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

 /*
  * drivers/pci/pcie/aer/aerdrv.c
  *
  * This file is subject to the terms and conditions of the GNU General Public
  * License.  See the file "COPYING" in the main directory of this archive
  * for more details.
  *
  * This file implements the AER root port service driver. The driver will
  * register an irq handler. When root port triggers an AER interrupt, the irq
  * handler will collect root port status and schedule a work.
  *
  * Copyright (C) 2006 Intel Corp.
  *	Tom Long Nguyen (tom.l.nguyen@intel.com)
  *	Zhang Yanmin (yanmin.zhang@intel.com)
  *
  */

 #include <linux/pci.h>
 #include <linux/pci-acpi.h>
 #include <linux/sched.h>
 #include <linux/kernel.h>
 #include <linux/errno.h>
 #include <linux/pm.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/delay.h>
 #include <linux/pcieport_if.h>
 #include <linux/slab.h>

 #include "aerdrv.h"
 #include "../../pci.h"

 static int aer_probe(struct pcie_device *dev);
 static void aer_remove(struct pcie_device *dev);
 static void aer_error_resume(struct pci_dev *dev);
 static pci_ers_result_t aer_root_reset(struct pci_dev *dev);

 static struct pcie_port_service_driver aerdriver = {
 	.name		= "aer",
 	.port_type	= PCI_EXP_TYPE_ROOT_PORT,
 	.service	= PCIE_PORT_SERVICE_AER,

 	.probe		= aer_probe,
 	.remove		= aer_remove,
 	.error_resume	= aer_error_resume,
 	.reset_link	= aer_root_reset,
 };

 static int pcie_aer_disable;

 void pci_no_aer(void)
 {
 	pcie_aer_disable = 1;
 }

 bool pci_aer_available(void)
 {
 	return !pcie_aer_disable && pci_msi_enabled();
 }

 static int set_device_error_reporting(struct pci_dev *dev, void *data)
 {
 	bool enable = *((bool *)data);
 	int type = pci_pcie_type(dev);

 	if ((type == PCI_EXP_TYPE_ROOT_PORT) ||
 	    (type == PCI_EXP_TYPE_UPSTREAM) ||
 	    (type == PCI_EXP_TYPE_DOWNSTREAM)) {
 		if (enable)
 			pci_enable_pcie_error_reporting(dev);
 		else
 			pci_disable_pcie_error_reporting(dev);
 	}

 	if (enable)
 		pcie_set_ecrc_checking(dev);

 	return 0;
 }

 /**
  * set_downstream_devices_error_reporting - enable/disable the error reporting  bits on the root port and its downstream ports.
  * @dev: pointer to root port's pci_dev data structure
  * @enable: true = enable error reporting, false = disable error reporting.
  */
 static void set_downstream_devices_error_reporting(struct pci_dev *dev,
 						   bool enable)
 {
 	set_device_error_reporting(dev, &enable);

 	if (!dev->subordinate)
 		return;
 	pci_walk_bus(dev->subordinate, set_device_error_reporting, &enable);
 }

 /**
  * aer_enable_rootport - enable Root Port's interrupts when receiving messages
  * @rpc: pointer to a Root Port data structure
  *
  * Invoked when PCIe bus loads AER service driver.
  */
 static void aer_enable_rootport(struct aer_rpc *rpc)
 {
 	struct pci_dev *pdev = rpc->rpd->port;
 	int aer_pos;
 	u16 reg16;
 	u32 reg32;

 	/* Clear PCIe Capability's Device Status */
 	pcie_capability_read_word(pdev, PCI_EXP_DEVSTA, &reg16);
 	pcie_capability_write_word(pdev, PCI_EXP_DEVSTA, reg16);

 	/* Disable system error generation in response to error messages */
 	pcie_capability_clear_word(pdev, PCI_EXP_RTCTL,
 				   SYSTEM_ERROR_INTR_ON_MESG_MASK);

 	aer_pos = pdev->aer_cap;
 	/* Clear error status */
 	pci_read_config_dword(pdev, aer_pos + PCI_ERR_ROOT_STATUS, &reg32);
 	pci_write_config_dword(pdev, aer_pos + PCI_ERR_ROOT_STATUS, reg32);
 	pci_read_config_dword(pdev, aer_pos + PCI_ERR_COR_STATUS, &reg32);
 	pci_write_config_dword(pdev, aer_pos + PCI_ERR_COR_STATUS, reg32);
 	pci_read_config_dword(pdev, aer_pos + PCI_ERR_UNCOR_STATUS, &reg32);
 	pci_write_config_dword(pdev, aer_pos + PCI_ERR_UNCOR_STATUS, reg32);

 	/*
 	 * Enable error reporting for the root port device and downstream port
 	 * devices.
 	 */
 	set_downstream_devices_error_reporting(pdev, true);

 	/* Enable Root Port's interrupt in response to error messages */
 	pci_read_config_dword(pdev, aer_pos + PCI_ERR_ROOT_COMMAND, &reg32);
 	reg32 |= ROOT_PORT_INTR_ON_MESG_MASK;
 	pci_write_config_dword(pdev, aer_pos + PCI_ERR_ROOT_COMMAND, reg32);
 }

 /**
  * aer_disable_rootport - disable Root Port's interrupts when receiving messages
  * @rpc: pointer to a Root Port data structure
  *
  * Invoked when PCIe bus unloads AER service driver.
  */
 static void aer_disable_rootport(struct aer_rpc *rpc)
 {
 	struct pci_dev *pdev = rpc->rpd->port;
 	u32 reg32;
 	int pos;

 	/*
 	 * Disable error reporting for the root port device and downstream port
 	 * devices.
 	 */
 	set_downstream_devices_error_reporting(pdev, false);

 	pos = pdev->aer_cap;
 	/* Disable Root's interrupt in response to error messages */
 	pci_read_config_dword(pdev, pos + PCI_ERR_ROOT_COMMAND, &reg32);
 	reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK;
 	pci_write_config_dword(pdev, pos + PCI_ERR_ROOT_COMMAND, reg32);

 	/* Clear Root's error status reg */
 	pci_read_config_dword(pdev, pos + PCI_ERR_ROOT_STATUS, &reg32);
 	pci_write_config_dword(pdev, pos + PCI_ERR_ROOT_STATUS, reg32);
 }

 /**
  * aer_irq - Root Port's ISR
  * @irq: IRQ assigned to Root Port
  * @context: pointer to Root Port data structure
  *
  * Invoked when Root Port detects AER messages.
  */
 irqreturn_t aer_irq(int irq, void *context)
 {
 	unsigned int status, id;
 	struct pcie_device *pdev = (struct pcie_device *)context;
 	struct aer_rpc *rpc = get_service_data(pdev);
 	int next_prod_idx;
 	unsigned long flags;
 	int pos;

 	pos = pdev->port->aer_cap;
 	/*
 	 * Must lock access to Root Error Status Reg, Root Error ID Reg,
 	 * and Root error producer/consumer index
 	 */
 	spin_lock_irqsave(&rpc->e_lock, flags);

 	/* Read error status */
 	pci_read_config_dword(pdev->port, pos + PCI_ERR_ROOT_STATUS, &status);
 	if (!(status & (PCI_ERR_ROOT_UNCOR_RCV|PCI_ERR_ROOT_COR_RCV))) {
 		spin_unlock_irqrestore(&rpc->e_lock, flags);
 		return IRQ_NONE;
 	}

 	/* Read error source and clear error status */
 	pci_read_config_dword(pdev->port, pos + PCI_ERR_ROOT_ERR_SRC, &id);
 	pci_write_config_dword(pdev->port, pos + PCI_ERR_ROOT_STATUS, status);

 	/* Store error source for later DPC handler */
 	next_prod_idx = rpc->prod_idx + 1;
 	if (next_prod_idx == AER_ERROR_SOURCES_MAX)
 		next_prod_idx = 0;
 	if (next_prod_idx == rpc->cons_idx) {
 		/*
 		 * Error Storm Condition - possibly the same error occurred.
 		 * Drop the error.
 		 */
 		spin_unlock_irqrestore(&rpc->e_lock, flags);
 		return IRQ_HANDLED;
 	}
 	rpc->e_sources[rpc->prod_idx].status =  status;
 	rpc->e_sources[rpc->prod_idx].id = id;
 	rpc->prod_idx = next_prod_idx;
 	spin_unlock_irqrestore(&rpc->e_lock, flags);

 	/*  Invoke DPC handler */
 	schedule_work(&rpc->dpc_handler);

 	return IRQ_HANDLED;
 }
 EXPORT_SYMBOL_GPL(aer_irq);

 /**
  * aer_alloc_rpc - allocate Root Port data structure
  * @dev: pointer to the pcie_dev data structure
  *
  * Invoked when Root Port's AER service is loaded.
  */
 static struct aer_rpc *aer_alloc_rpc(struct pcie_device *dev)
 {
 	struct aer_rpc *rpc;

 	rpc = kzalloc(sizeof(struct aer_rpc), GFP_KERNEL);
 	if (!rpc)
 		return NULL;

 	/* Initialize Root lock access, e_lock, to Root Error Status Reg */
 	spin_lock_init(&rpc->e_lock);

 	rpc->rpd = dev;
 	INIT_WORK(&rpc->dpc_handler, aer_isr);
 	mutex_init(&rpc->rpc_mutex);

 	/* Use PCIe bus function to store rpc into PCIe device */
 	set_service_data(dev, rpc);

 	return rpc;
 }

 /**
  * aer_remove - clean up resources
  * @dev: pointer to the pcie_dev data structure
  *
  * Invoked when PCI Express bus unloads or AER probe fails.
  */
 static void aer_remove(struct pcie_device *dev)
 {
 	struct aer_rpc *rpc = get_service_data(dev);

 	if (rpc) {
 		/* If register interrupt service, it must be free. */
 		if (rpc->isr)
 			free_irq(dev->irq, dev);

 		flush_work(&rpc->dpc_handler);
 		aer_disable_rootport(rpc);
 		kfree(rpc);
 		set_service_data(dev, NULL);
 	}
 }

 /**
  * aer_probe - initialize resources
  * @dev: pointer to the pcie_dev data structure
  *
  * Invoked when PCI Express bus loads AER service driver.
  */
 static int aer_probe(struct pcie_device *dev)
 {
 	int status;
 	struct aer_rpc *rpc;
 	struct device *device = &dev->port->dev;

 	/* Alloc rpc data structure */
 	rpc = aer_alloc_rpc(dev);
 	if (!rpc) {
 		dev_printk(KERN_DEBUG, device, "alloc AER rpc failed\n");
 		aer_remove(dev);
 		return -ENOMEM;
 	}

 	/* Request IRQ ISR */
 	status = request_irq(dev->irq, aer_irq, IRQF_SHARED, "aerdrv", dev);
 	if (status) {
 		dev_printk(KERN_DEBUG, device, "request AER IRQ %d failed\n",
 			   dev->irq);
 		aer_remove(dev);
 		return status;
 	}

 	rpc->isr = 1;

 	aer_enable_rootport(rpc);
 	dev_info(device, "AER enabled with IRQ %d\n", dev->irq);
 	return 0;
 }

 /**
  * aer_root_reset - reset link on Root Port
  * @dev: pointer to Root Port's pci_dev data structure
  *
  * Invoked by Port Bus driver when performing link reset at Root Port.
  */
 static pci_ers_result_t aer_root_reset(struct pci_dev *dev)
 {
 	u32 reg32;
 	int pos;

 	pos = dev->aer_cap;

 	/* Disable Root's interrupt in response to error messages */
 	pci_read_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, &reg32);
 	reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK;
 	pci_write_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, reg32);

 	pci_reset_bridge_secondary_bus(dev);
 	dev_printk(KERN_DEBUG, &dev->dev, "Root Port link has been reset\n");

 	/* Clear Root Error Status */
 	pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, &reg32);
 	pci_write_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, reg32);

 	/* Enable Root Port's interrupt in response to error messages */
 	pci_read_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, &reg32);
 	reg32 |= ROOT_PORT_INTR_ON_MESG_MASK;
 	pci_write_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, reg32);

 	return PCI_ERS_RESULT_RECOVERED;
 }

 /**
  * aer_error_resume - clean up corresponding error status bits
  * @dev: pointer to Root Port's pci_dev data structure
  *
  * Invoked by Port Bus driver during nonfatal recovery.
  */
 static void aer_error_resume(struct pci_dev *dev)
 {
 	int pos;
 	u32 status, mask;
 	u16 reg16;

 	/* Clean up Root device status */
 	pcie_capability_read_word(dev, PCI_EXP_DEVSTA, &reg16);
 	pcie_capability_write_word(dev, PCI_EXP_DEVSTA, reg16);

 	/* Clean AER Root Error Status */
 	pos = dev->aer_cap;
 	pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, &status);
 	pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_SEVER, &mask);
 	if (dev->error_state == pci_channel_io_normal)
 		status &= ~mask; /* Clear corresponding nonfatal bits */
 	else
 		status &= mask; /* Clear corresponding fatal bits */
 	pci_write_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, status);
 }

 /**
  * aer_service_init - register AER root service driver
  *
  * Invoked when AER root service driver is loaded.
  */
 static int __init aer_service_init(void)
 {
 	if (!pci_aer_available() || aer_acpi_firmware_first())
 		return -ENXIO;
 	return pcie_port_service_register(&aerdriver);
 }
 device_initcall(aer_service_init);
	/*
	* drivers/pci/pcie/aer/aerdrv.c
	*
	* This file is subject to the terms and conditions of the GNU General Public
	* License. See the file "COPYING" in the main directory of this archive
	* for more details.
	*
	* This file implements the AER root port service driver. The driver will
	* register an irq handler. When root port triggers an AER interrupt, the irq
	* handler will collect root port status and schedule a work.
	*
	* Copyright (C) 2006 Intel Corp.
	* Tom Long Nguyen (tom.l.nguyen@intel.com)
	* Zhang Yanmin (yanmin.zhang@intel.com)
	*
	*/

	#include <linux/pci.h>
	#include <linux/pci-acpi.h>
	#include <linux/sched.h>
	#include <linux/kernel.h>
	#include <linux/errno.h>
	#include <linux/pm.h>
	#include <linux/init.h>
	#include <linux/interrupt.h>
	#include <linux/delay.h>
	#include <linux/pcieport_if.h>
	#include <linux/slab.h>

	#include "aerdrv.h"
	#include "../../pci.h"

	static int aer_probe(struct pcie_device *dev);
	static void aer_remove(struct pcie_device *dev);
	static void aer_error_resume(struct pci_dev *dev);
	static pci_ers_result_t aer_root_reset(struct pci_dev *dev);

	static struct pcie_port_service_driver aerdriver = {
	.name = "aer",
	.port_type = PCI_EXP_TYPE_ROOT_PORT,
	.service = PCIE_PORT_SERVICE_AER,

	.probe = aer_probe,
	.remove = aer_remove,
	.error_resume = aer_error_resume,
	.reset_link = aer_root_reset,
	};

	static int pcie_aer_disable;

	void pci_no_aer(void)
	{
	pcie_aer_disable = 1;
	}

	bool pci_aer_available(void)
	{
	return !pcie_aer_disable && pci_msi_enabled();
	}

	static int set_device_error_reporting(struct pci_dev dev, void data)
	{
	bool enable = ((bool )data);
	int type = pci_pcie_type(dev);

	if ((type == PCI_EXP_TYPE_ROOT_PORT) \|\|
	(type == PCI_EXP_TYPE_UPSTREAM) \|\|
	(type == PCI_EXP_TYPE_DOWNSTREAM)) {
	if (enable)
	pci_enable_pcie_error_reporting(dev);
	else
	pci_disable_pcie_error_reporting(dev);
	}

	if (enable)
	pcie_set_ecrc_checking(dev);

	return 0;
	}

	/**
	* set_downstream_devices_error_reporting - enable/disable the error reporting bits on the root port and its downstream ports.
	* @dev: pointer to root port's pci_dev data structure
	* @enable: true = enable error reporting, false = disable error reporting.
	*/
	static void set_downstream_devices_error_reporting(struct pci_dev *dev,
	bool enable)
	{
	set_device_error_reporting(dev, &enable);

	if (!dev->subordinate)
	return;
	pci_walk_bus(dev->subordinate, set_device_error_reporting, &enable);
	}

	/**
	* aer_enable_rootport - enable Root Port's interrupts when receiving messages
	* @rpc: pointer to a Root Port data structure
	*
	* Invoked when PCIe bus loads AER service driver.
	*/
	static void aer_enable_rootport(struct aer_rpc *rpc)
	{
	struct pci_dev *pdev = rpc->rpd->port;
	int aer_pos;
	u16 reg16;
	u32 reg32;

	/* Clear PCIe Capability's Device Status */
	pcie_capability_read_word(pdev, PCI_EXP_DEVSTA, &reg16);
	pcie_capability_write_word(pdev, PCI_EXP_DEVSTA, reg16);

	/* Disable system error generation in response to error messages */
	pcie_capability_clear_word(pdev, PCI_EXP_RTCTL,
	SYSTEM_ERROR_INTR_ON_MESG_MASK);

	aer_pos = pdev->aer_cap;
	/* Clear error status */
	pci_read_config_dword(pdev, aer_pos + PCI_ERR_ROOT_STATUS, &reg32);
	pci_write_config_dword(pdev, aer_pos + PCI_ERR_ROOT_STATUS, reg32);
	pci_read_config_dword(pdev, aer_pos + PCI_ERR_COR_STATUS, &reg32);
	pci_write_config_dword(pdev, aer_pos + PCI_ERR_COR_STATUS, reg32);
	pci_read_config_dword(pdev, aer_pos + PCI_ERR_UNCOR_STATUS, &reg32);
	pci_write_config_dword(pdev, aer_pos + PCI_ERR_UNCOR_STATUS, reg32);

	/*
	* Enable error reporting for the root port device and downstream port
	* devices.
	*/
	set_downstream_devices_error_reporting(pdev, true);

	/* Enable Root Port's interrupt in response to error messages */
	pci_read_config_dword(pdev, aer_pos + PCI_ERR_ROOT_COMMAND, &reg32);
	reg32 \|= ROOT_PORT_INTR_ON_MESG_MASK;
	pci_write_config_dword(pdev, aer_pos + PCI_ERR_ROOT_COMMAND, reg32);
	}

	/**
	* aer_disable_rootport - disable Root Port's interrupts when receiving messages
	* @rpc: pointer to a Root Port data structure
	*
	* Invoked when PCIe bus unloads AER service driver.
	*/
	static void aer_disable_rootport(struct aer_rpc *rpc)
	{
	struct pci_dev *pdev = rpc->rpd->port;
	u32 reg32;
	int pos;

	/*
	* Disable error reporting for the root port device and downstream port
	* devices.
	*/
	set_downstream_devices_error_reporting(pdev, false);

	pos = pdev->aer_cap;
	/* Disable Root's interrupt in response to error messages */
	pci_read_config_dword(pdev, pos + PCI_ERR_ROOT_COMMAND, &reg32);
	reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK;
	pci_write_config_dword(pdev, pos + PCI_ERR_ROOT_COMMAND, reg32);

	/* Clear Root's error status reg */
	pci_read_config_dword(pdev, pos + PCI_ERR_ROOT_STATUS, &reg32);
	pci_write_config_dword(pdev, pos + PCI_ERR_ROOT_STATUS, reg32);
	}

	/**
	* aer_irq - Root Port's ISR
	* @irq: IRQ assigned to Root Port
	* @context: pointer to Root Port data structure
	*
	* Invoked when Root Port detects AER messages.
	*/
	irqreturn_t aer_irq(int irq, void *context)
	{
	unsigned int status, id;
	struct pcie_device pdev = (struct pcie_device )context;
	struct aer_rpc *rpc = get_service_data(pdev);
	int next_prod_idx;
	unsigned long flags;
	int pos;

	pos = pdev->port->aer_cap;
	/*
	* Must lock access to Root Error Status Reg, Root Error ID Reg,
	* and Root error producer/consumer index
	*/
	spin_lock_irqsave(&rpc->e_lock, flags);

	/* Read error status */
	pci_read_config_dword(pdev->port, pos + PCI_ERR_ROOT_STATUS, &status);
	if (!(status & (PCI_ERR_ROOT_UNCOR_RCV\|PCI_ERR_ROOT_COR_RCV))) {
	spin_unlock_irqrestore(&rpc->e_lock, flags);
	return IRQ_NONE;
	}

	/* Read error source and clear error status */
	pci_read_config_dword(pdev->port, pos + PCI_ERR_ROOT_ERR_SRC, &id);
	pci_write_config_dword(pdev->port, pos + PCI_ERR_ROOT_STATUS, status);

	/* Store error source for later DPC handler */
	next_prod_idx = rpc->prod_idx + 1;
	if (next_prod_idx == AER_ERROR_SOURCES_MAX)
	next_prod_idx = 0;
	if (next_prod_idx == rpc->cons_idx) {
	/*
	* Error Storm Condition - possibly the same error occurred.
	* Drop the error.
	*/
	spin_unlock_irqrestore(&rpc->e_lock, flags);
	return IRQ_HANDLED;
	}
	rpc->e_sources[rpc->prod_idx].status = status;
	rpc->e_sources[rpc->prod_idx].id = id;
	rpc->prod_idx = next_prod_idx;
	spin_unlock_irqrestore(&rpc->e_lock, flags);

	/* Invoke DPC handler */
	schedule_work(&rpc->dpc_handler);

	return IRQ_HANDLED;
	}
	EXPORT_SYMBOL_GPL(aer_irq);

	/**
	* aer_alloc_rpc - allocate Root Port data structure
	* @dev: pointer to the pcie_dev data structure
	*
	* Invoked when Root Port's AER service is loaded.
	*/
	static struct aer_rpc aer_alloc_rpc(struct pcie_device dev)
	{
	struct aer_rpc *rpc;

	rpc = kzalloc(sizeof(struct aer_rpc), GFP_KERNEL);
	if (!rpc)
	return NULL;

	/* Initialize Root lock access, e_lock, to Root Error Status Reg */
	spin_lock_init(&rpc->e_lock);

	rpc->rpd = dev;
	INIT_WORK(&rpc->dpc_handler, aer_isr);
	mutex_init(&rpc->rpc_mutex);

	/* Use PCIe bus function to store rpc into PCIe device */
	set_service_data(dev, rpc);

	return rpc;
	}

	/**
	* aer_remove - clean up resources
	* @dev: pointer to the pcie_dev data structure
	*
	* Invoked when PCI Express bus unloads or AER probe fails.
	*/
	static void aer_remove(struct pcie_device *dev)
	{
	struct aer_rpc *rpc = get_service_data(dev);

	if (rpc) {
	/* If register interrupt service, it must be free. */
	if (rpc->isr)
	free_irq(dev->irq, dev);

	flush_work(&rpc->dpc_handler);
	aer_disable_rootport(rpc);
	kfree(rpc);
	set_service_data(dev, NULL);
	}
	}

	/**
	* aer_probe - initialize resources
	* @dev: pointer to the pcie_dev data structure
	*
	* Invoked when PCI Express bus loads AER service driver.
	*/
	static int aer_probe(struct pcie_device *dev)
	{
	int status;
	struct aer_rpc *rpc;
	struct device *device = &dev->port->dev;

	/* Alloc rpc data structure */
	rpc = aer_alloc_rpc(dev);
	if (!rpc) {
	dev_printk(KERN_DEBUG, device, "alloc AER rpc failed\n");
	aer_remove(dev);
	return -ENOMEM;
	}

	/* Request IRQ ISR */
	status = request_irq(dev->irq, aer_irq, IRQF_SHARED, "aerdrv", dev);
	if (status) {
	dev_printk(KERN_DEBUG, device, "request AER IRQ %d failed\n",
	dev->irq);
	aer_remove(dev);
	return status;
	}

	rpc->isr = 1;

	aer_enable_rootport(rpc);
	dev_info(device, "AER enabled with IRQ %d\n", dev->irq);
	return 0;
	}

	/**
	* aer_root_reset - reset link on Root Port
	* @dev: pointer to Root Port's pci_dev data structure
	*
	* Invoked by Port Bus driver when performing link reset at Root Port.
	*/
	static pci_ers_result_t aer_root_reset(struct pci_dev *dev)
	{
	u32 reg32;
	int pos;

	pos = dev->aer_cap;

	/* Disable Root's interrupt in response to error messages */
	pci_read_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, &reg32);
	reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK;
	pci_write_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, reg32);

	pci_reset_bridge_secondary_bus(dev);
	dev_printk(KERN_DEBUG, &dev->dev, "Root Port link has been reset\n");

	/* Clear Root Error Status */
	pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, &reg32);
	pci_write_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, reg32);

	/* Enable Root Port's interrupt in response to error messages */
	pci_read_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, &reg32);
	reg32 \|= ROOT_PORT_INTR_ON_MESG_MASK;
	pci_write_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, reg32);

	return PCI_ERS_RESULT_RECOVERED;
	}

	/**
	* aer_error_resume - clean up corresponding error status bits
	* @dev: pointer to Root Port's pci_dev data structure
	*
	* Invoked by Port Bus driver during nonfatal recovery.
	*/
	static void aer_error_resume(struct pci_dev *dev)
	{
	int pos;
	u32 status, mask;
	u16 reg16;

	/* Clean up Root device status */
	pcie_capability_read_word(dev, PCI_EXP_DEVSTA, &reg16);
	pcie_capability_write_word(dev, PCI_EXP_DEVSTA, reg16);

	/* Clean AER Root Error Status */
	pos = dev->aer_cap;
	pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, &status);
	pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_SEVER, &mask);
	if (dev->error_state == pci_channel_io_normal)
	status &= ~mask; /* Clear corresponding nonfatal bits */
	else
	status &= mask; /* Clear corresponding fatal bits */
	pci_write_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, status);
	}

	/**
	* aer_service_init - register AER root service driver
	*
	* Invoked when AER root service driver is loaded.
	*/
	static int __init aer_service_init(void)
	{
	if (!pci_aer_available() \|\| aer_acpi_firmware_first())
	return -ENXIO;
	return pcie_port_service_register(&aerdriver);
	}
	device_initcall(aer_service_init);