hw/core: explicit OFW unit address callback for SysBusDeviceClass

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. An example is TYPE_PXB_HOST ("pxb-host").

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 <armbru@redhat.com>
Cc: Marcel Apfelbaum <marcel@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Marcel Apfelbaum <marcel@redhat.com>
Tested-by: Marcel Apfelbaum <marcel@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Laszlo Ersek 2015-06-19 04:40:16 +02:00 committed by Michael S. Tsirkin
parent d10dda2d60
commit 0b336b3b98
2 changed files with 28 additions and 0 deletions

View File

@ -281,6 +281,9 @@ 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);
/* 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),
@ -289,6 +292,14 @@ 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) {
addr = sbc->explicit_ofw_unit_address(s);
if (addr) {
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));
}

View File

@ -41,6 +41,23 @@ typedef struct SysBusDeviceClass {
/*< public >*/
int (*init)(SysBusDevice *dev);
/*
* Let the sysbus device format its own non-PIO, non-MMIO unit address.
*
* 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
* sysbus. For that end we expose this callback.
*
* The implementation is not supposed to change *@dev, or incur other
* observable change.
*
* The function returns a dynamically allocated string. On error, NULL
* should be returned; the unit address portion of the OFW node will be
* omitted then. (This is not considered a fatal error.)
*/
char *(*explicit_ofw_unit_address)(const SysBusDevice *dev);
} SysBusDeviceClass;
struct SysBusDevice {