Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1739 insertions, 0 deletions

diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
new file mode 100644
index 0000000000..51ec9e7e78
--- /dev/null
+++ b/drivers/pci/pci-driver.c
@@ -0,0 +1,1739 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * (C) Copyright 2002-2004, 2007 Greg Kroah-Hartman <greg@kroah.com>
+ * (C) Copyright 2007 Novell Inc.
+ */
+
+#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 <linux/sched/isolation.h>
+#include <linux/cpu.h>
+#include <linux/pm_runtime.h>
+#include <linux/suspend.h>
+#include <linux/kexec.h>
+#include <linux/of_device.h>
+#include <linux/acpi.h>
+#include <linux/dma-map-ops.h>
+#include <linux/iommu.h>
+#include "pci.h"
+#include "pcie/portdrv.h"
+
+struct pci_dynid {
+	struct list_head node;
+	struct pci_device_id id;
+};
+
+/**
+ * pci_add_dynid - add a new PCI device ID to this driver and re-probe devices
+ * @drv: target pci driver
+ * @vendor: PCI vendor ID
+ * @device: PCI device ID
+ * @subvendor: PCI subvendor ID
+ * @subdevice: PCI subdevice ID
+ * @class: PCI class
+ * @class_mask: PCI class mask
+ * @driver_data: private driver data
+ *
+ * Adds a new dynamic pci device ID to this driver and causes the
+ * driver to probe for all devices again.  @drv must have been
+ * registered prior to calling this function.
+ *
+ * CONTEXT:
+ * Does GFP_KERNEL allocation.
+ *
+ * RETURNS:
+ * 0 on success, -errno on failure.
+ */
+int pci_add_dynid(struct pci_driver *drv,
+		  unsigned int vendor, unsigned int device,
+		  unsigned int subvendor, unsigned int subdevice,
+		  unsigned int class, unsigned int class_mask,
+		  unsigned long driver_data)
+{
+	struct pci_dynid *dynid;
+
+	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 = driver_data;
+
+	spin_lock(&drv->dynids.lock);
+	list_add_tail(&dynid->node, &drv->dynids.list);
+	spin_unlock(&drv->dynids.lock);
+
+	return driver_attach(&drv->driver);
+}
+EXPORT_SYMBOL_GPL(pci_add_dynid);
+
+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);
+}
+
+/**
+ * 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 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;
+}
+EXPORT_SYMBOL(pci_match_id);
+
+static const struct pci_device_id pci_device_id_any = {
+	.vendor = PCI_ANY_ID,
+	.device = PCI_ANY_ID,
+	.subvendor = PCI_ANY_ID,
+	.subdevice = PCI_ANY_ID,
+};
+
+/**
+ * pci_match_device - See if a device matches a driver's list of IDs
+ * @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 is in its list of
+ * supported devices or in the dynids list, which may have been augmented
+ * via the sysfs "new_id" file.  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;
+	const struct pci_device_id *found_id = NULL, *ids;
+
+	/* When driver_override is set, only bind to the matching driver */
+	if (dev->driver_override && strcmp(dev->driver_override, drv->name))
+		return NULL;
+
+	/* 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)) {
+			found_id = &dynid->id;
+			break;
+		}
+	}
+	spin_unlock(&drv->dynids.lock);
+
+	if (found_id)
+		return found_id;
+
+	for (ids = drv->id_table; (found_id = pci_match_id(ids, dev));
+	     ids = found_id + 1) {
+		/*
+		 * The match table is split based on driver_override.
+		 * In case override_only was set, enforce driver_override
+		 * matching.
+		 */
+		if (found_id->override_only) {
+			if (dev->driver_override)
+				return found_id;
+		} else {
+			return found_id;
+		}
+	}
+
+	/* driver_override will always match, send a dummy id */
+	if (dev->driver_override)
+		return &pci_device_id_any;
+	return NULL;
+}
+
+/**
+ * new_id_store - sysfs frontend to pci_add_dynid()
+ * @driver: target device driver
+ * @buf: buffer for scanning device ID data
+ * @count: input size
+ *
+ * Allow PCI IDs to be added to an existing driver via sysfs.
+ */
+static ssize_t new_id_store(struct device_driver *driver, const char *buf,
+			    size_t count)
+{
+	struct pci_driver *pdrv = to_pci_driver(driver);
+	const struct pci_device_id *ids = pdrv->id_table;
+	u32 vendor, device, subvendor = PCI_ANY_ID,
+		subdevice = PCI_ANY_ID, class = 0, class_mask = 0;
+	unsigned long driver_data = 0;
+	int fields;
+	int retval = 0;
+
+	fields = sscanf(buf, "%x %x %x %x %x %x %lx",
+			&vendor, &device, &subvendor, &subdevice,
+			&class, &class_mask, &driver_data);
+	if (fields < 2)
+		return -EINVAL;
+
+	if (fields != 7) {
+		struct pci_dev *pdev = kzalloc(sizeof(*pdev), GFP_KERNEL);
+		if (!pdev)
+			return -ENOMEM;
+
+		pdev->vendor = vendor;
+		pdev->device = device;
+		pdev->subsystem_vendor = subvendor;
+		pdev->subsystem_device = subdevice;
+		pdev->class = class;
+
+		if (pci_match_device(pdrv, pdev))
+			retval = -EEXIST;
+
+		kfree(pdev);
+
+		if (retval)
+			return retval;
+	}
+
+	/* Only accept driver_data values that match an existing id_table
+	   entry */
+	if (ids) {
+		retval = -EINVAL;
+		while (ids->vendor || ids->subvendor || ids->class_mask) {
+			if (driver_data == ids->driver_data) {
+				retval = 0;
+				break;
+			}
+			ids++;
+		}
+		if (retval)	/* No match */
+			return retval;
+	}
+
+	retval = pci_add_dynid(pdrv, vendor, device, subvendor, subdevice,
+			       class, class_mask, driver_data);
+	if (retval)
+		return retval;
+	return count;
+}
+static DRIVER_ATTR_WO(new_id);
+
+/**
+ * remove_id_store - remove a PCI device ID from this driver
+ * @driver: target device driver
+ * @buf: buffer for scanning device ID data
+ * @count: input size
+ *
+ * Removes a dynamic pci device ID to this driver.
+ */
+static ssize_t remove_id_store(struct device_driver *driver, const char *buf,
+			       size_t count)
+{
+	struct pci_dynid *dynid, *n;
+	struct pci_driver *pdrv = to_pci_driver(driver);
+	u32 vendor, device, subvendor = PCI_ANY_ID,
+		subdevice = PCI_ANY_ID, class = 0, class_mask = 0;
+	int fields;
+	size_t retval = -ENODEV;
+
+	fields = sscanf(buf, "%x %x %x %x %x %x",
+			&vendor, &device, &subvendor, &subdevice,
+			&class, &class_mask);
+	if (fields < 2)
+		return -EINVAL;
+
+	spin_lock(&pdrv->dynids.lock);
+	list_for_each_entry_safe(dynid, n, &pdrv->dynids.list, node) {
+		struct pci_device_id *id = &dynid->id;
+		if ((id->vendor == vendor) &&
+		    (id->device == device) &&
+		    (subvendor == PCI_ANY_ID || id->subvendor == subvendor) &&
+		    (subdevice == PCI_ANY_ID || id->subdevice == subdevice) &&
+		    !((id->class ^ class) & class_mask)) {
+			list_del(&dynid->node);
+			kfree(dynid);
+			retval = count;
+			break;
+		}
+	}
+	spin_unlock(&pdrv->dynids.lock);
+
+	return retval;
+}
+static DRIVER_ATTR_WO(remove_id);
+
+static struct attribute *pci_drv_attrs[] = {
+	&driver_attr_new_id.attr,
+	&driver_attr_remove_id.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(pci_drv);
+
+struct drv_dev_and_id {
+	struct pci_driver *drv;
+	struct pci_dev *dev;
+	const struct pci_device_id *id;
+};
+
+static long local_pci_probe(void *_ddi)
+{
+	struct drv_dev_and_id *ddi = _ddi;
+	struct pci_dev *pci_dev = ddi->dev;
+	struct pci_driver *pci_drv = ddi->drv;
+	struct device *dev = &pci_dev->dev;
+	int rc;
+
+	/*
+	 * Unbound PCI devices are always put in D0, regardless of
+	 * runtime PM status.  During probe, the device is set to
+	 * active and the usage count is incremented.  If the driver
+	 * supports runtime PM, it should call pm_runtime_put_noidle(),
+	 * or any other runtime PM helper function decrementing the usage
+	 * count, in its probe routine and pm_runtime_get_noresume() in
+	 * its remove routine.
+	 */
+	pm_runtime_get_sync(dev);
+	pci_dev->driver = pci_drv;
+	rc = pci_drv->probe(pci_dev, ddi->id);
+	if (!rc)
+		return rc;
+	if (rc < 0) {
+		pci_dev->driver = NULL;
+		pm_runtime_put_sync(dev);
+		return rc;
+	}
+	/*
+	 * Probe function should return < 0 for failure, 0 for success
+	 * Treat values > 0 as success, but warn.
+	 */
+	pci_warn(pci_dev, "Driver probe function unexpectedly returned %d\n",
+		 rc);
+	return 0;
+}
+
+static bool pci_physfn_is_probed(struct pci_dev *dev)
+{
+#ifdef CONFIG_PCI_IOV
+	return dev->is_virtfn && dev->physfn->is_probed;
+#else
+	return false;
+#endif
+}
+
+static int pci_call_probe(struct pci_driver *drv, struct pci_dev *dev,
+			  const struct pci_device_id *id)
+{
+	int error, node, cpu;
+	struct drv_dev_and_id ddi = { drv, dev, id };
+
+	/*
+	 * Execute driver initialization on node where the device is
+	 * attached.  This way the driver likely allocates its local memory
+	 * on the right node.
+	 */
+	node = dev_to_node(&dev->dev);
+	dev->is_probed = 1;
+
+	cpu_hotplug_disable();
+
+	/*
+	 * Prevent nesting work_on_cpu() for the case where a Virtual Function
+	 * device is probed from work_on_cpu() of the Physical device.
+	 */
+	if (node < 0 || node >= MAX_NUMNODES || !node_online(node) ||
+	    pci_physfn_is_probed(dev)) {
+		cpu = nr_cpu_ids;
+	} else {
+		cpumask_var_t wq_domain_mask;
+
+		if (!zalloc_cpumask_var(&wq_domain_mask, GFP_KERNEL)) {
+			error = -ENOMEM;
+			goto out;
+		}
+		cpumask_and(wq_domain_mask,
+			    housekeeping_cpumask(HK_TYPE_WQ),
+			    housekeeping_cpumask(HK_TYPE_DOMAIN));
+
+		cpu = cpumask_any_and(cpumask_of_node(node),
+				      wq_domain_mask);
+		free_cpumask_var(wq_domain_mask);
+	}
+
+	if (cpu < nr_cpu_ids)
+		error = work_on_cpu(cpu, local_pci_probe, &ddi);
+	else
+		error = local_pci_probe(&ddi);
+out:
+	dev->is_probed = 0;
+	cpu_hotplug_enable();
+	return error;
+}
+
+/**
+ * __pci_device_probe - check if a driver wants to claim a specific PCI device
+ * @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 (drv->probe) {
+		error = -ENODEV;
+
+		id = pci_match_device(drv, pci_dev);
+		if (id)
+			error = pci_call_probe(drv, pci_dev, id);
+	}
+	return error;
+}
+
+int __weak pcibios_alloc_irq(struct pci_dev *dev)
+{
+	return 0;
+}
+
+void __weak pcibios_free_irq(struct pci_dev *dev)
+{
+}
+
+#ifdef CONFIG_PCI_IOV
+static inline bool pci_device_can_probe(struct pci_dev *pdev)
+{
+	return (!pdev->is_virtfn || pdev->physfn->sriov->drivers_autoprobe ||
+		pdev->driver_override);
+}
+#else
+static inline bool pci_device_can_probe(struct pci_dev *pdev)
+{
+	return true;
+}
+#endif
+
+static int pci_device_probe(struct device *dev)
+{
+	int error;
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	struct pci_driver *drv = to_pci_driver(dev->driver);
+
+	if (!pci_device_can_probe(pci_dev))
+		return -ENODEV;
+
+	pci_assign_irq(pci_dev);
+
+	error = pcibios_alloc_irq(pci_dev);
+	if (error < 0)
+		return error;
+
+	pci_dev_get(pci_dev);
+	error = __pci_device_probe(drv, pci_dev);
+	if (error) {
+		pcibios_free_irq(pci_dev);
+		pci_dev_put(pci_dev);
+	}
+
+	return error;
+}
+
+static void pci_device_remove(struct device *dev)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	struct pci_driver *drv = pci_dev->driver;
+
+	if (drv->remove) {
+		pm_runtime_get_sync(dev);
+		drv->remove(pci_dev);
+		pm_runtime_put_noidle(dev);
+	}
+	pcibios_free_irq(pci_dev);
+	pci_dev->driver = NULL;
+	pci_iov_remove(pci_dev);
+
+	/* Undo the runtime PM settings in local_pci_probe() */
+	pm_runtime_put_sync(dev);
+
+	/*
+	 * If the device is still on, set the power state as "unknown",
+	 * since it might change by the next time we load the driver.
+	 */
+	if (pci_dev->current_state == PCI_D0)
+		pci_dev->current_state = PCI_UNKNOWN;
+
+	/*
+	 * We would love to complain here if pci_dev->is_enabled is set, that
+	 * the driver should have called pci_disable_device(), but the
+	 * unfortunate fact is there are too many odd BIOS and bridge setups
+	 * that don't like drivers doing that all of the time.
+	 * Oh well, we can dream of sane hardware when we sleep, no matter how
+	 * horrible the crap we have to deal with is when we are awake...
+	 */
+
+	pci_dev_put(pci_dev);
+}
+
+static void pci_device_shutdown(struct device *dev)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	struct pci_driver *drv = pci_dev->driver;
+
+	pm_runtime_resume(dev);
+
+	if (drv && drv->shutdown)
+		drv->shutdown(pci_dev);
+
+	/*
+	 * If this is a kexec reboot, turn off Bus Master bit on the
+	 * device to tell it to not continue to do DMA. Don't touch
+	 * devices in D3cold or unknown states.
+	 * If it is not a kexec reboot, firmware will hit the PCI
+	 * devices with big hammer and stop their DMA any way.
+	 */
+	if (kexec_in_progress && (pci_dev->current_state <= PCI_D3hot))
+		pci_clear_master(pci_dev);
+}
+
+#ifdef CONFIG_PM_SLEEP
+
+/* Auxiliary functions used for system resume */
+
+/**
+ * pci_restore_standard_config - restore standard config registers of PCI device
+ * @pci_dev: PCI device to handle
+ */
+static int pci_restore_standard_config(struct pci_dev *pci_dev)
+{
+	pci_update_current_state(pci_dev, PCI_UNKNOWN);
+
+	if (pci_dev->current_state != PCI_D0) {
+		int error = pci_set_power_state(pci_dev, PCI_D0);
+		if (error)
+			return error;
+	}
+
+	pci_restore_state(pci_dev);
+	pci_pme_restore(pci_dev);
+	return 0;
+}
+#endif /* CONFIG_PM_SLEEP */
+
+#ifdef CONFIG_PM
+
+/* Auxiliary functions used for system resume and run-time resume */
+
+static void pci_pm_default_resume(struct pci_dev *pci_dev)
+{
+	pci_fixup_device(pci_fixup_resume, pci_dev);
+	pci_enable_wake(pci_dev, PCI_D0, false);
+}
+
+static void pci_pm_power_up_and_verify_state(struct pci_dev *pci_dev)
+{
+	pci_power_up(pci_dev);
+	pci_update_current_state(pci_dev, PCI_D0);
+}
+
+static void pci_pm_default_resume_early(struct pci_dev *pci_dev)
+{
+	pci_pm_power_up_and_verify_state(pci_dev);
+	pci_restore_state(pci_dev);
+	pci_pme_restore(pci_dev);
+}
+
+static void pci_pm_bridge_power_up_actions(struct pci_dev *pci_dev)
+{
+	int ret;
+
+	ret = pci_bridge_wait_for_secondary_bus(pci_dev, "resume");
+	if (ret) {
+		/*
+		 * The downstream link failed to come up, so mark the
+		 * devices below as disconnected to make sure we don't
+		 * attempt to resume them.
+		 */
+		pci_walk_bus(pci_dev->subordinate, pci_dev_set_disconnected,
+			     NULL);
+		return;
+	}
+
+	/*
+	 * When powering on a bridge from D3cold, the whole hierarchy may be
+	 * powered on into D0uninitialized state, resume them to give them a
+	 * chance to suspend again
+	 */
+	pci_resume_bus(pci_dev->subordinate);
+}
+
+#endif /* CONFIG_PM */
+
+#ifdef CONFIG_PM_SLEEP
+
+/*
+ * Default "suspend" method for devices that have no driver provided suspend,
+ * or not even a driver at all (second part).
+ */
+static void pci_pm_set_unknown_state(struct pci_dev *pci_dev)
+{
+	/*
+	 * mark its power state as "unknown", since we don't know if
+	 * e.g. the BIOS will change its device state when we suspend.
+	 */
+	if (pci_dev->current_state == PCI_D0)
+		pci_dev->current_state = PCI_UNKNOWN;
+}
+
+/*
+ * Default "resume" method for devices that have no driver provided resume,
+ * or not even a driver at all (second part).
+ */
+static int pci_pm_reenable_device(struct pci_dev *pci_dev)
+{
+	int retval;
+
+	/* if the device was enabled before suspend, re-enable */
+	retval = pci_reenable_device(pci_dev);
+	/*
+	 * if the device was busmaster before the suspend, make it busmaster
+	 * again
+	 */
+	if (pci_dev->is_busmaster)
+		pci_set_master(pci_dev);
+
+	return retval;
+}
+
+static int pci_legacy_suspend(struct device *dev, pm_message_t state)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	struct pci_driver *drv = pci_dev->driver;
+
+	if (drv && drv->suspend) {
+		pci_power_t prev = pci_dev->current_state;
+		int error;
+
+		error = drv->suspend(pci_dev, state);
+		suspend_report_result(dev, drv->suspend, error);
+		if (error)
+			return error;
+
+		if (!pci_dev->state_saved && pci_dev->current_state != PCI_D0
+		    && pci_dev->current_state != PCI_UNKNOWN) {
+			pci_WARN_ONCE(pci_dev, pci_dev->current_state != prev,
+				      "PCI PM: Device state not saved by %pS\n",
+				      drv->suspend);
+		}
+	}
+
+	pci_fixup_device(pci_fixup_suspend, pci_dev);
+
+	return 0;
+}
+
+static int pci_legacy_suspend_late(struct device *dev)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+
+	if (!pci_dev->state_saved)
+		pci_save_state(pci_dev);
+
+	pci_pm_set_unknown_state(pci_dev);
+
+	pci_fixup_device(pci_fixup_suspend_late, pci_dev);
+
+	return 0;
+}
+
+static int pci_legacy_resume(struct device *dev)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	struct pci_driver *drv = pci_dev->driver;
+
+	pci_fixup_device(pci_fixup_resume, pci_dev);
+
+	return drv && drv->resume ?
+			drv->resume(pci_dev) : pci_pm_reenable_device(pci_dev);
+}
+
+/* Auxiliary functions used by the new power management framework */
+
+static void pci_pm_default_suspend(struct pci_dev *pci_dev)
+{
+	/* Disable non-bridge devices without PM support */
+	if (!pci_has_subordinate(pci_dev))
+		pci_disable_enabled_device(pci_dev);
+}
+
+static bool pci_has_legacy_pm_support(struct pci_dev *pci_dev)
+{
+	struct pci_driver *drv = pci_dev->driver;
+	bool ret = drv && (drv->suspend || drv->resume);
+
+	/*
+	 * Legacy PM support is used by default, so warn if the new framework is
+	 * supported as well.  Drivers are supposed to support either the
+	 * former, or the latter, but not both at the same time.
+	 */
+	pci_WARN(pci_dev, ret && drv->driver.pm, "device %04x:%04x\n",
+		 pci_dev->vendor, pci_dev->device);
+
+	return ret;
+}
+
+/* New power management framework */
+
+static int pci_pm_prepare(struct device *dev)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+
+	if (pm && pm->prepare) {
+		int error = pm->prepare(dev);
+		if (error < 0)
+			return error;
+
+		if (!error && dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_PREPARE))
+			return 0;
+	}
+	if (pci_dev_need_resume(pci_dev))
+		return 0;
+
+	/*
+	 * The PME setting needs to be adjusted here in case the direct-complete
+	 * optimization is used with respect to this device.
+	 */
+	pci_dev_adjust_pme(pci_dev);
+	return 1;
+}
+
+static void pci_pm_complete(struct device *dev)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+
+	pci_dev_complete_resume(pci_dev);
+	pm_generic_complete(dev);
+
+	/* Resume device if platform firmware has put it in reset-power-on */
+	if (pm_runtime_suspended(dev) && pm_resume_via_firmware()) {
+		pci_power_t pre_sleep_state = pci_dev->current_state;
+
+		pci_refresh_power_state(pci_dev);
+		/*
+		 * On platforms with ACPI this check may also trigger for
+		 * devices sharing power resources if one of those power
+		 * resources has been activated as a result of a change of the
+		 * power state of another device sharing it.  However, in that
+		 * case it is also better to resume the device, in general.
+		 */
+		if (pci_dev->current_state < pre_sleep_state)
+			pm_request_resume(dev);
+	}
+}
+
+#else /* !CONFIG_PM_SLEEP */
+
+#define pci_pm_prepare	NULL
+#define pci_pm_complete	NULL
+
+#endif /* !CONFIG_PM_SLEEP */
+
+#ifdef CONFIG_SUSPEND
+static void pcie_pme_root_status_cleanup(struct pci_dev *pci_dev)
+{
+	/*
+	 * Some BIOSes forget to clear Root PME Status bits after system
+	 * wakeup, which breaks ACPI-based runtime wakeup on PCI Express.
+	 * Clear those bits now just in case (shouldn't hurt).
+	 */
+	if (pci_is_pcie(pci_dev) &&
+	    (pci_pcie_type(pci_dev) == PCI_EXP_TYPE_ROOT_PORT ||
+	     pci_pcie_type(pci_dev) == PCI_EXP_TYPE_RC_EC))
+		pcie_clear_root_pme_status(pci_dev);
+}
+
+static int pci_pm_suspend(struct device *dev)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+
+	pci_dev->skip_bus_pm = false;
+
+	/*
+	 * Disabling PTM allows some systems, e.g., Intel mobile chips
+	 * since Coffee Lake, to enter a lower-power PM state.
+	 */
+	pci_suspend_ptm(pci_dev);
+
+	if (pci_has_legacy_pm_support(pci_dev))
+		return pci_legacy_suspend(dev, PMSG_SUSPEND);
+
+	if (!pm) {
+		pci_pm_default_suspend(pci_dev);
+		return 0;
+	}
+
+	/*
+	 * PCI devices suspended at run time may need to be resumed at this
+	 * point, because in general it may be necessary to reconfigure them for
+	 * system suspend.  Namely, if the device is expected to wake up the
+	 * system from the sleep state, it may have to be reconfigured for this
+	 * purpose, or if the device is not expected to wake up the system from
+	 * the sleep state, it should be prevented from signaling wakeup events
+	 * going forward.
+	 *
+	 * Also if the driver of the device does not indicate that its system
+	 * suspend callbacks can cope with runtime-suspended devices, it is
+	 * better to resume the device from runtime suspend here.
+	 */
+	if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) ||
+	    pci_dev_need_resume(pci_dev)) {
+		pm_runtime_resume(dev);
+		pci_dev->state_saved = false;
+	} else {
+		pci_dev_adjust_pme(pci_dev);
+	}
+
+	if (pm->suspend) {
+		pci_power_t prev = pci_dev->current_state;
+		int error;
+
+		error = pm->suspend(dev);
+		suspend_report_result(dev, pm->suspend, error);
+		if (error)
+			return error;
+
+		if (!pci_dev->state_saved && pci_dev->current_state != PCI_D0
+		    && pci_dev->current_state != PCI_UNKNOWN) {
+			pci_WARN_ONCE(pci_dev, pci_dev->current_state != prev,
+				      "PCI PM: State of device not saved by %pS\n",
+				      pm->suspend);
+		}
+	}
+
+	return 0;
+}
+
+static int pci_pm_suspend_late(struct device *dev)
+{
+	if (dev_pm_skip_suspend(dev))
+		return 0;
+
+	pci_fixup_device(pci_fixup_suspend, to_pci_dev(dev));
+
+	return pm_generic_suspend_late(dev);
+}
+
+static int pci_pm_suspend_noirq(struct device *dev)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+
+	if (dev_pm_skip_suspend(dev))
+		return 0;
+
+	if (pci_has_legacy_pm_support(pci_dev))
+		return pci_legacy_suspend_late(dev);
+
+	if (!pm) {
+		pci_save_state(pci_dev);
+		goto Fixup;
+	}
+
+	if (pm->suspend_noirq) {
+		pci_power_t prev = pci_dev->current_state;
+		int error;
+
+		error = pm->suspend_noirq(dev);
+		suspend_report_result(dev, pm->suspend_noirq, error);
+		if (error)
+			return error;
+
+		if (!pci_dev->state_saved && pci_dev->current_state != PCI_D0
+		    && pci_dev->current_state != PCI_UNKNOWN) {
+			pci_WARN_ONCE(pci_dev, pci_dev->current_state != prev,
+				      "PCI PM: State of device not saved by %pS\n",
+				      pm->suspend_noirq);
+			goto Fixup;
+		}
+	}
+
+	if (!pci_dev->state_saved) {
+		pci_save_state(pci_dev);
+
+		/*
+		 * If the device is a bridge with a child in D0 below it,
+		 * it needs to stay in D0, so check skip_bus_pm to avoid
+		 * putting it into a low-power state in that case.
+		 */
+		if (!pci_dev->skip_bus_pm && pci_power_manageable(pci_dev))
+			pci_prepare_to_sleep(pci_dev);
+	}
+
+	pci_dbg(pci_dev, "PCI PM: Suspend power state: %s\n",
+		pci_power_name(pci_dev->current_state));
+
+	if (pci_dev->current_state == PCI_D0) {
+		pci_dev->skip_bus_pm = true;
+		/*
+		 * Per PCI PM r1.2, table 6-1, a bridge must be in D0 if any
+		 * downstream device is in D0, so avoid changing the power state
+		 * of the parent bridge by setting the skip_bus_pm flag for it.
+		 */
+		if (pci_dev->bus->self)
+			pci_dev->bus->self->skip_bus_pm = true;
+	}
+
+	if (pci_dev->skip_bus_pm && pm_suspend_no_platform()) {
+		pci_dbg(pci_dev, "PCI PM: Skipped\n");
+		goto Fixup;
+	}
+
+	pci_pm_set_unknown_state(pci_dev);
+
+	/*
+	 * Some BIOSes from ASUS have a bug: If a USB EHCI host controller's
+	 * PCI COMMAND register isn't 0, the BIOS assumes that the controller
+	 * hasn't been quiesced and tries to turn it off.  If the controller
+	 * is already in D3, this can hang or cause memory corruption.
+	 *
+	 * Since the value of the COMMAND register doesn't matter once the
+	 * device has been suspended, we can safely set it to 0 here.
+	 */
+	if (pci_dev->class == PCI_CLASS_SERIAL_USB_EHCI)
+		pci_write_config_word(pci_dev, PCI_COMMAND, 0);
+
+Fixup:
+	pci_fixup_device(pci_fixup_suspend_late, pci_dev);
+
+	/*
+	 * If the target system sleep state is suspend-to-idle, it is sufficient
+	 * to check whether or not the device's wakeup settings are good for
+	 * runtime PM.  Otherwise, the pm_resume_via_firmware() check will cause
+	 * pci_pm_complete() to take care of fixing up the device's state
+	 * anyway, if need be.
+	 */
+	if (device_can_wakeup(dev) && !device_may_wakeup(dev))
+		dev->power.may_skip_resume = false;
+
+	return 0;
+}
+
+static int pci_pm_resume_noirq(struct device *dev)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+	pci_power_t prev_state = pci_dev->current_state;
+	bool skip_bus_pm = pci_dev->skip_bus_pm;
+
+	if (dev_pm_skip_resume(dev))
+		return 0;
+
+	/*
+	 * In the suspend-to-idle case, devices left in D0 during suspend will
+	 * stay in D0, so it is not necessary to restore or update their
+	 * configuration here and attempting to put them into D0 again is
+	 * pointless, so avoid doing that.
+	 */
+	if (!(skip_bus_pm && pm_suspend_no_platform()))
+		pci_pm_default_resume_early(pci_dev);
+
+	pci_fixup_device(pci_fixup_resume_early, pci_dev);
+	pcie_pme_root_status_cleanup(pci_dev);
+
+	if (!skip_bus_pm && prev_state == PCI_D3cold)
+		pci_pm_bridge_power_up_actions(pci_dev);
+
+	if (pci_has_legacy_pm_support(pci_dev))
+		return 0;
+
+	if (pm && pm->resume_noirq)
+		return pm->resume_noirq(dev);
+
+	return 0;
+}
+
+static int pci_pm_resume_early(struct device *dev)
+{
+	if (dev_pm_skip_resume(dev))
+		return 0;
+
+	return pm_generic_resume_early(dev);
+}
+
+static int pci_pm_resume(struct device *dev)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+
+	/*
+	 * This is necessary for the suspend error path in which resume is
+	 * called without restoring the standard config registers of the device.
+	 */
+	if (pci_dev->state_saved)
+		pci_restore_standard_config(pci_dev);
+
+	pci_resume_ptm(pci_dev);
+
+	if (pci_has_legacy_pm_support(pci_dev))
+		return pci_legacy_resume(dev);
+
+	pci_pm_default_resume(pci_dev);
+
+	if (pm) {
+		if (pm->resume)
+			return pm->resume(dev);
+	} else {
+		pci_pm_reenable_device(pci_dev);
+	}
+
+	return 0;
+}
+
+#else /* !CONFIG_SUSPEND */
+
+#define pci_pm_suspend		NULL
+#define pci_pm_suspend_late	NULL
+#define pci_pm_suspend_noirq	NULL
+#define pci_pm_resume		NULL
+#define pci_pm_resume_early	NULL
+#define pci_pm_resume_noirq	NULL
+
+#endif /* !CONFIG_SUSPEND */
+
+#ifdef CONFIG_HIBERNATE_CALLBACKS
+
+static int pci_pm_freeze(struct device *dev)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+
+	if (pci_has_legacy_pm_support(pci_dev))
+		return pci_legacy_suspend(dev, PMSG_FREEZE);
+
+	if (!pm) {
+		pci_pm_default_suspend(pci_dev);
+		return 0;
+	}
+
+	/*
+	 * Resume all runtime-suspended devices before creating a snapshot
+	 * image of system memory, because the restore kernel generally cannot
+	 * be expected to always handle them consistently and they need to be
+	 * put into the runtime-active metastate during system resume anyway,
+	 * so it is better to ensure that the state saved in the image will be
+	 * always consistent with that.
+	 */
+	pm_runtime_resume(dev);
+	pci_dev->state_saved = false;
+
+	if (pm->freeze) {
+		int error;
+
+		error = pm->freeze(dev);
+		suspend_report_result(dev, pm->freeze, error);
+		if (error)
+			return error;
+	}
+
+	return 0;
+}
+
+static int pci_pm_freeze_noirq(struct device *dev)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+
+	if (pci_has_legacy_pm_support(pci_dev))
+		return pci_legacy_suspend_late(dev);
+
+	if (pm && pm->freeze_noirq) {
+		int error;
+
+		error = pm->freeze_noirq(dev);
+		suspend_report_result(dev, pm->freeze_noirq, error);
+		if (error)
+			return error;
+	}
+
+	if (!pci_dev->state_saved)
+		pci_save_state(pci_dev);
+
+	pci_pm_set_unknown_state(pci_dev);
+
+	return 0;
+}
+
+static int pci_pm_thaw_noirq(struct device *dev)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+
+	/*
+	 * The pm->thaw_noirq() callback assumes the device has been
+	 * returned to D0 and its config state has been restored.
+	 *
+	 * In addition, pci_restore_state() restores MSI-X state in MMIO
+	 * space, which requires the device to be in D0, so return it to D0
+	 * in case the driver's "freeze" callbacks put it into a low-power
+	 * state.
+	 */
+	pci_pm_power_up_and_verify_state(pci_dev);
+	pci_restore_state(pci_dev);
+
+	if (pci_has_legacy_pm_support(pci_dev))
+		return 0;
+
+	if (pm && pm->thaw_noirq)
+		return pm->thaw_noirq(dev);
+
+	return 0;
+}
+
+static int pci_pm_thaw(struct device *dev)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+	int error = 0;
+
+	if (pci_has_legacy_pm_support(pci_dev))
+		return pci_legacy_resume(dev);
+
+	if (pm) {
+		if (pm->thaw)
+			error = pm->thaw(dev);
+	} else {
+		pci_pm_reenable_device(pci_dev);
+	}
+
+	pci_dev->state_saved = false;
+
+	return error;
+}
+
+static int pci_pm_poweroff(struct device *dev)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+
+	if (pci_has_legacy_pm_support(pci_dev))
+		return pci_legacy_suspend(dev, PMSG_HIBERNATE);
+
+	if (!pm) {
+		pci_pm_default_suspend(pci_dev);
+		return 0;
+	}
+
+	/* The reason to do that is the same as in pci_pm_suspend(). */
+	if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) ||
+	    pci_dev_need_resume(pci_dev)) {
+		pm_runtime_resume(dev);
+		pci_dev->state_saved = false;
+	} else {
+		pci_dev_adjust_pme(pci_dev);
+	}
+
+	if (pm->poweroff) {
+		int error;
+
+		error = pm->poweroff(dev);
+		suspend_report_result(dev, pm->poweroff, error);
+		if (error)
+			return error;
+	}
+
+	return 0;
+}
+
+static int pci_pm_poweroff_late(struct device *dev)
+{
+	if (dev_pm_skip_suspend(dev))
+		return 0;
+
+	pci_fixup_device(pci_fixup_suspend, to_pci_dev(dev));
+
+	return pm_generic_poweroff_late(dev);
+}
+
+static int pci_pm_poweroff_noirq(struct device *dev)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+
+	if (dev_pm_skip_suspend(dev))
+		return 0;
+
+	if (pci_has_legacy_pm_support(pci_dev))
+		return pci_legacy_suspend_late(dev);
+
+	if (!pm) {
+		pci_fixup_device(pci_fixup_suspend_late, pci_dev);
+		return 0;
+	}
+
+	if (pm->poweroff_noirq) {
+		int error;
+
+		error = pm->poweroff_noirq(dev);
+		suspend_report_result(dev, pm->poweroff_noirq, error);
+		if (error)
+			return error;
+	}
+
+	if (!pci_dev->state_saved && !pci_has_subordinate(pci_dev))
+		pci_prepare_to_sleep(pci_dev);
+
+	/*
+	 * The reason for doing this here is the same as for the analogous code
+	 * in pci_pm_suspend_noirq().
+	 */
+	if (pci_dev->class == PCI_CLASS_SERIAL_USB_EHCI)
+		pci_write_config_word(pci_dev, PCI_COMMAND, 0);
+
+	pci_fixup_device(pci_fixup_suspend_late, pci_dev);
+
+	return 0;
+}
+
+static int pci_pm_restore_noirq(struct device *dev)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+
+	pci_pm_default_resume_early(pci_dev);
+	pci_fixup_device(pci_fixup_resume_early, pci_dev);
+
+	if (pci_has_legacy_pm_support(pci_dev))
+		return 0;
+
+	if (pm && pm->restore_noirq)
+		return pm->restore_noirq(dev);
+
+	return 0;
+}
+
+static int pci_pm_restore(struct device *dev)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+
+	/*
+	 * This is necessary for the hibernation error path in which restore is
+	 * called without restoring the standard config registers of the device.
+	 */
+	if (pci_dev->state_saved)
+		pci_restore_standard_config(pci_dev);
+
+	if (pci_has_legacy_pm_support(pci_dev))
+		return pci_legacy_resume(dev);
+
+	pci_pm_default_resume(pci_dev);
+
+	if (pm) {
+		if (pm->restore)
+			return pm->restore(dev);
+	} else {
+		pci_pm_reenable_device(pci_dev);
+	}
+
+	return 0;
+}
+
+#else /* !CONFIG_HIBERNATE_CALLBACKS */
+
+#define pci_pm_freeze		NULL
+#define pci_pm_freeze_noirq	NULL
+#define pci_pm_thaw		NULL
+#define pci_pm_thaw_noirq	NULL
+#define pci_pm_poweroff		NULL
+#define pci_pm_poweroff_late	NULL
+#define pci_pm_poweroff_noirq	NULL
+#define pci_pm_restore		NULL
+#define pci_pm_restore_noirq	NULL
+
+#endif /* !CONFIG_HIBERNATE_CALLBACKS */
+
+#ifdef CONFIG_PM
+
+static int pci_pm_runtime_suspend(struct device *dev)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+	pci_power_t prev = pci_dev->current_state;
+	int error;
+
+	pci_suspend_ptm(pci_dev);
+
+	/*
+	 * If pci_dev->driver is not set (unbound), we leave the device in D0,
+	 * but it may go to D3cold when the bridge above it runtime suspends.
+	 * Save its config space in case that happens.
+	 */
+	if (!pci_dev->driver) {
+		pci_save_state(pci_dev);
+		return 0;
+	}
+
+	pci_dev->state_saved = false;
+	if (pm && pm->runtime_suspend) {
+		error = pm->runtime_suspend(dev);
+		/*
+		 * -EBUSY and -EAGAIN is used to request the runtime PM core
+		 * to schedule a new suspend, so log the event only with debug
+		 * log level.
+		 */
+		if (error == -EBUSY || error == -EAGAIN) {
+			pci_dbg(pci_dev, "can't suspend now (%ps returned %d)\n",
+				pm->runtime_suspend, error);
+			return error;
+		} else if (error) {
+			pci_err(pci_dev, "can't suspend (%ps returned %d)\n",
+				pm->runtime_suspend, error);
+			return error;
+		}
+	}
+
+	pci_fixup_device(pci_fixup_suspend, pci_dev);
+
+	if (pm && pm->runtime_suspend
+	    && !pci_dev->state_saved && pci_dev->current_state != PCI_D0
+	    && pci_dev->current_state != PCI_UNKNOWN) {
+		pci_WARN_ONCE(pci_dev, pci_dev->current_state != prev,
+			      "PCI PM: State of device not saved by %pS\n",
+			      pm->runtime_suspend);
+		return 0;
+	}
+
+	if (!pci_dev->state_saved) {
+		pci_save_state(pci_dev);
+		pci_finish_runtime_suspend(pci_dev);
+	}
+
+	return 0;
+}
+
+static int pci_pm_runtime_resume(struct device *dev)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+	pci_power_t prev_state = pci_dev->current_state;
+	int error = 0;
+
+	/*
+	 * Restoring config space is necessary even if the device is not bound
+	 * to a driver because although we left it in D0, it may have gone to
+	 * D3cold when the bridge above it runtime suspended.
+	 */
+	pci_pm_default_resume_early(pci_dev);
+	pci_resume_ptm(pci_dev);
+
+	if (!pci_dev->driver)
+		return 0;
+
+	pci_fixup_device(pci_fixup_resume_early, pci_dev);
+	pci_pm_default_resume(pci_dev);
+
+	if (prev_state == PCI_D3cold)
+		pci_pm_bridge_power_up_actions(pci_dev);
+
+	if (pm && pm->runtime_resume)
+		error = pm->runtime_resume(dev);
+
+	return error;
+}
+
+static int pci_pm_runtime_idle(struct device *dev)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+
+	/*
+	 * If pci_dev->driver is not set (unbound), the device should
+	 * always remain in D0 regardless of the runtime PM status
+	 */
+	if (!pci_dev->driver)
+		return 0;
+
+	if (!pm)
+		return -ENOSYS;
+
+	if (pm->runtime_idle)
+		return pm->runtime_idle(dev);
+
+	return 0;
+}
+
+static const struct dev_pm_ops pci_dev_pm_ops = {
+	.prepare = pci_pm_prepare,
+	.complete = pci_pm_complete,
+	.suspend = pci_pm_suspend,
+	.suspend_late = pci_pm_suspend_late,
+	.resume = pci_pm_resume,
+	.resume_early = pci_pm_resume_early,
+	.freeze = pci_pm_freeze,
+	.thaw = pci_pm_thaw,
+	.poweroff = pci_pm_poweroff,
+	.poweroff_late = pci_pm_poweroff_late,
+	.restore = pci_pm_restore,
+	.suspend_noirq = pci_pm_suspend_noirq,
+	.resume_noirq = pci_pm_resume_noirq,
+	.freeze_noirq = pci_pm_freeze_noirq,
+	.thaw_noirq = pci_pm_thaw_noirq,
+	.poweroff_noirq = pci_pm_poweroff_noirq,
+	.restore_noirq = pci_pm_restore_noirq,
+	.runtime_suspend = pci_pm_runtime_suspend,
+	.runtime_resume = pci_pm_runtime_resume,
+	.runtime_idle = pci_pm_runtime_idle,
+};
+
+#define PCI_PM_OPS_PTR	(&pci_dev_pm_ops)
+
+#else /* !CONFIG_PM */
+
+#define pci_pm_runtime_suspend	NULL
+#define pci_pm_runtime_resume	NULL
+#define pci_pm_runtime_idle	NULL
+
+#define PCI_PM_OPS_PTR	NULL
+
+#endif /* !CONFIG_PM */
+
+/**
+ * __pci_register_driver - register a new pci driver
+ * @drv: the driver structure to register
+ * @owner: owner module of drv
+ * @mod_name: module name string
+ *
+ * Adds the driver structure to the list of registered drivers.
+ * Returns a negative value on error, otherwise 0.
+ * If no error occurred, the driver remains registered even if
+ * no device was claimed during registration.
+ */
+int __pci_register_driver(struct pci_driver *drv, struct module *owner,
+			  const char *mod_name)
+{
+	/* initialize common driver fields */
+	drv->driver.name = drv->name;
+	drv->driver.bus = &pci_bus_type;
+	drv->driver.owner = owner;
+	drv->driver.mod_name = mod_name;
+	drv->driver.groups = drv->groups;
+	drv->driver.dev_groups = drv->dev_groups;
+
+	spin_lock_init(&drv->dynids.lock);
+	INIT_LIST_HEAD(&drv->dynids.list);
+
+	/* register with core */
+	return driver_register(&drv->driver);
+}
+EXPORT_SYMBOL(__pci_register_driver);
+
+/**
+ * pci_unregister_driver - unregister a pci driver
+ * @drv: the driver structure to unregister
+ *
+ * Deletes the driver structure from the list of registered PCI drivers,
+ * gives it a chance to clean up by calling its remove() function for
+ * each device it was responsible for, and marks those devices as
+ * driverless.
+ */
+
+void pci_unregister_driver(struct pci_driver *drv)
+{
+	driver_unregister(&drv->driver);
+	pci_free_dynids(drv);
+}
+EXPORT_SYMBOL(pci_unregister_driver);
+
+static struct pci_driver pci_compat_driver = {
+	.name = "compat"
+};
+
+/**
+ * pci_dev_driver - get the pci_driver of a device
+ * @dev: the device to query
+ *
+ * Returns the appropriate pci_driver structure or %NULL if there is no
+ * registered driver for the device.
+ */
+struct pci_driver *pci_dev_driver(const struct pci_dev *dev)
+{
+	int i;
+
+	if (dev->driver)
+		return dev->driver;
+
+	for (i = 0; i <= PCI_ROM_RESOURCE; i++)
+		if (dev->resource[i].flags & IORESOURCE_BUSY)
+			return &pci_compat_driver;
+
+	return NULL;
+}
+EXPORT_SYMBOL(pci_dev_driver);
+
+/**
+ * pci_bus_match - Tell if a PCI device structure has a matching PCI device id structure
+ * @dev: the PCI device structure to match against
+ * @drv: the device driver to search for matching PCI device id structures
+ *
+ * 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 int pci_bus_match(struct device *dev, struct device_driver *drv)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	struct pci_driver *pci_drv;
+	const struct pci_device_id *found_id;
+
+	if (!pci_dev->match_driver)
+		return 0;
+
+	pci_drv = to_pci_driver(drv);
+	found_id = pci_match_device(pci_drv, pci_dev);
+	if (found_id)
+		return 1;
+
+	return 0;
+}
+
+/**
+ * pci_dev_get - increments the reference count of the pci device structure
+ * @dev: the device being referenced
+ *
+ * Each live reference to a device should be refcounted.
+ *
+ * Drivers for PCI devices should normally record such references in
+ * their probe() methods, when they bind to a device, and release
+ * them by calling pci_dev_put(), in their disconnect() methods.
+ *
+ * A pointer to the device with the incremented reference counter is returned.
+ */
+struct pci_dev *pci_dev_get(struct pci_dev *dev)
+{
+	if (dev)
+		get_device(&dev->dev);
+	return dev;
+}
+EXPORT_SYMBOL(pci_dev_get);
+
+/**
+ * pci_dev_put - release a use of the pci device structure
+ * @dev: device that's been disconnected
+ *
+ * Must be called when a user of a device is finished with it.  When the last
+ * user of the device calls this function, the memory of the device is freed.
+ */
+void pci_dev_put(struct pci_dev *dev)
+{
+	if (dev)
+		put_device(&dev->dev);
+}
+EXPORT_SYMBOL(pci_dev_put);
+
+static int pci_uevent(const struct device *dev, struct kobj_uevent_env *env)
+{
+	const struct pci_dev *pdev;
+
+	if (!dev)
+		return -ENODEV;
+
+	pdev = to_pci_dev(dev);
+
+	if (add_uevent_var(env, "PCI_CLASS=%04X", pdev->class))
+		return -ENOMEM;
+
+	if (add_uevent_var(env, "PCI_ID=%04X:%04X", pdev->vendor, pdev->device))
+		return -ENOMEM;
+
+	if (add_uevent_var(env, "PCI_SUBSYS_ID=%04X:%04X", pdev->subsystem_vendor,
+			   pdev->subsystem_device))
+		return -ENOMEM;
+
+	if (add_uevent_var(env, "PCI_SLOT_NAME=%s", pci_name(pdev)))
+		return -ENOMEM;
+
+	if (add_uevent_var(env, "MODALIAS=pci:v%08Xd%08Xsv%08Xsd%08Xbc%02Xsc%02Xi%02X",
+			   pdev->vendor, pdev->device,
+			   pdev->subsystem_vendor, pdev->subsystem_device,
+			   (u8)(pdev->class >> 16), (u8)(pdev->class >> 8),
+			   (u8)(pdev->class)))
+		return -ENOMEM;
+
+	return 0;
+}
+
+#if defined(CONFIG_PCIEAER) || defined(CONFIG_EEH)
+/**
+ * pci_uevent_ers - emit a uevent during recovery path of PCI device
+ * @pdev: PCI device undergoing error recovery
+ * @err_type: type of error event
+ */
+void pci_uevent_ers(struct pci_dev *pdev, enum pci_ers_result err_type)
+{
+	int idx = 0;
+	char *envp[3];
+
+	switch (err_type) {
+	case PCI_ERS_RESULT_NONE:
+	case PCI_ERS_RESULT_CAN_RECOVER:
+		envp[idx++] = "ERROR_EVENT=BEGIN_RECOVERY";
+		envp[idx++] = "DEVICE_ONLINE=0";
+		break;
+	case PCI_ERS_RESULT_RECOVERED:
+		envp[idx++] = "ERROR_EVENT=SUCCESSFUL_RECOVERY";
+		envp[idx++] = "DEVICE_ONLINE=1";
+		break;
+	case PCI_ERS_RESULT_DISCONNECT:
+		envp[idx++] = "ERROR_EVENT=FAILED_RECOVERY";
+		envp[idx++] = "DEVICE_ONLINE=0";
+		break;
+	default:
+		break;
+	}
+
+	if (idx > 0) {
+		envp[idx++] = NULL;
+		kobject_uevent_env(&pdev->dev.kobj, KOBJ_CHANGE, envp);
+	}
+}
+#endif
+
+static int pci_bus_num_vf(struct device *dev)
+{
+	return pci_num_vf(to_pci_dev(dev));
+}
+
+/**
+ * pci_dma_configure - Setup DMA configuration
+ * @dev: ptr to dev structure
+ *
+ * Function to update PCI devices's DMA configuration using the same
+ * info from the OF node or ACPI node of host bridge's parent (if any).
+ */
+static int pci_dma_configure(struct device *dev)
+{
+	struct pci_driver *driver = to_pci_driver(dev->driver);
+	struct device *bridge;
+	int ret = 0;
+
+	bridge = pci_get_host_bridge_device(to_pci_dev(dev));
+
+	if (IS_ENABLED(CONFIG_OF) && bridge->parent &&
+	    bridge->parent->of_node) {
+		ret = of_dma_configure(dev, bridge->parent->of_node, true);
+	} else if (has_acpi_companion(bridge)) {
+		struct acpi_device *adev = to_acpi_device_node(bridge->fwnode);
+
+		ret = acpi_dma_configure(dev, acpi_get_dma_attr(adev));
+	}
+
+	pci_put_host_bridge_device(bridge);
+
+	if (!ret && !driver->driver_managed_dma) {
+		ret = iommu_device_use_default_domain(dev);
+		if (ret)
+			arch_teardown_dma_ops(dev);
+	}
+
+	return ret;
+}
+
+static void pci_dma_cleanup(struct device *dev)
+{
+	struct pci_driver *driver = to_pci_driver(dev->driver);
+
+	if (!driver->driver_managed_dma)
+		iommu_device_unuse_default_domain(dev);
+}
+
+struct bus_type pci_bus_type = {
+	.name		= "pci",
+	.match		= pci_bus_match,
+	.uevent		= pci_uevent,
+	.probe		= pci_device_probe,
+	.remove		= pci_device_remove,
+	.shutdown	= pci_device_shutdown,
+	.dev_groups	= pci_dev_groups,
+	.bus_groups	= pci_bus_groups,
+	.drv_groups	= pci_drv_groups,
+	.pm		= PCI_PM_OPS_PTR,
+	.num_vf		= pci_bus_num_vf,
+	.dma_configure	= pci_dma_configure,
+	.dma_cleanup	= pci_dma_cleanup,
+};
+EXPORT_SYMBOL(pci_bus_type);
+
+#ifdef CONFIG_PCIEPORTBUS
+static int pcie_port_bus_match(struct device *dev, struct device_driver *drv)
+{
+	struct pcie_device *pciedev;
+	struct pcie_port_service_driver *driver;
+
+	if (drv->bus != &pcie_port_bus_type || dev->bus != &pcie_port_bus_type)
+		return 0;
+
+	pciedev = to_pcie_device(dev);
+	driver = to_service_driver(drv);
+
+	if (driver->service != pciedev->service)
+		return 0;
+
+	if (driver->port_type != PCIE_ANY_PORT &&
+	    driver->port_type != pci_pcie_type(pciedev->port))
+		return 0;
+
+	return 1;
+}
+
+struct bus_type pcie_port_bus_type = {
+	.name		= "pci_express",
+	.match		= pcie_port_bus_match,
+};
+#endif
+
+static int __init pci_driver_init(void)
+{
+	int ret;
+
+	ret = bus_register(&pci_bus_type);
+	if (ret)
+		return ret;
+
+#ifdef CONFIG_PCIEPORTBUS
+	ret = bus_register(&pcie_port_bus_type);
+	if (ret)
+		return ret;
+#endif
+	dma_debug_add_bus(&pci_bus_type);
+	return 0;
+}
+postcore_initcall(pci_driver_init);