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