hw/pci-host/raven: Add PCI_IO_BASE_ADDR definition

Rather than using the magic 0x80000000 number for the PCI I/O BAR
physical address on the main system bus, use a definition.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20210417103028.601124-6-f4bug@amsat.org>

hw/pci-host/raven.c

@@ -81,6 +81,8 @@ struct PRePPCIState {
 
 #define BIOS_SIZE (1 * MiB)
 
+#define PCI_IO_BASE_ADDR    0x80000000  /* Physical address on main bus */
+
 static inline uint32_t raven_pci_io_config(hwaddr addr)
 {
     int i;
@@ -158,7 +160,7 @@ static uint64_t raven_io_read(void *opaque, hwaddr addr,
     uint8_t buf[4];
 
     addr = raven_io_address(s, addr);
-    address_space_read(&s->pci_io_as, addr + 0x80000000,
+    address_space_read(&s->pci_io_as, addr + PCI_IO_BASE_ADDR,
                        MEMTXATTRS_UNSPECIFIED, buf, size);
 
     if (size == 1) {
@@ -190,7 +192,7 @@ static void raven_io_write(void *opaque, hwaddr addr,
         g_assert_not_reached();
     }
 
-    address_space_write(&s->pci_io_as, addr + 0x80000000,
+    address_space_write(&s->pci_io_as, addr + PCI_IO_BASE_ADDR,
                         MEMTXATTRS_UNSPECIFIED, buf, size);
 }
 
@@ -293,8 +295,9 @@ static void raven_pcihost_initfn(Object *obj)
     address_space_init(&s->pci_io_as, &s->pci_io, "raven-io");
 
     /* CPU address space */
-    memory_region_add_subregion(address_space_mem, 0x80000000, &s->pci_io);
-    memory_region_add_subregion_overlap(address_space_mem, 0x80000000,
+    memory_region_add_subregion(address_space_mem, PCI_IO_BASE_ADDR,
+                                &s->pci_io);
+    memory_region_add_subregion_overlap(address_space_mem, PCI_IO_BASE_ADDR,
                                         &s->pci_io_non_contiguous, 1);
     memory_region_add_subregion(address_space_mem, 0xc0000000, &s->pci_memory);
     pci_root_bus_new_inplace(&s->pci_bus, sizeof(s->pci_bus), DEVICE(obj), NULL,