37
38#include <sys/param.h>
39#include <sys/systm.h>
40#include <sys/kernel.h>
41#include <sys/ktr.h>
42#include <sys/proc.h>
43#include <sys/bus.h>
44#include <sys/lock.h>
45#include <sys/mutex.h>
46#include <sys/pcpu.h>
47#include <sys/sched.h>
48#include <sys/smp.h>
49#include <sys/sysctl.h>
50
51#include <machine/cpu.h>
52#include <machine/smp.h>
53
54#include "opt_sched.h"
55
56#ifdef SMP
57volatile cpuset_t stopped_cpus;
58volatile cpuset_t started_cpus;
59volatile cpuset_t suspended_cpus;
60cpuset_t hlt_cpus_mask;
61cpuset_t logical_cpus_mask;
62
63void (*cpustop_restartfunc)(void);
64#endif
65/* This is used in modules that need to work in both SMP and UP. */
66cpuset_t all_cpus;
67
68int mp_ncpus;
69/* export this for libkvm consumers. */
70int mp_maxcpus = MAXCPU;
71
72volatile int smp_started;
73u_int mp_maxid;
74
75static SYSCTL_NODE(_kern, OID_AUTO, smp, CTLFLAG_RD|CTLFLAG_CAPRD, NULL,
76 "Kernel SMP");
77
78SYSCTL_INT(_kern_smp, OID_AUTO, maxid, CTLFLAG_RD|CTLFLAG_CAPRD, &mp_maxid, 0,
79 "Max CPU ID.");
80
81SYSCTL_INT(_kern_smp, OID_AUTO, maxcpus, CTLFLAG_RD|CTLFLAG_CAPRD, &mp_maxcpus,
82 0, "Max number of CPUs that the system was compiled for.");
83
84int smp_active = 0; /* are the APs allowed to run? */
85SYSCTL_INT(_kern_smp, OID_AUTO, active, CTLFLAG_RW, &smp_active, 0,
86 "Number of Auxillary Processors (APs) that were successfully started");
87
88int smp_disabled = 0; /* has smp been disabled? */
89SYSCTL_INT(_kern_smp, OID_AUTO, disabled, CTLFLAG_RDTUN|CTLFLAG_CAPRD,
90 &smp_disabled, 0, "SMP has been disabled from the loader");
91TUNABLE_INT("kern.smp.disabled", &smp_disabled);
92
93int smp_cpus = 1; /* how many cpu's running */
94SYSCTL_INT(_kern_smp, OID_AUTO, cpus, CTLFLAG_RD|CTLFLAG_CAPRD, &smp_cpus, 0,
95 "Number of CPUs online");
96
97int smp_topology = 0; /* Which topology we're using. */
98SYSCTL_INT(_kern_smp, OID_AUTO, topology, CTLFLAG_RD, &smp_topology, 0,
99 "Topology override setting; 0 is default provided by hardware.");
100TUNABLE_INT("kern.smp.topology", &smp_topology);
101
102#ifdef SMP
103/* Enable forwarding of a signal to a process running on a different CPU */
104static int forward_signal_enabled = 1;
105SYSCTL_INT(_kern_smp, OID_AUTO, forward_signal_enabled, CTLFLAG_RW,
106 &forward_signal_enabled, 0,
107 "Forwarding of a signal to a process on a different CPU");
108
109/* Variables needed for SMP rendezvous. */
110static volatile int smp_rv_ncpus;
111static void (*volatile smp_rv_setup_func)(void *arg);
112static void (*volatile smp_rv_action_func)(void *arg);
113static void (*volatile smp_rv_teardown_func)(void *arg);
114static void *volatile smp_rv_func_arg;
115static volatile int smp_rv_waiters[4];
116
117/*
118 * Shared mutex to restrict busywaits between smp_rendezvous() and
119 * smp(_targeted)_tlb_shootdown(). A deadlock occurs if both of these
120 * functions trigger at once and cause multiple CPUs to busywait with
121 * interrupts disabled.
122 */
123struct mtx smp_ipi_mtx;
124
125/*
126 * Let the MD SMP code initialize mp_maxid very early if it can.
127 */
128static void
129mp_setmaxid(void *dummy)
130{
131 cpu_mp_setmaxid();
132}
133SYSINIT(cpu_mp_setmaxid, SI_SUB_TUNABLES, SI_ORDER_FIRST, mp_setmaxid, NULL);
134
135/*
136 * Call the MD SMP initialization code.
137 */
138static void
139mp_start(void *dummy)
140{
141
142 mtx_init(&smp_ipi_mtx, "smp rendezvous", NULL, MTX_SPIN);
143
144 /* Probe for MP hardware. */
145 if (smp_disabled != 0 || cpu_mp_probe() == 0) {
146 mp_ncpus = 1;
147 CPU_SETOF(PCPU_GET(cpuid), &all_cpus);
148 return;
149 }
150
151 cpu_mp_start();
152 printf("FreeBSD/SMP: Multiprocessor System Detected: %d CPUs\n",
153 mp_ncpus);
154 cpu_mp_announce();
155}
156SYSINIT(cpu_mp, SI_SUB_CPU, SI_ORDER_THIRD, mp_start, NULL);
157
158void
159forward_signal(struct thread *td)
160{
161 int id;
162
163 /*
164 * signotify() has already set TDF_ASTPENDING and TDF_NEEDSIGCHECK on
165 * this thread, so all we need to do is poke it if it is currently
166 * executing so that it executes ast().
167 */
168 THREAD_LOCK_ASSERT(td, MA_OWNED);
169 KASSERT(TD_IS_RUNNING(td),
170 ("forward_signal: thread is not TDS_RUNNING"));
171
172 CTR1(KTR_SMP, "forward_signal(%p)", td->td_proc);
173
174 if (!smp_started || cold || panicstr)
175 return;
176 if (!forward_signal_enabled)
177 return;
178
179 /* No need to IPI ourself. */
180 if (td == curthread)
181 return;
182
183 id = td->td_oncpu;
184 if (id == NOCPU)
185 return;
186 ipi_cpu(id, IPI_AST);
187}
188
189/*
190 * When called the executing CPU will send an IPI to all other CPUs
191 * requesting that they halt execution.
192 *
193 * Usually (but not necessarily) called with 'other_cpus' as its arg.
194 *
195 * - Signals all CPUs in map to stop.
196 * - Waits for each to stop.
197 *
198 * Returns:
199 * -1: error
200 * 0: NA
201 * 1: ok
202 *
203 */
204static int
205generic_stop_cpus(cpuset_t map, u_int type)
206{
207#ifdef KTR
208 char cpusetbuf[CPUSETBUFSIZ];
209#endif
210 static volatile u_int stopping_cpu = NOCPU;
211 int i;
212 volatile cpuset_t *cpus;
213
214 KASSERT(
215#if defined(__amd64__) || defined(__i386__)
216 type == IPI_STOP || type == IPI_STOP_HARD || type == IPI_SUSPEND,
217#else
218 type == IPI_STOP || type == IPI_STOP_HARD,
219#endif
220 ("%s: invalid stop type", __func__));
221
222 if (!smp_started)
223 return (0);
224
225 CTR2(KTR_SMP, "stop_cpus(%s) with %u type",
226 cpusetobj_strprint(cpusetbuf, &map), type);
227
| 37
38#include <sys/param.h>
39#include <sys/systm.h>
40#include <sys/kernel.h>
41#include <sys/ktr.h>
42#include <sys/proc.h>
43#include <sys/bus.h>
44#include <sys/lock.h>
45#include <sys/mutex.h>
46#include <sys/pcpu.h>
47#include <sys/sched.h>
48#include <sys/smp.h>
49#include <sys/sysctl.h>
50
51#include <machine/cpu.h>
52#include <machine/smp.h>
53
54#include "opt_sched.h"
55
56#ifdef SMP
57volatile cpuset_t stopped_cpus;
58volatile cpuset_t started_cpus;
59volatile cpuset_t suspended_cpus;
60cpuset_t hlt_cpus_mask;
61cpuset_t logical_cpus_mask;
62
63void (*cpustop_restartfunc)(void);
64#endif
65/* This is used in modules that need to work in both SMP and UP. */
66cpuset_t all_cpus;
67
68int mp_ncpus;
69/* export this for libkvm consumers. */
70int mp_maxcpus = MAXCPU;
71
72volatile int smp_started;
73u_int mp_maxid;
74
75static SYSCTL_NODE(_kern, OID_AUTO, smp, CTLFLAG_RD|CTLFLAG_CAPRD, NULL,
76 "Kernel SMP");
77
78SYSCTL_INT(_kern_smp, OID_AUTO, maxid, CTLFLAG_RD|CTLFLAG_CAPRD, &mp_maxid, 0,
79 "Max CPU ID.");
80
81SYSCTL_INT(_kern_smp, OID_AUTO, maxcpus, CTLFLAG_RD|CTLFLAG_CAPRD, &mp_maxcpus,
82 0, "Max number of CPUs that the system was compiled for.");
83
84int smp_active = 0; /* are the APs allowed to run? */
85SYSCTL_INT(_kern_smp, OID_AUTO, active, CTLFLAG_RW, &smp_active, 0,
86 "Number of Auxillary Processors (APs) that were successfully started");
87
88int smp_disabled = 0; /* has smp been disabled? */
89SYSCTL_INT(_kern_smp, OID_AUTO, disabled, CTLFLAG_RDTUN|CTLFLAG_CAPRD,
90 &smp_disabled, 0, "SMP has been disabled from the loader");
91TUNABLE_INT("kern.smp.disabled", &smp_disabled);
92
93int smp_cpus = 1; /* how many cpu's running */
94SYSCTL_INT(_kern_smp, OID_AUTO, cpus, CTLFLAG_RD|CTLFLAG_CAPRD, &smp_cpus, 0,
95 "Number of CPUs online");
96
97int smp_topology = 0; /* Which topology we're using. */
98SYSCTL_INT(_kern_smp, OID_AUTO, topology, CTLFLAG_RD, &smp_topology, 0,
99 "Topology override setting; 0 is default provided by hardware.");
100TUNABLE_INT("kern.smp.topology", &smp_topology);
101
102#ifdef SMP
103/* Enable forwarding of a signal to a process running on a different CPU */
104static int forward_signal_enabled = 1;
105SYSCTL_INT(_kern_smp, OID_AUTO, forward_signal_enabled, CTLFLAG_RW,
106 &forward_signal_enabled, 0,
107 "Forwarding of a signal to a process on a different CPU");
108
109/* Variables needed for SMP rendezvous. */
110static volatile int smp_rv_ncpus;
111static void (*volatile smp_rv_setup_func)(void *arg);
112static void (*volatile smp_rv_action_func)(void *arg);
113static void (*volatile smp_rv_teardown_func)(void *arg);
114static void *volatile smp_rv_func_arg;
115static volatile int smp_rv_waiters[4];
116
117/*
118 * Shared mutex to restrict busywaits between smp_rendezvous() and
119 * smp(_targeted)_tlb_shootdown(). A deadlock occurs if both of these
120 * functions trigger at once and cause multiple CPUs to busywait with
121 * interrupts disabled.
122 */
123struct mtx smp_ipi_mtx;
124
125/*
126 * Let the MD SMP code initialize mp_maxid very early if it can.
127 */
128static void
129mp_setmaxid(void *dummy)
130{
131 cpu_mp_setmaxid();
132}
133SYSINIT(cpu_mp_setmaxid, SI_SUB_TUNABLES, SI_ORDER_FIRST, mp_setmaxid, NULL);
134
135/*
136 * Call the MD SMP initialization code.
137 */
138static void
139mp_start(void *dummy)
140{
141
142 mtx_init(&smp_ipi_mtx, "smp rendezvous", NULL, MTX_SPIN);
143
144 /* Probe for MP hardware. */
145 if (smp_disabled != 0 || cpu_mp_probe() == 0) {
146 mp_ncpus = 1;
147 CPU_SETOF(PCPU_GET(cpuid), &all_cpus);
148 return;
149 }
150
151 cpu_mp_start();
152 printf("FreeBSD/SMP: Multiprocessor System Detected: %d CPUs\n",
153 mp_ncpus);
154 cpu_mp_announce();
155}
156SYSINIT(cpu_mp, SI_SUB_CPU, SI_ORDER_THIRD, mp_start, NULL);
157
158void
159forward_signal(struct thread *td)
160{
161 int id;
162
163 /*
164 * signotify() has already set TDF_ASTPENDING and TDF_NEEDSIGCHECK on
165 * this thread, so all we need to do is poke it if it is currently
166 * executing so that it executes ast().
167 */
168 THREAD_LOCK_ASSERT(td, MA_OWNED);
169 KASSERT(TD_IS_RUNNING(td),
170 ("forward_signal: thread is not TDS_RUNNING"));
171
172 CTR1(KTR_SMP, "forward_signal(%p)", td->td_proc);
173
174 if (!smp_started || cold || panicstr)
175 return;
176 if (!forward_signal_enabled)
177 return;
178
179 /* No need to IPI ourself. */
180 if (td == curthread)
181 return;
182
183 id = td->td_oncpu;
184 if (id == NOCPU)
185 return;
186 ipi_cpu(id, IPI_AST);
187}
188
189/*
190 * When called the executing CPU will send an IPI to all other CPUs
191 * requesting that they halt execution.
192 *
193 * Usually (but not necessarily) called with 'other_cpus' as its arg.
194 *
195 * - Signals all CPUs in map to stop.
196 * - Waits for each to stop.
197 *
198 * Returns:
199 * -1: error
200 * 0: NA
201 * 1: ok
202 *
203 */
204static int
205generic_stop_cpus(cpuset_t map, u_int type)
206{
207#ifdef KTR
208 char cpusetbuf[CPUSETBUFSIZ];
209#endif
210 static volatile u_int stopping_cpu = NOCPU;
211 int i;
212 volatile cpuset_t *cpus;
213
214 KASSERT(
215#if defined(__amd64__) || defined(__i386__)
216 type == IPI_STOP || type == IPI_STOP_HARD || type == IPI_SUSPEND,
217#else
218 type == IPI_STOP || type == IPI_STOP_HARD,
219#endif
220 ("%s: invalid stop type", __func__));
221
222 if (!smp_started)
223 return (0);
224
225 CTR2(KTR_SMP, "stop_cpus(%s) with %u type",
226 cpusetobj_strprint(cpusetbuf, &map), type);
227
|
271
272 stopping_cpu = NOCPU;
273 return (1);
274}
275
276int
277stop_cpus(cpuset_t map)
278{
279
280 return (generic_stop_cpus(map, IPI_STOP));
281}
282
283int
284stop_cpus_hard(cpuset_t map)
285{
286
287 return (generic_stop_cpus(map, IPI_STOP_HARD));
288}
289
290#if defined(__amd64__) || defined(__i386__)
291int
292suspend_cpus(cpuset_t map)
293{
294
295 return (generic_stop_cpus(map, IPI_SUSPEND));
296}
297#endif
298
299/*
300 * Called by a CPU to restart stopped CPUs.
301 *
302 * Usually (but not necessarily) called with 'stopped_cpus' as its arg.
303 *
304 * - Signals all CPUs in map to restart.
305 * - Waits for each to restart.
306 *
307 * Returns:
308 * -1: error
309 * 0: NA
310 * 1: ok
311 */
312static int
313generic_restart_cpus(cpuset_t map, u_int type)
314{
315#ifdef KTR
316 char cpusetbuf[CPUSETBUFSIZ];
317#endif
318 volatile cpuset_t *cpus;
319
320 KASSERT(
321#if defined(__amd64__) || defined(__i386__)
322 type == IPI_STOP || type == IPI_STOP_HARD || type == IPI_SUSPEND,
323#else
324 type == IPI_STOP || type == IPI_STOP_HARD,
325#endif
326 ("%s: invalid stop type", __func__));
327
328 if (!smp_started)
329 return 0;
330
331 CTR1(KTR_SMP, "restart_cpus(%s)", cpusetobj_strprint(cpusetbuf, &map));
332
333#if defined(__amd64__) || defined(__i386__)
334 if (type == IPI_SUSPEND)
335 cpus = &suspended_cpus;
336 else
337#endif
338 cpus = &stopped_cpus;
339
340 /* signal other cpus to restart */
341 CPU_COPY_STORE_REL(&map, &started_cpus);
342
343 /* wait for each to clear its bit */
344 while (CPU_OVERLAP(cpus, &map))
345 cpu_spinwait();
346
347 return 1;
348}
349
350int
351restart_cpus(cpuset_t map)
352{
353
354 return (generic_restart_cpus(map, IPI_STOP));
355}
356
357#if defined(__amd64__) || defined(__i386__)
358int
359resume_cpus(cpuset_t map)
360{
361
362 return (generic_restart_cpus(map, IPI_SUSPEND));
363}
364#endif
365
366/*
367 * All-CPU rendezvous. CPUs are signalled, all execute the setup function
368 * (if specified), rendezvous, execute the action function (if specified),
369 * rendezvous again, execute the teardown function (if specified), and then
370 * resume.
371 *
372 * Note that the supplied external functions _must_ be reentrant and aware
373 * that they are running in parallel and in an unknown lock context.
374 */
375void
376smp_rendezvous_action(void)
377{
378 struct thread *td;
379 void *local_func_arg;
380 void (*local_setup_func)(void*);
381 void (*local_action_func)(void*);
382 void (*local_teardown_func)(void*);
383#ifdef INVARIANTS
384 int owepreempt;
385#endif
386
387 /* Ensure we have up-to-date values. */
388 atomic_add_acq_int(&smp_rv_waiters[0], 1);
389 while (smp_rv_waiters[0] < smp_rv_ncpus)
390 cpu_spinwait();
391
392 /* Fetch rendezvous parameters after acquire barrier. */
393 local_func_arg = smp_rv_func_arg;
394 local_setup_func = smp_rv_setup_func;
395 local_action_func = smp_rv_action_func;
396 local_teardown_func = smp_rv_teardown_func;
397
398 /*
399 * Use a nested critical section to prevent any preemptions
400 * from occurring during a rendezvous action routine.
401 * Specifically, if a rendezvous handler is invoked via an IPI
402 * and the interrupted thread was in the critical_exit()
403 * function after setting td_critnest to 0 but before
404 * performing a deferred preemption, this routine can be
405 * invoked with td_critnest set to 0 and td_owepreempt true.
406 * In that case, a critical_exit() during the rendezvous
407 * action would trigger a preemption which is not permitted in
408 * a rendezvous action. To fix this, wrap all of the
409 * rendezvous action handlers in a critical section. We
410 * cannot use a regular critical section however as having
411 * critical_exit() preempt from this routine would also be
412 * problematic (the preemption must not occur before the IPI
413 * has been acknowledged via an EOI). Instead, we
414 * intentionally ignore td_owepreempt when leaving the
415 * critical section. This should be harmless because we do
416 * not permit rendezvous action routines to schedule threads,
417 * and thus td_owepreempt should never transition from 0 to 1
418 * during this routine.
419 */
420 td = curthread;
421 td->td_critnest++;
422#ifdef INVARIANTS
423 owepreempt = td->td_owepreempt;
424#endif
425
426 /*
427 * If requested, run a setup function before the main action
428 * function. Ensure all CPUs have completed the setup
429 * function before moving on to the action function.
430 */
431 if (local_setup_func != smp_no_rendevous_barrier) {
432 if (smp_rv_setup_func != NULL)
433 smp_rv_setup_func(smp_rv_func_arg);
434 atomic_add_int(&smp_rv_waiters[1], 1);
435 while (smp_rv_waiters[1] < smp_rv_ncpus)
436 cpu_spinwait();
437 }
438
439 if (local_action_func != NULL)
440 local_action_func(local_func_arg);
441
442 if (local_teardown_func != smp_no_rendevous_barrier) {
443 /*
444 * Signal that the main action has been completed. If a
445 * full exit rendezvous is requested, then all CPUs will
446 * wait here until all CPUs have finished the main action.
447 */
448 atomic_add_int(&smp_rv_waiters[2], 1);
449 while (smp_rv_waiters[2] < smp_rv_ncpus)
450 cpu_spinwait();
451
452 if (local_teardown_func != NULL)
453 local_teardown_func(local_func_arg);
454 }
455
456 /*
457 * Signal that the rendezvous is fully completed by this CPU.
458 * This means that no member of smp_rv_* pseudo-structure will be
459 * accessed by this target CPU after this point; in particular,
460 * memory pointed by smp_rv_func_arg.
461 */
462 atomic_add_int(&smp_rv_waiters[3], 1);
463
464 td->td_critnest--;
465 KASSERT(owepreempt == td->td_owepreempt,
466 ("rendezvous action changed td_owepreempt"));
467}
468
469void
470smp_rendezvous_cpus(cpuset_t map,
471 void (* setup_func)(void *),
472 void (* action_func)(void *),
473 void (* teardown_func)(void *),
474 void *arg)
475{
476 int curcpumap, i, ncpus = 0;
477
478 /* Look comments in the !SMP case. */
479 if (!smp_started) {
480 spinlock_enter();
481 if (setup_func != NULL)
482 setup_func(arg);
483 if (action_func != NULL)
484 action_func(arg);
485 if (teardown_func != NULL)
486 teardown_func(arg);
487 spinlock_exit();
488 return;
489 }
490
491 CPU_FOREACH(i) {
492 if (CPU_ISSET(i, &map))
493 ncpus++;
494 }
495 if (ncpus == 0)
496 panic("ncpus is 0 with non-zero map");
497
498 mtx_lock_spin(&smp_ipi_mtx);
499
500 /* Pass rendezvous parameters via global variables. */
501 smp_rv_ncpus = ncpus;
502 smp_rv_setup_func = setup_func;
503 smp_rv_action_func = action_func;
504 smp_rv_teardown_func = teardown_func;
505 smp_rv_func_arg = arg;
506 smp_rv_waiters[1] = 0;
507 smp_rv_waiters[2] = 0;
508 smp_rv_waiters[3] = 0;
509 atomic_store_rel_int(&smp_rv_waiters[0], 0);
510
511 /*
512 * Signal other processors, which will enter the IPI with
513 * interrupts off.
514 */
515 curcpumap = CPU_ISSET(curcpu, &map);
516 CPU_CLR(curcpu, &map);
517 ipi_selected(map, IPI_RENDEZVOUS);
518
519 /* Check if the current CPU is in the map */
520 if (curcpumap != 0)
521 smp_rendezvous_action();
522
523 /*
524 * Ensure that the master CPU waits for all the other
525 * CPUs to finish the rendezvous, so that smp_rv_*
526 * pseudo-structure and the arg are guaranteed to not
527 * be in use.
528 */
529 while (atomic_load_acq_int(&smp_rv_waiters[3]) < ncpus)
530 cpu_spinwait();
531
532 mtx_unlock_spin(&smp_ipi_mtx);
533}
534
535void
536smp_rendezvous(void (* setup_func)(void *),
537 void (* action_func)(void *),
538 void (* teardown_func)(void *),
539 void *arg)
540{
541 smp_rendezvous_cpus(all_cpus, setup_func, action_func, teardown_func, arg);
542}
543
544static struct cpu_group group[MAXCPU];
545
546struct cpu_group *
547smp_topo(void)
548{
549 char cpusetbuf[CPUSETBUFSIZ], cpusetbuf2[CPUSETBUFSIZ];
550 struct cpu_group *top;
551
552 /*
553 * Check for a fake topology request for debugging purposes.
554 */
555 switch (smp_topology) {
556 case 1:
557 /* Dual core with no sharing. */
558 top = smp_topo_1level(CG_SHARE_NONE, 2, 0);
559 break;
560 case 2:
561 /* No topology, all cpus are equal. */
562 top = smp_topo_none();
563 break;
564 case 3:
565 /* Dual core with shared L2. */
566 top = smp_topo_1level(CG_SHARE_L2, 2, 0);
567 break;
568 case 4:
569 /* quad core, shared l3 among each package, private l2. */
570 top = smp_topo_1level(CG_SHARE_L3, 4, 0);
571 break;
572 case 5:
573 /* quad core, 2 dualcore parts on each package share l2. */
574 top = smp_topo_2level(CG_SHARE_NONE, 2, CG_SHARE_L2, 2, 0);
575 break;
576 case 6:
577 /* Single-core 2xHTT */
578 top = smp_topo_1level(CG_SHARE_L1, 2, CG_FLAG_HTT);
579 break;
580 case 7:
581 /* quad core with a shared l3, 8 threads sharing L2. */
582 top = smp_topo_2level(CG_SHARE_L3, 4, CG_SHARE_L2, 8,
583 CG_FLAG_SMT);
584 break;
585 default:
586 /* Default, ask the system what it wants. */
587 top = cpu_topo();
588 break;
589 }
590 /*
591 * Verify the returned topology.
592 */
593 if (top->cg_count != mp_ncpus)
594 panic("Built bad topology at %p. CPU count %d != %d",
595 top, top->cg_count, mp_ncpus);
596 if (CPU_CMP(&top->cg_mask, &all_cpus))
597 panic("Built bad topology at %p. CPU mask (%s) != (%s)",
598 top, cpusetobj_strprint(cpusetbuf, &top->cg_mask),
599 cpusetobj_strprint(cpusetbuf2, &all_cpus));
600 return (top);
601}
602
603struct cpu_group *
604smp_topo_none(void)
605{
606 struct cpu_group *top;
607
608 top = &group[0];
609 top->cg_parent = NULL;
610 top->cg_child = NULL;
611 top->cg_mask = all_cpus;
612 top->cg_count = mp_ncpus;
613 top->cg_children = 0;
614 top->cg_level = CG_SHARE_NONE;
615 top->cg_flags = 0;
616
617 return (top);
618}
619
620static int
621smp_topo_addleaf(struct cpu_group *parent, struct cpu_group *child, int share,
622 int count, int flags, int start)
623{
624 char cpusetbuf[CPUSETBUFSIZ], cpusetbuf2[CPUSETBUFSIZ];
625 cpuset_t mask;
626 int i;
627
628 CPU_ZERO(&mask);
629 for (i = 0; i < count; i++, start++)
630 CPU_SET(start, &mask);
631 child->cg_parent = parent;
632 child->cg_child = NULL;
633 child->cg_children = 0;
634 child->cg_level = share;
635 child->cg_count = count;
636 child->cg_flags = flags;
637 child->cg_mask = mask;
638 parent->cg_children++;
639 for (; parent != NULL; parent = parent->cg_parent) {
640 if (CPU_OVERLAP(&parent->cg_mask, &child->cg_mask))
641 panic("Duplicate children in %p. mask (%s) child (%s)",
642 parent,
643 cpusetobj_strprint(cpusetbuf, &parent->cg_mask),
644 cpusetobj_strprint(cpusetbuf2, &child->cg_mask));
645 CPU_OR(&parent->cg_mask, &child->cg_mask);
646 parent->cg_count += child->cg_count;
647 }
648
649 return (start);
650}
651
652struct cpu_group *
653smp_topo_1level(int share, int count, int flags)
654{
655 struct cpu_group *child;
656 struct cpu_group *top;
657 int packages;
658 int cpu;
659 int i;
660
661 cpu = 0;
662 top = &group[0];
663 packages = mp_ncpus / count;
664 top->cg_child = child = &group[1];
665 top->cg_level = CG_SHARE_NONE;
666 for (i = 0; i < packages; i++, child++)
667 cpu = smp_topo_addleaf(top, child, share, count, flags, cpu);
668 return (top);
669}
670
671struct cpu_group *
672smp_topo_2level(int l2share, int l2count, int l1share, int l1count,
673 int l1flags)
674{
675 struct cpu_group *top;
676 struct cpu_group *l1g;
677 struct cpu_group *l2g;
678 int cpu;
679 int i;
680 int j;
681
682 cpu = 0;
683 top = &group[0];
684 l2g = &group[1];
685 top->cg_child = l2g;
686 top->cg_level = CG_SHARE_NONE;
687 top->cg_children = mp_ncpus / (l2count * l1count);
688 l1g = l2g + top->cg_children;
689 for (i = 0; i < top->cg_children; i++, l2g++) {
690 l2g->cg_parent = top;
691 l2g->cg_child = l1g;
692 l2g->cg_level = l2share;
693 for (j = 0; j < l2count; j++, l1g++)
694 cpu = smp_topo_addleaf(l2g, l1g, l1share, l1count,
695 l1flags, cpu);
696 }
697 return (top);
698}
699
700
701struct cpu_group *
702smp_topo_find(struct cpu_group *top, int cpu)
703{
704 struct cpu_group *cg;
705 cpuset_t mask;
706 int children;
707 int i;
708
709 CPU_SETOF(cpu, &mask);
710 cg = top;
711 for (;;) {
712 if (!CPU_OVERLAP(&cg->cg_mask, &mask))
713 return (NULL);
714 if (cg->cg_children == 0)
715 return (cg);
716 children = cg->cg_children;
717 for (i = 0, cg = cg->cg_child; i < children; cg++, i++)
718 if (CPU_OVERLAP(&cg->cg_mask, &mask))
719 break;
720 }
721 return (NULL);
722}
723#else /* !SMP */
724
725void
726smp_rendezvous_cpus(cpuset_t map,
727 void (*setup_func)(void *),
728 void (*action_func)(void *),
729 void (*teardown_func)(void *),
730 void *arg)
731{
732 /*
733 * In the !SMP case we just need to ensure the same initial conditions
734 * as the SMP case.
735 */
736 spinlock_enter();
737 if (setup_func != NULL)
738 setup_func(arg);
739 if (action_func != NULL)
740 action_func(arg);
741 if (teardown_func != NULL)
742 teardown_func(arg);
743 spinlock_exit();
744}
745
746void
747smp_rendezvous(void (*setup_func)(void *),
748 void (*action_func)(void *),
749 void (*teardown_func)(void *),
750 void *arg)
751{
752
753 /* Look comments in the smp_rendezvous_cpus() case. */
754 spinlock_enter();
755 if (setup_func != NULL)
756 setup_func(arg);
757 if (action_func != NULL)
758 action_func(arg);
759 if (teardown_func != NULL)
760 teardown_func(arg);
761 spinlock_exit();
762}
763
764/*
765 * Provide dummy SMP support for UP kernels. Modules that need to use SMP
766 * APIs will still work using this dummy support.
767 */
768static void
769mp_setvariables_for_up(void *dummy)
770{
771 mp_ncpus = 1;
772 mp_maxid = PCPU_GET(cpuid);
773 CPU_SETOF(mp_maxid, &all_cpus);
774 KASSERT(PCPU_GET(cpuid) == 0, ("UP must have a CPU ID of zero"));
775}
776SYSINIT(cpu_mp_setvariables, SI_SUB_TUNABLES, SI_ORDER_FIRST,
777 mp_setvariables_for_up, NULL);
778#endif /* SMP */
779
780void
781smp_no_rendevous_barrier(void *dummy)
782{
783#ifdef SMP
784 KASSERT((!smp_started),("smp_no_rendevous called and smp is started"));
785#endif
786}
787
788/*
789 * Wait specified idle threads to switch once. This ensures that even
790 * preempted threads have cycled through the switch function once,
791 * exiting their codepaths. This allows us to change global pointers
792 * with no other synchronization.
793 */
794int
795quiesce_cpus(cpuset_t map, const char *wmesg, int prio)
796{
797 struct pcpu *pcpu;
798 u_int gen[MAXCPU];
799 int error;
800 int cpu;
801
802 error = 0;
803 for (cpu = 0; cpu <= mp_maxid; cpu++) {
804 if (!CPU_ISSET(cpu, &map) || CPU_ABSENT(cpu))
805 continue;
806 pcpu = pcpu_find(cpu);
807 gen[cpu] = pcpu->pc_idlethread->td_generation;
808 }
809 for (cpu = 0; cpu <= mp_maxid; cpu++) {
810 if (!CPU_ISSET(cpu, &map) || CPU_ABSENT(cpu))
811 continue;
812 pcpu = pcpu_find(cpu);
813 thread_lock(curthread);
814 sched_bind(curthread, cpu);
815 thread_unlock(curthread);
816 while (gen[cpu] == pcpu->pc_idlethread->td_generation) {
817 error = tsleep(quiesce_cpus, prio, wmesg, 1);
818 if (error != EWOULDBLOCK)
819 goto out;
820 error = 0;
821 }
822 }
823out:
824 thread_lock(curthread);
825 sched_unbind(curthread);
826 thread_unlock(curthread);
827
828 return (error);
829}
830
831int
832quiesce_all_cpus(const char *wmesg, int prio)
833{
834
835 return quiesce_cpus(all_cpus, wmesg, prio);
836}
| 267
268 stopping_cpu = NOCPU;
269 return (1);
270}
271
272int
273stop_cpus(cpuset_t map)
274{
275
276 return (generic_stop_cpus(map, IPI_STOP));
277}
278
279int
280stop_cpus_hard(cpuset_t map)
281{
282
283 return (generic_stop_cpus(map, IPI_STOP_HARD));
284}
285
286#if defined(__amd64__) || defined(__i386__)
287int
288suspend_cpus(cpuset_t map)
289{
290
291 return (generic_stop_cpus(map, IPI_SUSPEND));
292}
293#endif
294
295/*
296 * Called by a CPU to restart stopped CPUs.
297 *
298 * Usually (but not necessarily) called with 'stopped_cpus' as its arg.
299 *
300 * - Signals all CPUs in map to restart.
301 * - Waits for each to restart.
302 *
303 * Returns:
304 * -1: error
305 * 0: NA
306 * 1: ok
307 */
308static int
309generic_restart_cpus(cpuset_t map, u_int type)
310{
311#ifdef KTR
312 char cpusetbuf[CPUSETBUFSIZ];
313#endif
314 volatile cpuset_t *cpus;
315
316 KASSERT(
317#if defined(__amd64__) || defined(__i386__)
318 type == IPI_STOP || type == IPI_STOP_HARD || type == IPI_SUSPEND,
319#else
320 type == IPI_STOP || type == IPI_STOP_HARD,
321#endif
322 ("%s: invalid stop type", __func__));
323
324 if (!smp_started)
325 return 0;
326
327 CTR1(KTR_SMP, "restart_cpus(%s)", cpusetobj_strprint(cpusetbuf, &map));
328
329#if defined(__amd64__) || defined(__i386__)
330 if (type == IPI_SUSPEND)
331 cpus = &suspended_cpus;
332 else
333#endif
334 cpus = &stopped_cpus;
335
336 /* signal other cpus to restart */
337 CPU_COPY_STORE_REL(&map, &started_cpus);
338
339 /* wait for each to clear its bit */
340 while (CPU_OVERLAP(cpus, &map))
341 cpu_spinwait();
342
343 return 1;
344}
345
346int
347restart_cpus(cpuset_t map)
348{
349
350 return (generic_restart_cpus(map, IPI_STOP));
351}
352
353#if defined(__amd64__) || defined(__i386__)
354int
355resume_cpus(cpuset_t map)
356{
357
358 return (generic_restart_cpus(map, IPI_SUSPEND));
359}
360#endif
361
362/*
363 * All-CPU rendezvous. CPUs are signalled, all execute the setup function
364 * (if specified), rendezvous, execute the action function (if specified),
365 * rendezvous again, execute the teardown function (if specified), and then
366 * resume.
367 *
368 * Note that the supplied external functions _must_ be reentrant and aware
369 * that they are running in parallel and in an unknown lock context.
370 */
371void
372smp_rendezvous_action(void)
373{
374 struct thread *td;
375 void *local_func_arg;
376 void (*local_setup_func)(void*);
377 void (*local_action_func)(void*);
378 void (*local_teardown_func)(void*);
379#ifdef INVARIANTS
380 int owepreempt;
381#endif
382
383 /* Ensure we have up-to-date values. */
384 atomic_add_acq_int(&smp_rv_waiters[0], 1);
385 while (smp_rv_waiters[0] < smp_rv_ncpus)
386 cpu_spinwait();
387
388 /* Fetch rendezvous parameters after acquire barrier. */
389 local_func_arg = smp_rv_func_arg;
390 local_setup_func = smp_rv_setup_func;
391 local_action_func = smp_rv_action_func;
392 local_teardown_func = smp_rv_teardown_func;
393
394 /*
395 * Use a nested critical section to prevent any preemptions
396 * from occurring during a rendezvous action routine.
397 * Specifically, if a rendezvous handler is invoked via an IPI
398 * and the interrupted thread was in the critical_exit()
399 * function after setting td_critnest to 0 but before
400 * performing a deferred preemption, this routine can be
401 * invoked with td_critnest set to 0 and td_owepreempt true.
402 * In that case, a critical_exit() during the rendezvous
403 * action would trigger a preemption which is not permitted in
404 * a rendezvous action. To fix this, wrap all of the
405 * rendezvous action handlers in a critical section. We
406 * cannot use a regular critical section however as having
407 * critical_exit() preempt from this routine would also be
408 * problematic (the preemption must not occur before the IPI
409 * has been acknowledged via an EOI). Instead, we
410 * intentionally ignore td_owepreempt when leaving the
411 * critical section. This should be harmless because we do
412 * not permit rendezvous action routines to schedule threads,
413 * and thus td_owepreempt should never transition from 0 to 1
414 * during this routine.
415 */
416 td = curthread;
417 td->td_critnest++;
418#ifdef INVARIANTS
419 owepreempt = td->td_owepreempt;
420#endif
421
422 /*
423 * If requested, run a setup function before the main action
424 * function. Ensure all CPUs have completed the setup
425 * function before moving on to the action function.
426 */
427 if (local_setup_func != smp_no_rendevous_barrier) {
428 if (smp_rv_setup_func != NULL)
429 smp_rv_setup_func(smp_rv_func_arg);
430 atomic_add_int(&smp_rv_waiters[1], 1);
431 while (smp_rv_waiters[1] < smp_rv_ncpus)
432 cpu_spinwait();
433 }
434
435 if (local_action_func != NULL)
436 local_action_func(local_func_arg);
437
438 if (local_teardown_func != smp_no_rendevous_barrier) {
439 /*
440 * Signal that the main action has been completed. If a
441 * full exit rendezvous is requested, then all CPUs will
442 * wait here until all CPUs have finished the main action.
443 */
444 atomic_add_int(&smp_rv_waiters[2], 1);
445 while (smp_rv_waiters[2] < smp_rv_ncpus)
446 cpu_spinwait();
447
448 if (local_teardown_func != NULL)
449 local_teardown_func(local_func_arg);
450 }
451
452 /*
453 * Signal that the rendezvous is fully completed by this CPU.
454 * This means that no member of smp_rv_* pseudo-structure will be
455 * accessed by this target CPU after this point; in particular,
456 * memory pointed by smp_rv_func_arg.
457 */
458 atomic_add_int(&smp_rv_waiters[3], 1);
459
460 td->td_critnest--;
461 KASSERT(owepreempt == td->td_owepreempt,
462 ("rendezvous action changed td_owepreempt"));
463}
464
465void
466smp_rendezvous_cpus(cpuset_t map,
467 void (* setup_func)(void *),
468 void (* action_func)(void *),
469 void (* teardown_func)(void *),
470 void *arg)
471{
472 int curcpumap, i, ncpus = 0;
473
474 /* Look comments in the !SMP case. */
475 if (!smp_started) {
476 spinlock_enter();
477 if (setup_func != NULL)
478 setup_func(arg);
479 if (action_func != NULL)
480 action_func(arg);
481 if (teardown_func != NULL)
482 teardown_func(arg);
483 spinlock_exit();
484 return;
485 }
486
487 CPU_FOREACH(i) {
488 if (CPU_ISSET(i, &map))
489 ncpus++;
490 }
491 if (ncpus == 0)
492 panic("ncpus is 0 with non-zero map");
493
494 mtx_lock_spin(&smp_ipi_mtx);
495
496 /* Pass rendezvous parameters via global variables. */
497 smp_rv_ncpus = ncpus;
498 smp_rv_setup_func = setup_func;
499 smp_rv_action_func = action_func;
500 smp_rv_teardown_func = teardown_func;
501 smp_rv_func_arg = arg;
502 smp_rv_waiters[1] = 0;
503 smp_rv_waiters[2] = 0;
504 smp_rv_waiters[3] = 0;
505 atomic_store_rel_int(&smp_rv_waiters[0], 0);
506
507 /*
508 * Signal other processors, which will enter the IPI with
509 * interrupts off.
510 */
511 curcpumap = CPU_ISSET(curcpu, &map);
512 CPU_CLR(curcpu, &map);
513 ipi_selected(map, IPI_RENDEZVOUS);
514
515 /* Check if the current CPU is in the map */
516 if (curcpumap != 0)
517 smp_rendezvous_action();
518
519 /*
520 * Ensure that the master CPU waits for all the other
521 * CPUs to finish the rendezvous, so that smp_rv_*
522 * pseudo-structure and the arg are guaranteed to not
523 * be in use.
524 */
525 while (atomic_load_acq_int(&smp_rv_waiters[3]) < ncpus)
526 cpu_spinwait();
527
528 mtx_unlock_spin(&smp_ipi_mtx);
529}
530
531void
532smp_rendezvous(void (* setup_func)(void *),
533 void (* action_func)(void *),
534 void (* teardown_func)(void *),
535 void *arg)
536{
537 smp_rendezvous_cpus(all_cpus, setup_func, action_func, teardown_func, arg);
538}
539
540static struct cpu_group group[MAXCPU];
541
542struct cpu_group *
543smp_topo(void)
544{
545 char cpusetbuf[CPUSETBUFSIZ], cpusetbuf2[CPUSETBUFSIZ];
546 struct cpu_group *top;
547
548 /*
549 * Check for a fake topology request for debugging purposes.
550 */
551 switch (smp_topology) {
552 case 1:
553 /* Dual core with no sharing. */
554 top = smp_topo_1level(CG_SHARE_NONE, 2, 0);
555 break;
556 case 2:
557 /* No topology, all cpus are equal. */
558 top = smp_topo_none();
559 break;
560 case 3:
561 /* Dual core with shared L2. */
562 top = smp_topo_1level(CG_SHARE_L2, 2, 0);
563 break;
564 case 4:
565 /* quad core, shared l3 among each package, private l2. */
566 top = smp_topo_1level(CG_SHARE_L3, 4, 0);
567 break;
568 case 5:
569 /* quad core, 2 dualcore parts on each package share l2. */
570 top = smp_topo_2level(CG_SHARE_NONE, 2, CG_SHARE_L2, 2, 0);
571 break;
572 case 6:
573 /* Single-core 2xHTT */
574 top = smp_topo_1level(CG_SHARE_L1, 2, CG_FLAG_HTT);
575 break;
576 case 7:
577 /* quad core with a shared l3, 8 threads sharing L2. */
578 top = smp_topo_2level(CG_SHARE_L3, 4, CG_SHARE_L2, 8,
579 CG_FLAG_SMT);
580 break;
581 default:
582 /* Default, ask the system what it wants. */
583 top = cpu_topo();
584 break;
585 }
586 /*
587 * Verify the returned topology.
588 */
589 if (top->cg_count != mp_ncpus)
590 panic("Built bad topology at %p. CPU count %d != %d",
591 top, top->cg_count, mp_ncpus);
592 if (CPU_CMP(&top->cg_mask, &all_cpus))
593 panic("Built bad topology at %p. CPU mask (%s) != (%s)",
594 top, cpusetobj_strprint(cpusetbuf, &top->cg_mask),
595 cpusetobj_strprint(cpusetbuf2, &all_cpus));
596 return (top);
597}
598
599struct cpu_group *
600smp_topo_none(void)
601{
602 struct cpu_group *top;
603
604 top = &group[0];
605 top->cg_parent = NULL;
606 top->cg_child = NULL;
607 top->cg_mask = all_cpus;
608 top->cg_count = mp_ncpus;
609 top->cg_children = 0;
610 top->cg_level = CG_SHARE_NONE;
611 top->cg_flags = 0;
612
613 return (top);
614}
615
616static int
617smp_topo_addleaf(struct cpu_group *parent, struct cpu_group *child, int share,
618 int count, int flags, int start)
619{
620 char cpusetbuf[CPUSETBUFSIZ], cpusetbuf2[CPUSETBUFSIZ];
621 cpuset_t mask;
622 int i;
623
624 CPU_ZERO(&mask);
625 for (i = 0; i < count; i++, start++)
626 CPU_SET(start, &mask);
627 child->cg_parent = parent;
628 child->cg_child = NULL;
629 child->cg_children = 0;
630 child->cg_level = share;
631 child->cg_count = count;
632 child->cg_flags = flags;
633 child->cg_mask = mask;
634 parent->cg_children++;
635 for (; parent != NULL; parent = parent->cg_parent) {
636 if (CPU_OVERLAP(&parent->cg_mask, &child->cg_mask))
637 panic("Duplicate children in %p. mask (%s) child (%s)",
638 parent,
639 cpusetobj_strprint(cpusetbuf, &parent->cg_mask),
640 cpusetobj_strprint(cpusetbuf2, &child->cg_mask));
641 CPU_OR(&parent->cg_mask, &child->cg_mask);
642 parent->cg_count += child->cg_count;
643 }
644
645 return (start);
646}
647
648struct cpu_group *
649smp_topo_1level(int share, int count, int flags)
650{
651 struct cpu_group *child;
652 struct cpu_group *top;
653 int packages;
654 int cpu;
655 int i;
656
657 cpu = 0;
658 top = &group[0];
659 packages = mp_ncpus / count;
660 top->cg_child = child = &group[1];
661 top->cg_level = CG_SHARE_NONE;
662 for (i = 0; i < packages; i++, child++)
663 cpu = smp_topo_addleaf(top, child, share, count, flags, cpu);
664 return (top);
665}
666
667struct cpu_group *
668smp_topo_2level(int l2share, int l2count, int l1share, int l1count,
669 int l1flags)
670{
671 struct cpu_group *top;
672 struct cpu_group *l1g;
673 struct cpu_group *l2g;
674 int cpu;
675 int i;
676 int j;
677
678 cpu = 0;
679 top = &group[0];
680 l2g = &group[1];
681 top->cg_child = l2g;
682 top->cg_level = CG_SHARE_NONE;
683 top->cg_children = mp_ncpus / (l2count * l1count);
684 l1g = l2g + top->cg_children;
685 for (i = 0; i < top->cg_children; i++, l2g++) {
686 l2g->cg_parent = top;
687 l2g->cg_child = l1g;
688 l2g->cg_level = l2share;
689 for (j = 0; j < l2count; j++, l1g++)
690 cpu = smp_topo_addleaf(l2g, l1g, l1share, l1count,
691 l1flags, cpu);
692 }
693 return (top);
694}
695
696
697struct cpu_group *
698smp_topo_find(struct cpu_group *top, int cpu)
699{
700 struct cpu_group *cg;
701 cpuset_t mask;
702 int children;
703 int i;
704
705 CPU_SETOF(cpu, &mask);
706 cg = top;
707 for (;;) {
708 if (!CPU_OVERLAP(&cg->cg_mask, &mask))
709 return (NULL);
710 if (cg->cg_children == 0)
711 return (cg);
712 children = cg->cg_children;
713 for (i = 0, cg = cg->cg_child; i < children; cg++, i++)
714 if (CPU_OVERLAP(&cg->cg_mask, &mask))
715 break;
716 }
717 return (NULL);
718}
719#else /* !SMP */
720
721void
722smp_rendezvous_cpus(cpuset_t map,
723 void (*setup_func)(void *),
724 void (*action_func)(void *),
725 void (*teardown_func)(void *),
726 void *arg)
727{
728 /*
729 * In the !SMP case we just need to ensure the same initial conditions
730 * as the SMP case.
731 */
732 spinlock_enter();
733 if (setup_func != NULL)
734 setup_func(arg);
735 if (action_func != NULL)
736 action_func(arg);
737 if (teardown_func != NULL)
738 teardown_func(arg);
739 spinlock_exit();
740}
741
742void
743smp_rendezvous(void (*setup_func)(void *),
744 void (*action_func)(void *),
745 void (*teardown_func)(void *),
746 void *arg)
747{
748
749 /* Look comments in the smp_rendezvous_cpus() case. */
750 spinlock_enter();
751 if (setup_func != NULL)
752 setup_func(arg);
753 if (action_func != NULL)
754 action_func(arg);
755 if (teardown_func != NULL)
756 teardown_func(arg);
757 spinlock_exit();
758}
759
760/*
761 * Provide dummy SMP support for UP kernels. Modules that need to use SMP
762 * APIs will still work using this dummy support.
763 */
764static void
765mp_setvariables_for_up(void *dummy)
766{
767 mp_ncpus = 1;
768 mp_maxid = PCPU_GET(cpuid);
769 CPU_SETOF(mp_maxid, &all_cpus);
770 KASSERT(PCPU_GET(cpuid) == 0, ("UP must have a CPU ID of zero"));
771}
772SYSINIT(cpu_mp_setvariables, SI_SUB_TUNABLES, SI_ORDER_FIRST,
773 mp_setvariables_for_up, NULL);
774#endif /* SMP */
775
776void
777smp_no_rendevous_barrier(void *dummy)
778{
779#ifdef SMP
780 KASSERT((!smp_started),("smp_no_rendevous called and smp is started"));
781#endif
782}
783
784/*
785 * Wait specified idle threads to switch once. This ensures that even
786 * preempted threads have cycled through the switch function once,
787 * exiting their codepaths. This allows us to change global pointers
788 * with no other synchronization.
789 */
790int
791quiesce_cpus(cpuset_t map, const char *wmesg, int prio)
792{
793 struct pcpu *pcpu;
794 u_int gen[MAXCPU];
795 int error;
796 int cpu;
797
798 error = 0;
799 for (cpu = 0; cpu <= mp_maxid; cpu++) {
800 if (!CPU_ISSET(cpu, &map) || CPU_ABSENT(cpu))
801 continue;
802 pcpu = pcpu_find(cpu);
803 gen[cpu] = pcpu->pc_idlethread->td_generation;
804 }
805 for (cpu = 0; cpu <= mp_maxid; cpu++) {
806 if (!CPU_ISSET(cpu, &map) || CPU_ABSENT(cpu))
807 continue;
808 pcpu = pcpu_find(cpu);
809 thread_lock(curthread);
810 sched_bind(curthread, cpu);
811 thread_unlock(curthread);
812 while (gen[cpu] == pcpu->pc_idlethread->td_generation) {
813 error = tsleep(quiesce_cpus, prio, wmesg, 1);
814 if (error != EWOULDBLOCK)
815 goto out;
816 error = 0;
817 }
818 }
819out:
820 thread_lock(curthread);
821 sched_unbind(curthread);
822 thread_unlock(curthread);
823
824 return (error);
825}
826
827int
828quiesce_all_cpus(const char *wmesg, int prio)
829{
830
831 return quiesce_cpus(all_cpus, wmesg, prio);
832}
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