hw/net/xilinx_ethlite: Access TX_CTRL register for each port

Rather than accessing the registers within the mixed RAM/MMIO
region as indexed register, declare a per-port TX_CTRL. This
will help to map the RAM as RAM (keeping MMIO as MMIO) in few
commits.

Previous s->regs[R_TX_CTRL0] and s->regs[R_TX_CTRL1] are now
unused. Not a concern, this array will soon disappear.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@amd.com>
Message-Id: <20241112181044.92193-15-philmd@linaro.org>

hw/net/xilinx_ethlite.c

@@ -64,6 +64,7 @@ typedef struct XlnxXpsEthLitePort {
     struct {
         uint32_t tx_len;
         uint32_t tx_gie;
+        uint32_t tx_ctrl;
 
         uint32_t rx_ctrl;
     } reg;
@@ -139,7 +140,7 @@ eth_read(void *opaque, hwaddr addr, unsigned int size)
 
         case R_TX_CTRL1:
         case R_TX_CTRL0:
-            r = s->regs[addr];
+            r = s->port[port_index].reg.tx_ctrl;
             break;
 
         case R_RX_CTRL1:
@@ -160,7 +161,6 @@ eth_write(void *opaque, hwaddr addr,
 {
     XlnxXpsEthLite *s = opaque;
     unsigned int port_index = addr_to_port_index(addr);
-    unsigned int base = 0;
     uint32_t value = val64;
 
     addr >>= 2;
@@ -168,24 +168,23 @@ eth_write(void *opaque, hwaddr addr,
     {
         case R_TX_CTRL0:
         case R_TX_CTRL1:
-            if (addr == R_TX_CTRL1)
-                base = 0x800 / 4;
-
             if ((value & (CTRL_P | CTRL_S)) == CTRL_S) {
                 qemu_send_packet(qemu_get_queue(s->nic),
                                  txbuf_ptr(s, port_index),
                                  s->port[port_index].reg.tx_len);
-                if (s->regs[base + R_TX_CTRL0] & CTRL_I)
+                if (s->port[port_index].reg.tx_ctrl & CTRL_I) {
                     eth_pulse_irq(s);
+                }
             } else if ((value & (CTRL_P | CTRL_S)) == (CTRL_P | CTRL_S)) {
                 memcpy(&s->conf.macaddr.a[0], txbuf_ptr(s, port_index), 6);
-                if (s->regs[base + R_TX_CTRL0] & CTRL_I)
+                if (s->port[port_index].reg.tx_ctrl & CTRL_I) {
                     eth_pulse_irq(s);
+                }
             }
 
             /* We are fast and get ready pretty much immediately so
                we actually never flip the S nor P bits to one.  */
-            s->regs[addr] = value & ~(CTRL_P | CTRL_S);
+            s->port[port_index].reg.tx_ctrl = value & ~(CTRL_P | CTRL_S);
             break;
 
         /* Keep these native.  */