pci_root.c

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/*
 *  pci_root.c - ACPI PCI Root Bridge Driver ($Revision: 40 $)
 *
 *  Copyright (C) 2001, 2002 Andy Grover <[email protected]>
 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <[email protected]>
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or (at
 *  your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful, but
 *  WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/mutex.h>
#include <linux/pm.h>
#include <linux/pm_runtime.h>
#include <linux/pci.h>
#include <linux/pci-acpi.h>
#include <linux/pci-aspm.h>
#include <linux/acpi.h>
#include <linux/slab.h>
#include <acpi/acpi_bus.h>
#include <acpi/acpi_drivers.h>
#include <acpi/apei.h>

#define PREFIX "ACPI: "

#define _COMPONENT      ACPI_PCI_COMPONENT
ACPI_MODULE_NAME("pci_root");
#define ACPI_PCI_ROOT_CLASS     "pci_bridge"
#define ACPI_PCI_ROOT_DEVICE_NAME   "PCI Root Bridge"
static int acpi_pci_root_add(struct acpi_device *device);
static int acpi_pci_root_remove(struct acpi_device *device, int type);
static int acpi_pci_root_start(struct acpi_device *device);

#define ACPI_PCIE_REQ_SUPPORT (OSC_EXT_PCI_CONFIG_SUPPORT \
                | OSC_ACTIVE_STATE_PWR_SUPPORT \
                | OSC_CLOCK_PWR_CAPABILITY_SUPPORT \
                | OSC_MSI_SUPPORT)

static const struct acpi_device_id root_device_ids[] = {
    {"PNP0A03", 0},
    {"", 0},
};
MODULE_DEVICE_TABLE(acpi, root_device_ids);

static struct acpi_driver acpi_pci_root_driver = {
    .name = "pci_root",
    .class = ACPI_PCI_ROOT_CLASS,
    .ids = root_device_ids,
    .ops = {
        .add = acpi_pci_root_add,
        .remove = acpi_pci_root_remove,
        .start = acpi_pci_root_start,
        },
};

/* Lock to protect both acpi_pci_roots and acpi_pci_drivers lists */
static DEFINE_MUTEX(acpi_pci_root_lock);
static LIST_HEAD(acpi_pci_roots);
static LIST_HEAD(acpi_pci_drivers);

static DEFINE_MUTEX(osc_lock);

int acpi_pci_register_driver(struct acpi_pci_driver *driver)
{
    int n = 0;
    struct acpi_pci_root *root;

    mutex_lock(&acpi_pci_root_lock);
    list_add_tail(&driver->node, &acpi_pci_drivers);
    if (driver->add)
        list_for_each_entry(root, &acpi_pci_roots, node) {
            driver->add(root);
            n++;
        }
    mutex_unlock(&acpi_pci_root_lock);

    return n;
}
EXPORT_SYMBOL(acpi_pci_register_driver);

void acpi_pci_unregister_driver(struct acpi_pci_driver *driver)
{
    struct acpi_pci_root *root;

    mutex_lock(&acpi_pci_root_lock);
    list_del(&driver->node);
    if (driver->remove)
        list_for_each_entry(root, &acpi_pci_roots, node)
            driver->remove(root);
    mutex_unlock(&acpi_pci_root_lock);
}
EXPORT_SYMBOL(acpi_pci_unregister_driver);

acpi_handle acpi_get_pci_rootbridge_handle(unsigned int seg, unsigned int bus)
{
    struct acpi_pci_root *root;
    acpi_handle handle = NULL;
    
    mutex_lock(&acpi_pci_root_lock);
    list_for_each_entry(root, &acpi_pci_roots, node)
        if ((root->segment == (u16) seg) &&
            (root->secondary.start == (u16) bus)) {
            handle = root->device->handle;
            break;
        }
    mutex_unlock(&acpi_pci_root_lock);
    return handle;
}

EXPORT_SYMBOL_GPL(acpi_get_pci_rootbridge_handle);

int acpi_is_root_bridge(acpi_handle handle)
{
    int ret;
    struct acpi_device *device;

    ret = acpi_bus_get_device(handle, &device);
    if (ret)
        return 0;

    ret = acpi_match_device_ids(device, root_device_ids);
    if (ret)
        return 0;
    else
        return 1;
}
EXPORT_SYMBOL_GPL(acpi_is_root_bridge);

static acpi_status
get_root_bridge_busnr_callback(struct acpi_resource *resource, void *data)
{
    struct resource *res = data;
    struct acpi_resource_address64 address;

    if (resource->type != ACPI_RESOURCE_TYPE_ADDRESS16 &&
        resource->type != ACPI_RESOURCE_TYPE_ADDRESS32 &&
        resource->type != ACPI_RESOURCE_TYPE_ADDRESS64)
        return AE_OK;

    acpi_resource_to_address64(resource, &address);
    if ((address.address_length > 0) &&
        (address.resource_type == ACPI_BUS_NUMBER_RANGE)) {
        res->start = address.minimum;
        res->end = address.minimum + address.address_length - 1;
    }

    return AE_OK;
}

static acpi_status try_get_root_bridge_busnr(acpi_handle handle,
                         struct resource *res)
{
    acpi_status status;

    res->start = -1;
    status =
        acpi_walk_resources(handle, METHOD_NAME__CRS,
                get_root_bridge_busnr_callback, res);
    if (ACPI_FAILURE(status))
        return status;
    if (res->start == -1)
        return AE_ERROR;
    return AE_OK;
}

static void acpi_pci_bridge_scan(struct acpi_device *device)
{
    int status;
    struct acpi_device *child = NULL;

    if (device->flags.bus_address)
        if (device->parent && device->parent->ops.bind) {
            status = device->parent->ops.bind(device);
            if (!status) {
                list_for_each_entry(child, &device->children, node)
                    acpi_pci_bridge_scan(child);
            }
        }
}

static u8 pci_osc_uuid_str[] = "33DB4D5B-1FF7-401C-9657-7441C03DD766";

static acpi_status acpi_pci_run_osc(acpi_handle handle,
                    const u32 *capbuf, u32 *retval)
{
    struct acpi_osc_context context = {
        .uuid_str = pci_osc_uuid_str,
        .rev = 1,
        .cap.length = 12,
        .cap.pointer = (void *)capbuf,
    };
    acpi_status status;

    status = acpi_run_osc(handle, &context);
    if (ACPI_SUCCESS(status)) {
        *retval = *((u32 *)(context.ret.pointer + 8));
        kfree(context.ret.pointer);
    }
    return status;
}

static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root,
                    u32 support,
                    u32 *control)
{
    acpi_status status;
    u32 result, capbuf[3];

    support &= OSC_PCI_SUPPORT_MASKS;
    support |= root->osc_support_set;

    capbuf[OSC_QUERY_TYPE] = OSC_QUERY_ENABLE;
    capbuf[OSC_SUPPORT_TYPE] = support;
    if (control) {
        *control &= OSC_PCI_CONTROL_MASKS;
        capbuf[OSC_CONTROL_TYPE] = *control | root->osc_control_set;
    } else {
        /* Run _OSC query for all possible controls. */
        capbuf[OSC_CONTROL_TYPE] = OSC_PCI_CONTROL_MASKS;
    }

    status = acpi_pci_run_osc(root->device->handle, capbuf, &result);
    if (ACPI_SUCCESS(status)) {
        root->osc_support_set = support;
        if (control)
            *control = result;
    }
    return status;
}

static acpi_status acpi_pci_osc_support(struct acpi_pci_root *root, u32 flags)
{
    acpi_status status;
    acpi_handle tmp;

    status = acpi_get_handle(root->device->handle, "_OSC", &tmp);
    if (ACPI_FAILURE(status))
        return status;
    mutex_lock(&osc_lock);
    status = acpi_pci_query_osc(root, flags, NULL);
    mutex_unlock(&osc_lock);
    return status;
}

struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle)
{
    struct acpi_pci_root *root;
    struct acpi_device *device;

    if (acpi_bus_get_device(handle, &device) ||
        acpi_match_device_ids(device, root_device_ids))
        return NULL;

    root = acpi_driver_data(device);

    return root;
}
EXPORT_SYMBOL_GPL(acpi_pci_find_root);

struct acpi_handle_node {
    struct list_head node;
    acpi_handle handle;
};

struct pci_dev *acpi_get_pci_dev(acpi_handle handle)
{
    int dev, fn;
    unsigned long long adr;
    acpi_status status;
    acpi_handle phandle;
    struct pci_bus *pbus;
    struct pci_dev *pdev = NULL;
    struct acpi_handle_node *node, *tmp;
    struct acpi_pci_root *root;
    LIST_HEAD(device_list);

    /*
     * Walk up the ACPI CA namespace until we reach a PCI root bridge.
     */
    phandle = handle;
    while (!acpi_is_root_bridge(phandle)) {
        node = kzalloc(sizeof(struct acpi_handle_node), GFP_KERNEL);
        if (!node)
            goto out;

        INIT_LIST_HEAD(&node->node);
        node->handle = phandle;
        list_add(&node->node, &device_list);

        status = acpi_get_parent(phandle, &phandle);
        if (ACPI_FAILURE(status))
            goto out;
    }

    root = acpi_pci_find_root(phandle);
    if (!root)
        goto out;

    pbus = root->bus;

    /*
     * Now, walk back down the PCI device tree until we return to our
     * original handle. Assumes that everything between the PCI root
     * bridge and the device we're looking for must be a P2P bridge.
     */
    list_for_each_entry(node, &device_list, node) {
        acpi_handle hnd = node->handle;
        status = acpi_evaluate_integer(hnd, "_ADR", NULL, &adr);
        if (ACPI_FAILURE(status))
            goto out;
        dev = (adr >> 16) & 0xffff;
        fn  = adr & 0xffff;

        pdev = pci_get_slot(pbus, PCI_DEVFN(dev, fn));
        if (!pdev || hnd == handle)
            break;

        pbus = pdev->subordinate;
        pci_dev_put(pdev);

        /*
         * This function may be called for a non-PCI device that has a
         * PCI parent (eg. a disk under a PCI SATA controller).  In that
         * case pdev->subordinate will be NULL for the parent.
         */
        if (!pbus) {
            dev_dbg(&pdev->dev, "Not a PCI-to-PCI bridge\n");
            pdev = NULL;
            break;
        }
    }
out:
    list_for_each_entry_safe(node, tmp, &device_list, node)
        kfree(node);

    return pdev;
}
EXPORT_SYMBOL_GPL(acpi_get_pci_dev);

acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 req)
{
    struct acpi_pci_root *root;
    acpi_status status;
    u32 ctrl, capbuf[3];
    acpi_handle tmp;

    if (!mask)
        return AE_BAD_PARAMETER;

    ctrl = *mask & OSC_PCI_CONTROL_MASKS;
    if ((ctrl & req) != req)
        return AE_TYPE;

    root = acpi_pci_find_root(handle);
    if (!root)
        return AE_NOT_EXIST;

    status = acpi_get_handle(handle, "_OSC", &tmp);
    if (ACPI_FAILURE(status))
        return status;

    mutex_lock(&osc_lock);

    *mask = ctrl | root->osc_control_set;
    /* No need to evaluate _OSC if the control was already granted. */
    if ((root->osc_control_set & ctrl) == ctrl)
        goto out;

    /* Need to check the available controls bits before requesting them. */
    while (*mask) {
        status = acpi_pci_query_osc(root, root->osc_support_set, mask);
        if (ACPI_FAILURE(status))
            goto out;
        if (ctrl == *mask)
            break;
        ctrl = *mask;
    }

    if ((ctrl & req) != req) {
        status = AE_SUPPORT;
        goto out;
    }

    capbuf[OSC_QUERY_TYPE] = 0;
    capbuf[OSC_SUPPORT_TYPE] = root->osc_support_set;
    capbuf[OSC_CONTROL_TYPE] = ctrl;
    status = acpi_pci_run_osc(handle, capbuf, mask);
    if (ACPI_SUCCESS(status))
        root->osc_control_set = *mask;
out:
    mutex_unlock(&osc_lock);
    return status;
}
EXPORT_SYMBOL(acpi_pci_osc_control_set);

static int __devinit acpi_pci_root_add(struct acpi_device *device)
{
    unsigned long long segment, bus;
    acpi_status status;
    int result;
    struct acpi_pci_root *root;
    acpi_handle handle;
    struct acpi_device *child;
    u32 flags, base_flags;

    root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
    if (!root)
        return -ENOMEM;

    segment = 0;
    status = acpi_evaluate_integer(device->handle, METHOD_NAME__SEG, NULL,
                       &segment);
    if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
        printk(KERN_ERR PREFIX "can't evaluate _SEG\n");
        result = -ENODEV;
        goto end;
    }

    /* Check _CRS first, then _BBN.  If no _BBN, default to zero. */
    root->secondary.flags = IORESOURCE_BUS;
    status = try_get_root_bridge_busnr(device->handle, &root->secondary);
    if (ACPI_FAILURE(status)) {
        /*
         * We need both the start and end of the downstream bus range
         * to interpret _CBA (MMCONFIG base address), so it really is
         * supposed to be in _CRS.  If we don't find it there, all we
         * can do is assume [_BBN-0xFF] or [0-0xFF].
         */
        root->secondary.end = 0xFF;
        printk(KERN_WARNING FW_BUG PREFIX
               "no secondary bus range in _CRS\n");
        status = acpi_evaluate_integer(device->handle, METHOD_NAME__BBN,
                           NULL, &bus);
        if (ACPI_SUCCESS(status))
            root->secondary.start = bus;
        else if (status == AE_NOT_FOUND)
            root->secondary.start = 0;
        else {
            printk(KERN_ERR PREFIX "can't evaluate _BBN\n");
            result = -ENODEV;
            goto end;
        }
    }

    INIT_LIST_HEAD(&root->node);
    root->device = device;
    root->segment = segment & 0xFFFF;
    strcpy(acpi_device_name(device), ACPI_PCI_ROOT_DEVICE_NAME);
    strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
    device->driver_data = root;

    root->mcfg_addr = acpi_pci_root_get_mcfg_addr(device->handle);

    /*
     * All supported architectures that use ACPI have support for
     * PCI domains, so we indicate this in _OSC support capabilities.
     */
    flags = base_flags = OSC_PCI_SEGMENT_GROUPS_SUPPORT;
    acpi_pci_osc_support(root, flags);

    /*
     * TBD: Need PCI interface for enumeration/configuration of roots.
     */

    mutex_lock(&acpi_pci_root_lock);
    list_add_tail(&root->node, &acpi_pci_roots);
    mutex_unlock(&acpi_pci_root_lock);

    printk(KERN_INFO PREFIX "%s [%s] (domain %04x %pR)\n",
           acpi_device_name(device), acpi_device_bid(device),
           root->segment, &root->secondary);

    /*
     * Scan the Root Bridge
     * --------------------
     * Must do this prior to any attempt to bind the root device, as the
     * PCI namespace does not get created until this call is made (and 
     * thus the root bridge's pci_dev does not exist).
     */
    root->bus = pci_acpi_scan_root(root);
    if (!root->bus) {
        printk(KERN_ERR PREFIX
                "Bus %04x:%02x not present in PCI namespace\n",
                root->segment, (unsigned int)root->secondary.start);
        result = -ENODEV;
        goto out_del_root;
    }

    /*
     * Attach ACPI-PCI Context
     * -----------------------
     * Thus binding the ACPI and PCI devices.
     */
    result = acpi_pci_bind_root(device);
    if (result)
        goto out_del_root;

    /*
     * PCI Routing Table
     * -----------------
     * Evaluate and parse _PRT, if exists.
     */
    status = acpi_get_handle(device->handle, METHOD_NAME__PRT, &handle);
    if (ACPI_SUCCESS(status))
        result = acpi_pci_irq_add_prt(device->handle, root->bus);

    /*
     * Scan and bind all _ADR-Based Devices
     */
    list_for_each_entry(child, &device->children, node)
        acpi_pci_bridge_scan(child);

    /* Indicate support for various _OSC capabilities. */
    if (pci_ext_cfg_avail(root->bus->self))
        flags |= OSC_EXT_PCI_CONFIG_SUPPORT;
    if (pcie_aspm_support_enabled())
        flags |= OSC_ACTIVE_STATE_PWR_SUPPORT |
            OSC_CLOCK_PWR_CAPABILITY_SUPPORT;
    if (pci_msi_enabled())
        flags |= OSC_MSI_SUPPORT;
    if (flags != base_flags) {
        status = acpi_pci_osc_support(root, flags);
        if (ACPI_FAILURE(status)) {
            dev_info(root->bus->bridge, "ACPI _OSC support "
                "notification failed, disabling PCIe ASPM\n");
            pcie_no_aspm();
            flags = base_flags;
        }
    }

    if (!pcie_ports_disabled
        && (flags & ACPI_PCIE_REQ_SUPPORT) == ACPI_PCIE_REQ_SUPPORT) {
        flags = OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL
            | OSC_PCI_EXPRESS_NATIVE_HP_CONTROL
            | OSC_PCI_EXPRESS_PME_CONTROL;

        if (pci_aer_available()) {
            if (aer_acpi_firmware_first())
                dev_dbg(root->bus->bridge,
                    "PCIe errors handled by BIOS.\n");
            else
                flags |= OSC_PCI_EXPRESS_AER_CONTROL;
        }

        dev_info(root->bus->bridge,
            "Requesting ACPI _OSC control (0x%02x)\n", flags);

        status = acpi_pci_osc_control_set(device->handle, &flags,
                    OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL);
        if (ACPI_SUCCESS(status)) {
            dev_info(root->bus->bridge,
                "ACPI _OSC control (0x%02x) granted\n", flags);
            if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
                /*
                 * We have ASPM control, but the FADT indicates
                 * that it's unsupported. Clear it.
                 */
                pcie_clear_aspm(root->bus);
            }
        } else {
            dev_info(root->bus->bridge,
                "ACPI _OSC request failed (%s), "
                "returned control mask: 0x%02x\n",
                acpi_format_exception(status), flags);
            pr_info("ACPI _OSC control for PCIe not granted, "
                "disabling ASPM\n");
            pcie_no_aspm();
        }
    } else {
        dev_info(root->bus->bridge,
             "Unable to request _OSC control "
             "(_OSC support mask: 0x%02x)\n", flags);
    }

    pci_acpi_add_bus_pm_notifier(device, root->bus);
    if (device->wakeup.flags.run_wake)
        device_set_run_wake(root->bus->bridge, true);

    return 0;

out_del_root:
    mutex_lock(&acpi_pci_root_lock);
    list_del(&root->node);
    mutex_unlock(&acpi_pci_root_lock);
end:
    kfree(root);
    return result;
}

static int acpi_pci_root_start(struct acpi_device *device)
{
    struct acpi_pci_root *root = acpi_driver_data(device);
    struct acpi_pci_driver *driver;

    mutex_lock(&acpi_pci_root_lock);
    list_for_each_entry(driver, &acpi_pci_drivers, node)
        if (driver->add)
            driver->add(root);
    mutex_unlock(&acpi_pci_root_lock);

    pci_bus_add_devices(root->bus);

    return 0;
}

static int acpi_pci_root_remove(struct acpi_device *device, int type)
{
    struct acpi_pci_root *root = acpi_driver_data(device);
    struct acpi_pci_driver *driver;

    mutex_lock(&acpi_pci_root_lock);
    list_for_each_entry(driver, &acpi_pci_drivers, node)
        if (driver->remove)
            driver->remove(root);

    device_set_run_wake(root->bus->bridge, false);
    pci_acpi_remove_bus_pm_notifier(device);

    list_del(&root->node);
    mutex_unlock(&acpi_pci_root_lock);
    kfree(root);
    return 0;
}

static int __init acpi_pci_root_init(void)
{
    acpi_hest_init();

    if (acpi_pci_disabled)
        return 0;

    pci_acpi_crs_quirks();
    if (acpi_bus_register_driver(&acpi_pci_root_driver) < 0)
        return -ENODEV;

    return 0;
}

subsys_initcall(acpi_pci_root_init);