[dragonfly.git] / sys / dev / acpica / acpi.c

/*-
 * Copyright (c) 2000 Takanori Watanabe <takawata@jp.kfreebsd.org>
 * Copyright (c) 2000 Mitsuru IWASAKI <iwasaki@jp.kfreebsd.org>
 * Copyright (c) 2000, 2001 Michael Smith
 * 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.
 *
 * 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.
 *
 * $FreeBSD: src/sys/dev/acpica/acpi.c,v 1.243.2.4.4.1 2009/04/15 03:14:26 kensmith Exp $
 */

#include "opt_acpi.h"
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/fcntl.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/bus.h>
#include <sys/conf.h>
#include <sys/reboot.h>
#include <sys/sysctl.h>
#include <sys/ctype.h>
#include <sys/linker.h>
#include <sys/power.h>
#include <sys/sbuf.h>
#include <sys/device.h>
#include <sys/spinlock.h>
#include <sys/spinlock2.h>
#include <sys/uuid.h>

#include <sys/rman.h>
#include <bus/isa/isavar.h>
#include <bus/isa/pnpvar.h>

#include "acpi.h"
#include <dev/acpica/acpivar.h>
#include <dev/acpica/acpiio.h>
#include <dev/acpica/acpiio_mcall.h>
#include "achware.h"
#include "acnamesp.h"
#include "acglobal.h"

#include "pci_if.h"
#include <bus/pci/pci_cfgreg.h>
#include <bus/pci/pcivar.h>
#include <bus/pci/pci_private.h>

#include <vm/vm_param.h>

MALLOC_DEFINE(M_ACPIDEV, "acpidev", "ACPI devices");

/* Hooks for the ACPICA debugging infrastructure */
#define _COMPONENT      ACPI_BUS
ACPI_MODULE_NAME("ACPI");

static d_open_t         acpiopen;
static d_close_t        acpiclose;
static d_ioctl_t        acpiioctl;

static struct dev_ops acpi_ops = {
        { "acpi", 0, 0 },
        .d_open = acpiopen,
        .d_close = acpiclose,
        .d_ioctl = acpiioctl
};

struct acpi_interface {
        ACPI_STRING     *data;
        int             num;
};

/* Global mutex for locking access to the ACPI subsystem. */
struct lock acpi_lock;

/* Bitmap of device quirks. */
int             acpi_quirks;

static int      acpi_modevent(struct module *mod, int event, void *junk);
static void     acpi_identify(driver_t *driver, device_t parent);
static int      acpi_probe(device_t dev);
static int      acpi_attach(device_t dev);
static int      acpi_suspend(device_t dev);
static int      acpi_resume(device_t dev);
static int      acpi_shutdown(device_t dev);
static device_t acpi_add_child(device_t bus, device_t parent, int order, const char *name,
                        int unit);
static int      acpi_print_child(device_t bus, device_t child);
static void     acpi_probe_nomatch(device_t bus, device_t child);
static void     acpi_driver_added(device_t dev, driver_t *driver);
static int      acpi_read_ivar(device_t dev, device_t child, int index,
                        uintptr_t *result);
static int      acpi_write_ivar(device_t dev, device_t child, int index,
                        uintptr_t value);
static struct resource_list *acpi_get_rlist(device_t dev, device_t child);
static int      acpi_sysres_alloc(device_t dev);
static struct resource *acpi_alloc_resource(device_t bus, device_t child,
                        int type, int *rid, u_long start, u_long end,
                        u_long count, u_int flags, int cpuid);
static int      acpi_release_resource(device_t bus, device_t child, int type,
                        int rid, struct resource *r);
static void     acpi_delete_resource(device_t bus, device_t child, int type,
                    int rid);
static uint32_t acpi_isa_get_logicalid(device_t dev);
static int      acpi_isa_get_compatid(device_t dev, uint32_t *cids, int count);
static char     *acpi_device_id_probe(device_t bus, device_t dev, char **ids);
static ACPI_STATUS acpi_device_eval_obj(device_t bus, device_t dev,
                    ACPI_STRING pathname, ACPI_OBJECT_LIST *parameters,
                    ACPI_BUFFER *ret);
static int      acpi_device_pwr_for_sleep(device_t bus, device_t dev,
                    int *dstate);
static ACPI_STATUS acpi_device_scan_cb(ACPI_HANDLE h, UINT32 level,
                    void *context, void **retval);
static ACPI_STATUS acpi_device_scan_children(device_t bus, device_t dev,
                    int max_depth, acpi_scan_cb_t user_fn, void *arg);
static int      acpi_set_powerstate_method(device_t bus, device_t child,
                    int state);
static int      acpi_isa_pnp_probe(device_t bus, device_t child,
                    struct isa_pnp_id *ids);
static void     acpi_probe_children(device_t bus);
static void     acpi_probe_order(ACPI_HANDLE handle, int *order);
static ACPI_STATUS acpi_probe_child(ACPI_HANDLE handle, UINT32 level,
                    void *context, void **status);
static ACPI_STATUS acpi_EnterSleepState(struct acpi_softc *sc, int state);
static void     acpi_shutdown_final(void *arg, int howto);
static void     acpi_enable_fixed_events(struct acpi_softc *sc);
static int      acpi_wake_sleep_prep(ACPI_HANDLE handle, int sstate);
static int      acpi_wake_run_prep(ACPI_HANDLE handle, int sstate);
static int      acpi_wake_prep_walk(int sstate);
static int      acpi_wake_sysctl_walk(device_t dev);
#ifdef notyet
static int      acpi_wake_set_sysctl(SYSCTL_HANDLER_ARGS);
#endif
static void     acpi_system_eventhandler_sleep(void *arg, int state);
static void     acpi_system_eventhandler_wakeup(void *arg, int state);
static int      acpi_supported_sleep_state_sysctl(SYSCTL_HANDLER_ARGS);
static int      acpi_sleep_state_sysctl(SYSCTL_HANDLER_ARGS);
static int      acpi_debug_objects_sysctl(SYSCTL_HANDLER_ARGS);
static int      acpi_pm_func(u_long cmd, void *arg, ...);
static int      acpi_child_location_str_method(device_t acdev, device_t child,
                                               char *buf, size_t buflen);
static int      acpi_child_pnpinfo_str_method(device_t acdev, device_t child,
                                              char *buf, size_t buflen);
static void     acpi_enable_pcie(void);
static void     acpi_reset_interfaces(device_t dev);

static device_method_t acpi_methods[] = {
    /* Device interface */
    DEVMETHOD(device_identify,          acpi_identify),
    DEVMETHOD(device_probe,             acpi_probe),
    DEVMETHOD(device_attach,            acpi_attach),
    DEVMETHOD(device_shutdown,          acpi_shutdown),
    DEVMETHOD(device_detach,            bus_generic_detach),
    DEVMETHOD(device_suspend,           acpi_suspend),
    DEVMETHOD(device_resume,            acpi_resume),

    /* Bus interface */
    DEVMETHOD(bus_add_child,            acpi_add_child),
    DEVMETHOD(bus_print_child,          acpi_print_child),
    DEVMETHOD(bus_probe_nomatch,        acpi_probe_nomatch),
    DEVMETHOD(bus_driver_added,         acpi_driver_added),
    DEVMETHOD(bus_read_ivar,            acpi_read_ivar),
    DEVMETHOD(bus_write_ivar,           acpi_write_ivar),
    DEVMETHOD(bus_get_resource_list,    acpi_get_rlist),
    DEVMETHOD(bus_set_resource,         bus_generic_rl_set_resource),
    DEVMETHOD(bus_get_resource,         bus_generic_rl_get_resource),
    DEVMETHOD(bus_alloc_resource,       acpi_alloc_resource),
    DEVMETHOD(bus_release_resource,     acpi_release_resource),
    DEVMETHOD(bus_delete_resource,      acpi_delete_resource),
    DEVMETHOD(bus_child_pnpinfo_str,    acpi_child_pnpinfo_str_method),
    DEVMETHOD(bus_child_location_str,   acpi_child_location_str_method),
    DEVMETHOD(bus_activate_resource,    bus_generic_activate_resource),
    DEVMETHOD(bus_deactivate_resource,  bus_generic_deactivate_resource),
    DEVMETHOD(bus_setup_intr,           bus_generic_setup_intr),
    DEVMETHOD(bus_teardown_intr,        bus_generic_teardown_intr),

    /* ACPI bus */
    DEVMETHOD(acpi_id_probe,            acpi_device_id_probe),
    DEVMETHOD(acpi_evaluate_object,     acpi_device_eval_obj),
    DEVMETHOD(acpi_pwr_for_sleep,       acpi_device_pwr_for_sleep),
    DEVMETHOD(acpi_scan_children,       acpi_device_scan_children),

    /* PCI emulation */
    DEVMETHOD(pci_set_powerstate,       acpi_set_powerstate_method),

    /* ISA emulation */
    DEVMETHOD(isa_pnp_probe,            acpi_isa_pnp_probe),

    DEVMETHOD_END
};

static driver_t acpi_driver = {
    "acpi",
    acpi_methods,
    sizeof(struct acpi_softc),
};

static devclass_t acpi_devclass;
DRIVER_MODULE(acpi, nexus, acpi_driver, acpi_devclass, acpi_modevent, NULL);
MODULE_VERSION(acpi, 1);

ACPI_SERIAL_DECL(acpi, "ACPI serializer");

/* Local pools for managing system resources for ACPI child devices. */
static struct rman acpi_rman_io, acpi_rman_mem;

#define ACPI_MINIMUM_AWAKETIME  5

static const char* sleep_state_names[] = {
    "S0", "S1", "S2", "S3", "S4", "S5", "NONE"};

SYSCTL_NODE(_debug, OID_AUTO, acpi, CTLFLAG_RD, NULL, "ACPI debugging");
static char acpi_ca_version[12];
SYSCTL_STRING(_debug_acpi, OID_AUTO, acpi_ca_version, CTLFLAG_RD,
              acpi_ca_version, 0, "Version of Intel ACPICA");

/*
 * Allow overriding _OSI methods.
 */
static char acpi_install_interface[256];
TUNABLE_STR("hw.acpi.install_interface", acpi_install_interface,
    sizeof(acpi_install_interface));
static char acpi_remove_interface[256];
TUNABLE_STR("hw.acpi.remove_interface", acpi_remove_interface,
    sizeof(acpi_remove_interface));

/*
 * Use this tunable to disable the control method auto-serialization
 * mechanism that was added in 20140214 and superseded the previous
 * AcpiGbl_SerializeAllMethods global.
 */
static int acpi_auto_serialize_methods = 1;
TUNABLE_INT("hw.acpi.auto_serialize_methods", &acpi_auto_serialize_methods);

/* Allow users to dump Debug objects without ACPI debugger. */
static int acpi_debug_objects;
TUNABLE_INT("debug.acpi.enable_debug_objects", &acpi_debug_objects);
SYSCTL_PROC(_debug_acpi, OID_AUTO, enable_debug_objects,
    CTLFLAG_RW | CTLTYPE_INT, NULL, 0, acpi_debug_objects_sysctl, "I",
    "Enable Debug objects.");

/* Allow ignoring the XSDT. */
static int acpi_ignore_xsdt;
TUNABLE_INT("debug.acpi.ignore_xsdt", &acpi_ignore_xsdt);
SYSCTL_INT(_debug_acpi, OID_AUTO, ignore_xsdt, CTLFLAG_RD,
    &acpi_ignore_xsdt, 1, "Ignore the XSDT, forcing the use of the RSDT.");

/* Allow the interpreter to ignore common mistakes in BIOS. */
static int acpi_interpreter_slack = 1;
TUNABLE_INT("debug.acpi.interpreter_slack", &acpi_interpreter_slack);
SYSCTL_INT(_debug_acpi, OID_AUTO, interpreter_slack, CTLFLAG_RD,
    &acpi_interpreter_slack, 1, "Turn on interpreter slack mode.");

/* Allow preferring 32-bit FADT register addresses over the 64-bit ones. */
static int acpi_fadt_addr32;
TUNABLE_INT("debug.acpi.fadt_addr32", &acpi_fadt_addr32);
SYSCTL_INT(_debug_acpi, OID_AUTO, fadt_addr32, CTLFLAG_RD,
    &acpi_fadt_addr32, 1,
    "Prefer 32-bit FADT register addresses over 64-bit ones.");

/* Prefer 32-bit FACS table addresses over the 64-bit ones. */
static int acpi_facs_addr32 = 1;
TUNABLE_INT("debug.acpi.facs_addr32", &acpi_facs_addr32);
SYSCTL_INT(_debug_acpi, OID_AUTO, facs_addr32, CTLFLAG_RD,
    &acpi_facs_addr32, 1,
    "Prefer 32-bit FACS table addresses over 64-bit ones.");

/* Power devices off and on in suspend and resume.  XXX Remove once tested. */
static int acpi_do_powerstate = 1;
TUNABLE_INT("debug.acpi.do_powerstate", &acpi_do_powerstate);
SYSCTL_INT(_debug_acpi, OID_AUTO, do_powerstate, CTLFLAG_RW,
    &acpi_do_powerstate, 1, "Turn off devices when suspending.");

/* Allow users to override quirks. */
TUNABLE_INT("debug.acpi.quirks", &acpi_quirks);

/* Allow to call ACPI methods from userland. */
static int acpi_allow_mcall;
TUNABLE_INT("debug.acpi.allow_method_calls", &acpi_allow_mcall);

static int acpi_susp_bounce;
SYSCTL_INT(_debug_acpi, OID_AUTO, suspend_bounce, CTLFLAG_RW,
    &acpi_susp_bounce, 0, "Don't actually suspend, just test devices.");

/*
 * ACPI can only be loaded as a module by the loader; activating it after
 * system bootstrap time is not useful, and can be fatal to the system.
 * It also cannot be unloaded, since the entire system bus heirarchy hangs
 * off it.
 */
static int
acpi_modevent(struct module *mod, int event, void *junk)
{
    switch (event) {
    case MOD_LOAD:
        if (!cold) {
            kprintf("The ACPI driver cannot be loaded after boot.\n");
            return (EPERM);
        }
        break;
    case MOD_UNLOAD:
        if (!cold && power_pm_get_type() == POWER_PM_TYPE_ACPI)
            return (EBUSY);
        break;
    default:
        break;
    }
    return (0);
}

/*
 * Perform early initialization.
 */
ACPI_STATUS
acpi_Startup(void)
{
    static int started = 0;
    ACPI_STATUS status;
    int val;

    ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);

    /* Only run the startup code once.  The MADT driver also calls this. */
    if (started)
        return_VALUE (AE_OK);
    started = 1;

    /*
     * Pre-allocate space for RSDT/XSDT and DSDT tables and allow resizing
     * if more tables exist.
     */
    if (ACPI_FAILURE(status = AcpiInitializeTables(NULL, 2, TRUE))) {
        kprintf("ACPI: Table initialisation failed: %s\n",
            AcpiFormatException(status));
        return_VALUE (status);
    }

    /* Set up any quirks we have for this system. */
    if (acpi_quirks == ACPI_Q_OK)
        acpi_table_quirks(&acpi_quirks);

    /* If the user manually set the disabled hint to 0, force-enable ACPI. */
    if (resource_int_value("acpi", 0, "disabled", &val) == 0 && val == 0)
        acpi_quirks &= ~ACPI_Q_BROKEN;
    if (acpi_quirks & ACPI_Q_BROKEN) {
        kprintf("ACPI disabled by blacklist.  Contact your BIOS vendor.\n");
        status = AE_SUPPORT;
    }

    return_VALUE (status);
}

/*
 * Detect ACPI, perform early initialisation
 */
static void
acpi_identify(driver_t *driver, device_t parent)
{
    device_t    child;

    ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);

    if (!cold)
        return_VOID;

    /* Check that we haven't been disabled with a hint. */
    if (resource_disabled("acpi", 0))
        return_VOID;

    /* Make sure we're not being doubly invoked. */
    if (device_find_child(parent, "acpi", 0) != NULL)
        return_VOID;

    ksnprintf(acpi_ca_version, sizeof(acpi_ca_version), "%x", ACPI_CA_VERSION);

    /* Initialize root tables. */
    if (ACPI_FAILURE(acpi_Startup())) {
        kprintf("ACPI: Try disabling either ACPI or apic support.\n");
        return_VOID;
    }

    /* Attach the actual ACPI device. */
    if ((child = BUS_ADD_CHILD(parent, parent, 10, "acpi", 0)) == NULL) {
        device_printf(parent, "device_identify failed\n");
        return_VOID;
    }
}

/*
 * Fetch some descriptive data from ACPI to put in our attach message.
 */
static int
acpi_probe(device_t dev)
{
    ACPI_TABLE_RSDP     *rsdp;
    ACPI_TABLE_HEADER   *rsdt;
    ACPI_PHYSICAL_ADDRESS paddr;
    char                buf[ACPI_OEM_ID_SIZE + ACPI_OEM_TABLE_ID_SIZE + 2];
    struct sbuf         sb;

    ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);

    if (power_pm_get_type() != POWER_PM_TYPE_NONE &&
        power_pm_get_type() != POWER_PM_TYPE_ACPI) {
        device_printf(dev, "probe failed, other PM system enabled.\n");
        return_VALUE (ENXIO);
    }

    if ((paddr = AcpiOsGetRootPointer()) == 0 ||
        (rsdp = AcpiOsMapMemory(paddr, sizeof(ACPI_TABLE_RSDP))) == NULL)
        return_VALUE (ENXIO);
    if (acpi_ignore_xsdt == 0 &&
        rsdp->Revision > 1 && rsdp->XsdtPhysicalAddress != 0)
        paddr = (ACPI_PHYSICAL_ADDRESS)rsdp->XsdtPhysicalAddress;
    else
        paddr = (ACPI_PHYSICAL_ADDRESS)rsdp->RsdtPhysicalAddress;
    AcpiOsUnmapMemory(rsdp, sizeof(ACPI_TABLE_RSDP));

    if ((rsdt = AcpiOsMapMemory(paddr, sizeof(ACPI_TABLE_HEADER))) == NULL)
        return_VALUE (ENXIO);
    sbuf_new(&sb, buf, sizeof(buf), SBUF_FIXEDLEN);
    sbuf_bcat(&sb, rsdt->OemId, ACPI_OEM_ID_SIZE);
    sbuf_trim(&sb);
    sbuf_putc(&sb, ' ');
    sbuf_bcat(&sb, rsdt->OemTableId, ACPI_OEM_TABLE_ID_SIZE);
    sbuf_trim(&sb);
    sbuf_finish(&sb);
    device_set_desc_copy(dev, sbuf_data(&sb));
    sbuf_delete(&sb);
    AcpiOsUnmapMemory(rsdt, sizeof(ACPI_TABLE_HEADER));

    return_VALUE (0);
}

static int
acpi_attach(device_t dev)
{
    struct acpi_softc   *sc;
    ACPI_STATUS         status;
    int                 error, state;
    UINT32              flags;
    UINT8               TypeA, TypeB;
    char                *env;

    ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);

    sc = device_get_softc(dev);
    sc->acpi_dev = dev;
    callout_init(&sc->susp_force_to);

    if ((error = acpi_task_thread_init())) {
        device_printf(dev, "Could not start task thread.\n");
        goto out;
    }

    error = ENXIO;

    /* Initialize resource manager. */
    acpi_rman_io.rm_type = RMAN_ARRAY;
    acpi_rman_io.rm_start = 0;
    acpi_rman_io.rm_end = 0xffff;
    acpi_rman_io.rm_descr = "ACPI I/O ports";
    if (rman_init(&acpi_rman_io, -1) != 0)
        panic("acpi rman_init IO ports failed");
    acpi_rman_mem.rm_type = RMAN_ARRAY;
    acpi_rman_mem.rm_start = 0;
    acpi_rman_mem.rm_end = ~0ul;
    acpi_rman_mem.rm_descr = "ACPI I/O memory addresses";
    if (rman_init(&acpi_rman_mem, -1) != 0)
        panic("acpi rman_init memory failed");

    /* Initialise the ACPI mutex */
    ACPI_LOCK_INIT(acpi, "acpi");
    ACPI_SERIAL_INIT(acpi);

    /*
     * Set the globals from our tunables.  This is needed because ACPICA
     * uses UINT8 for some values and we have no tunable_byte.
     */
    AcpiGbl_AutoSerializeMethods = acpi_auto_serialize_methods ? TRUE : FALSE;
    AcpiGbl_DoNotUseXsdt = acpi_ignore_xsdt ? TRUE : FALSE;
    AcpiGbl_EnableAmlDebugObject = acpi_debug_objects ? TRUE : FALSE;
    AcpiGbl_EnableInterpreterSlack = acpi_interpreter_slack ? TRUE : FALSE;
    AcpiGbl_Use32BitFadtAddresses = acpi_fadt_addr32 ? TRUE : FALSE;
    AcpiGbl_Use32BitFacsAddresses = acpi_facs_addr32 ? TRUE : FALSE;

#ifndef ACPI_DEBUG
    /*
     * Disable Debug Object output.
     */
    AcpiDbgLevel &= ~ACPI_LV_DEBUG_OBJECT;
#endif

    /* Start up the ACPICA subsystem. */
    status = AcpiInitializeSubsystem();
    if (ACPI_FAILURE(status)) {
        device_printf(dev, "Could not initialize Subsystem: %s\n",
                      AcpiFormatException(status));
        goto out;
    }

    /* Override OS interfaces if the user requested. */
    acpi_reset_interfaces(dev);

    /* Load ACPI name space. */
    status = AcpiLoadTables();
    if (ACPI_FAILURE(status)) {
        device_printf(dev, "Could not load Namespace: %s\n",
                      AcpiFormatException(status));
        goto out;
    }

    /* Handle MCFG table if present. */
    acpi_enable_pcie();

    /*
     * Note that some systems (specifically, those with namespace evaluation
     * issues that require the avoidance of parts of the namespace) must
     * avoid running _INI and _STA on everything, as well as dodging the final
     * object init pass.
     *
     * For these devices, we set ACPI_NO_DEVICE_INIT and ACPI_NO_OBJECT_INIT).
     *
     * XXX We should arrange for the object init pass after we have attached
     *     all our child devices, but on many systems it works here.
     */
    flags = ACPI_FULL_INITIALIZATION;
    if (ktestenv("debug.acpi.avoid"))
        flags = ACPI_NO_DEVICE_INIT | ACPI_NO_OBJECT_INIT;

    /* Bring the hardware and basic handlers online. */
    if (ACPI_FAILURE(status = AcpiEnableSubsystem(flags))) {
        device_printf(dev, "Could not enable ACPI: %s\n",
                      AcpiFormatException(status));
        goto out;
    }

    /*
     * Fix up the interrupt timer after enabling ACPI, so that the
     * interrupt cputimer that choked by ACPI power management could
     * be resurrected before probing various devices.
     */
    DELAY(5000);
    cputimer_intr_pmfixup();

    /*
     * Call the ECDT probe function to provide EC functionality before
     * the namespace has been evaluated.
     *
     * XXX This happens before the sysresource devices have been probed and
     * attached so its resources come from nexus0.  In practice, this isn't
     * a problem but should be addressed eventually.
     */
    acpi_ec_ecdt_probe(dev);

    /* Bring device objects and regions online. */
    if (ACPI_FAILURE(status = AcpiInitializeObjects(flags))) {
        device_printf(dev, "Could not initialize ACPI objects: %s\n",
                      AcpiFormatException(status));
        goto out;
    }

    /*
     * Setup our sysctl tree.
     *
     * XXX: This doesn't check to make sure that none of these fail.
     */
    sysctl_ctx_init(&sc->acpi_sysctl_ctx);
    sc->acpi_sysctl_tree = SYSCTL_ADD_NODE(&sc->acpi_sysctl_ctx,
                               SYSCTL_STATIC_CHILDREN(_hw), OID_AUTO,
                               device_get_name(dev), CTLFLAG_RD, 0, "");
    SYSCTL_ADD_PROC(&sc->acpi_sysctl_ctx, SYSCTL_CHILDREN(sc->acpi_sysctl_tree),
        OID_AUTO, "supported_sleep_state", CTLTYPE_STRING | CTLFLAG_RD,
        0, 0, acpi_supported_sleep_state_sysctl, "A", "");
    SYSCTL_ADD_PROC(&sc->acpi_sysctl_ctx, SYSCTL_CHILDREN(sc->acpi_sysctl_tree),
        OID_AUTO, "power_button_state", CTLTYPE_STRING | CTLFLAG_RW,
        &sc->acpi_power_button_sx, 0, acpi_sleep_state_sysctl, "A", "");
    SYSCTL_ADD_PROC(&sc->acpi_sysctl_ctx, SYSCTL_CHILDREN(sc->acpi_sysctl_tree),
        OID_AUTO, "sleep_button_state", CTLTYPE_STRING | CTLFLAG_RW,
        &sc->acpi_sleep_button_sx, 0, acpi_sleep_state_sysctl, "A", "");
    SYSCTL_ADD_PROC(&sc->acpi_sysctl_ctx, SYSCTL_CHILDREN(sc->acpi_sysctl_tree),
        OID_AUTO, "lid_switch_state", CTLTYPE_STRING | CTLFLAG_RW,
        &sc->acpi_lid_switch_sx, 0, acpi_sleep_state_sysctl, "A", "");
    SYSCTL_ADD_PROC(&sc->acpi_sysctl_ctx, SYSCTL_CHILDREN(sc->acpi_sysctl_tree),
        OID_AUTO, "standby_state", CTLTYPE_STRING | CTLFLAG_RW,
        &sc->acpi_standby_sx, 0, acpi_sleep_state_sysctl, "A", "");
    SYSCTL_ADD_PROC(&sc->acpi_sysctl_ctx, SYSCTL_CHILDREN(sc->acpi_sysctl_tree),
        OID_AUTO, "suspend_state", CTLTYPE_STRING | CTLFLAG_RW,
        &sc->acpi_suspend_sx, 0, acpi_sleep_state_sysctl, "A", "");
    SYSCTL_ADD_INT(&sc->acpi_sysctl_ctx, SYSCTL_CHILDREN(sc->acpi_sysctl_tree),
        OID_AUTO, "sleep_delay", CTLFLAG_RW, &sc->acpi_sleep_delay, 0,
        "sleep delay");
    SYSCTL_ADD_INT(&sc->acpi_sysctl_ctx, SYSCTL_CHILDREN(sc->acpi_sysctl_tree),
        OID_AUTO, "s4bios", CTLFLAG_RW, &sc->acpi_s4bios, 0, "S4BIOS mode");
    SYSCTL_ADD_INT(&sc->acpi_sysctl_ctx, SYSCTL_CHILDREN(sc->acpi_sysctl_tree),
        OID_AUTO, "verbose", CTLFLAG_RW, &sc->acpi_verbose, 0, "verbose mode");
    SYSCTL_ADD_INT(&sc->acpi_sysctl_ctx, SYSCTL_CHILDREN(sc->acpi_sysctl_tree),
        OID_AUTO, "disable_on_reboot", CTLFLAG_RW,
        &sc->acpi_do_disable, 0, "Disable ACPI when rebooting/halting system");
    SYSCTL_ADD_INT(&sc->acpi_sysctl_ctx, SYSCTL_CHILDREN(sc->acpi_sysctl_tree),
        OID_AUTO, "handle_reboot", CTLFLAG_RW,
        &sc->acpi_handle_reboot, 0, "Use ACPI Reset Register to reboot");

    /*
     * Default to 1 second before sleeping to give some machines time to
     * stabilize.
     */
    sc->acpi_sleep_delay = 1;
    if (bootverbose)
        sc->acpi_verbose = 1;
    if ((env = kgetenv("hw.acpi.verbose")) != NULL) {
        if (strcmp(env, "0") != 0)
            sc->acpi_verbose = 1;
        kfreeenv(env);
    }

    /* Only enable reboot by default if the FADT says it is available. */
    if (AcpiGbl_FADT.Flags & ACPI_FADT_RESET_REGISTER)
        sc->acpi_handle_reboot = 1;

    /* Only enable S4BIOS by default if the FACS says it is available. */
    if (AcpiGbl_FACS->Flags & ACPI_FACS_S4_BIOS_PRESENT)
        sc->acpi_s4bios = 1;

    /*
     * Dispatch the default sleep state to devices.  The lid switch is set
     * to NONE by default to avoid surprising users.
     */
    sc->acpi_power_button_sx = ACPI_STATE_S5;
    sc->acpi_lid_switch_sx = ACPI_S_STATES_MAX + 1;
    sc->acpi_standby_sx = ACPI_STATE_S1;
    sc->acpi_suspend_sx = ACPI_STATE_S3;

    /* Pick the first valid sleep state for the sleep button default. */
    sc->acpi_sleep_button_sx = ACPI_S_STATES_MAX + 1;
    for (state = ACPI_STATE_S1; state <= ACPI_STATE_S4; state++)
        if (ACPI_SUCCESS(AcpiGetSleepTypeData(state, &TypeA, &TypeB))) {
            sc->acpi_sleep_button_sx = state;
            break;
        }

    acpi_enable_fixed_events(sc);

    /*
     * Scan the namespace and attach/initialise children.
     */

    /* Register our shutdown handler. */
    EVENTHANDLER_REGISTER(shutdown_final, acpi_shutdown_final, sc,
        SHUTDOWN_PRI_LAST);

    /*
     * Register our acpi event handlers.
     * XXX should be configurable eg. via userland policy manager.
     */
    EVENTHANDLER_REGISTER(acpi_sleep_event, acpi_system_eventhandler_sleep,
        sc, ACPI_EVENT_PRI_LAST);
    EVENTHANDLER_REGISTER(acpi_wakeup_event, acpi_system_eventhandler_wakeup,
        sc, ACPI_EVENT_PRI_LAST);

    /* Flag our initial states. */
    sc->acpi_enabled = 1;
    sc->acpi_sstate = ACPI_STATE_S0;
    sc->acpi_sleep_disabled = 0;
    /* Create the control device */
    sc->acpi_dev_t = make_dev(&acpi_ops, 0, UID_ROOT, GID_WHEEL, 0644,
                              "acpi");
    sc->acpi_dev_t->si_drv1 = sc;

    if ((error = acpi_machdep_init(dev)))
        goto out;

    /* Register ACPI again to pass the correct argument of pm_func. */
    power_pm_register(POWER_PM_TYPE_ACPI, acpi_pm_func, sc);

    if (!acpi_disabled("bus"))
        acpi_probe_children(dev);

    /* Update all GPEs and enable runtime GPEs. */
    status = AcpiUpdateAllGpes();
    if (ACPI_FAILURE(status)) {
        device_printf(dev, "Could not update all GPEs: %s\n",
                      AcpiFormatException(status));
    }

    /* Allow sleep request after a while. */
    /* timeout(acpi_sleep_enable, sc, hz * ACPI_MINIMUM_AWAKETIME); */

    error = 0;

 out:
    cputimer_intr_pmfixup();
    acpi_task_thread_schedule();
    return_VALUE (error);
}

static int
acpi_suspend(device_t dev)
{
    device_t child, *devlist;
    int error, i, numdevs, pstate;

    /* First give child devices a chance to suspend. */
    error = bus_generic_suspend(dev);
    if (error)
        return (error);

    /*
     * Now, set them into the appropriate power state, usually D3.  If the
     * device has an _SxD method for the next sleep state, use that power
     * state instead.
     */
    device_get_children(dev, &devlist, &numdevs);
    for (i = 0; i < numdevs; i++) {
        /* If the device is not attached, we've powered it down elsewhere. */
        child = devlist[i];
        if (!device_is_attached(child))
            continue;

        /*
         * Default to D3 for all sleep states.  The _SxD method is optional
         * so set the powerstate even if it's absent.
         */
        pstate = PCI_POWERSTATE_D3;
        error = acpi_device_pwr_for_sleep(device_get_parent(child),
            child, &pstate);
        if ((error == 0 || error == ESRCH) && acpi_do_powerstate)
            pci_set_powerstate(child, pstate);
    }
    kfree(devlist, M_TEMP);
    error = 0;

    return (error);
}

static int
acpi_resume(device_t dev)
{
    ACPI_HANDLE handle;
    int i, numdevs;
    device_t child, *devlist;

    /*
     * Put all devices in D0 before resuming them.  Call _S0D on each one
     * since some systems expect this.
     */
    device_get_children(dev, &devlist, &numdevs);
    for (i = 0; i < numdevs; i++) {
        child = devlist[i];
        handle = acpi_get_handle(child);
        if (handle)
            AcpiEvaluateObject(handle, "_S0D", NULL, NULL);
        if (device_is_attached(child) && acpi_do_powerstate)
            pci_set_powerstate(child, PCI_POWERSTATE_D0);
    }
    kfree(devlist, M_TEMP);

    return (bus_generic_resume(dev));
}

static int
acpi_shutdown(device_t dev)
{
    /* Allow children to shutdown first. */
    bus_generic_shutdown(dev);

    /*
     * Enable any GPEs that are able to power-on the system (i.e., RTC).
     * Also, disable any that are not valid for this state (most).
     */
    acpi_wake_prep_walk(ACPI_STATE_S5);

    return (0);
}

/*
 * Handle a new device being added
 */
static device_t
acpi_add_child(device_t bus, device_t parent, int order, const char *name, int unit)
{
    struct acpi_device  *ad;
    device_t            child;

    if ((ad = kmalloc(sizeof(*ad), M_ACPIDEV, M_NOWAIT | M_ZERO)) == NULL)
        return (NULL);

    resource_list_init(&ad->ad_rl);
    child = device_add_child_ordered(parent, order, name, unit);
    if (child != NULL)
        device_set_ivars(child, ad);
    else
        kfree(ad, M_ACPIDEV);
    return (child);
}

static int
acpi_print_child(device_t bus, device_t child)
{
    struct acpi_device   *adev = device_get_ivars(child);
    struct resource_list *rl = &adev->ad_rl;
    int retval = 0;

    retval += bus_print_child_header(bus, child);
    retval += resource_list_print_type(rl, "port",  SYS_RES_IOPORT, "%#lx");
    retval += resource_list_print_type(rl, "iomem", SYS_RES_MEMORY, "%#lx");
    retval += resource_list_print_type(rl, "irq",   SYS_RES_IRQ,    "%ld");
    retval += resource_list_print_type(rl, "drq",   SYS_RES_DRQ,    "%ld");
    if (device_get_flags(child))
        retval += kprintf(" flags %#x", device_get_flags(child));
    retval += bus_print_child_footer(bus, child);

    return (retval);
}

/*
 * If this device is an ACPI child but no one claimed it, attempt
 * to power it off.  We'll power it back up when a driver is added.
 *
 * XXX Disabled for now since many necessary devices (like fdc and
 * ATA) don't claim the devices we created for them but still expect
 * them to be powered up.
 */
static void
acpi_probe_nomatch(device_t bus, device_t child)
{

    /* pci_set_powerstate(child, PCI_POWERSTATE_D3); */
}

/*
 * If a new driver has a chance to probe a child, first power it up.
 *
 * XXX Disabled for now (see acpi_probe_nomatch for details).
 */
static void
acpi_driver_added(device_t dev, driver_t *driver)
{
    device_t child, *devlist;
    int i, numdevs;

    DEVICE_IDENTIFY(driver, dev);
    device_get_children(dev, &devlist, &numdevs);
    for (i = 0; i < numdevs; i++) {
        child = devlist[i];
        if (device_get_state(child) == DS_NOTPRESENT) {
            /* pci_set_powerstate(child, PCI_POWERSTATE_D0); */
            if (device_probe_and_attach(child) != 0)
                ; /* pci_set_powerstate(child, PCI_POWERSTATE_D3); */
        }
    }
    kfree(devlist, M_TEMP);
}

/* Location hint for devctl(8) */
static int
acpi_child_location_str_method(device_t cbdev, device_t child, char *buf,
    size_t buflen)
{
    struct acpi_device *dinfo = device_get_ivars(child);

    if (dinfo->ad_handle)
        ksnprintf(buf, buflen, "handle=%s", acpi_name(dinfo->ad_handle));
    else
        ksnprintf(buf, buflen, "unknown");
    return (0);
}

/* PnP information for devctl(8) */
static int
acpi_child_pnpinfo_str_method(device_t cbdev, device_t child, char *buf,
    size_t buflen)
{
    ACPI_DEVICE_INFO *adinfo;
    struct acpi_device *dinfo = device_get_ivars(child);
    char *end;

    if (ACPI_FAILURE(AcpiGetObjectInfo(dinfo->ad_handle, &adinfo))) {
        ksnprintf(buf, buflen, "unknown");
    } else {
        ksnprintf(buf, buflen, "_HID=%s _UID=%lu",
                 (adinfo->Valid & ACPI_VALID_HID) ?
                 adinfo->HardwareId.String : "none",
                 (adinfo->Valid & ACPI_VALID_UID) ?
                 strtoul(adinfo->UniqueId.String, &end, 10) : 0);
        if (adinfo)
            AcpiOsFree(adinfo);
    }
    return (0);
}

/*
 * Handle per-device ivars
 */
static int
acpi_read_ivar(device_t dev, device_t child, int index, uintptr_t *result)
{
    struct acpi_device  *ad;

    if ((ad = device_get_ivars(child)) == NULL) {
        device_printf(child, "device has no ivars\n");
        return (ENOENT);
    }

    /* ACPI and ISA compatibility ivars */
    switch(index) {
    case ACPI_IVAR_HANDLE:
        *(ACPI_HANDLE *)result = ad->ad_handle;
        break;
    case ACPI_IVAR_MAGIC:
        *result = ad->ad_magic;
        break;
    case ACPI_IVAR_PRIVATE:
        *(void **)result = ad->ad_private;
        break;
    case ACPI_IVAR_FLAGS:
        *(int *)result = ad->ad_flags;
        break;
    case ISA_IVAR_VENDORID:
    case ISA_IVAR_SERIAL:
    case ISA_IVAR_COMPATID:
        *(int *)result = -1;
        break;
    case ISA_IVAR_LOGICALID:
        *(int *)result = acpi_isa_get_logicalid(child);
        break;
    default:
        return (ENOENT);
    }

    return (0);
}

static int
acpi_write_ivar(device_t dev, device_t child, int index, uintptr_t value)
{
    struct acpi_device  *ad;

    if ((ad = device_get_ivars(child)) == NULL) {
        device_printf(child, "device has no ivars\n");
        return (ENOENT);
    }

    switch(index) {
    case ACPI_IVAR_HANDLE:
        ad->ad_handle = (ACPI_HANDLE)value;
        break;
    case ACPI_IVAR_MAGIC:
        ad->ad_magic = value;
        break;
    case ACPI_IVAR_PRIVATE:
        ad->ad_private = (void *)value;
        break;
    case ACPI_IVAR_FLAGS:
        ad->ad_flags = (int)value;
        break;
    default:
        panic("bad ivar write request (%d)", index);
        return (ENOENT);
    }

    return (0);
}

/*
 * Handle child resource allocation/removal
 */
static struct resource_list *
acpi_get_rlist(device_t dev, device_t child)
{
    struct acpi_device          *ad;

    ad = device_get_ivars(child);
    return (&ad->ad_rl);
}

/*
 * Pre-allocate/manage all memory and IO resources.  Since rman can't handle
 * duplicates, we merge any in the sysresource attach routine.
 */
static int
acpi_sysres_alloc(device_t dev)
{
    struct resource *res;
    struct resource_list *rl;
    struct resource_list_entry *rle;
    struct rman *rm;
    char *sysres_ids[] = { "PNP0C01", "PNP0C02", NULL };
    device_t *children;
    int child_count, i;
    /*
     * Probe/attach any sysresource devices.  This would be unnecessary if we
     * had multi-pass probe/attach.
     */
    if (device_get_children(dev, &children, &child_count) != 0)
        return (ENXIO);
    for (i = 0; i < child_count; i++) {
        if (ACPI_ID_PROBE(dev, children[i], sysres_ids) != NULL)
            device_probe_and_attach(children[i]);
    }
    kfree(children, M_TEMP);

    rl = BUS_GET_RESOURCE_LIST(device_get_parent(dev), dev);
    if(!rl)
        return 0;
    SLIST_FOREACH(rle, rl, link) {
        if (rle->res != NULL) {
            device_printf(dev, "duplicate resource for %lx\n", rle->start);
            continue;
        }

        /* Only memory and IO resources are valid here. */
        switch (rle->type) {
        case SYS_RES_IOPORT:
            rm = &acpi_rman_io;
            break;
        case SYS_RES_MEMORY:
            rm = &acpi_rman_mem;
            break;
        default:
            continue;
        }

        /* Pre-allocate resource and add to our rman pool. */
        res = BUS_ALLOC_RESOURCE(device_get_parent(dev), dev, rle->type,
            &rle->rid, rle->start, rle->start + rle->count - 1, rle->count,
            0, -1);
        if (res != NULL) {
            rman_manage_region(rm, rman_get_start(res), rman_get_end(res));
            rle->res = res;
        } else
            device_printf(dev, "reservation of %lx, %lx (%d) failed\n",
                rle->start, rle->count, rle->type);
    }
    return (0);
}

static struct resource *
acpi_alloc_resource(device_t bus, device_t child, int type, int *rid,
    u_long start, u_long end, u_long count, u_int flags, int cpuid)
{
    ACPI_RESOURCE ares;
    struct acpi_device *ad = device_get_ivars(child);
    struct resource_list *rl = &ad->ad_rl;
    struct resource_list_entry *rle;
    struct resource *res;
    struct rman *rm;

    res = NULL;

    /* We only handle memory and IO resources through rman. */
    switch (type) {
    case SYS_RES_IOPORT:
        rm = &acpi_rman_io;
        break;
    case SYS_RES_MEMORY:
        rm = &acpi_rman_mem;
        break;
    default:
        rm = NULL;
    }

    ACPI_SERIAL_BEGIN(acpi);

    /*
     * If this is an allocation of the "default" range for a given RID, and
     * we know what the resources for this device are (i.e., they're on the
     * child's resource list), use those start/end values.
     */
    if (bus == device_get_parent(child) && start == 0UL && end == ~0UL) {
        rle = resource_list_find(rl, type, *rid);
        if (rle == NULL)
            goto out;
        start = rle->start;
        end = rle->end;
        count = rle->count;
        cpuid = rle->cpuid;
    }

    /*
     * If this is an allocation of a specific range, see if we can satisfy
     * the request from our system resource regions.  If we can't, pass the
     * request up to the parent.
     */
    if (start + count - 1 == end && rm != NULL)
        res = rman_reserve_resource(rm, start, end, count, flags & ~RF_ACTIVE,
            child);
    if (res == NULL) {
        res = BUS_ALLOC_RESOURCE(device_get_parent(bus), child, type, rid,
            start, end, count, flags, cpuid);
    } else {
        rman_set_rid(res, *rid);

        /* If requested, activate the resource using the parent's method. */
        if (flags & RF_ACTIVE)
            if (bus_activate_resource(child, type, *rid, res) != 0) {
                rman_release_resource(res);
                res = NULL;
                goto out;
            }
    }

    if (res != NULL && device_get_parent(child) == bus)
        switch (type) {
        case SYS_RES_IRQ:
            /*
             * Since bus_config_intr() takes immediate effect, we cannot
             * configure the interrupt associated with a device when we
             * parse the resources but have to defer it until a driver
             * actually allocates the interrupt via bus_alloc_resource().
             *
             * XXX: Should we handle the lookup failing?
             */
            if (ACPI_SUCCESS(acpi_lookup_irq_resource(child, *rid, res, &ares)))
                acpi_config_intr(child, &ares);
            else
                kprintf("irq resource not found\n");
            break;
        }

out:
    ACPI_SERIAL_END(acpi);
    return (res);
}

static int
acpi_release_resource(device_t bus, device_t child, int type, int rid,
    struct resource *r)
{
    struct rman *rm;
    int ret;

    /* We only handle memory and IO resources through rman. */
    switch (type) {
    case SYS_RES_IOPORT:
        rm = &acpi_rman_io;
        break;
    case SYS_RES_MEMORY:
        rm = &acpi_rman_mem;
        break;
    default:
        rm = NULL;
    }

    ACPI_SERIAL_BEGIN(acpi);

    /*
     * If this resource belongs to one of our internal managers,
     * deactivate it and release it to the local pool.  If it doesn't,
     * pass this request up to the parent.
     */
    if (rm != NULL && rman_is_region_manager(r, rm)) {
        if (rman_get_flags(r) & RF_ACTIVE) {
            ret = bus_deactivate_resource(child, type, rid, r);
            if (ret != 0)
                goto out;
        }
        ret = rman_release_resource(r);
    } else
        ret = BUS_RELEASE_RESOURCE(device_get_parent(bus), child, type, rid, r);

out:
    ACPI_SERIAL_END(acpi);
    return (ret);
}

static void
acpi_delete_resource(device_t bus, device_t child, int type, int rid)
{
    struct resource_list *rl;

    rl = acpi_get_rlist(bus, child);
    resource_list_delete(rl, type, rid);
}

/* Allocate an IO port or memory resource, given its GAS. */
int
acpi_bus_alloc_gas(device_t dev, int *type, int *rid, ACPI_GENERIC_ADDRESS *gas,
    struct resource **res, u_int flags)
{
    int error, res_type;

    error = ENOMEM;
    if (type == NULL || rid == NULL || gas == NULL || res == NULL)
        return (EINVAL);

    /* We only support memory and IO spaces. */
    switch (gas->SpaceId) {
    case ACPI_ADR_SPACE_SYSTEM_MEMORY:
        res_type = SYS_RES_MEMORY;
        break;
    case ACPI_ADR_SPACE_SYSTEM_IO:
        res_type = SYS_RES_IOPORT;
        break;
    default:
        return (EOPNOTSUPP);
    }

    /*
     * If the register width is less than 8, assume the BIOS author means
     * it is a bit field and just allocate a byte.
     */
    if (gas->BitWidth && gas->BitWidth < 8)
        gas->BitWidth = 8;

    /* Validate the address after we're sure we support the space. */
    if (gas->Address == 0 || gas->BitWidth == 0)
        return (EINVAL);

    bus_set_resource(dev, res_type, *rid, gas->Address,
        gas->BitWidth / 8, -1);
    *res = bus_alloc_resource_any(dev, res_type, rid, RF_ACTIVE | flags);
    if (*res != NULL) {
        *type = res_type;
        error = 0;
    } else
        bus_delete_resource(dev, res_type, *rid);

    return (error);
}

ACPI_STATUS
acpi_eval_osc(device_t dev, ACPI_HANDLE handle, const char *uuidstr,
    int revision, uint32_t *buf, int count)
{
    ACPI_BUFFER         retbuf = { ACPI_ALLOCATE_BUFFER, NULL };
    ACPI_OBJECT_LIST    arglist;
    ACPI_OBJECT         arg[4];
    ACPI_OBJECT         *retobj;
    ACPI_STATUS         status;
    struct uuid         uuid;
    uint32_t            error;
    uint8_t             oscuuid[16];
    int                 i;

    if (parse_uuid(uuidstr, &uuid) != 0)
            return (AE_ERROR);
    le_uuid_enc(oscuuid, &uuid);

    arglist.Pointer = arg;
    arglist.Count = 4;
    arg[0].Type = ACPI_TYPE_BUFFER;
    arg[0].Buffer.Length = sizeof(oscuuid);
    arg[0].Buffer.Pointer = oscuuid;            /* UUID */
    arg[1].Type = ACPI_TYPE_INTEGER;
    arg[1].Integer.Value = revision;            /* revision */
    arg[2].Type = ACPI_TYPE_INTEGER;
    arg[2].Integer.Value = count;               /* # of cap integers */
    arg[3].Type = ACPI_TYPE_BUFFER;
    arg[3].Buffer.Length = count * sizeof(uint32_t); /* capabilities buffer */
    arg[3].Buffer.Pointer = (uint8_t *)buf;

    status = AcpiEvaluateObject(handle, "_OSC", &arglist, &retbuf);
    if (ACPI_FAILURE(status))
        goto done;
    retobj = retbuf.Pointer;
    error = ((uint32_t *)retobj->Buffer.Pointer)[0] & ACPI_OSCERR_MASK;
    if (error == 0)
        goto done;
    status = AE_ERROR;
    if (error & ACPI_OSCERR_OSCFAIL)
        device_printf(dev, "_OSC unable to process request\n");
    if (error & ACPI_OSCERR_UUID)
        device_printf(dev, "_OSC unrecognized UUID (%s)\n", uuidstr);
    if (error & ACPI_OSCERR_REVISION)
        device_printf(dev, "_OSC unrecognized revision ID (%d)\n", revision);
    if (error & ACPI_OSCERR_CAPSMASKED) {
        if ((buf[0] & ACPI_OSC_QUERY_SUPPORT) == 0) {
            for (i = 1; i < count; i++) {
                device_printf(dev,
                    "_OSC capabilities have been masked: buf[%d]:%#x\n",
                    i, buf[i] & ~((uint32_t *)retobj->Buffer.Pointer)[i]);
            }
            status = AE_SUPPORT;
        } else {
            status = AE_OK;
        }
    }

done:
    if (retbuf.Pointer != NULL)
        AcpiOsFree(retbuf.Pointer);
    return (status);
}

/* Probe _HID and _CID for compatible ISA PNP ids. */
static uint32_t
acpi_isa_get_logicalid(device_t dev)
{
    ACPI_DEVICE_INFO    *devinfo;
    ACPI_HANDLE         h;
    uint32_t            pnpid;

    ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);

    devinfo = NULL;
    pnpid = 0;

    /* Fetch and validate the HID. */
    if ((h = acpi_get_handle(dev)) == NULL ||
        ACPI_FAILURE(AcpiGetObjectInfo(h, &devinfo)))
        goto out;

    if ((devinfo->Valid & ACPI_VALID_HID) != 0)
        pnpid = PNP_EISAID(devinfo->HardwareId.String);

out:
    if (devinfo)
        AcpiOsFree(devinfo);
    return_VALUE (pnpid);
}

static int
acpi_isa_get_compatid(device_t dev, uint32_t *cids, int count)
{
    ACPI_DEVICE_INFO    *devinfo;
    ACPI_HANDLE         h;
    uint32_t            *pnpid;
    int                 valid, i;

    ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);

    devinfo = NULL;
    pnpid = cids;
    valid = 0;

    /* Fetch and validate the CID */
    if ((h = acpi_get_handle(dev)) == NULL ||
        ACPI_FAILURE(AcpiGetObjectInfo(h, &devinfo)) ||
        (devinfo->Valid & ACPI_VALID_CID) == 0)
        goto out;

    if (devinfo->CompatibleIdList.Count < count)
        count = devinfo->CompatibleIdList.Count;
    for (i = 0; i < count; i++) {
        if (strncmp(devinfo->CompatibleIdList.Ids[i].String, "PNP", 3) != 0)
            continue;
        *pnpid++ = PNP_EISAID(devinfo->CompatibleIdList.Ids[i].String);
        valid++;
    }

out:
    if (devinfo)
        AcpiOsFree(devinfo);
    return_VALUE (valid);
}

static char *
acpi_device_id_probe(device_t bus, device_t dev, char **ids) 
{
    ACPI_HANDLE h;
    int i;

    h = acpi_get_handle(dev);
    if (ids == NULL || h == NULL || acpi_get_type(dev) != ACPI_TYPE_DEVICE)
        return (NULL);

    /* Try to match one of the array of IDs with a HID or CID. */
    for (i = 0; ids[i] != NULL; i++) {
        if (acpi_MatchHid(h, ids[i]))
            return (ids[i]);
    }
    return (NULL);
}

static ACPI_STATUS
acpi_device_eval_obj(device_t bus, device_t dev, ACPI_STRING pathname,
    ACPI_OBJECT_LIST *parameters, ACPI_BUFFER *ret)
{
    ACPI_HANDLE h;

    if (dev == NULL)
        h = ACPI_ROOT_OBJECT;
    else if ((h = acpi_get_handle(dev)) == NULL)
        return (AE_BAD_PARAMETER);
    return (AcpiEvaluateObject(h, pathname, parameters, ret));
}

static int
acpi_device_pwr_for_sleep(device_t bus, device_t dev, int *dstate)
{
    struct acpi_softc *sc;
    ACPI_HANDLE handle;
    ACPI_STATUS status;
    char sxd[8];
    int error;

    sc = device_get_softc(bus);
    handle = acpi_get_handle(dev);

    /*
     * XXX If we find these devices, don't try to power them down.
     * The serial and IRDA ports on my T23 hang the system when
     * set to D3 and it appears that such legacy devices may
     * need special handling in their drivers.
     */
    if (handle == NULL ||
        acpi_MatchHid(handle, "PNP0500") ||
        acpi_MatchHid(handle, "PNP0501") ||
        acpi_MatchHid(handle, "PNP0502") ||
        acpi_MatchHid(handle, "PNP0510") ||
        acpi_MatchHid(handle, "PNP0511"))
        return (ENXIO);

    /*
     * Override next state with the value from _SxD, if present.  If no
     * dstate argument was provided, don't fetch the return value.
     */
    ksnprintf(sxd, sizeof(sxd), "_S%dD", sc->acpi_sstate);
    if (dstate)
        status = acpi_GetInteger(handle, sxd, dstate);
    else
        status = AcpiEvaluateObject(handle, sxd, NULL, NULL);

    switch (status) {
    case AE_OK:
        error = 0;
        break;
    case AE_NOT_FOUND:
        error = ESRCH;
        break;
    default:
        error = ENXIO;
        break;
    }

    return (error);
}

/* Callback arg for our implementation of walking the namespace. */
struct acpi_device_scan_ctx {
    acpi_scan_cb_t      user_fn;
    void                *arg;
    ACPI_HANDLE         parent;
};

static ACPI_STATUS
acpi_device_scan_cb(ACPI_HANDLE h, UINT32 level, void *arg, void **retval)
{
    struct acpi_device_scan_ctx *ctx;
    device_t dev, old_dev;
    ACPI_STATUS status;
    ACPI_OBJECT_TYPE type;

    /*
     * Skip this device if we think we'll have trouble with it or it is
     * the parent where the scan began.
     */
    ctx = (struct acpi_device_scan_ctx *)arg;
    if (acpi_avoid(h) || h == ctx->parent)
        return (AE_OK);

    /* If this is not a valid device type (e.g., a method), skip it. */
    if (ACPI_FAILURE(AcpiGetType(h, &type)))
        return (AE_OK);
    if (type != ACPI_TYPE_DEVICE && type != ACPI_TYPE_PROCESSOR &&
        type != ACPI_TYPE_THERMAL && type != ACPI_TYPE_POWER)
        return (AE_OK);

    /*
     * Call the user function with the current device.  If it is unchanged
     * afterwards, return.  Otherwise, we update the handle to the new dev.
     */
    old_dev = acpi_get_device(h);
    dev = old_dev;
    status = ctx->user_fn(h, &dev, level, ctx->arg);
    if (ACPI_FAILURE(status) || old_dev == dev)
        return (status);

    /* Remove the old child and its connection to the handle. */
    if (old_dev != NULL) {
        device_delete_child(device_get_parent(old_dev), old_dev);
        AcpiDetachData(h, acpi_fake_objhandler);
    }

    /* Recreate the handle association if the user created a device. */
    if (dev != NULL)
        AcpiAttachData(h, acpi_fake_objhandler, dev);

    return (AE_OK);
}

static ACPI_STATUS
acpi_device_scan_children(device_t bus, device_t dev, int max_depth,
    acpi_scan_cb_t user_fn, void *arg)
{
    ACPI_HANDLE h;
    struct acpi_device_scan_ctx ctx;

    if (acpi_disabled("children"))
        return (AE_OK);

    if (dev == NULL)
        h = ACPI_ROOT_OBJECT;
    else if ((h = acpi_get_handle(dev)) == NULL)
        return (AE_BAD_PARAMETER);
    ctx.user_fn = user_fn;
    ctx.arg = arg;
    ctx.parent = h;
    return (AcpiWalkNamespace(ACPI_TYPE_ANY, h, max_depth,
        acpi_device_scan_cb, NULL, &ctx, NULL));
}

/*
 * Even though ACPI devices are not PCI, we use the PCI approach for setting
 * device power states since it's close enough to ACPI.
 */
static int
acpi_set_powerstate_method(device_t bus, device_t child, int state)
{
    ACPI_HANDLE h;
    ACPI_STATUS status;
    int error;

    error = 0;
    h = acpi_get_handle(child);
    if (state < ACPI_STATE_D0 || state > ACPI_STATE_D3)
        return (EINVAL);
    if (h == NULL)
        return (0);

    /* Ignore errors if the power methods aren't present. */
    status = acpi_pwr_switch_consumer(h, state);
    if (ACPI_FAILURE(status) && status != AE_NOT_FOUND
        && status != AE_BAD_PARAMETER)
        device_printf(bus, "failed to set ACPI power state D%d on %s: %s\n",
            state, acpi_name(h), AcpiFormatException(status));

    return (error);
}

static int
acpi_isa_pnp_probe(device_t bus, device_t child, struct isa_pnp_id *ids)
{
    int                 result, cid_count, i;
    uint32_t            lid, cids[8];

    ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);

    /*
     * ISA-style drivers attached to ACPI may persist and
     * probe manually if we return ENOENT.  We never want
     * that to happen, so don't ever return it.
     */
    result = ENXIO;

    /* Scan the supplied IDs for a match */
    lid = acpi_isa_get_logicalid(child);
    cid_count = acpi_isa_get_compatid(child, cids, 8);
    while (ids && ids->ip_id) {
        if (lid == ids->ip_id) {
            result = 0;
            goto out;
        }
        for (i = 0; i < cid_count; i++) {
            if (cids[i] == ids->ip_id) {
                result = 0;
                goto out;
            }
        }
        ids++;
    }

 out:
    if (result == 0 && ids->ip_desc)
        device_set_desc(child, ids->ip_desc);

    return_VALUE (result);
}

/*
 * Look for a MCFG table.  If it is present, use the settings for
 * domain (segment) 0 to setup PCI config space access via the memory
 * map.
 */
static void
acpi_enable_pcie(void)
{
        ACPI_TABLE_HEADER *hdr;
        ACPI_MCFG_ALLOCATION *alloc, *end;
        ACPI_STATUS status;

        status = AcpiGetTable(ACPI_SIG_MCFG, 1, &hdr);
        if (ACPI_FAILURE(status))
                return;

        end = (ACPI_MCFG_ALLOCATION *)((char *)hdr + hdr->Length);
        alloc = (ACPI_MCFG_ALLOCATION *)((ACPI_TABLE_MCFG *)hdr + 1);
        while (alloc < end) {
                if (alloc->PciSegment == 0) {
                        pcie_cfgregopen(alloc->Address, alloc->StartBusNumber,
                            alloc->EndBusNumber);
                        return;
                }
                alloc++;
        }
}

/*
 * Scan all of the ACPI namespace and attach child devices.
 *
 * We should only expect to find devices in the \_PR, \_TZ, \_SI, and
 * \_SB scopes, and \_PR and \_TZ became obsolete in the ACPI 2.0 spec.
 * However, in violation of the spec, some systems place their PCI link
 * devices in \, so we have to walk the whole namespace.  We check the
 * type of namespace nodes, so this should be ok.
 */
static void
acpi_probe_children(device_t bus)
{

    ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);

    /*
     * Scan the namespace and insert placeholders for all the devices that
     * we find.  We also probe/attach any early devices.
     *
     * Note that we use AcpiWalkNamespace rather than AcpiGetDevices because
     * we want to create nodes for all devices, not just those that are
     * currently present. (This assumes that we don't want to create/remove
     * devices as they appear, which might be smarter.)
     */
    ACPI_DEBUG_PRINT((ACPI_DB_OBJECTS, "namespace scan\n"));
    AcpiWalkNamespace(ACPI_TYPE_ANY, ACPI_ROOT_OBJECT, 100,
        acpi_probe_child, NULL, bus, NULL);

    /* Pre-allocate resources for our rman from any sysresource devices. */
    acpi_sysres_alloc(bus);
    /* Create any static children by calling device identify methods. */
    ACPI_DEBUG_PRINT((ACPI_DB_OBJECTS, "device identify routines\n"));
    bus_generic_probe(bus);

    /* Probe/attach all children, created staticly and from the namespace. */
    ACPI_DEBUG_PRINT((ACPI_DB_OBJECTS, "first bus_generic_attach\n"));
    bus_generic_attach(bus);

    /*
     * Some of these children may have attached others as part of their attach
     * process (eg. the root PCI bus driver), so rescan.
     */
    ACPI_DEBUG_PRINT((ACPI_DB_OBJECTS, "second bus_generic_attach\n"));
    bus_generic_attach(bus);

    /* Attach wake sysctls. */
    acpi_wake_sysctl_walk(bus);

    ACPI_DEBUG_PRINT((ACPI_DB_OBJECTS, "done attaching children\n"));
    return_VOID;
}

/*
 * Determine the probe order for a given device.
 */
static void
acpi_probe_order(ACPI_HANDLE handle, int *order)
{
    ACPI_OBJECT_TYPE type;

    /*
     * 1. I/O port and memory system resource holders
     * 2. Embedded controllers (to handle early accesses)
     * 3. PCI Link Devices
     * 100000. CPUs
     */
    AcpiGetType(handle, &type);
    if (acpi_MatchHid(handle, "PNP0C01") || acpi_MatchHid(handle, "PNP0C02"))
        *order = 1;
    else if (acpi_MatchHid(handle, "PNP0C09"))
        *order = 2;
    else if (acpi_MatchHid(handle, "PNP0C0F"))
        *order = 3;
    else if (type == ACPI_TYPE_PROCESSOR)
        *order = 100000;
}

/*
 * Evaluate a child device and determine whether we might attach a device to
 * it.
 */
static ACPI_STATUS
acpi_probe_child(ACPI_HANDLE handle, UINT32 level, void *context, void **status)
{
    struct acpi_prw_data prw;
    ACPI_OBJECT_TYPE type;
    ACPI_HANDLE h;
    device_t bus, child;
    int order;
    char *handle_str;

    ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);

    if (acpi_disabled("children"))
        return_ACPI_STATUS (AE_OK);

    /* Skip this device if we think we'll have trouble with it. */
    if (acpi_avoid(handle))
        return_ACPI_STATUS (AE_OK);

    bus = (device_t)context;
    if (ACPI_SUCCESS(AcpiGetType(handle, &type))) {
        handle_str = acpi_name(handle);
        switch (type) {
        case ACPI_TYPE_DEVICE:
            /*
             * Since we scan from \, be sure to skip system scope objects.
             * \_SB_ and \_TZ_ are defined in ACPICA as devices to work around
             * BIOS bugs.  For example, \_SB_ is to allow \_SB_._INI to be run
             * during the intialization and \_TZ_ is to support Notify() on it.
             */
            if (strcmp(handle_str, "\\_SB_") == 0 ||
                strcmp(handle_str, "\\_TZ_") == 0)
                break;

            if (acpi_parse_prw(handle, &prw) == 0)
                AcpiSetupGpeForWake(handle, prw.gpe_handle, prw.gpe_bit);

            /* FALLTHROUGH */
        case ACPI_TYPE_PROCESSOR:
        case ACPI_TYPE_THERMAL:
        case ACPI_TYPE_POWER:
            /* 
             * Create a placeholder device for this node.  Sort the
             * placeholder so that the probe/attach passes will run
             * breadth-first.  Orders less than ACPI_DEV_BASE_ORDER
             * are reserved for special objects (i.e., system
             * resources).  CPU devices have a very high order to
             * ensure they are probed after other devices.
             */
            ACPI_DEBUG_PRINT((ACPI_DB_OBJECTS, "scanning '%s'\n", handle_str));
            order = level * 10 + 100;
            acpi_probe_order(handle, &order);
            child = BUS_ADD_CHILD(bus, bus, order, NULL, -1);
            if (child == NULL)
                break;

            /* Associate the handle with the device_t and vice versa. */
            acpi_set_handle(child, handle);
            AcpiAttachData(handle, acpi_fake_objhandler, child);

            /*
             * Check that the device is present.  If it's not present,
             * leave it disabled (so that we have a device_t attached to
             * the handle, but we don't probe it).
             *
             * XXX PCI link devices sometimes report "present" but not
             * "functional" (i.e. if disabled).  Go ahead and probe them
             * anyway since we may enable them later.
             */
            if (type == ACPI_TYPE_DEVICE && !acpi_DeviceIsPresent(child)) {
                /* Never disable PCI link devices. */
                if (acpi_MatchHid(handle, "PNP0C0F"))
                    break;
                /*
                 * Docking stations should remain enabled since the system
                 * may be undocked at boot.
                 */
                if (ACPI_SUCCESS(AcpiGetHandle(handle, "_DCK", &h)))
                    break;

                device_disable(child);
                break;
            }

            /*
             * Get the device's resource settings and attach them.
             * Note that if the device has _PRS but no _CRS, we need
             * to decide when it's appropriate to try to configure the
             * device.  Ignore the return value here; it's OK for the
             * device not to have any resources.
             */
            acpi_parse_resources(child, handle, &acpi_res_parse_set, NULL);
            break;
        }
    }

    return_ACPI_STATUS (AE_OK);
}

/*
 * AcpiAttachData() requires an object handler but never uses it.  This is a
 * placeholder object handler so we can store a device_t in an ACPI_HANDLE.
 */
void
acpi_fake_objhandler(ACPI_HANDLE h, void *data)
{
}

static void
acpi_shutdown_final(void *arg, int howto)
{
    struct acpi_softc *sc;
    ACPI_STATUS status;

    /*
     * XXX Shutdown code should only run on the BSP (cpuid 0).
     * Some chipsets do not power off the system correctly if called from
     * an AP.
     */
    sc = arg;
    if ((howto & RB_POWEROFF) != 0) {
        status = AcpiEnterSleepStatePrep(ACPI_STATE_S5);
        if (ACPI_FAILURE(status)) {
            device_printf(sc->acpi_dev, "AcpiEnterSleepStatePrep failed - %s\n",
                   AcpiFormatException(status));
            return;
        }
        device_printf(sc->acpi_dev, "Powering system off\n");
        ACPI_DISABLE_IRQS();
        status = AcpiEnterSleepState(ACPI_STATE_S5);
        if (ACPI_FAILURE(status)) {
            device_printf(sc->acpi_dev, "power-off failed - %s\n",
                AcpiFormatException(status));
        } else {
            DELAY(1000000);
            device_printf(sc->acpi_dev, "power-off failed - timeout\n");
        }
    } else if ((howto & RB_HALT) == 0 && sc->acpi_handle_reboot) {
        /* Reboot using the reset register. */
        status = AcpiReset();
        if (ACPI_FAILURE(status)) {
            if (status != AE_NOT_EXIST)
                    device_printf(sc->acpi_dev, "reset failed - %s\n",
                        AcpiFormatException(status));
        } else {
            DELAY(1000000);
            device_printf(sc->acpi_dev, "reset failed - timeout\n");
        }
    } else if (sc->acpi_do_disable && panicstr == NULL) {
        /*
         * Only disable ACPI if the user requested.  On some systems, writing
         * the disable value to SMI_CMD hangs the system.
         */
        device_printf(sc->acpi_dev, "Shutting down\n");
        AcpiTerminate();
    }
}

static void
acpi_enable_fixed_events(struct acpi_softc *sc)
{
    static int  first_time = 1;

    /* Enable and clear fixed events and install handlers. */
    if ((AcpiGbl_FADT.Flags & ACPI_FADT_POWER_BUTTON) == 0) {
        AcpiClearEvent(ACPI_EVENT_POWER_BUTTON);
        AcpiInstallFixedEventHandler(ACPI_EVENT_POWER_BUTTON,
                                     acpi_event_power_button_sleep, sc);
        if (first_time)
            device_printf(sc->acpi_dev, "Power Button (fixed)\n");
    }
    if ((AcpiGbl_FADT.Flags & ACPI_FADT_SLEEP_BUTTON) == 0) {
        AcpiClearEvent(ACPI_EVENT_SLEEP_BUTTON);
        AcpiInstallFixedEventHandler(ACPI_EVENT_SLEEP_BUTTON,
                                     acpi_event_sleep_button_sleep, sc);
        if (first_time)
            device_printf(sc->acpi_dev, "Sleep Button (fixed)\n");
    }

    first_time = 0;
}

/*
 * Returns true if the device is actually present and should
 * be attached to.  This requires the present, enabled, UI-visible 
 * and diagnostics-passed bits to be set.
 */
BOOLEAN
acpi_DeviceIsPresent(device_t dev)
{
    ACPI_DEVICE_INFO    *devinfo;
    ACPI_HANDLE         h;
    int                 ret;

    ret = FALSE;
    if ((h = acpi_get_handle(dev)) == NULL ||
        ACPI_FAILURE(AcpiGetObjectInfo(h, &devinfo)))
        return (FALSE);

    /* If no _STA method, must be present */
    if ((devinfo->Valid & ACPI_VALID_STA) == 0)
        ret = TRUE;

    /* Return true for 'present' and 'functioning' */
    if (ACPI_DEVICE_PRESENT(devinfo->CurrentStatus))
        ret = TRUE;

    AcpiOsFree(devinfo);
    return (ret);
}

/*
 * Returns true if the battery is actually present and inserted.
 */
BOOLEAN
acpi_BatteryIsPresent(device_t dev)
{
    ACPI_DEVICE_INFO    *devinfo;
    ACPI_HANDLE         h;
    int                 ret;

    ret = FALSE;
    if ((h = acpi_get_handle(dev)) == NULL ||
        ACPI_FAILURE(AcpiGetObjectInfo(h, &devinfo)))
        return (FALSE);

    /* If no _STA method, must be present */
    if ((devinfo->Valid & ACPI_VALID_STA) == 0)
        ret = TRUE;

    /* Return true for 'present', 'battery present', and 'functioning' */
    if (ACPI_BATTERY_PRESENT(devinfo->CurrentStatus))
        ret = TRUE;

    AcpiOsFree(devinfo);
    return (ret);
}

/*
 * Match a HID string against a handle
 */
BOOLEAN
acpi_MatchHid(ACPI_HANDLE h, const char *hid)
{
    ACPI_DEVICE_INFO    *devinfo;
    int                 ret, i;

    ret = FALSE;
    if (hid == NULL || h == NULL ||
        ACPI_FAILURE(AcpiGetObjectInfo(h, &devinfo)))
        return (ret);

    if ((devinfo->Valid & ACPI_VALID_HID) != 0 &&
        strcmp(hid, devinfo->HardwareId.String) == 0)
            ret = TRUE;
    else if ((devinfo->Valid & ACPI_VALID_CID) != 0) {
        for (i = 0; i < devinfo->CompatibleIdList.Count; i++) {
            if (strcmp(hid, devinfo->CompatibleIdList.Ids[i].String) == 0) {
                ret = TRUE;
                break;
            }
        }
    }

    AcpiOsFree(devinfo);
    return (ret);
}

/*
 * Return the handle of a named object within our scope, ie. that of (parent)
 * or one if its parents.
 */
ACPI_STATUS
acpi_GetHandleInScope(ACPI_HANDLE parent, char *path, ACPI_HANDLE *result)
{
    ACPI_HANDLE         r;
    ACPI_STATUS         status;

    /* Walk back up the tree to the root */
    for (;;) {
        status = AcpiGetHandle(parent, path, &r);
        if (ACPI_SUCCESS(status)) {
            *result = r;
            return (AE_OK);
        }
        /* XXX Return error here? */
        if (status != AE_NOT_FOUND)
            return (AE_OK);
        if (ACPI_FAILURE(AcpiGetParent(parent, &r)))
            return (AE_NOT_FOUND);
        parent = r;
    }
}

/*
 * Allocate a buffer with a preset data size.
 */
ACPI_BUFFER *
acpi_AllocBuffer(int size)
{
    ACPI_BUFFER *buf;

    if ((buf = kmalloc(size + sizeof(*buf), M_ACPIDEV, M_NOWAIT)) == NULL)
        return (NULL);
    buf->Length = size;
    buf->Pointer = (void *)(buf + 1);
    return (buf);
}

ACPI_STATUS
acpi_SetInteger(ACPI_HANDLE handle, char *path, UINT32 number)
{
    ACPI_OBJECT arg1;
    ACPI_OBJECT_LIST args;

    arg1.Type = ACPI_TYPE_INTEGER;
    arg1.Integer.Value = number;
    args.Count = 1;
    args.Pointer = &arg1;

    return (AcpiEvaluateObject(handle, path, &args, NULL));
}

/*
 * Evaluate a path that should return an integer.
 */
ACPI_STATUS
acpi_GetInteger(ACPI_HANDLE handle, char *path, UINT32 *number)
{
    ACPI_STATUS status;
    ACPI_BUFFER buf;
    ACPI_OBJECT param;

    if (handle == NULL)
        handle = ACPI_ROOT_OBJECT;

    /*
     * Assume that what we've been pointed at is an Integer object, or
     * a method that will return an Integer.
     */
    buf.Pointer = &param;
    buf.Length = sizeof(param);
    status = AcpiEvaluateObject(handle, path, NULL, &buf);
    if (ACPI_SUCCESS(status)) {
        if (param.Type == ACPI_TYPE_INTEGER)
            *number = param.Integer.Value;
        else
            status = AE_TYPE;
    }

    /* 
     * In some applications, a method that's expected to return an Integer
     * may instead return a Buffer (probably to simplify some internal
     * arithmetic).  We'll try to fetch whatever it is, and if it's a Buffer,
     * convert it into an Integer as best we can.
     *
     * This is a hack.
     */
    if (status == AE_BUFFER_OVERFLOW) {
        if ((buf.Pointer = AcpiOsAllocate(buf.Length)) == NULL) {
            status = AE_NO_MEMORY;
        } else {
            status = AcpiEvaluateObject(handle, path, NULL, &buf);
            if (ACPI_SUCCESS(status))
                status = acpi_ConvertBufferToInteger(&buf, number);
            AcpiOsFree(buf.Pointer);
        }
    }
    return (status);
}

ACPI_STATUS
acpi_ConvertBufferToInteger(ACPI_BUFFER *bufp, UINT32 *number)
{
    ACPI_OBJECT *p;
    UINT8       *val;
    int         i;

    p = (ACPI_OBJECT *)bufp->Pointer;
    if (p->Type == ACPI_TYPE_INTEGER) {
        *number = p->Integer.Value;
        return (AE_OK);
    }
    if (p->Type != ACPI_TYPE_BUFFER)
        return (AE_TYPE);
    if (p->Buffer.Length > sizeof(int))
        return (AE_BAD_DATA);

    *number = 0;
    val = p->Buffer.Pointer;
    for (i = 0; i < p->Buffer.Length; i++)
        *number += val[i] << (i * 8);
    return (AE_OK);
}

/*
 * Iterate over the elements of an a package object, calling the supplied
 * function for each element.
 *
 * XXX possible enhancement might be to abort traversal on error.
 */
ACPI_STATUS
acpi_ForeachPackageObject(ACPI_OBJECT *pkg,
        void (*func)(ACPI_OBJECT *comp, void *arg), void *arg)
{
    ACPI_OBJECT *comp;
    int         i;

    if (pkg == NULL || pkg->Type != ACPI_TYPE_PACKAGE)
        return (AE_BAD_PARAMETER);

    /* Iterate over components */
    i = 0;
    comp = pkg->Package.Elements;
    for (; i < pkg->Package.Count; i++, comp++)
        func(comp, arg);

    return (AE_OK);
}

/*
 * Find the (index)th resource object in a set.
 */
ACPI_STATUS
acpi_FindIndexedResource(ACPI_BUFFER *buf, int index, ACPI_RESOURCE **resp)
{
    ACPI_RESOURCE       *rp;
    int                 i;

    rp = (ACPI_RESOURCE *)buf->Pointer;
    i = index;
    while (i-- > 0) {
        /* Range check */
        if (rp > (ACPI_RESOURCE *)((uint8_t *)buf->Pointer + buf->Length))
            return (AE_BAD_PARAMETER);

        /* Check for terminator */
        if (rp->Type == ACPI_RESOURCE_TYPE_END_TAG || rp->Length == 0)
            return (AE_NOT_FOUND);
        rp = ACPI_NEXT_RESOURCE(rp);
    }
    if (resp != NULL)
        *resp = rp;

    return (AE_OK);
}

/*
 * Append an ACPI_RESOURCE to an ACPI_BUFFER.
 *
 * Given a pointer to an ACPI_RESOURCE structure, expand the ACPI_BUFFER
 * provided to contain it.  If the ACPI_BUFFER is empty, allocate a sensible
 * backing block.  If the ACPI_RESOURCE is NULL, return an empty set of
 * resources.
 */
#define ACPI_INITIAL_RESOURCE_BUFFER_SIZE       512

ACPI_STATUS
acpi_AppendBufferResource(ACPI_BUFFER *buf, ACPI_RESOURCE *res)
{
    ACPI_RESOURCE       *rp;
    void                *newp;

    /* Initialise the buffer if necessary. */
    if (buf->Pointer == NULL) {
        buf->Length = ACPI_INITIAL_RESOURCE_BUFFER_SIZE;
        if ((buf->Pointer = AcpiOsAllocate(buf->Length)) == NULL)
            return (AE_NO_MEMORY);
        rp = (ACPI_RESOURCE *)buf->Pointer;
        rp->Type = ACPI_RESOURCE_TYPE_END_TAG;
        rp->Length = ACPI_RS_SIZE_MIN;
    }
    if (res == NULL)
        return (AE_OK);

    /*
     * Scan the current buffer looking for the terminator.
     * This will either find the terminator or hit the end
     * of the buffer and return an error.
     */
    rp = (ACPI_RESOURCE *)buf->Pointer;
    for (;;) {
        /* Range check, don't go outside the buffer */
        if (rp >= (ACPI_RESOURCE *)((uint8_t *)buf->Pointer + buf->Length))
            return (AE_BAD_PARAMETER);
        if (rp->Type == ACPI_RESOURCE_TYPE_END_TAG || rp->Length == 0)
            break;
        rp = ACPI_NEXT_RESOURCE(rp);
    }

    /*
     * Check the size of the buffer and expand if required.
     *
     * Required size is:
     *  size of existing resources before terminator + 
     *  size of new resource and header +
     *  size of terminator.
     *
     * Note that this loop should really only run once, unless
     * for some reason we are stuffing a *really* huge resource.
     */
    while ((((uint8_t *)rp - (uint8_t *)buf->Pointer) + 
            res->Length + ACPI_RS_SIZE_NO_DATA +
            ACPI_RS_SIZE_MIN) >= buf->Length) {
        if ((newp = AcpiOsAllocate(buf->Length * 2)) == NULL)
            return (AE_NO_MEMORY);
        bcopy(buf->Pointer, newp, buf->Length);
        rp = (ACPI_RESOURCE *)((uint8_t *)newp +
                               ((uint8_t *)rp - (uint8_t *)buf->Pointer));
        AcpiOsFree(buf->Pointer);
        buf->Pointer = newp;
        buf->Length += buf->Length;
    }

    /* Insert the new resource. */
    bcopy(res, rp, res->Length + ACPI_RS_SIZE_NO_DATA);

    /* And add the terminator. */
    rp = ACPI_NEXT_RESOURCE(rp);
    rp->Type = ACPI_RESOURCE_TYPE_END_TAG;
    rp->Length = ACPI_RS_SIZE_MIN;

    return (AE_OK);
}

/*
 * Set interrupt model.
 */
ACPI_STATUS
acpi_SetIntrModel(int model)
{

    return (acpi_SetInteger(ACPI_ROOT_OBJECT, "_PIC", model));
}

/*
 * DEPRECATED.  This interface has serious deficiencies and will be
 * removed.
 *
 * Immediately enter the sleep state.  In the old model, acpiconf(8) ran
 * rc.suspend and rc.resume so we don't have to notify devd(8) to do this.
 */
ACPI_STATUS
acpi_SetSleepState(struct acpi_softc *sc, int state)
{
    static int once;

    if (!once) {
        device_printf(sc->acpi_dev,
"warning: acpi_SetSleepState() deprecated, need to update your software\n");
        once = 1;
    }
    return (acpi_EnterSleepState(sc, state));
}

static void
acpi_sleep_force(void *arg)
{
    struct acpi_softc *sc;

    sc = arg;
    device_printf(sc->acpi_dev,
        "suspend request timed out, forcing sleep now\n");
    if (ACPI_FAILURE(acpi_EnterSleepState(sc, sc->acpi_next_sstate)))
        device_printf(sc->acpi_dev, "force sleep state S%d failed\n",
            sc->acpi_next_sstate);
}

/*
 * Request that the system enter the given suspend state.  All /dev/apm
 * devices and devd(8) will be notified.  Userland then has a chance to
 * save state and acknowledge the request.  The system sleeps once all
 * acks are in.
 */
int
acpi_ReqSleepState(struct acpi_softc *sc, int state)
{
#ifdef notyet
    struct apm_clone_data *clone;
#endif

    if (state < ACPI_STATE_S1 || state > ACPI_STATE_S5)
        return (EINVAL);

    /* S5 (soft-off) should be entered directly with no waiting. */
    if (state == ACPI_STATE_S5) {
        if (ACPI_SUCCESS(acpi_EnterSleepState(sc, state)))
            return (0);
        else
            return (ENXIO);
    }

    /* This platform does not support acpi suspend/resume. */
    return (EOPNOTSUPP);

    /* If a suspend request is already in progress, just return. */
    ACPI_LOCK(acpi);
    if (sc->acpi_next_sstate != 0) {
        ACPI_UNLOCK(acpi);
        return (0);
    }

    /* Record the pending state and notify all apm devices. */
    sc->acpi_next_sstate = state;
#if 0
    STAILQ_FOREACH(clone, &sc->apm_cdevs, entries) {
        clone->notify_status = APM_EV_NONE;
        if ((clone->flags & ACPI_EVF_DEVD) == 0) {
            KNOTE(&clone->sel_read.si_note, 0);
        }
    }
#endif

    /* If devd(8) is not running, immediately enter the sleep state. */
    if (devctl_process_running() == FALSE) {
        ACPI_UNLOCK(acpi);
        if (ACPI_SUCCESS(acpi_EnterSleepState(sc, sc->acpi_next_sstate))) {
            return (0);
        } else {
            return (ENXIO);
        }
    }

    /* Now notify devd(8) also. */
    acpi_UserNotify("Suspend", ACPI_ROOT_OBJECT, state);

    /*
     * Set a timeout to fire if userland doesn't ack the suspend request
     * in time.  This way we still eventually go to sleep if we were
     * overheating or running low on battery, even if userland is hung.
     * We cancel this timeout once all userland acks are in or the
     * suspend request is aborted.
     */
    callout_reset(&sc->susp_force_to, 10 * hz, acpi_sleep_force, sc);
    ACPI_UNLOCK(acpi);
    return (0);
}

/*
 * Acknowledge (or reject) a pending sleep state.  The caller has
 * prepared for suspend and is now ready for it to proceed.  If the
 * error argument is non-zero, it indicates suspend should be cancelled
 * and gives an errno value describing why.  Once all votes are in,
 * we suspend the system.
 */
int
acpi_AckSleepState(struct apm_clone_data *clone, int error)
{
    struct acpi_softc *sc;
    int ret, sleeping;

    /* This platform does not support acpi suspend/resume. */
    return (EOPNOTSUPP);

    /* If no pending sleep state, return an error. */
    ACPI_LOCK(acpi);
    sc = clone->acpi_sc;
    if (sc->acpi_next_sstate == 0) {
        ACPI_UNLOCK(acpi);
        return (ENXIO);
    }

    /* Caller wants to abort suspend process. */
    if (error) {
        sc->acpi_next_sstate = 0;
        callout_stop(&sc->susp_force_to);
        device_printf(sc->acpi_dev,
            "listener on %s cancelled the pending suspend\n",
            devtoname(clone->cdev));
        ACPI_UNLOCK(acpi);
        return (0);
    }

    /*
     * Mark this device as acking the suspend request.  Then, walk through
     * all devices, seeing if they agree yet.  We only count devices that
     * are writable since read-only devices couldn't ack the request.
     */
    clone->notify_status = APM_EV_ACKED;
    sleeping = TRUE;
    STAILQ_FOREACH(clone, &sc->apm_cdevs, entries) {
        if ((clone->flags & ACPI_EVF_WRITE) != 0 &&
            clone->notify_status != APM_EV_ACKED) {
            sleeping = FALSE;
            break;
        }
    }

    /* If all devices have voted "yes", we will suspend now. */
    if (sleeping)
        callout_stop(&sc->susp_force_to);
    ACPI_UNLOCK(acpi);
    ret = 0;
    if (sleeping) {
        if (ACPI_FAILURE(acpi_EnterSleepState(sc, sc->acpi_next_sstate)))
                ret = ENODEV;
    }

    return (ret);
}

static void
acpi_sleep_enable(void *arg)
{
    ((struct acpi_softc *)arg)->acpi_sleep_disabled = 0;
}

enum acpi_sleep_state {
    ACPI_SS_NONE,
    ACPI_SS_GPE_SET,
    ACPI_SS_DEV_SUSPEND,
    ACPI_SS_SLP_PREP,
    ACPI_SS_SLEPT,
};

/*
 * Enter the desired system sleep state.
 *
 * Currently we support S1-S5 but S4 is only S4BIOS
 */
static ACPI_STATUS
acpi_EnterSleepState(struct acpi_softc *sc, int state)
{
    ACPI_STATUS status;
    UINT8       TypeA;
    UINT8       TypeB;
    enum acpi_sleep_state slp_state;

    ACPI_FUNCTION_TRACE_U32((char *)(uintptr_t)__func__, state);

    /* Re-entry once we're suspending is not allowed. */
    status = AE_OK;
    ACPI_LOCK(acpi);
    if (sc->acpi_sleep_disabled) {
        ACPI_UNLOCK(acpi);
        device_printf(sc->acpi_dev,
            "suspend request ignored (not ready yet)\n");
        return (AE_ERROR);
    }
    sc->acpi_sleep_disabled = 1;
    ACPI_UNLOCK(acpi);

    /*
     * Be sure to hold Giant across DEVICE_SUSPEND/RESUME since non-MPSAFE
     * drivers need this.
     */
    //get_mplock();
    slp_state = ACPI_SS_NONE;
    switch (state) {
    case ACPI_STATE_S1:
    case ACPI_STATE_S2:
    case ACPI_STATE_S3:
    case ACPI_STATE_S4:
        status = AcpiGetSleepTypeData(state, &TypeA, &TypeB);
        if (status == AE_NOT_FOUND) {
            device_printf(sc->acpi_dev,
                          "Sleep state S%d not supported by BIOS\n", state);
            break;
        } else if (ACPI_FAILURE(status)) {
            device_printf(sc->acpi_dev, "AcpiGetSleepTypeData failed - %s\n",
                          AcpiFormatException(status));
            break;
        }

        sc->acpi_sstate = state;

        /* Enable any GPEs as appropriate and requested by the user. */
        acpi_wake_prep_walk(state);
        slp_state = ACPI_SS_GPE_SET;

        /*
         * Inform all devices that we are going to sleep.  If at least one
         * device fails, DEVICE_SUSPEND() automatically resumes the tree.
         *
         * XXX Note that a better two-pass approach with a 'veto' pass
         * followed by a "real thing" pass would be better, but the current
         * bus interface does not provide for this.
         */
        if (DEVICE_SUSPEND(root_bus) != 0) {
            device_printf(sc->acpi_dev, "device_suspend failed\n");
            break;
        }
        slp_state = ACPI_SS_DEV_SUSPEND;

        /* If testing device suspend only, back out of everything here. */
        if (acpi_susp_bounce)
            break;

        status = AcpiEnterSleepStatePrep(state);
        if (ACPI_FAILURE(status)) {
            device_printf(sc->acpi_dev, "AcpiEnterSleepStatePrep failed - %s\n",
                          AcpiFormatException(status));
            break;
        }
        slp_state = ACPI_SS_SLP_PREP;

        if (sc->acpi_sleep_delay > 0)
            DELAY(sc->acpi_sleep_delay * 1000000);

        if (state != ACPI_STATE_S1) {
            acpi_sleep_machdep(sc, state);

            /* Re-enable ACPI hardware on wakeup from sleep state 4. */
            if (state == ACPI_STATE_S4)
                AcpiEnable();
        } else {
            ACPI_DISABLE_IRQS();
            status = AcpiEnterSleepState(state);
            if (ACPI_FAILURE(status)) {
                device_printf(sc->acpi_dev, "AcpiEnterSleepState failed - %s\n",
                              AcpiFormatException(status));
                break;
            }
        }
        slp_state = ACPI_SS_SLEPT;
        break;
    case ACPI_STATE_S5:
        /*
         * Shut down cleanly and power off.  This will call us back through the
         * shutdown handlers.
         */
        shutdown_nice(RB_POWEROFF);
        break;
    case ACPI_STATE_S0:
    default:
        status = AE_BAD_PARAMETER;
        break;
    }

    /*
     * Back out state according to how far along we got in the suspend
     * process.  This handles both the error and success cases.
     */
    sc->acpi_next_sstate = 0;
    if (slp_state >= ACPI_SS_GPE_SET) {
        acpi_wake_prep_walk(state);
        sc->acpi_sstate = ACPI_STATE_S0;
    }
    if (slp_state >= ACPI_SS_SLP_PREP)
        AcpiLeaveSleepState(state);
    if (slp_state >= ACPI_SS_DEV_SUSPEND)
        DEVICE_RESUME(root_bus);
    if (slp_state >= ACPI_SS_SLEPT)
        acpi_enable_fixed_events(sc);

    /* Allow another sleep request after a while. */
    /* XXX: needs timeout */
    if (state != ACPI_STATE_S5)
              acpi_sleep_enable(sc);

    /* Run /etc/rc.resume after we are back. */
    acpi_UserNotify("Resume", ACPI_ROOT_OBJECT, state);

    //rel_mplock();
    return_ACPI_STATUS (status);
}

/* Enable or disable the device's GPE. */
int
acpi_wake_set_enable(device_t dev, int enable)
{
    struct acpi_prw_data prw;
    ACPI_STATUS status;
    int flags;

    /* Make sure the device supports waking the system and get the GPE. */
    if (acpi_parse_prw(acpi_get_handle(dev), &prw) != 0)
        return (ENXIO);

    flags = acpi_get_flags(dev);
    if (enable) {
        status = AcpiSetGpeWakeMask(prw.gpe_handle, prw.gpe_bit,
                                    ACPI_GPE_ENABLE);
        if (ACPI_FAILURE(status)) {
            device_printf(dev, "enable wake failed\n");
            return (ENXIO);
        }
        acpi_set_flags(dev, flags | ACPI_FLAG_WAKE_ENABLED);
    } else {
        status = AcpiSetGpeWakeMask(prw.gpe_handle, prw.gpe_bit,
                                    ACPI_GPE_DISABLE);
        if (ACPI_FAILURE(status)) {
            device_printf(dev, "disable wake failed\n");
            return (ENXIO);
        }
        acpi_set_flags(dev, flags & ~ACPI_FLAG_WAKE_ENABLED);
    }

    return (0);
}

static int
acpi_wake_sleep_prep(ACPI_HANDLE handle, int sstate)
{
    struct acpi_prw_data prw;
    device_t dev;

    /* Check that this is a wake-capable device and get its GPE. */
    if (acpi_parse_prw(handle, &prw) != 0)
        return (ENXIO);
    dev = acpi_get_device(handle);

    /*
     * The destination sleep state must be less than (i.e., higher power)
     * or equal to the value specified by _PRW.  If this GPE cannot be
     * enabled for the next sleep state, then disable it.  If it can and
     * the user requested it be enabled, turn on any required power resources
     * and set _PSW.
     */
    if (sstate > prw.lowest_wake) {
        AcpiSetGpeWakeMask(prw.gpe_handle, prw.gpe_bit, ACPI_GPE_DISABLE);
        if (bootverbose)
            device_printf(dev, "wake_prep disabled wake for %s (S%d)\n",
                acpi_name(handle), sstate);
    } else if (dev && (acpi_get_flags(dev) & ACPI_FLAG_WAKE_ENABLED) != 0) {
        acpi_pwr_wake_enable(handle, 1);
        acpi_SetInteger(handle, "_PSW", 1);
        if (bootverbose)
            device_printf(dev, "wake_prep enabled for %s (S%d)\n",
                acpi_name(handle), sstate);
    }

    return (0);
}

static int
acpi_wake_run_prep(ACPI_HANDLE handle, int sstate)
{
    struct acpi_prw_data prw;
    device_t dev;

    /*
     * Check that this is a wake-capable device and get its GPE.  Return
     * now if the user didn't enable this device for wake.
     */
    if (acpi_parse_prw(handle, &prw) != 0)
        return (ENXIO);
    dev = acpi_get_device(handle);
    if (dev == NULL || (acpi_get_flags(dev) & ACPI_FLAG_WAKE_ENABLED) == 0)
        return (0);

    /*
     * If this GPE couldn't be enabled for the previous sleep state, it was
     * disabled before going to sleep so re-enable it.  If it was enabled,
     * clear _PSW and turn off any power resources it used.
     */
    if (sstate > prw.lowest_wake) {
        AcpiSetGpeWakeMask(prw.gpe_handle, prw.gpe_bit, ACPI_GPE_ENABLE);
        if (bootverbose)
            device_printf(dev, "run_prep re-enabled %s\n", acpi_name(handle));
    } else {
        acpi_SetInteger(handle, "_PSW", 0);
        acpi_pwr_wake_enable(handle, 0);
        if (bootverbose)
            device_printf(dev, "run_prep cleaned up for %s\n",
                acpi_name(handle));
    }

    return (0);
}

static ACPI_STATUS
acpi_wake_prep(ACPI_HANDLE handle, UINT32 level, void *context, void **status)
{
    int sstate;

    /* If suspending, run the sleep prep function, otherwise wake. */
    sstate = *(int *)context;
    if (AcpiGbl_SystemAwakeAndRunning)
        acpi_wake_sleep_prep(handle, sstate);
    else
        acpi_wake_run_prep(handle, sstate);
    return (AE_OK);
}

/* Walk the tree rooted at acpi0 to prep devices for suspend/resume. */
static int
acpi_wake_prep_walk(int sstate)
{
    ACPI_HANDLE sb_handle;

    if (ACPI_SUCCESS(AcpiGetHandle(ACPI_ROOT_OBJECT, "\\_SB_", &sb_handle))) {
        AcpiWalkNamespace(ACPI_TYPE_DEVICE, sb_handle, 100,
            acpi_wake_prep, NULL, &sstate, NULL);
    }
    return (0);
}

/* Walk the tree rooted at acpi0 to attach per-device wake sysctls. */
static int
acpi_wake_sysctl_walk(device_t dev)
{
#ifdef notyet
    int error, i, numdevs;
    device_t *devlist;
    device_t child;
    ACPI_STATUS status;

    error = device_get_children(dev, &devlist, &numdevs);
    if (error != 0 || numdevs == 0) {
        if (numdevs == 0)
            kfree(devlist, M_TEMP);
        return (error);
    }
    for (i = 0; i < numdevs; i++) {
        child = devlist[i];
        acpi_wake_sysctl_walk(child);
        if (!device_is_attached(child))
            continue;
        status = AcpiEvaluateObject(acpi_get_handle(child), "_PRW", NULL, NULL);
        if (ACPI_SUCCESS(status)) {
            SYSCTL_ADD_PROC(device_get_sysctl_ctx(child),
                SYSCTL_CHILDREN(device_get_sysctl_tree(child)), OID_AUTO,
                "wake", CTLTYPE_INT | CTLFLAG_RW, child, 0,
                acpi_wake_set_sysctl, "I", "Device set to wake the system");
        }
    }
    kfree(devlist, M_TEMP);
#endif

    return (0);
}

#ifdef notyet
/* Enable or disable wake from userland. */
static int
acpi_wake_set_sysctl(SYSCTL_HANDLER_ARGS)
{
    int enable, error;
    device_t dev;

    dev = (device_t)arg1;
    enable = (acpi_get_flags(dev) & ACPI_FLAG_WAKE_ENABLED) ? 1 : 0;

    error = sysctl_handle_int(oidp, &enable, 0, req);
    if (error != 0 || req->newptr == NULL)
        return (error);
    if (enable != 0 && enable != 1)
        return (EINVAL);

    return (acpi_wake_set_enable(dev, enable));
}
#endif

/* Parse a device's _PRW into a structure. */
int
acpi_parse_prw(ACPI_HANDLE h, struct acpi_prw_data *prw)
{
    ACPI_STATUS                 status;
    ACPI_BUFFER                 prw_buffer;
    ACPI_OBJECT                 *res, *res2;
    int                         error, i, power_count;

    if (h == NULL || prw == NULL)
        return (EINVAL);

    /*
     * The _PRW object (7.2.9) is only required for devices that have the
     * ability to wake the system from a sleeping state.
     */
    error = EINVAL;
    prw_buffer.Pointer = NULL;
    prw_buffer.Length = ACPI_ALLOCATE_BUFFER;
    status = AcpiEvaluateObject(h, "_PRW", NULL, &prw_buffer);
    if (ACPI_FAILURE(status))
        return (ENOENT);
    res = (ACPI_OBJECT *)prw_buffer.Pointer;
    if (res == NULL)
        return (ENOENT);
    if (!ACPI_PKG_VALID(res, 2))
        goto out;

    /*
     * Element 1 of the _PRW object:
     * The lowest power system sleeping state that can be entered while still
     * providing wake functionality.  The sleeping state being entered must
     * be less than (i.e., higher power) or equal to this value.
     */
    if (acpi_PkgInt32(res, 1, &prw->lowest_wake) != 0)
        goto out;

    /*
     * Element 0 of the _PRW object:
     */
    switch (res->Package.Elements[0].Type) {
    case ACPI_TYPE_INTEGER:
        /*
         * If the data type of this package element is numeric, then this
         * _PRW package element is the bit index in the GPEx_EN, in the
         * GPE blocks described in the FADT, of the enable bit that is
         * enabled for the wake event.
         */
        prw->gpe_handle = NULL;
        prw->gpe_bit = res->Package.Elements[0].Integer.Value;
        error = 0;
        break;
    case ACPI_TYPE_PACKAGE:
        /*
         * If the data type of this package element is a package, then this
         * _PRW package element is itself a package containing two
         * elements.  The first is an object reference to the GPE Block
         * device that contains the GPE that will be triggered by the wake
         * event.  The second element is numeric and it contains the bit
         * index in the GPEx_EN, in the GPE Block referenced by the
         * first element in the package, of the enable bit that is enabled for
         * the wake event.
         *
         * For example, if this field is a package then it is of the form:
         * Package() {\_SB.PCI0.ISA.GPE, 2}
         */
        res2 = &res->Package.Elements[0];
        if (!ACPI_PKG_VALID(res2, 2))
            goto out;
        prw->gpe_handle = acpi_GetReference(NULL, &res2->Package.Elements[0]);
        if (prw->gpe_handle == NULL)
            goto out;
        if (acpi_PkgInt32(res2, 1, &prw->gpe_bit) != 0)
            goto out;
        error = 0;
        break;
    default:
        goto out;
    }

    /* Elements 2 to N of the _PRW object are power resources. */
    power_count = res->Package.Count - 2;
    if (power_count > ACPI_PRW_MAX_POWERRES) {
        kprintf("ACPI device %s has too many power resources\n", acpi_name(h));
        power_count = 0;
    }
    prw->power_res_count = power_count;
    for (i = 0; i < power_count; i++)
        prw->power_res[i] = res->Package.Elements[i];

out:
    if (prw_buffer.Pointer != NULL)
        AcpiOsFree(prw_buffer.Pointer);
    return (error);
}

/*
 * ACPI Event Handlers
 */

/* System Event Handlers (registered by EVENTHANDLER_REGISTER) */

static void
acpi_system_eventhandler_sleep(void *arg, int state)
{
    struct acpi_softc *sc;
    int ret;

    ACPI_FUNCTION_TRACE_U32((char *)(uintptr_t)__func__, state);

    sc = arg;

    /* Check if button action is disabled. */
    if (state == ACPI_S_STATES_MAX + 1)
        return;

    /* Request that the system prepare to enter the given suspend state. */
    ret = acpi_ReqSleepState((struct acpi_softc *)arg, state);
    if (ret != 0)
        device_printf(sc->acpi_dev,
            "request to enter state S%d failed (err %d)\n", state, ret);

    return_VOID;
}

static void
acpi_system_eventhandler_wakeup(void *arg, int state)
{

    ACPI_FUNCTION_TRACE_U32((char *)(uintptr_t)__func__, state);

    /* Currently, nothing to do for wakeup. */

    return_VOID;
}

/* 
 * ACPICA Event Handlers (FixedEvent, also called from button notify handler)
 */
UINT32
acpi_event_power_button_sleep(void *context)
{
    struct acpi_softc   *sc = (struct acpi_softc *)context;

    ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);

    EVENTHANDLER_INVOKE(acpi_sleep_event, sc->acpi_power_button_sx);

    return_VALUE (ACPI_INTERRUPT_HANDLED);
}

UINT32
acpi_event_power_button_wake(void *context)
{
    struct acpi_softc   *sc = (struct acpi_softc *)context;

    ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);

    EVENTHANDLER_INVOKE(acpi_wakeup_event, sc->acpi_power_button_sx);

    return_VALUE (ACPI_INTERRUPT_HANDLED);
}

UINT32
acpi_event_sleep_button_sleep(void *context)
{
    struct acpi_softc   *sc = (struct acpi_softc *)context;

    ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);

    EVENTHANDLER_INVOKE(acpi_sleep_event, sc->acpi_sleep_button_sx);

    return_VALUE (ACPI_INTERRUPT_HANDLED);
}

UINT32
acpi_event_sleep_button_wake(void *context)
{
    struct acpi_softc   *sc = (struct acpi_softc *)context;

    ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);

    EVENTHANDLER_INVOKE(acpi_wakeup_event, sc->acpi_sleep_button_sx);

    return_VALUE (ACPI_INTERRUPT_HANDLED);
}

/*
 * XXX This static buffer is suboptimal.  There is no locking so only
 * use this for single-threaded callers.
 */
char *
acpi_name(ACPI_HANDLE handle)
{
    ACPI_BUFFER buf;
    static char data[256];

    buf.Length = sizeof(data);
    buf.Pointer = data;

    if (handle && ACPI_SUCCESS(AcpiGetName(handle, ACPI_FULL_PATHNAME, &buf)))
        return (data);
    return ("(unknown)");
}

/*
 * Debugging/bug-avoidance.  Avoid trying to fetch info on various
 * parts of the namespace.
 */
int
acpi_avoid(ACPI_HANDLE handle)
{
    char        *cp, *env, *np;
    int         len;

    np = acpi_name(handle);
    if (*np == '\\')
        np++;
    if ((env = kgetenv("debug.acpi.avoid")) == NULL)
        return (0);

    /* Scan the avoid list checking for a match */
    cp = env;
    for (;;) {
        while (*cp != 0 && isspace(*cp))
            cp++;
        if (*cp == 0)
            break;
        len = 0;
        while (cp[len] != 0 && !isspace(cp[len]))
            len++;
        if (!strncmp(cp, np, len)) {
            kfreeenv(env);
            return(1);
        }
        cp += len;
    }
    kfreeenv(env);

    return (0);
}

/*
 * Debugging/bug-avoidance.  Disable ACPI subsystem components.
 */
int
acpi_disabled(char *subsys)
{
    char        *cp, *env;
    int         len;

    if ((env = kgetenv("debug.acpi.disabled")) == NULL)
        return (0);
    if (strcmp(env, "all") == 0) {
        kfreeenv(env);
        return (1);
    }

    /* Scan the disable list, checking for a match. */
    cp = env;
    for (;;) {
        while (*cp != '\0' && isspace(*cp))
            cp++;
        if (*cp == '\0')
            break;
        len = 0;
        while (cp[len] != '\0' && !isspace(cp[len]))
            len++;
        if (strncmp(cp, subsys, len) == 0) {
            kfreeenv(env);
            return (1);
        }
        cp += len;
    }
    kfreeenv(env);

    return (0);
}

/*
 * Debugging/bug-avoidance.  Enable ACPI subsystem components.  Most 
 * components are enabled by default.  The ones that are not have to be 
 * enabled via debug.acpi.enabled.
 */
int
acpi_enabled(char *subsys)
{
    char        *cp, *env;
    int         len;

    if ((env = kgetenv("debug.acpi.enabled")) == NULL)
        return (0);
    if (strcmp(env, "all") == 0) {
        kfreeenv(env);
        return (1);
    }

    /* Scan the enable list, checking for a match. */
    cp = env;
    for (;;) {
        while (*cp != '\0' && isspace(*cp))
            cp++;
        if (*cp == '\0')
            break;
        len = 0;
        while (cp[len] != '\0' && !isspace(cp[len]))
            len++;
        if (strncmp(cp, subsys, len) == 0) {
            kfreeenv(env);
            return (1);
        }
        cp += len;
    }
    kfreeenv(env);

    return (0);
}

/*
 * Control interface.
 *
 * We multiplex ioctls for all participating ACPI devices here.  Individual 
 * drivers wanting to be accessible via /dev/acpi should use the
 * register/deregister interface to make their handlers visible.
 */
struct acpi_ioctl_hook
{
    TAILQ_ENTRY(acpi_ioctl_hook) link;
    u_long                       cmd;
    acpi_ioctl_fn                fn;
    void                         *arg;
};

static TAILQ_HEAD(,acpi_ioctl_hook)     acpi_ioctl_hooks;
static int                              acpi_ioctl_hooks_initted;

int
acpi_register_ioctl(u_long cmd, acpi_ioctl_fn fn, void *arg)
{
    struct acpi_ioctl_hook      *hp;

    if ((hp = kmalloc(sizeof(*hp), M_ACPIDEV, M_NOWAIT)) == NULL)
        return (ENOMEM);
    hp->cmd = cmd;
    hp->fn = fn;
    hp->arg = arg;

    ACPI_LOCK(acpi);
    if (acpi_ioctl_hooks_initted == 0) {
        TAILQ_INIT(&acpi_ioctl_hooks);
        acpi_ioctl_hooks_initted = 1;
    }
    TAILQ_INSERT_TAIL(&acpi_ioctl_hooks, hp, link);
    ACPI_UNLOCK(acpi);

    return (0);
}

void
acpi_deregister_ioctl(u_long cmd, acpi_ioctl_fn fn)
{
    struct acpi_ioctl_hook      *hp;

    ACPI_LOCK(acpi);
    TAILQ_FOREACH(hp, &acpi_ioctl_hooks, link)
        if (hp->cmd == cmd && hp->fn == fn)
            break;

    if (hp != NULL) {
        TAILQ_REMOVE(&acpi_ioctl_hooks, hp, link);
        kfree(hp, M_ACPIDEV);
    }
    ACPI_UNLOCK(acpi);
}

static int
acpiopen(struct dev_open_args *ap)
{
    return (0);
}

static int
acpiclose(struct dev_close_args *ap)
{
    return (0);
}

static int
acpiioctl(struct dev_ioctl_args *ap)
{
    struct acpi_softc           *sc;
    struct acpi_ioctl_hook      *hp;
    int                         error, state;

    error = 0;
    hp = NULL;
    sc = ap->a_head.a_dev->si_drv1;

    /*
     * Scan the list of registered ioctls, looking for handlers.
     */
    ACPI_LOCK(acpi);
    if (acpi_ioctl_hooks_initted)
        TAILQ_FOREACH(hp, &acpi_ioctl_hooks, link) {
            if (hp->cmd == ap->a_cmd)
                break;
        }
    ACPI_UNLOCK(acpi);
    if (hp)
        return (hp->fn(ap->a_cmd, ap->a_data, hp->arg));

    /*
     * Core ioctls are not permitted for non-writable user.
     * Currently, other ioctls just fetch information.
     * Not changing system behavior.
     */
    if ((ap->a_fflag & FWRITE) == 0)
        return (EPERM);

    /* Core system ioctls. */
    switch (ap->a_cmd) {
    case ACPIIO_REQSLPSTATE:
        state = *(int *)ap->a_data;
        if (state != ACPI_STATE_S5)
            error = acpi_ReqSleepState(sc, state);
        else {
            device_printf(sc->acpi_dev,
                "power off via acpi ioctl not supported\n");
            error = ENXIO;
        }
        break;
    case ACPIIO_ACKSLPSTATE:
        error = EOPNOTSUPP;
#if 0 /* notyet */
        error = *(int *)ap->a_data;
        error = acpi_AckSleepState(sc->acpi_clone, error);
#endif
        break;
    case ACPIIO_SETSLPSTATE:    /* DEPRECATED */
        error = EINVAL;
        state = *(int *)ap->a_data;
        if (state >= ACPI_STATE_S0 && state <= ACPI_S_STATES_MAX)
            if (ACPI_SUCCESS(acpi_SetSleepState(sc, state)))
                error = 0;
        break;
    case ACPIIO_DO_MCALL:
        if (acpi_allow_mcall == 1) {
            struct acpi_mcall_ioctl_arg *params;
            ACPI_BUFFER result = { ACPI_ALLOCATE_BUFFER, NULL };
            ACPI_OBJECT *resobj;

            error = EINVAL;
            params = (struct acpi_mcall_ioctl_arg *)ap->a_data;
            params->retval = AcpiEvaluateObject(NULL, params->path,
                &params->args, &result);
            if (ACPI_SUCCESS(params->retval) && result.Pointer != NULL &&
                params->result.Pointer != NULL) {
                params->result.Length = min(params->result.Length,
                    result.Length);
                copyout(result.Pointer, params->result.Pointer,
                    params->result.Length);
                params->reslen = result.Length;
                if (result.Length >= sizeof(ACPI_OBJECT)) {
                    resobj = (ACPI_OBJECT *)params->result.Pointer;
                    switch (resobj->Type) {
                    case ACPI_TYPE_STRING:
                        resobj->String.Pointer = (char *)
                            ((UINT8 *)(resobj->String.Pointer) -
                                (UINT8 *)result.Pointer +
                                (UINT8 *)resobj);
                        break;
                    case ACPI_TYPE_BUFFER:
                        resobj->Buffer.Pointer -= (UINT8 *)result.Pointer -
                            (UINT8 *)resobj;
                        break;
                    }
                }
                error = 0;
            }
            if (result.Pointer != NULL)
                AcpiOsFree(result.Pointer);
        } else {
                device_printf(sc->acpi_dev,
                    "debug.acpi.allow_method_calls must be set\n");
                error = ENXIO;
        }
        break;
    default:
        error = ENXIO;
        break;
    }
    return (error);
}

static int
acpi_supported_sleep_state_sysctl(SYSCTL_HANDLER_ARGS)
{
    int error;
    struct sbuf sb;
    UINT8 state, TypeA, TypeB;

    sbuf_new(&sb, NULL, 32, SBUF_AUTOEXTEND);
    for (state = ACPI_STATE_S1; state < ACPI_S_STATES_MAX + 1; state++)
        if (ACPI_SUCCESS(AcpiGetSleepTypeData(state, &TypeA, &TypeB)))
            sbuf_printf(&sb, "S%d ", state);
    sbuf_trim(&sb);
    sbuf_finish(&sb);
    error = sysctl_handle_string(oidp, sbuf_data(&sb), sbuf_len(&sb), req);
    sbuf_delete(&sb);
    return (error);
}

static int
acpi_sleep_state_sysctl(SYSCTL_HANDLER_ARGS)
{
    char sleep_state[10];
    int error;
    u_int new_state, old_state;

    old_state = *(u_int *)oidp->oid_arg1;
    if (old_state > ACPI_S_STATES_MAX + 1)
        strlcpy(sleep_state, "unknown", sizeof(sleep_state));
    else
        strlcpy(sleep_state, sleep_state_names[old_state], sizeof(sleep_state));
    error = sysctl_handle_string(oidp, sleep_state, sizeof(sleep_state), req);
    if (error == 0 && req->newptr != NULL) {
        new_state = ACPI_STATE_S0;
        for (; new_state <= ACPI_S_STATES_MAX + 1; new_state++)
            if (strcmp(sleep_state, sleep_state_names[new_state]) == 0)
                break;
        if (new_state <= ACPI_S_STATES_MAX + 1) {
            if (new_state != old_state)
                *(u_int *)oidp->oid_arg1 = new_state;
        } else
            error = EINVAL;
    }

    return (error);
}

/* Inform devctl(4) when we receive a Notify. */
void
acpi_UserNotify(const char *subsystem, ACPI_HANDLE h, uint8_t notify)
{
    char                notify_buf[16];
    ACPI_BUFFER         handle_buf;
    ACPI_STATUS         status;

    if (subsystem == NULL)
        return;

    handle_buf.Pointer = NULL;
    handle_buf.Length = ACPI_ALLOCATE_BUFFER;
    status = AcpiNsHandleToPathname(h, &handle_buf, FALSE);
    if (ACPI_FAILURE(status))
        return;
    ksnprintf(notify_buf, sizeof(notify_buf), "notify=0x%02x", notify);
    devctl_notify("ACPI", subsystem, handle_buf.Pointer, notify_buf);
    AcpiOsFree(handle_buf.Pointer);
}

#ifdef ACPI_DEBUG
/*
 * Support for parsing debug options from the kernel environment.
 *
 * Bits may be set in the AcpiDbgLayer and AcpiDbgLevel debug registers
 * by specifying the names of the bits in the debug.acpi.layer and
 * debug.acpi.level environment variables.  Bits may be unset by 
 * prefixing the bit name with !.
 */
struct debugtag
{
    char        *name;
    UINT32      value;
};

static struct debugtag  dbg_layer[] = {
    {"ACPI_UTILITIES",          ACPI_UTILITIES},
    {"ACPI_HARDWARE",           ACPI_HARDWARE},
    {"ACPI_EVENTS",             ACPI_EVENTS},
    {"ACPI_TABLES",             ACPI_TABLES},
    {"ACPI_NAMESPACE",          ACPI_NAMESPACE},
    {"ACPI_PARSER",             ACPI_PARSER},
    {"ACPI_DISPATCHER",         ACPI_DISPATCHER},
    {"ACPI_EXECUTER",           ACPI_EXECUTER},
    {"ACPI_RESOURCES",          ACPI_RESOURCES},
    {"ACPI_CA_DEBUGGER",        ACPI_CA_DEBUGGER},
    {"ACPI_OS_SERVICES",        ACPI_OS_SERVICES},
    {"ACPI_CA_DISASSEMBLER",    ACPI_CA_DISASSEMBLER},
    {"ACPI_ALL_COMPONENTS",     ACPI_ALL_COMPONENTS},

    {"ACPI_AC_ADAPTER",         ACPI_AC_ADAPTER},
    {"ACPI_BATTERY",            ACPI_BATTERY},
    {"ACPI_BUS",                ACPI_BUS},
    {"ACPI_BUTTON",             ACPI_BUTTON},
    {"ACPI_EC",                 ACPI_EC},
    {"ACPI_FAN",                ACPI_FAN},
    {"ACPI_POWERRES",           ACPI_POWERRES},
    {"ACPI_PROCESSOR",          ACPI_PROCESSOR},
    {"ACPI_THERMAL",            ACPI_THERMAL},
    {"ACPI_TIMER",              ACPI_TIMER},
    {"ACPI_ALL_DRIVERS",        ACPI_ALL_DRIVERS},
    {NULL, 0}
};

static struct debugtag dbg_level[] = {
    {"ACPI_LV_INIT",            ACPI_LV_INIT},
    {"ACPI_LV_DEBUG_OBJECT",    ACPI_LV_DEBUG_OBJECT},
    {"ACPI_LV_INFO",            ACPI_LV_INFO},
    {"ACPI_LV_REPAIR",          ACPI_LV_REPAIR},
    {"ACPI_LV_ALL_EXCEPTIONS",  ACPI_LV_ALL_EXCEPTIONS},

    /* Trace verbosity level 1 [Standard Trace Level] */
    {"ACPI_LV_INIT_NAMES",      ACPI_LV_INIT_NAMES},
    {"ACPI_LV_PARSE",           ACPI_LV_PARSE},
    {"ACPI_LV_LOAD",            ACPI_LV_LOAD},
    {"ACPI_LV_DISPATCH",        ACPI_LV_DISPATCH},
    {"ACPI_LV_EXEC",            ACPI_LV_EXEC},
    {"ACPI_LV_NAMES",           ACPI_LV_NAMES},
    {"ACPI_LV_OPREGION",        ACPI_LV_OPREGION},
    {"ACPI_LV_BFIELD",          ACPI_LV_BFIELD},
    {"ACPI_LV_TABLES",          ACPI_LV_TABLES},
    {"ACPI_LV_VALUES",          ACPI_LV_VALUES},
    {"ACPI_LV_OBJECTS",         ACPI_LV_OBJECTS},
    {"ACPI_LV_RESOURCES",       ACPI_LV_RESOURCES},
    {"ACPI_LV_USER_REQUESTS",   ACPI_LV_USER_REQUESTS},
    {"ACPI_LV_PACKAGE",         ACPI_LV_PACKAGE},
    {"ACPI_LV_VERBOSITY1",      ACPI_LV_VERBOSITY1},

    /* Trace verbosity level 2 [Function tracing and memory allocation] */
    {"ACPI_LV_ALLOCATIONS",     ACPI_LV_ALLOCATIONS},
    {"ACPI_LV_FUNCTIONS",       ACPI_LV_FUNCTIONS},
    {"ACPI_LV_OPTIMIZATIONS",   ACPI_LV_OPTIMIZATIONS},
    {"ACPI_LV_VERBOSITY2",      ACPI_LV_VERBOSITY2},
    {"ACPI_LV_ALL",             ACPI_LV_ALL},

    /* Trace verbosity level 3 [Threading, I/O, and Interrupts] */
    {"ACPI_LV_MUTEX",           ACPI_LV_MUTEX},
    {"ACPI_LV_THREADS",         ACPI_LV_THREADS},
    {"ACPI_LV_IO",              ACPI_LV_IO},
    {"ACPI_LV_INTERRUPTS",      ACPI_LV_INTERRUPTS},
    {"ACPI_LV_VERBOSITY3",      ACPI_LV_VERBOSITY3},

    /* Exceptionally verbose output -- also used in the global "DebugLevel"  */
    {"ACPI_LV_AML_DISASSEMBLE", ACPI_LV_AML_DISASSEMBLE},
    {"ACPI_LV_VERBOSE_INFO",    ACPI_LV_VERBOSE_INFO},
    {"ACPI_LV_FULL_TABLES",     ACPI_LV_FULL_TABLES},
    {"ACPI_LV_EVENTS",          ACPI_LV_EVENTS},
    {"ACPI_LV_VERBOSE",         ACPI_LV_VERBOSE},
    {NULL, 0}
};    

static void
acpi_parse_debug(char *cp, struct debugtag *tag, UINT32 *flag)
{
    char        *ep;
    int         i, l;
    int         set;

    while (*cp) {
        if (isspace(*cp)) {
            cp++;
            continue;
        }
        ep = cp;
        while (*ep && !isspace(*ep))
            ep++;
        if (*cp == '!') {
            set = 0;
            cp++;
            if (cp == ep)
                continue;
        } else {
            set = 1;
        }
        l = ep - cp;
        for (i = 0; tag[i].name != NULL; i++) {
            if (!strncmp(cp, tag[i].name, l)) {
                if (set)
                    *flag |= tag[i].value;
                else
                    *flag &= ~tag[i].value;
            }
        }
        cp = ep;
    }
}

static void
acpi_set_debugging(void *junk)
{
    char        *layer, *level;

    if (cold) {
        AcpiDbgLayer = 0;
        AcpiDbgLevel = 0;
    }

    layer = kgetenv("debug.acpi.layer");
    level = kgetenv("debug.acpi.level");
    if (layer == NULL && level == NULL)
        return;

    kprintf("ACPI set debug");
    if (layer != NULL) {
        if (strcmp("NONE", layer) != 0)
            kprintf(" layer '%s'", layer);
        acpi_parse_debug(layer, &dbg_layer[0], &AcpiDbgLayer);
        kfreeenv(layer);
    }
    if (level != NULL) {
        if (strcmp("NONE", level) != 0)
            kprintf(" level '%s'", level);
        acpi_parse_debug(level, &dbg_level[0], &AcpiDbgLevel);
        kfreeenv(level);
    }
    kprintf("\n");
}

SYSINIT(acpi_debugging, SI_BOOT1_TUNABLES, SI_ORDER_ANY, acpi_set_debugging,
        NULL);

static int
acpi_debug_sysctl(SYSCTL_HANDLER_ARGS)
{
    int          error, *dbg;
    struct       debugtag *tag;
    struct       sbuf sb;

    if (sbuf_new(&sb, NULL, 128, SBUF_AUTOEXTEND) == NULL)
        return (ENOMEM);
    if (strcmp(oidp->oid_arg1, "debug.acpi.layer") == 0) {
        tag = &dbg_layer[0];
        dbg = &AcpiDbgLayer;
    } else {
        tag = &dbg_level[0];
        dbg = &AcpiDbgLevel;
    }

    /* Get old values if this is a get request. */
    ACPI_SERIAL_BEGIN(acpi);
    if (*dbg == 0) {
        sbuf_cpy(&sb, "NONE");
    } else if (req->newptr == NULL) {
        for (; tag->name != NULL; tag++) {
            if ((*dbg & tag->value) == tag->value)
                sbuf_printf(&sb, "%s ", tag->name);
        }
    }
    sbuf_trim(&sb);
    sbuf_finish(&sb);

    /* Copy out the old values to the user. */
    error = SYSCTL_OUT(req, sbuf_data(&sb), sbuf_len(&sb));
    sbuf_delete(&sb);

    /* If the user is setting a string, parse it. */
    if (error == 0 && req->newptr != NULL) {
        *dbg = 0;
        ksetenv((char *)oidp->oid_arg1, (char *)req->newptr);
        acpi_set_debugging(NULL);
    }
    ACPI_SERIAL_END(acpi);

    return (error);
}

SYSCTL_PROC(_debug_acpi, OID_AUTO, layer, CTLFLAG_RW | CTLTYPE_STRING,
            "debug.acpi.layer", 0, acpi_debug_sysctl, "A", "");
SYSCTL_PROC(_debug_acpi, OID_AUTO, level, CTLFLAG_RW | CTLTYPE_STRING,
            "debug.acpi.level", 0, acpi_debug_sysctl, "A", "");
#endif /* ACPI_DEBUG */

static int
acpi_debug_objects_sysctl(SYSCTL_HANDLER_ARGS)
{
        int     error;
        int     old;

        old = acpi_debug_objects;
        error = sysctl_handle_int(oidp, &acpi_debug_objects, 0, req);
        if (error != 0 || req->newptr == NULL)
                return (error);
        if (old == acpi_debug_objects || (old && acpi_debug_objects))
                return (0);

        ACPI_SERIAL_BEGIN(acpi);
        AcpiGbl_EnableAmlDebugObject = acpi_debug_objects ? TRUE : FALSE;
        ACPI_SERIAL_END(acpi);

        return (0);
}


static int
acpi_parse_interfaces(char *str, struct acpi_interface *iface)
{
        char *p;
        size_t len;
        int i, j;

        p = str;
        while (isspace(*p) || *p == ',')
                p++;
        len = strlen(p);
        if (len == 0)
                return (0);
        p = kstrdup(p, M_TEMP);
        for (i = 0; i < len; i++)
                if (p[i] == ',')
                        p[i] = '\0';
        i = j = 0;
        while (i < len)
                if (isspace(p[i]) || p[i] == '\0')
                        i++;
                else {
                        i += strlen(p + i) + 1;
                        j++;
                }
        if (j == 0) {
                kfree(p, M_TEMP);
                return (0);
        }
        iface->data = kmalloc(sizeof(*iface->data) * j, M_TEMP, M_WAITOK);
        iface->num = j;
        i = j = 0;
        while (i < len)
                if (isspace(p[i]) || p[i] == '\0')
                        i++;
                else {
                        iface->data[j] = p + i;
                        i += strlen(p + i) + 1;
                        j++;
                }

        return (j);
}

static void
acpi_free_interfaces(struct acpi_interface *iface)
{
        kfree(iface->data[0], M_TEMP);
        kfree(iface->data, M_TEMP);
}

static void
acpi_reset_interfaces(device_t dev)
{
        struct acpi_interface list;
        ACPI_STATUS status;
        int i;

        if (acpi_parse_interfaces(acpi_install_interface, &list) > 0) {
                for (i = 0; i < list.num; i++) {
                        status = AcpiInstallInterface(list.data[i]);
                        if (ACPI_FAILURE(status))
                                device_printf(dev,
                                    "failed to install _OSI(\"%s\"): %s\n",
                                    list.data[i], AcpiFormatException(status));
                        else if (bootverbose)
                                device_printf(dev, "installed _OSI(\"%s\")\n",
                                    list.data[i]);
                }
                acpi_free_interfaces(&list);
        }
        if (acpi_parse_interfaces(acpi_remove_interface, &list) > 0) {
                for (i = 0; i < list.num; i++) {
                        status = AcpiRemoveInterface(list.data[i]);
                        if (ACPI_FAILURE(status))
                                device_printf(dev,
                                    "failed to remove _OSI(\"%s\"): %s\n",
                                    list.data[i], AcpiFormatException(status));
                        else if (bootverbose)
                                device_printf(dev, "removed _OSI(\"%s\")\n",
                                    list.data[i]);
                }
                acpi_free_interfaces(&list);
        }
}

static int
acpi_pm_func(u_long cmd, void *arg, ...)
{
        int     state, acpi_state;
        int     error;
        struct  acpi_softc *sc;
        va_list ap;

        error = 0;
        switch (cmd) {
        case POWER_CMD_SUSPEND:
                sc = (struct acpi_softc *)arg;
                if (sc == NULL) {
                        error = EINVAL;
                        goto out;
                }

                va_start(ap, arg);
                state = va_arg(ap, int);
                va_end(ap);

                switch (state) {
                case POWER_SLEEP_STATE_STANDBY:
                        acpi_state = sc->acpi_standby_sx;
                        break;
                case POWER_SLEEP_STATE_SUSPEND:
                        acpi_state = sc->acpi_suspend_sx;
                        break;
                case POWER_SLEEP_STATE_HIBERNATE:
                        acpi_state = ACPI_STATE_S4;
                        break;
                default:
                        error = EINVAL;
                        goto out;
                }

                if (ACPI_FAILURE(acpi_EnterSleepState(sc, acpi_state)))
                        error = ENXIO;
                break;
        default:
                error = EINVAL;
                goto out;
        }

out:
        return (error);
}

static void
acpi_pm_register(void *arg)
{
    if (!cold || resource_disabled("acpi", 0))
        return;

    power_pm_register(POWER_PM_TYPE_ACPI, acpi_pm_func, NULL);
}

SYSINIT(power, SI_BOOT2_KLD, SI_ORDER_ANY, acpi_pm_register, 0);