xref: /titanic_50/usr/src/uts/common/os/cpu.c (revision fb3fb4f3d76d55b64440afd0af72775dfad3bd1d)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 /*
30  * Architecture-independent CPU control functions.
31  */
32 
33 #include <sys/types.h>
34 #include <sys/param.h>
35 #include <sys/var.h>
36 #include <sys/thread.h>
37 #include <sys/cpuvar.h>
38 #include <sys/kstat.h>
39 #include <sys/uadmin.h>
40 #include <sys/systm.h>
41 #include <sys/errno.h>
42 #include <sys/cmn_err.h>
43 #include <sys/procset.h>
44 #include <sys/processor.h>
45 #include <sys/debug.h>
46 #include <sys/cpupart.h>
47 #include <sys/lgrp.h>
48 #include <sys/pset.h>
49 #include <sys/chip.h>
50 #include <sys/kmem.h>
51 #include <sys/kmem_impl.h>	/* to set per-cpu kmem_cache offset */
52 #include <sys/atomic.h>
53 #include <sys/callb.h>
54 #include <sys/vtrace.h>
55 #include <sys/cyclic.h>
56 #include <sys/bitmap.h>
57 #include <sys/nvpair.h>
58 #include <sys/pool_pset.h>
59 #include <sys/msacct.h>
60 #include <sys/time.h>
61 #include <sys/archsystm.h>
62 #if defined(__i386) || defined(__amd64)
63 #include <sys/x86_archext.h>
64 #endif
65 
66 extern int	mp_cpu_start(cpu_t *);
67 extern int	mp_cpu_stop(cpu_t *);
68 extern int	mp_cpu_poweron(cpu_t *);
69 extern int	mp_cpu_poweroff(cpu_t *);
70 extern int	mp_cpu_configure(int);
71 extern int	mp_cpu_unconfigure(int);
72 extern void	mp_cpu_faulted_enter(cpu_t *);
73 extern void	mp_cpu_faulted_exit(cpu_t *);
74 
75 extern int cmp_cpu_to_chip(processorid_t cpuid);
76 #ifdef __sparcv9
77 extern char *cpu_fru_fmri(cpu_t *cp);
78 #endif
79 
80 static void cpu_add_active_internal(cpu_t *cp);
81 static void cpu_remove_active(cpu_t *cp);
82 static void cpu_info_kstat_create(cpu_t *cp);
83 static void cpu_info_kstat_destroy(cpu_t *cp);
84 static void cpu_stats_kstat_create(cpu_t *cp);
85 static void cpu_stats_kstat_destroy(cpu_t *cp);
86 
87 static int cpu_sys_stats_ks_update(kstat_t *ksp, int rw);
88 static int cpu_vm_stats_ks_update(kstat_t *ksp, int rw);
89 static int cpu_stat_ks_update(kstat_t *ksp, int rw);
90 static int cpu_state_change_hooks(int, cpu_setup_t, cpu_setup_t);
91 
92 /*
93  * cpu_lock protects ncpus, ncpus_online, cpu_flag, cpu_list, cpu_active,
94  * and dispatch queue reallocations.  The lock ordering with respect to
95  * related locks is:
96  *
97  *	cpu_lock --> thread_free_lock  --->  p_lock  --->  thread_lock()
98  *
99  * Warning:  Certain sections of code do not use the cpu_lock when
100  * traversing the cpu_list (e.g. mutex_vector_enter(), clock()).  Since
101  * all cpus are paused during modifications to this list, a solution
102  * to protect the list is too either disable kernel preemption while
103  * walking the list, *or* recheck the cpu_next pointer at each
104  * iteration in the loop.  Note that in no cases can any cached
105  * copies of the cpu pointers be kept as they may become invalid.
106  */
107 kmutex_t	cpu_lock;
108 cpu_t		*cpu_list;		/* list of all CPUs */
109 cpu_t		*cpu_active;		/* list of active CPUs */
110 static cpuset_t	cpu_available;		/* set of available CPUs */
111 cpuset_t	cpu_seqid_inuse;	/* which cpu_seqids are in use */
112 
113 /*
114  * max_ncpus keeps the max cpus the system can have. Initially
115  * it's NCPU, but since most archs scan the devtree for cpus
116  * fairly early on during boot, the real max can be known before
117  * ncpus is set (useful for early NCPU based allocations).
118  */
119 int max_ncpus = NCPU;
120 /*
121  * platforms that set max_ncpus to maxiumum number of cpus that can be
122  * dynamically added will set boot_max_ncpus to the number of cpus found
123  * at device tree scan time during boot.
124  */
125 int boot_max_ncpus = -1;
126 /*
127  * Maximum possible CPU id.  This can never be >= NCPU since NCPU is
128  * used to size arrays that are indexed by CPU id.
129  */
130 processorid_t max_cpuid = NCPU - 1;
131 
132 int ncpus = 1;
133 int ncpus_online = 1;
134 
135 /*
136  * CPU that we're trying to offline.  Protected by cpu_lock.
137  */
138 cpu_t *cpu_inmotion;
139 
140 /*
141  * Can be raised to suppress further weakbinding, which are instead
142  * satisfied by disabling preemption.  Must be raised/lowered under cpu_lock,
143  * while individual thread weakbinding synchronisation is done under thread
144  * lock.
145  */
146 int weakbindingbarrier;
147 
148 /*
149  * values for safe_list.  Pause state that CPUs are in.
150  */
151 #define	PAUSE_IDLE	0		/* normal state */
152 #define	PAUSE_READY	1		/* paused thread ready to spl */
153 #define	PAUSE_WAIT	2		/* paused thread is spl-ed high */
154 #define	PAUSE_DIE	3		/* tell pause thread to leave */
155 #define	PAUSE_DEAD	4		/* pause thread has left */
156 
157 /*
158  * Variables used in pause_cpus().
159  */
160 static volatile char safe_list[NCPU];
161 
162 static struct _cpu_pause_info {
163 	int		cp_spl;		/* spl saved in pause_cpus() */
164 	volatile int	cp_go;		/* Go signal sent after all ready */
165 	int		cp_count;	/* # of CPUs to pause */
166 	ksema_t		cp_sem;		/* synch pause_cpus & cpu_pause */
167 	kthread_id_t	cp_paused;
168 } cpu_pause_info;
169 
170 static kmutex_t pause_free_mutex;
171 static kcondvar_t pause_free_cv;
172 
173 static struct cpu_sys_stats_ks_data {
174 	kstat_named_t cpu_ticks_idle;
175 	kstat_named_t cpu_ticks_user;
176 	kstat_named_t cpu_ticks_kernel;
177 	kstat_named_t cpu_ticks_wait;
178 	kstat_named_t cpu_nsec_idle;
179 	kstat_named_t cpu_nsec_user;
180 	kstat_named_t cpu_nsec_kernel;
181 	kstat_named_t wait_ticks_io;
182 	kstat_named_t bread;
183 	kstat_named_t bwrite;
184 	kstat_named_t lread;
185 	kstat_named_t lwrite;
186 	kstat_named_t phread;
187 	kstat_named_t phwrite;
188 	kstat_named_t pswitch;
189 	kstat_named_t trap;
190 	kstat_named_t intr;
191 	kstat_named_t syscall;
192 	kstat_named_t sysread;
193 	kstat_named_t syswrite;
194 	kstat_named_t sysfork;
195 	kstat_named_t sysvfork;
196 	kstat_named_t sysexec;
197 	kstat_named_t readch;
198 	kstat_named_t writech;
199 	kstat_named_t rcvint;
200 	kstat_named_t xmtint;
201 	kstat_named_t mdmint;
202 	kstat_named_t rawch;
203 	kstat_named_t canch;
204 	kstat_named_t outch;
205 	kstat_named_t msg;
206 	kstat_named_t sema;
207 	kstat_named_t namei;
208 	kstat_named_t ufsiget;
209 	kstat_named_t ufsdirblk;
210 	kstat_named_t ufsipage;
211 	kstat_named_t ufsinopage;
212 	kstat_named_t procovf;
213 	kstat_named_t intrthread;
214 	kstat_named_t intrblk;
215 	kstat_named_t intrunpin;
216 	kstat_named_t idlethread;
217 	kstat_named_t inv_swtch;
218 	kstat_named_t nthreads;
219 	kstat_named_t cpumigrate;
220 	kstat_named_t xcalls;
221 	kstat_named_t mutex_adenters;
222 	kstat_named_t rw_rdfails;
223 	kstat_named_t rw_wrfails;
224 	kstat_named_t modload;
225 	kstat_named_t modunload;
226 	kstat_named_t bawrite;
227 	kstat_named_t iowait;
228 } cpu_sys_stats_ks_data_template = {
229 	{ "cpu_ticks_idle", 	KSTAT_DATA_UINT64 },
230 	{ "cpu_ticks_user", 	KSTAT_DATA_UINT64 },
231 	{ "cpu_ticks_kernel", 	KSTAT_DATA_UINT64 },
232 	{ "cpu_ticks_wait", 	KSTAT_DATA_UINT64 },
233 	{ "cpu_nsec_idle",	KSTAT_DATA_UINT64 },
234 	{ "cpu_nsec_user",	KSTAT_DATA_UINT64 },
235 	{ "cpu_nsec_kernel",	KSTAT_DATA_UINT64 },
236 	{ "wait_ticks_io", 	KSTAT_DATA_UINT64 },
237 	{ "bread", 		KSTAT_DATA_UINT64 },
238 	{ "bwrite", 		KSTAT_DATA_UINT64 },
239 	{ "lread", 		KSTAT_DATA_UINT64 },
240 	{ "lwrite", 		KSTAT_DATA_UINT64 },
241 	{ "phread", 		KSTAT_DATA_UINT64 },
242 	{ "phwrite", 		KSTAT_DATA_UINT64 },
243 	{ "pswitch", 		KSTAT_DATA_UINT64 },
244 	{ "trap", 		KSTAT_DATA_UINT64 },
245 	{ "intr", 		KSTAT_DATA_UINT64 },
246 	{ "syscall", 		KSTAT_DATA_UINT64 },
247 	{ "sysread", 		KSTAT_DATA_UINT64 },
248 	{ "syswrite", 		KSTAT_DATA_UINT64 },
249 	{ "sysfork", 		KSTAT_DATA_UINT64 },
250 	{ "sysvfork", 		KSTAT_DATA_UINT64 },
251 	{ "sysexec", 		KSTAT_DATA_UINT64 },
252 	{ "readch", 		KSTAT_DATA_UINT64 },
253 	{ "writech", 		KSTAT_DATA_UINT64 },
254 	{ "rcvint", 		KSTAT_DATA_UINT64 },
255 	{ "xmtint", 		KSTAT_DATA_UINT64 },
256 	{ "mdmint", 		KSTAT_DATA_UINT64 },
257 	{ "rawch", 		KSTAT_DATA_UINT64 },
258 	{ "canch", 		KSTAT_DATA_UINT64 },
259 	{ "outch", 		KSTAT_DATA_UINT64 },
260 	{ "msg", 		KSTAT_DATA_UINT64 },
261 	{ "sema", 		KSTAT_DATA_UINT64 },
262 	{ "namei", 		KSTAT_DATA_UINT64 },
263 	{ "ufsiget", 		KSTAT_DATA_UINT64 },
264 	{ "ufsdirblk", 		KSTAT_DATA_UINT64 },
265 	{ "ufsipage", 		KSTAT_DATA_UINT64 },
266 	{ "ufsinopage", 	KSTAT_DATA_UINT64 },
267 	{ "procovf", 		KSTAT_DATA_UINT64 },
268 	{ "intrthread", 	KSTAT_DATA_UINT64 },
269 	{ "intrblk", 		KSTAT_DATA_UINT64 },
270 	{ "intrunpin",		KSTAT_DATA_UINT64 },
271 	{ "idlethread", 	KSTAT_DATA_UINT64 },
272 	{ "inv_swtch", 		KSTAT_DATA_UINT64 },
273 	{ "nthreads", 		KSTAT_DATA_UINT64 },
274 	{ "cpumigrate", 	KSTAT_DATA_UINT64 },
275 	{ "xcalls", 		KSTAT_DATA_UINT64 },
276 	{ "mutex_adenters", 	KSTAT_DATA_UINT64 },
277 	{ "rw_rdfails", 	KSTAT_DATA_UINT64 },
278 	{ "rw_wrfails", 	KSTAT_DATA_UINT64 },
279 	{ "modload", 		KSTAT_DATA_UINT64 },
280 	{ "modunload", 		KSTAT_DATA_UINT64 },
281 	{ "bawrite", 		KSTAT_DATA_UINT64 },
282 	{ "iowait",		KSTAT_DATA_UINT64 },
283 };
284 
285 static struct cpu_vm_stats_ks_data {
286 	kstat_named_t pgrec;
287 	kstat_named_t pgfrec;
288 	kstat_named_t pgin;
289 	kstat_named_t pgpgin;
290 	kstat_named_t pgout;
291 	kstat_named_t pgpgout;
292 	kstat_named_t swapin;
293 	kstat_named_t pgswapin;
294 	kstat_named_t swapout;
295 	kstat_named_t pgswapout;
296 	kstat_named_t zfod;
297 	kstat_named_t dfree;
298 	kstat_named_t scan;
299 	kstat_named_t rev;
300 	kstat_named_t hat_fault;
301 	kstat_named_t as_fault;
302 	kstat_named_t maj_fault;
303 	kstat_named_t cow_fault;
304 	kstat_named_t prot_fault;
305 	kstat_named_t softlock;
306 	kstat_named_t kernel_asflt;
307 	kstat_named_t pgrrun;
308 	kstat_named_t execpgin;
309 	kstat_named_t execpgout;
310 	kstat_named_t execfree;
311 	kstat_named_t anonpgin;
312 	kstat_named_t anonpgout;
313 	kstat_named_t anonfree;
314 	kstat_named_t fspgin;
315 	kstat_named_t fspgout;
316 	kstat_named_t fsfree;
317 } cpu_vm_stats_ks_data_template = {
318 	{ "pgrec",		KSTAT_DATA_UINT64 },
319 	{ "pgfrec",		KSTAT_DATA_UINT64 },
320 	{ "pgin",		KSTAT_DATA_UINT64 },
321 	{ "pgpgin",		KSTAT_DATA_UINT64 },
322 	{ "pgout",		KSTAT_DATA_UINT64 },
323 	{ "pgpgout",		KSTAT_DATA_UINT64 },
324 	{ "swapin",		KSTAT_DATA_UINT64 },
325 	{ "pgswapin",		KSTAT_DATA_UINT64 },
326 	{ "swapout",		KSTAT_DATA_UINT64 },
327 	{ "pgswapout",		KSTAT_DATA_UINT64 },
328 	{ "zfod",		KSTAT_DATA_UINT64 },
329 	{ "dfree",		KSTAT_DATA_UINT64 },
330 	{ "scan",		KSTAT_DATA_UINT64 },
331 	{ "rev",		KSTAT_DATA_UINT64 },
332 	{ "hat_fault",		KSTAT_DATA_UINT64 },
333 	{ "as_fault",		KSTAT_DATA_UINT64 },
334 	{ "maj_fault",		KSTAT_DATA_UINT64 },
335 	{ "cow_fault",		KSTAT_DATA_UINT64 },
336 	{ "prot_fault",		KSTAT_DATA_UINT64 },
337 	{ "softlock",		KSTAT_DATA_UINT64 },
338 	{ "kernel_asflt",	KSTAT_DATA_UINT64 },
339 	{ "pgrrun",		KSTAT_DATA_UINT64 },
340 	{ "execpgin",		KSTAT_DATA_UINT64 },
341 	{ "execpgout",		KSTAT_DATA_UINT64 },
342 	{ "execfree",		KSTAT_DATA_UINT64 },
343 	{ "anonpgin",		KSTAT_DATA_UINT64 },
344 	{ "anonpgout",		KSTAT_DATA_UINT64 },
345 	{ "anonfree",		KSTAT_DATA_UINT64 },
346 	{ "fspgin",		KSTAT_DATA_UINT64 },
347 	{ "fspgout",		KSTAT_DATA_UINT64 },
348 	{ "fsfree",		KSTAT_DATA_UINT64 },
349 };
350 
351 /*
352  * Force the specified thread to migrate to the appropriate processor.
353  * Called with thread lock held, returns with it dropped.
354  */
355 static void
356 force_thread_migrate(kthread_id_t tp)
357 {
358 	ASSERT(THREAD_LOCK_HELD(tp));
359 	if (tp == curthread) {
360 		THREAD_TRANSITION(tp);
361 		CL_SETRUN(tp);
362 		thread_unlock_nopreempt(tp);
363 		swtch();
364 	} else {
365 		if (tp->t_state == TS_ONPROC) {
366 			cpu_surrender(tp);
367 		} else if (tp->t_state == TS_RUN) {
368 			(void) dispdeq(tp);
369 			setbackdq(tp);
370 		}
371 		thread_unlock(tp);
372 	}
373 }
374 
375 /*
376  * Set affinity for a specified CPU.
377  * A reference count is incremented and the affinity is held until the
378  * reference count is decremented to zero by thread_affinity_clear().
379  * This is so regions of code requiring affinity can be nested.
380  * Caller needs to ensure that cpu_id remains valid, which can be
381  * done by holding cpu_lock across this call, unless the caller
382  * specifies CPU_CURRENT in which case the cpu_lock will be acquired
383  * by thread_affinity_set and CPU->cpu_id will be the target CPU.
384  */
385 void
386 thread_affinity_set(kthread_id_t t, int cpu_id)
387 {
388 	cpu_t		*cp;
389 	int		c;
390 
391 	ASSERT(!(t == curthread && t->t_weakbound_cpu != NULL));
392 
393 	if ((c = cpu_id) == CPU_CURRENT) {
394 		mutex_enter(&cpu_lock);
395 		cpu_id = CPU->cpu_id;
396 	}
397 	/*
398 	 * We should be asserting that cpu_lock is held here, but
399 	 * the NCA code doesn't acquire it.  The following assert
400 	 * should be uncommented when the NCA code is fixed.
401 	 *
402 	 * ASSERT(MUTEX_HELD(&cpu_lock));
403 	 */
404 	ASSERT((cpu_id >= 0) && (cpu_id < NCPU));
405 	cp = cpu[cpu_id];
406 	ASSERT(cp != NULL);		/* user must provide a good cpu_id */
407 	/*
408 	 * If there is already a hard affinity requested, and this affinity
409 	 * conflicts with that, panic.
410 	 */
411 	thread_lock(t);
412 	if (t->t_affinitycnt > 0 && t->t_bound_cpu != cp) {
413 		panic("affinity_set: setting %p but already bound to %p",
414 		    (void *)cp, (void *)t->t_bound_cpu);
415 	}
416 	t->t_affinitycnt++;
417 	t->t_bound_cpu = cp;
418 
419 	/*
420 	 * Make sure we're running on the right CPU.
421 	 */
422 	if (cp != t->t_cpu || t != curthread) {
423 		force_thread_migrate(t);	/* drops thread lock */
424 	} else {
425 		thread_unlock(t);
426 	}
427 
428 	if (c == CPU_CURRENT)
429 		mutex_exit(&cpu_lock);
430 }
431 
432 /*
433  *	Wrapper for backward compatibility.
434  */
435 void
436 affinity_set(int cpu_id)
437 {
438 	thread_affinity_set(curthread, cpu_id);
439 }
440 
441 /*
442  * Decrement the affinity reservation count and if it becomes zero,
443  * clear the CPU affinity for the current thread, or set it to the user's
444  * software binding request.
445  */
446 void
447 thread_affinity_clear(kthread_id_t t)
448 {
449 	register processorid_t binding;
450 
451 	thread_lock(t);
452 	if (--t->t_affinitycnt == 0) {
453 		if ((binding = t->t_bind_cpu) == PBIND_NONE) {
454 			/*
455 			 * Adjust disp_max_unbound_pri if necessary.
456 			 */
457 			disp_adjust_unbound_pri(t);
458 			t->t_bound_cpu = NULL;
459 			if (t->t_cpu->cpu_part != t->t_cpupart) {
460 				force_thread_migrate(t);
461 				return;
462 			}
463 		} else {
464 			t->t_bound_cpu = cpu[binding];
465 			/*
466 			 * Make sure the thread is running on the bound CPU.
467 			 */
468 			if (t->t_cpu != t->t_bound_cpu) {
469 				force_thread_migrate(t);
470 				return;		/* already dropped lock */
471 			}
472 		}
473 	}
474 	thread_unlock(t);
475 }
476 
477 /*
478  * Wrapper for backward compatibility.
479  */
480 void
481 affinity_clear(void)
482 {
483 	thread_affinity_clear(curthread);
484 }
485 
486 /*
487  * Weak cpu affinity.  Bind to the "current" cpu for short periods
488  * of time during which the thread must not block (but may be preempted).
489  * Use this instead of kpreempt_disable() when it is only "no migration"
490  * rather than "no preemption" semantics that are required - disabling
491  * preemption holds higher priority threads off of cpu and if the
492  * operation that is protected is more than momentary this is not good
493  * for realtime etc.
494  *
495  * Weakly bound threads will not prevent a cpu from being offlined -
496  * we'll only run them on the cpu to which they are weakly bound but
497  * (because they do not block) we'll always be able to move them on to
498  * another cpu at offline time if we give them just a short moment to
499  * run during which they will unbind.  To give a cpu a chance of offlining,
500  * however, we require a barrier to weak bindings that may be raised for a
501  * given cpu (offline/move code may set this and then wait a short time for
502  * existing weak bindings to drop); the cpu_inmotion pointer is that barrier.
503  *
504  * There are few restrictions on the calling context of thread_nomigrate.
505  * The caller must not hold the thread lock.  Calls may be nested.
506  *
507  * After weakbinding a thread must not perform actions that may block.
508  * In particular it must not call thread_affinity_set; calling that when
509  * already weakbound is nonsensical anyway.
510  *
511  * If curthread is prevented from migrating for other reasons
512  * (kernel preemption disabled; high pil; strongly bound; interrupt thread)
513  * then the weak binding will succeed even if this cpu is the target of an
514  * offline/move request.
515  */
516 void
517 thread_nomigrate(void)
518 {
519 	cpu_t *cp;
520 	kthread_id_t t = curthread;
521 
522 again:
523 	kpreempt_disable();
524 	cp = CPU;
525 
526 	/*
527 	 * A highlevel interrupt must not modify t_nomigrate or
528 	 * t_weakbound_cpu of the thread it has interrupted.  A lowlevel
529 	 * interrupt thread cannot migrate and we can avoid the
530 	 * thread_lock call below by short-circuiting here.  In either
531 	 * case we can just return since no migration is possible and
532 	 * the condition will persist (ie, when we test for these again
533 	 * in thread_allowmigrate they can't have changed).   Migration
534 	 * is also impossible if we're at or above DISP_LEVEL pil.
535 	 */
536 	if (CPU_ON_INTR(cp) || t->t_flag & T_INTR_THREAD ||
537 	    getpil() >= DISP_LEVEL) {
538 		kpreempt_enable();
539 		return;
540 	}
541 
542 	/*
543 	 * We must be consistent with existing weak bindings.  Since we
544 	 * may be interrupted between the increment of t_nomigrate and
545 	 * the store to t_weakbound_cpu below we cannot assume that
546 	 * t_weakbound_cpu will be set if t_nomigrate is.  Note that we
547 	 * cannot assert t_weakbound_cpu == t_bind_cpu since that is not
548 	 * always the case.
549 	 */
550 	if (t->t_nomigrate && t->t_weakbound_cpu && t->t_weakbound_cpu != cp) {
551 		if (!panicstr)
552 			panic("thread_nomigrate: binding to %p but already "
553 			    "bound to %p", (void *)cp,
554 			    (void *)t->t_weakbound_cpu);
555 	}
556 
557 	/*
558 	 * At this point we have preemption disabled and we don't yet hold
559 	 * the thread lock.  So it's possible that somebody else could
560 	 * set t_bind_cpu here and not be able to force us across to the
561 	 * new cpu (since we have preemption disabled).
562 	 */
563 	thread_lock(curthread);
564 
565 	/*
566 	 * If further weak bindings are being (temporarily) suppressed then
567 	 * we'll settle for disabling kernel preemption (which assures
568 	 * no migration provided the thread does not block which it is
569 	 * not allowed to if using thread_nomigrate).  We must remember
570 	 * this disposition so we can take appropriate action in
571 	 * thread_allowmigrate.  If this is a nested call and the
572 	 * thread is already weakbound then fall through as normal.
573 	 * We remember the decision to settle for kpreempt_disable through
574 	 * negative nesting counting in t_nomigrate.  Once a thread has had one
575 	 * weakbinding request satisfied in this way any further (nested)
576 	 * requests will continue to be satisfied in the same way,
577 	 * even if weak bindings have recommenced.
578 	 */
579 	if (t->t_nomigrate < 0 || weakbindingbarrier && t->t_nomigrate == 0) {
580 		--t->t_nomigrate;
581 		thread_unlock(curthread);
582 		return;		/* with kpreempt_disable still active */
583 	}
584 
585 	/*
586 	 * We hold thread_lock so t_bind_cpu cannot change.  We could,
587 	 * however, be running on a different cpu to which we are t_bound_cpu
588 	 * to (as explained above).  If we grant the weak binding request
589 	 * in that case then the dispatcher must favour our weak binding
590 	 * over our strong (in which case, just as when preemption is
591 	 * disabled, we can continue to run on a cpu other than the one to
592 	 * which we are strongbound; the difference in this case is that
593 	 * this thread can be preempted and so can appear on the dispatch
594 	 * queues of a cpu other than the one it is strongbound to).
595 	 *
596 	 * If the cpu we are running on does not appear to be a current
597 	 * offline target (we check cpu_inmotion to determine this - since
598 	 * we don't hold cpu_lock we may not see a recent store to that,
599 	 * so it's possible that we at times can grant a weak binding to a
600 	 * cpu that is an offline target, but that one request will not
601 	 * prevent the offline from succeeding) then we will always grant
602 	 * the weak binding request.  This includes the case above where
603 	 * we grant a weakbinding not commensurate with our strong binding.
604 	 *
605 	 * If our cpu does appear to be an offline target then we're inclined
606 	 * not to grant the weakbinding request just yet - we'd prefer to
607 	 * migrate to another cpu and grant the request there.  The
608 	 * exceptions are those cases where going through preemption code
609 	 * will not result in us changing cpu:
610 	 *
611 	 *	. interrupts have already bypassed this case (see above)
612 	 *	. we are already weakbound to this cpu (dispatcher code will
613 	 *	  always return us to the weakbound cpu)
614 	 *	. preemption was disabled even before we disabled it above
615 	 *	. we are strongbound to this cpu (if we're strongbound to
616 	 *	another and not yet running there the trip through the
617 	 *	dispatcher will move us to the strongbound cpu and we
618 	 *	will grant the weak binding there)
619 	 */
620 	if (cp != cpu_inmotion || t->t_nomigrate > 0 || t->t_preempt > 1 ||
621 	    t->t_bound_cpu == cp) {
622 		/*
623 		 * Don't be tempted to store to t_weakbound_cpu only on
624 		 * the first nested bind request - if we're interrupted
625 		 * after the increment of t_nomigrate and before the
626 		 * store to t_weakbound_cpu and the interrupt calls
627 		 * thread_nomigrate then the assertion in thread_allowmigrate
628 		 * would fail.
629 		 */
630 		t->t_nomigrate++;
631 		t->t_weakbound_cpu = cp;
632 		membar_producer();
633 		thread_unlock(curthread);
634 		/*
635 		 * Now that we have dropped the thread_lock another thread
636 		 * can set our t_weakbound_cpu, and will try to migrate us
637 		 * to the strongbound cpu (which will not be prevented by
638 		 * preemption being disabled since we're about to enable
639 		 * preemption).  We have granted the weakbinding to the current
640 		 * cpu, so again we are in the position that is is is possible
641 		 * that our weak and strong bindings differ.  Again this
642 		 * is catered for by dispatcher code which will favour our
643 		 * weak binding.
644 		 */
645 		kpreempt_enable();
646 	} else {
647 		/*
648 		 * Move to another cpu before granting the request by
649 		 * forcing this thread through preemption code.  When we
650 		 * get to set{front,back}dq called from CL_PREEMPT()
651 		 * cpu_choose() will be used to select a cpu to queue
652 		 * us on - that will see cpu_inmotion and take
653 		 * steps to avoid returning us to this cpu.
654 		 */
655 		cp->cpu_kprunrun = 1;
656 		thread_unlock(curthread);
657 		kpreempt_enable();	/* will call preempt() */
658 		goto again;
659 	}
660 }
661 
662 void
663 thread_allowmigrate(void)
664 {
665 	kthread_id_t t = curthread;
666 
667 	ASSERT(t->t_weakbound_cpu == CPU ||
668 	    (t->t_nomigrate < 0 && t->t_preempt > 0) ||
669 	    CPU_ON_INTR(CPU) || t->t_flag & T_INTR_THREAD ||
670 	    getpil() >= DISP_LEVEL);
671 
672 	if (CPU_ON_INTR(CPU) || (t->t_flag & T_INTR_THREAD) ||
673 	    getpil() >= DISP_LEVEL)
674 		return;
675 
676 	if (t->t_nomigrate < 0) {
677 		/*
678 		 * This thread was granted "weak binding" in the
679 		 * stronger form of kernel preemption disabling.
680 		 * Undo a level of nesting for both t_nomigrate
681 		 * and t_preempt.
682 		 */
683 		++t->t_nomigrate;
684 		kpreempt_enable();
685 	} else if (--t->t_nomigrate == 0) {
686 		/*
687 		 * Time to drop the weak binding.  We need to cater
688 		 * for the case where we're weakbound to a different
689 		 * cpu than that to which we're strongbound (a very
690 		 * temporary arrangement that must only persist until
691 		 * weak binding drops).  We don't acquire thread_lock
692 		 * here so even as this code executes t_bound_cpu
693 		 * may be changing.  So we disable preemption and
694 		 * a) in the case that t_bound_cpu changes while we
695 		 * have preemption disabled kprunrun will be set
696 		 * asynchronously, and b) if before disabling
697 		 * preemption we were already on a different cpu to
698 		 * our t_bound_cpu then we set kprunrun ourselves
699 		 * to force a trip through the dispatcher when
700 		 * preemption is enabled.
701 		 */
702 		kpreempt_disable();
703 		if (t->t_bound_cpu &&
704 		    t->t_weakbound_cpu != t->t_bound_cpu)
705 			CPU->cpu_kprunrun = 1;
706 		t->t_weakbound_cpu = NULL;
707 		membar_producer();
708 		kpreempt_enable();
709 	}
710 }
711 
712 /*
713  * weakbinding_stop can be used to temporarily cause weakbindings made
714  * with thread_nomigrate to be satisfied through the stronger action of
715  * kpreempt_disable.  weakbinding_start recommences normal weakbinding.
716  */
717 
718 void
719 weakbinding_stop(void)
720 {
721 	ASSERT(MUTEX_HELD(&cpu_lock));
722 	weakbindingbarrier = 1;
723 	membar_producer();	/* make visible before subsequent thread_lock */
724 }
725 
726 void
727 weakbinding_start(void)
728 {
729 	ASSERT(MUTEX_HELD(&cpu_lock));
730 	weakbindingbarrier = 0;
731 }
732 
733 /*
734  * This routine is called to place the CPUs in a safe place so that
735  * one of them can be taken off line or placed on line.  What we are
736  * trying to do here is prevent a thread from traversing the list
737  * of active CPUs while we are changing it or from getting placed on
738  * the run queue of a CPU that has just gone off line.  We do this by
739  * creating a thread with the highest possible prio for each CPU and
740  * having it call this routine.  The advantage of this method is that
741  * we can eliminate all checks for CPU_ACTIVE in the disp routines.
742  * This makes disp faster at the expense of making p_online() slower
743  * which is a good trade off.
744  */
745 static void
746 cpu_pause(volatile char *safe)
747 {
748 	int s;
749 	struct _cpu_pause_info *cpi = &cpu_pause_info;
750 
751 	ASSERT((curthread->t_bound_cpu != NULL) || (*safe == PAUSE_DIE));
752 
753 	while (*safe != PAUSE_DIE) {
754 		*safe = PAUSE_READY;
755 		membar_enter();		/* make sure stores are flushed */
756 		sema_v(&cpi->cp_sem);	/* signal requesting thread */
757 
758 		/*
759 		 * Wait here until all pause threads are running.  That
760 		 * indicates that it's safe to do the spl.  Until
761 		 * cpu_pause_info.cp_go is set, we don't want to spl
762 		 * because that might block clock interrupts needed
763 		 * to preempt threads on other CPUs.
764 		 */
765 		while (cpi->cp_go == 0)
766 			;
767 		/*
768 		 * Even though we are at the highest disp prio, we need
769 		 * to block out all interrupts below LOCK_LEVEL so that
770 		 * an intr doesn't come in, wake up a thread, and call
771 		 * setbackdq/setfrontdq.
772 		 */
773 		s = splhigh();
774 		/*
775 		 * This cpu is now safe.
776 		 */
777 		*safe = PAUSE_WAIT;
778 		membar_enter();		/* make sure stores are flushed */
779 
780 		/*
781 		 * Now we wait.  When we are allowed to continue, safe will
782 		 * be set to PAUSE_IDLE.
783 		 */
784 		while (*safe != PAUSE_IDLE)
785 			;
786 
787 		splx(s);
788 		/*
789 		 * Waiting is at an end. Switch out of cpu_pause
790 		 * loop and resume useful work.
791 		 */
792 		swtch();
793 	}
794 
795 	mutex_enter(&pause_free_mutex);
796 	*safe = PAUSE_DEAD;
797 	cv_broadcast(&pause_free_cv);
798 	mutex_exit(&pause_free_mutex);
799 }
800 
801 /*
802  * Allow the cpus to start running again.
803  */
804 void
805 start_cpus()
806 {
807 	int i;
808 
809 	ASSERT(MUTEX_HELD(&cpu_lock));
810 	ASSERT(cpu_pause_info.cp_paused);
811 	cpu_pause_info.cp_paused = NULL;
812 	for (i = 0; i < NCPU; i++)
813 		safe_list[i] = PAUSE_IDLE;
814 	membar_enter();			/* make sure stores are flushed */
815 	affinity_clear();
816 	splx(cpu_pause_info.cp_spl);
817 	kpreempt_enable();
818 }
819 
820 /*
821  * Allocate a pause thread for a CPU.
822  */
823 static void
824 cpu_pause_alloc(cpu_t *cp)
825 {
826 	kthread_id_t	t;
827 	int		cpun = cp->cpu_id;
828 
829 	/*
830 	 * Note, v.v_nglobpris will not change value as long as I hold
831 	 * cpu_lock.
832 	 */
833 	t = thread_create(NULL, 0, cpu_pause, (caddr_t)&safe_list[cpun],
834 	    0, &p0, TS_STOPPED, v.v_nglobpris - 1);
835 	thread_lock(t);
836 	t->t_bound_cpu = cp;
837 	t->t_disp_queue = cp->cpu_disp;
838 	t->t_affinitycnt = 1;
839 	t->t_preempt = 1;
840 	thread_unlock(t);
841 	cp->cpu_pause_thread = t;
842 	/*
843 	 * Registering a thread in the callback table is usually done
844 	 * in the initialization code of the thread.  In this
845 	 * case, we do it right after thread creation because the
846 	 * thread itself may never run, and we need to register the
847 	 * fact that it is safe for cpr suspend.
848 	 */
849 	CALLB_CPR_INIT_SAFE(t, "cpu_pause");
850 }
851 
852 /*
853  * Free a pause thread for a CPU.
854  */
855 static void
856 cpu_pause_free(cpu_t *cp)
857 {
858 	kthread_id_t	t;
859 	int		cpun = cp->cpu_id;
860 
861 	ASSERT(MUTEX_HELD(&cpu_lock));
862 	/*
863 	 * We have to get the thread and tell him to die.
864 	 */
865 	if ((t = cp->cpu_pause_thread) == NULL) {
866 		ASSERT(safe_list[cpun] == PAUSE_IDLE);
867 		return;
868 	}
869 	thread_lock(t);
870 	t->t_cpu = CPU;		/* disp gets upset if last cpu is quiesced. */
871 	t->t_bound_cpu = NULL;	/* Must un-bind; cpu may not be running. */
872 	t->t_pri = v.v_nglobpris - 1;
873 	ASSERT(safe_list[cpun] == PAUSE_IDLE);
874 	safe_list[cpun] = PAUSE_DIE;
875 	THREAD_TRANSITION(t);
876 	setbackdq(t);
877 	thread_unlock_nopreempt(t);
878 
879 	/*
880 	 * If we don't wait for the thread to actually die, it may try to
881 	 * run on the wrong cpu as part of an actual call to pause_cpus().
882 	 */
883 	mutex_enter(&pause_free_mutex);
884 	while (safe_list[cpun] != PAUSE_DEAD) {
885 		cv_wait(&pause_free_cv, &pause_free_mutex);
886 	}
887 	mutex_exit(&pause_free_mutex);
888 	safe_list[cpun] = PAUSE_IDLE;
889 
890 	cp->cpu_pause_thread = NULL;
891 }
892 
893 /*
894  * Initialize basic structures for pausing CPUs.
895  */
896 void
897 cpu_pause_init()
898 {
899 	sema_init(&cpu_pause_info.cp_sem, 0, NULL, SEMA_DEFAULT, NULL);
900 	/*
901 	 * Create initial CPU pause thread.
902 	 */
903 	cpu_pause_alloc(CPU);
904 }
905 
906 /*
907  * Start the threads used to pause another CPU.
908  */
909 static int
910 cpu_pause_start(processorid_t cpu_id)
911 {
912 	int	i;
913 	int	cpu_count = 0;
914 
915 	for (i = 0; i < NCPU; i++) {
916 		cpu_t		*cp;
917 		kthread_id_t	t;
918 
919 		cp = cpu[i];
920 		if (!CPU_IN_SET(cpu_available, i) || (i == cpu_id)) {
921 			safe_list[i] = PAUSE_WAIT;
922 			continue;
923 		}
924 
925 		/*
926 		 * Skip CPU if it is quiesced or not yet started.
927 		 */
928 		if ((cp->cpu_flags & (CPU_QUIESCED | CPU_READY)) != CPU_READY) {
929 			safe_list[i] = PAUSE_WAIT;
930 			continue;
931 		}
932 
933 		/*
934 		 * Start this CPU's pause thread.
935 		 */
936 		t = cp->cpu_pause_thread;
937 		thread_lock(t);
938 		/*
939 		 * Reset the priority, since nglobpris may have
940 		 * changed since the thread was created, if someone
941 		 * has loaded the RT (or some other) scheduling
942 		 * class.
943 		 */
944 		t->t_pri = v.v_nglobpris - 1;
945 		THREAD_TRANSITION(t);
946 		setbackdq(t);
947 		thread_unlock_nopreempt(t);
948 		++cpu_count;
949 	}
950 	return (cpu_count);
951 }
952 
953 
954 /*
955  * Pause all of the CPUs except the one we are on by creating a high
956  * priority thread bound to those CPUs.
957  *
958  * Note that one must be extremely careful regarding code
959  * executed while CPUs are paused.  Since a CPU may be paused
960  * while a thread scheduling on that CPU is holding an adaptive
961  * lock, code executed with CPUs paused must not acquire adaptive
962  * (or low-level spin) locks.  Also, such code must not block,
963  * since the thread that is supposed to initiate the wakeup may
964  * never run.
965  *
966  * With a few exceptions, the restrictions on code executed with CPUs
967  * paused match those for code executed at high-level interrupt
968  * context.
969  */
970 void
971 pause_cpus(cpu_t *off_cp)
972 {
973 	processorid_t	cpu_id;
974 	int		i;
975 	struct _cpu_pause_info	*cpi = &cpu_pause_info;
976 
977 	ASSERT(MUTEX_HELD(&cpu_lock));
978 	ASSERT(cpi->cp_paused == NULL);
979 	cpi->cp_count = 0;
980 	cpi->cp_go = 0;
981 	for (i = 0; i < NCPU; i++)
982 		safe_list[i] = PAUSE_IDLE;
983 	kpreempt_disable();
984 
985 	/*
986 	 * If running on the cpu that is going offline, get off it.
987 	 * This is so that it won't be necessary to rechoose a CPU
988 	 * when done.
989 	 */
990 	if (CPU == off_cp)
991 		cpu_id = off_cp->cpu_next_part->cpu_id;
992 	else
993 		cpu_id = CPU->cpu_id;
994 	affinity_set(cpu_id);
995 
996 	/*
997 	 * Start the pause threads and record how many were started
998 	 */
999 	cpi->cp_count = cpu_pause_start(cpu_id);
1000 
1001 	/*
1002 	 * Now wait for all CPUs to be running the pause thread.
1003 	 */
1004 	while (cpi->cp_count > 0) {
1005 		/*
1006 		 * Spin reading the count without grabbing the disp
1007 		 * lock to make sure we don't prevent the pause
1008 		 * threads from getting the lock.
1009 		 */
1010 		while (sema_held(&cpi->cp_sem))
1011 			;
1012 		if (sema_tryp(&cpi->cp_sem))
1013 			--cpi->cp_count;
1014 	}
1015 	cpi->cp_go = 1;			/* all have reached cpu_pause */
1016 
1017 	/*
1018 	 * Now wait for all CPUs to spl. (Transition from PAUSE_READY
1019 	 * to PAUSE_WAIT.)
1020 	 */
1021 	for (i = 0; i < NCPU; i++) {
1022 		while (safe_list[i] != PAUSE_WAIT)
1023 			;
1024 	}
1025 	cpi->cp_spl = splhigh();	/* block dispatcher on this CPU */
1026 	cpi->cp_paused = curthread;
1027 }
1028 
1029 /*
1030  * Check whether the current thread has CPUs paused
1031  */
1032 int
1033 cpus_paused(void)
1034 {
1035 	if (cpu_pause_info.cp_paused != NULL) {
1036 		ASSERT(cpu_pause_info.cp_paused == curthread);
1037 		return (1);
1038 	}
1039 	return (0);
1040 }
1041 
1042 static cpu_t *
1043 cpu_get_all(processorid_t cpun)
1044 {
1045 	ASSERT(MUTEX_HELD(&cpu_lock));
1046 
1047 	if (cpun >= NCPU || cpun < 0 || !CPU_IN_SET(cpu_available, cpun))
1048 		return (NULL);
1049 	return (cpu[cpun]);
1050 }
1051 
1052 /*
1053  * Check whether cpun is a valid processor id and whether it should be
1054  * visible from the current zone. If it is, return a pointer to the
1055  * associated CPU structure.
1056  */
1057 cpu_t *
1058 cpu_get(processorid_t cpun)
1059 {
1060 	cpu_t *c;
1061 
1062 	ASSERT(MUTEX_HELD(&cpu_lock));
1063 	c = cpu_get_all(cpun);
1064 	if (c != NULL && !INGLOBALZONE(curproc) && pool_pset_enabled() &&
1065 	    zone_pset_get(curproc->p_zone) != cpupart_query_cpu(c))
1066 		return (NULL);
1067 	return (c);
1068 }
1069 
1070 /*
1071  * The following functions should be used to check CPU states in the kernel.
1072  * They should be invoked with cpu_lock held.  Kernel subsystems interested
1073  * in CPU states should *not* use cpu_get_state() and various P_ONLINE/etc
1074  * states.  Those are for user-land (and system call) use only.
1075  */
1076 
1077 /*
1078  * Determine whether the CPU is online and handling interrupts.
1079  */
1080 int
1081 cpu_is_online(cpu_t *cpu)
1082 {
1083 	ASSERT(MUTEX_HELD(&cpu_lock));
1084 	return (cpu_flagged_online(cpu->cpu_flags));
1085 }
1086 
1087 /*
1088  * Determine whether the CPU is offline (this includes spare and faulted).
1089  */
1090 int
1091 cpu_is_offline(cpu_t *cpu)
1092 {
1093 	ASSERT(MUTEX_HELD(&cpu_lock));
1094 	return (cpu_flagged_offline(cpu->cpu_flags));
1095 }
1096 
1097 /*
1098  * Determine whether the CPU is powered off.
1099  */
1100 int
1101 cpu_is_poweredoff(cpu_t *cpu)
1102 {
1103 	ASSERT(MUTEX_HELD(&cpu_lock));
1104 	return (cpu_flagged_poweredoff(cpu->cpu_flags));
1105 }
1106 
1107 /*
1108  * Determine whether the CPU is handling interrupts.
1109  */
1110 int
1111 cpu_is_nointr(cpu_t *cpu)
1112 {
1113 	ASSERT(MUTEX_HELD(&cpu_lock));
1114 	return (cpu_flagged_nointr(cpu->cpu_flags));
1115 }
1116 
1117 /*
1118  * Determine whether the CPU is active (scheduling threads).
1119  */
1120 int
1121 cpu_is_active(cpu_t *cpu)
1122 {
1123 	ASSERT(MUTEX_HELD(&cpu_lock));
1124 	return (cpu_flagged_active(cpu->cpu_flags));
1125 }
1126 
1127 /*
1128  * Same as above, but these require cpu_flags instead of cpu_t pointers.
1129  */
1130 int
1131 cpu_flagged_online(cpu_flag_t cpu_flags)
1132 {
1133 	return (cpu_flagged_active(cpu_flags) &&
1134 	    (cpu_flags & CPU_ENABLE));
1135 }
1136 
1137 int
1138 cpu_flagged_offline(cpu_flag_t cpu_flags)
1139 {
1140 	return (((cpu_flags & CPU_POWEROFF) == 0) &&
1141 	    ((cpu_flags & (CPU_READY | CPU_OFFLINE)) != CPU_READY));
1142 }
1143 
1144 int
1145 cpu_flagged_poweredoff(cpu_flag_t cpu_flags)
1146 {
1147 	return ((cpu_flags & CPU_POWEROFF) == CPU_POWEROFF);
1148 }
1149 
1150 int
1151 cpu_flagged_nointr(cpu_flag_t cpu_flags)
1152 {
1153 	return (cpu_flagged_active(cpu_flags) &&
1154 	    (cpu_flags & CPU_ENABLE) == 0);
1155 }
1156 
1157 int
1158 cpu_flagged_active(cpu_flag_t cpu_flags)
1159 {
1160 	return (((cpu_flags & (CPU_POWEROFF | CPU_FAULTED | CPU_SPARE)) == 0) &&
1161 	    ((cpu_flags & (CPU_READY | CPU_OFFLINE)) == CPU_READY));
1162 }
1163 
1164 /*
1165  * Bring the indicated CPU online.
1166  */
1167 int
1168 cpu_online(cpu_t *cp)
1169 {
1170 	int	error = 0;
1171 
1172 	/*
1173 	 * Handle on-line request.
1174 	 *	This code must put the new CPU on the active list before
1175 	 *	starting it because it will not be paused, and will start
1176 	 * 	using the active list immediately.  The real start occurs
1177 	 *	when the CPU_QUIESCED flag is turned off.
1178 	 */
1179 
1180 	ASSERT(MUTEX_HELD(&cpu_lock));
1181 
1182 	/*
1183 	 * Put all the cpus into a known safe place.
1184 	 * No mutexes can be entered while CPUs are paused.
1185 	 */
1186 	error = mp_cpu_start(cp);	/* arch-dep hook */
1187 	if (error == 0) {
1188 		pause_cpus(NULL);
1189 		cpu_add_active_internal(cp);
1190 		if (cp->cpu_flags & CPU_FAULTED) {
1191 			cp->cpu_flags &= ~CPU_FAULTED;
1192 			mp_cpu_faulted_exit(cp);
1193 		}
1194 		cp->cpu_flags &= ~(CPU_QUIESCED | CPU_OFFLINE | CPU_FROZEN |
1195 		    CPU_SPARE);
1196 		start_cpus();
1197 		cpu_stats_kstat_create(cp);
1198 		cpu_create_intrstat(cp);
1199 		lgrp_kstat_create(cp);
1200 		cpu_state_change_notify(cp->cpu_id, CPU_ON);
1201 		cpu_intr_enable(cp);	/* arch-dep hook */
1202 		cyclic_online(cp);
1203 		poke_cpu(cp->cpu_id);
1204 	}
1205 
1206 	return (error);
1207 }
1208 
1209 /*
1210  * Take the indicated CPU offline.
1211  */
1212 int
1213 cpu_offline(cpu_t *cp, int flags)
1214 {
1215 	cpupart_t *pp;
1216 	int	error = 0;
1217 	cpu_t	*ncp;
1218 	int	intr_enable;
1219 	int	cyclic_off = 0;
1220 	int	loop_count;
1221 	int	no_quiesce = 0;
1222 	int	(*bound_func)(struct cpu *, int);
1223 	kthread_t *t;
1224 	lpl_t	*cpu_lpl;
1225 	proc_t	*p;
1226 	int	lgrp_diff_lpl;
1227 
1228 	ASSERT(MUTEX_HELD(&cpu_lock));
1229 
1230 	/*
1231 	 * If we're going from faulted or spare to offline, just
1232 	 * clear these flags and update CPU state.
1233 	 */
1234 	if (cp->cpu_flags & (CPU_FAULTED | CPU_SPARE)) {
1235 		if (cp->cpu_flags & CPU_FAULTED) {
1236 			cp->cpu_flags &= ~CPU_FAULTED;
1237 			mp_cpu_faulted_exit(cp);
1238 		}
1239 		cp->cpu_flags &= ~CPU_SPARE;
1240 		cpu_set_state(cp);
1241 		return (0);
1242 	}
1243 
1244 	/*
1245 	 * Handle off-line request.
1246 	 */
1247 	pp = cp->cpu_part;
1248 	/*
1249 	 * Don't offline last online CPU in partition
1250 	 */
1251 	if (ncpus_online <= 1 || pp->cp_ncpus <= 1 || cpu_intr_count(cp) < 2)
1252 		return (EBUSY);
1253 	/*
1254 	 * Unbind all thread bound to our CPU if we were asked to.
1255 	 */
1256 	if (flags & CPU_FORCED && (error = cpu_unbind(cp->cpu_id)) != 0)
1257 		return (error);
1258 	/*
1259 	 * We shouldn't be bound to this CPU ourselves.
1260 	 */
1261 	if (curthread->t_bound_cpu == cp)
1262 		return (EBUSY);
1263 
1264 	/*
1265 	 * Tell interested parties that this CPU is going offline.
1266 	 */
1267 	cpu_state_change_notify(cp->cpu_id, CPU_OFF);
1268 
1269 	/*
1270 	 * Take the CPU out of interrupt participation so we won't find
1271 	 * bound kernel threads.  If the architecture cannot completely
1272 	 * shut off interrupts on the CPU, don't quiesce it, but don't
1273 	 * run anything but interrupt thread... this is indicated by
1274 	 * the CPU_OFFLINE flag being on but the CPU_QUIESCE flag being
1275 	 * off.
1276 	 */
1277 	intr_enable = cp->cpu_flags & CPU_ENABLE;
1278 	if (intr_enable)
1279 		no_quiesce = cpu_intr_disable(cp);
1280 
1281 	/*
1282 	 * Record that we are aiming to offline this cpu.  This acts as
1283 	 * a barrier to further weak binding requests in thread_nomigrate
1284 	 * and also causes cpu_choose, disp_lowpri_cpu and setfrontdq to
1285 	 * lean away from this cpu.  Further strong bindings are already
1286 	 * avoided since we hold cpu_lock.  Since threads that are set
1287 	 * runnable around now and others coming off the target cpu are
1288 	 * directed away from the target, existing strong and weak bindings
1289 	 * (especially the latter) to the target cpu stand maximum chance of
1290 	 * being able to unbind during the short delay loop below (if other
1291 	 * unbound threads compete they may not see cpu in time to unbind
1292 	 * even if they would do so immediately.
1293 	 */
1294 	cpu_inmotion = cp;
1295 	membar_enter();
1296 
1297 	/*
1298 	 * Check for kernel threads (strong or weak) bound to that CPU.
1299 	 * Strongly bound threads may not unbind, and we'll have to return
1300 	 * EBUSY.  Weakly bound threads should always disappear - we've
1301 	 * stopped more weak binding with cpu_inmotion and existing
1302 	 * bindings will drain imminently (they may not block).  Nonetheless
1303 	 * we will wait for a fixed period for all bound threads to disappear.
1304 	 * Inactive interrupt threads are OK (they'll be in TS_FREE
1305 	 * state).  If test finds some bound threads, wait a few ticks
1306 	 * to give short-lived threads (such as interrupts) chance to
1307 	 * complete.  Note that if no_quiesce is set, i.e. this cpu
1308 	 * is required to service interrupts, then we take the route
1309 	 * that permits interrupt threads to be active (or bypassed).
1310 	 */
1311 	bound_func = no_quiesce ? disp_bound_threads : disp_bound_anythreads;
1312 
1313 again:	for (loop_count = 0; (*bound_func)(cp, 0); loop_count++) {
1314 		if (loop_count >= 5) {
1315 			error = EBUSY;	/* some threads still bound */
1316 			break;
1317 		}
1318 
1319 		/*
1320 		 * If some threads were assigned, give them
1321 		 * a chance to complete or move.
1322 		 *
1323 		 * This assumes that the clock_thread is not bound
1324 		 * to any CPU, because the clock_thread is needed to
1325 		 * do the delay(hz/100).
1326 		 *
1327 		 * Note: we still hold the cpu_lock while waiting for
1328 		 * the next clock tick.  This is OK since it isn't
1329 		 * needed for anything else except processor_bind(2),
1330 		 * and system initialization.  If we drop the lock,
1331 		 * we would risk another p_online disabling the last
1332 		 * processor.
1333 		 */
1334 		delay(hz/100);
1335 	}
1336 
1337 	if (error == 0 && cyclic_off == 0) {
1338 		if (!cyclic_offline(cp)) {
1339 			/*
1340 			 * We must have bound cyclics...
1341 			 */
1342 			error = EBUSY;
1343 			goto out;
1344 		}
1345 		cyclic_off = 1;
1346 	}
1347 
1348 	/*
1349 	 * Call mp_cpu_stop() to perform any special operations
1350 	 * needed for this machine architecture to offline a CPU.
1351 	 */
1352 	if (error == 0)
1353 		error = mp_cpu_stop(cp);	/* arch-dep hook */
1354 
1355 	/*
1356 	 * If that all worked, take the CPU offline and decrement
1357 	 * ncpus_online.
1358 	 */
1359 	if (error == 0) {
1360 		/*
1361 		 * Put all the cpus into a known safe place.
1362 		 * No mutexes can be entered while CPUs are paused.
1363 		 */
1364 		pause_cpus(cp);
1365 		/*
1366 		 * Repeat the operation, if necessary, to make sure that
1367 		 * all outstanding low-level interrupts run to completion
1368 		 * before we set the CPU_QUIESCED flag.  It's also possible
1369 		 * that a thread has weak bound to the cpu despite our raising
1370 		 * cpu_inmotion above since it may have loaded that
1371 		 * value before the barrier became visible (this would have
1372 		 * to be the thread that was on the target cpu at the time
1373 		 * we raised the barrier).
1374 		 */
1375 		if ((!no_quiesce && cp->cpu_intr_actv != 0) ||
1376 		    (*bound_func)(cp, 1)) {
1377 			start_cpus();
1378 			(void) mp_cpu_start(cp);
1379 			goto again;
1380 		}
1381 		ncp = cp->cpu_next_part;
1382 		cpu_lpl = cp->cpu_lpl;
1383 		ASSERT(cpu_lpl != NULL);
1384 
1385 		/*
1386 		 * Remove the CPU from the list of active CPUs.
1387 		 */
1388 		cpu_remove_active(cp);
1389 
1390 		/*
1391 		 * Walk the active process list and look for threads
1392 		 * whose home lgroup needs to be updated, or
1393 		 * the last CPU they run on is the one being offlined now.
1394 		 */
1395 
1396 		ASSERT(curthread->t_cpu != cp);
1397 		for (p = practive; p != NULL; p = p->p_next) {
1398 
1399 			t = p->p_tlist;
1400 
1401 			if (t == NULL)
1402 				continue;
1403 
1404 			lgrp_diff_lpl = 0;
1405 
1406 			do {
1407 				ASSERT(t->t_lpl != NULL);
1408 				/*
1409 				 * Taking last CPU in lpl offline
1410 				 * Rehome thread if it is in this lpl
1411 				 * Otherwise, update the count of how many
1412 				 * threads are in this CPU's lgroup but have
1413 				 * a different lpl.
1414 				 */
1415 
1416 				if (cpu_lpl->lpl_ncpu == 0) {
1417 					if (t->t_lpl == cpu_lpl)
1418 						lgrp_move_thread(t,
1419 						    lgrp_choose(t,
1420 						    t->t_cpupart), 0);
1421 					else if (t->t_lpl->lpl_lgrpid ==
1422 					    cpu_lpl->lpl_lgrpid)
1423 						lgrp_diff_lpl++;
1424 				}
1425 				ASSERT(t->t_lpl->lpl_ncpu > 0);
1426 
1427 				/*
1428 				 * Update CPU last ran on if it was this CPU
1429 				 */
1430 				if (t->t_cpu == cp && t->t_bound_cpu != cp)
1431 				    t->t_cpu = disp_lowpri_cpu(ncp, t->t_lpl,
1432 					t->t_pri, NULL);
1433 				ASSERT(t->t_cpu != cp || t->t_bound_cpu == cp ||
1434 				    t->t_weakbound_cpu == cp);
1435 
1436 				t = t->t_forw;
1437 			} while (t != p->p_tlist);
1438 
1439 			/*
1440 			 * Didn't find any threads in the same lgroup as this
1441 			 * CPU with a different lpl, so remove the lgroup from
1442 			 * the process lgroup bitmask.
1443 			 */
1444 
1445 			if (lgrp_diff_lpl == 0)
1446 				klgrpset_del(p->p_lgrpset, cpu_lpl->lpl_lgrpid);
1447 		}
1448 
1449 		/*
1450 		 * Walk thread list looking for threads that need to be
1451 		 * rehomed, since there are some threads that are not in
1452 		 * their process's p_tlist.
1453 		 */
1454 
1455 		t = curthread;
1456 		do {
1457 			ASSERT(t != NULL && t->t_lpl != NULL);
1458 
1459 			/*
1460 			 * Rehome threads with same lpl as this CPU when this
1461 			 * is the last CPU in the lpl.
1462 			 */
1463 
1464 			if ((cpu_lpl->lpl_ncpu == 0) && (t->t_lpl == cpu_lpl))
1465 				lgrp_move_thread(t,
1466 				    lgrp_choose(t, t->t_cpupart), 1);
1467 
1468 			ASSERT(t->t_lpl->lpl_ncpu > 0);
1469 
1470 			/*
1471 			 * Update CPU last ran on if it was this CPU
1472 			 */
1473 
1474 			if (t->t_cpu == cp && t->t_bound_cpu != cp) {
1475 				t->t_cpu = disp_lowpri_cpu(ncp,
1476 				    t->t_lpl, t->t_pri, NULL);
1477 			}
1478 			ASSERT(t->t_cpu != cp || t->t_bound_cpu == cp ||
1479 			    t->t_weakbound_cpu == cp);
1480 			t = t->t_next;
1481 
1482 		} while (t != curthread);
1483 		ASSERT((cp->cpu_flags & (CPU_FAULTED | CPU_SPARE)) == 0);
1484 		cp->cpu_flags |= CPU_OFFLINE;
1485 		disp_cpu_inactive(cp);
1486 		if (!no_quiesce)
1487 			cp->cpu_flags |= CPU_QUIESCED;
1488 		ncpus_online--;
1489 		cpu_set_state(cp);
1490 		cpu_inmotion = NULL;
1491 		start_cpus();
1492 		cpu_stats_kstat_destroy(cp);
1493 		cpu_delete_intrstat(cp);
1494 		lgrp_kstat_destroy(cp);
1495 	}
1496 
1497 out:
1498 	cpu_inmotion = NULL;
1499 
1500 	/*
1501 	 * If we failed, re-enable interrupts.
1502 	 * Do this even if cpu_intr_disable returned an error, because
1503 	 * it may have partially disabled interrupts.
1504 	 */
1505 	if (error && intr_enable)
1506 		cpu_intr_enable(cp);
1507 
1508 	/*
1509 	 * If we failed, but managed to offline the cyclic subsystem on this
1510 	 * CPU, bring it back online.
1511 	 */
1512 	if (error && cyclic_off)
1513 		cyclic_online(cp);
1514 
1515 	/*
1516 	 * If we failed, we need to notify everyone that this CPU is back on.
1517 	 */
1518 	if (error != 0)
1519 		cpu_state_change_notify(cp->cpu_id, CPU_ON);
1520 
1521 	return (error);
1522 }
1523 
1524 /*
1525  * Mark the indicated CPU as faulted, taking it offline.
1526  */
1527 int
1528 cpu_faulted(cpu_t *cp, int flags)
1529 {
1530 	int	error = 0;
1531 
1532 	ASSERT(MUTEX_HELD(&cpu_lock));
1533 	ASSERT(!cpu_is_poweredoff(cp));
1534 
1535 	if (cpu_is_offline(cp)) {
1536 		cp->cpu_flags &= ~CPU_SPARE;
1537 		cp->cpu_flags |= CPU_FAULTED;
1538 		mp_cpu_faulted_enter(cp);
1539 		cpu_set_state(cp);
1540 		return (0);
1541 	}
1542 
1543 	if ((error = cpu_offline(cp, flags)) == 0) {
1544 		cp->cpu_flags |= CPU_FAULTED;
1545 		mp_cpu_faulted_enter(cp);
1546 		cpu_set_state(cp);
1547 	}
1548 
1549 	return (error);
1550 }
1551 
1552 /*
1553  * Mark the indicated CPU as a spare, taking it offline.
1554  */
1555 int
1556 cpu_spare(cpu_t *cp, int flags)
1557 {
1558 	int	error = 0;
1559 
1560 	ASSERT(MUTEX_HELD(&cpu_lock));
1561 	ASSERT(!cpu_is_poweredoff(cp));
1562 
1563 	if (cpu_is_offline(cp)) {
1564 		if (cp->cpu_flags & CPU_FAULTED) {
1565 			cp->cpu_flags &= ~CPU_FAULTED;
1566 			mp_cpu_faulted_exit(cp);
1567 		}
1568 		cp->cpu_flags |= CPU_SPARE;
1569 		cpu_set_state(cp);
1570 		return (0);
1571 	}
1572 
1573 	if ((error = cpu_offline(cp, flags)) == 0) {
1574 		cp->cpu_flags |= CPU_SPARE;
1575 		cpu_set_state(cp);
1576 	}
1577 
1578 	return (error);
1579 }
1580 
1581 /*
1582  * Take the indicated CPU from poweroff to offline.
1583  */
1584 int
1585 cpu_poweron(cpu_t *cp)
1586 {
1587 	int	error = ENOTSUP;
1588 
1589 	ASSERT(MUTEX_HELD(&cpu_lock));
1590 	ASSERT(cpu_is_poweredoff(cp));
1591 
1592 	error = mp_cpu_poweron(cp);	/* arch-dep hook */
1593 	if (error == 0)
1594 		cpu_set_state(cp);
1595 
1596 	return (error);
1597 }
1598 
1599 /*
1600  * Take the indicated CPU from any inactive state to powered off.
1601  */
1602 int
1603 cpu_poweroff(cpu_t *cp)
1604 {
1605 	int	error = ENOTSUP;
1606 
1607 	ASSERT(MUTEX_HELD(&cpu_lock));
1608 	ASSERT(cpu_is_offline(cp));
1609 
1610 	if (!(cp->cpu_flags & CPU_QUIESCED))
1611 		return (EBUSY);		/* not completely idle */
1612 
1613 	error = mp_cpu_poweroff(cp);	/* arch-dep hook */
1614 	if (error == 0)
1615 		cpu_set_state(cp);
1616 
1617 	return (error);
1618 }
1619 
1620 /*
1621  * Initialize the CPU lists for the first CPU.
1622  */
1623 void
1624 cpu_list_init(cpu_t *cp)
1625 {
1626 	cp->cpu_next = cp;
1627 	cp->cpu_prev = cp;
1628 	cpu_list = cp;
1629 
1630 	cp->cpu_next_onln = cp;
1631 	cp->cpu_prev_onln = cp;
1632 	cpu_active = cp;
1633 
1634 	cp->cpu_seqid = 0;
1635 	CPUSET_ADD(cpu_seqid_inuse, 0);
1636 	cp->cpu_cache_offset = KMEM_CACHE_SIZE(cp->cpu_seqid);
1637 	cp_default.cp_cpulist = cp;
1638 	cp_default.cp_ncpus = 1;
1639 	cp->cpu_next_part = cp;
1640 	cp->cpu_prev_part = cp;
1641 	cp->cpu_part = &cp_default;
1642 
1643 	CPUSET_ADD(cpu_available, cp->cpu_id);
1644 }
1645 
1646 /*
1647  * Insert a CPU into the list of available CPUs.
1648  */
1649 void
1650 cpu_add_unit(cpu_t *cp)
1651 {
1652 	int seqid;
1653 
1654 	ASSERT(MUTEX_HELD(&cpu_lock));
1655 	ASSERT(cpu_list != NULL);	/* list started in cpu_list_init */
1656 
1657 	lgrp_config(LGRP_CONFIG_CPU_ADD, (uintptr_t)cp, 0);
1658 
1659 	/*
1660 	 * Note: most users of the cpu_list will grab the
1661 	 * cpu_lock to insure that it isn't modified.  However,
1662 	 * certain users can't or won't do that.  To allow this
1663 	 * we pause the other cpus.  Users who walk the list
1664 	 * without cpu_lock, must disable kernel preemption
1665 	 * to insure that the list isn't modified underneath
1666 	 * them.  Also, any cached pointers to cpu structures
1667 	 * must be revalidated by checking to see if the
1668 	 * cpu_next pointer points to itself.  This check must
1669 	 * be done with the cpu_lock held or kernel preemption
1670 	 * disabled.  This check relies upon the fact that
1671 	 * old cpu structures are not free'ed or cleared after
1672 	 * then are removed from the cpu_list.
1673 	 *
1674 	 * Note that the clock code walks the cpu list dereferencing
1675 	 * the cpu_part pointer, so we need to initialize it before
1676 	 * adding the cpu to the list.
1677 	 */
1678 	cp->cpu_part = &cp_default;
1679 	(void) pause_cpus(NULL);
1680 	cp->cpu_next = cpu_list;
1681 	cp->cpu_prev = cpu_list->cpu_prev;
1682 	cpu_list->cpu_prev->cpu_next = cp;
1683 	cpu_list->cpu_prev = cp;
1684 	start_cpus();
1685 
1686 	for (seqid = 0; CPU_IN_SET(cpu_seqid_inuse, seqid); seqid++)
1687 		continue;
1688 	CPUSET_ADD(cpu_seqid_inuse, seqid);
1689 	cp->cpu_seqid = seqid;
1690 	ASSERT(ncpus < max_ncpus);
1691 	ncpus++;
1692 	cp->cpu_cache_offset = KMEM_CACHE_SIZE(cp->cpu_seqid);
1693 	cpu[cp->cpu_id] = cp;
1694 	CPUSET_ADD(cpu_available, cp->cpu_id);
1695 
1696 	/*
1697 	 * allocate a pause thread for this CPU.
1698 	 */
1699 	cpu_pause_alloc(cp);
1700 
1701 	/*
1702 	 * So that new CPUs won't have NULL prev_onln and next_onln pointers,
1703 	 * link them into a list of just that CPU.
1704 	 * This is so that disp_lowpri_cpu will work for thread_create in
1705 	 * pause_cpus() when called from the startup thread in a new CPU.
1706 	 */
1707 	cp->cpu_next_onln = cp;
1708 	cp->cpu_prev_onln = cp;
1709 	cpu_info_kstat_create(cp);
1710 	cp->cpu_next_part = cp;
1711 	cp->cpu_prev_part = cp;
1712 
1713 	init_cpu_mstate(cp, CMS_SYSTEM);
1714 
1715 	pool_pset_mod = gethrtime();
1716 }
1717 
1718 /*
1719  * Do the opposite of cpu_add_unit().
1720  */
1721 void
1722 cpu_del_unit(int cpuid)
1723 {
1724 	struct cpu	*cp, *cpnext;
1725 
1726 	ASSERT(MUTEX_HELD(&cpu_lock));
1727 	cp = cpu[cpuid];
1728 	ASSERT(cp != NULL);
1729 
1730 	ASSERT(cp->cpu_next_onln == cp);
1731 	ASSERT(cp->cpu_prev_onln == cp);
1732 	ASSERT(cp->cpu_next_part == cp);
1733 	ASSERT(cp->cpu_prev_part == cp);
1734 
1735 	chip_cpu_fini(cp);
1736 
1737 	/*
1738 	 * Destroy kstat stuff.
1739 	 */
1740 	cpu_info_kstat_destroy(cp);
1741 	term_cpu_mstate(cp);
1742 	/*
1743 	 * Free up pause thread.
1744 	 */
1745 	cpu_pause_free(cp);
1746 	CPUSET_DEL(cpu_available, cp->cpu_id);
1747 	cpu[cp->cpu_id] = NULL;
1748 	/*
1749 	 * The clock thread and mutex_vector_enter cannot hold the
1750 	 * cpu_lock while traversing the cpu list, therefore we pause
1751 	 * all other threads by pausing the other cpus. These, and any
1752 	 * other routines holding cpu pointers while possibly sleeping
1753 	 * must be sure to call kpreempt_disable before processing the
1754 	 * list and be sure to check that the cpu has not been deleted
1755 	 * after any sleeps (check cp->cpu_next != NULL). We guarantee
1756 	 * to keep the deleted cpu structure around.
1757 	 *
1758 	 * Note that this MUST be done AFTER cpu_available
1759 	 * has been updated so that we don't waste time
1760 	 * trying to pause the cpu we're trying to delete.
1761 	 */
1762 	(void) pause_cpus(NULL);
1763 
1764 	cpnext = cp->cpu_next;
1765 	cp->cpu_prev->cpu_next = cp->cpu_next;
1766 	cp->cpu_next->cpu_prev = cp->cpu_prev;
1767 	if (cp == cpu_list)
1768 	    cpu_list = cpnext;
1769 
1770 	/*
1771 	 * Signals that the cpu has been deleted (see above).
1772 	 */
1773 	cp->cpu_next = NULL;
1774 	cp->cpu_prev = NULL;
1775 
1776 	start_cpus();
1777 
1778 	CPUSET_DEL(cpu_seqid_inuse, cp->cpu_seqid);
1779 	ncpus--;
1780 	lgrp_config(LGRP_CONFIG_CPU_DEL, (uintptr_t)cp, 0);
1781 
1782 	pool_pset_mod = gethrtime();
1783 }
1784 
1785 /*
1786  * Add a CPU to the list of active CPUs.
1787  *	This routine must not get any locks, because other CPUs are paused.
1788  */
1789 static void
1790 cpu_add_active_internal(cpu_t *cp)
1791 {
1792 	cpupart_t	*pp = cp->cpu_part;
1793 
1794 	ASSERT(MUTEX_HELD(&cpu_lock));
1795 	ASSERT(cpu_list != NULL);	/* list started in cpu_list_init */
1796 
1797 	ncpus_online++;
1798 	cpu_set_state(cp);
1799 	cp->cpu_next_onln = cpu_active;
1800 	cp->cpu_prev_onln = cpu_active->cpu_prev_onln;
1801 	cpu_active->cpu_prev_onln->cpu_next_onln = cp;
1802 	cpu_active->cpu_prev_onln = cp;
1803 
1804 	if (pp->cp_cpulist) {
1805 		cp->cpu_next_part = pp->cp_cpulist;
1806 		cp->cpu_prev_part = pp->cp_cpulist->cpu_prev_part;
1807 		pp->cp_cpulist->cpu_prev_part->cpu_next_part = cp;
1808 		pp->cp_cpulist->cpu_prev_part = cp;
1809 	} else {
1810 		ASSERT(pp->cp_ncpus == 0);
1811 		pp->cp_cpulist = cp->cpu_next_part = cp->cpu_prev_part = cp;
1812 	}
1813 	pp->cp_ncpus++;
1814 	if (pp->cp_ncpus == 1) {
1815 		cp_numparts_nonempty++;
1816 		ASSERT(cp_numparts_nonempty != 0);
1817 	}
1818 
1819 	chip_cpu_assign(cp);
1820 
1821 	lgrp_config(LGRP_CONFIG_CPU_ONLINE, (uintptr_t)cp, 0);
1822 
1823 	bzero(&cp->cpu_loadavg, sizeof (cp->cpu_loadavg));
1824 }
1825 
1826 /*
1827  * Add a CPU to the list of active CPUs.
1828  *	This is called from machine-dependent layers when a new CPU is started.
1829  */
1830 void
1831 cpu_add_active(cpu_t *cp)
1832 {
1833 	pause_cpus(NULL);
1834 	cpu_add_active_internal(cp);
1835 	start_cpus();
1836 	cpu_stats_kstat_create(cp);
1837 	cpu_create_intrstat(cp);
1838 	lgrp_kstat_create(cp);
1839 	cpu_state_change_notify(cp->cpu_id, CPU_INIT);
1840 }
1841 
1842 
1843 /*
1844  * Remove a CPU from the list of active CPUs.
1845  *	This routine must not get any locks, because other CPUs are paused.
1846  */
1847 /* ARGSUSED */
1848 static void
1849 cpu_remove_active(cpu_t *cp)
1850 {
1851 	cpupart_t	*pp = cp->cpu_part;
1852 
1853 	ASSERT(MUTEX_HELD(&cpu_lock));
1854 	ASSERT(cp->cpu_next_onln != cp);	/* not the last one */
1855 	ASSERT(cp->cpu_prev_onln != cp);	/* not the last one */
1856 
1857 	chip_cpu_unassign(cp);
1858 
1859 	lgrp_config(LGRP_CONFIG_CPU_OFFLINE, (uintptr_t)cp, 0);
1860 
1861 	cp->cpu_prev_onln->cpu_next_onln = cp->cpu_next_onln;
1862 	cp->cpu_next_onln->cpu_prev_onln = cp->cpu_prev_onln;
1863 	if (cpu_active == cp) {
1864 		cpu_active = cp->cpu_next_onln;
1865 	}
1866 	cp->cpu_next_onln = cp;
1867 	cp->cpu_prev_onln = cp;
1868 
1869 	cp->cpu_prev_part->cpu_next_part = cp->cpu_next_part;
1870 	cp->cpu_next_part->cpu_prev_part = cp->cpu_prev_part;
1871 	if (pp->cp_cpulist == cp) {
1872 		pp->cp_cpulist = cp->cpu_next_part;
1873 		ASSERT(pp->cp_cpulist != cp);
1874 	}
1875 	cp->cpu_next_part = cp;
1876 	cp->cpu_prev_part = cp;
1877 	pp->cp_ncpus--;
1878 	if (pp->cp_ncpus == 0) {
1879 		cp_numparts_nonempty--;
1880 		ASSERT(cp_numparts_nonempty != 0);
1881 	}
1882 }
1883 
1884 /*
1885  * Routine used to setup a newly inserted CPU in preparation for starting
1886  * it running code.
1887  */
1888 int
1889 cpu_configure(int cpuid)
1890 {
1891 	int retval = 0;
1892 
1893 	ASSERT(MUTEX_HELD(&cpu_lock));
1894 
1895 	/*
1896 	 * Some structures are statically allocated based upon
1897 	 * the maximum number of cpus the system supports.  Do not
1898 	 * try to add anything beyond this limit.
1899 	 */
1900 	if (cpuid < 0 || cpuid >= NCPU) {
1901 		return (EINVAL);
1902 	}
1903 
1904 	if ((cpu[cpuid] != NULL) && (cpu[cpuid]->cpu_flags != 0)) {
1905 		return (EALREADY);
1906 	}
1907 
1908 	if ((retval = mp_cpu_configure(cpuid)) != 0) {
1909 		return (retval);
1910 	}
1911 
1912 	cpu[cpuid]->cpu_flags = CPU_QUIESCED | CPU_OFFLINE | CPU_POWEROFF;
1913 	cpu_set_state(cpu[cpuid]);
1914 	retval = cpu_state_change_hooks(cpuid, CPU_CONFIG, CPU_UNCONFIG);
1915 	if (retval != 0)
1916 		(void) mp_cpu_unconfigure(cpuid);
1917 
1918 	return (retval);
1919 }
1920 
1921 /*
1922  * Routine used to cleanup a CPU that has been powered off.  This will
1923  * destroy all per-cpu information related to this cpu.
1924  */
1925 int
1926 cpu_unconfigure(int cpuid)
1927 {
1928 	int error;
1929 
1930 	ASSERT(MUTEX_HELD(&cpu_lock));
1931 
1932 	if (cpu[cpuid] == NULL) {
1933 		return (ENODEV);
1934 	}
1935 
1936 	if (cpu[cpuid]->cpu_flags == 0) {
1937 		return (EALREADY);
1938 	}
1939 
1940 	if ((cpu[cpuid]->cpu_flags & CPU_POWEROFF) == 0) {
1941 		return (EBUSY);
1942 	}
1943 
1944 	if (cpu[cpuid]->cpu_props != NULL) {
1945 		(void) nvlist_free(cpu[cpuid]->cpu_props);
1946 		cpu[cpuid]->cpu_props = NULL;
1947 	}
1948 
1949 	error = cpu_state_change_hooks(cpuid, CPU_UNCONFIG, CPU_CONFIG);
1950 
1951 	if (error != 0)
1952 		return (error);
1953 
1954 	return (mp_cpu_unconfigure(cpuid));
1955 }
1956 
1957 /*
1958  * Routines for registering and de-registering cpu_setup callback functions.
1959  *
1960  * Caller's context
1961  *	These routines must not be called from a driver's attach(9E) or
1962  *	detach(9E) entry point.
1963  *
1964  * NOTE: CPU callbacks should not block. They are called with cpu_lock held.
1965  */
1966 
1967 /*
1968  * Ideally, these would be dynamically allocated and put into a linked
1969  * list; however that is not feasible because the registration routine
1970  * has to be available before the kmem allocator is working (in fact,
1971  * it is called by the kmem allocator init code).  In any case, there
1972  * are quite a few extra entries for future users.
1973  */
1974 #define	NCPU_SETUPS	20
1975 
1976 struct cpu_setup {
1977 	cpu_setup_func_t *func;
1978 	void *arg;
1979 } cpu_setups[NCPU_SETUPS];
1980 
1981 void
1982 register_cpu_setup_func(cpu_setup_func_t *func, void *arg)
1983 {
1984 	int i;
1985 
1986 	ASSERT(MUTEX_HELD(&cpu_lock));
1987 
1988 	for (i = 0; i < NCPU_SETUPS; i++)
1989 		if (cpu_setups[i].func == NULL)
1990 		    break;
1991 	if (i >= NCPU_SETUPS)
1992 		cmn_err(CE_PANIC, "Ran out of cpu_setup callback entries");
1993 
1994 	cpu_setups[i].func = func;
1995 	cpu_setups[i].arg = arg;
1996 }
1997 
1998 void
1999 unregister_cpu_setup_func(cpu_setup_func_t *func, void *arg)
2000 {
2001 	int i;
2002 
2003 	ASSERT(MUTEX_HELD(&cpu_lock));
2004 
2005 	for (i = 0; i < NCPU_SETUPS; i++)
2006 		if ((cpu_setups[i].func == func) &&
2007 		    (cpu_setups[i].arg == arg))
2008 		    break;
2009 	if (i >= NCPU_SETUPS)
2010 		cmn_err(CE_PANIC, "Could not find cpu_setup callback to "
2011 		    "deregister");
2012 
2013 	cpu_setups[i].func = NULL;
2014 	cpu_setups[i].arg = 0;
2015 }
2016 
2017 /*
2018  * Call any state change hooks for this CPU, ignore any errors.
2019  */
2020 void
2021 cpu_state_change_notify(int id, cpu_setup_t what)
2022 {
2023 	int i;
2024 
2025 	ASSERT(MUTEX_HELD(&cpu_lock));
2026 
2027 	for (i = 0; i < NCPU_SETUPS; i++) {
2028 		if (cpu_setups[i].func != NULL) {
2029 			cpu_setups[i].func(what, id, cpu_setups[i].arg);
2030 		}
2031 	}
2032 }
2033 
2034 /*
2035  * Call any state change hooks for this CPU, undo it if error found.
2036  */
2037 static int
2038 cpu_state_change_hooks(int id, cpu_setup_t what, cpu_setup_t undo)
2039 {
2040 	int i;
2041 	int retval = 0;
2042 
2043 	ASSERT(MUTEX_HELD(&cpu_lock));
2044 
2045 	for (i = 0; i < NCPU_SETUPS; i++) {
2046 		if (cpu_setups[i].func != NULL) {
2047 			retval = cpu_setups[i].func(what, id,
2048 			    cpu_setups[i].arg);
2049 			if (retval) {
2050 				for (i--; i >= 0; i--) {
2051 					if (cpu_setups[i].func != NULL)
2052 						cpu_setups[i].func(undo,
2053 						    id, cpu_setups[i].arg);
2054 				}
2055 				break;
2056 			}
2057 		}
2058 	}
2059 	return (retval);
2060 }
2061 
2062 /*
2063  * Export information about this CPU via the kstat mechanism.
2064  */
2065 static struct {
2066 	kstat_named_t ci_state;
2067 	kstat_named_t ci_state_begin;
2068 	kstat_named_t ci_cpu_type;
2069 	kstat_named_t ci_fpu_type;
2070 	kstat_named_t ci_clock_MHz;
2071 	kstat_named_t ci_chip_id;
2072 	kstat_named_t ci_implementation;
2073 	kstat_named_t ci_brandstr;
2074 	kstat_named_t ci_core_id;
2075 #if defined(__sparcv9)
2076 	kstat_named_t ci_device_ID;
2077 	kstat_named_t ci_cpu_fru;
2078 #endif
2079 #if defined(__i386) || defined(__amd64)
2080 	kstat_named_t ci_vendorstr;
2081 	kstat_named_t ci_family;
2082 	kstat_named_t ci_model;
2083 	kstat_named_t ci_step;
2084 	kstat_named_t ci_clogid;
2085 #endif
2086 } cpu_info_template = {
2087 	{ "state",		KSTAT_DATA_CHAR },
2088 	{ "state_begin",	KSTAT_DATA_LONG },
2089 	{ "cpu_type",		KSTAT_DATA_CHAR },
2090 	{ "fpu_type",		KSTAT_DATA_CHAR },
2091 	{ "clock_MHz",		KSTAT_DATA_LONG },
2092 	{ "chip_id",		KSTAT_DATA_LONG },
2093 	{ "implementation",	KSTAT_DATA_STRING },
2094 	{ "brand",		KSTAT_DATA_STRING },
2095 	{ "core_id",		KSTAT_DATA_LONG },
2096 #if defined(__sparcv9)
2097 	{ "device_ID",		KSTAT_DATA_UINT64 },
2098 	{ "cpu_fru",		KSTAT_DATA_STRING },
2099 #endif
2100 #if defined(__i386) || defined(__amd64)
2101 	{ "vendor_id",		KSTAT_DATA_STRING },
2102 	{ "family",		KSTAT_DATA_INT32 },
2103 	{ "model",		KSTAT_DATA_INT32 },
2104 	{ "stepping",		KSTAT_DATA_INT32 },
2105 	{ "clog_id",		KSTAT_DATA_INT32 },
2106 #endif
2107 };
2108 
2109 static kmutex_t cpu_info_template_lock;
2110 
2111 static int
2112 cpu_info_kstat_update(kstat_t *ksp, int rw)
2113 {
2114 	cpu_t	*cp = ksp->ks_private;
2115 	const char *pi_state;
2116 
2117 	if (rw == KSTAT_WRITE)
2118 		return (EACCES);
2119 
2120 	switch (cp->cpu_type_info.pi_state) {
2121 	case P_ONLINE:
2122 		pi_state = PS_ONLINE;
2123 		break;
2124 	case P_POWEROFF:
2125 		pi_state = PS_POWEROFF;
2126 		break;
2127 	case P_NOINTR:
2128 		pi_state = PS_NOINTR;
2129 		break;
2130 	case P_FAULTED:
2131 		pi_state = PS_FAULTED;
2132 		break;
2133 	case P_SPARE:
2134 		pi_state = PS_SPARE;
2135 		break;
2136 	case P_OFFLINE:
2137 		pi_state = PS_OFFLINE;
2138 		break;
2139 	default:
2140 		pi_state = "unknown";
2141 	}
2142 	(void) strcpy(cpu_info_template.ci_state.value.c, pi_state);
2143 	cpu_info_template.ci_state_begin.value.l = cp->cpu_state_begin;
2144 	(void) strncpy(cpu_info_template.ci_cpu_type.value.c,
2145 	    cp->cpu_type_info.pi_processor_type, 15);
2146 	(void) strncpy(cpu_info_template.ci_fpu_type.value.c,
2147 	    cp->cpu_type_info.pi_fputypes, 15);
2148 	cpu_info_template.ci_clock_MHz.value.l = cp->cpu_type_info.pi_clock;
2149 	cpu_info_template.ci_chip_id.value.l = chip_plat_get_chipid(cp);
2150 	kstat_named_setstr(&cpu_info_template.ci_implementation,
2151 	    cp->cpu_idstr);
2152 	kstat_named_setstr(&cpu_info_template.ci_brandstr, cp->cpu_brandstr);
2153 
2154 #if defined(__sparcv9)
2155 	cpu_info_template.ci_device_ID.value.ui64 =
2156 	    cpunodes[cp->cpu_id].device_id;
2157 	kstat_named_setstr(&cpu_info_template.ci_cpu_fru, cpu_fru_fmri(cp));
2158 #endif
2159 #if defined(__i386) || defined(__amd64)
2160 	cpu_info_template.ci_core_id.value.l = chip_plat_get_coreid(cp);
2161 	kstat_named_setstr(&cpu_info_template.ci_vendorstr,
2162 	    cpuid_getvendorstr(cp));
2163 	cpu_info_template.ci_family.value.l = cpuid_getfamily(cp);
2164 	cpu_info_template.ci_model.value.l = cpuid_getmodel(cp);
2165 	cpu_info_template.ci_step.value.l = cpuid_getstep(cp);
2166 	cpu_info_template.ci_clogid.value.l = chip_plat_get_clogid(cp);
2167 #endif
2168 
2169 	return (0);
2170 }
2171 
2172 static void
2173 cpu_info_kstat_create(cpu_t *cp)
2174 {
2175 	zoneid_t zoneid;
2176 
2177 	ASSERT(MUTEX_HELD(&cpu_lock));
2178 
2179 	if (pool_pset_enabled())
2180 		zoneid = GLOBAL_ZONEID;
2181 	else
2182 		zoneid = ALL_ZONES;
2183 	if ((cp->cpu_info_kstat = kstat_create_zone("cpu_info", cp->cpu_id,
2184 	    NULL, "misc", KSTAT_TYPE_NAMED,
2185 		    sizeof (cpu_info_template) / sizeof (kstat_named_t),
2186 		    KSTAT_FLAG_VIRTUAL, zoneid)) != NULL) {
2187 		cp->cpu_info_kstat->ks_data_size += 2 * CPU_IDSTRLEN;
2188 #if defined(__sparcv9)
2189 		cp->cpu_info_kstat->ks_data_size +=
2190 		    strlen(cpu_fru_fmri(cp)) + 1;
2191 #endif
2192 #if defined(__i386) || defined(__amd64)
2193 		cp->cpu_info_kstat->ks_data_size += X86_VENDOR_STRLEN;
2194 #endif
2195 		cp->cpu_info_kstat->ks_lock = &cpu_info_template_lock;
2196 		cp->cpu_info_kstat->ks_data = &cpu_info_template;
2197 		cp->cpu_info_kstat->ks_private = cp;
2198 		cp->cpu_info_kstat->ks_update = cpu_info_kstat_update;
2199 		kstat_install(cp->cpu_info_kstat);
2200 	}
2201 }
2202 
2203 static void
2204 cpu_info_kstat_destroy(cpu_t *cp)
2205 {
2206 	ASSERT(MUTEX_HELD(&cpu_lock));
2207 
2208 	kstat_delete(cp->cpu_info_kstat);
2209 	cp->cpu_info_kstat = NULL;
2210 }
2211 
2212 /*
2213  * Create and install kstats for the boot CPU.
2214  */
2215 void
2216 cpu_kstat_init(cpu_t *cp)
2217 {
2218 	mutex_enter(&cpu_lock);
2219 	cpu_info_kstat_create(cp);
2220 	cpu_stats_kstat_create(cp);
2221 	cpu_create_intrstat(cp);
2222 	chip_kstat_create(cp->cpu_chip);
2223 	cpu_set_state(cp);
2224 	mutex_exit(&cpu_lock);
2225 }
2226 
2227 /*
2228  * Make visible to the zone that subset of the cpu information that would be
2229  * initialized when a cpu is configured (but still offline).
2230  */
2231 void
2232 cpu_visibility_configure(cpu_t *cp, zone_t *zone)
2233 {
2234 	zoneid_t zoneid = zone ? zone->zone_id : ALL_ZONES;
2235 
2236 	ASSERT(MUTEX_HELD(&cpu_lock));
2237 	ASSERT(pool_pset_enabled());
2238 	ASSERT(cp != NULL);
2239 
2240 	if (zoneid != ALL_ZONES && zoneid != GLOBAL_ZONEID) {
2241 		zone->zone_ncpus++;
2242 		ASSERT(zone->zone_ncpus <= ncpus);
2243 	}
2244 	if (cp->cpu_info_kstat != NULL)
2245 		kstat_zone_add(cp->cpu_info_kstat, zoneid);
2246 }
2247 
2248 /*
2249  * Make visible to the zone that subset of the cpu information that would be
2250  * initialized when a previously configured cpu is onlined.
2251  */
2252 void
2253 cpu_visibility_online(cpu_t *cp, zone_t *zone)
2254 {
2255 	kstat_t *ksp;
2256 	char name[sizeof ("cpu_stat") + 10];	/* enough for 32-bit cpuids */
2257 	zoneid_t zoneid = zone ? zone->zone_id : ALL_ZONES;
2258 	processorid_t cpun;
2259 
2260 	ASSERT(MUTEX_HELD(&cpu_lock));
2261 	ASSERT(pool_pset_enabled());
2262 	ASSERT(cp != NULL);
2263 	ASSERT(cpu_is_active(cp));
2264 
2265 	cpun = cp->cpu_id;
2266 	if (zoneid != ALL_ZONES && zoneid != GLOBAL_ZONEID) {
2267 		zone->zone_ncpus_online++;
2268 		ASSERT(zone->zone_ncpus_online <= ncpus_online);
2269 	}
2270 	(void) snprintf(name, sizeof (name), "cpu_stat%d", cpun);
2271 	if ((ksp = kstat_hold_byname("cpu_stat", cpun, name, ALL_ZONES))
2272 	    != NULL) {
2273 		kstat_zone_add(ksp, zoneid);
2274 		kstat_rele(ksp);
2275 	}
2276 	if ((ksp = kstat_hold_byname("cpu", cpun, "sys", ALL_ZONES)) != NULL) {
2277 		kstat_zone_add(ksp, zoneid);
2278 		kstat_rele(ksp);
2279 	}
2280 	if ((ksp = kstat_hold_byname("cpu", cpun, "vm", ALL_ZONES)) != NULL) {
2281 		kstat_zone_add(ksp, zoneid);
2282 		kstat_rele(ksp);
2283 	}
2284 	if ((ksp = kstat_hold_byname("cpu", cpun, "intrstat", ALL_ZONES)) !=
2285 	    NULL) {
2286 		kstat_zone_add(ksp, zoneid);
2287 		kstat_rele(ksp);
2288 	}
2289 }
2290 
2291 /*
2292  * Update relevant kstats such that cpu is now visible to processes
2293  * executing in specified zone.
2294  */
2295 void
2296 cpu_visibility_add(cpu_t *cp, zone_t *zone)
2297 {
2298 	cpu_visibility_configure(cp, zone);
2299 	if (cpu_is_active(cp))
2300 		cpu_visibility_online(cp, zone);
2301 }
2302 
2303 /*
2304  * Make invisible to the zone that subset of the cpu information that would be
2305  * torn down when a previously offlined cpu is unconfigured.
2306  */
2307 void
2308 cpu_visibility_unconfigure(cpu_t *cp, zone_t *zone)
2309 {
2310 	zoneid_t zoneid = zone ? zone->zone_id : ALL_ZONES;
2311 
2312 	ASSERT(MUTEX_HELD(&cpu_lock));
2313 	ASSERT(pool_pset_enabled());
2314 	ASSERT(cp != NULL);
2315 
2316 	if (zoneid != ALL_ZONES && zoneid != GLOBAL_ZONEID) {
2317 		ASSERT(zone->zone_ncpus != 0);
2318 		zone->zone_ncpus--;
2319 	}
2320 	if (cp->cpu_info_kstat)
2321 		kstat_zone_remove(cp->cpu_info_kstat, zoneid);
2322 }
2323 
2324 /*
2325  * Make invisible to the zone that subset of the cpu information that would be
2326  * torn down when a cpu is offlined (but still configured).
2327  */
2328 void
2329 cpu_visibility_offline(cpu_t *cp, zone_t *zone)
2330 {
2331 	kstat_t *ksp;
2332 	char name[sizeof ("cpu_stat") + 10];	/* enough for 32-bit cpuids */
2333 	zoneid_t zoneid = zone ? zone->zone_id : ALL_ZONES;
2334 	processorid_t cpun;
2335 
2336 	ASSERT(MUTEX_HELD(&cpu_lock));
2337 	ASSERT(pool_pset_enabled());
2338 	ASSERT(cp != NULL);
2339 	ASSERT(cpu_is_active(cp));
2340 
2341 	cpun = cp->cpu_id;
2342 	if (zoneid != ALL_ZONES && zoneid != GLOBAL_ZONEID) {
2343 		ASSERT(zone->zone_ncpus_online != 0);
2344 		zone->zone_ncpus_online--;
2345 	}
2346 
2347 	if ((ksp = kstat_hold_byname("cpu", cpun, "intrstat", ALL_ZONES)) !=
2348 	    NULL) {
2349 		kstat_zone_remove(ksp, zoneid);
2350 		kstat_rele(ksp);
2351 	}
2352 	if ((ksp = kstat_hold_byname("cpu", cpun, "vm", ALL_ZONES)) != NULL) {
2353 		kstat_zone_remove(ksp, zoneid);
2354 		kstat_rele(ksp);
2355 	}
2356 	if ((ksp = kstat_hold_byname("cpu", cpun, "sys", ALL_ZONES)) != NULL) {
2357 		kstat_zone_remove(ksp, zoneid);
2358 		kstat_rele(ksp);
2359 	}
2360 	(void) snprintf(name, sizeof (name), "cpu_stat%d", cpun);
2361 	if ((ksp = kstat_hold_byname("cpu_stat", cpun, name, ALL_ZONES))
2362 	    != NULL) {
2363 		kstat_zone_remove(ksp, zoneid);
2364 		kstat_rele(ksp);
2365 	}
2366 }
2367 
2368 /*
2369  * Update relevant kstats such that cpu is no longer visible to processes
2370  * executing in specified zone.
2371  */
2372 void
2373 cpu_visibility_remove(cpu_t *cp, zone_t *zone)
2374 {
2375 	if (cpu_is_active(cp))
2376 		cpu_visibility_offline(cp, zone);
2377 	cpu_visibility_unconfigure(cp, zone);
2378 }
2379 
2380 /*
2381  * Bind a thread to a CPU as requested.
2382  */
2383 int
2384 cpu_bind_thread(kthread_id_t tp, processorid_t bind, processorid_t *obind,
2385     int *error)
2386 {
2387 	processorid_t	binding;
2388 	cpu_t		*cp;
2389 
2390 	ASSERT(MUTEX_HELD(&cpu_lock));
2391 	ASSERT(MUTEX_HELD(&ttoproc(tp)->p_lock));
2392 
2393 	thread_lock(tp);
2394 
2395 	/*
2396 	 * Record old binding, but change the obind, which was initialized
2397 	 * to PBIND_NONE, only if this thread has a binding.  This avoids
2398 	 * reporting PBIND_NONE for a process when some LWPs are bound.
2399 	 */
2400 	binding = tp->t_bind_cpu;
2401 	if (binding != PBIND_NONE)
2402 		*obind = binding;	/* record old binding */
2403 
2404 	if (bind == PBIND_QUERY) {
2405 		thread_unlock(tp);
2406 		return (0);
2407 	}
2408 
2409 	/*
2410 	 * If this thread/LWP cannot be bound because of permission
2411 	 * problems, just note that and return success so that the
2412 	 * other threads/LWPs will be bound.  This is the way
2413 	 * processor_bind() is defined to work.
2414 	 *
2415 	 * Binding will get EPERM if the thread is of system class
2416 	 * or hasprocperm() fails.
2417 	 */
2418 	if (tp->t_cid == 0 || !hasprocperm(tp->t_cred, CRED())) {
2419 		*error = EPERM;
2420 		thread_unlock(tp);
2421 		return (0);
2422 	}
2423 
2424 	binding = bind;
2425 	if (binding != PBIND_NONE) {
2426 		cp = cpu[binding];
2427 		/*
2428 		 * Make sure binding is in right partition.
2429 		 */
2430 		if (tp->t_cpupart != cp->cpu_part) {
2431 			*error = EINVAL;
2432 			thread_unlock(tp);
2433 			return (0);
2434 		}
2435 	}
2436 	tp->t_bind_cpu = binding;	/* set new binding */
2437 
2438 	/*
2439 	 * If there is no system-set reason for affinity, set
2440 	 * the t_bound_cpu field to reflect the binding.
2441 	 */
2442 	if (tp->t_affinitycnt == 0) {
2443 		if (binding == PBIND_NONE) {
2444 			/*
2445 			 * We may need to adjust disp_max_unbound_pri
2446 			 * since we're becoming unbound.
2447 			 */
2448 			disp_adjust_unbound_pri(tp);
2449 
2450 			tp->t_bound_cpu = NULL;	/* set new binding */
2451 
2452 			/*
2453 			 * Move thread to lgroup with strongest affinity
2454 			 * after unbinding
2455 			 */
2456 			if (tp->t_lgrp_affinity)
2457 				lgrp_move_thread(tp,
2458 				    lgrp_choose(tp, tp->t_cpupart), 1);
2459 
2460 			if (tp->t_state == TS_ONPROC &&
2461 			    tp->t_cpu->cpu_part != tp->t_cpupart)
2462 				cpu_surrender(tp);
2463 		} else {
2464 			lpl_t	*lpl;
2465 
2466 			tp->t_bound_cpu = cp;
2467 			ASSERT(cp->cpu_lpl != NULL);
2468 
2469 			/*
2470 			 * Set home to lgroup with most affinity containing CPU
2471 			 * that thread is being bound or minimum bounding
2472 			 * lgroup if no affinities set
2473 			 */
2474 			if (tp->t_lgrp_affinity)
2475 				lpl = lgrp_affinity_best(tp, tp->t_cpupart, 0);
2476 			else
2477 				lpl = cp->cpu_lpl;
2478 
2479 			if (tp->t_lpl != lpl) {
2480 				/* can't grab cpu_lock */
2481 				lgrp_move_thread(tp, lpl, 1);
2482 			}
2483 
2484 			/*
2485 			 * Make the thread switch to the bound CPU.
2486 			 * If the thread is runnable, we need to
2487 			 * requeue it even if t_cpu is already set
2488 			 * to the right CPU, since it may be on a
2489 			 * kpreempt queue and need to move to a local
2490 			 * queue.  We could check t_disp_queue to
2491 			 * avoid unnecessary overhead if it's already
2492 			 * on the right queue, but since this isn't
2493 			 * a performance-critical operation it doesn't
2494 			 * seem worth the extra code and complexity.
2495 			 *
2496 			 * If the thread is weakbound to the cpu then it will
2497 			 * resist the new binding request until the weak
2498 			 * binding drops.  The cpu_surrender or requeueing
2499 			 * below could be skipped in such cases (since it
2500 			 * will have no effect), but that would require
2501 			 * thread_allowmigrate to acquire thread_lock so
2502 			 * we'll take the very occasional hit here instead.
2503 			 */
2504 			if (tp->t_state == TS_ONPROC) {
2505 				cpu_surrender(tp);
2506 			} else if (tp->t_state == TS_RUN) {
2507 				cpu_t *ocp = tp->t_cpu;
2508 
2509 				(void) dispdeq(tp);
2510 				setbackdq(tp);
2511 				/*
2512 				 * Either on the bound CPU's disp queue now,
2513 				 * or swapped out or on the swap queue.
2514 				 */
2515 				ASSERT(tp->t_disp_queue == cp->cpu_disp ||
2516 				    tp->t_weakbound_cpu == ocp ||
2517 				    (tp->t_schedflag & (TS_LOAD | TS_ON_SWAPQ))
2518 				    != TS_LOAD);
2519 			}
2520 		}
2521 	}
2522 
2523 	/*
2524 	 * Our binding has changed; set TP_CHANGEBIND.
2525 	 */
2526 	tp->t_proc_flag |= TP_CHANGEBIND;
2527 	aston(tp);
2528 
2529 	thread_unlock(tp);
2530 
2531 	return (0);
2532 }
2533 
2534 #if CPUSET_WORDS > 1
2535 
2536 /*
2537  * Functions for implementing cpuset operations when a cpuset is more
2538  * than one word.  On platforms where a cpuset is a single word these
2539  * are implemented as macros in cpuvar.h.
2540  */
2541 
2542 void
2543 cpuset_all(cpuset_t *s)
2544 {
2545 	int i;
2546 
2547 	for (i = 0; i < CPUSET_WORDS; i++)
2548 		s->cpub[i] = ~0UL;
2549 }
2550 
2551 void
2552 cpuset_all_but(cpuset_t *s, uint_t cpu)
2553 {
2554 	cpuset_all(s);
2555 	CPUSET_DEL(*s, cpu);
2556 }
2557 
2558 void
2559 cpuset_only(cpuset_t *s, uint_t cpu)
2560 {
2561 	CPUSET_ZERO(*s);
2562 	CPUSET_ADD(*s, cpu);
2563 }
2564 
2565 int
2566 cpuset_isnull(cpuset_t *s)
2567 {
2568 	int i;
2569 
2570 	for (i = 0; i < CPUSET_WORDS; i++)
2571 		if (s->cpub[i] != 0)
2572 			return (0);
2573 	return (1);
2574 }
2575 
2576 int
2577 cpuset_cmp(cpuset_t *s1, cpuset_t *s2)
2578 {
2579 	int i;
2580 
2581 	for (i = 0; i < CPUSET_WORDS; i++)
2582 		if (s1->cpub[i] != s2->cpub[i])
2583 			return (0);
2584 	return (1);
2585 }
2586 
2587 uint_t
2588 cpuset_find(cpuset_t *s)
2589 {
2590 
2591 	uint_t	i;
2592 	uint_t	cpu = (uint_t)-1;
2593 
2594 	/*
2595 	 * Find a cpu in the cpuset
2596 	 */
2597 	for (i = 0; (i < CPUSET_WORDS && cpu == (uint_t)-1); i++)
2598 		cpu = (uint_t)(lowbit(s->cpub[i]) - 1);
2599 	return (cpu);
2600 }
2601 
2602 #endif	/* CPUSET_WORDS */
2603 
2604 /*
2605  * Unbind all user threads bound to a given CPU.
2606  */
2607 int
2608 cpu_unbind(processorid_t cpu)
2609 {
2610 	processorid_t obind;
2611 	kthread_t *tp;
2612 	int ret = 0;
2613 	proc_t *pp;
2614 	int err, berr = 0;
2615 
2616 	ASSERT(MUTEX_HELD(&cpu_lock));
2617 
2618 	mutex_enter(&pidlock);
2619 	for (pp = practive; pp != NULL; pp = pp->p_next) {
2620 		mutex_enter(&pp->p_lock);
2621 		tp = pp->p_tlist;
2622 		/*
2623 		 * Skip zombies, kernel processes, and processes in
2624 		 * other zones, if called from a non-global zone.
2625 		 */
2626 		if (tp == NULL || (pp->p_flag & SSYS) ||
2627 		    !HASZONEACCESS(curproc, pp->p_zone->zone_id)) {
2628 			mutex_exit(&pp->p_lock);
2629 			continue;
2630 		}
2631 		do {
2632 			if (tp->t_bind_cpu != cpu)
2633 				continue;
2634 			err = cpu_bind_thread(tp, PBIND_NONE, &obind, &berr);
2635 			if (ret == 0)
2636 				ret = err;
2637 		} while ((tp = tp->t_forw) != pp->p_tlist);
2638 		mutex_exit(&pp->p_lock);
2639 	}
2640 	mutex_exit(&pidlock);
2641 	if (ret == 0)
2642 		ret = berr;
2643 	return (ret);
2644 }
2645 
2646 
2647 /*
2648  * Destroy all remaining bound threads on a cpu.
2649  */
2650 void
2651 cpu_destroy_bound_threads(cpu_t *cp)
2652 {
2653 	extern id_t syscid;
2654 	register kthread_id_t	t, tlist, tnext;
2655 
2656 	/*
2657 	 * Destroy all remaining bound threads on the cpu.  This
2658 	 * should include both the interrupt threads and the idle thread.
2659 	 * This requires some care, since we need to traverse the
2660 	 * thread list with the pidlock mutex locked, but thread_free
2661 	 * also locks the pidlock mutex.  So, we collect the threads
2662 	 * we're going to reap in a list headed by "tlist", then we
2663 	 * unlock the pidlock mutex and traverse the tlist list,
2664 	 * doing thread_free's on the thread's.	 Simple, n'est pas?
2665 	 * Also, this depends on thread_free not mucking with the
2666 	 * t_next and t_prev links of the thread.
2667 	 */
2668 
2669 	if ((t = curthread) != NULL) {
2670 
2671 		tlist = NULL;
2672 		mutex_enter(&pidlock);
2673 		do {
2674 			tnext = t->t_next;
2675 			if (t->t_bound_cpu == cp) {
2676 
2677 				/*
2678 				 * We've found a bound thread, carefully unlink
2679 				 * it out of the thread list, and add it to
2680 				 * our "tlist".	 We "know" we don't have to
2681 				 * worry about unlinking curthread (the thread
2682 				 * that is executing this code).
2683 				 */
2684 				t->t_next->t_prev = t->t_prev;
2685 				t->t_prev->t_next = t->t_next;
2686 				t->t_next = tlist;
2687 				tlist = t;
2688 				ASSERT(t->t_cid == syscid);
2689 				/* wake up anyone blocked in thread_join */
2690 				cv_broadcast(&t->t_joincv);
2691 				/*
2692 				 * t_lwp set by interrupt threads and not
2693 				 * cleared.
2694 				 */
2695 				t->t_lwp = NULL;
2696 				/*
2697 				 * Pause and idle threads always have
2698 				 * t_state set to TS_ONPROC.
2699 				 */
2700 				t->t_state = TS_FREE;
2701 				t->t_prev = NULL;	/* Just in case */
2702 			}
2703 
2704 		} while ((t = tnext) != curthread);
2705 
2706 		mutex_exit(&pidlock);
2707 
2708 
2709 		for (t = tlist; t != NULL; t = tnext) {
2710 			tnext = t->t_next;
2711 			thread_free(t);
2712 		}
2713 	}
2714 }
2715 
2716 /*
2717  * processor_info(2) and p_online(2) status support functions
2718  *   The constants returned by the cpu_get_state() and cpu_get_state_str() are
2719  *   for use in communicating processor state information to userland.  Kernel
2720  *   subsystems should only be using the cpu_flags value directly.  Subsystems
2721  *   modifying cpu_flags should record the state change via a call to the
2722  *   cpu_set_state().
2723  */
2724 
2725 /*
2726  * Update the pi_state of this CPU.  This function provides the CPU status for
2727  * the information returned by processor_info(2).
2728  */
2729 void
2730 cpu_set_state(cpu_t *cpu)
2731 {
2732 	ASSERT(MUTEX_HELD(&cpu_lock));
2733 	cpu->cpu_type_info.pi_state = cpu_get_state(cpu);
2734 	cpu->cpu_state_begin = gethrestime_sec();
2735 	pool_cpu_mod = gethrtime();
2736 }
2737 
2738 /*
2739  * Return offline/online/other status for the indicated CPU.  Use only for
2740  * communication with user applications; cpu_flags provides the in-kernel
2741  * interface.
2742  */
2743 int
2744 cpu_get_state(cpu_t *cpu)
2745 {
2746 	ASSERT(MUTEX_HELD(&cpu_lock));
2747 	if (cpu->cpu_flags & CPU_POWEROFF)
2748 		return (P_POWEROFF);
2749 	else if (cpu->cpu_flags & CPU_FAULTED)
2750 		return (P_FAULTED);
2751 	else if (cpu->cpu_flags & CPU_SPARE)
2752 		return (P_SPARE);
2753 	else if ((cpu->cpu_flags & (CPU_READY | CPU_OFFLINE)) != CPU_READY)
2754 		return (P_OFFLINE);
2755 	else if (cpu->cpu_flags & CPU_ENABLE)
2756 		return (P_ONLINE);
2757 	else
2758 		return (P_NOINTR);
2759 }
2760 
2761 /*
2762  * Return processor_info(2) state as a string.
2763  */
2764 const char *
2765 cpu_get_state_str(cpu_t *cpu)
2766 {
2767 	const char *string;
2768 
2769 	switch (cpu_get_state(cpu)) {
2770 	case P_ONLINE:
2771 		string = PS_ONLINE;
2772 		break;
2773 	case P_POWEROFF:
2774 		string = PS_POWEROFF;
2775 		break;
2776 	case P_NOINTR:
2777 		string = PS_NOINTR;
2778 		break;
2779 	case P_SPARE:
2780 		string = PS_SPARE;
2781 		break;
2782 	case P_FAULTED:
2783 		string = PS_FAULTED;
2784 		break;
2785 	case P_OFFLINE:
2786 		string = PS_OFFLINE;
2787 		break;
2788 	default:
2789 		string = "unknown";
2790 		break;
2791 	}
2792 	return (string);
2793 }
2794 
2795 /*
2796  * Export this CPU's statistics (cpu_stat_t and cpu_stats_t) as raw and named
2797  * kstats, respectively.  This is done when a CPU is initialized or placed
2798  * online via p_online(2).
2799  */
2800 static void
2801 cpu_stats_kstat_create(cpu_t *cp)
2802 {
2803 	int 	instance = cp->cpu_id;
2804 	char 	*module = "cpu";
2805 	char 	*class = "misc";
2806 	kstat_t	*ksp;
2807 	zoneid_t zoneid;
2808 
2809 	ASSERT(MUTEX_HELD(&cpu_lock));
2810 
2811 	if (pool_pset_enabled())
2812 		zoneid = GLOBAL_ZONEID;
2813 	else
2814 		zoneid = ALL_ZONES;
2815 	/*
2816 	 * Create named kstats
2817 	 */
2818 #define	CPU_STATS_KS_CREATE(name, tsize, update_func)                    \
2819 	ksp = kstat_create_zone(module, instance, (name), class,         \
2820 	    KSTAT_TYPE_NAMED, (tsize) / sizeof (kstat_named_t), 0,       \
2821 	    zoneid);                                                     \
2822 	if (ksp != NULL) {                                               \
2823 		ksp->ks_private = cp;                                    \
2824 		ksp->ks_update = (update_func);                          \
2825 		kstat_install(ksp);                                      \
2826 	} else                                                           \
2827 		cmn_err(CE_WARN, "cpu: unable to create %s:%d:%s kstat", \
2828 		    module, instance, (name));
2829 
2830 	CPU_STATS_KS_CREATE("sys", sizeof (cpu_sys_stats_ks_data_template),
2831 	    cpu_sys_stats_ks_update);
2832 	CPU_STATS_KS_CREATE("vm", sizeof (cpu_vm_stats_ks_data_template),
2833 	    cpu_vm_stats_ks_update);
2834 
2835 	/*
2836 	 * Export the familiar cpu_stat_t KSTAT_TYPE_RAW kstat.
2837 	 */
2838 	ksp = kstat_create_zone("cpu_stat", cp->cpu_id, NULL,
2839 	    "misc", KSTAT_TYPE_RAW, sizeof (cpu_stat_t), 0, zoneid);
2840 	if (ksp != NULL) {
2841 		ksp->ks_update = cpu_stat_ks_update;
2842 		ksp->ks_private = cp;
2843 		kstat_install(ksp);
2844 	}
2845 }
2846 
2847 static void
2848 cpu_stats_kstat_destroy(cpu_t *cp)
2849 {
2850 	char ks_name[KSTAT_STRLEN];
2851 
2852 	(void) sprintf(ks_name, "cpu_stat%d", cp->cpu_id);
2853 	kstat_delete_byname("cpu_stat", cp->cpu_id, ks_name);
2854 
2855 	kstat_delete_byname("cpu", cp->cpu_id, "sys");
2856 	kstat_delete_byname("cpu", cp->cpu_id, "vm");
2857 }
2858 
2859 static int
2860 cpu_sys_stats_ks_update(kstat_t *ksp, int rw)
2861 {
2862 	cpu_t *cp = (cpu_t *)ksp->ks_private;
2863 	struct cpu_sys_stats_ks_data *csskd;
2864 	cpu_sys_stats_t *css;
2865 	hrtime_t msnsecs[NCMSTATES];
2866 	int	i;
2867 
2868 	if (rw == KSTAT_WRITE)
2869 		return (EACCES);
2870 
2871 	csskd = ksp->ks_data;
2872 	css = &cp->cpu_stats.sys;
2873 
2874 	/*
2875 	 * Read CPU mstate, but compare with the last values we
2876 	 * received to make sure that the returned kstats never
2877 	 * decrease.
2878 	 */
2879 
2880 	get_cpu_mstate(cp, msnsecs);
2881 	if (csskd->cpu_nsec_idle.value.ui64 > msnsecs[CMS_IDLE])
2882 		msnsecs[CMS_IDLE] = csskd->cpu_nsec_idle.value.ui64;
2883 	if (csskd->cpu_nsec_user.value.ui64 > msnsecs[CMS_USER])
2884 		msnsecs[CMS_USER] = csskd->cpu_nsec_user.value.ui64;
2885 	if (csskd->cpu_nsec_kernel.value.ui64 > msnsecs[CMS_SYSTEM])
2886 		msnsecs[CMS_SYSTEM] = csskd->cpu_nsec_kernel.value.ui64;
2887 
2888 	bcopy(&cpu_sys_stats_ks_data_template, ksp->ks_data,
2889 	    sizeof (cpu_sys_stats_ks_data_template));
2890 
2891 	csskd->cpu_ticks_wait.value.ui64 = 0;
2892 	csskd->wait_ticks_io.value.ui64 = 0;
2893 
2894 	csskd->cpu_nsec_idle.value.ui64 = msnsecs[CMS_IDLE];
2895 	csskd->cpu_nsec_user.value.ui64 = msnsecs[CMS_USER];
2896 	csskd->cpu_nsec_kernel.value.ui64 = msnsecs[CMS_SYSTEM];
2897 	csskd->cpu_ticks_idle.value.ui64 =
2898 	    NSEC_TO_TICK(csskd->cpu_nsec_idle.value.ui64);
2899 	csskd->cpu_ticks_user.value.ui64 =
2900 	    NSEC_TO_TICK(csskd->cpu_nsec_user.value.ui64);
2901 	csskd->cpu_ticks_kernel.value.ui64 =
2902 	    NSEC_TO_TICK(csskd->cpu_nsec_kernel.value.ui64);
2903 	csskd->bread.value.ui64 = css->bread;
2904 	csskd->bwrite.value.ui64 = css->bwrite;
2905 	csskd->lread.value.ui64 = css->lread;
2906 	csskd->lwrite.value.ui64 = css->lwrite;
2907 	csskd->phread.value.ui64 = css->phread;
2908 	csskd->phwrite.value.ui64 = css->phwrite;
2909 	csskd->pswitch.value.ui64 = css->pswitch;
2910 	csskd->trap.value.ui64 = css->trap;
2911 	csskd->intr.value.ui64 = 0;
2912 	for (i = 0; i < PIL_MAX; i++)
2913 		csskd->intr.value.ui64 += css->intr[i];
2914 	csskd->syscall.value.ui64 = css->syscall;
2915 	csskd->sysread.value.ui64 = css->sysread;
2916 	csskd->syswrite.value.ui64 = css->syswrite;
2917 	csskd->sysfork.value.ui64 = css->sysfork;
2918 	csskd->sysvfork.value.ui64 = css->sysvfork;
2919 	csskd->sysexec.value.ui64 = css->sysexec;
2920 	csskd->readch.value.ui64 = css->readch;
2921 	csskd->writech.value.ui64 = css->writech;
2922 	csskd->rcvint.value.ui64 = css->rcvint;
2923 	csskd->xmtint.value.ui64 = css->xmtint;
2924 	csskd->mdmint.value.ui64 = css->mdmint;
2925 	csskd->rawch.value.ui64 = css->rawch;
2926 	csskd->canch.value.ui64 = css->canch;
2927 	csskd->outch.value.ui64 = css->outch;
2928 	csskd->msg.value.ui64 = css->msg;
2929 	csskd->sema.value.ui64 = css->sema;
2930 	csskd->namei.value.ui64 = css->namei;
2931 	csskd->ufsiget.value.ui64 = css->ufsiget;
2932 	csskd->ufsdirblk.value.ui64 = css->ufsdirblk;
2933 	csskd->ufsipage.value.ui64 = css->ufsipage;
2934 	csskd->ufsinopage.value.ui64 = css->ufsinopage;
2935 	csskd->procovf.value.ui64 = css->procovf;
2936 	csskd->intrthread.value.ui64 = 0;
2937 	for (i = 0; i < LOCK_LEVEL; i++)
2938 		csskd->intrthread.value.ui64 += css->intr[i];
2939 	csskd->intrblk.value.ui64 = css->intrblk;
2940 	csskd->intrunpin.value.ui64 = css->intrunpin;
2941 	csskd->idlethread.value.ui64 = css->idlethread;
2942 	csskd->inv_swtch.value.ui64 = css->inv_swtch;
2943 	csskd->nthreads.value.ui64 = css->nthreads;
2944 	csskd->cpumigrate.value.ui64 = css->cpumigrate;
2945 	csskd->xcalls.value.ui64 = css->xcalls;
2946 	csskd->mutex_adenters.value.ui64 = css->mutex_adenters;
2947 	csskd->rw_rdfails.value.ui64 = css->rw_rdfails;
2948 	csskd->rw_wrfails.value.ui64 = css->rw_wrfails;
2949 	csskd->modload.value.ui64 = css->modload;
2950 	csskd->modunload.value.ui64 = css->modunload;
2951 	csskd->bawrite.value.ui64 = css->bawrite;
2952 	csskd->iowait.value.ui64 = 0;
2953 
2954 	return (0);
2955 }
2956 
2957 static int
2958 cpu_vm_stats_ks_update(kstat_t *ksp, int rw)
2959 {
2960 	cpu_t *cp = (cpu_t *)ksp->ks_private;
2961 	struct cpu_vm_stats_ks_data *cvskd;
2962 	cpu_vm_stats_t *cvs;
2963 
2964 	if (rw == KSTAT_WRITE)
2965 		return (EACCES);
2966 
2967 	cvs = &cp->cpu_stats.vm;
2968 	cvskd = ksp->ks_data;
2969 
2970 	bcopy(&cpu_vm_stats_ks_data_template, ksp->ks_data,
2971 	    sizeof (cpu_vm_stats_ks_data_template));
2972 	cvskd->pgrec.value.ui64 = cvs->pgrec;
2973 	cvskd->pgfrec.value.ui64 = cvs->pgfrec;
2974 	cvskd->pgin.value.ui64 = cvs->pgin;
2975 	cvskd->pgpgin.value.ui64 = cvs->pgpgin;
2976 	cvskd->pgout.value.ui64 = cvs->pgout;
2977 	cvskd->pgpgout.value.ui64 = cvs->pgpgout;
2978 	cvskd->swapin.value.ui64 = cvs->swapin;
2979 	cvskd->pgswapin.value.ui64 = cvs->pgswapin;
2980 	cvskd->swapout.value.ui64 = cvs->swapout;
2981 	cvskd->pgswapout.value.ui64 = cvs->pgswapout;
2982 	cvskd->zfod.value.ui64 = cvs->zfod;
2983 	cvskd->dfree.value.ui64 = cvs->dfree;
2984 	cvskd->scan.value.ui64 = cvs->scan;
2985 	cvskd->rev.value.ui64 = cvs->rev;
2986 	cvskd->hat_fault.value.ui64 = cvs->hat_fault;
2987 	cvskd->as_fault.value.ui64 = cvs->as_fault;
2988 	cvskd->maj_fault.value.ui64 = cvs->maj_fault;
2989 	cvskd->cow_fault.value.ui64 = cvs->cow_fault;
2990 	cvskd->prot_fault.value.ui64 = cvs->prot_fault;
2991 	cvskd->softlock.value.ui64 = cvs->softlock;
2992 	cvskd->kernel_asflt.value.ui64 = cvs->kernel_asflt;
2993 	cvskd->pgrrun.value.ui64 = cvs->pgrrun;
2994 	cvskd->execpgin.value.ui64 = cvs->execpgin;
2995 	cvskd->execpgout.value.ui64 = cvs->execpgout;
2996 	cvskd->execfree.value.ui64 = cvs->execfree;
2997 	cvskd->anonpgin.value.ui64 = cvs->anonpgin;
2998 	cvskd->anonpgout.value.ui64 = cvs->anonpgout;
2999 	cvskd->anonfree.value.ui64 = cvs->anonfree;
3000 	cvskd->fspgin.value.ui64 = cvs->fspgin;
3001 	cvskd->fspgout.value.ui64 = cvs->fspgout;
3002 	cvskd->fsfree.value.ui64 = cvs->fsfree;
3003 
3004 	return (0);
3005 }
3006 
3007 static int
3008 cpu_stat_ks_update(kstat_t *ksp, int rw)
3009 {
3010 	cpu_stat_t *cso;
3011 	cpu_t *cp;
3012 	int i;
3013 	hrtime_t msnsecs[NCMSTATES];
3014 
3015 	cso = (cpu_stat_t *)ksp->ks_data;
3016 	cp = (cpu_t *)ksp->ks_private;
3017 
3018 	if (rw == KSTAT_WRITE)
3019 		return (EACCES);
3020 
3021 	/*
3022 	 * Read CPU mstate, but compare with the last values we
3023 	 * received to make sure that the returned kstats never
3024 	 * decrease.
3025 	 */
3026 
3027 	get_cpu_mstate(cp, msnsecs);
3028 	msnsecs[CMS_IDLE] = NSEC_TO_TICK(msnsecs[CMS_IDLE]);
3029 	msnsecs[CMS_USER] = NSEC_TO_TICK(msnsecs[CMS_USER]);
3030 	msnsecs[CMS_SYSTEM] = NSEC_TO_TICK(msnsecs[CMS_SYSTEM]);
3031 	if (cso->cpu_sysinfo.cpu[CPU_IDLE] < msnsecs[CMS_IDLE])
3032 		cso->cpu_sysinfo.cpu[CPU_IDLE] = msnsecs[CMS_IDLE];
3033 	if (cso->cpu_sysinfo.cpu[CPU_USER] < msnsecs[CMS_USER])
3034 		cso->cpu_sysinfo.cpu[CPU_USER] = msnsecs[CMS_USER];
3035 	if (cso->cpu_sysinfo.cpu[CPU_KERNEL] < msnsecs[CMS_SYSTEM])
3036 		cso->cpu_sysinfo.cpu[CPU_KERNEL] = msnsecs[CMS_SYSTEM];
3037 	cso->cpu_sysinfo.cpu[CPU_WAIT] 	= 0;
3038 	cso->cpu_sysinfo.wait[W_IO] 	= 0;
3039 	cso->cpu_sysinfo.wait[W_SWAP]	= 0;
3040 	cso->cpu_sysinfo.wait[W_PIO]	= 0;
3041 	cso->cpu_sysinfo.bread 		= CPU_STATS(cp, sys.bread);
3042 	cso->cpu_sysinfo.bwrite 	= CPU_STATS(cp, sys.bwrite);
3043 	cso->cpu_sysinfo.lread 		= CPU_STATS(cp, sys.lread);
3044 	cso->cpu_sysinfo.lwrite 	= CPU_STATS(cp, sys.lwrite);
3045 	cso->cpu_sysinfo.phread 	= CPU_STATS(cp, sys.phread);
3046 	cso->cpu_sysinfo.phwrite 	= CPU_STATS(cp, sys.phwrite);
3047 	cso->cpu_sysinfo.pswitch 	= CPU_STATS(cp, sys.pswitch);
3048 	cso->cpu_sysinfo.trap 		= CPU_STATS(cp, sys.trap);
3049 	cso->cpu_sysinfo.intr		= 0;
3050 	for (i = 0; i < PIL_MAX; i++)
3051 		cso->cpu_sysinfo.intr += CPU_STATS(cp, sys.intr[i]);
3052 	cso->cpu_sysinfo.syscall	= CPU_STATS(cp, sys.syscall);
3053 	cso->cpu_sysinfo.sysread	= CPU_STATS(cp, sys.sysread);
3054 	cso->cpu_sysinfo.syswrite	= CPU_STATS(cp, sys.syswrite);
3055 	cso->cpu_sysinfo.sysfork	= CPU_STATS(cp, sys.sysfork);
3056 	cso->cpu_sysinfo.sysvfork	= CPU_STATS(cp, sys.sysvfork);
3057 	cso->cpu_sysinfo.sysexec	= CPU_STATS(cp, sys.sysexec);
3058 	cso->cpu_sysinfo.readch		= CPU_STATS(cp, sys.readch);
3059 	cso->cpu_sysinfo.writech	= CPU_STATS(cp, sys.writech);
3060 	cso->cpu_sysinfo.rcvint		= CPU_STATS(cp, sys.rcvint);
3061 	cso->cpu_sysinfo.xmtint		= CPU_STATS(cp, sys.xmtint);
3062 	cso->cpu_sysinfo.mdmint		= CPU_STATS(cp, sys.mdmint);
3063 	cso->cpu_sysinfo.rawch		= CPU_STATS(cp, sys.rawch);
3064 	cso->cpu_sysinfo.canch		= CPU_STATS(cp, sys.canch);
3065 	cso->cpu_sysinfo.outch		= CPU_STATS(cp, sys.outch);
3066 	cso->cpu_sysinfo.msg		= CPU_STATS(cp, sys.msg);
3067 	cso->cpu_sysinfo.sema		= CPU_STATS(cp, sys.sema);
3068 	cso->cpu_sysinfo.namei		= CPU_STATS(cp, sys.namei);
3069 	cso->cpu_sysinfo.ufsiget	= CPU_STATS(cp, sys.ufsiget);
3070 	cso->cpu_sysinfo.ufsdirblk	= CPU_STATS(cp, sys.ufsdirblk);
3071 	cso->cpu_sysinfo.ufsipage	= CPU_STATS(cp, sys.ufsipage);
3072 	cso->cpu_sysinfo.ufsinopage	= CPU_STATS(cp, sys.ufsinopage);
3073 	cso->cpu_sysinfo.inodeovf	= 0;
3074 	cso->cpu_sysinfo.fileovf	= 0;
3075 	cso->cpu_sysinfo.procovf	= CPU_STATS(cp, sys.procovf);
3076 	cso->cpu_sysinfo.intrthread	= 0;
3077 	for (i = 0; i < LOCK_LEVEL; i++)
3078 		cso->cpu_sysinfo.intrthread += CPU_STATS(cp, sys.intr[i]);
3079 	cso->cpu_sysinfo.intrblk	= CPU_STATS(cp, sys.intrblk);
3080 	cso->cpu_sysinfo.idlethread	= CPU_STATS(cp, sys.idlethread);
3081 	cso->cpu_sysinfo.inv_swtch	= CPU_STATS(cp, sys.inv_swtch);
3082 	cso->cpu_sysinfo.nthreads	= CPU_STATS(cp, sys.nthreads);
3083 	cso->cpu_sysinfo.cpumigrate	= CPU_STATS(cp, sys.cpumigrate);
3084 	cso->cpu_sysinfo.xcalls		= CPU_STATS(cp, sys.xcalls);
3085 	cso->cpu_sysinfo.mutex_adenters	= CPU_STATS(cp, sys.mutex_adenters);
3086 	cso->cpu_sysinfo.rw_rdfails	= CPU_STATS(cp, sys.rw_rdfails);
3087 	cso->cpu_sysinfo.rw_wrfails	= CPU_STATS(cp, sys.rw_wrfails);
3088 	cso->cpu_sysinfo.modload	= CPU_STATS(cp, sys.modload);
3089 	cso->cpu_sysinfo.modunload	= CPU_STATS(cp, sys.modunload);
3090 	cso->cpu_sysinfo.bawrite	= CPU_STATS(cp, sys.bawrite);
3091 	cso->cpu_sysinfo.rw_enters	= 0;
3092 	cso->cpu_sysinfo.win_uo_cnt	= 0;
3093 	cso->cpu_sysinfo.win_uu_cnt	= 0;
3094 	cso->cpu_sysinfo.win_so_cnt	= 0;
3095 	cso->cpu_sysinfo.win_su_cnt	= 0;
3096 	cso->cpu_sysinfo.win_suo_cnt	= 0;
3097 
3098 	cso->cpu_syswait.iowait		= 0;
3099 	cso->cpu_syswait.swap		= 0;
3100 	cso->cpu_syswait.physio		= 0;
3101 
3102 	cso->cpu_vminfo.pgrec		= CPU_STATS(cp, vm.pgrec);
3103 	cso->cpu_vminfo.pgfrec		= CPU_STATS(cp, vm.pgfrec);
3104 	cso->cpu_vminfo.pgin		= CPU_STATS(cp, vm.pgin);
3105 	cso->cpu_vminfo.pgpgin		= CPU_STATS(cp, vm.pgpgin);
3106 	cso->cpu_vminfo.pgout		= CPU_STATS(cp, vm.pgout);
3107 	cso->cpu_vminfo.pgpgout		= CPU_STATS(cp, vm.pgpgout);
3108 	cso->cpu_vminfo.swapin		= CPU_STATS(cp, vm.swapin);
3109 	cso->cpu_vminfo.pgswapin	= CPU_STATS(cp, vm.pgswapin);
3110 	cso->cpu_vminfo.swapout		= CPU_STATS(cp, vm.swapout);
3111 	cso->cpu_vminfo.pgswapout	= CPU_STATS(cp, vm.pgswapout);
3112 	cso->cpu_vminfo.zfod		= CPU_STATS(cp, vm.zfod);
3113 	cso->cpu_vminfo.dfree		= CPU_STATS(cp, vm.dfree);
3114 	cso->cpu_vminfo.scan		= CPU_STATS(cp, vm.scan);
3115 	cso->cpu_vminfo.rev		= CPU_STATS(cp, vm.rev);
3116 	cso->cpu_vminfo.hat_fault	= CPU_STATS(cp, vm.hat_fault);
3117 	cso->cpu_vminfo.as_fault	= CPU_STATS(cp, vm.as_fault);
3118 	cso->cpu_vminfo.maj_fault	= CPU_STATS(cp, vm.maj_fault);
3119 	cso->cpu_vminfo.cow_fault	= CPU_STATS(cp, vm.cow_fault);
3120 	cso->cpu_vminfo.prot_fault	= CPU_STATS(cp, vm.prot_fault);
3121 	cso->cpu_vminfo.softlock	= CPU_STATS(cp, vm.softlock);
3122 	cso->cpu_vminfo.kernel_asflt	= CPU_STATS(cp, vm.kernel_asflt);
3123 	cso->cpu_vminfo.pgrrun		= CPU_STATS(cp, vm.pgrrun);
3124 	cso->cpu_vminfo.execpgin	= CPU_STATS(cp, vm.execpgin);
3125 	cso->cpu_vminfo.execpgout	= CPU_STATS(cp, vm.execpgout);
3126 	cso->cpu_vminfo.execfree	= CPU_STATS(cp, vm.execfree);
3127 	cso->cpu_vminfo.anonpgin	= CPU_STATS(cp, vm.anonpgin);
3128 	cso->cpu_vminfo.anonpgout	= CPU_STATS(cp, vm.anonpgout);
3129 	cso->cpu_vminfo.anonfree	= CPU_STATS(cp, vm.anonfree);
3130 	cso->cpu_vminfo.fspgin		= CPU_STATS(cp, vm.fspgin);
3131 	cso->cpu_vminfo.fspgout		= CPU_STATS(cp, vm.fspgout);
3132 	cso->cpu_vminfo.fsfree		= CPU_STATS(cp, vm.fsfree);
3133 
3134 	return (0);
3135 }
3136