uts: make emu10k non-verbose

[unleashed.git] / kernel / os / 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) 1991, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright (c) 2012 by Delphix. All rights reserved.
 */

/*
 * Architecture-independent CPU control functions.
 */

#include <sys/types.h>
#include <sys/param.h>
#include <sys/var.h>
#include <sys/thread.h>
#include <sys/cpuvar.h>
#include <sys/cpu_event.h>
#include <sys/kstat.h>
#include <sys/uadmin.h>
#include <sys/systm.h>
#include <sys/errno.h>
#include <sys/cmn_err.h>
#include <sys/procset.h>
#include <sys/processor.h>
#include <sys/debug.h>
#include <sys/cpupart.h>
#include <sys/lgrp.h>
#include <sys/pset.h>
#include <sys/pghw.h>
#include <sys/kmem.h>
#include <sys/kmem_impl.h>      /* to set per-cpu kmem_cache offset */
#include <sys/atomic.h>
#include <sys/callb.h>
#include <sys/vtrace.h>
#include <sys/cyclic.h>
#include <sys/bitmap.h>
#include <sys/nvpair.h>
#include <sys/pool_pset.h>
#include <sys/msacct.h>
#include <sys/time.h>
#include <sys/archsystm.h>
#include <sys/sdt.h>
#if defined(__x86) || defined(__amd64)
#include <sys/x86_archext.h>
#endif
#include <sys/callo.h>

extern int      mp_cpu_start(cpu_t *);
extern int      mp_cpu_stop(cpu_t *);
extern int      mp_cpu_poweron(cpu_t *);
extern int      mp_cpu_poweroff(cpu_t *);
extern int      mp_cpu_configure(int);
extern int      mp_cpu_unconfigure(int);
extern void     mp_cpu_faulted_enter(cpu_t *);
extern void     mp_cpu_faulted_exit(cpu_t *);

extern int cmp_cpu_to_chip(processorid_t cpuid);
#ifdef __sparcv9
extern char *cpu_fru_fmri(cpu_t *cp);
#endif

static void cpu_add_active_internal(cpu_t *cp);
static void cpu_remove_active(cpu_t *cp);
static void cpu_info_kstat_create(cpu_t *cp);
static void cpu_info_kstat_destroy(cpu_t *cp);
static void cpu_stats_kstat_create(cpu_t *cp);
static void cpu_stats_kstat_destroy(cpu_t *cp);

static int cpu_sys_stats_ks_update(kstat_t *ksp, int rw);
static int cpu_vm_stats_ks_update(kstat_t *ksp, int rw);
static int cpu_stat_ks_update(kstat_t *ksp, int rw);
static int cpu_state_change_hooks(int, cpu_setup_t, cpu_setup_t);

/*
 * cpu_lock protects ncpus, ncpus_online, cpu_flag, cpu_list, cpu_active,
 * max_cpu_seqid_ever, and dispatch queue reallocations.  The lock ordering with
 * respect to related locks is:
 *
 *      cpu_lock --> thread_free_lock  --->  p_lock  --->  thread_lock()
 *
 * Warning:  Certain sections of code do not use the cpu_lock when
 * traversing the cpu_list (e.g. mutex_vector_enter(), clock()).  Since
 * all cpus are paused during modifications to this list, a solution
 * to protect the list is too either disable kernel preemption while
 * walking the list, *or* recheck the cpu_next pointer at each
 * iteration in the loop.  Note that in no cases can any cached
 * copies of the cpu pointers be kept as they may become invalid.
 */
kmutex_t        cpu_lock;
cpu_t           *cpu_list;              /* list of all CPUs */
cpu_t           *clock_cpu_list;        /* used by clock to walk CPUs */
cpu_t           *cpu_active;            /* list of active CPUs */
static cpuset_t cpu_available;          /* set of available CPUs */
cpuset_t        cpu_seqid_inuse;        /* which cpu_seqids are in use */

cpu_t           **cpu_seq;              /* ptrs to CPUs, indexed by seq_id */

/*
 * max_ncpus keeps the max cpus the system can have. Initially
 * it's NCPU, but since most archs scan the devtree for cpus
 * fairly early on during boot, the real max can be known before
 * ncpus is set (useful for early NCPU based allocations).
 */
int max_ncpus = NCPU;
/*
 * platforms that set max_ncpus to maxiumum number of cpus that can be
 * dynamically added will set boot_max_ncpus to the number of cpus found
 * at device tree scan time during boot.
 */
int boot_max_ncpus = -1;
int boot_ncpus = -1;
/*
 * Maximum possible CPU id.  This can never be >= NCPU since NCPU is
 * used to size arrays that are indexed by CPU id.
 */
processorid_t max_cpuid = NCPU - 1;

/*
 * Maximum cpu_seqid was given. This number can only grow and never shrink. It
 * can be used to optimize NCPU loops to avoid going through CPUs which were
 * never on-line.
 */
processorid_t max_cpu_seqid_ever = 0;

int ncpus = 1;
int ncpus_online = 1;

/*
 * CPU that we're trying to offline.  Protected by cpu_lock.
 */
cpu_t *cpu_inmotion;

/*
 * Can be raised to suppress further weakbinding, which are instead
 * satisfied by disabling preemption.  Must be raised/lowered under cpu_lock,
 * while individual thread weakbinding synchronization is done under thread
 * lock.
 */
int weakbindingbarrier;

/*
 * Variables used in pause_cpus().
 */
static volatile char safe_list[NCPU];

static struct _cpu_pause_info {
        int             cp_spl;         /* spl saved in pause_cpus() */
        volatile int    cp_go;          /* Go signal sent after all ready */
        int             cp_count;       /* # of CPUs to pause */
        ksema_t         cp_sem;         /* synch pause_cpus & cpu_pause */
        kthread_id_t    cp_paused;
        void            *(*cp_func)(void *);
} cpu_pause_info;

static kmutex_t pause_free_mutex;
static kcondvar_t pause_free_cv;


static struct cpu_sys_stats_ks_data {
        kstat_named_t cpu_ticks_idle;
        kstat_named_t cpu_ticks_user;
        kstat_named_t cpu_ticks_kernel;
        kstat_named_t cpu_ticks_wait;
        kstat_named_t cpu_nsec_idle;
        kstat_named_t cpu_nsec_user;
        kstat_named_t cpu_nsec_kernel;
        kstat_named_t cpu_nsec_dtrace;
        kstat_named_t cpu_nsec_intr;
        kstat_named_t cpu_load_intr;
        kstat_named_t wait_ticks_io;
        kstat_named_t dtrace_probes;
        kstat_named_t bread;
        kstat_named_t bwrite;
        kstat_named_t lread;
        kstat_named_t lwrite;
        kstat_named_t phread;
        kstat_named_t phwrite;
        kstat_named_t pswitch;
        kstat_named_t trap;
        kstat_named_t intr;
        kstat_named_t syscall;
        kstat_named_t sysread;
        kstat_named_t syswrite;
        kstat_named_t sysfork;
        kstat_named_t sysvfork;
        kstat_named_t sysexec;
        kstat_named_t readch;
        kstat_named_t writech;
        kstat_named_t rcvint;
        kstat_named_t xmtint;
        kstat_named_t mdmint;
        kstat_named_t rawch;
        kstat_named_t canch;
        kstat_named_t outch;
        kstat_named_t msg;
        kstat_named_t sema;
        kstat_named_t namei;
        kstat_named_t ufsiget;
        kstat_named_t ufsdirblk;
        kstat_named_t ufsipage;
        kstat_named_t ufsinopage;
        kstat_named_t procovf;
        kstat_named_t intrthread;
        kstat_named_t intrblk;
        kstat_named_t intrunpin;
        kstat_named_t idlethread;
        kstat_named_t inv_swtch;
        kstat_named_t nthreads;
        kstat_named_t cpumigrate;
        kstat_named_t xcalls;
        kstat_named_t mutex_adenters;
        kstat_named_t rw_rdfails;
        kstat_named_t rw_wrfails;
        kstat_named_t modload;
        kstat_named_t modunload;
        kstat_named_t bawrite;
        kstat_named_t iowait;
} cpu_sys_stats_ks_data_template = {
        { "cpu_ticks_idle",     KSTAT_DATA_UINT64 },
        { "cpu_ticks_user",     KSTAT_DATA_UINT64 },
        { "cpu_ticks_kernel",   KSTAT_DATA_UINT64 },
        { "cpu_ticks_wait",     KSTAT_DATA_UINT64 },
        { "cpu_nsec_idle",      KSTAT_DATA_UINT64 },
        { "cpu_nsec_user",      KSTAT_DATA_UINT64 },
        { "cpu_nsec_kernel",    KSTAT_DATA_UINT64 },
        { "cpu_nsec_dtrace",    KSTAT_DATA_UINT64 },
        { "cpu_nsec_intr",      KSTAT_DATA_UINT64 },
        { "cpu_load_intr",      KSTAT_DATA_UINT64 },
        { "wait_ticks_io",      KSTAT_DATA_UINT64 },
        { "dtrace_probes",      KSTAT_DATA_UINT64 },
        { "bread",              KSTAT_DATA_UINT64 },
        { "bwrite",             KSTAT_DATA_UINT64 },
        { "lread",              KSTAT_DATA_UINT64 },
        { "lwrite",             KSTAT_DATA_UINT64 },
        { "phread",             KSTAT_DATA_UINT64 },
        { "phwrite",            KSTAT_DATA_UINT64 },
        { "pswitch",            KSTAT_DATA_UINT64 },
        { "trap",               KSTAT_DATA_UINT64 },
        { "intr",               KSTAT_DATA_UINT64 },
        { "syscall",            KSTAT_DATA_UINT64 },
        { "sysread",            KSTAT_DATA_UINT64 },
        { "syswrite",           KSTAT_DATA_UINT64 },
        { "sysfork",            KSTAT_DATA_UINT64 },
        { "sysvfork",           KSTAT_DATA_UINT64 },
        { "sysexec",            KSTAT_DATA_UINT64 },
        { "readch",             KSTAT_DATA_UINT64 },
        { "writech",            KSTAT_DATA_UINT64 },
        { "rcvint",             KSTAT_DATA_UINT64 },
        { "xmtint",             KSTAT_DATA_UINT64 },
        { "mdmint",             KSTAT_DATA_UINT64 },
        { "rawch",              KSTAT_DATA_UINT64 },
        { "canch",              KSTAT_DATA_UINT64 },
        { "outch",              KSTAT_DATA_UINT64 },
        { "msg",                KSTAT_DATA_UINT64 },
        { "sema",               KSTAT_DATA_UINT64 },
        { "namei",              KSTAT_DATA_UINT64 },
        { "ufsiget",            KSTAT_DATA_UINT64 },
        { "ufsdirblk",          KSTAT_DATA_UINT64 },
        { "ufsipage",           KSTAT_DATA_UINT64 },
        { "ufsinopage",         KSTAT_DATA_UINT64 },
        { "procovf",            KSTAT_DATA_UINT64 },
        { "intrthread",         KSTAT_DATA_UINT64 },
        { "intrblk",            KSTAT_DATA_UINT64 },
        { "intrunpin",          KSTAT_DATA_UINT64 },
        { "idlethread",         KSTAT_DATA_UINT64 },
        { "inv_swtch",          KSTAT_DATA_UINT64 },
        { "nthreads",           KSTAT_DATA_UINT64 },
        { "cpumigrate",         KSTAT_DATA_UINT64 },
        { "xcalls",             KSTAT_DATA_UINT64 },
        { "mutex_adenters",     KSTAT_DATA_UINT64 },
        { "rw_rdfails",         KSTAT_DATA_UINT64 },
        { "rw_wrfails",         KSTAT_DATA_UINT64 },
        { "modload",            KSTAT_DATA_UINT64 },
        { "modunload",          KSTAT_DATA_UINT64 },
        { "bawrite",            KSTAT_DATA_UINT64 },
        { "iowait",             KSTAT_DATA_UINT64 },
};

static struct cpu_vm_stats_ks_data {
        kstat_named_t pgrec;
        kstat_named_t pgfrec;
        kstat_named_t pgin;
        kstat_named_t pgpgin;
        kstat_named_t pgout;
        kstat_named_t pgpgout;
        kstat_named_t zfod;
        kstat_named_t dfree;
        kstat_named_t scan;
        kstat_named_t rev;
        kstat_named_t hat_fault;
        kstat_named_t as_fault;
        kstat_named_t maj_fault;
        kstat_named_t cow_fault;
        kstat_named_t prot_fault;
        kstat_named_t softlock;
        kstat_named_t kernel_asflt;
        kstat_named_t pgrrun;
        kstat_named_t execpgin;
        kstat_named_t execpgout;
        kstat_named_t execfree;
        kstat_named_t anonpgin;
        kstat_named_t anonpgout;
        kstat_named_t anonfree;
        kstat_named_t fspgin;
        kstat_named_t fspgout;
        kstat_named_t fsfree;
} cpu_vm_stats_ks_data_template = {
        { "pgrec",              KSTAT_DATA_UINT64 },
        { "pgfrec",             KSTAT_DATA_UINT64 },
        { "pgin",               KSTAT_DATA_UINT64 },
        { "pgpgin",             KSTAT_DATA_UINT64 },
        { "pgout",              KSTAT_DATA_UINT64 },
        { "pgpgout",            KSTAT_DATA_UINT64 },
        { "zfod",               KSTAT_DATA_UINT64 },
        { "dfree",              KSTAT_DATA_UINT64 },
        { "scan",               KSTAT_DATA_UINT64 },
        { "rev",                KSTAT_DATA_UINT64 },
        { "hat_fault",          KSTAT_DATA_UINT64 },
        { "as_fault",           KSTAT_DATA_UINT64 },
        { "maj_fault",          KSTAT_DATA_UINT64 },
        { "cow_fault",          KSTAT_DATA_UINT64 },
        { "prot_fault",         KSTAT_DATA_UINT64 },
        { "softlock",           KSTAT_DATA_UINT64 },
        { "kernel_asflt",       KSTAT_DATA_UINT64 },
        { "pgrrun",             KSTAT_DATA_UINT64 },
        { "execpgin",           KSTAT_DATA_UINT64 },
        { "execpgout",          KSTAT_DATA_UINT64 },
        { "execfree",           KSTAT_DATA_UINT64 },
        { "anonpgin",           KSTAT_DATA_UINT64 },
        { "anonpgout",          KSTAT_DATA_UINT64 },
        { "anonfree",           KSTAT_DATA_UINT64 },
        { "fspgin",             KSTAT_DATA_UINT64 },
        { "fspgout",            KSTAT_DATA_UINT64 },
        { "fsfree",             KSTAT_DATA_UINT64 },
};

/*
 * Force the specified thread to migrate to the appropriate processor.
 * Called with thread lock held, returns with it dropped.
 */
static void
force_thread_migrate(kthread_id_t tp)
{
        ASSERT(THREAD_LOCK_HELD(tp));
        if (tp == curthread) {
                THREAD_TRANSITION(tp);
                CL_SETRUN(tp);
                thread_unlock_nopreempt(tp);
                swtch();
        } else {
                if (tp->t_state == TS_ONPROC) {
                        cpu_surrender(tp);
                } else if (tp->t_state == TS_RUN) {
                        (void) dispdeq(tp);
                        setbackdq(tp);
                }
                thread_unlock(tp);
        }
}

/*
 * Set affinity for a specified CPU.
 * A reference count is incremented and the affinity is held until the
 * reference count is decremented to zero by thread_affinity_clear().
 * This is so regions of code requiring affinity can be nested.
 * Caller needs to ensure that cpu_id remains valid, which can be
 * done by holding cpu_lock across this call, unless the caller
 * specifies CPU_CURRENT in which case the cpu_lock will be acquired
 * by thread_affinity_set and CPU->cpu_id will be the target CPU.
 */
void
thread_affinity_set(kthread_id_t t, int cpu_id)
{
        cpu_t           *cp;
        int             c;

        ASSERT(!(t == curthread && t->t_weakbound_cpu != NULL));

        if ((c = cpu_id) == CPU_CURRENT) {
                mutex_enter(&cpu_lock);
                cpu_id = CPU->cpu_id;
        }
        ASSERT(MUTEX_HELD(&cpu_lock));
        ASSERT((cpu_id >= 0) && (cpu_id < NCPU));
        cp = cpu[cpu_id];
        ASSERT(cp != NULL);             /* user must provide a good cpu_id */
        /*
         * If there is already a hard affinity requested, and this affinity
         * conflicts with that, panic.
         */
        thread_lock(t);
        if (t->t_affinitycnt > 0 && t->t_bound_cpu != cp) {
                panic("affinity_set: setting %p but already bound to %p",
                    (void *)cp, (void *)t->t_bound_cpu);
        }
        t->t_affinitycnt++;
        t->t_bound_cpu = cp;

        /*
         * Make sure we're running on the right CPU.
         */
        if (cp != t->t_cpu || t != curthread) {
                force_thread_migrate(t);        /* drops thread lock */
        } else {
                thread_unlock(t);
        }

        if (c == CPU_CURRENT)
                mutex_exit(&cpu_lock);
}

/*
 *      Wrapper for backward compatibility.
 */
void
affinity_set(int cpu_id)
{
        thread_affinity_set(curthread, cpu_id);
}

/*
 * Decrement the affinity reservation count and if it becomes zero,
 * clear the CPU affinity for the current thread, or set it to the user's
 * software binding request.
 */
void
thread_affinity_clear(kthread_id_t t)
{
        register processorid_t binding;

        thread_lock(t);
        if (--t->t_affinitycnt == 0) {
                if ((binding = t->t_bind_cpu) == PBIND_NONE) {
                        /*
                         * Adjust disp_max_unbound_pri if necessary.
                         */
                        disp_adjust_unbound_pri(t);
                        t->t_bound_cpu = NULL;
                        if (t->t_cpu->cpu_part != t->t_cpupart) {
                                force_thread_migrate(t);
                                return;
                        }
                } else {
                        t->t_bound_cpu = cpu[binding];
                        /*
                         * Make sure the thread is running on the bound CPU.
                         */
                        if (t->t_cpu != t->t_bound_cpu) {
                                force_thread_migrate(t);
                                return;         /* already dropped lock */
                        }
                }
        }
        thread_unlock(t);
}

/*
 * Wrapper for backward compatibility.
 */
void
affinity_clear(void)
{
        thread_affinity_clear(curthread);
}

/*
 * Weak cpu affinity.  Bind to the "current" cpu for short periods
 * of time during which the thread must not block (but may be preempted).
 * Use this instead of kpreempt_disable() when it is only "no migration"
 * rather than "no preemption" semantics that are required - disabling
 * preemption holds higher priority threads off of cpu and if the
 * operation that is protected is more than momentary this is not good
 * for realtime etc.
 *
 * Weakly bound threads will not prevent a cpu from being offlined -
 * we'll only run them on the cpu to which they are weakly bound but
 * (because they do not block) we'll always be able to move them on to
 * another cpu at offline time if we give them just a short moment to
 * run during which they will unbind.  To give a cpu a chance of offlining,
 * however, we require a barrier to weak bindings that may be raised for a
 * given cpu (offline/move code may set this and then wait a short time for
 * existing weak bindings to drop); the cpu_inmotion pointer is that barrier.
 *
 * There are few restrictions on the calling context of thread_nomigrate.
 * The caller must not hold the thread lock.  Calls may be nested.
 *
 * After weakbinding a thread must not perform actions that may block.
 * In particular it must not call thread_affinity_set; calling that when
 * already weakbound is nonsensical anyway.
 *
 * If curthread is prevented from migrating for other reasons
 * (kernel preemption disabled; high pil; strongly bound; interrupt thread)
 * then the weak binding will succeed even if this cpu is the target of an
 * offline/move request.
 */
void
thread_nomigrate(void)
{
        cpu_t *cp;
        kthread_id_t t = curthread;

again:
        kpreempt_disable();
        cp = CPU;

        /*
         * A highlevel interrupt must not modify t_nomigrate or
         * t_weakbound_cpu of the thread it has interrupted.  A lowlevel
         * interrupt thread cannot migrate and we can avoid the
         * thread_lock call below by short-circuiting here.  In either
         * case we can just return since no migration is possible and
         * the condition will persist (ie, when we test for these again
         * in thread_allowmigrate they can't have changed).   Migration
         * is also impossible if we're at or above DISP_LEVEL pil.
         */
        if (CPU_ON_INTR(cp) || t->t_flag & T_INTR_THREAD ||
            getpil() >= DISP_LEVEL) {
                kpreempt_enable();
                return;
        }

        /*
         * We must be consistent with existing weak bindings.  Since we
         * may be interrupted between the increment of t_nomigrate and
         * the store to t_weakbound_cpu below we cannot assume that
         * t_weakbound_cpu will be set if t_nomigrate is.  Note that we
         * cannot assert t_weakbound_cpu == t_bind_cpu since that is not
         * always the case.
         */
        if (t->t_nomigrate && t->t_weakbound_cpu && t->t_weakbound_cpu != cp) {
                if (!panicstr)
                        panic("thread_nomigrate: binding to %p but already "
                            "bound to %p", (void *)cp,
                            (void *)t->t_weakbound_cpu);
        }

        /*
         * At this point we have preemption disabled and we don't yet hold
         * the thread lock.  So it's possible that somebody else could
         * set t_bind_cpu here and not be able to force us across to the
         * new cpu (since we have preemption disabled).
         */
        thread_lock(curthread);

        /*
         * If further weak bindings are being (temporarily) suppressed then
         * we'll settle for disabling kernel preemption (which assures
         * no migration provided the thread does not block which it is
         * not allowed to if using thread_nomigrate).  We must remember
         * this disposition so we can take appropriate action in
         * thread_allowmigrate.  If this is a nested call and the
         * thread is already weakbound then fall through as normal.
         * We remember the decision to settle for kpreempt_disable through
         * negative nesting counting in t_nomigrate.  Once a thread has had one
         * weakbinding request satisfied in this way any further (nested)
         * requests will continue to be satisfied in the same way,
         * even if weak bindings have recommenced.
         */
        if (t->t_nomigrate < 0 || weakbindingbarrier && t->t_nomigrate == 0) {
                --t->t_nomigrate;
                thread_unlock(curthread);
                return;         /* with kpreempt_disable still active */
        }

        /*
         * We hold thread_lock so t_bind_cpu cannot change.  We could,
         * however, be running on a different cpu to which we are t_bound_cpu
         * to (as explained above).  If we grant the weak binding request
         * in that case then the dispatcher must favour our weak binding
         * over our strong (in which case, just as when preemption is
         * disabled, we can continue to run on a cpu other than the one to
         * which we are strongbound; the difference in this case is that
         * this thread can be preempted and so can appear on the dispatch
         * queues of a cpu other than the one it is strongbound to).
         *
         * If the cpu we are running on does not appear to be a current
         * offline target (we check cpu_inmotion to determine this - since
         * we don't hold cpu_lock we may not see a recent store to that,
         * so it's possible that we at times can grant a weak binding to a
         * cpu that is an offline target, but that one request will not
         * prevent the offline from succeeding) then we will always grant
         * the weak binding request.  This includes the case above where
         * we grant a weakbinding not commensurate with our strong binding.
         *
         * If our cpu does appear to be an offline target then we're inclined
         * not to grant the weakbinding request just yet - we'd prefer to
         * migrate to another cpu and grant the request there.  The
         * exceptions are those cases where going through preemption code
         * will not result in us changing cpu:
         *
         *      . interrupts have already bypassed this case (see above)
         *      . we are already weakbound to this cpu (dispatcher code will
         *        always return us to the weakbound cpu)
         *      . preemption was disabled even before we disabled it above
         *      . we are strongbound to this cpu (if we're strongbound to
         *      another and not yet running there the trip through the
         *      dispatcher will move us to the strongbound cpu and we
         *      will grant the weak binding there)
         */
        if (cp != cpu_inmotion || t->t_nomigrate > 0 || t->t_preempt > 1 ||
            t->t_bound_cpu == cp) {
                /*
                 * Don't be tempted to store to t_weakbound_cpu only on
                 * the first nested bind request - if we're interrupted
                 * after the increment of t_nomigrate and before the
                 * store to t_weakbound_cpu and the interrupt calls
                 * thread_nomigrate then the assertion in thread_allowmigrate
                 * would fail.
                 */
                t->t_nomigrate++;
                t->t_weakbound_cpu = cp;
                membar_producer();
                thread_unlock(curthread);
                /*
                 * Now that we have dropped the thread_lock another thread
                 * can set our t_weakbound_cpu, and will try to migrate us
                 * to the strongbound cpu (which will not be prevented by
                 * preemption being disabled since we're about to enable
                 * preemption).  We have granted the weakbinding to the current
                 * cpu, so again we are in the position that is is is possible
                 * that our weak and strong bindings differ.  Again this
                 * is catered for by dispatcher code which will favour our
                 * weak binding.
                 */
                kpreempt_enable();
        } else {
                /*
                 * Move to another cpu before granting the request by
                 * forcing this thread through preemption code.  When we
                 * get to set{front,back}dq called from CL_PREEMPT()
                 * cpu_choose() will be used to select a cpu to queue
                 * us on - that will see cpu_inmotion and take
                 * steps to avoid returning us to this cpu.
                 */
                cp->cpu_kprunrun = 1;
                thread_unlock(curthread);
                kpreempt_enable();      /* will call preempt() */
                goto again;
        }
}

void
thread_allowmigrate(void)
{
        kthread_id_t t = curthread;

        ASSERT(t->t_weakbound_cpu == CPU ||
            (t->t_nomigrate < 0 && t->t_preempt > 0) ||
            CPU_ON_INTR(CPU) || t->t_flag & T_INTR_THREAD ||
            getpil() >= DISP_LEVEL);

        if (CPU_ON_INTR(CPU) || (t->t_flag & T_INTR_THREAD) ||
            getpil() >= DISP_LEVEL)
                return;

        if (t->t_nomigrate < 0) {
                /*
                 * This thread was granted "weak binding" in the
                 * stronger form of kernel preemption disabling.
                 * Undo a level of nesting for both t_nomigrate
                 * and t_preempt.
                 */
                ++t->t_nomigrate;
                kpreempt_enable();
        } else if (--t->t_nomigrate == 0) {
                /*
                 * Time to drop the weak binding.  We need to cater
                 * for the case where we're weakbound to a different
                 * cpu than that to which we're strongbound (a very
                 * temporary arrangement that must only persist until
                 * weak binding drops).  We don't acquire thread_lock
                 * here so even as this code executes t_bound_cpu
                 * may be changing.  So we disable preemption and
                 * a) in the case that t_bound_cpu changes while we
                 * have preemption disabled kprunrun will be set
                 * asynchronously, and b) if before disabling
                 * preemption we were already on a different cpu to
                 * our t_bound_cpu then we set kprunrun ourselves
                 * to force a trip through the dispatcher when
                 * preemption is enabled.
                 */
                kpreempt_disable();
                if (t->t_bound_cpu &&
                    t->t_weakbound_cpu != t->t_bound_cpu)
                        CPU->cpu_kprunrun = 1;
                t->t_weakbound_cpu = NULL;
                membar_producer();
                kpreempt_enable();
        }
}

/*
 * weakbinding_stop can be used to temporarily cause weakbindings made
 * with thread_nomigrate to be satisfied through the stronger action of
 * kpreempt_disable.  weakbinding_start recommences normal weakbinding.
 */

void
weakbinding_stop(void)
{
        ASSERT(MUTEX_HELD(&cpu_lock));
        weakbindingbarrier = 1;
        membar_producer();      /* make visible before subsequent thread_lock */
}

void
weakbinding_start(void)
{
        ASSERT(MUTEX_HELD(&cpu_lock));
        weakbindingbarrier = 0;
}

void
null_xcall(void)
{
}

/*
 * This routine is called to place the CPUs in a safe place so that
 * one of them can be taken off line or placed on line.  What we are
 * trying to do here is prevent a thread from traversing the list
 * of active CPUs while we are changing it or from getting placed on
 * the run queue of a CPU that has just gone off line.  We do this by
 * creating a thread with the highest possible prio for each CPU and
 * having it call this routine.  The advantage of this method is that
 * we can eliminate all checks for CPU_ACTIVE in the disp routines.
 * This makes disp faster at the expense of making p_online() slower
 * which is a good trade off.
 */
static void
cpu_pause(int index)
{
        int s;
        struct _cpu_pause_info *cpi = &cpu_pause_info;
        volatile char *safe = &safe_list[index];
        long    lindex = index;

        ASSERT((curthread->t_bound_cpu != NULL) || (*safe == PAUSE_DIE));

        while (*safe != PAUSE_DIE) {
                *safe = PAUSE_READY;
                membar_enter();         /* make sure stores are flushed */
                sema_v(&cpi->cp_sem);   /* signal requesting thread */

                /*
                 * Wait here until all pause threads are running.  That
                 * indicates that it's safe to do the spl.  Until
                 * cpu_pause_info.cp_go is set, we don't want to spl
                 * because that might block clock interrupts needed
                 * to preempt threads on other CPUs.
                 */
                while (cpi->cp_go == 0)
                        ;
                /*
                 * Even though we are at the highest disp prio, we need
                 * to block out all interrupts below LOCK_LEVEL so that
                 * an intr doesn't come in, wake up a thread, and call
                 * setbackdq/setfrontdq.
                 */
                s = splhigh();
                /*
                 * if cp_func has been set then call it using index as the
                 * argument, currently only used by cpr_suspend_cpus().
                 * This function is used as the code to execute on the
                 * "paused" cpu's when a machine comes out of a sleep state
                 * and CPU's were powered off.  (could also be used for
                 * hotplugging CPU's).
                 */
                if (cpi->cp_func != NULL)
                        (*cpi->cp_func)((void *)lindex);

                mach_cpu_pause(safe);

                splx(s);
                /*
                 * Waiting is at an end. Switch out of cpu_pause
                 * loop and resume useful work.
                 */
                swtch();
        }

        mutex_enter(&pause_free_mutex);
        *safe = PAUSE_DEAD;
        cv_broadcast(&pause_free_cv);
        mutex_exit(&pause_free_mutex);
}

/*
 * Allow the cpus to start running again.
 */
void
start_cpus()
{
        int i;

        ASSERT(MUTEX_HELD(&cpu_lock));
        ASSERT(cpu_pause_info.cp_paused);
        cpu_pause_info.cp_paused = NULL;
        for (i = 0; i < NCPU; i++)
                safe_list[i] = PAUSE_IDLE;
        membar_enter();                 /* make sure stores are flushed */
        affinity_clear();
        splx(cpu_pause_info.cp_spl);
        kpreempt_enable();
}

/*
 * Allocate a pause thread for a CPU.
 */
static void
cpu_pause_alloc(cpu_t *cp)
{
        kthread_id_t    t;
        long            cpun = cp->cpu_id;

        /*
         * Note, v.v_nglobpris will not change value as long as I hold
         * cpu_lock.
         */
        t = thread_create(NULL, 0, cpu_pause, (void *)cpun,
            0, &p0, TS_STOPPED, v.v_nglobpris - 1);
        thread_lock(t);
        t->t_bound_cpu = cp;
        t->t_disp_queue = cp->cpu_disp;
        t->t_affinitycnt = 1;
        t->t_preempt = 1;
        thread_unlock(t);
        cp->cpu_pause_thread = t;
        /*
         * Registering a thread in the callback table is usually done
         * in the initialization code of the thread.  In this
         * case, we do it right after thread creation because the
         * thread itself may never run, and we need to register the
         * fact that it is safe for cpr suspend.
         */
        CALLB_CPR_INIT_SAFE(t, "cpu_pause");
}

/*
 * Free a pause thread for a CPU.
 */
static void
cpu_pause_free(cpu_t *cp)
{
        kthread_id_t    t;
        int             cpun = cp->cpu_id;

        ASSERT(MUTEX_HELD(&cpu_lock));
        /*
         * We have to get the thread and tell it to die.
         */
        if ((t = cp->cpu_pause_thread) == NULL) {
                ASSERT(safe_list[cpun] == PAUSE_IDLE);
                return;
        }
        thread_lock(t);
        t->t_cpu = CPU;         /* disp gets upset if last cpu is quiesced. */
        t->t_bound_cpu = NULL;  /* Must un-bind; cpu may not be running. */
        t->t_pri = v.v_nglobpris - 1;
        ASSERT(safe_list[cpun] == PAUSE_IDLE);
        safe_list[cpun] = PAUSE_DIE;
        THREAD_TRANSITION(t);
        setbackdq(t);
        thread_unlock_nopreempt(t);

        /*
         * If we don't wait for the thread to actually die, it may try to
         * run on the wrong cpu as part of an actual call to pause_cpus().
         */
        mutex_enter(&pause_free_mutex);
        while (safe_list[cpun] != PAUSE_DEAD) {
                cv_wait(&pause_free_cv, &pause_free_mutex);
        }
        mutex_exit(&pause_free_mutex);
        safe_list[cpun] = PAUSE_IDLE;

        cp->cpu_pause_thread = NULL;
}

/*
 * Initialize basic structures for pausing CPUs.
 */
void
cpu_pause_init()
{
        sema_init(&cpu_pause_info.cp_sem, 0, NULL, SEMA_DEFAULT, NULL);
        /*
         * Create initial CPU pause thread.
         */
        cpu_pause_alloc(CPU);
}

/*
 * Start the threads used to pause another CPU.
 */
static int
cpu_pause_start(processorid_t cpu_id)
{
        int     i;
        int     cpu_count = 0;

        for (i = 0; i < NCPU; i++) {
                cpu_t           *cp;
                kthread_id_t    t;

                cp = cpu[i];
                if (!CPU_IN_SET(cpu_available, i) || (i == cpu_id)) {
                        safe_list[i] = PAUSE_WAIT;
                        continue;
                }

                /*
                 * Skip CPU if it is quiesced or not yet started.
                 */
                if ((cp->cpu_flags & (CPU_QUIESCED | CPU_READY)) != CPU_READY) {
                        safe_list[i] = PAUSE_WAIT;
                        continue;
                }

                /*
                 * Start this CPU's pause thread.
                 */
                t = cp->cpu_pause_thread;
                thread_lock(t);
                /*
                 * Reset the priority, since nglobpris may have
                 * changed since the thread was created, if someone
                 * has loaded the RT (or some other) scheduling
                 * class.
                 */
                t->t_pri = v.v_nglobpris - 1;
                THREAD_TRANSITION(t);
                setbackdq(t);
                thread_unlock_nopreempt(t);
                ++cpu_count;
        }
        return (cpu_count);
}


/*
 * Pause all of the CPUs except the one we are on by creating a high
 * priority thread bound to those CPUs.
 *
 * Note that one must be extremely careful regarding code
 * executed while CPUs are paused.  Since a CPU may be paused
 * while a thread scheduling on that CPU is holding an adaptive
 * lock, code executed with CPUs paused must not acquire adaptive
 * (or low-level spin) locks.  Also, such code must not block,
 * since the thread that is supposed to initiate the wakeup may
 * never run.
 *
 * With a few exceptions, the restrictions on code executed with CPUs
 * paused match those for code executed at high-level interrupt
 * context.
 */
void
pause_cpus(cpu_t *off_cp, void *(*func)(void *))
{
        processorid_t   cpu_id;
        int             i;
        struct _cpu_pause_info  *cpi = &cpu_pause_info;

        ASSERT(MUTEX_HELD(&cpu_lock));
        ASSERT(cpi->cp_paused == NULL);
        cpi->cp_count = 0;
        cpi->cp_go = 0;
        for (i = 0; i < NCPU; i++)
                safe_list[i] = PAUSE_IDLE;
        kpreempt_disable();

        cpi->cp_func = func;

        /*
         * If running on the cpu that is going offline, get off it.
         * This is so that it won't be necessary to rechoose a CPU
         * when done.
         */
        if (CPU == off_cp)
                cpu_id = off_cp->cpu_next_part->cpu_id;
        else
                cpu_id = CPU->cpu_id;
        affinity_set(cpu_id);

        /*
         * Start the pause threads and record how many were started
         */
        cpi->cp_count = cpu_pause_start(cpu_id);

        /*
         * Now wait for all CPUs to be running the pause thread.
         */
        while (cpi->cp_count > 0) {
                /*
                 * Spin reading the count without grabbing the disp
                 * lock to make sure we don't prevent the pause
                 * threads from getting the lock.
                 */
                while (sema_held(&cpi->cp_sem))
                        ;
                if (sema_tryp(&cpi->cp_sem))
                        --cpi->cp_count;
        }
        cpi->cp_go = 1;                 /* all have reached cpu_pause */

        /*
         * Now wait for all CPUs to spl. (Transition from PAUSE_READY
         * to PAUSE_WAIT.)
         */
        for (i = 0; i < NCPU; i++) {
                while (safe_list[i] != PAUSE_WAIT)
                        ;
        }
        cpi->cp_spl = splhigh();        /* block dispatcher on this CPU */
        cpi->cp_paused = curthread;
}

/*
 * Check whether the current thread has CPUs paused
 */
int
cpus_paused(void)
{
        if (cpu_pause_info.cp_paused != NULL) {
                ASSERT(cpu_pause_info.cp_paused == curthread);
                return (1);
        }
        return (0);
}

static cpu_t *
cpu_get_all(processorid_t cpun)
{
        ASSERT(MUTEX_HELD(&cpu_lock));

        if (cpun >= NCPU || cpun < 0 || !CPU_IN_SET(cpu_available, cpun))
                return (NULL);
        return (cpu[cpun]);
}

/*
 * Check whether cpun is a valid processor id and whether it should be
 * visible from the current zone. If it is, return a pointer to the
 * associated CPU structure.
 */
cpu_t *
cpu_get(processorid_t cpun)
{
        cpu_t *c;

        ASSERT(MUTEX_HELD(&cpu_lock));
        c = cpu_get_all(cpun);
        if (c != NULL && !INGLOBALZONE(curproc) && pool_pset_enabled() &&
            zone_pset_get(curproc->p_zone) != cpupart_query_cpu(c))
                return (NULL);
        return (c);
}

/*
 * The following functions should be used to check CPU states in the kernel.
 * They should be invoked with cpu_lock held.  Kernel subsystems interested
 * in CPU states should *not* use cpu_get_state() and various P_ONLINE/etc
 * states.  Those are for user-land (and system call) use only.
 */

/*
 * Determine whether the CPU is online and handling interrupts.
 */
int
cpu_is_online(cpu_t *cpu)
{
        ASSERT(MUTEX_HELD(&cpu_lock));
        return (cpu_flagged_online(cpu->cpu_flags));
}

/*
 * Determine whether the CPU is offline (this includes spare and faulted).
 */
int
cpu_is_offline(cpu_t *cpu)
{
        ASSERT(MUTEX_HELD(&cpu_lock));
        return (cpu_flagged_offline(cpu->cpu_flags));
}

/*
 * Determine whether the CPU is powered off.
 */
int
cpu_is_poweredoff(cpu_t *cpu)
{
        ASSERT(MUTEX_HELD(&cpu_lock));
        return (cpu_flagged_poweredoff(cpu->cpu_flags));
}

/*
 * Determine whether the CPU is handling interrupts.
 */
int
cpu_is_nointr(cpu_t *cpu)
{
        ASSERT(MUTEX_HELD(&cpu_lock));
        return (cpu_flagged_nointr(cpu->cpu_flags));
}

/*
 * Determine whether the CPU is active (scheduling threads).
 */
int
cpu_is_active(cpu_t *cpu)
{
        ASSERT(MUTEX_HELD(&cpu_lock));
        return (cpu_flagged_active(cpu->cpu_flags));
}

/*
 * Same as above, but these require cpu_flags instead of cpu_t pointers.
 */
int
cpu_flagged_online(cpu_flag_t cpu_flags)
{
        return (cpu_flagged_active(cpu_flags) &&
            (cpu_flags & CPU_ENABLE));
}

int
cpu_flagged_offline(cpu_flag_t cpu_flags)
{
        return (((cpu_flags & CPU_POWEROFF) == 0) &&
            ((cpu_flags & (CPU_READY | CPU_OFFLINE)) != CPU_READY));
}

int
cpu_flagged_poweredoff(cpu_flag_t cpu_flags)
{
        return ((cpu_flags & CPU_POWEROFF) == CPU_POWEROFF);
}

int
cpu_flagged_nointr(cpu_flag_t cpu_flags)
{
        return (cpu_flagged_active(cpu_flags) &&
            (cpu_flags & CPU_ENABLE) == 0);
}

int
cpu_flagged_active(cpu_flag_t cpu_flags)
{
        return (((cpu_flags & (CPU_POWEROFF | CPU_FAULTED | CPU_SPARE)) == 0) &&
            ((cpu_flags & (CPU_READY | CPU_OFFLINE)) == CPU_READY));
}

/*
 * Bring the indicated CPU online.
 */
int
cpu_online(cpu_t *cp)
{
        int     error = 0;

        /*
         * Handle on-line request.
         *      This code must put the new CPU on the active list before
         *      starting it because it will not be paused, and will start
         *      using the active list immediately.  The real start occurs
         *      when the CPU_QUIESCED flag is turned off.
         */

        ASSERT(MUTEX_HELD(&cpu_lock));

        /*
         * Put all the cpus into a known safe place.
         * No mutexes can be entered while CPUs are paused.
         */
        error = mp_cpu_start(cp);       /* arch-dep hook */
        if (error == 0) {
                pg_cpupart_in(cp, cp->cpu_part);
                pause_cpus(NULL, NULL);
                cpu_add_active_internal(cp);
                if (cp->cpu_flags & CPU_FAULTED) {
                        cp->cpu_flags &= ~CPU_FAULTED;
                        mp_cpu_faulted_exit(cp);
                }
                cp->cpu_flags &= ~(CPU_QUIESCED | CPU_OFFLINE | CPU_FROZEN |
                    CPU_SPARE);
                CPU_NEW_GENERATION(cp);
                start_cpus();
                cpu_stats_kstat_create(cp);
                cpu_create_intrstat(cp);
                lgrp_kstat_create(cp);
                cpu_state_change_notify(cp->cpu_id, CPU_ON);
                cpu_intr_enable(cp);    /* arch-dep hook */
                cpu_state_change_notify(cp->cpu_id, CPU_INTR_ON);
                cpu_set_state(cp);
                cyclic_online(cp);
                /*
                 * This has to be called only after cyclic_online(). This
                 * function uses cyclics.
                 */
                callout_cpu_online(cp);
                poke_cpu(cp->cpu_id);
        }

        return (error);
}

/*
 * Take the indicated CPU offline.
 */
int
cpu_offline(cpu_t *cp, int flags)
{
        cpupart_t *pp;
        int     error = 0;
        cpu_t   *ncp;
        int     intr_enable;
        int     cyclic_off = 0;
        int     callout_off = 0;
        int     loop_count;
        int     no_quiesce = 0;
        int     (*bound_func)(struct cpu *, int);
        kthread_t *t;
        lpl_t   *cpu_lpl;
        proc_t  *p;
        int     lgrp_diff_lpl;
        boolean_t unbind_all_threads = (flags & CPU_FORCED) != 0;

        ASSERT(MUTEX_HELD(&cpu_lock));

        /*
         * If we're going from faulted or spare to offline, just
         * clear these flags and update CPU state.
         */
        if (cp->cpu_flags & (CPU_FAULTED | CPU_SPARE)) {
                if (cp->cpu_flags & CPU_FAULTED) {
                        cp->cpu_flags &= ~CPU_FAULTED;
                        mp_cpu_faulted_exit(cp);
                }
                cp->cpu_flags &= ~CPU_SPARE;
                cpu_set_state(cp);
                return (0);
        }

        /*
         * Handle off-line request.
         */
        pp = cp->cpu_part;
        /*
         * Don't offline last online CPU in partition
         */
        if (ncpus_online <= 1 || pp->cp_ncpus <= 1 || cpu_intr_count(cp) < 2)
                return (EBUSY);
        /*
         * Unbind all soft-bound threads bound to our CPU and hard bound threads
         * if we were asked to.
         */
        error = cpu_unbind(cp->cpu_id, unbind_all_threads);
        if (error != 0)
                return (error);
        /*
         * We shouldn't be bound to this CPU ourselves.
         */
        if (curthread->t_bound_cpu == cp)
                return (EBUSY);

        /*
         * Tell interested parties that this CPU is going offline.
         */
        CPU_NEW_GENERATION(cp);
        cpu_state_change_notify(cp->cpu_id, CPU_OFF);

        /*
         * Tell the PG subsystem that the CPU is leaving the partition
         */
        pg_cpupart_out(cp, pp);

        /*
         * Take the CPU out of interrupt participation so we won't find
         * bound kernel threads.  If the architecture cannot completely
         * shut off interrupts on the CPU, don't quiesce it, but don't
         * run anything but interrupt thread... this is indicated by
         * the CPU_OFFLINE flag being on but the CPU_QUIESCE flag being
         * off.
         */
        intr_enable = cp->cpu_flags & CPU_ENABLE;
        if (intr_enable)
                no_quiesce = cpu_intr_disable(cp);

        /*
         * Record that we are aiming to offline this cpu.  This acts as
         * a barrier to further weak binding requests in thread_nomigrate
         * and also causes cpu_choose, disp_lowpri_cpu and setfrontdq to
         * lean away from this cpu.  Further strong bindings are already
         * avoided since we hold cpu_lock.  Since threads that are set
         * runnable around now and others coming off the target cpu are
         * directed away from the target, existing strong and weak bindings
         * (especially the latter) to the target cpu stand maximum chance of
         * being able to unbind during the short delay loop below (if other
         * unbound threads compete they may not see cpu in time to unbind
         * even if they would do so immediately.
         */
        cpu_inmotion = cp;
        membar_enter();

        /*
         * Check for kernel threads (strong or weak) bound to that CPU.
         * Strongly bound threads may not unbind, and we'll have to return
         * EBUSY.  Weakly bound threads should always disappear - we've
         * stopped more weak binding with cpu_inmotion and existing
         * bindings will drain imminently (they may not block).  Nonetheless
         * we will wait for a fixed period for all bound threads to disappear.
         * Inactive interrupt threads are OK (they'll be in TS_FREE
         * state).  If test finds some bound threads, wait a few ticks
         * to give short-lived threads (such as interrupts) chance to
         * complete.  Note that if no_quiesce is set, i.e. this cpu
         * is required to service interrupts, then we take the route
         * that permits interrupt threads to be active (or bypassed).
         */
        bound_func = no_quiesce ? disp_bound_threads : disp_bound_anythreads;

again:  for (loop_count = 0; (*bound_func)(cp, 0); loop_count++) {
                if (loop_count >= 5) {
                        error = EBUSY;  /* some threads still bound */
                        break;
                }

                /*
                 * If some threads were assigned, give them
                 * a chance to complete or move.
                 *
                 * This assumes that the clock_thread is not bound
                 * to any CPU, because the clock_thread is needed to
                 * do the delay(hz/100).
                 *
                 * Note: we still hold the cpu_lock while waiting for
                 * the next clock tick.  This is OK since it isn't
                 * needed for anything else except processor_bind(2),
                 * and system initialization.  If we drop the lock,
                 * we would risk another p_online disabling the last
                 * processor.
                 */
                delay(hz/100);
        }

        if (error == 0 && callout_off == 0) {
                callout_cpu_offline(cp);
                callout_off = 1;
        }

        if (error == 0 && cyclic_off == 0) {
                if (!cyclic_offline(cp)) {
                        /*
                         * We must have bound cyclics...
                         */
                        error = EBUSY;
                        goto out;
                }
                cyclic_off = 1;
        }

        /*
         * Call mp_cpu_stop() to perform any special operations
         * needed for this machine architecture to offline a CPU.
         */
        if (error == 0)
                error = mp_cpu_stop(cp);        /* arch-dep hook */

        /*
         * If that all worked, take the CPU offline and decrement
         * ncpus_online.
         */
        if (error == 0) {
                /*
                 * Put all the cpus into a known safe place.
                 * No mutexes can be entered while CPUs are paused.
                 */
                pause_cpus(cp, NULL);
                /*
                 * Repeat the operation, if necessary, to make sure that
                 * all outstanding low-level interrupts run to completion
                 * before we set the CPU_QUIESCED flag.  It's also possible
                 * that a thread has weak bound to the cpu despite our raising
                 * cpu_inmotion above since it may have loaded that
                 * value before the barrier became visible (this would have
                 * to be the thread that was on the target cpu at the time
                 * we raised the barrier).
                 */
                if ((!no_quiesce && cp->cpu_intr_actv != 0) ||
                    (*bound_func)(cp, 1)) {
                        start_cpus();
                        (void) mp_cpu_start(cp);
                        goto again;
                }
                ncp = cp->cpu_next_part;
                cpu_lpl = cp->cpu_lpl;
                ASSERT(cpu_lpl != NULL);

                /*
                 * Remove the CPU from the list of active CPUs.
                 */
                cpu_remove_active(cp);

                /*
                 * Walk the active process list and look for threads
                 * whose home lgroup needs to be updated, or
                 * the last CPU they run on is the one being offlined now.
                 */

                ASSERT(curthread->t_cpu != cp);
                for (p = practive; p != NULL; p = p->p_next) {

                        t = p->p_tlist;

                        if (t == NULL)
                                continue;

                        lgrp_diff_lpl = 0;

                        do {
                                ASSERT(t->t_lpl != NULL);
                                /*
                                 * Taking last CPU in lpl offline
                                 * Rehome thread if it is in this lpl
                                 * Otherwise, update the count of how many
                                 * threads are in this CPU's lgroup but have
                                 * a different lpl.
                                 */

                                if (cpu_lpl->lpl_ncpu == 0) {
                                        if (t->t_lpl == cpu_lpl)
                                                lgrp_move_thread(t,
                                                    lgrp_choose(t,
                                                    t->t_cpupart), 0);
                                        else if (t->t_lpl->lpl_lgrpid ==
                                            cpu_lpl->lpl_lgrpid)
                                                lgrp_diff_lpl++;
                                }
                                ASSERT(t->t_lpl->lpl_ncpu > 0);

                                /*
                                 * Update CPU last ran on if it was this CPU
                                 */
                                if (t->t_cpu == cp && t->t_bound_cpu != cp)
                                        t->t_cpu = disp_lowpri_cpu(ncp,
                                            t->t_lpl, t->t_pri, NULL);
                                ASSERT(t->t_cpu != cp || t->t_bound_cpu == cp ||
                                    t->t_weakbound_cpu == cp);

                                t = t->t_forw;
                        } while (t != p->p_tlist);

                        /*
                         * Didn't find any threads in the same lgroup as this
                         * CPU with a different lpl, so remove the lgroup from
                         * the process lgroup bitmask.
                         */

                        if (lgrp_diff_lpl == 0)
                                klgrpset_del(p->p_lgrpset, cpu_lpl->lpl_lgrpid);
                }

                /*
                 * Walk thread list looking for threads that need to be
                 * rehomed, since there are some threads that are not in
                 * their process's p_tlist.
                 */

                t = curthread;
                do {
                        ASSERT(t != NULL && t->t_lpl != NULL);

                        /*
                         * Rehome threads with same lpl as this CPU when this
                         * is the last CPU in the lpl.
                         */

                        if ((cpu_lpl->lpl_ncpu == 0) && (t->t_lpl == cpu_lpl))
                                lgrp_move_thread(t,
                                    lgrp_choose(t, t->t_cpupart), 1);

                        ASSERT(t->t_lpl->lpl_ncpu > 0);

                        /*
                         * Update CPU last ran on if it was this CPU
                         */

                        if (t->t_cpu == cp && t->t_bound_cpu != cp) {
                                t->t_cpu = disp_lowpri_cpu(ncp,
                                    t->t_lpl, t->t_pri, NULL);
                        }
                        ASSERT(t->t_cpu != cp || t->t_bound_cpu == cp ||
                            t->t_weakbound_cpu == cp);
                        t = t->t_next;

                } while (t != curthread);
                ASSERT((cp->cpu_flags & (CPU_FAULTED | CPU_SPARE)) == 0);
                cp->cpu_flags |= CPU_OFFLINE;
                disp_cpu_inactive(cp);
                if (!no_quiesce)
                        cp->cpu_flags |= CPU_QUIESCED;
                ncpus_online--;
                cpu_set_state(cp);
                cpu_inmotion = NULL;
                start_cpus();
                cpu_stats_kstat_destroy(cp);
                cpu_delete_intrstat(cp);
                lgrp_kstat_destroy(cp);
        }

out:
        cpu_inmotion = NULL;

        /*
         * If we failed, re-enable interrupts.
         * Do this even if cpu_intr_disable returned an error, because
         * it may have partially disabled interrupts.
         */
        if (error && intr_enable)
                cpu_intr_enable(cp);

        /*
         * If we failed, but managed to offline the cyclic subsystem on this
         * CPU, bring it back online.
         */
        if (error && cyclic_off)
                cyclic_online(cp);

        /*
         * If we failed, but managed to offline callouts on this CPU,
         * bring it back online.
         */
        if (error && callout_off)
                callout_cpu_online(cp);

        /*
         * If we failed, tell the PG subsystem that the CPU is back
         */
        pg_cpupart_in(cp, pp);

        /*
         * If we failed, we need to notify everyone that this CPU is back on.
         */
        if (error != 0) {
                CPU_NEW_GENERATION(cp);
                cpu_state_change_notify(cp->cpu_id, CPU_ON);
                cpu_state_change_notify(cp->cpu_id, CPU_INTR_ON);
        }

        return (error);
}

/*
 * Mark the indicated CPU as faulted, taking it offline.
 */
int
cpu_faulted(cpu_t *cp, int flags)
{
        int     error = 0;

        ASSERT(MUTEX_HELD(&cpu_lock));
        ASSERT(!cpu_is_poweredoff(cp));

        if (cpu_is_offline(cp)) {
                cp->cpu_flags &= ~CPU_SPARE;
                cp->cpu_flags |= CPU_FAULTED;
                mp_cpu_faulted_enter(cp);
                cpu_set_state(cp);
                return (0);
        }

        if ((error = cpu_offline(cp, flags)) == 0) {
                cp->cpu_flags |= CPU_FAULTED;
                mp_cpu_faulted_enter(cp);
                cpu_set_state(cp);
        }

        return (error);
}

/*
 * Mark the indicated CPU as a spare, taking it offline.
 */
int
cpu_spare(cpu_t *cp, int flags)
{
        int     error = 0;

        ASSERT(MUTEX_HELD(&cpu_lock));
        ASSERT(!cpu_is_poweredoff(cp));

        if (cpu_is_offline(cp)) {
                if (cp->cpu_flags & CPU_FAULTED) {
                        cp->cpu_flags &= ~CPU_FAULTED;
                        mp_cpu_faulted_exit(cp);
                }
                cp->cpu_flags |= CPU_SPARE;
                cpu_set_state(cp);
                return (0);
        }

        if ((error = cpu_offline(cp, flags)) == 0) {
                cp->cpu_flags |= CPU_SPARE;
                cpu_set_state(cp);
        }

        return (error);
}

/*
 * Take the indicated CPU from poweroff to offline.
 */
int
cpu_poweron(cpu_t *cp)
{
        int     error = ENOTSUP;

        ASSERT(MUTEX_HELD(&cpu_lock));
        ASSERT(cpu_is_poweredoff(cp));

        error = mp_cpu_poweron(cp);     /* arch-dep hook */
        if (error == 0)
                cpu_set_state(cp);

        return (error);
}

/*
 * Take the indicated CPU from any inactive state to powered off.
 */
int
cpu_poweroff(cpu_t *cp)
{
        int     error = ENOTSUP;

        ASSERT(MUTEX_HELD(&cpu_lock));
        ASSERT(cpu_is_offline(cp));

        if (!(cp->cpu_flags & CPU_QUIESCED))
                return (EBUSY);         /* not completely idle */

        error = mp_cpu_poweroff(cp);    /* arch-dep hook */
        if (error == 0)
                cpu_set_state(cp);

        return (error);
}

/*
 * Initialize the Sequential CPU id lookup table
 */
void
cpu_seq_tbl_init()
{
        cpu_t   **tbl;

        tbl = kmem_zalloc(sizeof (struct cpu *) * max_ncpus, KM_SLEEP);
        tbl[0] = CPU;

        cpu_seq = tbl;
}

/*
 * Initialize the CPU lists for the first CPU.
 */
void
cpu_list_init(cpu_t *cp)
{
        cp->cpu_next = cp;
        cp->cpu_prev = cp;
        cpu_list = cp;
        clock_cpu_list = cp;

        cp->cpu_next_onln = cp;
        cp->cpu_prev_onln = cp;
        cpu_active = cp;

        cp->cpu_seqid = 0;
        CPUSET_ADD(cpu_seqid_inuse, 0);

        /*
         * Bootstrap cpu_seq using cpu_list
         * The cpu_seq[] table will be dynamically allocated
         * when kmem later becomes available (but before going MP)
         */
        cpu_seq = &cpu_list;

        cp->cpu_cache_offset = KMEM_CPU_CACHE_OFFSET(cp->cpu_seqid);
        cp_default.cp_cpulist = cp;
        cp_default.cp_ncpus = 1;
        cp->cpu_next_part = cp;
        cp->cpu_prev_part = cp;
        cp->cpu_part = &cp_default;

        CPUSET_ADD(cpu_available, cp->cpu_id);
}

/*
 * Insert a CPU into the list of available CPUs.
 */
void
cpu_add_unit(cpu_t *cp)
{
        int seqid;

        ASSERT(MUTEX_HELD(&cpu_lock));
        ASSERT(cpu_list != NULL);       /* list started in cpu_list_init */

        lgrp_config(LGRP_CONFIG_CPU_ADD, (uintptr_t)cp, 0);

        /*
         * Note: most users of the cpu_list will grab the
         * cpu_lock to insure that it isn't modified.  However,
         * certain users can't or won't do that.  To allow this
         * we pause the other cpus.  Users who walk the list
         * without cpu_lock, must disable kernel preemption
         * to insure that the list isn't modified underneath
         * them.  Also, any cached pointers to cpu structures
         * must be revalidated by checking to see if the
         * cpu_next pointer points to itself.  This check must
         * be done with the cpu_lock held or kernel preemption
         * disabled.  This check relies upon the fact that
         * old cpu structures are not free'ed or cleared after
         * then are removed from the cpu_list.
         *
         * Note that the clock code walks the cpu list dereferencing
         * the cpu_part pointer, so we need to initialize it before
         * adding the cpu to the list.
         */
        cp->cpu_part = &cp_default;
        pause_cpus(NULL, NULL);
        cp->cpu_next = cpu_list;
        cp->cpu_prev = cpu_list->cpu_prev;
        cpu_list->cpu_prev->cpu_next = cp;
        cpu_list->cpu_prev = cp;
        start_cpus();

        for (seqid = 0; CPU_IN_SET(cpu_seqid_inuse, seqid); seqid++)
                continue;
        CPUSET_ADD(cpu_seqid_inuse, seqid);
        cp->cpu_seqid = seqid;

        if (seqid > max_cpu_seqid_ever)
                max_cpu_seqid_ever = seqid;

        ASSERT(ncpus < max_ncpus);
        ncpus++;
        cp->cpu_cache_offset = KMEM_CPU_CACHE_OFFSET(cp->cpu_seqid);
        cpu[cp->cpu_id] = cp;
        CPUSET_ADD(cpu_available, cp->cpu_id);
        cpu_seq[cp->cpu_seqid] = cp;

        /*
         * allocate a pause thread for this CPU.
         */
        cpu_pause_alloc(cp);

        /*
         * So that new CPUs won't have NULL prev_onln and next_onln pointers,
         * link them into a list of just that CPU.
         * This is so that disp_lowpri_cpu will work for thread_create in
         * pause_cpus() when called from the startup thread in a new CPU.
         */
        cp->cpu_next_onln = cp;
        cp->cpu_prev_onln = cp;
        cpu_info_kstat_create(cp);
        cp->cpu_next_part = cp;
        cp->cpu_prev_part = cp;

        init_cpu_mstate(cp, CMS_SYSTEM);

        pool_pset_mod = gethrtime();
}

/*
 * Do the opposite of cpu_add_unit().
 */
void
cpu_del_unit(int cpuid)
{
        struct cpu      *cp, *cpnext;

        ASSERT(MUTEX_HELD(&cpu_lock));
        cp = cpu[cpuid];
        ASSERT(cp != NULL);

        ASSERT(cp->cpu_next_onln == cp);
        ASSERT(cp->cpu_prev_onln == cp);
        ASSERT(cp->cpu_next_part == cp);
        ASSERT(cp->cpu_prev_part == cp);

        /*
         * Tear down the CPU's physical ID cache, and update any
         * processor groups
         */
        pg_cpu_fini(cp, NULL);
        pghw_physid_destroy(cp);

        /*
         * Destroy kstat stuff.
         */
        cpu_info_kstat_destroy(cp);
        term_cpu_mstate(cp);
        /*
         * Free up pause thread.
         */
        cpu_pause_free(cp);
        CPUSET_DEL(cpu_available, cp->cpu_id);
        cpu[cp->cpu_id] = NULL;
        cpu_seq[cp->cpu_seqid] = NULL;

        /*
         * The clock thread and mutex_vector_enter cannot hold the
         * cpu_lock while traversing the cpu list, therefore we pause
         * all other threads by pausing the other cpus. These, and any
         * other routines holding cpu pointers while possibly sleeping
         * must be sure to call kpreempt_disable before processing the
         * list and be sure to check that the cpu has not been deleted
         * after any sleeps (check cp->cpu_next != NULL). We guarantee
         * to keep the deleted cpu structure around.
         *
         * Note that this MUST be done AFTER cpu_available
         * has been updated so that we don't waste time
         * trying to pause the cpu we're trying to delete.
         */
        pause_cpus(NULL, NULL);

        cpnext = cp->cpu_next;
        cp->cpu_prev->cpu_next = cp->cpu_next;
        cp->cpu_next->cpu_prev = cp->cpu_prev;
        if (cp == cpu_list)
                cpu_list = cpnext;

        /*
         * Signals that the cpu has been deleted (see above).
         */
        cp->cpu_next = NULL;
        cp->cpu_prev = NULL;

        start_cpus();

        CPUSET_DEL(cpu_seqid_inuse, cp->cpu_seqid);
        ncpus--;
        lgrp_config(LGRP_CONFIG_CPU_DEL, (uintptr_t)cp, 0);

        pool_pset_mod = gethrtime();
}

/*
 * Add a CPU to the list of active CPUs.
 *      This routine must not get any locks, because other CPUs are paused.
 */
static void
cpu_add_active_internal(cpu_t *cp)
{
        cpupart_t       *pp = cp->cpu_part;

        ASSERT(MUTEX_HELD(&cpu_lock));
        ASSERT(cpu_list != NULL);       /* list started in cpu_list_init */

        ncpus_online++;
        cpu_set_state(cp);
        cp->cpu_next_onln = cpu_active;
        cp->cpu_prev_onln = cpu_active->cpu_prev_onln;
        cpu_active->cpu_prev_onln->cpu_next_onln = cp;
        cpu_active->cpu_prev_onln = cp;

        if (pp->cp_cpulist) {
                cp->cpu_next_part = pp->cp_cpulist;
                cp->cpu_prev_part = pp->cp_cpulist->cpu_prev_part;
                pp->cp_cpulist->cpu_prev_part->cpu_next_part = cp;
                pp->cp_cpulist->cpu_prev_part = cp;
        } else {
                ASSERT(pp->cp_ncpus == 0);
                pp->cp_cpulist = cp->cpu_next_part = cp->cpu_prev_part = cp;
        }
        pp->cp_ncpus++;
        if (pp->cp_ncpus == 1) {
                cp_numparts_nonempty++;
                ASSERT(cp_numparts_nonempty != 0);
        }

        pg_cpu_active(cp);
        lgrp_config(LGRP_CONFIG_CPU_ONLINE, (uintptr_t)cp, 0);

        bzero(&cp->cpu_loadavg, sizeof (cp->cpu_loadavg));
}

/*
 * Add a CPU to the list of active CPUs.
 *      This is called from machine-dependent layers when a new CPU is started.
 */
void
cpu_add_active(cpu_t *cp)
{
        pg_cpupart_in(cp, cp->cpu_part);

        pause_cpus(NULL, NULL);
        cpu_add_active_internal(cp);
        start_cpus();

        cpu_stats_kstat_create(cp);
        cpu_create_intrstat(cp);
        lgrp_kstat_create(cp);
        cpu_state_change_notify(cp->cpu_id, CPU_INIT);
}


/*
 * Remove a CPU from the list of active CPUs.
 *      This routine must not get any locks, because other CPUs are paused.
 */
/* ARGSUSED */
static void
cpu_remove_active(cpu_t *cp)
{
        cpupart_t       *pp = cp->cpu_part;

        ASSERT(MUTEX_HELD(&cpu_lock));
        ASSERT(cp->cpu_next_onln != cp);        /* not the last one */
        ASSERT(cp->cpu_prev_onln != cp);        /* not the last one */

        pg_cpu_inactive(cp);

        lgrp_config(LGRP_CONFIG_CPU_OFFLINE, (uintptr_t)cp, 0);

        if (cp == clock_cpu_list)
                clock_cpu_list = cp->cpu_next_onln;

        cp->cpu_prev_onln->cpu_next_onln = cp->cpu_next_onln;
        cp->cpu_next_onln->cpu_prev_onln = cp->cpu_prev_onln;
        if (cpu_active == cp) {
                cpu_active = cp->cpu_next_onln;
        }
        cp->cpu_next_onln = cp;
        cp->cpu_prev_onln = cp;

        cp->cpu_prev_part->cpu_next_part = cp->cpu_next_part;
        cp->cpu_next_part->cpu_prev_part = cp->cpu_prev_part;
        if (pp->cp_cpulist == cp) {
                pp->cp_cpulist = cp->cpu_next_part;
                ASSERT(pp->cp_cpulist != cp);
        }
        cp->cpu_next_part = cp;
        cp->cpu_prev_part = cp;
        pp->cp_ncpus--;
        if (pp->cp_ncpus == 0) {
                cp_numparts_nonempty--;
                ASSERT(cp_numparts_nonempty != 0);
        }
}

/*
 * Routine used to setup a newly inserted CPU in preparation for starting
 * it running code.
 */
int
cpu_configure(int cpuid)
{
        int retval = 0;

        ASSERT(MUTEX_HELD(&cpu_lock));

        /*
         * Some structures are statically allocated based upon
         * the maximum number of cpus the system supports.  Do not
         * try to add anything beyond this limit.
         */
        if (cpuid < 0 || cpuid >= NCPU) {
                return (EINVAL);
        }

        if ((cpu[cpuid] != NULL) && (cpu[cpuid]->cpu_flags != 0)) {
                return (EALREADY);
        }

        if ((retval = mp_cpu_configure(cpuid)) != 0) {
                return (retval);
        }

        cpu[cpuid]->cpu_flags = CPU_QUIESCED | CPU_OFFLINE | CPU_POWEROFF;
        cpu_set_state(cpu[cpuid]);
        retval = cpu_state_change_hooks(cpuid, CPU_CONFIG, CPU_UNCONFIG);
        if (retval != 0)
                (void) mp_cpu_unconfigure(cpuid);

        return (retval);
}

/*
 * Routine used to cleanup a CPU that has been powered off.  This will
 * destroy all per-cpu information related to this cpu.
 */
int
cpu_unconfigure(int cpuid)
{
        int error;

        ASSERT(MUTEX_HELD(&cpu_lock));

        if (cpu[cpuid] == NULL) {
                return (ENODEV);
        }

        if (cpu[cpuid]->cpu_flags == 0) {
                return (EALREADY);
        }

        if ((cpu[cpuid]->cpu_flags & CPU_POWEROFF) == 0) {
                return (EBUSY);
        }

        if (cpu[cpuid]->cpu_props != NULL) {
                (void) nvlist_free(cpu[cpuid]->cpu_props);
                cpu[cpuid]->cpu_props = NULL;
        }

        error = cpu_state_change_hooks(cpuid, CPU_UNCONFIG, CPU_CONFIG);

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

        return (mp_cpu_unconfigure(cpuid));
}

/*
 * Routines for registering and de-registering cpu_setup callback functions.
 *
 * Caller's context
 *      These routines must not be called from a driver's attach(9E) or
 *      detach(9E) entry point.
 *
 * NOTE: CPU callbacks should not block. They are called with cpu_lock held.
 */

/*
 * Ideally, these would be dynamically allocated and put into a linked
 * list; however that is not feasible because the registration routine
 * has to be available before the kmem allocator is working (in fact,
 * it is called by the kmem allocator init code).  In any case, there
 * are quite a few extra entries for future users.
 */
#define NCPU_SETUPS     20

struct cpu_setup {
        cpu_setup_func_t *func;
        void *arg;
} cpu_setups[NCPU_SETUPS];

void
register_cpu_setup_func(cpu_setup_func_t *func, void *arg)
{
        int i;

        ASSERT(MUTEX_HELD(&cpu_lock));

        for (i = 0; i < NCPU_SETUPS; i++)
                if (cpu_setups[i].func == NULL)
                        break;
        if (i >= NCPU_SETUPS)
                cmn_err(CE_PANIC, "Ran out of cpu_setup callback entries");

        cpu_setups[i].func = func;
        cpu_setups[i].arg = arg;
}

void
unregister_cpu_setup_func(cpu_setup_func_t *func, void *arg)
{
        int i;

        ASSERT(MUTEX_HELD(&cpu_lock));

        for (i = 0; i < NCPU_SETUPS; i++)
                if ((cpu_setups[i].func == func) &&
                    (cpu_setups[i].arg == arg))
                        break;
        if (i >= NCPU_SETUPS)
                cmn_err(CE_PANIC, "Could not find cpu_setup callback to "
                    "deregister");

        cpu_setups[i].func = NULL;
        cpu_setups[i].arg = 0;
}

/*
 * Call any state change hooks for this CPU, ignore any errors.
 */
void
cpu_state_change_notify(int id, cpu_setup_t what)
{
        int i;

        ASSERT(MUTEX_HELD(&cpu_lock));

        for (i = 0; i < NCPU_SETUPS; i++) {
                if (cpu_setups[i].func != NULL) {
                        cpu_setups[i].func(what, id, cpu_setups[i].arg);
                }
        }
}

/*
 * Call any state change hooks for this CPU, undo it if error found.
 */
static int
cpu_state_change_hooks(int id, cpu_setup_t what, cpu_setup_t undo)
{
        int i;
        int retval = 0;

        ASSERT(MUTEX_HELD(&cpu_lock));

        for (i = 0; i < NCPU_SETUPS; i++) {
                if (cpu_setups[i].func != NULL) {
                        retval = cpu_setups[i].func(what, id,
                            cpu_setups[i].arg);
                        if (retval) {
                                for (i--; i >= 0; i--) {
                                        if (cpu_setups[i].func != NULL)
                                                cpu_setups[i].func(undo,
                                                    id, cpu_setups[i].arg);
                                }
                                break;
                        }
                }
        }
        return (retval);
}

/*
 * Export information about this CPU via the kstat mechanism.
 */
static struct {
        kstat_named_t ci_state;
        kstat_named_t ci_state_begin;
        kstat_named_t ci_cpu_type;
        kstat_named_t ci_fpu_type;
        kstat_named_t ci_clock_MHz;
        kstat_named_t ci_chip_id;
        kstat_named_t ci_implementation;
        kstat_named_t ci_brandstr;
        kstat_named_t ci_core_id;
        kstat_named_t ci_curr_clock_Hz;
        kstat_named_t ci_supp_freq_Hz;
        kstat_named_t ci_pg_id;
#if defined(__sparcv9)
        kstat_named_t ci_device_ID;
        kstat_named_t ci_cpu_fru;
#endif
#if defined(__x86)
        kstat_named_t ci_vendorstr;
        kstat_named_t ci_family;
        kstat_named_t ci_model;
        kstat_named_t ci_step;
        kstat_named_t ci_clogid;
        kstat_named_t ci_pkg_core_id;
        kstat_named_t ci_ncpuperchip;
        kstat_named_t ci_ncoreperchip;
        kstat_named_t ci_max_cstates;
        kstat_named_t ci_curr_cstate;
        kstat_named_t ci_cacheid;
        kstat_named_t ci_sktstr;
#endif
} cpu_info_template = {
        { "state",                      KSTAT_DATA_CHAR },
        { "state_begin",                KSTAT_DATA_LONG },
        { "cpu_type",                   KSTAT_DATA_CHAR },
        { "fpu_type",                   KSTAT_DATA_CHAR },
        { "clock_MHz",                  KSTAT_DATA_LONG },
        { "chip_id",                    KSTAT_DATA_LONG },
        { "implementation",             KSTAT_DATA_STRING },
        { "brand",                      KSTAT_DATA_STRING },
        { "core_id",                    KSTAT_DATA_LONG },
        { "current_clock_Hz",           KSTAT_DATA_UINT64 },
        { "supported_frequencies_Hz",   KSTAT_DATA_STRING },
        { "pg_id",                      KSTAT_DATA_LONG },
#if defined(__sparcv9)
        { "device_ID",                  KSTAT_DATA_UINT64 },
        { "cpu_fru",                    KSTAT_DATA_STRING },
#endif
#if defined(__x86)
        { "vendor_id",                  KSTAT_DATA_STRING },
        { "family",                     KSTAT_DATA_INT32 },
        { "model",                      KSTAT_DATA_INT32 },
        { "stepping",                   KSTAT_DATA_INT32 },
        { "clog_id",                    KSTAT_DATA_INT32 },
        { "pkg_core_id",                KSTAT_DATA_LONG },
        { "ncpu_per_chip",              KSTAT_DATA_INT32 },
        { "ncore_per_chip",             KSTAT_DATA_INT32 },
        { "supported_max_cstates",      KSTAT_DATA_INT32 },
        { "current_cstate",             KSTAT_DATA_INT32 },
        { "cache_id",                   KSTAT_DATA_INT32 },
        { "socket_type",                KSTAT_DATA_STRING },
#endif
};

static kmutex_t cpu_info_template_lock;

static int
cpu_info_kstat_update(kstat_t *ksp, int rw)
{
        cpu_t   *cp = ksp->ks_private;
        const char *pi_state;

        if (rw == KSTAT_WRITE)
                return (EACCES);

#if defined(__x86)
        /* Is the cpu still initialising itself? */
        if (cpuid_checkpass(cp, 1) == 0)
                return (ENXIO);
#endif
        switch (cp->cpu_type_info.pi_state) {
        case P_ONLINE:
                pi_state = PS_ONLINE;
                break;
        case P_POWEROFF:
                pi_state = PS_POWEROFF;
                break;
        case P_NOINTR:
                pi_state = PS_NOINTR;
                break;
        case P_FAULTED:
                pi_state = PS_FAULTED;
                break;
        case P_SPARE:
                pi_state = PS_SPARE;
                break;
        case P_OFFLINE:
                pi_state = PS_OFFLINE;
                break;
        default:
                pi_state = "unknown";
        }
        (void) strcpy(cpu_info_template.ci_state.value.c, pi_state);
        cpu_info_template.ci_state_begin.value.l = cp->cpu_state_begin;
        (void) strncpy(cpu_info_template.ci_cpu_type.value.c,
            cp->cpu_type_info.pi_processor_type, 15);
        (void) strncpy(cpu_info_template.ci_fpu_type.value.c,
            cp->cpu_type_info.pi_fputypes, 15);
        cpu_info_template.ci_clock_MHz.value.l = cp->cpu_type_info.pi_clock;
        cpu_info_template.ci_chip_id.value.l =
            pg_plat_hw_instance_id(cp, PGHW_CHIP);
        kstat_named_setstr(&cpu_info_template.ci_implementation,
            cp->cpu_idstr);
        kstat_named_setstr(&cpu_info_template.ci_brandstr, cp->cpu_brandstr);
        cpu_info_template.ci_core_id.value.l = pg_plat_get_core_id(cp);
        cpu_info_template.ci_curr_clock_Hz.value.ui64 =
            cp->cpu_curr_clock;
        cpu_info_template.ci_pg_id.value.l =
            cp->cpu_pg && cp->cpu_pg->cmt_lineage ?
            cp->cpu_pg->cmt_lineage->pg_id : -1;
        kstat_named_setstr(&cpu_info_template.ci_supp_freq_Hz,
            cp->cpu_supp_freqs);
#if defined(__sparcv9)
        cpu_info_template.ci_device_ID.value.ui64 =
            cpunodes[cp->cpu_id].device_id;
        kstat_named_setstr(&cpu_info_template.ci_cpu_fru, cpu_fru_fmri(cp));
#endif
#if defined(__x86)
        kstat_named_setstr(&cpu_info_template.ci_vendorstr,
            cpuid_getvendorstr(cp));
        cpu_info_template.ci_family.value.l = cpuid_getfamily(cp);
        cpu_info_template.ci_model.value.l = cpuid_getmodel(cp);
        cpu_info_template.ci_step.value.l = cpuid_getstep(cp);
        cpu_info_template.ci_clogid.value.l = cpuid_get_clogid(cp);
        cpu_info_template.ci_ncpuperchip.value.l = cpuid_get_ncpu_per_chip(cp);
        cpu_info_template.ci_ncoreperchip.value.l =
            cpuid_get_ncore_per_chip(cp);
        cpu_info_template.ci_pkg_core_id.value.l = cpuid_get_pkgcoreid(cp);
        cpu_info_template.ci_max_cstates.value.l = cp->cpu_m.max_cstates;
        cpu_info_template.ci_curr_cstate.value.l = cpu_idle_get_cpu_state(cp);
        cpu_info_template.ci_cacheid.value.i32 = cpuid_get_cacheid(cp);
        kstat_named_setstr(&cpu_info_template.ci_sktstr,
            cpuid_getsocketstr(cp));
#endif

        return (0);
}

static void
cpu_info_kstat_create(cpu_t *cp)
{
        zoneid_t zoneid;

        ASSERT(MUTEX_HELD(&cpu_lock));

        if (pool_pset_enabled())
                zoneid = GLOBAL_ZONEID;
        else
                zoneid = ALL_ZONES;
        if ((cp->cpu_info_kstat = kstat_create_zone("cpu_info", cp->cpu_id,
            NULL, "misc", KSTAT_TYPE_NAMED,
            sizeof (cpu_info_template) / sizeof (kstat_named_t),
            KSTAT_FLAG_VIRTUAL | KSTAT_FLAG_VAR_SIZE, zoneid)) != NULL) {
                cp->cpu_info_kstat->ks_data_size += 2 * CPU_IDSTRLEN;
#if defined(__sparcv9)
                cp->cpu_info_kstat->ks_data_size +=
                    strlen(cpu_fru_fmri(cp)) + 1;
#endif
#if defined(__x86)
                cp->cpu_info_kstat->ks_data_size += X86_VENDOR_STRLEN;
#endif
                if (cp->cpu_supp_freqs != NULL)
                        cp->cpu_info_kstat->ks_data_size +=
                            strlen(cp->cpu_supp_freqs) + 1;
                cp->cpu_info_kstat->ks_lock = &cpu_info_template_lock;
                cp->cpu_info_kstat->ks_data = &cpu_info_template;
                cp->cpu_info_kstat->ks_private = cp;
                cp->cpu_info_kstat->ks_update = cpu_info_kstat_update;
                kstat_install(cp->cpu_info_kstat);
        }
}

static void
cpu_info_kstat_destroy(cpu_t *cp)
{
        ASSERT(MUTEX_HELD(&cpu_lock));

        kstat_delete(cp->cpu_info_kstat);
        cp->cpu_info_kstat = NULL;
}

/*
 * Create and install kstats for the boot CPU.
 */
void
cpu_kstat_init(cpu_t *cp)
{
        mutex_enter(&cpu_lock);
        cpu_info_kstat_create(cp);
        cpu_stats_kstat_create(cp);
        cpu_create_intrstat(cp);
        cpu_set_state(cp);
        mutex_exit(&cpu_lock);
}

/*
 * Make visible to the zone that subset of the cpu information that would be
 * initialized when a cpu is configured (but still offline).
 */
void
cpu_visibility_configure(cpu_t *cp, zone_t *zone)
{
        zoneid_t zoneid = zone ? zone->zone_id : ALL_ZONES;

        ASSERT(MUTEX_HELD(&cpu_lock));
        ASSERT(pool_pset_enabled());
        ASSERT(cp != NULL);

        if (zoneid != ALL_ZONES && zoneid != GLOBAL_ZONEID) {
                zone->zone_ncpus++;
                ASSERT(zone->zone_ncpus <= ncpus);
        }
        if (cp->cpu_info_kstat != NULL)
                kstat_zone_add(cp->cpu_info_kstat, zoneid);
}

/*
 * Make visible to the zone that subset of the cpu information that would be
 * initialized when a previously configured cpu is onlined.
 */
void
cpu_visibility_online(cpu_t *cp, zone_t *zone)
{
        kstat_t *ksp;
        char name[sizeof ("cpu_stat") + 10];    /* enough for 32-bit cpuids */
        zoneid_t zoneid = zone ? zone->zone_id : ALL_ZONES;
        processorid_t cpun;

        ASSERT(MUTEX_HELD(&cpu_lock));
        ASSERT(pool_pset_enabled());
        ASSERT(cp != NULL);
        ASSERT(cpu_is_active(cp));

        cpun = cp->cpu_id;
        if (zoneid != ALL_ZONES && zoneid != GLOBAL_ZONEID) {
                zone->zone_ncpus_online++;
                ASSERT(zone->zone_ncpus_online <= ncpus_online);
        }
        (void) snprintf(name, sizeof (name), "cpu_stat%d", cpun);
        if ((ksp = kstat_hold_byname("cpu_stat", cpun, name, ALL_ZONES))
            != NULL) {
                kstat_zone_add(ksp, zoneid);
                kstat_rele(ksp);
        }
        if ((ksp = kstat_hold_byname("cpu", cpun, "sys", ALL_ZONES)) != NULL) {
                kstat_zone_add(ksp, zoneid);
                kstat_rele(ksp);
        }
        if ((ksp = kstat_hold_byname("cpu", cpun, "vm", ALL_ZONES)) != NULL) {
                kstat_zone_add(ksp, zoneid);
                kstat_rele(ksp);
        }
        if ((ksp = kstat_hold_byname("cpu", cpun, "intrstat", ALL_ZONES)) !=
            NULL) {
                kstat_zone_add(ksp, zoneid);
                kstat_rele(ksp);
        }
}

/*
 * Update relevant kstats such that cpu is now visible to processes
 * executing in specified zone.
 */
void
cpu_visibility_add(cpu_t *cp, zone_t *zone)
{
        cpu_visibility_configure(cp, zone);
        if (cpu_is_active(cp))
                cpu_visibility_online(cp, zone);
}

/*
 * Make invisible to the zone that subset of the cpu information that would be
 * torn down when a previously offlined cpu is unconfigured.
 */
void
cpu_visibility_unconfigure(cpu_t *cp, zone_t *zone)
{
        zoneid_t zoneid = zone ? zone->zone_id : ALL_ZONES;

        ASSERT(MUTEX_HELD(&cpu_lock));
        ASSERT(pool_pset_enabled());
        ASSERT(cp != NULL);

        if (zoneid != ALL_ZONES && zoneid != GLOBAL_ZONEID) {
                ASSERT(zone->zone_ncpus != 0);
                zone->zone_ncpus--;
        }
        if (cp->cpu_info_kstat)
                kstat_zone_remove(cp->cpu_info_kstat, zoneid);
}

/*
 * Make invisible to the zone that subset of the cpu information that would be
 * torn down when a cpu is offlined (but still configured).
 */
void
cpu_visibility_offline(cpu_t *cp, zone_t *zone)
{
        kstat_t *ksp;
        char name[sizeof ("cpu_stat") + 10];    /* enough for 32-bit cpuids */
        zoneid_t zoneid = zone ? zone->zone_id : ALL_ZONES;
        processorid_t cpun;

        ASSERT(MUTEX_HELD(&cpu_lock));
        ASSERT(pool_pset_enabled());
        ASSERT(cp != NULL);
        ASSERT(cpu_is_active(cp));

        cpun = cp->cpu_id;
        if (zoneid != ALL_ZONES && zoneid != GLOBAL_ZONEID) {
                ASSERT(zone->zone_ncpus_online != 0);
                zone->zone_ncpus_online--;
        }

        if ((ksp = kstat_hold_byname("cpu", cpun, "intrstat", ALL_ZONES)) !=
            NULL) {
                kstat_zone_remove(ksp, zoneid);
                kstat_rele(ksp);
        }
        if ((ksp = kstat_hold_byname("cpu", cpun, "vm", ALL_ZONES)) != NULL) {
                kstat_zone_remove(ksp, zoneid);
                kstat_rele(ksp);
        }
        if ((ksp = kstat_hold_byname("cpu", cpun, "sys", ALL_ZONES)) != NULL) {
                kstat_zone_remove(ksp, zoneid);
                kstat_rele(ksp);
        }
        (void) snprintf(name, sizeof (name), "cpu_stat%d", cpun);
        if ((ksp = kstat_hold_byname("cpu_stat", cpun, name, ALL_ZONES))
            != NULL) {
                kstat_zone_remove(ksp, zoneid);
                kstat_rele(ksp);
        }
}

/*
 * Update relevant kstats such that cpu is no longer visible to processes
 * executing in specified zone.
 */
void
cpu_visibility_remove(cpu_t *cp, zone_t *zone)
{
        if (cpu_is_active(cp))
                cpu_visibility_offline(cp, zone);
        cpu_visibility_unconfigure(cp, zone);
}

/*
 * Bind a thread to a CPU as requested.
 */
int
cpu_bind_thread(kthread_id_t tp, processorid_t bind, processorid_t *obind,
    int *error)
{
        processorid_t   binding;
        cpu_t           *cp = NULL;

        ASSERT(MUTEX_HELD(&cpu_lock));
        ASSERT(MUTEX_HELD(&ttoproc(tp)->p_lock));

        thread_lock(tp);

        /*
         * Record old binding, but change the obind, which was initialized
         * to PBIND_NONE, only if this thread has a binding.  This avoids
         * reporting PBIND_NONE for a process when some LWPs are bound.
         */
        binding = tp->t_bind_cpu;
        if (binding != PBIND_NONE)
                *obind = binding;       /* record old binding */

        switch (bind) {
        case PBIND_QUERY:
                /* Just return the old binding */
                thread_unlock(tp);
                return (0);

        case PBIND_QUERY_TYPE:
                /* Return the binding type */
                *obind = TB_CPU_IS_SOFT(tp) ? PBIND_SOFT : PBIND_HARD;
                thread_unlock(tp);
                return (0);

        case PBIND_SOFT:
                /*
                 *  Set soft binding for this thread and return the actual
                 *  binding
                 */
                TB_CPU_SOFT_SET(tp);
                thread_unlock(tp);
                return (0);

        case PBIND_HARD:
                /*
                 *  Set hard binding for this thread and return the actual
                 *  binding
                 */
                TB_CPU_HARD_SET(tp);
                thread_unlock(tp);
                return (0);

        default:
                break;
        }

        /*
         * If this thread/LWP cannot be bound because of permission
         * problems, just note that and return success so that the
         * other threads/LWPs will be bound.  This is the way
         * processor_bind() is defined to work.
         *
         * Binding will get EPERM if the thread is of system class
         * or hasprocperm() fails.
         */
        if (tp->t_cid == 0 || !hasprocperm(tp->t_cred, CRED())) {
                *error = EPERM;
                thread_unlock(tp);
                return (0);
        }

        binding = bind;
        if (binding != PBIND_NONE) {
                cp = cpu_get((processorid_t)binding);
                /*
                 * Make sure binding is valid and is in right partition.
                 */
                if (cp == NULL || tp->t_cpupart != cp->cpu_part) {
                        *error = EINVAL;
                        thread_unlock(tp);
                        return (0);
                }
        }
        tp->t_bind_cpu = binding;       /* set new binding */

        /*
         * If there is no system-set reason for affinity, set
         * the t_bound_cpu field to reflect the binding.
         */
        if (tp->t_affinitycnt == 0) {
                if (binding == PBIND_NONE) {
                        /*
                         * We may need to adjust disp_max_unbound_pri
                         * since we're becoming unbound.
                         */
                        disp_adjust_unbound_pri(tp);

                        tp->t_bound_cpu = NULL; /* set new binding */

                        /*
                         * Move thread to lgroup with strongest affinity
                         * after unbinding
                         */
                        if (tp->t_lgrp_affinity)
                                lgrp_move_thread(tp,
                                    lgrp_choose(tp, tp->t_cpupart), 1);

                        if (tp->t_state == TS_ONPROC &&
                            tp->t_cpu->cpu_part != tp->t_cpupart)
                                cpu_surrender(tp);
                } else {
                        lpl_t   *lpl;

                        tp->t_bound_cpu = cp;
                        ASSERT(cp->cpu_lpl != NULL);

                        /*
                         * Set home to lgroup with most affinity containing CPU
                         * that thread is being bound or minimum bounding
                         * lgroup if no affinities set
                         */
                        if (tp->t_lgrp_affinity)
                                lpl = lgrp_affinity_best(tp, tp->t_cpupart,
                                    LGRP_NONE, B_FALSE);
                        else
                                lpl = cp->cpu_lpl;

                        if (tp->t_lpl != lpl) {
                                /* can't grab cpu_lock */
                                lgrp_move_thread(tp, lpl, 1);
                        }

                        /*
                         * Make the thread switch to the bound CPU.
                         * If the thread is runnable, we need to
                         * requeue it even if t_cpu is already set
                         * to the right CPU, since it may be on a
                         * kpreempt queue and need to move to a local
                         * queue.  We could check t_disp_queue to
                         * avoid unnecessary overhead if it's already
                         * on the right queue, but since this isn't
                         * a performance-critical operation it doesn't
                         * seem worth the extra code and complexity.
                         *
                         * If the thread is weakbound to the cpu then it will
                         * resist the new binding request until the weak
                         * binding drops.  The cpu_surrender or requeueing
                         * below could be skipped in such cases (since it
                         * will have no effect), but that would require
                         * thread_allowmigrate to acquire thread_lock so
                         * we'll take the very occasional hit here instead.
                         */
                        if (tp->t_state == TS_ONPROC) {
                                cpu_surrender(tp);
                        } else if (tp->t_state == TS_RUN) {
                                cpu_t *ocp = tp->t_cpu;

                                (void) dispdeq(tp);
                                setbackdq(tp);
                                /*
                                 * On the bound CPU's disp queue now.
                                 */
                                ASSERT(tp->t_disp_queue == cp->cpu_disp ||
                                    tp->t_weakbound_cpu == ocp);
                        }
                }
        }

        /*
         * Our binding has changed; set TP_CHANGEBIND.
         */
        tp->t_proc_flag |= TP_CHANGEBIND;
        aston(tp);

        thread_unlock(tp);

        return (0);
}

#if CPUSET_WORDS > 1

/*
 * Functions for implementing cpuset operations when a cpuset is more
 * than one word.  On platforms where a cpuset is a single word these
 * are implemented as macros in cpuvar.h.
 */

void
cpuset_all(cpuset_t *s)
{
        int i;

        for (i = 0; i < CPUSET_WORDS; i++)
                s->cpub[i] = ~0UL;
}

void
cpuset_all_but(cpuset_t *s, uint_t cpu)
{
        cpuset_all(s);
        CPUSET_DEL(*s, cpu);
}

void
cpuset_only(cpuset_t *s, uint_t cpu)
{
        CPUSET_ZERO(*s);
        CPUSET_ADD(*s, cpu);
}

int
cpuset_isnull(cpuset_t *s)
{
        int i;

        for (i = 0; i < CPUSET_WORDS; i++)
                if (s->cpub[i] != 0)
                        return (0);
        return (1);
}

int
cpuset_cmp(cpuset_t *s1, cpuset_t *s2)
{
        int i;

        for (i = 0; i < CPUSET_WORDS; i++)
                if (s1->cpub[i] != s2->cpub[i])
                        return (0);
        return (1);
}

uint_t
cpuset_find(cpuset_t *s)
{

        uint_t  i;
        uint_t  cpu = (uint_t)-1;

        /*
         * Find a cpu in the cpuset
         */
        for (i = 0; i < CPUSET_WORDS; i++) {
                cpu = (uint_t)(lowbit(s->cpub[i]) - 1);
                if (cpu != (uint_t)-1) {
                        cpu += i * BT_NBIPUL;
                        break;
                }
        }
        return (cpu);
}

void
cpuset_bounds(cpuset_t *s, uint_t *smallestid, uint_t *largestid)
{
        int     i, j;
        uint_t  bit;

        /*
         * First, find the smallest cpu id in the set.
         */
        for (i = 0; i < CPUSET_WORDS; i++) {
                if (s->cpub[i] != 0) {
                        bit = (uint_t)(lowbit(s->cpub[i]) - 1);
                        ASSERT(bit != (uint_t)-1);
                        *smallestid = bit + (i * BT_NBIPUL);

                        /*
                         * Now find the largest cpu id in
                         * the set and return immediately.
                         * Done in an inner loop to avoid
                         * having to break out of the first
                         * loop.
                         */
                        for (j = CPUSET_WORDS - 1; j >= i; j--) {
                                if (s->cpub[j] != 0) {
                                        bit = (uint_t)(highbit(s->cpub[j]) - 1);
                                        ASSERT(bit != (uint_t)-1);
                                        *largestid = bit + (j * BT_NBIPUL);
                                        ASSERT(*largestid >= *smallestid);
                                        return;
                                }
                        }

                        /*
                         * If this code is reached, a
                         * smallestid was found, but not a
                         * largestid. The cpuset must have
                         * been changed during the course
                         * of this function call.
                         */
                        ASSERT(0);
                }
        }
        *smallestid = *largestid = CPUSET_NOTINSET;
}

#endif  /* CPUSET_WORDS */

/*
 * Unbind threads bound to specified CPU.
 *
 * If `unbind_all_threads' is true, unbind all user threads bound to a given
 * CPU. Otherwise unbind all soft-bound user threads.
 */
int
cpu_unbind(processorid_t cpu, boolean_t unbind_all_threads)
{
        processorid_t obind;
        kthread_t *tp;
        int ret = 0;
        proc_t *pp;
        int err, berr = 0;

        ASSERT(MUTEX_HELD(&cpu_lock));

        mutex_enter(&pidlock);
        for (pp = practive; pp != NULL; pp = pp->p_next) {
                mutex_enter(&pp->p_lock);
                tp = pp->p_tlist;
                /*
                 * Skip zombies, kernel processes, and processes in
                 * other zones, if called from a non-global zone.
                 */
                if (tp == NULL || (pp->p_flag & SSYS) ||
                    !HASZONEACCESS(curproc, pp->p_zone->zone_id)) {
                        mutex_exit(&pp->p_lock);
                        continue;
                }
                do {
                        if (tp->t_bind_cpu != cpu)
                                continue;
                        /*
                         * Skip threads with hard binding when
                         * `unbind_all_threads' is not specified.
                         */
                        if (!unbind_all_threads && TB_CPU_IS_HARD(tp))
                                continue;
                        err = cpu_bind_thread(tp, PBIND_NONE, &obind, &berr);
                        if (ret == 0)
                                ret = err;
                } while ((tp = tp->t_forw) != pp->p_tlist);
                mutex_exit(&pp->p_lock);
        }
        mutex_exit(&pidlock);
        if (ret == 0)
                ret = berr;
        return (ret);
}


/*
 * Destroy all remaining bound threads on a cpu.
 */
void
cpu_destroy_bound_threads(cpu_t *cp)
{
        extern id_t syscid;
        register kthread_id_t   t, tlist, tnext;

        /*
         * Destroy all remaining bound threads on the cpu.  This
         * should include both the interrupt threads and the idle thread.
         * This requires some care, since we need to traverse the
         * thread list with the pidlock mutex locked, but thread_free
         * also locks the pidlock mutex.  So, we collect the threads
         * we're going to reap in a list headed by "tlist", then we
         * unlock the pidlock mutex and traverse the tlist list,
         * doing thread_free's on the thread's.  Simple, n'est pas?
         * Also, this depends on thread_free not mucking with the
         * t_next and t_prev links of the thread.
         */

        if ((t = curthread) != NULL) {

                tlist = NULL;
                mutex_enter(&pidlock);
                do {
                        tnext = t->t_next;
                        if (t->t_bound_cpu == cp) {

                                /*
                                 * We've found a bound thread, carefully unlink
                                 * it out of the thread list, and add it to
                                 * our "tlist".  We "know" we don't have to
                                 * worry about unlinking curthread (the thread
                                 * that is executing this code).
                                 */
                                t->t_next->t_prev = t->t_prev;
                                t->t_prev->t_next = t->t_next;
                                t->t_next = tlist;
                                tlist = t;
                                ASSERT(t->t_cid == syscid);
                                /* wake up anyone blocked in thread_join */
                                cv_broadcast(&t->t_joincv);
                                /*
                                 * t_lwp set by interrupt threads and not
                                 * cleared.
                                 */
                                t->t_lwp = NULL;
                                /*
                                 * Pause and idle threads always have
                                 * t_state set to TS_ONPROC.
                                 */
                                t->t_state = TS_FREE;
                                t->t_prev = NULL;       /* Just in case */
                        }

                } while ((t = tnext) != curthread);

                mutex_exit(&pidlock);

                mutex_sync();
                for (t = tlist; t != NULL; t = tnext) {
                        tnext = t->t_next;
                        thread_free(t);
                }
        }
}

/*
 * Update the cpu_supp_freqs of this cpu. This information is returned
 * as part of cpu_info kstats. If the cpu_info_kstat exists already, then
 * maintain the kstat data size.
 */
void
cpu_set_supp_freqs(cpu_t *cp, const char *freqs)
{
        char clkstr[sizeof ("18446744073709551615") + 1]; /* ui64 MAX */
        const char *lfreqs = clkstr;
        boolean_t kstat_exists = B_FALSE;
        kstat_t *ksp;
        size_t len;

        /*
         * A NULL pointer means we only support one speed.
         */
        if (freqs == NULL)
                (void) snprintf(clkstr, sizeof (clkstr), "%"PRIu64,
                    cp->cpu_curr_clock);
        else
                lfreqs = freqs;

        /*
         * Make sure the frequency doesn't change while a snapshot is
         * going on. Of course, we only need to worry about this if
         * the kstat exists.
         */
        if ((ksp = cp->cpu_info_kstat) != NULL) {
                mutex_enter(ksp->ks_lock);
                kstat_exists = B_TRUE;
        }

        /*
         * Free any previously allocated string and if the kstat
         * already exists, then update its data size.
         */
        if (cp->cpu_supp_freqs != NULL) {
                len = strlen(cp->cpu_supp_freqs) + 1;
                kmem_free(cp->cpu_supp_freqs, len);
                if (kstat_exists)
                        ksp->ks_data_size -= len;
        }

        /*
         * Allocate the new string and set the pointer.
         */
        len = strlen(lfreqs) + 1;
        cp->cpu_supp_freqs = kmem_alloc(len, KM_SLEEP);
        (void) strcpy(cp->cpu_supp_freqs, lfreqs);

        /*
         * If the kstat already exists then update the data size and
         * free the lock.
         */
        if (kstat_exists) {
                ksp->ks_data_size += len;
                mutex_exit(ksp->ks_lock);
        }
}

/*
 * Indicate the current CPU's clock freqency (in Hz).
 * The calling context must be such that CPU references are safe.
 */
void
cpu_set_curr_clock(uint64_t new_clk)
{
        uint64_t old_clk;

        old_clk = CPU->cpu_curr_clock;
        CPU->cpu_curr_clock = new_clk;

        /*
         * The cpu-change-speed DTrace probe exports the frequency in Hz
         */
        DTRACE_PROBE3(cpu__change__speed, processorid_t, CPU->cpu_id,
            uint64_t, old_clk, uint64_t, new_clk);
}

/*
 * processor_info(2) and p_online(2) status support functions
 *   The constants returned by the cpu_get_state() and cpu_get_state_str() are
 *   for use in communicating processor state information to userland.  Kernel
 *   subsystems should only be using the cpu_flags value directly.  Subsystems
 *   modifying cpu_flags should record the state change via a call to the
 *   cpu_set_state().
 */

/*
 * Update the pi_state of this CPU.  This function provides the CPU status for
 * the information returned by processor_info(2).
 */
void
cpu_set_state(cpu_t *cpu)
{
        ASSERT(MUTEX_HELD(&cpu_lock));
        cpu->cpu_type_info.pi_state = cpu_get_state(cpu);
        cpu->cpu_state_begin = gethrestime_sec();
        pool_cpu_mod = gethrtime();
}

/*
 * Return offline/online/other status for the indicated CPU.  Use only for
 * communication with user applications; cpu_flags provides the in-kernel
 * interface.
 */
int
cpu_get_state(cpu_t *cpu)
{
        ASSERT(MUTEX_HELD(&cpu_lock));
        if (cpu->cpu_flags & CPU_POWEROFF)
                return (P_POWEROFF);
        else if (cpu->cpu_flags & CPU_FAULTED)
                return (P_FAULTED);
        else if (cpu->cpu_flags & CPU_SPARE)
                return (P_SPARE);
        else if ((cpu->cpu_flags & (CPU_READY | CPU_OFFLINE)) != CPU_READY)
                return (P_OFFLINE);
        else if (cpu->cpu_flags & CPU_ENABLE)
                return (P_ONLINE);
        else
                return (P_NOINTR);
}

/*
 * Return processor_info(2) state as a string.
 */
const char *
cpu_get_state_str(cpu_t *cpu)
{
        const char *string;

        switch (cpu_get_state(cpu)) {
        case P_ONLINE:
                string = PS_ONLINE;
                break;
        case P_POWEROFF:
                string = PS_POWEROFF;
                break;
        case P_NOINTR:
                string = PS_NOINTR;
                break;
        case P_SPARE:
                string = PS_SPARE;
                break;
        case P_FAULTED:
                string = PS_FAULTED;
                break;
        case P_OFFLINE:
                string = PS_OFFLINE;
                break;
        default:
                string = "unknown";
                break;
        }
        return (string);
}

/*
 * Export this CPU's statistics (cpu_stat_t and cpu_stats_t) as raw and named
 * kstats, respectively.  This is done when a CPU is initialized or placed
 * online via p_online(2).
 */
static void
cpu_stats_kstat_create(cpu_t *cp)
{
        int     instance = cp->cpu_id;
        char    *module = "cpu";
        char    *class = "misc";
        kstat_t *ksp;
        zoneid_t zoneid;

        ASSERT(MUTEX_HELD(&cpu_lock));

        if (pool_pset_enabled())
                zoneid = GLOBAL_ZONEID;
        else
                zoneid = ALL_ZONES;
        /*
         * Create named kstats
         */
#define CPU_STATS_KS_CREATE(name, tsize, update_func)                    \
        ksp = kstat_create_zone(module, instance, (name), class,         \
            KSTAT_TYPE_NAMED, (tsize) / sizeof (kstat_named_t), 0,       \
            zoneid);                                                     \
        if (ksp != NULL) {                                               \
                ksp->ks_private = cp;                                    \
                ksp->ks_update = (update_func);                          \
                kstat_install(ksp);                                      \
        } else                                                           \
                cmn_err(CE_WARN, "cpu: unable to create %s:%d:%s kstat", \
                    module, instance, (name));

        CPU_STATS_KS_CREATE("sys", sizeof (cpu_sys_stats_ks_data_template),
            cpu_sys_stats_ks_update);
        CPU_STATS_KS_CREATE("vm", sizeof (cpu_vm_stats_ks_data_template),
            cpu_vm_stats_ks_update);

        /*
         * Export the familiar cpu_stat_t KSTAT_TYPE_RAW kstat.
         */
        ksp = kstat_create_zone("cpu_stat", cp->cpu_id, NULL,
            "misc", KSTAT_TYPE_RAW, sizeof (cpu_stat_t), 0, zoneid);
        if (ksp != NULL) {
                ksp->ks_update = cpu_stat_ks_update;
                ksp->ks_private = cp;
                kstat_install(ksp);
        }
}

static void
cpu_stats_kstat_destroy(cpu_t *cp)
{
        char ks_name[KSTAT_STRLEN];

        (void) sprintf(ks_name, "cpu_stat%d", cp->cpu_id);
        kstat_delete_byname("cpu_stat", cp->cpu_id, ks_name);

        kstat_delete_byname("cpu", cp->cpu_id, "sys");
        kstat_delete_byname("cpu", cp->cpu_id, "vm");
}

static int
cpu_sys_stats_ks_update(kstat_t *ksp, int rw)
{
        cpu_t *cp = (cpu_t *)ksp->ks_private;
        struct cpu_sys_stats_ks_data *csskd;
        cpu_sys_stats_t *css;
        hrtime_t msnsecs[NCMSTATES];
        int     i;

        if (rw == KSTAT_WRITE)
                return (EACCES);

        csskd = ksp->ks_data;
        css = &cp->cpu_stats.sys;

        /*
         * Read CPU mstate, but compare with the last values we
         * received to make sure that the returned kstats never
         * decrease.
         */

        get_cpu_mstate(cp, msnsecs);
        if (csskd->cpu_nsec_idle.value.ui64 > msnsecs[CMS_IDLE])
                msnsecs[CMS_IDLE] = csskd->cpu_nsec_idle.value.ui64;
        if (csskd->cpu_nsec_user.value.ui64 > msnsecs[CMS_USER])
                msnsecs[CMS_USER] = csskd->cpu_nsec_user.value.ui64;
        if (csskd->cpu_nsec_kernel.value.ui64 > msnsecs[CMS_SYSTEM])
                msnsecs[CMS_SYSTEM] = csskd->cpu_nsec_kernel.value.ui64;

        bcopy(&cpu_sys_stats_ks_data_template, ksp->ks_data,
            sizeof (cpu_sys_stats_ks_data_template));

        csskd->cpu_ticks_wait.value.ui64 = 0;
        csskd->wait_ticks_io.value.ui64 = 0;

        csskd->cpu_nsec_idle.value.ui64 = msnsecs[CMS_IDLE];
        csskd->cpu_nsec_user.value.ui64 = msnsecs[CMS_USER];
        csskd->cpu_nsec_kernel.value.ui64 = msnsecs[CMS_SYSTEM];
        csskd->cpu_ticks_idle.value.ui64 =
            NSEC_TO_TICK(csskd->cpu_nsec_idle.value.ui64);
        csskd->cpu_ticks_user.value.ui64 =
            NSEC_TO_TICK(csskd->cpu_nsec_user.value.ui64);
        csskd->cpu_ticks_kernel.value.ui64 =
            NSEC_TO_TICK(csskd->cpu_nsec_kernel.value.ui64);
        csskd->cpu_nsec_dtrace.value.ui64 = cp->cpu_dtrace_nsec;
        csskd->dtrace_probes.value.ui64 = cp->cpu_dtrace_probes;
        csskd->cpu_nsec_intr.value.ui64 = cp->cpu_intrlast;
        csskd->cpu_load_intr.value.ui64 = cp->cpu_intrload;
        csskd->bread.value.ui64 = css->bread;
        csskd->bwrite.value.ui64 = css->bwrite;
        csskd->lread.value.ui64 = css->lread;
        csskd->lwrite.value.ui64 = css->lwrite;
        csskd->phread.value.ui64 = css->phread;
        csskd->phwrite.value.ui64 = css->phwrite;
        csskd->pswitch.value.ui64 = css->pswitch;
        csskd->trap.value.ui64 = css->trap;
        csskd->intr.value.ui64 = 0;
        for (i = 0; i < PIL_MAX; i++)
                csskd->intr.value.ui64 += css->intr[i];
        csskd->syscall.value.ui64 = css->syscall;
        csskd->sysread.value.ui64 = css->sysread;
        csskd->syswrite.value.ui64 = css->syswrite;
        csskd->sysfork.value.ui64 = css->sysfork;
        csskd->sysvfork.value.ui64 = css->sysvfork;
        csskd->sysexec.value.ui64 = css->sysexec;
        csskd->readch.value.ui64 = css->readch;
        csskd->writech.value.ui64 = css->writech;
        csskd->rcvint.value.ui64 = css->rcvint;
        csskd->xmtint.value.ui64 = css->xmtint;
        csskd->mdmint.value.ui64 = css->mdmint;
        csskd->rawch.value.ui64 = css->rawch;
        csskd->canch.value.ui64 = css->canch;
        csskd->outch.value.ui64 = css->outch;
        csskd->msg.value.ui64 = css->msg;
        csskd->sema.value.ui64 = css->sema;
        csskd->namei.value.ui64 = css->namei;
        csskd->ufsiget.value.ui64 = css->ufsiget;
        csskd->ufsdirblk.value.ui64 = css->ufsdirblk;
        csskd->ufsipage.value.ui64 = css->ufsipage;
        csskd->ufsinopage.value.ui64 = css->ufsinopage;
        csskd->procovf.value.ui64 = css->procovf;
        csskd->intrthread.value.ui64 = 0;
        for (i = 0; i < LOCK_LEVEL - 1; i++)
                csskd->intrthread.value.ui64 += css->intr[i];
        csskd->intrblk.value.ui64 = css->intrblk;
        csskd->intrunpin.value.ui64 = css->intrunpin;
        csskd->idlethread.value.ui64 = css->idlethread;
        csskd->inv_swtch.value.ui64 = css->inv_swtch;
        csskd->nthreads.value.ui64 = css->nthreads;
        csskd->cpumigrate.value.ui64 = css->cpumigrate;
        csskd->xcalls.value.ui64 = css->xcalls;
        csskd->mutex_adenters.value.ui64 = css->mutex_adenters;
        csskd->rw_rdfails.value.ui64 = css->rw_rdfails;
        csskd->rw_wrfails.value.ui64 = css->rw_wrfails;
        csskd->modload.value.ui64 = css->modload;
        csskd->modunload.value.ui64 = css->modunload;
        csskd->bawrite.value.ui64 = css->bawrite;
        csskd->iowait.value.ui64 = css->iowait;

        return (0);
}

static int
cpu_vm_stats_ks_update(kstat_t *ksp, int rw)
{
        cpu_t *cp = (cpu_t *)ksp->ks_private;
        struct cpu_vm_stats_ks_data *cvskd;
        cpu_vm_stats_t *cvs;

        if (rw == KSTAT_WRITE)
                return (EACCES);

        cvs = &cp->cpu_stats.vm;
        cvskd = ksp->ks_data;

        bcopy(&cpu_vm_stats_ks_data_template, ksp->ks_data,
            sizeof (cpu_vm_stats_ks_data_template));
        cvskd->pgrec.value.ui64 = cvs->pgrec;
        cvskd->pgfrec.value.ui64 = cvs->pgfrec;
        cvskd->pgin.value.ui64 = cvs->pgin;
        cvskd->pgpgin.value.ui64 = cvs->pgpgin;
        cvskd->pgout.value.ui64 = cvs->pgout;
        cvskd->pgpgout.value.ui64 = cvs->pgpgout;
        cvskd->zfod.value.ui64 = cvs->zfod;
        cvskd->dfree.value.ui64 = cvs->dfree;
        cvskd->scan.value.ui64 = cvs->scan;
        cvskd->rev.value.ui64 = cvs->rev;
        cvskd->hat_fault.value.ui64 = cvs->hat_fault;
        cvskd->as_fault.value.ui64 = cvs->as_fault;
        cvskd->maj_fault.value.ui64 = cvs->maj_fault;
        cvskd->cow_fault.value.ui64 = cvs->cow_fault;
        cvskd->prot_fault.value.ui64 = cvs->prot_fault;
        cvskd->softlock.value.ui64 = cvs->softlock;
        cvskd->kernel_asflt.value.ui64 = cvs->kernel_asflt;
        cvskd->pgrrun.value.ui64 = cvs->pgrrun;
        cvskd->execpgin.value.ui64 = cvs->execpgin;
        cvskd->execpgout.value.ui64 = cvs->execpgout;
        cvskd->execfree.value.ui64 = cvs->execfree;
        cvskd->anonpgin.value.ui64 = cvs->anonpgin;
        cvskd->anonpgout.value.ui64 = cvs->anonpgout;
        cvskd->anonfree.value.ui64 = cvs->anonfree;
        cvskd->fspgin.value.ui64 = cvs->fspgin;
        cvskd->fspgout.value.ui64 = cvs->fspgout;
        cvskd->fsfree.value.ui64 = cvs->fsfree;

        return (0);
}

static int
cpu_stat_ks_update(kstat_t *ksp, int rw)
{
        cpu_stat_t *cso;
        cpu_t *cp;
        int i;
        hrtime_t msnsecs[NCMSTATES];

        cso = (cpu_stat_t *)ksp->ks_data;
        cp = (cpu_t *)ksp->ks_private;

        if (rw == KSTAT_WRITE)
                return (EACCES);

        /*
         * Read CPU mstate, but compare with the last values we
         * received to make sure that the returned kstats never
         * decrease.
         */

        get_cpu_mstate(cp, msnsecs);
        msnsecs[CMS_IDLE] = NSEC_TO_TICK(msnsecs[CMS_IDLE]);
        msnsecs[CMS_USER] = NSEC_TO_TICK(msnsecs[CMS_USER]);
        msnsecs[CMS_SYSTEM] = NSEC_TO_TICK(msnsecs[CMS_SYSTEM]);
        if (cso->cpu_sysinfo.cpu[CPU_IDLE] < msnsecs[CMS_IDLE])
                cso->cpu_sysinfo.cpu[CPU_IDLE] = msnsecs[CMS_IDLE];
        if (cso->cpu_sysinfo.cpu[CPU_USER] < msnsecs[CMS_USER])
                cso->cpu_sysinfo.cpu[CPU_USER] = msnsecs[CMS_USER];
        if (cso->cpu_sysinfo.cpu[CPU_KERNEL] < msnsecs[CMS_SYSTEM])
                cso->cpu_sysinfo.cpu[CPU_KERNEL] = msnsecs[CMS_SYSTEM];
        cso->cpu_sysinfo.cpu[CPU_WAIT]  = 0;
        cso->cpu_sysinfo.wait[W_IO]     = 0;
        cso->cpu_sysinfo.wait[W_SWAP]   = 0;
        cso->cpu_sysinfo.wait[W_PIO]    = 0;
        cso->cpu_sysinfo.bread          = CPU_STATS(cp, sys.bread);
        cso->cpu_sysinfo.bwrite         = CPU_STATS(cp, sys.bwrite);
        cso->cpu_sysinfo.lread          = CPU_STATS(cp, sys.lread);
        cso->cpu_sysinfo.lwrite         = CPU_STATS(cp, sys.lwrite);
        cso->cpu_sysinfo.phread         = CPU_STATS(cp, sys.phread);
        cso->cpu_sysinfo.phwrite        = CPU_STATS(cp, sys.phwrite);
        cso->cpu_sysinfo.pswitch        = CPU_STATS(cp, sys.pswitch);
        cso->cpu_sysinfo.trap           = CPU_STATS(cp, sys.trap);
        cso->cpu_sysinfo.intr           = 0;
        for (i = 0; i < PIL_MAX; i++)
                cso->cpu_sysinfo.intr += CPU_STATS(cp, sys.intr[i]);
        cso->cpu_sysinfo.syscall        = CPU_STATS(cp, sys.syscall);
        cso->cpu_sysinfo.sysread        = CPU_STATS(cp, sys.sysread);
        cso->cpu_sysinfo.syswrite       = CPU_STATS(cp, sys.syswrite);
        cso->cpu_sysinfo.sysfork        = CPU_STATS(cp, sys.sysfork);
        cso->cpu_sysinfo.sysvfork       = CPU_STATS(cp, sys.sysvfork);
        cso->cpu_sysinfo.sysexec        = CPU_STATS(cp, sys.sysexec);
        cso->cpu_sysinfo.readch         = CPU_STATS(cp, sys.readch);
        cso->cpu_sysinfo.writech        = CPU_STATS(cp, sys.writech);
        cso->cpu_sysinfo.rcvint         = CPU_STATS(cp, sys.rcvint);
        cso->cpu_sysinfo.xmtint         = CPU_STATS(cp, sys.xmtint);
        cso->cpu_sysinfo.mdmint         = CPU_STATS(cp, sys.mdmint);
        cso->cpu_sysinfo.rawch          = CPU_STATS(cp, sys.rawch);
        cso->cpu_sysinfo.canch          = CPU_STATS(cp, sys.canch);
        cso->cpu_sysinfo.outch          = CPU_STATS(cp, sys.outch);
        cso->cpu_sysinfo.msg            = CPU_STATS(cp, sys.msg);
        cso->cpu_sysinfo.sema           = CPU_STATS(cp, sys.sema);
        cso->cpu_sysinfo.namei          = CPU_STATS(cp, sys.namei);
        cso->cpu_sysinfo.ufsiget        = CPU_STATS(cp, sys.ufsiget);
        cso->cpu_sysinfo.ufsdirblk      = CPU_STATS(cp, sys.ufsdirblk);
        cso->cpu_sysinfo.ufsipage       = CPU_STATS(cp, sys.ufsipage);
        cso->cpu_sysinfo.ufsinopage     = CPU_STATS(cp, sys.ufsinopage);
        cso->cpu_sysinfo.inodeovf       = 0;
        cso->cpu_sysinfo.fileovf        = 0;
        cso->cpu_sysinfo.procovf        = CPU_STATS(cp, sys.procovf);
        cso->cpu_sysinfo.intrthread     = 0;
        for (i = 0; i < LOCK_LEVEL - 1; i++)
                cso->cpu_sysinfo.intrthread += CPU_STATS(cp, sys.intr[i]);
        cso->cpu_sysinfo.intrblk        = CPU_STATS(cp, sys.intrblk);
        cso->cpu_sysinfo.idlethread     = CPU_STATS(cp, sys.idlethread);
        cso->cpu_sysinfo.inv_swtch      = CPU_STATS(cp, sys.inv_swtch);
        cso->cpu_sysinfo.nthreads       = CPU_STATS(cp, sys.nthreads);
        cso->cpu_sysinfo.cpumigrate     = CPU_STATS(cp, sys.cpumigrate);
        cso->cpu_sysinfo.xcalls         = CPU_STATS(cp, sys.xcalls);
        cso->cpu_sysinfo.mutex_adenters = CPU_STATS(cp, sys.mutex_adenters);
        cso->cpu_sysinfo.rw_rdfails     = CPU_STATS(cp, sys.rw_rdfails);
        cso->cpu_sysinfo.rw_wrfails     = CPU_STATS(cp, sys.rw_wrfails);
        cso->cpu_sysinfo.modload        = CPU_STATS(cp, sys.modload);
        cso->cpu_sysinfo.modunload      = CPU_STATS(cp, sys.modunload);
        cso->cpu_sysinfo.bawrite        = CPU_STATS(cp, sys.bawrite);
        cso->cpu_sysinfo.rw_enters      = 0;
        cso->cpu_sysinfo.win_uo_cnt     = 0;
        cso->cpu_sysinfo.win_uu_cnt     = 0;
        cso->cpu_sysinfo.win_so_cnt     = 0;
        cso->cpu_sysinfo.win_su_cnt     = 0;
        cso->cpu_sysinfo.win_suo_cnt    = 0;

        cso->cpu_syswait.iowait         = CPU_STATS(cp, sys.iowait);
        cso->cpu_syswait.swap           = 0;
        cso->cpu_syswait.physio         = 0;

        cso->cpu_vminfo.pgrec           = CPU_STATS(cp, vm.pgrec);
        cso->cpu_vminfo.pgfrec          = CPU_STATS(cp, vm.pgfrec);
        cso->cpu_vminfo.pgin            = CPU_STATS(cp, vm.pgin);
        cso->cpu_vminfo.pgpgin          = CPU_STATS(cp, vm.pgpgin);
        cso->cpu_vminfo.pgout           = CPU_STATS(cp, vm.pgout);
        cso->cpu_vminfo.pgpgout         = CPU_STATS(cp, vm.pgpgout);
        cso->cpu_vminfo.zfod            = CPU_STATS(cp, vm.zfod);
        cso->cpu_vminfo.dfree           = CPU_STATS(cp, vm.dfree);
        cso->cpu_vminfo.scan            = CPU_STATS(cp, vm.scan);
        cso->cpu_vminfo.rev             = CPU_STATS(cp, vm.rev);
        cso->cpu_vminfo.hat_fault       = CPU_STATS(cp, vm.hat_fault);
        cso->cpu_vminfo.as_fault        = CPU_STATS(cp, vm.as_fault);
        cso->cpu_vminfo.maj_fault       = CPU_STATS(cp, vm.maj_fault);
        cso->cpu_vminfo.cow_fault       = CPU_STATS(cp, vm.cow_fault);
        cso->cpu_vminfo.prot_fault      = CPU_STATS(cp, vm.prot_fault);
        cso->cpu_vminfo.softlock        = CPU_STATS(cp, vm.softlock);
        cso->cpu_vminfo.kernel_asflt    = CPU_STATS(cp, vm.kernel_asflt);
        cso->cpu_vminfo.pgrrun          = CPU_STATS(cp, vm.pgrrun);
        cso->cpu_vminfo.execpgin        = CPU_STATS(cp, vm.execpgin);
        cso->cpu_vminfo.execpgout       = CPU_STATS(cp, vm.execpgout);
        cso->cpu_vminfo.execfree        = CPU_STATS(cp, vm.execfree);
        cso->cpu_vminfo.anonpgin        = CPU_STATS(cp, vm.anonpgin);
        cso->cpu_vminfo.anonpgout       = CPU_STATS(cp, vm.anonpgout);
        cso->cpu_vminfo.anonfree        = CPU_STATS(cp, vm.anonfree);
        cso->cpu_vminfo.fspgin          = CPU_STATS(cp, vm.fspgin);
        cso->cpu_vminfo.fspgout         = CPU_STATS(cp, vm.fspgout);
        cso->cpu_vminfo.fsfree          = CPU_STATS(cp, vm.fsfree);

        return (0);
}