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// SPDX-License-Identifier: GPL-2.0
/*
* Implement the core part of PCIe AER. When a PCIe error is delivered, an
* error message will be collected and printed to console, then an error
* recovery procedure will be executed by following the PCI error recovery
* rules.
*
* Copyright (C) 2006 Intel Corp.
* Tom Long Nguyen (tom.l.nguyen@intel.com)
* Zhang Yanmin (yanmin.zhang@intel.com)
*/
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/pm.h>
#include <linux/suspend.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/kfifo.h>
#include "aerdrv.h"
#include "../../pci.h"
#define PCI_EXP_AER_FLAGS (PCI_EXP_DEVCTL_CERE | PCI_EXP_DEVCTL_NFERE | \
PCI_EXP_DEVCTL_FERE | PCI_EXP_DEVCTL_URRE)
int pci_enable_pcie_error_reporting(struct pci_dev *dev)
{
if (pcie_aer_get_firmware_first(dev))
return -EIO;
if (!dev->aer_cap)
return -EIO;
return pcie_capability_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_AER_FLAGS);
}
EXPORT_SYMBOL_GPL(pci_enable_pcie_error_reporting);
int pci_disable_pcie_error_reporting(struct pci_dev *dev)
{
if (pcie_aer_get_firmware_first(dev))
return -EIO;
return pcie_capability_clear_word(dev, PCI_EXP_DEVCTL,
PCI_EXP_AER_FLAGS);
}
EXPORT_SYMBOL_GPL(pci_disable_pcie_error_reporting);
int pci_cleanup_aer_uncorrect_error_status(struct pci_dev *dev)
{
int pos;
u32 status;
pos = dev->aer_cap;
if (!pos)
return -EIO;
pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, &status);
if (status)
pci_write_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, status);
return 0;
}
EXPORT_SYMBOL_GPL(pci_cleanup_aer_uncorrect_error_status);
int pci_cleanup_aer_error_status_regs(struct pci_dev *dev)
{
int pos;
u32 status;
int port_type;
if (!pci_is_pcie(dev))
return -ENODEV;
pos = dev->aer_cap;
if (!pos)
return -EIO;
port_type = pci_pcie_type(dev);
if (port_type == PCI_EXP_TYPE_ROOT_PORT) {
pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, &status);
pci_write_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, status);
}
pci_read_config_dword(dev, pos + PCI_ERR_COR_STATUS, &status);
pci_write_config_dword(dev, pos + PCI_ERR_COR_STATUS, status);
pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, &status);
pci_write_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, status);
return 0;
}
int pci_aer_init(struct pci_dev *dev)
{
dev->aer_cap = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
return pci_cleanup_aer_error_status_regs(dev);
}
/**
* 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] = 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 pos;
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, ®16);
if (!(reg16 & PCI_EXP_AER_FLAGS))
return false;
pos = dev->aer_cap;
if (!pos)
return false;
/* Check if error is recorded */
if (e_info->severity == AER_CORRECTABLE) {
pci_read_config_dword(dev, pos + PCI_ERR_COR_STATUS, &status);
pci_read_config_dword(dev, pos + PCI_ERR_COR_MASK, &mask);
} else {
pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, &status);
pci_read_config_dword(dev, pos + 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;
pci_walk_bus(parent->subordinate, find_device_iter, e_info);
if (!e_info->error_dev_num) {
pci_printk(KERN_DEBUG, 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 pos;
if (info->severity == AER_CORRECTABLE) {
/*
* Correctable error does not need software intervention.
* No need to go through error recovery process.
*/
pos = dev->aer_cap;
if (pos)
pci_write_config_dword(dev, pos + PCI_ERR_COR_STATUS,
info->status);
} else if (info->severity == AER_NONFATAL)
pcie_do_nonfatal_recovery(dev);
else if (info->severity == AER_FATAL)
pcie_do_fatal_recovery(dev, PCIE_PORT_SERVICE_AER);
}
#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("AER recover: Can not find 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_nonfatal_recovery(pdev);
else if (entry.severity == AER_FATAL)
pcie_do_fatal_recovery(pdev, PCIE_PORT_SERVICE_AER);
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)
{
unsigned long flags;
struct aer_recover_entry entry = {
.bus = bus,
.devfn = devfn,
.domain = domain,
.severity = severity,
.regs = aer_regs,
};
spin_lock_irqsave(&aer_recover_ring_lock, flags);
if (kfifo_put(&aer_recover_ring, entry))
schedule_work(&aer_recover_work);
else
pr_err("AER recover: Buffer overflow when recovering AER for %04x:%02x:%02x:%x\n",
domain, bus, PCI_SLOT(devfn), PCI_FUNC(devfn));
spin_unlock_irqrestore(&aer_recover_ring_lock, flags);
}
EXPORT_SYMBOL_GPL(aer_recover_queue);
#endif
/**
* 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.
*/
static int get_device_error_info(struct pci_dev *dev, struct aer_err_info *info)
{
int pos, temp;
/* Must reset in this function */
info->status = 0;
info->tlp_header_valid = 0;
pos = dev->aer_cap;
/* The device might not support AER */
if (!pos)
return 0;
if (info->severity == AER_CORRECTABLE) {
pci_read_config_dword(dev, pos + PCI_ERR_COR_STATUS,
&info->status);
pci_read_config_dword(dev, pos + PCI_ERR_COR_MASK,
&info->mask);
if (!(info->status & ~info->mask))
return 0;
} else if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE ||
info->severity == AER_NONFATAL) {
/* Link is still healthy for IO reads */
pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS,
&info->status);
pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_MASK,
&info->mask);
if (!(info->status & ~info->mask))
return 0;
/* Get First Error Pointer */
pci_read_config_dword(dev, pos + 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,
pos + PCI_ERR_HEADER_LOG, &info->tlp.dw0);
pci_read_config_dword(dev,
pos + PCI_ERR_HEADER_LOG + 4, &info->tlp.dw1);
pci_read_config_dword(dev,
pos + PCI_ERR_HEADER_LOG + 8, &info->tlp.dw2);
pci_read_config_dword(dev,
pos + 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 (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 (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
* @p_device: pointer to error root port service device
* @e_src: pointer to an error source
*/
static void aer_isr_one_error(struct pcie_device *p_device,
struct aer_err_source *e_src)
{
struct aer_rpc *rpc = get_service_data(p_device);
struct aer_err_info *e_info = &rpc->e_info;
/*
* 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(p_device->port, e_info);
if (find_source_device(p_device->port, 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(p_device->port, e_info);
if (find_source_device(p_device->port, e_info))
aer_process_err_devices(e_info);
}
}
/**
* get_e_source - retrieve an error source
* @rpc: pointer to the root port which holds an error
* @e_src: pointer to store retrieved error source
*
* Return 1 if an error source is retrieved, otherwise 0.
*
* Invoked by DPC handler to consume an error.
*/
static int get_e_source(struct aer_rpc *rpc, struct aer_err_source *e_src)
{
unsigned long flags;
/* Lock access to Root error producer/consumer index */
spin_lock_irqsave(&rpc->e_lock, flags);
if (rpc->prod_idx == rpc->cons_idx) {
spin_unlock_irqrestore(&rpc->e_lock, flags);
return 0;
}
*e_src = rpc->e_sources[rpc->cons_idx];
rpc->cons_idx++;
if (rpc->cons_idx == AER_ERROR_SOURCES_MAX)
rpc->cons_idx = 0;
spin_unlock_irqrestore(&rpc->e_lock, flags);
return 1;
}
/**
* aer_isr - consume errors detected by root port
* @work: definition of this work item
*
* Invoked, as DPC, when root port records new detected error
*/
void aer_isr(struct work_struct *work)
{
struct aer_rpc *rpc = container_of(work, struct aer_rpc, dpc_handler);
struct pcie_device *p_device = rpc->rpd;
struct aer_err_source uninitialized_var(e_src);
mutex_lock(&rpc->rpc_mutex);
while (get_e_source(rpc, &e_src))
aer_isr_one_error(p_device, &e_src);
mutex_unlock(&rpc->rpc_mutex);
}
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