[Qemu-devel] [PATCH 1/2] sysbus: always allow explicit_ofw_unit_address() to override address generation

[Mark Cave-Ayland]

Some SysBusDevices either use sysbus_init_mmio() without
sysbus_mmio_map() or the first MMIO memory region doesn't represent the
bus address, causing a firmware device path with an invalid address to
be generated.

SysBusDeviceClass does provide a virtual explicit_ofw_unit_address()
method that can be used to override this process, but it was originally intended
only as as a fallback option meaning that any existing MMIO memory regions still
take priority whilst determining the firmware device address.

There is currently only one user of explicit_ofw_unit_address() and that
is the PCI expander bridge (PXB) device which has no MMIO/PIO resources
defined. This enables us to allow explicit_ofw_unit_address() to take
priority without affecting backwards compatibility, allowing the address
to be customised as required.

Signed-off-by: Mark Cave-Ayland <address@hidden>
Reviewed-by: Laszlo Ersek <address@hidden>
---
 hw/core/sysbus.c | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/hw/core/sysbus.c b/hw/core/sysbus.c
index 3c8e53b188..7ac36ad3e7 100644
--- a/hw/core/sysbus.c
+++ b/hw/core/sysbus.c
@@ -293,16 +293,8 @@ static char *sysbus_get_fw_dev_path(DeviceState *dev)
 {
     SysBusDevice *s = SYS_BUS_DEVICE(dev);
     SysBusDeviceClass *sbc = SYS_BUS_DEVICE_GET_CLASS(s);
-    /* for the explicit unit address fallback case: */
     char *addr, *fw_dev_path;
 
-    if (s->num_mmio) {
-        return g_strdup_printf("%s@" TARGET_FMT_plx, qdev_fw_name(dev),
-                               s->mmio[0].addr);
-    }
-    if (s->num_pio) {
-        return g_strdup_printf("address@hidden", qdev_fw_name(dev), s->pio[0]);
-    }
     if (sbc->explicit_ofw_unit_address) {
         addr = sbc->explicit_ofw_unit_address(s);
         if (addr) {
@@ -311,6 +303,13 @@ static char *sysbus_get_fw_dev_path(DeviceState *dev)
             return fw_dev_path;
         }
     }
+    if (s->num_mmio) {
+        return g_strdup_printf("%s@" TARGET_FMT_plx, qdev_fw_name(dev),
+                               s->mmio[0].addr);
+    }
+    if (s->num_pio) {
+        return g_strdup_printf("address@hidden", qdev_fw_name(dev), s->pio[0]);
+    }
     return g_strdup(qdev_fw_name(dev));
 }
 
-- 
2.11.0