OpenCloudOS-Kernel/drivers/pci/pcie/aer.c

1428 lines
39 KiB
C

// 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)
{
if (!pcie_aer_is_native(dev))
return;
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)) {
struct pci_driver *pdrv = dev->driver;
if (pdrv && pdrv->err_handler &&
pdrv->err_handler->cor_error_detected)
pdrv->err_handler->cor_error_detected(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;
}
/**
* 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 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 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);
}