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 <asm/fadump.h>
26 #include "pseries.h"
27 
28 static bool rtas_hp_event;
29 
30 unsigned long pseries_memory_block_size(void)
31 {
32 	struct device_node *np;
33 	unsigned int memblock_size = MIN_MEMORY_BLOCK_SIZE;
34 	struct resource r;
35 
36 	np = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
37 	if (np) {
38 		const __be64 *size;
39 
40 		size = of_get_property(np, "ibm,lmb-size", NULL);
41 		if (size)
42 			memblock_size = be64_to_cpup(size);
43 		of_node_put(np);
44 	} else  if (machine_is(pseries)) {
45 		/* This fallback really only applies to pseries */
46 		unsigned int memzero_size = 0;
47 
48 		np = of_find_node_by_path("/memory@0");
49 		if (np) {
50 			if (!of_address_to_resource(np, 0, &r))
51 				memzero_size = resource_size(&r);
52 			of_node_put(np);
53 		}
54 
55 		if (memzero_size) {
56 			/* We now know the size of memory@0, use this to find
57 			 * the first memoryblock and get its size.
58 			 */
59 			char buf[64];
60 
61 			sprintf(buf, "/memory@%x", memzero_size);
62 			np = of_find_node_by_path(buf);
63 			if (np) {
64 				if (!of_address_to_resource(np, 0, &r))
65 					memblock_size = resource_size(&r);
66 				of_node_put(np);
67 			}
68 		}
69 	}
70 	return memblock_size;
71 }
72 
73 static void dlpar_free_property(struct property *prop)
74 {
75 	kfree(prop->name);
76 	kfree(prop->value);
77 	kfree(prop);
78 }
79 
80 static struct property *dlpar_clone_property(struct property *prop,
81 					     u32 prop_size)
82 {
83 	struct property *new_prop;
84 
85 	new_prop = kzalloc(sizeof(*new_prop), GFP_KERNEL);
86 	if (!new_prop)
87 		return NULL;
88 
89 	new_prop->name = kstrdup(prop->name, GFP_KERNEL);
90 	new_prop->value = kzalloc(prop_size, GFP_KERNEL);
91 	if (!new_prop->name || !new_prop->value) {
92 		dlpar_free_property(new_prop);
93 		return NULL;
94 	}
95 
96 	memcpy(new_prop->value, prop->value, prop->length);
97 	new_prop->length = prop_size;
98 
99 	of_property_set_flag(new_prop, OF_DYNAMIC);
100 	return new_prop;
101 }
102 
103 static struct property *dlpar_clone_drconf_property(struct device_node *dn)
104 {
105 	struct property *prop, *new_prop;
106 	struct of_drconf_cell *lmbs;
107 	u32 num_lmbs, *p;
108 	int i;
109 
110 	prop = of_find_property(dn, "ibm,dynamic-memory", NULL);
111 	if (!prop)
112 		return NULL;
113 
114 	new_prop = dlpar_clone_property(prop, prop->length);
115 	if (!new_prop)
116 		return NULL;
117 
118 	/* Convert the property to cpu endian-ness */
119 	p = new_prop->value;
120 	*p = be32_to_cpu(*p);
121 
122 	num_lmbs = *p++;
123 	lmbs = (struct of_drconf_cell *)p;
124 
125 	for (i = 0; i < num_lmbs; i++) {
126 		lmbs[i].base_addr = be64_to_cpu(lmbs[i].base_addr);
127 		lmbs[i].drc_index = be32_to_cpu(lmbs[i].drc_index);
128 		lmbs[i].aa_index = be32_to_cpu(lmbs[i].aa_index);
129 		lmbs[i].flags = be32_to_cpu(lmbs[i].flags);
130 	}
131 
132 	return new_prop;
133 }
134 
135 static void dlpar_update_drconf_property(struct device_node *dn,
136 					 struct property *prop)
137 {
138 	struct of_drconf_cell *lmbs;
139 	u32 num_lmbs, *p;
140 	int i;
141 
142 	/* Convert the property back to BE */
143 	p = prop->value;
144 	num_lmbs = *p;
145 	*p = cpu_to_be32(*p);
146 	p++;
147 
148 	lmbs = (struct of_drconf_cell *)p;
149 	for (i = 0; i < num_lmbs; i++) {
150 		lmbs[i].base_addr = cpu_to_be64(lmbs[i].base_addr);
151 		lmbs[i].drc_index = cpu_to_be32(lmbs[i].drc_index);
152 		lmbs[i].aa_index = cpu_to_be32(lmbs[i].aa_index);
153 		lmbs[i].flags = cpu_to_be32(lmbs[i].flags);
154 	}
155 
156 	rtas_hp_event = true;
157 	of_update_property(dn, prop);
158 	rtas_hp_event = false;
159 }
160 
161 static int dlpar_update_device_tree_lmb(struct of_drconf_cell *lmb)
162 {
163 	struct device_node *dn;
164 	struct property *prop;
165 	struct of_drconf_cell *lmbs;
166 	u32 *p, num_lmbs;
167 	int i;
168 
169 	dn = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
170 	if (!dn)
171 		return -ENODEV;
172 
173 	prop = dlpar_clone_drconf_property(dn);
174 	if (!prop) {
175 		of_node_put(dn);
176 		return -ENODEV;
177 	}
178 
179 	p = prop->value;
180 	num_lmbs = *p++;
181 	lmbs = (struct of_drconf_cell *)p;
182 
183 	for (i = 0; i < num_lmbs; i++) {
184 		if (lmbs[i].drc_index == lmb->drc_index) {
185 			lmbs[i].flags = lmb->flags;
186 			lmbs[i].aa_index = lmb->aa_index;
187 
188 			dlpar_update_drconf_property(dn, prop);
189 			break;
190 		}
191 	}
192 
193 	of_node_put(dn);
194 	return 0;
195 }
196 
197 static u32 find_aa_index(struct device_node *dr_node,
198 			 struct property *ala_prop, const u32 *lmb_assoc)
199 {
200 	u32 *assoc_arrays;
201 	u32 aa_index;
202 	int aa_arrays, aa_array_entries, aa_array_sz;
203 	int i, index;
204 
205 	/*
206 	 * The ibm,associativity-lookup-arrays property is defined to be
207 	 * a 32-bit value specifying the number of associativity arrays
208 	 * followed by a 32-bitvalue specifying the number of entries per
209 	 * array, followed by the associativity arrays.
210 	 */
211 	assoc_arrays = ala_prop->value;
212 
213 	aa_arrays = be32_to_cpu(assoc_arrays[0]);
214 	aa_array_entries = be32_to_cpu(assoc_arrays[1]);
215 	aa_array_sz = aa_array_entries * sizeof(u32);
216 
217 	aa_index = -1;
218 	for (i = 0; i < aa_arrays; i++) {
219 		index = (i * aa_array_entries) + 2;
220 
221 		if (memcmp(&assoc_arrays[index], &lmb_assoc[1], aa_array_sz))
222 			continue;
223 
224 		aa_index = i;
225 		break;
226 	}
227 
228 	if (aa_index == -1) {
229 		struct property *new_prop;
230 		u32 new_prop_size;
231 
232 		new_prop_size = ala_prop->length + aa_array_sz;
233 		new_prop = dlpar_clone_property(ala_prop, new_prop_size);
234 		if (!new_prop)
235 			return -1;
236 
237 		assoc_arrays = new_prop->value;
238 
239 		/* increment the number of entries in the lookup array */
240 		assoc_arrays[0] = cpu_to_be32(aa_arrays + 1);
241 
242 		/* copy the new associativity into the lookup array */
243 		index = aa_arrays * aa_array_entries + 2;
244 		memcpy(&assoc_arrays[index], &lmb_assoc[1], aa_array_sz);
245 
246 		of_update_property(dr_node, new_prop);
247 
248 		/*
249 		 * The associativity lookup array index for this lmb is
250 		 * number of entries - 1 since we added its associativity
251 		 * to the end of the lookup array.
252 		 */
253 		aa_index = be32_to_cpu(assoc_arrays[0]) - 1;
254 	}
255 
256 	return aa_index;
257 }
258 
259 static u32 lookup_lmb_associativity_index(struct of_drconf_cell *lmb)
260 {
261 	struct device_node *parent, *lmb_node, *dr_node;
262 	struct property *ala_prop;
263 	const u32 *lmb_assoc;
264 	u32 aa_index;
265 
266 	parent = of_find_node_by_path("/");
267 	if (!parent)
268 		return -ENODEV;
269 
270 	lmb_node = dlpar_configure_connector(cpu_to_be32(lmb->drc_index),
271 					     parent);
272 	of_node_put(parent);
273 	if (!lmb_node)
274 		return -EINVAL;
275 
276 	lmb_assoc = of_get_property(lmb_node, "ibm,associativity", NULL);
277 	if (!lmb_assoc) {
278 		dlpar_free_cc_nodes(lmb_node);
279 		return -ENODEV;
280 	}
281 
282 	dr_node = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
283 	if (!dr_node) {
284 		dlpar_free_cc_nodes(lmb_node);
285 		return -ENODEV;
286 	}
287 
288 	ala_prop = of_find_property(dr_node, "ibm,associativity-lookup-arrays",
289 				    NULL);
290 	if (!ala_prop) {
291 		of_node_put(dr_node);
292 		dlpar_free_cc_nodes(lmb_node);
293 		return -ENODEV;
294 	}
295 
296 	aa_index = find_aa_index(dr_node, ala_prop, lmb_assoc);
297 
298 	dlpar_free_cc_nodes(lmb_node);
299 	return aa_index;
300 }
301 
302 static int dlpar_add_device_tree_lmb(struct of_drconf_cell *lmb)
303 {
304 	int aa_index;
305 
306 	lmb->flags |= DRCONF_MEM_ASSIGNED;
307 
308 	aa_index = lookup_lmb_associativity_index(lmb);
309 	if (aa_index < 0) {
310 		pr_err("Couldn't find associativity index for drc index %x\n",
311 		       lmb->drc_index);
312 		return aa_index;
313 	}
314 
315 	lmb->aa_index = aa_index;
316 	return dlpar_update_device_tree_lmb(lmb);
317 }
318 
319 static int dlpar_remove_device_tree_lmb(struct of_drconf_cell *lmb)
320 {
321 	lmb->flags &= ~DRCONF_MEM_ASSIGNED;
322 	lmb->aa_index = 0xffffffff;
323 	return dlpar_update_device_tree_lmb(lmb);
324 }
325 
326 static struct memory_block *lmb_to_memblock(struct of_drconf_cell *lmb)
327 {
328 	unsigned long section_nr;
329 	struct mem_section *mem_sect;
330 	struct memory_block *mem_block;
331 
332 	section_nr = pfn_to_section_nr(PFN_DOWN(lmb->base_addr));
333 	mem_sect = __nr_to_section(section_nr);
334 
335 	mem_block = find_memory_block(mem_sect);
336 	return mem_block;
337 }
338 
339 #ifdef CONFIG_MEMORY_HOTREMOVE
340 static int pseries_remove_memblock(unsigned long base, unsigned int memblock_size)
341 {
342 	unsigned long block_sz, start_pfn;
343 	int sections_per_block;
344 	int i, nid;
345 
346 	start_pfn = base >> PAGE_SHIFT;
347 
348 	lock_device_hotplug();
349 
350 	if (!pfn_valid(start_pfn))
351 		goto out;
352 
353 	block_sz = pseries_memory_block_size();
354 	sections_per_block = block_sz / MIN_MEMORY_BLOCK_SIZE;
355 	nid = memory_add_physaddr_to_nid(base);
356 
357 	for (i = 0; i < sections_per_block; i++) {
358 		remove_memory(nid, base, MIN_MEMORY_BLOCK_SIZE);
359 		base += MIN_MEMORY_BLOCK_SIZE;
360 	}
361 
362 out:
363 	/* Update memory regions for memory remove */
364 	memblock_remove(base, memblock_size);
365 	unlock_device_hotplug();
366 	return 0;
367 }
368 
369 static int pseries_remove_mem_node(struct device_node *np)
370 {
371 	const char *type;
372 	const __be32 *regs;
373 	unsigned long base;
374 	unsigned int lmb_size;
375 	int ret = -EINVAL;
376 
377 	/*
378 	 * Check to see if we are actually removing memory
379 	 */
380 	type = of_get_property(np, "device_type", NULL);
381 	if (type == NULL || strcmp(type, "memory") != 0)
382 		return 0;
383 
384 	/*
385 	 * Find the base address and size of the memblock
386 	 */
387 	regs = of_get_property(np, "reg", NULL);
388 	if (!regs)
389 		return ret;
390 
391 	base = be64_to_cpu(*(unsigned long *)regs);
392 	lmb_size = be32_to_cpu(regs[3]);
393 
394 	pseries_remove_memblock(base, lmb_size);
395 	return 0;
396 }
397 
398 static bool lmb_is_removable(struct of_drconf_cell *lmb)
399 {
400 	int i, scns_per_block;
401 	int rc = 1;
402 	unsigned long pfn, block_sz;
403 	u64 phys_addr;
404 
405 	if (!(lmb->flags & DRCONF_MEM_ASSIGNED))
406 		return false;
407 
408 	block_sz = memory_block_size_bytes();
409 	scns_per_block = block_sz / MIN_MEMORY_BLOCK_SIZE;
410 	phys_addr = lmb->base_addr;
411 
412 #ifdef CONFIG_FA_DUMP
413 	/* Don't hot-remove memory that falls in fadump boot memory area */
414 	if (is_fadump_boot_memory_area(phys_addr, block_sz))
415 		return false;
416 #endif
417 
418 	for (i = 0; i < scns_per_block; i++) {
419 		pfn = PFN_DOWN(phys_addr);
420 		if (!pfn_present(pfn))
421 			continue;
422 
423 		rc &= is_mem_section_removable(pfn, PAGES_PER_SECTION);
424 		phys_addr += MIN_MEMORY_BLOCK_SIZE;
425 	}
426 
427 	return rc ? true : false;
428 }
429 
430 static int dlpar_add_lmb(struct of_drconf_cell *);
431 
432 static int dlpar_remove_lmb(struct of_drconf_cell *lmb)
433 {
434 	struct memory_block *mem_block;
435 	unsigned long block_sz;
436 	int nid, rc;
437 
438 	if (!lmb_is_removable(lmb))
439 		return -EINVAL;
440 
441 	mem_block = lmb_to_memblock(lmb);
442 	if (!mem_block)
443 		return -EINVAL;
444 
445 	rc = device_offline(&mem_block->dev);
446 	put_device(&mem_block->dev);
447 	if (rc)
448 		return rc;
449 
450 	block_sz = pseries_memory_block_size();
451 	nid = memory_add_physaddr_to_nid(lmb->base_addr);
452 
453 	remove_memory(nid, lmb->base_addr, block_sz);
454 
455 	/* Update memory regions for memory remove */
456 	memblock_remove(lmb->base_addr, block_sz);
457 
458 	dlpar_remove_device_tree_lmb(lmb);
459 	return 0;
460 }
461 
462 static int dlpar_memory_remove_by_count(u32 lmbs_to_remove,
463 					struct property *prop)
464 {
465 	struct of_drconf_cell *lmbs;
466 	int lmbs_removed = 0;
467 	int lmbs_available = 0;
468 	u32 num_lmbs, *p;
469 	int i, rc;
470 
471 	pr_info("Attempting to hot-remove %d LMB(s)\n", lmbs_to_remove);
472 
473 	if (lmbs_to_remove == 0)
474 		return -EINVAL;
475 
476 	p = prop->value;
477 	num_lmbs = *p++;
478 	lmbs = (struct of_drconf_cell *)p;
479 
480 	/* Validate that there are enough LMBs to satisfy the request */
481 	for (i = 0; i < num_lmbs; i++) {
482 		if (lmb_is_removable(&lmbs[i]))
483 			lmbs_available++;
484 	}
485 
486 	if (lmbs_available < lmbs_to_remove) {
487 		pr_info("Not enough LMBs available (%d of %d) to satisfy request\n",
488 			lmbs_available, lmbs_to_remove);
489 		return -EINVAL;
490 	}
491 
492 	for (i = 0; i < num_lmbs && lmbs_removed < lmbs_to_remove; i++) {
493 		rc = dlpar_remove_lmb(&lmbs[i]);
494 		if (rc)
495 			continue;
496 
497 		lmbs_removed++;
498 
499 		/* Mark this lmb so we can add it later if all of the
500 		 * requested LMBs cannot be removed.
501 		 */
502 		lmbs[i].reserved = 1;
503 	}
504 
505 	if (lmbs_removed != lmbs_to_remove) {
506 		pr_err("Memory hot-remove failed, adding LMB's back\n");
507 
508 		for (i = 0; i < num_lmbs; i++) {
509 			if (!lmbs[i].reserved)
510 				continue;
511 
512 			rc = dlpar_add_lmb(&lmbs[i]);
513 			if (rc)
514 				pr_err("Failed to add LMB back, drc index %x\n",
515 				       lmbs[i].drc_index);
516 
517 			lmbs[i].reserved = 0;
518 		}
519 
520 		rc = -EINVAL;
521 	} else {
522 		for (i = 0; i < num_lmbs; i++) {
523 			if (!lmbs[i].reserved)
524 				continue;
525 
526 			dlpar_release_drc(lmbs[i].drc_index);
527 			pr_info("Memory at %llx was hot-removed\n",
528 				lmbs[i].base_addr);
529 
530 			lmbs[i].reserved = 0;
531 		}
532 		rc = 0;
533 	}
534 
535 	return rc;
536 }
537 
538 static int dlpar_memory_remove_by_index(u32 drc_index, struct property *prop)
539 {
540 	struct of_drconf_cell *lmbs;
541 	u32 num_lmbs, *p;
542 	int lmb_found;
543 	int i, rc;
544 
545 	pr_info("Attempting to hot-remove LMB, drc index %x\n", drc_index);
546 
547 	p = prop->value;
548 	num_lmbs = *p++;
549 	lmbs = (struct of_drconf_cell *)p;
550 
551 	lmb_found = 0;
552 	for (i = 0; i < num_lmbs; i++) {
553 		if (lmbs[i].drc_index == drc_index) {
554 			lmb_found = 1;
555 			rc = dlpar_remove_lmb(&lmbs[i]);
556 			if (!rc)
557 				dlpar_release_drc(lmbs[i].drc_index);
558 
559 			break;
560 		}
561 	}
562 
563 	if (!lmb_found)
564 		rc = -EINVAL;
565 
566 	if (rc)
567 		pr_info("Failed to hot-remove memory at %llx\n",
568 			lmbs[i].base_addr);
569 	else
570 		pr_info("Memory at %llx was hot-removed\n", lmbs[i].base_addr);
571 
572 	return rc;
573 }
574 
575 static int dlpar_memory_readd_by_index(u32 drc_index, struct property *prop)
576 {
577 	struct of_drconf_cell *lmbs;
578 	u32 num_lmbs, *p;
579 	int lmb_found;
580 	int i, rc;
581 
582 	pr_info("Attempting to update LMB, drc index %x\n", drc_index);
583 
584 	p = prop->value;
585 	num_lmbs = *p++;
586 	lmbs = (struct of_drconf_cell *)p;
587 
588 	lmb_found = 0;
589 	for (i = 0; i < num_lmbs; i++) {
590 		if (lmbs[i].drc_index == drc_index) {
591 			lmb_found = 1;
592 			rc = dlpar_remove_lmb(&lmbs[i]);
593 			if (!rc) {
594 				rc = dlpar_add_lmb(&lmbs[i]);
595 				if (rc)
596 					dlpar_release_drc(lmbs[i].drc_index);
597 			}
598 			break;
599 		}
600 	}
601 
602 	if (!lmb_found)
603 		rc = -EINVAL;
604 
605 	if (rc)
606 		pr_info("Failed to update memory at %llx\n",
607 			lmbs[i].base_addr);
608 	else
609 		pr_info("Memory at %llx was updated\n", lmbs[i].base_addr);
610 
611 	return rc;
612 }
613 
614 static int dlpar_memory_remove_by_ic(u32 lmbs_to_remove, u32 drc_index,
615 				     struct property *prop)
616 {
617 	struct of_drconf_cell *lmbs;
618 	u32 num_lmbs, *p;
619 	int i, rc, start_lmb_found;
620 	int lmbs_available = 0, start_index = 0, end_index;
621 
622 	pr_info("Attempting to hot-remove %u LMB(s) at %x\n",
623 		lmbs_to_remove, drc_index);
624 
625 	if (lmbs_to_remove == 0)
626 		return -EINVAL;
627 
628 	p = prop->value;
629 	num_lmbs = *p++;
630 	lmbs = (struct of_drconf_cell *)p;
631 	start_lmb_found = 0;
632 
633 	/* Navigate to drc_index */
634 	while (start_index < num_lmbs) {
635 		if (lmbs[start_index].drc_index == drc_index) {
636 			start_lmb_found = 1;
637 			break;
638 		}
639 
640 		start_index++;
641 	}
642 
643 	if (!start_lmb_found)
644 		return -EINVAL;
645 
646 	end_index = start_index + lmbs_to_remove;
647 
648 	/* Validate that there are enough LMBs to satisfy the request */
649 	for (i = start_index; i < end_index; i++) {
650 		if (lmbs[i].flags & DRCONF_MEM_RESERVED)
651 			break;
652 
653 		lmbs_available++;
654 	}
655 
656 	if (lmbs_available < lmbs_to_remove)
657 		return -EINVAL;
658 
659 	for (i = start_index; i < end_index; i++) {
660 		if (!(lmbs[i].flags & DRCONF_MEM_ASSIGNED))
661 			continue;
662 
663 		rc = dlpar_remove_lmb(&lmbs[i]);
664 		if (rc)
665 			break;
666 
667 		lmbs[i].reserved = 1;
668 	}
669 
670 	if (rc) {
671 		pr_err("Memory indexed-count-remove failed, adding any removed LMBs\n");
672 
673 		for (i = start_index; i < end_index; i++) {
674 			if (!lmbs[i].reserved)
675 				continue;
676 
677 			rc = dlpar_add_lmb(&lmbs[i]);
678 			if (rc)
679 				pr_err("Failed to add LMB, drc index %x\n",
680 				       be32_to_cpu(lmbs[i].drc_index));
681 
682 			lmbs[i].reserved = 0;
683 		}
684 		rc = -EINVAL;
685 	} else {
686 		for (i = start_index; i < end_index; i++) {
687 			if (!lmbs[i].reserved)
688 				continue;
689 
690 			dlpar_release_drc(lmbs[i].drc_index);
691 			pr_info("Memory at %llx (drc index %x) was hot-removed\n",
692 				lmbs[i].base_addr, lmbs[i].drc_index);
693 
694 			lmbs[i].reserved = 0;
695 		}
696 	}
697 
698 	return rc;
699 }
700 
701 #else
702 static inline int pseries_remove_memblock(unsigned long base,
703 					  unsigned int memblock_size)
704 {
705 	return -EOPNOTSUPP;
706 }
707 static inline int pseries_remove_mem_node(struct device_node *np)
708 {
709 	return 0;
710 }
711 static inline int dlpar_memory_remove(struct pseries_hp_errorlog *hp_elog)
712 {
713 	return -EOPNOTSUPP;
714 }
715 static int dlpar_remove_lmb(struct of_drconf_cell *lmb)
716 {
717 	return -EOPNOTSUPP;
718 }
719 static int dlpar_memory_remove_by_count(u32 lmbs_to_remove,
720 					struct property *prop)
721 {
722 	return -EOPNOTSUPP;
723 }
724 static int dlpar_memory_remove_by_index(u32 drc_index, struct property *prop)
725 {
726 	return -EOPNOTSUPP;
727 }
728 static int dlpar_memory_readd_by_index(u32 drc_index, struct property *prop)
729 {
730 	return -EOPNOTSUPP;
731 }
732 
733 static int dlpar_memory_remove_by_ic(u32 lmbs_to_remove, u32 drc_index,
734 				     struct property *prop)
735 {
736 	return -EOPNOTSUPP;
737 }
738 #endif /* CONFIG_MEMORY_HOTREMOVE */
739 
740 static int dlpar_online_lmb(struct of_drconf_cell *lmb)
741 {
742 	struct memory_block *mem_block;
743 	int rc;
744 
745 	mem_block = lmb_to_memblock(lmb);
746 	if (!mem_block)
747 		return -EINVAL;
748 
749 	rc = device_online(&mem_block->dev);
750 	put_device(&mem_block->dev);
751 	return rc;
752 }
753 
754 static int dlpar_add_lmb(struct of_drconf_cell *lmb)
755 {
756 	unsigned long block_sz;
757 	int nid, rc;
758 
759 	if (lmb->flags & DRCONF_MEM_ASSIGNED)
760 		return -EINVAL;
761 
762 	rc = dlpar_add_device_tree_lmb(lmb);
763 	if (rc) {
764 		pr_err("Couldn't update device tree for drc index %x\n",
765 		       lmb->drc_index);
766 		dlpar_release_drc(lmb->drc_index);
767 		return rc;
768 	}
769 
770 	block_sz = memory_block_size_bytes();
771 
772 	/* Find the node id for this address */
773 	nid = memory_add_physaddr_to_nid(lmb->base_addr);
774 
775 	/* Add the memory */
776 	rc = add_memory(nid, lmb->base_addr, block_sz);
777 	if (rc) {
778 		dlpar_remove_device_tree_lmb(lmb);
779 		return rc;
780 	}
781 
782 	rc = dlpar_online_lmb(lmb);
783 	if (rc) {
784 		remove_memory(nid, lmb->base_addr, block_sz);
785 		dlpar_remove_device_tree_lmb(lmb);
786 	} else {
787 		lmb->flags |= DRCONF_MEM_ASSIGNED;
788 	}
789 
790 	return rc;
791 }
792 
793 static int dlpar_memory_add_by_count(u32 lmbs_to_add, struct property *prop)
794 {
795 	struct of_drconf_cell *lmbs;
796 	u32 num_lmbs, *p;
797 	int lmbs_available = 0;
798 	int lmbs_added = 0;
799 	int i, rc;
800 
801 	pr_info("Attempting to hot-add %d LMB(s)\n", lmbs_to_add);
802 
803 	if (lmbs_to_add == 0)
804 		return -EINVAL;
805 
806 	p = prop->value;
807 	num_lmbs = *p++;
808 	lmbs = (struct of_drconf_cell *)p;
809 
810 	/* Validate that there are enough LMBs to satisfy the request */
811 	for (i = 0; i < num_lmbs; i++) {
812 		if (!(lmbs[i].flags & DRCONF_MEM_ASSIGNED))
813 			lmbs_available++;
814 	}
815 
816 	if (lmbs_available < lmbs_to_add)
817 		return -EINVAL;
818 
819 	for (i = 0; i < num_lmbs && lmbs_to_add != lmbs_added; i++) {
820 		rc = dlpar_acquire_drc(lmbs[i].drc_index);
821 		if (rc)
822 			continue;
823 
824 		rc = dlpar_add_lmb(&lmbs[i]);
825 		if (rc) {
826 			dlpar_release_drc(lmbs[i].drc_index);
827 			continue;
828 		}
829 
830 		lmbs_added++;
831 
832 		/* Mark this lmb so we can remove it later if all of the
833 		 * requested LMBs cannot be added.
834 		 */
835 		lmbs[i].reserved = 1;
836 	}
837 
838 	if (lmbs_added != lmbs_to_add) {
839 		pr_err("Memory hot-add failed, removing any added LMBs\n");
840 
841 		for (i = 0; i < num_lmbs; i++) {
842 			if (!lmbs[i].reserved)
843 				continue;
844 
845 			rc = dlpar_remove_lmb(&lmbs[i]);
846 			if (rc)
847 				pr_err("Failed to remove LMB, drc index %x\n",
848 				       be32_to_cpu(lmbs[i].drc_index));
849 			else
850 				dlpar_release_drc(lmbs[i].drc_index);
851 		}
852 		rc = -EINVAL;
853 	} else {
854 		for (i = 0; i < num_lmbs; i++) {
855 			if (!lmbs[i].reserved)
856 				continue;
857 
858 			pr_info("Memory at %llx (drc index %x) was hot-added\n",
859 				lmbs[i].base_addr, lmbs[i].drc_index);
860 			lmbs[i].reserved = 0;
861 		}
862 	}
863 
864 	return rc;
865 }
866 
867 static int dlpar_memory_add_by_index(u32 drc_index, struct property *prop)
868 {
869 	struct of_drconf_cell *lmbs;
870 	u32 num_lmbs, *p;
871 	int i, lmb_found;
872 	int rc;
873 
874 	pr_info("Attempting to hot-add LMB, drc index %x\n", drc_index);
875 
876 	p = prop->value;
877 	num_lmbs = *p++;
878 	lmbs = (struct of_drconf_cell *)p;
879 
880 	lmb_found = 0;
881 	for (i = 0; i < num_lmbs; i++) {
882 		if (lmbs[i].drc_index == drc_index) {
883 			lmb_found = 1;
884 			rc = dlpar_acquire_drc(lmbs[i].drc_index);
885 			if (!rc) {
886 				rc = dlpar_add_lmb(&lmbs[i]);
887 				if (rc)
888 					dlpar_release_drc(lmbs[i].drc_index);
889 			}
890 
891 			break;
892 		}
893 	}
894 
895 	if (!lmb_found)
896 		rc = -EINVAL;
897 
898 	if (rc)
899 		pr_info("Failed to hot-add memory, drc index %x\n", drc_index);
900 	else
901 		pr_info("Memory at %llx (drc index %x) was hot-added\n",
902 			lmbs[i].base_addr, drc_index);
903 
904 	return rc;
905 }
906 
907 static int dlpar_memory_add_by_ic(u32 lmbs_to_add, u32 drc_index,
908 				  struct property *prop)
909 {
910 	struct of_drconf_cell *lmbs;
911 	u32 num_lmbs, *p;
912 	int i, rc, start_lmb_found;
913 	int lmbs_available = 0, start_index = 0, end_index;
914 
915 	pr_info("Attempting to hot-add %u LMB(s) at index %x\n",
916 		lmbs_to_add, drc_index);
917 
918 	if (lmbs_to_add == 0)
919 		return -EINVAL;
920 
921 	p = prop->value;
922 	num_lmbs = *p++;
923 	lmbs = (struct of_drconf_cell *)p;
924 	start_lmb_found = 0;
925 
926 	/* Navigate to drc_index */
927 	while (start_index < num_lmbs) {
928 		if (lmbs[start_index].drc_index == drc_index) {
929 			start_lmb_found = 1;
930 			break;
931 		}
932 
933 		start_index++;
934 	}
935 
936 	if (!start_lmb_found)
937 		return -EINVAL;
938 
939 	end_index = start_index + lmbs_to_add;
940 
941 	/* Validate that the LMBs in this range are not reserved */
942 	for (i = start_index; i < end_index; i++) {
943 		if (lmbs[i].flags & DRCONF_MEM_RESERVED)
944 			break;
945 
946 		lmbs_available++;
947 	}
948 
949 	if (lmbs_available < lmbs_to_add)
950 		return -EINVAL;
951 
952 	for (i = start_index; i < end_index; i++) {
953 		if (lmbs[i].flags & DRCONF_MEM_ASSIGNED)
954 			continue;
955 
956 		rc = dlpar_acquire_drc(lmbs[i].drc_index);
957 		if (rc)
958 			break;
959 
960 		rc = dlpar_add_lmb(&lmbs[i]);
961 		if (rc) {
962 			dlpar_release_drc(lmbs[i].drc_index);
963 			break;
964 		}
965 
966 		lmbs[i].reserved = 1;
967 	}
968 
969 	if (rc) {
970 		pr_err("Memory indexed-count-add failed, removing any added LMBs\n");
971 
972 		for (i = start_index; i < end_index; i++) {
973 			if (!lmbs[i].reserved)
974 				continue;
975 
976 			rc = dlpar_remove_lmb(&lmbs[i]);
977 			if (rc)
978 				pr_err("Failed to remove LMB, drc index %x\n",
979 				       be32_to_cpu(lmbs[i].drc_index));
980 			else
981 				dlpar_release_drc(lmbs[i].drc_index);
982 		}
983 		rc = -EINVAL;
984 	} else {
985 		for (i = start_index; i < end_index; i++) {
986 			if (!lmbs[i].reserved)
987 				continue;
988 
989 			pr_info("Memory at %llx (drc index %x) was hot-added\n",
990 				lmbs[i].base_addr, lmbs[i].drc_index);
991 			lmbs[i].reserved = 0;
992 		}
993 	}
994 
995 	return rc;
996 }
997 
998 int dlpar_memory(struct pseries_hp_errorlog *hp_elog)
999 {
1000 	struct device_node *dn;
1001 	struct property *prop;
1002 	u32 count, drc_index;
1003 	int rc;
1004 
1005 	lock_device_hotplug();
1006 
1007 	dn = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
1008 	if (!dn) {
1009 		rc = -EINVAL;
1010 		goto dlpar_memory_out;
1011 	}
1012 
1013 	prop = dlpar_clone_drconf_property(dn);
1014 	if (!prop) {
1015 		rc = -EINVAL;
1016 		goto dlpar_memory_out;
1017 	}
1018 
1019 	switch (hp_elog->action) {
1020 	case PSERIES_HP_ELOG_ACTION_ADD:
1021 		if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_COUNT) {
1022 			count = hp_elog->_drc_u.drc_count;
1023 			rc = dlpar_memory_add_by_count(count, prop);
1024 		} else if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_INDEX) {
1025 			drc_index = hp_elog->_drc_u.drc_index;
1026 			rc = dlpar_memory_add_by_index(drc_index, prop);
1027 		} else if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_IC) {
1028 			count = hp_elog->_drc_u.ic.count;
1029 			drc_index = hp_elog->_drc_u.ic.index;
1030 			rc = dlpar_memory_add_by_ic(count, drc_index, prop);
1031 		} else {
1032 			rc = -EINVAL;
1033 		}
1034 
1035 		break;
1036 	case PSERIES_HP_ELOG_ACTION_REMOVE:
1037 		if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_COUNT) {
1038 			count = hp_elog->_drc_u.drc_count;
1039 			rc = dlpar_memory_remove_by_count(count, prop);
1040 		} else if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_INDEX) {
1041 			drc_index = hp_elog->_drc_u.drc_index;
1042 			rc = dlpar_memory_remove_by_index(drc_index, prop);
1043 		} else if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_IC) {
1044 			count = hp_elog->_drc_u.ic.count;
1045 			drc_index = hp_elog->_drc_u.ic.index;
1046 			rc = dlpar_memory_remove_by_ic(count, drc_index, prop);
1047 		} else {
1048 			rc = -EINVAL;
1049 		}
1050 
1051 		break;
1052 	case PSERIES_HP_ELOG_ACTION_READD:
1053 		drc_index = hp_elog->_drc_u.drc_index;
1054 		rc = dlpar_memory_readd_by_index(drc_index, prop);
1055 		break;
1056 	default:
1057 		pr_err("Invalid action (%d) specified\n", hp_elog->action);
1058 		rc = -EINVAL;
1059 		break;
1060 	}
1061 
1062 	dlpar_free_property(prop);
1063 
1064 dlpar_memory_out:
1065 	of_node_put(dn);
1066 	unlock_device_hotplug();
1067 	return rc;
1068 }
1069 
1070 static int pseries_add_mem_node(struct device_node *np)
1071 {
1072 	const char *type;
1073 	const __be32 *regs;
1074 	unsigned long base;
1075 	unsigned int lmb_size;
1076 	int ret = -EINVAL;
1077 
1078 	/*
1079 	 * Check to see if we are actually adding memory
1080 	 */
1081 	type = of_get_property(np, "device_type", NULL);
1082 	if (type == NULL || strcmp(type, "memory") != 0)
1083 		return 0;
1084 
1085 	/*
1086 	 * Find the base and size of the memblock
1087 	 */
1088 	regs = of_get_property(np, "reg", NULL);
1089 	if (!regs)
1090 		return ret;
1091 
1092 	base = be64_to_cpu(*(unsigned long *)regs);
1093 	lmb_size = be32_to_cpu(regs[3]);
1094 
1095 	/*
1096 	 * Update memory region to represent the memory add
1097 	 */
1098 	ret = memblock_add(base, lmb_size);
1099 	return (ret < 0) ? -EINVAL : 0;
1100 }
1101 
1102 static int pseries_update_drconf_memory(struct of_reconfig_data *pr)
1103 {
1104 	struct of_drconf_cell *new_drmem, *old_drmem;
1105 	unsigned long memblock_size;
1106 	u32 entries;
1107 	__be32 *p;
1108 	int i, rc = -EINVAL;
1109 
1110 	if (rtas_hp_event)
1111 		return 0;
1112 
1113 	memblock_size = pseries_memory_block_size();
1114 	if (!memblock_size)
1115 		return -EINVAL;
1116 
1117 	p = (__be32 *) pr->old_prop->value;
1118 	if (!p)
1119 		return -EINVAL;
1120 
1121 	/* The first int of the property is the number of lmb's described
1122 	 * by the property. This is followed by an array of of_drconf_cell
1123 	 * entries. Get the number of entries and skip to the array of
1124 	 * of_drconf_cell's.
1125 	 */
1126 	entries = be32_to_cpu(*p++);
1127 	old_drmem = (struct of_drconf_cell *)p;
1128 
1129 	p = (__be32 *)pr->prop->value;
1130 	p++;
1131 	new_drmem = (struct of_drconf_cell *)p;
1132 
1133 	for (i = 0; i < entries; i++) {
1134 		if ((be32_to_cpu(old_drmem[i].flags) & DRCONF_MEM_ASSIGNED) &&
1135 		    (!(be32_to_cpu(new_drmem[i].flags) & DRCONF_MEM_ASSIGNED))) {
1136 			rc = pseries_remove_memblock(
1137 				be64_to_cpu(old_drmem[i].base_addr),
1138 						     memblock_size);
1139 			break;
1140 		} else if ((!(be32_to_cpu(old_drmem[i].flags) &
1141 			    DRCONF_MEM_ASSIGNED)) &&
1142 			    (be32_to_cpu(new_drmem[i].flags) &
1143 			    DRCONF_MEM_ASSIGNED)) {
1144 			rc = memblock_add(be64_to_cpu(old_drmem[i].base_addr),
1145 					  memblock_size);
1146 			rc = (rc < 0) ? -EINVAL : 0;
1147 			break;
1148 		}
1149 	}
1150 	return rc;
1151 }
1152 
1153 static int pseries_memory_notifier(struct notifier_block *nb,
1154 				   unsigned long action, void *data)
1155 {
1156 	struct of_reconfig_data *rd = data;
1157 	int err = 0;
1158 
1159 	switch (action) {
1160 	case OF_RECONFIG_ATTACH_NODE:
1161 		err = pseries_add_mem_node(rd->dn);
1162 		break;
1163 	case OF_RECONFIG_DETACH_NODE:
1164 		err = pseries_remove_mem_node(rd->dn);
1165 		break;
1166 	case OF_RECONFIG_UPDATE_PROPERTY:
1167 		if (!strcmp(rd->prop->name, "ibm,dynamic-memory"))
1168 			err = pseries_update_drconf_memory(rd);
1169 		break;
1170 	}
1171 	return notifier_from_errno(err);
1172 }
1173 
1174 static struct notifier_block pseries_mem_nb = {
1175 	.notifier_call = pseries_memory_notifier,
1176 };
1177 
1178 static int __init pseries_memory_hotplug_init(void)
1179 {
1180 	if (firmware_has_feature(FW_FEATURE_LPAR))
1181 		of_reconfig_notifier_register(&pseries_mem_nb);
1182 
1183 	return 0;
1184 }
1185 machine_device_initcall(pseries, pseries_memory_hotplug_init);
1186