drivers/pci/hotplug/rpaphp_pci.c - kernel/msm-4.9 - Gitiles

 /*
  * PCI Hot Plug Controller Driver for RPA-compliant PPC64 platform.
  * Copyright (C) 2003 Linda Xie <lxie@us.ibm.com>
  *
  * All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or (at
  * your option) any later version.
  *
  * This program is distributed in the hope that it will be useful, but
  * WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  * NON INFRINGEMENT.  See the GNU General Public License for more
  * details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  *
  * Send feedback to <lxie@us.ibm.com>
  *
  */
 #include <linux/pci.h>
 #include <linux/string.h>

 #include <asm/pci-bridge.h>
 #include <asm/rtas.h>
 #include <asm/machdep.h>

 #include "../pci.h"		/* for pci_add_new_bus */
 #include "rpaphp.h"

 static struct pci_bus *find_bus_among_children(struct pci_bus *bus,
 					struct device_node *dn)
 {
 	struct pci_bus *child = NULL;
 	struct list_head *tmp;
 	struct device_node *busdn;

 	busdn = pci_bus_to_OF_node(bus);
 	if (busdn == dn)
 		return bus;

 	list_for_each(tmp, &bus->children) {
 		child = find_bus_among_children(pci_bus_b(tmp), dn);
 		if (child)
 			break;
 	}
 	return child;
 }

 struct pci_bus *rpaphp_find_pci_bus(struct device_node *dn)
 {
 	struct pci_dn *pdn = dn->data;

 	if (!pdn  || !pdn->phb || !pdn->phb->bus)
 		return NULL;

 	return find_bus_among_children(pdn->phb->bus, dn);
 }
 EXPORT_SYMBOL_GPL(rpaphp_find_pci_bus);

 int rpaphp_claim_resource(struct pci_dev *dev, int resource)
 {
 	struct resource *res = &dev->resource[resource];
 	struct resource *root = pci_find_parent_resource(dev, res);
 	char *dtype = resource < PCI_BRIDGE_RESOURCES ? "device" : "bridge";
 	int err = -EINVAL;

 	if (root != NULL) {
 		err = request_resource(root, res);
 	}

 	if (err) {
 		err("PCI: %s region %d of %s %s [%lx:%lx]\n",
 		    root ? "Address space collision on" :
 		    "No parent found for",
 		    resource, dtype, pci_name(dev), res->start, res->end);
 	}
 	return err;
 }

 EXPORT_SYMBOL_GPL(rpaphp_claim_resource);

 static int rpaphp_get_sensor_state(struct slot *slot, int *state)
 {
 	int rc;
 	int setlevel;

 	rc = rtas_get_sensor(DR_ENTITY_SENSE, slot->index, state);

 	if (rc < 0) {
 		if (rc == -EFAULT || rc == -EEXIST) {
 			dbg("%s: slot must be power up to get sensor-state\n",
 			    __FUNCTION__);

 			/* some slots have to be powered up
 			 * before get-sensor will succeed.
 			 */
 			rc = rtas_set_power_level(slot->power_domain, POWER_ON,
 						  &setlevel);
 			if (rc < 0) {
 				dbg("%s: power on slot[%s] failed rc=%d.\n",
 				    __FUNCTION__, slot->name, rc);
 			} else {
 				rc = rtas_get_sensor(DR_ENTITY_SENSE,
 						     slot->index, state);
 			}
 		} else if (rc == -ENODEV)
 			info("%s: slot is unusable\n", __FUNCTION__);
 		else
 			err("%s failed to get sensor state\n", __FUNCTION__);
 	}
 	return rc;
 }

 /**
  * get_pci_adapter_status - get the status of a slot
  *
  * 0-- slot is empty
  * 1-- adapter is configured
  * 2-- adapter is not configured
  * 3-- not valid
  */
 int rpaphp_get_pci_adapter_status(struct slot *slot, int is_init, u8 * value)
 {
 	struct pci_bus *bus;
 	int state, rc;

 	*value = NOT_VALID;
 	rc = rpaphp_get_sensor_state(slot, &state);
 	if (rc)
 		goto exit;

  	if (state == EMPTY)
  		*value = EMPTY;
  	else if (state == PRESENT) {
 		if (!is_init) {
 			/* at run-time slot->state can be changed by */
 			/* config/unconfig adapter */
 			*value = slot->state;
 		} else {
 			bus = rpaphp_find_pci_bus(slot->dn);
 			if (bus && !list_empty(&bus->devices))
 				*value = CONFIGURED;
 			else
 				*value = NOT_CONFIGURED;
 		}
 	}
 exit:
 	return rc;
 }

 /* Must be called before pci_bus_add_devices */
 void rpaphp_fixup_new_pci_devices(struct pci_bus *bus, int fix_bus)
 {
 	struct pci_dev *dev;

 	list_for_each_entry(dev, &bus->devices, bus_list) {
 		/*
 		 * Skip already-present devices (which are on the
 		 * global device list.)
 		 */
 		if (list_empty(&dev->global_list)) {
 			int i;

 			/* Need to setup IOMMU tables */
 			ppc_md.iommu_dev_setup(dev);

 			if(fix_bus)
 				pcibios_fixup_device_resources(dev, bus);
 			pci_read_irq_line(dev);
 			for (i = 0; i < PCI_NUM_RESOURCES; i++) {
 				struct resource *r = &dev->resource[i];

 				if (r->parent || !r->start || !r->flags)
 					continue;
 				rpaphp_claim_resource(dev, i);
 			}
 		}
 	}
 }

 static void rpaphp_eeh_add_bus_device(struct pci_bus *bus)
 {
 	struct pci_dev *dev;

 	list_for_each_entry(dev, &bus->devices, bus_list) {
 		eeh_add_device_late(dev);
 		if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
 			struct pci_bus *subbus = dev->subordinate;
 			if (subbus)
 				rpaphp_eeh_add_bus_device (subbus);
 		}
 	}
 }

 static int rpaphp_pci_config_bridge(struct pci_dev *dev)
 {
 	u8 sec_busno;
 	struct pci_bus *child_bus;
 	struct pci_dev *child_dev;

 	dbg("Enter %s:  BRIDGE dev=%s\n", __FUNCTION__, pci_name(dev));

 	/* get busno of downstream bus */
 	pci_read_config_byte(dev, PCI_SECONDARY_BUS, &sec_busno);

 	/* add to children of PCI bridge dev->bus */
 	child_bus = pci_add_new_bus(dev->bus, dev, sec_busno);
 	if (!child_bus) {
 		err("%s: could not add second bus\n", __FUNCTION__);
 		return -EIO;
 	}
 	sprintf(child_bus->name, "PCI Bus #%02x", child_bus->number);
 	/* do pci_scan_child_bus */
 	pci_scan_child_bus(child_bus);

 	list_for_each_entry(child_dev, &child_bus->devices, bus_list) {
 		eeh_add_device_late(child_dev);
 	}

 	 /* fixup new pci devices without touching bus struct */
 	rpaphp_fixup_new_pci_devices(child_bus, 0);

 	/* Make the discovered devices available */
 	pci_bus_add_devices(child_bus);
 	return 0;
 }

 void rpaphp_init_new_devs(struct pci_bus *bus)
 {
 	rpaphp_fixup_new_pci_devices(bus, 0);
 	rpaphp_eeh_add_bus_device(bus);
 }
 EXPORT_SYMBOL_GPL(rpaphp_init_new_devs);

 /*****************************************************************************
  rpaphp_pci_config_slot() will  configure all devices under the
  given slot->dn and return the the first pci_dev.
  *****************************************************************************/
 static struct pci_dev *
 rpaphp_pci_config_slot(struct pci_bus *bus)
 {
 	struct device_node *dn = pci_bus_to_OF_node(bus);
 	struct pci_dev *dev = NULL;
 	int slotno;
 	int num;

 	dbg("Enter %s: dn=%s bus=%s\n", __FUNCTION__, dn->full_name, bus->name);
 	if (!dn || !dn->child)
 		return NULL;

 	if (_machine == PLATFORM_PSERIES_LPAR) {
 		of_scan_bus(dn, bus);
 		if (list_empty(&bus->devices)) {
 			err("%s: No new device found\n", __FUNCTION__);
 			return NULL;
 		}

 		rpaphp_init_new_devs(bus);
 		pci_bus_add_devices(bus);
 		dev = list_entry(&bus->devices, struct pci_dev, bus_list);
 	} else {
 		slotno = PCI_SLOT(PCI_DN(dn->child)->devfn);

 		/* pci_scan_slot should find all children */
 		num = pci_scan_slot(bus, PCI_DEVFN(slotno, 0));
 		if (num) {
 			rpaphp_fixup_new_pci_devices(bus, 1);
 			pci_bus_add_devices(bus);
 		}
 		if (list_empty(&bus->devices)) {
 			err("%s: No new device found\n", __FUNCTION__);
 			return NULL;
 		}
 		list_for_each_entry(dev, &bus->devices, bus_list) {
 			if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE)
 				rpaphp_pci_config_bridge(dev);

 			rpaphp_eeh_add_bus_device(bus);
 		}
 	}

 	return dev;
 }

 void rpaphp_eeh_init_nodes(struct device_node *dn)
 {
 	struct device_node *sib;

 	for (sib = dn->child; sib; sib = sib->sibling)
 		rpaphp_eeh_init_nodes(sib);
 	eeh_add_device_early(dn);
 	return;

 }
 EXPORT_SYMBOL_GPL(rpaphp_eeh_init_nodes);

 static void print_slot_pci_funcs(struct pci_bus *bus)
 {
 	struct device_node *dn;
 	struct pci_dev *dev;

 	dn = pci_bus_to_OF_node(bus);
 	if (!dn)
 		return;

 	dbg("%s: pci_devs of slot[%s]\n", __FUNCTION__, dn->full_name);
 	list_for_each_entry (dev, &bus->devices, bus_list)
 		dbg("\t%s\n", pci_name(dev));
 	return;
 }

 int rpaphp_config_pci_adapter(struct pci_bus *bus)
 {
 	struct device_node *dn = pci_bus_to_OF_node(bus);
 	struct pci_dev *dev;
 	int rc = -ENODEV;

 	dbg("Entry %s: slot[%s]\n", __FUNCTION__, dn->full_name);
 	if (!dn)
 		goto exit;

 	rpaphp_eeh_init_nodes(dn);
 	dev = rpaphp_pci_config_slot(bus);
 	if (!dev) {
 		err("%s: can't find any devices.\n", __FUNCTION__);
 		goto exit;
 	}
 	print_slot_pci_funcs(bus);
 	rc = 0;
 exit:
 	dbg("Exit %s:  rc=%d\n", __FUNCTION__, rc);
 	return rc;
 }
 EXPORT_SYMBOL_GPL(rpaphp_config_pci_adapter);

 static void rpaphp_eeh_remove_bus_device(struct pci_dev *dev)
 {
 	eeh_remove_device(dev);
 	if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
 		struct pci_bus *bus = dev->subordinate;
 		struct list_head *ln;
 		if (!bus)
 			return;
 		for (ln = bus->devices.next; ln != &bus->devices; ln = ln->next) {
 			struct pci_dev *pdev = pci_dev_b(ln);
 			if (pdev)
 				rpaphp_eeh_remove_bus_device(pdev);
 		}

 	}
 	return;
 }

 int rpaphp_unconfig_pci_adapter(struct pci_bus *bus)
 {
 	struct pci_dev *dev, *tmp;

 	list_for_each_entry_safe(dev, tmp, &bus->devices, bus_list) {
 		rpaphp_eeh_remove_bus_device(dev);
 		pci_remove_bus_device(dev);
 	}
 	return 0;
 }
 EXPORT_SYMBOL_GPL(rpaphp_unconfig_pci_adapter);

 static int setup_pci_hotplug_slot_info(struct slot *slot)
 {
 	dbg("%s Initilize the PCI slot's hotplug->info structure ...\n",
 	    __FUNCTION__);
 	rpaphp_get_power_status(slot, &slot->hotplug_slot->info->power_status);
 	rpaphp_get_pci_adapter_status(slot, 1,
 				      &slot->hotplug_slot->info->
 				      adapter_status);
 	if (slot->hotplug_slot->info->adapter_status == NOT_VALID) {
 		err("%s: NOT_VALID: skip dn->full_name=%s\n",
 		    __FUNCTION__, slot->dn->full_name);
 		return -EINVAL;
 	}
 	return 0;
 }

 static void set_slot_name(struct slot *slot)
 {
 	struct pci_bus *bus = slot->bus;
 	struct pci_dev *bridge;

 	bridge = bus->self;
 	if (bridge)
 		strcpy(slot->name, pci_name(bridge));
 	else
 		sprintf(slot->name, "%04x:%02x:00.0", pci_domain_nr(bus),
 			bus->number);
 }

 static int setup_pci_slot(struct slot *slot)
 {
 	struct device_node *dn = slot->dn;
 	struct pci_bus *bus;

 	BUG_ON(!dn);
 	bus = rpaphp_find_pci_bus(dn);
 	if (!bus) {
 		err("%s: no pci_bus for dn %s\n", __FUNCTION__, dn->full_name);
 		goto exit_rc;
 	}

 	slot->bus = bus;
 	slot->pci_devs = &bus->devices;
 	set_slot_name(slot);

 	/* find slot's pci_dev if it's not empty */
 	if (slot->hotplug_slot->info->adapter_status == EMPTY) {
 		slot->state = EMPTY;	/* slot is empty */
 	} else {
 		/* slot is occupied */
 		if (!dn->child) {
 			/* non-empty slot has to have child */
 			err("%s: slot[%s]'s device_node doesn't have child for adapter\n",
 				__FUNCTION__, slot->name);
 			goto exit_rc;
 		}

 		if (slot->hotplug_slot->info->adapter_status == NOT_CONFIGURED) {
 			dbg("%s CONFIGURING pci adapter in slot[%s]\n",
 				__FUNCTION__, slot->name);
 			if (rpaphp_config_pci_adapter(slot->bus)) {
 				err("%s: CONFIG pci adapter failed\n", __FUNCTION__);
 				goto exit_rc;
 			}

 		} else if (slot->hotplug_slot->info->adapter_status != CONFIGURED) {
 			err("%s: slot[%s]'s adapter_status is NOT_VALID.\n",
 				__FUNCTION__, slot->name);
 			goto exit_rc;
 		}
 		print_slot_pci_funcs(slot->bus);
 		if (!list_empty(slot->pci_devs)) {
 			slot->state = CONFIGURED;
 		} else {
 			/* DLPAR add as opposed to
 		 	 * boot time */
 			slot->state = NOT_CONFIGURED;
 		}
 	}
 	return 0;
 exit_rc:
 	dealloc_slot_struct(slot);
 	return -EINVAL;
 }

 int register_pci_slot(struct slot *slot)
 {
 	int rc = -EINVAL;

 	if (setup_pci_hotplug_slot_info(slot))
 		goto exit_rc;
 	if (setup_pci_slot(slot))
 		goto exit_rc;
 	rc = register_slot(slot);
 exit_rc:
 	return rc;
 }

 int rpaphp_enable_pci_slot(struct slot *slot)
 {
 	int retval = 0, state;

 	retval = rpaphp_get_sensor_state(slot, &state);
 	if (retval)
 		goto exit;
 	dbg("%s: sensor state[%d]\n", __FUNCTION__, state);
 	/* if slot is not empty, enable the adapter */
 	if (state == PRESENT) {
 		dbg("%s : slot[%s] is occupied.\n", __FUNCTION__, slot->name);
 		retval = rpaphp_config_pci_adapter(slot->bus);
 		if (!retval) {
 			slot->state = CONFIGURED;
 			info("%s: devices in slot[%s] configured\n",
 					__FUNCTION__, slot->name);
 		} else {
 			slot->state = NOT_CONFIGURED;
 			dbg("%s: no pci_dev struct for adapter in slot[%s]\n",
 			    __FUNCTION__, slot->name);
 		}
 	} else if (state == EMPTY) {
 		dbg("%s : slot[%s] is empty\n", __FUNCTION__, slot->name);
 		slot->state = EMPTY;
 	} else {
 		err("%s: slot[%s] is in invalid state\n", __FUNCTION__,
 		    slot->name);
 		slot->state = NOT_VALID;
 		retval = -EINVAL;
 	}
 exit:
 	dbg("%s - Exit: rc[%d]\n", __FUNCTION__, retval);
 	return retval;
 }
	/*
	* PCI Hot Plug Controller Driver for RPA-compliant PPC64 platform.
	* Copyright (C) 2003 Linda Xie <lxie@us.ibm.com>
	*
	* All rights reserved.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or (at
	* your option) any later version.
	*
	* This program is distributed in the hope that it will be useful, but
	* WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
	* NON INFRINGEMENT. See the GNU General Public License for more
	* details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	*
	* Send feedback to <lxie@us.ibm.com>
	*
	*/
	#include <linux/pci.h>
	#include <linux/string.h>

	#include <asm/pci-bridge.h>
	#include <asm/rtas.h>
	#include <asm/machdep.h>

	#include "../pci.h" /* for pci_add_new_bus */
	#include "rpaphp.h"

	static struct pci_bus find_bus_among_children(struct pci_bus bus,
	struct device_node *dn)
	{
	struct pci_bus *child = NULL;
	struct list_head *tmp;
	struct device_node *busdn;

	busdn = pci_bus_to_OF_node(bus);
	if (busdn == dn)
	return bus;

	list_for_each(tmp, &bus->children) {
	child = find_bus_among_children(pci_bus_b(tmp), dn);
	if (child)
	break;
	}
	return child;
	}

	struct pci_bus rpaphp_find_pci_bus(struct device_node dn)
	{
	struct pci_dn *pdn = dn->data;

	if (!pdn \|\| !pdn->phb \|\| !pdn->phb->bus)
	return NULL;

	return find_bus_among_children(pdn->phb->bus, dn);
	}
	EXPORT_SYMBOL_GPL(rpaphp_find_pci_bus);

	int rpaphp_claim_resource(struct pci_dev *dev, int resource)
	{
	struct resource *res = &dev->resource[resource];
	struct resource *root = pci_find_parent_resource(dev, res);
	char *dtype = resource < PCI_BRIDGE_RESOURCES ? "device" : "bridge";
	int err = -EINVAL;

	if (root != NULL) {
	err = request_resource(root, res);
	}

	if (err) {
	err("PCI: %s region %d of %s %s [%lx:%lx]\n",
	root ? "Address space collision on" :
	"No parent found for",
	resource, dtype, pci_name(dev), res->start, res->end);
	}
	return err;
	}

	EXPORT_SYMBOL_GPL(rpaphp_claim_resource);

	static int rpaphp_get_sensor_state(struct slot slot, int state)
	{
	int rc;
	int setlevel;

	rc = rtas_get_sensor(DR_ENTITY_SENSE, slot->index, state);

	if (rc < 0) {
	if (rc == -EFAULT \|\| rc == -EEXIST) {
	dbg("%s: slot must be power up to get sensor-state\n",
	__FUNCTION__);

	/* some slots have to be powered up
	* before get-sensor will succeed.
	*/
	rc = rtas_set_power_level(slot->power_domain, POWER_ON,
	&setlevel);
	if (rc < 0) {
	dbg("%s: power on slot[%s] failed rc=%d.\n",
	__FUNCTION__, slot->name, rc);
	} else {
	rc = rtas_get_sensor(DR_ENTITY_SENSE,
	slot->index, state);
	}
	} else if (rc == -ENODEV)
	info("%s: slot is unusable\n", __FUNCTION__);
	else
	err("%s failed to get sensor state\n", __FUNCTION__);
	}
	return rc;
	}

	/**
	* get_pci_adapter_status - get the status of a slot
	*
	* 0-- slot is empty
	* 1-- adapter is configured
	* 2-- adapter is not configured
	* 3-- not valid
	*/
	int rpaphp_get_pci_adapter_status(struct slot slot, int is_init, u8 value)
	{
	struct pci_bus *bus;
	int state, rc;

	*value = NOT_VALID;
	rc = rpaphp_get_sensor_state(slot, &state);
	if (rc)
	goto exit;

	if (state == EMPTY)
	*value = EMPTY;
	else if (state == PRESENT) {
	if (!is_init) {
	/* at run-time slot->state can be changed by */
	/* config/unconfig adapter */
	*value = slot->state;
	} else {
	bus = rpaphp_find_pci_bus(slot->dn);
	if (bus && !list_empty(&bus->devices))
	*value = CONFIGURED;
	else
	*value = NOT_CONFIGURED;
	}
	}
	exit:
	return rc;
	}

	/* Must be called before pci_bus_add_devices */
	void rpaphp_fixup_new_pci_devices(struct pci_bus *bus, int fix_bus)
	{
	struct pci_dev *dev;

	list_for_each_entry(dev, &bus->devices, bus_list) {
	/*
	* Skip already-present devices (which are on the
	* global device list.)
	*/
	if (list_empty(&dev->global_list)) {
	int i;

	/* Need to setup IOMMU tables */
	ppc_md.iommu_dev_setup(dev);

	if(fix_bus)
	pcibios_fixup_device_resources(dev, bus);
	pci_read_irq_line(dev);
	for (i = 0; i < PCI_NUM_RESOURCES; i++) {
	struct resource *r = &dev->resource[i];

	if (r->parent \|\| !r->start \|\| !r->flags)
	continue;
	rpaphp_claim_resource(dev, i);
	}
	}
	}
	}

	static void rpaphp_eeh_add_bus_device(struct pci_bus *bus)
	{
	struct pci_dev *dev;

	list_for_each_entry(dev, &bus->devices, bus_list) {
	eeh_add_device_late(dev);
	if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
	struct pci_bus *subbus = dev->subordinate;
	if (subbus)
	rpaphp_eeh_add_bus_device (subbus);
	}
	}
	}

	static int rpaphp_pci_config_bridge(struct pci_dev *dev)
	{
	u8 sec_busno;
	struct pci_bus *child_bus;
	struct pci_dev *child_dev;

	dbg("Enter %s: BRIDGE dev=%s\n", __FUNCTION__, pci_name(dev));

	/* get busno of downstream bus */
	pci_read_config_byte(dev, PCI_SECONDARY_BUS, &sec_busno);

	/* add to children of PCI bridge dev->bus */
	child_bus = pci_add_new_bus(dev->bus, dev, sec_busno);
	if (!child_bus) {
	err("%s: could not add second bus\n", __FUNCTION__);
	return -EIO;
	}
	sprintf(child_bus->name, "PCI Bus #%02x", child_bus->number);
	/* do pci_scan_child_bus */
	pci_scan_child_bus(child_bus);

	list_for_each_entry(child_dev, &child_bus->devices, bus_list) {
	eeh_add_device_late(child_dev);
	}

	/* fixup new pci devices without touching bus struct */
	rpaphp_fixup_new_pci_devices(child_bus, 0);

	/* Make the discovered devices available */
	pci_bus_add_devices(child_bus);
	return 0;
	}

	void rpaphp_init_new_devs(struct pci_bus *bus)
	{
	rpaphp_fixup_new_pci_devices(bus, 0);
	rpaphp_eeh_add_bus_device(bus);
	}
	EXPORT_SYMBOL_GPL(rpaphp_init_new_devs);

	/*****************************************************************************
	rpaphp_pci_config_slot() will configure all devices under the
	given slot->dn and return the the first pci_dev.
	*****************************************************************************/
	static struct pci_dev *
	rpaphp_pci_config_slot(struct pci_bus *bus)
	{
	struct device_node *dn = pci_bus_to_OF_node(bus);
	struct pci_dev *dev = NULL;
	int slotno;
	int num;

	dbg("Enter %s: dn=%s bus=%s\n", __FUNCTION__, dn->full_name, bus->name);
	if (!dn \|\| !dn->child)
	return NULL;

	if (_machine == PLATFORM_PSERIES_LPAR) {
	of_scan_bus(dn, bus);
	if (list_empty(&bus->devices)) {
	err("%s: No new device found\n", __FUNCTION__);
	return NULL;
	}

	rpaphp_init_new_devs(bus);
	pci_bus_add_devices(bus);
	dev = list_entry(&bus->devices, struct pci_dev, bus_list);
	} else {
	slotno = PCI_SLOT(PCI_DN(dn->child)->devfn);

	/* pci_scan_slot should find all children */
	num = pci_scan_slot(bus, PCI_DEVFN(slotno, 0));
	if (num) {
	rpaphp_fixup_new_pci_devices(bus, 1);
	pci_bus_add_devices(bus);
	}
	if (list_empty(&bus->devices)) {
	err("%s: No new device found\n", __FUNCTION__);
	return NULL;
	}
	list_for_each_entry(dev, &bus->devices, bus_list) {
	if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE)
	rpaphp_pci_config_bridge(dev);

	rpaphp_eeh_add_bus_device(bus);
	}
	}

	return dev;
	}

	void rpaphp_eeh_init_nodes(struct device_node *dn)
	{
	struct device_node *sib;

	for (sib = dn->child; sib; sib = sib->sibling)
	rpaphp_eeh_init_nodes(sib);
	eeh_add_device_early(dn);
	return;

	}
	EXPORT_SYMBOL_GPL(rpaphp_eeh_init_nodes);

	static void print_slot_pci_funcs(struct pci_bus *bus)
	{
	struct device_node *dn;
	struct pci_dev *dev;

	dn = pci_bus_to_OF_node(bus);
	if (!dn)
	return;

	dbg("%s: pci_devs of slot[%s]\n", __FUNCTION__, dn->full_name);
	list_for_each_entry (dev, &bus->devices, bus_list)
	dbg("\t%s\n", pci_name(dev));
	return;
	}

	int rpaphp_config_pci_adapter(struct pci_bus *bus)
	{
	struct device_node *dn = pci_bus_to_OF_node(bus);
	struct pci_dev *dev;
	int rc = -ENODEV;

	dbg("Entry %s: slot[%s]\n", __FUNCTION__, dn->full_name);
	if (!dn)
	goto exit;

	rpaphp_eeh_init_nodes(dn);
	dev = rpaphp_pci_config_slot(bus);
	if (!dev) {
	err("%s: can't find any devices.\n", __FUNCTION__);
	goto exit;
	}
	print_slot_pci_funcs(bus);
	rc = 0;
	exit:
	dbg("Exit %s: rc=%d\n", __FUNCTION__, rc);
	return rc;
	}
	EXPORT_SYMBOL_GPL(rpaphp_config_pci_adapter);

	static void rpaphp_eeh_remove_bus_device(struct pci_dev *dev)
	{
	eeh_remove_device(dev);
	if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
	struct pci_bus *bus = dev->subordinate;
	struct list_head *ln;
	if (!bus)
	return;
	for (ln = bus->devices.next; ln != &bus->devices; ln = ln->next) {
	struct pci_dev *pdev = pci_dev_b(ln);
	if (pdev)
	rpaphp_eeh_remove_bus_device(pdev);
	}

	}
	return;
	}

	int rpaphp_unconfig_pci_adapter(struct pci_bus *bus)
	{
	struct pci_dev dev, tmp;

	list_for_each_entry_safe(dev, tmp, &bus->devices, bus_list) {
	rpaphp_eeh_remove_bus_device(dev);
	pci_remove_bus_device(dev);
	}
	return 0;
	}
	EXPORT_SYMBOL_GPL(rpaphp_unconfig_pci_adapter);

	static int setup_pci_hotplug_slot_info(struct slot *slot)
	{
	dbg("%s Initilize the PCI slot's hotplug->info structure ...\n",
	__FUNCTION__);
	rpaphp_get_power_status(slot, &slot->hotplug_slot->info->power_status);
	rpaphp_get_pci_adapter_status(slot, 1,
	&slot->hotplug_slot->info->
	adapter_status);
	if (slot->hotplug_slot->info->adapter_status == NOT_VALID) {
	err("%s: NOT_VALID: skip dn->full_name=%s\n",
	__FUNCTION__, slot->dn->full_name);
	return -EINVAL;
	}
	return 0;
	}

	static void set_slot_name(struct slot *slot)
	{
	struct pci_bus *bus = slot->bus;
	struct pci_dev *bridge;

	bridge = bus->self;
	if (bridge)
	strcpy(slot->name, pci_name(bridge));
	else
	sprintf(slot->name, "%04x:%02x:00.0", pci_domain_nr(bus),
	bus->number);
	}

	static int setup_pci_slot(struct slot *slot)
	{
	struct device_node *dn = slot->dn;
	struct pci_bus *bus;

	BUG_ON(!dn);
	bus = rpaphp_find_pci_bus(dn);
	if (!bus) {
	err("%s: no pci_bus for dn %s\n", __FUNCTION__, dn->full_name);
	goto exit_rc;
	}

	slot->bus = bus;
	slot->pci_devs = &bus->devices;
	set_slot_name(slot);

	/* find slot's pci_dev if it's not empty */
	if (slot->hotplug_slot->info->adapter_status == EMPTY) {
	slot->state = EMPTY; /* slot is empty */
	} else {
	/* slot is occupied */
	if (!dn->child) {
	/* non-empty slot has to have child */
	err("%s: slot[%s]'s device_node doesn't have child for adapter\n",
	__FUNCTION__, slot->name);
	goto exit_rc;
	}

	if (slot->hotplug_slot->info->adapter_status == NOT_CONFIGURED) {
	dbg("%s CONFIGURING pci adapter in slot[%s]\n",
	__FUNCTION__, slot->name);
	if (rpaphp_config_pci_adapter(slot->bus)) {
	err("%s: CONFIG pci adapter failed\n", __FUNCTION__);
	goto exit_rc;
	}

	} else if (slot->hotplug_slot->info->adapter_status != CONFIGURED) {
	err("%s: slot[%s]'s adapter_status is NOT_VALID.\n",
	__FUNCTION__, slot->name);
	goto exit_rc;
	}
	print_slot_pci_funcs(slot->bus);
	if (!list_empty(slot->pci_devs)) {
	slot->state = CONFIGURED;
	} else {
	/* DLPAR add as opposed to
	* boot time */
	slot->state = NOT_CONFIGURED;
	}
	}
	return 0;
	exit_rc:
	dealloc_slot_struct(slot);
	return -EINVAL;
	}

	int register_pci_slot(struct slot *slot)
	{
	int rc = -EINVAL;

	if (setup_pci_hotplug_slot_info(slot))
	goto exit_rc;
	if (setup_pci_slot(slot))
	goto exit_rc;
	rc = register_slot(slot);
	exit_rc:
	return rc;
	}

	int rpaphp_enable_pci_slot(struct slot *slot)
	{
	int retval = 0, state;

	retval = rpaphp_get_sensor_state(slot, &state);
	if (retval)
	goto exit;
	dbg("%s: sensor state[%d]\n", __FUNCTION__, state);
	/* if slot is not empty, enable the adapter */
	if (state == PRESENT) {
	dbg("%s : slot[%s] is occupied.\n", __FUNCTION__, slot->name);
	retval = rpaphp_config_pci_adapter(slot->bus);
	if (!retval) {
	slot->state = CONFIGURED;
	info("%s: devices in slot[%s] configured\n",
	__FUNCTION__, slot->name);
	} else {
	slot->state = NOT_CONFIGURED;
	dbg("%s: no pci_dev struct for adapter in slot[%s]\n",
	__FUNCTION__, slot->name);
	}
	} else if (state == EMPTY) {
	dbg("%s : slot[%s] is empty\n", __FUNCTION__, slot->name);
	slot->state = EMPTY;
	} else {
	err("%s: slot[%s] is in invalid state\n", __FUNCTION__,
	slot->name);
	slot->state = NOT_VALID;
	retval = -EINVAL;
	}
	exit:
	dbg("%s - Exit: rc[%d]\n", __FUNCTION__, retval);
	return retval;
	}