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
27static bool rtas_hp_event;
28
29unsigned 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
72static void dlpar_free_drconf_property(struct property *prop)
73{
74	kfree(prop->name);
75	kfree(prop->value);
76	kfree(prop);
77}
78
79static 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
119static 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
133static 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
155out:
156	/* Update memory regions for memory remove */
157	memblock_remove(base, memblock_size);
158	unlock_device_hotplug();
159	return 0;
160}
161
162static 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
191static 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
217static int dlpar_add_lmb(struct of_drconf_cell *);
218
219static 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
251static 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
323static 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
358static inline int pseries_remove_memblock(unsigned long base,
359					  unsigned int memblock_size)
360{
361	return -EOPNOTSUPP;
362}
363static inline int pseries_remove_mem_node(struct device_node *np)
364{
365	return 0;
366}
367static inline int dlpar_memory_remove(struct pseries_hp_errorlog *hp_elog)
368{
369	return -EOPNOTSUPP;
370}
371static int dlpar_remove_lmb(struct of_drconf_cell *lmb)
372{
373	return -EOPNOTSUPP;
374}
375static int dlpar_memory_remove_by_count(u32 lmbs_to_remove,
376					struct property *prop)
377{
378	return -EOPNOTSUPP;
379}
380static int dlpar_memory_remove_by_index(u32 drc_index, struct property *prop)
381{
382	return -EOPNOTSUPP;
383}
384
385#endif /* CONFIG_MEMORY_HOTREMOVE */
386
387static 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
439static 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
505static 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
539static 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
564int 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
616dlpar_memory_out:
617	of_node_put(dn);
618	unlock_device_hotplug();
619	return rc;
620}
621
622static 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
654static 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
705static 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
726static struct notifier_block pseries_mem_nb = {
727	.notifier_call = pseries_memory_notifier,
728};
729
730static 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}
737machine_device_initcall(pseries, pseries_memory_hotplug_init);
738