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 static bool rtas_hp_event;
26 
27 unsigned long pseries_memory_block_size(void)
28 {
29 	struct device_node *np;
30 	unsigned int memblock_size = MIN_MEMORY_BLOCK_SIZE;
31 	struct resource r;
32 
33 	np = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
34 	if (np) {
35 		const __be64 *size;
36 
37 		size = of_get_property(np, "ibm,lmb-size", NULL);
38 		if (size)
39 			memblock_size = be64_to_cpup(size);
40 		of_node_put(np);
41 	} else  if (machine_is(pseries)) {
42 		/* This fallback really only applies to pseries */
43 		unsigned int memzero_size = 0;
44 
45 		np = of_find_node_by_path("/memory@0");
46 		if (np) {
47 			if (!of_address_to_resource(np, 0, &r))
48 				memzero_size = resource_size(&r);
49 			of_node_put(np);
50 		}
51 
52 		if (memzero_size) {
53 			/* We now know the size of memory@0, use this to find
54 			 * the first memoryblock and get its size.
55 			 */
56 			char buf[64];
57 
58 			sprintf(buf, "/memory@%x", memzero_size);
59 			np = of_find_node_by_path(buf);
60 			if (np) {
61 				if (!of_address_to_resource(np, 0, &r))
62 					memblock_size = resource_size(&r);
63 				of_node_put(np);
64 			}
65 		}
66 	}
67 	return memblock_size;
68 }
69 
70 static void dlpar_free_property(struct property *prop)
71 {
72 	kfree(prop->name);
73 	kfree(prop->value);
74 	kfree(prop);
75 }
76 
77 static struct property *dlpar_clone_property(struct property *prop,
78 					     u32 prop_size)
79 {
80 	struct property *new_prop;
81 
82 	new_prop = kzalloc(sizeof(*new_prop), GFP_KERNEL);
83 	if (!new_prop)
84 		return NULL;
85 
86 	new_prop->name = kstrdup(prop->name, GFP_KERNEL);
87 	new_prop->value = kzalloc(prop_size, GFP_KERNEL);
88 	if (!new_prop->name || !new_prop->value) {
89 		dlpar_free_property(new_prop);
90 		return NULL;
91 	}
92 
93 	memcpy(new_prop->value, prop->value, prop->length);
94 	new_prop->length = prop_size;
95 
96 	of_property_set_flag(new_prop, OF_DYNAMIC);
97 	return new_prop;
98 }
99 
100 static bool find_aa_index(struct device_node *dr_node,
101 			 struct property *ala_prop,
102 			 const u32 *lmb_assoc, u32 *aa_index)
103 {
104 	u32 *assoc_arrays, new_prop_size;
105 	struct property *new_prop;
106 	int aa_arrays, aa_array_entries, aa_array_sz;
107 	int i, index;
108 
109 	/*
110 	 * The ibm,associativity-lookup-arrays property is defined to be
111 	 * a 32-bit value specifying the number of associativity arrays
112 	 * followed by a 32-bitvalue specifying the number of entries per
113 	 * array, followed by the associativity arrays.
114 	 */
115 	assoc_arrays = ala_prop->value;
116 
117 	aa_arrays = be32_to_cpu(assoc_arrays[0]);
118 	aa_array_entries = be32_to_cpu(assoc_arrays[1]);
119 	aa_array_sz = aa_array_entries * sizeof(u32);
120 
121 	for (i = 0; i < aa_arrays; i++) {
122 		index = (i * aa_array_entries) + 2;
123 
124 		if (memcmp(&assoc_arrays[index], &lmb_assoc[1], aa_array_sz))
125 			continue;
126 
127 		*aa_index = i;
128 		return true;
129 	}
130 
131 	new_prop_size = ala_prop->length + aa_array_sz;
132 	new_prop = dlpar_clone_property(ala_prop, new_prop_size);
133 	if (!new_prop)
134 		return false;
135 
136 	assoc_arrays = new_prop->value;
137 
138 	/* increment the number of entries in the lookup array */
139 	assoc_arrays[0] = cpu_to_be32(aa_arrays + 1);
140 
141 	/* copy the new associativity into the lookup array */
142 	index = aa_arrays * aa_array_entries + 2;
143 	memcpy(&assoc_arrays[index], &lmb_assoc[1], aa_array_sz);
144 
145 	of_update_property(dr_node, new_prop);
146 
147 	/*
148 	 * The associativity lookup array index for this lmb is
149 	 * number of entries - 1 since we added its associativity
150 	 * to the end of the lookup array.
151 	 */
152 	*aa_index = be32_to_cpu(assoc_arrays[0]) - 1;
153 	return true;
154 }
155 
156 static int update_lmb_associativity_index(struct drmem_lmb *lmb)
157 {
158 	struct device_node *parent, *lmb_node, *dr_node;
159 	struct property *ala_prop;
160 	const u32 *lmb_assoc;
161 	u32 aa_index;
162 	bool found;
163 
164 	parent = of_find_node_by_path("/");
165 	if (!parent)
166 		return -ENODEV;
167 
168 	lmb_node = dlpar_configure_connector(cpu_to_be32(lmb->drc_index),
169 					     parent);
170 	of_node_put(parent);
171 	if (!lmb_node)
172 		return -EINVAL;
173 
174 	lmb_assoc = of_get_property(lmb_node, "ibm,associativity", NULL);
175 	if (!lmb_assoc) {
176 		dlpar_free_cc_nodes(lmb_node);
177 		return -ENODEV;
178 	}
179 
180 	dr_node = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
181 	if (!dr_node) {
182 		dlpar_free_cc_nodes(lmb_node);
183 		return -ENODEV;
184 	}
185 
186 	ala_prop = of_find_property(dr_node, "ibm,associativity-lookup-arrays",
187 				    NULL);
188 	if (!ala_prop) {
189 		of_node_put(dr_node);
190 		dlpar_free_cc_nodes(lmb_node);
191 		return -ENODEV;
192 	}
193 
194 	found = find_aa_index(dr_node, ala_prop, lmb_assoc, &aa_index);
195 
196 	of_node_put(dr_node);
197 	dlpar_free_cc_nodes(lmb_node);
198 
199 	if (!found) {
200 		pr_err("Could not find LMB associativity\n");
201 		return -1;
202 	}
203 
204 	lmb->aa_index = aa_index;
205 	return 0;
206 }
207 
208 static struct memory_block *lmb_to_memblock(struct drmem_lmb *lmb)
209 {
210 	unsigned long section_nr;
211 	struct mem_section *mem_sect;
212 	struct memory_block *mem_block;
213 
214 	section_nr = pfn_to_section_nr(PFN_DOWN(lmb->base_addr));
215 	mem_sect = __nr_to_section(section_nr);
216 
217 	mem_block = find_memory_block(mem_sect);
218 	return mem_block;
219 }
220 
221 static int get_lmb_range(u32 drc_index, int n_lmbs,
222 			 struct drmem_lmb **start_lmb,
223 			 struct drmem_lmb **end_lmb)
224 {
225 	struct drmem_lmb *lmb, *start, *end;
226 	struct drmem_lmb *limit;
227 
228 	start = NULL;
229 	for_each_drmem_lmb(lmb) {
230 		if (lmb->drc_index == drc_index) {
231 			start = lmb;
232 			break;
233 		}
234 	}
235 
236 	if (!start)
237 		return -EINVAL;
238 
239 	end = &start[n_lmbs];
240 
241 	limit = &drmem_info->lmbs[drmem_info->n_lmbs];
242 	if (end > limit)
243 		return -EINVAL;
244 
245 	*start_lmb = start;
246 	*end_lmb = end;
247 	return 0;
248 }
249 
250 static int dlpar_change_lmb_state(struct drmem_lmb *lmb, bool online)
251 {
252 	struct memory_block *mem_block;
253 	int rc;
254 
255 	mem_block = lmb_to_memblock(lmb);
256 	if (!mem_block)
257 		return -EINVAL;
258 
259 	if (online && mem_block->dev.offline)
260 		rc = device_online(&mem_block->dev);
261 	else if (!online && !mem_block->dev.offline)
262 		rc = device_offline(&mem_block->dev);
263 	else
264 		rc = 0;
265 
266 	put_device(&mem_block->dev);
267 
268 	return rc;
269 }
270 
271 static int dlpar_online_lmb(struct drmem_lmb *lmb)
272 {
273 	return dlpar_change_lmb_state(lmb, true);
274 }
275 
276 #ifdef CONFIG_MEMORY_HOTREMOVE
277 static int dlpar_offline_lmb(struct drmem_lmb *lmb)
278 {
279 	return dlpar_change_lmb_state(lmb, false);
280 }
281 
282 static int pseries_remove_memblock(unsigned long base, unsigned int memblock_size)
283 {
284 	unsigned long block_sz, start_pfn;
285 	int sections_per_block;
286 	int i, nid;
287 
288 	start_pfn = base >> PAGE_SHIFT;
289 
290 	lock_device_hotplug();
291 
292 	if (!pfn_valid(start_pfn))
293 		goto out;
294 
295 	block_sz = pseries_memory_block_size();
296 	sections_per_block = block_sz / MIN_MEMORY_BLOCK_SIZE;
297 	nid = memory_add_physaddr_to_nid(base);
298 
299 	for (i = 0; i < sections_per_block; i++) {
300 		__remove_memory(nid, base, MIN_MEMORY_BLOCK_SIZE);
301 		base += MIN_MEMORY_BLOCK_SIZE;
302 	}
303 
304 out:
305 	/* Update memory regions for memory remove */
306 	memblock_remove(base, memblock_size);
307 	unlock_device_hotplug();
308 	return 0;
309 }
310 
311 static int pseries_remove_mem_node(struct device_node *np)
312 {
313 	const __be32 *regs;
314 	unsigned long base;
315 	unsigned int lmb_size;
316 	int ret = -EINVAL;
317 
318 	/*
319 	 * Check to see if we are actually removing memory
320 	 */
321 	if (!of_node_is_type(np, "memory"))
322 		return 0;
323 
324 	/*
325 	 * Find the base address and size of the memblock
326 	 */
327 	regs = of_get_property(np, "reg", NULL);
328 	if (!regs)
329 		return ret;
330 
331 	base = be64_to_cpu(*(unsigned long *)regs);
332 	lmb_size = be32_to_cpu(regs[3]);
333 
334 	pseries_remove_memblock(base, lmb_size);
335 	return 0;
336 }
337 
338 static bool lmb_is_removable(struct drmem_lmb *lmb)
339 {
340 	if (!(lmb->flags & DRCONF_MEM_ASSIGNED))
341 		return false;
342 
343 #ifdef CONFIG_FA_DUMP
344 	/*
345 	 * Don't hot-remove memory that falls in fadump boot memory area
346 	 * and memory that is reserved for capturing old kernel memory.
347 	 */
348 	if (is_fadump_memory_area(lmb->base_addr, memory_block_size_bytes()))
349 		return false;
350 #endif
351 	/* device_offline() will determine if we can actually remove this lmb */
352 	return true;
353 }
354 
355 static int dlpar_add_lmb(struct drmem_lmb *);
356 
357 static int dlpar_remove_lmb(struct drmem_lmb *lmb)
358 {
359 	unsigned long block_sz;
360 	int rc;
361 
362 	if (!lmb_is_removable(lmb))
363 		return -EINVAL;
364 
365 	rc = dlpar_offline_lmb(lmb);
366 	if (rc)
367 		return rc;
368 
369 	block_sz = pseries_memory_block_size();
370 
371 	__remove_memory(lmb->nid, lmb->base_addr, block_sz);
372 
373 	/* Update memory regions for memory remove */
374 	memblock_remove(lmb->base_addr, block_sz);
375 
376 	invalidate_lmb_associativity_index(lmb);
377 	lmb_clear_nid(lmb);
378 	lmb->flags &= ~DRCONF_MEM_ASSIGNED;
379 
380 	return 0;
381 }
382 
383 static int dlpar_memory_remove_by_count(u32 lmbs_to_remove)
384 {
385 	struct drmem_lmb *lmb;
386 	int lmbs_removed = 0;
387 	int lmbs_available = 0;
388 	int rc;
389 
390 	pr_info("Attempting to hot-remove %d LMB(s)\n", lmbs_to_remove);
391 
392 	if (lmbs_to_remove == 0)
393 		return -EINVAL;
394 
395 	/* Validate that there are enough LMBs to satisfy the request */
396 	for_each_drmem_lmb(lmb) {
397 		if (lmb_is_removable(lmb))
398 			lmbs_available++;
399 
400 		if (lmbs_available == lmbs_to_remove)
401 			break;
402 	}
403 
404 	if (lmbs_available < lmbs_to_remove) {
405 		pr_info("Not enough LMBs available (%d of %d) to satisfy request\n",
406 			lmbs_available, lmbs_to_remove);
407 		return -EINVAL;
408 	}
409 
410 	for_each_drmem_lmb(lmb) {
411 		rc = dlpar_remove_lmb(lmb);
412 		if (rc)
413 			continue;
414 
415 		/* Mark this lmb so we can add it later if all of the
416 		 * requested LMBs cannot be removed.
417 		 */
418 		drmem_mark_lmb_reserved(lmb);
419 
420 		lmbs_removed++;
421 		if (lmbs_removed == lmbs_to_remove)
422 			break;
423 	}
424 
425 	if (lmbs_removed != lmbs_to_remove) {
426 		pr_err("Memory hot-remove failed, adding LMB's back\n");
427 
428 		for_each_drmem_lmb(lmb) {
429 			if (!drmem_lmb_reserved(lmb))
430 				continue;
431 
432 			rc = dlpar_add_lmb(lmb);
433 			if (rc)
434 				pr_err("Failed to add LMB back, drc index %x\n",
435 				       lmb->drc_index);
436 
437 			drmem_remove_lmb_reservation(lmb);
438 		}
439 
440 		rc = -EINVAL;
441 	} else {
442 		for_each_drmem_lmb(lmb) {
443 			if (!drmem_lmb_reserved(lmb))
444 				continue;
445 
446 			dlpar_release_drc(lmb->drc_index);
447 			pr_info("Memory at %llx was hot-removed\n",
448 				lmb->base_addr);
449 
450 			drmem_remove_lmb_reservation(lmb);
451 		}
452 		rc = 0;
453 	}
454 
455 	return rc;
456 }
457 
458 static int dlpar_memory_remove_by_index(u32 drc_index)
459 {
460 	struct drmem_lmb *lmb;
461 	int lmb_found;
462 	int rc;
463 
464 	pr_info("Attempting to hot-remove LMB, drc index %x\n", drc_index);
465 
466 	lmb_found = 0;
467 	for_each_drmem_lmb(lmb) {
468 		if (lmb->drc_index == drc_index) {
469 			lmb_found = 1;
470 			rc = dlpar_remove_lmb(lmb);
471 			if (!rc)
472 				dlpar_release_drc(lmb->drc_index);
473 
474 			break;
475 		}
476 	}
477 
478 	if (!lmb_found)
479 		rc = -EINVAL;
480 
481 	if (rc)
482 		pr_info("Failed to hot-remove memory at %llx\n",
483 			lmb->base_addr);
484 	else
485 		pr_info("Memory at %llx was hot-removed\n", lmb->base_addr);
486 
487 	return rc;
488 }
489 
490 static int dlpar_memory_readd_by_index(u32 drc_index)
491 {
492 	struct drmem_lmb *lmb;
493 	int lmb_found;
494 	int rc;
495 
496 	pr_info("Attempting to update LMB, drc index %x\n", drc_index);
497 
498 	lmb_found = 0;
499 	for_each_drmem_lmb(lmb) {
500 		if (lmb->drc_index == drc_index) {
501 			lmb_found = 1;
502 			rc = dlpar_remove_lmb(lmb);
503 			if (!rc) {
504 				rc = dlpar_add_lmb(lmb);
505 				if (rc)
506 					dlpar_release_drc(lmb->drc_index);
507 			}
508 			break;
509 		}
510 	}
511 
512 	if (!lmb_found)
513 		rc = -EINVAL;
514 
515 	if (rc)
516 		pr_info("Failed to update memory at %llx\n",
517 			lmb->base_addr);
518 	else
519 		pr_info("Memory at %llx was updated\n", lmb->base_addr);
520 
521 	return rc;
522 }
523 
524 static int dlpar_memory_remove_by_ic(u32 lmbs_to_remove, u32 drc_index)
525 {
526 	struct drmem_lmb *lmb, *start_lmb, *end_lmb;
527 	int lmbs_available = 0;
528 	int rc;
529 
530 	pr_info("Attempting to hot-remove %u LMB(s) at %x\n",
531 		lmbs_to_remove, drc_index);
532 
533 	if (lmbs_to_remove == 0)
534 		return -EINVAL;
535 
536 	rc = get_lmb_range(drc_index, lmbs_to_remove, &start_lmb, &end_lmb);
537 	if (rc)
538 		return -EINVAL;
539 
540 	/* Validate that there are enough LMBs to satisfy the request */
541 	for_each_drmem_lmb_in_range(lmb, start_lmb, end_lmb) {
542 		if (lmb->flags & DRCONF_MEM_RESERVED)
543 			break;
544 
545 		lmbs_available++;
546 	}
547 
548 	if (lmbs_available < lmbs_to_remove)
549 		return -EINVAL;
550 
551 	for_each_drmem_lmb_in_range(lmb, start_lmb, end_lmb) {
552 		if (!(lmb->flags & DRCONF_MEM_ASSIGNED))
553 			continue;
554 
555 		rc = dlpar_remove_lmb(lmb);
556 		if (rc)
557 			break;
558 
559 		drmem_mark_lmb_reserved(lmb);
560 	}
561 
562 	if (rc) {
563 		pr_err("Memory indexed-count-remove failed, adding any removed LMBs\n");
564 
565 
566 		for_each_drmem_lmb_in_range(lmb, start_lmb, end_lmb) {
567 			if (!drmem_lmb_reserved(lmb))
568 				continue;
569 
570 			rc = dlpar_add_lmb(lmb);
571 			if (rc)
572 				pr_err("Failed to add LMB, drc index %x\n",
573 				       lmb->drc_index);
574 
575 			drmem_remove_lmb_reservation(lmb);
576 		}
577 		rc = -EINVAL;
578 	} else {
579 		for_each_drmem_lmb_in_range(lmb, start_lmb, end_lmb) {
580 			if (!drmem_lmb_reserved(lmb))
581 				continue;
582 
583 			dlpar_release_drc(lmb->drc_index);
584 			pr_info("Memory at %llx (drc index %x) was hot-removed\n",
585 				lmb->base_addr, lmb->drc_index);
586 
587 			drmem_remove_lmb_reservation(lmb);
588 		}
589 	}
590 
591 	return rc;
592 }
593 
594 #else
595 static inline int pseries_remove_memblock(unsigned long base,
596 					  unsigned int memblock_size)
597 {
598 	return -EOPNOTSUPP;
599 }
600 static inline int pseries_remove_mem_node(struct device_node *np)
601 {
602 	return 0;
603 }
604 static inline int dlpar_memory_remove(struct pseries_hp_errorlog *hp_elog)
605 {
606 	return -EOPNOTSUPP;
607 }
608 static int dlpar_remove_lmb(struct drmem_lmb *lmb)
609 {
610 	return -EOPNOTSUPP;
611 }
612 static int dlpar_memory_remove_by_count(u32 lmbs_to_remove)
613 {
614 	return -EOPNOTSUPP;
615 }
616 static int dlpar_memory_remove_by_index(u32 drc_index)
617 {
618 	return -EOPNOTSUPP;
619 }
620 static int dlpar_memory_readd_by_index(u32 drc_index)
621 {
622 	return -EOPNOTSUPP;
623 }
624 
625 static int dlpar_memory_remove_by_ic(u32 lmbs_to_remove, u32 drc_index)
626 {
627 	return -EOPNOTSUPP;
628 }
629 #endif /* CONFIG_MEMORY_HOTREMOVE */
630 
631 static int dlpar_add_lmb(struct drmem_lmb *lmb)
632 {
633 	unsigned long block_sz;
634 	int rc;
635 
636 	if (lmb->flags & DRCONF_MEM_ASSIGNED)
637 		return -EINVAL;
638 
639 	rc = update_lmb_associativity_index(lmb);
640 	if (rc) {
641 		dlpar_release_drc(lmb->drc_index);
642 		return rc;
643 	}
644 
645 	lmb_set_nid(lmb);
646 	block_sz = memory_block_size_bytes();
647 
648 	/* Add the memory */
649 	rc = __add_memory(lmb->nid, lmb->base_addr, block_sz);
650 	if (rc) {
651 		invalidate_lmb_associativity_index(lmb);
652 		return rc;
653 	}
654 
655 	rc = dlpar_online_lmb(lmb);
656 	if (rc) {
657 		__remove_memory(lmb->nid, lmb->base_addr, block_sz);
658 		invalidate_lmb_associativity_index(lmb);
659 		lmb_clear_nid(lmb);
660 	} else {
661 		lmb->flags |= DRCONF_MEM_ASSIGNED;
662 	}
663 
664 	return rc;
665 }
666 
667 static int dlpar_memory_add_by_count(u32 lmbs_to_add)
668 {
669 	struct drmem_lmb *lmb;
670 	int lmbs_available = 0;
671 	int lmbs_added = 0;
672 	int rc;
673 
674 	pr_info("Attempting to hot-add %d LMB(s)\n", lmbs_to_add);
675 
676 	if (lmbs_to_add == 0)
677 		return -EINVAL;
678 
679 	/* Validate that there are enough LMBs to satisfy the request */
680 	for_each_drmem_lmb(lmb) {
681 		if (!(lmb->flags & DRCONF_MEM_ASSIGNED))
682 			lmbs_available++;
683 
684 		if (lmbs_available == lmbs_to_add)
685 			break;
686 	}
687 
688 	if (lmbs_available < lmbs_to_add)
689 		return -EINVAL;
690 
691 	for_each_drmem_lmb(lmb) {
692 		if (lmb->flags & DRCONF_MEM_ASSIGNED)
693 			continue;
694 
695 		rc = dlpar_acquire_drc(lmb->drc_index);
696 		if (rc)
697 			continue;
698 
699 		rc = dlpar_add_lmb(lmb);
700 		if (rc) {
701 			dlpar_release_drc(lmb->drc_index);
702 			continue;
703 		}
704 
705 		/* Mark this lmb so we can remove it later if all of the
706 		 * requested LMBs cannot be added.
707 		 */
708 		drmem_mark_lmb_reserved(lmb);
709 
710 		lmbs_added++;
711 		if (lmbs_added == lmbs_to_add)
712 			break;
713 	}
714 
715 	if (lmbs_added != lmbs_to_add) {
716 		pr_err("Memory hot-add failed, removing any added LMBs\n");
717 
718 		for_each_drmem_lmb(lmb) {
719 			if (!drmem_lmb_reserved(lmb))
720 				continue;
721 
722 			rc = dlpar_remove_lmb(lmb);
723 			if (rc)
724 				pr_err("Failed to remove LMB, drc index %x\n",
725 				       lmb->drc_index);
726 			else
727 				dlpar_release_drc(lmb->drc_index);
728 
729 			drmem_remove_lmb_reservation(lmb);
730 		}
731 		rc = -EINVAL;
732 	} else {
733 		for_each_drmem_lmb(lmb) {
734 			if (!drmem_lmb_reserved(lmb))
735 				continue;
736 
737 			pr_info("Memory at %llx (drc index %x) was hot-added\n",
738 				lmb->base_addr, lmb->drc_index);
739 			drmem_remove_lmb_reservation(lmb);
740 		}
741 		rc = 0;
742 	}
743 
744 	return rc;
745 }
746 
747 static int dlpar_memory_add_by_index(u32 drc_index)
748 {
749 	struct drmem_lmb *lmb;
750 	int rc, lmb_found;
751 
752 	pr_info("Attempting to hot-add LMB, drc index %x\n", drc_index);
753 
754 	lmb_found = 0;
755 	for_each_drmem_lmb(lmb) {
756 		if (lmb->drc_index == drc_index) {
757 			lmb_found = 1;
758 			rc = dlpar_acquire_drc(lmb->drc_index);
759 			if (!rc) {
760 				rc = dlpar_add_lmb(lmb);
761 				if (rc)
762 					dlpar_release_drc(lmb->drc_index);
763 			}
764 
765 			break;
766 		}
767 	}
768 
769 	if (!lmb_found)
770 		rc = -EINVAL;
771 
772 	if (rc)
773 		pr_info("Failed to hot-add memory, drc index %x\n", drc_index);
774 	else
775 		pr_info("Memory at %llx (drc index %x) was hot-added\n",
776 			lmb->base_addr, drc_index);
777 
778 	return rc;
779 }
780 
781 static int dlpar_memory_add_by_ic(u32 lmbs_to_add, u32 drc_index)
782 {
783 	struct drmem_lmb *lmb, *start_lmb, *end_lmb;
784 	int lmbs_available = 0;
785 	int rc;
786 
787 	pr_info("Attempting to hot-add %u LMB(s) at index %x\n",
788 		lmbs_to_add, drc_index);
789 
790 	if (lmbs_to_add == 0)
791 		return -EINVAL;
792 
793 	rc = get_lmb_range(drc_index, lmbs_to_add, &start_lmb, &end_lmb);
794 	if (rc)
795 		return -EINVAL;
796 
797 	/* Validate that the LMBs in this range are not reserved */
798 	for_each_drmem_lmb_in_range(lmb, start_lmb, end_lmb) {
799 		if (lmb->flags & DRCONF_MEM_RESERVED)
800 			break;
801 
802 		lmbs_available++;
803 	}
804 
805 	if (lmbs_available < lmbs_to_add)
806 		return -EINVAL;
807 
808 	for_each_drmem_lmb_in_range(lmb, start_lmb, end_lmb) {
809 		if (lmb->flags & DRCONF_MEM_ASSIGNED)
810 			continue;
811 
812 		rc = dlpar_acquire_drc(lmb->drc_index);
813 		if (rc)
814 			break;
815 
816 		rc = dlpar_add_lmb(lmb);
817 		if (rc) {
818 			dlpar_release_drc(lmb->drc_index);
819 			break;
820 		}
821 
822 		drmem_mark_lmb_reserved(lmb);
823 	}
824 
825 	if (rc) {
826 		pr_err("Memory indexed-count-add failed, removing any added LMBs\n");
827 
828 		for_each_drmem_lmb_in_range(lmb, start_lmb, end_lmb) {
829 			if (!drmem_lmb_reserved(lmb))
830 				continue;
831 
832 			rc = dlpar_remove_lmb(lmb);
833 			if (rc)
834 				pr_err("Failed to remove LMB, drc index %x\n",
835 				       lmb->drc_index);
836 			else
837 				dlpar_release_drc(lmb->drc_index);
838 
839 			drmem_remove_lmb_reservation(lmb);
840 		}
841 		rc = -EINVAL;
842 	} else {
843 		for_each_drmem_lmb_in_range(lmb, start_lmb, end_lmb) {
844 			if (!drmem_lmb_reserved(lmb))
845 				continue;
846 
847 			pr_info("Memory at %llx (drc index %x) was hot-added\n",
848 				lmb->base_addr, lmb->drc_index);
849 			drmem_remove_lmb_reservation(lmb);
850 		}
851 	}
852 
853 	return rc;
854 }
855 
856 int dlpar_memory(struct pseries_hp_errorlog *hp_elog)
857 {
858 	u32 count, drc_index;
859 	int rc;
860 
861 	lock_device_hotplug();
862 
863 	switch (hp_elog->action) {
864 	case PSERIES_HP_ELOG_ACTION_ADD:
865 		switch (hp_elog->id_type) {
866 		case PSERIES_HP_ELOG_ID_DRC_COUNT:
867 			count = hp_elog->_drc_u.drc_count;
868 			rc = dlpar_memory_add_by_count(count);
869 			break;
870 		case PSERIES_HP_ELOG_ID_DRC_INDEX:
871 			drc_index = hp_elog->_drc_u.drc_index;
872 			rc = dlpar_memory_add_by_index(drc_index);
873 			break;
874 		case PSERIES_HP_ELOG_ID_DRC_IC:
875 			count = hp_elog->_drc_u.ic.count;
876 			drc_index = hp_elog->_drc_u.ic.index;
877 			rc = dlpar_memory_add_by_ic(count, drc_index);
878 			break;
879 		default:
880 			rc = -EINVAL;
881 			break;
882 		}
883 
884 		break;
885 	case PSERIES_HP_ELOG_ACTION_REMOVE:
886 		switch (hp_elog->id_type) {
887 		case PSERIES_HP_ELOG_ID_DRC_COUNT:
888 			count = hp_elog->_drc_u.drc_count;
889 			rc = dlpar_memory_remove_by_count(count);
890 			break;
891 		case PSERIES_HP_ELOG_ID_DRC_INDEX:
892 			drc_index = hp_elog->_drc_u.drc_index;
893 			rc = dlpar_memory_remove_by_index(drc_index);
894 			break;
895 		case PSERIES_HP_ELOG_ID_DRC_IC:
896 			count = hp_elog->_drc_u.ic.count;
897 			drc_index = hp_elog->_drc_u.ic.index;
898 			rc = dlpar_memory_remove_by_ic(count, drc_index);
899 			break;
900 		default:
901 			rc = -EINVAL;
902 			break;
903 		}
904 
905 		break;
906 	case PSERIES_HP_ELOG_ACTION_READD:
907 		drc_index = hp_elog->_drc_u.drc_index;
908 		rc = dlpar_memory_readd_by_index(drc_index);
909 		break;
910 	default:
911 		pr_err("Invalid action (%d) specified\n", hp_elog->action);
912 		rc = -EINVAL;
913 		break;
914 	}
915 
916 	if (!rc) {
917 		rtas_hp_event = true;
918 		rc = drmem_update_dt();
919 		rtas_hp_event = false;
920 	}
921 
922 	unlock_device_hotplug();
923 	return rc;
924 }
925 
926 static int pseries_add_mem_node(struct device_node *np)
927 {
928 	const __be32 *regs;
929 	unsigned long base;
930 	unsigned int lmb_size;
931 	int ret = -EINVAL;
932 
933 	/*
934 	 * Check to see if we are actually adding memory
935 	 */
936 	if (!of_node_is_type(np, "memory"))
937 		return 0;
938 
939 	/*
940 	 * Find the base and size of the memblock
941 	 */
942 	regs = of_get_property(np, "reg", NULL);
943 	if (!regs)
944 		return ret;
945 
946 	base = be64_to_cpu(*(unsigned long *)regs);
947 	lmb_size = be32_to_cpu(regs[3]);
948 
949 	/*
950 	 * Update memory region to represent the memory add
951 	 */
952 	ret = memblock_add(base, lmb_size);
953 	return (ret < 0) ? -EINVAL : 0;
954 }
955 
956 static int pseries_update_drconf_memory(struct of_reconfig_data *pr)
957 {
958 	struct of_drconf_cell_v1 *new_drmem, *old_drmem;
959 	unsigned long memblock_size;
960 	u32 entries;
961 	__be32 *p;
962 	int i, rc = -EINVAL;
963 
964 	if (rtas_hp_event)
965 		return 0;
966 
967 	memblock_size = pseries_memory_block_size();
968 	if (!memblock_size)
969 		return -EINVAL;
970 
971 	if (!pr->old_prop)
972 		return 0;
973 
974 	p = (__be32 *) pr->old_prop->value;
975 	if (!p)
976 		return -EINVAL;
977 
978 	/* The first int of the property is the number of lmb's described
979 	 * by the property. This is followed by an array of of_drconf_cell
980 	 * entries. Get the number of entries and skip to the array of
981 	 * of_drconf_cell's.
982 	 */
983 	entries = be32_to_cpu(*p++);
984 	old_drmem = (struct of_drconf_cell_v1 *)p;
985 
986 	p = (__be32 *)pr->prop->value;
987 	p++;
988 	new_drmem = (struct of_drconf_cell_v1 *)p;
989 
990 	for (i = 0; i < entries; i++) {
991 		if ((be32_to_cpu(old_drmem[i].flags) & DRCONF_MEM_ASSIGNED) &&
992 		    (!(be32_to_cpu(new_drmem[i].flags) & DRCONF_MEM_ASSIGNED))) {
993 			rc = pseries_remove_memblock(
994 				be64_to_cpu(old_drmem[i].base_addr),
995 						     memblock_size);
996 			break;
997 		} else if ((!(be32_to_cpu(old_drmem[i].flags) &
998 			    DRCONF_MEM_ASSIGNED)) &&
999 			    (be32_to_cpu(new_drmem[i].flags) &
1000 			    DRCONF_MEM_ASSIGNED)) {
1001 			rc = memblock_add(be64_to_cpu(old_drmem[i].base_addr),
1002 					  memblock_size);
1003 			rc = (rc < 0) ? -EINVAL : 0;
1004 			break;
1005 		}
1006 	}
1007 	return rc;
1008 }
1009 
1010 static int pseries_memory_notifier(struct notifier_block *nb,
1011 				   unsigned long action, void *data)
1012 {
1013 	struct of_reconfig_data *rd = data;
1014 	int err = 0;
1015 
1016 	switch (action) {
1017 	case OF_RECONFIG_ATTACH_NODE:
1018 		err = pseries_add_mem_node(rd->dn);
1019 		break;
1020 	case OF_RECONFIG_DETACH_NODE:
1021 		err = pseries_remove_mem_node(rd->dn);
1022 		break;
1023 	case OF_RECONFIG_UPDATE_PROPERTY:
1024 		if (!strcmp(rd->prop->name, "ibm,dynamic-memory"))
1025 			err = pseries_update_drconf_memory(rd);
1026 		break;
1027 	}
1028 	return notifier_from_errno(err);
1029 }
1030 
1031 static struct notifier_block pseries_mem_nb = {
1032 	.notifier_call = pseries_memory_notifier,
1033 };
1034 
1035 static int __init pseries_memory_hotplug_init(void)
1036 {
1037 	if (firmware_has_feature(FW_FEATURE_LPAR))
1038 		of_reconfig_notifier_register(&pseries_mem_nb);
1039 
1040 	return 0;
1041 }
1042 machine_device_initcall(pseries, pseries_memory_hotplug_init);
1043