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authorLaszlo Ersek <lersek@redhat.com>2015-06-19 04:40:16 +0200
committerMichael S. Tsirkin <mst@redhat.com>2015-06-23 22:58:36 +0200
commit0b336b3b98d8983d821ef9b0f159acc7c77cbac7 (patch)
treee0763bec9e05cb59795b6ae0be84a19b98727b97 /include
parentd10dda2d60c8c225a89a53d53add799b69f6bb46 (diff)
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>
Diffstat (limited to 'include')
-rw-r--r--include/hw/sysbus.h17
1 files changed, 17 insertions, 0 deletions
diff --git a/include/hw/sysbus.h b/include/hw/sysbus.h
index d1f3f000f9..34f93c39bf 100644
--- a/include/hw/sysbus.h
+++ b/include/hw/sysbus.h
@@ -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 {