/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2015-2016 Landon Fuller <landon@landonf.org>
 * Copyright (c) 2017 The FreeBSD Foundation
 * All rights reserved.
 *
 * Portions of this software were developed by Landon Fuller
 * under sponsorship from the FreeBSD Foundation.
 *
 * 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,
 *    without modification.
 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
 *    similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
 *    redistribution must be conditioned upon including a substantially
 *    similar Disclaimer requirement for further binary redistribution.
 *
 * NO WARRANTY
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
 * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR 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 DAMAGES.
 */

#include <sys/param.h>
#include <sys/bus.h>
#include <sys/refcount.h>
#include <sys/systm.h>

#include <machine/bus.h>
#include <sys/rman.h>
#include <machine/resource.h>

#include <dev/bhnd/siba/sibareg.h>

#include <dev/bhnd/cores/chipc/chipcreg.h>

#include "nvram/bhnd_nvram.h"

#include "bhnd_chipc_if.h"

#include "bhnd_nvram_if.h"
#include "bhnd_nvram_map.h"

#include "bhndreg.h"
#include "bhndvar.h"
#include "bhnd_private.h"

static void     bhnd_service_registry_free_entry(
                    struct bhnd_service_entry *entry);

static int      compare_ascending_probe_order(const void *lhs, const void *rhs);
static int      compare_descending_probe_order(const void *lhs,
                    const void *rhs);

/* BHND core device description table. */
static const struct bhnd_core_desc {
        uint16_t         vendor;
        uint16_t         device;
        bhnd_devclass_t  class;
        const char      *desc;
} bhnd_core_descs[] = {
        #define BHND_CDESC(_mfg, _cid, _cls, _desc)             \
            { BHND_MFGID_ ## _mfg, BHND_COREID_ ## _cid,        \
                BHND_DEVCLASS_ ## _cls, _desc }

        BHND_CDESC(BCM, CC,             CC,             "ChipCommon I/O Controller"),
        BHND_CDESC(BCM, ILINE20,        OTHER,          "iLine20 HPNA"),
        BHND_CDESC(BCM, SRAM,           RAM,            "SRAM"),
        BHND_CDESC(BCM, SDRAM,          RAM,            "SDRAM"),
        BHND_CDESC(BCM, PCI,            PCI,            "PCI Bridge"),
        BHND_CDESC(BCM, MIPS,           CPU,            "BMIPS CPU"),
        BHND_CDESC(BCM, ENET,           ENET_MAC,       "Fast Ethernet MAC"),
        BHND_CDESC(BCM, V90_CODEC,      SOFTMODEM,      "V.90 SoftModem Codec"),
        BHND_CDESC(BCM, USB,            USB_DUAL,       "USB 1.1 Device/Host Controller"),
        BHND_CDESC(BCM, ADSL,           OTHER,          "ADSL Core"),
        BHND_CDESC(BCM, ILINE100,       OTHER,          "iLine100 HPNA"),
        BHND_CDESC(BCM, IPSEC,          OTHER,          "IPsec Accelerator"),
        BHND_CDESC(BCM, UTOPIA,         OTHER,          "UTOPIA ATM Core"),
        BHND_CDESC(BCM, PCMCIA,         PCCARD,         "PCMCIA Bridge"),
        BHND_CDESC(BCM, SOCRAM,         RAM,            "Internal Memory"),
        BHND_CDESC(BCM, MEMC,           MEMC,           "MEMC SDRAM Controller"),
        BHND_CDESC(BCM, OFDM,           OTHER,          "OFDM PHY"),
        BHND_CDESC(BCM, EXTIF,          OTHER,          "External Interface"),
        BHND_CDESC(BCM, D11,            WLAN,           "802.11 MAC/PHY/Radio"),
        BHND_CDESC(BCM, APHY,           WLAN_PHY,       "802.11a PHY"),
        BHND_CDESC(BCM, BPHY,           WLAN_PHY,       "802.11b PHY"),
        BHND_CDESC(BCM, GPHY,           WLAN_PHY,       "802.11g PHY"),
        BHND_CDESC(BCM, MIPS33,         CPU,            "BMIPS33 CPU"),
        BHND_CDESC(BCM, USB11H,         USB_HOST,       "USB 1.1 Host Controller"),
        BHND_CDESC(BCM, USB11D,         USB_DEV,        "USB 1.1 Device Controller"),
        BHND_CDESC(BCM, USB20H,         USB_HOST,       "USB 2.0 Host Controller"),
        BHND_CDESC(BCM, USB20D,         USB_DEV,        "USB 2.0 Device Controller"),
        BHND_CDESC(BCM, SDIOH,          OTHER,          "SDIO Host Controller"),
        BHND_CDESC(BCM, ROBO,           OTHER,          "RoboSwitch"),
        BHND_CDESC(BCM, ATA100,         OTHER,          "Parallel ATA Controller"),
        BHND_CDESC(BCM, SATAXOR,        OTHER,          "SATA DMA/XOR Controller"),
        BHND_CDESC(BCM, GIGETH,         ENET_MAC,       "Gigabit Ethernet MAC"),
        BHND_CDESC(BCM, PCIE,           PCIE,           "PCIe Bridge"),
        BHND_CDESC(BCM, NPHY,           WLAN_PHY,       "802.11n 2x2 PHY"),
        BHND_CDESC(BCM, SRAMC,          MEMC,           "SRAM Controller"),
        BHND_CDESC(BCM, MINIMAC,        OTHER,          "MINI MAC/PHY"),
        BHND_CDESC(BCM, ARM11,          CPU,            "ARM1176 CPU"),
        BHND_CDESC(BCM, ARM7S,          CPU,            "ARM7TDMI-S CPU"),
        BHND_CDESC(BCM, LPPHY,          WLAN_PHY,       "802.11a/b/g PHY"),
        BHND_CDESC(BCM, PMU,            PMU,            "PMU"),
        BHND_CDESC(BCM, SSNPHY,         WLAN_PHY,       "802.11n Single-Stream PHY"),
        BHND_CDESC(BCM, SDIOD,          OTHER,          "SDIO Device Core"),
        BHND_CDESC(BCM, ARMCM3,         CPU,            "ARM Cortex-M3 CPU"),
        BHND_CDESC(BCM, HTPHY,          WLAN_PHY,       "802.11n 4x4 PHY"),
        BHND_CDESC(MIPS,MIPS74K,        CPU,            "MIPS74k CPU"),
        BHND_CDESC(BCM, GMAC,           ENET_MAC,       "Gigabit MAC core"),
        BHND_CDESC(BCM, DMEMC,          MEMC,           "DDR1/DDR2 Memory Controller"),
        BHND_CDESC(BCM, PCIERC,         OTHER,          "PCIe Root Complex"),
        BHND_CDESC(BCM, OCP,            SOC_BRIDGE,     "OCP to OCP Bridge"),
        BHND_CDESC(BCM, SC,             OTHER,          "Shared Common Core"),
        BHND_CDESC(BCM, AHB,            SOC_BRIDGE,     "OCP to AHB Bridge"),
        BHND_CDESC(BCM, SPIH,           OTHER,          "SPI Host Controller"),
        BHND_CDESC(BCM, I2S,            OTHER,          "I2S Digital Audio Interface"),
        BHND_CDESC(BCM, DMEMS,          MEMC,           "SDR/DDR1 Memory Controller"),
        BHND_CDESC(BCM, UBUS_SHIM,      OTHER,          "BCM6362/UBUS WLAN SHIM"),
        BHND_CDESC(BCM, PCIE2,          PCIE,           "PCIe Bridge (Gen2)"),

        BHND_CDESC(ARM, APB_BRIDGE,     SOC_BRIDGE,     "BP135 AMBA3 AXI to APB Bridge"),
        BHND_CDESC(ARM, PL301,          SOC_ROUTER,     "PL301 AMBA3 Interconnect"),
        BHND_CDESC(ARM, EROM,           EROM,           "PL366 Device Enumeration ROM"),
        BHND_CDESC(ARM, OOB_ROUTER,     OTHER,          "PL367 OOB Interrupt Router"),
        BHND_CDESC(ARM, AXI_UNMAPPED,   OTHER,          "Unmapped Address Ranges"),

        BHND_CDESC(BCM, 4706_CC,        CC,             "ChipCommon I/O Controller"),
        BHND_CDESC(BCM, NS_PCIE2,       PCIE,           "PCIe Bridge (Gen2)"),
        BHND_CDESC(BCM, NS_DMA,         OTHER,          "DMA engine"),
        BHND_CDESC(BCM, NS_SDIO,        OTHER,          "SDIO 3.0 Host Controller"),
        BHND_CDESC(BCM, NS_USB20H,      USB_HOST,       "USB 2.0 Host Controller"),
        BHND_CDESC(BCM, NS_USB30H,      USB_HOST,       "USB 3.0 Host Controller"),
        BHND_CDESC(BCM, NS_A9JTAG,      OTHER,          "ARM Cortex A9 JTAG Interface"),
        BHND_CDESC(BCM, NS_DDR23_MEMC,  MEMC,           "Denali DDR2/DD3 Memory Controller"),
        BHND_CDESC(BCM, NS_ROM,         NVRAM,          "System ROM"),
        BHND_CDESC(BCM, NS_NAND,        NVRAM,          "NAND Flash Controller"),
        BHND_CDESC(BCM, NS_QSPI,        NVRAM,          "QSPI Flash Controller"),
        BHND_CDESC(BCM, NS_CC_B,        CC_B,           "ChipCommon B Auxiliary I/O Controller"),
        BHND_CDESC(BCM, 4706_SOCRAM,    RAM,            "Internal Memory"),
        BHND_CDESC(BCM, IHOST_ARMCA9,   CPU,            "ARM Cortex A9 CPU"),
        BHND_CDESC(BCM, 4706_GMAC_CMN,  ENET,           "Gigabit MAC (Common)"),
        BHND_CDESC(BCM, 4706_GMAC,      ENET_MAC,       "Gigabit MAC"),
        BHND_CDESC(BCM, AMEMC,          MEMC,           "Denali DDR1/DDR2 Memory Controller"),
#undef  BHND_CDESC

        /* Derived from inspection of the BCM4331 cores that provide PrimeCell
         * IDs. Due to lack of documentation, the surmised device name/purpose
         * provided here may be incorrect. */
        { BHND_MFGID_ARM,       BHND_PRIMEID_EROM,      BHND_DEVCLASS_OTHER,
            "PL364 Device Enumeration ROM" },
        { BHND_MFGID_ARM,       BHND_PRIMEID_SWRAP,     BHND_DEVCLASS_OTHER,
            "PL368 Device Management Interface" },
        { BHND_MFGID_ARM,       BHND_PRIMEID_MWRAP,     BHND_DEVCLASS_OTHER,
            "PL369 Device Management Interface" },
        { 0, 0, 0, NULL }
};

static const struct bhnd_device_quirk bhnd_chipc_clkctl_quirks[];
static const struct bhnd_device_quirk bhnd_pcmcia_clkctl_quirks[];

/**
 * Device table entries for core-specific CLKCTL quirk lookup.
 */
static const struct bhnd_device bhnd_clkctl_devices[] = {
        BHND_DEVICE(BCM, CC,            NULL,   bhnd_chipc_clkctl_quirks),
        BHND_DEVICE(BCM, PCMCIA,        NULL,   bhnd_pcmcia_clkctl_quirks),
        BHND_DEVICE_END,
};

/** ChipCommon CLKCTL quirks */
static const struct bhnd_device_quirk bhnd_chipc_clkctl_quirks[] = {
        /* HTAVAIL/ALPAVAIL are bitswapped in chipc's CLKCTL */
        BHND_CHIP_QUIRK(4328,   HWREV_ANY,      BHND_CLKCTL_QUIRK_CCS0),
        BHND_CHIP_QUIRK(5354,   HWREV_ANY,      BHND_CLKCTL_QUIRK_CCS0),
        BHND_DEVICE_QUIRK_END
};

/** PCMCIA CLKCTL quirks */
static const struct bhnd_device_quirk bhnd_pcmcia_clkctl_quirks[] = {
        /* HTAVAIL/ALPAVAIL are bitswapped in pcmcia's CLKCTL */
        BHND_CHIP_QUIRK(4328,   HWREV_ANY,      BHND_CLKCTL_QUIRK_CCS0),
        BHND_CHIP_QUIRK(5354,   HWREV_ANY,      BHND_CLKCTL_QUIRK_CCS0),
        BHND_DEVICE_QUIRK_END
};

/**
 * Return the name for a given JEP106 manufacturer ID.
 * 
 * @param vendor A JEP106 Manufacturer ID, including the non-standard ARM 4-bit
 * JEP106 continuation code.
 */
const char *
bhnd_vendor_name(uint16_t vendor)
{
        switch (vendor) {
        case BHND_MFGID_ARM:
                return "ARM";
        case BHND_MFGID_BCM:
                return "Broadcom";
        case BHND_MFGID_MIPS:
                return "MIPS";
        default:
                return "unknown";
        }
}

/**
 * Return the name of a port type.
 * 
 * @param port_type The port type to look up.
 */
const char *
bhnd_port_type_name(bhnd_port_type port_type)
{
        switch (port_type) {
        case BHND_PORT_DEVICE:
                return ("device");
        case BHND_PORT_BRIDGE:
                return ("bridge");
        case BHND_PORT_AGENT:
                return ("agent");
        default:
                return "unknown";
        }
}

/**
 * Return the name of an NVRAM source.
 * 
 * @param nvram_src The NVRAM source type to look up.
 */
const char *
bhnd_nvram_src_name(bhnd_nvram_src nvram_src)
{
        switch (nvram_src) {
        case BHND_NVRAM_SRC_FLASH:
                return ("flash");
        case BHND_NVRAM_SRC_OTP:
                return ("OTP");
        case BHND_NVRAM_SRC_SPROM:
                return ("SPROM");
        case BHND_NVRAM_SRC_UNKNOWN:
                return ("none");
        default:
                return ("unknown");
        }
}

static const struct bhnd_core_desc *
bhnd_find_core_desc(uint16_t vendor, uint16_t device)
{
        for (u_int i = 0; bhnd_core_descs[i].desc != NULL; i++) {
                if (bhnd_core_descs[i].vendor != vendor)
                        continue;
                
                if (bhnd_core_descs[i].device != device)
                        continue;
                
                return (&bhnd_core_descs[i]);
        }

        return (NULL);
}

/**
 * Return a human-readable name for a BHND core.
 * 
 * @param vendor The core designer's JEDEC-106 Manufacturer ID.
 * @param device The core identifier.
 */
const char *
bhnd_find_core_name(uint16_t vendor, uint16_t device)
{
        const struct bhnd_core_desc *desc;

        if ((desc = bhnd_find_core_desc(vendor, device)) == NULL)
                return ("unknown");

        return desc->desc;
}

/**
 * Return the device class for a BHND core.
 * 
 * @param vendor The core designer's JEDEC-106 Manufacturer ID.
 * @param device The core identifier.
 */
bhnd_devclass_t
bhnd_find_core_class(uint16_t vendor, uint16_t device)
{
        const struct bhnd_core_desc *desc;

        if ((desc = bhnd_find_core_desc(vendor, device)) == NULL)
                return (BHND_DEVCLASS_OTHER);

        return desc->class;
}

/**
 * Return a human-readable name for a BHND core.
 * 
 * @param ci The core's info record.
 */
const char *
bhnd_core_name(const struct bhnd_core_info *ci)
{
        return bhnd_find_core_name(ci->vendor, ci->device);
}

/**
 * Return the device class for a BHND core.
 * 
 * @param ci The core's info record.
 */
bhnd_devclass_t
bhnd_core_class(const struct bhnd_core_info *ci)
{
        return bhnd_find_core_class(ci->vendor, ci->device);
}

/**
 * Write a human readable name representation of the given
 * BHND_CHIPID_* constant to @p buffer.
 * 
 * @param buffer Output buffer, or NULL to compute the required size.
 * @param size Capacity of @p buffer, in bytes.
 * @param chip_id Chip ID to be formatted.
 * 
 * @return The required number of bytes on success, or a negative integer on
 * failure. No more than @p size-1 characters be written, with the @p size'th
 * set to '\0'.
 * 
 * @sa BHND_CHIPID_MAX_NAMELEN
 */
int
bhnd_format_chip_id(char *buffer, size_t size, uint16_t chip_id)
{
        /* All hex formatted IDs are within the range of 0x4000-0x9C3F (40000-1) */
        if (chip_id >= 0x4000 && chip_id <= 0x9C3F)
                return (snprintf(buffer, size, "BCM%hX", chip_id));
        else
                return (snprintf(buffer, size, "BCM%hu", chip_id));
}

/**
 * Return a core info record populated from a bhnd-attached @p dev.
 * 
 * @param dev A bhnd device.
 * 
 * @return A core info record for @p dev.
 */
struct bhnd_core_info
bhnd_get_core_info(device_t dev) {
        return (struct bhnd_core_info) {
                .vendor         = bhnd_get_vendor(dev),
                .device         = bhnd_get_device(dev),
                .hwrev          = bhnd_get_hwrev(dev),
                .core_idx       = bhnd_get_core_index(dev),
                .unit           = bhnd_get_core_unit(dev)
        };
}

/**
 * Find a @p class child device with @p unit on @p bus.
 * 
 * @param bus The bhnd-compatible bus to be searched.
 * @param class The device class to match on.
 * @param unit The core unit number; specify -1 to return the first match
 * regardless of unit number.
 * 
 * @retval device_t if a matching child device is found.
 * @retval NULL if no matching child device is found.
 */
device_t
bhnd_bus_find_child(device_t bus, bhnd_devclass_t class, int unit)
{
        struct bhnd_core_match md = {
                BHND_MATCH_CORE_CLASS(class),
                BHND_MATCH_CORE_UNIT(unit)
        };

        if (unit == -1)
                md.m.match.core_unit = 0;

        return bhnd_bus_match_child(bus, &md);
}

/**
 * Find the first child device on @p bus that matches @p desc.
 * 
 * @param bus The bhnd-compatible bus to be searched.
 * @param desc A match descriptor.
 * 
 * @retval device_t if a matching child device is found.
 * @retval NULL if no matching child device is found.
 */
device_t
bhnd_bus_match_child(device_t bus, const struct bhnd_core_match *desc)
{
        device_t        *devlistp;
        device_t         match;
        int              devcnt;
        int              error;

        error = device_get_children(bus, &devlistp, &devcnt);
        if (error != 0)
                return (NULL);

        match = NULL;
        for (int i = 0; i < devcnt; i++) {
                struct bhnd_core_info ci = bhnd_get_core_info(devlistp[i]);

                if (bhnd_core_matches(&ci, desc)) {
                        match = devlistp[i];
                        goto done;
                }
        }

done:
        free(devlistp, M_TEMP);
        return match;
}

/**
 * Retrieve an ordered list of all device instances currently connected to
 * @p bus, returning a pointer to the array in @p devlistp and the count
 * in @p ndevs.
 * 
 * The memory allocated for the table must be freed via
 * bhnd_bus_free_children().
 * 
 * @param       bus             The bhnd-compatible bus to be queried.
 * @param[out]  devlist         The array of devices.
 * @param[out]  devcount        The number of devices in @p devlistp
 * @param       order           The order in which devices will be returned
 *                              in @p devlist.
 * 
 * @retval 0            success
 * @retval non-zero     if an error occurs, a regular unix error code will
 *                      be returned.
 */
int
bhnd_bus_get_children(device_t bus, device_t **devlist, int *devcount,
    bhnd_device_order order)
{
        int error;

        /* Fetch device array */
        if ((error = device_get_children(bus, devlist, devcount)))
                return (error);

        /* Perform requested sorting */
        if ((error = bhnd_sort_devices(*devlist, *devcount, order))) {
                bhnd_bus_free_children(*devlist);
                return (error);
        }

        return (0);
}

/**
 * Free any memory allocated in a previous call to bhnd_bus_get_children().
 *
 * @param devlist The device array returned by bhnd_bus_get_children().
 */
void
bhnd_bus_free_children(device_t *devlist)
{
        free(devlist, M_TEMP);
}

/**
 * Perform in-place sorting of an array of bhnd device instances.
 * 
 * @param devlist       An array of bhnd devices.
 * @param devcount      The number of devices in @p devs.
 * @param order         The sort order to be used.
 * 
 * @retval 0            success
 * @retval EINVAL       if the sort order is unknown.
 */
int
bhnd_sort_devices(device_t *devlist, size_t devcount, bhnd_device_order order)
{
        int (*compare)(const void *, const void *);

        switch (order) {
        case BHND_DEVICE_ORDER_ATTACH:
                compare = compare_ascending_probe_order;
                break;
        case BHND_DEVICE_ORDER_DETACH:
                compare = compare_descending_probe_order;
                break;
        default:
                printf("unknown sort order: %d\n", order);
                return (EINVAL);
        }

        qsort(devlist, devcount, sizeof(*devlist), compare);
        return (0);
}

/*
 * Ascending comparison of bhnd device's probe order.
 */
static int
compare_ascending_probe_order(const void *lhs, const void *rhs)
{
        device_t        ldev, rdev;
        int             lorder, rorder;

        ldev = (*(const device_t *) lhs);
        rdev = (*(const device_t *) rhs);

        lorder = BHND_BUS_GET_PROBE_ORDER(device_get_parent(ldev), ldev);
        rorder = BHND_BUS_GET_PROBE_ORDER(device_get_parent(rdev), rdev);

        if (lorder < rorder) {
                return (-1);
        } else if (lorder > rorder) {
                return (1);
        } else {
                return (0);
        }
}

/*
 * Descending comparison of bhnd device's probe order.
 */
static int
compare_descending_probe_order(const void *lhs, const void *rhs)
{
        return (compare_ascending_probe_order(rhs, lhs));
}

/**
 * Call device_probe_and_attach() for each of the bhnd bus device's
 * children, in bhnd attach order.
 * 
 * @param bus The bhnd-compatible bus for which all children should be probed
 * and attached.
 */
int
bhnd_bus_probe_children(device_t bus)
{
        device_t        *devs;
        int              ndevs;
        int              error;

        /* Fetch children in attach order */
        error = bhnd_bus_get_children(bus, &devs, &ndevs,
            BHND_DEVICE_ORDER_ATTACH);
        if (error)
                return (error);

        /* Probe and attach all children */
        for (int i = 0; i < ndevs; i++) {
                device_t child = devs[i];
                device_probe_and_attach(child);
        }

        bhnd_bus_free_children(devs);

        return (0);
}

/**
 * Walk up the bhnd device hierarchy to locate the root device
 * to which the bhndb bridge is attached.
 * 
 * This can be used from within bhnd host bridge drivers to locate the
 * actual upstream host device.
 * 
 * @param dev A bhnd device.
 * @param bus_class The expected bus (e.g. "pci") to which the bridge root
 * should be attached.
 * 
 * @retval device_t if a matching parent device is found.
 * @retval NULL if @p dev is not attached via a bhndb bus.
 * @retval NULL if no parent device is attached via @p bus_class.
 */
device_t
bhnd_find_bridge_root(device_t dev, devclass_t bus_class)
{
        devclass_t      bhndb_class;
        device_t        parent;

        KASSERT(device_get_devclass(device_get_parent(dev)) ==
            devclass_find("bhnd"),
           ("%s not a bhnd device", device_get_nameunit(dev)));

        bhndb_class = devclass_find("bhndb");

        /* Walk the device tree until we hit a bridge */
        parent = dev;
        while ((parent = device_get_parent(parent)) != NULL) {
                if (device_get_devclass(parent) == bhndb_class)
                        break;
        }

        /* No bridge? */
        if (parent == NULL)
                return (NULL);

        /* Search for a parent attached to the expected bus class */
        while ((parent = device_get_parent(parent)) != NULL) {
                device_t bus;

                bus = device_get_parent(parent);
                if (bus != NULL && device_get_devclass(bus) == bus_class)
                        return (parent);
        }

        /* Not found */
        return (NULL);
}

/**
 * Find the first core in @p cores that matches @p desc.
 * 
 * @param cores The table to search.
 * @param num_cores The length of @p cores.
 * @param desc A match descriptor.
 * 
 * @retval bhnd_core_info if a matching core is found.
 * @retval NULL if no matching core is found.
 */
const struct bhnd_core_info *
bhnd_match_core(const struct bhnd_core_info *cores, u_int num_cores,
    const struct bhnd_core_match *desc)
{
        for (u_int i = 0; i < num_cores; i++) {
                if (bhnd_core_matches(&cores[i], desc))
                        return &cores[i];
        }

        return (NULL);
}

/**
 * Find the first core in @p cores with the given @p class.
 * 
 * @param cores The table to search.
 * @param num_cores The length of @p cores.
 * @param class The device class to match on.
 * 
 * @retval non-NULL if a matching core is found.
 * @retval NULL if no matching core is found.
 */
const struct bhnd_core_info *
bhnd_find_core(const struct bhnd_core_info *cores, u_int num_cores,
    bhnd_devclass_t class)
{
        struct bhnd_core_match md = {
                BHND_MATCH_CORE_CLASS(class)
        };

        return bhnd_match_core(cores, num_cores, &md);
}

/**
 * Create an equality match descriptor for @p core.
 * 
 * @param core The core info to be matched on.
 * 
 * @return an equality match descriptor for @p core.
 */
struct bhnd_core_match
bhnd_core_get_match_desc(const struct bhnd_core_info *core)
{
        return ((struct bhnd_core_match) {
                BHND_MATCH_CORE_VENDOR(core->vendor),
                BHND_MATCH_CORE_ID(core->device),
                BHND_MATCH_CORE_REV(HWREV_EQ(core->hwrev)),
                BHND_MATCH_CORE_CLASS(bhnd_core_class(core)),
                BHND_MATCH_CORE_IDX(core->core_idx),
                BHND_MATCH_CORE_UNIT(core->unit)
        });
}

/**
 * Return true if the @p lhs is equal to @p rhs.
 * 
 * @param lhs The first bhnd core descriptor to compare.
 * @param rhs The second bhnd core descriptor to compare.
 * 
 * @retval true if @p lhs is equal to @p rhs
 * @retval false if @p lhs is not equal to @p rhs
 */
bool
bhnd_cores_equal(const struct bhnd_core_info *lhs,
    const struct bhnd_core_info *rhs)
{
        struct bhnd_core_match md;

        /* Use an equality match descriptor to perform the comparison */
        md = bhnd_core_get_match_desc(rhs);
        return (bhnd_core_matches(lhs, &md));
}

/**
 * Return true if the @p core matches @p desc.
 * 
 * @param core A bhnd core descriptor.
 * @param desc A match descriptor to compare against @p core.
 * 
 * @retval true if @p core matches @p match.
 * @retval false if @p core does not match @p match.
 */
bool
bhnd_core_matches(const struct bhnd_core_info *core,
    const struct bhnd_core_match *desc)
{
        if (desc->m.match.core_vendor && desc->core_vendor != core->vendor)
                return (false);

        if (desc->m.match.core_id && desc->core_id != core->device)
                return (false);

        if (desc->m.match.core_unit && desc->core_unit != core->unit)
                return (false);

        if (desc->m.match.core_rev && 
            !bhnd_hwrev_matches(core->hwrev, &desc->core_rev))
                return (false);

        if (desc->m.match.core_idx && desc->core_idx != core->core_idx)
                return (false);

        if (desc->m.match.core_class &&
            desc->core_class != bhnd_core_class(core))
                return (false);

        return true;
}

/**
 * Return true if the @p chip matches @p desc.
 * 
 * @param chip A bhnd chip identifier.
 * @param desc A match descriptor to compare against @p chip.
 * 
 * @retval true if @p chip matches @p match.
 * @retval false if @p chip does not match @p match.
 */
bool
bhnd_chip_matches(const struct bhnd_chipid *chip,
    const struct bhnd_chip_match *desc)
{
        if (desc->m.match.chip_id && chip->chip_id != desc->chip_id)
                return (false);

        if (desc->m.match.chip_pkg && chip->chip_pkg != desc->chip_pkg)
                return (false);

        if (desc->m.match.chip_rev &&
            !bhnd_hwrev_matches(chip->chip_rev, &desc->chip_rev))
                return (false);

        if (desc->m.match.chip_type && chip->chip_type != desc->chip_type)
                return (false);

        return (true);
}

/**
 * Return true if the @p board matches @p desc.
 * 
 * @param board The bhnd board info.
 * @param desc A match descriptor to compare against @p board.
 * 
 * @retval true if @p chip matches @p match.
 * @retval false if @p chip does not match @p match.
 */
bool
bhnd_board_matches(const struct bhnd_board_info *board,
    const struct bhnd_board_match *desc)
{
        if (desc->m.match.board_srom_rev &&
            !bhnd_hwrev_matches(board->board_srom_rev, &desc->board_srom_rev))
                return (false);

        if (desc->m.match.board_vendor &&
            board->board_vendor != desc->board_vendor)
                return (false);

        if (desc->m.match.board_type && board->board_type != desc->board_type)
                return (false);

        if (desc->m.match.board_devid &&
            board->board_devid != desc->board_devid)
                return (false);

        if (desc->m.match.board_rev &&
            !bhnd_hwrev_matches(board->board_rev, &desc->board_rev))
                return (false);

        return (true);
}

/**
 * Return true if the @p hwrev matches @p desc.
 * 
 * @param hwrev A bhnd hardware revision.
 * @param desc A match descriptor to compare against @p core.
 * 
 * @retval true if @p hwrev matches @p match.
 * @retval false if @p hwrev does not match @p match.
 */
bool
bhnd_hwrev_matches(uint16_t hwrev, const struct bhnd_hwrev_match *desc)
{
        if (desc->start != BHND_HWREV_INVALID &&
            desc->start > hwrev)
                return false;
                
        if (desc->end != BHND_HWREV_INVALID &&
            desc->end < hwrev)
                return false;

        return true;
}

/**
 * Return true if the @p dev matches @p desc.
 * 
 * @param dev A bhnd device.
 * @param desc A match descriptor to compare against @p dev.
 * 
 * @retval true if @p dev matches @p match.
 * @retval false if @p dev does not match @p match.
 */
bool
bhnd_device_matches(device_t dev, const struct bhnd_device_match *desc)
{
        struct bhnd_core_info            core;
        const struct bhnd_chipid        *chip;
        struct bhnd_board_info           board;
        device_t                         parent;
        int                              error;

        /* Construct individual match descriptors */
        struct bhnd_core_match  m_core  = { _BHND_CORE_MATCH_COPY(desc) };
        struct bhnd_chip_match  m_chip  = { _BHND_CHIP_MATCH_COPY(desc) };
        struct bhnd_board_match m_board = { _BHND_BOARD_MATCH_COPY(desc) };

        /* Fetch and match core info */
        if (m_core.m.match_flags) {
                /* Only applicable to bhnd-attached cores */
                parent = device_get_parent(dev);
                if (device_get_devclass(parent) != devclass_find("bhnd")) {
                        device_printf(dev, "attempting to match core "
                            "attributes against non-core device\n");
                        return (false);
                }

                core = bhnd_get_core_info(dev);
                if (!bhnd_core_matches(&core, &m_core))
                        return (false);
        }

        /* Fetch and match chip info */
        if (m_chip.m.match_flags) {
                chip = bhnd_get_chipid(dev);

                if (!bhnd_chip_matches(chip, &m_chip))
                        return (false);
        }

        /* Fetch and match board info.
         *
         * This is not available until  after NVRAM is up; earlier device
         * matches should not include board requirements */
        if (m_board.m.match_flags) {
                if ((error = bhnd_read_board_info(dev, &board))) {
                        device_printf(dev, "failed to read required board info "
                            "during device matching: %d\n", error);
                        return (false);
                }

                if (!bhnd_board_matches(&board, &m_board))
                        return (false);
        }

        /* All matched */
        return (true);
}

/**
 * Search @p table for an entry matching @p dev.
 * 
 * @param dev A bhnd device to match against @p table.
 * @param table The device table to search.
 * @param entry_size The @p table entry size, in bytes.
 * 
 * @retval non-NULL the first matching device, if any.
 * @retval NULL if no matching device is found in @p table.
 */
const struct bhnd_device *
bhnd_device_lookup(device_t dev, const struct bhnd_device *table,
    size_t entry_size)
{
        const struct bhnd_device        *entry;
        device_t                         hostb, parent;
        bhnd_attach_type                 attach_type;
        uint32_t                         dflags;

        parent = device_get_parent(dev);
        hostb = bhnd_bus_find_hostb_device(parent);
        attach_type = bhnd_get_attach_type(dev);

        for (entry = table; !BHND_DEVICE_IS_END(entry); entry =
            (const struct bhnd_device *) ((const char *) entry + entry_size))
        {
                /* match core info */
                if (!bhnd_device_matches(dev, &entry->core))
                        continue;

                /* match device flags */
                dflags = entry->device_flags;

                /* hostb implies BHND_ATTACH_ADAPTER requirement */
                if (dflags & BHND_DF_HOSTB)
                        dflags |= BHND_DF_ADAPTER;

                if (dflags & BHND_DF_ADAPTER)
                        if (attach_type != BHND_ATTACH_ADAPTER)
                                continue;

                if (dflags & BHND_DF_HOSTB)
                        if (dev != hostb)
                                continue;

                if (dflags & BHND_DF_SOC)
                        if (attach_type != BHND_ATTACH_NATIVE)
                                continue;

                /* device found */
                return (entry);
        }

        /* not found */
        return (NULL);
}

/**
 * Scan the device @p table for all quirk flags applicable to @p dev.
 * 
 * @param dev A bhnd device to match against @p table.
 * @param table The device table to search.
 * @param entry_size The @p table entry size, in bytes.
 * 
 * @return all matching quirk flags.
 */
uint32_t
bhnd_device_quirks(device_t dev, const struct bhnd_device *table,
    size_t entry_size)
{
        const struct bhnd_device        *dent;
        const struct bhnd_device_quirk  *qent, *qtable;
        uint32_t                         quirks;

        /* Locate the device entry */
        if ((dent = bhnd_device_lookup(dev, table, entry_size)) == NULL)
                return (0);

        /* Quirks table is optional */
        qtable = dent->quirks_table;
        if (qtable == NULL)
                return (0);

        /* Collect matching device quirk entries */
        quirks = 0;
        for (qent = qtable; !BHND_DEVICE_QUIRK_IS_END(qent); qent++) {
                if (bhnd_device_matches(dev, &qent->desc))
                        quirks |= qent->quirks;
        }

        return (quirks);
}

/**
 * Allocate bhnd(4) resources defined in @p rs from a parent bus.
 * 
 * @param dev The device requesting ownership of the resources.
 * @param rs A standard bus resource specification. This will be updated
 * with the allocated resource's RIDs.
 * @param res On success, the allocated bhnd resources.
 * 
 * @retval 0 success
 * @retval non-zero if allocation of any non-RF_OPTIONAL resource fails,
 *                  all allocated resources will be released and a regular
 *                  unix error code will be returned.
 */
int
bhnd_alloc_resources(device_t dev, struct resource_spec *rs,
    struct bhnd_resource **res)
{
        /* Initialize output array */
        for (u_int i = 0; rs[i].type != -1; i++)
                res[i] = NULL;

        for (u_int i = 0; rs[i].type != -1; i++) {
                res[i] = bhnd_alloc_resource_any(dev, rs[i].type, rs[i].rid,
                    rs[i].flags);

                /* Clean up all allocations on failure */
                if (res[i] == NULL && !(rs[i].flags & RF_OPTIONAL)) {
                        bhnd_release_resources(dev, rs, res);
                        return (ENXIO);
                }
        }

        return (0);
}

/**
 * Release bhnd(4) resources defined in @p rs from a parent bus.
 * 
 * @param dev The device that owns the resources.
 * @param rs A standard bus resource specification previously initialized
 * by @p bhnd_alloc_resources.
 * @param res The bhnd resources to be released.
 */
void
bhnd_release_resources(device_t dev, const struct resource_spec *rs,
    struct bhnd_resource **res)
{
        for (u_int i = 0; rs[i].type != -1; i++) {
                if (res[i] == NULL)
                        continue;

                bhnd_release_resource(dev, res[i]);
                res[i] = NULL;
        }
}

/**
 * Allocate and return a new per-core PMU clock control/status (clkctl)
 * instance for @p dev.
 * 
 * @param dev           The bhnd(4) core device mapped by @p r.
 * @param pmu_dev       The bhnd(4) PMU device, implmenting the bhnd_pmu_if
 *                      interface. The caller is responsible for ensuring that
 *                      this reference remains valid for the lifetime of the
 *                      returned clkctl instance.
 * @param r             A resource mapping the core's clock control register
 *                      (see BHND_CLK_CTL_ST). The caller is responsible for
 *                      ensuring that this resource remains valid for the
 *                      lifetime of the returned clkctl instance.
 * @param offset        The offset to the clock control register within @p r.
 * @param max_latency   The PMU's maximum state transition latency in
 *                      microseconds; this upper bound will be used to busy-wait
 *                      on PMU state transitions.
 * 
 * @retval non-NULL     success
 * @retval NULL         if allocation fails.
 * 
 */
struct bhnd_core_clkctl *
bhnd_alloc_core_clkctl(device_t dev, device_t pmu_dev, struct bhnd_resource *r,
    bus_size_t offset, u_int max_latency)
{
        struct bhnd_core_clkctl *clkctl;

        clkctl = malloc(sizeof(*clkctl), M_BHND, M_ZERO | M_NOWAIT);
        if (clkctl == NULL)
                return (NULL);

        clkctl->cc_dev = dev;
        clkctl->cc_pmu_dev = pmu_dev;
        clkctl->cc_res = r;
        clkctl->cc_res_offset = offset;
        clkctl->cc_max_latency = max_latency;
        clkctl->cc_quirks = bhnd_device_quirks(dev, bhnd_clkctl_devices,
            sizeof(bhnd_clkctl_devices[0]));

        BHND_CLKCTL_LOCK_INIT(clkctl);

        return (clkctl);
}

/**
 * Free a clkctl instance previously allocated via bhnd_alloc_core_clkctl().
 * 
 * @param clkctl        The clkctl instance to be freed.
 */
void
bhnd_free_core_clkctl(struct bhnd_core_clkctl *clkctl)
{
        BHND_CLKCTL_LOCK_DESTROY(clkctl);

        free(clkctl, M_BHND);
}

/**
 * Wait for the per-core clock status to be equal to @p value after
 * applying @p mask, timing out after the maximum transition latency is reached.
 * 
 * @param clkctl        Per-core clkctl state to be queryied.
 * @param value         Value to wait for.
 * @param mask          Mask to apply prior to value comparison.
 * 
 * @retval 0            success
 * @retval ETIMEDOUT    if the PMU's maximum transition delay is reached before
 *                      the clock status matches @p value and @p mask.
 */
int
bhnd_core_clkctl_wait(struct bhnd_core_clkctl *clkctl, uint32_t value,
    uint32_t mask)
{
        uint32_t        clkst;

        BHND_CLKCTL_LOCK_ASSERT(clkctl, MA_OWNED);

        /* Bitswapped HTAVAIL/ALPAVAIL work-around */
        if (clkctl->cc_quirks & BHND_CLKCTL_QUIRK_CCS0) {
                uint32_t fmask, fval;

                fmask = mask & ~(BHND_CCS_HTAVAIL | BHND_CCS_ALPAVAIL);
                fval = value & ~(BHND_CCS_HTAVAIL | BHND_CCS_ALPAVAIL);

                if (mask & BHND_CCS_HTAVAIL)
                        fmask |= BHND_CCS0_HTAVAIL;
                if (value & BHND_CCS_HTAVAIL)
                        fval |= BHND_CCS0_HTAVAIL;

                if (mask & BHND_CCS_ALPAVAIL) 
                        fmask |= BHND_CCS0_ALPAVAIL;
                if (value & BHND_CCS_ALPAVAIL)
                        fval |= BHND_CCS0_ALPAVAIL;

                mask = fmask;
                value = fval;
        }

        for (u_int i = 0; i < clkctl->cc_max_latency; i += 10) {
                clkst = bhnd_bus_read_4(clkctl->cc_res, clkctl->cc_res_offset);
                if ((clkst & mask) == (value & mask))
                        return (0);

                DELAY(10);
        }

        device_printf(clkctl->cc_dev, "clkst wait timeout (value=%#x, "
            "mask=%#x)\n", value, mask);

        return (ETIMEDOUT);
}

/**
 * Read an NVRAM variable's NUL-terminated string value.
 *
 * @param       dev     A bhnd bus child device.
 * @param       name    The NVRAM variable name.
 * @param[out]  buf     A buffer large enough to hold @p len bytes. On
 *                      success, the NUL-terminated string value will be
 *                      written to this buffer. This argment may be NULL if
 *                      the value is not desired.
 * @param       len     The maximum capacity of @p buf.
 * @param[out]  rlen    On success, will be set to the actual size of
 *                      the requested value (including NUL termination). This
 *                      argment may be NULL if the size is not desired.
 *
 * @retval 0            success
 * @retval ENOENT       The requested variable was not found.
 * @retval ENODEV       No valid NVRAM source could be found.
 * @retval ENOMEM       If @p buf is non-NULL and a buffer of @p len is too
 *                      small to hold the requested value.
 * @retval EFTYPE       If the variable data cannot be coerced to a valid
 *                      string representation.
 * @retval ERANGE       If value coercion would overflow @p type.
 * @retval non-zero     If reading @p name otherwise fails, a regular unix
 *                      error code will be returned.
 */
int
bhnd_nvram_getvar_str(device_t dev, const char *name, char *buf, size_t len,
    size_t *rlen)
{
        size_t  larg;
        int     error;

        larg = len;
        error = bhnd_nvram_getvar(dev, name, buf, &larg,
            BHND_NVRAM_TYPE_STRING);
        if (rlen != NULL)
                *rlen = larg;

        return (error);
}

/**
 * Read an NVRAM variable's unsigned integer value.
 *
 * @param               dev     A bhnd bus child device.
 * @param               name    The NVRAM variable name.
 * @param[out]          value   On success, the requested value will be written
 *                              to this pointer.
 * @param               width   The output integer type width (1, 2, or
 *                              4 bytes).
 * 
 * @retval 0            success
 * @retval ENOENT       The requested variable was not found.
 * @retval ENODEV       No valid NVRAM source could be found.
 * @retval EFTYPE       If the variable data cannot be coerced to a
 *                      a valid unsigned integer representation.
 * @retval ERANGE       If value coercion would overflow (or underflow) an
 *                      unsigned representation of the given @p width.
 * @retval non-zero     If reading @p name otherwise fails, a regular unix
 *                      error code will be returned.
 */
int
bhnd_nvram_getvar_uint(device_t dev, const char *name, void *value, int width)
{
        bhnd_nvram_type type;
        size_t          len;

        switch (width) {
        case 1:
                type = BHND_NVRAM_TYPE_UINT8;
                break;
        case 2:
                type = BHND_NVRAM_TYPE_UINT16;
                break;
        case 4:
                type = BHND_NVRAM_TYPE_UINT32;
                break;
        default:
                device_printf(dev, "unsupported NVRAM integer width: %d\n",
                    width);
                return (EINVAL);
        }

        len = width;
        return (bhnd_nvram_getvar(dev, name, value, &len, type));
}

/**
 * Read an NVRAM variable's unsigned 8-bit integer value.
 *
 * @param               dev     A bhnd bus child device.
 * @param               name    The NVRAM variable name.
 * @param[out]          value   On success, the requested value will be written
 *                              to this pointer.
 * 
 * @retval 0            success
 * @retval ENOENT       The requested variable was not found.
 * @retval ENODEV       No valid NVRAM source could be found.
 * @retval EFTYPE       If the variable data cannot be coerced to a
 *                      a valid unsigned integer representation.
 * @retval ERANGE       If value coercion would overflow (or underflow) uint8_t.
 * @retval non-zero     If reading @p name otherwise fails, a regular unix
 *                      error code will be returned.
 */
int
bhnd_nvram_getvar_uint8(device_t dev, const char *name, uint8_t *value)
{
        return (bhnd_nvram_getvar_uint(dev, name, value, sizeof(*value)));
}

/**
 * Read an NVRAM variable's unsigned 16-bit integer value.
 *
 * @param               dev     A bhnd bus child device.
 * @param               name    The NVRAM variable name.
 * @param[out]          value   On success, the requested value will be written
 *                              to this pointer.
 * 
 * @retval 0            success
 * @retval ENOENT       The requested variable was not found.
 * @retval ENODEV       No valid NVRAM source could be found.
 * @retval EFTYPE       If the variable data cannot be coerced to a
 *                      a valid unsigned integer representation.
 * @retval ERANGE       If value coercion would overflow (or underflow)
 *                      uint16_t.
 * @retval non-zero     If reading @p name otherwise fails, a regular unix
 *                      error code will be returned.
 */
int
bhnd_nvram_getvar_uint16(device_t dev, const char *name, uint16_t *value)
{
        return (bhnd_nvram_getvar_uint(dev, name, value, sizeof(*value)));
}

/**
 * Read an NVRAM variable's unsigned 32-bit integer value.
 *
 * @param               dev     A bhnd bus child device.
 * @param               name    The NVRAM variable name.
 * @param[out]          value   On success, the requested value will be written
 *                              to this pointer.
 * 
 * @retval 0            success
 * @retval ENOENT       The requested variable was not found.
 * @retval ENODEV       No valid NVRAM source could be found.
 * @retval EFTYPE       If the variable data cannot be coerced to a
 *                      a valid unsigned integer representation.
 * @retval ERANGE       If value coercion would overflow (or underflow)
 *                      uint32_t.
 * @retval non-zero     If reading @p name otherwise fails, a regular unix
 *                      error code will be returned.
 */
int
bhnd_nvram_getvar_uint32(device_t dev, const char *name, uint32_t *value)
{
        return (bhnd_nvram_getvar_uint(dev, name, value, sizeof(*value)));
}

/**
 * Read an NVRAM variable's signed integer value.
 *
 * @param               dev     A bhnd bus child device.
 * @param               name    The NVRAM variable name.
 * @param[out]          value   On success, the requested value will be written
 *                              to this pointer.
 * @param               width   The output integer type width (1, 2, or
 *                              4 bytes).
 * 
 * @retval 0            success
 * @retval ENOENT       The requested variable was not found.
 * @retval ENODEV       No valid NVRAM source could be found.
 * @retval EFTYPE       If the variable data cannot be coerced to a
 *                      a valid integer representation.
 * @retval ERANGE       If value coercion would overflow (or underflow) an
 *                      signed representation of the given @p width.
 * @retval non-zero     If reading @p name otherwise fails, a regular unix
 *                      error code will be returned.
 */
int
bhnd_nvram_getvar_int(device_t dev, const char *name, void *value, int width)
{
        bhnd_nvram_type type;
        size_t          len;

        switch (width) {
        case 1:
                type = BHND_NVRAM_TYPE_INT8;
                break;
        case 2:
                type = BHND_NVRAM_TYPE_INT16;
                break;
        case 4:
                type = BHND_NVRAM_TYPE_INT32;
                break;
        default:
                device_printf(dev, "unsupported NVRAM integer width: %d\n",
                    width);
                return (EINVAL);
        }

        len = width;
        return (bhnd_nvram_getvar(dev, name, value, &len, type));
}

/**
 * Read an NVRAM variable's signed 8-bit integer value.
 *
 * @param               dev     A bhnd bus child device.
 * @param               name    The NVRAM variable name.
 * @param[out]          value   On success, the requested value will be written
 *                              to this pointer.
 * 
 * @retval 0            success
 * @retval ENOENT       The requested variable was not found.
 * @retval ENODEV       No valid NVRAM source could be found.
 * @retval EFTYPE       If the variable data cannot be coerced to a
 *                      a valid integer representation.
 * @retval ERANGE       If value coercion would overflow (or underflow) int8_t.
 * @retval non-zero     If reading @p name otherwise fails, a regular unix
 *                      error code will be returned.
 */
int
bhnd_nvram_getvar_int8(device_t dev, const char *name, int8_t *value)
{
        return (bhnd_nvram_getvar_int(dev, name, value, sizeof(*value)));
}

/**
 * Read an NVRAM variable's signed 16-bit integer value.
 *
 * @param               dev     A bhnd bus child device.
 * @param               name    The NVRAM variable name.
 * @param[out]          value   On success, the requested value will be written
 *                              to this pointer.
 * 
 * @retval 0            success
 * @retval ENOENT       The requested variable was not found.
 * @retval ENODEV       No valid NVRAM source could be found.
 * @retval EFTYPE       If the variable data cannot be coerced to a
 *                      a valid integer representation.
 * @retval ERANGE       If value coercion would overflow (or underflow)
 *                      int16_t.
 * @retval non-zero     If reading @p name otherwise fails, a regular unix
 *                      error code will be returned.
 */
int
bhnd_nvram_getvar_int16(device_t dev, const char *name, int16_t *value)
{
        return (bhnd_nvram_getvar_int(dev, name, value, sizeof(*value)));
}

/**
 * Read an NVRAM variable's signed 32-bit integer value.
 *
 * @param               dev     A bhnd bus child device.
 * @param               name    The NVRAM variable name.
 * @param[out]          value   On success, the requested value will be written
 *                              to this pointer.
 * 
 * @retval 0            success
 * @retval ENOENT       The requested variable was not found.
 * @retval ENODEV       No valid NVRAM source could be found.
 * @retval EFTYPE       If the variable data cannot be coerced to a
 *                      a valid integer representation.
 * @retval ERANGE       If value coercion would overflow (or underflow)
 *                      int32_t.
 * @retval non-zero     If reading @p name otherwise fails, a regular unix
 *                      error code will be returned.
 */
int
bhnd_nvram_getvar_int32(device_t dev, const char *name, int32_t *value)
{
        return (bhnd_nvram_getvar_int(dev, name, value, sizeof(*value)));
}

/**
 * Read an NVRAM variable's array value.
 *
 * @param               dev     A bhnd bus child device.
 * @param               name    The NVRAM variable name.
 * @param[out]          buf     A buffer large enough to hold @p size bytes.
 *                              On success, the requested value will be written
 *                              to this buffer.
 * @param[in,out]       size    The required number of bytes to write to
 *                              @p buf.
 * @param               type    The desired array element data representation.
 * 
 * @retval 0            success
 * @retval ENOENT       The requested variable was not found.
 * @retval ENODEV       No valid NVRAM source could be found.
 * @retval ENXIO        If less than @p size bytes are available.
 * @retval ENOMEM       If a buffer of @p size is too small to hold the
 *                      requested value.
 * @retval EFTYPE       If the variable data cannot be coerced to a
 *                      a valid instance of @p type.
 * @retval ERANGE       If value coercion would overflow (or underflow) a
 *                      representation of @p type.
 * @retval non-zero     If reading @p name otherwise fails, a regular unix
 *                      error code will be returned.
 */
int
bhnd_nvram_getvar_array(device_t dev, const char *name, void *buf, size_t size,
    bhnd_nvram_type type)
{
        size_t  nbytes;
        int     error;

        /* Attempt read */
        nbytes = size;
        if ((error = bhnd_nvram_getvar(dev, name, buf, &nbytes, type)))
                return (error);

        /* Verify that the expected number of bytes were fetched */
        if (nbytes < size)
                return (ENXIO);

        return (0);
}

/**
 * Initialize a service provider registry.
 * 
 * @param bsr           The service registry to initialize.
 * 
 * @retval 0            success
 * @retval non-zero     if an error occurs initializing the service registry,
 *                      a regular unix error code will be returned.

 */
int
bhnd_service_registry_init(struct bhnd_service_registry *bsr)
{
        STAILQ_INIT(&bsr->entries);
        mtx_init(&bsr->lock, "bhnd_service_registry lock", NULL, MTX_DEF);

        return (0);
}

/**
 * Release all resources held by @p bsr.
 * 
 * @param bsr           A service registry instance previously successfully
 *                      initialized via bhnd_service_registry_init().
 *
 * @retval 0            success
 * @retval EBUSY        if active references to service providers registered
 *                      with @p bsr exist.
 */
int
bhnd_service_registry_fini(struct bhnd_service_registry *bsr)
{
        struct bhnd_service_entry *entry, *enext;

        /* Remove everthing we can */
        mtx_lock(&bsr->lock);
        STAILQ_FOREACH_SAFE(entry, &bsr->entries, link, enext) {
                if (entry->refs > 0)
                        continue;

                STAILQ_REMOVE(&bsr->entries, entry, bhnd_service_entry, link);
                free(entry, M_BHND);
        }

        if (!STAILQ_EMPTY(&bsr->entries)) {
                mtx_unlock(&bsr->lock);
                return (EBUSY);
        }
        mtx_unlock(&bsr->lock);

        mtx_destroy(&bsr->lock);
        return (0);
}

/**
 * Register a @p provider for the given @p service.
 *
 * @param bsr           Service registry to be modified.
 * @param provider      Service provider to register.
 * @param service       Service for which @p provider will be registered.
 * @param flags         Service provider flags (see BHND_SPF_*).
 *
 * @retval 0            success
 * @retval EEXIST       if an entry for @p service already exists.
 * @retval EINVAL       if @p service is BHND_SERVICE_ANY.
 * @retval non-zero     if registering @p provider otherwise fails, a regular
 *                      unix error code will be returned.
 */
int
bhnd_service_registry_add(struct bhnd_service_registry *bsr, device_t provider,
    bhnd_service_t service, uint32_t flags)
{
        struct bhnd_service_entry *entry;

        if (service == BHND_SERVICE_ANY)
                return (EINVAL);

        mtx_lock(&bsr->lock);

        /* Is a service provider already registered? */
        STAILQ_FOREACH(entry, &bsr->entries, link) {
                if (entry->service == service) {
                        mtx_unlock(&bsr->lock);
                        return (EEXIST);
                }
        }

        /* Initialize and insert our new entry */
        entry = malloc(sizeof(*entry), M_BHND, M_NOWAIT);
        if (entry == NULL) {
                mtx_unlock(&bsr->lock);
                return (ENOMEM);
        }

        entry->provider = provider;
        entry->service = service;
        entry->flags = flags;
        refcount_init(&entry->refs, 0);

        STAILQ_INSERT_HEAD(&bsr->entries, entry, link);

        mtx_unlock(&bsr->lock);
        return (0);
}

/**
 * Free an unreferenced registry entry.
 * 
 * @param entry The entry to be deallocated.
 */
static void
bhnd_service_registry_free_entry(struct bhnd_service_entry *entry)
{
        KASSERT(entry->refs == 0, ("provider has active references"));
        free(entry, M_BHND);
}

/**
 * Attempt to remove the @p service provider registration for @p provider.
 *
 * @param bsr           The service registry to be modified.
 * @param provider      The service provider to be deregistered.
 * @param service       The service for which @p provider will be deregistered,
 *                      or BHND_SERVICE_ANY to remove all service
 *                      registrations for @p provider.
 *
 * @retval 0            success
 * @retval EBUSY        if active references to @p provider exist; see
 *                      bhnd_service_registry_retain() and
 *                      bhnd_service_registry_release().
 */
int
bhnd_service_registry_remove(struct bhnd_service_registry *bsr,
    device_t provider, bhnd_service_t service)
{
        struct bhnd_service_entry *entry, *enext;

        mtx_lock(&bsr->lock);

#define BHND_PROV_MATCH(_e)     \
        ((_e)->provider == provider &&  \
         (service == BHND_SERVICE_ANY || (_e)->service == service))

        /* Validate matching provider entries before making any
         * modifications */
        STAILQ_FOREACH(entry, &bsr->entries, link) {
                /* Skip non-matching entries */
                if (!BHND_PROV_MATCH(entry))
                        continue;

                /* Entry is in use? */
                if (entry->refs > 0) {
                        mtx_unlock(&bsr->lock);
                        return (EBUSY);
                }
        }

        /* We can now safely remove matching entries */
        STAILQ_FOREACH_SAFE(entry, &bsr->entries, link, enext) {
                /* Skip non-matching entries */
                if (!BHND_PROV_MATCH(entry))
                        continue;

                /* Remove from list */
                STAILQ_REMOVE(&bsr->entries, entry, bhnd_service_entry, link);

                /* Free provider entry */
                bhnd_service_registry_free_entry(entry);
        }
#undef  BHND_PROV_MATCH

        mtx_unlock(&bsr->lock);
        return (0);
}

/**
 * Retain and return a reference to a registered @p service provider, if any.
 *
 * @param bsr           The service registry to be queried.
 * @param service       The service for which a provider should be returned.
 *
 * On success, the caller assumes ownership the returned provider, and
 * is responsible for releasing this reference via
 * bhnd_service_registry_release().
 *
 * @retval device_t     success
 * @retval NULL         if no provider is registered for @p service.
 */
device_t
bhnd_service_registry_retain(struct bhnd_service_registry *bsr,
    bhnd_service_t service)
{
        struct bhnd_service_entry *entry;

        mtx_lock(&bsr->lock);
        STAILQ_FOREACH(entry, &bsr->entries, link) {
                if (entry->service != service)
                        continue;

                /* With a live refcount, entry is gauranteed to remain alive
                 * after we release our lock */
                refcount_acquire(&entry->refs);

                mtx_unlock(&bsr->lock);
                return (entry->provider);
        }
        mtx_unlock(&bsr->lock);

        /* Not found */
        return (NULL);
}

/**
 * Release a reference to a service provider previously returned by
 * bhnd_service_registry_retain().
 * 
 * If this is the last reference to an inherited service provider registration
 * (see BHND_SPF_INHERITED), the registration will also be removed, and
 * true will be returned.
 *
 * @param bsr           The service registry from which @p provider
 *                      was returned.
 * @param provider      The provider to be released.
 * @param service       The service for which @p provider was previously
 *                      retained.
 * @retval true         The inherited service provider registration was removed;
 *                      the caller should release its own reference to the
 *                      provider.
 * @retval false        The service provider was not inherited, or active
 *                      references to the provider remain.
 * 
 * @see BHND_SPF_INHERITED
 */
bool
bhnd_service_registry_release(struct bhnd_service_registry *bsr,
    device_t provider, bhnd_service_t service)
{
        struct bhnd_service_entry *entry;

        /* Exclusive lock, as we need to prevent any new references to the
         * entry from being taken if it's to be removed */
        mtx_lock(&bsr->lock);
        STAILQ_FOREACH(entry, &bsr->entries, link) {
                bool removed;

                if (entry->provider != provider)
                        continue;

                if (entry->service != service)
                        continue;

                if (refcount_release(&entry->refs) &&
                    (entry->flags & BHND_SPF_INHERITED))
                {
                        /* If an inherited entry is no longer actively
                         * referenced, remove the local registration and inform
                         * the caller. */
                        STAILQ_REMOVE(&bsr->entries, entry, bhnd_service_entry,
                            link);
                        bhnd_service_registry_free_entry(entry);
                        removed = true;
                } else {
                        removed = false;
                }

                mtx_unlock(&bsr->lock);
                return (removed);
        }

        /* Caller owns a reference, but no such provider is registered? */
        panic("invalid service provider reference");
}

/**
 * Using the bhnd(4) bus-level core information and a custom core name,
 * populate @p dev's device description.
 * 
 * @param dev A bhnd-bus attached device.
 * @param dev_name The core's name (e.g. "SDIO Device Core").
 */
void
bhnd_set_custom_core_desc(device_t dev, const char *dev_name)
{
        const char *vendor_name;

        vendor_name = bhnd_get_vendor_name(dev);
        device_set_descf(dev, "%s %s, rev %hhu", vendor_name, dev_name,
            bhnd_get_hwrev(dev));
}

/**
 * Using the bhnd(4) bus-level core information, populate @p dev's device
 * description.
 * 
 * @param dev A bhnd-bus attached device.
 */
void
bhnd_set_default_core_desc(device_t dev)
{
        bhnd_set_custom_core_desc(dev, bhnd_get_device_name(dev));
}

/**
 * Using the bhnd @p chip_id, populate the bhnd(4) bus @p dev's device
 * description.
 * 
 * @param dev A bhnd-bus attached device.
 * @param chip_id The chip identification.
 */
void
bhnd_set_default_bus_desc(device_t dev, const struct bhnd_chipid *chip_id)
{
        const char      *bus_name;
        char             chip_name[BHND_CHIPID_MAX_NAMELEN];

        /* Determine chip type's bus name */
        switch (chip_id->chip_type) {
        case BHND_CHIPTYPE_SIBA:
                bus_name = "SIBA bus";
                break;
        case BHND_CHIPTYPE_BCMA:
        case BHND_CHIPTYPE_BCMA_ALT:
                bus_name = "BCMA bus";
                break;
        case BHND_CHIPTYPE_UBUS:
                bus_name = "UBUS bus";
                break;
        default:
                bus_name = "Unknown Type";
                break;
        }

        /* Format chip name */
        bhnd_format_chip_id(chip_name, sizeof(chip_name),
             chip_id->chip_id);

        /* Format and set device description */
        device_set_descf(dev, "%s %s", chip_name, bus_name);
}

/**
 * Helper function for implementing BHND_BUS_REGISTER_PROVIDER().
 * 
 * This implementation delegates the request to the BHND_BUS_REGISTER_PROVIDER()
 * method on the parent of @p dev. If no parent exists, the implementation
 * will return an error. 
 */
int
bhnd_bus_generic_register_provider(device_t dev, device_t child,
    device_t provider, bhnd_service_t service)
{
        device_t parent = device_get_parent(dev);

        if (parent != NULL) {
                return (BHND_BUS_REGISTER_PROVIDER(parent, child,
                    provider, service));
        }

        return (ENXIO);
}

/**
 * Helper function for implementing BHND_BUS_DEREGISTER_PROVIDER().
 * 
 * This implementation delegates the request to the
 * BHND_BUS_DEREGISTER_PROVIDER() method on the parent of @p dev. If no parent
 * exists, the implementation will panic.
 */
int
bhnd_bus_generic_deregister_provider(device_t dev, device_t child,
    device_t provider, bhnd_service_t service)
{
        device_t parent = device_get_parent(dev);

        if (parent != NULL) {
                return (BHND_BUS_DEREGISTER_PROVIDER(parent, child,
                    provider, service));
        }

        panic("missing BHND_BUS_DEREGISTER_PROVIDER()");
}

/**
 * Helper function for implementing BHND_BUS_RETAIN_PROVIDER().
 * 
 * This implementation delegates the request to the
 * BHND_BUS_DEREGISTER_PROVIDER() method on the parent of @p dev. If no parent
 * exists, the implementation will return NULL.
 */
device_t
bhnd_bus_generic_retain_provider(device_t dev, device_t child,
    bhnd_service_t service)
{
        device_t parent = device_get_parent(dev);

        if (parent != NULL) {
                return (BHND_BUS_RETAIN_PROVIDER(parent, child,
                    service));
        }

        return (NULL);
}

/**
 * Helper function for implementing BHND_BUS_RELEASE_PROVIDER().
 * 
 * This implementation delegates the request to the
 * BHND_BUS_DEREGISTER_PROVIDER() method on the parent of @p dev. If no parent
 * exists, the implementation will panic.
 */
void
bhnd_bus_generic_release_provider(device_t dev, device_t child,
    device_t provider, bhnd_service_t service)
{
        device_t parent = device_get_parent(dev);

        if (parent != NULL) {
                return (BHND_BUS_RELEASE_PROVIDER(parent, child,
                    provider, service));
        }

        panic("missing BHND_BUS_RELEASE_PROVIDER()");
}

/**
 * Helper function for implementing BHND_BUS_REGISTER_PROVIDER().
 * 
 * This implementation uses the bhnd_service_registry_add() function to
 * do most of the work. It calls BHND_BUS_GET_SERVICE_REGISTRY() to find
 * a suitable service registry to edit.
 */
int
bhnd_bus_generic_sr_register_provider(device_t dev, device_t child,
    device_t provider, bhnd_service_t service)
{
        struct bhnd_service_registry *bsr;

        bsr = BHND_BUS_GET_SERVICE_REGISTRY(dev, child);

        KASSERT(bsr != NULL, ("NULL service registry"));

        return (bhnd_service_registry_add(bsr, provider, service, 0));
}

/**
 * Helper function for implementing BHND_BUS_DEREGISTER_PROVIDER().
 * 
 * This implementation uses the bhnd_service_registry_remove() function to
 * do most of the work. It calls BHND_BUS_GET_SERVICE_REGISTRY() to find
 * a suitable service registry to edit.
 */
int
bhnd_bus_generic_sr_deregister_provider(device_t dev, device_t child,
    device_t provider, bhnd_service_t service)
{
        struct bhnd_service_registry *bsr;

        bsr = BHND_BUS_GET_SERVICE_REGISTRY(dev, child);

        KASSERT(bsr != NULL, ("NULL service registry"));

        return (bhnd_service_registry_remove(bsr, provider, service));
}

/**
 * Helper function for implementing BHND_BUS_RETAIN_PROVIDER().
 * 
 * This implementation uses the bhnd_service_registry_retain() function to
 * do most of the work. It calls BHND_BUS_GET_SERVICE_REGISTRY() to find
 * a suitable service registry.
 * 
 * If a local provider for the service is not available, and a parent device is
 * available, this implementation will attempt to fetch and locally register
 * a service provider reference from the parent of @p dev.
 */
device_t
bhnd_bus_generic_sr_retain_provider(device_t dev, device_t child,
    bhnd_service_t service)
{
        struct bhnd_service_registry    *bsr;
        device_t                         parent, provider;
        int                              error;

        bsr = BHND_BUS_GET_SERVICE_REGISTRY(dev, child);
        KASSERT(bsr != NULL, ("NULL service registry"));

        /*
         * Attempt to fetch a service provider reference from either the local
         * service registry, or if not found, from our parent.
         * 
         * If we fetch a provider from our parent, we register the provider
         * with the local service registry to prevent conflicting local
         * registrations from being added.
         */
        while (1) {
                /* Check the local service registry first */
                provider = bhnd_service_registry_retain(bsr, service);
                if (provider != NULL)
                        return (provider);

                /* Otherwise, try to delegate to our parent (if any) */
                if ((parent = device_get_parent(dev)) == NULL)
                        return (NULL);

                provider = BHND_BUS_RETAIN_PROVIDER(parent, dev, service);
                if (provider == NULL)
                        return (NULL);

                /* Register the inherited service registration with the local
                 * registry */
                error = bhnd_service_registry_add(bsr, provider, service,
                    BHND_SPF_INHERITED);
                if (error) {
                        BHND_BUS_RELEASE_PROVIDER(parent, dev, provider,
                            service);
                        if (error == EEXIST) {
                                /* A valid service provider was registered
                                 * concurrently; retry fetching from the local
                                 * registry */
                                continue;
                        }

                        device_printf(dev, "failed to register service "
                            "provider: %d\n", error);
                        return (NULL);
                }
        }
}

/**
 * Helper function for implementing BHND_BUS_RELEASE_PROVIDER().
 * 
 * This implementation uses the bhnd_service_registry_release() function to
 * do most of the work. It calls BHND_BUS_GET_SERVICE_REGISTRY() to find
 * a suitable service registry.
 */
void
bhnd_bus_generic_sr_release_provider(device_t dev, device_t child,
    device_t provider, bhnd_service_t service)
{
        struct bhnd_service_registry    *bsr;

        bsr = BHND_BUS_GET_SERVICE_REGISTRY(dev, child);
        KASSERT(bsr != NULL, ("NULL service registry"));

        /* Release the provider reference; if the refcount hits zero on an
         * inherited reference, true will be returned, and we need to drop
         * our own bus reference to the provider */
        if (!bhnd_service_registry_release(bsr, provider, service))
                return;

        /* Drop our reference to the borrowed provider */
        BHND_BUS_RELEASE_PROVIDER(device_get_parent(dev), dev, provider,
            service);
}

/**
 * Helper function for implementing BHND_BUS_IS_HW_DISABLED().
 * 
 * If a parent device is available, this implementation delegates the
 * request to the BHND_BUS_IS_HW_DISABLED() method on the parent of @p dev.
 * 
 * If no parent device is available (i.e. on a the bus root), the hardware
 * is assumed to be usable and false is returned.
 */
bool
bhnd_bus_generic_is_hw_disabled(device_t dev, device_t child)
{
        if (device_get_parent(dev) != NULL)
                return (BHND_BUS_IS_HW_DISABLED(device_get_parent(dev), child));

        return (false);
}

/**
 * Helper function for implementing BHND_BUS_GET_CHIPID().
 * 
 * This implementation delegates the request to the BHND_BUS_GET_CHIPID()
 * method on the parent of @p dev. If no parent exists, the implementation
 * will panic.
 */
const struct bhnd_chipid *
bhnd_bus_generic_get_chipid(device_t dev, device_t child)
{
        if (device_get_parent(dev) != NULL)
                return (BHND_BUS_GET_CHIPID(device_get_parent(dev), child));

        panic("missing BHND_BUS_GET_CHIPID()");
}

/**
 * Helper function for implementing BHND_BUS_GET_DMA_TRANSLATION().
 * 
 * If a parent device is available, this implementation delegates the
 * request to the BHND_BUS_GET_DMA_TRANSLATION() method on the parent of @p dev.
 *
 * If no parent device is available, this implementation will panic.
 */
int
bhnd_bus_generic_get_dma_translation(device_t dev, device_t child, u_int width,
    uint32_t flags, bus_dma_tag_t *dmat,
    struct bhnd_dma_translation *translation)
{
        if (device_get_parent(dev) != NULL) {
                return (BHND_BUS_GET_DMA_TRANSLATION(device_get_parent(dev),
                    child, width, flags, dmat, translation));
        }

        panic("missing BHND_BUS_GET_DMA_TRANSLATION()");
}

/* nvram board_info population macros for bhnd_bus_generic_read_board_info() */
#define BHND_GV(_dest, _name)   \
        bhnd_nvram_getvar_uint(child, BHND_NVAR_ ## _name, &_dest,      \
            sizeof(_dest))

#define REQ_BHND_GV(_dest, _name)               do {                    \
        if ((error = BHND_GV(_dest, _name))) {                          \
                device_printf(dev,                                      \
                    "error reading " __STRING(_name) ": %d\n", error);  \
                return (error);                                         \
        }                                                               \
} while(0)

#define OPT_BHND_GV(_dest, _name, _default)     do {                    \
        if ((error = BHND_GV(_dest, _name))) {                          \
                if (error != ENOENT) {                                  \
                        device_printf(dev,                              \
                            "error reading "                            \
                               __STRING(_name) ": %d\n", error);        \
                        return (error);                                 \
                }                                                       \
                _dest = _default;                                       \
        }                                                               \
} while(0)

/**
 * Helper function for implementing BHND_BUS_READ_BOARDINFO().
 * 
 * This implementation populates @p info with information from NVRAM,
 * defaulting board_vendor and board_type fields to 0 if the
 * requested variables cannot be found.
 * 
 * This behavior is correct for most SoCs, but must be overridden on
 * bridged (PCI, PCMCIA, etc) devices to produce a complete bhnd_board_info
 * result.
 */
int
bhnd_bus_generic_read_board_info(device_t dev, device_t child,
    struct bhnd_board_info *info)
{
        int     error;

        OPT_BHND_GV(info->board_vendor, BOARDVENDOR,    0);
        OPT_BHND_GV(info->board_type,   BOARDTYPE,      0);     /* srom >= 2 */
        OPT_BHND_GV(info->board_devid,  DEVID,          0);     /* srom >= 8 */
        REQ_BHND_GV(info->board_rev,    BOARDREV);
        OPT_BHND_GV(info->board_srom_rev,SROMREV,       0);     /* missing in
                                                                   some SoC
                                                                   NVRAM */
        REQ_BHND_GV(info->board_flags,  BOARDFLAGS);
        OPT_BHND_GV(info->board_flags2, BOARDFLAGS2,    0);     /* srom >= 4 */
        OPT_BHND_GV(info->board_flags3, BOARDFLAGS3,    0);     /* srom >= 11 */

        return (0);
}

#undef  BHND_GV
#undef  BHND_GV_REQ
#undef  BHND_GV_OPT

/**
 * Helper function for implementing BHND_BUS_GET_NVRAM_VAR().
 * 
 * This implementation searches @p dev for a usable NVRAM child device.
 * 
 * If no usable child device is found on @p dev, the request is delegated to
 * the BHND_BUS_GET_NVRAM_VAR() method on the parent of @p dev.
 */
int
bhnd_bus_generic_get_nvram_var(device_t dev, device_t child, const char *name,
    void *buf, size_t *size, bhnd_nvram_type type)
{
        device_t        nvram;
        device_t        parent;

        bus_topo_assert();

        /* Look for a directly-attached NVRAM child */
        if ((nvram = device_find_child(dev, "bhnd_nvram", DEVICE_UNIT_ANY)) != NULL)
                return BHND_NVRAM_GETVAR(nvram, name, buf, size, type);

        /* Try to delegate to parent */
        if ((parent = device_get_parent(dev)) == NULL)
                return (ENODEV);

        return (BHND_BUS_GET_NVRAM_VAR(device_get_parent(dev), child,
            name, buf, size, type));
}

/**
 * Helper function for implementing BHND_BUS_ALLOC_RESOURCE().
 * 
 * This implementation of BHND_BUS_ALLOC_RESOURCE() delegates allocation
 * of the underlying resource to BUS_ALLOC_RESOURCE(), and activation
 * to @p dev's BHND_BUS_ACTIVATE_RESOURCE().
 */
struct bhnd_resource *
bhnd_bus_generic_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 bhnd_resource    *br;
        struct resource         *res;
        int                      error;

        br = NULL;
        res = NULL;

        /* Allocate the real bus resource (without activating it) */
        res = BUS_ALLOC_RESOURCE(dev, child, type, rid, start, end, count,
            (flags & ~RF_ACTIVE));
        if (res == NULL)
                return (NULL);

        /* Allocate our bhnd resource wrapper. */
        br = malloc(sizeof(struct bhnd_resource), M_BHND, M_NOWAIT);
        if (br == NULL)
                goto failed;

        br->direct = false;
        br->res = res;

        /* Attempt activation */
        if (flags & RF_ACTIVE) {
                error = BHND_BUS_ACTIVATE_RESOURCE(dev, child, br);
                if (error)
                        goto failed;
        }

        return (br);

failed:
        if (res != NULL)
                BUS_RELEASE_RESOURCE(dev, child, res);

        free(br, M_BHND);
        return (NULL);
}

/**
 * Helper function for implementing BHND_BUS_RELEASE_RESOURCE().
 * 
 * This implementation of BHND_BUS_RELEASE_RESOURCE() delegates release of
 * the backing resource to BUS_RELEASE_RESOURCE().
 */
int
bhnd_bus_generic_release_resource(device_t dev, device_t child,
    struct bhnd_resource *r)
{
        int error;

        if ((error = BUS_RELEASE_RESOURCE(dev, child, r->res)))
                return (error);

        free(r, M_BHND);
        return (0);
}

/**
 * Helper function for implementing BHND_BUS_ACTIVATE_RESOURCE().
 * 
 * This implementation of BHND_BUS_ACTIVATE_RESOURCE() first calls the
 * BHND_BUS_ACTIVATE_RESOURCE() method of the parent of @p dev.
 * 
 * If this fails, and if @p dev is the direct parent of @p child, standard
 * resource activation is attempted via bus_activate_resource(). This enables
 * direct use of the bhnd(4) resource APIs on devices that may not be attached
 * to a parent bhnd bus or bridge.
 */
int
bhnd_bus_generic_activate_resource(device_t dev, device_t child,
    struct bhnd_resource *r)
{
        int     error;
        bool    passthrough;

        passthrough = (device_get_parent(child) != dev);

        /* Try to delegate to the parent */
        if (device_get_parent(dev) != NULL) {
                error = BHND_BUS_ACTIVATE_RESOURCE(device_get_parent(dev),
                    child, r);
        } else {
                error = ENODEV;
        }

        /* If bhnd(4) activation has failed and we're the child's direct
         * parent, try falling back on standard resource activation.
         */
        if (error && !passthrough) {
                error = bus_activate_resource(child, r->res);
                if (!error)
                        r->direct = true;
        }

        return (error);
}

/**
 * Helper function for implementing BHND_BUS_DEACTIVATE_RESOURCE().
 * 
 * This implementation of BHND_BUS_ACTIVATE_RESOURCE() simply calls the
 * BHND_BUS_ACTIVATE_RESOURCE() method of the parent of @p dev.
 */
int
bhnd_bus_generic_deactivate_resource(device_t dev, device_t child,
    struct bhnd_resource *r)
{
        if (device_get_parent(dev) != NULL)
                return (BHND_BUS_DEACTIVATE_RESOURCE(device_get_parent(dev),
                    child, r));

        return (EINVAL);
}

/**
 * Helper function for implementing BHND_BUS_GET_INTR_DOMAIN().
 * 
 * This implementation simply returns the address of nearest bhnd(4) bus,
 * which may be @p dev; this behavior may be incompatible with FDT/OFW targets.
 */
uintptr_t
bhnd_bus_generic_get_intr_domain(device_t dev, device_t child, bool self)
{
        return ((uintptr_t)dev);
}