Beispiel #1
0
/*
 * name_child
 *
 * This function is called from init_child to name a node. It is
 * also passed as a callback for node merging functions.
 *
 * return value: DDI_SUCCESS, DDI_FAILURE
 */
static int
ppb_name_child(dev_info_t *child, char *name, int namelen)
{
	pci_regspec_t *pci_rp;
	uint_t slot, func;
	char **unit_addr;
	uint_t n;

	/*
	 * Pseudo nodes indicate a prototype node with per-instance
	 * properties to be merged into the real h/w device node.
	 * The interpretation of the unit-address is DD[,F]
	 * where DD is the device id and F is the function.
	 */
	if (ndi_dev_is_persistent_node(child) == 0) {
		if (ddi_prop_lookup_string_array(DDI_DEV_T_ANY, child,
		    DDI_PROP_DONTPASS, "unit-address", &unit_addr, &n) !=
		    DDI_PROP_SUCCESS) {
			cmn_err(CE_WARN, "cannot name node from %s.conf",
			    ddi_driver_name(child));
			return (DDI_FAILURE);
		}
		if (n != 1 || *unit_addr == NULL || **unit_addr == 0) {
			cmn_err(CE_WARN, "unit-address property in %s.conf"
			    " not well-formed", ddi_driver_name(child));
			ddi_prop_free(unit_addr);
			return (DDI_FAILURE);
		}
		(void) snprintf(name, namelen, "%s", *unit_addr);
		ddi_prop_free(unit_addr);
		return (DDI_SUCCESS);
	}

	/*
	 * Get the address portion of the node name based on
	 * the function and device number.
	 */
	if (ddi_prop_lookup_int_array(DDI_DEV_T_ANY, child, DDI_PROP_DONTPASS,
	    "reg", (int **)&pci_rp, &n) != DDI_SUCCESS) {
		return (DDI_FAILURE);
	}

	slot = PCI_REG_DEV_G(pci_rp[0].pci_phys_hi);
	func = PCI_REG_FUNC_G(pci_rp[0].pci_phys_hi);

	if (func != 0)
		(void) snprintf(name, namelen, "%x,%x", slot, func);
	else
		(void) snprintf(name, namelen, "%x", slot);

	ddi_prop_free(pci_rp);
	return (DDI_SUCCESS);
}
Beispiel #2
0
/*
 * Check if driver should be treated as an old pre 2.6 driver
 */
static int
old_driver(dev_info_t *dip)
{
	extern int ignore_hardware_nodes;	/* force flag from ddi_impl.c */

	if (ndi_dev_is_persistent_node(dip)) {
		if (ignore_hardware_nodes)
			return (1);
		if (ddi_getprop(DDI_DEV_T_ANY, dip, DDI_PROP_DONTPASS,
		    "ignore-hardware-nodes", -1) != -1)
			return (1);
	}
	return (0);
}
Beispiel #3
0
static int
ppb_name_child(dev_info_t *child, char *name, int namelen)
{
	pci_regspec_t *pci_rp;
	uint_t slot, func;
	char **unit_addr;
	uint_t n;

	/*
	 * For .conf nodes, use unit-address property as name
	 */
	if (ndi_dev_is_persistent_node(child) == 0) {
		if (ddi_prop_lookup_string_array(DDI_DEV_T_ANY, child,
		    DDI_PROP_DONTPASS, "unit-address", &unit_addr, &n) !=
		    DDI_PROP_SUCCESS) {
			cmn_err(CE_WARN,
			    "cannot find unit-address in %s.conf",
			    ddi_driver_name(child));
			return (DDI_FAILURE);
		}
		if (n != 1 || *unit_addr == NULL || **unit_addr == 0) {
			cmn_err(CE_WARN, "unit-address property in %s.conf"
			    " not well-formed", ddi_driver_name(child));
			ddi_prop_free(unit_addr);
			return (DDI_SUCCESS);
		}
		(void) snprintf(name, namelen, "%s", *unit_addr);
		ddi_prop_free(unit_addr);
		return (DDI_SUCCESS);
	}

	/* get child "reg" property */
	if (ddi_prop_lookup_int_array(DDI_DEV_T_ANY, child,
	    DDI_PROP_DONTPASS, "reg", (int **)&pci_rp, &n) != DDI_SUCCESS) {
		return (DDI_FAILURE);
	}

	/* copy the device identifications */
	slot = PCI_REG_DEV_G(pci_rp->pci_phys_hi);
	func = PCI_REG_FUNC_G(pci_rp->pci_phys_hi);

	if (func != 0)
		(void) snprintf(name, namelen, "%x,%x", slot, func);
	else
		(void) snprintf(name, namelen, "%x", slot);

	ddi_prop_free(pci_rp);
	return (DDI_SUCCESS);
}
Beispiel #4
0
static int
init_child(dev_info_t *child)
{
	char name[MAXNAMELEN];

	(void) name_child(child, name, MAXNAMELEN);
	ddi_set_name_addr(child, name);
	if ((ndi_dev_is_persistent_node(child) == 0) &&
	    (ndi_merge_node(child, name_child) == DDI_SUCCESS)) {
		impl_ddi_sunbus_removechild(child);
		return (DDI_FAILURE);
	}

	return (DDI_SUCCESS);
}
Beispiel #5
0
/*ARGSUSED*/
static int
pcmem_ctlops(dev_info_t *dip, dev_info_t *rdip,
	ddi_ctl_enum_t ctlop, void *arg, void *result)
{

	char    name[MAXNAMELEN];
	int	techreg, cissp;

	switch (ctlop) {
	case DDI_CTLOPS_REPORTDEV:
		if (rdip == (dev_info_t *)0) {
			return (DDI_FAILURE);
		}
		PCMEM_DEBUG((CE_CONT,
		    "?pcmem_ctlops: %s%d at %s in socket %d\n",
		    ddi_get_name(rdip), ddi_get_instance(rdip),
		    ddi_get_name(dip),
		    ddi_getprop(DDI_DEV_T_NONE, rdip,
			DDI_PROP_DONTPASS, "socket", -1)));

		return (DDI_SUCCESS);

	case DDI_CTLOPS_INITCHILD:

		PCMEM_DEBUG((CE_CONT,
		    "pcmem_ctlops - DDI_CTLOPS_INITCHILD persistent=%x\n",
		    ndi_dev_is_persistent_node((dev_info_t *)arg)));

		if (!ndi_dev_is_persistent_node((dev_info_t *)arg))
			return (DDI_FAILURE);
		/*
		 * XXXX - Read card CIS to determine technology
		 *	region(tn) and CIS space(dn).
		 *	Refer to Bugid 1179336.
		 */

		/*
		 * see cis_handler.h for CISTPL_DEVICE
		 *	and CISTPL_DEVICE_A
		 *
		 * CISTPL_DEVICE_DTYPE_NULL	0x00	NULL device
		 * CISTPL_DEVICE_DTYPE_ROM	0x01	ROM
		 * CISTPL_DEVICE_DTYPE_OTPROM	0x02	OTPROM
		 * CISTPL_DEVICE_DTYPE_EPROM	0x03    EPROM
		 * CISTPL_DEVICE_DTYPE_EEPROM	0x04	EEPROM
		 * CISTPL_DEVICE_DTYPE_FLASH	0x05	FLASH
		 * CISTPL_DEVICE_DTYPE_SRAM	0x06	SRAM
		 * CISTPL_DEVICE_DTYPE_DRAM	0x07	DRAM
		 *
		 */
		/*
		 * XXXX - For now set to default SRAM device
		 */
		techreg = CISTPL_DEVICE_DTYPE_SRAM;
		cissp = 0;
		(void) sprintf(name, "%d,%d", techreg, cissp);
		ddi_set_name_addr((dev_info_t *)arg, name);

		PCMEM_DEBUG((CE_CONT,
		    "pcmem_ctlops - DDI_CTLOPS_INITCHILD name=%s\n", name));

		return (DDI_SUCCESS);

	case DDI_CTLOPS_UNINITCHILD:
		ddi_set_name_addr((dev_info_t *)arg, NULL);

		PCMEM_DEBUG((CE_CONT,
		    "pcmem_ctlops - DDI_CTLOPS_UNINITCHILD child: %s(%d)\n",
		    ddi_node_name(arg), ddi_get_instance(arg)));

		return (DDI_SUCCESS);

	default:
		return (ddi_ctlops(dip, rdip, ctlop, arg, result));
	}
}
Beispiel #6
0
/*ARGSUSED*/
static int
isa_ctlops(dev_info_t *dip, dev_info_t *rdip,
	ddi_ctl_enum_t ctlop, void *arg, void *result)
{
	int rn;
	struct ddi_parent_private_data *pdp;

	switch (ctlop) {
	case DDI_CTLOPS_REPORTDEV:
		if (rdip == (dev_info_t *)0)
			return (DDI_FAILURE);
		cmn_err(CE_CONT, "?ISA-device: %s%d\n",
		    ddi_driver_name(rdip), ddi_get_instance(rdip));
		return (DDI_SUCCESS);

	case DDI_CTLOPS_INITCHILD:
		/*
		 * older drivers aren't expecting the "standard" device
		 * node format used by the hardware nodes.  these drivers
		 * only expect their own properties set in their driver.conf
		 * files.  so they tell us not to call them with hardware
		 * nodes by setting the property "ignore-hardware-nodes".
		 */
		if (old_driver((dev_info_t *)arg)) {
			return (DDI_NOT_WELL_FORMED);
		}

		return (isa_initchild((dev_info_t *)arg));

	case DDI_CTLOPS_UNINITCHILD:
		impl_ddi_sunbus_removechild((dev_info_t *)arg);
		return (DDI_SUCCESS);

	case DDI_CTLOPS_SIDDEV:
		if (ndi_dev_is_persistent_node(rdip))
			return (DDI_SUCCESS);
		/*
		 * All ISA devices need to do confirming probes
		 * unless they are PnP ISA.
		 */
		if (is_pnpisa(rdip))
			return (DDI_SUCCESS);
		else
			return (DDI_FAILURE);

	case DDI_CTLOPS_REGSIZE:
	case DDI_CTLOPS_NREGS:
		if (rdip == (dev_info_t *)0)
			return (DDI_FAILURE);

		if ((pdp = ddi_get_parent_data(rdip)) == NULL)
			return (DDI_FAILURE);

		if (ctlop == DDI_CTLOPS_NREGS) {
			*(int *)result = pdp->par_nreg;
		} else {
			rn = *(int *)arg;
			if (rn >= pdp->par_nreg)
				return (DDI_FAILURE);
			*(off_t *)result = (off_t)pdp->par_reg[rn].regspec_size;
		}
		return (DDI_SUCCESS);

	case DDI_CTLOPS_ATTACH:
	case DDI_CTLOPS_DETACH:
	case DDI_CTLOPS_PEEK:
	case DDI_CTLOPS_POKE:
		return (DDI_FAILURE);

	default:
		return (ddi_ctlops(dip, rdip, ctlop, arg, result));
	}
}
Beispiel #7
0
static int
ppb_initchild(dev_info_t *child)
{
	char name[MAXNAMELEN];
	ddi_acc_handle_t config_handle;
	ushort_t command_preserve, command;
	uint_t n;
	ushort_t bcr;
	uchar_t header_type;
	uchar_t min_gnt, latency_timer;
	ppb_devstate_t *ppb;

	/*
	 * Name the child
	 */
	if (ppb_name_child(child, name, MAXNAMELEN) != DDI_SUCCESS)
		return (DDI_FAILURE);

	ddi_set_name_addr(child, name);
	ddi_set_parent_data(child, NULL);

	/*
	 * Pseudo nodes indicate a prototype node with per-instance
	 * properties to be merged into the real h/w device node.
	 * The interpretation of the unit-address is DD[,F]
	 * where DD is the device id and F is the function.
	 */
	if (ndi_dev_is_persistent_node(child) == 0) {
		extern int pci_allow_pseudo_children;

		/*
		 * Try to merge the properties from this prototype
		 * node into real h/w nodes.
		 */
		if (ndi_merge_node(child, ppb_name_child) == DDI_SUCCESS) {
			/*
			 * Merged ok - return failure to remove the node.
			 */
			ppb_removechild(child);
			return (DDI_FAILURE);
		}

		/* workaround for ddivs to run under PCI */
		if (pci_allow_pseudo_children)
			return (DDI_SUCCESS);

		/*
		 * The child was not merged into a h/w node,
		 * but there's not much we can do with it other
		 * than return failure to cause the node to be removed.
		 */
		cmn_err(CE_WARN, "!%s@%s: %s.conf properties not merged",
		    ddi_driver_name(child), ddi_get_name_addr(child),
		    ddi_driver_name(child));
		ppb_removechild(child);
		return (DDI_NOT_WELL_FORMED);
	}

	ppb = (ppb_devstate_t *)ddi_get_soft_state(ppb_state,
	    ddi_get_instance(ddi_get_parent(child)));

	ddi_set_parent_data(child, NULL);

	/*
	 * If hardware is PM capable, set up the power info structure.
	 * This also ensures the the bus will not be off (0MHz) otherwise
	 * system panics during a bus access.
	 */
	if (PM_CAPABLE(ppb->ppb_pwr_p)) {
		/*
		 * Create a pwr_info struct for child.  Bus will be
		 * at full speed after creating info.
		 */
		pci_pwr_create_info(ppb->ppb_pwr_p, child);
#ifdef DEBUG
		ASSERT(ppb->ppb_pwr_p->current_lvl == PM_LEVEL_B0);
#endif
	}

	/*
	 * If configuration registers were previously saved by
	 * child (before it entered D3), then let the child do the
	 * restore to set up the config regs as it'll first need to
	 * power the device out of D3.
	 */
	if (ddi_prop_exists(DDI_DEV_T_ANY, child, DDI_PROP_DONTPASS,
	    "config-regs-saved-by-child") == 1) {
		DEBUG2(DBG_PWR, ddi_get_parent(child),
		    "INITCHILD: config regs to be restored by child"
		    " for %s@%s\n", ddi_node_name(child),
		    ddi_get_name_addr(child));

		return (DDI_SUCCESS);
	}

	DEBUG2(DBG_PWR, ddi_get_parent(child),
	    "INITCHILD: config regs setup for %s@%s\n",
	    ddi_node_name(child), ddi_get_name_addr(child));

	if (pci_config_setup(child, &config_handle) != DDI_SUCCESS) {
		if (PM_CAPABLE(ppb->ppb_pwr_p)) {
			pci_pwr_rm_info(ppb->ppb_pwr_p, child);
		}

		return (DDI_FAILURE);
	}

	/*
	 * Determine the configuration header type.
	 */
	header_type = pci_config_get8(config_handle, PCI_CONF_HEADER);

	/*
	 * Support for the "command-preserve" property.
	 */
	command_preserve = ddi_prop_get_int(DDI_DEV_T_ANY, child,
	    DDI_PROP_DONTPASS, "command-preserve", 0);
	command = pci_config_get16(config_handle, PCI_CONF_COMM);
	command &= (command_preserve | PCI_COMM_BACK2BACK_ENAB);
	command |= (ppb_command_default & ~command_preserve);
	pci_config_put16(config_handle, PCI_CONF_COMM, command);

	/*
	 * If the device has a bus control register then program it
	 * based on the settings in the command register.
	 */
	if ((header_type  & PCI_HEADER_TYPE_M) == PCI_HEADER_ONE) {
		bcr = pci_config_get8(config_handle, PCI_BCNF_BCNTRL);
		if (ppb_command_default & PCI_COMM_PARITY_DETECT)
			bcr |= PCI_BCNF_BCNTRL_PARITY_ENABLE;
		if (ppb_command_default & PCI_COMM_SERR_ENABLE)
			bcr |= PCI_BCNF_BCNTRL_SERR_ENABLE;
		bcr |= PCI_BCNF_BCNTRL_MAST_AB_MODE;
		pci_config_put8(config_handle, PCI_BCNF_BCNTRL, bcr);
	}

	/*
	 * Initialize cache-line-size configuration register if needed.
	 */
	if (ppb_set_cache_line_size_register &&
	    ddi_getprop(DDI_DEV_T_ANY, child, DDI_PROP_DONTPASS,
	    "cache-line-size", 0) == 0) {
		pci_config_put8(config_handle, PCI_CONF_CACHE_LINESZ,
		    ppb->ppb_cache_line_size);
		n = pci_config_get8(config_handle, PCI_CONF_CACHE_LINESZ);
		if (n != 0) {
			(void) ndi_prop_update_int(DDI_DEV_T_NONE, child,
			    "cache-line-size", n);
		}
	}

	/*
	 * Initialize latency timer configuration registers if needed.
	 */
	if (ppb_set_latency_timer_register &&
	    ddi_getprop(DDI_DEV_T_ANY, child, DDI_PROP_DONTPASS,
	    "latency-timer", 0) == 0) {

		if ((header_type & PCI_HEADER_TYPE_M) == PCI_HEADER_ONE) {
			latency_timer = ppb->ppb_latency_timer;
			pci_config_put8(config_handle, PCI_BCNF_LATENCY_TIMER,
			    ppb->ppb_latency_timer);
		} else {
			min_gnt = pci_config_get8(config_handle,
			    PCI_CONF_MIN_G);
			latency_timer = min_gnt * 8;
		}
		pci_config_put8(config_handle, PCI_CONF_LATENCY_TIMER,
		    latency_timer);
		n = pci_config_get8(config_handle, PCI_CONF_LATENCY_TIMER);
		if (n != 0) {
			(void) ndi_prop_update_int(DDI_DEV_T_NONE, child,
			    "latency-timer", n);
		}
	}

	/*
	 * SPARC PCIe FMA specific
	 *
	 * Note: parent_data for parent is created only if this is sparc PCI-E
	 * platform, for which, SG take a different route to handle device
	 * errors.
	 */
	if (ppb->parent_bus == PCIE_PCIECAP_DEV_TYPE_PCIE_DEV) {
		if (pcie_init_cfghdl(child) != DDI_SUCCESS) {
			pci_config_teardown(&config_handle);
			return (DDI_FAILURE);
		}
		pcie_init_dom(child);
	}

	/*
	 * Check to see if the XMITS/PCI-X workaround applies.
	 */
	n = ddi_getprop(DDI_DEV_T_ANY, child, DDI_PROP_NOTPROM,
	    "pcix-update-cmd-reg", -1);

	if (n != -1) {
		extern void pcix_set_cmd_reg(dev_info_t *child, uint16_t value);
		DEBUG1(DBG_INIT_CLD, child, "Turning on XMITS NCPQ "
		    "Workaround: value = %x\n", n);
		pcix_set_cmd_reg(child, n);
	}
	pci_config_teardown(&config_handle);
	return (DDI_SUCCESS);
}
Beispiel #8
0
static int
ppb_initchild(dev_info_t *child)
{
	struct ddi_parent_private_data *pdptr;
	ppb_devstate_t *ppb;
	char name[MAXNAMELEN];
	ddi_acc_handle_t config_handle;
	ushort_t command_preserve, command;

	ppb = (ppb_devstate_t *)ddi_get_soft_state(ppb_state,
	    ddi_get_instance(ddi_get_parent(child)));

	if (ppb_name_child(child, name, MAXNAMELEN) != DDI_SUCCESS)
		return (DDI_FAILURE);
	ddi_set_name_addr(child, name);

	/*
	 * Pseudo nodes indicate a prototype node with per-instance
	 * properties to be merged into the real h/w device node.
	 * The interpretation of the unit-address is DD[,F]
	 * where DD is the device id and F is the function.
	 */
	if (ndi_dev_is_persistent_node(child) == 0) {
		extern int pci_allow_pseudo_children;

		ddi_set_parent_data(child, NULL);

		/*
		 * Try to merge the properties from this prototype
		 * node into real h/w nodes.
		 */
		if (ndi_merge_node(child, ppb_name_child) == DDI_SUCCESS) {
			/*
			 * Merged ok - return failure to remove the node.
			 */
			ddi_set_name_addr(child, NULL);
			return (DDI_FAILURE);
		}

		/* workaround for ddivs to run under PCI */
		if (pci_allow_pseudo_children)
			return (DDI_SUCCESS);

		/*
		 * The child was not merged into a h/w node,
		 * but there's not much we can do with it other
		 * than return failure to cause the node to be removed.
		 */
		cmn_err(CE_WARN, "!%s@%s: %s.conf properties not merged",
		    ddi_driver_name(child), ddi_get_name_addr(child),
		    ddi_driver_name(child));
		ddi_set_name_addr(child, NULL);
		return (DDI_NOT_WELL_FORMED);
	}

	ddi_set_parent_data(child, NULL);

	/*
	 * PCIe FMA specific
	 *
	 * Note: parent_data for parent is created only if this is PCI-E
	 * platform, for which, SG take a different route to handle device
	 * errors.
	 */
	if (ppb->parent_bus == PCIE_PCIECAP_DEV_TYPE_PCIE_DEV) {
		if (pcie_init_cfghdl(child) != DDI_SUCCESS)
			return (DDI_FAILURE);
		pcie_init_dom(child);
	}

	/* transfer select properties from PROM to kernel */
	if (ddi_getprop(DDI_DEV_T_NONE, child, DDI_PROP_DONTPASS,
	    "interrupts", -1) != -1) {
		pdptr = kmem_zalloc((sizeof (struct ddi_parent_private_data) +
		    sizeof (struct intrspec)), KM_SLEEP);
		pdptr->par_intr = (struct intrspec *)(pdptr + 1);
		pdptr->par_nintr = 1;
		ddi_set_parent_data(child, pdptr);
	} else
		ddi_set_parent_data(child, NULL);

	if (pci_config_setup(child, &config_handle) != DDI_SUCCESS) {
		pcie_fini_dom(child);
		return (DDI_FAILURE);
	}

	/*
	 * Support for the "command-preserve" property.
	 */
	command_preserve = ddi_prop_get_int(DDI_DEV_T_ANY, child,
	    DDI_PROP_DONTPASS, "command-preserve", 0);
	command = pci_config_get16(config_handle, PCI_CONF_COMM);
	command &= (command_preserve | PCI_COMM_BACK2BACK_ENAB);
	command |= (ppb_command_default & ~command_preserve);
	pci_config_put16(config_handle, PCI_CONF_COMM, command);

	pci_config_teardown(&config_handle);
	return (DDI_SUCCESS);
}
Beispiel #9
0
static int
pci_initchild(dev_info_t *child)
{
	char name[80];
	ddi_acc_handle_t config_handle;
	ushort_t command_preserve, command;

	if (pci_common_name_child(child, name, 80) != DDI_SUCCESS) {
		return (DDI_FAILURE);
	}
	ddi_set_name_addr(child, name);

	/*
	 * Pseudo nodes indicate a prototype node with per-instance
	 * properties to be merged into the real h/w device node.
	 * The interpretation of the unit-address is DD[,F]
	 * where DD is the device id and F is the function.
	 */
	if (ndi_dev_is_persistent_node(child) == 0) {
		extern int pci_allow_pseudo_children;

		ddi_set_parent_data(child, NULL);

		/*
		 * Try to merge the properties from this prototype
		 * node into real h/w nodes.
		 */
		if (ndi_merge_node(child, pci_common_name_child) ==
		    DDI_SUCCESS) {
			/*
			 * Merged ok - return failure to remove the node.
			 */
			ddi_set_name_addr(child, NULL);
			return (DDI_FAILURE);
		}

		/* workaround for ddivs to run under PCI */
		if (pci_allow_pseudo_children) {
			/*
			 * If the "interrupts" property doesn't exist,
			 * this must be the ddivs no-intr case, and it returns
			 * DDI_SUCCESS instead of DDI_FAILURE.
			 */
			if (ddi_prop_get_int(DDI_DEV_T_ANY, child,
			    DDI_PROP_DONTPASS, "interrupts", -1) == -1)
				return (DDI_SUCCESS);
			/*
			 * Create the ddi_parent_private_data for a pseudo
			 * child.
			 */
			pci_common_set_parent_private_data(child);
			return (DDI_SUCCESS);
		}

		/*
		 * The child was not merged into a h/w node,
		 * but there's not much we can do with it other
		 * than return failure to cause the node to be removed.
		 */
		cmn_err(CE_WARN, "!%s@%s: %s.conf properties not merged",
		    ddi_get_name(child), ddi_get_name_addr(child),
		    ddi_get_name(child));
		ddi_set_name_addr(child, NULL);
		return (DDI_NOT_WELL_FORMED);
	}

	if (ddi_prop_get_int(DDI_DEV_T_ANY, child, DDI_PROP_DONTPASS,
	    "interrupts", -1) != -1)
		pci_common_set_parent_private_data(child);
	else
		ddi_set_parent_data(child, NULL);

	/*
	 * initialize command register
	 */
	if (pci_config_setup(child, &config_handle) != DDI_SUCCESS)
		return (DDI_FAILURE);

	/*
	 * Support for the "command-preserve" property.
	 */
	command_preserve = ddi_prop_get_int(DDI_DEV_T_ANY, child,
	    DDI_PROP_DONTPASS, "command-preserve", 0);
	command = pci_config_get16(config_handle, PCI_CONF_COMM);
	command &= (command_preserve | PCI_COMM_BACK2BACK_ENAB);
	command |= (pci_command_default & ~command_preserve);
	pci_config_put16(config_handle, PCI_CONF_COMM, command);

	pci_config_teardown(&config_handle);
	return (DDI_SUCCESS);
}