The sysbus_get_fw_dev_path() function formats OpenFirmware device path
nodes ("driver-name@unit-address") 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 the sake of such devices, introduce the explicit_ofw_unit_address()
"virtual member function". With this function, each sysbus device in the
same SysBusDeviceClass can state its own address.
Cc: Markus Armbruster <arm...@redhat.com>
Cc: Marcel Apfelbaum <mar...@redhat.com>
Cc: Michael S. Tsirkin <m...@redhat.com>
Signed-off-by: Laszlo Ersek <ler...@redhat.com>
---
Notes:
v4:
- Yet another approach. Instead of allowing the creator of the device to
set a string property statically, introduce a class level callback.
v3:
- new in v3
- new approach
include/hw/sysbus.h | 9 +++++++++
hw/core/sysbus.c | 13 +++++++++++++
2 files changed, 22 insertions(+)
diff --git a/include/hw/sysbus.h b/include/hw/sysbus.h
index d1f3f00..63b036b 100644
--- a/include/hw/sysbus.h
+++ b/include/hw/sysbus.h
@@ -41,6 +41,15 @@ typedef struct SysBusDeviceClass {
/*< public >*/
int (*init)(SysBusDevice *dev);
+
+ /*
+ * Sometimes a class of SysBusDevices has neither MMIO nor PIO resources,
+ * yet instances of it would like to distinguish themselves, in
+ * OpenFirmware device paths, from other instances of the same class on the
+ * same sysbus. For that end we expose this callback. It returns a
+ * dynamically allocated string.
+ */
+ char *(*explicit_ofw_unit_address)(SysBusDevice *dev);
} SysBusDeviceClass;
struct SysBusDevice {
diff --git a/hw/core/sysbus.c b/hw/core/sysbus.c
index 0ebb4e2..a0ec814 100644
--- a/hw/core/sysbus.c
+++ b/hw/core/sysbus.c
@@ -281,6 +281,7 @@ static void sysbus_dev_print(Monitor *mon, DeviceState
*dev, int indent)
static char *sysbus_get_fw_dev_path(DeviceState *dev)
{
SysBusDevice *s = SYS_BUS_DEVICE(dev);
+ SysBusDeviceClass *sbc = SYS_BUS_DEVICE_GET_CLASS(s);
if (s->num_mmio) {
return g_strdup_printf("%s@"TARGET_FMT_plx, qdev_fw_name(dev),
@@ -289,6 +290,18 @@ static char *sysbus_get_fw_dev_path(DeviceState *dev)
if (s->num_pio) {
return g_strdup_printf("%s@i%04x", qdev_fw_name(dev), s->pio[0]);
}
+ if (sbc->explicit_ofw_unit_address) {
+ char *addr;
+
+ addr = sbc->explicit_ofw_unit_address(s);
+ if (addr) {
+ char *fw_dev_path;
+
+ fw_dev_path = g_strdup_printf("%s@%s", qdev_fw_name(dev), addr);
+ g_free(addr);
+ return fw_dev_path;
+ }
+ }
return g_strdup(qdev_fw_name(dev));
}
--
1.8.3.1
