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linux/drivers/pci/pcie/aer/aerdrv_core.c
Zhang, Yanmin 6c2b374d74 PCI-Express AER implemetation: AER core and aerdriver 
Patch 3 implements the core part of PCI-Express AER and aerdrv
port service driver.

When a root port service device is probed, the aerdrv will call
request_irq to register irq handler for AER error interrupt.

When a device sends an PCI-Express error message to the root port,
the root port will trigger an interrupt, by either MSI or IO-APIC,
then kernel would run the irq handler. The handler collects root
error status register and schedules a work. The work will call
the core part to process the error based on its type
(Correctable/non-fatal/fatal).

As for Correctable errors, the patch chooses to just clear the correctable
error status register of the device.

As for the non-fatal error, the patch follows generic PCI error handler
rules to call the error callback functions of the endpoint's driver. If
the device is a bridge, the patch chooses to broadcast the error to
downstream devices.

As for the fatal error, the patch resets the pci-express link and
follows generic PCI error handler rules to call the error callback
functions of the endpoint's driver. If the device is a bridge, the patch
chooses to broadcast the error to downstream devices.

Signed-off-by: Zhang Yanmin <yanmin.zhang@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-09-26 17:43:53 -07:00

757 lines
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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/acpi.h>
#include <linux/pci-acpi.h>
#include <linux/delay.h>
#include "aerdrv.h"
static int forceload;
module_param(forceload, bool, 0);
#define PCI_CFG_SPACE_SIZE (0x100)
int pci_find_aer_capability(struct pci_dev *dev)
{
int pos;
u32 reg32 = 0;
/* Check if it's a pci-express device */
pos = pci_find_capability(dev, PCI_CAP_ID_EXP);
if (!pos)
return 0;
/* Check if it supports pci-express AER */
pos = PCI_CFG_SPACE_SIZE;
while (pos) {
if (pci_read_config_dword(dev, pos, &reg32))
return 0;
/* some broken boards return ~0 */
if (reg32 == 0xffffffff)
return 0;
if (PCI_EXT_CAP_ID(reg32) == PCI_EXT_CAP_ID_ERR)
break;
pos = reg32 >> 20;
}
return pos;
}
int pci_enable_pcie_error_reporting(struct pci_dev *dev)
{
u16 reg16 = 0;
int pos;
pos = pci_find_capability(dev, PCI_CAP_ID_EXP);
if (!pos)
return -EIO;
pci_read_config_word(dev, pos+PCI_EXP_DEVCTL, &reg16);
reg16 = reg16 |
PCI_EXP_DEVCTL_CERE |
PCI_EXP_DEVCTL_NFERE |
PCI_EXP_DEVCTL_FERE |
PCI_EXP_DEVCTL_URRE;
pci_write_config_word(dev, pos+PCI_EXP_DEVCTL,
reg16);
return 0;
}
int pci_disable_pcie_error_reporting(struct pci_dev *dev)
{
u16 reg16 = 0;
int pos;
pos = pci_find_capability(dev, PCI_CAP_ID_EXP);
if (!pos)
return -EIO;
pci_read_config_word(dev, pos+PCI_EXP_DEVCTL, &reg16);
reg16 = reg16 & ~(PCI_EXP_DEVCTL_CERE |
PCI_EXP_DEVCTL_NFERE |
PCI_EXP_DEVCTL_FERE |
PCI_EXP_DEVCTL_URRE);
pci_write_config_word(dev, pos+PCI_EXP_DEVCTL,
reg16);
return 0;
}
int pci_cleanup_aer_uncorrect_error_status(struct pci_dev *dev)
{
int pos;
u32 status, mask;
pos = pci_find_aer_capability(dev);
if (!pos)
return -EIO;
pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, &status);
pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_SEVER, &mask);
if (dev->error_state == pci_channel_io_normal)
status &= ~mask; /* Clear corresponding nonfatal bits */
else
status &= mask; /* Clear corresponding fatal bits */
pci_write_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, status);
return 0;
}
static int find_device_iter(struct device *device, void *data)
{
struct pci_dev *dev;
u16 id = *(unsigned long *)data;
u8 secondary, subordinate, d_bus = id >> 8;
if (device->bus == &pci_bus_type) {
dev = to_pci_dev(device);
if (id == ((dev->bus->number << 8) | dev->devfn)) {
/*
* Device ID match
*/
*(unsigned long*)data = (unsigned long)device;
return 1;
}
/*
* If device is P2P, check if it is an upstream?
*/
if (dev->hdr_type & PCI_HEADER_TYPE_BRIDGE) {
pci_read_config_byte(dev, PCI_SECONDARY_BUS,
&secondary);
pci_read_config_byte(dev, PCI_SUBORDINATE_BUS,
&subordinate);
if (d_bus >= secondary && d_bus <= subordinate) {
*(unsigned long*)data = (unsigned long)device;
return 1;
}
}
}
return 0;
}
/**
* find_source_device - search through device hierarchy for source device
* @p_dev: pointer to Root Port pci_dev data structure
* @id: device ID of agent who sends an error message to this Root Port
*
* Invoked when error is detected at the Root Port.
**/
static struct device* find_source_device(struct pci_dev *parent, u16 id)
{
struct pci_dev *dev = parent;
struct device *device;
unsigned long device_addr;
int status;
/* Is Root Port an agent that sends error message? */
if (id == ((dev->bus->number << 8) | dev->devfn))
return &dev->dev;
do {
device_addr = id;
if ((status = device_for_each_child(&dev->dev,
&device_addr, find_device_iter))) {
device = (struct device*)device_addr;
dev = to_pci_dev(device);
if (id == ((dev->bus->number << 8) | dev->devfn))
return device;
}
}while (status);
return NULL;
}
static void report_error_detected(struct pci_dev *dev, void *data)
{
pci_ers_result_t vote;
struct pci_error_handlers *err_handler;
struct aer_broadcast_data *result_data;
result_data = (struct aer_broadcast_data *) data;
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.
*/
printk(KERN_DEBUG "Device ID[%s] has %s\n",
dev->dev.bus_id, (dev->driver) ?
"no AER-aware driver" : "no driver");
}
return;
}
err_handler = dev->driver->err_handler;
vote = err_handler->error_detected(dev, result_data->state);
result_data->result = merge_result(result_data->result, vote);
return;
}
static void report_mmio_enabled(struct pci_dev *dev, void *data)
{
pci_ers_result_t vote;
struct pci_error_handlers *err_handler;
struct aer_broadcast_data *result_data;
result_data = (struct aer_broadcast_data *) data;
if (!dev->driver ||
!dev->driver->err_handler ||
!dev->driver->err_handler->mmio_enabled)
return;
err_handler = dev->driver->err_handler;
vote = err_handler->mmio_enabled(dev);
result_data->result = merge_result(result_data->result, vote);
return;
}
static void report_slot_reset(struct pci_dev *dev, void *data)
{
pci_ers_result_t vote;
struct pci_error_handlers *err_handler;
struct aer_broadcast_data *result_data;
result_data = (struct aer_broadcast_data *) data;
if (!dev->driver ||
!dev->driver->err_handler ||
!dev->driver->err_handler->slot_reset)
return;
err_handler = dev->driver->err_handler;
vote = err_handler->slot_reset(dev);
result_data->result = merge_result(result_data->result, vote);
return;
}
static void report_resume(struct pci_dev *dev, void *data)
{
struct pci_error_handlers *err_handler;
dev->error_state = pci_channel_io_normal;
if (!dev->driver ||
!dev->driver->err_handler ||
!dev->driver->err_handler->slot_reset)
return;
err_handler = dev->driver->err_handler;
err_handler->resume(dev);
return;
}
/**
* broadcast_error_message - handle message broadcast to downstream drivers
* @device: pointer to from where in a hierarchy message is broadcasted down
* @api: callback to be broadcasted
* @state: error state
*
* 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,
void (*cb)(struct pci_dev *, void *))
{
struct aer_broadcast_data result_data;
printk(KERN_DEBUG "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;
}
struct find_aer_service_data {
struct pcie_port_service_driver *aer_driver;
int is_downstream;
};
static int find_aer_service_iter(struct device *device, void *data)
{
struct device_driver *driver;
struct pcie_port_service_driver *service_driver;
struct pcie_device *pcie_dev;
struct find_aer_service_data *result;
result = (struct find_aer_service_data *) data;
if (device->bus == &pcie_port_bus_type) {
pcie_dev = to_pcie_device(device);
if (pcie_dev->id.port_type == PCIE_SW_DOWNSTREAM_PORT)
result->is_downstream = 1;
driver = device->driver;
if (driver) {
service_driver = to_service_driver(driver);
if (service_driver->id_table->service_type ==
PCIE_PORT_SERVICE_AER) {
result->aer_driver = service_driver;
return 1;
}
}
}
return 0;
}
static void find_aer_service(struct pci_dev *dev,
struct find_aer_service_data *data)
{
device_for_each_child(&dev->dev, data, find_aer_service_iter);
}
static pci_ers_result_t reset_link(struct pcie_device *aerdev,
struct pci_dev *dev)
{
struct pci_dev *udev;
pci_ers_result_t status;
struct find_aer_service_data data;
if (dev->hdr_type & PCI_HEADER_TYPE_BRIDGE)
udev = dev;
else
udev= dev->bus->self;
data.is_downstream = 0;
data.aer_driver = NULL;
find_aer_service(udev, &data);
/*
* Use the aer driver of the error agent firstly.
* If it hasn't the aer driver, use the root port's
*/
if (!data.aer_driver || !data.aer_driver->reset_link) {
if (data.is_downstream &&
aerdev->device.driver &&
to_service_driver(aerdev->device.driver)->reset_link) {
data.aer_driver =
to_service_driver(aerdev->device.driver);
} else {
printk(KERN_DEBUG "No link-reset support to Device ID"
"[%s]\n",
dev->dev.bus_id);
return PCI_ERS_RESULT_DISCONNECT;
}
}
status = data.aer_driver->reset_link(udev);
if (status != PCI_ERS_RESULT_RECOVERED) {
printk(KERN_DEBUG "Link reset at upstream Device ID"
"[%s] failed\n",
udev->dev.bus_id);
return PCI_ERS_RESULT_DISCONNECT;
}
return status;
}
/**
* do_recovery - handle nonfatal/fatal error recovery process
* @aerdev: pointer to a pcie_device data structure of root port
* @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 pci_ers_result_t do_recovery(struct pcie_device *aerdev,
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(aerdev, dev);
if (result != PCI_ERS_RESULT_RECOVERED) {
/* TODO: Should panic here? */
return result;
}
}
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)
broadcast_error_message(dev,
state,
"resume",
report_resume);
return status;
}
/**
* 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)
{
pci_ers_result_t status = 0;
int pos;
if (info.severity == AER_CORRECTABLE) {
/*
* Correctable error does not need software intevention.
* No need to go through error recovery process.
*/
pos = pci_find_aer_capability(dev);
if (pos)
pci_write_config_dword(dev, pos + PCI_ERR_COR_STATUS,
info.status);
} else {
status = do_recovery(aerdev, dev, info.severity);
if (status == PCI_ERS_RESULT_RECOVERED) {
printk(KERN_DEBUG "AER driver successfully recovered\n");
} else {
/* TODO: Should kernel panic here? */
printk(KERN_DEBUG "AER driver didn't recover\n");
}
}
}
/**
* 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.
**/
void aer_enable_rootport(struct aer_rpc *rpc)
{
struct pci_dev *pdev = rpc->rpd->port;
int pos, aer_pos;
u16 reg16;
u32 reg32;
pos = pci_find_capability(pdev, PCI_CAP_ID_EXP);
/* Clear PCIE Capability's Device Status */
pci_read_config_word(pdev, pos+PCI_EXP_DEVSTA, &reg16);
pci_write_config_word(pdev, pos+PCI_EXP_DEVSTA, reg16);
/* Disable system error generation in response to error messages */
pci_read_config_word(pdev, pos + PCI_EXP_RTCTL, &reg16);
reg16 &= ~(SYSTEM_ERROR_INTR_ON_MESG_MASK);
pci_write_config_word(pdev, pos + PCI_EXP_RTCTL, reg16);
aer_pos = pci_find_aer_capability(pdev);
/* Clear error status */
pci_read_config_dword(pdev, aer_pos + PCI_ERR_ROOT_STATUS, &reg32);
pci_write_config_dword(pdev, aer_pos + PCI_ERR_ROOT_STATUS, reg32);
pci_read_config_dword(pdev, aer_pos + PCI_ERR_COR_STATUS, &reg32);
pci_write_config_dword(pdev, aer_pos + PCI_ERR_COR_STATUS, reg32);
pci_read_config_dword(pdev, aer_pos + PCI_ERR_UNCOR_STATUS, &reg32);
pci_write_config_dword(pdev, aer_pos + PCI_ERR_UNCOR_STATUS, reg32);
/* Enable Root Port device reporting error itself */
pci_read_config_word(pdev, pos+PCI_EXP_DEVCTL, &reg16);
reg16 = reg16 |
PCI_EXP_DEVCTL_CERE |
PCI_EXP_DEVCTL_NFERE |
PCI_EXP_DEVCTL_FERE |
PCI_EXP_DEVCTL_URRE;
pci_write_config_word(pdev, pos+PCI_EXP_DEVCTL,
reg16);
/* Enable Root Port's interrupt in response to error messages */
pci_write_config_dword(pdev,
aer_pos + PCI_ERR_ROOT_COMMAND,
ROOT_PORT_INTR_ON_MESG_MASK);
}
/**
* disable_root_aer - 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 disable_root_aer(struct aer_rpc *rpc)
{
struct pci_dev *pdev = rpc->rpd->port;
u32 reg32;
int pos;
pos = pci_find_aer_capability(pdev);
/* Disable Root's interrupt in response to error messages */
pci_write_config_dword(pdev, pos + PCI_ERR_ROOT_COMMAND, 0);
/* Clear Root's error status reg */
pci_read_config_dword(pdev, pos + PCI_ERR_ROOT_STATUS, &reg32);
pci_write_config_dword(pdev, pos + PCI_ERR_ROOT_STATUS, reg32);
}
/**
* get_e_source - retrieve an error source
* @rpc: pointer to the root port which holds an error
*
* Invoked by DPC handler to consume an error.
**/
static struct aer_err_source* get_e_source(struct aer_rpc *rpc)
{
struct aer_err_source *e_source;
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 NULL;
}
e_source = &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 e_source;
}
static int get_device_error_info(struct pci_dev *dev, struct aer_err_info *info)
{
int pos;
pos = pci_find_aer_capability(dev);
/* The device might not support AER */
if (!pos)
return AER_SUCCESS;
if (info->severity == AER_CORRECTABLE) {
pci_read_config_dword(dev, pos + PCI_ERR_COR_STATUS,
&info->status);
if (!(info->status & ERR_CORRECTABLE_ERROR_MASK))
return AER_UNSUCCESS;
} 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);
if (!(info->status & ERR_UNCORRECTABLE_ERROR_MASK))
return AER_UNSUCCESS;
if (info->status & AER_LOG_TLP_MASKS) {
info->flags |= AER_TLP_HEADER_VALID_FLAG;
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 AER_SUCCESS;
}
/**
* 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 device *s_device;
struct aer_err_info e_info = {0, 0, 0,};
int i;
u16 id;
/*
* There is a possibility that both correctable error and
* uncorrectable error being logged. Report correctable error first.
*/
for (i = 1; i & ROOT_ERR_STATUS_MASKS ; i <<= 2) {
if (i > 4)
break;
if (!(e_src->status & i))
continue;
/* Init comprehensive error information */
if (i & PCI_ERR_ROOT_COR_RCV) {
id = ERR_COR_ID(e_src->id);
e_info.severity = AER_CORRECTABLE;
} else {
id = ERR_UNCOR_ID(e_src->id);
e_info.severity = ((e_src->status >> 6) & 1);
}
if (e_src->status &
(PCI_ERR_ROOT_MULTI_COR_RCV |
PCI_ERR_ROOT_MULTI_UNCOR_RCV))
e_info.flags |= AER_MULTI_ERROR_VALID_FLAG;
if (!(s_device = find_source_device(p_device->port, id))) {
printk(KERN_DEBUG "%s->can't find device of ID%04x\n",
__FUNCTION__, id);
continue;
}
if (get_device_error_info(to_pci_dev(s_device), &e_info) ==
AER_SUCCESS) {
aer_print_error(to_pci_dev(s_device), &e_info);
handle_error_source(p_device,
to_pci_dev(s_device),
e_info);
}
}
}
/**
* aer_isr - consume errors detected by root port
* @context: pointer to a private data of pcie device
*
* Invoked, as DPC, when root port records new detected error
**/
void aer_isr(void *context)
{
struct pcie_device *p_device = (struct pcie_device *) context;
struct aer_rpc *rpc = get_service_data(p_device);
struct aer_err_source *e_src;
mutex_lock(&rpc->rpc_mutex);
e_src = get_e_source(rpc);
while (e_src) {
aer_isr_one_error(p_device, e_src);
e_src = get_e_source(rpc);
}
mutex_unlock(&rpc->rpc_mutex);
wake_up(&rpc->wait_release);
}
/**
* aer_delete_rootport - disable root port aer and delete service data
* @rpc: pointer to a root port device being deleted
*
* Invoked when AER service unloaded on a specific Root Port
**/
void aer_delete_rootport(struct aer_rpc *rpc)
{
/* Disable root port AER itself */
disable_root_aer(rpc);
kfree(rpc);
}
/**
* 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)
{
int status;
/* Run _OSC Method */
status = aer_osc_setup(dev->port);
if(status != OSC_METHOD_RUN_SUCCESS) {
printk(KERN_DEBUG "%s: AER service init fails - %s\n",
__FUNCTION__,
(status == OSC_METHOD_NOT_SUPPORTED) ?
"No ACPI _OSC support" : "Run ACPI _OSC fails");
if (!forceload)
return status;
}
return AER_SUCCESS;
}
EXPORT_SYMBOL_GPL(pci_find_aer_capability);
EXPORT_SYMBOL_GPL(pci_enable_pcie_error_reporting);
EXPORT_SYMBOL_GPL(pci_disable_pcie_error_reporting);
EXPORT_SYMBOL_GPL(pci_cleanup_aer_uncorrect_error_status);
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