allow coexistance of N build and AC build.

[tomato.git] / release / src-rt-6.x / linux / linux-2.6 / drivers / pci / pcie / aer / aerdrv_core.c

/*
 * 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);