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