drivers/pci/pcie/portdrv_core.c - arm/linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * File:	portdrv_core.c
  * Purpose:	PCI Express Port Bus Driver's Core Functions
  *
  * Copyright (C) 2004 Intel
  * Copyright (C) Tom Long Nguyen (tom.l.nguyen@intel.com)
  */

 #include <linux/module.h>
 #include <linux/pci.h>
 #include <linux/kernel.h>
 #include <linux/errno.h>
 #include <linux/pm.h>
 #include <linux/pm_runtime.h>
 #include <linux/string.h>
 #include <linux/slab.h>
 #include <linux/pcieport_if.h>
 #include <linux/aer.h>

 #include "../pci.h"
 #include "portdrv.h"

 bool pciehp_msi_disabled;

 static int __init pciehp_setup(char *str)
 {
 	if (!strncmp(str, "nomsi", 5))
 		pciehp_msi_disabled = true;

 	return 1;
 }
 __setup("pcie_hp=", pciehp_setup);

 /**
  * release_pcie_device - free PCI Express port service device structure
  * @dev: Port service device to release
  *
  * Invoked automatically when device is being removed in response to
  * device_unregister(dev).  Release all resources being claimed.
  */
 static void release_pcie_device(struct device *dev)
 {
 	kfree(to_pcie_device(dev));
 }

 /**
  * pcie_port_enable_irq_vec - try to set up MSI-X or MSI as interrupt mode
  * for given port
  * @dev: PCI Express port to handle
  * @irqs: Array of interrupt vectors to populate
  * @mask: Bitmask of port capabilities returned by get_port_device_capability()
  *
  * Return value: 0 on success, error code on failure
  */
 static int pcie_port_enable_irq_vec(struct pci_dev *dev, int *irqs, int mask)
 {
 	int nr_entries, entry, nvec = 0;

 	/*
 	 * Allocate as many entries as the port wants, so that we can check
 	 * which of them will be useful.  Moreover, if nr_entries is correctly
 	 * equal to the number of entries this port actually uses, we'll happily
 	 * go through without any tricks.
 	 */
 	nr_entries = pci_alloc_irq_vectors(dev, 1, PCIE_PORT_MAX_MSI_ENTRIES,
 			PCI_IRQ_MSIX | PCI_IRQ_MSI);
 	if (nr_entries < 0)
 		return nr_entries;

 	if (mask & (PCIE_PORT_SERVICE_PME | PCIE_PORT_SERVICE_HP)) {
 		u16 reg16;

 		/*
 		 * Per PCIe r3.1, sec 6.1.6, "PME and Hot-Plug Event
 		 * interrupts (when both are implemented) always share the
 		 * same MSI or MSI-X vector, as indicated by the Interrupt
 		 * Message Number field in the PCI Express Capabilities
 		 * register".
 		 *
 		 * Per sec 7.8.2, "For MSI, the [Interrupt Message Number]
 		 * indicates the offset between the base Message Data and
 		 * the interrupt message that is generated."
 		 *
 		 * "For MSI-X, the [Interrupt Message Number] indicates
 		 * which MSI-X Table entry is used to generate the
 		 * interrupt message."
 		 */
 		pcie_capability_read_word(dev, PCI_EXP_FLAGS, &reg16);
 		entry = (reg16 & PCI_EXP_FLAGS_IRQ) >> 9;
 		if (entry >= nr_entries)
 			goto out_free_irqs;

 		irqs[PCIE_PORT_SERVICE_PME_SHIFT] = pci_irq_vector(dev, entry);
 		irqs[PCIE_PORT_SERVICE_HP_SHIFT] = pci_irq_vector(dev, entry);

 		nvec = max(nvec, entry + 1);
 	}

 	if (mask & PCIE_PORT_SERVICE_AER) {
 		u32 reg32, pos;

 		/*
 		 * Per PCIe r3.1, sec 7.10.10, the Advanced Error Interrupt
 		 * Message Number in the Root Error Status register
 		 * indicates which MSI/MSI-X vector is used for AER.
 		 *
 		 * "For MSI, the [Advanced Error Interrupt Message Number]
 		 * indicates the offset between the base Message Data and
 		 * the interrupt message that is generated."
 		 *
 		 * "For MSI-X, the [Advanced Error Interrupt Message
 		 * Number] indicates which MSI-X Table entry is used to
 		 * generate the interrupt message."
 		 */
 		pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
 		pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, &reg32);
 		entry = reg32 >> 27;
 		if (entry >= nr_entries)
 			goto out_free_irqs;

 		irqs[PCIE_PORT_SERVICE_AER_SHIFT] = pci_irq_vector(dev, entry);

 		nvec = max(nvec, entry + 1);
 	}

 	if (mask & PCIE_PORT_SERVICE_DPC) {
 		u16 reg16, pos;

 		/*
 		 * Per PCIe r4.0 (v0.9), sec 7.9.15.2, the DPC Interrupt
 		 * Message Number in the DPC Capability register indicates
 		 * which MSI/MSI-X vector is used for DPC.
 		 *
 		 * "For MSI, the [DPC Interrupt Message Number] indicates
 		 * the offset between the base Message Data and the
 		 * interrupt message that is generated."
 		 *
 		 * "For MSI-X, the [DPC Interrupt Message Number] indicates
 		 * which MSI-X Table entry is used to generate the
 		 * interrupt message."
 		 */
 		pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DPC);
 		pci_read_config_word(dev, pos + PCI_EXP_DPC_CAP, &reg16);
 		entry = reg16 & 0x1f;
 		if (entry >= nr_entries)
 			goto out_free_irqs;

 		irqs[PCIE_PORT_SERVICE_DPC_SHIFT] = pci_irq_vector(dev, entry);

 		nvec = max(nvec, entry + 1);
 	}

 	/*
 	 * If nvec is equal to the allocated number of entries, we can just use
 	 * what we have.  Otherwise, the port has some extra entries not for the
 	 * services we know and we need to work around that.
 	 */
 	if (nvec != nr_entries) {
 		/* Drop the temporary MSI-X setup */
 		pci_free_irq_vectors(dev);

 		/* Now allocate the MSI-X vectors for real */
 		nr_entries = pci_alloc_irq_vectors(dev, nvec, nvec,
 				PCI_IRQ_MSIX | PCI_IRQ_MSI);
 		if (nr_entries < 0)
 			return nr_entries;
 	}

 	return 0;

 out_free_irqs:
 	pci_free_irq_vectors(dev);
 	return -EIO;
 }

 /**
  * pcie_init_service_irqs - initialize irqs for PCI Express port services
  * @dev: PCI Express port to handle
  * @irqs: Array of irqs to populate
  * @mask: Bitmask of port capabilities returned by get_port_device_capability()
  *
  * Return value: Interrupt mode associated with the port
  */
 static int pcie_init_service_irqs(struct pci_dev *dev, int *irqs, int mask)
 {
 	int ret, i;

 	for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++)
 		irqs[i] = -1;

 	/*
 	 * If we support PME or hotplug, but we can't use MSI/MSI-X for
 	 * them, we have to fall back to INTx or other interrupts, e.g., a
 	 * system shared interrupt.
 	 */
 	if ((mask & PCIE_PORT_SERVICE_PME) && pcie_pme_no_msi())
 		goto legacy_irq;

 	if ((mask & PCIE_PORT_SERVICE_HP) && pciehp_no_msi())
 		goto legacy_irq;

 	/* Try to use MSI-X or MSI if supported */
 	if (pcie_port_enable_irq_vec(dev, irqs, mask) == 0)
 		return 0;

 legacy_irq:
 	/* fall back to legacy IRQ */
 	ret = pci_alloc_irq_vectors(dev, 1, 1, PCI_IRQ_LEGACY);
 	if (ret < 0)
 		return -ENODEV;

 	for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++) {
 		if (i != PCIE_PORT_SERVICE_VC_SHIFT)
 			irqs[i] = pci_irq_vector(dev, 0);
 	}

 	return 0;
 }

 /**
  * get_port_device_capability - discover capabilities of a PCI Express port
  * @dev: PCI Express port to examine
  *
  * The capabilities are read from the port's PCI Express configuration registers
  * as described in PCI Express Base Specification 1.0a sections 7.8.2, 7.8.9 and
  * 7.9 - 7.11.
  *
  * Return value: Bitmask of discovered port capabilities
  */
 static int get_port_device_capability(struct pci_dev *dev)
 {
 	int services = 0;
 	int cap_mask = 0;

 	if (pcie_ports_disabled)
 		return 0;

 	cap_mask = PCIE_PORT_SERVICE_PME | PCIE_PORT_SERVICE_HP
 			| PCIE_PORT_SERVICE_VC | PCIE_PORT_SERVICE_DPC;
 	if (pci_aer_available())
 		cap_mask |= PCIE_PORT_SERVICE_AER;

 	if (pcie_ports_auto)
 		pcie_port_platform_notify(dev, &cap_mask);

 	/* Hot-Plug Capable */
 	if ((cap_mask & PCIE_PORT_SERVICE_HP) && dev->is_hotplug_bridge) {
 		services |= PCIE_PORT_SERVICE_HP;
 		/*
 		 * Disable hot-plug interrupts in case they have been enabled
 		 * by the BIOS and the hot-plug service driver is not loaded.
 		 */
 		pcie_capability_clear_word(dev, PCI_EXP_SLTCTL,
 			  PCI_EXP_SLTCTL_CCIE | PCI_EXP_SLTCTL_HPIE);
 	}
 	/* AER capable */
 	if ((cap_mask & PCIE_PORT_SERVICE_AER)
 	    && pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR)) {
 		services |= PCIE_PORT_SERVICE_AER;
 		/*
 		 * Disable AER on this port in case it's been enabled by the
 		 * BIOS (the AER service driver will enable it when necessary).
 		 */
 		pci_disable_pcie_error_reporting(dev);
 	}
 	/* VC support */
 	if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_VC))
 		services |= PCIE_PORT_SERVICE_VC;
 	/* Root ports are capable of generating PME too */
 	if ((cap_mask & PCIE_PORT_SERVICE_PME)
 	    && pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT) {
 		services |= PCIE_PORT_SERVICE_PME;
 		/*
 		 * Disable PME interrupt on this port in case it's been enabled
 		 * by the BIOS (the PME service driver will enable it when
 		 * necessary).
 		 */
 		pcie_pme_interrupt_enable(dev, false);
 	}
 	if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DPC))
 		services |= PCIE_PORT_SERVICE_DPC;

 	return services;
 }

 /**
  * pcie_device_init - allocate and initialize PCI Express port service device
  * @pdev: PCI Express port to associate the service device with
  * @service: Type of service to associate with the service device
  * @irq: Interrupt vector to associate with the service device
  */
 static int pcie_device_init(struct pci_dev *pdev, int service, int irq)
 {
 	int retval;
 	struct pcie_device *pcie;
 	struct device *device;

 	pcie = kzalloc(sizeof(*pcie), GFP_KERNEL);
 	if (!pcie)
 		return -ENOMEM;
 	pcie->port = pdev;
 	pcie->irq = irq;
 	pcie->service = service;

 	/* Initialize generic device interface */
 	device = &pcie->device;
 	device->bus = &pcie_port_bus_type;
 	device->release = release_pcie_device;	/* callback to free pcie dev */
 	dev_set_name(device, "%s:pcie%03x",
 		     pci_name(pdev),
 		     get_descriptor_id(pci_pcie_type(pdev), service));
 	device->parent = &pdev->dev;
 	device_enable_async_suspend(device);

 	retval = device_register(device);
 	if (retval) {
 		put_device(device);
 		return retval;
 	}

 	pm_runtime_no_callbacks(device);

 	return 0;
 }

 /**
  * pcie_port_device_register - register PCI Express port
  * @dev: PCI Express port to register
  *
  * Allocate the port extension structure and register services associated with
  * the port.
  */
 int pcie_port_device_register(struct pci_dev *dev)
 {
 	int status, capabilities, i, nr_service;
 	int irqs[PCIE_PORT_DEVICE_MAXSERVICES];

 	/* Enable PCI Express port device */
 	status = pci_enable_device(dev);
 	if (status)
 		return status;

 	/* Get and check PCI Express port services */
 	capabilities = get_port_device_capability(dev);
 	if (!capabilities)
 		return 0;

 	pci_set_master(dev);
 	/*
 	 * Initialize service irqs. Don't use service devices that
 	 * require interrupts if there is no way to generate them.
 	 * However, some drivers may have a polling mode (e.g. pciehp_poll_mode)
 	 * that can be used in the absence of irqs.  Allow them to determine
 	 * if that is to be used.
 	 */
 	status = pcie_init_service_irqs(dev, irqs, capabilities);
 	if (status) {
 		capabilities &= PCIE_PORT_SERVICE_VC | PCIE_PORT_SERVICE_HP;
 		if (!capabilities)
 			goto error_disable;
 	}

 	/* Allocate child services if any */
 	status = -ENODEV;
 	nr_service = 0;
 	for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++) {
 		int service = 1 << i;
 		if (!(capabilities & service))
 			continue;
 		if (!pcie_device_init(dev, service, irqs[i]))
 			nr_service++;
 	}
 	if (!nr_service)
 		goto error_cleanup_irqs;

 	return 0;

 error_cleanup_irqs:
 	pci_free_irq_vectors(dev);
 error_disable:
 	pci_disable_device(dev);
 	return status;
 }

 #ifdef CONFIG_PM
 static int suspend_iter(struct device *dev, void *data)
 {
 	struct pcie_port_service_driver *service_driver;

 	if ((dev->bus == &pcie_port_bus_type) && dev->driver) {
 		service_driver = to_service_driver(dev->driver);
 		if (service_driver->suspend)
 			service_driver->suspend(to_pcie_device(dev));
 	}
 	return 0;
 }

 /**
  * pcie_port_device_suspend - suspend port services associated with a PCIe port
  * @dev: PCI Express port to handle
  */
 int pcie_port_device_suspend(struct device *dev)
 {
 	return device_for_each_child(dev, NULL, suspend_iter);
 }

 static int resume_iter(struct device *dev, void *data)
 {
 	struct pcie_port_service_driver *service_driver;

 	if ((dev->bus == &pcie_port_bus_type) &&
 	    (dev->driver)) {
 		service_driver = to_service_driver(dev->driver);
 		if (service_driver->resume)
 			service_driver->resume(to_pcie_device(dev));
 	}
 	return 0;
 }

 /**
  * pcie_port_device_resume - resume port services associated with a PCIe port
  * @dev: PCI Express port to handle
  */
 int pcie_port_device_resume(struct device *dev)
 {
 	return device_for_each_child(dev, NULL, resume_iter);
 }
 #endif /* PM */

 static int remove_iter(struct device *dev, void *data)
 {
 	if (dev->bus == &pcie_port_bus_type)
 		device_unregister(dev);
 	return 0;
 }

 /**
  * pcie_port_device_remove - unregister PCI Express port service devices
  * @dev: PCI Express port the service devices to unregister are associated with
  *
  * Remove PCI Express port service devices associated with given port and
  * disable MSI-X or MSI for the port.
  */
 void pcie_port_device_remove(struct pci_dev *dev)
 {
 	device_for_each_child(&dev->dev, NULL, remove_iter);
 	pci_free_irq_vectors(dev);
 	pci_disable_device(dev);
 }

 /**
  * pcie_port_probe_service - probe driver for given PCI Express port service
  * @dev: PCI Express port service device to probe against
  *
  * If PCI Express port service driver is registered with
  * pcie_port_service_register(), this function will be called by the driver core
  * whenever match is found between the driver and a port service device.
  */
 static int pcie_port_probe_service(struct device *dev)
 {
 	struct pcie_device *pciedev;
 	struct pcie_port_service_driver *driver;
 	int status;

 	if (!dev || !dev->driver)
 		return -ENODEV;

 	driver = to_service_driver(dev->driver);
 	if (!driver || !driver->probe)
 		return -ENODEV;

 	pciedev = to_pcie_device(dev);
 	status = driver->probe(pciedev);
 	if (status)
 		return status;

 	get_device(dev);
 	return 0;
 }

 /**
  * pcie_port_remove_service - detach driver from given PCI Express port service
  * @dev: PCI Express port service device to handle
  *
  * If PCI Express port service driver is registered with
  * pcie_port_service_register(), this function will be called by the driver core
  * when device_unregister() is called for the port service device associated
  * with the driver.
  */
 static int pcie_port_remove_service(struct device *dev)
 {
 	struct pcie_device *pciedev;
 	struct pcie_port_service_driver *driver;

 	if (!dev || !dev->driver)
 		return 0;

 	pciedev = to_pcie_device(dev);
 	driver = to_service_driver(dev->driver);
 	if (driver && driver->remove) {
 		driver->remove(pciedev);
 		put_device(dev);
 	}
 	return 0;
 }

 /**
  * pcie_port_shutdown_service - shut down given PCI Express port service
  * @dev: PCI Express port service device to handle
  *
  * If PCI Express port service driver is registered with
  * pcie_port_service_register(), this function will be called by the driver core
  * when device_shutdown() is called for the port service device associated
  * with the driver.
  */
 static void pcie_port_shutdown_service(struct device *dev) {}

 /**
  * pcie_port_service_register - register PCI Express port service driver
  * @new: PCI Express port service driver to register
  */
 int pcie_port_service_register(struct pcie_port_service_driver *new)
 {
 	if (pcie_ports_disabled)
 		return -ENODEV;

 	new->driver.name = new->name;
 	new->driver.bus = &pcie_port_bus_type;
 	new->driver.probe = pcie_port_probe_service;
 	new->driver.remove = pcie_port_remove_service;
 	new->driver.shutdown = pcie_port_shutdown_service;

 	return driver_register(&new->driver);
 }
 EXPORT_SYMBOL(pcie_port_service_register);

 /**
  * pcie_port_service_unregister - unregister PCI Express port service driver
  * @drv: PCI Express port service driver to unregister
  */
 void pcie_port_service_unregister(struct pcie_port_service_driver *drv)
 {
 	driver_unregister(&drv->driver);
 }
 EXPORT_SYMBOL(pcie_port_service_unregister);
	// SPDX-License-Identifier: GPL-2.0
	/*
	* File: portdrv_core.c
	* Purpose: PCI Express Port Bus Driver's Core Functions
	*
	* Copyright (C) 2004 Intel
	* Copyright (C) Tom Long Nguyen (tom.l.nguyen@intel.com)
	*/

	#include <linux/module.h>
	#include <linux/pci.h>
	#include <linux/kernel.h>
	#include <linux/errno.h>
	#include <linux/pm.h>
	#include <linux/pm_runtime.h>
	#include <linux/string.h>
	#include <linux/slab.h>
	#include <linux/pcieport_if.h>
	#include <linux/aer.h>

	#include "../pci.h"
	#include "portdrv.h"

	bool pciehp_msi_disabled;

	static int __init pciehp_setup(char *str)
	{
	if (!strncmp(str, "nomsi", 5))
	pciehp_msi_disabled = true;

	return 1;
	}
	__setup("pcie_hp=", pciehp_setup);

	/**
	* release_pcie_device - free PCI Express port service device structure
	* @dev: Port service device to release
	*
	* Invoked automatically when device is being removed in response to
	* device_unregister(dev). Release all resources being claimed.
	*/
	static void release_pcie_device(struct device *dev)
	{
	kfree(to_pcie_device(dev));
	}

	/**
	* pcie_port_enable_irq_vec - try to set up MSI-X or MSI as interrupt mode
	* for given port
	* @dev: PCI Express port to handle
	* @irqs: Array of interrupt vectors to populate
	* @mask: Bitmask of port capabilities returned by get_port_device_capability()
	*
	* Return value: 0 on success, error code on failure
	*/
	static int pcie_port_enable_irq_vec(struct pci_dev dev, int irqs, int mask)
	{
	int nr_entries, entry, nvec = 0;

	/*
	* Allocate as many entries as the port wants, so that we can check
	* which of them will be useful. Moreover, if nr_entries is correctly
	* equal to the number of entries this port actually uses, we'll happily
	* go through without any tricks.
	*/
	nr_entries = pci_alloc_irq_vectors(dev, 1, PCIE_PORT_MAX_MSI_ENTRIES,
	PCI_IRQ_MSIX \| PCI_IRQ_MSI);
	if (nr_entries < 0)
	return nr_entries;

	if (mask & (PCIE_PORT_SERVICE_PME \| PCIE_PORT_SERVICE_HP)) {
	u16 reg16;

	/*
	* Per PCIe r3.1, sec 6.1.6, "PME and Hot-Plug Event
	* interrupts (when both are implemented) always share the
	* same MSI or MSI-X vector, as indicated by the Interrupt
	* Message Number field in the PCI Express Capabilities
	* register".
	*
	* Per sec 7.8.2, "For MSI, the [Interrupt Message Number]
	* indicates the offset between the base Message Data and
	* the interrupt message that is generated."
	*
	* "For MSI-X, the [Interrupt Message Number] indicates
	* which MSI-X Table entry is used to generate the
	* interrupt message."
	*/
	pcie_capability_read_word(dev, PCI_EXP_FLAGS, &reg16);
	entry = (reg16 & PCI_EXP_FLAGS_IRQ) >> 9;
	if (entry >= nr_entries)
	goto out_free_irqs;

	irqs[PCIE_PORT_SERVICE_PME_SHIFT] = pci_irq_vector(dev, entry);
	irqs[PCIE_PORT_SERVICE_HP_SHIFT] = pci_irq_vector(dev, entry);

	nvec = max(nvec, entry + 1);
	}

	if (mask & PCIE_PORT_SERVICE_AER) {
	u32 reg32, pos;

	/*
	* Per PCIe r3.1, sec 7.10.10, the Advanced Error Interrupt
	* Message Number in the Root Error Status register
	* indicates which MSI/MSI-X vector is used for AER.
	*
	* "For MSI, the [Advanced Error Interrupt Message Number]
	* indicates the offset between the base Message Data and
	* the interrupt message that is generated."
	*
	* "For MSI-X, the [Advanced Error Interrupt Message
	* Number] indicates which MSI-X Table entry is used to
	* generate the interrupt message."
	*/
	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
	pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, &reg32);
	entry = reg32 >> 27;
	if (entry >= nr_entries)
	goto out_free_irqs;

	irqs[PCIE_PORT_SERVICE_AER_SHIFT] = pci_irq_vector(dev, entry);

	nvec = max(nvec, entry + 1);
	}

	if (mask & PCIE_PORT_SERVICE_DPC) {
	u16 reg16, pos;

	/*
	* Per PCIe r4.0 (v0.9), sec 7.9.15.2, the DPC Interrupt
	* Message Number in the DPC Capability register indicates
	* which MSI/MSI-X vector is used for DPC.
	*
	* "For MSI, the [DPC Interrupt Message Number] indicates
	* the offset between the base Message Data and the
	* interrupt message that is generated."
	*
	* "For MSI-X, the [DPC Interrupt Message Number] indicates
	* which MSI-X Table entry is used to generate the
	* interrupt message."
	*/
	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DPC);
	pci_read_config_word(dev, pos + PCI_EXP_DPC_CAP, &reg16);
	entry = reg16 & 0x1f;
	if (entry >= nr_entries)
	goto out_free_irqs;

	irqs[PCIE_PORT_SERVICE_DPC_SHIFT] = pci_irq_vector(dev, entry);

	nvec = max(nvec, entry + 1);
	}

	/*
	* If nvec is equal to the allocated number of entries, we can just use
	* what we have. Otherwise, the port has some extra entries not for the
	* services we know and we need to work around that.
	*/
	if (nvec != nr_entries) {
	/* Drop the temporary MSI-X setup */
	pci_free_irq_vectors(dev);

	/* Now allocate the MSI-X vectors for real */
	nr_entries = pci_alloc_irq_vectors(dev, nvec, nvec,
	PCI_IRQ_MSIX \| PCI_IRQ_MSI);
	if (nr_entries < 0)
	return nr_entries;
	}

	return 0;

	out_free_irqs:
	pci_free_irq_vectors(dev);
	return -EIO;
	}

	/**
	* pcie_init_service_irqs - initialize irqs for PCI Express port services
	* @dev: PCI Express port to handle
	* @irqs: Array of irqs to populate
	* @mask: Bitmask of port capabilities returned by get_port_device_capability()
	*
	* Return value: Interrupt mode associated with the port
	*/
	static int pcie_init_service_irqs(struct pci_dev dev, int irqs, int mask)
	{
	int ret, i;

	for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++)
	irqs[i] = -1;

	/*
	* If we support PME or hotplug, but we can't use MSI/MSI-X for
	* them, we have to fall back to INTx or other interrupts, e.g., a
	* system shared interrupt.
	*/
	if ((mask & PCIE_PORT_SERVICE_PME) && pcie_pme_no_msi())
	goto legacy_irq;

	if ((mask & PCIE_PORT_SERVICE_HP) && pciehp_no_msi())
	goto legacy_irq;

	/* Try to use MSI-X or MSI if supported */
	if (pcie_port_enable_irq_vec(dev, irqs, mask) == 0)
	return 0;

	legacy_irq:
	/* fall back to legacy IRQ */
	ret = pci_alloc_irq_vectors(dev, 1, 1, PCI_IRQ_LEGACY);
	if (ret < 0)
	return -ENODEV;

	for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++) {
	if (i != PCIE_PORT_SERVICE_VC_SHIFT)
	irqs[i] = pci_irq_vector(dev, 0);
	}

	return 0;
	}

	/**
	* get_port_device_capability - discover capabilities of a PCI Express port
	* @dev: PCI Express port to examine
	*
	* The capabilities are read from the port's PCI Express configuration registers
	* as described in PCI Express Base Specification 1.0a sections 7.8.2, 7.8.9 and
	* 7.9 - 7.11.
	*
	* Return value: Bitmask of discovered port capabilities
	*/
	static int get_port_device_capability(struct pci_dev *dev)
	{
	int services = 0;
	int cap_mask = 0;

	if (pcie_ports_disabled)
	return 0;

	cap_mask = PCIE_PORT_SERVICE_PME \| PCIE_PORT_SERVICE_HP
	\| PCIE_PORT_SERVICE_VC \| PCIE_PORT_SERVICE_DPC;
	if (pci_aer_available())
	cap_mask \|= PCIE_PORT_SERVICE_AER;

	if (pcie_ports_auto)
	pcie_port_platform_notify(dev, &cap_mask);

	/* Hot-Plug Capable */
	if ((cap_mask & PCIE_PORT_SERVICE_HP) && dev->is_hotplug_bridge) {
	services \|= PCIE_PORT_SERVICE_HP;
	/*
	* Disable hot-plug interrupts in case they have been enabled
	* by the BIOS and the hot-plug service driver is not loaded.
	*/
	pcie_capability_clear_word(dev, PCI_EXP_SLTCTL,
	PCI_EXP_SLTCTL_CCIE \| PCI_EXP_SLTCTL_HPIE);
	}
	/* AER capable */
	if ((cap_mask & PCIE_PORT_SERVICE_AER)
	&& pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR)) {
	services \|= PCIE_PORT_SERVICE_AER;
	/*
	* Disable AER on this port in case it's been enabled by the
	* BIOS (the AER service driver will enable it when necessary).
	*/
	pci_disable_pcie_error_reporting(dev);
	}
	/* VC support */
	if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_VC))
	services \|= PCIE_PORT_SERVICE_VC;
	/* Root ports are capable of generating PME too */
	if ((cap_mask & PCIE_PORT_SERVICE_PME)
	&& pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT) {
	services \|= PCIE_PORT_SERVICE_PME;
	/*
	* Disable PME interrupt on this port in case it's been enabled
	* by the BIOS (the PME service driver will enable it when
	* necessary).
	*/
	pcie_pme_interrupt_enable(dev, false);
	}
	if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DPC))
	services \|= PCIE_PORT_SERVICE_DPC;

	return services;
	}

	/**
	* pcie_device_init - allocate and initialize PCI Express port service device
	* @pdev: PCI Express port to associate the service device with
	* @service: Type of service to associate with the service device
	* @irq: Interrupt vector to associate with the service device
	*/
	static int pcie_device_init(struct pci_dev *pdev, int service, int irq)
	{
	int retval;
	struct pcie_device *pcie;
	struct device *device;

	pcie = kzalloc(sizeof(*pcie), GFP_KERNEL);
	if (!pcie)
	return -ENOMEM;
	pcie->port = pdev;
	pcie->irq = irq;
	pcie->service = service;

	/* Initialize generic device interface */
	device = &pcie->device;
	device->bus = &pcie_port_bus_type;
	device->release = release_pcie_device; /* callback to free pcie dev */
	dev_set_name(device, "%s:pcie%03x",
	pci_name(pdev),
	get_descriptor_id(pci_pcie_type(pdev), service));
	device->parent = &pdev->dev;
	device_enable_async_suspend(device);

	retval = device_register(device);
	if (retval) {
	put_device(device);
	return retval;
	}

	pm_runtime_no_callbacks(device);

	return 0;
	}

	/**
	* pcie_port_device_register - register PCI Express port
	* @dev: PCI Express port to register
	*
	* Allocate the port extension structure and register services associated with
	* the port.
	*/
	int pcie_port_device_register(struct pci_dev *dev)
	{
	int status, capabilities, i, nr_service;
	int irqs[PCIE_PORT_DEVICE_MAXSERVICES];

	/* Enable PCI Express port device */
	status = pci_enable_device(dev);
	if (status)
	return status;

	/* Get and check PCI Express port services */
	capabilities = get_port_device_capability(dev);
	if (!capabilities)
	return 0;

	pci_set_master(dev);
	/*
	* Initialize service irqs. Don't use service devices that
	* require interrupts if there is no way to generate them.
	* However, some drivers may have a polling mode (e.g. pciehp_poll_mode)
	* that can be used in the absence of irqs. Allow them to determine
	* if that is to be used.
	*/
	status = pcie_init_service_irqs(dev, irqs, capabilities);
	if (status) {
	capabilities &= PCIE_PORT_SERVICE_VC \| PCIE_PORT_SERVICE_HP;
	if (!capabilities)
	goto error_disable;
	}

	/* Allocate child services if any */
	status = -ENODEV;
	nr_service = 0;
	for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++) {
	int service = 1 << i;
	if (!(capabilities & service))
	continue;
	if (!pcie_device_init(dev, service, irqs[i]))
	nr_service++;
	}
	if (!nr_service)
	goto error_cleanup_irqs;

	return 0;

	error_cleanup_irqs:
	pci_free_irq_vectors(dev);
	error_disable:
	pci_disable_device(dev);
	return status;
	}

	#ifdef CONFIG_PM
	static int suspend_iter(struct device dev, void data)
	{
	struct pcie_port_service_driver *service_driver;

	if ((dev->bus == &pcie_port_bus_type) && dev->driver) {
	service_driver = to_service_driver(dev->driver);
	if (service_driver->suspend)
	service_driver->suspend(to_pcie_device(dev));
	}
	return 0;
	}

	/**
	* pcie_port_device_suspend - suspend port services associated with a PCIe port
	* @dev: PCI Express port to handle
	*/
	int pcie_port_device_suspend(struct device *dev)
	{
	return device_for_each_child(dev, NULL, suspend_iter);
	}

	static int resume_iter(struct device dev, void data)
	{
	struct pcie_port_service_driver *service_driver;

	if ((dev->bus == &pcie_port_bus_type) &&
	(dev->driver)) {
	service_driver = to_service_driver(dev->driver);
	if (service_driver->resume)
	service_driver->resume(to_pcie_device(dev));
	}
	return 0;
	}

	/**
	* pcie_port_device_resume - resume port services associated with a PCIe port
	* @dev: PCI Express port to handle
	*/
	int pcie_port_device_resume(struct device *dev)
	{
	return device_for_each_child(dev, NULL, resume_iter);
	}
	#endif /* PM */

	static int remove_iter(struct device dev, void data)
	{
	if (dev->bus == &pcie_port_bus_type)
	device_unregister(dev);
	return 0;
	}

	/**
	* pcie_port_device_remove - unregister PCI Express port service devices
	* @dev: PCI Express port the service devices to unregister are associated with
	*
	* Remove PCI Express port service devices associated with given port and
	* disable MSI-X or MSI for the port.
	*/
	void pcie_port_device_remove(struct pci_dev *dev)
	{
	device_for_each_child(&dev->dev, NULL, remove_iter);
	pci_free_irq_vectors(dev);
	pci_disable_device(dev);
	}

	/**
	* pcie_port_probe_service - probe driver for given PCI Express port service
	* @dev: PCI Express port service device to probe against
	*
	* If PCI Express port service driver is registered with
	* pcie_port_service_register(), this function will be called by the driver core
	* whenever match is found between the driver and a port service device.
	*/
	static int pcie_port_probe_service(struct device *dev)
	{
	struct pcie_device *pciedev;
	struct pcie_port_service_driver *driver;
	int status;

	if (!dev \|\| !dev->driver)
	return -ENODEV;

	driver = to_service_driver(dev->driver);
	if (!driver \|\| !driver->probe)
	return -ENODEV;

	pciedev = to_pcie_device(dev);
	status = driver->probe(pciedev);
	if (status)
	return status;

	get_device(dev);
	return 0;
	}

	/**
	* pcie_port_remove_service - detach driver from given PCI Express port service
	* @dev: PCI Express port service device to handle
	*
	* If PCI Express port service driver is registered with
	* pcie_port_service_register(), this function will be called by the driver core
	* when device_unregister() is called for the port service device associated
	* with the driver.
	*/
	static int pcie_port_remove_service(struct device *dev)
	{
	struct pcie_device *pciedev;
	struct pcie_port_service_driver *driver;

	if (!dev \|\| !dev->driver)
	return 0;

	pciedev = to_pcie_device(dev);
	driver = to_service_driver(dev->driver);
	if (driver && driver->remove) {
	driver->remove(pciedev);
	put_device(dev);
	}
	return 0;
	}

	/**
	* pcie_port_shutdown_service - shut down given PCI Express port service
	* @dev: PCI Express port service device to handle
	*
	* If PCI Express port service driver is registered with
	* pcie_port_service_register(), this function will be called by the driver core
	* when device_shutdown() is called for the port service device associated
	* with the driver.
	*/
	static void pcie_port_shutdown_service(struct device *dev) {}

	/**
	* pcie_port_service_register - register PCI Express port service driver
	* @new: PCI Express port service driver to register
	*/
	int pcie_port_service_register(struct pcie_port_service_driver *new)
	{
	if (pcie_ports_disabled)
	return -ENODEV;

	new->driver.name = new->name;
	new->driver.bus = &pcie_port_bus_type;
	new->driver.probe = pcie_port_probe_service;
	new->driver.remove = pcie_port_remove_service;
	new->driver.shutdown = pcie_port_shutdown_service;

	return driver_register(&new->driver);
	}
	EXPORT_SYMBOL(pcie_port_service_register);

	/**
	* pcie_port_service_unregister - unregister PCI Express port service driver
	* @drv: PCI Express port service driver to unregister
	*/
	void pcie_port_service_unregister(struct pcie_port_service_driver *drv)
	{
	driver_unregister(&drv->driver);
	}
	EXPORT_SYMBOL(pcie_port_service_unregister);