/*
 * PCI HotPlug Utility functions
 *
 * Copyright (c) 1995,2001 Compaq Computer Corporation
 * Copyright (c) 2001 Greg Kroah-Hartman (greg@kroah.com)
 * Copyright (c) 2001 IBM Corp.
 *
 * 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 <greg@kroah.com>
 *
 */

#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/pci.h>
#include "pci_hotplug.h"


#if !defined(CONFIG_HOTPLUG_PCI_MODULE)
	#define MY_NAME	"pci_hotplug"
#else
	#define MY_NAME	THIS_MODULE->name
#endif

#define dbg(fmt, arg...) do { if (debug) printk(KERN_DEBUG "%s: %s: " fmt , MY_NAME , __FUNCTION__ , ## arg); } while (0)
#define err(format, arg...) printk(KERN_ERR "%s: " format , MY_NAME , ## arg)
#define info(format, arg...) printk(KERN_INFO "%s: " format , MY_NAME , ## arg)
#define warn(format, arg...) printk(KERN_WARNING "%s: " format , MY_NAME , ## arg)


/* local variables */
static int debug;


/*
 * This is code that scans the pci buses.
 * Every bus and every function is presented to a custom
 * function that can act upon it.
 */

static int pci_visit_bus (struct pci_visit * fn, struct pci_bus_wrapped *wrapped_bus, struct pci_dev_wrapped *wrapped_parent)
{
	struct list_head *ln;
	struct pci_dev *dev;
	struct pci_dev_wrapped wrapped_dev;
	int result = 0;

	dbg("scanning bus %02x\n", wrapped_bus->bus->number);

	if (fn->pre_visit_pci_bus) {
		result = fn->pre_visit_pci_bus(wrapped_bus, wrapped_parent);
		if (result)
			return result;
	}

	ln = wrapped_bus->bus->devices.next; 
	while (ln != &wrapped_bus->bus->devices) {
		dev = pci_dev_b(ln);
		ln = ln->next;

		memset(&wrapped_dev, 0, sizeof(struct pci_dev_wrapped));
		wrapped_dev.dev = dev;

		result = pci_visit_dev(fn, &wrapped_dev, wrapped_bus);
		if (result)
			return result;
	}

	if (fn->post_visit_pci_bus)
		result = fn->post_visit_pci_bus(wrapped_bus, wrapped_parent);

	return result;
}


static int pci_visit_bridge (struct pci_visit * fn, struct pci_dev_wrapped *wrapped_dev, struct pci_bus_wrapped *wrapped_parent)
{
	struct pci_bus *bus;
	struct pci_bus_wrapped wrapped_bus;
	int result = 0;

	dbg("scanning bridge %02x, %02x\n", PCI_SLOT(wrapped_dev->dev->devfn),
	    PCI_FUNC(wrapped_dev->dev->devfn));

	if (fn->visit_pci_dev) {
		result = fn->visit_pci_dev(wrapped_dev, wrapped_parent);
		if (result)
			return result;
	}

	bus = wrapped_dev->dev->subordinate;
	if(bus) {
		memset(&wrapped_bus, 0, sizeof(struct pci_bus_wrapped));
		wrapped_bus.bus = bus;

		result = pci_visit_bus(fn, &wrapped_bus, wrapped_dev);
	}
	return result;
}


int pci_visit_dev (struct pci_visit *fn, struct pci_dev_wrapped *wrapped_dev, struct pci_bus_wrapped *wrapped_parent)
{
	struct pci_dev* dev = wrapped_dev ? wrapped_dev->dev : NULL;
	int result = 0;

	if (!dev)
		return 0;

	if (fn->pre_visit_pci_dev) {
		result = fn->pre_visit_pci_dev(wrapped_dev, wrapped_parent);
		if (result)
			return result;
	}

	switch (dev->class >> 8) {
		case PCI_CLASS_BRIDGE_PCI:
			result = pci_visit_bridge(fn, wrapped_dev,
						  wrapped_parent);
			if (result)
				return result;
			break;
		default:
			dbg("scanning device %02x, %02x\n",
			    PCI_SLOT(dev->devfn), PCI_FUNC(dev->devfn));
			if (fn->visit_pci_dev) {
				result = fn->visit_pci_dev (wrapped_dev,
							    wrapped_parent);
				if (result)
					return result;
			}
	}

	if (fn->post_visit_pci_dev)
		result = fn->post_visit_pci_dev(wrapped_dev, wrapped_parent);

	return result;
}

/**
 * pci_is_dev_in_use - query devices' usage
 * @dev: PCI device to query
 *
 * Queries whether a given PCI device is in use by a driver or not.
 * Returns 1 if the device is in use, 0 if it is not.
 */
int pci_is_dev_in_use(struct pci_dev *dev)
{
	/* 
	 * dev->driver will be set if the device is in use by a new-style 
	 * driver -- otherwise, check the device's regions to see if any
	 * driver has claimed them.
	 */

	int i;
	int inuse = 0;

	if (dev->driver) {
		/* Assume driver feels responsible */
		return 1;
	}

	for (i = 0; !dev->driver && !inuse && (i < 6); i++) {
		if (!pci_resource_start(dev, i))
			continue;
		if (pci_resource_flags(dev, i) & IORESOURCE_IO) {
			inuse = check_region(pci_resource_start(dev, i),
					     pci_resource_len(dev, i));
		} else if (pci_resource_flags(dev, i) & IORESOURCE_MEM) {
			inuse = check_mem_region(pci_resource_start(dev, i),
						 pci_resource_len(dev, i));
		}
	}
	return inuse;
}

/**
 * pci_remove_device_safe - remove an unused hotplug device
 * @dev: the device to remove
 *
 * Delete the device structure from the device lists and 
 * notify userspace (/sbin/hotplug), but only if the device
 * in question is not being used by a driver.
 * Returns 0 on success.
 */
int pci_remove_device_safe(struct pci_dev *dev)
{
	if (pci_is_dev_in_use(dev)) {
		return -EBUSY;
	}
	pci_remove_device(dev);
	return 0;
}

EXPORT_SYMBOL(pci_visit_dev);
EXPORT_SYMBOL(pci_is_dev_in_use);
EXPORT_SYMBOL(pci_remove_device_safe);