1 /*
2  * pseries Memory Hotplug infrastructure.
3  *
4  * Copyright (C) 2008 Badari Pulavarty, IBM Corporation
5  *
6  *      This program is free software; you can redistribute it and/or
7  *      modify it under the terms of the GNU General Public License
8  *      as published by the Free Software Foundation; either version
9  *      2 of the License, or (at your option) any later version.
10  */
11 
12 #define pr_fmt(fmt)	"pseries-hotplug-mem: " fmt
13 
14 #include <linux/of.h>
15 #include <linux/of_address.h>
16 #include <linux/memblock.h>
17 #include <linux/memory.h>
18 #include <linux/memory_hotplug.h>
19 #include <linux/slab.h>
20 
21 #include <asm/firmware.h>
22 #include <asm/machdep.h>
23 #include <asm/prom.h>
24 #include <asm/sparsemem.h>
25 #include "pseries.h"
26 
27 static bool rtas_hp_event;
28 
29 unsigned long pseries_memory_block_size(void)
30 {
31 	struct device_node *np;
32 	unsigned int memblock_size = MIN_MEMORY_BLOCK_SIZE;
33 	struct resource r;
34 
35 	np = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
36 	if (np) {
37 		const __be64 *size;
38 
39 		size = of_get_property(np, "ibm,lmb-size", NULL);
40 		if (size)
41 			memblock_size = be64_to_cpup(size);
42 		of_node_put(np);
43 	} else  if (machine_is(pseries)) {
44 		/* This fallback really only applies to pseries */
45 		unsigned int memzero_size = 0;
46 
47 		np = of_find_node_by_path("/memory@0");
48 		if (np) {
49 			if (!of_address_to_resource(np, 0, &r))
50 				memzero_size = resource_size(&r);
51 			of_node_put(np);
52 		}
53 
54 		if (memzero_size) {
55 			/* We now know the size of memory@0, use this to find
56 			 * the first memoryblock and get its size.
57 			 */
58 			char buf[64];
59 
60 			sprintf(buf, "/memory@%x", memzero_size);
61 			np = of_find_node_by_path(buf);
62 			if (np) {
63 				if (!of_address_to_resource(np, 0, &r))
64 					memblock_size = resource_size(&r);
65 				of_node_put(np);
66 			}
67 		}
68 	}
69 	return memblock_size;
70 }
71 
72 static void dlpar_free_drconf_property(struct property *prop)
73 {
74 	kfree(prop->name);
75 	kfree(prop->value);
76 	kfree(prop);
77 }
78 
79 static struct property *dlpar_clone_drconf_property(struct device_node *dn)
80 {
81 	struct property *prop, *new_prop;
82 	struct of_drconf_cell *lmbs;
83 	u32 num_lmbs, *p;
84 	int i;
85 
86 	prop = of_find_property(dn, "ibm,dynamic-memory", NULL);
87 	if (!prop)
88 		return NULL;
89 
90 	new_prop = kzalloc(sizeof(*new_prop), GFP_KERNEL);
91 	if (!new_prop)
92 		return NULL;
93 
94 	new_prop->name = kstrdup(prop->name, GFP_KERNEL);
95 	new_prop->value = kmemdup(prop->value, prop->length, GFP_KERNEL);
96 	if (!new_prop->name || !new_prop->value) {
97 		dlpar_free_drconf_property(new_prop);
98 		return NULL;
99 	}
100 
101 	new_prop->length = prop->length;
102 
103 	/* Convert the property to cpu endian-ness */
104 	p = new_prop->value;
105 	*p = be32_to_cpu(*p);
106 
107 	num_lmbs = *p++;
108 	lmbs = (struct of_drconf_cell *)p;
109 
110 	for (i = 0; i < num_lmbs; i++) {
111 		lmbs[i].base_addr = be64_to_cpu(lmbs[i].base_addr);
112 		lmbs[i].drc_index = be32_to_cpu(lmbs[i].drc_index);
113 		lmbs[i].flags = be32_to_cpu(lmbs[i].flags);
114 	}
115 
116 	return new_prop;
117 }
118 
119 static struct memory_block *lmb_to_memblock(struct of_drconf_cell *lmb)
120 {
121 	unsigned long section_nr;
122 	struct mem_section *mem_sect;
123 	struct memory_block *mem_block;
124 
125 	section_nr = pfn_to_section_nr(PFN_DOWN(lmb->base_addr));
126 	mem_sect = __nr_to_section(section_nr);
127 
128 	mem_block = find_memory_block(mem_sect);
129 	return mem_block;
130 }
131 
132 #ifdef CONFIG_MEMORY_HOTREMOVE
133 static int pseries_remove_memblock(unsigned long base, unsigned int memblock_size)
134 {
135 	unsigned long block_sz, start_pfn;
136 	int sections_per_block;
137 	int i, nid;
138 
139 	start_pfn = base >> PAGE_SHIFT;
140 
141 	lock_device_hotplug();
142 
143 	if (!pfn_valid(start_pfn))
144 		goto out;
145 
146 	block_sz = pseries_memory_block_size();
147 	sections_per_block = block_sz / MIN_MEMORY_BLOCK_SIZE;
148 	nid = memory_add_physaddr_to_nid(base);
149 
150 	for (i = 0; i < sections_per_block; i++) {
151 		remove_memory(nid, base, MIN_MEMORY_BLOCK_SIZE);
152 		base += MIN_MEMORY_BLOCK_SIZE;
153 	}
154 
155 out:
156 	/* Update memory regions for memory remove */
157 	memblock_remove(base, memblock_size);
158 	unlock_device_hotplug();
159 	return 0;
160 }
161 
162 static int pseries_remove_mem_node(struct device_node *np)
163 {
164 	const char *type;
165 	const __be32 *regs;
166 	unsigned long base;
167 	unsigned int lmb_size;
168 	int ret = -EINVAL;
169 
170 	/*
171 	 * Check to see if we are actually removing memory
172 	 */
173 	type = of_get_property(np, "device_type", NULL);
174 	if (type == NULL || strcmp(type, "memory") != 0)
175 		return 0;
176 
177 	/*
178 	 * Find the base address and size of the memblock
179 	 */
180 	regs = of_get_property(np, "reg", NULL);
181 	if (!regs)
182 		return ret;
183 
184 	base = be64_to_cpu(*(unsigned long *)regs);
185 	lmb_size = be32_to_cpu(regs[3]);
186 
187 	pseries_remove_memblock(base, lmb_size);
188 	return 0;
189 }
190 
191 static bool lmb_is_removable(struct of_drconf_cell *lmb)
192 {
193 	int i, scns_per_block;
194 	int rc = 1;
195 	unsigned long pfn, block_sz;
196 	u64 phys_addr;
197 
198 	if (!(lmb->flags & DRCONF_MEM_ASSIGNED))
199 		return false;
200 
201 	block_sz = memory_block_size_bytes();
202 	scns_per_block = block_sz / MIN_MEMORY_BLOCK_SIZE;
203 	phys_addr = lmb->base_addr;
204 
205 	for (i = 0; i < scns_per_block; i++) {
206 		pfn = PFN_DOWN(phys_addr);
207 		if (!pfn_present(pfn))
208 			continue;
209 
210 		rc &= is_mem_section_removable(pfn, PAGES_PER_SECTION);
211 		phys_addr += MIN_MEMORY_BLOCK_SIZE;
212 	}
213 
214 	return rc ? true : false;
215 }
216 
217 static int dlpar_add_lmb(struct of_drconf_cell *);
218 
219 static int dlpar_remove_lmb(struct of_drconf_cell *lmb)
220 {
221 	struct memory_block *mem_block;
222 	unsigned long block_sz;
223 	int nid, rc;
224 
225 	if (!lmb_is_removable(lmb))
226 		return -EINVAL;
227 
228 	mem_block = lmb_to_memblock(lmb);
229 	if (!mem_block)
230 		return -EINVAL;
231 
232 	rc = device_offline(&mem_block->dev);
233 	put_device(&mem_block->dev);
234 	if (rc)
235 		return rc;
236 
237 	block_sz = pseries_memory_block_size();
238 	nid = memory_add_physaddr_to_nid(lmb->base_addr);
239 
240 	remove_memory(nid, lmb->base_addr, block_sz);
241 
242 	/* Update memory regions for memory remove */
243 	memblock_remove(lmb->base_addr, block_sz);
244 
245 	dlpar_release_drc(lmb->drc_index);
246 
247 	lmb->flags &= ~DRCONF_MEM_ASSIGNED;
248 	return 0;
249 }
250 
251 static int dlpar_memory_remove_by_count(u32 lmbs_to_remove,
252 					struct property *prop)
253 {
254 	struct of_drconf_cell *lmbs;
255 	int lmbs_removed = 0;
256 	int lmbs_available = 0;
257 	u32 num_lmbs, *p;
258 	int i, rc;
259 
260 	pr_info("Attempting to hot-remove %d LMB(s)\n", lmbs_to_remove);
261 
262 	if (lmbs_to_remove == 0)
263 		return -EINVAL;
264 
265 	p = prop->value;
266 	num_lmbs = *p++;
267 	lmbs = (struct of_drconf_cell *)p;
268 
269 	/* Validate that there are enough LMBs to satisfy the request */
270 	for (i = 0; i < num_lmbs; i++) {
271 		if (lmbs[i].flags & DRCONF_MEM_ASSIGNED)
272 			lmbs_available++;
273 	}
274 
275 	if (lmbs_available < lmbs_to_remove)
276 		return -EINVAL;
277 
278 	for (i = 0; i < num_lmbs && lmbs_removed < lmbs_to_remove; i++) {
279 		rc = dlpar_remove_lmb(&lmbs[i]);
280 		if (rc)
281 			continue;
282 
283 		lmbs_removed++;
284 
285 		/* Mark this lmb so we can add it later if all of the
286 		 * requested LMBs cannot be removed.
287 		 */
288 		lmbs[i].reserved = 1;
289 	}
290 
291 	if (lmbs_removed != lmbs_to_remove) {
292 		pr_err("Memory hot-remove failed, adding LMB's back\n");
293 
294 		for (i = 0; i < num_lmbs; i++) {
295 			if (!lmbs[i].reserved)
296 				continue;
297 
298 			rc = dlpar_add_lmb(&lmbs[i]);
299 			if (rc)
300 				pr_err("Failed to add LMB back, drc index %x\n",
301 				       lmbs[i].drc_index);
302 
303 			lmbs[i].reserved = 0;
304 		}
305 
306 		rc = -EINVAL;
307 	} else {
308 		for (i = 0; i < num_lmbs; i++) {
309 			if (!lmbs[i].reserved)
310 				continue;
311 
312 			pr_info("Memory at %llx was hot-removed\n",
313 				lmbs[i].base_addr);
314 
315 			lmbs[i].reserved = 0;
316 		}
317 		rc = 0;
318 	}
319 
320 	return rc;
321 }
322 
323 static int dlpar_memory_remove_by_index(u32 drc_index, struct property *prop)
324 {
325 	struct of_drconf_cell *lmbs;
326 	u32 num_lmbs, *p;
327 	int lmb_found;
328 	int i, rc;
329 
330 	pr_info("Attempting to hot-remove LMB, drc index %x\n", drc_index);
331 
332 	p = prop->value;
333 	num_lmbs = *p++;
334 	lmbs = (struct of_drconf_cell *)p;
335 
336 	lmb_found = 0;
337 	for (i = 0; i < num_lmbs; i++) {
338 		if (lmbs[i].drc_index == drc_index) {
339 			lmb_found = 1;
340 			rc = dlpar_remove_lmb(&lmbs[i]);
341 			break;
342 		}
343 	}
344 
345 	if (!lmb_found)
346 		rc = -EINVAL;
347 
348 	if (rc)
349 		pr_info("Failed to hot-remove memory at %llx\n",
350 			lmbs[i].base_addr);
351 	else
352 		pr_info("Memory at %llx was hot-removed\n", lmbs[i].base_addr);
353 
354 	return rc;
355 }
356 
357 #else
358 static inline int pseries_remove_memblock(unsigned long base,
359 					  unsigned int memblock_size)
360 {
361 	return -EOPNOTSUPP;
362 }
363 static inline int pseries_remove_mem_node(struct device_node *np)
364 {
365 	return 0;
366 }
367 static inline int dlpar_memory_remove(struct pseries_hp_errorlog *hp_elog)
368 {
369 	return -EOPNOTSUPP;
370 }
371 static int dlpar_remove_lmb(struct of_drconf_cell *lmb)
372 {
373 	return -EOPNOTSUPP;
374 }
375 static int dlpar_memory_remove_by_count(u32 lmbs_to_remove,
376 					struct property *prop)
377 {
378 	return -EOPNOTSUPP;
379 }
380 static int dlpar_memory_remove_by_index(u32 drc_index, struct property *prop)
381 {
382 	return -EOPNOTSUPP;
383 }
384 
385 #endif /* CONFIG_MEMORY_HOTREMOVE */
386 
387 static int dlpar_add_lmb(struct of_drconf_cell *lmb)
388 {
389 	struct memory_block *mem_block;
390 	unsigned long block_sz;
391 	int nid, rc;
392 
393 	if (lmb->flags & DRCONF_MEM_ASSIGNED)
394 		return -EINVAL;
395 
396 	block_sz = memory_block_size_bytes();
397 
398 	rc = dlpar_acquire_drc(lmb->drc_index);
399 	if (rc)
400 		return rc;
401 
402 	/* Find the node id for this address */
403 	nid = memory_add_physaddr_to_nid(lmb->base_addr);
404 
405 	/* Add the memory */
406 	rc = add_memory(nid, lmb->base_addr, block_sz);
407 	if (rc) {
408 		dlpar_release_drc(lmb->drc_index);
409 		return rc;
410 	}
411 
412 	/* Register this block of memory */
413 	rc = memblock_add(lmb->base_addr, block_sz);
414 	if (rc) {
415 		remove_memory(nid, lmb->base_addr, block_sz);
416 		dlpar_release_drc(lmb->drc_index);
417 		return rc;
418 	}
419 
420 	mem_block = lmb_to_memblock(lmb);
421 	if (!mem_block) {
422 		remove_memory(nid, lmb->base_addr, block_sz);
423 		dlpar_release_drc(lmb->drc_index);
424 		return -EINVAL;
425 	}
426 
427 	rc = device_online(&mem_block->dev);
428 	put_device(&mem_block->dev);
429 	if (rc) {
430 		remove_memory(nid, lmb->base_addr, block_sz);
431 		dlpar_release_drc(lmb->drc_index);
432 		return rc;
433 	}
434 
435 	lmb->flags |= DRCONF_MEM_ASSIGNED;
436 	return 0;
437 }
438 
439 static int dlpar_memory_add_by_count(u32 lmbs_to_add, struct property *prop)
440 {
441 	struct of_drconf_cell *lmbs;
442 	u32 num_lmbs, *p;
443 	int lmbs_available = 0;
444 	int lmbs_added = 0;
445 	int i, rc;
446 
447 	pr_info("Attempting to hot-add %d LMB(s)\n", lmbs_to_add);
448 
449 	if (lmbs_to_add == 0)
450 		return -EINVAL;
451 
452 	p = prop->value;
453 	num_lmbs = *p++;
454 	lmbs = (struct of_drconf_cell *)p;
455 
456 	/* Validate that there are enough LMBs to satisfy the request */
457 	for (i = 0; i < num_lmbs; i++) {
458 		if (!(lmbs[i].flags & DRCONF_MEM_ASSIGNED))
459 			lmbs_available++;
460 	}
461 
462 	if (lmbs_available < lmbs_to_add)
463 		return -EINVAL;
464 
465 	for (i = 0; i < num_lmbs && lmbs_to_add != lmbs_added; i++) {
466 		rc = dlpar_add_lmb(&lmbs[i]);
467 		if (rc)
468 			continue;
469 
470 		lmbs_added++;
471 
472 		/* Mark this lmb so we can remove it later if all of the
473 		 * requested LMBs cannot be added.
474 		 */
475 		lmbs[i].reserved = 1;
476 	}
477 
478 	if (lmbs_added != lmbs_to_add) {
479 		pr_err("Memory hot-add failed, removing any added LMBs\n");
480 
481 		for (i = 0; i < num_lmbs; i++) {
482 			if (!lmbs[i].reserved)
483 				continue;
484 
485 			rc = dlpar_remove_lmb(&lmbs[i]);
486 			if (rc)
487 				pr_err("Failed to remove LMB, drc index %x\n",
488 				       be32_to_cpu(lmbs[i].drc_index));
489 		}
490 		rc = -EINVAL;
491 	} else {
492 		for (i = 0; i < num_lmbs; i++) {
493 			if (!lmbs[i].reserved)
494 				continue;
495 
496 			pr_info("Memory at %llx (drc index %x) was hot-added\n",
497 				lmbs[i].base_addr, lmbs[i].drc_index);
498 			lmbs[i].reserved = 0;
499 		}
500 	}
501 
502 	return rc;
503 }
504 
505 static int dlpar_memory_add_by_index(u32 drc_index, struct property *prop)
506 {
507 	struct of_drconf_cell *lmbs;
508 	u32 num_lmbs, *p;
509 	int i, lmb_found;
510 	int rc;
511 
512 	pr_info("Attempting to hot-add LMB, drc index %x\n", drc_index);
513 
514 	p = prop->value;
515 	num_lmbs = *p++;
516 	lmbs = (struct of_drconf_cell *)p;
517 
518 	lmb_found = 0;
519 	for (i = 0; i < num_lmbs; i++) {
520 		if (lmbs[i].drc_index == drc_index) {
521 			lmb_found = 1;
522 			rc = dlpar_add_lmb(&lmbs[i]);
523 			break;
524 		}
525 	}
526 
527 	if (!lmb_found)
528 		rc = -EINVAL;
529 
530 	if (rc)
531 		pr_info("Failed to hot-add memory, drc index %x\n", drc_index);
532 	else
533 		pr_info("Memory at %llx (drc index %x) was hot-added\n",
534 			lmbs[i].base_addr, drc_index);
535 
536 	return rc;
537 }
538 
539 static void dlpar_update_drconf_property(struct device_node *dn,
540 					 struct property *prop)
541 {
542 	struct of_drconf_cell *lmbs;
543 	u32 num_lmbs, *p;
544 	int i;
545 
546 	/* Convert the property back to BE */
547 	p = prop->value;
548 	num_lmbs = *p;
549 	*p = cpu_to_be32(*p);
550 	p++;
551 
552 	lmbs = (struct of_drconf_cell *)p;
553 	for (i = 0; i < num_lmbs; i++) {
554 		lmbs[i].base_addr = cpu_to_be64(lmbs[i].base_addr);
555 		lmbs[i].drc_index = cpu_to_be32(lmbs[i].drc_index);
556 		lmbs[i].flags = cpu_to_be32(lmbs[i].flags);
557 	}
558 
559 	rtas_hp_event = true;
560 	of_update_property(dn, prop);
561 	rtas_hp_event = false;
562 }
563 
564 int dlpar_memory(struct pseries_hp_errorlog *hp_elog)
565 {
566 	struct device_node *dn;
567 	struct property *prop;
568 	u32 count, drc_index;
569 	int rc;
570 
571 	count = hp_elog->_drc_u.drc_count;
572 	drc_index = hp_elog->_drc_u.drc_index;
573 
574 	lock_device_hotplug();
575 
576 	dn = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
577 	if (!dn) {
578 		rc = -EINVAL;
579 		goto dlpar_memory_out;
580 	}
581 
582 	prop = dlpar_clone_drconf_property(dn);
583 	if (!prop) {
584 		rc = -EINVAL;
585 		goto dlpar_memory_out;
586 	}
587 
588 	switch (hp_elog->action) {
589 	case PSERIES_HP_ELOG_ACTION_ADD:
590 		if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_COUNT)
591 			rc = dlpar_memory_add_by_count(count, prop);
592 		else if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_INDEX)
593 			rc = dlpar_memory_add_by_index(drc_index, prop);
594 		else
595 			rc = -EINVAL;
596 		break;
597 	case PSERIES_HP_ELOG_ACTION_REMOVE:
598 		if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_COUNT)
599 			rc = dlpar_memory_remove_by_count(count, prop);
600 		else if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_INDEX)
601 			rc = dlpar_memory_remove_by_index(drc_index, prop);
602 		else
603 			rc = -EINVAL;
604 		break;
605 	default:
606 		pr_err("Invalid action (%d) specified\n", hp_elog->action);
607 		rc = -EINVAL;
608 		break;
609 	}
610 
611 	if (rc)
612 		dlpar_free_drconf_property(prop);
613 	else
614 		dlpar_update_drconf_property(dn, prop);
615 
616 dlpar_memory_out:
617 	of_node_put(dn);
618 	unlock_device_hotplug();
619 	return rc;
620 }
621 
622 static int pseries_add_mem_node(struct device_node *np)
623 {
624 	const char *type;
625 	const __be32 *regs;
626 	unsigned long base;
627 	unsigned int lmb_size;
628 	int ret = -EINVAL;
629 
630 	/*
631 	 * Check to see if we are actually adding memory
632 	 */
633 	type = of_get_property(np, "device_type", NULL);
634 	if (type == NULL || strcmp(type, "memory") != 0)
635 		return 0;
636 
637 	/*
638 	 * Find the base and size of the memblock
639 	 */
640 	regs = of_get_property(np, "reg", NULL);
641 	if (!regs)
642 		return ret;
643 
644 	base = be64_to_cpu(*(unsigned long *)regs);
645 	lmb_size = be32_to_cpu(regs[3]);
646 
647 	/*
648 	 * Update memory region to represent the memory add
649 	 */
650 	ret = memblock_add(base, lmb_size);
651 	return (ret < 0) ? -EINVAL : 0;
652 }
653 
654 static int pseries_update_drconf_memory(struct of_reconfig_data *pr)
655 {
656 	struct of_drconf_cell *new_drmem, *old_drmem;
657 	unsigned long memblock_size;
658 	u32 entries;
659 	__be32 *p;
660 	int i, rc = -EINVAL;
661 
662 	if (rtas_hp_event)
663 		return 0;
664 
665 	memblock_size = pseries_memory_block_size();
666 	if (!memblock_size)
667 		return -EINVAL;
668 
669 	p = (__be32 *) pr->old_prop->value;
670 	if (!p)
671 		return -EINVAL;
672 
673 	/* The first int of the property is the number of lmb's described
674 	 * by the property. This is followed by an array of of_drconf_cell
675 	 * entries. Get the number of entries and skip to the array of
676 	 * of_drconf_cell's.
677 	 */
678 	entries = be32_to_cpu(*p++);
679 	old_drmem = (struct of_drconf_cell *)p;
680 
681 	p = (__be32 *)pr->prop->value;
682 	p++;
683 	new_drmem = (struct of_drconf_cell *)p;
684 
685 	for (i = 0; i < entries; i++) {
686 		if ((be32_to_cpu(old_drmem[i].flags) & DRCONF_MEM_ASSIGNED) &&
687 		    (!(be32_to_cpu(new_drmem[i].flags) & DRCONF_MEM_ASSIGNED))) {
688 			rc = pseries_remove_memblock(
689 				be64_to_cpu(old_drmem[i].base_addr),
690 						     memblock_size);
691 			break;
692 		} else if ((!(be32_to_cpu(old_drmem[i].flags) &
693 			    DRCONF_MEM_ASSIGNED)) &&
694 			    (be32_to_cpu(new_drmem[i].flags) &
695 			    DRCONF_MEM_ASSIGNED)) {
696 			rc = memblock_add(be64_to_cpu(old_drmem[i].base_addr),
697 					  memblock_size);
698 			rc = (rc < 0) ? -EINVAL : 0;
699 			break;
700 		}
701 	}
702 	return rc;
703 }
704 
705 static int pseries_memory_notifier(struct notifier_block *nb,
706 				   unsigned long action, void *data)
707 {
708 	struct of_reconfig_data *rd = data;
709 	int err = 0;
710 
711 	switch (action) {
712 	case OF_RECONFIG_ATTACH_NODE:
713 		err = pseries_add_mem_node(rd->dn);
714 		break;
715 	case OF_RECONFIG_DETACH_NODE:
716 		err = pseries_remove_mem_node(rd->dn);
717 		break;
718 	case OF_RECONFIG_UPDATE_PROPERTY:
719 		if (!strcmp(rd->prop->name, "ibm,dynamic-memory"))
720 			err = pseries_update_drconf_memory(rd);
721 		break;
722 	}
723 	return notifier_from_errno(err);
724 }
725 
726 static struct notifier_block pseries_mem_nb = {
727 	.notifier_call = pseries_memory_notifier,
728 };
729 
730 static int __init pseries_memory_hotplug_init(void)
731 {
732 	if (firmware_has_feature(FW_FEATURE_LPAR))
733 		of_reconfig_notifier_register(&pseries_mem_nb);
734 
735 	return 0;
736 }
737 machine_device_initcall(pseries, pseries_memory_hotplug_init);
738