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