From 0b336b3b98d8983d821ef9b0f159acc7c77cbac7 Mon Sep 17 00:00:00 2001 From: Laszlo Ersek Date: Fri, 19 Jun 2015 04:40:16 +0200 Subject: 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 Cc: Marcel Apfelbaum Cc: Michael S. Tsirkin Signed-off-by: Laszlo Ersek Reviewed-by: Marcel Apfelbaum Tested-by: Marcel Apfelbaum Reviewed-by: Markus Armbruster Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- include/hw/sysbus.h | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) (limited to 'include/hw') 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 { -- cgit v1.2.1