portdrv_pci.c

Go to the documentation of this file.

/*
 * File:    portdrv_pci.c
 * Purpose: PCI Express Port Bus Driver
 *
 * Copyright (C) 2004 Intel
 * Copyright (C) Tom Long Nguyen ([email protected])
 */

#include <linux/module.h>
#include <linux/pci.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/pm.h>
#include <linux/pm_runtime.h>
#include <linux/init.h>
#include <linux/pcieport_if.h>
#include <linux/aer.h>
#include <linux/dmi.h>
#include <linux/pci-aspm.h>

#include "portdrv.h"
#include "aer/aerdrv.h"

/*
 * Version Information
 */
#define DRIVER_VERSION "v1.0"
#define DRIVER_AUTHOR "[email protected]"
#define DRIVER_DESC "PCIe Port Bus Driver"
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");

/* If this switch is set, PCIe port native services should not be enabled. */
bool pcie_ports_disabled;

/*
 * If this switch is set, ACPI _OSC will be used to determine whether or not to
 * enable PCIe port native services.
 */
bool pcie_ports_auto = true;

static int __init pcie_port_setup(char *str)
{
    if (!strncmp(str, "compat", 6)) {
        pcie_ports_disabled = true;
    } else if (!strncmp(str, "native", 6)) {
        pcie_ports_disabled = false;
        pcie_ports_auto = false;
    } else if (!strncmp(str, "auto", 4)) {
        pcie_ports_disabled = false;
        pcie_ports_auto = true;
    }

    return 1;
}
__setup("pcie_ports=", pcie_port_setup);

/* global data */

void pcie_clear_root_pme_status(struct pci_dev *dev)
{
    pcie_capability_set_dword(dev, PCI_EXP_RTSTA, PCI_EXP_RTSTA_PME);
}

static int pcie_portdrv_restore_config(struct pci_dev *dev)
{
    int retval;

    retval = pci_enable_device(dev);
    if (retval)
        return retval;
    pci_set_master(dev);
    return 0;
}

#ifdef CONFIG_PM
static int pcie_port_resume_noirq(struct device *dev)
{
    struct pci_dev *pdev = to_pci_dev(dev);

    /*
     * Some BIOSes forget to clear Root PME Status bits after system wakeup
     * which breaks ACPI-based runtime wakeup on PCI Express, so clear those
     * bits now just in case (shouldn't hurt).
     */
    if (pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT)
        pcie_clear_root_pme_status(pdev);
    return 0;
}

#ifdef CONFIG_PM_RUNTIME
struct d3cold_info {
    bool no_d3cold;
    unsigned int d3cold_delay;
};

static int pci_dev_d3cold_info(struct pci_dev *pdev, void *data)
{
    struct d3cold_info *info = data;

    info->d3cold_delay = max_t(unsigned int, pdev->d3cold_delay,
                   info->d3cold_delay);
    if (pdev->no_d3cold)
        info->no_d3cold = true;
    return 0;
}

static int pcie_port_runtime_suspend(struct device *dev)
{
    struct pci_dev *pdev = to_pci_dev(dev);
    struct d3cold_info d3cold_info = {
        .no_d3cold  = false,
        .d3cold_delay   = PCI_PM_D3_WAIT,
    };

    /*
     * If any subordinate device disable D3cold, we should not put
     * the port into D3cold.  The D3cold delay of port should be
     * the max of that of all subordinate devices.
     */
    pci_walk_bus(pdev->subordinate, pci_dev_d3cold_info, &d3cold_info);
    pdev->no_d3cold = d3cold_info.no_d3cold;
    pdev->d3cold_delay = d3cold_info.d3cold_delay;
    return 0;
}

static int pcie_port_runtime_resume(struct device *dev)
{
    return 0;
}

static int pcie_port_runtime_idle(struct device *dev)
{
    /* Delay for a short while to prevent too frequent suspend/resume */
    pm_schedule_suspend(dev, 10);
    return -EBUSY;
}
#else
#define pcie_port_runtime_suspend   NULL
#define pcie_port_runtime_resume    NULL
#define pcie_port_runtime_idle      NULL
#endif

static const struct dev_pm_ops pcie_portdrv_pm_ops = {
    .suspend    = pcie_port_device_suspend,
    .resume     = pcie_port_device_resume,
    .freeze     = pcie_port_device_suspend,
    .thaw       = pcie_port_device_resume,
    .poweroff   = pcie_port_device_suspend,
    .restore    = pcie_port_device_resume,
    .resume_noirq   = pcie_port_resume_noirq,
    .runtime_suspend = pcie_port_runtime_suspend,
    .runtime_resume = pcie_port_runtime_resume,
    .runtime_idle   = pcie_port_runtime_idle,
};

#define PCIE_PORTDRV_PM_OPS (&pcie_portdrv_pm_ops)

#else /* !PM */

#define PCIE_PORTDRV_PM_OPS NULL
#endif /* !PM */

/*
 * PCIe port runtime suspend is broken for some chipsets, so use a
 * black list to disable runtime PM for these chipsets.
 */
static const struct pci_device_id port_runtime_pm_black_list[] = {
    { /* end: all zeroes */ }
};

/*
 * pcie_portdrv_probe - Probe PCI-Express port devices
 * @dev: PCI-Express port device being probed
 *
 * If detected invokes the pcie_port_device_register() method for
 * this port device.
 *
 */
static int __devinit pcie_portdrv_probe(struct pci_dev *dev,
                    const struct pci_device_id *id)
{
    int status;

    if (!pci_is_pcie(dev) ||
        ((pci_pcie_type(dev) != PCI_EXP_TYPE_ROOT_PORT) &&
         (pci_pcie_type(dev) != PCI_EXP_TYPE_UPSTREAM) &&
         (pci_pcie_type(dev) != PCI_EXP_TYPE_DOWNSTREAM)))
        return -ENODEV;

    if (!dev->irq && dev->pin) {
        dev_warn(&dev->dev, "device [%04x:%04x] has invalid IRQ; "
             "check vendor BIOS\n", dev->vendor, dev->device);
    }
    status = pcie_port_device_register(dev);
    if (status)
        return status;

    pci_save_state(dev);
    /*
     * D3cold may not work properly on some PCIe port, so disable
     * it by default.
     */
    dev->d3cold_allowed = false;
    if (!pci_match_id(port_runtime_pm_black_list, dev))
        pm_runtime_put_noidle(&dev->dev);

    return 0;
}

static void pcie_portdrv_remove(struct pci_dev *dev)
{
    if (!pci_match_id(port_runtime_pm_black_list, dev))
        pm_runtime_get_noresume(&dev->dev);
    pcie_port_device_remove(dev);
    pci_disable_device(dev);
}

static int error_detected_iter(struct device *device, void *data)
{
    struct pcie_device *pcie_device;
    struct pcie_port_service_driver *driver;
    struct aer_broadcast_data *result_data;
    pci_ers_result_t status;

    result_data = (struct aer_broadcast_data *) data;

    if (device->bus == &pcie_port_bus_type && device->driver) {
        driver = to_service_driver(device->driver);
        if (!driver ||
            !driver->err_handler ||
            !driver->err_handler->error_detected)
            return 0;

        pcie_device = to_pcie_device(device);

        /* Forward error detected message to service drivers */
        status = driver->err_handler->error_detected(
            pcie_device->port,
            result_data->state);
        result_data->result =
            merge_result(result_data->result, status);
    }

    return 0;
}

static pci_ers_result_t pcie_portdrv_error_detected(struct pci_dev *dev,
                    enum pci_channel_state error)
{
    struct aer_broadcast_data data = {error, PCI_ERS_RESULT_CAN_RECOVER};
    int ret;

    /* can not fail */
    ret = device_for_each_child(&dev->dev, &data, error_detected_iter);

    return data.result;
}

static int mmio_enabled_iter(struct device *device, void *data)
{
    struct pcie_device *pcie_device;
    struct pcie_port_service_driver *driver;
    pci_ers_result_t status, *result;

    result = (pci_ers_result_t *) data;

    if (device->bus == &pcie_port_bus_type && device->driver) {
        driver = to_service_driver(device->driver);
        if (driver &&
            driver->err_handler &&
            driver->err_handler->mmio_enabled) {
            pcie_device = to_pcie_device(device);

            /* Forward error message to service drivers */
            status = driver->err_handler->mmio_enabled(
                    pcie_device->port);
            *result = merge_result(*result, status);
        }
    }

    return 0;
}

static pci_ers_result_t pcie_portdrv_mmio_enabled(struct pci_dev *dev)
{
    pci_ers_result_t status = PCI_ERS_RESULT_RECOVERED;
    int retval;

    /* get true return value from &status */
    retval = device_for_each_child(&dev->dev, &status, mmio_enabled_iter);
    return status;
}

static int slot_reset_iter(struct device *device, void *data)
{
    struct pcie_device *pcie_device;
    struct pcie_port_service_driver *driver;
    pci_ers_result_t status, *result;

    result = (pci_ers_result_t *) data;

    if (device->bus == &pcie_port_bus_type && device->driver) {
        driver = to_service_driver(device->driver);
        if (driver &&
            driver->err_handler &&
            driver->err_handler->slot_reset) {
            pcie_device = to_pcie_device(device);

            /* Forward error message to service drivers */
            status = driver->err_handler->slot_reset(
                    pcie_device->port);
            *result = merge_result(*result, status);
        }
    }

    return 0;
}

static pci_ers_result_t pcie_portdrv_slot_reset(struct pci_dev *dev)
{
    pci_ers_result_t status = PCI_ERS_RESULT_RECOVERED;
    int retval;

    /* If fatal, restore cfg space for possible link reset at upstream */
    if (dev->error_state == pci_channel_io_frozen) {
        dev->state_saved = true;
        pci_restore_state(dev);
        pcie_portdrv_restore_config(dev);
        pci_enable_pcie_error_reporting(dev);
    }

    /* get true return value from &status */
    retval = device_for_each_child(&dev->dev, &status, slot_reset_iter);

    return status;
}

static int resume_iter(struct device *device, void *data)
{
    struct pcie_device *pcie_device;
    struct pcie_port_service_driver *driver;

    if (device->bus == &pcie_port_bus_type && device->driver) {
        driver = to_service_driver(device->driver);
        if (driver &&
            driver->err_handler &&
            driver->err_handler->resume) {
            pcie_device = to_pcie_device(device);

            /* Forward error message to service drivers */
            driver->err_handler->resume(pcie_device->port);
        }
    }

    return 0;
}

static void pcie_portdrv_err_resume(struct pci_dev *dev)
{
    int retval;
    /* nothing to do with error value, if it ever happens */
    retval = device_for_each_child(&dev->dev, NULL, resume_iter);
}

/*
 * LINUX Device Driver Model
 */
static const struct pci_device_id port_pci_ids[] = { {
    /* handle any PCI-Express port */
    PCI_DEVICE_CLASS(((PCI_CLASS_BRIDGE_PCI << 8) | 0x00), ~0),
    }, { /* end: all zeroes */ }
};
MODULE_DEVICE_TABLE(pci, port_pci_ids);

static const struct pci_error_handlers pcie_portdrv_err_handler = {
    .error_detected = pcie_portdrv_error_detected,
    .mmio_enabled = pcie_portdrv_mmio_enabled,
    .slot_reset = pcie_portdrv_slot_reset,
    .resume = pcie_portdrv_err_resume,
};

static struct pci_driver pcie_portdriver = {
    .name       = "pcieport",
    .id_table   = &port_pci_ids[0],

    .probe      = pcie_portdrv_probe,
    .remove     = pcie_portdrv_remove,

    .err_handler    = &pcie_portdrv_err_handler,

    .driver.pm  = PCIE_PORTDRV_PM_OPS,
};

static int __init dmi_pcie_pme_disable_msi(const struct dmi_system_id *d)
{
    pr_notice("%s detected: will not use MSI for PCIe PME signaling\n",
            d->ident);
    pcie_pme_disable_msi();
    return 0;
}

static struct dmi_system_id __initdata pcie_portdrv_dmi_table[] = {
    /*
     * Boxes that should not use MSI for PCIe PME signaling.
     */
    {
     .callback = dmi_pcie_pme_disable_msi,
     .ident = "MSI Wind U-100",
     .matches = {
             DMI_MATCH(DMI_SYS_VENDOR,
                    "MICRO-STAR INTERNATIONAL CO., LTD"),
             DMI_MATCH(DMI_PRODUCT_NAME, "U-100"),
             },
     },
     {}
};

static int __init pcie_portdrv_init(void)
{
    int retval;

    if (pcie_ports_disabled)
        return pci_register_driver(&pcie_portdriver);

    dmi_check_system(pcie_portdrv_dmi_table);

    retval = pcie_port_bus_register();
    if (retval) {
        printk(KERN_WARNING "PCIE: bus_register error: %d\n", retval);
        goto out;
    }
    retval = pci_register_driver(&pcie_portdriver);
    if (retval)
        pcie_port_bus_unregister();
 out:
    return retval;
}

module_init(pcie_portdrv_init);