// SPDX-License-Identifier: GPL-2.0-only
/*
 *      Low-Level PCI Support for PC
 *
 *      (c) 1999--2000 Martin Mares <mj@ucw.cz>
 */

#include <linux/sched.h>
#include <linux/pci.h>
#include <linux/pci-acpi.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/dmi.h>
#include <linux/slab.h>

#include <asm/acpi.h>
#include <asm/segment.h>
#include <asm/io.h>
#include <asm/smp.h>
#include <asm/pci_x86.h>
#include <asm/setup.h>
#include <asm/irqdomain.h>

unsigned int pci_probe = PCI_PROBE_BIOS | PCI_PROBE_CONF1 | PCI_PROBE_CONF2 |
                                PCI_PROBE_MMCONF;

static int pci_bf_sort;
int pci_routeirq;
int noioapicquirk;
#ifdef CONFIG_X86_REROUTE_FOR_BROKEN_BOOT_IRQS
int noioapicreroute = 0;
#else
int noioapicreroute = 1;
#endif
int pcibios_last_bus = -1;
unsigned long pirq_table_addr;
const struct pci_raw_ops *__read_mostly raw_pci_ops;
const struct pci_raw_ops *__read_mostly raw_pci_ext_ops;

int raw_pci_read(unsigned int domain, unsigned int bus, unsigned int devfn,
                                                int reg, int len, u32 *val)
{
        if (domain == 0 && reg < 256 && raw_pci_ops)
                return raw_pci_ops->read(domain, bus, devfn, reg, len, val);
        if (raw_pci_ext_ops)
                return raw_pci_ext_ops->read(domain, bus, devfn, reg, len, val);
        return -EINVAL;
}

int raw_pci_write(unsigned int domain, unsigned int bus, unsigned int devfn,
                                                int reg, int len, u32 val)
{
        if (domain == 0 && reg < 256 && raw_pci_ops)
                return raw_pci_ops->write(domain, bus, devfn, reg, len, val);
        if (raw_pci_ext_ops)
                return raw_pci_ext_ops->write(domain, bus, devfn, reg, len, val);
        return -EINVAL;
}

static int pci_read(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 *value)
{
        return raw_pci_read(pci_domain_nr(bus), bus->number,
                                 devfn, where, size, value);
}

static int pci_write(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 value)
{
        return raw_pci_write(pci_domain_nr(bus), bus->number,
                                  devfn, where, size, value);
}

struct pci_ops pci_root_ops = {
        .read = pci_read,
        .write = pci_write,
};

/*
 * This interrupt-safe spinlock protects all accesses to PCI configuration
 * space, except for the mmconfig (ECAM) based operations.
 */
DEFINE_RAW_SPINLOCK(pci_config_lock);

static int __init can_skip_ioresource_align(const struct dmi_system_id *d)
{
        pci_probe |= PCI_CAN_SKIP_ISA_ALIGN;
        printk(KERN_INFO "PCI: %s detected, can skip ISA alignment\n", d->ident);
        return 0;
}

static const struct dmi_system_id can_skip_pciprobe_dmi_table[] __initconst = {
/*
 * Systems where PCI IO resource ISA alignment can be skipped
 * when the ISA enable bit in the bridge control is not set
 */
        {
                .callback = can_skip_ioresource_align,
                .ident = "IBM System x3800",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "x3800"),
                },
        },
        {
                .callback = can_skip_ioresource_align,
                .ident = "IBM System x3850",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "x3850"),
                },
        },
        {
                .callback = can_skip_ioresource_align,
                .ident = "IBM System x3950",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "x3950"),
                },
        },
        {}
};

void __init dmi_check_skip_isa_align(void)
{
        dmi_check_system(can_skip_pciprobe_dmi_table);
}

static void pcibios_fixup_device_resources(struct pci_dev *dev)
{
        struct resource *rom_r = &dev->resource[PCI_ROM_RESOURCE];
        struct resource *bar_r;
        int bar;

        if (pci_probe & PCI_NOASSIGN_BARS) {
                /*
                * If the BIOS did not assign the BAR, zero out the
                * resource so the kernel doesn't attempt to assign
                * it later on in pci_assign_unassigned_resources
                */
                for (bar = 0; bar < PCI_STD_NUM_BARS; bar++) {
                        bar_r = &dev->resource[bar];
                        if (bar_r->start == 0 && bar_r->end != 0) {
                                bar_r->flags = 0;
                                bar_r->end = 0;
                        }
                }
        }

        if (pci_probe & PCI_NOASSIGN_ROMS) {
                if (rom_r->parent)
                        return;
                if (rom_r->start) {
                        /* we deal with BIOS assigned ROM later */
                        return;
                }
                rom_r->start = rom_r->end = rom_r->flags = 0;
        }
}

/*
 *  Called after each bus is probed, but before its children
 *  are examined.
 */

void pcibios_fixup_bus(struct pci_bus *b)
{
        struct pci_dev *dev;

        pci_read_bridge_bases(b);
        list_for_each_entry(dev, &b->devices, bus_list)
                pcibios_fixup_device_resources(dev);
}

void pcibios_add_bus(struct pci_bus *bus)
{
        acpi_pci_add_bus(bus);
}

void pcibios_remove_bus(struct pci_bus *bus)
{
        acpi_pci_remove_bus(bus);
}

/*
 * Only use DMI information to set this if nothing was passed
 * on the kernel command line (which was parsed earlier).
 */

static int __init set_bf_sort(const struct dmi_system_id *d)
{
        if (pci_bf_sort == pci_bf_sort_default) {
                pci_bf_sort = pci_dmi_bf;
                printk(KERN_INFO "PCI: %s detected, enabling pci=bfsort.\n", d->ident);
        }
        return 0;
}

static void __init read_dmi_type_b1(const struct dmi_header *dm,
                                    void *private_data)
{
        u8 *data = (u8 *)dm + 4;

        if (dm->type != 0xB1)
                return;
        if ((((*(u32 *)data) >> 9) & 0x03) == 0x01)
                set_bf_sort((const struct dmi_system_id *)private_data);
}

static int __init find_sort_method(const struct dmi_system_id *d)
{
        dmi_walk(read_dmi_type_b1, (void *)d);
        return 0;
}

/*
 * Enable renumbering of PCI bus# ranges to reach all PCI busses (Cardbus)
 */
#ifdef __i386__
static int __init assign_all_busses(const struct dmi_system_id *d)
{
        pci_probe |= PCI_ASSIGN_ALL_BUSSES;
        printk(KERN_INFO "%s detected: enabling PCI bus# renumbering"
                        " (pci=assign-busses)\n", d->ident);
        return 0;
}
#endif

static int __init set_scan_all(const struct dmi_system_id *d)
{
        printk(KERN_INFO "PCI: %s detected, enabling pci=pcie_scan_all\n",
               d->ident);
        pci_add_flags(PCI_SCAN_ALL_PCIE_DEVS);
        return 0;
}

static const struct dmi_system_id pciprobe_dmi_table[] __initconst = {
#ifdef __i386__
/*
 * Laptops which need pci=assign-busses to see Cardbus cards
 */
        {
                .callback = assign_all_busses,
                .ident = "Samsung X20 Laptop",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "Samsung Electronics"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "SX20S"),
                },
        },
#endif          /* __i386__ */
        {
                .callback = set_bf_sort,
                .ident = "Dell PowerEdge 1950",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1950"),
                },
        },
        {
                .callback = set_bf_sort,
                .ident = "Dell PowerEdge 1955",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1955"),
                },
        },
        {
                .callback = set_bf_sort,
                .ident = "Dell PowerEdge 2900",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2900"),
                },
        },
        {
                .callback = set_bf_sort,
                .ident = "Dell PowerEdge 2950",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2950"),
                },
        },
        {
                .callback = set_bf_sort,
                .ident = "Dell PowerEdge R900",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge R900"),
                },
        },
        {
                .callback = find_sort_method,
                .ident = "Dell System",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc"),
                },
        },
        {
                .callback = set_bf_sort,
                .ident = "HP ProLiant BL20p G3",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "HP"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant BL20p G3"),
                },
        },
        {
                .callback = set_bf_sort,
                .ident = "HP ProLiant BL20p G4",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "HP"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant BL20p G4"),
                },
        },
        {
                .callback = set_bf_sort,
                .ident = "HP ProLiant BL30p G1",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "HP"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant BL30p G1"),
                },
        },
        {
                .callback = set_bf_sort,
                .ident = "HP ProLiant BL25p G1",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "HP"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant BL25p G1"),
                },
        },
        {
                .callback = set_bf_sort,
                .ident = "HP ProLiant BL35p G1",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "HP"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant BL35p G1"),
                },
        },
        {
                .callback = set_bf_sort,
                .ident = "HP ProLiant BL45p G1",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "HP"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant BL45p G1"),
                },
        },
        {
                .callback = set_bf_sort,
                .ident = "HP ProLiant BL45p G2",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "HP"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant BL45p G2"),
                },
        },
        {
                .callback = set_bf_sort,
                .ident = "HP ProLiant BL460c G1",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "HP"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant BL460c G1"),
                },
        },
        {
                .callback = set_bf_sort,
                .ident = "HP ProLiant BL465c G1",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "HP"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant BL465c G1"),
                },
        },
        {
                .callback = set_bf_sort,
                .ident = "HP ProLiant BL480c G1",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "HP"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant BL480c G1"),
                },
        },
        {
                .callback = set_bf_sort,
                .ident = "HP ProLiant BL685c G1",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "HP"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant BL685c G1"),
                },
        },
        {
                .callback = set_bf_sort,
                .ident = "HP ProLiant DL360",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "HP"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant DL360"),
                },
        },
        {
                .callback = set_bf_sort,
                .ident = "HP ProLiant DL380",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "HP"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant DL380"),
                },
        },
#ifdef __i386__
        {
                .callback = assign_all_busses,
                .ident = "Compaq EVO N800c",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "Compaq"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "EVO N800c"),
                },
        },
#endif
        {
                .callback = set_bf_sort,
                .ident = "HP ProLiant DL385 G2",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "HP"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant DL385 G2"),
                },
        },
        {
                .callback = set_bf_sort,
                .ident = "HP ProLiant DL585 G2",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "HP"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "ProLiant DL585 G2"),
                },
        },
        {
                .callback = set_scan_all,
                .ident = "Stratus/NEC ftServer",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "Stratus"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "ftServer"),
                },
        },
        {
                .callback = set_scan_all,
                .ident = "Stratus/NEC ftServer",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "NEC"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "Express5800/R32"),
                },
        },
        {
                .callback = set_scan_all,
                .ident = "Stratus/NEC ftServer",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "NEC"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "Express5800/R31"),
                },
        },
        {}
};

void __init dmi_check_pciprobe(void)
{
        dmi_check_system(pciprobe_dmi_table);
}

void pcibios_scan_root(int busnum)
{
        struct pci_bus *bus;
        struct pci_sysdata *sd;
        LIST_HEAD(resources);

        sd = kzalloc(sizeof(*sd), GFP_KERNEL);
        if (!sd) {
                printk(KERN_ERR "PCI: OOM, skipping PCI bus %02x\n", busnum);
                return;
        }
        sd->node = x86_pci_root_bus_node(busnum);
        x86_pci_root_bus_resources(busnum, &resources);
        printk(KERN_DEBUG "PCI: Probing PCI hardware (bus %02x)\n", busnum);
        bus = pci_scan_root_bus(NULL, busnum, &pci_root_ops, sd, &resources);
        if (!bus) {
                pci_free_resource_list(&resources);
                kfree(sd);
                return;
        }
        pci_bus_add_devices(bus);
}

void __init pcibios_set_cache_line_size(void)
{
        struct cpuinfo_x86 *c = &boot_cpu_data;

        /*
         * Set PCI cacheline size to that of the CPU if the CPU has reported it.
         * (For older CPUs that don't support cpuid, we se it to 32 bytes
         * It's also good for 386/486s (which actually have 16)
         * as quite a few PCI devices do not support smaller values.
         */
        if (c->x86_clflush_size > 0) {
                pci_dfl_cache_line_size = c->x86_clflush_size >> 2;
                printk(KERN_DEBUG "PCI: pci_cache_line_size set to %d bytes\n",
                        pci_dfl_cache_line_size << 2);
        } else {
                pci_dfl_cache_line_size = 32 >> 2;
                printk(KERN_DEBUG "PCI: Unknown cacheline size. Setting to 32 bytes\n");
        }
}

int __init pcibios_init(void)
{
        if (!raw_pci_ops && !raw_pci_ext_ops) {
                printk(KERN_WARNING "PCI: System does not support PCI\n");
                return 0;
        }

        pcibios_set_cache_line_size();
        pcibios_resource_survey();

        if (pci_bf_sort >= pci_force_bf)
                pci_sort_breadthfirst();
        return 0;
}

char *__init pcibios_setup(char *str)
{
        if (!strcmp(str, "off")) {
                pci_probe = 0;
                return NULL;
        } else if (!strcmp(str, "bfsort")) {
                pci_bf_sort = pci_force_bf;
                return NULL;
        } else if (!strcmp(str, "nobfsort")) {
                pci_bf_sort = pci_force_nobf;
                return NULL;
        }
#ifdef CONFIG_PCI_BIOS
        else if (!strcmp(str, "bios")) {
                pci_probe = PCI_PROBE_BIOS;
                return NULL;
        } else if (!strcmp(str, "nobios")) {
                pci_probe &= ~PCI_PROBE_BIOS;
                return NULL;
        } else if (!strcmp(str, "biosirq")) {
                pci_probe |= PCI_BIOS_IRQ_SCAN;
                return NULL;
        } else if (!strncmp(str, "pirqaddr=", 9)) {
                pirq_table_addr = simple_strtoul(str+9, NULL, 0);
                return NULL;
        }
#endif
#ifdef CONFIG_PCI_DIRECT
        else if (!strcmp(str, "conf1")) {
                pci_probe = PCI_PROBE_CONF1 | PCI_NO_CHECKS;
                return NULL;
        }
        else if (!strcmp(str, "conf2")) {
                pci_probe = PCI_PROBE_CONF2 | PCI_NO_CHECKS;
                return NULL;
        }
#endif
#ifdef CONFIG_PCI_MMCONFIG
        else if (!strcmp(str, "nommconf")) {
                pci_probe &= ~PCI_PROBE_MMCONF;
                return NULL;
        }
        else if (!strcmp(str, "check_enable_amd_mmconf")) {
                pci_probe |= PCI_CHECK_ENABLE_AMD_MMCONF;
                return NULL;
        }
#endif
        else if (!strcmp(str, "noacpi")) {
                acpi_noirq_set();
                return NULL;
        }
        else if (!strcmp(str, "noearly")) {
                pci_probe |= PCI_PROBE_NOEARLY;
                return NULL;
        }
        else if (!strcmp(str, "usepirqmask")) {
                pci_probe |= PCI_USE_PIRQ_MASK;
                return NULL;
        } else if (!strncmp(str, "irqmask=", 8)) {
                pcibios_irq_mask = simple_strtol(str+8, NULL, 0);
                return NULL;
        } else if (!strncmp(str, "lastbus=", 8)) {
                pcibios_last_bus = simple_strtol(str+8, NULL, 0);
                return NULL;
        } else if (!strcmp(str, "rom")) {
                pci_probe |= PCI_ASSIGN_ROMS;
                return NULL;
        } else if (!strcmp(str, "norom")) {
                pci_probe |= PCI_NOASSIGN_ROMS;
                return NULL;
        } else if (!strcmp(str, "nobar")) {
                pci_probe |= PCI_NOASSIGN_BARS;
                return NULL;
        } else if (!strcmp(str, "assign-busses")) {
                pci_probe |= PCI_ASSIGN_ALL_BUSSES;
                return NULL;
        } else if (!strcmp(str, "use_crs")) {
                pci_probe |= PCI_USE__CRS;
                return NULL;
        } else if (!strcmp(str, "nocrs")) {
                pci_probe |= PCI_ROOT_NO_CRS;
                return NULL;
        } else if (!strcmp(str, "use_e820")) {
                pci_probe |= PCI_USE_E820;
                add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_STILL_OK);
                return NULL;
        } else if (!strcmp(str, "no_e820")) {
                pci_probe |= PCI_NO_E820;
                add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_STILL_OK);
                return NULL;
#ifdef CONFIG_PHYS_ADDR_T_64BIT
        } else if (!strcmp(str, "big_root_window")) {
                pci_probe |= PCI_BIG_ROOT_WINDOW;
                return NULL;
#endif
        } else if (!strcmp(str, "routeirq")) {
                pci_routeirq = 1;
                return NULL;
        } else if (!strcmp(str, "skip_isa_align")) {
                pci_probe |= PCI_CAN_SKIP_ISA_ALIGN;
                return NULL;
        } else if (!strcmp(str, "noioapicquirk")) {
                noioapicquirk = 1;
                return NULL;
        } else if (!strcmp(str, "ioapicreroute")) {
                if (noioapicreroute != -1)
                        noioapicreroute = 0;
                return NULL;
        } else if (!strcmp(str, "noioapicreroute")) {
                if (noioapicreroute != -1)
                        noioapicreroute = 1;
                return NULL;
        }
        return str;
}

unsigned int pcibios_assign_all_busses(void)
{
        return (pci_probe & PCI_ASSIGN_ALL_BUSSES) ? 1 : 0;
}

static void set_dev_domain_options(struct pci_dev *pdev)
{
        if (is_vmd(pdev->bus))
                pdev->hotplug_user_indicators = 1;
}

int pcibios_device_add(struct pci_dev *dev)
{
        struct pci_setup_rom *rom;
        struct irq_domain *msidom;
        struct setup_data *data;
        u64 pa_data;

        pa_data = boot_params.hdr.setup_data;
        while (pa_data) {
                data = memremap(pa_data, sizeof(*rom), MEMREMAP_WB);
                if (!data)
                        return -ENOMEM;

                if (data->type == SETUP_PCI) {
                        rom = (struct pci_setup_rom *)data;

                        if ((pci_domain_nr(dev->bus) == rom->segment) &&
                            (dev->bus->number == rom->bus) &&
                            (PCI_SLOT(dev->devfn) == rom->device) &&
                            (PCI_FUNC(dev->devfn) == rom->function) &&
                            (dev->vendor == rom->vendor) &&
                            (dev->device == rom->devid)) {
                                dev->rom = pa_data +
                                      offsetof(struct pci_setup_rom, romdata);
                                dev->romlen = rom->pcilen;
                        }
                }
                pa_data = data->next;
                memunmap(data);
        }
        set_dev_domain_options(dev);

        /*
         * Setup the initial MSI domain of the device. If the underlying
         * bus has a PCI/MSI irqdomain associated use the bus domain,
         * otherwise set the default domain. This ensures that special irq
         * domains e.g. VMD are preserved. The default ensures initial
         * operation if irq remapping is not active. If irq remapping is
         * active it will overwrite the domain pointer when the device is
         * associated to a remapping domain.
         */
        msidom = dev_get_msi_domain(&dev->bus->dev);
        if (!msidom)
                msidom = x86_pci_msi_default_domain;
        dev_set_msi_domain(&dev->dev, msidom);
        return 0;
}

int pcibios_enable_device(struct pci_dev *dev, int mask)
{
        int err;

        if ((err = pci_enable_resources(dev, mask)) < 0)
                return err;

        if (!pci_dev_msi_enabled(dev))
                return pcibios_enable_irq(dev);
        return 0;
}

void pcibios_disable_device (struct pci_dev *dev)
{
        if (!pci_dev_msi_enabled(dev) && pcibios_disable_irq)
                pcibios_disable_irq(dev);
}

#ifdef CONFIG_ACPI_HOTPLUG_IOAPIC
void pcibios_release_device(struct pci_dev *dev)
{
        if (atomic_dec_return(&dev->enable_cnt) >= 0)
                pcibios_disable_device(dev);

}
#endif

int pci_ext_cfg_avail(void)
{
        if (raw_pci_ext_ops)
                return 1;
        else
                return 0;
}

#if IS_ENABLED(CONFIG_VMD)
struct pci_dev *pci_real_dma_dev(struct pci_dev *dev)
{
        if (is_vmd(dev->bus))
                return to_pci_sysdata(dev->bus)->vmd_dev;

        return dev;
}
#endif