arch/powerpc/mm/numa.c

   1 /*
   2  * pSeries NUMA support
   3  *
   4  * Copyright (C) 2002 Anton Blanchard <anton@au.ibm.com>, IBM
   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 #define pr_fmt(fmt) "numa: " fmt
  12
  13 #include <linux/threads.h>
  14 #include <linux/bootmem.h>
  15 #include <linux/init.h>
  16 #include <linux/mm.h>
  17 #include <linux/mmzone.h>
  18 #include <linux/export.h>
  19 #include <linux/nodemask.h>
  20 #include <linux/cpu.h>
  21 #include <linux/notifier.h>
  22 #include <linux/memblock.h>
  23 #include <linux/of.h>
  24 #include <linux/pfn.h>
  25 #include <linux/cpuset.h>
  26 #include <linux/node.h>
  27 #include <linux/stop_machine.h>
  28 #include <linux/proc_fs.h>
  29 #include <linux/seq_file.h>
  30 #include <linux/uaccess.h>
  31 #include <linux/slab.h>
  32 #include <asm/cputhreads.h>
  33 #include <asm/sparsemem.h>
  34 #include <asm/prom.h>
  35 #include <asm/smp.h>
  36 #include <asm/cputhreads.h>
  37 #include <asm/topology.h>
  38 #include <asm/firmware.h>
  39 #include <asm/paca.h>
  40 #include <asm/hvcall.h>
  41 #include <asm/setup.h>
  42 #include <asm/vdso.h>
  43
  44 static int numa_enabled = 1;
  45
  46 static char *cmdline __initdata;
  47
  48 static int numa_debug;
  49 #define dbg(args...) if (numa_debug) { printk(KERN_INFO args); }
  50
  51 int numa_cpu_lookup_table[NR_CPUS];
  52 cpumask_var_t node_to_cpumask_map[MAX_NUMNODES];
  53 struct pglist_data *node_data[MAX_NUMNODES];
  54
  55 EXPORT_SYMBOL(numa_cpu_lookup_table);
  56 EXPORT_SYMBOL(node_to_cpumask_map);
  57 EXPORT_SYMBOL(node_data);
  58
  59 static int min_common_depth;
  60 static int n_mem_addr_cells, n_mem_size_cells;
  61 static int form1_affinity;
  62
  63 #define MAX_DISTANCE_REF_POINTS 4
  64 static int distance_ref_points_depth;
  65 static const __be32 *distance_ref_points;
  66 static int distance_lookup_table[MAX_NUMNODES][MAX_DISTANCE_REF_POINTS];
  67
  68 /*
  69  * Allocate node_to_cpumask_map based on number of available nodes
  70  * Requires node_possible_map to be valid.
  71  *
  72  * Note: cpumask_of_node() is not valid until after this is done.
  73  */
  74 static void __init setup_node_to_cpumask_map(void)
  75 {
  76         unsigned int node;
  77
  78         /* setup nr_node_ids if not done yet */
  79         if (nr_node_ids == MAX_NUMNODES)
  80                 setup_nr_node_ids();
  81
  82         /* allocate the map */
  83         for (node = 0; node < nr_node_ids; node++)
  84                 alloc_bootmem_cpumask_var(&node_to_cpumask_map[node]);
  85
  86         /* cpumask_of_node() will now work */
  87         dbg("Node to cpumask map for %d nodes\n", nr_node_ids);
  88 }
  89
  90 static int __init fake_numa_create_new_node(unsigned long end_pfn,
  91                                                 unsigned int *nid)
  92 {
  93         unsigned long long mem;
  94         char *p = cmdline;
  95         static unsigned int fake_nid;
  96         static unsigned long long curr_boundary;
  97
  98         /*
  99          * Modify node id, iff we started creating NUMA nodes
 100          * We want to continue from where we left of the last time
 101          */
 102         if (fake_nid)
 103                 *nid = fake_nid;
 104         /*
 105          * In case there are no more arguments to parse, the
 106          * node_id should be the same as the last fake node id
 107          * (we've handled this above).
 108          */
 109         if (!p)
 110                 return 0;
 111
 112         mem = memparse(p, &p);
 113         if (!mem)
 114                 return 0;
 115
 116         if (mem < curr_boundary)
 117                 return 0;
 118
 119         curr_boundary = mem;
 120
 121         if ((end_pfn << PAGE_SHIFT) > mem) {
 122                 /*
 123                  * Skip commas and spaces
 124                  */
 125                 while (*p == ',' || *p == ' ' || *p == '\t')
 126                         p++;
 127
 128                 cmdline = p;
 129                 fake_nid++;
 130                 *nid = fake_nid;
 131                 dbg("created new fake_node with id %d\n", fake_nid);
 132                 return 1;
 133         }
 134         return 0;
 135 }
 136
 137 /*
 138  * get_node_active_region - Return active region containing pfn
 139  * Active range returned is empty if none found.
 140  * @pfn: The page to return the region for
 141  * @node_ar: Returned set to the active region containing @pfn
 142  */
 143 static void __init get_node_active_region(unsigned long pfn,
 144                                           struct node_active_region *node_ar)
 145 {
 146         unsigned long start_pfn, end_pfn;
 147         int i, nid;
 148
 149         for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) {
 150                 if (pfn >= start_pfn && pfn < end_pfn) {
 151                         node_ar->nid = nid;
 152                         node_ar->start_pfn = start_pfn;
 153                         node_ar->end_pfn = end_pfn;
 154                         break;
 155                 }
 156         }
 157 }
 158
 159 static void reset_numa_cpu_lookup_table(void)
 160 {
 161         unsigned int cpu;
 162
 163         for_each_possible_cpu(cpu)
 164                 numa_cpu_lookup_table[cpu] = -1;
 165 }
 166
 167 static void update_numa_cpu_lookup_table(unsigned int cpu, int node)
 168 {
 169         numa_cpu_lookup_table[cpu] = node;
 170 }
 171
 172 static void map_cpu_to_node(int cpu, int node)
 173 {
 174         update_numa_cpu_lookup_table(cpu, node);
 175
 176         dbg("adding cpu %d to node %d\n", cpu, node);
 177
 178         if (!(cpumask_test_cpu(cpu, node_to_cpumask_map[node])))
 179                 cpumask_set_cpu(cpu, node_to_cpumask_map[node]);
 180 }
 181
 182 #if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_PPC_SPLPAR)
 183 static void unmap_cpu_from_node(unsigned long cpu)
 184 {
 185         int node = numa_cpu_lookup_table[cpu];
 186
 187         dbg("removing cpu %lu from node %d\n", cpu, node);
 188
 189         if (cpumask_test_cpu(cpu, node_to_cpumask_map[node])) {
 190                 cpumask_clear_cpu(cpu, node_to_cpumask_map[node]);
 191         } else {
 192                 printk(KERN_ERR "WARNING: cpu %lu not found in node %d\n",
 193                        cpu, node);
 194         }
 195 }
 196 #endif /* CONFIG_HOTPLUG_CPU || CONFIG_PPC_SPLPAR */
 197
 198 /* must hold reference to node during call */
 199 static const __be32 *of_get_associativity(struct device_node *dev)
 200 {
 201         return of_get_property(dev, "ibm,associativity", NULL);
 202 }
 203
 204 /*
 205  * Returns the property linux,drconf-usable-memory if
 206  * it exists (the property exists only in kexec/kdump kernels,
 207  * added by kexec-tools)
 208  */
 209 static const __be32 *of_get_usable_memory(struct device_node *memory)
 210 {
 211         const __be32 *prop;
 212         u32 len;
 213         prop = of_get_property(memory, "linux,drconf-usable-memory", &len);
 214         if (!prop || len < sizeof(unsigned int))
 215                 return NULL;
 216         return prop;
 217 }
 218
 219 int __node_distance(int a, int b)
 220 {
 221         int i;
 222         int distance = LOCAL_DISTANCE;
 223
 224         if (!form1_affinity)
 225                 return ((a == b) ? LOCAL_DISTANCE : REMOTE_DISTANCE);
 226
 227         for (i = 0; i < distance_ref_points_depth; i++) {
 228                 if (distance_lookup_table[a][i] == distance_lookup_table[b][i])
 229                         break;
 230
 231                 /* Double the distance for each NUMA level */
 232                 distance *= 2;
 233         }
 234
 235         return distance;
 236 }
 237 EXPORT_SYMBOL(__node_distance);
 238
 239 static void initialize_distance_lookup_table(int nid,
 240                 const __be32 *associativity)
 241 {
 242         int i;
 243
 244         if (!form1_affinity)
 245                 return;
 246
 247         for (i = 0; i < distance_ref_points_depth; i++) {
 248                 const __be32 *entry;
 249
 250                 entry = &associativity[be32_to_cpu(distance_ref_points[i])];
 251                 distance_lookup_table[nid][i] = of_read_number(entry, 1);
 252         }
 253 }
 254
 255 /* Returns nid in the range [0..MAX_NUMNODES-1], or -1 if no useful numa
 256  * info is found.
 257  */
 258 static int associativity_to_nid(const __be32 *associativity)
 259 {
 260         int nid = -1;
 261
 262         if (min_common_depth == -1)
 263                 goto out;
 264
 265         if (of_read_number(associativity, 1) >= min_common_depth)
 266                 nid = of_read_number(&associativity[min_common_depth], 1);
 267
 268         /* POWER4 LPAR uses 0xffff as invalid node */
 269         if (nid == 0xffff || nid >= MAX_NUMNODES)
 270                 nid = -1;
 271
 272         if (nid > 0 &&
 273             of_read_number(associativity, 1) >= distance_ref_points_depth)
 274                 initialize_distance_lookup_table(nid, associativity);
 275
 276 out:
 277         return nid;
 278 }
 279
 280 /* Returns the nid associated with the given device tree node,
 281  * or -1 if not found.
 282  */
 283 static int of_node_to_nid_single(struct device_node *device)
 284 {
 285         int nid = -1;
 286         const __be32 *tmp;
 287
 288         tmp = of_get_associativity(device);
 289         if (tmp)
 290                 nid = associativity_to_nid(tmp);
 291         return nid;
 292 }
 293
 294 /* Walk the device tree upwards, looking for an associativity id */
 295 int of_node_to_nid(struct device_node *device)
 296 {
 297         struct device_node *tmp;
 298         int nid = -1;
 299
 300         of_node_get(device);
 301         while (device) {
 302                 nid = of_node_to_nid_single(device);
 303                 if (nid != -1)
 304                         break;
 305
 306                 tmp = device;
 307                 device = of_get_parent(tmp);
 308                 of_node_put(tmp);
 309         }
 310         of_node_put(device);
 311
 312         return nid;
 313 }
 314 EXPORT_SYMBOL_GPL(of_node_to_nid);
 315
 316 static int __init find_min_common_depth(void)
 317 {
 318         int depth;
 319         struct device_node *root;
 320
 321         if (firmware_has_feature(FW_FEATURE_OPAL))
 322                 root = of_find_node_by_path("/ibm,opal");
 323         else
 324                 root = of_find_node_by_path("/rtas");
 325         if (!root)
 326                 root = of_find_node_by_path("/");
 327
 328         /*
 329          * This property is a set of 32-bit integers, each representing
 330          * an index into the ibm,associativity nodes.
 331          *
 332          * With form 0 affinity the first integer is for an SMP configuration
 333          * (should be all 0's) and the second is for a normal NUMA
 334          * configuration. We have only one level of NUMA.
 335          *
 336          * With form 1 affinity the first integer is the most significant
 337          * NUMA boundary and the following are progressively less significant
 338          * boundaries. There can be more than one level of NUMA.
 339          */
 340         distance_ref_points = of_get_property(root,
 341                                         "ibm,associativity-reference-points",
 342                                         &distance_ref_points_depth);
 343
 344         if (!distance_ref_points) {
 345                 dbg("NUMA: ibm,associativity-reference-points not found.\n");
 346                 goto err;
 347         }
 348
 349         distance_ref_points_depth /= sizeof(int);
 350
 351         if (firmware_has_feature(FW_FEATURE_OPAL) ||
 352             firmware_has_feature(FW_FEATURE_TYPE1_AFFINITY)) {
 353                 dbg("Using form 1 affinity\n");
 354                 form1_affinity = 1;
 355         }
 356
 357         if (form1_affinity) {
 358                 depth = of_read_number(distance_ref_points, 1);
 359         } else {
 360                 if (distance_ref_points_depth < 2) {
 361                         printk(KERN_WARNING "NUMA: "
 362                                 "short ibm,associativity-reference-points\n");
 363                         goto err;
 364                 }
 365
 366                 depth = of_read_number(&distance_ref_points[1], 1);
 367         }
 368
 369         /*
 370          * Warn and cap if the hardware supports more than
 371          * MAX_DISTANCE_REF_POINTS domains.
 372          */
 373         if (distance_ref_points_depth > MAX_DISTANCE_REF_POINTS) {
 374                 printk(KERN_WARNING "NUMA: distance array capped at "
 375                         "%d entries\n", MAX_DISTANCE_REF_POINTS);
 376                 distance_ref_points_depth = MAX_DISTANCE_REF_POINTS;
 377         }
 378
 379         of_node_put(root);
 380         return depth;
 381
 382 err:
 383         of_node_put(root);
 384         return -1;
 385 }
 386
 387 static void __init get_n_mem_cells(int *n_addr_cells, int *n_size_cells)
 388 {
 389         struct device_node *memory = NULL;
 390
 391         memory = of_find_node_by_type(memory, "memory");
 392         if (!memory)
 393                 panic("numa.c: No memory nodes found!");
 394
 395         *n_addr_cells = of_n_addr_cells(memory);
 396         *n_size_cells = of_n_size_cells(memory);
 397         of_node_put(memory);
 398 }
 399
 400 static unsigned long read_n_cells(int n, const __be32 **buf)
 401 {
 402         unsigned long result = 0;
 403
 404         while (n--) {
 405                 result = (result << 32) | of_read_number(*buf, 1);
 406                 (*buf)++;
 407         }
 408         return result;
 409 }
 410
 411 /*
 412  * Read the next memblock list entry from the ibm,dynamic-memory property
 413  * and return the information in the provided of_drconf_cell structure.
 414  */
 415 static void read_drconf_cell(struct of_drconf_cell *drmem, const __be32 **cellp)
 416 {
 417         const __be32 *cp;
 418
 419         drmem->base_addr = read_n_cells(n_mem_addr_cells, cellp);
 420
 421         cp = *cellp;
 422         drmem->drc_index = of_read_number(cp, 1);
 423         drmem->reserved = of_read_number(&cp[1], 1);
 424         drmem->aa_index = of_read_number(&cp[2], 1);
 425         drmem->flags = of_read_number(&cp[3], 1);
 426
 427         *cellp = cp + 4;
 428 }
 429
 430 /*
 431  * Retrieve and validate the ibm,dynamic-memory property of the device tree.
 432  *
 433  * The layout of the ibm,dynamic-memory property is a number N of memblock
 434  * list entries followed by N memblock list entries.  Each memblock list entry
 435  * contains information as laid out in the of_drconf_cell struct above.
 436  */
 437 static int of_get_drconf_memory(struct device_node *memory, const __be32 **dm)
 438 {
 439         const __be32 *prop;
 440         u32 len, entries;
 441
 442         prop = of_get_property(memory, "ibm,dynamic-memory", &len);
 443         if (!prop || len < sizeof(unsigned int))
 444                 return 0;
 445
 446         entries = of_read_number(prop++, 1);
 447
 448         /* Now that we know the number of entries, revalidate the size
 449          * of the property read in to ensure we have everything
 450          */
 451         if (len < (entries * (n_mem_addr_cells + 4) + 1) * sizeof(unsigned int))
 452                 return 0;
 453
 454         *dm = prop;
 455         return entries;
 456 }
 457
 458 /*
 459  * Retrieve and validate the ibm,lmb-size property for drconf memory
 460  * from the device tree.
 461  */
 462 static u64 of_get_lmb_size(struct device_node *memory)
 463 {
 464         const __be32 *prop;
 465         u32 len;
 466
 467         prop = of_get_property(memory, "ibm,lmb-size", &len);
 468         if (!prop || len < sizeof(unsigned int))
 469                 return 0;
 470
 471         return read_n_cells(n_mem_size_cells, &prop);
 472 }
 473
 474 struct assoc_arrays {
 475         u32     n_arrays;
 476         u32     array_sz;
 477         const __be32 *arrays;
 478 };
 479
 480 /*
 481  * Retrieve and validate the list of associativity arrays for drconf
 482  * memory from the ibm,associativity-lookup-arrays property of the
 483  * device tree..
 484  *
 485  * The layout of the ibm,associativity-lookup-arrays property is a number N
 486  * indicating the number of associativity arrays, followed by a number M
 487  * indicating the size of each associativity array, followed by a list
 488  * of N associativity arrays.
 489  */
 490 static int of_get_assoc_arrays(struct device_node *memory,
 491                                struct assoc_arrays *aa)
 492 {
 493         const __be32 *prop;
 494         u32 len;
 495
 496         prop = of_get_property(memory, "ibm,associativity-lookup-arrays", &len);
 497         if (!prop || len < 2 * sizeof(unsigned int))
 498                 return -1;
 499
 500         aa->n_arrays = of_read_number(prop++, 1);
 501         aa->array_sz = of_read_number(prop++, 1);
 502
 503         /* Now that we know the number of arrays and size of each array,
 504          * revalidate the size of the property read in.
 505          */
 506         if (len < (aa->n_arrays * aa->array_sz + 2) * sizeof(unsigned int))
 507                 return -1;
 508
 509         aa->arrays = prop;
 510         return 0;
 511 }
 512
 513 /*
 514  * This is like of_node_to_nid_single() for memory represented in the
 515  * ibm,dynamic-reconfiguration-memory node.
 516  */
 517 static int of_drconf_to_nid_single(struct of_drconf_cell *drmem,
 518                                    struct assoc_arrays *aa)
 519 {
 520         int default_nid = 0;
 521         int nid = default_nid;
 522         int index;
 523
 524         if (min_common_depth > 0 && min_common_depth <= aa->array_sz &&
 525             !(drmem->flags & DRCONF_MEM_AI_INVALID) &&
 526             drmem->aa_index < aa->n_arrays) {
 527                 index = drmem->aa_index * aa->array_sz + min_common_depth - 1;
 528                 nid = of_read_number(&aa->arrays[index], 1);
 529
 530                 if (nid == 0xffff || nid >= MAX_NUMNODES)
 531                         nid = default_nid;
 532         }
 533
 534         return nid;
 535 }
 536
 537 /*
 538  * Figure out to which domain a cpu belongs and stick it there.
 539  * Return the id of the domain used.
 540  */
 541 static int numa_setup_cpu(unsigned long lcpu)
 542 {
 543         int nid = -1;
 544         struct device_node *cpu;
 545
 546         /*
 547          * If a valid cpu-to-node mapping is already available, use it
 548          * directly instead of querying the firmware, since it represents
 549          * the most recent mapping notified to us by the platform (eg: VPHN).
 550          */
 551         if ((nid = numa_cpu_lookup_table[lcpu]) >= 0) {
 552                 map_cpu_to_node(lcpu, nid);
 553                 return nid;
 554         }
 555
 556         cpu = of_get_cpu_node(lcpu, NULL);
 557
 558         if (!cpu) {
 559                 WARN_ON(1);
 560                 if (cpu_present(lcpu))
 561                         goto out_present;
 562                 else
 563                         goto out;
 564         }
 565
 566         nid = of_node_to_nid_single(cpu);
 567
 568 out_present:
 569         if (nid < 0 || !node_online(nid))
 570                 nid = first_online_node;
 571
 572         map_cpu_to_node(lcpu, nid);
 573         of_node_put(cpu);
 574 out:
 575         return nid;
 576 }
 577
 578 static void verify_cpu_node_mapping(int cpu, int node)
 579 {
 580         int base, sibling, i;
 581
 582         /* Verify that all the threads in the core belong to the same node */
 583         base = cpu_first_thread_sibling(cpu);
 584
 585         for (i = 0; i < threads_per_core; i++) {
 586                 sibling = base + i;
 587
 588                 if (sibling == cpu || cpu_is_offline(sibling))
 589                         continue;
 590
 591                 if (cpu_to_node(sibling) != node) {
 592                         WARN(1, "CPU thread siblings %d and %d don't belong"
 593                                 " to the same node!\n", cpu, sibling);
 594                         break;
 595                 }
 596         }
 597 }
 598
 599 static int cpu_numa_callback(struct notifier_block *nfb, unsigned long action,
 600                              void *hcpu)
 601 {
 602         unsigned long lcpu = (unsigned long)hcpu;
 603         int ret = NOTIFY_DONE, nid;
 604
 605         switch (action) {
 606         case CPU_UP_PREPARE:
 607         case CPU_UP_PREPARE_FROZEN:
 608                 nid = numa_setup_cpu(lcpu);
 609                 verify_cpu_node_mapping((int)lcpu, nid);
 610                 ret = NOTIFY_OK;
 611                 break;
 612 #ifdef CONFIG_HOTPLUG_CPU
 613         case CPU_DEAD:
 614         case CPU_DEAD_FROZEN:
 615         case CPU_UP_CANCELED:
 616         case CPU_UP_CANCELED_FROZEN:
 617                 unmap_cpu_from_node(lcpu);
 618                 ret = NOTIFY_OK;
 619                 break;
 620 #endif
 621         }
 622         return ret;
 623 }
 624
 625 /*
 626  * Check and possibly modify a memory region to enforce the memory limit.
 627  *
 628  * Returns the size the region should have to enforce the memory limit.
 629  * This will either be the original value of size, a truncated value,
 630  * or zero. If the returned value of size is 0 the region should be
 631  * discarded as it lies wholly above the memory limit.
 632  */
 633 static unsigned long __init numa_enforce_memory_limit(unsigned long start,
 634                                                       unsigned long size)
 635 {
 636         /*
 637          * We use memblock_end_of_DRAM() in here instead of memory_limit because
 638          * we've already adjusted it for the limit and it takes care of
 639          * having memory holes below the limit.  Also, in the case of
 640          * iommu_is_off, memory_limit is not set but is implicitly enforced.
 641          */
 642
 643         if (start + size <= memblock_end_of_DRAM())
 644                 return size;
 645
 646         if (start >= memblock_end_of_DRAM())
 647                 return 0;
 648
 649         return memblock_end_of_DRAM() - start;
 650 }
 651
 652 /*
 653  * Reads the counter for a given entry in
 654  * linux,drconf-usable-memory property
 655  */
 656 static inline int __init read_usm_ranges(const __be32 **usm)
 657 {
 658         /*
 659          * For each lmb in ibm,dynamic-memory a corresponding
 660          * entry in linux,drconf-usable-memory property contains
 661          * a counter followed by that many (base, size) duple.
 662          * read the counter from linux,drconf-usable-memory
 663          */
 664         return read_n_cells(n_mem_size_cells, usm);
 665 }
 666
 667 /*
 668  * Extract NUMA information from the ibm,dynamic-reconfiguration-memory
 669  * node.  This assumes n_mem_{addr,size}_cells have been set.
 670  */
 671 static void __init parse_drconf_memory(struct device_node *memory)
 672 {
 673         const __be32 *uninitialized_var(dm), *usm;
 674         unsigned int n, rc, ranges, is_kexec_kdump = 0;
 675         unsigned long lmb_size, base, size, sz;
 676         int nid;
 677         struct assoc_arrays aa = { .arrays = NULL };
 678
 679         n = of_get_drconf_memory(memory, &dm);
 680         if (!n)
 681                 return;
 682
 683         lmb_size = of_get_lmb_size(memory);
 684         if (!lmb_size)
 685                 return;
 686
 687         rc = of_get_assoc_arrays(memory, &aa);
 688         if (rc)
 689                 return;
 690
 691         /* check if this is a kexec/kdump kernel */
 692         usm = of_get_usable_memory(memory);
 693         if (usm != NULL)
 694                 is_kexec_kdump = 1;
 695
 696         for (; n != 0; --n) {
 697                 struct of_drconf_cell drmem;
 698
 699                 read_drconf_cell(&drmem, &dm);
 700
 701                 /* skip this block if the reserved bit is set in flags (0x80)
 702                    or if the block is not assigned to this partition (0x8) */
 703                 if ((drmem.flags & DRCONF_MEM_RESERVED)
 704                     || !(drmem.flags & DRCONF_MEM_ASSIGNED))
 705                         continue;
 706
 707                 base = drmem.base_addr;
 708                 size = lmb_size;
 709                 ranges = 1;
 710
 711                 if (is_kexec_kdump) {
 712                         ranges = read_usm_ranges(&usm);
 713                         if (!ranges) /* there are no (base, size) duple */
 714                                 continue;
 715                 }
 716                 do {
 717                         if (is_kexec_kdump) {
 718                                 base = read_n_cells(n_mem_addr_cells, &usm);
 719                                 size = read_n_cells(n_mem_size_cells, &usm);
 720                         }
 721                         nid = of_drconf_to_nid_single(&drmem, &aa);
 722                         fake_numa_create_new_node(
 723                                 ((base + size) >> PAGE_SHIFT),
 724                                            &nid);
 725                         node_set_online(nid);
 726                         sz = numa_enforce_memory_limit(base, size);
 727                         if (sz)
 728                                 memblock_set_node(base, sz,
 729                                                   &memblock.memory, nid);
 730                 } while (--ranges);
 731         }
 732 }
 733
 734 static int __init parse_numa_properties(void)
 735 {
 736         struct device_node *memory;
 737         int default_nid = 0;
 738         unsigned long i;
 739
 740         if (numa_enabled == 0) {
 741                 printk(KERN_WARNING "NUMA disabled by user\n");
 742                 return -1;
 743         }
 744
 745         min_common_depth = find_min_common_depth();
 746
 747         if (min_common_depth < 0)
 748                 return min_common_depth;
 749
 750         dbg("NUMA associativity depth for CPU/Memory: %d\n", min_common_depth);
 751
 752         /*
 753          * Even though we connect cpus to numa domains later in SMP
 754          * init, we need to know the node ids now. This is because
 755          * each node to be onlined must have NODE_DATA etc backing it.
 756          */
 757         for_each_present_cpu(i) {
 758                 struct device_node *cpu;
 759                 int nid;
 760
 761                 cpu = of_get_cpu_node(i, NULL);
 762                 BUG_ON(!cpu);
 763                 nid = of_node_to_nid_single(cpu);
 764                 of_node_put(cpu);
 765
 766                 /*
 767                  * Don't fall back to default_nid yet -- we will plug
 768                  * cpus into nodes once the memory scan has discovered
 769                  * the topology.
 770                  */
 771                 if (nid < 0)
 772                         continue;
 773                 node_set_online(nid);
 774         }
 775
 776         get_n_mem_cells(&n_mem_addr_cells, &n_mem_size_cells);
 777
 778         for_each_node_by_type(memory, "memory") {
 779                 unsigned long start;
 780                 unsigned long size;
 781                 int nid;
 782                 int ranges;
 783                 const __be32 *memcell_buf;
 784                 unsigned int len;
 785
 786                 memcell_buf = of_get_property(memory,
 787                         "linux,usable-memory", &len);
 788                 if (!memcell_buf || len <= 0)
 789                         memcell_buf = of_get_property(memory, "reg", &len);
 790                 if (!memcell_buf || len <= 0)
 791                         continue;
 792
 793                 /* ranges in cell */
 794                 ranges = (len >> 2) / (n_mem_addr_cells + n_mem_size_cells);
 795 new_range:
 796                 /* these are order-sensitive, and modify the buffer pointer */
 797                 start = read_n_cells(n_mem_addr_cells, &memcell_buf);
 798                 size = read_n_cells(n_mem_size_cells, &memcell_buf);
 799
 800                 /*
 801                  * Assumption: either all memory nodes or none will
 802                  * have associativity properties.  If none, then
 803                  * everything goes to default_nid.
 804                  */
 805                 nid = of_node_to_nid_single(memory);
 806                 if (nid < 0)
 807                         nid = default_nid;
 808
 809                 fake_numa_create_new_node(((start + size) >> PAGE_SHIFT), &nid);
 810                 node_set_online(nid);
 811
 812                 if (!(size = numa_enforce_memory_limit(start, size))) {
 813                         if (--ranges)
 814                                 goto new_range;
 815                         else
 816                                 continue;
 817                 }
 818
 819                 memblock_set_node(start, size, &memblock.memory, nid);
 820
 821                 if (--ranges)
 822                         goto new_range;
 823         }
 824
 825         /*
 826          * Now do the same thing for each MEMBLOCK listed in the
 827          * ibm,dynamic-memory property in the
 828          * ibm,dynamic-reconfiguration-memory node.
 829          */
 830         memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
 831         if (memory)
 832                 parse_drconf_memory(memory);
 833
 834         return 0;
 835 }
 836
 837 static void __init setup_nonnuma(void)
 838 {
 839         unsigned long top_of_ram = memblock_end_of_DRAM();
 840         unsigned long total_ram = memblock_phys_mem_size();
 841         unsigned long start_pfn, end_pfn;
 842         unsigned int nid = 0;
 843         struct memblock_region *reg;
 844
 845         printk(KERN_DEBUG "Top of RAM: 0x%lx, Total RAM: 0x%lx\n",
 846                top_of_ram, total_ram);
 847         printk(KERN_DEBUG "Memory hole size: %ldMB\n",
 848                (top_of_ram - total_ram) >> 20);
 849
 850         for_each_memblock(memory, reg) {
 851                 start_pfn = memblock_region_memory_base_pfn(reg);
 852                 end_pfn = memblock_region_memory_end_pfn(reg);
 853
 854                 fake_numa_create_new_node(end_pfn, &nid);
 855                 memblock_set_node(PFN_PHYS(start_pfn),
 856                                   PFN_PHYS(end_pfn - start_pfn),
 857                                   &memblock.memory, nid);
 858                 node_set_online(nid);
 859         }
 860 }
 861
 862 void __init dump_numa_cpu_topology(void)
 863 {
 864         unsigned int node;
 865         unsigned int cpu, count;
 866
 867         if (min_common_depth == -1 || !numa_enabled)
 868                 return;
 869
 870         for_each_online_node(node) {
 871                 printk(KERN_DEBUG "Node %d CPUs:", node);
 872
 873                 count = 0;
 874                 /*
 875                  * If we used a CPU iterator here we would miss printing
 876                  * the holes in the cpumap.
 877                  */
 878                 for (cpu = 0; cpu < nr_cpu_ids; cpu++) {
 879                         if (cpumask_test_cpu(cpu,
 880                                         node_to_cpumask_map[node])) {
 881                                 if (count == 0)
 882                                         printk(" %u", cpu);
 883                                 ++count;
 884                         } else {
 885                                 if (count > 1)
 886                                         printk("-%u", cpu - 1);
 887                                 count = 0;
 888                         }
 889                 }
 890
 891                 if (count > 1)
 892                         printk("-%u", nr_cpu_ids - 1);
 893                 printk("\n");
 894         }
 895 }
 896
 897 static void __init dump_numa_memory_topology(void)
 898 {
 899         unsigned int node;
 900         unsigned int count;
 901
 902         if (min_common_depth == -1 || !numa_enabled)
 903                 return;
 904
 905         for_each_online_node(node) {
 906                 unsigned long i;
 907
 908                 printk(KERN_DEBUG "Node %d Memory:", node);
 909
 910                 count = 0;
 911
 912                 for (i = 0; i < memblock_end_of_DRAM();
 913                      i += (1 << SECTION_SIZE_BITS)) {
 914                         if (early_pfn_to_nid(i >> PAGE_SHIFT) == node) {
 915                                 if (count == 0)
 916                                         printk(" 0x%lx", i);
 917                                 ++count;
 918                         } else {
 919                                 if (count > 0)
 920                                         printk("-0x%lx", i);
 921                                 count = 0;
 922                         }
 923                 }
 924
 925                 if (count > 0)
 926                         printk("-0x%lx", i);
 927                 printk("\n");
 928         }
 929 }
 930
 931 /*
 932  * Allocate some memory, satisfying the memblock or bootmem allocator where
 933  * required. nid is the preferred node and end is the physical address of
 934  * the highest address in the node.
 935  *
 936  * Returns the virtual address of the memory.
 937  */
 938 static void __init *careful_zallocation(int nid, unsigned long size,
 939                                        unsigned long align,
 940                                        unsigned long end_pfn)
 941 {
 942         void *ret;
 943         int new_nid;
 944         unsigned long ret_paddr;
 945
 946         ret_paddr = __memblock_alloc_base(size, align, end_pfn << PAGE_SHIFT);
 947
 948         /* retry over all memory */
 949         if (!ret_paddr)
 950                 ret_paddr = __memblock_alloc_base(size, align, memblock_end_of_DRAM());
 951
 952         if (!ret_paddr)
 953                 panic("numa.c: cannot allocate %lu bytes for node %d",
 954                       size, nid);
 955
 956         ret = __va(ret_paddr);
 957
 958         /*
 959          * We initialize the nodes in numeric order: 0, 1, 2...
 960          * and hand over control from the MEMBLOCK allocator to the
 961          * bootmem allocator.  If this function is called for
 962          * node 5, then we know that all nodes <5 are using the
 963          * bootmem allocator instead of the MEMBLOCK allocator.
 964          *
 965          * So, check the nid from which this allocation came
 966          * and double check to see if we need to use bootmem
 967          * instead of the MEMBLOCK.  We don't free the MEMBLOCK memory
 968          * since it would be useless.
 969          */
 970         new_nid = early_pfn_to_nid(ret_paddr >> PAGE_SHIFT);
 971         if (new_nid < nid) {
 972                 ret = __alloc_bootmem_node(NODE_DATA(new_nid),
 973                                 size, align, 0);
 974
 975                 dbg("alloc_bootmem %p %lx\n", ret, size);
 976         }
 977
 978         memset(ret, 0, size);
 979         return ret;
 980 }
 981
 982 static struct notifier_block ppc64_numa_nb = {
 983         .notifier_call = cpu_numa_callback,
 984         .priority = 1 /* Must run before sched domains notifier. */
 985 };
 986
 987 static void __init mark_reserved_regions_for_nid(int nid)
 988 {
 989         struct pglist_data *node = NODE_DATA(nid);
 990         struct memblock_region *reg;
 991
 992         for_each_memblock(reserved, reg) {
 993                 unsigned long physbase = reg->base;
 994                 unsigned long size = reg->size;
 995                 unsigned long start_pfn = physbase >> PAGE_SHIFT;
 996                 unsigned long end_pfn = PFN_UP(physbase + size);
 997                 struct node_active_region node_ar;
 998                 unsigned long node_end_pfn = pgdat_end_pfn(node);
 999
1000                 /*
1001                  * Check to make sure that this memblock.reserved area is
1002                  * within the bounds of the node that we care about.
1003                  * Checking the nid of the start and end points is not
1004                  * sufficient because the reserved area could span the
1005                  * entire node.
1006                  */
1007                 if (end_pfn <= node->node_start_pfn ||
1008                     start_pfn >= node_end_pfn)
1009                         continue;
1010
1011                 get_node_active_region(start_pfn, &node_ar);
1012                 while (start_pfn < end_pfn &&
1013                         node_ar.start_pfn < node_ar.end_pfn) {
1014                         unsigned long reserve_size = size;
1015                         /*
1016                          * if reserved region extends past active region
1017                          * then trim size to active region
1018                          */
1019                         if (end_pfn > node_ar.end_pfn)
1020                                 reserve_size = (node_ar.end_pfn << PAGE_SHIFT)
1021                                         - physbase;
1022                         /*
1023                          * Only worry about *this* node, others may not
1024                          * yet have valid NODE_DATA().
1025                          */
1026                         if (node_ar.nid == nid) {
1027                                 dbg("reserve_bootmem %lx %lx nid=%d\n",
1028                                         physbase, reserve_size, node_ar.nid);
1029                                 reserve_bootmem_node(NODE_DATA(node_ar.nid),
1030                                                 physbase, reserve_size,
1031                                                 BOOTMEM_DEFAULT);
1032                         }
1033                         /*
1034                          * if reserved region is contained in the active region
1035                          * then done.
1036                          */
1037                         if (end_pfn <= node_ar.end_pfn)
1038                                 break;
1039
1040                         /*
1041                          * reserved region extends past the active region
1042                          *   get next active region that contains this
1043                          *   reserved region
1044                          */
1045                         start_pfn = node_ar.end_pfn;
1046                         physbase = start_pfn << PAGE_SHIFT;
1047                         size = size - reserve_size;
1048                         get_node_active_region(start_pfn, &node_ar);
1049                 }
1050         }
1051 }
1052
1053
1054 void __init do_init_bootmem(void)
1055 {
1056         int nid, cpu;
1057
1058         min_low_pfn = 0;
1059         max_low_pfn = memblock_end_of_DRAM() >> PAGE_SHIFT;
1060         max_pfn = max_low_pfn;
1061
1062         if (parse_numa_properties())
1063                 setup_nonnuma();
1064         else
1065                 dump_numa_memory_topology();
1066
1067         for_each_online_node(nid) {
1068                 unsigned long start_pfn, end_pfn;
1069                 void *bootmem_vaddr;
1070                 unsigned long bootmap_pages;
1071
1072                 get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
1073
1074                 /*
1075                  * Allocate the node structure node local if possible
1076                  *
1077                  * Be careful moving this around, as it relies on all
1078                  * previous nodes' bootmem to be initialized and have
1079                  * all reserved areas marked.
1080                  */
1081                 NODE_DATA(nid) = careful_zallocation(nid,
1082                                         sizeof(struct pglist_data),
1083                                         SMP_CACHE_BYTES, end_pfn);
1084
1085                 dbg("node %d\n", nid);
1086                 dbg("NODE_DATA() = %p\n", NODE_DATA(nid));
1087
1088                 NODE_DATA(nid)->bdata = &bootmem_node_data[nid];
1089                 NODE_DATA(nid)->node_start_pfn = start_pfn;
1090                 NODE_DATA(nid)->node_spanned_pages = end_pfn - start_pfn;
1091
1092                 if (NODE_DATA(nid)->node_spanned_pages == 0)
1093                         continue;
1094
1095                 dbg("start_paddr = %lx\n", start_pfn << PAGE_SHIFT);
1096                 dbg("end_paddr = %lx\n", end_pfn << PAGE_SHIFT);
1097
1098                 bootmap_pages = bootmem_bootmap_pages(end_pfn - start_pfn);
1099                 bootmem_vaddr = careful_zallocation(nid,
1100                                         bootmap_pages << PAGE_SHIFT,
1101                                         PAGE_SIZE, end_pfn);
1102
1103                 dbg("bootmap_vaddr = %p\n", bootmem_vaddr);
1104
1105                 init_bootmem_node(NODE_DATA(nid),
1106                                   __pa(bootmem_vaddr) >> PAGE_SHIFT,
1107                                   start_pfn, end_pfn);
1108
1109                 free_bootmem_with_active_regions(nid, end_pfn);
1110                 /*
1111                  * Be very careful about moving this around.  Future
1112                  * calls to careful_zallocation() depend on this getting
1113                  * done correctly.
1114                  */
1115                 mark_reserved_regions_for_nid(nid);
1116                 sparse_memory_present_with_active_regions(nid);
1117         }
1118
1119         init_bootmem_done = 1;
1120
1121         /*
1122          * Now bootmem is initialised we can create the node to cpumask
1123          * lookup tables and setup the cpu callback to populate them.
1124          */
1125         setup_node_to_cpumask_map();
1126
1127         reset_numa_cpu_lookup_table();
1128         register_cpu_notifier(&ppc64_numa_nb);
1129         /*
1130          * We need the numa_cpu_lookup_table to be accurate for all CPUs,
1131          * even before we online them, so that we can use cpu_to_{node,mem}
1132          * early in boot, cf. smp_prepare_cpus().
1133          */
1134         for_each_present_cpu(cpu) {
1135                 numa_setup_cpu((unsigned long)cpu);
1136         }
1137 }
1138
1139 static int __init early_numa(char *p)
1140 {
1141         if (!p)
1142                 return 0;
1143
1144         if (strstr(p, "off"))
1145                 numa_enabled = 0;
1146
1147         if (strstr(p, "debug"))
1148                 numa_debug = 1;
1149
1150         p = strstr(p, "fake=");
1151         if (p)
1152                 cmdline = p + strlen("fake=");
1153
1154         return 0;
1155 }
1156 early_param("numa", early_numa);
1157
1158 static bool topology_updates_enabled = true;
1159
1160 static int __init early_topology_updates(char *p)
1161 {
1162         if (!p)
1163                 return 0;
1164
1165         if (!strcmp(p, "off")) {
1166                 pr_info("Disabling topology updates\n");
1167                 topology_updates_enabled = false;
1168         }
1169
1170         return 0;
1171 }
1172 early_param("topology_updates", early_topology_updates);
1173
1174 #ifdef CONFIG_MEMORY_HOTPLUG
1175 /*
1176  * Find the node associated with a hot added memory section for
1177  * memory represented in the device tree by the property
1178  * ibm,dynamic-reconfiguration-memory/ibm,dynamic-memory.
1179  */
1180 static int hot_add_drconf_scn_to_nid(struct device_node *memory,
1181                                      unsigned long scn_addr)
1182 {
1183         const __be32 *dm;
1184         unsigned int drconf_cell_cnt, rc;
1185         unsigned long lmb_size;
1186         struct assoc_arrays aa;
1187         int nid = -1;
1188
1189         drconf_cell_cnt = of_get_drconf_memory(memory, &dm);
1190         if (!drconf_cell_cnt)
1191                 return -1;
1192
1193         lmb_size = of_get_lmb_size(memory);
1194         if (!lmb_size)
1195                 return -1;
1196
1197         rc = of_get_assoc_arrays(memory, &aa);
1198         if (rc)
1199                 return -1;
1200
1201         for (; drconf_cell_cnt != 0; --drconf_cell_cnt) {
1202                 struct of_drconf_cell drmem;
1203
1204                 read_drconf_cell(&drmem, &dm);
1205
1206                 /* skip this block if it is reserved or not assigned to
1207                  * this partition */
1208                 if ((drmem.flags & DRCONF_MEM_RESERVED)
1209                     || !(drmem.flags & DRCONF_MEM_ASSIGNED))
1210                         continue;
1211
1212                 if ((scn_addr < drmem.base_addr)
1213                     || (scn_addr >= (drmem.base_addr + lmb_size)))
1214                         continue;
1215
1216                 nid = of_drconf_to_nid_single(&drmem, &aa);
1217                 break;
1218         }
1219
1220         return nid;
1221 }
1222
1223 /*
1224  * Find the node associated with a hot added memory section for memory
1225  * represented in the device tree as a node (i.e. memory@XXXX) for
1226  * each memblock.
1227  */
1228 static int hot_add_node_scn_to_nid(unsigned long scn_addr)
1229 {
1230         struct device_node *memory;
1231         int nid = -1;
1232
1233         for_each_node_by_type(memory, "memory") {
1234                 unsigned long start, size;
1235                 int ranges;
1236                 const __be32 *memcell_buf;
1237                 unsigned int len;
1238
1239                 memcell_buf = of_get_property(memory, "reg", &len);
1240                 if (!memcell_buf || len <= 0)
1241                         continue;
1242
1243                 /* ranges in cell */
1244                 ranges = (len >> 2) / (n_mem_addr_cells + n_mem_size_cells);
1245
1246                 while (ranges--) {
1247                         start = read_n_cells(n_mem_addr_cells, &memcell_buf);
1248                         size = read_n_cells(n_mem_size_cells, &memcell_buf);
1249
1250                         if ((scn_addr < start) || (scn_addr >= (start + size)))
1251                                 continue;
1252
1253                         nid = of_node_to_nid_single(memory);
1254                         break;
1255                 }
1256
1257                 if (nid >= 0)
1258                         break;
1259         }
1260
1261         of_node_put(memory);
1262
1263         return nid;
1264 }
1265
1266 /*
1267  * Find the node associated with a hot added memory section.  Section
1268  * corresponds to a SPARSEMEM section, not an MEMBLOCK.  It is assumed that
1269  * sections are fully contained within a single MEMBLOCK.
1270  */
1271 int hot_add_scn_to_nid(unsigned long scn_addr)
1272 {
1273         struct device_node *memory = NULL;
1274         int nid, found = 0;
1275
1276         if (!numa_enabled || (min_common_depth < 0))
1277                 return first_online_node;
1278
1279         memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
1280         if (memory) {
1281                 nid = hot_add_drconf_scn_to_nid(memory, scn_addr);
1282                 of_node_put(memory);
1283         } else {
1284                 nid = hot_add_node_scn_to_nid(scn_addr);
1285         }
1286
1287         if (nid < 0 || !node_online(nid))
1288                 nid = first_online_node;
1289
1290         if (NODE_DATA(nid)->node_spanned_pages)
1291                 return nid;
1292
1293         for_each_online_node(nid) {
1294                 if (NODE_DATA(nid)->node_spanned_pages) {
1295                         found = 1;
1296                         break;
1297                 }
1298         }
1299
1300         BUG_ON(!found);
1301         return nid;
1302 }
1303
1304 static u64 hot_add_drconf_memory_max(void)
1305 {
1306         struct device_node *memory = NULL;
1307         unsigned int drconf_cell_cnt = 0;
1308         u64 lmb_size = 0;
1309         const __be32 *dm = NULL;
1310
1311         memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
1312         if (memory) {
1313                 drconf_cell_cnt = of_get_drconf_memory(memory, &dm);
1314                 lmb_size = of_get_lmb_size(memory);
1315                 of_node_put(memory);
1316         }
1317         return lmb_size * drconf_cell_cnt;
1318 }
1319
1320 /*
1321  * memory_hotplug_max - return max address of memory that may be added
1322  *
1323  * This is currently only used on systems that support drconfig memory
1324  * hotplug.
1325  */
1326 u64 memory_hotplug_max(void)
1327 {
1328         return max(hot_add_drconf_memory_max(), memblock_end_of_DRAM());
1329 }
1330 #endif /* CONFIG_MEMORY_HOTPLUG */
1331
1332 /* Virtual Processor Home Node (VPHN) support */
1333 #ifdef CONFIG_PPC_SPLPAR
1334 struct topology_update_data {
1335         struct topology_update_data *next;
1336         unsigned int cpu;
1337         int old_nid;
1338         int new_nid;
1339 };
1340
1341 static u8 vphn_cpu_change_counts[NR_CPUS][MAX_DISTANCE_REF_POINTS];
1342 static cpumask_t cpu_associativity_changes_mask;
1343 static int vphn_enabled;
1344 static int prrn_enabled;
1345 static void reset_topology_timer(void);
1346
1347 /*
1348  * Store the current values of the associativity change counters in the
1349  * hypervisor.
1350  */
1351 static void setup_cpu_associativity_change_counters(void)
1352 {
1353         int cpu;
1354
1355         /* The VPHN feature supports a maximum of 8 reference points */
1356         BUILD_BUG_ON(MAX_DISTANCE_REF_POINTS > 8);
1357
1358         for_each_possible_cpu(cpu) {
1359                 int i;
1360                 u8 *counts = vphn_cpu_change_counts[cpu];
1361                 volatile u8 *hypervisor_counts = lppaca[cpu].vphn_assoc_counts;
1362
1363                 for (i = 0; i < distance_ref_points_depth; i++)
1364                         counts[i] = hypervisor_counts[i];
1365         }
1366 }
1367
1368 /*
1369  * The hypervisor maintains a set of 8 associativity change counters in
1370  * the VPA of each cpu that correspond to the associativity levels in the
1371  * ibm,associativity-reference-points property. When an associativity
1372  * level changes, the corresponding counter is incremented.
1373  *
1374  * Set a bit in cpu_associativity_changes_mask for each cpu whose home
1375  * node associativity levels have changed.
1376  *
1377  * Returns the number of cpus with unhandled associativity changes.
1378  */
1379 static int update_cpu_associativity_changes_mask(void)
1380 {
1381         int cpu;
1382         cpumask_t *changes = &cpu_associativity_changes_mask;
1383
1384         for_each_possible_cpu(cpu) {
1385                 int i, changed = 0;
1386                 u8 *counts = vphn_cpu_change_counts[cpu];
1387                 volatile u8 *hypervisor_counts = lppaca[cpu].vphn_assoc_counts;
1388
1389                 for (i = 0; i < distance_ref_points_depth; i++) {
1390                         if (hypervisor_counts[i] != counts[i]) {
1391                                 counts[i] = hypervisor_counts[i];
1392                                 changed = 1;
1393                         }
1394                 }
1395                 if (changed) {
1396                         cpumask_or(changes, changes, cpu_sibling_mask(cpu));
1397                         cpu = cpu_last_thread_sibling(cpu);
1398                 }
1399         }
1400
1401         return cpumask_weight(changes);
1402 }
1403
1404 /*
1405  * 6 64-bit registers unpacked into 12 32-bit associativity values. To form
1406  * the complete property we have to add the length in the first cell.
1407  */
1408 #define VPHN_ASSOC_BUFSIZE (6*sizeof(u64)/sizeof(u32) + 1)
1409
1410 /*
1411  * Convert the associativity domain numbers returned from the hypervisor
1412  * to the sequence they would appear in the ibm,associativity property.
1413  */
1414 static int vphn_unpack_associativity(const long *packed, __be32 *unpacked)
1415 {
1416         int i, nr_assoc_doms = 0;
1417         const __be16 *field = (const __be16 *) packed;
1418
1419 #define VPHN_FIELD_UNUSED       (0xffff)
1420 #define VPHN_FIELD_MSB          (0x8000)
1421 #define VPHN_FIELD_MASK         (~VPHN_FIELD_MSB)
1422
1423         for (i = 1; i < VPHN_ASSOC_BUFSIZE; i++) {
1424                 if (be16_to_cpup(field) == VPHN_FIELD_UNUSED) {
1425                         /* All significant fields processed, and remaining
1426                          * fields contain the reserved value of all 1's.
1427                          * Just store them.
1428                          */
1429                         unpacked[i] = *((__be32 *)field);
1430                         field += 2;
1431                 } else if (be16_to_cpup(field) & VPHN_FIELD_MSB) {
1432                         /* Data is in the lower 15 bits of this field */
1433                         unpacked[i] = cpu_to_be32(
1434                                 be16_to_cpup(field) & VPHN_FIELD_MASK);
1435                         field++;
1436                         nr_assoc_doms++;
1437                 } else {
1438                         /* Data is in the lower 15 bits of this field
1439                          * concatenated with the next 16 bit field
1440                          */
1441                         unpacked[i] = *((__be32 *)field);
1442                         field += 2;
1443                         nr_assoc_doms++;
1444                 }
1445         }
1446
1447         /* The first cell contains the length of the property */
1448         unpacked[0] = cpu_to_be32(nr_assoc_doms);
1449
1450         return nr_assoc_doms;
1451 }
1452
1453 /*
1454  * Retrieve the new associativity information for a virtual processor's
1455  * home node.
1456  */
1457 static long hcall_vphn(unsigned long cpu, __be32 *associativity)
1458 {
1459         long rc;
1460         long retbuf[PLPAR_HCALL9_BUFSIZE] = {0};
1461         u64 flags = 1;
1462         int hwcpu = get_hard_smp_processor_id(cpu);
1463         int i;
1464
1465         rc = plpar_hcall9(H_HOME_NODE_ASSOCIATIVITY, retbuf, flags, hwcpu);
1466         for (i = 0; i < 6; i++)
1467                 retbuf[i] = cpu_to_be64(retbuf[i]);
1468         vphn_unpack_associativity(retbuf, associativity);
1469
1470         return rc;
1471 }
1472
1473 static long vphn_get_associativity(unsigned long cpu,
1474                                         __be32 *associativity)
1475 {
1476         long rc;
1477
1478         rc = hcall_vphn(cpu, associativity);
1479
1480         switch (rc) {
1481         case H_FUNCTION:
1482                 printk(KERN_INFO
1483                         "VPHN is not supported. Disabling polling...\n");
1484                 stop_topology_update();
1485                 break;
1486         case H_HARDWARE:
1487                 printk(KERN_ERR
1488                         "hcall_vphn() experienced a hardware fault "
1489                         "preventing VPHN. Disabling polling...\n");
1490                 stop_topology_update();
1491         }
1492
1493         return rc;
1494 }
1495
1496 /*
1497  * Update the CPU maps and sysfs entries for a single CPU when its NUMA
1498  * characteristics change. This function doesn't perform any locking and is
1499  * only safe to call from stop_machine().
1500  */
1501 static int update_cpu_topology(void *data)
1502 {
1503         struct topology_update_data *update;
1504         unsigned long cpu;
1505
1506         if (!data)
1507                 return -EINVAL;
1508
1509         cpu = smp_processor_id();
1510
1511         for (update = data; update; update = update->next) {
1512                 int new_nid = update->new_nid;
1513                 if (cpu != update->cpu)
1514                         continue;
1515
1516                 unmap_cpu_from_node(cpu);
1517                 map_cpu_to_node(cpu, new_nid);
1518                 set_cpu_numa_node(cpu, new_nid);
1519                 set_cpu_numa_mem(cpu, local_memory_node(new_nid));
1520                 vdso_getcpu_init();
1521         }
1522
1523         return 0;
1524 }
1525
1526 static int update_lookup_table(void *data)
1527 {
1528         struct topology_update_data *update;
1529
1530         if (!data)
1531                 return -EINVAL;
1532
1533         /*
1534          * Upon topology update, the numa-cpu lookup table needs to be updated
1535          * for all threads in the core, including offline CPUs, to ensure that
1536          * future hotplug operations respect the cpu-to-node associativity
1537          * properly.
1538          */
1539         for (update = data; update; update = update->next) {
1540                 int nid, base, j;
1541
1542                 nid = update->new_nid;
1543                 base = cpu_first_thread_sibling(update->cpu);
1544
1545                 for (j = 0; j < threads_per_core; j++) {
1546                         update_numa_cpu_lookup_table(base + j, nid);
1547                 }
1548         }
1549
1550         return 0;
1551 }
1552
1553 /*
1554  * Update the node maps and sysfs entries for each cpu whose home node
1555  * has changed. Returns 1 when the topology has changed, and 0 otherwise.
1556  */
1557 int arch_update_cpu_topology(void)
1558 {
1559         unsigned int cpu, sibling, changed = 0;
1560         struct topology_update_data *updates, *ud;
1561         __be32 associativity[VPHN_ASSOC_BUFSIZE] = {0};
1562         cpumask_t updated_cpus;
1563         struct device *dev;
1564         int weight, new_nid, i = 0;
1565
1566         if (!prrn_enabled && !vphn_enabled)
1567                 return 0;
1568
1569         weight = cpumask_weight(&cpu_associativity_changes_mask);
1570         if (!weight)
1571                 return 0;
1572
1573         updates = kzalloc(weight * (sizeof(*updates)), GFP_KERNEL);
1574         if (!updates)
1575                 return 0;
1576
1577         cpumask_clear(&updated_cpus);
1578
1579         for_each_cpu(cpu, &cpu_associativity_changes_mask) {
1580                 /*
1581                  * If siblings aren't flagged for changes, updates list
1582                  * will be too short. Skip on this update and set for next
1583                  * update.
1584                  */
1585                 if (!cpumask_subset(cpu_sibling_mask(cpu),
1586                                         &cpu_associativity_changes_mask)) {
1587                         pr_info("Sibling bits not set for associativity "
1588                                         "change, cpu%d\n", cpu);
1589                         cpumask_or(&cpu_associativity_changes_mask,
1590                                         &cpu_associativity_changes_mask,
1591                                         cpu_sibling_mask(cpu));
1592                         cpu = cpu_last_thread_sibling(cpu);
1593                         continue;
1594                 }
1595
1596                 /* Use associativity from first thread for all siblings */
1597                 vphn_get_associativity(cpu, associativity);
1598                 new_nid = associativity_to_nid(associativity);
1599                 if (new_nid < 0 || !node_online(new_nid))
1600                         new_nid = first_online_node;
1601
1602                 if (new_nid == numa_cpu_lookup_table[cpu]) {
1603                         cpumask_andnot(&cpu_associativity_changes_mask,
1604                                         &cpu_associativity_changes_mask,
1605                                         cpu_sibling_mask(cpu));
1606                         cpu = cpu_last_thread_sibling(cpu);
1607                         continue;
1608                 }
1609
1610                 for_each_cpu(sibling, cpu_sibling_mask(cpu)) {
1611                         ud = &updates[i++];
1612                         ud->cpu = sibling;
1613                         ud->new_nid = new_nid;
1614                         ud->old_nid = numa_cpu_lookup_table[sibling];
1615                         cpumask_set_cpu(sibling, &updated_cpus);
1616                         if (i < weight)
1617                                 ud->next = &updates[i];
1618                 }
1619                 cpu = cpu_last_thread_sibling(cpu);
1620         }
1621
1622         pr_debug("Topology update for the following CPUs:\n");
1623         if (cpumask_weight(&updated_cpus)) {
1624                 for (ud = &updates[0]; ud; ud = ud->next) {
1625                         pr_debug("cpu %d moving from node %d "
1626                                           "to %d\n", ud->cpu,
1627                                           ud->old_nid, ud->new_nid);
1628                 }
1629         }
1630
1631         /*
1632          * In cases where we have nothing to update (because the updates list
1633          * is too short or because the new topology is same as the old one),
1634          * skip invoking update_cpu_topology() via stop-machine(). This is
1635          * necessary (and not just a fast-path optimization) since stop-machine
1636          * can end up electing a random CPU to run update_cpu_topology(), and
1637          * thus trick us into setting up incorrect cpu-node mappings (since
1638          * 'updates' is kzalloc()'ed).
1639          *
1640          * And for the similar reason, we will skip all the following updating.
1641          */
1642         if (!cpumask_weight(&updated_cpus))
1643                 goto out;
1644
1645         stop_machine(update_cpu_topology, &updates[0], &updated_cpus);
1646
1647         /*
1648          * Update the numa-cpu lookup table with the new mappings, even for
1649          * offline CPUs. It is best to perform this update from the stop-
1650          * machine context.
1651          */
1652         stop_machine(update_lookup_table, &updates[0],
1653                                         cpumask_of(raw_smp_processor_id()));
1654
1655         for (ud = &updates[0]; ud; ud = ud->next) {
1656                 unregister_cpu_under_node(ud->cpu, ud->old_nid);
1657                 register_cpu_under_node(ud->cpu, ud->new_nid);
1658
1659                 dev = get_cpu_device(ud->cpu);
1660                 if (dev)
1661                         kobject_uevent(&dev->kobj, KOBJ_CHANGE);
1662                 cpumask_clear_cpu(ud->cpu, &cpu_associativity_changes_mask);
1663                 changed = 1;
1664         }
1665
1666 out:
1667         kfree(updates);
1668         return changed;
1669 }
1670
1671 static void topology_work_fn(struct work_struct *work)
1672 {
1673         rebuild_sched_domains();
1674 }
1675 static DECLARE_WORK(topology_work, topology_work_fn);
1676
1677 static void topology_schedule_update(void)
1678 {
1679         schedule_work(&topology_work);
1680 }
1681
1682 static void topology_timer_fn(unsigned long ignored)
1683 {
1684         if (prrn_enabled && cpumask_weight(&cpu_associativity_changes_mask))
1685                 topology_schedule_update();
1686         else if (vphn_enabled) {
1687                 if (update_cpu_associativity_changes_mask() > 0)
1688                         topology_schedule_update();
1689                 reset_topology_timer();
1690         }
1691 }
1692 static struct timer_list topology_timer =
1693         TIMER_INITIALIZER(topology_timer_fn, 0, 0);
1694
1695 static void reset_topology_timer(void)
1696 {
1697         topology_timer.data = 0;
1698         topology_timer.expires = jiffies + 60 * HZ;
1699         mod_timer(&topology_timer, topology_timer.expires);
1700 }
1701
1702 #ifdef CONFIG_SMP
1703
1704 static void stage_topology_update(int core_id)
1705 {
1706         cpumask_or(&cpu_associativity_changes_mask,
1707                 &cpu_associativity_changes_mask, cpu_sibling_mask(core_id));
1708         reset_topology_timer();
1709 }
1710
1711 static int dt_update_callback(struct notifier_block *nb,
1712                                 unsigned long action, void *data)
1713 {
1714         struct of_prop_reconfig *update;
1715         int rc = NOTIFY_DONE;
1716
1717         switch (action) {
1718         case OF_RECONFIG_UPDATE_PROPERTY:
1719                 update = (struct of_prop_reconfig *)data;
1720                 if (!of_prop_cmp(update->dn->type, "cpu") &&
1721                     !of_prop_cmp(update->prop->name, "ibm,associativity")) {
1722                         u32 core_id;
1723                         of_property_read_u32(update->dn, "reg", &core_id);
1724                         stage_topology_update(core_id);
1725                         rc = NOTIFY_OK;
1726                 }
1727                 break;
1728         }
1729
1730         return rc;
1731 }
1732
1733 static struct notifier_block dt_update_nb = {
1734         .notifier_call = dt_update_callback,
1735 };
1736
1737 #endif
1738
1739 /*
1740  * Start polling for associativity changes.
1741  */
1742 int start_topology_update(void)
1743 {
1744         int rc = 0;
1745
1746         if (firmware_has_feature(FW_FEATURE_PRRN)) {
1747                 if (!prrn_enabled) {
1748                         prrn_enabled = 1;
1749                         vphn_enabled = 0;
1750 #ifdef CONFIG_SMP
1751                         rc = of_reconfig_notifier_register(&dt_update_nb);
1752 #endif
1753                 }
1754         } else if (firmware_has_feature(FW_FEATURE_VPHN) &&
1755                    lppaca_shared_proc(get_lppaca())) {
1756                 if (!vphn_enabled) {
1757                         prrn_enabled = 0;
1758                         vphn_enabled = 1;
1759                         setup_cpu_associativity_change_counters();
1760                         init_timer_deferrable(&topology_timer);
1761                         reset_topology_timer();
1762                 }
1763         }
1764
1765         return rc;
1766 }
1767
1768 /*
1769  * Disable polling for VPHN associativity changes.
1770  */
1771 int stop_topology_update(void)
1772 {
1773         int rc = 0;
1774
1775         if (prrn_enabled) {
1776                 prrn_enabled = 0;
1777 #ifdef CONFIG_SMP
1778                 rc = of_reconfig_notifier_unregister(&dt_update_nb);
1779 #endif
1780         } else if (vphn_enabled) {
1781                 vphn_enabled = 0;
1782                 rc = del_timer_sync(&topology_timer);
1783         }
1784
1785         return rc;
1786 }
1787
1788 int prrn_is_enabled(void)
1789 {
1790         return prrn_enabled;
1791 }
1792
1793 static int topology_read(struct seq_file *file, void *v)
1794 {
1795         if (vphn_enabled || prrn_enabled)
1796                 seq_puts(file, "on\n");
1797         else
1798                 seq_puts(file, "off\n");
1799
1800         return 0;
1801 }
1802
1803 static int topology_open(struct inode *inode, struct file *file)
1804 {
1805         return single_open(file, topology_read, NULL);
1806 }
1807
1808 static ssize_t topology_write(struct file *file, const char __user *buf,
1809                               size_t count, loff_t *off)
1810 {
1811         char kbuf[4]; /* "on" or "off" plus null. */
1812         int read_len;
1813
1814         read_len = count < 3 ? count : 3;
1815         if (copy_from_user(kbuf, buf, read_len))
1816                 return -EINVAL;
1817
1818         kbuf[read_len] = '\0';
1819
1820         if (!strncmp(kbuf, "on", 2))
1821                 start_topology_update();
1822         else if (!strncmp(kbuf, "off", 3))
1823                 stop_topology_update();
1824         else
1825                 return -EINVAL;
1826
1827         return count;
1828 }
1829
1830 static const struct file_operations topology_ops = {
1831         .read = seq_read,
1832         .write = topology_write,
1833         .open = topology_open,
1834         .release = single_release
1835 };
1836
1837 static int topology_update_init(void)
1838 {
1839         /* Do not poll for changes if disabled at boot */
1840         if (topology_updates_enabled)
1841                 start_topology_update();
1842
1843         if (!proc_create("powerpc/topology_updates", 0644, NULL, &topology_ops))
1844                 return -ENOMEM;
1845
1846         return 0;
1847 }
1848 device_initcall(topology_update_init);
1849 #endif /* CONFIG_PPC_SPLPAR */