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linux/drivers/pci/pcie/aer/aerdrv_core.c
David Howells 65f27f3844 WorkStruct: Pass the work_struct pointer instead of context data 
Pass the work_struct pointer to the work function rather than context data.
The work function can use container_of() to work out the data.

For the cases where the container of the work_struct may go away the moment the
pending bit is cleared, it is made possible to defer the release of the
structure by deferring the clearing of the pending bit.

To make this work, an extra flag is introduced into the management side of the
work_struct.  This governs auto-release of the structure upon execution.

Ordinarily, the work queue executor would release the work_struct for further
scheduling or deallocation by clearing the pending bit prior to jumping to the
work function.  This means that, unless the driver makes some guarantee itself
that the work_struct won't go away, the work function may not access anything
else in the work_struct or its container lest they be deallocated..  This is a
problem if the auxiliary data is taken away (as done by the last patch).

However, if the pending bit is *not* cleared before jumping to the work
function, then the work function *may* access the work_struct and its container
with no problems.  But then the work function must itself release the
work_struct by calling work_release().

In most cases, automatic release is fine, so this is the default.  Special
initiators exist for the non-auto-release case (ending in _NAR).


Signed-Off-By: David Howells <dhowells@redhat.com>
2006-11-22 14:55:48 +00:00

759 lines
20 KiB
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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)
{
int retval;
retval = 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
* @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 *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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