probe.c

来自「linux 内核源代码」· C语言 代码 · 共 1,257 行 · 第 1/3 页

	if (pci_read_config_dword(dev, 256, &status) != PCIBIOS_SUCCESSFUL)
		goto fail;
	if (status == 0xffffffff)
		goto fail;

	return PCI_CFG_SPACE_EXP_SIZE;

 fail:
	return PCI_CFG_SPACE_SIZE;
}

static void pci_release_bus_bridge_dev(struct device *dev)
{
	kfree(dev);
}

struct pci_dev *alloc_pci_dev(void)
{
	struct pci_dev *dev;

	dev = kzalloc(sizeof(struct pci_dev), GFP_KERNEL);
	if (!dev)
		return NULL;

	INIT_LIST_HEAD(&dev->global_list);
	INIT_LIST_HEAD(&dev->bus_list);

	pci_msi_init_pci_dev(dev);

	return dev;
}
EXPORT_SYMBOL(alloc_pci_dev);

/*
 * Read the config data for a PCI device, sanity-check it
 * and fill in the dev structure...
 */
static struct pci_dev * __devinit
pci_scan_device(struct pci_bus *bus, int devfn)
{
	struct pci_dev *dev;
	u32 l;
	u8 hdr_type;
	int delay = 1;

	if (pci_bus_read_config_dword(bus, devfn, PCI_VENDOR_ID, &l))
		return NULL;

	/* some broken boards return 0 or ~0 if a slot is empty: */
	if (l == 0xffffffff || l == 0x00000000 ||
	    l == 0x0000ffff || l == 0xffff0000)
		return NULL;

	/* Configuration request Retry Status */
	while (l == 0xffff0001) {
		msleep(delay);
		delay *= 2;
		if (pci_bus_read_config_dword(bus, devfn, PCI_VENDOR_ID, &l))
			return NULL;
		/* Card hasn't responded in 60 seconds?  Must be stuck. */
		if (delay > 60 * 1000) {
			printk(KERN_WARNING "Device %04x:%02x:%02x.%d not "
					"responding\n", pci_domain_nr(bus),
					bus->number, PCI_SLOT(devfn),
					PCI_FUNC(devfn));
			return NULL;
		}
	}

	if (pci_bus_read_config_byte(bus, devfn, PCI_HEADER_TYPE, &hdr_type))
		return NULL;

	dev = alloc_pci_dev();
	if (!dev)
		return NULL;

	dev->bus = bus;
	dev->sysdata = bus->sysdata;
	dev->dev.parent = bus->bridge;
	dev->dev.bus = &pci_bus_type;
	dev->devfn = devfn;
	dev->hdr_type = hdr_type & 0x7f;
	dev->multifunction = !!(hdr_type & 0x80);
	dev->vendor = l & 0xffff;
	dev->device = (l >> 16) & 0xffff;
	dev->cfg_size = pci_cfg_space_size(dev);
	dev->error_state = pci_channel_io_normal;
	set_pcie_port_type(dev);

	/* Assume 32-bit PCI; let 64-bit PCI cards (which are far rarer)
	   set this higher, assuming the system even supports it.  */
	dev->dma_mask = 0xffffffff;
	if (pci_setup_device(dev) < 0) {
		kfree(dev);
		return NULL;
	}

	return dev;
}

void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
{
	device_initialize(&dev->dev);
	dev->dev.release = pci_release_dev;
	pci_dev_get(dev);

	set_dev_node(&dev->dev, pcibus_to_node(bus));
	dev->dev.dma_mask = &dev->dma_mask;
	dev->dev.coherent_dma_mask = 0xffffffffull;

	/* Fix up broken headers */
	pci_fixup_device(pci_fixup_header, dev);

	/*
	 * Add the device to our list of discovered devices
	 * and the bus list for fixup functions, etc.
	 */
	INIT_LIST_HEAD(&dev->global_list);
	down_write(&pci_bus_sem);
	list_add_tail(&dev->bus_list, &bus->devices);
	up_write(&pci_bus_sem);
}

struct pci_dev *pci_scan_single_device(struct pci_bus *bus, int devfn)
{
	struct pci_dev *dev;

	dev = pci_scan_device(bus, devfn);
	if (!dev)
		return NULL;

	pci_device_add(dev, bus);

	return dev;
}

/**
 * pci_scan_slot - scan a PCI slot on a bus for devices.
 * @bus: PCI bus to scan
 * @devfn: slot number to scan (must have zero function.)
 *
 * Scan a PCI slot on the specified PCI bus for devices, adding
 * discovered devices to the @bus->devices list.  New devices
 * will have an empty dev->global_list head.
 */
int pci_scan_slot(struct pci_bus *bus, int devfn)
{
	int func, nr = 0;
	int scan_all_fns;

	scan_all_fns = pcibios_scan_all_fns(bus, devfn);

	for (func = 0; func < 8; func++, devfn++) {
		struct pci_dev *dev;

		dev = pci_scan_single_device(bus, devfn);
		if (dev) {
			nr++;

			/*
		 	 * If this is a single function device,
		 	 * don't scan past the first function.
		 	 */
			if (!dev->multifunction) {
				if (func > 0) {
					dev->multifunction = 1;
				} else {
 					break;
				}
			}
		} else {
			if (func == 0 && !scan_all_fns)
				break;
		}
	}
	return nr;
}

unsigned int pci_scan_child_bus(struct pci_bus *bus)
{
	unsigned int devfn, pass, max = bus->secondary;
	struct pci_dev *dev;

	pr_debug("PCI: Scanning bus %04x:%02x\n", pci_domain_nr(bus), bus->number);

	/* Go find them, Rover! */
	for (devfn = 0; devfn < 0x100; devfn += 8)
		pci_scan_slot(bus, devfn);

	/*
	 * After performing arch-dependent fixup of the bus, look behind
	 * all PCI-to-PCI bridges on this bus.
	 */
	pr_debug("PCI: Fixups for bus %04x:%02x\n", pci_domain_nr(bus), bus->number);
	pcibios_fixup_bus(bus);
	for (pass=0; pass < 2; pass++)
		list_for_each_entry(dev, &bus->devices, bus_list) {
			if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE ||
			    dev->hdr_type == PCI_HEADER_TYPE_CARDBUS)
				max = pci_scan_bridge(bus, dev, max, pass);
		}

	/*
	 * We've scanned the bus and so we know all about what's on
	 * the other side of any bridges that may be on this bus plus
	 * any devices.
	 *
	 * Return how far we've got finding sub-buses.
	 */
	pr_debug("PCI: Bus scan for %04x:%02x returning with max=%02x\n",
		pci_domain_nr(bus), bus->number, max);
	return max;
}

unsigned int __devinit pci_do_scan_bus(struct pci_bus *bus)
{
	unsigned int max;

	max = pci_scan_child_bus(bus);

	/*
	 * Make the discovered devices available.
	 */
	pci_bus_add_devices(bus);

	return max;
}

struct pci_bus * pci_create_bus(struct device *parent,
		int bus, struct pci_ops *ops, void *sysdata)
{
	int error;
	struct pci_bus *b;
	struct device *dev;

	b = pci_alloc_bus();
	if (!b)
		return NULL;

	dev = kmalloc(sizeof(*dev), GFP_KERNEL);
	if (!dev){
		kfree(b);
		return NULL;
	}

	b->sysdata = sysdata;
	b->ops = ops;

	if (pci_find_bus(pci_domain_nr(b), bus)) {
		/* If we already got to this bus through a different bridge, ignore it */
		pr_debug("PCI: Bus %04x:%02x already known\n", pci_domain_nr(b), bus);
		goto err_out;
	}

	down_write(&pci_bus_sem);
	list_add_tail(&b->node, &pci_root_buses);
	up_write(&pci_bus_sem);

	memset(dev, 0, sizeof(*dev));
	dev->parent = parent;
	dev->release = pci_release_bus_bridge_dev;
	sprintf(dev->bus_id, "pci%04x:%02x", pci_domain_nr(b), bus);
	error = device_register(dev);
	if (error)
		goto dev_reg_err;
	b->bridge = get_device(dev);

	b->class_dev.class = &pcibus_class;
	sprintf(b->class_dev.class_id, "%04x:%02x", pci_domain_nr(b), bus);
	error = class_device_register(&b->class_dev);
	if (error)
		goto class_dev_reg_err;
	error = class_device_create_file(&b->class_dev, &class_device_attr_cpuaffinity);
	if (error)
		goto class_dev_create_file_err;

	/* Create legacy_io and legacy_mem files for this bus */
	pci_create_legacy_files(b);

	error = sysfs_create_link(&b->class_dev.kobj, &b->bridge->kobj, "bridge");
	if (error)
		goto sys_create_link_err;

	b->number = b->secondary = bus;
	b->resource[0] = &ioport_resource;
	b->resource[1] = &iomem_resource;

	return b;

sys_create_link_err:
	class_device_remove_file(&b->class_dev, &class_device_attr_cpuaffinity);
class_dev_create_file_err:
	class_device_unregister(&b->class_dev);
class_dev_reg_err:
	device_unregister(dev);
dev_reg_err:
	down_write(&pci_bus_sem);
	list_del(&b->node);
	up_write(&pci_bus_sem);
err_out:
	kfree(dev);
	kfree(b);
	return NULL;
}
EXPORT_SYMBOL_GPL(pci_create_bus);

struct pci_bus *pci_scan_bus_parented(struct device *parent,
		int bus, struct pci_ops *ops, void *sysdata)
{
	struct pci_bus *b;

	b = pci_create_bus(parent, bus, ops, sysdata);
	if (b)
		b->subordinate = pci_scan_child_bus(b);
	return b;
}
EXPORT_SYMBOL(pci_scan_bus_parented);

#ifdef CONFIG_HOTPLUG
EXPORT_SYMBOL(pci_add_new_bus);
EXPORT_SYMBOL(pci_do_scan_bus);
EXPORT_SYMBOL(pci_scan_slot);
EXPORT_SYMBOL(pci_scan_bridge);
EXPORT_SYMBOL(pci_scan_single_device);
EXPORT_SYMBOL_GPL(pci_scan_child_bus);
#endif

static int __init pci_sort_bf_cmp(const struct pci_dev *a, const struct pci_dev *b)
{
	if      (pci_domain_nr(a->bus) < pci_domain_nr(b->bus)) return -1;
	else if (pci_domain_nr(a->bus) > pci_domain_nr(b->bus)) return  1;

	if      (a->bus->number < b->bus->number) return -1;
	else if (a->bus->number > b->bus->number) return  1;

	if      (a->devfn < b->devfn) return -1;
	else if (a->devfn > b->devfn) return  1;

	return 0;
}

/*
 * Yes, this forcably breaks the klist abstraction temporarily.  It
 * just wants to sort the klist, not change reference counts and
 * take/drop locks rapidly in the process.  It does all this while
 * holding the lock for the list, so objects can't otherwise be
 * added/removed while we're swizzling.
 */
static void __init pci_insertion_sort_klist(struct pci_dev *a, struct list_head *list)
{
	struct list_head *pos;
	struct klist_node *n;
	struct device *dev;
	struct pci_dev *b;

	list_for_each(pos, list) {
		n = container_of(pos, struct klist_node, n_node);
		dev = container_of(n, struct device, knode_bus);
		b = to_pci_dev(dev);
		if (pci_sort_bf_cmp(a, b) <= 0) {
			list_move_tail(&a->dev.knode_bus.n_node, &b->dev.knode_bus.n_node);
			return;
		}
	}
	list_move_tail(&a->dev.knode_bus.n_node, list);
}

static void __init pci_sort_breadthfirst_klist(void)
{
	LIST_HEAD(sorted_devices);
	struct list_head *pos, *tmp;
	struct klist_node *n;
	struct device *dev;
	struct pci_dev *pdev;

	spin_lock(&pci_bus_type.klist_devices.k_lock);
	list_for_each_safe(pos, tmp, &pci_bus_type.klist_devices.k_list) {
		n = container_of(pos, struct klist_node, n_node);
		dev = container_of(n, struct device, knode_bus);
		pdev = to_pci_dev(dev);
		pci_insertion_sort_klist(pdev, &sorted_devices);
	}
	list_splice(&sorted_devices, &pci_bus_type.klist_devices.k_list);
	spin_unlock(&pci_bus_type.klist_devices.k_lock);
}

static void __init pci_insertion_sort_devices(struct pci_dev *a, struct list_head *list)
{
	struct pci_dev *b;

	list_for_each_entry(b, list, global_list) {
		if (pci_sort_bf_cmp(a, b) <= 0) {
			list_move_tail(&a->global_list, &b->global_list);
			return;
		}
	}
	list_move_tail(&a->global_list, list);
}

static void __init pci_sort_breadthfirst_devices(void)
{
	LIST_HEAD(sorted_devices);
	struct pci_dev *dev, *tmp;

	down_write(&pci_bus_sem);
	list_for_each_entry_safe(dev, tmp, &pci_devices, global_list) {
		pci_insertion_sort_devices(dev, &sorted_devices);
	}
	list_splice(&sorted_devices, &pci_devices);
	up_write(&pci_bus_sem);
}

void __init pci_sort_breadthfirst(void)
{
	pci_sort_breadthfirst_devices();
	pci_sort_breadthfirst_klist();
}