pcnet-pci: Fix PIO word access to PROM

Implement the various IO access widths according to the spec. This
specifically unbreaks word and dword access to the PROM area that is
mapped into IO space. It also drops redundant upper limit checks and
spurious "return void".
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

hw/pcnet-pci.c

@@ -76,12 +76,24 @@ static uint64_t pcnet_ioport_read(void *opaque, target_phys_addr_t addr,
 {
     PCNetState *d = opaque;
 
-    if (addr < 16 && size == 1) {
-        return pcnet_aprom_readb(d, addr);
-    } else if (addr >= 0x10 && addr < 0x20 && size == 2) {
-        return pcnet_ioport_readw(d, addr);
-    } else if (addr >= 0x10 && addr < 0x20 && size == 4) {
-        return pcnet_ioport_readl(d, addr);
+    if (addr < 0x10) {
+        if (!BCR_DWIO(d) && size == 1) {
+            return pcnet_aprom_readb(d, addr);
+        } else if (!BCR_DWIO(d) && (addr & 1) == 0 && size == 2) {
+            return pcnet_aprom_readb(d, addr) |
+                   (pcnet_aprom_readb(d, addr + 1) << 8);
+        } else if (BCR_DWIO(d) && (addr & 3) == 0 && size == 4) {
+            return pcnet_aprom_readb(d, addr) |
+                   (pcnet_aprom_readb(d, addr + 1) << 8) |
+                   (pcnet_aprom_readb(d, addr + 2) << 16) |
+                   (pcnet_aprom_readb(d, addr + 3) << 24);
+        }
+    } else {
+        if (size == 2) {
+            return pcnet_ioport_readw(d, addr);
+        } else if (size == 4) {
+            return pcnet_ioport_readl(d, addr);
+        }
     }
     return ((uint64_t)1 << (size * 8)) - 1;
 }
@@ -91,12 +103,24 @@ static void pcnet_ioport_write(void *opaque, target_phys_addr_t addr,
 {
     PCNetState *d = opaque;
 
-    if (addr < 16 && size == 1) {
-        return pcnet_aprom_writeb(d, addr, data);
-    } else if (addr >= 0x10 && addr < 0x20 && size == 2) {
-        return pcnet_ioport_writew(d, addr, data);
-    } else if (addr >= 0x10 && addr < 0x20 && size == 4) {
-        return pcnet_ioport_writel(d, addr, data);
+    if (addr < 0x10) {
+        if (!BCR_DWIO(d) && size == 1) {
+            pcnet_aprom_writeb(d, addr, data);
+        } else if (!BCR_DWIO(d) && (addr & 1) == 0 && size == 2) {
+            pcnet_aprom_writeb(d, addr, data & 0xff);
+            pcnet_aprom_writeb(d, addr + 1, data >> 8);
+        } else if (BCR_DWIO(d) && (addr & 3) == 0 && size == 4) {
+            pcnet_aprom_writeb(d, addr, data & 0xff);
+            pcnet_aprom_writeb(d, addr + 1, (data >> 8) & 0xff);
+            pcnet_aprom_writeb(d, addr + 2, (data >> 16) & 0xff);
+            pcnet_aprom_writeb(d, addr + 3, data >> 24);
+        }
+    } else {
+        if (size == 2) {
+            pcnet_ioport_writew(d, addr, data);
+        } else if (size == 4) {
+            pcnet_ioport_writel(d, addr, data);
+        }
     }
 }