1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * pseries Memory Hotplug infrastructure.
4  *
5  * Copyright (C) 2008 Badari Pulavarty, IBM Corporation
6  */
7 
8 #define pr_fmt(fmt)	"pseries-hotplug-mem: " fmt
9 
10 #include <linux/of.h>
11 #include <linux/of_address.h>
12 #include <linux/memblock.h>
13 #include <linux/memory.h>
14 #include <linux/memory_hotplug.h>
15 #include <linux/slab.h>
16 
17 #include <asm/firmware.h>
18 #include <asm/machdep.h>
19 #include <asm/prom.h>
20 #include <asm/sparsemem.h>
21 #include <asm/fadump.h>
22 #include <asm/drmem.h>
23 #include "pseries.h"
24 
25 unsigned long pseries_memory_block_size(void)
26 {
27 	struct device_node *np;
28 	u64 memblock_size = MIN_MEMORY_BLOCK_SIZE;
29 	struct resource r;
30 
31 	np = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
32 	if (np) {
33 		const __be64 *size;
34 
35 		size = of_get_property(np, "ibm,lmb-size", NULL);
36 		if (size)
37 			memblock_size = be64_to_cpup(size);
38 		of_node_put(np);
39 	} else  if (machine_is(pseries)) {
40 		/* This fallback really only applies to pseries */
41 		unsigned int memzero_size = 0;
42 
43 		np = of_find_node_by_path("/memory@0");
44 		if (np) {
45 			if (!of_address_to_resource(np, 0, &r))
46 				memzero_size = resource_size(&r);
47 			of_node_put(np);
48 		}
49 
50 		if (memzero_size) {
51 			/* We now know the size of memory@0, use this to find
52 			 * the first memoryblock and get its size.
53 			 */
54 			char buf[64];
55 
56 			sprintf(buf, "/memory@%x", memzero_size);
57 			np = of_find_node_by_path(buf);
58 			if (np) {
59 				if (!of_address_to_resource(np, 0, &r))
60 					memblock_size = resource_size(&r);
61 				of_node_put(np);
62 			}
63 		}
64 	}
65 	return memblock_size;
66 }
67 
68 static void dlpar_free_property(struct property *prop)
69 {
70 	kfree(prop->name);
71 	kfree(prop->value);
72 	kfree(prop);
73 }
74 
75 static struct property *dlpar_clone_property(struct property *prop,
76 					     u32 prop_size)
77 {
78 	struct property *new_prop;
79 
80 	new_prop = kzalloc(sizeof(*new_prop), GFP_KERNEL);
81 	if (!new_prop)
82 		return NULL;
83 
84 	new_prop->name = kstrdup(prop->name, GFP_KERNEL);
85 	new_prop->value = kzalloc(prop_size, GFP_KERNEL);
86 	if (!new_prop->name || !new_prop->value) {
87 		dlpar_free_property(new_prop);
88 		return NULL;
89 	}
90 
91 	memcpy(new_prop->value, prop->value, prop->length);
92 	new_prop->length = prop_size;
93 
94 	of_property_set_flag(new_prop, OF_DYNAMIC);
95 	return new_prop;
96 }
97 
98 static bool find_aa_index(struct device_node *dr_node,
99 			 struct property *ala_prop,
100 			 const u32 *lmb_assoc, u32 *aa_index)
101 {
102 	u32 *assoc_arrays, new_prop_size;
103 	struct property *new_prop;
104 	int aa_arrays, aa_array_entries, aa_array_sz;
105 	int i, index;
106 
107 	/*
108 	 * The ibm,associativity-lookup-arrays property is defined to be
109 	 * a 32-bit value specifying the number of associativity arrays
110 	 * followed by a 32-bitvalue specifying the number of entries per
111 	 * array, followed by the associativity arrays.
112 	 */
113 	assoc_arrays = ala_prop->value;
114 
115 	aa_arrays = be32_to_cpu(assoc_arrays[0]);
116 	aa_array_entries = be32_to_cpu(assoc_arrays[1]);
117 	aa_array_sz = aa_array_entries * sizeof(u32);
118 
119 	for (i = 0; i < aa_arrays; i++) {
120 		index = (i * aa_array_entries) + 2;
121 
122 		if (memcmp(&assoc_arrays[index], &lmb_assoc[1], aa_array_sz))
123 			continue;
124 
125 		*aa_index = i;
126 		return true;
127 	}
128 
129 	new_prop_size = ala_prop->length + aa_array_sz;
130 	new_prop = dlpar_clone_property(ala_prop, new_prop_size);
131 	if (!new_prop)
132 		return false;
133 
134 	assoc_arrays = new_prop->value;
135 
136 	/* increment the number of entries in the lookup array */
137 	assoc_arrays[0] = cpu_to_be32(aa_arrays + 1);
138 
139 	/* copy the new associativity into the lookup array */
140 	index = aa_arrays * aa_array_entries + 2;
141 	memcpy(&assoc_arrays[index], &lmb_assoc[1], aa_array_sz);
142 
143 	of_update_property(dr_node, new_prop);
144 
145 	/*
146 	 * The associativity lookup array index for this lmb is
147 	 * number of entries - 1 since we added its associativity
148 	 * to the end of the lookup array.
149 	 */
150 	*aa_index = be32_to_cpu(assoc_arrays[0]) - 1;
151 	return true;
152 }
153 
154 static int update_lmb_associativity_index(struct drmem_lmb *lmb)
155 {
156 	struct device_node *parent, *lmb_node, *dr_node;
157 	struct property *ala_prop;
158 	const u32 *lmb_assoc;
159 	u32 aa_index;
160 	bool found;
161 
162 	parent = of_find_node_by_path("/");
163 	if (!parent)
164 		return -ENODEV;
165 
166 	lmb_node = dlpar_configure_connector(cpu_to_be32(lmb->drc_index),
167 					     parent);
168 	of_node_put(parent);
169 	if (!lmb_node)
170 		return -EINVAL;
171 
172 	lmb_assoc = of_get_property(lmb_node, "ibm,associativity", NULL);
173 	if (!lmb_assoc) {
174 		dlpar_free_cc_nodes(lmb_node);
175 		return -ENODEV;
176 	}
177 
178 	dr_node = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
179 	if (!dr_node) {
180 		dlpar_free_cc_nodes(lmb_node);
181 		return -ENODEV;
182 	}
183 
184 	ala_prop = of_find_property(dr_node, "ibm,associativity-lookup-arrays",
185 				    NULL);
186 	if (!ala_prop) {
187 		of_node_put(dr_node);
188 		dlpar_free_cc_nodes(lmb_node);
189 		return -ENODEV;
190 	}
191 
192 	found = find_aa_index(dr_node, ala_prop, lmb_assoc, &aa_index);
193 
194 	of_node_put(dr_node);
195 	dlpar_free_cc_nodes(lmb_node);
196 
197 	if (!found) {
198 		pr_err("Could not find LMB associativity\n");
199 		return -1;
200 	}
201 
202 	lmb->aa_index = aa_index;
203 	return 0;
204 }
205 
206 static struct memory_block *lmb_to_memblock(struct drmem_lmb *lmb)
207 {
208 	unsigned long section_nr;
209 	struct mem_section *mem_sect;
210 	struct memory_block *mem_block;
211 
212 	section_nr = pfn_to_section_nr(PFN_DOWN(lmb->base_addr));
213 	mem_sect = __nr_to_section(section_nr);
214 
215 	mem_block = find_memory_block(mem_sect);
216 	return mem_block;
217 }
218 
219 static int get_lmb_range(u32 drc_index, int n_lmbs,
220 			 struct drmem_lmb **start_lmb,
221 			 struct drmem_lmb **end_lmb)
222 {
223 	struct drmem_lmb *lmb, *start, *end;
224 	struct drmem_lmb *limit;
225 
226 	start = NULL;
227 	for_each_drmem_lmb(lmb) {
228 		if (lmb->drc_index == drc_index) {
229 			start = lmb;
230 			break;
231 		}
232 	}
233 
234 	if (!start)
235 		return -EINVAL;
236 
237 	end = &start[n_lmbs];
238 
239 	limit = &drmem_info->lmbs[drmem_info->n_lmbs];
240 	if (end > limit)
241 		return -EINVAL;
242 
243 	*start_lmb = start;
244 	*end_lmb = end;
245 	return 0;
246 }
247 
248 static int dlpar_change_lmb_state(struct drmem_lmb *lmb, bool online)
249 {
250 	struct memory_block *mem_block;
251 	int rc;
252 
253 	mem_block = lmb_to_memblock(lmb);
254 	if (!mem_block)
255 		return -EINVAL;
256 
257 	if (online && mem_block->dev.offline)
258 		rc = device_online(&mem_block->dev);
259 	else if (!online && !mem_block->dev.offline)
260 		rc = device_offline(&mem_block->dev);
261 	else
262 		rc = 0;
263 
264 	put_device(&mem_block->dev);
265 
266 	return rc;
267 }
268 
269 static int dlpar_online_lmb(struct drmem_lmb *lmb)
270 {
271 	return dlpar_change_lmb_state(lmb, true);
272 }
273 
274 #ifdef CONFIG_MEMORY_HOTREMOVE
275 static int dlpar_offline_lmb(struct drmem_lmb *lmb)
276 {
277 	return dlpar_change_lmb_state(lmb, false);
278 }
279 
280 static int pseries_remove_memblock(unsigned long base, unsigned int memblock_size)
281 {
282 	unsigned long block_sz, start_pfn;
283 	int sections_per_block;
284 	int i, nid;
285 
286 	start_pfn = base >> PAGE_SHIFT;
287 
288 	lock_device_hotplug();
289 
290 	if (!pfn_valid(start_pfn))
291 		goto out;
292 
293 	block_sz = pseries_memory_block_size();
294 	sections_per_block = block_sz / MIN_MEMORY_BLOCK_SIZE;
295 	nid = memory_add_physaddr_to_nid(base);
296 
297 	for (i = 0; i < sections_per_block; i++) {
298 		__remove_memory(nid, base, MIN_MEMORY_BLOCK_SIZE);
299 		base += MIN_MEMORY_BLOCK_SIZE;
300 	}
301 
302 out:
303 	/* Update memory regions for memory remove */
304 	memblock_remove(base, memblock_size);
305 	unlock_device_hotplug();
306 	return 0;
307 }
308 
309 static int pseries_remove_mem_node(struct device_node *np)
310 {
311 	const __be32 *regs;
312 	unsigned long base;
313 	unsigned int lmb_size;
314 	int ret = -EINVAL;
315 
316 	/*
317 	 * Check to see if we are actually removing memory
318 	 */
319 	if (!of_node_is_type(np, "memory"))
320 		return 0;
321 
322 	/*
323 	 * Find the base address and size of the memblock
324 	 */
325 	regs = of_get_property(np, "reg", NULL);
326 	if (!regs)
327 		return ret;
328 
329 	base = be64_to_cpu(*(unsigned long *)regs);
330 	lmb_size = be32_to_cpu(regs[3]);
331 
332 	pseries_remove_memblock(base, lmb_size);
333 	return 0;
334 }
335 
336 static bool lmb_is_removable(struct drmem_lmb *lmb)
337 {
338 	if (!(lmb->flags & DRCONF_MEM_ASSIGNED))
339 		return false;
340 
341 #ifdef CONFIG_FA_DUMP
342 	/*
343 	 * Don't hot-remove memory that falls in fadump boot memory area
344 	 * and memory that is reserved for capturing old kernel memory.
345 	 */
346 	if (is_fadump_memory_area(lmb->base_addr, memory_block_size_bytes()))
347 		return false;
348 #endif
349 	/* device_offline() will determine if we can actually remove this lmb */
350 	return true;
351 }
352 
353 static int dlpar_add_lmb(struct drmem_lmb *);
354 
355 static int dlpar_remove_lmb(struct drmem_lmb *lmb)
356 {
357 	unsigned long block_sz;
358 	int rc;
359 
360 	if (!lmb_is_removable(lmb))
361 		return -EINVAL;
362 
363 	rc = dlpar_offline_lmb(lmb);
364 	if (rc)
365 		return rc;
366 
367 	block_sz = pseries_memory_block_size();
368 
369 	__remove_memory(lmb->nid, lmb->base_addr, block_sz);
370 
371 	/* Update memory regions for memory remove */
372 	memblock_remove(lmb->base_addr, block_sz);
373 
374 	invalidate_lmb_associativity_index(lmb);
375 	lmb_clear_nid(lmb);
376 	lmb->flags &= ~DRCONF_MEM_ASSIGNED;
377 
378 	return 0;
379 }
380 
381 static int dlpar_memory_remove_by_count(u32 lmbs_to_remove)
382 {
383 	struct drmem_lmb *lmb;
384 	int lmbs_removed = 0;
385 	int lmbs_available = 0;
386 	int rc;
387 
388 	pr_info("Attempting to hot-remove %d LMB(s)\n", lmbs_to_remove);
389 
390 	if (lmbs_to_remove == 0)
391 		return -EINVAL;
392 
393 	/* Validate that there are enough LMBs to satisfy the request */
394 	for_each_drmem_lmb(lmb) {
395 		if (lmb_is_removable(lmb))
396 			lmbs_available++;
397 
398 		if (lmbs_available == lmbs_to_remove)
399 			break;
400 	}
401 
402 	if (lmbs_available < lmbs_to_remove) {
403 		pr_info("Not enough LMBs available (%d of %d) to satisfy request\n",
404 			lmbs_available, lmbs_to_remove);
405 		return -EINVAL;
406 	}
407 
408 	for_each_drmem_lmb(lmb) {
409 		rc = dlpar_remove_lmb(lmb);
410 		if (rc)
411 			continue;
412 
413 		/* Mark this lmb so we can add it later if all of the
414 		 * requested LMBs cannot be removed.
415 		 */
416 		drmem_mark_lmb_reserved(lmb);
417 
418 		lmbs_removed++;
419 		if (lmbs_removed == lmbs_to_remove)
420 			break;
421 	}
422 
423 	if (lmbs_removed != lmbs_to_remove) {
424 		pr_err("Memory hot-remove failed, adding LMB's back\n");
425 
426 		for_each_drmem_lmb(lmb) {
427 			if (!drmem_lmb_reserved(lmb))
428 				continue;
429 
430 			rc = dlpar_add_lmb(lmb);
431 			if (rc)
432 				pr_err("Failed to add LMB back, drc index %x\n",
433 				       lmb->drc_index);
434 
435 			drmem_remove_lmb_reservation(lmb);
436 		}
437 
438 		rc = -EINVAL;
439 	} else {
440 		for_each_drmem_lmb(lmb) {
441 			if (!drmem_lmb_reserved(lmb))
442 				continue;
443 
444 			dlpar_release_drc(lmb->drc_index);
445 			pr_info("Memory at %llx was hot-removed\n",
446 				lmb->base_addr);
447 
448 			drmem_remove_lmb_reservation(lmb);
449 		}
450 		rc = 0;
451 	}
452 
453 	return rc;
454 }
455 
456 static int dlpar_memory_remove_by_index(u32 drc_index)
457 {
458 	struct drmem_lmb *lmb;
459 	int lmb_found;
460 	int rc;
461 
462 	pr_info("Attempting to hot-remove LMB, drc index %x\n", drc_index);
463 
464 	lmb_found = 0;
465 	for_each_drmem_lmb(lmb) {
466 		if (lmb->drc_index == drc_index) {
467 			lmb_found = 1;
468 			rc = dlpar_remove_lmb(lmb);
469 			if (!rc)
470 				dlpar_release_drc(lmb->drc_index);
471 
472 			break;
473 		}
474 	}
475 
476 	if (!lmb_found)
477 		rc = -EINVAL;
478 
479 	if (rc)
480 		pr_info("Failed to hot-remove memory at %llx\n",
481 			lmb->base_addr);
482 	else
483 		pr_info("Memory at %llx was hot-removed\n", lmb->base_addr);
484 
485 	return rc;
486 }
487 
488 static int dlpar_memory_remove_by_ic(u32 lmbs_to_remove, u32 drc_index)
489 {
490 	struct drmem_lmb *lmb, *start_lmb, *end_lmb;
491 	int lmbs_available = 0;
492 	int rc;
493 
494 	pr_info("Attempting to hot-remove %u LMB(s) at %x\n",
495 		lmbs_to_remove, drc_index);
496 
497 	if (lmbs_to_remove == 0)
498 		return -EINVAL;
499 
500 	rc = get_lmb_range(drc_index, lmbs_to_remove, &start_lmb, &end_lmb);
501 	if (rc)
502 		return -EINVAL;
503 
504 	/* Validate that there are enough LMBs to satisfy the request */
505 	for_each_drmem_lmb_in_range(lmb, start_lmb, end_lmb) {
506 		if (lmb->flags & DRCONF_MEM_RESERVED)
507 			break;
508 
509 		lmbs_available++;
510 	}
511 
512 	if (lmbs_available < lmbs_to_remove)
513 		return -EINVAL;
514 
515 	for_each_drmem_lmb_in_range(lmb, start_lmb, end_lmb) {
516 		if (!(lmb->flags & DRCONF_MEM_ASSIGNED))
517 			continue;
518 
519 		rc = dlpar_remove_lmb(lmb);
520 		if (rc)
521 			break;
522 
523 		drmem_mark_lmb_reserved(lmb);
524 	}
525 
526 	if (rc) {
527 		pr_err("Memory indexed-count-remove failed, adding any removed LMBs\n");
528 
529 
530 		for_each_drmem_lmb_in_range(lmb, start_lmb, end_lmb) {
531 			if (!drmem_lmb_reserved(lmb))
532 				continue;
533 
534 			rc = dlpar_add_lmb(lmb);
535 			if (rc)
536 				pr_err("Failed to add LMB, drc index %x\n",
537 				       lmb->drc_index);
538 
539 			drmem_remove_lmb_reservation(lmb);
540 		}
541 		rc = -EINVAL;
542 	} else {
543 		for_each_drmem_lmb_in_range(lmb, start_lmb, end_lmb) {
544 			if (!drmem_lmb_reserved(lmb))
545 				continue;
546 
547 			dlpar_release_drc(lmb->drc_index);
548 			pr_info("Memory at %llx (drc index %x) was hot-removed\n",
549 				lmb->base_addr, lmb->drc_index);
550 
551 			drmem_remove_lmb_reservation(lmb);
552 		}
553 	}
554 
555 	return rc;
556 }
557 
558 #else
559 static inline int pseries_remove_memblock(unsigned long base,
560 					  unsigned int memblock_size)
561 {
562 	return -EOPNOTSUPP;
563 }
564 static inline int pseries_remove_mem_node(struct device_node *np)
565 {
566 	return 0;
567 }
568 static inline int dlpar_memory_remove(struct pseries_hp_errorlog *hp_elog)
569 {
570 	return -EOPNOTSUPP;
571 }
572 static int dlpar_remove_lmb(struct drmem_lmb *lmb)
573 {
574 	return -EOPNOTSUPP;
575 }
576 static int dlpar_memory_remove_by_count(u32 lmbs_to_remove)
577 {
578 	return -EOPNOTSUPP;
579 }
580 static int dlpar_memory_remove_by_index(u32 drc_index)
581 {
582 	return -EOPNOTSUPP;
583 }
584 
585 static int dlpar_memory_remove_by_ic(u32 lmbs_to_remove, u32 drc_index)
586 {
587 	return -EOPNOTSUPP;
588 }
589 #endif /* CONFIG_MEMORY_HOTREMOVE */
590 
591 static int dlpar_add_lmb(struct drmem_lmb *lmb)
592 {
593 	unsigned long block_sz;
594 	int rc;
595 
596 	if (lmb->flags & DRCONF_MEM_ASSIGNED)
597 		return -EINVAL;
598 
599 	rc = update_lmb_associativity_index(lmb);
600 	if (rc) {
601 		dlpar_release_drc(lmb->drc_index);
602 		return rc;
603 	}
604 
605 	lmb_set_nid(lmb);
606 	block_sz = memory_block_size_bytes();
607 
608 	/* Add the memory */
609 	rc = __add_memory(lmb->nid, lmb->base_addr, block_sz);
610 	if (rc) {
611 		invalidate_lmb_associativity_index(lmb);
612 		return rc;
613 	}
614 
615 	rc = dlpar_online_lmb(lmb);
616 	if (rc) {
617 		__remove_memory(lmb->nid, lmb->base_addr, block_sz);
618 		invalidate_lmb_associativity_index(lmb);
619 		lmb_clear_nid(lmb);
620 	} else {
621 		lmb->flags |= DRCONF_MEM_ASSIGNED;
622 	}
623 
624 	return rc;
625 }
626 
627 static int dlpar_memory_add_by_count(u32 lmbs_to_add)
628 {
629 	struct drmem_lmb *lmb;
630 	int lmbs_available = 0;
631 	int lmbs_added = 0;
632 	int rc;
633 
634 	pr_info("Attempting to hot-add %d LMB(s)\n", lmbs_to_add);
635 
636 	if (lmbs_to_add == 0)
637 		return -EINVAL;
638 
639 	/* Validate that there are enough LMBs to satisfy the request */
640 	for_each_drmem_lmb(lmb) {
641 		if (!(lmb->flags & DRCONF_MEM_ASSIGNED))
642 			lmbs_available++;
643 
644 		if (lmbs_available == lmbs_to_add)
645 			break;
646 	}
647 
648 	if (lmbs_available < lmbs_to_add)
649 		return -EINVAL;
650 
651 	for_each_drmem_lmb(lmb) {
652 		if (lmb->flags & DRCONF_MEM_ASSIGNED)
653 			continue;
654 
655 		rc = dlpar_acquire_drc(lmb->drc_index);
656 		if (rc)
657 			continue;
658 
659 		rc = dlpar_add_lmb(lmb);
660 		if (rc) {
661 			dlpar_release_drc(lmb->drc_index);
662 			continue;
663 		}
664 
665 		/* Mark this lmb so we can remove it later if all of the
666 		 * requested LMBs cannot be added.
667 		 */
668 		drmem_mark_lmb_reserved(lmb);
669 
670 		lmbs_added++;
671 		if (lmbs_added == lmbs_to_add)
672 			break;
673 	}
674 
675 	if (lmbs_added != lmbs_to_add) {
676 		pr_err("Memory hot-add failed, removing any added LMBs\n");
677 
678 		for_each_drmem_lmb(lmb) {
679 			if (!drmem_lmb_reserved(lmb))
680 				continue;
681 
682 			rc = dlpar_remove_lmb(lmb);
683 			if (rc)
684 				pr_err("Failed to remove LMB, drc index %x\n",
685 				       lmb->drc_index);
686 			else
687 				dlpar_release_drc(lmb->drc_index);
688 
689 			drmem_remove_lmb_reservation(lmb);
690 		}
691 		rc = -EINVAL;
692 	} else {
693 		for_each_drmem_lmb(lmb) {
694 			if (!drmem_lmb_reserved(lmb))
695 				continue;
696 
697 			pr_info("Memory at %llx (drc index %x) was hot-added\n",
698 				lmb->base_addr, lmb->drc_index);
699 			drmem_remove_lmb_reservation(lmb);
700 		}
701 		rc = 0;
702 	}
703 
704 	return rc;
705 }
706 
707 static int dlpar_memory_add_by_index(u32 drc_index)
708 {
709 	struct drmem_lmb *lmb;
710 	int rc, lmb_found;
711 
712 	pr_info("Attempting to hot-add LMB, drc index %x\n", drc_index);
713 
714 	lmb_found = 0;
715 	for_each_drmem_lmb(lmb) {
716 		if (lmb->drc_index == drc_index) {
717 			lmb_found = 1;
718 			rc = dlpar_acquire_drc(lmb->drc_index);
719 			if (!rc) {
720 				rc = dlpar_add_lmb(lmb);
721 				if (rc)
722 					dlpar_release_drc(lmb->drc_index);
723 			}
724 
725 			break;
726 		}
727 	}
728 
729 	if (!lmb_found)
730 		rc = -EINVAL;
731 
732 	if (rc)
733 		pr_info("Failed to hot-add memory, drc index %x\n", drc_index);
734 	else
735 		pr_info("Memory at %llx (drc index %x) was hot-added\n",
736 			lmb->base_addr, drc_index);
737 
738 	return rc;
739 }
740 
741 static int dlpar_memory_add_by_ic(u32 lmbs_to_add, u32 drc_index)
742 {
743 	struct drmem_lmb *lmb, *start_lmb, *end_lmb;
744 	int lmbs_available = 0;
745 	int rc;
746 
747 	pr_info("Attempting to hot-add %u LMB(s) at index %x\n",
748 		lmbs_to_add, drc_index);
749 
750 	if (lmbs_to_add == 0)
751 		return -EINVAL;
752 
753 	rc = get_lmb_range(drc_index, lmbs_to_add, &start_lmb, &end_lmb);
754 	if (rc)
755 		return -EINVAL;
756 
757 	/* Validate that the LMBs in this range are not reserved */
758 	for_each_drmem_lmb_in_range(lmb, start_lmb, end_lmb) {
759 		if (lmb->flags & DRCONF_MEM_RESERVED)
760 			break;
761 
762 		lmbs_available++;
763 	}
764 
765 	if (lmbs_available < lmbs_to_add)
766 		return -EINVAL;
767 
768 	for_each_drmem_lmb_in_range(lmb, start_lmb, end_lmb) {
769 		if (lmb->flags & DRCONF_MEM_ASSIGNED)
770 			continue;
771 
772 		rc = dlpar_acquire_drc(lmb->drc_index);
773 		if (rc)
774 			break;
775 
776 		rc = dlpar_add_lmb(lmb);
777 		if (rc) {
778 			dlpar_release_drc(lmb->drc_index);
779 			break;
780 		}
781 
782 		drmem_mark_lmb_reserved(lmb);
783 	}
784 
785 	if (rc) {
786 		pr_err("Memory indexed-count-add failed, removing any added LMBs\n");
787 
788 		for_each_drmem_lmb_in_range(lmb, start_lmb, end_lmb) {
789 			if (!drmem_lmb_reserved(lmb))
790 				continue;
791 
792 			rc = dlpar_remove_lmb(lmb);
793 			if (rc)
794 				pr_err("Failed to remove LMB, drc index %x\n",
795 				       lmb->drc_index);
796 			else
797 				dlpar_release_drc(lmb->drc_index);
798 
799 			drmem_remove_lmb_reservation(lmb);
800 		}
801 		rc = -EINVAL;
802 	} else {
803 		for_each_drmem_lmb_in_range(lmb, start_lmb, end_lmb) {
804 			if (!drmem_lmb_reserved(lmb))
805 				continue;
806 
807 			pr_info("Memory at %llx (drc index %x) was hot-added\n",
808 				lmb->base_addr, lmb->drc_index);
809 			drmem_remove_lmb_reservation(lmb);
810 		}
811 	}
812 
813 	return rc;
814 }
815 
816 int dlpar_memory(struct pseries_hp_errorlog *hp_elog)
817 {
818 	u32 count, drc_index;
819 	int rc;
820 
821 	lock_device_hotplug();
822 
823 	switch (hp_elog->action) {
824 	case PSERIES_HP_ELOG_ACTION_ADD:
825 		switch (hp_elog->id_type) {
826 		case PSERIES_HP_ELOG_ID_DRC_COUNT:
827 			count = hp_elog->_drc_u.drc_count;
828 			rc = dlpar_memory_add_by_count(count);
829 			break;
830 		case PSERIES_HP_ELOG_ID_DRC_INDEX:
831 			drc_index = hp_elog->_drc_u.drc_index;
832 			rc = dlpar_memory_add_by_index(drc_index);
833 			break;
834 		case PSERIES_HP_ELOG_ID_DRC_IC:
835 			count = hp_elog->_drc_u.ic.count;
836 			drc_index = hp_elog->_drc_u.ic.index;
837 			rc = dlpar_memory_add_by_ic(count, drc_index);
838 			break;
839 		default:
840 			rc = -EINVAL;
841 			break;
842 		}
843 
844 		break;
845 	case PSERIES_HP_ELOG_ACTION_REMOVE:
846 		switch (hp_elog->id_type) {
847 		case PSERIES_HP_ELOG_ID_DRC_COUNT:
848 			count = hp_elog->_drc_u.drc_count;
849 			rc = dlpar_memory_remove_by_count(count);
850 			break;
851 		case PSERIES_HP_ELOG_ID_DRC_INDEX:
852 			drc_index = hp_elog->_drc_u.drc_index;
853 			rc = dlpar_memory_remove_by_index(drc_index);
854 			break;
855 		case PSERIES_HP_ELOG_ID_DRC_IC:
856 			count = hp_elog->_drc_u.ic.count;
857 			drc_index = hp_elog->_drc_u.ic.index;
858 			rc = dlpar_memory_remove_by_ic(count, drc_index);
859 			break;
860 		default:
861 			rc = -EINVAL;
862 			break;
863 		}
864 
865 		break;
866 	default:
867 		pr_err("Invalid action (%d) specified\n", hp_elog->action);
868 		rc = -EINVAL;
869 		break;
870 	}
871 
872 	if (!rc)
873 		rc = drmem_update_dt();
874 
875 	unlock_device_hotplug();
876 	return rc;
877 }
878 
879 static int pseries_add_mem_node(struct device_node *np)
880 {
881 	const __be32 *regs;
882 	unsigned long base;
883 	unsigned int lmb_size;
884 	int ret = -EINVAL;
885 
886 	/*
887 	 * Check to see if we are actually adding memory
888 	 */
889 	if (!of_node_is_type(np, "memory"))
890 		return 0;
891 
892 	/*
893 	 * Find the base and size of the memblock
894 	 */
895 	regs = of_get_property(np, "reg", NULL);
896 	if (!regs)
897 		return ret;
898 
899 	base = be64_to_cpu(*(unsigned long *)regs);
900 	lmb_size = be32_to_cpu(regs[3]);
901 
902 	/*
903 	 * Update memory region to represent the memory add
904 	 */
905 	ret = memblock_add(base, lmb_size);
906 	return (ret < 0) ? -EINVAL : 0;
907 }
908 
909 static int pseries_memory_notifier(struct notifier_block *nb,
910 				   unsigned long action, void *data)
911 {
912 	struct of_reconfig_data *rd = data;
913 	int err = 0;
914 
915 	switch (action) {
916 	case OF_RECONFIG_ATTACH_NODE:
917 		err = pseries_add_mem_node(rd->dn);
918 		break;
919 	case OF_RECONFIG_DETACH_NODE:
920 		err = pseries_remove_mem_node(rd->dn);
921 		break;
922 	}
923 	return notifier_from_errno(err);
924 }
925 
926 static struct notifier_block pseries_mem_nb = {
927 	.notifier_call = pseries_memory_notifier,
928 };
929 
930 static int __init pseries_memory_hotplug_init(void)
931 {
932 	if (firmware_has_feature(FW_FEATURE_LPAR))
933 		of_reconfig_notifier_register(&pseries_mem_nb);
934 
935 	return 0;
936 }
937 machine_device_initcall(pseries, pseries_memory_hotplug_init);
938