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_property(struct property *prop)
73 {
74 	kfree(prop->name);
75 	kfree(prop->value);
76 	kfree(prop);
77 }
78 
79 static struct property *dlpar_clone_property(struct property *prop,
80 					     u32 prop_size)
81 {
82 	struct property *new_prop;
83 
84 	new_prop = kzalloc(sizeof(*new_prop), GFP_KERNEL);
85 	if (!new_prop)
86 		return NULL;
87 
88 	new_prop->name = kstrdup(prop->name, GFP_KERNEL);
89 	new_prop->value = kzalloc(prop_size, GFP_KERNEL);
90 	if (!new_prop->name || !new_prop->value) {
91 		dlpar_free_property(new_prop);
92 		return NULL;
93 	}
94 
95 	memcpy(new_prop->value, prop->value, prop->length);
96 	new_prop->length = prop_size;
97 
98 	of_property_set_flag(new_prop, OF_DYNAMIC);
99 	return new_prop;
100 }
101 
102 static struct property *dlpar_clone_drconf_property(struct device_node *dn)
103 {
104 	struct property *prop, *new_prop;
105 	struct of_drconf_cell *lmbs;
106 	u32 num_lmbs, *p;
107 	int i;
108 
109 	prop = of_find_property(dn, "ibm,dynamic-memory", NULL);
110 	if (!prop)
111 		return NULL;
112 
113 	new_prop = dlpar_clone_property(prop, prop->length);
114 	if (!new_prop)
115 		return NULL;
116 
117 	/* Convert the property to cpu endian-ness */
118 	p = new_prop->value;
119 	*p = be32_to_cpu(*p);
120 
121 	num_lmbs = *p++;
122 	lmbs = (struct of_drconf_cell *)p;
123 
124 	for (i = 0; i < num_lmbs; i++) {
125 		lmbs[i].base_addr = be64_to_cpu(lmbs[i].base_addr);
126 		lmbs[i].drc_index = be32_to_cpu(lmbs[i].drc_index);
127 		lmbs[i].flags = be32_to_cpu(lmbs[i].flags);
128 	}
129 
130 	return new_prop;
131 }
132 
133 static void dlpar_update_drconf_property(struct device_node *dn,
134 					 struct property *prop)
135 {
136 	struct of_drconf_cell *lmbs;
137 	u32 num_lmbs, *p;
138 	int i;
139 
140 	/* Convert the property back to BE */
141 	p = prop->value;
142 	num_lmbs = *p;
143 	*p = cpu_to_be32(*p);
144 	p++;
145 
146 	lmbs = (struct of_drconf_cell *)p;
147 	for (i = 0; i < num_lmbs; i++) {
148 		lmbs[i].base_addr = cpu_to_be64(lmbs[i].base_addr);
149 		lmbs[i].drc_index = cpu_to_be32(lmbs[i].drc_index);
150 		lmbs[i].flags = cpu_to_be32(lmbs[i].flags);
151 	}
152 
153 	rtas_hp_event = true;
154 	of_update_property(dn, prop);
155 	rtas_hp_event = false;
156 }
157 
158 static int dlpar_update_device_tree_lmb(struct of_drconf_cell *lmb)
159 {
160 	struct device_node *dn;
161 	struct property *prop;
162 	struct of_drconf_cell *lmbs;
163 	u32 *p, num_lmbs;
164 	int i;
165 
166 	dn = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
167 	if (!dn)
168 		return -ENODEV;
169 
170 	prop = dlpar_clone_drconf_property(dn);
171 	if (!prop) {
172 		of_node_put(dn);
173 		return -ENODEV;
174 	}
175 
176 	p = prop->value;
177 	num_lmbs = *p++;
178 	lmbs = (struct of_drconf_cell *)p;
179 
180 	for (i = 0; i < num_lmbs; i++) {
181 		if (lmbs[i].drc_index == lmb->drc_index) {
182 			lmbs[i].flags = lmb->flags;
183 			lmbs[i].aa_index = lmb->aa_index;
184 
185 			dlpar_update_drconf_property(dn, prop);
186 			break;
187 		}
188 	}
189 
190 	of_node_put(dn);
191 	return 0;
192 }
193 
194 static u32 find_aa_index(struct device_node *dr_node,
195 			 struct property *ala_prop, const u32 *lmb_assoc)
196 {
197 	u32 *assoc_arrays;
198 	u32 aa_index;
199 	int aa_arrays, aa_array_entries, aa_array_sz;
200 	int i, index;
201 
202 	/*
203 	 * The ibm,associativity-lookup-arrays property is defined to be
204 	 * a 32-bit value specifying the number of associativity arrays
205 	 * followed by a 32-bitvalue specifying the number of entries per
206 	 * array, followed by the associativity arrays.
207 	 */
208 	assoc_arrays = ala_prop->value;
209 
210 	aa_arrays = be32_to_cpu(assoc_arrays[0]);
211 	aa_array_entries = be32_to_cpu(assoc_arrays[1]);
212 	aa_array_sz = aa_array_entries * sizeof(u32);
213 
214 	aa_index = -1;
215 	for (i = 0; i < aa_arrays; i++) {
216 		index = (i * aa_array_entries) + 2;
217 
218 		if (memcmp(&assoc_arrays[index], &lmb_assoc[1], aa_array_sz))
219 			continue;
220 
221 		aa_index = i;
222 		break;
223 	}
224 
225 	if (aa_index == -1) {
226 		struct property *new_prop;
227 		u32 new_prop_size;
228 
229 		new_prop_size = ala_prop->length + aa_array_sz;
230 		new_prop = dlpar_clone_property(ala_prop, new_prop_size);
231 		if (!new_prop)
232 			return -1;
233 
234 		assoc_arrays = new_prop->value;
235 
236 		/* increment the number of entries in the lookup array */
237 		assoc_arrays[0] = cpu_to_be32(aa_arrays + 1);
238 
239 		/* copy the new associativity into the lookup array */
240 		index = aa_arrays * aa_array_entries + 2;
241 		memcpy(&assoc_arrays[index], &lmb_assoc[1], aa_array_sz);
242 
243 		of_update_property(dr_node, new_prop);
244 
245 		/*
246 		 * The associativity lookup array index for this lmb is
247 		 * number of entries - 1 since we added its associativity
248 		 * to the end of the lookup array.
249 		 */
250 		aa_index = be32_to_cpu(assoc_arrays[0]) - 1;
251 	}
252 
253 	return aa_index;
254 }
255 
256 static u32 lookup_lmb_associativity_index(struct of_drconf_cell *lmb)
257 {
258 	struct device_node *parent, *lmb_node, *dr_node;
259 	struct property *ala_prop;
260 	const u32 *lmb_assoc;
261 	u32 aa_index;
262 
263 	parent = of_find_node_by_path("/");
264 	if (!parent)
265 		return -ENODEV;
266 
267 	lmb_node = dlpar_configure_connector(cpu_to_be32(lmb->drc_index),
268 					     parent);
269 	of_node_put(parent);
270 	if (!lmb_node)
271 		return -EINVAL;
272 
273 	lmb_assoc = of_get_property(lmb_node, "ibm,associativity", NULL);
274 	if (!lmb_assoc) {
275 		dlpar_free_cc_nodes(lmb_node);
276 		return -ENODEV;
277 	}
278 
279 	dr_node = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
280 	if (!dr_node) {
281 		dlpar_free_cc_nodes(lmb_node);
282 		return -ENODEV;
283 	}
284 
285 	ala_prop = of_find_property(dr_node, "ibm,associativity-lookup-arrays",
286 				    NULL);
287 	if (!ala_prop) {
288 		of_node_put(dr_node);
289 		dlpar_free_cc_nodes(lmb_node);
290 		return -ENODEV;
291 	}
292 
293 	aa_index = find_aa_index(dr_node, ala_prop, lmb_assoc);
294 
295 	dlpar_free_cc_nodes(lmb_node);
296 	return aa_index;
297 }
298 
299 static int dlpar_add_device_tree_lmb(struct of_drconf_cell *lmb)
300 {
301 	int aa_index;
302 
303 	lmb->flags |= DRCONF_MEM_ASSIGNED;
304 
305 	aa_index = lookup_lmb_associativity_index(lmb);
306 	if (aa_index < 0) {
307 		pr_err("Couldn't find associativity index for drc index %x\n",
308 		       lmb->drc_index);
309 		return aa_index;
310 	}
311 
312 	lmb->aa_index = aa_index;
313 	return dlpar_update_device_tree_lmb(lmb);
314 }
315 
316 static int dlpar_remove_device_tree_lmb(struct of_drconf_cell *lmb)
317 {
318 	lmb->flags &= ~DRCONF_MEM_ASSIGNED;
319 	lmb->aa_index = 0xffffffff;
320 	return dlpar_update_device_tree_lmb(lmb);
321 }
322 
323 #ifdef CONFIG_MEMORY_HOTREMOVE
324 static int pseries_remove_memblock(unsigned long base, unsigned int memblock_size)
325 {
326 	unsigned long block_sz, start_pfn;
327 	int sections_per_block;
328 	int i, nid;
329 
330 	start_pfn = base >> PAGE_SHIFT;
331 
332 	lock_device_hotplug();
333 
334 	if (!pfn_valid(start_pfn))
335 		goto out;
336 
337 	block_sz = pseries_memory_block_size();
338 	sections_per_block = block_sz / MIN_MEMORY_BLOCK_SIZE;
339 	nid = memory_add_physaddr_to_nid(base);
340 
341 	for (i = 0; i < sections_per_block; i++) {
342 		remove_memory(nid, base, MIN_MEMORY_BLOCK_SIZE);
343 		base += MIN_MEMORY_BLOCK_SIZE;
344 	}
345 
346 out:
347 	/* Update memory regions for memory remove */
348 	memblock_remove(base, memblock_size);
349 	unlock_device_hotplug();
350 	return 0;
351 }
352 
353 static int pseries_remove_mem_node(struct device_node *np)
354 {
355 	const char *type;
356 	const __be32 *regs;
357 	unsigned long base;
358 	unsigned int lmb_size;
359 	int ret = -EINVAL;
360 
361 	/*
362 	 * Check to see if we are actually removing memory
363 	 */
364 	type = of_get_property(np, "device_type", NULL);
365 	if (type == NULL || strcmp(type, "memory") != 0)
366 		return 0;
367 
368 	/*
369 	 * Find the base address and size of the memblock
370 	 */
371 	regs = of_get_property(np, "reg", NULL);
372 	if (!regs)
373 		return ret;
374 
375 	base = be64_to_cpu(*(unsigned long *)regs);
376 	lmb_size = be32_to_cpu(regs[3]);
377 
378 	pseries_remove_memblock(base, lmb_size);
379 	return 0;
380 }
381 
382 static bool lmb_is_removable(struct of_drconf_cell *lmb)
383 {
384 	int i, scns_per_block;
385 	int rc = 1;
386 	unsigned long pfn, block_sz;
387 	u64 phys_addr;
388 
389 	if (!(lmb->flags & DRCONF_MEM_ASSIGNED))
390 		return false;
391 
392 	block_sz = memory_block_size_bytes();
393 	scns_per_block = block_sz / MIN_MEMORY_BLOCK_SIZE;
394 	phys_addr = lmb->base_addr;
395 
396 	for (i = 0; i < scns_per_block; i++) {
397 		pfn = PFN_DOWN(phys_addr);
398 		if (!pfn_present(pfn))
399 			continue;
400 
401 		rc &= is_mem_section_removable(pfn, PAGES_PER_SECTION);
402 		phys_addr += MIN_MEMORY_BLOCK_SIZE;
403 	}
404 
405 	return rc ? true : false;
406 }
407 
408 static int dlpar_add_lmb(struct of_drconf_cell *);
409 
410 static struct memory_block *lmb_to_memblock(struct of_drconf_cell *lmb)
411 {
412 	unsigned long section_nr;
413 	struct mem_section *mem_sect;
414 	struct memory_block *mem_block;
415 
416 	section_nr = pfn_to_section_nr(PFN_DOWN(lmb->base_addr));
417 	mem_sect = __nr_to_section(section_nr);
418 
419 	mem_block = find_memory_block(mem_sect);
420 	return mem_block;
421 }
422 
423 static int dlpar_remove_lmb(struct of_drconf_cell *lmb)
424 {
425 	struct memory_block *mem_block;
426 	unsigned long block_sz;
427 	int nid, rc;
428 
429 	if (!lmb_is_removable(lmb))
430 		return -EINVAL;
431 
432 	mem_block = lmb_to_memblock(lmb);
433 	if (!mem_block)
434 		return -EINVAL;
435 
436 	rc = device_offline(&mem_block->dev);
437 	put_device(&mem_block->dev);
438 	if (rc)
439 		return rc;
440 
441 	block_sz = pseries_memory_block_size();
442 	nid = memory_add_physaddr_to_nid(lmb->base_addr);
443 
444 	remove_memory(nid, lmb->base_addr, block_sz);
445 
446 	/* Update memory regions for memory remove */
447 	memblock_remove(lmb->base_addr, block_sz);
448 
449 	dlpar_release_drc(lmb->drc_index);
450 	dlpar_remove_device_tree_lmb(lmb);
451 
452 	return 0;
453 }
454 
455 static int dlpar_memory_remove_by_count(u32 lmbs_to_remove,
456 					struct property *prop)
457 {
458 	struct of_drconf_cell *lmbs;
459 	int lmbs_removed = 0;
460 	int lmbs_available = 0;
461 	u32 num_lmbs, *p;
462 	int i, rc;
463 
464 	pr_info("Attempting to hot-remove %d LMB(s)\n", lmbs_to_remove);
465 
466 	if (lmbs_to_remove == 0)
467 		return -EINVAL;
468 
469 	p = prop->value;
470 	num_lmbs = *p++;
471 	lmbs = (struct of_drconf_cell *)p;
472 
473 	/* Validate that there are enough LMBs to satisfy the request */
474 	for (i = 0; i < num_lmbs; i++) {
475 		if (lmbs[i].flags & DRCONF_MEM_ASSIGNED)
476 			lmbs_available++;
477 	}
478 
479 	if (lmbs_available < lmbs_to_remove)
480 		return -EINVAL;
481 
482 	for (i = 0; i < num_lmbs && lmbs_removed < lmbs_to_remove; i++) {
483 		rc = dlpar_remove_lmb(&lmbs[i]);
484 		if (rc)
485 			continue;
486 
487 		lmbs_removed++;
488 
489 		/* Mark this lmb so we can add it later if all of the
490 		 * requested LMBs cannot be removed.
491 		 */
492 		lmbs[i].reserved = 1;
493 	}
494 
495 	if (lmbs_removed != lmbs_to_remove) {
496 		pr_err("Memory hot-remove failed, adding LMB's back\n");
497 
498 		for (i = 0; i < num_lmbs; i++) {
499 			if (!lmbs[i].reserved)
500 				continue;
501 
502 			rc = dlpar_add_lmb(&lmbs[i]);
503 			if (rc)
504 				pr_err("Failed to add LMB back, drc index %x\n",
505 				       lmbs[i].drc_index);
506 
507 			lmbs[i].reserved = 0;
508 		}
509 
510 		rc = -EINVAL;
511 	} else {
512 		for (i = 0; i < num_lmbs; i++) {
513 			if (!lmbs[i].reserved)
514 				continue;
515 
516 			pr_info("Memory at %llx was hot-removed\n",
517 				lmbs[i].base_addr);
518 
519 			lmbs[i].reserved = 0;
520 		}
521 		rc = 0;
522 	}
523 
524 	return rc;
525 }
526 
527 static int dlpar_memory_remove_by_index(u32 drc_index, struct property *prop)
528 {
529 	struct of_drconf_cell *lmbs;
530 	u32 num_lmbs, *p;
531 	int lmb_found;
532 	int i, rc;
533 
534 	pr_info("Attempting to hot-remove LMB, drc index %x\n", drc_index);
535 
536 	p = prop->value;
537 	num_lmbs = *p++;
538 	lmbs = (struct of_drconf_cell *)p;
539 
540 	lmb_found = 0;
541 	for (i = 0; i < num_lmbs; i++) {
542 		if (lmbs[i].drc_index == drc_index) {
543 			lmb_found = 1;
544 			rc = dlpar_remove_lmb(&lmbs[i]);
545 			break;
546 		}
547 	}
548 
549 	if (!lmb_found)
550 		rc = -EINVAL;
551 
552 	if (rc)
553 		pr_info("Failed to hot-remove memory at %llx\n",
554 			lmbs[i].base_addr);
555 	else
556 		pr_info("Memory at %llx was hot-removed\n", lmbs[i].base_addr);
557 
558 	return rc;
559 }
560 
561 #else
562 static inline int pseries_remove_memblock(unsigned long base,
563 					  unsigned int memblock_size)
564 {
565 	return -EOPNOTSUPP;
566 }
567 static inline int pseries_remove_mem_node(struct device_node *np)
568 {
569 	return 0;
570 }
571 static inline int dlpar_memory_remove(struct pseries_hp_errorlog *hp_elog)
572 {
573 	return -EOPNOTSUPP;
574 }
575 static int dlpar_remove_lmb(struct of_drconf_cell *lmb)
576 {
577 	return -EOPNOTSUPP;
578 }
579 static int dlpar_memory_remove_by_count(u32 lmbs_to_remove,
580 					struct property *prop)
581 {
582 	return -EOPNOTSUPP;
583 }
584 static int dlpar_memory_remove_by_index(u32 drc_index, struct property *prop)
585 {
586 	return -EOPNOTSUPP;
587 }
588 
589 #endif /* CONFIG_MEMORY_HOTREMOVE */
590 
591 static int dlpar_add_lmb(struct of_drconf_cell *lmb)
592 {
593 	unsigned long block_sz;
594 	int nid, rc;
595 
596 	if (lmb->flags & DRCONF_MEM_ASSIGNED)
597 		return -EINVAL;
598 
599 	rc = dlpar_acquire_drc(lmb->drc_index);
600 	if (rc)
601 		return rc;
602 
603 	rc = dlpar_add_device_tree_lmb(lmb);
604 	if (rc) {
605 		pr_err("Couldn't update device tree for drc index %x\n",
606 		       lmb->drc_index);
607 		dlpar_release_drc(lmb->drc_index);
608 		return rc;
609 	}
610 
611 	block_sz = memory_block_size_bytes();
612 
613 	/* Find the node id for this address */
614 	nid = memory_add_physaddr_to_nid(lmb->base_addr);
615 
616 	/* Add the memory */
617 	rc = add_memory(nid, lmb->base_addr, block_sz);
618 	if (rc) {
619 		dlpar_remove_device_tree_lmb(lmb);
620 		dlpar_release_drc(lmb->drc_index);
621 	} else {
622 		lmb->flags |= DRCONF_MEM_ASSIGNED;
623 	}
624 
625 	return rc;
626 }
627 
628 static int dlpar_memory_add_by_count(u32 lmbs_to_add, struct property *prop)
629 {
630 	struct of_drconf_cell *lmbs;
631 	u32 num_lmbs, *p;
632 	int lmbs_available = 0;
633 	int lmbs_added = 0;
634 	int i, rc;
635 
636 	pr_info("Attempting to hot-add %d LMB(s)\n", lmbs_to_add);
637 
638 	if (lmbs_to_add == 0)
639 		return -EINVAL;
640 
641 	p = prop->value;
642 	num_lmbs = *p++;
643 	lmbs = (struct of_drconf_cell *)p;
644 
645 	/* Validate that there are enough LMBs to satisfy the request */
646 	for (i = 0; i < num_lmbs; i++) {
647 		if (!(lmbs[i].flags & DRCONF_MEM_ASSIGNED))
648 			lmbs_available++;
649 	}
650 
651 	if (lmbs_available < lmbs_to_add)
652 		return -EINVAL;
653 
654 	for (i = 0; i < num_lmbs && lmbs_to_add != lmbs_added; i++) {
655 		rc = dlpar_add_lmb(&lmbs[i]);
656 		if (rc)
657 			continue;
658 
659 		lmbs_added++;
660 
661 		/* Mark this lmb so we can remove it later if all of the
662 		 * requested LMBs cannot be added.
663 		 */
664 		lmbs[i].reserved = 1;
665 	}
666 
667 	if (lmbs_added != lmbs_to_add) {
668 		pr_err("Memory hot-add failed, removing any added LMBs\n");
669 
670 		for (i = 0; i < num_lmbs; i++) {
671 			if (!lmbs[i].reserved)
672 				continue;
673 
674 			rc = dlpar_remove_lmb(&lmbs[i]);
675 			if (rc)
676 				pr_err("Failed to remove LMB, drc index %x\n",
677 				       be32_to_cpu(lmbs[i].drc_index));
678 		}
679 		rc = -EINVAL;
680 	} else {
681 		for (i = 0; i < num_lmbs; i++) {
682 			if (!lmbs[i].reserved)
683 				continue;
684 
685 			pr_info("Memory at %llx (drc index %x) was hot-added\n",
686 				lmbs[i].base_addr, lmbs[i].drc_index);
687 			lmbs[i].reserved = 0;
688 		}
689 	}
690 
691 	return rc;
692 }
693 
694 static int dlpar_memory_add_by_index(u32 drc_index, struct property *prop)
695 {
696 	struct of_drconf_cell *lmbs;
697 	u32 num_lmbs, *p;
698 	int i, lmb_found;
699 	int rc;
700 
701 	pr_info("Attempting to hot-add LMB, drc index %x\n", drc_index);
702 
703 	p = prop->value;
704 	num_lmbs = *p++;
705 	lmbs = (struct of_drconf_cell *)p;
706 
707 	lmb_found = 0;
708 	for (i = 0; i < num_lmbs; i++) {
709 		if (lmbs[i].drc_index == drc_index) {
710 			lmb_found = 1;
711 			rc = dlpar_add_lmb(&lmbs[i]);
712 			break;
713 		}
714 	}
715 
716 	if (!lmb_found)
717 		rc = -EINVAL;
718 
719 	if (rc)
720 		pr_info("Failed to hot-add memory, drc index %x\n", drc_index);
721 	else
722 		pr_info("Memory at %llx (drc index %x) was hot-added\n",
723 			lmbs[i].base_addr, drc_index);
724 
725 	return rc;
726 }
727 
728 int dlpar_memory(struct pseries_hp_errorlog *hp_elog)
729 {
730 	struct device_node *dn;
731 	struct property *prop;
732 	u32 count, drc_index;
733 	int rc;
734 
735 	count = hp_elog->_drc_u.drc_count;
736 	drc_index = hp_elog->_drc_u.drc_index;
737 
738 	lock_device_hotplug();
739 
740 	dn = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
741 	if (!dn) {
742 		rc = -EINVAL;
743 		goto dlpar_memory_out;
744 	}
745 
746 	prop = dlpar_clone_drconf_property(dn);
747 	if (!prop) {
748 		rc = -EINVAL;
749 		goto dlpar_memory_out;
750 	}
751 
752 	switch (hp_elog->action) {
753 	case PSERIES_HP_ELOG_ACTION_ADD:
754 		if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_COUNT)
755 			rc = dlpar_memory_add_by_count(count, prop);
756 		else if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_INDEX)
757 			rc = dlpar_memory_add_by_index(drc_index, prop);
758 		else
759 			rc = -EINVAL;
760 		break;
761 	case PSERIES_HP_ELOG_ACTION_REMOVE:
762 		if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_COUNT)
763 			rc = dlpar_memory_remove_by_count(count, prop);
764 		else if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_INDEX)
765 			rc = dlpar_memory_remove_by_index(drc_index, prop);
766 		else
767 			rc = -EINVAL;
768 		break;
769 	default:
770 		pr_err("Invalid action (%d) specified\n", hp_elog->action);
771 		rc = -EINVAL;
772 		break;
773 	}
774 
775 	dlpar_free_property(prop);
776 
777 dlpar_memory_out:
778 	of_node_put(dn);
779 	unlock_device_hotplug();
780 	return rc;
781 }
782 
783 static int pseries_add_mem_node(struct device_node *np)
784 {
785 	const char *type;
786 	const __be32 *regs;
787 	unsigned long base;
788 	unsigned int lmb_size;
789 	int ret = -EINVAL;
790 
791 	/*
792 	 * Check to see if we are actually adding memory
793 	 */
794 	type = of_get_property(np, "device_type", NULL);
795 	if (type == NULL || strcmp(type, "memory") != 0)
796 		return 0;
797 
798 	/*
799 	 * Find the base and size of the memblock
800 	 */
801 	regs = of_get_property(np, "reg", NULL);
802 	if (!regs)
803 		return ret;
804 
805 	base = be64_to_cpu(*(unsigned long *)regs);
806 	lmb_size = be32_to_cpu(regs[3]);
807 
808 	/*
809 	 * Update memory region to represent the memory add
810 	 */
811 	ret = memblock_add(base, lmb_size);
812 	return (ret < 0) ? -EINVAL : 0;
813 }
814 
815 static int pseries_update_drconf_memory(struct of_reconfig_data *pr)
816 {
817 	struct of_drconf_cell *new_drmem, *old_drmem;
818 	unsigned long memblock_size;
819 	u32 entries;
820 	__be32 *p;
821 	int i, rc = -EINVAL;
822 
823 	if (rtas_hp_event)
824 		return 0;
825 
826 	memblock_size = pseries_memory_block_size();
827 	if (!memblock_size)
828 		return -EINVAL;
829 
830 	p = (__be32 *) pr->old_prop->value;
831 	if (!p)
832 		return -EINVAL;
833 
834 	/* The first int of the property is the number of lmb's described
835 	 * by the property. This is followed by an array of of_drconf_cell
836 	 * entries. Get the number of entries and skip to the array of
837 	 * of_drconf_cell's.
838 	 */
839 	entries = be32_to_cpu(*p++);
840 	old_drmem = (struct of_drconf_cell *)p;
841 
842 	p = (__be32 *)pr->prop->value;
843 	p++;
844 	new_drmem = (struct of_drconf_cell *)p;
845 
846 	for (i = 0; i < entries; i++) {
847 		if ((be32_to_cpu(old_drmem[i].flags) & DRCONF_MEM_ASSIGNED) &&
848 		    (!(be32_to_cpu(new_drmem[i].flags) & DRCONF_MEM_ASSIGNED))) {
849 			rc = pseries_remove_memblock(
850 				be64_to_cpu(old_drmem[i].base_addr),
851 						     memblock_size);
852 			break;
853 		} else if ((!(be32_to_cpu(old_drmem[i].flags) &
854 			    DRCONF_MEM_ASSIGNED)) &&
855 			    (be32_to_cpu(new_drmem[i].flags) &
856 			    DRCONF_MEM_ASSIGNED)) {
857 			rc = memblock_add(be64_to_cpu(old_drmem[i].base_addr),
858 					  memblock_size);
859 			rc = (rc < 0) ? -EINVAL : 0;
860 			break;
861 		}
862 	}
863 	return rc;
864 }
865 
866 static int pseries_memory_notifier(struct notifier_block *nb,
867 				   unsigned long action, void *data)
868 {
869 	struct of_reconfig_data *rd = data;
870 	int err = 0;
871 
872 	switch (action) {
873 	case OF_RECONFIG_ATTACH_NODE:
874 		err = pseries_add_mem_node(rd->dn);
875 		break;
876 	case OF_RECONFIG_DETACH_NODE:
877 		err = pseries_remove_mem_node(rd->dn);
878 		break;
879 	case OF_RECONFIG_UPDATE_PROPERTY:
880 		if (!strcmp(rd->prop->name, "ibm,dynamic-memory"))
881 			err = pseries_update_drconf_memory(rd);
882 		break;
883 	}
884 	return notifier_from_errno(err);
885 }
886 
887 static struct notifier_block pseries_mem_nb = {
888 	.notifier_call = pseries_memory_notifier,
889 };
890 
891 static int __init pseries_memory_hotplug_init(void)
892 {
893 	if (firmware_has_feature(FW_FEATURE_LPAR))
894 		of_reconfig_notifier_register(&pseries_mem_nb);
895 
896 	return 0;
897 }
898 machine_device_initcall(pseries, pseries_memory_hotplug_init);
899