xref: /linux/drivers/acpi/numa/srat.c (revision a8aa6a6ddce9b5585f2b74f27f3feea1427fb4e7)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  acpi_numa.c - ACPI NUMA support
4  *
5  *  Copyright (C) 2002 Takayoshi Kochi <t-kochi@bq.jp.nec.com>
6  */
7 
8 #define pr_fmt(fmt) "ACPI: " fmt
9 
10 #include <linux/module.h>
11 #include <linux/init.h>
12 #include <linux/kernel.h>
13 #include <linux/types.h>
14 #include <linux/errno.h>
15 #include <linux/acpi.h>
16 #include <linux/memblock.h>
17 #include <linux/numa.h>
18 #include <linux/nodemask.h>
19 #include <linux/topology.h>
20 #include <linux/numa_memblks.h>
21 
22 static nodemask_t nodes_found_map = NODE_MASK_NONE;
23 
24 /* maps to convert between proximity domain and logical node ID */
25 static int pxm_to_node_map[MAX_PXM_DOMAINS]
26 			= { [0 ... MAX_PXM_DOMAINS - 1] = NUMA_NO_NODE };
27 static int node_to_pxm_map[MAX_NUMNODES]
28 			= { [0 ... MAX_NUMNODES - 1] = PXM_INVAL };
29 
30 unsigned char acpi_srat_revision __initdata;
31 static int acpi_numa __initdata;
32 
33 static int last_real_pxm;
34 
35 void __init disable_srat(void)
36 {
37 	acpi_numa = -1;
38 }
39 
40 int pxm_to_node(int pxm)
41 {
42 	if (pxm < 0 || pxm >= MAX_PXM_DOMAINS || numa_off)
43 		return NUMA_NO_NODE;
44 	return pxm_to_node_map[pxm];
45 }
46 EXPORT_SYMBOL(pxm_to_node);
47 
48 int node_to_pxm(int node)
49 {
50 	if (node < 0)
51 		return PXM_INVAL;
52 	return node_to_pxm_map[node];
53 }
54 
55 static void __acpi_map_pxm_to_node(int pxm, int node)
56 {
57 	if (pxm_to_node_map[pxm] == NUMA_NO_NODE || node < pxm_to_node_map[pxm])
58 		pxm_to_node_map[pxm] = node;
59 	if (node_to_pxm_map[node] == PXM_INVAL || pxm < node_to_pxm_map[node])
60 		node_to_pxm_map[node] = pxm;
61 }
62 
63 int acpi_map_pxm_to_node(int pxm)
64 {
65 	int node;
66 
67 	if (pxm < 0 || pxm >= MAX_PXM_DOMAINS || numa_off)
68 		return NUMA_NO_NODE;
69 
70 	node = pxm_to_node_map[pxm];
71 
72 	if (node == NUMA_NO_NODE) {
73 		node = first_unset_node(nodes_found_map);
74 		if (node >= MAX_NUMNODES)
75 			return NUMA_NO_NODE;
76 		__acpi_map_pxm_to_node(pxm, node);
77 		node_set(node, nodes_found_map);
78 	}
79 
80 	return node;
81 }
82 EXPORT_SYMBOL(acpi_map_pxm_to_node);
83 
84 #ifdef CONFIG_NUMA_EMU
85 /*
86  * Take max_nid - 1 fake-numa nodes into account in both
87  * pxm_to_node_map()/node_to_pxm_map[] tables.
88  */
89 int __init fix_pxm_node_maps(int max_nid)
90 {
91 	static int pxm_to_node_map_copy[MAX_PXM_DOMAINS] __initdata
92 			= { [0 ... MAX_PXM_DOMAINS - 1] = NUMA_NO_NODE };
93 	static int node_to_pxm_map_copy[MAX_NUMNODES] __initdata
94 			= { [0 ... MAX_NUMNODES - 1] = PXM_INVAL };
95 	int i, j, index = -1, count = 0;
96 	nodemask_t nodes_to_enable;
97 
98 	if (numa_off || srat_disabled())
99 		return -1;
100 
101 	/* find fake nodes PXM mapping */
102 	for (i = 0; i < MAX_NUMNODES; i++) {
103 		if (node_to_pxm_map[i] != PXM_INVAL) {
104 			for (j = 0; j <= max_nid; j++) {
105 				if ((emu_nid_to_phys[j] == i) &&
106 				    WARN(node_to_pxm_map_copy[j] != PXM_INVAL,
107 					 "Node %d is already binded to PXM %d\n",
108 					 j, node_to_pxm_map_copy[j]))
109 					return -1;
110 				if (emu_nid_to_phys[j] == i) {
111 					node_to_pxm_map_copy[j] =
112 						node_to_pxm_map[i];
113 					if (j > index)
114 						index = j;
115 					count++;
116 				}
117 			}
118 		}
119 	}
120 	if (WARN(index != max_nid, "%d max nid  when expected %d\n",
121 		      index, max_nid))
122 		return -1;
123 
124 	nodes_clear(nodes_to_enable);
125 
126 	/* map phys nodes not used for fake nodes */
127 	for (i = 0; i < MAX_NUMNODES; i++) {
128 		if (node_to_pxm_map[i] != PXM_INVAL) {
129 			for (j = 0; j <= max_nid; j++)
130 				if (emu_nid_to_phys[j] == i)
131 					break;
132 			/* fake nodes PXM mapping has been done */
133 			if (j <= max_nid)
134 				continue;
135 			/* find first hole */
136 			for (j = 0;
137 			     j < MAX_NUMNODES &&
138 				 node_to_pxm_map_copy[j] != PXM_INVAL;
139 			     j++)
140 			;
141 			if (WARN(j == MAX_NUMNODES,
142 			    "Number of nodes exceeds MAX_NUMNODES\n"))
143 				return -1;
144 			node_to_pxm_map_copy[j] = node_to_pxm_map[i];
145 			node_set(j, nodes_to_enable);
146 			count++;
147 		}
148 	}
149 
150 	/* creating reverse mapping in pxm_to_node_map[] */
151 	for (i = 0; i < MAX_NUMNODES; i++)
152 		if (node_to_pxm_map_copy[i] != PXM_INVAL &&
153 		    pxm_to_node_map_copy[node_to_pxm_map_copy[i]] == NUMA_NO_NODE)
154 			pxm_to_node_map_copy[node_to_pxm_map_copy[i]] = i;
155 
156 	/* overwrite with new mapping */
157 	for (i = 0; i < MAX_NUMNODES; i++) {
158 		node_to_pxm_map[i] = node_to_pxm_map_copy[i];
159 		pxm_to_node_map[i] = pxm_to_node_map_copy[i];
160 	}
161 
162 	/* enable other nodes found in PXM for hotplug */
163 	nodes_or(numa_nodes_parsed, nodes_to_enable, numa_nodes_parsed);
164 
165 	pr_debug("found %d total number of nodes\n", count);
166 	return 0;
167 }
168 #endif
169 
170 static void __init
171 acpi_table_print_srat_entry(struct acpi_subtable_header *header)
172 {
173 	switch (header->type) {
174 	case ACPI_SRAT_TYPE_CPU_AFFINITY:
175 		{
176 			struct acpi_srat_cpu_affinity *p =
177 			    (struct acpi_srat_cpu_affinity *)header;
178 			pr_debug("SRAT Processor (id[0x%02x] eid[0x%02x]) in proximity domain %d %s\n",
179 				 p->apic_id, p->local_sapic_eid,
180 				 p->proximity_domain_lo,
181 				 (p->flags & ACPI_SRAT_CPU_ENABLED) ?
182 				 "enabled" : "disabled");
183 		}
184 		break;
185 
186 	case ACPI_SRAT_TYPE_MEMORY_AFFINITY:
187 		{
188 			struct acpi_srat_mem_affinity *p =
189 			    (struct acpi_srat_mem_affinity *)header;
190 			pr_debug("SRAT Memory (0x%llx length 0x%llx) in proximity domain %d %s%s%s\n",
191 				 (unsigned long long)p->base_address,
192 				 (unsigned long long)p->length,
193 				 p->proximity_domain,
194 				 (p->flags & ACPI_SRAT_MEM_ENABLED) ?
195 				 "enabled" : "disabled",
196 				 (p->flags & ACPI_SRAT_MEM_HOT_PLUGGABLE) ?
197 				 " hot-pluggable" : "",
198 				 (p->flags & ACPI_SRAT_MEM_NON_VOLATILE) ?
199 				 " non-volatile" : "");
200 		}
201 		break;
202 
203 	case ACPI_SRAT_TYPE_X2APIC_CPU_AFFINITY:
204 		{
205 			struct acpi_srat_x2apic_cpu_affinity *p =
206 			    (struct acpi_srat_x2apic_cpu_affinity *)header;
207 			pr_debug("SRAT Processor (x2apicid[0x%08x]) in proximity domain %d %s\n",
208 				 p->apic_id,
209 				 p->proximity_domain,
210 				 (p->flags & ACPI_SRAT_CPU_ENABLED) ?
211 				 "enabled" : "disabled");
212 		}
213 		break;
214 
215 	case ACPI_SRAT_TYPE_GICC_AFFINITY:
216 		{
217 			struct acpi_srat_gicc_affinity *p =
218 			    (struct acpi_srat_gicc_affinity *)header;
219 			pr_debug("SRAT Processor (acpi id[0x%04x]) in proximity domain %d %s\n",
220 				 p->acpi_processor_uid,
221 				 p->proximity_domain,
222 				 (p->flags & ACPI_SRAT_GICC_ENABLED) ?
223 				 "enabled" : "disabled");
224 		}
225 		break;
226 
227 	case ACPI_SRAT_TYPE_GENERIC_AFFINITY:
228 	{
229 		struct acpi_srat_generic_affinity *p =
230 			(struct acpi_srat_generic_affinity *)header;
231 
232 		if (p->device_handle_type == 0) {
233 			/*
234 			 * For pci devices this may be the only place they
235 			 * are assigned a proximity domain
236 			 */
237 			pr_debug("SRAT Generic Initiator(Seg:%u BDF:%u) in proximity domain %d %s\n",
238 				 *(u16 *)(&p->device_handle[0]),
239 				 *(u16 *)(&p->device_handle[2]),
240 				 p->proximity_domain,
241 				 (p->flags & ACPI_SRAT_GENERIC_AFFINITY_ENABLED) ?
242 				"enabled" : "disabled");
243 		} else {
244 			/*
245 			 * In this case we can rely on the device having a
246 			 * proximity domain reference
247 			 */
248 			pr_debug("SRAT Generic Initiator(HID=%.8s UID=%.4s) in proximity domain %d %s\n",
249 				(char *)(&p->device_handle[0]),
250 				(char *)(&p->device_handle[8]),
251 				p->proximity_domain,
252 				(p->flags & ACPI_SRAT_GENERIC_AFFINITY_ENABLED) ?
253 				"enabled" : "disabled");
254 		}
255 	}
256 	break;
257 
258 	case ACPI_SRAT_TYPE_RINTC_AFFINITY:
259 		{
260 			struct acpi_srat_rintc_affinity *p =
261 			    (struct acpi_srat_rintc_affinity *)header;
262 			pr_debug("SRAT Processor (acpi id[0x%04x]) in proximity domain %d %s\n",
263 				 p->acpi_processor_uid,
264 				 p->proximity_domain,
265 				 (p->flags & ACPI_SRAT_RINTC_ENABLED) ?
266 				 "enabled" : "disabled");
267 		}
268 		break;
269 
270 	default:
271 		pr_warn("Found unsupported SRAT entry (type = 0x%x)\n",
272 			header->type);
273 		break;
274 	}
275 }
276 
277 /*
278  * A lot of BIOS fill in 10 (= no distance) everywhere. This messes
279  * up the NUMA heuristics which wants the local node to have a smaller
280  * distance than the others.
281  * Do some quick checks here and only use the SLIT if it passes.
282  */
283 static int __init slit_valid(struct acpi_table_slit *slit)
284 {
285 	int i, j;
286 	int d = slit->locality_count;
287 	for (i = 0; i < d; i++) {
288 		for (j = 0; j < d; j++) {
289 			u8 val = slit->entry[d*i + j];
290 			if (i == j) {
291 				if (val != LOCAL_DISTANCE)
292 					return 0;
293 			} else if (val <= LOCAL_DISTANCE)
294 				return 0;
295 		}
296 	}
297 	return 1;
298 }
299 
300 void __init bad_srat(void)
301 {
302 	pr_err("SRAT: SRAT not used.\n");
303 	disable_srat();
304 }
305 
306 int __init srat_disabled(void)
307 {
308 	return acpi_numa < 0;
309 }
310 
311 __weak int __init numa_fill_memblks(u64 start, u64 end)
312 {
313 	return NUMA_NO_MEMBLK;
314 }
315 
316 /*
317  * Callback for SLIT parsing.  pxm_to_node() returns NUMA_NO_NODE for
318  * I/O localities since SRAT does not list them.  I/O localities are
319  * not supported at this point.
320  */
321 static int __init acpi_parse_slit(struct acpi_table_header *table)
322 {
323 	struct acpi_table_slit *slit = (struct acpi_table_slit *)table;
324 	int i, j;
325 
326 	if (!slit_valid(slit)) {
327 		pr_info("SLIT table looks invalid. Not used.\n");
328 		return -EINVAL;
329 	}
330 
331 	for (i = 0; i < slit->locality_count; i++) {
332 		const int from_node = pxm_to_node(i);
333 
334 		if (from_node == NUMA_NO_NODE)
335 			continue;
336 
337 		for (j = 0; j < slit->locality_count; j++) {
338 			const int to_node = pxm_to_node(j);
339 
340 			if (to_node == NUMA_NO_NODE)
341 				continue;
342 
343 			numa_set_distance(from_node, to_node,
344 				slit->entry[slit->locality_count * i + j]);
345 		}
346 	}
347 
348 	return 0;
349 }
350 
351 static int parsed_numa_memblks __initdata;
352 
353 static int __init
354 acpi_parse_memory_affinity(union acpi_subtable_headers *header,
355 			   const unsigned long table_end)
356 {
357 	struct acpi_srat_mem_affinity *ma;
358 	u64 start, end;
359 	u32 hotpluggable;
360 	int node, pxm;
361 
362 	ma = (struct acpi_srat_mem_affinity *)header;
363 
364 	acpi_table_print_srat_entry(&header->common);
365 
366 	if (srat_disabled())
367 		return 0;
368 	if (ma->header.length < sizeof(struct acpi_srat_mem_affinity)) {
369 		pr_err("SRAT: Unexpected header length: %d\n",
370 		       ma->header.length);
371 		goto out_err_bad_srat;
372 	}
373 	if ((ma->flags & ACPI_SRAT_MEM_ENABLED) == 0)
374 		return 0;
375 	hotpluggable = IS_ENABLED(CONFIG_MEMORY_HOTPLUG) &&
376 		(ma->flags & ACPI_SRAT_MEM_HOT_PLUGGABLE);
377 
378 	start = ma->base_address;
379 	end = start + ma->length;
380 	pxm = ma->proximity_domain;
381 	if (acpi_srat_revision <= 1)
382 		pxm &= 0xff;
383 
384 	node = acpi_map_pxm_to_node(pxm);
385 	if (node == NUMA_NO_NODE) {
386 		pr_err("SRAT: Too many proximity domains.\n");
387 		goto out_err_bad_srat;
388 	}
389 
390 	if (numa_add_memblk(node, start, end) < 0) {
391 		pr_err("SRAT: Failed to add memblk to node %u [mem %#010Lx-%#010Lx]\n",
392 		       node, (unsigned long long) start,
393 		       (unsigned long long) end - 1);
394 		goto out_err_bad_srat;
395 	}
396 
397 	node_set(node, numa_nodes_parsed);
398 
399 	pr_info("SRAT: Node %u PXM %u [mem %#010Lx-%#010Lx]%s%s\n",
400 		node, pxm,
401 		(unsigned long long) start, (unsigned long long) end - 1,
402 		hotpluggable ? " hotplug" : "",
403 		ma->flags & ACPI_SRAT_MEM_NON_VOLATILE ? " non-volatile" : "");
404 
405 	/* Mark hotplug range in memblock. */
406 	if (hotpluggable && memblock_mark_hotplug(start, ma->length))
407 		pr_warn("SRAT: Failed to mark hotplug range [mem %#010Lx-%#010Lx] in memblock\n",
408 			(unsigned long long)start, (unsigned long long)end - 1);
409 
410 	max_possible_pfn = max(max_possible_pfn, PFN_UP(end - 1));
411 
412 	parsed_numa_memblks++;
413 
414 	return 0;
415 
416 out_err_bad_srat:
417 	/* Just disable SRAT, but do not fail and ignore errors. */
418 	bad_srat();
419 
420 	return 0;
421 }
422 
423 static int __init acpi_parse_cfmws(union acpi_subtable_headers *header,
424 				   void *arg, const unsigned long table_end)
425 {
426 	struct acpi_cedt_cfmws *cfmws;
427 	int *fake_pxm = arg;
428 	u64 start, end;
429 	int node;
430 
431 	cfmws = (struct acpi_cedt_cfmws *)header;
432 	start = cfmws->base_hpa;
433 	end = cfmws->base_hpa + cfmws->window_size;
434 
435 	/*
436 	 * The SRAT may have already described NUMA details for all,
437 	 * or a portion of, this CFMWS HPA range. Extend the memblks
438 	 * found for any portion of the window to cover the entire
439 	 * window.
440 	 */
441 	if (!numa_fill_memblks(start, end))
442 		return 0;
443 
444 	/* No SRAT description. Create a new node. */
445 	node = acpi_map_pxm_to_node(*fake_pxm);
446 
447 	if (node == NUMA_NO_NODE) {
448 		pr_err("ACPI NUMA: Too many proximity domains while processing CFMWS.\n");
449 		return -EINVAL;
450 	}
451 
452 	if (numa_add_memblk(node, start, end) < 0) {
453 		/* CXL driver must handle the NUMA_NO_NODE case */
454 		pr_warn("ACPI NUMA: Failed to add memblk for CFMWS node %d [mem %#llx-%#llx]\n",
455 			node, start, end);
456 	}
457 	node_set(node, numa_nodes_parsed);
458 
459 	/* Set the next available fake_pxm value */
460 	(*fake_pxm)++;
461 	return 0;
462 }
463 
464 void __init __weak
465 acpi_numa_x2apic_affinity_init(struct acpi_srat_x2apic_cpu_affinity *pa)
466 {
467 	pr_warn("Found unsupported x2apic [0x%08x] SRAT entry\n", pa->apic_id);
468 }
469 
470 static int __init
471 acpi_parse_x2apic_affinity(union acpi_subtable_headers *header,
472 			   const unsigned long end)
473 {
474 	struct acpi_srat_x2apic_cpu_affinity *processor_affinity;
475 
476 	processor_affinity = (struct acpi_srat_x2apic_cpu_affinity *)header;
477 
478 	acpi_table_print_srat_entry(&header->common);
479 
480 	/* let architecture-dependent part to do it */
481 	acpi_numa_x2apic_affinity_init(processor_affinity);
482 
483 	return 0;
484 }
485 
486 static int __init
487 acpi_parse_processor_affinity(union acpi_subtable_headers *header,
488 			      const unsigned long end)
489 {
490 	struct acpi_srat_cpu_affinity *processor_affinity;
491 
492 	processor_affinity = (struct acpi_srat_cpu_affinity *)header;
493 
494 	acpi_table_print_srat_entry(&header->common);
495 
496 	/* let architecture-dependent part to do it */
497 	acpi_numa_processor_affinity_init(processor_affinity);
498 
499 	return 0;
500 }
501 
502 static int __init
503 acpi_parse_gicc_affinity(union acpi_subtable_headers *header,
504 			 const unsigned long end)
505 {
506 	struct acpi_srat_gicc_affinity *processor_affinity;
507 
508 	processor_affinity = (struct acpi_srat_gicc_affinity *)header;
509 
510 	acpi_table_print_srat_entry(&header->common);
511 
512 	/* let architecture-dependent part to do it */
513 	acpi_numa_gicc_affinity_init(processor_affinity);
514 
515 	return 0;
516 }
517 
518 #if defined(CONFIG_X86) || defined(CONFIG_ARM64)
519 static int __init
520 acpi_parse_gi_affinity(union acpi_subtable_headers *header,
521 		       const unsigned long end)
522 {
523 	struct acpi_srat_generic_affinity *gi_affinity;
524 	int node;
525 
526 	gi_affinity = (struct acpi_srat_generic_affinity *)header;
527 	if (!gi_affinity)
528 		return -EINVAL;
529 	acpi_table_print_srat_entry(&header->common);
530 
531 	if (!(gi_affinity->flags & ACPI_SRAT_GENERIC_AFFINITY_ENABLED))
532 		return -EINVAL;
533 
534 	node = acpi_map_pxm_to_node(gi_affinity->proximity_domain);
535 	if (node == NUMA_NO_NODE) {
536 		pr_err("SRAT: Too many proximity domains.\n");
537 		return -EINVAL;
538 	}
539 	node_set(node, numa_nodes_parsed);
540 	node_set_state(node, N_GENERIC_INITIATOR);
541 
542 	return 0;
543 }
544 #else
545 static int __init
546 acpi_parse_gi_affinity(union acpi_subtable_headers *header,
547 		       const unsigned long end)
548 {
549 	return 0;
550 }
551 #endif /* defined(CONFIG_X86) || defined (CONFIG_ARM64) */
552 
553 static int __init
554 acpi_parse_rintc_affinity(union acpi_subtable_headers *header,
555 			  const unsigned long end)
556 {
557 	struct acpi_srat_rintc_affinity *rintc_affinity;
558 
559 	rintc_affinity = (struct acpi_srat_rintc_affinity *)header;
560 	acpi_table_print_srat_entry(&header->common);
561 
562 	/* let architecture-dependent part to do it */
563 	acpi_numa_rintc_affinity_init(rintc_affinity);
564 
565 	return 0;
566 }
567 
568 static int __init acpi_parse_srat(struct acpi_table_header *table)
569 {
570 	struct acpi_table_srat *srat = (struct acpi_table_srat *)table;
571 
572 	acpi_srat_revision = srat->header.revision;
573 
574 	/* Real work done in acpi_table_parse_srat below. */
575 
576 	return 0;
577 }
578 
579 static int __init
580 acpi_table_parse_srat(enum acpi_srat_type id,
581 		      acpi_tbl_entry_handler handler, unsigned int max_entries)
582 {
583 	return acpi_table_parse_entries(ACPI_SIG_SRAT,
584 					    sizeof(struct acpi_table_srat), id,
585 					    handler, max_entries);
586 }
587 
588 int __init acpi_numa_init(void)
589 {
590 	int i, fake_pxm, cnt = 0;
591 
592 	if (acpi_disabled)
593 		return -EINVAL;
594 
595 	/*
596 	 * Should not limit number with cpu num that is from NR_CPUS or nr_cpus=
597 	 * SRAT cpu entries could have different order with that in MADT.
598 	 * So go over all cpu entries in SRAT to get apicid to node mapping.
599 	 */
600 
601 	/* SRAT: System Resource Affinity Table */
602 	if (!acpi_table_parse(ACPI_SIG_SRAT, acpi_parse_srat)) {
603 		struct acpi_subtable_proc srat_proc[5];
604 
605 		memset(srat_proc, 0, sizeof(srat_proc));
606 		srat_proc[0].id = ACPI_SRAT_TYPE_CPU_AFFINITY;
607 		srat_proc[0].handler = acpi_parse_processor_affinity;
608 		srat_proc[1].id = ACPI_SRAT_TYPE_X2APIC_CPU_AFFINITY;
609 		srat_proc[1].handler = acpi_parse_x2apic_affinity;
610 		srat_proc[2].id = ACPI_SRAT_TYPE_GICC_AFFINITY;
611 		srat_proc[2].handler = acpi_parse_gicc_affinity;
612 		srat_proc[3].id = ACPI_SRAT_TYPE_GENERIC_AFFINITY;
613 		srat_proc[3].handler = acpi_parse_gi_affinity;
614 		srat_proc[4].id = ACPI_SRAT_TYPE_RINTC_AFFINITY;
615 		srat_proc[4].handler = acpi_parse_rintc_affinity;
616 
617 		acpi_table_parse_entries_array(ACPI_SIG_SRAT,
618 					sizeof(struct acpi_table_srat),
619 					srat_proc, ARRAY_SIZE(srat_proc), 0);
620 
621 		cnt = acpi_table_parse_srat(ACPI_SRAT_TYPE_MEMORY_AFFINITY,
622 					    acpi_parse_memory_affinity, 0);
623 	}
624 
625 	/* SLIT: System Locality Information Table */
626 	acpi_table_parse(ACPI_SIG_SLIT, acpi_parse_slit);
627 
628 	/*
629 	 * CXL Fixed Memory Window Structures (CFMWS) must be parsed
630 	 * after the SRAT. Create NUMA Nodes for CXL memory ranges that
631 	 * are defined in the CFMWS and not already defined in the SRAT.
632 	 * Initialize a fake_pxm as the first available PXM to emulate.
633 	 */
634 
635 	/* fake_pxm is the next unused PXM value after SRAT parsing */
636 	for (i = 0, fake_pxm = -1; i < MAX_NUMNODES; i++) {
637 		if (node_to_pxm_map[i] > fake_pxm)
638 			fake_pxm = node_to_pxm_map[i];
639 	}
640 	last_real_pxm = fake_pxm;
641 	fake_pxm++;
642 	acpi_table_parse_cedt(ACPI_CEDT_TYPE_CFMWS, acpi_parse_cfmws,
643 			      &fake_pxm);
644 
645 	if (cnt < 0)
646 		return cnt;
647 	else if (!parsed_numa_memblks)
648 		return -ENOENT;
649 	return 0;
650 }
651 
652 bool acpi_node_backed_by_real_pxm(int nid)
653 {
654 	int pxm = node_to_pxm(nid);
655 
656 	return pxm <= last_real_pxm;
657 }
658 EXPORT_SYMBOL_GPL(acpi_node_backed_by_real_pxm);
659 
660 static int acpi_get_pxm(acpi_handle h)
661 {
662 	unsigned long long pxm;
663 	acpi_status status;
664 	acpi_handle handle;
665 	acpi_handle phandle = h;
666 
667 	do {
668 		handle = phandle;
669 		status = acpi_evaluate_integer(handle, "_PXM", NULL, &pxm);
670 		if (ACPI_SUCCESS(status))
671 			return pxm;
672 		status = acpi_get_parent(handle, &phandle);
673 	} while (ACPI_SUCCESS(status));
674 	return -1;
675 }
676 
677 int acpi_get_node(acpi_handle handle)
678 {
679 	int pxm;
680 
681 	pxm = acpi_get_pxm(handle);
682 
683 	return pxm_to_node(pxm);
684 }
685 EXPORT_SYMBOL(acpi_get_node);
686