libtopo/common/cpu.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright (c) 2006, 2011, Oracle and/or its affiliates. All rights reserved.
 */


#include <errno.h>
#include <limits.h>
#include <strings.h>
#include <unistd.h>
#include <topo_error.h>
#include <fm/topo_mod.h>
#include <sys/fm/protocol.h>

#include <topo_method.h>
#include <topo_fmri.h>
#include <sys/processor.h>
#include <fm/fmd_fmri.h>
#include <cpu.h>

/*
 * platform specific cpu module
 */
#define PLATFORM_CPU_VERSION    CPU_VERSION
#define PLATFORM_CPU_NAME   "platform-cpu"

static int cpu_enum(topo_mod_t *, tnode_t *, const char *, topo_instance_t,
    topo_instance_t, void *, void *);
static void cpu_release(topo_mod_t *, tnode_t *);
static int cpu_nvl2str(topo_mod_t *, tnode_t *, topo_version_t, nvlist_t *,
    nvlist_t **);
static int cpu_str2nvl(topo_mod_t *, tnode_t *, topo_version_t, nvlist_t *,
    nvlist_t **);
static int cpu_fmri_asru(topo_mod_t *, tnode_t *, topo_version_t, nvlist_t *,
    nvlist_t **);
static int cpu_fmri_create_meth(topo_mod_t *, tnode_t *, topo_version_t,
    nvlist_t *, nvlist_t **);
static int cpu_fmri_strcmp_path(topo_mod_t *, tnode_t *, topo_version_t,
    nvlist_t *, nvlist_t **);
static int cpu_fmri_strcmp_ident(topo_mod_t *, tnode_t *, topo_version_t,
    nvlist_t *, nvlist_t **);
static int cpu_fmri_strhash_path(topo_mod_t *, tnode_t *, topo_version_t,
    nvlist_t *, nvlist_t **);
static int cpu_fmri_service_state(topo_mod_t *, tnode_t *, topo_version_t,
    nvlist_t *, nvlist_t **);
static nvlist_t *fmri_create(topo_mod_t *, uint32_t, uint8_t, char *);

static const topo_method_t cpu_methods[] = {
    { TOPO_METH_NVL2STR, TOPO_METH_NVL2STR_DESC, TOPO_METH_NVL2STR_VERSION,
        TOPO_STABILITY_INTERNAL, cpu_nvl2str },
    { TOPO_METH_STR2NVL, TOPO_METH_STR2NVL_DESC, TOPO_METH_STR2NVL_VERSION,
        TOPO_STABILITY_INTERNAL, cpu_str2nvl },
    { TOPO_METH_ASRU_COMPUTE, TOPO_METH_ASRU_COMPUTE_DESC,
        TOPO_METH_ASRU_COMPUTE_VERSION, TOPO_STABILITY_INTERNAL,
        cpu_fmri_asru },
    { TOPO_METH_FMRI, TOPO_METH_FMRI_DESC, TOPO_METH_FMRI_VERSION,
        TOPO_STABILITY_INTERNAL, cpu_fmri_create_meth },
    { TOPO_METH_STRCMP_PATH, TOPO_METH_STRCMP_PATH_DESC,
        TOPO_METH_STRCMP_VERSION, TOPO_STABILITY_INTERNAL,
        cpu_fmri_strcmp_path },
    { TOPO_METH_STRCMP_IDENT, TOPO_METH_STRCMP_IDENT_DESC,
        TOPO_METH_STRCMP_VERSION, TOPO_STABILITY_INTERNAL,
        cpu_fmri_strcmp_ident },
    { TOPO_METH_STRHASH_PATH, TOPO_METH_STRHASH_PATH_DESC,
        TOPO_METH_STRHASH_VERSION, TOPO_STABILITY_INTERNAL,
        cpu_fmri_strhash_path },
    { TOPO_METH_SERVICE_STATE, TOPO_METH_SERVICE_STATE_DESC,
        TOPO_METH_SERVICE_STATE_VERSION, TOPO_STABILITY_INTERNAL,
        cpu_fmri_service_state },
    { NULL }
};

static const topo_modops_t cpu_ops =
    { cpu_enum, cpu_release };

static const topo_modinfo_t cpu_info =
    { "cpu", FM_FMRI_SCHEME_CPU, CPU_VERSION, &cpu_ops };

int
cpu_init(topo_mod_t *mod, topo_version_t version)
{
    cpu_node_t *cpuip;

    if (getenv("TOPOCPUDEBUG"))
        topo_mod_setdebug(mod);
    topo_mod_dprintf(mod, "initializing cpu builtin\n");

    if (version != CPU_VERSION)
        return (topo_mod_seterrno(mod, EMOD_VER_NEW));

    if ((cpuip = topo_mod_zalloc(mod, sizeof (cpu_node_t))) == NULL)
        return (topo_mod_seterrno(mod, EMOD_NOMEM));

    if ((cpuip->cn_kc = kstat_open()) == NULL) {
        topo_mod_dprintf(mod, "kstat_open failed: %s\n",
            strerror(errno));
        topo_mod_free(mod, cpuip, sizeof (cpu_node_t));
        return (-1);
    }

    cpuip->cn_ncpustats = sysconf(_SC_CPUID_MAX);
    if ((cpuip->cn_cpustats = topo_mod_zalloc(mod, (
        cpuip->cn_ncpustats + 1) * sizeof (kstat_t *))) == NULL) {
        (void) kstat_close(cpuip->cn_kc);
        topo_mod_free(mod, cpuip, sizeof (cpu_node_t));
        return (-1);
    }

    if (topo_mod_register(mod, &cpu_info, TOPO_VERSION) != 0) {
        topo_mod_dprintf(mod, "failed to register cpu_info: "
            "%s\n", topo_mod_errmsg(mod));
        topo_mod_free(mod, cpuip->cn_cpustats,
            (cpuip->cn_ncpustats + 1) * sizeof (kstat_t *));
        (void) kstat_close(cpuip->cn_kc);
        topo_mod_free(mod, cpuip, sizeof (cpu_node_t));
        return (-1);
    }

    topo_mod_setspecific(mod, (void *)cpuip);

    return (0);
}

void
cpu_fini(topo_mod_t *mod)
{
    cpu_node_t *cpuip;

    cpuip = topo_mod_getspecific(mod);

    if (cpuip->cn_cpustats != NULL)
        topo_mod_free(mod, cpuip->cn_cpustats,
            (cpuip->cn_ncpustats + 1) * sizeof (kstat_t *));

    (void) kstat_close(cpuip->cn_kc);
    topo_mod_free(mod, cpuip, sizeof (cpu_node_t));

    topo_mod_unregister(mod);
}

static int
cpu_kstat_init(cpu_node_t *cpuip, int i)
{
    kstat_t *ksp;

    if (cpuip->cn_cpustats[i] == NULL) {
        if ((ksp = kstat_lookup(cpuip->cn_kc, "cpu_info", i, NULL)) ==
            NULL || kstat_read(cpuip->cn_kc, ksp, NULL) < 0)
            return (-1);

        cpuip->cn_cpustats[i] = ksp;
    } else {
        ksp = cpuip->cn_cpustats[i];
    }

    return (ksp->ks_instance);
}

/*ARGSUSED*/
static int
cpu_create(topo_mod_t *mod, tnode_t *rnode, const char *name,
    topo_instance_t min, topo_instance_t max, cpu_node_t *cpuip)
{
    int i;
    processorid_t cpu_id;
    char *s, sbuf[21];
    kstat_named_t *ks;
    nvlist_t *fmri;

    for (i = 0; i <= cpuip->cn_ncpustats; i++) {

        if ((cpu_id = cpu_kstat_init(cpuip, i)) < 0)
            continue;

        if ((ks = kstat_data_lookup(cpuip->cn_cpustats[i],
            "device_ID")) != NULL) {
            (void) snprintf(sbuf, 21, "%llX", ks->value.ui64);
            s = sbuf;
        } else {
            s = NULL;
        }

        if ((fmri = fmri_create(mod, cpu_id, 0, s)) == NULL)
            continue;
        (void) topo_node_bind(mod, rnode, name, cpu_id, fmri);
        nvlist_free(fmri);
    }

    return (0);
}


/*ARGSUSED*/
static int
cpu_enum(topo_mod_t *mod, tnode_t *pnode, const char *name,
    topo_instance_t min, topo_instance_t max, void *arg, void *notused2)
{
    topo_mod_t *nmp;
    cpu_node_t *cpuip = (cpu_node_t *)arg;

    if ((nmp = topo_mod_load(mod, PLATFORM_CPU_NAME,
        PLATFORM_CPU_VERSION)) == NULL) {
        if (topo_mod_errno(mod) == ETOPO_MOD_NOENT) {
            /*
             * There is no platform specific cpu module, so use
             * the default enumeration with kstats of this builtin
             * cpu module.
             */
            if (topo_node_range_create(mod, pnode, name, 0,
                cpuip->cn_ncpustats + 1) < 0) {
                topo_mod_dprintf(mod,
                    "cpu enumeration failed to create "
                    "cpu range [0-%d]: %s\n",
                    cpuip->cn_ncpustats + 1,
                    topo_mod_errmsg(mod));
                return (-1); /* mod_errno set */
            }
            (void) topo_method_register(mod, pnode, cpu_methods);
            return (cpu_create(mod, pnode, name, min, max, cpuip));

        } else {
            /* Fail to load the module */
            topo_mod_dprintf(mod,
                "Failed to load module %s: %s",
                PLATFORM_CPU_NAME,
                topo_mod_errmsg(mod));
            return (-1);
        }
    }

    if (topo_mod_enumerate(nmp, pnode, PLATFORM_CPU_NAME, name,
        min, max, NULL) < 0) {
        topo_mod_dprintf(mod,
            "%s failed to enumerate: %s",
            PLATFORM_CPU_NAME,
            topo_mod_errmsg(mod));
        return (-1);
    }
    (void) topo_method_register(mod, pnode, cpu_methods);

    return (0);
}

static void
cpu_release(topo_mod_t *mod, tnode_t *node)
{
    topo_method_unregister_all(mod, node);
}

ssize_t
fmri_nvl2str(nvlist_t *nvl, uint8_t version, char *buf, size_t buflen)
{
    int rc;
    uint8_t type;
    uint32_t cpuid, way;
    uint32_t    index;
    uint16_t    bit;
    uint64_t serint;
    char *serstr = NULL;

    if (version == CPU_SCHEME_VERSION0) {
        if (nvlist_lookup_uint32(nvl, FM_FMRI_CPU_ID, &cpuid) != 0 ||
            nvlist_lookup_uint64(nvl, FM_FMRI_CPU_SERIAL_ID, &serint)
            != 0)
            return (0);

        return (snprintf(buf, buflen, "cpu:///%s=%u/%s=%llX",
            FM_FMRI_CPU_ID, cpuid, FM_FMRI_CPU_SERIAL_ID,
            (u_longlong_t)serint));

    } else if (version == CPU_SCHEME_VERSION1) {
        if (nvlist_lookup_uint32(nvl, FM_FMRI_CPU_ID, &cpuid) != 0)
            return (0);

        /*
         * Serial number is an optional element
         */
        if ((rc = nvlist_lookup_string(nvl, FM_FMRI_CPU_SERIAL_ID,
            &serstr)) != 0)

            if (rc != ENOENT)
                return (0);

        /*
         * Cache index, way and type are optional elements
         * But if we have one of them, we must have them all.
         */
        rc = nvlist_lookup_uint32(nvl, FM_FMRI_CPU_CACHE_INDEX,
            &index);
        rc |= nvlist_lookup_uint32(nvl, FM_FMRI_CPU_CACHE_WAY, &way);
        rc |= nvlist_lookup_uint16(nvl, FM_FMRI_CPU_CACHE_BIT, &bit);
        rc |= nvlist_lookup_uint8(nvl, FM_FMRI_CPU_CACHE_TYPE, &type);

        /* Insure there were no errors accessing the nvl */
        if (rc != 0 && rc != ENOENT)
            return (0);

        if (serstr == NULL) {
            /* If we have a serial string and no cache info */
            if (rc == ENOENT)
                return (snprintf(buf, buflen, "cpu:///%s=%u",
                    FM_FMRI_CPU_ID, cpuid));
            else {
                return (snprintf(buf, buflen,
                    "cpu:///%s=%u/%s=%u/%s=%u/%s=%d/%s=%d",
                    FM_FMRI_CPU_ID, cpuid,
                    FM_FMRI_CPU_CACHE_INDEX, index,
                    FM_FMRI_CPU_CACHE_WAY, way,
                    FM_FMRI_CPU_CACHE_BIT, bit,
                    FM_FMRI_CPU_CACHE_TYPE, type));
            }
        } else {
            if (rc == ENOENT) {
                return (snprintf(buf, buflen,
                    "cpu:///%s=%u/%s=%s",
                    FM_FMRI_CPU_ID, cpuid,
                    FM_FMRI_CPU_SERIAL_ID, serstr));
            } else {
                return (snprintf(buf, buflen,
                "cpu:///%s=%u/%s=%s/%s=%u/%s=%u/%s=%d/%s=%d",
                    FM_FMRI_CPU_ID, cpuid,
                    FM_FMRI_CPU_SERIAL_ID, serstr,
                    FM_FMRI_CPU_CACHE_INDEX, index,
                    FM_FMRI_CPU_CACHE_WAY, way,
                    FM_FMRI_CPU_CACHE_BIT, bit,
                    FM_FMRI_CPU_CACHE_TYPE, type));
            }
        }
    } else
        return (0);
}

/*ARGSUSED*/
static int
cpu_nvl2str(topo_mod_t *mod, tnode_t *node, topo_version_t version,
    nvlist_t *in, nvlist_t **out)
{
    uint8_t fver;
    ssize_t len;
    char *name;

    if (version > TOPO_METH_NVL2STR_VERSION)
        return (topo_mod_seterrno(mod, EMOD_VER_NEW));

    if (nvlist_lookup_uint8(in, FM_VERSION, &fver) != 0)
        return (topo_mod_seterrno(mod, EMOD_FMRI_VERSION));

    if ((len = fmri_nvl2str(in, fver, NULL, 0)) == 0 ||
        (name = topo_mod_alloc(mod, len + 1)) == NULL ||
        fmri_nvl2str(in, fver, name, len + 1) == 0)
        return (topo_mod_seterrno(mod, EMOD_FMRI_NVL));

    if (topo_mod_nvalloc(mod, out, NV_UNIQUE_NAME) < 0) {
        topo_mod_free(mod, name, len + 1);
        return (topo_mod_seterrno(mod, EMOD_FMRI_NVL));
    }

    if (nvlist_add_string(*out, "fmri-string", name) != 0) {
        topo_mod_free(mod, name, len + 1);
        return (topo_mod_seterrno(mod, EMOD_FMRI_NVL));
    }
    topo_mod_free(mod, name, len + 1);

    return (0);
}

/*ARGSUSED*/
static int
cpu_str2nvl(topo_mod_t *mod, tnode_t *node, topo_version_t version,
    nvlist_t *in, nvlist_t **out)
{
    int err;
    ulong_t cpuid;
    uint8_t type = 0;
    uint32_t way = 0;
    uint32_t index = 0;
    int index_present = 0;
    uint16_t    bit = 0;
    char *str, *s, *end, *serial_end;
    char *serial = NULL;
    nvlist_t *fmri;

    if (version > TOPO_METH_STR2NVL_VERSION)
        return (topo_mod_seterrno(mod, EMOD_VER_NEW));

    if (nvlist_lookup_string(in, "fmri-string", &str) != 0)
        return (topo_mod_seterrno(mod, EMOD_FMRI_NVL));

    /* We're expecting a string version of a cpu scheme FMRI */
    if (strncmp(str, "cpu:///", 7) != 0)
        return (topo_mod_seterrno(mod, EMOD_FMRI_MALFORM));

    s = strchr(str + 7, '=');
    if (s == NULL)
        return (topo_mod_seterrno(mod, EMOD_FMRI_MALFORM));

    ++s;
    cpuid = strtoul(s, &end, 0);

    if (cpuid == ULONG_MAX && errno == ERANGE)
        return (topo_mod_seterrno(mod, EMOD_FMRI_MALFORM));

    /* If there is a serial #, then there might also be cache data */
    if (*(s = end) == '/') {
        s = strchr(s, '=');
        ++s;
        serial = s;
        serial_end = strchr(s, '/');
        /* If there is cache data, all must be present */
        if (serial_end != NULL) {
            /* Now terminate the serial string */
            *serial_end = '\0';
            index_present = 1;
            s = serial_end + 1;
            s = strchr(s, '=');
            ++s;
            index = strtoul(s, &end, 0);
            if (*(s = end) != '/') {
                return (topo_mod_seterrno(mod,
                    EMOD_FMRI_MALFORM));
            }
            s = strchr(s, '=');
            if (s == NULL) {
                return (topo_mod_seterrno(mod,
                    EMOD_FMRI_MALFORM));
            }
            ++s;
            way = strtoul(s, &end, 0);
            if (*(s = end) != '/') {
                return (topo_mod_seterrno(mod,
                    EMOD_FMRI_MALFORM));
            }
            s = strchr(s, '=');
            if (s == NULL) {
                return (topo_mod_seterrno(mod,
                    EMOD_FMRI_MALFORM));
            }
            ++s;
            bit = strtoul(s, &end, 0);
            if (*(s = end) != '/') {
                return (topo_mod_seterrno(mod,
                    EMOD_FMRI_MALFORM));
            }
            s = strchr(s, '=');
            if (s == NULL) {
                return (topo_mod_seterrno(mod,
                    EMOD_FMRI_MALFORM));
            }
            ++s;
            type = strtoul(s, &end, 0);
        }

    }
    if (topo_mod_nvalloc(mod, &fmri, NV_UNIQUE_NAME) != 0)
        return (topo_mod_seterrno(mod, EMOD_FMRI_NVL));

    err = nvlist_add_uint8(fmri, FM_VERSION, CPU_SCHEME_VERSION1);
    err |= nvlist_add_string(fmri, FM_FMRI_SCHEME, FM_FMRI_SCHEME_CPU);
    err |= nvlist_add_uint32(fmri, FM_FMRI_CPU_ID, (uint32_t)cpuid);
    err |= nvlist_add_uint8(fmri, FM_FMRI_CPU_MASK, 0);
    if (serial != NULL)
        err |= nvlist_add_string(fmri, FM_FMRI_CPU_SERIAL_ID,
            serial);

    if (index_present) {
        err |= nvlist_add_uint32(fmri, FM_FMRI_CPU_CACHE_INDEX,
            index);
        err |= nvlist_add_uint32(fmri, FM_FMRI_CPU_CACHE_WAY,
            way);
        err |= nvlist_add_uint16(fmri, FM_FMRI_CPU_CACHE_BIT,
            bit);
        err |= nvlist_add_uint8(fmri, FM_FMRI_CPU_CACHE_TYPE,
            type);
    }
    if (err != 0) {
        nvlist_free(fmri);
        return (topo_mod_seterrno(mod, EMOD_FMRI_NVL));
    }
    *out = fmri;

    return (0);
}

static nvlist_t *
fmri_create(topo_mod_t *mod, uint32_t cpu_id, uint8_t cpumask, char *s)
{
    int err;
    nvlist_t *fmri;

    if (topo_mod_nvalloc(mod, &fmri, NV_UNIQUE_NAME) != 0) {
        (void) topo_mod_seterrno(mod, EMOD_FMRI_NVL);
        return (NULL);
    }

    err = nvlist_add_uint8(fmri, FM_VERSION, FM_CPU_SCHEME_VERSION);
    err |= nvlist_add_string(fmri, FM_FMRI_SCHEME, FM_FMRI_SCHEME_CPU);
    err |= nvlist_add_uint32(fmri, FM_FMRI_CPU_ID, cpu_id);
    err |= nvlist_add_uint8(fmri, FM_FMRI_CPU_MASK, cpumask);
    if (s != NULL)
        err |= nvlist_add_string(fmri, FM_FMRI_CPU_SERIAL_ID, s);
    if (err != 0) {
        nvlist_free(fmri);
        (void) topo_mod_seterrno(mod, EMOD_FMRI_NVL);
        return (NULL);
    }

    return (fmri);
}

/*ARGSUSED*/
static int
cpu_fmri_asru(topo_mod_t *mod, tnode_t *node, topo_version_t version,
    nvlist_t *in, nvlist_t **out)
{
    int rc;
    uint32_t cpu_id;
    uint8_t cpumask = 0;
    char *serial = NULL;

    if ((rc = nvlist_lookup_uint32(in, FM_FMRI_CPU_ID, &cpu_id)) != 0) {
        if (rc == ENOENT)
            return (topo_mod_seterrno(mod, EMOD_METHOD_INVAL));
        else
            return (topo_mod_seterrno(mod, EMOD_FMRI_NVL));
    }

    (void) nvlist_lookup_string(in, FM_FMRI_CPU_SERIAL_ID, &serial);
    (void) nvlist_lookup_uint8(in, FM_FMRI_CPU_MASK, &cpumask);

    *out = fmri_create(mod, cpu_id, cpumask, serial);

    return (0);
}

/*ARGSUSED*/
static int
cpu_fmri_create_meth(topo_mod_t *mod, tnode_t *node, topo_version_t version,
    nvlist_t *in, nvlist_t **out)
{
    int     rc;
    nvlist_t    *args;
    uint32_t    cpu_id;
    uint8_t     cpumask = 0;
    char        *serial = NULL;

    if (version > TOPO_METH_FMRI_VERSION) {
        return (topo_mod_seterrno(mod, EMOD_VER_NEW));
    }

    rc = nvlist_lookup_nvlist(in, TOPO_METH_FMRI_ARG_NVL, &args);
    if (rc != 0) {
        /*
         * This routine requires arguments to be packed in the
         * format used in topo_fmri_create()
         */
        return (topo_mod_seterrno(mod, EMOD_METHOD_INVAL));
    }

    if (nvlist_lookup_string(args, FM_FMRI_CPU_SERIAL_ID, &serial) != 0 ||
        nvlist_lookup_uint32(args, FM_FMRI_CPU_ID, &cpu_id) != 0 ||
        nvlist_lookup_uint8(args, FM_FMRI_CPU_MASK, &cpumask) != 0) {
        return (topo_mod_seterrno(mod, EMOD_METHOD_INVAL));
    }

    *out = fmri_create(mod, cpu_id, cpumask, serial);
    if (*out == NULL) {
        return (-1);
    }

    return (0);
}

/*ARGSUSED*/
static int
cpu_fmri_service_state(topo_mod_t *mod, tnode_t *node, topo_version_t version,
    nvlist_t *in, nvlist_t **out)
{
    int state;
    uint32_t cpuid;
    uint8_t fmversion;

    if (nvlist_lookup_uint8(in, FM_VERSION, &fmversion) != 0 ||
        fmversion > FM_CPU_SCHEME_VERSION)
        return (topo_mod_seterrno(mod, EMOD_FMRI_MALFORM));

    if (version > TOPO_METH_SERVICE_STATE_VERSION)
        return (topo_mod_seterrno(mod, EMOD_VER_NEW));

    if (nvlist_lookup_uint32(in, FM_FMRI_CPU_ID, &cpuid) != 0)
        return (topo_mod_seterrno(mod, EMOD_FMRI_MALFORM));

    state = p_online(cpuid, P_STATUS) == P_FAULTED ?
        FMD_SERVICE_STATE_UNUSABLE : FMD_SERVICE_STATE_OK;

    if (topo_mod_nvalloc(mod, out, NV_UNIQUE_NAME) != 0)
        return (topo_mod_seterrno(mod, EMOD_NVL_INVAL));
    if (nvlist_add_uint32(*out, TOPO_METH_SERVICE_STATE_RET,
        state) != 0) {
        nvlist_free(*out);
        return (topo_mod_seterrno(mod, EMOD_NVL_INVAL));
    }

    return (0);
}

/*ARGSUSED*/
static int
cpu_fmri_strhash_path(topo_mod_t *mod, tnode_t *node, topo_version_t version,
    nvlist_t *in, nvlist_t **out)
{
    char *fmri =  (char *)in, *f;
    uint64_t h = 0;
    uint64_t *rval = (uint64_t *)(void *)out;
    int len;

    if ((f = strchr(fmri + 7, '/')) != NULL)
        len = f++ - fmri;
    h += topo_fmri_strhash_one(fmri, len);

    if (f != NULL && strncmp(f, FM_FMRI_CPU_SERIAL_ID,
        sizeof (FM_FMRI_CPU_SERIAL_ID) - 1) == 0)
        if ((f = strchr(f, '/')) != NULL)
            f++;
    if (f != NULL)
        h += topo_fmri_strhash_one(f, strlen(f));
    *rval = h;
    return (0);
}

/*ARGSUSED*/
static int
cpu_fmri_strcmp_path(topo_mod_t *mod, tnode_t *node, topo_version_t version,
    nvlist_t *in, nvlist_t **out)
{
    char *a = (char *)in, *b = (char *)out;
    char *fa, *fb;
    int lena = -1, lenb = -1;

    /*
     * just skip the next char ("/") as there is no auth for cpu
     */
    a++;
    b++;

    /*
     * First compare the cpuid bit (first element)
     */
    if ((fa = strchr(a, '/')) != NULL)
        lena = fa++ - a;
    if ((fb = strchr(b, '/')) != NULL)
        lenb = fb++ - b;
    if (lena != lenb)
        return (B_FALSE);
    if (strncmp(a, b, lena) != 0)
        return (B_FALSE);

    /*
     * If next element is FM_FMRI_CPU_SERIAL_ID then skip it
     * and compare what's left.
     */
    if (fa != NULL && strncmp(fa, FM_FMRI_CPU_SERIAL_ID,
        sizeof (FM_FMRI_CPU_SERIAL_ID) - 1) == 0)
        if ((fa = strchr(fa, '/')) != NULL)
            fa++;
    if (fb != NULL && strncmp(fb, FM_FMRI_CPU_SERIAL_ID,
        sizeof (FM_FMRI_CPU_SERIAL_ID) - 1) == 0)
        if ((fb = strchr(fb, '/')) != NULL)
            fb++;
    if (fa == NULL && fb == NULL)
        return (B_TRUE);
    else if (fa == NULL || fb == NULL)
        return (B_FALSE);
    else
        return (strcmp(fa, fb) == 0);
}

/*ARGSUSED*/
static int
cpu_fmri_strcmp_ident(topo_mod_t *mod, tnode_t *node, topo_version_t version,
    nvlist_t *in, nvlist_t **out)
{
    char *a = (char *)in, *b = (char *)out;
    char *fa, *fb;
    int lena = -1, lenb = -1;

    a = strstr(a, FM_FMRI_CPU_SERIAL_ID);
    b = strstr(b, FM_FMRI_CPU_SERIAL_ID);
    if (a == NULL && b == NULL)
        return (B_TRUE);
    else if (a == NULL || b == NULL)
        return (B_FALSE);

    if ((fa = strchr(a, '/')) != NULL)
        lena = fa - a;
    if ((fb = strchr(b, '/')) != NULL)
        lenb = fb - b;
    if (lena != lenb)
        return (B_FALSE);
    return (strncmp(a, b, lena) == 0);
}