xref: /freebsd/sys/dev/acpica/acpi_pxm.c (revision 2ed3236082a4473c1da8f72c1ebc071a7b54321f)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2010 Hudson River Trading LLC
5  * Written by: John H. Baldwin <jhb@FreeBSD.org>
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include "opt_vm.h"
34 
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/bus.h>
38 #include <sys/kernel.h>
39 #include <sys/lock.h>
40 #include <sys/mutex.h>
41 #include <sys/smp.h>
42 #include <sys/vmmeter.h>
43 #include <vm/vm.h>
44 #include <vm/pmap.h>
45 #include <vm/vm_param.h>
46 #include <vm/vm_page.h>
47 #include <vm/vm_phys.h>
48 
49 #include <contrib/dev/acpica/include/acpi.h>
50 #include <contrib/dev/acpica/include/aclocal.h>
51 #include <contrib/dev/acpica/include/actables.h>
52 
53 #include <machine/md_var.h>
54 
55 #include <dev/acpica/acpivar.h>
56 
57 #if MAXMEMDOM > 1
58 static struct cpu_info {
59 	int enabled:1;
60 	int has_memory:1;
61 	int domain;
62 	int id;
63 } *cpus;
64 
65 static int max_cpus;
66 static int last_cpu;
67 
68 struct mem_affinity mem_info[VM_PHYSSEG_MAX + 1];
69 int num_mem;
70 
71 static ACPI_TABLE_SRAT *srat;
72 static vm_paddr_t srat_physaddr;
73 
74 static int domain_pxm[MAXMEMDOM];
75 static int ndomain;
76 static vm_paddr_t maxphyaddr;
77 
78 static ACPI_TABLE_SLIT *slit;
79 static vm_paddr_t slit_physaddr;
80 static int vm_locality_table[MAXMEMDOM * MAXMEMDOM];
81 
82 static void	srat_walk_table(acpi_subtable_handler *handler, void *arg);
83 
84 /*
85  * SLIT parsing.
86  */
87 
88 static void
89 slit_parse_table(ACPI_TABLE_SLIT *s)
90 {
91 	int i, j;
92 	int i_domain, j_domain;
93 	int offset = 0;
94 	uint8_t e;
95 
96 	/*
97 	 * This maps the SLIT data into the VM-domain centric view.
98 	 * There may be sparse entries in the PXM namespace, so
99 	 * remap them to a VM-domain ID and if it doesn't exist,
100 	 * skip it.
101 	 *
102 	 * It should result in a packed 2d array of VM-domain
103 	 * locality information entries.
104 	 */
105 
106 	if (bootverbose)
107 		printf("SLIT.Localities: %d\n", (int) s->LocalityCount);
108 	for (i = 0; i < s->LocalityCount; i++) {
109 		i_domain = acpi_map_pxm_to_vm_domainid(i);
110 		if (i_domain < 0)
111 			continue;
112 
113 		if (bootverbose)
114 			printf("%d: ", i);
115 		for (j = 0; j < s->LocalityCount; j++) {
116 			j_domain = acpi_map_pxm_to_vm_domainid(j);
117 			if (j_domain < 0)
118 				continue;
119 			e = s->Entry[i * s->LocalityCount + j];
120 			if (bootverbose)
121 				printf("%d ", (int) e);
122 			/* 255 == "no locality information" */
123 			if (e == 255)
124 				vm_locality_table[offset] = -1;
125 			else
126 				vm_locality_table[offset] = e;
127 			offset++;
128 		}
129 		if (bootverbose)
130 			printf("\n");
131 	}
132 }
133 
134 /*
135  * Look for an ACPI System Locality Distance Information Table ("SLIT")
136  */
137 static int
138 parse_slit(void)
139 {
140 
141 	if (resource_disabled("slit", 0)) {
142 		return (-1);
143 	}
144 
145 	slit_physaddr = acpi_find_table(ACPI_SIG_SLIT);
146 	if (slit_physaddr == 0) {
147 		return (-1);
148 	}
149 
150 	/*
151 	 * Make a pass over the table to populate the cpus[] and
152 	 * mem_info[] tables.
153 	 */
154 	slit = acpi_map_table(slit_physaddr, ACPI_SIG_SLIT);
155 	slit_parse_table(slit);
156 	acpi_unmap_table(slit);
157 	slit = NULL;
158 
159 	return (0);
160 }
161 
162 /*
163  * SRAT parsing.
164  */
165 
166 /*
167  * Returns true if a memory range overlaps with at least one range in
168  * phys_avail[].
169  */
170 static int
171 overlaps_phys_avail(vm_paddr_t start, vm_paddr_t end)
172 {
173 	int i;
174 
175 	for (i = 0; phys_avail[i] != 0 && phys_avail[i + 1] != 0; i += 2) {
176 		if (phys_avail[i + 1] <= start)
177 			continue;
178 		if (phys_avail[i] < end)
179 			return (1);
180 		break;
181 	}
182 	return (0);
183 }
184 
185 /*
186  * On x86 we can use the cpuid to index the cpus array, but on arm64
187  * we have an ACPI Processor UID with a larger range.
188  *
189  * Use this variable to indicate if the cpus can be stored by index.
190  */
191 #ifdef __aarch64__
192 static const int cpus_use_indexing = 0;
193 #else
194 static const int cpus_use_indexing = 1;
195 #endif
196 
197 /*
198  * Find CPU by processor ID (APIC ID on x86, Processor UID on arm64)
199  */
200 static struct cpu_info *
201 cpu_find(int cpuid)
202 {
203 	int i;
204 
205 	if (cpus_use_indexing) {
206 		if (cpuid <= last_cpu && cpus[cpuid].enabled)
207 			return (&cpus[cpuid]);
208 	} else {
209 		for (i = 0; i <= last_cpu; i++)
210 			if (cpus[i].id == cpuid)
211 				return (&cpus[i]);
212 	}
213 	return (NULL);
214 }
215 
216 /*
217  * Find CPU by pcpu pointer.
218  */
219 static struct cpu_info *
220 cpu_get_info(struct pcpu *pc)
221 {
222 	struct cpu_info *cpup;
223 	int id;
224 
225 #ifdef __aarch64__
226 	id = pc->pc_acpi_id;
227 #else
228 	id = pc->pc_apic_id;
229 #endif
230 	cpup = cpu_find(id);
231 	if (cpup == NULL)
232 		panic("SRAT: CPU with ID %u is not known", id);
233 	return (cpup);
234 }
235 
236 /*
237  * Add proximity information for a new CPU.
238  */
239 static struct cpu_info *
240 cpu_add(int cpuid, int domain)
241 {
242 	struct cpu_info *cpup;
243 
244 	if (cpus_use_indexing) {
245 		if (cpuid >= max_cpus)
246 			return (NULL);
247 		last_cpu = imax(last_cpu, cpuid);
248 		cpup = &cpus[cpuid];
249 	} else {
250 		if (last_cpu >= max_cpus - 1)
251 			return (NULL);
252 		cpup = &cpus[++last_cpu];
253 	}
254 	cpup->domain = domain;
255 	cpup->id = cpuid;
256 	cpup->enabled = 1;
257 	return (cpup);
258 }
259 
260 static void
261 srat_parse_entry(ACPI_SUBTABLE_HEADER *entry, void *arg)
262 {
263 	ACPI_SRAT_CPU_AFFINITY *cpu;
264 	ACPI_SRAT_X2APIC_CPU_AFFINITY *x2apic;
265 	ACPI_SRAT_MEM_AFFINITY *mem;
266 	ACPI_SRAT_GICC_AFFINITY *gicc;
267 	static struct cpu_info *cpup;
268 	int domain, i, slot;
269 
270 	switch (entry->Type) {
271 	case ACPI_SRAT_TYPE_CPU_AFFINITY:
272 		cpu = (ACPI_SRAT_CPU_AFFINITY *)entry;
273 		domain = cpu->ProximityDomainLo |
274 		    cpu->ProximityDomainHi[0] << 8 |
275 		    cpu->ProximityDomainHi[1] << 16 |
276 		    cpu->ProximityDomainHi[2] << 24;
277 		if (bootverbose)
278 			printf("SRAT: Found CPU APIC ID %u domain %d: %s\n",
279 			    cpu->ApicId, domain,
280 			    (cpu->Flags & ACPI_SRAT_CPU_ENABLED) ?
281 			    "enabled" : "disabled");
282 		if (!(cpu->Flags & ACPI_SRAT_CPU_ENABLED))
283 			break;
284 		cpup = cpu_find(cpu->ApicId);
285 		if (cpup != NULL) {
286 			printf("SRAT: Duplicate local APIC ID %u\n",
287 			    cpu->ApicId);
288 			*(int *)arg = ENXIO;
289 			break;
290 		}
291 		cpup = cpu_add(cpu->ApicId, domain);
292 		if (cpup == NULL)
293 			printf("SRAT: Ignoring local APIC ID %u (too high)\n",
294 			    cpu->ApicId);
295 		break;
296 	case ACPI_SRAT_TYPE_X2APIC_CPU_AFFINITY:
297 		x2apic = (ACPI_SRAT_X2APIC_CPU_AFFINITY *)entry;
298 		if (bootverbose)
299 			printf("SRAT: Found CPU APIC ID %u domain %d: %s\n",
300 			    x2apic->ApicId, x2apic->ProximityDomain,
301 			    (x2apic->Flags & ACPI_SRAT_CPU_ENABLED) ?
302 			    "enabled" : "disabled");
303 		if (!(x2apic->Flags & ACPI_SRAT_CPU_ENABLED))
304 			break;
305 		KASSERT(cpu_find(x2apic->ApicId) == NULL,
306 		    ("Duplicate local APIC ID %u", x2apic->ApicId));
307 		cpup = cpu_add(x2apic->ApicId, x2apic->ProximityDomain);
308 		if (cpup == NULL)
309 			printf("SRAT: Ignoring local APIC ID %u (too high)\n",
310 			    x2apic->ApicId);
311 		break;
312 	case ACPI_SRAT_TYPE_GICC_AFFINITY:
313 		gicc = (ACPI_SRAT_GICC_AFFINITY *)entry;
314 		if (bootverbose)
315 			printf("SRAT: Found CPU UID %u domain %d: %s\n",
316 			    gicc->AcpiProcessorUid, gicc->ProximityDomain,
317 			    (gicc->Flags & ACPI_SRAT_GICC_ENABLED) ?
318 			    "enabled" : "disabled");
319 		if (!(gicc->Flags & ACPI_SRAT_GICC_ENABLED))
320 			break;
321 		KASSERT(cpu_find(gicc->AcpiProcessorUid) == NULL,
322 		    ("Duplicate CPU UID %u", gicc->AcpiProcessorUid));
323 		cpup = cpu_add(gicc->AcpiProcessorUid, gicc->ProximityDomain);
324 		if (cpup == NULL)
325 			printf("SRAT: Ignoring CPU UID %u (too high)\n",
326 			    gicc->AcpiProcessorUid);
327 		break;
328 	case ACPI_SRAT_TYPE_MEMORY_AFFINITY:
329 		mem = (ACPI_SRAT_MEM_AFFINITY *)entry;
330 		if (bootverbose)
331 			printf(
332 		    "SRAT: Found memory domain %d addr 0x%jx len 0x%jx: %s\n",
333 			    mem->ProximityDomain, (uintmax_t)mem->BaseAddress,
334 			    (uintmax_t)mem->Length,
335 			    (mem->Flags & ACPI_SRAT_MEM_ENABLED) ?
336 			    "enabled" : "disabled");
337 		if (!(mem->Flags & ACPI_SRAT_MEM_ENABLED))
338 			break;
339 		if (mem->BaseAddress >= maxphyaddr ||
340 		    !overlaps_phys_avail(mem->BaseAddress,
341 		    mem->BaseAddress + mem->Length)) {
342 			printf("SRAT: Ignoring memory at addr 0x%jx\n",
343 			    (uintmax_t)mem->BaseAddress);
344 			break;
345 		}
346 		if (num_mem == VM_PHYSSEG_MAX) {
347 			printf("SRAT: Too many memory regions\n");
348 			*(int *)arg = ENXIO;
349 			break;
350 		}
351 		slot = num_mem;
352 		for (i = 0; i < num_mem; i++) {
353 			if (mem_info[i].end <= mem->BaseAddress)
354 				continue;
355 			if (mem_info[i].start <
356 			    (mem->BaseAddress + mem->Length)) {
357 				printf("SRAT: Overlapping memory entries\n");
358 				*(int *)arg = ENXIO;
359 				return;
360 			}
361 			slot = i;
362 		}
363 		for (i = num_mem; i > slot; i--)
364 			mem_info[i] = mem_info[i - 1];
365 		mem_info[slot].start = mem->BaseAddress;
366 		mem_info[slot].end = mem->BaseAddress + mem->Length;
367 		mem_info[slot].domain = mem->ProximityDomain;
368 		num_mem++;
369 		break;
370 	}
371 }
372 
373 /*
374  * Ensure each memory domain has at least one CPU and that each CPU
375  * has at least one memory domain.
376  */
377 static int
378 check_domains(void)
379 {
380 	int found, i, j;
381 
382 	for (i = 0; i < num_mem; i++) {
383 		found = 0;
384 		for (j = 0; j <= last_cpu; j++)
385 			if (cpus[j].enabled &&
386 			    cpus[j].domain == mem_info[i].domain) {
387 				cpus[j].has_memory = 1;
388 				found++;
389 			}
390 		if (!found) {
391 			printf("SRAT: No CPU found for memory domain %d\n",
392 			    mem_info[i].domain);
393 			return (ENXIO);
394 		}
395 	}
396 	for (i = 0; i <= last_cpu; i++)
397 		if (cpus[i].enabled && !cpus[i].has_memory) {
398 			found = 0;
399 			for (j = 0; j < num_mem && !found; j++) {
400 				if (mem_info[j].domain == cpus[i].domain)
401 					found = 1;
402 			}
403 			if (!found) {
404 				if (bootverbose)
405 					printf("SRAT: mem dom %d is empty\n",
406 					    cpus[i].domain);
407 				mem_info[num_mem].start = 0;
408 				mem_info[num_mem].end = 0;
409 				mem_info[num_mem].domain = cpus[i].domain;
410 				num_mem++;
411 			}
412 		}
413 	return (0);
414 }
415 
416 /*
417  * Check that the SRAT memory regions cover all of the regions in
418  * phys_avail[].
419  */
420 static int
421 check_phys_avail(void)
422 {
423 	vm_paddr_t address;
424 	int i, j;
425 
426 	/* j is the current offset into phys_avail[]. */
427 	address = phys_avail[0];
428 	j = 0;
429 	for (i = 0; i < num_mem; i++) {
430 		/*
431 		 * Consume as many phys_avail[] entries as fit in this
432 		 * region.
433 		 */
434 		while (address >= mem_info[i].start &&
435 		    address <= mem_info[i].end) {
436 			/*
437 			 * If we cover the rest of this phys_avail[] entry,
438 			 * advance to the next entry.
439 			 */
440 			if (phys_avail[j + 1] <= mem_info[i].end) {
441 				j += 2;
442 				if (phys_avail[j] == 0 &&
443 				    phys_avail[j + 1] == 0) {
444 					return (0);
445 				}
446 				address = phys_avail[j];
447 			} else
448 				address = mem_info[i].end + 1;
449 		}
450 	}
451 	printf("SRAT: No memory region found for 0x%jx - 0x%jx\n",
452 	    (uintmax_t)phys_avail[j], (uintmax_t)phys_avail[j + 1]);
453 	return (ENXIO);
454 }
455 
456 /*
457  * Renumber the memory domains to be compact and zero-based if not
458  * already.  Returns an error if there are too many domains.
459  */
460 static int
461 renumber_domains(void)
462 {
463 	int i, j, slot;
464 
465 	/* Enumerate all the domains. */
466 	ndomain = 0;
467 	for (i = 0; i < num_mem; i++) {
468 		/* See if this domain is already known. */
469 		for (j = 0; j < ndomain; j++) {
470 			if (domain_pxm[j] >= mem_info[i].domain)
471 				break;
472 		}
473 		if (j < ndomain && domain_pxm[j] == mem_info[i].domain)
474 			continue;
475 
476 		if (ndomain >= MAXMEMDOM) {
477 			ndomain = 1;
478 			printf("SRAT: Too many memory domains\n");
479 			return (EFBIG);
480 		}
481 
482 		/* Insert the new domain at slot 'j'. */
483 		slot = j;
484 		for (j = ndomain; j > slot; j--)
485 			domain_pxm[j] = domain_pxm[j - 1];
486 		domain_pxm[slot] = mem_info[i].domain;
487 		ndomain++;
488 	}
489 
490 	/* Renumber each domain to its index in the sorted 'domain_pxm' list. */
491 	for (i = 0; i < ndomain; i++) {
492 		/*
493 		 * If the domain is already the right value, no need
494 		 * to renumber.
495 		 */
496 		if (domain_pxm[i] == i)
497 			continue;
498 
499 		/* Walk the cpu[] and mem_info[] arrays to renumber. */
500 		for (j = 0; j < num_mem; j++)
501 			if (mem_info[j].domain == domain_pxm[i])
502 				mem_info[j].domain = i;
503 		for (j = 0; j <= last_cpu; j++)
504 			if (cpus[j].enabled && cpus[j].domain == domain_pxm[i])
505 				cpus[j].domain = i;
506 	}
507 
508 	return (0);
509 }
510 
511 /*
512  * Look for an ACPI System Resource Affinity Table ("SRAT"),
513  * allocate space for cpu information, and initialize globals.
514  */
515 int
516 acpi_pxm_init(int ncpus, vm_paddr_t maxphys)
517 {
518 	unsigned int idx, size;
519 	vm_paddr_t addr;
520 
521 	if (resource_disabled("srat", 0))
522 		return (-1);
523 
524 	max_cpus = ncpus;
525 	last_cpu = -1;
526 	maxphyaddr = maxphys;
527 	srat_physaddr = acpi_find_table(ACPI_SIG_SRAT);
528 	if (srat_physaddr == 0)
529 		return (-1);
530 
531 	/*
532 	 * Allocate data structure:
533 	 *
534 	 * Find the last physical memory region and steal some memory from
535 	 * it. This is done because at this point in the boot process
536 	 * malloc is still not usable.
537 	 */
538 	for (idx = 0; phys_avail[idx + 1] != 0; idx += 2);
539 	KASSERT(idx != 0, ("phys_avail is empty!"));
540 	idx -= 2;
541 
542 	size =  sizeof(*cpus) * max_cpus;
543 	addr = trunc_page(phys_avail[idx + 1] - size);
544 	KASSERT(addr >= phys_avail[idx],
545 	    ("Not enough memory for SRAT table items"));
546 	phys_avail[idx + 1] = addr - 1;
547 
548 	/*
549 	 * We cannot rely on PHYS_TO_DMAP because this code is also used in
550 	 * i386, so use pmap_mapbios to map the memory, this will end up using
551 	 * the default memory attribute (WB), and the DMAP when available.
552 	 */
553 	cpus = (struct cpu_info *)pmap_mapbios(addr, size);
554 	bzero(cpus, size);
555 	return (0);
556 }
557 
558 static int
559 parse_srat(void)
560 {
561 	int error;
562 
563 	/*
564 	 * Make a pass over the table to populate the cpus[] and
565 	 * mem_info[] tables.
566 	 */
567 	srat = acpi_map_table(srat_physaddr, ACPI_SIG_SRAT);
568 	error = 0;
569 	srat_walk_table(srat_parse_entry, &error);
570 	acpi_unmap_table(srat);
571 	srat = NULL;
572 	if (error || check_domains() != 0 || check_phys_avail() != 0 ||
573 	    renumber_domains() != 0) {
574 		srat_physaddr = 0;
575 		return (-1);
576 	}
577 
578 	return (0);
579 }
580 
581 static void
582 init_mem_locality(void)
583 {
584 	int i;
585 
586 	/*
587 	 * For now, assume -1 == "no locality information for
588 	 * this pairing.
589 	 */
590 	for (i = 0; i < MAXMEMDOM * MAXMEMDOM; i++)
591 		vm_locality_table[i] = -1;
592 }
593 
594 /*
595  * Parse SRAT and SLIT to save proximity info. Don't do
596  * anything if SRAT is not available.
597  */
598 void
599 acpi_pxm_parse_tables(void)
600 {
601 
602 	if (srat_physaddr == 0)
603 		return;
604 	if (parse_srat() < 0)
605 		return;
606 	init_mem_locality();
607 	(void)parse_slit();
608 }
609 
610 /*
611  * Use saved data from SRAT/SLIT to update memory locality.
612  */
613 void
614 acpi_pxm_set_mem_locality(void)
615 {
616 
617 	if (srat_physaddr == 0)
618 		return;
619 	vm_phys_register_domains(ndomain, mem_info, vm_locality_table);
620 }
621 
622 static void
623 srat_walk_table(acpi_subtable_handler *handler, void *arg)
624 {
625 
626 	acpi_walk_subtables(srat + 1, (char *)srat + srat->Header.Length,
627 	    handler, arg);
628 }
629 
630 /*
631  * Set up per-CPU domain IDs from information saved in 'cpus' and tear down data
632  * structures allocated by acpi_pxm_init().
633  */
634 void
635 acpi_pxm_set_cpu_locality(void)
636 {
637 	struct cpu_info *cpu;
638 	struct pcpu *pc;
639 	u_int i;
640 
641 	if (srat_physaddr == 0)
642 		return;
643 	for (i = 0; i < MAXCPU; i++) {
644 		if (CPU_ABSENT(i))
645 			continue;
646 		pc = pcpu_find(i);
647 		KASSERT(pc != NULL, ("no pcpu data for CPU %u", i));
648 		cpu = cpu_get_info(pc);
649 		pc->pc_domain = vm_ndomains > 1 ? cpu->domain : 0;
650 		CPU_SET(i, &cpuset_domain[pc->pc_domain]);
651 		if (bootverbose)
652 			printf("SRAT: CPU %u has memory domain %d\n", i,
653 			    pc->pc_domain);
654 	}
655 	/* XXXMJ the page is leaked. */
656 	pmap_unmapbios((vm_offset_t)cpus, sizeof(*cpus) * max_cpus);
657 	srat_physaddr = 0;
658 	cpus = NULL;
659 }
660 
661 int
662 acpi_pxm_get_cpu_locality(int apic_id)
663 {
664 	struct cpu_info *cpu;
665 
666 	cpu = cpu_find(apic_id);
667 	if (cpu == NULL)
668 		panic("SRAT: CPU with ID %u is not known", apic_id);
669 	return (cpu->domain);
670 }
671 
672 /*
673  * Map a _PXM value to a VM domain ID.
674  *
675  * Returns the domain ID, or -1 if no domain ID was found.
676  */
677 int
678 acpi_map_pxm_to_vm_domainid(int pxm)
679 {
680 	int i;
681 
682 	for (i = 0; i < ndomain; i++) {
683 		if (domain_pxm[i] == pxm)
684 			return (vm_ndomains > 1 ? i : 0);
685 	}
686 
687 	return (-1);
688 }
689 
690 #else /* MAXMEMDOM == 1 */
691 
692 int
693 acpi_map_pxm_to_vm_domainid(int pxm)
694 {
695 
696 	return (-1);
697 }
698 
699 #endif /* MAXMEMDOM > 1 */
700