FreeBSD/Linux Kernel Cross Reference
sys/dev/acpica/acpi.c

     /*-
      * Copyright (c) 2000 Takanori Watanabe <takawata@jp.freebsd.org>
      * Copyright (c) 2000 Mitsuru IWASAKI <iwasaki@jp.freebsd.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.
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD: releng/10.3/sys/dev/acpica/acpi.c 295131 2016-02-01 23:07:31Z jhb $");
    
    #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/ioccom.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/sched.h>
    #include <sys/smp.h>
    #include <sys/timetc.h>
    
    #if defined(__i386__) || defined(__amd64__)
    #include <machine/pci_cfgreg.h>
    #endif
    #include <machine/resource.h>
    #include <machine/bus.h>
    #include <sys/rman.h>
    #include <isa/isavar.h>
    #include <isa/pnpvar.h>
    
    #include <contrib/dev/acpica/include/acpi.h>
    #include <contrib/dev/acpica/include/accommon.h>
    #include <contrib/dev/acpica/include/acnamesp.h>
    
    #include <dev/acpica/acpivar.h>
    #include <dev/acpica/acpiio.h>
    
    #include <vm/vm_param.h>
    
    static MALLOC_DEFINE(M_ACPIDEV, "acpidev", "ACPI devices");
    
    /* Hooks for the ACPI CA 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 cdevsw acpi_cdevsw = {
            .d_version =    D_VERSION,
            .d_open =       acpiopen,
            .d_close =      acpiclose,
            .d_ioctl =      acpiioctl,
            .d_name =       "acpi",
    };
    
    struct acpi_interface {
            ACPI_STRING     *data;
            int             num;
    };
    
    /* Global mutex for locking access to the ACPI subsystem. */
    struct mtx      acpi_mutex;
    
    /* Bitmap of device quirks. */
    int             acpi_quirks;
    
   /* Supported sleep states. */
   static BOOLEAN  acpi_sleep_states[ACPI_S_STATE_COUNT];
   
   static void     acpi_lookup(void *arg, const char *name, device_t *dev);
   static int      acpi_modevent(struct module *mod, int event, void *junk);
   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, u_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 void     acpi_reserve_resources(device_t dev);
   static int      acpi_sysres_alloc(device_t dev);
   static int      acpi_set_resource(device_t dev, device_t child, int type,
                           int rid, u_long start, u_long count);
   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);
   static int      acpi_adjust_resource(device_t bus, device_t child, int type,
                           struct resource *r, u_long start, u_long end);
   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 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(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 void     acpi_sleep_enable(void *arg);
   static ACPI_STATUS acpi_sleep_disable(struct acpi_softc *sc);
   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 BOOLEAN  acpi_has_hid(ACPI_HANDLE handle);
   static void     acpi_resync_clock(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);
   static int      acpi_wake_set_sysctl(SYSCTL_HANDLER_ARGS);
   static void     acpi_system_eventhandler_sleep(void *arg, int state);
   static void     acpi_system_eventhandler_wakeup(void *arg, int state);
   static int      acpi_sname2sstate(const char *sname);
   static const char *acpi_sstate2sname(int sstate);
   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);
   #if defined(__i386__) || defined(__amd64__)
   static void     acpi_enable_pcie(void);
   #endif
   static void     acpi_hint_device_unit(device_t acdev, device_t child,
                       const char *name, int *unitp);
   static void     acpi_reset_interfaces(device_t dev);
   
   static device_method_t acpi_methods[] = {
       /* Device interface */
       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,         acpi_set_resource),
       DEVMETHOD(bus_get_resource,         bus_generic_rl_get_resource),
       DEVMETHOD(bus_alloc_resource,       acpi_alloc_resource),
       DEVMETHOD(bus_adjust_resource,      acpi_adjust_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),
       DEVMETHOD(bus_hint_device_unit,     acpi_hint_device_unit),
       DEVMETHOD(bus_get_domain,           acpi_get_domain),
   
       /* 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),
   
       /* 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, 0);
   MODULE_VERSION(acpi, 1);
   
   ACPI_SERIAL_DECL(acpi, "ACPI root bus");
   
   /* Local pools for managing system resources for ACPI child devices. */
   static struct rman acpi_rman_io, acpi_rman_mem;
   
   #define ACPI_MINIMUM_AWAKETIME  5
   
   /* Holds the description of the acpi0 device. */
   static char acpi_desc[ACPI_OEM_ID_SIZE + ACPI_OEM_TABLE_ID_SIZE + 2];
   
   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 ACPI-CA");
   
   /*
    * 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));
   
   /* 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 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_RDTUN,
       &acpi_interpreter_slack, 1, "Turn on interpreter slack mode.");
   
   /* Ignore register widths set by FADT and use default widths instead. */
   static int acpi_ignore_reg_width = 1;
   TUNABLE_INT("debug.acpi.default_register_width", &acpi_ignore_reg_width);
   SYSCTL_INT(_debug_acpi, OID_AUTO, default_register_width, CTLFLAG_RDTUN,
       &acpi_ignore_reg_width, 1, "Ignore register widths set by FADT");
   
   #ifdef __amd64__
   /* Reset system clock while resuming.  XXX Remove once tested. */
   static int acpi_reset_clock = 1;
   TUNABLE_INT("debug.acpi.reset_clock", &acpi_reset_clock);
   SYSCTL_INT(_debug_acpi, OID_AUTO, reset_clock, CTLFLAG_RW,
       &acpi_reset_clock, 1, "Reset system clock while resuming.");
   #endif
   
   /* Allow users to override quirks. */
   TUNABLE_INT("debug.acpi.quirks", &acpi_quirks);
   
   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 hierarchy hangs
    * off it.
    */
   static int
   acpi_modevent(struct module *mod, int event, void *junk)
   {
       switch (event) {
       case MOD_LOAD:
           if (!cold) {
               printf("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))) {
           printf("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) {
           printf("ACPI disabled by blacklist.  Contact your BIOS vendor.\n");
           status = AE_SUPPORT;
       }
   
       return_VALUE (status);
   }
   
   /*
    * Detect ACPI and perform early initialisation.
    */
   int
   acpi_identify(void)
   {
       ACPI_TABLE_RSDP     *rsdp;
       ACPI_TABLE_HEADER   *rsdt;
       ACPI_PHYSICAL_ADDRESS paddr;
       struct sbuf         sb;
   
       ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
   
       if (!cold)
           return (ENXIO);
   
       /* Check that we haven't been disabled with a hint. */
       if (resource_disabled("acpi", 0))
           return (ENXIO);
   
       /* Check for other PM systems. */
       if (power_pm_get_type() != POWER_PM_TYPE_NONE &&
           power_pm_get_type() != POWER_PM_TYPE_ACPI) {
           printf("ACPI identify failed, other PM system enabled.\n");
           return (ENXIO);
       }
   
       /* Initialize root tables. */
       if (ACPI_FAILURE(acpi_Startup())) {
           printf("ACPI: Try disabling either ACPI or apic support.\n");
           return (ENXIO);
       }
   
       if ((paddr = AcpiOsGetRootPointer()) == 0 ||
           (rsdp = AcpiOsMapMemory(paddr, sizeof(ACPI_TABLE_RSDP))) == NULL)
           return (ENXIO);
       if (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 (ENXIO);
       sbuf_new(&sb, acpi_desc, sizeof(acpi_desc), 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);
       sbuf_delete(&sb);
       AcpiOsUnmapMemory(rsdt, sizeof(ACPI_TABLE_HEADER));
   
       snprintf(acpi_ca_version, sizeof(acpi_ca_version), "%x", ACPI_CA_VERSION);
   
       return (0);
   }
   
   /*
    * Fetch some descriptive data from ACPI to put in our attach message.
    */
   static int
   acpi_probe(device_t dev)
   {
   
       ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
   
       device_set_desc(dev, acpi_desc);
   
       return_VALUE (BUS_PROBE_NOWILDCARD);
   }
   
   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, TRUE);
   
       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) != 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) != 0)
           panic("acpi rman_init memory failed");
   
       /* Initialise the ACPI mutex */
       mtx_init(&acpi_mutex, "ACPI global lock", NULL, MTX_DEF);
   
       /*
        * Set the globals from our tunables.  This is needed because ACPI-CA
        * uses UINT8 for some values and we have no tunable_byte.
        */
       AcpiGbl_EnableInterpreterSlack = acpi_interpreter_slack ? TRUE : FALSE;
       AcpiGbl_EnableAmlDebugObject = acpi_debug_objects ? TRUE : FALSE;
       AcpiGbl_UseDefaultRegisterWidths = acpi_ignore_reg_width ? TRUE : FALSE;
   
   #ifndef ACPI_DEBUG
       /*
        * Disable all debugging layers and levels.
        */
       AcpiDbgLayer = 0;
       AcpiDbgLevel = 0;
   #endif
   
       /* Start up the ACPI CA 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;
       }
   
   #if defined(__i386__) || defined(__amd64__)
       /* Handle MCFG table if present. */
       acpi_enable_pcie();
   #endif
   
       /*
        * 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 = 0;
       if (testenv("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;
       }
   
       /*
        * 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 in seconds");
       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 = getenv("hw.acpi.verbose")) != NULL) {
           if (strcmp(env, "") != 0)
               sc->acpi_verbose = 1;
           freeenv(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;
   
       /* Probe all supported sleep states. */
       acpi_sleep_states[ACPI_STATE_S0] = TRUE;
       for (state = ACPI_STATE_S1; state < ACPI_S_STATE_COUNT; state++)
           if (ACPI_SUCCESS(AcpiEvaluateObject(ACPI_ROOT_OBJECT,
               __DECONST(char *, AcpiGbl_SleepStateNames[state]), NULL, NULL)) &&
               ACPI_SUCCESS(AcpiGetSleepTypeData(state, &TypeA, &TypeB)))
               acpi_sleep_states[state] = TRUE;
   
       /*
        * Dispatch the default sleep state to devices.  The lid switch is set
        * to UNKNOWN by default to avoid surprising users.
        */
       sc->acpi_power_button_sx = acpi_sleep_states[ACPI_STATE_S5] ?
           ACPI_STATE_S5 : ACPI_STATE_UNKNOWN;
       sc->acpi_lid_switch_sx = ACPI_STATE_UNKNOWN;
       sc->acpi_standby_sx = acpi_sleep_states[ACPI_STATE_S1] ?
           ACPI_STATE_S1 : ACPI_STATE_UNKNOWN;
       sc->acpi_suspend_sx = acpi_sleep_states[ACPI_STATE_S3] ?
           ACPI_STATE_S3 : ACPI_STATE_UNKNOWN;
   
       /* Pick the first valid sleep state for the sleep button default. */
       sc->acpi_sleep_button_sx = ACPI_STATE_UNKNOWN;
       for (state = ACPI_STATE_S1; state <= ACPI_STATE_S4; state++)
           if (acpi_sleep_states[state]) {
               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 = TRUE;
       sc->acpi_sstate = ACPI_STATE_S0;
       sc->acpi_sleep_disabled = TRUE;
   
       /* Create the control device */
       sc->acpi_dev_t = make_dev(&acpi_cdevsw, 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")) {
           EVENTHANDLER_REGISTER(dev_lookup, acpi_lookup, NULL, 1000);
           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:
       return_VALUE (error);
   }
   
   static void
   acpi_set_power_children(device_t dev, int state)
   {
           device_t child, parent;
           device_t *devlist;
           struct pci_devinfo *dinfo;
           int dstate, i, numdevs;
   
           if (device_get_children(dev, &devlist, &numdevs) != 0)
                   return;
   
           /*
            * Retrieve and set D-state for the sleep state if _SxD is present.
            * Skip children who aren't attached since they are handled separately.
            */
           parent = device_get_parent(dev);
           for (i = 0; i < numdevs; i++) {
                   child = devlist[i];
                   dinfo = device_get_ivars(child);
                   dstate = state;
                   if (device_is_attached(child) &&
                       acpi_device_pwr_for_sleep(parent, dev, &dstate) == 0)
                           acpi_set_powerstate(child, dstate);
           }
           free(devlist, M_TEMP);
   }
   
   static int
   acpi_suspend(device_t dev)
   {
       int error;
   
       GIANT_REQUIRED;
   
       error = bus_generic_suspend(dev);
       if (error == 0)
           acpi_set_power_children(dev, ACPI_STATE_D3);
   
       return (error);
   }
   
   static int
   acpi_resume(device_t dev)
   {
   
       GIANT_REQUIRED;
   
       acpi_set_power_children(dev, ACPI_STATE_D0);
   
       return (bus_generic_resume(dev));
   }
   
   static int
   acpi_shutdown(device_t dev)
   {
   
       GIANT_REQUIRED;
   
       /* 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, u_int order, const char *name, int unit)
   {
       struct acpi_device  *ad;
       device_t            child;
   
       if ((ad = malloc(sizeof(*ad), M_ACPIDEV, M_NOWAIT | M_ZERO)) == NULL)
           return (NULL);
   
       resource_list_init(&ad->ad_rl);
   
       child = device_add_child_ordered(bus, order, name, unit);
       if (child != NULL)
           device_set_ivars(child, ad);
       else
           free(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 += printf(" flags %#x", device_get_flags(child));
       retval += bus_print_child_domain(bus, 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)
   {
   #ifdef ACPI_ENABLE_POWERDOWN_NODRIVER
       acpi_set_powerstate(child, ACPI_STATE_D3);
   #endif
   }
   
   /*
    * 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);
       if (device_get_children(dev, &devlist, &numdevs))
               return;
       for (i = 0; i < numdevs; i++) {
           child = devlist[i];
           if (device_get_state(child) == DS_NOTPRESENT) {
   #ifdef ACPI_ENABLE_POWERDOWN_NODRIVER
               acpi_set_powerstate(child, ACPI_STATE_D0);
               if (device_probe_and_attach(child) != 0)
                   acpi_set_powerstate(child, ACPI_STATE_D3);
   #else
               device_probe_and_attach(child);
   #endif
           }
       }
       free(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);
       char buf2[32];
       int pxm;
   
       if (dinfo->ad_handle) {
           snprintf(buf, buflen, "handle=%s", acpi_name(dinfo->ad_handle));
           if (ACPI_SUCCESS(acpi_GetInteger(dinfo->ad_handle, "_PXM", &pxm))) {
                   snprintf(buf2, 32, " _PXM=%d", pxm);
                   strlcat(buf, buf2, buflen);
           }
       } else {
           snprintf(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)
   {
       struct acpi_device *dinfo = device_get_ivars(child);
       ACPI_DEVICE_INFO *adinfo;
   
       if (ACPI_FAILURE(AcpiGetObjectInfo(dinfo->ad_handle, &adinfo))) {
           snprintf(buf, buflen, "unknown");
           return (0);
       }
   
       snprintf(buf, buflen, "_HID=%s _UID=%lu",
           (adinfo->Valid & ACPI_VALID_HID) ?
           adinfo->HardwareId.String : "none",
           (adinfo->Valid & ACPI_VALID_UID) ?
           strtoul(adinfo->UniqueId.String, NULL, 10) : 0UL);
       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_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_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);
   }
   
   static int
   acpi_match_resource_hint(device_t dev, int type, long value)
   {
       struct acpi_device *ad = device_get_ivars(dev);
       struct resource_list *rl = &ad->ad_rl;
       struct resource_list_entry *rle;
   
       STAILQ_FOREACH(rle, rl, link) {
           if (rle->type != type)
               continue;
           if (rle->start <= value && rle->end >= value)
               return (1);
       }
       return (0);
   }
   
   /*
    * Wire device unit numbers based on resource matches in hints.
    */
   static void
   acpi_hint_device_unit(device_t acdev, device_t child, const char *name,
       int *unitp)
   {
       const char *s;
       long value;
       int line, matches, unit;
  
      /*
       * Iterate over all the hints for the devices with the specified
       * name to see if one's resources are a subset of this device.
       */
      line = 0;
      for (;;) {
          if (resource_find_dev(&line, name, &unit, "at", NULL) != 0)
              break;
  
          /* Must have an "at" for acpi or isa. */
          resource_string_value(name, unit, "at", &s);
          if (!(strcmp(s, "acpi0") == 0 || strcmp(s, "acpi") == 0 ||
              strcmp(s, "isa0") == 0 || strcmp(s, "isa") == 0))
              continue;
  
          /*
           * Check for matching resources.  We must have at least one match.
           * Since I/O and memory resources cannot be shared, if we get a
           * match on either of those, ignore any mismatches in IRQs or DRQs.
           *
           * XXX: We may want to revisit this to be more lenient and wire
           * as long as it gets one match.
           */
          matches = 0;
          if (resource_long_value(name, unit, "port", &value) == 0) {
              /*
               * Floppy drive controllers are notorious for having a
               * wide variety of resources not all of which include the
               * first port that is specified by the hint (typically
               * 0x3f0) (see the comment above fdc_isa_alloc_resources()
               * in fdc_isa.c).  However, they do all seem to include
               * port + 2 (e.g. 0x3f2) so for a floppy device, look for
               * 'value + 2' in the port resources instead of the hint
               * value.
               */
              if (strcmp(name, "fdc") == 0)
                  value += 2;
              if (acpi_match_resource_hint(child, SYS_RES_IOPORT, value))
                  matches++;
              else
                  continue;
          }
          if (resource_long_value(name, unit, "maddr", &value) == 0) {
              if (acpi_match_resource_hint(child, SYS_RES_MEMORY, value))
                  matches++;
              else
                  continue;
          }
          if (matches > 0)
              goto matched;
          if (resource_long_value(name, unit, "irq", &value) == 0) {
              if (acpi_match_resource_hint(child, SYS_RES_IRQ, value))
                  matches++;
              else
                  continue;
          }
          if (resource_long_value(name, unit, "drq", &value) == 0) {
              if (acpi_match_resource_hint(child, SYS_RES_DRQ, value))
                  matches++;
              else
                  continue;
          }
  
      matched:
          if (matches > 0) {
              /* We have a winner! */
              *unitp = unit;
              break;
          }
      }
  }
  
  /*
   * Fech the NUMA domain for the given device.
   *
   * If a device has a _PXM method, map that to a NUMA domain.
   *
   * If none is found, then it'll call the parent method.
   * If there's no domain, return ENOENT.
   */
  int
  acpi_get_domain(device_t dev, device_t child, int *domain)
  {
  #if MAXMEMDOM > 1
          ACPI_HANDLE h;
          int d, pxm;
  
          h = acpi_get_handle(child);
          if ((h != NULL) &&
              ACPI_SUCCESS(acpi_GetInteger(h, "_PXM", &pxm))) {
                  d = acpi_map_pxm_to_vm_domainid(pxm);
                  if (d < 0)
                          return (ENOENT);
                  *domain = d;
                  return (0);
          }
  #endif
          /* No _PXM node; go up a level */
          return (bus_generic_get_domain(dev, child, domain));
  }
  
  /*
   * 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]);
      }
      free(children, M_TEMP);
  
      rl = BUS_GET_RESOURCE_LIST(device_get_parent(dev), dev);
      STAILQ_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);
          if (res != NULL) {
              rman_manage_region(rm, rman_get_start(res), rman_get_end(res));
              rle->res = res;
          } else if (bootverbose)
              device_printf(dev, "reservation of %lx, %lx (%d) failed\n",
                  rle->start, rle->count, rle->type);
      }
      return (0);
  }
  
  static char *pcilink_ids[] = { "PNP0C0F", NULL };
  static char *sysres_ids[] = { "PNP0C01", "PNP0C02", NULL };
  
  /*
   * Reserve declared resources for devices found during attach once system
   * resources have been allocated.
   */
  static void
  acpi_reserve_resources(device_t dev)
  {
      struct resource_list_entry *rle;
      struct resource_list *rl;
      struct acpi_device *ad;
      struct acpi_softc *sc;
      device_t *children;
      int child_count, i;
  
      sc = device_get_softc(dev);
      if (device_get_children(dev, &children, &child_count) != 0)
          return;
      for (i = 0; i < child_count; i++) {
          ad = device_get_ivars(children[i]);
          rl = &ad->ad_rl;
  
          /* Don't reserve system resources. */
          if (ACPI_ID_PROBE(dev, children[i], sysres_ids) != NULL)
              continue;
  
          STAILQ_FOREACH(rle, rl, link) {
              /*
               * Don't reserve IRQ resources.  There are many sticky things
               * to get right otherwise (e.g. IRQs for psm, atkbd, and HPET
               * when using legacy routing).
               */
              if (rle->type == SYS_RES_IRQ)
                  continue;
  
              /*
               * Don't reserve the resource if it is already allocated.
               * The acpi_ec(4) driver can allocate its resources early
               * if ECDT is present.
               */
              if (rle->res != NULL)
                  continue;
  
              /*
               * Try to reserve the resource from our parent.  If this
               * fails because the resource is a system resource, just
               * let it be.  The resource range is already reserved so
               * that other devices will not use it.  If the driver
               * needs to allocate the resource, then
               * acpi_alloc_resource() will sub-alloc from the system
               * resource.
               */
              resource_list_reserve(rl, dev, children[i], rle->type, &rle->rid,
                  rle->start, rle->end, rle->count, 0);
          }
      }
      free(children, M_TEMP);
      sc->acpi_resources_reserved = 1;
  }
  
  static int
  acpi_set_resource(device_t dev, device_t child, int type, int rid,
      u_long start, u_long count)
  {
      struct acpi_softc *sc = device_get_softc(dev);
      struct acpi_device *ad = device_get_ivars(child);
      struct resource_list *rl = &ad->ad_rl;
      ACPI_DEVICE_INFO *devinfo;
      u_long end;
      
      /* Ignore IRQ resources for PCI link devices. */
      if (type == SYS_RES_IRQ && ACPI_ID_PROBE(dev, child, pcilink_ids) != NULL)
          return (0);
  
      /*
       * Ignore most resources for PCI root bridges.  Some BIOSes
       * incorrectly enumerate the memory ranges they decode as plain
       * memory resources instead of as ResourceProducer ranges.  Other
       * BIOSes incorrectly list system resource entries for I/O ranges
       * under the PCI bridge.  Do allow the one known-correct case on
       * x86 of a PCI bridge claiming the I/O ports used for PCI config
       * access.
       */
      if (type == SYS_RES_MEMORY || type == SYS_RES_IOPORT) {
          if (ACPI_SUCCESS(AcpiGetObjectInfo(ad->ad_handle, &devinfo))) {
              if ((devinfo->Flags & ACPI_PCI_ROOT_BRIDGE) != 0) {
  #if defined(__i386__) || defined(__amd64__)
                  if (!(type == SYS_RES_IOPORT && start == CONF1_ADDR_PORT))
  #endif
                  {
                      AcpiOsFree(devinfo);
                      return (0);
                  }
              }
              AcpiOsFree(devinfo);
          }
      }
  
      /* If the resource is already allocated, fail. */
      if (resource_list_busy(rl, type, rid))
          return (EBUSY);
  
      /* If the resource is already reserved, release it. */
      if (resource_list_reserved(rl, type, rid))
          resource_list_unreserve(rl, dev, child, type, rid);
  
      /* Add the resource. */
      end = (start + count - 1);
      resource_list_add(rl, type, rid, start, end, count);
  
      /* Don't reserve resources until the system resources are allocated. */
      if (!sc->acpi_resources_reserved)
          return (0);
  
      /* Don't reserve system resources. */
      if (ACPI_ID_PROBE(dev, child, sysres_ids) != NULL)
          return (0);
  
      /*
       * Don't reserve IRQ resources.  There are many sticky things to
       * get right otherwise (e.g. IRQs for psm, atkbd, and HPET when
       * using legacy routing).
       */
      if (type == SYS_RES_IRQ)
          return (0);
  
      /*
       * Reserve the resource.
       *
       * XXX: Ignores failure for now.  Failure here is probably a
       * BIOS/firmware bug?
       */
      resource_list_reserve(rl, dev, child, type, &rid, start, end, count, 0);
      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)
  {
      ACPI_RESOURCE ares;
      struct acpi_device *ad;
      struct resource_list_entry *rle;
      struct resource_list *rl;
      struct resource *res;
      int isdefault = (start == 0UL && end == ~0UL);
  
      /*
       * First attempt at allocating the resource.  For direct children,
       * use resource_list_alloc() to handle reserved resources.  For
       * other devices, pass the request up to our parent.
       */
      if (bus == device_get_parent(child)) {
          ad = device_get_ivars(child);
          rl = &ad->ad_rl;
  
          /*
           * Simulate the behavior of the ISA bus for direct children
           * devices.  That is, if a non-default range is specified for
           * a resource that doesn't exist, use bus_set_resource() to
           * add the resource before allocating it.  Note that these
           * resources will not be reserved.
           */
          if (!isdefault && resource_list_find(rl, type, *rid) == NULL)
                  resource_list_add(rl, type, *rid, start, end, count);
          res = resource_list_alloc(rl, bus, child, type, rid, start, end, count,
              flags);
          if (res != NULL && type == 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);
          }
  
          /*
           * If this is an allocation of the "default" range for a given
           * RID, fetch the exact bounds for this resource from the
           * resource list entry to try to allocate the range from the
           * system resource regions.
           */
          if (res == NULL && isdefault) {
              rle = resource_list_find(rl, type, *rid);
              if (rle != NULL) {
                  start = rle->start;
                  end = rle->end;
                  count = rle->count;
              }
          }
      } else
          res = BUS_ALLOC_RESOURCE(device_get_parent(bus), child, type, rid,
              start, end, count, flags);
  
      /*
       * If the first attempt failed and this is an allocation of a
       * specific range, try to satisfy the request via a suballocation
       * from our system resource regions.
       */
      if (res == NULL && start + count - 1 == end)
          res = acpi_alloc_sysres(child, type, rid, start, end, count, flags);
      return (res);
  }
  
  /*
   * Attempt to allocate a specific resource range from the system
   * resource ranges.  Note that we only handle memory and I/O port
   * system resources.
   */
  struct resource *
  acpi_alloc_sysres(device_t child, int type, int *rid, u_long start, u_long end,
      u_long count, u_int flags)
  {
      struct rman *rm;
      struct resource *res;
  
      switch (type) {
      case SYS_RES_IOPORT:
          rm = &acpi_rman_io;
          break;
      case SYS_RES_MEMORY:
          rm = &acpi_rman_mem;
          break;
      default:
          return (NULL);
      }
  
      KASSERT(start + count - 1 == end, ("wildcard resource range"));
      res = rman_reserve_resource(rm, start, end, count, flags & ~RF_ACTIVE,
          child);
      if (res == NULL)
          return (NULL);
  
      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);
              return (NULL);
          }
  
      return (res);
  }
  
  static int
  acpi_is_resource_managed(int type, struct resource *r)
  {
  
      /* We only handle memory and IO resources through rman. */
      switch (type) {
      case SYS_RES_IOPORT:
          return (rman_is_region_manager(r, &acpi_rman_io));
      case SYS_RES_MEMORY:
          return (rman_is_region_manager(r, &acpi_rman_mem));
      }
      return (0);
  }
  
  static int
  acpi_adjust_resource(device_t bus, device_t child, int type, struct resource *r,
      u_long start, u_long end)
  {
  
      if (acpi_is_resource_managed(type, r))
          return (rman_adjust_resource(r, start, end));
      return (bus_generic_adjust_resource(bus, child, type, r, start, end));
  }
  
  static int
  acpi_release_resource(device_t bus, device_t child, int type, int rid,
      struct resource *r)
  {
      int ret;
  
      /*
       * If this resource belongs to one of our internal managers,
       * deactivate it and release it to the local pool.
       */
      if (acpi_is_resource_managed(type, r)) {
          if (rman_get_flags(r) & RF_ACTIVE) {
              ret = bus_deactivate_resource(child, type, rid, r);
              if (ret != 0)
                  return (ret);
          }
          return (rman_release_resource(r));
      }
  
      return (bus_generic_rl_release_resource(bus, child, type, rid, r));
  }
  
  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);
      if (resource_list_busy(rl, type, rid)) {
          device_printf(bus, "delete_resource: Resource still owned by child"
              " (type=%d, rid=%d)\n", type, rid);
          return;
      }
      resource_list_unreserve(rl, bus, child, type, rid);
      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);
      *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);
  }
  
  /* 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__);
  
      /* Fetch and validate the HID. */
      if ((h = acpi_get_handle(dev)) == NULL ||
          ACPI_FAILURE(AcpiGetObjectInfo(h, &devinfo)))
          return_VALUE (0);
  
      pnpid = (devinfo->Valid & ACPI_VALID_HID) != 0 &&
          devinfo->HardwareId.Length >= ACPI_EISAID_STRING_SIZE ?
          PNP_EISAID(devinfo->HardwareId.String) : 0;
      AcpiOsFree(devinfo);
  
      return_VALUE (pnpid);
  }
  
  static int
  acpi_isa_get_compatid(device_t dev, uint32_t *cids, int count)
  {
      ACPI_DEVICE_INFO    *devinfo;
      ACPI_PNP_DEVICE_ID  *ids;
      ACPI_HANDLE         h;
      uint32_t            *pnpid;
      int                 i, valid;
  
      ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
  
      pnpid = cids;
  
      /* Fetch and validate the CID */
      if ((h = acpi_get_handle(dev)) == NULL ||
          ACPI_FAILURE(AcpiGetObjectInfo(h, &devinfo)))
          return_VALUE (0);
  
      if ((devinfo->Valid & ACPI_VALID_CID) == 0) {
          AcpiOsFree(devinfo);
          return_VALUE (0);
      }
  
      if (devinfo->CompatibleIdList.Count < count)
          count = devinfo->CompatibleIdList.Count;
      ids = devinfo->CompatibleIdList.Ids;
      for (i = 0, valid = 0; i < count; i++)
          if (ids[i].Length >= ACPI_EISAID_STRING_SIZE &&
              strncmp(ids[i].String, "PNP", 3) == 0) {
              *pnpid++ = PNP_EISAID(ids[i].String);
              valid++;
          }
      AcpiOsFree(devinfo);
  
      return_VALUE (valid);
  }
  
  static char *
  acpi_device_id_probe(device_t bus, device_t dev, char **ids) 
  {
      ACPI_HANDLE h;
      ACPI_OBJECT_TYPE t;
      int i;
  
      h = acpi_get_handle(dev);
      if (ids == NULL || h == NULL)
          return (NULL);
      t = acpi_get_type(dev);
      if (t != ACPI_TYPE_DEVICE && t != ACPI_TYPE_PROCESSOR)
          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));
  }
  
  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];
  
      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 (dstate == NULL || 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.
       * Note illegal _S0D is evaluated because some systems expect this.
       */
      sc = device_get_softc(bus);
      snprintf(sxd, sizeof(sxd), "_S%dD", sc->acpi_sstate);
      status = acpi_GetInteger(handle, sxd, dstate);
      if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
              device_printf(dev, "failed to get %s on %s: %s\n", sxd,
                  acpi_name(handle), AcpiFormatException(status));
              return (ENXIO);
      }
  
      return (0);
  }
  
  /* 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(device_t child, int state)
  {
      ACPI_HANDLE h;
      ACPI_STATUS status;
  
      h = acpi_get_handle(child);
      if (state < ACPI_STATE_D0 || state > ACPI_D_STATES_MAX)
          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_SUCCESS(status)) {
          if (bootverbose)
              device_printf(child, "set ACPI power state D%d on %s\n",
                  state, acpi_name(h));
      } else if (status != AE_NOT_FOUND)
          device_printf(child,
              "failed to set ACPI power state D%d on %s: %s\n", state,
              acpi_name(h), AcpiFormatException(status));
  
      return (0);
  }
  
  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);
  }
  
  #if defined(__i386__) || defined(__amd64__)
  /*
   * 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++;
          }
  }
  #endif
  
  /*
   * 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);
  
      /* Reserve resources already allocated to children. */
      acpi_reserve_resources(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 statically and from the namespace. */
      ACPI_DEBUG_PRINT((ACPI_DB_OBJECTS, "acpi 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;
  
          /*
           * 0. CPUs
           * 1. I/O port and memory system resource holders
           * 2. Clocks and timers (to handle early accesses)
           * 3. Embedded controllers (to handle early accesses)
           * 4. PCI Link Devices
           */
          AcpiGetType(handle, &type);
          if (type == ACPI_TYPE_PROCESSOR)
                  *order = 0;
          else if (acpi_MatchHid(handle, "PNP0C01") ||
              acpi_MatchHid(handle, "PNP0C02"))
                  *order = 1;
          else if (acpi_MatchHid(handle, "PNP0100") ||
              acpi_MatchHid(handle, "PNP0103") ||
              acpi_MatchHid(handle, "PNP0B00"))
                  *order = 2;
          else if (acpi_MatchHid(handle, "PNP0C09"))
                  *order = 3;
          else if (acpi_MatchHid(handle, "PNP0C0F"))
                  *order = 4;
  }
  
  /*
   * 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;
      char *handle_str;
      int order;
  
      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);
  
              /*
               * Ignore devices that do not have a _HID or _CID.  They should
               * be discovered by other buses (e.g. the PCI bus driver).
               */
              if (!acpi_has_hid(handle))
                  break;
              /* 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).
               */
              ACPI_DEBUG_PRINT((ACPI_DB_OBJECTS, "scanning '%s'\n", handle_str));
              order = level * 10 + ACPI_DEV_BASE_ORDER;
              acpi_probe_order(handle, &order);
              child = BUS_ADD_CHILD(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 = (struct acpi_softc *)arg;
      register_t intr;
      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.
       */
      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");
          intr = intr_disable();
          status = AcpiEnterSleepState(ACPI_STATE_S5);
          if (ACPI_FAILURE(status)) {
              intr_restore(intr);
              device_printf(sc->acpi_dev, "power-off failed - %s\n",
                  AcpiFormatException(status));
          } else {
              DELAY(1000000);
              intr_restore(intr);
              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_SUCCESS(status)) {
              DELAY(1000000);
              device_printf(sc->acpi_dev, "reset failed - timeout\n");
          } else if (status != AE_NOT_EXIST)
              device_printf(sc->acpi_dev, "reset failed - %s\n",
                  AcpiFormatException(status));
      } 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;
      BOOLEAN             present;
  
      if ((h = acpi_get_handle(dev)) == NULL ||
          ACPI_FAILURE(AcpiGetObjectInfo(h, &devinfo)))
          return (FALSE);
  
      /* If no _STA method, must be present */
      present = (devinfo->Valid & ACPI_VALID_STA) == 0 ||
          ACPI_DEVICE_PRESENT(devinfo->CurrentStatus) ? TRUE : FALSE;
  
      AcpiOsFree(devinfo);
      return (present);
  }
  
  /*
   * Returns true if the battery is actually present and inserted.
   */
  BOOLEAN
  acpi_BatteryIsPresent(device_t dev)
  {
      ACPI_DEVICE_INFO    *devinfo;
      ACPI_HANDLE         h;
      BOOLEAN             present;
  
      if ((h = acpi_get_handle(dev)) == NULL ||
          ACPI_FAILURE(AcpiGetObjectInfo(h, &devinfo)))
          return (FALSE);
  
      /* If no _STA method, must be present */
      present = (devinfo->Valid & ACPI_VALID_STA) == 0 ||
          ACPI_BATTERY_PRESENT(devinfo->CurrentStatus) ? TRUE : FALSE;
  
      AcpiOsFree(devinfo);
      return (present);
  }
  
  /*
   * Returns true if a device has at least one valid device ID.
   */
  static BOOLEAN
  acpi_has_hid(ACPI_HANDLE h)
  {
      ACPI_DEVICE_INFO    *devinfo;
      BOOLEAN             ret;
  
      if (h == NULL ||
          ACPI_FAILURE(AcpiGetObjectInfo(h, &devinfo)))
          return (FALSE);
  
      ret = FALSE;
      if ((devinfo->Valid & ACPI_VALID_HID) != 0)
          ret = TRUE;
      else if ((devinfo->Valid & ACPI_VALID_CID) != 0)
          if (devinfo->CompatibleIdList.Count > 0)
              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;
      BOOLEAN             ret;
      int                 i;
  
      if (hid == NULL || h == NULL ||
          ACPI_FAILURE(AcpiGetObjectInfo(h, &devinfo)))
          return (FALSE);
  
      ret = FALSE;
      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 = malloc(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 *)((u_int8_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 *)((u_int8_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 ((((u_int8_t *)rp - (u_int8_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 *)((u_int8_t *)newp +
                                 ((u_int8_t *)rp - (u_int8_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));
  }
  
  /*
   * Walk subtables of a table and call a callback routine for each
   * subtable.  The caller should provide the first subtable and a
   * pointer to the end of the table.  This can be used to walk tables
   * such as MADT and SRAT that use subtable entries.
   */
  void
  acpi_walk_subtables(void *first, void *end, acpi_subtable_handler *handler,
      void *arg)
  {
      ACPI_SUBTABLE_HEADER *entry;
  
      for (entry = first; (void *)entry < end; ) {
          /* Avoid an infinite loop if we hit a bogus entry. */
          if (entry->Length < sizeof(ACPI_SUBTABLE_HEADER))
              return;
  
          handler(entry, arg);
          entry = ACPI_ADD_PTR(ACPI_SUBTABLE_HEADER, entry, entry->Length);
      }
  }
  
  /*
   * 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));
  }
  
  #if defined(__amd64__) || defined(__i386__)
  static void
  acpi_sleep_force_task(void *context)
  {
      struct acpi_softc *sc = (struct acpi_softc *)context;
  
      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);
  }
  
  static void
  acpi_sleep_force(void *arg)
  {
      struct acpi_softc *sc = (struct acpi_softc *)arg;
  
      device_printf(sc->acpi_dev,
          "suspend request timed out, forcing sleep now\n");
      /*
       * XXX Suspending from callout cause the freeze in DEVICE_SUSPEND().
       * Suspend from acpi_task thread in stead.
       */
      if (ACPI_FAILURE(AcpiOsExecute(OSL_NOTIFY_HANDLER,
          acpi_sleep_force_task, sc)))
          device_printf(sc->acpi_dev, "AcpiOsExecute() for sleeping failed\n");
  }
  #endif
  
  /*
   * 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)
  {
  #if defined(__amd64__) || defined(__i386__)
      struct apm_clone_data *clone;
      ACPI_STATUS status;
  
      if (state < ACPI_STATE_S1 || state > ACPI_S_STATES_MAX)
          return (EINVAL);
      if (!acpi_sleep_states[state])
          return (EOPNOTSUPP);
  
      /*
       * If a reboot/shutdown/suspend request is already in progress or
       * suspend is blocked due to an upcoming shutdown, just return.
       */
      if (rebooting || sc->acpi_next_sstate != 0 || suspend_blocked) {
          return (0);
      }
  
      /* Wait until sleep is enabled. */
      while (sc->acpi_sleep_disabled) {
          AcpiOsSleep(1000);
      }
  
      ACPI_LOCK(acpi);
  
      sc->acpi_next_sstate = state;
  
      /* S5 (soft-off) should be entered directly with no waiting. */
      if (state == ACPI_STATE_S5) {
          ACPI_UNLOCK(acpi);
          status = acpi_EnterSleepState(sc, state);
          return (ACPI_SUCCESS(status) ? 0 : ENXIO);
      }
  
      /* Record the pending state and notify all apm devices. */
      STAILQ_FOREACH(clone, &sc->apm_cdevs, entries) {
          clone->notify_status = APM_EV_NONE;
          if ((clone->flags & ACPI_EVF_DEVD) == 0) {
              selwakeuppri(&clone->sel_read, PZERO);
              KNOTE_LOCKED(&clone->sel_read.si_note, 0);
          }
      }
  
      /* If devd(8) is not running, immediately enter the sleep state. */
      if (!devctl_process_running()) {
          ACPI_UNLOCK(acpi);
          status = acpi_EnterSleepState(sc, state);
          return (ACPI_SUCCESS(status) ? 0 : ENXIO);
      }
  
      /*
       * 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);
  
      /* Now notify devd(8) also. */
      acpi_UserNotify("Suspend", ACPI_ROOT_OBJECT, state);
  
      return (0);
  #else
      /* This platform does not support acpi suspend/resume. */
      return (EOPNOTSUPP);
  #endif
  }
  
  /*
   * 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)
  {
  #if defined(__amd64__) || defined(__i386__)
      struct acpi_softc *sc;
      int ret, sleeping;
  
      /* 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.
       */
      sleeping = TRUE;
      clone->notify_status = APM_EV_ACKED;
      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);
  #else
      /* This platform does not support acpi suspend/resume. */
      return (EOPNOTSUPP);
  #endif
  }
  
  static void
  acpi_sleep_enable(void *arg)
  {
      struct acpi_softc   *sc = (struct acpi_softc *)arg;
  
      /* Reschedule if the system is not fully up and running. */
      if (!AcpiGbl_SystemAwakeAndRunning) {
          timeout(acpi_sleep_enable, sc, hz * ACPI_MINIMUM_AWAKETIME);
          return;
      }
  
      ACPI_LOCK(acpi);
      sc->acpi_sleep_disabled = FALSE;
      ACPI_UNLOCK(acpi);
  }
  
  static ACPI_STATUS
  acpi_sleep_disable(struct acpi_softc *sc)
  {
      ACPI_STATUS         status;
  
      /* Fail if the system is not fully up and running. */
      if (!AcpiGbl_SystemAwakeAndRunning)
          return (AE_ERROR);
  
      ACPI_LOCK(acpi);
      status = sc->acpi_sleep_disabled ? AE_ERROR : AE_OK;
      sc->acpi_sleep_disabled = TRUE;
      ACPI_UNLOCK(acpi);
  
      return (status);
  }
  
  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)
  {
      register_t intr;
      ACPI_STATUS status;
      ACPI_EVENT_STATUS power_button_status;
      enum acpi_sleep_state slp_state;
      int sleep_result;
  
      ACPI_FUNCTION_TRACE_U32((char *)(uintptr_t)__func__, state);
  
      if (state < ACPI_STATE_S1 || state > ACPI_S_STATES_MAX)
          return_ACPI_STATUS (AE_BAD_PARAMETER);
      if (!acpi_sleep_states[state]) {
          device_printf(sc->acpi_dev, "Sleep state S%d not supported by BIOS\n",
              state);
          return (AE_SUPPORT);
      }
  
      /* Re-entry once we're suspending is not allowed. */
      status = acpi_sleep_disable(sc);
      if (ACPI_FAILURE(status)) {
          device_printf(sc->acpi_dev,
              "suspend request ignored (not ready yet)\n");
          return (status);
      }
  
      if (state == ACPI_STATE_S5) {
          /*
           * Shut down cleanly and power off.  This will call us back through the
           * shutdown handlers.
           */
          shutdown_nice(RB_POWEROFF);
          return_ACPI_STATUS (AE_OK);
      }
  
      EVENTHANDLER_INVOKE(power_suspend_early);
      stop_all_proc();
      EVENTHANDLER_INVOKE(power_suspend);
  
      if (smp_started) {
          thread_lock(curthread);
          sched_bind(curthread, 0);
          thread_unlock(curthread);
      }
  
      /*
       * Be sure to hold Giant across DEVICE_SUSPEND/RESUME since non-MPSAFE
       * drivers need this.
       */
      mtx_lock(&Giant);
  
      slp_state = ACPI_SS_NONE;
  
      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");
          goto backout;
      }
      slp_state = ACPI_SS_DEV_SUSPEND;
  
      /* If testing device suspend only, back out of everything here. */
      if (acpi_susp_bounce)
          goto backout;
  
      status = AcpiEnterSleepStatePrep(state);
      if (ACPI_FAILURE(status)) {
          device_printf(sc->acpi_dev, "AcpiEnterSleepStatePrep failed - %s\n",
                        AcpiFormatException(status));
          goto backout;
      }
      slp_state = ACPI_SS_SLP_PREP;
  
      if (sc->acpi_sleep_delay > 0)
          DELAY(sc->acpi_sleep_delay * 1000000);
  
      intr = intr_disable();
      if (state != ACPI_STATE_S1) {
          sleep_result = acpi_sleep_machdep(sc, state);
          acpi_wakeup_machdep(sc, state, sleep_result, 0);
  
          /*
           * XXX According to ACPI specification SCI_EN bit should be restored
           * by ACPI platform (BIOS, firmware) to its pre-sleep state.
           * Unfortunately some BIOSes fail to do that and that leads to
           * unexpected and serious consequences during wake up like a system
           * getting stuck in SMI handlers.
           * This hack is picked up from Linux, which claims that it follows
           * Windows behavior.
           */
          if (sleep_result == 1 && state != ACPI_STATE_S4)
              AcpiWriteBitRegister(ACPI_BITREG_SCI_ENABLE, ACPI_ENABLE_EVENT);
  
          AcpiLeaveSleepStatePrep(state);
  
          if (sleep_result == 1 && state == ACPI_STATE_S3) {
              /*
               * Prevent mis-interpretation of the wakeup by power button
               * as a request for power off.
               * Ideally we should post an appropriate wakeup event,
               * perhaps using acpi_event_power_button_wake or alike.
               *
               * Clearing of power button status after wakeup is mandated
               * by ACPI specification in section "Fixed Power Button".
               *
               * XXX As of ACPICA 20121114 AcpiGetEventStatus provides
               * status as 0/1 corressponding to inactive/active despite
               * its type being ACPI_EVENT_STATUS.  In other words,
               * we should not test for ACPI_EVENT_FLAG_SET for time being.
               */
              if (ACPI_SUCCESS(AcpiGetEventStatus(ACPI_EVENT_POWER_BUTTON,
                  &power_button_status)) && power_button_status != 0) {
                  AcpiClearEvent(ACPI_EVENT_POWER_BUTTON);
                  device_printf(sc->acpi_dev,
                      "cleared fixed power button status\n");
              }
          }
  
          intr_restore(intr);
  
          /* call acpi_wakeup_machdep() again with interrupt enabled */
          acpi_wakeup_machdep(sc, state, sleep_result, 1);
  
          if (sleep_result == -1)
                  goto backout;
  
          /* Re-enable ACPI hardware on wakeup from sleep state 4. */
          if (state == ACPI_STATE_S4)
              AcpiEnable();
      } else {
          status = AcpiEnterSleepState(state);
          AcpiLeaveSleepStatePrep(state);
          intr_restore(intr);
          if (ACPI_FAILURE(status)) {
              device_printf(sc->acpi_dev, "AcpiEnterSleepState failed - %s\n",
                            AcpiFormatException(status));
              goto backout;
          }
      }
      slp_state = ACPI_SS_SLEPT;
  
      /*
       * Back out state according to how far along we got in the suspend
       * process.  This handles both the error and success cases.
       */
  backout:
      if (slp_state >= ACPI_SS_GPE_SET) {
          acpi_wake_prep_walk(state);
          sc->acpi_sstate = ACPI_STATE_S0;
      }
      if (slp_state >= ACPI_SS_DEV_SUSPEND)
          DEVICE_RESUME(root_bus);
      if (slp_state >= ACPI_SS_SLP_PREP)
          AcpiLeaveSleepState(state);
      if (slp_state >= ACPI_SS_SLEPT) {
          acpi_resync_clock(sc);
          acpi_enable_fixed_events(sc);
      }
      sc->acpi_next_sstate = 0;
  
      mtx_unlock(&Giant);
  
      if (smp_started) {
          thread_lock(curthread);
          sched_unbind(curthread);
          thread_unlock(curthread);
      }
  
      resume_all_proc();
  
      EVENTHANDLER_INVOKE(power_resume);
  
      /* Allow another sleep request after a while. */
      timeout(acpi_sleep_enable, sc, hz * ACPI_MINIMUM_AWAKETIME);
  
      /* Run /etc/rc.resume after we are back. */
      if (devctl_process_running())
          acpi_UserNotify("Resume", ACPI_ROOT_OBJECT, state);
  
      return_ACPI_STATUS (status);
  }
  
  static void
  acpi_resync_clock(struct acpi_softc *sc)
  {
  #ifdef __amd64__
      if (!acpi_reset_clock)
          return;
  
      /*
       * Warm up timecounter again and reset system clock.
       */
      (void)timecounter->tc_get_timecount(timecounter);
      (void)timecounter->tc_get_timecount(timecounter);
      inittodr(time_second + sc->acpi_sleep_delay);
  #endif
  }
  
  /* Enable or disable the device's wake 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)
  {
      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)
              free(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");
          }
      }
      free(devlist, M_TEMP);
  
      return (0);
  }
  
  /* 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));
  }
  
  /* 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) {
          printf("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 = (struct acpi_softc *)arg;
      int ret;
  
      ACPI_FUNCTION_TRACE_U32((char *)(uintptr_t)__func__, state);
  
      /* Check if button action is disabled or unknown. */
      if (state == ACPI_STATE_UNKNOWN)
          return;
  
      /* Request that the system prepare to enter the given suspend state. */
      ret = acpi_ReqSleepState(sc, 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)
   */
  static void
  acpi_invoke_sleep_eventhandler(void *context)
  {
  
      EVENTHANDLER_INVOKE(acpi_sleep_event, *(int *)context);
  }
  
  static void
  acpi_invoke_wake_eventhandler(void *context)
  {
  
      EVENTHANDLER_INVOKE(acpi_wakeup_event, *(int *)context);
  }
  
  UINT32
  acpi_event_power_button_sleep(void *context)
  {
      struct acpi_softc   *sc = (struct acpi_softc *)context;
  
      ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
  
      if (ACPI_FAILURE(AcpiOsExecute(OSL_NOTIFY_HANDLER,
          acpi_invoke_sleep_eventhandler, &sc->acpi_power_button_sx)))
          return_VALUE (ACPI_INTERRUPT_NOT_HANDLED);
      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__);
  
      if (ACPI_FAILURE(AcpiOsExecute(OSL_NOTIFY_HANDLER,
          acpi_invoke_wake_eventhandler, &sc->acpi_power_button_sx)))
          return_VALUE (ACPI_INTERRUPT_NOT_HANDLED);
      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__);
  
      if (ACPI_FAILURE(AcpiOsExecute(OSL_NOTIFY_HANDLER,
          acpi_invoke_sleep_eventhandler, &sc->acpi_sleep_button_sx)))
          return_VALUE (ACPI_INTERRUPT_NOT_HANDLED);
      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__);
  
      if (ACPI_FAILURE(AcpiOsExecute(OSL_NOTIFY_HANDLER,
          acpi_invoke_wake_eventhandler, &sc->acpi_sleep_button_sx)))
          return_VALUE (ACPI_INTERRUPT_NOT_HANDLED);
      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 = getenv("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)) {
              freeenv(env);
              return(1);
          }
          cp += len;
      }
      freeenv(env);
  
      return (0);
  }
  
  /*
   * Debugging/bug-avoidance.  Disable ACPI subsystem components.
   */
  int
  acpi_disabled(char *subsys)
  {
      char        *cp, *env;
      int         len;
  
      if ((env = getenv("debug.acpi.disabled")) == NULL)
          return (0);
      if (strcmp(env, "all") == 0) {
          freeenv(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) {
              freeenv(env);
              return (1);
          }
          cp += len;
      }
      freeenv(env);
  
      return (0);
  }
  
  static void
  acpi_lookup(void *arg, const char *name, device_t *dev)
  {
      ACPI_HANDLE handle;
  
      if (*dev != NULL)
          return;
  
      /*
       * Allow any handle name that is specified as an absolute path and
       * starts with '\'.  We could restrict this to \_SB and friends,
       * but see acpi_probe_children() for notes on why we scan the entire
       * namespace for devices.
       *
       * XXX: The pathname argument to AcpiGetHandle() should be fixed to
       * be const.
       */
      if (name[0] != '\\')
          return;
      if (ACPI_FAILURE(AcpiGetHandle(ACPI_ROOT_OBJECT, __DECONST(char *, name),
          &handle)))
          return;
      *dev = acpi_get_device(handle);
  }
  
  /*
   * 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 = malloc(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);
          free(hp, M_ACPIDEV);
      }
      ACPI_UNLOCK(acpi);
  }
  
  static int
  acpiopen(struct cdev *dev, int flag, int fmt, struct thread *td)
  {
      return (0);
  }
  
  static int
  acpiclose(struct cdev *dev, int flag, int fmt, struct thread *td)
  {
      return (0);
  }
  
  static int
  acpiioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flag, struct thread *td)
  {
      struct acpi_softc           *sc;
      struct acpi_ioctl_hook      *hp;
      int                         error, state;
  
      error = 0;
      hp = NULL;
      sc = 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 == cmd)
                  break;
          }
      ACPI_UNLOCK(acpi);
      if (hp)
          return (hp->fn(cmd, addr, hp->arg));
  
      /*
       * Core ioctls are not permitted for non-writable user.
       * Currently, other ioctls just fetch information.
       * Not changing system behavior.
       */
      if ((flag & FWRITE) == 0)
          return (EPERM);
  
      /* Core system ioctls. */
      switch (cmd) {
      case ACPIIO_REQSLPSTATE:
          state = *(int *)addr;
          if (state != ACPI_STATE_S5)
              return (acpi_ReqSleepState(sc, state));
          device_printf(sc->acpi_dev, "power off via acpi ioctl not supported\n");
          error = EOPNOTSUPP;
          break;
      case ACPIIO_ACKSLPSTATE:
          error = *(int *)addr;
          error = acpi_AckSleepState(sc->acpi_clone, error);
          break;
      case ACPIIO_SETSLPSTATE:    /* DEPRECATED */
          state = *(int *)addr;
          if (state < ACPI_STATE_S0 || state > ACPI_S_STATES_MAX)
              return (EINVAL);
          if (!acpi_sleep_states[state])
              return (EOPNOTSUPP);
          if (ACPI_FAILURE(acpi_SetSleepState(sc, state)))
              error = ENXIO;
          break;
      default:
          error = ENXIO;
          break;
      }
  
      return (error);
  }
  
  static int
  acpi_sname2sstate(const char *sname)
  {
      int sstate;
  
      if (toupper(sname[0]) == 'S') {
          sstate = sname[1] - '';
          if (sstate >= ACPI_STATE_S0 && sstate <= ACPI_STATE_S5 &&
              sname[2] == '\0')
              return (sstate);
      } else if (strcasecmp(sname, "NONE") == 0)
          return (ACPI_STATE_UNKNOWN);
      return (-1);
  }
  
  static const char *
  acpi_sstate2sname(int sstate)
  {
      static const char *snames[] = { "S0", "S1", "S2", "S3", "S4", "S5" };
  
      if (sstate >= ACPI_STATE_S0 && sstate <= ACPI_STATE_S5)
          return (snames[sstate]);
      else if (sstate == ACPI_STATE_UNKNOWN)
          return ("NONE");
      return (NULL);
  }
  
  static int
  acpi_supported_sleep_state_sysctl(SYSCTL_HANDLER_ARGS)
  {
      int error;
      struct sbuf sb;
      UINT8 state;
  
      sbuf_new(&sb, NULL, 32, SBUF_AUTOEXTEND);
      for (state = ACPI_STATE_S1; state < ACPI_S_STATE_COUNT; state++)
          if (acpi_sleep_states[state])
              sbuf_printf(&sb, "%s ", acpi_sstate2sname(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, new_state, old_state;
  
      old_state = *(int *)oidp->oid_arg1;
      strlcpy(sleep_state, acpi_sstate2sname(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_sname2sstate(sleep_state);
          if (new_state < ACPI_STATE_S1)
              return (EINVAL);
          if (new_state < ACPI_S_STATE_COUNT && !acpi_sleep_states[new_state])
              return (EOPNOTSUPP);
          if (new_state != old_state)
              *(int *)oidp->oid_arg1 = new_state;
      }
      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);
      if (ACPI_FAILURE(status))
          return;
      snprintf(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 = getenv("debug.acpi.layer");
      level = getenv("debug.acpi.level");
      if (layer == NULL && level == NULL)
          return;
  
      printf("ACPI set debug");
      if (layer != NULL) {
          if (strcmp("NONE", layer) != 0)
              printf(" layer '%s'", layer);
          acpi_parse_debug(layer, &dbg_layer[0], &AcpiDbgLayer);
          freeenv(layer);
      }
      if (level != NULL) {
          if (strcmp("NONE", level) != 0)
              printf(" level '%s'", level);
          acpi_parse_debug(level, &dbg_level[0], &AcpiDbgLevel);
          freeenv(level);
      }
      printf("\n");
  }
  
  SYSINIT(acpi_debugging, SI_SUB_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;
      char         temp[128];
  
      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);
      strlcpy(temp, sbuf_data(&sb), sizeof(temp));
      sbuf_delete(&sb);
  
      error = sysctl_handle_string(oidp, temp, sizeof(temp), req);
  
      /* Check for error or no change */
      if (error == 0 && req->newptr != NULL) {
          *dbg = 0;
          setenv((char *)oidp->oid_arg1, temp);
          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 = strdup(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) {
                  free(p, M_TEMP);
                  return (0);
          }
          iface->data = malloc(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)
  {
  
          free(iface->data[0], M_TEMP);
          free(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_SUB_KLD, SI_ORDER_ANY, acpi_pm_register, 0);