probe.c

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	/*
	 * Set up the primary, secondary and subordinate
	 * bus numbers.
	 */
	child->number = child->secondary = busnr;
	child->primary = parent->secondary;
	child->subordinate = 0xff;

	/* Set up default resource pointers and names.. */
	for (i = 0; i < 4; i++) {
		child->resource[i] = &bridge->resource[PCI_BRIDGE_RESOURCES+i];
		child->resource[i]->name = child->name;
	}
	bridge->subordinate = child;

	return child;

error_file_create:
	class_device_unregister(&child->class_dev);
error_register:
	kfree(child);
	return NULL;
}

struct pci_bus *pci_add_new_bus(struct pci_bus *parent, struct pci_dev *dev, int busnr)
{
	struct pci_bus *child;

	child = pci_alloc_child_bus(parent, dev, busnr);
	if (child) {
		down_write(&pci_bus_sem);
		list_add_tail(&child->node, &parent->children);
		up_write(&pci_bus_sem);
	}
	return child;
}

static void pci_fixup_parent_subordinate_busnr(struct pci_bus *child, int max)
{
	struct pci_bus *parent = child->parent;

	/* Attempts to fix that up are really dangerous unless
	   we're going to re-assign all bus numbers. */
	if (!pcibios_assign_all_busses())
		return;

	while (parent->parent && parent->subordinate < max) {
		parent->subordinate = max;
		pci_write_config_byte(parent->self, PCI_SUBORDINATE_BUS, max);
		parent = parent->parent;
	}
}

unsigned int pci_scan_child_bus(struct pci_bus *bus);

/*
 * If it's a bridge, configure it and scan the bus behind it.
 * For CardBus bridges, we don't scan behind as the devices will
 * be handled by the bridge driver itself.
 *
 * We need to process bridges in two passes -- first we scan those
 * already configured by the BIOS and after we are done with all of
 * them, we proceed to assigning numbers to the remaining buses in
 * order to avoid overlaps between old and new bus numbers.
 */
int pci_scan_bridge(struct pci_bus *bus, struct pci_dev * dev, int max, int pass)
{
	struct pci_bus *child;
	int is_cardbus = (dev->hdr_type == PCI_HEADER_TYPE_CARDBUS);
	u32 buses, i, j = 0;
	u16 bctl;

	pci_read_config_dword(dev, PCI_PRIMARY_BUS, &buses);

	pr_debug("PCI: Scanning behind PCI bridge %s, config %06x, pass %d\n",
		 pci_name(dev), buses & 0xffffff, pass);

	/* Disable MasterAbortMode during probing to avoid reporting
	   of bus errors (in some architectures) */ 
	pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &bctl);
	pci_write_config_word(dev, PCI_BRIDGE_CONTROL,
			      bctl & ~PCI_BRIDGE_CTL_MASTER_ABORT);

	if ((buses & 0xffff00) && !pcibios_assign_all_busses() && !is_cardbus) {
		unsigned int cmax, busnr;
		/*
		 * Bus already configured by firmware, process it in the first
		 * pass and just note the configuration.
		 */
		if (pass)
			goto out;
		busnr = (buses >> 8) & 0xFF;

		/*
		 * If we already got to this bus through a different bridge,
		 * ignore it.  This can happen with the i450NX chipset.
		 */
		if (pci_find_bus(pci_domain_nr(bus), busnr)) {
			printk(KERN_INFO "PCI: Bus %04x:%02x already known\n",
					pci_domain_nr(bus), busnr);
			goto out;
		}

		child = pci_add_new_bus(bus, dev, busnr);
		if (!child)
			goto out;
		child->primary = buses & 0xFF;
		child->subordinate = (buses >> 16) & 0xFF;
		child->bridge_ctl = bctl;

		cmax = pci_scan_child_bus(child);
		if (cmax > max)
			max = cmax;
		if (child->subordinate > max)
			max = child->subordinate;
	} else {
		/*
		 * We need to assign a number to this bus which we always
		 * do in the second pass.
		 */
		if (!pass) {
			if (pcibios_assign_all_busses())
				/* Temporarily disable forwarding of the
				   configuration cycles on all bridges in
				   this bus segment to avoid possible
				   conflicts in the second pass between two
				   bridges programmed with overlapping
				   bus ranges. */
				pci_write_config_dword(dev, PCI_PRIMARY_BUS,
						       buses & ~0xffffff);
			goto out;
		}

		/* Clear errors */
		pci_write_config_word(dev, PCI_STATUS, 0xffff);

		/* Prevent assigning a bus number that already exists.
		 * This can happen when a bridge is hot-plugged */
		if (pci_find_bus(pci_domain_nr(bus), max+1))
			goto out;
		child = pci_add_new_bus(bus, dev, ++max);
		buses = (buses & 0xff000000)
		      | ((unsigned int)(child->primary)     <<  0)
		      | ((unsigned int)(child->secondary)   <<  8)
		      | ((unsigned int)(child->subordinate) << 16);

		/*
		 * yenta.c forces a secondary latency timer of 176.
		 * Copy that behaviour here.
		 */
		if (is_cardbus) {
			buses &= ~0xff000000;
			buses |= CARDBUS_LATENCY_TIMER << 24;
		}
			
		/*
		 * We need to blast all three values with a single write.
		 */
		pci_write_config_dword(dev, PCI_PRIMARY_BUS, buses);

		if (!is_cardbus) {
			child->bridge_ctl = bctl;
			/*
			 * Adjust subordinate busnr in parent buses.
			 * We do this before scanning for children because
			 * some devices may not be detected if the bios
			 * was lazy.
			 */
			pci_fixup_parent_subordinate_busnr(child, max);
			/* Now we can scan all subordinate buses... */
			max = pci_scan_child_bus(child);
			/*
			 * now fix it up again since we have found
			 * the real value of max.
			 */
			pci_fixup_parent_subordinate_busnr(child, max);
		} else {
			/*
			 * For CardBus bridges, we leave 4 bus numbers
			 * as cards with a PCI-to-PCI bridge can be
			 * inserted later.
			 */
			for (i=0; i<CARDBUS_RESERVE_BUSNR; i++) {
				struct pci_bus *parent = bus;
				if (pci_find_bus(pci_domain_nr(bus),
							max+i+1))
					break;
				while (parent->parent) {
					if ((!pcibios_assign_all_busses()) &&
					    (parent->subordinate > max) &&
					    (parent->subordinate <= max+i)) {
						j = 1;
					}
					parent = parent->parent;
				}
				if (j) {
					/*
					 * Often, there are two cardbus bridges
					 * -- try to leave one valid bus number
					 * for each one.
					 */
					i /= 2;
					break;
				}
			}
			max += i;
			pci_fixup_parent_subordinate_busnr(child, max);
		}
		/*
		 * Set the subordinate bus number to its real value.
		 */
		child->subordinate = max;
		pci_write_config_byte(dev, PCI_SUBORDINATE_BUS, max);
	}

	sprintf(child->name, (is_cardbus ? "PCI CardBus #%02x" : "PCI Bus #%02x"), child->number);

	/* Has only triggered on CardBus, fixup is in yenta_socket */
	while (bus->parent) {
		if ((child->subordinate > bus->subordinate) ||
		    (child->number > bus->subordinate) ||
		    (child->number < bus->number) ||
		    (child->subordinate < bus->number)) {
			pr_debug("PCI: Bus #%02x (-#%02x) is %s"
				"hidden behind%s bridge #%02x (-#%02x)\n",
				child->number, child->subordinate,
				(bus->number > child->subordinate &&
				 bus->subordinate < child->number) ?
					"wholly " : " partially",
				bus->self->transparent ? " transparent" : " ",
				bus->number, bus->subordinate);
		}
		bus = bus->parent;
	}

out:
	pci_write_config_word(dev, PCI_BRIDGE_CONTROL, bctl);

	return max;
}

/*
 * Read interrupt line and base address registers.
 * The architecture-dependent code can tweak these, of course.
 */
static void pci_read_irq(struct pci_dev *dev)
{
	unsigned char irq;

	pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &irq);
	dev->pin = irq;
	if (irq)
		pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &irq);
	dev->irq = irq;
}

#define LEGACY_IO_RESOURCE	(IORESOURCE_IO | IORESOURCE_PCI_FIXED)

/**
 * pci_setup_device - fill in class and map information of a device
 * @dev: the device structure to fill
 *
 * Initialize the device structure with information about the device's 
 * vendor,class,memory and IO-space addresses,IRQ lines etc.
 * Called at initialisation of the PCI subsystem and by CardBus services.
 * Returns 0 on success and -1 if unknown type of device (not normal, bridge
 * or CardBus).
 */
static int pci_setup_device(struct pci_dev * dev)
{
	u32 class;

	sprintf(pci_name(dev), "%04x:%02x:%02x.%d", pci_domain_nr(dev->bus),
		dev->bus->number, PCI_SLOT(dev->devfn), PCI_FUNC(dev->devfn));

	pci_read_config_dword(dev, PCI_CLASS_REVISION, &class);
	dev->revision = class & 0xff;
	class >>= 8;				    /* upper 3 bytes */
	dev->class = class;
	class >>= 8;

	pr_debug("PCI: Found %s [%04x/%04x] %06x %02x\n", pci_name(dev),
		 dev->vendor, dev->device, class, dev->hdr_type);

	/* "Unknown power state" */
	dev->current_state = PCI_UNKNOWN;

	/* Early fixups, before probing the BARs */
	pci_fixup_device(pci_fixup_early, dev);
	class = dev->class >> 8;

	switch (dev->hdr_type) {		    /* header type */
	case PCI_HEADER_TYPE_NORMAL:		    /* standard header */
		if (class == PCI_CLASS_BRIDGE_PCI)
			goto bad;
		pci_read_irq(dev);
		pci_read_bases(dev, 6, PCI_ROM_ADDRESS);
		pci_read_config_word(dev, PCI_SUBSYSTEM_VENDOR_ID, &dev->subsystem_vendor);
		pci_read_config_word(dev, PCI_SUBSYSTEM_ID, &dev->subsystem_device);

		/*
		 *	Do the ugly legacy mode stuff here rather than broken chip
		 *	quirk code. Legacy mode ATA controllers have fixed
		 *	addresses. These are not always echoed in BAR0-3, and
		 *	BAR0-3 in a few cases contain junk!
		 */
		if (class == PCI_CLASS_STORAGE_IDE) {
			u8 progif;
			pci_read_config_byte(dev, PCI_CLASS_PROG, &progif);
			if ((progif & 1) == 0) {
				dev->resource[0].start = 0x1F0;
				dev->resource[0].end = 0x1F7;
				dev->resource[0].flags = LEGACY_IO_RESOURCE;
				dev->resource[1].start = 0x3F6;
				dev->resource[1].end = 0x3F6;
				dev->resource[1].flags = LEGACY_IO_RESOURCE;
			}
			if ((progif & 4) == 0) {
				dev->resource[2].start = 0x170;
				dev->resource[2].end = 0x177;
				dev->resource[2].flags = LEGACY_IO_RESOURCE;
				dev->resource[3].start = 0x376;
				dev->resource[3].end = 0x376;
				dev->resource[3].flags = LEGACY_IO_RESOURCE;
			}
		}
		break;

	case PCI_HEADER_TYPE_BRIDGE:		    /* bridge header */
		if (class != PCI_CLASS_BRIDGE_PCI)
			goto bad;
		/* The PCI-to-PCI bridge spec requires that subtractive
		   decoding (i.e. transparent) bridge must have programming
		   interface code of 0x01. */ 
		pci_read_irq(dev);
		dev->transparent = ((dev->class & 0xff) == 1);
		pci_read_bases(dev, 2, PCI_ROM_ADDRESS1);
		break;

	case PCI_HEADER_TYPE_CARDBUS:		    /* CardBus bridge header */
		if (class != PCI_CLASS_BRIDGE_CARDBUS)
			goto bad;
		pci_read_irq(dev);
		pci_read_bases(dev, 1, 0);
		pci_read_config_word(dev, PCI_CB_SUBSYSTEM_VENDOR_ID, &dev->subsystem_vendor);
		pci_read_config_word(dev, PCI_CB_SUBSYSTEM_ID, &dev->subsystem_device);
		break;

	default:				    /* unknown header */
		printk(KERN_ERR "PCI: device %s has unknown header type %02x, ignoring.\n",
			pci_name(dev), dev->hdr_type);
		return -1;

	bad:
		printk(KERN_ERR "PCI: %s: class %x doesn't match header type %02x. Ignoring class.\n",
		       pci_name(dev), class, dev->hdr_type);
		dev->class = PCI_CLASS_NOT_DEFINED;
	}

	/* We found a fine healthy device, go go go... */
	return 0;
}

/**
 * pci_release_dev - free a pci device structure when all users of it are finished.
 * @dev: device that's been disconnected
 *
 * Will be called only by the device core when all users of this pci device are
 * done.
 */
static void pci_release_dev(struct device *dev)
{
	struct pci_dev *pci_dev;

	pci_dev = to_pci_dev(dev);
	kfree(pci_dev);
}

static void set_pcie_port_type(struct pci_dev *pdev)
{
	int pos;
	u16 reg16;

	pos = pci_find_capability(pdev, PCI_CAP_ID_EXP);
	if (!pos)
		return;
	pdev->is_pcie = 1;
	pci_read_config_word(pdev, pos + PCI_EXP_FLAGS, &reg16);
	pdev->pcie_type = (reg16 & PCI_EXP_FLAGS_TYPE) >> 4;
}

/**
 * pci_cfg_space_size - get the configuration space size of the PCI device.
 * @dev: PCI device
 *
 * Regular PCI devices have 256 bytes, but PCI-X 2 and PCI Express devices
 * have 4096 bytes.  Even if the device is capable, that doesn't mean we can
 * access it.  Maybe we don't have a way to generate extended config space
 * accesses, or the device is behind a reverse Express bridge.  So we try
 * reading the dword at 0x100 which must either be 0 or a valid extended
 * capability header.
 */
int pci_cfg_space_size(struct pci_dev *dev)
{
	int pos;
	u32 status;

	pos = pci_find_capability(dev, PCI_CAP_ID_EXP);
	if (!pos) {
		pos = pci_find_capability(dev, PCI_CAP_ID_PCIX);
		if (!pos)
			goto fail;

		pci_read_config_dword(dev, pos + PCI_X_STATUS, &status);
		if (!(status & (PCI_X_STATUS_266MHZ | PCI_X_STATUS_533MHZ)))
			goto fail;
	}