The sysbus_get_fw_dev_path() function formats OpenFirmware device path
nodes ("address@hidden") for sysbus devices. The first choice
for "unit-address" is the base address of the device's first MMIO region.
The second choice is its first IO port.
However, if two sysbus devices with the same "driver-name" lack both MMIO
and PIO resources, then there is no good way to distinguish them based on
their OFW nodes, because in this case unit-address is omitted completely
for both devices.
For such devices, delegate a fallback property,
"explicit_ofw_unit_address", to whoever creates the device. The creator
can set the property to any appropriate value.
Cc: Markus Armbruster <address@hidden>
Cc: Marcel Apfelbaum <address@hidden>
Cc: Michael S. Tsirkin <address@hidden>
Signed-off-by: Laszlo Ersek <address@hidden>
---
Notes:
v3:
- new in v3
- new approach
include/hw/sysbus.h | 8 ++++++++
hw/core/sysbus.c | 11 +++++++++++
2 files changed, 19 insertions(+)
diff --git a/include/hw/sysbus.h b/include/hw/sysbus.h
index d1f3f00..de41b06 100644
--- a/include/hw/sysbus.h
+++ b/include/hw/sysbus.h
@@ -55,6 +55,14 @@ struct SysBusDevice {
} mmio[QDEV_MAX_MMIO];
int num_pio;
pio_addr_t pio[QDEV_MAX_PIO];
+
+ /*
+ * Sometimes a SysBusDevice has neither MMIO nor PIO resources, yet it
+ * would like to distinguish itself, in OpenFirmware device paths, from
+ * other instances of the same class on the same sysbus. For that end we
+ * expose this property.
+ */
+ char *explicit_ofw_unit_address;
};
typedef int FindSysbusDeviceFunc(SysBusDevice *sbdev, void *opaque);
diff --git a/hw/core/sysbus.c b/hw/core/sysbus.c
index 0ebb4e2..6e9af1c 100644
--- a/hw/core/sysbus.c
+++ b/hw/core/sysbus.c
@@ -289,6 +289,10 @@ static char *sysbus_get_fw_dev_path(DeviceState *dev)
if (s->num_pio) {
return g_strdup_printf("address@hidden", qdev_fw_name(dev),
s->pio[0]);
}
+ if (s->explicit_ofw_unit_address) {
+ return g_strdup_printf("address@hidden", qdev_fw_name(dev),
+ s->explicit_ofw_unit_address);
+ }
return g_strdup(qdev_fw_name(dev));
}
@@ -303,11 +307,18 @@ MemoryRegion *sysbus_address_space(SysBusDevice *dev)
return get_system_memory();
}
+static Property sysbus_device_properties[] = {
+ DEFINE_PROP_STRING("explicit_ofw_unit_address", SysBusDevice,
+ explicit_ofw_unit_address),
+ DEFINE_PROP_END_OF_LIST()
+};
+
static void sysbus_device_class_init(ObjectClass *klass, void *data)
{
DeviceClass *k = DEVICE_CLASS(klass);
k->init = sysbus_device_init;
k->bus_type = TYPE_SYSTEM_BUS;
+ k->props = sysbus_device_properties;
}
static const TypeInfo sysbus_device_type_info = {