Adding upstream version 6.1.76.upstream/6.1.76

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

1 files changed, 1466 insertions, 0 deletions

diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
new file mode 100644
index 000000000..e2d8a74f8
--- /dev/null
+++ b/drivers/pci/pcie/aer.c
@@ -0,0 +1,1466 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Implement the AER root port service driver. The driver registers an IRQ
+ * handler. When a root port triggers an AER interrupt, the IRQ handler
+ * collects root port status and schedules work.
+ *
+ * Copyright (C) 2006 Intel Corp.
+ *	Tom Long Nguyen (tom.l.nguyen@intel.com)
+ *	Zhang Yanmin (yanmin.zhang@intel.com)
+ *
+ * (C) Copyright 2009 Hewlett-Packard Development Company, L.P.
+ *    Andrew Patterson <andrew.patterson@hp.com>
+ */
+
+#define pr_fmt(fmt) "AER: " fmt
+#define dev_fmt pr_fmt
+
+#include <linux/bitops.h>
+#include <linux/cper.h>
+#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/kfifo.h>
+#include <linux/slab.h>
+#include <acpi/apei.h>
+#include <ras/ras_event.h>
+
+#include "../pci.h"
+#include "portdrv.h"
+
+#define AER_ERROR_SOURCES_MAX		128
+
+#define AER_MAX_TYPEOF_COR_ERRS		16	/* as per PCI_ERR_COR_STATUS */
+#define AER_MAX_TYPEOF_UNCOR_ERRS	27	/* as per PCI_ERR_UNCOR_STATUS*/
+
+struct aer_err_source {
+	unsigned int status;
+	unsigned int id;
+};
+
+struct aer_rpc {
+	struct pci_dev *rpd;		/* Root Port device */
+	DECLARE_KFIFO(aer_fifo, struct aer_err_source, AER_ERROR_SOURCES_MAX);
+};
+
+/* AER stats for the device */
+struct aer_stats {
+
+	/*
+	 * Fields for all AER capable devices. They indicate the errors
+	 * "as seen by this device". Note that this may mean that if an
+	 * end point is causing problems, the AER counters may increment
+	 * at its link partner (e.g. root port) because the errors will be
+	 * "seen" by the link partner and not the problematic end point
+	 * itself (which may report all counters as 0 as it never saw any
+	 * problems).
+	 */
+	/* Counters for different type of correctable errors */
+	u64 dev_cor_errs[AER_MAX_TYPEOF_COR_ERRS];
+	/* Counters for different type of fatal uncorrectable errors */
+	u64 dev_fatal_errs[AER_MAX_TYPEOF_UNCOR_ERRS];
+	/* Counters for different type of nonfatal uncorrectable errors */
+	u64 dev_nonfatal_errs[AER_MAX_TYPEOF_UNCOR_ERRS];
+	/* Total number of ERR_COR sent by this device */
+	u64 dev_total_cor_errs;
+	/* Total number of ERR_FATAL sent by this device */
+	u64 dev_total_fatal_errs;
+	/* Total number of ERR_NONFATAL sent by this device */
+	u64 dev_total_nonfatal_errs;
+
+	/*
+	 * Fields for Root ports & root complex event collectors only, these
+	 * indicate the total number of ERR_COR, ERR_FATAL, and ERR_NONFATAL
+	 * messages received by the root port / event collector, INCLUDING the
+	 * ones that are generated internally (by the rootport itself)
+	 */
+	u64 rootport_total_cor_errs;
+	u64 rootport_total_fatal_errs;
+	u64 rootport_total_nonfatal_errs;
+};
+
+#define AER_LOG_TLP_MASKS		(PCI_ERR_UNC_POISON_TLP|	\
+					PCI_ERR_UNC_ECRC|		\
+					PCI_ERR_UNC_UNSUP|		\
+					PCI_ERR_UNC_COMP_ABORT|		\
+					PCI_ERR_UNC_UNX_COMP|		\
+					PCI_ERR_UNC_MALF_TLP)
+
+#define SYSTEM_ERROR_INTR_ON_MESG_MASK	(PCI_EXP_RTCTL_SECEE|	\
+					PCI_EXP_RTCTL_SENFEE|	\
+					PCI_EXP_RTCTL_SEFEE)
+#define ROOT_PORT_INTR_ON_MESG_MASK	(PCI_ERR_ROOT_CMD_COR_EN|	\
+					PCI_ERR_ROOT_CMD_NONFATAL_EN|	\
+					PCI_ERR_ROOT_CMD_FATAL_EN)
+#define ERR_COR_ID(d)			(d & 0xffff)
+#define ERR_UNCOR_ID(d)			(d >> 16)
+
+#define AER_ERR_STATUS_MASK		(PCI_ERR_ROOT_UNCOR_RCV |	\
+					PCI_ERR_ROOT_COR_RCV |		\
+					PCI_ERR_ROOT_MULTI_COR_RCV |	\
+					PCI_ERR_ROOT_MULTI_UNCOR_RCV)
+
+static int pcie_aer_disable;
+static pci_ers_result_t aer_root_reset(struct pci_dev *dev);
+
+void pci_no_aer(void)
+{
+	pcie_aer_disable = 1;
+}
+
+bool pci_aer_available(void)
+{
+	return !pcie_aer_disable && pci_msi_enabled();
+}
+
+#ifdef CONFIG_PCIE_ECRC
+
+#define ECRC_POLICY_DEFAULT 0		/* ECRC set by BIOS */
+#define ECRC_POLICY_OFF     1		/* ECRC off for performance */
+#define ECRC_POLICY_ON      2		/* ECRC on for data integrity */
+
+static int ecrc_policy = ECRC_POLICY_DEFAULT;
+
+static const char * const ecrc_policy_str[] = {
+	[ECRC_POLICY_DEFAULT] = "bios",
+	[ECRC_POLICY_OFF] = "off",
+	[ECRC_POLICY_ON] = "on"
+};
+
+/**
+ * enable_ecrc_checking - enable PCIe ECRC checking for a device
+ * @dev: the PCI device
+ *
+ * Returns 0 on success, or negative on failure.
+ */
+static int enable_ecrc_checking(struct pci_dev *dev)
+{
+	int aer = dev->aer_cap;
+	u32 reg32;
+
+	if (!aer)
+		return -ENODEV;
+
+	pci_read_config_dword(dev, aer + PCI_ERR_CAP, &reg32);
+	if (reg32 & PCI_ERR_CAP_ECRC_GENC)
+		reg32 |= PCI_ERR_CAP_ECRC_GENE;
+	if (reg32 & PCI_ERR_CAP_ECRC_CHKC)
+		reg32 |= PCI_ERR_CAP_ECRC_CHKE;
+	pci_write_config_dword(dev, aer + PCI_ERR_CAP, reg32);
+
+	return 0;
+}
+
+/**
+ * disable_ecrc_checking - disables PCIe ECRC checking for a device
+ * @dev: the PCI device
+ *
+ * Returns 0 on success, or negative on failure.
+ */
+static int disable_ecrc_checking(struct pci_dev *dev)
+{
+	int aer = dev->aer_cap;
+	u32 reg32;
+
+	if (!aer)
+		return -ENODEV;
+
+	pci_read_config_dword(dev, aer + PCI_ERR_CAP, &reg32);
+	reg32 &= ~(PCI_ERR_CAP_ECRC_GENE | PCI_ERR_CAP_ECRC_CHKE);
+	pci_write_config_dword(dev, aer + PCI_ERR_CAP, reg32);
+
+	return 0;
+}
+
+/**
+ * pcie_set_ecrc_checking - set/unset PCIe ECRC checking for a device based on global policy
+ * @dev: the PCI device
+ */
+void pcie_set_ecrc_checking(struct pci_dev *dev)
+{
+	switch (ecrc_policy) {
+	case ECRC_POLICY_DEFAULT:
+		return;
+	case ECRC_POLICY_OFF:
+		disable_ecrc_checking(dev);
+		break;
+	case ECRC_POLICY_ON:
+		enable_ecrc_checking(dev);
+		break;
+	default:
+		return;
+	}
+}
+
+/**
+ * pcie_ecrc_get_policy - parse kernel command-line ecrc option
+ * @str: ECRC policy from kernel command line to use
+ */
+void pcie_ecrc_get_policy(char *str)
+{
+	int i;
+
+	i = match_string(ecrc_policy_str, ARRAY_SIZE(ecrc_policy_str), str);
+	if (i < 0)
+		return;
+
+	ecrc_policy = i;
+}
+#endif	/* CONFIG_PCIE_ECRC */
+
+#define	PCI_EXP_AER_FLAGS	(PCI_EXP_DEVCTL_CERE | PCI_EXP_DEVCTL_NFERE | \
+				 PCI_EXP_DEVCTL_FERE | PCI_EXP_DEVCTL_URRE)
+
+int pcie_aer_is_native(struct pci_dev *dev)
+{
+	struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);
+
+	if (!dev->aer_cap)
+		return 0;
+
+	return pcie_ports_native || host->native_aer;
+}
+
+int pci_enable_pcie_error_reporting(struct pci_dev *dev)
+{
+	int rc;
+
+	if (!pcie_aer_is_native(dev))
+		return -EIO;
+
+	rc = pcie_capability_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_AER_FLAGS);
+	return pcibios_err_to_errno(rc);
+}
+EXPORT_SYMBOL_GPL(pci_enable_pcie_error_reporting);
+
+int pci_disable_pcie_error_reporting(struct pci_dev *dev)
+{
+	int rc;
+
+	if (!pcie_aer_is_native(dev))
+		return -EIO;
+
+	rc = pcie_capability_clear_word(dev, PCI_EXP_DEVCTL, PCI_EXP_AER_FLAGS);
+	return pcibios_err_to_errno(rc);
+}
+EXPORT_SYMBOL_GPL(pci_disable_pcie_error_reporting);
+
+int pci_aer_clear_nonfatal_status(struct pci_dev *dev)
+{
+	int aer = dev->aer_cap;
+	u32 status, sev;
+
+	if (!pcie_aer_is_native(dev))
+		return -EIO;
+
+	/* Clear status bits for ERR_NONFATAL errors only */
+	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, &status);
+	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_SEVER, &sev);
+	status &= ~sev;
+	if (status)
+		pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, status);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(pci_aer_clear_nonfatal_status);
+
+void pci_aer_clear_fatal_status(struct pci_dev *dev)
+{
+	int aer = dev->aer_cap;
+	u32 status, sev;
+
+	if (!pcie_aer_is_native(dev))
+		return;
+
+	/* Clear status bits for ERR_FATAL errors only */
+	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, &status);
+	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_SEVER, &sev);
+	status &= sev;
+	if (status)
+		pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, status);
+}
+
+/**
+ * pci_aer_raw_clear_status - Clear AER error registers.
+ * @dev: the PCI device
+ *
+ * Clearing AER error status registers unconditionally, regardless of
+ * whether they're owned by firmware or the OS.
+ *
+ * Returns 0 on success, or negative on failure.
+ */
+int pci_aer_raw_clear_status(struct pci_dev *dev)
+{
+	int aer = dev->aer_cap;
+	u32 status;
+	int port_type;
+
+	if (!aer)
+		return -EIO;
+
+	port_type = pci_pcie_type(dev);
+	if (port_type == PCI_EXP_TYPE_ROOT_PORT ||
+	    port_type == PCI_EXP_TYPE_RC_EC) {
+		pci_read_config_dword(dev, aer + PCI_ERR_ROOT_STATUS, &status);
+		pci_write_config_dword(dev, aer + PCI_ERR_ROOT_STATUS, status);
+	}
+
+	pci_read_config_dword(dev, aer + PCI_ERR_COR_STATUS, &status);
+	pci_write_config_dword(dev, aer + PCI_ERR_COR_STATUS, status);
+
+	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, &status);
+	pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, status);
+
+	return 0;
+}
+
+int pci_aer_clear_status(struct pci_dev *dev)
+{
+	if (!pcie_aer_is_native(dev))
+		return -EIO;
+
+	return pci_aer_raw_clear_status(dev);
+}
+
+void pci_save_aer_state(struct pci_dev *dev)
+{
+	int aer = dev->aer_cap;
+	struct pci_cap_saved_state *save_state;
+	u32 *cap;
+
+	if (!aer)
+		return;
+
+	save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_ERR);
+	if (!save_state)
+		return;
+
+	cap = &save_state->cap.data[0];
+	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_MASK, cap++);
+	pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_SEVER, cap++);
+	pci_read_config_dword(dev, aer + PCI_ERR_COR_MASK, cap++);
+	pci_read_config_dword(dev, aer + PCI_ERR_CAP, cap++);
+	if (pcie_cap_has_rtctl(dev))
+		pci_read_config_dword(dev, aer + PCI_ERR_ROOT_COMMAND, cap++);
+}
+
+void pci_restore_aer_state(struct pci_dev *dev)
+{
+	int aer = dev->aer_cap;
+	struct pci_cap_saved_state *save_state;
+	u32 *cap;
+
+	if (!aer)
+		return;
+
+	save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_ERR);
+	if (!save_state)
+		return;
+
+	cap = &save_state->cap.data[0];
+	pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_MASK, *cap++);
+	pci_write_config_dword(dev, aer + PCI_ERR_UNCOR_SEVER, *cap++);
+	pci_write_config_dword(dev, aer + PCI_ERR_COR_MASK, *cap++);
+	pci_write_config_dword(dev, aer + PCI_ERR_CAP, *cap++);
+	if (pcie_cap_has_rtctl(dev))
+		pci_write_config_dword(dev, aer + PCI_ERR_ROOT_COMMAND, *cap++);
+}
+
+void pci_aer_init(struct pci_dev *dev)
+{
+	int n;
+
+	dev->aer_cap = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
+	if (!dev->aer_cap)
+		return;
+
+	dev->aer_stats = kzalloc(sizeof(struct aer_stats), GFP_KERNEL);
+
+	/*
+	 * We save/restore PCI_ERR_UNCOR_MASK, PCI_ERR_UNCOR_SEVER,
+	 * PCI_ERR_COR_MASK, and PCI_ERR_CAP.  Root and Root Complex Event
+	 * Collectors also implement PCI_ERR_ROOT_COMMAND (PCIe r5.0, sec
+	 * 7.8.4).
+	 */
+	n = pcie_cap_has_rtctl(dev) ? 5 : 4;
+	pci_add_ext_cap_save_buffer(dev, PCI_EXT_CAP_ID_ERR, sizeof(u32) * n);
+
+	pci_aer_clear_status(dev);
+
+	if (pci_aer_available())
+		pci_enable_pcie_error_reporting(dev);
+
+	pcie_set_ecrc_checking(dev);
+}
+
+void pci_aer_exit(struct pci_dev *dev)
+{
+	kfree(dev->aer_stats);
+	dev->aer_stats = NULL;
+}
+
+#define AER_AGENT_RECEIVER		0
+#define AER_AGENT_REQUESTER		1
+#define AER_AGENT_COMPLETER		2
+#define AER_AGENT_TRANSMITTER		3
+
+#define AER_AGENT_REQUESTER_MASK(t)	((t == AER_CORRECTABLE) ?	\
+	0 : (PCI_ERR_UNC_COMP_TIME|PCI_ERR_UNC_UNSUP))
+#define AER_AGENT_COMPLETER_MASK(t)	((t == AER_CORRECTABLE) ?	\
+	0 : PCI_ERR_UNC_COMP_ABORT)
+#define AER_AGENT_TRANSMITTER_MASK(t)	((t == AER_CORRECTABLE) ?	\
+	(PCI_ERR_COR_REP_ROLL|PCI_ERR_COR_REP_TIMER) : 0)
+
+#define AER_GET_AGENT(t, e)						\
+	((e & AER_AGENT_COMPLETER_MASK(t)) ? AER_AGENT_COMPLETER :	\
+	(e & AER_AGENT_REQUESTER_MASK(t)) ? AER_AGENT_REQUESTER :	\
+	(e & AER_AGENT_TRANSMITTER_MASK(t)) ? AER_AGENT_TRANSMITTER :	\
+	AER_AGENT_RECEIVER)
+
+#define AER_PHYSICAL_LAYER_ERROR	0
+#define AER_DATA_LINK_LAYER_ERROR	1
+#define AER_TRANSACTION_LAYER_ERROR	2
+
+#define AER_PHYSICAL_LAYER_ERROR_MASK(t) ((t == AER_CORRECTABLE) ?	\
+	PCI_ERR_COR_RCVR : 0)
+#define AER_DATA_LINK_LAYER_ERROR_MASK(t) ((t == AER_CORRECTABLE) ?	\
+	(PCI_ERR_COR_BAD_TLP|						\
+	PCI_ERR_COR_BAD_DLLP|						\
+	PCI_ERR_COR_REP_ROLL|						\
+	PCI_ERR_COR_REP_TIMER) : PCI_ERR_UNC_DLP)
+
+#define AER_GET_LAYER_ERROR(t, e)					\
+	((e & AER_PHYSICAL_LAYER_ERROR_MASK(t)) ? AER_PHYSICAL_LAYER_ERROR : \
+	(e & AER_DATA_LINK_LAYER_ERROR_MASK(t)) ? AER_DATA_LINK_LAYER_ERROR : \
+	AER_TRANSACTION_LAYER_ERROR)
+
+/*
+ * AER error strings
+ */
+static const char *aer_error_severity_string[] = {
+	"Uncorrected (Non-Fatal)",
+	"Uncorrected (Fatal)",
+	"Corrected"
+};
+
+static const char *aer_error_layer[] = {
+	"Physical Layer",
+	"Data Link Layer",
+	"Transaction Layer"
+};
+
+static const char *aer_correctable_error_string[] = {
+	"RxErr",			/* Bit Position 0	*/
+	NULL,
+	NULL,
+	NULL,
+	NULL,
+	NULL,
+	"BadTLP",			/* Bit Position 6	*/
+	"BadDLLP",			/* Bit Position 7	*/
+	"Rollover",			/* Bit Position 8	*/
+	NULL,
+	NULL,
+	NULL,
+	"Timeout",			/* Bit Position 12	*/
+	"NonFatalErr",			/* Bit Position 13	*/
+	"CorrIntErr",			/* Bit Position 14	*/
+	"HeaderOF",			/* Bit Position 15	*/
+	NULL,				/* Bit Position 16	*/
+	NULL,				/* Bit Position 17	*/
+	NULL,				/* Bit Position 18	*/
+	NULL,				/* Bit Position 19	*/
+	NULL,				/* Bit Position 20	*/
+	NULL,				/* Bit Position 21	*/
+	NULL,				/* Bit Position 22	*/
+	NULL,				/* Bit Position 23	*/
+	NULL,				/* Bit Position 24	*/
+	NULL,				/* Bit Position 25	*/
+	NULL,				/* Bit Position 26	*/
+	NULL,				/* Bit Position 27	*/
+	NULL,				/* Bit Position 28	*/
+	NULL,				/* Bit Position 29	*/
+	NULL,				/* Bit Position 30	*/
+	NULL,				/* Bit Position 31	*/
+};
+
+static const char *aer_uncorrectable_error_string[] = {
+	"Undefined",			/* Bit Position 0	*/
+	NULL,
+	NULL,
+	NULL,
+	"DLP",				/* Bit Position 4	*/
+	"SDES",				/* Bit Position 5	*/
+	NULL,
+	NULL,
+	NULL,
+	NULL,
+	NULL,
+	NULL,
+	"TLP",				/* Bit Position 12	*/
+	"FCP",				/* Bit Position 13	*/
+	"CmpltTO",			/* Bit Position 14	*/
+	"CmpltAbrt",			/* Bit Position 15	*/
+	"UnxCmplt",			/* Bit Position 16	*/
+	"RxOF",				/* Bit Position 17	*/
+	"MalfTLP",			/* Bit Position 18	*/
+	"ECRC",				/* Bit Position 19	*/
+	"UnsupReq",			/* Bit Position 20	*/
+	"ACSViol",			/* Bit Position 21	*/
+	"UncorrIntErr",			/* Bit Position 22	*/
+	"BlockedTLP",			/* Bit Position 23	*/
+	"AtomicOpBlocked",		/* Bit Position 24	*/
+	"TLPBlockedErr",		/* Bit Position 25	*/
+	"PoisonTLPBlocked",		/* Bit Position 26	*/
+	NULL,				/* Bit Position 27	*/
+	NULL,				/* Bit Position 28	*/
+	NULL,				/* Bit Position 29	*/
+	NULL,				/* Bit Position 30	*/
+	NULL,				/* Bit Position 31	*/
+};
+
+static const char *aer_agent_string[] = {
+	"Receiver ID",
+	"Requester ID",
+	"Completer ID",
+	"Transmitter ID"
+};
+
+#define aer_stats_dev_attr(name, stats_array, strings_array,		\
+			   total_string, total_field)			\
+	static ssize_t							\
+	name##_show(struct device *dev, struct device_attribute *attr,	\
+		     char *buf)						\
+{									\
+	unsigned int i;							\
+	struct pci_dev *pdev = to_pci_dev(dev);				\
+	u64 *stats = pdev->aer_stats->stats_array;			\
+	size_t len = 0;							\
+									\
+	for (i = 0; i < ARRAY_SIZE(pdev->aer_stats->stats_array); i++) {\
+		if (strings_array[i])					\
+			len += sysfs_emit_at(buf, len, "%s %llu\n",	\
+					     strings_array[i],		\
+					     stats[i]);			\
+		else if (stats[i])					\
+			len += sysfs_emit_at(buf, len,			\
+					     #stats_array "_bit[%d] %llu\n",\
+					     i, stats[i]);		\
+	}								\
+	len += sysfs_emit_at(buf, len, "TOTAL_%s %llu\n", total_string,	\
+			     pdev->aer_stats->total_field);		\
+	return len;							\
+}									\
+static DEVICE_ATTR_RO(name)
+
+aer_stats_dev_attr(aer_dev_correctable, dev_cor_errs,
+		   aer_correctable_error_string, "ERR_COR",
+		   dev_total_cor_errs);
+aer_stats_dev_attr(aer_dev_fatal, dev_fatal_errs,
+		   aer_uncorrectable_error_string, "ERR_FATAL",
+		   dev_total_fatal_errs);
+aer_stats_dev_attr(aer_dev_nonfatal, dev_nonfatal_errs,
+		   aer_uncorrectable_error_string, "ERR_NONFATAL",
+		   dev_total_nonfatal_errs);
+
+#define aer_stats_rootport_attr(name, field)				\
+	static ssize_t							\
+	name##_show(struct device *dev, struct device_attribute *attr,	\
+		     char *buf)						\
+{									\
+	struct pci_dev *pdev = to_pci_dev(dev);				\
+	return sysfs_emit(buf, "%llu\n", pdev->aer_stats->field);	\
+}									\
+static DEVICE_ATTR_RO(name)
+
+aer_stats_rootport_attr(aer_rootport_total_err_cor,
+			 rootport_total_cor_errs);
+aer_stats_rootport_attr(aer_rootport_total_err_fatal,
+			 rootport_total_fatal_errs);
+aer_stats_rootport_attr(aer_rootport_total_err_nonfatal,
+			 rootport_total_nonfatal_errs);
+
+static struct attribute *aer_stats_attrs[] __ro_after_init = {
+	&dev_attr_aer_dev_correctable.attr,
+	&dev_attr_aer_dev_fatal.attr,
+	&dev_attr_aer_dev_nonfatal.attr,
+	&dev_attr_aer_rootport_total_err_cor.attr,
+	&dev_attr_aer_rootport_total_err_fatal.attr,
+	&dev_attr_aer_rootport_total_err_nonfatal.attr,
+	NULL
+};
+
+static umode_t aer_stats_attrs_are_visible(struct kobject *kobj,
+					   struct attribute *a, int n)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct pci_dev *pdev = to_pci_dev(dev);
+
+	if (!pdev->aer_stats)
+		return 0;
+
+	if ((a == &dev_attr_aer_rootport_total_err_cor.attr ||
+	     a == &dev_attr_aer_rootport_total_err_fatal.attr ||
+	     a == &dev_attr_aer_rootport_total_err_nonfatal.attr) &&
+	    ((pci_pcie_type(pdev) != PCI_EXP_TYPE_ROOT_PORT) &&
+	     (pci_pcie_type(pdev) != PCI_EXP_TYPE_RC_EC)))
+		return 0;
+
+	return a->mode;
+}
+
+const struct attribute_group aer_stats_attr_group = {
+	.attrs  = aer_stats_attrs,
+	.is_visible = aer_stats_attrs_are_visible,
+};
+
+static void pci_dev_aer_stats_incr(struct pci_dev *pdev,
+				   struct aer_err_info *info)
+{
+	unsigned long status = info->status & ~info->mask;
+	int i, max = -1;
+	u64 *counter = NULL;
+	struct aer_stats *aer_stats = pdev->aer_stats;
+
+	if (!aer_stats)
+		return;
+
+	switch (info->severity) {
+	case AER_CORRECTABLE:
+		aer_stats->dev_total_cor_errs++;
+		counter = &aer_stats->dev_cor_errs[0];
+		max = AER_MAX_TYPEOF_COR_ERRS;
+		break;
+	case AER_NONFATAL:
+		aer_stats->dev_total_nonfatal_errs++;
+		counter = &aer_stats->dev_nonfatal_errs[0];
+		max = AER_MAX_TYPEOF_UNCOR_ERRS;
+		break;
+	case AER_FATAL:
+		aer_stats->dev_total_fatal_errs++;
+		counter = &aer_stats->dev_fatal_errs[0];
+		max = AER_MAX_TYPEOF_UNCOR_ERRS;
+		break;
+	}
+
+	for_each_set_bit(i, &status, max)
+		counter[i]++;
+}
+
+static void pci_rootport_aer_stats_incr(struct pci_dev *pdev,
+				 struct aer_err_source *e_src)
+{
+	struct aer_stats *aer_stats = pdev->aer_stats;
+
+	if (!aer_stats)
+		return;
+
+	if (e_src->status & PCI_ERR_ROOT_COR_RCV)
+		aer_stats->rootport_total_cor_errs++;
+
+	if (e_src->status & PCI_ERR_ROOT_UNCOR_RCV) {
+		if (e_src->status & PCI_ERR_ROOT_FATAL_RCV)
+			aer_stats->rootport_total_fatal_errs++;
+		else
+			aer_stats->rootport_total_nonfatal_errs++;
+	}
+}
+
+static void __print_tlp_header(struct pci_dev *dev,
+			       struct aer_header_log_regs *t)
+{
+	pci_err(dev, "  TLP Header: %08x %08x %08x %08x\n",
+		t->dw0, t->dw1, t->dw2, t->dw3);
+}
+
+static void __aer_print_error(struct pci_dev *dev,
+			      struct aer_err_info *info)
+{
+	const char **strings;
+	unsigned long status = info->status & ~info->mask;
+	const char *level, *errmsg;
+	int i;
+
+	if (info->severity == AER_CORRECTABLE) {
+		strings = aer_correctable_error_string;
+		level = KERN_WARNING;
+	} else {
+		strings = aer_uncorrectable_error_string;
+		level = KERN_ERR;
+	}
+
+	for_each_set_bit(i, &status, 32) {
+		errmsg = strings[i];
+		if (!errmsg)
+			errmsg = "Unknown Error Bit";
+
+		pci_printk(level, dev, "   [%2d] %-22s%s\n", i, errmsg,
+				info->first_error == i ? " (First)" : "");
+	}
+	pci_dev_aer_stats_incr(dev, info);
+}
+
+void aer_print_error(struct pci_dev *dev, struct aer_err_info *info)
+{
+	int layer, agent;
+	int id = ((dev->bus->number << 8) | dev->devfn);
+	const char *level;
+
+	if (!info->status) {
+		pci_err(dev, "PCIe Bus Error: severity=%s, type=Inaccessible, (Unregistered Agent ID)\n",
+			aer_error_severity_string[info->severity]);
+		goto out;
+	}
+
+	layer = AER_GET_LAYER_ERROR(info->severity, info->status);
+	agent = AER_GET_AGENT(info->severity, info->status);
+
+	level = (info->severity == AER_CORRECTABLE) ? KERN_WARNING : KERN_ERR;
+
+	pci_printk(level, dev, "PCIe Bus Error: severity=%s, type=%s, (%s)\n",
+		   aer_error_severity_string[info->severity],
+		   aer_error_layer[layer], aer_agent_string[agent]);
+
+	pci_printk(level, dev, "  device [%04x:%04x] error status/mask=%08x/%08x\n",
+		   dev->vendor, dev->device, info->status, info->mask);
+
+	__aer_print_error(dev, info);
+
+	if (info->tlp_header_valid)
+		__print_tlp_header(dev, &info->tlp);
+
+out:
+	if (info->id && info->error_dev_num > 1 && info->id == id)
+		pci_err(dev, "  Error of this Agent is reported first\n");
+
+	trace_aer_event(dev_name(&dev->dev), (info->status & ~info->mask),
+			info->severity, info->tlp_header_valid, &info->tlp);
+}
+
+static void aer_print_port_info(struct pci_dev *dev, struct aer_err_info *info)
+{
+	u8 bus = info->id >> 8;
+	u8 devfn = info->id & 0xff;
+
+	pci_info(dev, "%s%s error received: %04x:%02x:%02x.%d\n",
+		 info->multi_error_valid ? "Multiple " : "",
+		 aer_error_severity_string[info->severity],
+		 pci_domain_nr(dev->bus), bus, PCI_SLOT(devfn),
+		 PCI_FUNC(devfn));
+}
+
+#ifdef CONFIG_ACPI_APEI_PCIEAER
+int cper_severity_to_aer(int cper_severity)
+{
+	switch (cper_severity) {
+	case CPER_SEV_RECOVERABLE:
+		return AER_NONFATAL;
+	case CPER_SEV_FATAL:
+		return AER_FATAL;
+	default:
+		return AER_CORRECTABLE;
+	}
+}
+EXPORT_SYMBOL_GPL(cper_severity_to_aer);
+
+void cper_print_aer(struct pci_dev *dev, int aer_severity,
+		    struct aer_capability_regs *aer)
+{
+	int layer, agent, tlp_header_valid = 0;
+	u32 status, mask;
+	struct aer_err_info info;
+
+	if (aer_severity == AER_CORRECTABLE) {
+		status = aer->cor_status;
+		mask = aer->cor_mask;
+	} else {
+		status = aer->uncor_status;
+		mask = aer->uncor_mask;
+		tlp_header_valid = status & AER_LOG_TLP_MASKS;
+	}
+
+	layer = AER_GET_LAYER_ERROR(aer_severity, status);
+	agent = AER_GET_AGENT(aer_severity, status);
+
+	memset(&info, 0, sizeof(info));
+	info.severity = aer_severity;
+	info.status = status;
+	info.mask = mask;
+	info.first_error = PCI_ERR_CAP_FEP(aer->cap_control);
+
+	pci_err(dev, "aer_status: 0x%08x, aer_mask: 0x%08x\n", status, mask);
+	__aer_print_error(dev, &info);
+	pci_err(dev, "aer_layer=%s, aer_agent=%s\n",
+		aer_error_layer[layer], aer_agent_string[agent]);
+
+	if (aer_severity != AER_CORRECTABLE)
+		pci_err(dev, "aer_uncor_severity: 0x%08x\n",
+			aer->uncor_severity);
+
+	if (tlp_header_valid)
+		__print_tlp_header(dev, &aer->header_log);
+
+	trace_aer_event(dev_name(&dev->dev), (status & ~mask),
+			aer_severity, tlp_header_valid, &aer->header_log);
+}
+#endif
+
+/**
+ * add_error_device - list device to be handled
+ * @e_info: pointer to error info
+ * @dev: pointer to pci_dev to be added
+ */
+static int add_error_device(struct aer_err_info *e_info, struct pci_dev *dev)
+{
+	if (e_info->error_dev_num < AER_MAX_MULTI_ERR_DEVICES) {
+		e_info->dev[e_info->error_dev_num] = pci_dev_get(dev);
+		e_info->error_dev_num++;
+		return 0;
+	}
+	return -ENOSPC;
+}
+
+/**
+ * is_error_source - check whether the device is source of reported error
+ * @dev: pointer to pci_dev to be checked
+ * @e_info: pointer to reported error info
+ */
+static bool is_error_source(struct pci_dev *dev, struct aer_err_info *e_info)
+{
+	int aer = dev->aer_cap;
+	u32 status, mask;
+	u16 reg16;
+
+	/*
+	 * When bus id is equal to 0, it might be a bad id
+	 * reported by root port.
+	 */
+	if ((PCI_BUS_NUM(e_info->id) != 0) &&
+	    !(dev->bus->bus_flags & PCI_BUS_FLAGS_NO_AERSID)) {
+		/* Device ID match? */
+		if (e_info->id == ((dev->bus->number << 8) | dev->devfn))
+			return true;
+
+		/* Continue id comparing if there is no multiple error */
+		if (!e_info->multi_error_valid)
+			return false;
+	}
+
+	/*
+	 * When either
+	 *      1) bus id is equal to 0. Some ports might lose the bus
+	 *              id of error source id;
+	 *      2) bus flag PCI_BUS_FLAGS_NO_AERSID is set
+	 *      3) There are multiple errors and prior ID comparing fails;
+	 * We check AER status registers to find possible reporter.
+	 */
+	if (atomic_read(&dev->enable_cnt) == 0)
+		return false;
+
+	/* Check if AER is enabled */
+	pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &reg16);
+	if (!(reg16 & PCI_EXP_AER_FLAGS))
+		return false;
+
+	if (!aer)
+		return false;
+
+	/* Check if error is recorded */
+	if (e_info->severity == AER_CORRECTABLE) {
+		pci_read_config_dword(dev, aer + PCI_ERR_COR_STATUS, &status);
+		pci_read_config_dword(dev, aer + PCI_ERR_COR_MASK, &mask);
+	} else {
+		pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS, &status);
+		pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_MASK, &mask);
+	}
+	if (status & ~mask)
+		return true;
+
+	return false;
+}
+
+static int find_device_iter(struct pci_dev *dev, void *data)
+{
+	struct aer_err_info *e_info = (struct aer_err_info *)data;
+
+	if (is_error_source(dev, e_info)) {
+		/* List this device */
+		if (add_error_device(e_info, dev)) {
+			/* We cannot handle more... Stop iteration */
+			/* TODO: Should print error message here? */
+			return 1;
+		}
+
+		/* If there is only a single error, stop iteration */
+		if (!e_info->multi_error_valid)
+			return 1;
+	}
+	return 0;
+}
+
+/**
+ * find_source_device - search through device hierarchy for source device
+ * @parent: pointer to Root Port pci_dev data structure
+ * @e_info: including detailed error information such like id
+ *
+ * Return true if found.
+ *
+ * Invoked by DPC when error is detected at the Root Port.
+ * Caller of this function must set id, severity, and multi_error_valid of
+ * struct aer_err_info pointed by @e_info properly.  This function must fill
+ * e_info->error_dev_num and e_info->dev[], based on the given information.
+ */
+static bool find_source_device(struct pci_dev *parent,
+		struct aer_err_info *e_info)
+{
+	struct pci_dev *dev = parent;
+	int result;
+
+	/* Must reset in this function */
+	e_info->error_dev_num = 0;
+
+	/* Is Root Port an agent that sends error message? */
+	result = find_device_iter(dev, e_info);
+	if (result)
+		return true;
+
+	if (pci_pcie_type(parent) == PCI_EXP_TYPE_RC_EC)
+		pcie_walk_rcec(parent, find_device_iter, e_info);
+	else
+		pci_walk_bus(parent->subordinate, find_device_iter, e_info);
+
+	if (!e_info->error_dev_num) {
+		pci_info(parent, "can't find device of ID%04x\n", e_info->id);
+		return false;
+	}
+	return true;
+}
+
+/**
+ * handle_error_source - handle logging error into an event log
+ * @dev: pointer to pci_dev data structure of error source device
+ * @info: comprehensive error information
+ *
+ * Invoked when an error being detected by Root Port.
+ */
+static void handle_error_source(struct pci_dev *dev, struct aer_err_info *info)
+{
+	int aer = dev->aer_cap;
+
+	if (info->severity == AER_CORRECTABLE) {
+		/*
+		 * Correctable error does not need software intervention.
+		 * No need to go through error recovery process.
+		 */
+		if (aer)
+			pci_write_config_dword(dev, aer + PCI_ERR_COR_STATUS,
+					info->status);
+		if (pcie_aer_is_native(dev))
+			pcie_clear_device_status(dev);
+	} else if (info->severity == AER_NONFATAL)
+		pcie_do_recovery(dev, pci_channel_io_normal, aer_root_reset);
+	else if (info->severity == AER_FATAL)
+		pcie_do_recovery(dev, pci_channel_io_frozen, aer_root_reset);
+	pci_dev_put(dev);
+}
+
+#ifdef CONFIG_ACPI_APEI_PCIEAER
+
+#define AER_RECOVER_RING_ORDER		4
+#define AER_RECOVER_RING_SIZE		(1 << AER_RECOVER_RING_ORDER)
+
+struct aer_recover_entry {
+	u8	bus;
+	u8	devfn;
+	u16	domain;
+	int	severity;
+	struct aer_capability_regs *regs;
+};
+
+static DEFINE_KFIFO(aer_recover_ring, struct aer_recover_entry,
+		    AER_RECOVER_RING_SIZE);
+
+static void aer_recover_work_func(struct work_struct *work)
+{
+	struct aer_recover_entry entry;
+	struct pci_dev *pdev;
+
+	while (kfifo_get(&aer_recover_ring, &entry)) {
+		pdev = pci_get_domain_bus_and_slot(entry.domain, entry.bus,
+						   entry.devfn);
+		if (!pdev) {
+			pr_err("no pci_dev for %04x:%02x:%02x.%x\n",
+			       entry.domain, entry.bus,
+			       PCI_SLOT(entry.devfn), PCI_FUNC(entry.devfn));
+			continue;
+		}
+		cper_print_aer(pdev, entry.severity, entry.regs);
+		if (entry.severity == AER_NONFATAL)
+			pcie_do_recovery(pdev, pci_channel_io_normal,
+					 aer_root_reset);
+		else if (entry.severity == AER_FATAL)
+			pcie_do_recovery(pdev, pci_channel_io_frozen,
+					 aer_root_reset);
+		pci_dev_put(pdev);
+	}
+}
+
+/*
+ * Mutual exclusion for writers of aer_recover_ring, reader side don't
+ * need lock, because there is only one reader and lock is not needed
+ * between reader and writer.
+ */
+static DEFINE_SPINLOCK(aer_recover_ring_lock);
+static DECLARE_WORK(aer_recover_work, aer_recover_work_func);
+
+void aer_recover_queue(int domain, unsigned int bus, unsigned int devfn,
+		       int severity, struct aer_capability_regs *aer_regs)
+{
+	struct aer_recover_entry entry = {
+		.bus		= bus,
+		.devfn		= devfn,
+		.domain		= domain,
+		.severity	= severity,
+		.regs		= aer_regs,
+	};
+
+	if (kfifo_in_spinlocked(&aer_recover_ring, &entry, 1,
+				 &aer_recover_ring_lock))
+		schedule_work(&aer_recover_work);
+	else
+		pr_err("buffer overflow in recovery for %04x:%02x:%02x.%x\n",
+		       domain, bus, PCI_SLOT(devfn), PCI_FUNC(devfn));
+}
+EXPORT_SYMBOL_GPL(aer_recover_queue);
+#endif
+
+/**
+ * aer_get_device_error_info - read error status from dev and store it to info
+ * @dev: pointer to the device expected to have a error record
+ * @info: pointer to structure to store the error record
+ *
+ * Return 1 on success, 0 on error.
+ *
+ * Note that @info is reused among all error devices. Clear fields properly.
+ */
+int aer_get_device_error_info(struct pci_dev *dev, struct aer_err_info *info)
+{
+	int type = pci_pcie_type(dev);
+	int aer = dev->aer_cap;
+	int temp;
+
+	/* Must reset in this function */
+	info->status = 0;
+	info->tlp_header_valid = 0;
+
+	/* The device might not support AER */
+	if (!aer)
+		return 0;
+
+	if (info->severity == AER_CORRECTABLE) {
+		pci_read_config_dword(dev, aer + PCI_ERR_COR_STATUS,
+			&info->status);
+		pci_read_config_dword(dev, aer + PCI_ERR_COR_MASK,
+			&info->mask);
+		if (!(info->status & ~info->mask))
+			return 0;
+	} else if (type == PCI_EXP_TYPE_ROOT_PORT ||
+		   type == PCI_EXP_TYPE_RC_EC ||
+		   type == PCI_EXP_TYPE_DOWNSTREAM ||
+		   info->severity == AER_NONFATAL) {
+
+		/* Link is still healthy for IO reads */
+		pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_STATUS,
+			&info->status);
+		pci_read_config_dword(dev, aer + PCI_ERR_UNCOR_MASK,
+			&info->mask);
+		if (!(info->status & ~info->mask))
+			return 0;
+
+		/* Get First Error Pointer */
+		pci_read_config_dword(dev, aer + PCI_ERR_CAP, &temp);
+		info->first_error = PCI_ERR_CAP_FEP(temp);
+
+		if (info->status & AER_LOG_TLP_MASKS) {
+			info->tlp_header_valid = 1;
+			pci_read_config_dword(dev,
+				aer + PCI_ERR_HEADER_LOG, &info->tlp.dw0);
+			pci_read_config_dword(dev,
+				aer + PCI_ERR_HEADER_LOG + 4, &info->tlp.dw1);
+			pci_read_config_dword(dev,
+				aer + PCI_ERR_HEADER_LOG + 8, &info->tlp.dw2);
+			pci_read_config_dword(dev,
+				aer + PCI_ERR_HEADER_LOG + 12, &info->tlp.dw3);
+		}
+	}
+
+	return 1;
+}
+
+static inline void aer_process_err_devices(struct aer_err_info *e_info)
+{
+	int i;
+
+	/* Report all before handle them, not to lost records by reset etc. */
+	for (i = 0; i < e_info->error_dev_num && e_info->dev[i]; i++) {
+		if (aer_get_device_error_info(e_info->dev[i], e_info))
+			aer_print_error(e_info->dev[i], e_info);
+	}
+	for (i = 0; i < e_info->error_dev_num && e_info->dev[i]; i++) {
+		if (aer_get_device_error_info(e_info->dev[i], e_info))
+			handle_error_source(e_info->dev[i], e_info);
+	}
+}
+
+/**
+ * aer_isr_one_error - consume an error detected by root port
+ * @rpc: pointer to the root port which holds an error
+ * @e_src: pointer to an error source
+ */
+static void aer_isr_one_error(struct aer_rpc *rpc,
+		struct aer_err_source *e_src)
+{
+	struct pci_dev *pdev = rpc->rpd;
+	struct aer_err_info e_info;
+
+	pci_rootport_aer_stats_incr(pdev, e_src);
+
+	/*
+	 * There is a possibility that both correctable error and
+	 * uncorrectable error being logged. Report correctable error first.
+	 */
+	if (e_src->status & PCI_ERR_ROOT_COR_RCV) {
+		e_info.id = ERR_COR_ID(e_src->id);
+		e_info.severity = AER_CORRECTABLE;
+
+		if (e_src->status & PCI_ERR_ROOT_MULTI_COR_RCV)
+			e_info.multi_error_valid = 1;
+		else
+			e_info.multi_error_valid = 0;
+		aer_print_port_info(pdev, &e_info);
+
+		if (find_source_device(pdev, &e_info))
+			aer_process_err_devices(&e_info);
+	}
+
+	if (e_src->status & PCI_ERR_ROOT_UNCOR_RCV) {
+		e_info.id = ERR_UNCOR_ID(e_src->id);
+
+		if (e_src->status & PCI_ERR_ROOT_FATAL_RCV)
+			e_info.severity = AER_FATAL;
+		else
+			e_info.severity = AER_NONFATAL;
+
+		if (e_src->status & PCI_ERR_ROOT_MULTI_UNCOR_RCV)
+			e_info.multi_error_valid = 1;
+		else
+			e_info.multi_error_valid = 0;
+
+		aer_print_port_info(pdev, &e_info);
+
+		if (find_source_device(pdev, &e_info))
+			aer_process_err_devices(&e_info);
+	}
+}
+
+/**
+ * aer_isr - consume errors detected by root port
+ * @irq: IRQ assigned to Root Port
+ * @context: pointer to Root Port data structure
+ *
+ * Invoked, as DPC, when root port records new detected error
+ */
+static irqreturn_t aer_isr(int irq, void *context)
+{
+	struct pcie_device *dev = (struct pcie_device *)context;
+	struct aer_rpc *rpc = get_service_data(dev);
+	struct aer_err_source e_src;
+
+	if (kfifo_is_empty(&rpc->aer_fifo))
+		return IRQ_NONE;
+
+	while (kfifo_get(&rpc->aer_fifo, &e_src))
+		aer_isr_one_error(rpc, &e_src);
+	return IRQ_HANDLED;
+}
+
+/**
+ * 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.
+ */
+static irqreturn_t aer_irq(int irq, void *context)
+{
+	struct pcie_device *pdev = (struct pcie_device *)context;
+	struct aer_rpc *rpc = get_service_data(pdev);
+	struct pci_dev *rp = rpc->rpd;
+	int aer = rp->aer_cap;
+	struct aer_err_source e_src = {};
+
+	pci_read_config_dword(rp, aer + PCI_ERR_ROOT_STATUS, &e_src.status);
+	if (!(e_src.status & AER_ERR_STATUS_MASK))
+		return IRQ_NONE;
+
+	pci_read_config_dword(rp, aer + PCI_ERR_ROOT_ERR_SRC, &e_src.id);
+	pci_write_config_dword(rp, aer + PCI_ERR_ROOT_STATUS, e_src.status);
+
+	if (!kfifo_put(&rpc->aer_fifo, e_src))
+		return IRQ_HANDLED;
+
+	return IRQ_WAKE_THREAD;
+}
+
+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_RC_EC) ||
+	    (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);
+	}
+
+	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 (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_EC)
+		pcie_walk_rcec(dev, set_device_error_reporting, &enable);
+	else if (dev->subordinate)
+		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;
+	int aer = pdev->aer_cap;
+	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);
+
+	/* Clear error status */
+	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_STATUS, &reg32);
+	pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_STATUS, reg32);
+	pci_read_config_dword(pdev, aer + PCI_ERR_COR_STATUS, &reg32);
+	pci_write_config_dword(pdev, aer + PCI_ERR_COR_STATUS, reg32);
+	pci_read_config_dword(pdev, aer + PCI_ERR_UNCOR_STATUS, &reg32);
+	pci_write_config_dword(pdev, aer + 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 + PCI_ERR_ROOT_COMMAND, &reg32);
+	reg32 |= ROOT_PORT_INTR_ON_MESG_MASK;
+	pci_write_config_dword(pdev, aer + 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;
+	int aer = pdev->aer_cap;
+	u32 reg32;
+
+	/*
+	 * Disable error reporting for the root port device and downstream port
+	 * devices.
+	 */
+	set_downstream_devices_error_reporting(pdev, false);
+
+	/* Disable Root's interrupt in response to error messages */
+	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, &reg32);
+	reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK;
+	pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_COMMAND, reg32);
+
+	/* Clear Root's error status reg */
+	pci_read_config_dword(pdev, aer + PCI_ERR_ROOT_STATUS, &reg32);
+	pci_write_config_dword(pdev, aer + PCI_ERR_ROOT_STATUS, reg32);
+}
+
+/**
+ * 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);
+
+	aer_disable_rootport(rpc);
+}
+
+/**
+ * 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->device;
+	struct pci_dev *port = dev->port;
+
+	BUILD_BUG_ON(ARRAY_SIZE(aer_correctable_error_string) <
+		     AER_MAX_TYPEOF_COR_ERRS);
+	BUILD_BUG_ON(ARRAY_SIZE(aer_uncorrectable_error_string) <
+		     AER_MAX_TYPEOF_UNCOR_ERRS);
+
+	/* Limit to Root Ports or Root Complex Event Collectors */
+	if ((pci_pcie_type(port) != PCI_EXP_TYPE_RC_EC) &&
+	    (pci_pcie_type(port) != PCI_EXP_TYPE_ROOT_PORT))
+		return -ENODEV;
+
+	rpc = devm_kzalloc(device, sizeof(struct aer_rpc), GFP_KERNEL);
+	if (!rpc)
+		return -ENOMEM;
+
+	rpc->rpd = port;
+	INIT_KFIFO(rpc->aer_fifo);
+	set_service_data(dev, rpc);
+
+	status = devm_request_threaded_irq(device, dev->irq, aer_irq, aer_isr,
+					   IRQF_SHARED, "aerdrv", dev);
+	if (status) {
+		pci_err(port, "request AER IRQ %d failed\n", dev->irq);
+		return status;
+	}
+
+	aer_enable_rootport(rpc);
+	pci_info(port, "enabled with IRQ %d\n", dev->irq);
+	return 0;
+}
+
+/**
+ * aer_root_reset - reset Root Port hierarchy, RCEC, or RCiEP
+ * @dev: pointer to Root Port, RCEC, or RCiEP
+ *
+ * Invoked by Port Bus driver when performing reset.
+ */
+static pci_ers_result_t aer_root_reset(struct pci_dev *dev)
+{
+	int type = pci_pcie_type(dev);
+	struct pci_dev *root;
+	int aer;
+	struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);
+	u32 reg32;
+	int rc;
+
+	/*
+	 * Only Root Ports and RCECs have AER Root Command and Root Status
+	 * registers.  If "dev" is an RCiEP, the relevant registers are in
+	 * the RCEC.
+	 */
+	if (type == PCI_EXP_TYPE_RC_END)
+		root = dev->rcec;
+	else
+		root = pcie_find_root_port(dev);
+
+	/*
+	 * If the platform retained control of AER, an RCiEP may not have
+	 * an RCEC visible to us, so dev->rcec ("root") may be NULL.  In
+	 * that case, firmware is responsible for these registers.
+	 */
+	aer = root ? root->aer_cap : 0;
+
+	if ((host->native_aer || pcie_ports_native) && aer) {
+		/* Disable Root's interrupt in response to error messages */
+		pci_read_config_dword(root, aer + PCI_ERR_ROOT_COMMAND, &reg32);
+		reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK;
+		pci_write_config_dword(root, aer + PCI_ERR_ROOT_COMMAND, reg32);
+	}
+
+	if (type == PCI_EXP_TYPE_RC_EC || type == PCI_EXP_TYPE_RC_END) {
+		rc = pcie_reset_flr(dev, PCI_RESET_DO_RESET);
+		if (!rc)
+			pci_info(dev, "has been reset\n");
+		else
+			pci_info(dev, "not reset (no FLR support: %d)\n", rc);
+	} else {
+		rc = pci_bus_error_reset(dev);
+		pci_info(dev, "%s Port link has been reset (%d)\n",
+			pci_is_root_bus(dev->bus) ? "Root" : "Downstream", rc);
+	}
+
+	if ((host->native_aer || pcie_ports_native) && aer) {
+		/* Clear Root Error Status */
+		pci_read_config_dword(root, aer + PCI_ERR_ROOT_STATUS, &reg32);
+		pci_write_config_dword(root, aer + PCI_ERR_ROOT_STATUS, reg32);
+
+		/* Enable Root Port's interrupt in response to error messages */
+		pci_read_config_dword(root, aer + PCI_ERR_ROOT_COMMAND, &reg32);
+		reg32 |= ROOT_PORT_INTR_ON_MESG_MASK;
+		pci_write_config_dword(root, aer + PCI_ERR_ROOT_COMMAND, reg32);
+	}
+
+	return rc ? PCI_ERS_RESULT_DISCONNECT : PCI_ERS_RESULT_RECOVERED;
+}
+
+static struct pcie_port_service_driver aerdriver = {
+	.name		= "aer",
+	.port_type	= PCIE_ANY_PORT,
+	.service	= PCIE_PORT_SERVICE_AER,
+
+	.probe		= aer_probe,
+	.remove		= aer_remove,
+};
+
+/**
+ * pcie_aer_init - register AER root service driver
+ *
+ * Invoked when AER root service driver is loaded.
+ */
+int __init pcie_aer_init(void)
+{
+	if (!pci_aer_available())
+		return -ENXIO;
+	return pcie_port_service_register(&aerdriver);
+}