Merge tag 'gcc-plugins-v4.9-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git...
[cascardo/linux.git] / arch / powerpc / platforms / pseries / hotplug-memory.c
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);