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