2 * Copyright (c) 2001, John Baldwin <jhb@FreeBSD.org>.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * This module holds the global variables and machine independent functions
29 * used for the kernel SMP support.
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/kernel.h>
42 #include <sys/malloc.h>
43 #include <sys/mutex.h>
45 #include <sys/sched.h>
47 #include <sys/sysctl.h>
49 #include <machine/cpu.h>
50 #include <machine/smp.h>
52 #include "opt_sched.h"
55 MALLOC_DEFINE(M_TOPO, "toponodes", "SMP topology data");
57 volatile cpuset_t stopped_cpus;
58 volatile cpuset_t started_cpus;
59 volatile cpuset_t suspended_cpus;
60 cpuset_t hlt_cpus_mask;
61 cpuset_t logical_cpus_mask;
63 void (*cpustop_restartfunc)(void);
66 static int sysctl_kern_smp_active(SYSCTL_HANDLER_ARGS);
68 /* This is used in modules that need to work in both SMP and UP. */
72 /* export this for libkvm consumers. */
73 int mp_maxcpus = MAXCPU;
75 volatile int smp_started;
78 static SYSCTL_NODE(_kern, OID_AUTO, smp, CTLFLAG_RD|CTLFLAG_CAPRD, NULL,
81 SYSCTL_INT(_kern_smp, OID_AUTO, maxid, CTLFLAG_RD|CTLFLAG_CAPRD, &mp_maxid, 0,
84 SYSCTL_INT(_kern_smp, OID_AUTO, maxcpus, CTLFLAG_RD|CTLFLAG_CAPRD, &mp_maxcpus,
85 0, "Max number of CPUs that the system was compiled for.");
87 SYSCTL_PROC(_kern_smp, OID_AUTO, active, CTLFLAG_RD|CTLTYPE_INT|CTLFLAG_MPSAFE,
88 NULL, 0, sysctl_kern_smp_active, "I",
89 "Indicates system is running in SMP mode");
91 int smp_disabled = 0; /* has smp been disabled? */
92 SYSCTL_INT(_kern_smp, OID_AUTO, disabled, CTLFLAG_RDTUN|CTLFLAG_CAPRD,
93 &smp_disabled, 0, "SMP has been disabled from the loader");
95 int smp_cpus = 1; /* how many cpu's running */
96 SYSCTL_INT(_kern_smp, OID_AUTO, cpus, CTLFLAG_RD|CTLFLAG_CAPRD, &smp_cpus, 0,
97 "Number of CPUs online");
99 int smp_topology = 0; /* Which topology we're using. */
100 SYSCTL_INT(_kern_smp, OID_AUTO, topology, CTLFLAG_RDTUN, &smp_topology, 0,
101 "Topology override setting; 0 is default provided by hardware.");
104 /* Enable forwarding of a signal to a process running on a different CPU */
105 static int forward_signal_enabled = 1;
106 SYSCTL_INT(_kern_smp, OID_AUTO, forward_signal_enabled, CTLFLAG_RW,
107 &forward_signal_enabled, 0,
108 "Forwarding of a signal to a process on a different CPU");
110 /* Variables needed for SMP rendezvous. */
111 static volatile int smp_rv_ncpus;
112 static void (*volatile smp_rv_setup_func)(void *arg);
113 static void (*volatile smp_rv_action_func)(void *arg);
114 static void (*volatile smp_rv_teardown_func)(void *arg);
115 static void *volatile smp_rv_func_arg;
116 static volatile int smp_rv_waiters[4];
119 * Shared mutex to restrict busywaits between smp_rendezvous() and
120 * smp(_targeted)_tlb_shootdown(). A deadlock occurs if both of these
121 * functions trigger at once and cause multiple CPUs to busywait with
122 * interrupts disabled.
124 struct mtx smp_ipi_mtx;
127 * Let the MD SMP code initialize mp_maxid very early if it can.
130 mp_setmaxid(void *dummy)
135 KASSERT(mp_ncpus >= 1, ("%s: CPU count < 1", __func__));
136 KASSERT(mp_ncpus > 1 || mp_maxid == 0,
137 ("%s: one CPU but mp_maxid is not zero", __func__));
138 KASSERT(mp_maxid >= mp_ncpus - 1,
139 ("%s: counters out of sync: max %d, count %d", __func__,
140 mp_maxid, mp_ncpus));
142 SYSINIT(cpu_mp_setmaxid, SI_SUB_TUNABLES, SI_ORDER_FIRST, mp_setmaxid, NULL);
145 * Call the MD SMP initialization code.
148 mp_start(void *dummy)
151 mtx_init(&smp_ipi_mtx, "smp rendezvous", NULL, MTX_SPIN);
153 /* Probe for MP hardware. */
154 if (smp_disabled != 0 || cpu_mp_probe() == 0) {
156 CPU_SETOF(PCPU_GET(cpuid), &all_cpus);
161 printf("FreeBSD/SMP: Multiprocessor System Detected: %d CPUs\n",
165 SYSINIT(cpu_mp, SI_SUB_CPU, SI_ORDER_THIRD, mp_start, NULL);
168 forward_signal(struct thread *td)
173 * signotify() has already set TDF_ASTPENDING and TDF_NEEDSIGCHECK on
174 * this thread, so all we need to do is poke it if it is currently
175 * executing so that it executes ast().
177 THREAD_LOCK_ASSERT(td, MA_OWNED);
178 KASSERT(TD_IS_RUNNING(td),
179 ("forward_signal: thread is not TDS_RUNNING"));
181 CTR1(KTR_SMP, "forward_signal(%p)", td->td_proc);
183 if (!smp_started || cold || panicstr)
185 if (!forward_signal_enabled)
188 /* No need to IPI ourself. */
195 ipi_cpu(id, IPI_AST);
199 * When called the executing CPU will send an IPI to all other CPUs
200 * requesting that they halt execution.
202 * Usually (but not necessarily) called with 'other_cpus' as its arg.
204 * - Signals all CPUs in map to stop.
205 * - Waits for each to stop.
213 #if defined(__amd64__) || defined(__i386__)
219 generic_stop_cpus(cpuset_t map, u_int type)
222 char cpusetbuf[CPUSETBUFSIZ];
224 static volatile u_int stopping_cpu = NOCPU;
226 volatile cpuset_t *cpus;
229 type == IPI_STOP || type == IPI_STOP_HARD
231 || type == IPI_SUSPEND
233 , ("%s: invalid stop type", __func__));
238 CTR2(KTR_SMP, "stop_cpus(%s) with %u type",
239 cpusetobj_strprint(cpusetbuf, &map), type);
243 * When suspending, ensure there are are no IPIs in progress.
244 * IPIs that have been issued, but not yet delivered (e.g.
245 * not pending on a vCPU when running under virtualization)
246 * will be lost, violating FreeBSD's assumption of reliable
249 if (type == IPI_SUSPEND)
250 mtx_lock_spin(&smp_ipi_mtx);
254 if (!nmi_is_broadcast || nmi_kdb_lock == 0) {
256 if (stopping_cpu != PCPU_GET(cpuid))
257 while (atomic_cmpset_int(&stopping_cpu, NOCPU,
258 PCPU_GET(cpuid)) == 0)
259 while (stopping_cpu != NOCPU)
260 cpu_spinwait(); /* spin */
262 /* send the stop IPI to all CPUs in map */
263 ipi_selected(map, type);
269 if (type == IPI_SUSPEND)
270 cpus = &suspended_cpus;
273 cpus = &stopped_cpus;
276 while (!CPU_SUBSET(cpus, &map)) {
280 if (i == 100000000) {
281 printf("timeout stopping cpus\n");
287 if (type == IPI_SUSPEND)
288 mtx_unlock_spin(&smp_ipi_mtx);
291 stopping_cpu = NOCPU;
296 stop_cpus(cpuset_t map)
299 return (generic_stop_cpus(map, IPI_STOP));
303 stop_cpus_hard(cpuset_t map)
306 return (generic_stop_cpus(map, IPI_STOP_HARD));
311 suspend_cpus(cpuset_t map)
314 return (generic_stop_cpus(map, IPI_SUSPEND));
319 * Called by a CPU to restart stopped CPUs.
321 * Usually (but not necessarily) called with 'stopped_cpus' as its arg.
323 * - Signals all CPUs in map to restart.
324 * - Waits for each to restart.
332 generic_restart_cpus(cpuset_t map, u_int type)
335 char cpusetbuf[CPUSETBUFSIZ];
337 volatile cpuset_t *cpus;
339 KASSERT(type == IPI_STOP || type == IPI_STOP_HARD
341 || type == IPI_SUSPEND
343 , ("%s: invalid stop type", __func__));
348 CTR1(KTR_SMP, "restart_cpus(%s)", cpusetobj_strprint(cpusetbuf, &map));
351 if (type == IPI_SUSPEND)
352 cpus = &suspended_cpus;
355 cpus = &stopped_cpus;
357 /* signal other cpus to restart */
358 CPU_COPY_STORE_REL(&map, &started_cpus);
361 if (!nmi_is_broadcast || nmi_kdb_lock == 0) {
363 /* wait for each to clear its bit */
364 while (CPU_OVERLAP(cpus, &map))
374 restart_cpus(cpuset_t map)
377 return (generic_restart_cpus(map, IPI_STOP));
382 resume_cpus(cpuset_t map)
385 return (generic_restart_cpus(map, IPI_SUSPEND));
391 * All-CPU rendezvous. CPUs are signalled, all execute the setup function
392 * (if specified), rendezvous, execute the action function (if specified),
393 * rendezvous again, execute the teardown function (if specified), and then
396 * Note that the supplied external functions _must_ be reentrant and aware
397 * that they are running in parallel and in an unknown lock context.
400 smp_rendezvous_action(void)
403 void *local_func_arg;
404 void (*local_setup_func)(void*);
405 void (*local_action_func)(void*);
406 void (*local_teardown_func)(void*);
411 /* Ensure we have up-to-date values. */
412 atomic_add_acq_int(&smp_rv_waiters[0], 1);
413 while (smp_rv_waiters[0] < smp_rv_ncpus)
416 /* Fetch rendezvous parameters after acquire barrier. */
417 local_func_arg = smp_rv_func_arg;
418 local_setup_func = smp_rv_setup_func;
419 local_action_func = smp_rv_action_func;
420 local_teardown_func = smp_rv_teardown_func;
423 * Use a nested critical section to prevent any preemptions
424 * from occurring during a rendezvous action routine.
425 * Specifically, if a rendezvous handler is invoked via an IPI
426 * and the interrupted thread was in the critical_exit()
427 * function after setting td_critnest to 0 but before
428 * performing a deferred preemption, this routine can be
429 * invoked with td_critnest set to 0 and td_owepreempt true.
430 * In that case, a critical_exit() during the rendezvous
431 * action would trigger a preemption which is not permitted in
432 * a rendezvous action. To fix this, wrap all of the
433 * rendezvous action handlers in a critical section. We
434 * cannot use a regular critical section however as having
435 * critical_exit() preempt from this routine would also be
436 * problematic (the preemption must not occur before the IPI
437 * has been acknowledged via an EOI). Instead, we
438 * intentionally ignore td_owepreempt when leaving the
439 * critical section. This should be harmless because we do
440 * not permit rendezvous action routines to schedule threads,
441 * and thus td_owepreempt should never transition from 0 to 1
442 * during this routine.
447 owepreempt = td->td_owepreempt;
451 * If requested, run a setup function before the main action
452 * function. Ensure all CPUs have completed the setup
453 * function before moving on to the action function.
455 if (local_setup_func != smp_no_rendezvous_barrier) {
456 if (smp_rv_setup_func != NULL)
457 smp_rv_setup_func(smp_rv_func_arg);
458 atomic_add_int(&smp_rv_waiters[1], 1);
459 while (smp_rv_waiters[1] < smp_rv_ncpus)
463 if (local_action_func != NULL)
464 local_action_func(local_func_arg);
466 if (local_teardown_func != smp_no_rendezvous_barrier) {
468 * Signal that the main action has been completed. If a
469 * full exit rendezvous is requested, then all CPUs will
470 * wait here until all CPUs have finished the main action.
472 atomic_add_int(&smp_rv_waiters[2], 1);
473 while (smp_rv_waiters[2] < smp_rv_ncpus)
476 if (local_teardown_func != NULL)
477 local_teardown_func(local_func_arg);
481 * Signal that the rendezvous is fully completed by this CPU.
482 * This means that no member of smp_rv_* pseudo-structure will be
483 * accessed by this target CPU after this point; in particular,
484 * memory pointed by smp_rv_func_arg.
486 * The release semantic ensures that all accesses performed by
487 * the current CPU are visible when smp_rendezvous_cpus()
488 * returns, by synchronizing with the
489 * atomic_load_acq_int(&smp_rv_waiters[3]).
491 atomic_add_rel_int(&smp_rv_waiters[3], 1);
494 KASSERT(owepreempt == td->td_owepreempt,
495 ("rendezvous action changed td_owepreempt"));
499 smp_rendezvous_cpus(cpuset_t map,
500 void (* setup_func)(void *),
501 void (* action_func)(void *),
502 void (* teardown_func)(void *),
505 int curcpumap, i, ncpus = 0;
507 /* Look comments in the !SMP case. */
510 if (setup_func != NULL)
512 if (action_func != NULL)
514 if (teardown_func != NULL)
521 if (CPU_ISSET(i, &map))
525 panic("ncpus is 0 with non-zero map");
527 mtx_lock_spin(&smp_ipi_mtx);
529 /* Pass rendezvous parameters via global variables. */
530 smp_rv_ncpus = ncpus;
531 smp_rv_setup_func = setup_func;
532 smp_rv_action_func = action_func;
533 smp_rv_teardown_func = teardown_func;
534 smp_rv_func_arg = arg;
535 smp_rv_waiters[1] = 0;
536 smp_rv_waiters[2] = 0;
537 smp_rv_waiters[3] = 0;
538 atomic_store_rel_int(&smp_rv_waiters[0], 0);
541 * Signal other processors, which will enter the IPI with
544 curcpumap = CPU_ISSET(curcpu, &map);
545 CPU_CLR(curcpu, &map);
546 ipi_selected(map, IPI_RENDEZVOUS);
548 /* Check if the current CPU is in the map */
550 smp_rendezvous_action();
553 * Ensure that the master CPU waits for all the other
554 * CPUs to finish the rendezvous, so that smp_rv_*
555 * pseudo-structure and the arg are guaranteed to not
558 * Load acquire synchronizes with the release add in
559 * smp_rendezvous_action(), which ensures that our caller sees
560 * all memory actions done by the called functions on other
563 while (atomic_load_acq_int(&smp_rv_waiters[3]) < ncpus)
566 mtx_unlock_spin(&smp_ipi_mtx);
570 smp_rendezvous(void (* setup_func)(void *),
571 void (* action_func)(void *),
572 void (* teardown_func)(void *),
575 smp_rendezvous_cpus(all_cpus, setup_func, action_func, teardown_func, arg);
578 static struct cpu_group group[MAXCPU * MAX_CACHE_LEVELS + 1];
583 char cpusetbuf[CPUSETBUFSIZ], cpusetbuf2[CPUSETBUFSIZ];
584 struct cpu_group *top;
587 * Check for a fake topology request for debugging purposes.
589 switch (smp_topology) {
591 /* Dual core with no sharing. */
592 top = smp_topo_1level(CG_SHARE_NONE, 2, 0);
595 /* No topology, all cpus are equal. */
596 top = smp_topo_none();
599 /* Dual core with shared L2. */
600 top = smp_topo_1level(CG_SHARE_L2, 2, 0);
603 /* quad core, shared l3 among each package, private l2. */
604 top = smp_topo_1level(CG_SHARE_L3, 4, 0);
607 /* quad core, 2 dualcore parts on each package share l2. */
608 top = smp_topo_2level(CG_SHARE_NONE, 2, CG_SHARE_L2, 2, 0);
611 /* Single-core 2xHTT */
612 top = smp_topo_1level(CG_SHARE_L1, 2, CG_FLAG_HTT);
615 /* quad core with a shared l3, 8 threads sharing L2. */
616 top = smp_topo_2level(CG_SHARE_L3, 4, CG_SHARE_L2, 8,
620 /* Default, ask the system what it wants. */
625 * Verify the returned topology.
627 if (top->cg_count != mp_ncpus)
628 panic("Built bad topology at %p. CPU count %d != %d",
629 top, top->cg_count, mp_ncpus);
630 if (CPU_CMP(&top->cg_mask, &all_cpus))
631 panic("Built bad topology at %p. CPU mask (%s) != (%s)",
632 top, cpusetobj_strprint(cpusetbuf, &top->cg_mask),
633 cpusetobj_strprint(cpusetbuf2, &all_cpus));
636 * Collapse nonsense levels that may be created out of convenience by
637 * the MD layers. They cause extra work in the search functions.
639 while (top->cg_children == 1) {
640 top = &top->cg_child[0];
641 top->cg_parent = NULL;
647 smp_topo_alloc(u_int count)
654 return (&group[curr]);
660 struct cpu_group *top;
663 top->cg_parent = NULL;
664 top->cg_child = NULL;
665 top->cg_mask = all_cpus;
666 top->cg_count = mp_ncpus;
667 top->cg_children = 0;
668 top->cg_level = CG_SHARE_NONE;
675 smp_topo_addleaf(struct cpu_group *parent, struct cpu_group *child, int share,
676 int count, int flags, int start)
678 char cpusetbuf[CPUSETBUFSIZ], cpusetbuf2[CPUSETBUFSIZ];
683 for (i = 0; i < count; i++, start++)
684 CPU_SET(start, &mask);
685 child->cg_parent = parent;
686 child->cg_child = NULL;
687 child->cg_children = 0;
688 child->cg_level = share;
689 child->cg_count = count;
690 child->cg_flags = flags;
691 child->cg_mask = mask;
692 parent->cg_children++;
693 for (; parent != NULL; parent = parent->cg_parent) {
694 if (CPU_OVERLAP(&parent->cg_mask, &child->cg_mask))
695 panic("Duplicate children in %p. mask (%s) child (%s)",
697 cpusetobj_strprint(cpusetbuf, &parent->cg_mask),
698 cpusetobj_strprint(cpusetbuf2, &child->cg_mask));
699 CPU_OR(&parent->cg_mask, &child->cg_mask);
700 parent->cg_count += child->cg_count;
707 smp_topo_1level(int share, int count, int flags)
709 struct cpu_group *child;
710 struct cpu_group *top;
717 packages = mp_ncpus / count;
718 top->cg_child = child = &group[1];
719 top->cg_level = CG_SHARE_NONE;
720 for (i = 0; i < packages; i++, child++)
721 cpu = smp_topo_addleaf(top, child, share, count, flags, cpu);
726 smp_topo_2level(int l2share, int l2count, int l1share, int l1count,
729 struct cpu_group *top;
730 struct cpu_group *l1g;
731 struct cpu_group *l2g;
740 top->cg_level = CG_SHARE_NONE;
741 top->cg_children = mp_ncpus / (l2count * l1count);
742 l1g = l2g + top->cg_children;
743 for (i = 0; i < top->cg_children; i++, l2g++) {
744 l2g->cg_parent = top;
746 l2g->cg_level = l2share;
747 for (j = 0; j < l2count; j++, l1g++)
748 cpu = smp_topo_addleaf(l2g, l1g, l1share, l1count,
756 smp_topo_find(struct cpu_group *top, int cpu)
758 struct cpu_group *cg;
763 CPU_SETOF(cpu, &mask);
766 if (!CPU_OVERLAP(&cg->cg_mask, &mask))
768 if (cg->cg_children == 0)
770 children = cg->cg_children;
771 for (i = 0, cg = cg->cg_child; i < children; cg++, i++)
772 if (CPU_OVERLAP(&cg->cg_mask, &mask))
780 smp_rendezvous_cpus(cpuset_t map,
781 void (*setup_func)(void *),
782 void (*action_func)(void *),
783 void (*teardown_func)(void *),
787 * In the !SMP case we just need to ensure the same initial conditions
791 if (setup_func != NULL)
793 if (action_func != NULL)
795 if (teardown_func != NULL)
801 smp_rendezvous(void (*setup_func)(void *),
802 void (*action_func)(void *),
803 void (*teardown_func)(void *),
807 smp_rendezvous_cpus(all_cpus, setup_func, action_func, teardown_func,
812 * Provide dummy SMP support for UP kernels. Modules that need to use SMP
813 * APIs will still work using this dummy support.
816 mp_setvariables_for_up(void *dummy)
819 mp_maxid = PCPU_GET(cpuid);
820 CPU_SETOF(mp_maxid, &all_cpus);
821 KASSERT(PCPU_GET(cpuid) == 0, ("UP must have a CPU ID of zero"));
823 SYSINIT(cpu_mp_setvariables, SI_SUB_TUNABLES, SI_ORDER_FIRST,
824 mp_setvariables_for_up, NULL);
828 smp_no_rendezvous_barrier(void *dummy)
831 KASSERT((!smp_started),("smp_no_rendezvous called and smp is started"));
836 * Wait for specified idle threads to switch once. This ensures that even
837 * preempted threads have cycled through the switch function once,
838 * exiting their codepaths. This allows us to change global pointers
839 * with no other synchronization.
842 quiesce_cpus(cpuset_t map, const char *wmesg, int prio)
850 for (cpu = 0; cpu <= mp_maxid; cpu++) {
851 if (!CPU_ISSET(cpu, &map) || CPU_ABSENT(cpu))
853 pcpu = pcpu_find(cpu);
854 gen[cpu] = pcpu->pc_idlethread->td_generation;
856 for (cpu = 0; cpu <= mp_maxid; cpu++) {
857 if (!CPU_ISSET(cpu, &map) || CPU_ABSENT(cpu))
859 pcpu = pcpu_find(cpu);
860 thread_lock(curthread);
861 sched_bind(curthread, cpu);
862 thread_unlock(curthread);
863 while (gen[cpu] == pcpu->pc_idlethread->td_generation) {
864 error = tsleep(quiesce_cpus, prio, wmesg, 1);
865 if (error != EWOULDBLOCK)
871 thread_lock(curthread);
872 sched_unbind(curthread);
873 thread_unlock(curthread);
879 quiesce_all_cpus(const char *wmesg, int prio)
882 return quiesce_cpus(all_cpus, wmesg, prio);
885 /* Extra care is taken with this sysctl because the data type is volatile */
887 sysctl_kern_smp_active(SYSCTL_HANDLER_ARGS)
891 active = smp_started;
892 error = SYSCTL_OUT(req, &active, sizeof(active));
899 topo_init_node(struct topo_node *node)
902 bzero(node, sizeof(*node));
903 TAILQ_INIT(&node->children);
907 topo_init_root(struct topo_node *root)
910 topo_init_node(root);
911 root->type = TOPO_TYPE_SYSTEM;
915 * Add a child node with the given ID under the given parent.
916 * Do nothing if there is already a child with that ID.
919 topo_add_node_by_hwid(struct topo_node *parent, int hwid,
920 topo_node_type type, uintptr_t subtype)
922 struct topo_node *node;
924 TAILQ_FOREACH_REVERSE(node, &parent->children,
925 topo_children, siblings) {
926 if (node->hwid == hwid
927 && node->type == type && node->subtype == subtype) {
932 node = malloc(sizeof(*node), M_TOPO, M_WAITOK);
933 topo_init_node(node);
934 node->parent = parent;
937 node->subtype = subtype;
938 TAILQ_INSERT_TAIL(&parent->children, node, siblings);
945 * Find a child node with the given ID under the given parent.
948 topo_find_node_by_hwid(struct topo_node *parent, int hwid,
949 topo_node_type type, uintptr_t subtype)
952 struct topo_node *node;
954 TAILQ_FOREACH(node, &parent->children, siblings) {
955 if (node->hwid == hwid
956 && node->type == type && node->subtype == subtype) {
965 * Given a node change the order of its parent's child nodes such
966 * that the node becomes the firt child while preserving the cyclic
967 * order of the children. In other words, the given node is promoted
971 topo_promote_child(struct topo_node *child)
973 struct topo_node *next;
974 struct topo_node *node;
975 struct topo_node *parent;
977 parent = child->parent;
978 next = TAILQ_NEXT(child, siblings);
979 TAILQ_REMOVE(&parent->children, child, siblings);
980 TAILQ_INSERT_HEAD(&parent->children, child, siblings);
982 while (next != NULL) {
984 next = TAILQ_NEXT(node, siblings);
985 TAILQ_REMOVE(&parent->children, node, siblings);
986 TAILQ_INSERT_AFTER(&parent->children, child, node, siblings);
992 * Iterate to the next node in the depth-first search (traversal) of
996 topo_next_node(struct topo_node *top, struct topo_node *node)
998 struct topo_node *next;
1000 if ((next = TAILQ_FIRST(&node->children)) != NULL)
1003 if ((next = TAILQ_NEXT(node, siblings)) != NULL)
1006 while (node != top && (node = node->parent) != top)
1007 if ((next = TAILQ_NEXT(node, siblings)) != NULL)
1014 * Iterate to the next node in the depth-first search of the topology tree,
1015 * but without descending below the current node.
1018 topo_next_nonchild_node(struct topo_node *top, struct topo_node *node)
1020 struct topo_node *next;
1022 if ((next = TAILQ_NEXT(node, siblings)) != NULL)
1025 while (node != top && (node = node->parent) != top)
1026 if ((next = TAILQ_NEXT(node, siblings)) != NULL)
1033 * Assign the given ID to the given topology node that represents a logical
1037 topo_set_pu_id(struct topo_node *node, cpuid_t id)
1040 KASSERT(node->type == TOPO_TYPE_PU,
1041 ("topo_set_pu_id: wrong node type: %u", node->type));
1042 KASSERT(CPU_EMPTY(&node->cpuset) && node->cpu_count == 0,
1043 ("topo_set_pu_id: cpuset already not empty"));
1045 CPU_SET(id, &node->cpuset);
1046 node->cpu_count = 1;
1049 while ((node = node->parent) != NULL) {
1050 KASSERT(!CPU_ISSET(id, &node->cpuset),
1051 ("logical ID %u is already set in node %p", id, node));
1052 CPU_SET(id, &node->cpuset);
1057 static struct topology_spec {
1058 topo_node_type type;
1061 } topology_level_table[TOPO_LEVEL_COUNT] = {
1062 [TOPO_LEVEL_PKG] = { .type = TOPO_TYPE_PKG, },
1063 [TOPO_LEVEL_GROUP] = { .type = TOPO_TYPE_GROUP, },
1064 [TOPO_LEVEL_CACHEGROUP] = {
1065 .type = TOPO_TYPE_CACHE,
1066 .match_subtype = true,
1067 .subtype = CG_SHARE_L3,
1069 [TOPO_LEVEL_CORE] = { .type = TOPO_TYPE_CORE, },
1070 [TOPO_LEVEL_THREAD] = { .type = TOPO_TYPE_PU, },
1074 topo_analyze_table(struct topo_node *root, int all, enum topo_level level,
1075 struct topo_analysis *results)
1077 struct topology_spec *spec;
1078 struct topo_node *node;
1081 if (level >= TOPO_LEVEL_COUNT)
1084 spec = &topology_level_table[level];
1086 node = topo_next_node(root, root);
1088 while (node != NULL) {
1089 if (node->type != spec->type ||
1090 (spec->match_subtype && node->subtype != spec->subtype)) {
1091 node = topo_next_node(root, node);
1094 if (!all && CPU_EMPTY(&node->cpuset)) {
1095 node = topo_next_nonchild_node(root, node);
1101 if (!topo_analyze_table(node, all, level + 1, results))
1104 node = topo_next_nonchild_node(root, node);
1107 /* No explicit subgroups is essentially one subgroup. */
1111 if (!topo_analyze_table(root, all, level + 1, results))
1115 if (results->entities[level] == -1)
1116 results->entities[level] = count;
1117 else if (results->entities[level] != count)
1124 * Check if the topology is uniform, that is, each package has the same number
1125 * of cores in it and each core has the same number of threads (logical
1126 * processors) in it. If so, calculate the number of packages, the number of
1127 * groups per package, the number of cachegroups per group, and the number of
1128 * logical processors per cachegroup. 'all' parameter tells whether to include
1129 * administratively disabled logical processors into the analysis.
1132 topo_analyze(struct topo_node *topo_root, int all,
1133 struct topo_analysis *results)
1136 results->entities[TOPO_LEVEL_PKG] = -1;
1137 results->entities[TOPO_LEVEL_CORE] = -1;
1138 results->entities[TOPO_LEVEL_THREAD] = -1;
1139 results->entities[TOPO_LEVEL_GROUP] = -1;
1140 results->entities[TOPO_LEVEL_CACHEGROUP] = -1;
1142 if (!topo_analyze_table(topo_root, all, TOPO_LEVEL_PKG, results))
1145 KASSERT(results->entities[TOPO_LEVEL_PKG] > 0,
1146 ("bug in topology or analysis"));