->rxbuf * (0x800 / 4);
-    int i;
 
     /* DA filter.  */
     if (!(buf[0] & 0x80) && memcmp(&s->conf.macaddr.a[0], buf, 6))
@@ -186,12 +179,6 @@
     D(qemu_log("%s %d rxbase=%x\n", __func__, size, rxbase));
     memcpy(&s->regs[rxbase + R_RX_BUF0], buf, size);
 
-    /* Bring it into host endianess.  */
-    for (i = 0; i < ((size + 3) / 4); i++) {
-       uint32_t d = s->regs[rxbase + R_RX_BUF0 + i];
-       s->regs[rxbase + R_RX_BUF0 + i] = be32_to_cpu(d);
-    }
-
     s->regs[rxbase + R_RX_CTRL0] |= CTRL_S;
     if (s->regs[rxbase + R_RX_CTRL0] & CTRL_I)
         eth_pulse_irq(s);