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

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/*
* drivers/pci/pcie/aer/aerdrv_core.c
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* This file implements the core part of PCI-Express AER. When an pci-express
* 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"
static bool forceload;
static bool nosourceid;
module_param(forceload, bool, 0);
module_param(nosourceid, bool, 0);
#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 (!pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR))
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 = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
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);
/**
* 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 (!nosourceid && (PCI_BUS_NUM(e_info->id) != 0)) {
/* 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) nosourceid==y;
* 2) bus id is equal to 0. Some ports might lose the bus
* id of error source id;
* 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;
pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
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) {
dev_printk(KERN_DEBUG, &parent->dev,
"can't find device of ID%04x\n",
e_info->id);
return false;
}
return true;
}
static int report_error_detected(struct pci_dev *dev, void *data)
{
pci_ers_result_t vote;
const struct pci_error_handlers *err_handler;
struct aer_broadcast_data *result_data;
result_data = (struct aer_broadcast_data *) data;
device_lock(&dev->dev);
dev->error_state = result_data->state;
if (!dev->driver ||
!dev->driver->err_handler ||
!dev->driver->err_handler->error_detected) {
if (result_data->state == pci_channel_io_frozen &&
!(dev->hdr_type & PCI_HEADER_TYPE_BRIDGE)) {
/*
* In case of fatal recovery, if one of down-
* stream device has no driver. We might be
* unable to recover because a later insmod
* of a driver for this device is unaware of
* its hw state.
*/
dev_printk(KERN_DEBUG, &dev->dev, "device has %s\n",
dev->driver ?
"no AER-aware driver" : "no driver");
}
/*
* If there's any device in the subtree that does not
* have an error_detected callback, returning
* PCI_ERS_RESULT_NO_AER_DRIVER prevents calling of
* the subsequent mmio_enabled/slot_reset/resume
* callbacks of "any" device in the subtree. All the
* devices in the subtree are left in the error state
* without recovery.
*/
if (!(dev->hdr_type & PCI_HEADER_TYPE_BRIDGE))
vote = PCI_ERS_RESULT_NO_AER_DRIVER;
else
vote = PCI_ERS_RESULT_NONE;
} else {
err_handler = dev->driver->err_handler;
vote = err_handler->error_detected(dev, result_data->state);
}
result_data->result = merge_result(result_data->result, vote);
device_unlock(&dev->dev);
return 0;
}
static int report_mmio_enabled(struct pci_dev *dev, void *data)
{
pci_ers_result_t vote;
const struct pci_error_handlers *err_handler;
struct aer_broadcast_data *result_data;
result_data = (struct aer_broadcast_data *) data;
device_lock(&dev->dev);
if (!dev->driver ||
!dev->driver->err_handler ||
!dev->driver->err_handler->mmio_enabled)
goto out;
err_handler = dev->driver->err_handler;
vote = err_handler->mmio_enabled(dev);
result_data->result = merge_result(result_data->result, vote);
out:
device_unlock(&dev->dev);
return 0;
}
static int report_slot_reset(struct pci_dev *dev, void *data)
{
pci_ers_result_t vote;
const struct pci_error_handlers *err_handler;
struct aer_broadcast_data *result_data;
result_data = (struct aer_broadcast_data *) data;
device_lock(&dev->dev);
if (!dev->driver ||
!dev->driver->err_handler ||
!dev->driver->err_handler->slot_reset)
goto out;
err_handler = dev->driver->err_handler;
vote = err_handler->slot_reset(dev);
result_data->result = merge_result(result_data->result, vote);
out:
device_unlock(&dev->dev);
return 0;
}
static int report_resume(struct pci_dev *dev, void *data)
{
const struct pci_error_handlers *err_handler;
device_lock(&dev->dev);
dev->error_state = pci_channel_io_normal;
if (!dev->driver ||
!dev->driver->err_handler ||
!dev->driver->err_handler->resume)
goto out;
err_handler = dev->driver->err_handler;
err_handler->resume(dev);
out:
device_unlock(&dev->dev);
return 0;
}
/**
* broadcast_error_message - handle message broadcast to downstream drivers
* @dev: pointer to from where in a hierarchy message is broadcasted down
* @state: error state
* @error_mesg: message to print
* @cb: callback to be broadcasted
*
* Invoked during error recovery process. Once being invoked, the content
* of error severity will be broadcasted to all downstream drivers in a
* hierarchy in question.
*/
static pci_ers_result_t broadcast_error_message(struct pci_dev *dev,
enum pci_channel_state state,
char *error_mesg,
int (*cb)(struct pci_dev *, void *))
{
struct aer_broadcast_data result_data;
dev_printk(KERN_DEBUG, &dev->dev, "broadcast %s message\n", error_mesg);
result_data.state = state;
if (cb == report_error_detected)
result_data.result = PCI_ERS_RESULT_CAN_RECOVER;
else
result_data.result = PCI_ERS_RESULT_RECOVERED;
if (dev->hdr_type & PCI_HEADER_TYPE_BRIDGE) {
/*
* If the error is reported by a bridge, we think this error
* is related to the downstream link of the bridge, so we
* do error recovery on all subordinates of the bridge instead
* of the bridge and clear the error status of the bridge.
*/
if (cb == report_error_detected)
dev->error_state = state;
pci_walk_bus(dev->subordinate, cb, &result_data);
if (cb == report_resume) {
pci_cleanup_aer_uncorrect_error_status(dev);
dev->error_state = pci_channel_io_normal;
}
} else {
/*
* If the error is reported by an end point, we think this
* error is related to the upstream link of the end point.
*/
pci_walk_bus(dev->bus, cb, &result_data);
}
return result_data.result;
}
/**
* default_reset_link - default reset function
* @dev: pointer to pci_dev data structure
*
* Invoked when performing link reset on a Downstream Port or a
* Root Port with no aer driver.
*/
static pci_ers_result_t default_reset_link(struct pci_dev *dev)
{
pci_reset_bridge_secondary_bus(dev);
dev_printk(KERN_DEBUG, &dev->dev, "downstream link has been reset\n");
return PCI_ERS_RESULT_RECOVERED;
}
static int find_aer_service_iter(struct device *device, void *data)
{
struct pcie_port_service_driver *service_driver, **drv;
drv = (struct pcie_port_service_driver **) data;
if (device->bus == &pcie_port_bus_type && device->driver) {
service_driver = to_service_driver(device->driver);
if (service_driver->service == PCIE_PORT_SERVICE_AER) {
*drv = service_driver;
return 1;
}
}
return 0;
}
static struct pcie_port_service_driver *find_aer_service(struct pci_dev *dev)
{
struct pcie_port_service_driver *drv = NULL;
device_for_each_child(&dev->dev, &drv, find_aer_service_iter);
return drv;
}
static pci_ers_result_t reset_link(struct pci_dev *dev)
{
struct pci_dev *udev;
pci_ers_result_t status;
struct pcie_port_service_driver *driver;
if (dev->hdr_type & PCI_HEADER_TYPE_BRIDGE) {
/* Reset this port for all subordinates */
udev = dev;
} else {
/* Reset the upstream component (likely downstream port) */
udev = dev->bus->self;
}
/* Use the aer driver of the component firstly */
driver = find_aer_service(udev);
if (driver && driver->reset_link) {
status = driver->reset_link(udev);
} else if (pci_pcie_type(udev) == PCI_EXP_TYPE_DOWNSTREAM ||
pci_pcie_type(udev) == PCI_EXP_TYPE_ROOT_PORT) {
status = default_reset_link(udev);
} else {
dev_printk(KERN_DEBUG, &dev->dev,
"no link-reset support at upstream device %s\n",
pci_name(udev));
return PCI_ERS_RESULT_DISCONNECT;
}
if (status != PCI_ERS_RESULT_RECOVERED) {
dev_printk(KERN_DEBUG, &dev->dev,
"link reset at upstream device %s failed\n",
pci_name(udev));
return PCI_ERS_RESULT_DISCONNECT;
}
return status;
}
/**
* do_recovery - handle nonfatal/fatal error recovery process
* @dev: pointer to a pci_dev data structure of agent detecting an error
* @severity: error severity type
*
* Invoked when an error is nonfatal/fatal. Once being invoked, broadcast
* error detected message to all downstream drivers within a hierarchy in
* question and return the returned code.
*/
static void do_recovery(struct pci_dev *dev, int severity)
{
pci_ers_result_t status, result = PCI_ERS_RESULT_RECOVERED;
enum pci_channel_state state;
if (severity == AER_FATAL)
state = pci_channel_io_frozen;
else
state = pci_channel_io_normal;
status = broadcast_error_message(dev,
state,
"error_detected",
report_error_detected);
if (severity == AER_FATAL) {
result = reset_link(dev);
if (result != PCI_ERS_RESULT_RECOVERED)
goto failed;
}
if (status == PCI_ERS_RESULT_CAN_RECOVER)
status = broadcast_error_message(dev,
state,
"mmio_enabled",
report_mmio_enabled);
if (status == PCI_ERS_RESULT_NEED_RESET) {
/*
* TODO: Should call platform-specific
* functions to reset slot before calling
* drivers' slot_reset callbacks?
*/
status = broadcast_error_message(dev,
state,
"slot_reset",
report_slot_reset);
}
if (status != PCI_ERS_RESULT_RECOVERED)
goto failed;
broadcast_error_message(dev,
state,
"resume",
report_resume);
dev_info(&dev->dev, "AER: Device recovery successful\n");
return;
failed:
/* TODO: Should kernel panic here? */
dev_info(&dev->dev, "AER: Device recovery failed\n");
}
/**
* handle_error_source - handle logging error into an event log
* @aerdev: pointer to pcie_device data structure of the root port
* @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 pcie_device *aerdev,
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 = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
if (pos)
pci_write_config_dword(dev, pos + PCI_ERR_COR_STATUS,
info->status);
} else
do_recovery(dev, info->severity);
}
#ifdef CONFIG_ACPI_APEI_PCIEAER
static void aer_recover_work_func(struct work_struct *work);
#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);
/*
* 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);
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);
do_recovery(pdev, entry.severity);
pci_dev_put(pdev);
}
}
#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 = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
/* The device might not support AER */
if (!pos)
return 1;
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 pcie_device *p_device,
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(p_device, 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_err_info *e_info;
/* struct aer_err_info might be big, so we allocate it with slab */
e_info = kmalloc(sizeof(struct aer_err_info), GFP_KERNEL);
if (!e_info) {
dev_printk(KERN_DEBUG, &p_device->port->dev,
"Can't allocate mem when processing AER errors\n");
return;
}
/*
* 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(p_device, 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(p_device, e_info);
}
kfree(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);
wake_up(&rpc->wait_release);
}
/**
* aer_init - provide AER initialization
* @dev: pointer to AER pcie device
*
* Invoked when AER service driver is loaded.
*/
int aer_init(struct pcie_device *dev)
{
if (forceload) {
dev_printk(KERN_DEBUG, &dev->device,
"aerdrv forceload requested.\n");
pcie_aer_force_firmware_first(dev->port, 0);
}
return 0;
}
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