pci.c

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/*
 * Copyright (c) 2009, Intel Corporation.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope 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.
 *
 * Author: Weidong Han <[email protected]>
 */

#include <linux/pci.h>
#include <linux/acpi.h>
#include <xen/xen.h>
#include <xen/interface/physdev.h>
#include <xen/interface/xen.h>

#include <asm/xen/hypervisor.h>
#include <asm/xen/hypercall.h>
#include "../pci/pci.h"

static bool __read_mostly pci_seg_supported = true;

static int xen_add_device(struct device *dev)
{
    int r;
    struct pci_dev *pci_dev = to_pci_dev(dev);
#ifdef CONFIG_PCI_IOV
    struct pci_dev *physfn = pci_dev->physfn;
#endif

    if (pci_seg_supported) {
        struct physdev_pci_device_add add = {
            .seg = pci_domain_nr(pci_dev->bus),
            .bus = pci_dev->bus->number,
            .devfn = pci_dev->devfn
        };
#ifdef CONFIG_ACPI
        acpi_handle handle;
#endif

#ifdef CONFIG_PCI_IOV
        if (pci_dev->is_virtfn) {
            add.flags = XEN_PCI_DEV_VIRTFN;
            add.physfn.bus = physfn->bus->number;
            add.physfn.devfn = physfn->devfn;
        } else
#endif
        if (pci_ari_enabled(pci_dev->bus) && PCI_SLOT(pci_dev->devfn))
            add.flags = XEN_PCI_DEV_EXTFN;

#ifdef CONFIG_ACPI
        handle = DEVICE_ACPI_HANDLE(&pci_dev->dev);
        if (!handle && pci_dev->bus->bridge)
            handle = DEVICE_ACPI_HANDLE(pci_dev->bus->bridge);
#ifdef CONFIG_PCI_IOV
        if (!handle && pci_dev->is_virtfn)
            handle = DEVICE_ACPI_HANDLE(physfn->bus->bridge);
#endif
        if (handle) {
            acpi_status status;

            do {
                unsigned long long pxm;

                status = acpi_evaluate_integer(handle, "_PXM",
                                   NULL, &pxm);
                if (ACPI_SUCCESS(status)) {
                    add.optarr[0] = pxm;
                    add.flags |= XEN_PCI_DEV_PXM;
                    break;
                }
                status = acpi_get_parent(handle, &handle);
            } while (ACPI_SUCCESS(status));
        }
#endif /* CONFIG_ACPI */

        r = HYPERVISOR_physdev_op(PHYSDEVOP_pci_device_add, &add);
        if (r != -ENOSYS)
            return r;
        pci_seg_supported = false;
    }

    if (pci_domain_nr(pci_dev->bus))
        r = -ENOSYS;
#ifdef CONFIG_PCI_IOV
    else if (pci_dev->is_virtfn) {
        struct physdev_manage_pci_ext manage_pci_ext = {
            .bus        = pci_dev->bus->number,
            .devfn      = pci_dev->devfn,
            .is_virtfn  = 1,
            .physfn.bus = physfn->bus->number,
            .physfn.devfn   = physfn->devfn,
        };

        r = HYPERVISOR_physdev_op(PHYSDEVOP_manage_pci_add_ext,
            &manage_pci_ext);
    }
#endif
    else if (pci_ari_enabled(pci_dev->bus) && PCI_SLOT(pci_dev->devfn)) {
        struct physdev_manage_pci_ext manage_pci_ext = {
            .bus        = pci_dev->bus->number,
            .devfn      = pci_dev->devfn,
            .is_extfn   = 1,
        };

        r = HYPERVISOR_physdev_op(PHYSDEVOP_manage_pci_add_ext,
            &manage_pci_ext);
    } else {
        struct physdev_manage_pci manage_pci = {
            .bus    = pci_dev->bus->number,
            .devfn  = pci_dev->devfn,
        };

        r = HYPERVISOR_physdev_op(PHYSDEVOP_manage_pci_add,
            &manage_pci);
    }

    return r;
}

static int xen_remove_device(struct device *dev)
{
    int r;
    struct pci_dev *pci_dev = to_pci_dev(dev);

    if (pci_seg_supported) {
        struct physdev_pci_device device = {
            .seg = pci_domain_nr(pci_dev->bus),
            .bus = pci_dev->bus->number,
            .devfn = pci_dev->devfn
        };

        r = HYPERVISOR_physdev_op(PHYSDEVOP_pci_device_remove,
                      &device);
    } else if (pci_domain_nr(pci_dev->bus))
        r = -ENOSYS;
    else {
        struct physdev_manage_pci manage_pci = {
            .bus = pci_dev->bus->number,
            .devfn = pci_dev->devfn
        };

        r = HYPERVISOR_physdev_op(PHYSDEVOP_manage_pci_remove,
                      &manage_pci);
    }

    return r;
}

static int xen_pci_notifier(struct notifier_block *nb,
                unsigned long action, void *data)
{
    struct device *dev = data;
    int r = 0;

    switch (action) {
    case BUS_NOTIFY_ADD_DEVICE:
        r = xen_add_device(dev);
        break;
    case BUS_NOTIFY_DEL_DEVICE:
        r = xen_remove_device(dev);
        break;
    default:
        return NOTIFY_DONE;
    }
    if (r)
        dev_err(dev, "Failed to %s - passthrough or MSI/MSI-X might fail!\n",
            action == BUS_NOTIFY_ADD_DEVICE ? "add" :
            (action == BUS_NOTIFY_DEL_DEVICE ? "delete" : "?"));
    return NOTIFY_OK;
}

static struct notifier_block device_nb = {
    .notifier_call = xen_pci_notifier,
};

static int __init register_xen_pci_notifier(void)
{
    if (!xen_initial_domain())
        return 0;

    return bus_register_notifier(&pci_bus_type, &device_nb);
}

arch_initcall(register_xen_pci_notifier);