path: root/drivers/pci/pci-driver.c

/*
 * drivers/pci/pci-driver.c
 *
 * (C) Copyright 2002-2004, 2007 Greg Kroah-Hartman <greg@kroah.com>
 * (C) Copyright 2007 Novell Inc.
 *
 * Released under the GPL v2 only.
 *
 */

#include <linux/pci.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/mempolicy.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include "pci.h"

/*
 * Dynamic device IDs are disabled for !CONFIG_HOTPLUG
 */

struct pci_dynid {
	struct list_head node;
	struct pci_device_id id;
};

#ifdef CONFIG_HOTPLUG

/**
 * store_new_id - add a new PCI device ID to this driver and re-probe devices
 * @driver: target device driver
 * @buf: buffer for scanning device ID data
 * @count: input size
 *
 * Adds a new dynamic pci device ID to this driver,
 * and causes the driver to probe for all devices again.
 */
static ssize_t
store_new_id(struct device_driver *driver, const char *buf, size_t count)
{
	struct pci_dynid *dynid;
	struct pci_driver *pdrv = to_pci_driver(driver);
	__u32 vendor, device, subvendor=PCI_ANY_ID,
		subdevice=PCI_ANY_ID, class=0, class_mask=0;
	unsigned long driver_data=0;
	int fields=0;
	int retval = 0;

	fields = sscanf(buf, "%x %x %x %x %x %x %lux",
			&vendor, &device, &subvendor, &subdevice,
			&class, &class_mask, &driver_data);
	if (fields < 2)
		return -EINVAL;

	dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
	if (!dynid)
		return -ENOMEM;

	dynid->id.vendor = vendor;
	dynid->id.device = device;
	dynid->id.subvendor = subvendor;
	dynid->id.subdevice = subdevice;
	dynid->id.class = class;
	dynid->id.class_mask = class_mask;
	dynid->id.driver_data = pdrv->dynids.use_driver_data ?
		driver_data : 0UL;

	spin_lock(&pdrv->dynids.lock);
	list_add_tail(&dynid->node, &pdrv->dynids.list);
	spin_unlock(&pdrv->dynids.lock);

	if (get_driver(&pdrv->driver)) {
		retval = driver_attach(&pdrv->driver);
		put_driver(&pdrv->driver);
	}

	if (retval)
		return retval;
	return count;
}
static DRIVER_ATTR(new_id, S_IWUSR, NULL, store_new_id);

static void
pci_free_dynids(struct pci_driver *drv)
{
	struct pci_dynid *dynid, *n;

	spin_lock(&drv->dynids.lock);
	list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
		list_del(&dynid->node);
		kfree(dynid);
	}
	spin_unlock(&drv->dynids.lock);
}

static int
pci_create_newid_file(struct pci_driver *drv)
{
	int error = 0;
	if (drv->probe != NULL)
		error = driver_create_file(&drv->driver, &driver_attr_new_id);
	return error;
}

static void pci_remove_newid_file(struct pci_driver *drv)
{
	driver_remove_file(&drv->driver, &driver_attr_new_id);
}
#else /* !CONFIG_HOTPLUG */
static inline void pci_free_dynids(struct pci_driver *drv) {}
static inline int pci_create_newid_file(struct pci_driver *drv)
{
	return 0;
}
static inline void pci_remove_newid_file(struct pci_driver *drv) {}
#endif

/**
 * pci_match_id - See if a pci device matches a given pci_id table
 * @ids: array of PCI device id structures to search in
 * @dev: the PCI device structure to match against.
 *
 * Used by a driver to check whether a PCI device present in the
 * system is in its list of supported devices.  Returns the matching
 * pci_device_id structure or %NULL if there is no match.
 *
 * Deprecated, don't use this as it will not catch any dynamic ids
 * that a driver might want to check for.
 */
const struct pci_device_id *pci_match_id(const struct pci_device_id *ids,
					 struct pci_dev *dev)
{
	if (ids) {
		while (ids->vendor || ids->subvendor || ids->class_mask) {
			if (pci_match_one_device(ids, dev))
				return ids;
			ids++;
		}
	}
	return NULL;
}

/**
 * pci_match_device - Tell if a PCI device structure has a matching PCI device id structure
 * @drv: the PCI driver to match against
 * @dev: the PCI device structure to match against
 *
 * Used by a driver to check whether a PCI device present in the
 * system is in its list of supported devices.  Returns the matching
 * pci_device_id structure or %NULL if there is no match.
 */
static const struct pci_device_id *pci_match_device(struct pci_driver *drv,
						    struct pci_dev *dev)
{
	struct pci_dynid *dynid;

	/* Look at the dynamic ids first, before the static ones */
	spin_lock(&drv->dynids.lock);
	list_for_each_entry(dynid, &drv->dynids.list, node) {
		if (pci_match_one_device(&dynid->id, dev)) {
			spin_unlock(&drv->dynids.lock);
			return &dynid->id;
		}
	}
	spin_unlock(&drv->dynids.lock);

	return pci_match_id(drv->id_table, dev);
}

static int pci_call_probe(struct pci_driver *drv, struct pci_dev *dev,
			  const struct pci_device_id *id)
{
	int error;
#ifdef CONFIG_NUMA
	/* Execute driver initialization on node where the
	   device's bus is attached to.  This way the driver likely
	   allocates its local memory on the right node without
	   any need to change it. */
	struct mempolicy *oldpol;
	cpumask_t oldmask = current->cpus_allowed;
	int node = pcibus_to_node(dev->bus);
	if (node >= 0 && node_online(node))
	    set_cpus_allowed(current, node_to_cpumask(node));
	/* And set default memory allocation policy */
	oldpol = current->mempolicy;
	current->mempolicy = NULL;	/* fall back to system default policy */
#endif
	error = drv->probe(dev, id);
#ifdef CONFIG_NUMA
	set_cpus_allowed(current, oldmask);
	current->mempolicy = oldpol;
#endif
	return error;
}

/**
 * __pci_device_probe()
 * @drv: driver to call to check if it wants the PCI device
 * @pci_dev: PCI device being probed
 * 
 * returns 0 on success, else error.
 * side-effect: pci_dev->driver is set to drv when drv claims pci_dev.
 */
static int
__pci_device_probe(struct pci_driver *drv, struct pci_dev *pci_dev)
{
	const struct pci_device_id *id;
	int error = 0;

	if (!pci_dev->driver && drv->probe) {
		error = -ENODEV;

		id = pci_match_device(drv, pci_dev);
		if (id)
			error = pci_call_probe(drv, pci_dev, id);
		if (error >= 0) {
			pci_dev->driver = drv;
			error = 0;
		}
	}
	return error;
}

static int pci_device_probe(struct device * dev)
{
	int error = 0;
	struct pci_driver *drv;
	struct pci_dev *pci_dev;

	drv = to_pci_driver(dev->driver);
	pci_dev = to_pci_dev(dev);
	pci_dev_get(pci_dev);
	error = __pci_device_probe(drv, pci_dev);
	if (error)
		pci_dev_put(pci_dev);

	return error;
}

static int pci_device_remove(struct device * dev)
{
	struct pci_dev * pci_dev = to_pci_dev(dev);
	struct pci_driver * drv = pci_dev->driver;

	if (drv) {
		if (drv->remove)
			drv->remove(pci_dev);
		pci_dev->driver = NULL;
	}

	/*
	 * If the device is still on, set the power state as "unknown",
	 * since it might change by the next time we load the driver.