自学教程：C++ BUS_ADD_CHILD函数代码示例

/*------------------ Private Device Attachment Functions  --------------------*/static voidprivcmd_identify(driver_t *driver, device_t parent){	KASSERT(xen_domain(),	    ("Trying to attach privcmd device on non Xen domain"));	if (BUS_ADD_CHILD(parent, 0, "privcmd", 0) == NULL)		panic("unable to attach privcmd user-space device");}

static voidvpo_identify(driver_t *driver, device_t parent){	device_t dev;	dev = device_find_child(parent, "vpo", -1);	if (!dev)		BUS_ADD_CHILD(parent, 0, "vpo", -1);}

static voidwiibus_identify(driver_t *driver, device_t parent){	if (strcmp(installed_platform(), "wii") != 0)		return;	if (device_find_child(parent, "wiibus", -1) == NULL)		BUS_ADD_CHILD(parent, 0, "wiibus", 0);}

static voidspibus_hinted_child(device_t bus, const char *dname, int dunit){	device_t child;	struct spibus_ivar *devi;	child = BUS_ADD_CHILD(bus, 0, dname, dunit);	devi = SPIBUS_IVAR(child);	resource_int_value(dname, dunit, "cs", &devi->cs);}

static voidvmbus_identify(driver_t *driver, device_t parent){	if (!hv_vmbus_query_hypervisor_presence())		return;	vm_guest = VM_GUEST_HV;	BUS_ADD_CHILD(parent, 0, "vmbus", 0);}

static voidiicbus_hinted_child(device_t bus, const char *dname, int dunit){	device_t child;	struct iicbus_ivar *devi;	child = BUS_ADD_CHILD(bus, 0, dname, dunit);	devi = IICBUS_IVAR(child);	resource_int_value(dname, dunit, "addr", &devi->addr);}

static voidsc_identify(driver_t *driver, device_t parent){	/*	 * Add with a priority guaranteed to make it last on	 * the device list.	 */	BUS_ADD_CHILD(parent, INT_MAX, SC_DRIVER_NAME, 0);}

static voidbcm2835_cpufreq_identify(driver_t *driver, device_t parent){	DPRINTF("driver=%p, parent=%p/n", driver, parent);	if (device_find_child(parent, "bcm2835_cpufreq", -1) != NULL)		return;	if (BUS_ADD_CHILD(parent, 0, "bcm2835_cpufreq", -1) == NULL)		device_printf(parent, "add child failed/n");}

/* * Locate the ACPI timer using the FADT, set up and allocate the I/O resources * we will be using. */static intacpi_hpet_identify(driver_t *driver, device_t parent){	ACPI_TABLE_HPET *hpet;	ACPI_TABLE_HEADER *hdr;	ACPI_STATUS status;	device_t child;	/*	 * Just try once, do nothing if the 'acpi' bus is rescanned.	 */	if (device_get_state(parent) == DS_ATTACHED)		return 0;	ACPI_FUNCTION_TRACE((char *)(uintptr_t) __func__);	/* Only one HPET device can be added. */	if (devclass_get_device(acpi_hpet_devclass, 0))		return ENXIO;	/* Currently, ID and minimum clock tick info is unused. */	status = AcpiGetTable(ACPI_SIG_HPET, 1, &hdr);	if (ACPI_FAILURE(status))		return ENXIO;	/*	 * The unit number could be derived from hdr->Sequence but we only	 * support one HPET device.	 */	hpet = (ACPI_TABLE_HPET *)hdr;	if (hpet->Sequence != 0) {		kprintf("ACPI HPET table warning: Sequence is non-zero (%d)/n",			hpet->Sequence);	}	child = BUS_ADD_CHILD(parent, parent, 0, "acpi_hpet", 0);	if (child == NULL) {		device_printf(parent, "%s: can't add acpi_hpet0/n", __func__);		return ENXIO;	}	/* Record a magic value so we can detect this device later. */	acpi_set_magic(child, (uintptr_t)&acpi_hpet_devclass);	acpi_hpet_res_start = hpet->Address.Address;	if (bus_set_resource(child, SYS_RES_MEMORY, 0,			     hpet->Address.Address, HPET_MEM_WIDTH, -1)) {		device_printf(child, "could not set iomem resources: "			      "0x%jx, %d/n", (uintmax_t)hpet->Address.Address,			      HPET_MEM_WIDTH);		return ENOMEM;	}	return 0;}

static intnexus_acpi_attach(device_t dev){	nexus_init_resources();	bus_generic_probe(dev);	if (BUS_ADD_CHILD(dev, 10, "acpi", 0) == NULL)		panic("failed to add acpi0 device");	return (bus_generic_attach(dev));}

/* * Define the syscons nexus device attachment */static voidofwfb_scidentify(driver_t *driver, device_t parent){	device_t child;	/*	 * Add with a priority guaranteed to make it last on	 * the device list	 */	child = BUS_ADD_CHILD(parent, INT_MAX, SC_DRIVER_NAME, 0);}

static voidixp425_hinted_child(device_t bus, const char *dname, int dunit){	device_t child;	struct ixp425_ivar *ivar;	child = BUS_ADD_CHILD(bus, 0, dname, dunit);	ivar = IXP425_IVAR(child);	resource_int_value(dname, dunit, "addr", &ivar->addr);	resource_int_value(dname, dunit, "irq", &ivar->irq);}

static voidoctm_identify(driver_t *drv, device_t parent){	unsigned i;	if (!octeon_has_feature(OCTEON_FEATURE_MGMT_PORT))		return;	for (i = 0; i < CVMX_MGMT_PORT_NUM_PORTS; i++)		BUS_ADD_CHILD(parent, 0, "octm", i);}

static voidxc_identify(driver_t *driver, device_t parent){	device_t child;	if (!xen_pv_domain())		return;	child = BUS_ADD_CHILD(parent, 0, driver_name, 0);	device_set_driver(child, driver);	device_set_desc(child, "Xen Console");}

static voidgic_v3_acpi_identify(driver_t *driver, device_t parent){	struct madt_table_data madt_data;	ACPI_TABLE_MADT *madt;	vm_paddr_t physaddr;	device_t dev;	physaddr = acpi_find_table(ACPI_SIG_MADT);	if (physaddr == 0)		return;	madt = acpi_map_table(physaddr, ACPI_SIG_MADT);	if (madt == NULL) {		device_printf(parent, "gic: Unable to map the MADT/n");		return;	}	madt_data.parent = parent;	madt_data.dist = NULL;	madt_data.count = 0;	acpi_walk_subtables(madt + 1, (char *)madt + madt->Header.Length,	    madt_handler, &madt_data);	if (madt_data.dist == NULL) {		device_printf(parent,		    "No gic interrupt or distributor table/n");		goto out;	}	/* This is for the wrong GIC version */	if (madt_data.dist->Version != ACPI_MADT_GIC_VERSION_V3)		goto out;	dev = BUS_ADD_CHILD(parent, BUS_PASS_INTERRUPT + BUS_PASS_ORDER_MIDDLE,	    "gic", -1);	if (dev == NULL) {		device_printf(parent, "add gic child failed/n");		goto out;	}	/* Add the MADT data */	BUS_SET_RESOURCE(parent, dev, SYS_RES_MEMORY, 0,	    madt_data.dist->BaseAddress, 128 * 1024);	madt_data.dev = dev;	acpi_walk_subtables(madt + 1, (char *)madt + madt->Header.Length,	    rdist_map, &madt_data);	acpi_set_private(dev, (void *)(uintptr_t)madt_data.dist->Version);out:	acpi_unmap_table(madt);}

static voidefirtc_identify(driver_t *driver, device_t parent){	/* Don't add the driver unless we have working runtime services. */	if (efi_rt_ok() != 0)		return;	if (device_find_child(parent, "efirtc", -1) != NULL)		return;	if (BUS_ADD_CHILD(parent, 0, "efirtc", -1) == NULL)		device_printf(parent, "add child failed/n");}

static voidxendebug_identify(driver_t *driver, device_t parent){	KASSERT(xen_domain(),	    ("Trying to add Xen debug device to non-xen guest"));	if (xen_hvm_domain() && !xen_vector_callback_enabled)		return;	if (BUS_ADD_CHILD(parent, 0, "debug", 0) == NULL)		panic("Unable to add Xen debug device.");}

static voidcferes_identify(driver_t* driver, device_t parent){	device_t		 child;	int			 i;	struct resource		*res;	int			 result;	int			 rid;	struct cferes_softc	*sc;	uint64_t		 addr, len, type;	child = BUS_ADD_CHILD(parent, 100, "cferes", -1);	device_set_driver(child, driver);	sc = device_get_softc(child);	sc->rnum = 0;	for (i = 0; i < ~0U; i++) {		result = cfe_enummem(i, CFE_FLG_FULL_ARENA, &addr, &len, &type);		if (result < 0)			break;		if (type != CFE_MI_RESERVED) {			if (bootverbose)			printf("%s: skipping non reserved range 0x%0jx(%jd)/n",			    device_getnameunit(child),			    (uintmax_t)addr, (uintmax_t)len);			continue;		}		bus_set_resource(child, SYS_RES_MEMORY, sc->rnum, addr, len);		rid = sc->rnum;		res = bus_alloc_resource_any(child, SYS_RES_MEMORY, &rid, 0);		if (res == NULL) {			bus_delete_resource(child, SYS_RES_MEMORY, sc->rnum);			continue;		}		sc->rid[sc->rnum] = rid;		sc->res[sc->rnum] = res;		sc->rnum++;		if (sc->rnum == MAX_CFE_RESERVATIONS)			break;	}	if (sc->rnum == 0) {		device_delete_child(parent, child);		return;	}	device_set_desc(child, "CFE reserved memory");}

static voidisahint_add_device(device_t parent, const char *name, int unit){	device_t	child;	int		sensitive, start, count, t;	int		order;	/* device-specific flag overrides any wildcard */	sensitive = 0;	if (resource_int_value(name, unit, "sensitive", &sensitive) != 0)		resource_int_value(name, -1, "sensitive", &sensitive);	if (sensitive)		order = ISA_ORDER_SENSITIVE;	else		order = ISA_ORDER_SPECULATIVE;	child = BUS_ADD_CHILD(parent, parent, order, name, unit);	if (child == 0)		return;	start = 0;	count = 0;	resource_int_value(name, unit, "port", &start);	resource_int_value(name, unit, "portsize", &count);	if (start > 0 || count > 0)		bus_set_resource(child, SYS_RES_IOPORT, 0, start, count, -1);	start = 0;	count = 0;	resource_int_value(name, unit, "maddr", &start);	resource_int_value(name, unit, "msize", &count);	if (start > 0 || count > 0)		bus_set_resource(child, SYS_RES_MEMORY, 0, start, count, -1);	if (resource_int_value(name, unit, "irq", &start) == 0 && start > 0) {		bus_set_resource(child, SYS_RES_IRQ, 0, start, 1,		    machintr_legacy_intr_cpuid(start));	}	if (resource_int_value(name, unit, "drq", &start) == 0 && start >= 0)		bus_set_resource(child, SYS_RES_DRQ, 0, start, 1, -1);	if (resource_int_value(name, unit, "flags", &t) == 0)		device_set_flags(child, t);	if (resource_int_value(name, unit, "disabled", &t) == 0 && t != 0)		device_disable(child);}

static voiduart_chipc_identify(driver_t *driver, device_t parent){	struct chipc_capabilities	*caps;	caps = BHND_CHIPC_GET_CAPABILITIES(parent);	if (caps->num_uarts == 0)		return;	/*	 * TODO: add more than one UART	 */	BUS_ADD_CHILD(parent, 0, "uart", -1);}

static voidpmtimer_identify(driver_t *driver, device_t parent){	device_t child;	/*	 * Only add a child if one doesn't exist already.	 */	child = devclass_get_device(pmtimer_devclass, 0);	if (child == NULL) {		child = BUS_ADD_CHILD(parent, 0, "pmtimer", 0);		if (child == NULL)			panic("pmtimer_identify");	}}

static intnandsim_start_ctrl(int num){	device_t nexus, ndev;	devclass_t nexus_devclass;	int ret = 0;	nand_debug(NDBG_SIM,"start ctlr num:%d", num);	if (num >= MAX_SIM_DEV)		return (EINVAL);	if (!ctrls[num].created)		return (ENODEV);	if (ctrls[num].running)		return (EBUSY);	/* We will add our device as a child of the nexus0 device */	if (!(nexus_devclass = devclass_find("nexus")) ||	    !(nexus = devclass_get_device(nexus_devclass, 0)))		return (EFAULT);	/*	 * Create a newbus device representing this frontend instance	 *	 * XXX powerpc nexus doesn't implement bus_add_child, so child	 * must be added by device_add_child().	 */#if defined(__powerpc__)	ndev = device_add_child(nexus, "nandsim", num);#else	ndev = BUS_ADD_CHILD(nexus, 0, "nandsim", num);#endif	if (!ndev)		return (EFAULT);	mtx_lock(&Giant);	ret = device_probe_and_attach(ndev);	mtx_unlock(&Giant);	if (ret == 0) {		ctrls[num].sim_ctrl_dev = ndev;		ctrls[num].running = 1;	}	return (ret);}

static voidiicbus_hinted_child(device_t bus, const char *dname, int dunit){	device_t child;	int irq;	struct iicbus_ivar *devi;	child = BUS_ADD_CHILD(bus, 0, dname, dunit);	devi = IICBUS_IVAR(child);	resource_int_value(dname, dunit, "addr", &devi->addr);	if (resource_int_value(dname, dunit, "irq", &irq) == 0) {		if (bus_set_resource(child, SYS_RES_IRQ, 0, irq, 1) != 0)			device_printf(bus,			    "warning: bus_set_resource() failed/n");	}}

static intnexus_attach(device_t dev){	/*	 * Mask the legacy PICs - we will use the I/O SAPIC for interrupt.	 */	outb(IO_ICU1+1, 0xff);	outb(IO_ICU2+1, 0xff);	if (acpi_identify() == 0)		BUS_ADD_CHILD(dev, 10, "acpi", 0);	clock_register(dev, 1000);	bus_generic_attach(dev);	return 0;}