/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1994,1995 Stefan Esser, Wolfgang StanglMeier
 * Copyright (c) 2000 Michael Smith <msmith@freebsd.org>
 * Copyright (c) 2000 BSDi
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>
/*
 * PCI:PCI bridge support.
 */

#include "opt_pci.h"

#include <sys/param.h>
#include <sys/bus.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/pciio.h>
#include <sys/rman.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
#include <sys/taskqueue.h>

#include <dev/pci/pcivar.h>
#include <dev/pci/pcireg.h>
#include <dev/pci/pci_private.h>
#include <dev/pci/pcib_private.h>

#include "pcib_if.h"

static int              pcib_probe(device_t dev);
static int              pcib_resume(device_t dev);

static bus_child_present_t      pcib_child_present;
static bus_alloc_resource_t     pcib_alloc_resource;
static bus_adjust_resource_t    pcib_adjust_resource;
static bus_release_resource_t   pcib_release_resource;
static bus_activate_resource_t  pcib_activate_resource;
static bus_deactivate_resource_t pcib_deactivate_resource;
static bus_map_resource_t       pcib_map_resource;
static bus_unmap_resource_t     pcib_unmap_resource;
static int              pcib_reset_child(device_t dev, device_t child, int flags);

static int              pcib_power_for_sleep(device_t pcib, device_t dev,
                            int *pstate);
static int              pcib_ari_get_id(device_t pcib, device_t dev,
    enum pci_id_type type, uintptr_t *id);
static uint32_t         pcib_read_config(device_t dev, u_int b, u_int s,
    u_int f, u_int reg, int width);
static void             pcib_write_config(device_t dev, u_int b, u_int s,
    u_int f, u_int reg, uint32_t val, int width);
static int              pcib_ari_maxslots(device_t dev);
static int              pcib_ari_maxfuncs(device_t dev);
static int              pcib_try_enable_ari(device_t pcib, device_t dev);
static int              pcib_ari_enabled(device_t pcib);
static void             pcib_ari_decode_rid(device_t pcib, uint16_t rid,
                            int *bus, int *slot, int *func);
#ifdef PCI_HP
static void             pcib_pcie_ab_timeout(void *arg, int pending);
static void             pcib_pcie_cc_timeout(void *arg, int pending);
static void             pcib_pcie_dll_timeout(void *arg, int pending);
#endif
static int              pcib_request_feature_default(device_t pcib, device_t dev,
                            enum pci_feature feature);

static device_method_t pcib_methods[] = {
    /* Device interface */
    DEVMETHOD(device_probe,             pcib_probe),
    DEVMETHOD(device_attach,            pcib_attach),
    DEVMETHOD(device_detach,            pcib_detach),
    DEVMETHOD(device_shutdown,          bus_generic_shutdown),
    DEVMETHOD(device_suspend,           bus_generic_suspend),
    DEVMETHOD(device_resume,            pcib_resume),

    /* Bus interface */
    DEVMETHOD(bus_child_present,        pcib_child_present),
    DEVMETHOD(bus_read_ivar,            pcib_read_ivar),
    DEVMETHOD(bus_write_ivar,           pcib_write_ivar),
    DEVMETHOD(bus_alloc_resource,       pcib_alloc_resource),
    DEVMETHOD(bus_adjust_resource,      pcib_adjust_resource),
    DEVMETHOD(bus_release_resource,     pcib_release_resource),
    DEVMETHOD(bus_activate_resource,    pcib_activate_resource),
    DEVMETHOD(bus_deactivate_resource,  pcib_deactivate_resource),
    DEVMETHOD(bus_map_resource,         pcib_map_resource),
    DEVMETHOD(bus_unmap_resource,       pcib_unmap_resource),
    DEVMETHOD(bus_setup_intr,           bus_generic_setup_intr),
    DEVMETHOD(bus_teardown_intr,        bus_generic_teardown_intr),
    DEVMETHOD(bus_reset_child,          pcib_reset_child),

    /* pcib interface */
    DEVMETHOD(pcib_maxslots,            pcib_ari_maxslots),
    DEVMETHOD(pcib_maxfuncs,            pcib_ari_maxfuncs),
    DEVMETHOD(pcib_read_config,         pcib_read_config),
    DEVMETHOD(pcib_write_config,        pcib_write_config),
    DEVMETHOD(pcib_route_interrupt,     pcib_route_interrupt),
    DEVMETHOD(pcib_alloc_msi,           pcib_alloc_msi),
    DEVMETHOD(pcib_release_msi,         pcib_release_msi),
    DEVMETHOD(pcib_alloc_msix,          pcib_alloc_msix),
    DEVMETHOD(pcib_release_msix,        pcib_release_msix),
    DEVMETHOD(pcib_map_msi,             pcib_map_msi),
    DEVMETHOD(pcib_power_for_sleep,     pcib_power_for_sleep),
    DEVMETHOD(pcib_get_id,              pcib_ari_get_id),
    DEVMETHOD(pcib_try_enable_ari,      pcib_try_enable_ari),
    DEVMETHOD(pcib_ari_enabled,         pcib_ari_enabled),
    DEVMETHOD(pcib_decode_rid,          pcib_ari_decode_rid),
    DEVMETHOD(pcib_request_feature,     pcib_request_feature_default),

    DEVMETHOD_END
};

DEFINE_CLASS_0(pcib, pcib_driver, pcib_methods, sizeof(struct pcib_softc));
EARLY_DRIVER_MODULE(pcib, pci, pcib_driver, NULL, NULL, BUS_PASS_BUS);

SYSCTL_DECL(_hw_pci);

static int pci_clear_pcib;
SYSCTL_INT(_hw_pci, OID_AUTO, clear_pcib, CTLFLAG_RDTUN, &pci_clear_pcib, 0,
    "Clear firmware-assigned resources for PCI-PCI bridge I/O windows.");

/*
 * Get the corresponding window if this resource from a child device was
 * sub-allocated from one of our window resource managers.
 */
static struct pcib_window *
pcib_get_resource_window(struct pcib_softc *sc, struct resource *r)
{
        switch (rman_get_type(r)) {
        case SYS_RES_IOPORT:
                if (rman_is_region_manager(r, &sc->io.rman))
                        return (&sc->io);
                break;
        case SYS_RES_MEMORY:
                /* Prefetchable resources may live in either memory rman. */
                if (rman_get_flags(r) & RF_PREFETCHABLE &&
                    rman_is_region_manager(r, &sc->pmem.rman))
                        return (&sc->pmem);
                if (rman_is_region_manager(r, &sc->mem.rman))
                        return (&sc->mem);
                break;
        }
        return (NULL);
}

/*
 * Is a resource from a child device sub-allocated from one of our
 * resource managers?
 */
static int
pcib_is_resource_managed(struct pcib_softc *sc, struct resource *r)
{

        if (rman_get_type(r) == PCI_RES_BUS)
                return (rman_is_region_manager(r, &sc->bus.rman));
        return (pcib_get_resource_window(sc, r) != NULL);
}

static int
pcib_is_window_open(struct pcib_window *pw)
{

        return (pw->valid && pw->base < pw->limit);
}

/*
 * XXX: If RF_ACTIVE did not also imply allocating a bus space tag and
 * handle for the resource, we could pass RF_ACTIVE up to the PCI bus
 * when allocating the resource windows and rely on the PCI bus driver
 * to do this for us.
 */
static void
pcib_activate_window(struct pcib_softc *sc, int type)
{

        PCI_ENABLE_IO(device_get_parent(sc->dev), sc->dev, type);
}

static void
pcib_write_windows(struct pcib_softc *sc, int mask)
{
        device_t dev;
        uint32_t val;

        dev = sc->dev;
        if (sc->io.valid && mask & WIN_IO) {
                val = pci_read_config(dev, PCIR_IOBASEL_1, 1);
                if ((val & PCIM_BRIO_MASK) == PCIM_BRIO_32) {
                        pci_write_config(dev, PCIR_IOBASEH_1,
                            sc->io.base >> 16, 2);
                        pci_write_config(dev, PCIR_IOLIMITH_1,
                            sc->io.limit >> 16, 2);
                }
                pci_write_config(dev, PCIR_IOBASEL_1, sc->io.base >> 8, 1);
                pci_write_config(dev, PCIR_IOLIMITL_1, sc->io.limit >> 8, 1);
        }

        if (mask & WIN_MEM) {
                pci_write_config(dev, PCIR_MEMBASE_1, sc->mem.base >> 16, 2);
                pci_write_config(dev, PCIR_MEMLIMIT_1, sc->mem.limit >> 16, 2);
        }

        if (sc->pmem.valid && mask & WIN_PMEM) {
                val = pci_read_config(dev, PCIR_PMBASEL_1, 2);
                if ((val & PCIM_BRPM_MASK) == PCIM_BRPM_64) {
                        pci_write_config(dev, PCIR_PMBASEH_1,
                            sc->pmem.base >> 32, 4);
                        pci_write_config(dev, PCIR_PMLIMITH_1,
                            sc->pmem.limit >> 32, 4);
                }
                pci_write_config(dev, PCIR_PMBASEL_1, sc->pmem.base >> 16, 2);
                pci_write_config(dev, PCIR_PMLIMITL_1, sc->pmem.limit >> 16, 2);
        }
}

/*
 * This is used to reject I/O port allocations that conflict with an
 * ISA alias range.
 */
static int
pcib_is_isa_range(struct pcib_softc *sc, rman_res_t start, rman_res_t end,
    rman_res_t count)
{
        rman_res_t next_alias;

        if (!(sc->bridgectl & PCIB_BCR_ISA_ENABLE))
                return (0);

        /* Only check fixed ranges for overlap. */
        if (start + count - 1 != end)
                return (0);

        /* ISA aliases are only in the lower 64KB of I/O space. */
        if (start >= 65536)
                return (0);

        /* Check for overlap with 0x000 - 0x0ff as a special case. */
        if (start < 0x100)
                goto alias;

        /*
         * If the start address is an alias, the range is an alias.
         * Otherwise, compute the start of the next alias range and
         * check if it is before the end of the candidate range.
         */
        if ((start & 0x300) != 0)
                goto alias;
        next_alias = (start & ~0x3fful) | 0x100;
        if (next_alias <= end)
                goto alias;
        return (0);

alias:
        if (bootverbose)
                device_printf(sc->dev,
                    "I/O range %#jx-%#jx overlaps with an ISA alias\n", start,
                    end);
        return (1);
}

static void
pcib_add_window_resources(struct pcib_window *w, struct resource **res,
    int count)
{
        struct resource **newarray;
        int error, i;

        newarray = malloc(sizeof(struct resource *) * (w->count + count),
            M_DEVBUF, M_WAITOK);
        if (w->res != NULL)
                bcopy(w->res, newarray, sizeof(struct resource *) * w->count);
        bcopy(res, newarray + w->count, sizeof(struct resource *) * count);
        free(w->res, M_DEVBUF);
        w->res = newarray;
        w->count += count;

        for (i = 0; i < count; i++) {
                error = rman_manage_region(&w->rman, rman_get_start(res[i]),
                    rman_get_end(res[i]));
                if (error)
                        panic("Failed to add resource to rman");
        }
}

typedef void (nonisa_callback)(rman_res_t start, rman_res_t end, void *arg);

static void
pcib_walk_nonisa_ranges(rman_res_t start, rman_res_t end, nonisa_callback *cb,
    void *arg)
{
        rman_res_t next_end;

        /*
         * If start is within an ISA alias range, move up to the start
         * of the next non-alias range.  As a special case, addresses
         * in the range 0x000 - 0x0ff should also be skipped since
         * those are used for various system I/O devices in ISA
         * systems.
         */
        if (start <= 65535) {
                if (start < 0x100 || (start & 0x300) != 0) {
                        start &= ~0x3ff;
                        start += 0x400;
                }
        }

        /* ISA aliases are only in the lower 64KB of I/O space. */
        while (start <= MIN(end, 65535)) {
                next_end = MIN(start | 0xff, end);
                cb(start, next_end, arg);
                start += 0x400;
        }

        if (start <= end)
                cb(start, end, arg);
}

static void
count_ranges(rman_res_t start, rman_res_t end, void *arg)
{
        int *countp;

        countp = arg;
        (*countp)++;
}

struct alloc_state {
        struct resource **res;
        struct pcib_softc *sc;
        int count, error;
};

static void
alloc_ranges(rman_res_t start, rman_res_t end, void *arg)
{
        struct alloc_state *as;
        struct pcib_window *w;
        int rid;

        as = arg;
        if (as->error != 0)
                return;

        w = &as->sc->io;
        rid = w->reg;
        if (bootverbose)
                device_printf(as->sc->dev,
                    "allocating non-ISA range %#jx-%#jx\n", start, end);
        as->res[as->count] = bus_alloc_resource(as->sc->dev, SYS_RES_IOPORT,
            &rid, start, end, end - start + 1, RF_ACTIVE | RF_UNMAPPED);
        if (as->res[as->count] == NULL)
                as->error = ENXIO;
        else
                as->count++;
}

static int
pcib_alloc_nonisa_ranges(struct pcib_softc *sc, rman_res_t start, rman_res_t end)
{
        struct alloc_state as;
        int i, new_count;

        /* First, see how many ranges we need. */
        new_count = 0;
        pcib_walk_nonisa_ranges(start, end, count_ranges, &new_count);

        /* Second, allocate the ranges. */
        as.res = malloc(sizeof(struct resource *) * new_count, M_DEVBUF,
            M_WAITOK);
        as.sc = sc;
        as.count = 0;
        as.error = 0;
        pcib_walk_nonisa_ranges(start, end, alloc_ranges, &as);
        if (as.error != 0) {
                for (i = 0; i < as.count; i++)
                        bus_release_resource(sc->dev, SYS_RES_IOPORT,
                            sc->io.reg, as.res[i]);
                free(as.res, M_DEVBUF);
                return (as.error);
        }
        KASSERT(as.count == new_count, ("%s: count mismatch", __func__));

        /* Third, add the ranges to the window. */
        pcib_add_window_resources(&sc->io, as.res, as.count);
        free(as.res, M_DEVBUF);
        return (0);
}

static void
pcib_alloc_window(struct pcib_softc *sc, struct pcib_window *w, int type,
    int flags, pci_addr_t max_address)
{
        struct resource *res;
        char buf[64];
        int error, rid;

        if (max_address != (rman_res_t)max_address)
                max_address = ~0;
        w->rman.rm_start = 0;
        w->rman.rm_end = max_address;
        w->rman.rm_type = RMAN_ARRAY;
        snprintf(buf, sizeof(buf), "%s %s window",
            device_get_nameunit(sc->dev), w->name);
        w->rman.rm_descr = strdup(buf, M_DEVBUF);
        error = rman_init(&w->rman);
        if (error)
                panic("Failed to initialize %s %s rman",
                    device_get_nameunit(sc->dev), w->name);

        if (!pcib_is_window_open(w))
                return;

        /*
         * Assume that a window where both the base and limit read as
         * zero is not really open, or at least not assigned a valid
         * range by the firmware.  This can happen if a bridge device
         * is never initialized by firmware, or if a platform driver
         * resets the bridge.
         *
         * If devices behind this bridge have firmware-assigned
         * resources in this range then the window will be reallocated
         * on-demand.
         */
        if (w->base == 0 && w->limit == ((pci_addr_t)1 << w->step) - 1) {
                w->base = max_address;
                w->limit = 0;
                pcib_write_windows(sc, w->mask);
                return;
        }

        if (w->base > max_address || w->limit > max_address) {
                device_printf(sc->dev,
                    "initial %s window has too many bits, ignoring\n", w->name);
                return;
        }
        if (type == SYS_RES_IOPORT && sc->bridgectl & PCIB_BCR_ISA_ENABLE)
                (void)pcib_alloc_nonisa_ranges(sc, w->base, w->limit);
        else {
                rid = w->reg;
                res = bus_alloc_resource(sc->dev, type, &rid, w->base, w->limit,
                    w->limit - w->base + 1, flags | RF_ACTIVE | RF_UNMAPPED);
                if (res != NULL)
                        pcib_add_window_resources(w, &res, 1);
        }
        if (w->res == NULL) {
                device_printf(sc->dev,
                    "failed to allocate initial %s window: %#jx-%#jx\n",
                    w->name, (uintmax_t)w->base, (uintmax_t)w->limit);
                w->base = max_address;
                w->limit = 0;
                pcib_write_windows(sc, w->mask);
                return;
        }
        pcib_activate_window(sc, type);
}

/*
 * Initialize I/O windows.
 */
static void
pcib_probe_windows(struct pcib_softc *sc)
{
        pci_addr_t max;
        device_t dev;
        uint32_t val;

        dev = sc->dev;

        if (pci_clear_pcib) {
                pcib_bridge_init(dev);
        }

        /* Determine if the I/O port window is implemented. */
        val = pci_read_config(dev, PCIR_IOBASEL_1, 1);
        if (val == 0) {
                /*
                 * If 'val' is zero, then only 16-bits of I/O space
                 * are supported.
                 */
                pci_write_config(dev, PCIR_IOBASEL_1, 0xff, 1);
                if (pci_read_config(dev, PCIR_IOBASEL_1, 1) != 0) {
                        sc->io.valid = 1;
                        pci_write_config(dev, PCIR_IOBASEL_1, 0, 1);
                }
        } else
                sc->io.valid = 1;

        /* Read the existing I/O port window. */
        if (sc->io.valid) {
                sc->io.reg = PCIR_IOBASEL_1;
                sc->io.step = 12;
                sc->io.mask = WIN_IO;
                sc->io.name = "I/O port";
                if ((val & PCIM_BRIO_MASK) == PCIM_BRIO_32) {
                        sc->io.base = PCI_PPBIOBASE(
                            pci_read_config(dev, PCIR_IOBASEH_1, 2), val);
                        sc->io.limit = PCI_PPBIOLIMIT(
                            pci_read_config(dev, PCIR_IOLIMITH_1, 2),
                            pci_read_config(dev, PCIR_IOLIMITL_1, 1));
                        max = 0xffffffff;
                } else {
                        sc->io.base = PCI_PPBIOBASE(0, val);
                        sc->io.limit = PCI_PPBIOLIMIT(0,
                            pci_read_config(dev, PCIR_IOLIMITL_1, 1));
                        max = 0xffff;
                }
                pcib_alloc_window(sc, &sc->io, SYS_RES_IOPORT, 0, max);
        }

        /* Read the existing memory window. */
        sc->mem.valid = 1;
        sc->mem.reg = PCIR_MEMBASE_1;
        sc->mem.step = 20;
        sc->mem.mask = WIN_MEM;
        sc->mem.name = "memory";
        sc->mem.base = PCI_PPBMEMBASE(0,
            pci_read_config(dev, PCIR_MEMBASE_1, 2));
        sc->mem.limit = PCI_PPBMEMLIMIT(0,
            pci_read_config(dev, PCIR_MEMLIMIT_1, 2));
        pcib_alloc_window(sc, &sc->mem, SYS_RES_MEMORY, 0, 0xffffffff);

        /* Determine if the prefetchable memory window is implemented. */
        val = pci_read_config(dev, PCIR_PMBASEL_1, 2);
        if (val == 0) {
                /*
                 * If 'val' is zero, then only 32-bits of memory space
                 * are supported.
                 */
                pci_write_config(dev, PCIR_PMBASEL_1, 0xffff, 2);
                if (pci_read_config(dev, PCIR_PMBASEL_1, 2) != 0) {
                        sc->pmem.valid = 1;
                        pci_write_config(dev, PCIR_PMBASEL_1, 0, 2);
                }
        } else
                sc->pmem.valid = 1;

        /* Read the existing prefetchable memory window. */
        if (sc->pmem.valid) {
                sc->pmem.reg = PCIR_PMBASEL_1;
                sc->pmem.step = 20;
                sc->pmem.mask = WIN_PMEM;
                sc->pmem.name = "prefetch";
                if ((val & PCIM_BRPM_MASK) == PCIM_BRPM_64) {
                        sc->pmem.base = PCI_PPBMEMBASE(
                            pci_read_config(dev, PCIR_PMBASEH_1, 4), val);
                        sc->pmem.limit = PCI_PPBMEMLIMIT(
                            pci_read_config(dev, PCIR_PMLIMITH_1, 4),
                            pci_read_config(dev, PCIR_PMLIMITL_1, 2));
                        max = 0xffffffffffffffff;
                } else {
                        sc->pmem.base = PCI_PPBMEMBASE(0, val);
                        sc->pmem.limit = PCI_PPBMEMLIMIT(0,
                            pci_read_config(dev, PCIR_PMLIMITL_1, 2));
                        max = 0xffffffff;
                }
                pcib_alloc_window(sc, &sc->pmem, SYS_RES_MEMORY,
                    RF_PREFETCHABLE, max);
        }
}

static void
pcib_release_window(struct pcib_softc *sc, struct pcib_window *w, int type)
{
        device_t dev;
        int error, i;

        if (!w->valid)
                return;

        dev = sc->dev;
        error = rman_fini(&w->rman);
        if (error) {
                device_printf(dev, "failed to release %s rman\n", w->name);
                return;
        }
        free(__DECONST(char *, w->rman.rm_descr), M_DEVBUF);

        for (i = 0; i < w->count; i++) {
                error = bus_free_resource(dev, type, w->res[i]);
                if (error)
                        device_printf(dev,
                            "failed to release %s resource: %d\n", w->name,
                            error);
        }
        free(w->res, M_DEVBUF);
}

static void
pcib_free_windows(struct pcib_softc *sc)
{

        pcib_release_window(sc, &sc->pmem, SYS_RES_MEMORY);
        pcib_release_window(sc, &sc->mem, SYS_RES_MEMORY);
        pcib_release_window(sc, &sc->io, SYS_RES_IOPORT);
}

/*
 * Allocate a suitable secondary bus for this bridge if needed and
 * initialize the resource manager for the secondary bus range.  Note
 * that the minimum count is a desired value and this may allocate a
 * smaller range.
 */
void
pcib_setup_secbus(device_t dev, struct pcib_secbus *bus, int min_count)
{
        char buf[64];
        int error, rid, sec_reg;

        switch (pci_read_config(dev, PCIR_HDRTYPE, 1) & PCIM_HDRTYPE) {
        case PCIM_HDRTYPE_BRIDGE:
                sec_reg = PCIR_SECBUS_1;
                bus->sub_reg = PCIR_SUBBUS_1;
                break;
        case PCIM_HDRTYPE_CARDBUS:
                sec_reg = PCIR_SECBUS_2;
                bus->sub_reg = PCIR_SUBBUS_2;
                break;
        default:
                panic("not a PCI bridge");
        }
        bus->sec = pci_read_config(dev, sec_reg, 1);
        bus->sub = pci_read_config(dev, bus->sub_reg, 1);
        bus->dev = dev;
        bus->rman.rm_start = 0;
        bus->rman.rm_end = PCI_BUSMAX;
        bus->rman.rm_type = RMAN_ARRAY;
        snprintf(buf, sizeof(buf), "%s bus numbers", device_get_nameunit(dev));
        bus->rman.rm_descr = strdup(buf, M_DEVBUF);
        error = rman_init(&bus->rman);
        if (error)
                panic("Failed to initialize %s bus number rman",
                    device_get_nameunit(dev));

        /*
         * Allocate a bus range.  This will return an existing bus range
         * if one exists, or a new bus range if one does not.
         */
        rid = 0;
        bus->res = bus_alloc_resource_anywhere(dev, PCI_RES_BUS, &rid,
            min_count, RF_ACTIVE);
        if (bus->res == NULL) {
                /*
                 * Fall back to just allocating a range of a single bus
                 * number.
                 */
                bus->res = bus_alloc_resource_anywhere(dev, PCI_RES_BUS, &rid,
                    1, RF_ACTIVE);
        } else if (rman_get_size(bus->res) < min_count)
                /*
                 * Attempt to grow the existing range to satisfy the
                 * minimum desired count.
                 */
                (void)bus_adjust_resource(dev, PCI_RES_BUS, bus->res,
                    rman_get_start(bus->res), rman_get_start(bus->res) +
                    min_count - 1);

        /*
         * Add the initial resource to the rman.
         */
        if (bus->res != NULL) {
                error = rman_manage_region(&bus->rman, rman_get_start(bus->res),
                    rman_get_end(bus->res));
                if (error)
                        panic("Failed to add resource to rman");
                bus->sec = rman_get_start(bus->res);
                bus->sub = rman_get_end(bus->res);
        }
}

void
pcib_free_secbus(device_t dev, struct pcib_secbus *bus)
{
        int error;

        error = rman_fini(&bus->rman);
        if (error) {
                device_printf(dev, "failed to release bus number rman\n");
                return;
        }
        free(__DECONST(char *, bus->rman.rm_descr), M_DEVBUF);

        error = bus_free_resource(dev, PCI_RES_BUS, bus->res);
        if (error)
                device_printf(dev,
                    "failed to release bus numbers resource: %d\n", error);
}

static struct resource *
pcib_suballoc_bus(struct pcib_secbus *bus, device_t child, int rid,
    rman_res_t start, rman_res_t end, rman_res_t count, u_int flags)
{
        struct resource *res;

        res = rman_reserve_resource(&bus->rman, start, end, count, flags,
            child);
        if (res == NULL)
                return (NULL);

        if (bootverbose)
                device_printf(bus->dev,
                    "allocated bus range (%ju-%ju) for rid %d of %s\n",
                    rman_get_start(res), rman_get_end(res), rid,
                    pcib_child_name(child));
        rman_set_rid(res, rid);
        rman_set_type(res, PCI_RES_BUS);
        return (res);
}

/*
 * Attempt to grow the secondary bus range.  This is much simpler than
 * for I/O windows as the range can only be grown by increasing
 * subbus.
 */
static int
pcib_grow_subbus(struct pcib_secbus *bus, rman_res_t new_end)
{
        rman_res_t old_end;
        int error;

        old_end = rman_get_end(bus->res);
        KASSERT(new_end > old_end, ("attempt to shrink subbus"));
        error = bus_adjust_resource(bus->dev, PCI_RES_BUS, bus->res,
            rman_get_start(bus->res), new_end);
        if (error)
                return (error);
        if (bootverbose)
                device_printf(bus->dev, "grew bus range to %ju-%ju\n",
                    rman_get_start(bus->res), rman_get_end(bus->res));
        error = rman_manage_region(&bus->rman, old_end + 1,
            rman_get_end(bus->res));
        if (error)
                panic("Failed to add resource to rman");
        bus->sub = rman_get_end(bus->res);
        pci_write_config(bus->dev, bus->sub_reg, bus->sub, 1);
        return (0);
}

struct resource *
pcib_alloc_subbus(struct pcib_secbus *bus, device_t child, int rid,
    rman_res_t start, rman_res_t end, rman_res_t count, u_int flags)
{
        struct resource *res;
        rman_res_t start_free, end_free, new_end;

        /*
         * First, see if the request can be satisified by the existing
         * bus range.
         */
        res = pcib_suballoc_bus(bus, child, rid, start, end, count, flags);
        if (res != NULL)
                return (res);

        /*
         * Figure out a range to grow the bus range.  First, find the
         * first bus number after the last allocated bus in the rman and
         * enforce that as a minimum starting point for the range.
         */
        if (rman_last_free_region(&bus->rman, &start_free, &end_free) != 0 ||
            end_free != bus->sub)
                start_free = bus->sub + 1;
        if (start_free < start)
                start_free = start;
        new_end = start_free + count - 1;

        /*
         * See if this new range would satisfy the request if it
         * succeeds.
         */
        if (new_end > end)
                return (NULL);

        /* Finally, attempt to grow the existing resource. */
        if (bootverbose) {
                device_printf(bus->dev,
                    "attempting to grow bus range for %ju buses\n", count);
                printf("\tback candidate range: %ju-%ju\n", start_free,
                    new_end);
        }
        if (pcib_grow_subbus(bus, new_end) == 0)
                return (pcib_suballoc_bus(bus, child, rid, start, end, count,
                    flags));
        return (NULL);
}

#ifdef PCI_HP
/*
 * PCI-express HotPlug support.
 */
static int pci_enable_pcie_hp = 1;
SYSCTL_INT(_hw_pci, OID_AUTO, enable_pcie_hp, CTLFLAG_RDTUN,
    &pci_enable_pcie_hp, 0,
    "Enable support for native PCI-express HotPlug.");

static sbintime_t pcie_hp_detach_timeout = 5 * SBT_1S;
SYSCTL_SBINTIME_MSEC(_hw_pci, OID_AUTO, pcie_hp_detach_timeout, CTLFLAG_RWTUN,
    &pcie_hp_detach_timeout,
    "Attention Button delay for PCI-express Eject.");

static void
pcib_probe_hotplug(struct pcib_softc *sc)
{
        device_t dev;
        uint32_t link_cap;
        uint16_t link_sta, slot_sta;

        if (!pci_enable_pcie_hp)
                return;

        dev = sc->dev;
        if (pci_find_cap(dev, PCIY_EXPRESS, NULL) != 0)
                return;

        if (!(pcie_read_config(dev, PCIER_FLAGS, 2) & PCIEM_FLAGS_SLOT))
                return;

        sc->pcie_slot_cap = pcie_read_config(dev, PCIER_SLOT_CAP, 4);

        if ((sc->pcie_slot_cap & PCIEM_SLOT_CAP_HPC) == 0)
                return;
        link_cap = pcie_read_config(dev, PCIER_LINK_CAP, 4);
        if ((link_cap & PCIEM_LINK_CAP_DL_ACTIVE) == 0)
                return;

        /*
         * Some devices report that they have an MRL when they actually
         * do not.  Since they always report that the MRL is open, child
         * devices would be ignored.  Try to detect these devices and
         * ignore their claim of HotPlug support.
         *
         * If there is an open MRL but the Data Link Layer is active,
         * the MRL is not real.
         */
        if ((sc->pcie_slot_cap & PCIEM_SLOT_CAP_MRLSP) != 0) {
                link_sta = pcie_read_config(dev, PCIER_LINK_STA, 2);
                slot_sta = pcie_read_config(dev, PCIER_SLOT_STA, 2);
                if ((slot_sta & PCIEM_SLOT_STA_MRLSS) != 0 &&
                    (link_sta & PCIEM_LINK_STA_DL_ACTIVE) != 0) {
                        return;
                }
        }

        /*
         * Now that we're sure we want to do hot plug, ask the
         * firmware, if any, if that's OK.
         */
        if (pcib_request_feature(dev, PCI_FEATURE_HP) != 0) {
                if (bootverbose)
                        device_printf(dev, "Unable to activate hot plug feature.\n");
                return;
        }

        sc->flags |= PCIB_HOTPLUG;
}

/*
 * Send a HotPlug command to the slot control register.  If this slot
 * uses command completion interrupts and a previous command is still
 * in progress, then the command is dropped.  Once the previous
 * command completes or times out, pcib_pcie_hotplug_update() will be
 * invoked to post a new command based on the slot's state at that
 * time.
 */
static void
pcib_pcie_hotplug_command(struct pcib_softc *sc, uint16_t val, uint16_t mask)
{
        device_t dev;
        uint16_t ctl, new;

        dev = sc->dev;

        if (sc->flags & PCIB_HOTPLUG_CMD_PENDING)
                return;

        ctl = pcie_read_config(dev, PCIER_SLOT_CTL, 2);
        new = (ctl & ~mask) | val;
        if (new == ctl)
                return;
        if (bootverbose)
                device_printf(dev, "HotPlug command: %04x -> %04x\n", ctl, new);
        pcie_write_config(dev, PCIER_SLOT_CTL, new, 2);
        if (!(sc->pcie_slot_cap & PCIEM_SLOT_CAP_NCCS) &&
            (ctl & new) & PCIEM_SLOT_CTL_CCIE) {
                sc->flags |= PCIB_HOTPLUG_CMD_PENDING;
                if (!cold)
                        taskqueue_enqueue_timeout(taskqueue_bus,
                            &sc->pcie_cc_task, hz);
        }
}

static void
pcib_pcie_hotplug_command_completed(struct pcib_softc *sc)
{
        device_t dev;

        dev = sc->dev;

        if (bootverbose)
                device_printf(dev, "Command Completed\n");
        if (!(sc->flags & PCIB_HOTPLUG_CMD_PENDING))
                return;
        taskqueue_cancel_timeout(taskqueue_bus, &sc->pcie_cc_task, NULL);
        sc->flags &= ~PCIB_HOTPLUG_CMD_PENDING;
        wakeup(sc);
}

/*
 * Returns true if a card is fully inserted from the user's
 * perspective.  It may not yet be ready for access, but the driver
 * can now start enabling access if necessary.
 */
static bool
pcib_hotplug_inserted(struct pcib_softc *sc)
{

        /* Pretend the card isn't present if a detach is forced. */
        if (sc->flags & PCIB_DETACHING)
                return (false);

        /* Card must be present in the slot. */
        if ((sc->pcie_slot_sta & PCIEM_SLOT_STA_PDS) == 0)
                return (false);

        /* A power fault implicitly turns off power to the slot. */
        if (sc->pcie_slot_cap & PCIEM_SLOT_CAP_PCP &&
            sc->pcie_slot_sta & PCIEM_SLOT_STA_PFD)
                return (false);

        /* If the MRL is disengaged, the slot is powered off. */
        if (sc->pcie_slot_cap & PCIEM_SLOT_CAP_MRLSP &&
            (sc->pcie_slot_sta & PCIEM_SLOT_STA_MRLSS) != 0)
                return (false);

        return (true);
}

/*
 * Returns -1 if the card is fully inserted, powered, and ready for
 * access.  Otherwise, returns 0.
 */
static int
pcib_hotplug_present(struct pcib_softc *sc)
{

        /* Card must be inserted. */
        if (!pcib_hotplug_inserted(sc))
                return (0);

        /* Require the Data Link Layer to be active. */
        if (!(sc->pcie_link_sta & PCIEM_LINK_STA_DL_ACTIVE))
                return (0);

        return (-1);
}

static int pci_enable_pcie_ei = 0;
SYSCTL_INT(_hw_pci, OID_AUTO, enable_pcie_ei, CTLFLAG_RWTUN,
    &pci_enable_pcie_ei, 0,
    "Enable support for PCI-express Electromechanical Interlock.");

static void
pcib_pcie_hotplug_update(struct pcib_softc *sc, uint16_t val, uint16_t mask,
    bool schedule_task)
{
        bool card_inserted, ei_engaged;

        /* Clear DETACHING if Presence Detect has cleared. */
        if ((sc->pcie_slot_sta & (PCIEM_SLOT_STA_PDC | PCIEM_SLOT_STA_PDS)) ==
            PCIEM_SLOT_STA_PDC)
                sc->flags &= ~PCIB_DETACHING;

        card_inserted = pcib_hotplug_inserted(sc);

        /* Turn the power indicator on if a card is inserted. */
        if (sc->pcie_slot_cap & PCIEM_SLOT_CAP_PIP) {
                mask |= PCIEM_SLOT_CTL_PIC;
                if (card_inserted)
                        val |= PCIEM_SLOT_CTL_PI_ON;
                else if (sc->flags & PCIB_DETACH_PENDING)
                        val |= PCIEM_SLOT_CTL_PI_BLINK;
                else
                        val |= PCIEM_SLOT_CTL_PI_OFF;
        }

        /* Turn the power on via the Power Controller if a card is inserted. */
        if (sc->pcie_slot_cap & PCIEM_SLOT_CAP_PCP) {
                mask |= PCIEM_SLOT_CTL_PCC;
                if (card_inserted)
                        val |= PCIEM_SLOT_CTL_PC_ON;
                else
                        val |= PCIEM_SLOT_CTL_PC_OFF;
        }

        /*
         * If a card is inserted, enable the Electromechanical
         * Interlock.  If a card is not inserted (or we are in the
         * process of detaching), disable the Electromechanical
         * Interlock.
         */
        if ((sc->pcie_slot_cap & PCIEM_SLOT_CAP_EIP) &&
            pci_enable_pcie_ei) {
                mask |= PCIEM_SLOT_CTL_EIC;
                ei_engaged = (sc->pcie_slot_sta & PCIEM_SLOT_STA_EIS) != 0;
                if (card_inserted != ei_engaged)
                        val |= PCIEM_SLOT_CTL_EIC;
        }

        /*
         * Start a timer to see if the Data Link Layer times out.
         * Note that we only start the timer if Presence Detect or MRL Sensor
         * changed on this interrupt.  Stop any scheduled timer if
         * the Data Link Layer is active.
         */
        if (card_inserted &&
            !(sc->pcie_link_sta & PCIEM_LINK_STA_DL_ACTIVE) &&
            sc->pcie_slot_sta &
            (PCIEM_SLOT_STA_MRLSC | PCIEM_SLOT_STA_PDC)) {
                if (cold)
                        device_printf(sc->dev,
                            "Data Link Layer inactive\n");
                else
                        taskqueue_enqueue_timeout(taskqueue_bus,
                            &sc->pcie_dll_task, hz);
        } else if (sc->pcie_link_sta & PCIEM_LINK_STA_DL_ACTIVE)
                taskqueue_cancel_timeout(taskqueue_bus, &sc->pcie_dll_task,
                    NULL);

        pcib_pcie_hotplug_command(sc, val, mask);

        /*
         * During attach the child "pci" device is added synchronously;
         * otherwise, the task is scheduled to manage the child
         * device.
         */
        if (schedule_task &&
            (pcib_hotplug_present(sc) != 0) != (sc->child != NULL))
                taskqueue_enqueue(taskqueue_bus, &sc->pcie_hp_task);
}

static void
pcib_pcie_intr_hotplug(void *arg)
{
        struct pcib_softc *sc;
        device_t dev;
        uint16_t old_slot_sta;

        sc = arg;
        dev = sc->dev;
        PCIB_HP_LOCK(sc);
        old_slot_sta = sc->pcie_slot_sta;
        sc->pcie_slot_sta = pcie_read_config(dev, PCIER_SLOT_STA, 2);

        /* Clear the events just reported. */
        pcie_write_config(dev, PCIER_SLOT_STA, sc->pcie_slot_sta, 2);

        if (bootverbose)
                device_printf(dev, "HotPlug interrupt: %#x\n",
                    sc->pcie_slot_sta);

        if (sc->pcie_slot_sta & PCIEM_SLOT_STA_ABP) {
                if (sc->flags & PCIB_DETACH_PENDING) {  
                        device_printf(dev,
                            "Attention Button Pressed: Detach Cancelled\n");
                        sc->flags &= ~PCIB_DETACH_PENDING;
                        taskqueue_cancel_timeout(taskqueue_bus,
                            &sc->pcie_ab_task, NULL);
                } else if (old_slot_sta & PCIEM_SLOT_STA_PDS) {
                        /* Only initiate detach sequence if device present. */
                        if (pcie_hp_detach_timeout != 0) {
                                device_printf(dev,
                            "Attention Button Pressed: Detaching in %ld ms\n",
                            (long)(pcie_hp_detach_timeout / SBT_1MS));
                                sc->flags |= PCIB_DETACH_PENDING;
                                taskqueue_enqueue_timeout_sbt(taskqueue_bus,
                                    &sc->pcie_ab_task, pcie_hp_detach_timeout,
                                    SBT_1S, 0);
                        } else {
                                sc->flags |= PCIB_DETACHING;
                        }
                }
        }
        if (sc->pcie_slot_sta & PCIEM_SLOT_STA_PFD)
                device_printf(dev, "Power Fault Detected\n");
        if (sc->pcie_slot_sta & PCIEM_SLOT_STA_MRLSC)
                device_printf(dev, "MRL Sensor Changed to %s\n",
                    sc->pcie_slot_sta & PCIEM_SLOT_STA_MRLSS ? "open" :
                    "closed");
        if (bootverbose && sc->pcie_slot_sta & PCIEM_SLOT_STA_PDC)
                device_printf(dev, "Presence Detect Changed to %s\n",
                    sc->pcie_slot_sta & PCIEM_SLOT_STA_PDS ? "card present" :
                    "empty");
        if (sc->pcie_slot_sta & PCIEM_SLOT_STA_CC)
                pcib_pcie_hotplug_command_completed(sc);
        if (sc->pcie_slot_sta & PCIEM_SLOT_STA_DLLSC) {
                sc->pcie_link_sta = pcie_read_config(dev, PCIER_LINK_STA, 2);
                if (bootverbose)
                        device_printf(dev,
                            "Data Link Layer State Changed to %s\n",
                            sc->pcie_link_sta & PCIEM_LINK_STA_DL_ACTIVE ?
                            "active" : "inactive");
        }

        pcib_pcie_hotplug_update(sc, 0, 0, true);
        PCIB_HP_UNLOCK(sc);
}

static void
pcib_pcie_hotplug_task(void *context, int pending)
{
        struct pcib_softc *sc;
        device_t dev;

        sc = context;
        PCIB_HP_LOCK(sc);
        dev = sc->dev;
        if (pcib_hotplug_present(sc) != 0) {
                if (sc->child == NULL) {
                        sc->child = device_add_child(dev, "pci", DEVICE_UNIT_ANY);
                        bus_attach_children(dev);
                }
        } else {
                if (sc->child != NULL) {
                        if (device_delete_child(dev, sc->child) == 0)
                                sc->child = NULL;
                }
        }
        PCIB_HP_UNLOCK(sc);
}

static void
pcib_pcie_ab_timeout(void *arg, int pending)
{
        struct pcib_softc *sc = arg;

        PCIB_HP_LOCK(sc);
        if (sc->flags & PCIB_DETACH_PENDING) {
                sc->flags |= PCIB_DETACHING;
                sc->flags &= ~PCIB_DETACH_PENDING;
                pcib_pcie_hotplug_update(sc, 0, 0, true);
        }
        PCIB_HP_UNLOCK(sc);
}

static void
pcib_pcie_cc_timeout(void *arg, int pending)
{
        struct pcib_softc *sc = arg;
        device_t dev = sc->dev;
        uint16_t sta;

        PCIB_HP_LOCK(sc);
        sta = pcie_read_config(dev, PCIER_SLOT_STA, 2);
        if (!(sta & PCIEM_SLOT_STA_CC)) {
                device_printf(dev, "HotPlug Command Timed Out\n");
                sc->flags &= ~PCIB_HOTPLUG_CMD_PENDING;
        } else {
                device_printf(dev,
            "Missed HotPlug interrupt waiting for Command Completion\n");
                pcib_pcie_intr_hotplug(sc);
        }
        PCIB_HP_UNLOCK(sc);
}

static void
pcib_pcie_dll_timeout(void *arg, int pending)
{
        struct pcib_softc *sc = arg;
        device_t dev = sc->dev;
        uint16_t sta;

        PCIB_HP_LOCK(sc);
        sta = pcie_read_config(dev, PCIER_LINK_STA, 2);
        if (!(sta & PCIEM_LINK_STA_DL_ACTIVE)) {
                device_printf(dev,
                    "Timed out waiting for Data Link Layer Active\n");
                sc->flags |= PCIB_DETACHING;
                pcib_pcie_hotplug_update(sc, 0, 0, true);
        } else if (sta != sc->pcie_link_sta) {
                device_printf(dev,
                    "Missed HotPlug interrupt waiting for DLL Active\n");
                pcib_pcie_intr_hotplug(sc);
        }
        PCIB_HP_UNLOCK(sc);
}

static int
pcib_alloc_pcie_irq(struct pcib_softc *sc)
{
        device_t dev;
        int count, error, mem_rid, rid;

        rid = -1;
        dev = sc->dev;

        /*
         * For simplicity, only use MSI-X if there is a single message.
         * To support a device with multiple messages we would have to
         * use remap intr if the MSI number is not 0.
         */
        count = pci_msix_count(dev);
        if (count == 1) {
                mem_rid = pci_msix_table_bar(dev);
                sc->pcie_mem = bus_alloc_resource_any(dev, SYS_RES_MEMORY,
                    &mem_rid, RF_ACTIVE);
                if (sc->pcie_mem == NULL) {
                        device_printf(dev,
                            "Failed to allocate BAR for MSI-X table\n");
                } else {
                        error = pci_alloc_msix(dev, &count);
                        if (error == 0)
                                rid = 1;
                }
        }

        if (rid < 0 && pci_msi_count(dev) > 0) {
                count = 1;
                error = pci_alloc_msi(dev, &count);
                if (error == 0)
                        rid = 1;
        }

        if (rid < 0)
                rid = 0;

        sc->pcie_irq = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
            RF_ACTIVE | RF_SHAREABLE);
        if (sc->pcie_irq == NULL) {
                device_printf(dev,
                    "Failed to allocate interrupt for PCI-e events\n");
                if (rid > 0)
                        pci_release_msi(dev);
                return (ENXIO);
        }

        error = bus_setup_intr(dev, sc->pcie_irq, INTR_TYPE_MISC|INTR_MPSAFE,
            NULL, pcib_pcie_intr_hotplug, sc, &sc->pcie_ihand);
        if (error) {
                device_printf(dev, "Failed to setup PCI-e interrupt handler\n");
                bus_release_resource(dev, SYS_RES_IRQ, rid, sc->pcie_irq);
                if (rid > 0)
                        pci_release_msi(dev);
                return (error);
        }
        return (0);
}

static int
pcib_release_pcie_irq(struct pcib_softc *sc)
{
        device_t dev;
        int error;

        dev = sc->dev;
        error = bus_teardown_intr(dev, sc->pcie_irq, sc->pcie_ihand);
        if (error)
                return (error);
        error = bus_free_resource(dev, SYS_RES_IRQ, sc->pcie_irq);
        if (error)
                return (error);
        error = pci_release_msi(dev);
        if (error)
                return (error);
        if (sc->pcie_mem != NULL)
                error = bus_free_resource(dev, SYS_RES_MEMORY, sc->pcie_mem);
        return (error);
}

static void
pcib_setup_hotplug(struct pcib_softc *sc)
{
        device_t dev;
        uint16_t mask, val;

        dev = sc->dev;
        TASK_INIT(&sc->pcie_hp_task, 0, pcib_pcie_hotplug_task, sc);
        TIMEOUT_TASK_INIT(taskqueue_bus, &sc->pcie_ab_task, 0,
            pcib_pcie_ab_timeout, sc);
        TIMEOUT_TASK_INIT(taskqueue_bus, &sc->pcie_cc_task, 0,
            pcib_pcie_cc_timeout, sc);
        TIMEOUT_TASK_INIT(taskqueue_bus, &sc->pcie_dll_task, 0,
            pcib_pcie_dll_timeout, sc);
        sc->pcie_hp_lock = bus_topo_mtx();

        /* Allocate IRQ. */
        if (pcib_alloc_pcie_irq(sc) != 0)
                return;

        sc->pcie_link_sta = pcie_read_config(dev, PCIER_LINK_STA, 2);
        sc->pcie_slot_sta = pcie_read_config(dev, PCIER_SLOT_STA, 2);

        /* Clear any events previously pending. */
        pcie_write_config(dev, PCIER_SLOT_STA, sc->pcie_slot_sta, 2);
        sc->pcie_slot_sta = pcie_read_config(dev, PCIER_SLOT_STA, 2);

        /* Enable HotPlug events. */
        mask = PCIEM_SLOT_CTL_DLLSCE | PCIEM_SLOT_CTL_HPIE |
            PCIEM_SLOT_CTL_CCIE | PCIEM_SLOT_CTL_PDCE | PCIEM_SLOT_CTL_MRLSCE |
            PCIEM_SLOT_CTL_PFDE | PCIEM_SLOT_CTL_ABPE;
        val = PCIEM_SLOT_CTL_DLLSCE | PCIEM_SLOT_CTL_HPIE | PCIEM_SLOT_CTL_PDCE;
        if (sc->pcie_slot_cap & PCIEM_SLOT_CAP_APB)
                val |= PCIEM_SLOT_CTL_ABPE;
        if (sc->pcie_slot_cap & PCIEM_SLOT_CAP_PCP)
                val |= PCIEM_SLOT_CTL_PFDE;
        if (sc->pcie_slot_cap & PCIEM_SLOT_CAP_MRLSP)
                val |= PCIEM_SLOT_CTL_MRLSCE;
        if (!(sc->pcie_slot_cap & PCIEM_SLOT_CAP_NCCS))
                val |= PCIEM_SLOT_CTL_CCIE;

        /* Turn the attention indicator off. */
        if (sc->pcie_slot_cap & PCIEM_SLOT_CAP_AIP) {
                mask |= PCIEM_SLOT_CTL_AIC;
                val |= PCIEM_SLOT_CTL_AI_OFF;
        }

        pcib_pcie_hotplug_update(sc, val, mask, false);
}

static int
pcib_detach_hotplug(struct pcib_softc *sc)
{
        uint16_t mask, val;
        int error;

        /* Disable the card in the slot and force it to detach. */
        if (sc->flags & PCIB_DETACH_PENDING) {
                sc->flags &= ~PCIB_DETACH_PENDING;
                taskqueue_cancel_timeout(taskqueue_bus, &sc->pcie_ab_task,
                    NULL);
        }
        sc->flags |= PCIB_DETACHING;

        if (sc->flags & PCIB_HOTPLUG_CMD_PENDING) {
                taskqueue_cancel_timeout(taskqueue_bus, &sc->pcie_cc_task,
                    NULL);
                tsleep(sc, 0, "hpcmd", hz);
                sc->flags &= ~PCIB_HOTPLUG_CMD_PENDING;
        }

        /* Disable HotPlug events. */
        mask = PCIEM_SLOT_CTL_DLLSCE | PCIEM_SLOT_CTL_HPIE |
            PCIEM_SLOT_CTL_CCIE | PCIEM_SLOT_CTL_PDCE | PCIEM_SLOT_CTL_MRLSCE |
            PCIEM_SLOT_CTL_PFDE | PCIEM_SLOT_CTL_ABPE;
        val = 0;

        /* Turn the attention indicator off. */
        if (sc->pcie_slot_cap & PCIEM_SLOT_CAP_AIP) {
                mask |= PCIEM_SLOT_CTL_AIC;
                val |= PCIEM_SLOT_CTL_AI_OFF;
        }

        pcib_pcie_hotplug_update(sc, val, mask, false);

        error = pcib_release_pcie_irq(sc);
        if (error)
                return (error);
        taskqueue_drain(taskqueue_bus, &sc->pcie_hp_task);
        taskqueue_drain_timeout(taskqueue_bus, &sc->pcie_ab_task);
        taskqueue_drain_timeout(taskqueue_bus, &sc->pcie_cc_task);
        taskqueue_drain_timeout(taskqueue_bus, &sc->pcie_dll_task);
        return (0);
}
#endif

/*
 * Restore previous bridge configuration.
 */
static void
pcib_cfg_restore(struct pcib_softc *sc)
{
        pcib_write_windows(sc, WIN_IO | WIN_MEM | WIN_PMEM);
}

/*
 * Generic device interface
 */
static int
pcib_probe(device_t dev)
{
    if ((pci_get_class(dev) == PCIC_BRIDGE) &&
        (pci_get_subclass(dev) == PCIS_BRIDGE_PCI)) {
        device_set_desc(dev, "PCI-PCI bridge");
        return(-10000);
    }
    return(ENXIO);
}

void
pcib_attach_common(device_t dev)
{
    struct pcib_softc   *sc;
    struct sysctl_ctx_list *sctx;
    struct sysctl_oid   *soid;
    int comma;

    sc = device_get_softc(dev);
    sc->dev = dev;

    /*
     * Get current bridge configuration.
     */
    sc->domain = pci_get_domain(dev);
    sc->bridgectl = pci_read_config(dev, PCIR_BRIDGECTL_1, 2);

    /*
     * The primary bus register should always be the bus of the
     * parent.
     */
    sc->pribus = pci_get_bus(dev);
    pci_write_config(dev, PCIR_PRIBUS_1, sc->pribus, 1);

    /*
     * Setup sysctl reporting nodes
     */
    sctx = device_get_sysctl_ctx(dev);
    soid = device_get_sysctl_tree(dev);
    SYSCTL_ADD_UINT(sctx, SYSCTL_CHILDREN(soid), OID_AUTO, "domain",
      CTLFLAG_RD, &sc->domain, 0, "Domain number");
    SYSCTL_ADD_UINT(sctx, SYSCTL_CHILDREN(soid), OID_AUTO, "pribus",
      CTLFLAG_RD, &sc->pribus, 0, "Primary bus number");
    SYSCTL_ADD_UINT(sctx, SYSCTL_CHILDREN(soid), OID_AUTO, "secbus",
      CTLFLAG_RD, &sc->bus.sec, 0, "Secondary bus number");
    SYSCTL_ADD_UINT(sctx, SYSCTL_CHILDREN(soid), OID_AUTO, "subbus",
      CTLFLAG_RD, &sc->bus.sub, 0, "Subordinate bus number");

    /*
     * Quirk handling.
     */
    switch (pci_get_devid(dev)) {
    /*
     * The i82380FB mobile docking controller is a PCI-PCI bridge,
     * and it is a subtractive bridge.  However, the ProgIf is wrong
     * so the normal setting of PCIB_SUBTRACTIVE bit doesn't
     * happen.  There are also Toshiba and Cavium ThunderX bridges
     * that behave this way.
     */
    case 0xa002177d:            /* Cavium ThunderX */
    case 0x124b8086:            /* Intel 82380FB Mobile */
    case 0x060513d7:            /* Toshiba ???? */
        sc->flags |= PCIB_SUBTRACTIVE;
        break;
    }

    if (pci_msi_device_blacklisted(dev))
        sc->flags |= PCIB_DISABLE_MSI;

    if (pci_msix_device_blacklisted(dev))
        sc->flags |= PCIB_DISABLE_MSIX;

    /*
     * Intel 815, 845 and other chipsets say they are PCI-PCI bridges,
     * but have a ProgIF of 0x80.  The 82801 family (AA, AB, BAM/CAM,
     * BA/CA/DB and E) PCI bridges are HUB-PCI bridges, in Intelese.
     * This means they act as if they were subtractively decoding
     * bridges and pass all transactions.  Mark them and real ProgIf 1
     * parts as subtractive.
     */
    if ((pci_get_devid(dev) & 0xff00ffff) == 0x24008086 ||
      pci_read_config(dev, PCIR_PROGIF, 1) == PCIP_BRIDGE_PCI_SUBTRACTIVE)
        sc->flags |= PCIB_SUBTRACTIVE;

#ifdef PCI_HP
    pcib_probe_hotplug(sc);
#endif
    pcib_setup_secbus(dev, &sc->bus, 1);
    pcib_probe_windows(sc);
#ifdef PCI_HP
    if (sc->flags & PCIB_HOTPLUG)
            pcib_setup_hotplug(sc);
#endif
    if (bootverbose) {
        device_printf(dev, "  domain            %d\n", sc->domain);
        device_printf(dev, "  secondary bus     %d\n", sc->bus.sec);
        device_printf(dev, "  subordinate bus   %d\n", sc->bus.sub);
        if (pcib_is_window_open(&sc->io))
            device_printf(dev, "  I/O decode        0x%jx-0x%jx\n",
              (uintmax_t)sc->io.base, (uintmax_t)sc->io.limit);
        if (pcib_is_window_open(&sc->mem))
            device_printf(dev, "  memory decode     0x%jx-0x%jx\n",
              (uintmax_t)sc->mem.base, (uintmax_t)sc->mem.limit);
        if (pcib_is_window_open(&sc->pmem))
            device_printf(dev, "  prefetched decode 0x%jx-0x%jx\n",
              (uintmax_t)sc->pmem.base, (uintmax_t)sc->pmem.limit);
        if (sc->bridgectl & (PCIB_BCR_ISA_ENABLE | PCIB_BCR_VGA_ENABLE) ||
            sc->flags & PCIB_SUBTRACTIVE) {
                device_printf(dev, "  special decode    ");
                comma = 0;
                if (sc->bridgectl & PCIB_BCR_ISA_ENABLE) {
                        printf("ISA");
                        comma = 1;
                }
                if (sc->bridgectl & PCIB_BCR_VGA_ENABLE) {
                        printf("%sVGA", comma ? ", " : "");
                        comma = 1;
                }
                if (sc->flags & PCIB_SUBTRACTIVE)
                        printf("%ssubtractive", comma ? ", " : "");
                printf("\n");
        }
    }

    /*
     * Always enable busmastering on bridges so that transactions
     * initiated on the secondary bus are passed through to the
     * primary bus.
     */
    pci_enable_busmaster(dev);
}

#ifdef PCI_HP
static int
pcib_present(struct pcib_softc *sc)
{

        if (sc->flags & PCIB_HOTPLUG)
                return (pcib_hotplug_present(sc) != 0);
        return (1);
}
#endif

int
pcib_attach_child(device_t dev)
{
        struct pcib_softc *sc;

        sc = device_get_softc(dev);
        if (sc->bus.sec == 0) {
                /* no secondary bus; we should have fixed this */
                return(0);
        }

#ifdef PCI_HP
        if (!pcib_present(sc)) {
                /* An empty HotPlug slot, so don't add a PCI bus yet. */
                return (0);
        }
#endif

        sc->child = device_add_child(dev, "pci", DEVICE_UNIT_ANY);
        bus_attach_children(dev);
        return (0);
}

int
pcib_attach(device_t dev)
{

    pcib_attach_common(dev);
    return (pcib_attach_child(dev));
}

int
pcib_detach(device_t dev)
{
        struct pcib_softc *sc;
        int error;

        sc = device_get_softc(dev);
        error = bus_detach_children(dev);
        if (error)
                return (error);
#ifdef PCI_HP
        if (sc->flags & PCIB_HOTPLUG) {
                error = pcib_detach_hotplug(sc);
                if (error)
                        return (error);
        }
#endif
        error = device_delete_children(dev);
        if (error)
                return (error);
        pcib_free_windows(sc);
        pcib_free_secbus(dev, &sc->bus);
        return (0);
}

int
pcib_resume(device_t dev)
{

        pcib_cfg_restore(device_get_softc(dev));

        /*
         * Restore the Command register only after restoring the windows.
         * The bridge should not be claiming random windows.
         */
        pci_write_config(dev, PCIR_COMMAND, pci_get_cmdreg(dev), 2);
        return (bus_generic_resume(dev));
}

void
pcib_bridge_init(device_t dev)
{
        pci_write_config(dev, PCIR_IOBASEL_1, 0xff, 1);
        pci_write_config(dev, PCIR_IOBASEH_1, 0xffff, 2);
        pci_write_config(dev, PCIR_IOLIMITL_1, 0, 1);
        pci_write_config(dev, PCIR_IOLIMITH_1, 0, 2);
        pci_write_config(dev, PCIR_MEMBASE_1, 0xffff, 2);
        pci_write_config(dev, PCIR_MEMLIMIT_1, 0, 2);
        pci_write_config(dev, PCIR_PMBASEL_1, 0xffff, 2);
        pci_write_config(dev, PCIR_PMBASEH_1, 0xffffffff, 4);
        pci_write_config(dev, PCIR_PMLIMITL_1, 0, 2);
        pci_write_config(dev, PCIR_PMLIMITH_1, 0, 4);
}

int
pcib_child_present(device_t dev, device_t child)
{
#ifdef PCI_HP
        struct pcib_softc *sc = device_get_softc(dev);
        int retval;

        retval = bus_child_present(dev);
        if (retval != 0 && sc->flags & PCIB_HOTPLUG)
                retval = pcib_hotplug_present(sc);
        return (retval);
#else
        return (bus_child_present(dev));
#endif
}

int
pcib_read_ivar(device_t dev, device_t child, int which, uintptr_t *result)
{
    struct pcib_softc   *sc = device_get_softc(dev);

    switch (which) {
    case PCIB_IVAR_DOMAIN:
        *result = sc->domain;
        return(0);
    case PCIB_IVAR_BUS:
        *result = sc->bus.sec;
        return(0);
    }
    return(ENOENT);
}

int
pcib_write_ivar(device_t dev, device_t child, int which, uintptr_t value)
{

    switch (which) {
    case PCIB_IVAR_DOMAIN:
        return(EINVAL);
    case PCIB_IVAR_BUS:
        return(EINVAL);
    }
    return(ENOENT);
}

/*
 * Attempt to allocate a resource from the existing resources assigned
 * to a window.
 */
static struct resource *
pcib_suballoc_resource(struct pcib_softc *sc, struct pcib_window *w,
    device_t child, int type, int rid, rman_res_t start, rman_res_t end,
    rman_res_t count, u_int flags)
{
        struct resource *res;

        if (!pcib_is_window_open(w))
                return (NULL);

        res = rman_reserve_resource(&w->rman, start, end, count,
            flags & ~RF_ACTIVE, child);
        if (res == NULL)
                return (NULL);

        if (bootverbose)
                device_printf(sc->dev,
                    "allocated %s range (%#jx-%#jx) for rid %x of %s\n",
                    w->name, rman_get_start(res), rman_get_end(res), rid,
                    pcib_child_name(child));
        rman_set_rid(res, rid);
        rman_set_type(res, type);

        if (flags & RF_ACTIVE) {
                if (bus_activate_resource(child, type, rid, res) != 0) {
                        rman_release_resource(res);
                        return (NULL);
                }
        }

        return (res);
}

/* Allocate a fresh resource range for an unconfigured window. */
static int
pcib_alloc_new_window(struct pcib_softc *sc, struct pcib_window *w, int type,
    rman_res_t start, rman_res_t end, rman_res_t count, u_int flags)
{
        struct resource *res;
        rman_res_t base, limit, wmask;
        int rid;

        /*
         * If this is an I/O window on a bridge with ISA enable set
         * and the start address is below 64k, then try to allocate an
         * initial window of 0x1000 bytes long starting at address
         * 0xf000 and walking down.  Note that if the original request
         * was larger than the non-aliased range size of 0x100 our
         * caller would have raised the start address up to 64k
         * already.
         */
        if (type == SYS_RES_IOPORT && sc->bridgectl & PCIB_BCR_ISA_ENABLE &&
            start < 65536) {
                for (base = 0xf000; (long)base >= 0; base -= 0x1000) {
                        limit = base + 0xfff;

                        /*
                         * Skip ranges that wouldn't work for the
                         * original request.  Note that the actual
                         * window that overlaps are the non-alias
                         * ranges within [base, limit], so this isn't
                         * quite a simple comparison.
                         */
                        if (start + count > limit - 0x400)
                                continue;
                        if (base == 0) {
                                /*
                                 * The first open region for the window at
                                 * 0 is 0x400-0x4ff.
                                 */
                                if (end - count + 1 < 0x400)
                                        continue;
                        } else {
                                if (end - count + 1 < base)
                                        continue;
                        }

                        if (pcib_alloc_nonisa_ranges(sc, base, limit) == 0) {
                                w->base = base;
                                w->limit = limit;
                                return (0);
                        }
                }
                return (ENOSPC);
        }

        wmask = ((rman_res_t)1 << w->step) - 1;
        if (RF_ALIGNMENT(flags) < w->step) {
                flags &= ~RF_ALIGNMENT_MASK;
                flags |= RF_ALIGNMENT_LOG2(w->step);
        }
        start &= ~wmask;
        end |= wmask;
        count = roundup2(count, (rman_res_t)1 << w->step);
        rid = w->reg;
        res = bus_alloc_resource(sc->dev, type, &rid, start, end, count,
            flags | RF_ACTIVE | RF_UNMAPPED);
        if (res == NULL)
                return (ENOSPC);
        pcib_add_window_resources(w, &res, 1);
        pcib_activate_window(sc, type);
        w->base = rman_get_start(res);
        w->limit = rman_get_end(res);
        return (0);
}

/* Try to expand an existing window to the requested base and limit. */
static int
pcib_expand_window(struct pcib_softc *sc, struct pcib_window *w, int type,
    rman_res_t base, rman_res_t limit)
{
        struct resource *res;
        int error, i, force_64k_base;

        KASSERT(base <= w->base && limit >= w->limit,
            ("attempting to shrink window"));

        /*
         * XXX: pcib_grow_window() doesn't try to do this anyway and
         * the error handling for all the edge cases would be tedious.
         */
        KASSERT(limit == w->limit || base == w->base,
            ("attempting to grow both ends of a window"));

        /*
         * Yet more special handling for requests to expand an I/O
         * window behind an ISA-enabled bridge.  Since I/O windows
         * have to grow in 0x1000 increments and the end of the 0xffff
         * range is an alias, growing a window below 64k will always
         * result in allocating new resources and never adjusting an
         * existing resource.
         */
        if (type == SYS_RES_IOPORT && sc->bridgectl & PCIB_BCR_ISA_ENABLE &&
            (limit <= 65535 || (base <= 65535 && base != w->base))) {
                KASSERT(limit == w->limit || limit <= 65535,
                    ("attempting to grow both ends across 64k ISA alias"));

                if (base != w->base)
                        error = pcib_alloc_nonisa_ranges(sc, base, w->base - 1);
                else
                        error = pcib_alloc_nonisa_ranges(sc, w->limit + 1,
                            limit);
                if (error == 0) {
                        w->base = base;
                        w->limit = limit;
                }
                return (error);
        }

        /*
         * Find the existing resource to adjust.  Usually there is only one,
         * but for an ISA-enabled bridge we might be growing the I/O window
         * above 64k and need to find the existing resource that maps all
         * of the area above 64k.
         */
        for (i = 0; i < w->count; i++) {
                if (rman_get_end(w->res[i]) == w->limit)
                        break;
        }
        KASSERT(i != w->count, ("did not find existing resource"));
        res = w->res[i];

        /*
         * Usually the resource we found should match the window's
         * existing range.  The one exception is the ISA-enabled case
         * mentioned above in which case the resource should start at
         * 64k.
         */
        if (type == SYS_RES_IOPORT && sc->bridgectl & PCIB_BCR_ISA_ENABLE &&
            w->base <= 65535) {
                KASSERT(rman_get_start(res) == 65536,
                    ("existing resource mismatch"));
                force_64k_base = 1;
        } else {
                KASSERT(w->base == rman_get_start(res),
                    ("existing resource mismatch"));
                force_64k_base = 0;
        }

        error = bus_adjust_resource(sc->dev, type, res, force_64k_base ?
            rman_get_start(res) : base, limit);
        if (error)
                return (error);

        /* Add the newly allocated region to the resource manager. */
        if (w->base != base) {
                error = rman_manage_region(&w->rman, base, w->base - 1);
                w->base = base;
        } else {
                error = rman_manage_region(&w->rman, w->limit + 1, limit);
                w->limit = limit;
        }
        if (error) {
                if (bootverbose)
                        device_printf(sc->dev,
                            "failed to expand %s resource manager\n", w->name);
                (void)bus_adjust_resource(sc->dev, type, res, force_64k_base ?
                    rman_get_start(res) : w->base, w->limit);
        }
        return (error);
}

/*
 * Attempt to grow a window to make room for a given resource request.
 */
static int
pcib_grow_window(struct pcib_softc *sc, struct pcib_window *w, int type,
    rman_res_t start, rman_res_t end, rman_res_t count, u_int flags)
{
        rman_res_t align, start_free, end_free, front, back, wmask;
        int error;

        /*
         * Clamp the desired resource range to the maximum address
         * this window supports.  Reject impossible requests.
         *
         * For I/O port requests behind a bridge with the ISA enable
         * bit set, force large allocations to start above 64k.
         */
        if (!w->valid)
                return (EINVAL);
        if (sc->bridgectl & PCIB_BCR_ISA_ENABLE && count > 0x100 &&
            start < 65536)
                start = 65536;
        if (end > w->rman.rm_end)
                end = w->rman.rm_end;
        if (start + count - 1 > end || start + count < start)
                return (EINVAL);
        wmask = ((rman_res_t)1 << w->step) - 1;

        /*
         * If there is no resource at all, just try to allocate enough
         * aligned space for this resource.
         */
        if (w->res == NULL) {
                error = pcib_alloc_new_window(sc, w, type, start, end, count,
                    flags);
                if (error) {
                        if (bootverbose)
                                device_printf(sc->dev,
                    "failed to allocate initial %s window (%#jx-%#jx,%#jx)\n",
                                    w->name, start, end, count);
                        return (error);
                }
                if (bootverbose)
                        device_printf(sc->dev,
                            "allocated initial %s window of %#jx-%#jx\n",
                            w->name, (uintmax_t)w->base, (uintmax_t)w->limit);
                goto updatewin;
        }

        /*
         * See if growing the window would help.  Compute the minimum
         * amount of address space needed on both the front and back
         * ends of the existing window to satisfy the allocation.
         *
         * For each end, build a candidate region adjusting for the
         * required alignment, etc.  If there is a free region at the
         * edge of the window, grow from the inner edge of the free
         * region.  Otherwise grow from the window boundary.
         *
         * Growing an I/O window below 64k for a bridge with the ISA
         * enable bit doesn't require any special magic as the step
         * size of an I/O window (1k) always includes multiple
         * non-alias ranges when it is grown in either direction.
         *
         * XXX: Special case: if w->res is completely empty and the
         * request size is larger than w->res, we should find the
         * optimal aligned buffer containing w->res and allocate that.
         */
        if (bootverbose)
                device_printf(sc->dev,
                    "attempting to grow %s window for (%#jx-%#jx,%#jx)\n",
                    w->name, start, end, count);
        align = (rman_res_t)1 << RF_ALIGNMENT(flags);
        if (start < w->base) {
                if (rman_first_free_region(&w->rman, &start_free, &end_free) !=
                    0 || start_free != w->base)
                        end_free = w->base;
                if (end_free > end)
                        end_free = end + 1;

                /* Move end_free down until it is properly aligned. */
                end_free &= ~(align - 1);
                end_free--;
                front = end_free - (count - 1);

                /*
                 * The resource would now be allocated at (front,
                 * end_free).  Ensure that fits in the (start, end)
                 * bounds.  end_free is checked above.  If 'front' is
                 * ok, ensure it is properly aligned for this window.
                 * Also check for underflow.
                 */
                if (front >= start && front <= end_free) {
                        if (bootverbose)
                                printf("\tfront candidate range: %#jx-%#jx\n",
                                    front, end_free);
                        front &= ~wmask;
                        front = w->base - front;
                } else
                        front = 0;
        } else
                front = 0;
        if (end > w->limit) {
                if (rman_last_free_region(&w->rman, &start_free, &end_free) !=
                    0 || end_free != w->limit)
                        start_free = w->limit + 1;
                if (start_free < start)
                        start_free = start;

                /* Move start_free up until it is properly aligned. */
                start_free = roundup2(start_free, align);
                back = start_free + count - 1;

                /*
                 * The resource would now be allocated at (start_free,
                 * back).  Ensure that fits in the (start, end)
                 * bounds.  start_free is checked above.  If 'back' is
                 * ok, ensure it is properly aligned for this window.
                 * Also check for overflow.
                 */
                if (back <= end && start_free <= back) {
                        if (bootverbose)
                                printf("\tback candidate range: %#jx-%#jx\n",
                                    start_free, back);
                        back |= wmask;
                        back -= w->limit;
                } else
                        back = 0;
        } else
                back = 0;

        /*
         * Try to allocate the smallest needed region first.
         * If that fails, fall back to the other region.
         */
        error = ENOSPC;
        while (front != 0 || back != 0) {
                if (front != 0 && (front <= back || back == 0)) {
                        error = pcib_expand_window(sc, w, type, w->base - front,
                            w->limit);
                        if (error == 0)
                                break;
                        front = 0;
                } else {
                        error = pcib_expand_window(sc, w, type, w->base,
                            w->limit + back);
                        if (error == 0)
                                break;
                        back = 0;
                }
        }

        if (error)
                return (error);
        if (bootverbose)
                device_printf(sc->dev, "grew %s window to %#jx-%#jx\n",
                    w->name, (uintmax_t)w->base, (uintmax_t)w->limit);

updatewin:
        /* Write the new window. */
        KASSERT((w->base & wmask) == 0, ("start address is not aligned"));
        KASSERT((w->limit & wmask) == wmask, ("end address is not aligned"));
        pcib_write_windows(sc, w->mask);
        return (0);
}

/*
 * We have to trap resource allocation requests and ensure that the bridge
 * is set up to, or capable of handling them.
 */
static struct resource *
pcib_alloc_resource(device_t dev, device_t child, int type, int rid,
    rman_res_t start, rman_res_t end, rman_res_t count, u_int flags)
{
        struct pcib_softc *sc;
        struct resource *r;

        sc = device_get_softc(dev);

        /*
         * VGA resources are decoded iff the VGA enable bit is set in
         * the bridge control register.  VGA resources do not fall into
         * the resource windows and are passed up to the parent.
         */
        if ((type == SYS_RES_IOPORT && pci_is_vga_ioport_range(start, end)) ||
            (type == SYS_RES_MEMORY && pci_is_vga_memory_range(start, end))) {
                if (sc->bridgectl & PCIB_BCR_VGA_ENABLE)
                        return (bus_generic_alloc_resource(dev, child, type,
                            rid, start, end, count, flags));
                else
                        return (NULL);
        }

        switch (type) {
        case PCI_RES_BUS:
                return (pcib_alloc_subbus(&sc->bus, child, rid, start, end,
                    count, flags));
        case SYS_RES_IOPORT:
                if (pcib_is_isa_range(sc, start, end, count))
                        return (NULL);
                r = pcib_suballoc_resource(sc, &sc->io, child, type, rid, start,
                    end, count, flags);
                if (r != NULL || (sc->flags & PCIB_SUBTRACTIVE) != 0)
                        break;
                if (pcib_grow_window(sc, &sc->io, type, start, end, count,
                    flags) == 0)
                        r = pcib_suballoc_resource(sc, &sc->io, child, type,
                            rid, start, end, count, flags);
                break;
        case SYS_RES_MEMORY:
                /*
                 * For prefetchable resources, prefer the prefetchable
                 * memory window, but fall back to the regular memory
                 * window if that fails.  Try both windows before
                 * attempting to grow a window in case the firmware
                 * has used a range in the regular memory window to
                 * map a prefetchable BAR.
                 */
                if (flags & RF_PREFETCHABLE) {
                        r = pcib_suballoc_resource(sc, &sc->pmem, child, type,
                            rid, start, end, count, flags);
                        if (r != NULL)
                                break;
                }
                r = pcib_suballoc_resource(sc, &sc->mem, child, type, rid,
                    start, end, count, flags);
                if (r != NULL || (sc->flags & PCIB_SUBTRACTIVE) != 0)
                        break;
                if (flags & RF_PREFETCHABLE) {
                        if (pcib_grow_window(sc, &sc->pmem, type, start, end,
                            count, flags) == 0) {
                                r = pcib_suballoc_resource(sc, &sc->pmem, child,
                                    type, rid, start, end, count, flags);
                                if (r != NULL)
                                        break;
                        }
                }
                if (pcib_grow_window(sc, &sc->mem, type, start, end, count,
                    flags & ~RF_PREFETCHABLE) == 0)
                        r = pcib_suballoc_resource(sc, &sc->mem, child, type,
                            rid, start, end, count, flags);
                break;
        default:
                return (bus_generic_alloc_resource(dev, child, type, rid,
                    start, end, count, flags));
        }

        /*
         * If attempts to suballocate from the window fail but this is a
         * subtractive bridge, pass the request up the tree.
         */
        if (sc->flags & PCIB_SUBTRACTIVE && r == NULL)
                return (bus_generic_alloc_resource(dev, child, type, rid,
                    start, end, count, flags));
        return (r);
}

static int
pcib_adjust_resource(device_t bus, device_t child, struct resource *r,
    rman_res_t start, rman_res_t end)
{
        struct pcib_softc *sc;
        struct pcib_window *w;
        rman_res_t wmask;
        int error, type;

        sc = device_get_softc(bus);
        type = rman_get_type(r);

        /*
         * If the resource wasn't sub-allocated from one of our region
         * managers then just pass the request up.
         */
        if (!pcib_is_resource_managed(sc, r))
                return (bus_generic_adjust_resource(bus, child, r, start, end));

        if (type == PCI_RES_BUS) {
                /*
                 * If our bus range isn't big enough to grow the sub-allocation
                 * then we need to grow our bus range. Any request that would
                 * require us to decrease the start of our own bus range is
                 * invalid, we can only extend the end; ignore such requests
                 * and let rman_adjust_resource fail below.
                 */
                if (start >= sc->bus.sec && end > sc->bus.sub) {
                        error = pcib_grow_subbus(&sc->bus, end);
                        if (error != 0)
                                return (error);
                }
        } else {
                /*
                 * Resource is managed and not a secondary bus number, must
                 * be from one of our windows.
                 */
                w = pcib_get_resource_window(sc, r);
                KASSERT(w != NULL,
                    ("%s: no window for resource (%#jx-%#jx) type %d",
                    __func__, rman_get_start(r), rman_get_end(r), type));

                /*
                 * If our window isn't big enough to grow the sub-allocation
                 * then we need to expand the window.
                 */
                if (start < w->base || end > w->limit) {
                        wmask = ((rman_res_t)1 << w->step) - 1;
                        error = pcib_expand_window(sc, w, type,
                            MIN(start & ~wmask, w->base),
                            MAX(end | wmask, w->limit));
                        if (error != 0)
                                return (error);
                        if (bootverbose)
                                device_printf(sc->dev,
                                    "grew %s window to %#jx-%#jx\n",
                                    w->name, (uintmax_t)w->base,
                                    (uintmax_t)w->limit);
                        pcib_write_windows(sc, w->mask);
                }
        }

        return (rman_adjust_resource(r, start, end));
}

static int
pcib_release_resource(device_t dev, device_t child, struct resource *r)
{
        struct pcib_softc *sc;
        int error;

        sc = device_get_softc(dev);
        if (pcib_is_resource_managed(sc, r)) {
                if (rman_get_flags(r) & RF_ACTIVE) {
                        error = bus_deactivate_resource(child, r);
                        if (error)
                                return (error);
                }
                return (rman_release_resource(r));
        }
        return (bus_generic_release_resource(dev, child, r));
}

static int
pcib_activate_resource(device_t dev, device_t child, struct resource *r)
{
        struct pcib_softc *sc = device_get_softc(dev);
        struct resource_map map;
        int error, type;

        if (!pcib_is_resource_managed(sc, r))
                return (bus_generic_activate_resource(dev, child, r));

        error = rman_activate_resource(r);
        if (error != 0)
                return (error);

        type = rman_get_type(r);
        if ((rman_get_flags(r) & RF_UNMAPPED) == 0 &&
            (type == SYS_RES_MEMORY || type == SYS_RES_IOPORT)) {
                error = BUS_MAP_RESOURCE(dev, child, r, NULL, &map);
                if (error != 0) {
                        rman_deactivate_resource(r);
                        return (error);
                }

                rman_set_mapping(r, &map);
        }
        return (0);
}

static int
pcib_deactivate_resource(device_t dev, device_t child, struct resource *r)
{
        struct pcib_softc *sc = device_get_softc(dev);
        struct resource_map map;
        int error, type;

        if (!pcib_is_resource_managed(sc, r))
                return (bus_generic_deactivate_resource(dev, child, r));

        error = rman_deactivate_resource(r);
        if (error != 0)
                return (error);

        type = rman_get_type(r);
        if ((rman_get_flags(r) & RF_UNMAPPED) == 0 &&
            (type == SYS_RES_MEMORY || type == SYS_RES_IOPORT)) {
                rman_get_mapping(r, &map);
                BUS_UNMAP_RESOURCE(dev, child, r, &map);
        }
        return (0);
}

static struct resource *
pcib_find_parent_resource(struct pcib_window *w, struct resource *r)
{
        for (int i = 0; i < w->count; i++) {
                if (rman_get_start(w->res[i]) <= rman_get_start(r) &&
                    rman_get_end(w->res[i]) >= rman_get_end(r))
                        return (w->res[i]);
        }
        return (NULL);
}

static int
pcib_map_resource(device_t dev, device_t child, struct resource *r,
    struct resource_map_request *argsp, struct resource_map *map)
{
        struct pcib_softc *sc = device_get_softc(dev);
        struct resource_map_request args;
        struct pcib_window *w;
        struct resource *pres;
        rman_res_t length, start;
        int error;

        w = pcib_get_resource_window(sc, r);
        if (w == NULL)
                return (bus_generic_map_resource(dev, child, r, argsp, map));

        /* Resources must be active to be mapped. */
        if (!(rman_get_flags(r) & RF_ACTIVE))
                return (ENXIO);

        resource_init_map_request(&args);
        error = resource_validate_map_request(r, argsp, &args, &start, &length);
        if (error)
                return (error);

        pres = pcib_find_parent_resource(w, r);
        if (pres == NULL)
                return (ENOENT);

        args.offset = start - rman_get_start(pres);
        args.length = length;
        return (bus_map_resource(dev, pres, &args, map));
}

static int
pcib_unmap_resource(device_t dev, device_t child, struct resource *r,
    struct resource_map *map)
{
        struct pcib_softc *sc = device_get_softc(dev);
        struct pcib_window *w;
        struct resource *pres;

        w = pcib_get_resource_window(sc, r);
        if (w == NULL)
                return (bus_generic_unmap_resource(dev, child, r, map));

        pres = pcib_find_parent_resource(w, r);
        if (pres == NULL)
                return (ENOENT);
        return (bus_unmap_resource(dev, pres, map));
}

/*
 * If ARI is enabled on this downstream port, translate the function number
 * to the non-ARI slot/function.  The downstream port will convert it back in
 * hardware.  If ARI is not enabled slot and func are not modified.
 */
static __inline void
pcib_xlate_ari(device_t pcib, int bus, int *slot, int *func)
{
        struct pcib_softc *sc;
        int ari_func;

        sc = device_get_softc(pcib);
        ari_func = *func;

        if (sc->flags & PCIB_ENABLE_ARI) {
                KASSERT(*slot == 0,
                    ("Non-zero slot number with ARI enabled!"));
                *slot = PCIE_ARI_SLOT(ari_func);
                *func = PCIE_ARI_FUNC(ari_func);
        }
}

static void
pcib_enable_ari(struct pcib_softc *sc, uint32_t pcie_pos)
{
        uint32_t ctl2;

        ctl2 = pci_read_config(sc->dev, pcie_pos + PCIER_DEVICE_CTL2, 4);
        ctl2 |= PCIEM_CTL2_ARI;
        pci_write_config(sc->dev, pcie_pos + PCIER_DEVICE_CTL2, ctl2, 4);

        sc->flags |= PCIB_ENABLE_ARI;
}

/*
 * PCIB interface.
 */
int
pcib_maxslots(device_t dev)
{
#if !defined(__amd64__) && !defined(__i386__)
        uint32_t pcie_pos;
        uint16_t val;

        /*
         * If this is a PCIe rootport or downstream switch port, there's only
         * one slot permitted.
         */
        if (pci_find_cap(dev, PCIY_EXPRESS, &pcie_pos) == 0) {
                val = pci_read_config(dev, pcie_pos + PCIER_FLAGS, 2);
                val &= PCIEM_FLAGS_TYPE;
                if (val == PCIEM_TYPE_ROOT_PORT ||
                    val == PCIEM_TYPE_DOWNSTREAM_PORT)
                        return (0);
        }
#endif
        return (PCI_SLOTMAX);
}

static int
pcib_ari_maxslots(device_t dev)
{
        struct pcib_softc *sc;

        sc = device_get_softc(dev);

        if (sc->flags & PCIB_ENABLE_ARI)
                return (PCIE_ARI_SLOTMAX);
        else
                return (pcib_maxslots(dev));
}

static int
pcib_ari_maxfuncs(device_t dev)
{
        struct pcib_softc *sc;

        sc = device_get_softc(dev);

        if (sc->flags & PCIB_ENABLE_ARI)
                return (PCIE_ARI_FUNCMAX);
        else
                return (PCI_FUNCMAX);
}

static void
pcib_ari_decode_rid(device_t pcib, uint16_t rid, int *bus, int *slot,
    int *func)
{
        struct pcib_softc *sc;

        sc = device_get_softc(pcib);

        *bus = PCI_RID2BUS(rid);
        if (sc->flags & PCIB_ENABLE_ARI) {
                *slot = PCIE_ARI_RID2SLOT(rid);
                *func = PCIE_ARI_RID2FUNC(rid);
        } else {
                *slot = PCI_RID2SLOT(rid);
                *func = PCI_RID2FUNC(rid);
        }
}

/*
 * Since we are a child of a PCI bus, its parent must support the pcib interface.
 */
static uint32_t
pcib_read_config(device_t dev, u_int b, u_int s, u_int f, u_int reg, int width)
{
#ifdef PCI_HP
        struct pcib_softc *sc;

        sc = device_get_softc(dev);
        if (!pcib_present(sc)) {
                switch (width) {
                case 2:
                        return (0xffff);
                case 1:
                        return (0xff);
                default:
                        return (0xffffffff);
                }
        }
#endif
        pcib_xlate_ari(dev, b, &s, &f);
        return(PCIB_READ_CONFIG(device_get_parent(device_get_parent(dev)), b, s,
            f, reg, width));
}

static void
pcib_write_config(device_t dev, u_int b, u_int s, u_int f, u_int reg, uint32_t val, int width)
{
#ifdef PCI_HP
        struct pcib_softc *sc;

        sc = device_get_softc(dev);
        if (!pcib_present(sc))
                return;
#endif
        pcib_xlate_ari(dev, b, &s, &f);
        PCIB_WRITE_CONFIG(device_get_parent(device_get_parent(dev)), b, s, f,
            reg, val, width);
}

/*
 * Route an interrupt across a PCI bridge.
 */
int
pcib_route_interrupt(device_t pcib, device_t dev, int pin)
{
    device_t    bus;
    int         parent_intpin;
    int         intnum;

    /*
     *
     * The PCI standard defines a swizzle of the child-side device/intpin to
     * the parent-side intpin as follows.
     *
     * device = device on child bus
     * child_intpin = intpin on child bus slot (0-3)
     * parent_intpin = intpin on parent bus slot (0-3)
     *
     * parent_intpin = (device + child_intpin) % 4
     */
    parent_intpin = (pci_get_slot(dev) + (pin - 1)) % 4;

    /*
     * Our parent is a PCI bus.  Its parent must export the pcib interface
     * which includes the ability to route interrupts.
     */
    bus = device_get_parent(pcib);
    intnum = PCIB_ROUTE_INTERRUPT(device_get_parent(bus), pcib, parent_intpin + 1);
    if (PCI_INTERRUPT_VALID(intnum) && bootverbose) {
        device_printf(pcib, "slot %d INT%c is routed to irq %d\n",
            pci_get_slot(dev), 'A' + pin - 1, intnum);
    }
    return(intnum);
}

/* Pass request to alloc MSI/MSI-X messages up to the parent bridge. */
int
pcib_alloc_msi(device_t pcib, device_t dev, int count, int maxcount, int *irqs)
{
        struct pcib_softc *sc = device_get_softc(pcib);
        device_t bus;

        if (sc->flags & PCIB_DISABLE_MSI)
                return (ENXIO);
        bus = device_get_parent(pcib);
        return (PCIB_ALLOC_MSI(device_get_parent(bus), dev, count, maxcount,
            irqs));
}

/* Pass request to release MSI/MSI-X messages up to the parent bridge. */
int
pcib_release_msi(device_t pcib, device_t dev, int count, int *irqs)
{
        device_t bus;

        bus = device_get_parent(pcib);
        return (PCIB_RELEASE_MSI(device_get_parent(bus), dev, count, irqs));
}

/* Pass request to alloc an MSI-X message up to the parent bridge. */
int
pcib_alloc_msix(device_t pcib, device_t dev, int *irq)
{
        struct pcib_softc *sc = device_get_softc(pcib);
        device_t bus;

        if (sc->flags & PCIB_DISABLE_MSIX)
                return (ENXIO);
        bus = device_get_parent(pcib);
        return (PCIB_ALLOC_MSIX(device_get_parent(bus), dev, irq));
}

/* Pass request to release an MSI-X message up to the parent bridge. */
int
pcib_release_msix(device_t pcib, device_t dev, int irq)
{
        device_t bus;

        bus = device_get_parent(pcib);
        return (PCIB_RELEASE_MSIX(device_get_parent(bus), dev, irq));
}

/* Pass request to map MSI/MSI-X message up to parent bridge. */
int
pcib_map_msi(device_t pcib, device_t dev, int irq, uint64_t *addr,
    uint32_t *data)
{
        device_t bus;
        int error;

        bus = device_get_parent(pcib);
        error = PCIB_MAP_MSI(device_get_parent(bus), dev, irq, addr, data);
        if (error)
                return (error);

        pci_ht_map_msi(pcib, *addr);
        return (0);
}

/* Pass request for device power state up to parent bridge. */
int
pcib_power_for_sleep(device_t pcib, device_t dev, int *pstate)
{
        device_t bus;

        bus = device_get_parent(pcib);
        return (PCIB_POWER_FOR_SLEEP(bus, dev, pstate));
}

static int
pcib_ari_enabled(device_t pcib)
{
        struct pcib_softc *sc;

        sc = device_get_softc(pcib);

        return ((sc->flags & PCIB_ENABLE_ARI) != 0);
}

static int
pcib_ari_get_id(device_t pcib, device_t dev, enum pci_id_type type,
    uintptr_t *id)
{
        struct pcib_softc *sc;
        device_t bus_dev;
        uint8_t bus, slot, func;

        if (type != PCI_ID_RID) {
                bus_dev = device_get_parent(pcib);
                return (PCIB_GET_ID(device_get_parent(bus_dev), dev, type, id));
        }

        sc = device_get_softc(pcib);

        if (sc->flags & PCIB_ENABLE_ARI) {
                bus = pci_get_bus(dev);
                func = pci_get_function(dev);

                *id = (PCI_ARI_RID(bus, func));
        } else {
                bus = pci_get_bus(dev);
                slot = pci_get_slot(dev);
                func = pci_get_function(dev);

                *id = (PCI_RID(bus, slot, func));
        }

        return (0);
}

/*
 * Check that the downstream port (pcib) and the endpoint device (dev) both
 * support ARI.  If so, enable it and return 0, otherwise return an error.
 */
static int
pcib_try_enable_ari(device_t pcib, device_t dev)
{
        struct pcib_softc *sc;
        int error;
        uint32_t cap2;
        int ari_cap_off;
        uint32_t ari_ver;
        uint32_t pcie_pos;

        sc = device_get_softc(pcib);

        /*
         * ARI is controlled in a register in the PCIe capability structure.
         * If the downstream port does not have the PCIe capability structure
         * then it does not support ARI.
         */
        error = pci_find_cap(pcib, PCIY_EXPRESS, &pcie_pos);
        if (error != 0)
                return (ENODEV);

        /* Check that the PCIe port advertises ARI support. */
        cap2 = pci_read_config(pcib, pcie_pos + PCIER_DEVICE_CAP2, 4);
        if (!(cap2 & PCIEM_CAP2_ARI))
                return (ENODEV);

        /*
         * Check that the endpoint device advertises ARI support via the ARI
         * extended capability structure.
         */
        error = pci_find_extcap(dev, PCIZ_ARI, &ari_cap_off);
        if (error != 0)
                return (ENODEV);

        /*
         * Finally, check that the endpoint device supports the same version
         * of ARI that we do.
         */
        ari_ver = pci_read_config(dev, ari_cap_off, 4);
        if (PCI_EXTCAP_VER(ari_ver) != PCIB_SUPPORTED_ARI_VER) {
                if (bootverbose)
                        device_printf(pcib,
                            "Unsupported version of ARI (%d) detected\n",
                            PCI_EXTCAP_VER(ari_ver));

                return (ENXIO);
        }

        pcib_enable_ari(sc, pcie_pos);

        return (0);
}

int
pcib_request_feature_allow(device_t pcib, device_t dev,
    enum pci_feature feature)
{
        /*
         * No host firmware we have to negotiate with, so we allow
         * every valid feature requested.
         */
        switch (feature) {
        case PCI_FEATURE_AER:
        case PCI_FEATURE_HP:
                break;
        default:
                return (EINVAL);
        }

        return (0);
}

int
pcib_request_feature(device_t dev, enum pci_feature feature)
{

        /*
         * Invoke PCIB_REQUEST_FEATURE of this bridge first in case
         * the firmware overrides the method of PCI-PCI bridges.
         */
        return (PCIB_REQUEST_FEATURE(dev, dev, feature));
}

/*
 * Pass the request to use this PCI feature up the tree. Either there's a
 * firmware like ACPI that's using this feature that will approve (or deny) the
 * request to take it over, or the platform has no such firmware, in which case
 * the request will be approved. If the request is approved, the OS is expected
 * to make use of the feature or render it harmless.
 */
static int
pcib_request_feature_default(device_t pcib, device_t dev,
    enum pci_feature feature)
{
        device_t bus;

        /*
         * Our parent is necessarily a pci bus. Its parent will either be
         * another pci bridge (which passes it up) or a host bridge that can
         * approve or reject the request.
         */
        bus = device_get_parent(pcib);
        return (PCIB_REQUEST_FEATURE(device_get_parent(bus), dev, feature));
}

static int
pcib_reset_child(device_t dev, device_t child, int flags)
{
        struct pci_devinfo *pdinfo;
        int error;

        error = 0;
        if (dev == NULL || device_get_parent(child) != dev)
                goto out;
        error = ENXIO;
        if (device_get_devclass(child) != devclass_find("pci"))
                goto out;
        pdinfo = device_get_ivars(dev);
        if (pdinfo->cfg.pcie.pcie_location != 0 &&
            (pdinfo->cfg.pcie.pcie_type == PCIEM_TYPE_DOWNSTREAM_PORT ||
            pdinfo->cfg.pcie.pcie_type == PCIEM_TYPE_ROOT_PORT)) {
                error = bus_helper_reset_prepare(child, flags);
                if (error == 0) {
                        error = pcie_link_reset(dev,
                            pdinfo->cfg.pcie.pcie_location);
                        /* XXXKIB call _post even if error != 0 ? */
                        bus_helper_reset_post(child, flags);
                }
        }
out:
        return (error);
}