arch/powerpc/mm/numa.c

/* [<][>][^][v][top][bottom][index][help] */
This source file includes following definitions.
setup_node_to_cpumask_map
fake_numa_create_new_node
reset_numa_cpu_lookup_table
map_cpu_to_node
unmap_cpu_from_node
cpu_distance
of_get_associativity
__node_distance
initialize_distance_lookup_table
associativity_to_nid
of_node_to_nid_single
of_node_to_nid
find_min_common_depth
get_n_mem_cells
read_n_cells
of_get_assoc_arrays
of_drconf_to_nid_single
numa_setup_cpu
verify_cpu_node_mapping
ppc_numa_cpu_prepare
ppc_numa_cpu_dead
numa_enforce_memory_limit
read_usm_ranges
numa_setup_drmem_lmb
parse_numa_properties
setup_nonnuma
dump_numa_cpu_topology
setup_node_data
find_possible_nodes
mem_topology_setup
initmem_init
early_numa
early_topology_updates
hot_add_drconf_scn_to_nid
hot_add_node_scn_to_nid
hot_add_scn_to_nid
hot_add_drconf_memory_max
memory_hotplug_max
timed_topology_update
setup_cpu_associativity_change_counters
update_cpu_associativity_changes_mask
vphn_get_associativity
find_and_online_cpu_nid
update_cpu_topology
update_lookup_table
numa_update_cpu_topology
arch_update_cpu_topology
topology_work_fn
topology_schedule_update
topology_timer_fn
reset_topology_timer
dt_update_callback
start_topology_update
stop_topology_update
prrn_is_enabled
shared_proc_topology_init
topology_read
topology_open
topology_write
topology_update_init
   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * pSeries NUMA support
   4  *
   5  * Copyright (C) 2002 Anton Blanchard <anton@au.ibm.com>, IBM
   6  */
   7 #define pr_fmt(fmt) "numa: " fmt
   8 
   9 #include <linux/threads.h>
  10 #include <linux/memblock.h>
  11 #include <linux/init.h>
  12 #include <linux/mm.h>
  13 #include <linux/mmzone.h>
  14 #include <linux/export.h>
  15 #include <linux/nodemask.h>
  16 #include <linux/cpu.h>
  17 #include <linux/notifier.h>
  18 #include <linux/of.h>
  19 #include <linux/pfn.h>
  20 #include <linux/cpuset.h>
  21 #include <linux/node.h>
  22 #include <linux/stop_machine.h>
  23 #include <linux/proc_fs.h>
  24 #include <linux/seq_file.h>
  25 #include <linux/uaccess.h>
  26 #include <linux/slab.h>
  27 #include <asm/cputhreads.h>
  28 #include <asm/sparsemem.h>
  29 #include <asm/prom.h>
  30 #include <asm/smp.h>
  31 #include <asm/topology.h>
  32 #include <asm/firmware.h>
  33 #include <asm/paca.h>
  34 #include <asm/hvcall.h>
  35 #include <asm/setup.h>
  36 #include <asm/vdso.h>
  37 #include <asm/drmem.h>
  38 
  39 static int numa_enabled = 1;
  40 
  41 static char *cmdline __initdata;
  42 
  43 static int numa_debug;
  44 #define dbg(args...) if (numa_debug) { printk(KERN_INFO args); }
  45 
  46 int numa_cpu_lookup_table[NR_CPUS];
  47 cpumask_var_t node_to_cpumask_map[MAX_NUMNODES];
  48 struct pglist_data *node_data[MAX_NUMNODES];
  49 
  50 EXPORT_SYMBOL(numa_cpu_lookup_table);
  51 EXPORT_SYMBOL(node_to_cpumask_map);
  52 EXPORT_SYMBOL(node_data);
  53 
  54 static int min_common_depth;
  55 static int n_mem_addr_cells, n_mem_size_cells;
  56 static int form1_affinity;
  57 
  58 #define MAX_DISTANCE_REF_POINTS 4
  59 static int distance_ref_points_depth;
  60 static const __be32 *distance_ref_points;
  61 static int distance_lookup_table[MAX_NUMNODES][MAX_DISTANCE_REF_POINTS];
  62 
  63 /*
  64  * Allocate node_to_cpumask_map based on number of available nodes
  65  * Requires node_possible_map to be valid.
  66  *
  67  * Note: cpumask_of_node() is not valid until after this is done.
  68  */
  69 static void __init setup_node_to_cpumask_map(void)
  70 {
  71         unsigned int node;
  72 
  73         /* setup nr_node_ids if not done yet */
  74         if (nr_node_ids == MAX_NUMNODES)
  75                 setup_nr_node_ids();
  76 
  77         /* allocate the map */
  78         for_each_node(node)
  79                 alloc_bootmem_cpumask_var(&node_to_cpumask_map[node]);
  80 
  81         /* cpumask_of_node() will now work */
  82         dbg("Node to cpumask map for %u nodes\n", nr_node_ids);
  83 }
  84 
  85 static int __init fake_numa_create_new_node(unsigned long end_pfn,
  86                                                 unsigned int *nid)
  87 {
  88         unsigned long long mem;
  89         char *p = cmdline;
  90         static unsigned int fake_nid;
  91         static unsigned long long curr_boundary;
  92 
  93         /*
  94          * Modify node id, iff we started creating NUMA nodes
  95          * We want to continue from where we left of the last time
  96          */
  97         if (fake_nid)
  98                 *nid = fake_nid;
  99         /*
 100          * In case there are no more arguments to parse, the
 101          * node_id should be the same as the last fake node id
 102          * (we've handled this above).
 103          */
 104         if (!p)
 105                 return 0;
 106 
 107         mem = memparse(p, &p);
 108         if (!mem)
 109                 return 0;
 110 
 111         if (mem < curr_boundary)
 112                 return 0;
 113 
 114         curr_boundary = mem;
 115 
 116         if ((end_pfn << PAGE_SHIFT) > mem) {
 117                 /*
 118                  * Skip commas and spaces
 119                  */
 120                 while (*p == ',' || *p == ' ' || *p == '\t')
 121                         p++;
 122 
 123                 cmdline = p;
 124                 fake_nid++;
 125                 *nid = fake_nid;
 126                 dbg("created new fake_node with id %d\n", fake_nid);
 127                 return 1;
 128         }
 129         return 0;
 130 }
 131 
 132 static void reset_numa_cpu_lookup_table(void)
 133 {
 134         unsigned int cpu;
 135 
 136         for_each_possible_cpu(cpu)
 137                 numa_cpu_lookup_table[cpu] = -1;
 138 }
 139 
 140 static void map_cpu_to_node(int cpu, int node)
 141 {
 142         update_numa_cpu_lookup_table(cpu, node);
 143 
 144         dbg("adding cpu %d to node %d\n", cpu, node);
 145 
 146         if (!(cpumask_test_cpu(cpu, node_to_cpumask_map[node])))
 147                 cpumask_set_cpu(cpu, node_to_cpumask_map[node]);
 148 }
 149 
 150 #if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_PPC_SPLPAR)
 151 static void unmap_cpu_from_node(unsigned long cpu)
 152 {
 153         int node = numa_cpu_lookup_table[cpu];
 154 
 155         dbg("removing cpu %lu from node %d\n", cpu, node);
 156 
 157         if (cpumask_test_cpu(cpu, node_to_cpumask_map[node])) {
 158                 cpumask_clear_cpu(cpu, node_to_cpumask_map[node]);
 159         } else {
 160                 printk(KERN_ERR "WARNING: cpu %lu not found in node %d\n",
 161                        cpu, node);
 162         }
 163 }
 164 #endif /* CONFIG_HOTPLUG_CPU || CONFIG_PPC_SPLPAR */
 165 
 166 int cpu_distance(__be32 *cpu1_assoc, __be32 *cpu2_assoc)
 167 {
 168         int dist = 0;
 169 
 170         int i, index;
 171 
 172         for (i = 0; i < distance_ref_points_depth; i++) {
 173                 index = be32_to_cpu(distance_ref_points[i]);
 174                 if (cpu1_assoc[index] == cpu2_assoc[index])
 175                         break;
 176                 dist++;
 177         }
 178 
 179         return dist;
 180 }
 181 
 182 /* must hold reference to node during call */
 183 static const __be32 *of_get_associativity(struct device_node *dev)
 184 {
 185         return of_get_property(dev, "ibm,associativity", NULL);
 186 }
 187 
 188 int __node_distance(int a, int b)
 189 {
 190         int i;
 191         int distance = LOCAL_DISTANCE;
 192 
 193         if (!form1_affinity)
 194                 return ((a == b) ? LOCAL_DISTANCE : REMOTE_DISTANCE);
 195 
 196         for (i = 0; i < distance_ref_points_depth; i++) {
 197                 if (distance_lookup_table[a][i] == distance_lookup_table[b][i])
 198                         break;
 199 
 200                 /* Double the distance for each NUMA level */
 201                 distance *= 2;
 202         }
 203 
 204         return distance;
 205 }
 206 EXPORT_SYMBOL(__node_distance);
 207 
 208 static void initialize_distance_lookup_table(int nid,
 209                 const __be32 *associativity)
 210 {
 211         int i;
 212 
 213         if (!form1_affinity)
 214                 return;
 215 
 216         for (i = 0; i < distance_ref_points_depth; i++) {
 217                 const __be32 *entry;
 218 
 219                 entry = &associativity[be32_to_cpu(distance_ref_points[i]) - 1];
 220                 distance_lookup_table[nid][i] = of_read_number(entry, 1);
 221         }
 222 }
 223 
 224 /* Returns nid in the range [0..MAX_NUMNODES-1], or -1 if no useful numa
 225  * info is found.
 226  */
 227 static int associativity_to_nid(const __be32 *associativity)
 228 {
 229         int nid = NUMA_NO_NODE;
 230 
 231         if (!numa_enabled)
 232                 goto out;
 233 
 234         if (of_read_number(associativity, 1) >= min_common_depth)
 235                 nid = of_read_number(&associativity[min_common_depth], 1);
 236 
 237         /* POWER4 LPAR uses 0xffff as invalid node */
 238         if (nid == 0xffff || nid >= MAX_NUMNODES)
 239                 nid = NUMA_NO_NODE;
 240 
 241         if (nid > 0 &&
 242                 of_read_number(associativity, 1) >= distance_ref_points_depth) {
 243                 /*
 244                  * Skip the length field and send start of associativity array
 245                  */
 246                 initialize_distance_lookup_table(nid, associativity + 1);
 247         }
 248 
 249 out:
 250         return nid;
 251 }
 252 
 253 /* Returns the nid associated with the given device tree node,
 254  * or -1 if not found.
 255  */
 256 static int of_node_to_nid_single(struct device_node *device)
 257 {
 258         int nid = NUMA_NO_NODE;
 259         const __be32 *tmp;
 260 
 261         tmp = of_get_associativity(device);
 262         if (tmp)
 263                 nid = associativity_to_nid(tmp);
 264         return nid;
 265 }
 266 
 267 /* Walk the device tree upwards, looking for an associativity id */
 268 int of_node_to_nid(struct device_node *device)
 269 {
 270         int nid = NUMA_NO_NODE;
 271 
 272         of_node_get(device);
 273         while (device) {
 274                 nid = of_node_to_nid_single(device);
 275                 if (nid != -1)
 276                         break;
 277 
 278                 device = of_get_next_parent(device);
 279         }
 280         of_node_put(device);
 281 
 282         return nid;
 283 }
 284 EXPORT_SYMBOL(of_node_to_nid);
 285 
 286 static int __init find_min_common_depth(void)
 287 {
 288         int depth;
 289         struct device_node *root;
 290 
 291         if (firmware_has_feature(FW_FEATURE_OPAL))
 292                 root = of_find_node_by_path("/ibm,opal");
 293         else
 294                 root = of_find_node_by_path("/rtas");
 295         if (!root)
 296                 root = of_find_node_by_path("/");
 297 
 298         /*
 299          * This property is a set of 32-bit integers, each representing
 300          * an index into the ibm,associativity nodes.
 301          *
 302          * With form 0 affinity the first integer is for an SMP configuration
 303          * (should be all 0's) and the second is for a normal NUMA
 304          * configuration. We have only one level of NUMA.
 305          *
 306          * With form 1 affinity the first integer is the most significant
 307          * NUMA boundary and the following are progressively less significant
 308          * boundaries. There can be more than one level of NUMA.
 309          */
 310         distance_ref_points = of_get_property(root,
 311                                         "ibm,associativity-reference-points",
 312                                         &distance_ref_points_depth);
 313 
 314         if (!distance_ref_points) {
 315                 dbg("NUMA: ibm,associativity-reference-points not found.\n");
 316                 goto err;
 317         }
 318 
 319         distance_ref_points_depth /= sizeof(int);
 320 
 321         if (firmware_has_feature(FW_FEATURE_OPAL) ||
 322             firmware_has_feature(FW_FEATURE_TYPE1_AFFINITY)) {
 323                 dbg("Using form 1 affinity\n");
 324                 form1_affinity = 1;
 325         }
 326 
 327         if (form1_affinity) {
 328                 depth = of_read_number(distance_ref_points, 1);
 329         } else {
 330                 if (distance_ref_points_depth < 2) {
 331                         printk(KERN_WARNING "NUMA: "
 332                                 "short ibm,associativity-reference-points\n");
 333                         goto err;
 334                 }
 335 
 336                 depth = of_read_number(&distance_ref_points[1], 1);
 337         }
 338 
 339         /*
 340          * Warn and cap if the hardware supports more than
 341          * MAX_DISTANCE_REF_POINTS domains.
 342          */
 343         if (distance_ref_points_depth > MAX_DISTANCE_REF_POINTS) {
 344                 printk(KERN_WARNING "NUMA: distance array capped at "
 345                         "%d entries\n", MAX_DISTANCE_REF_POINTS);
 346                 distance_ref_points_depth = MAX_DISTANCE_REF_POINTS;
 347         }
 348 
 349         of_node_put(root);
 350         return depth;
 351 
 352 err:
 353         of_node_put(root);
 354         return -1;
 355 }
 356 
 357 static void __init get_n_mem_cells(int *n_addr_cells, int *n_size_cells)
 358 {
 359         struct device_node *memory = NULL;
 360 
 361         memory = of_find_node_by_type(memory, "memory");
 362         if (!memory)
 363                 panic("numa.c: No memory nodes found!");
 364 
 365         *n_addr_cells = of_n_addr_cells(memory);
 366         *n_size_cells = of_n_size_cells(memory);
 367         of_node_put(memory);
 368 }
 369 
 370 static unsigned long read_n_cells(int n, const __be32 **buf)
 371 {
 372         unsigned long result = 0;
 373 
 374         while (n--) {
 375                 result = (result << 32) | of_read_number(*buf, 1);
 376                 (*buf)++;
 377         }
 378         return result;
 379 }
 380 
 381 struct assoc_arrays {
 382         u32     n_arrays;
 383         u32     array_sz;
 384         const __be32 *arrays;
 385 };
 386 
 387 /*
 388  * Retrieve and validate the list of associativity arrays for drconf
 389  * memory from the ibm,associativity-lookup-arrays property of the
 390  * device tree..
 391  *
 392  * The layout of the ibm,associativity-lookup-arrays property is a number N
 393  * indicating the number of associativity arrays, followed by a number M
 394  * indicating the size of each associativity array, followed by a list
 395  * of N associativity arrays.
 396  */
 397 static int of_get_assoc_arrays(struct assoc_arrays *aa)
 398 {
 399         struct device_node *memory;
 400         const __be32 *prop;
 401         u32 len;
 402 
 403         memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
 404         if (!memory)
 405                 return -1;
 406 
 407         prop = of_get_property(memory, "ibm,associativity-lookup-arrays", &len);
 408         if (!prop || len < 2 * sizeof(unsigned int)) {
 409                 of_node_put(memory);
 410                 return -1;
 411         }
 412 
 413         aa->n_arrays = of_read_number(prop++, 1);
 414         aa->array_sz = of_read_number(prop++, 1);
 415 
 416         of_node_put(memory);
 417 
 418         /* Now that we know the number of arrays and size of each array,
 419          * revalidate the size of the property read in.
 420          */
 421         if (len < (aa->n_arrays * aa->array_sz + 2) * sizeof(unsigned int))
 422                 return -1;
 423 
 424         aa->arrays = prop;
 425         return 0;
 426 }
 427 
 428 /*
 429  * This is like of_node_to_nid_single() for memory represented in the
 430  * ibm,dynamic-reconfiguration-memory node.
 431  */
 432 static int of_drconf_to_nid_single(struct drmem_lmb *lmb)
 433 {
 434         struct assoc_arrays aa = { .arrays = NULL };
 435         int default_nid = NUMA_NO_NODE;
 436         int nid = default_nid;
 437         int rc, index;
 438 
 439         if ((min_common_depth < 0) || !numa_enabled)
 440                 return default_nid;
 441 
 442         rc = of_get_assoc_arrays(&aa);
 443         if (rc)
 444                 return default_nid;
 445 
 446         if (min_common_depth <= aa.array_sz &&
 447             !(lmb->flags & DRCONF_MEM_AI_INVALID) && lmb->aa_index < aa.n_arrays) {
 448                 index = lmb->aa_index * aa.array_sz + min_common_depth - 1;
 449                 nid = of_read_number(&aa.arrays[index], 1);
 450 
 451                 if (nid == 0xffff || nid >= MAX_NUMNODES)
 452                         nid = default_nid;
 453 
 454                 if (nid > 0) {
 455                         index = lmb->aa_index * aa.array_sz;
 456                         initialize_distance_lookup_table(nid,
 457                                                         &aa.arrays[index]);
 458                 }
 459         }
 460 
 461         return nid;
 462 }
 463 
 464 /*
 465  * Figure out to which domain a cpu belongs and stick it there.
 466  * Return the id of the domain used.
 467  */
 468 static int numa_setup_cpu(unsigned long lcpu)
 469 {
 470         int nid = NUMA_NO_NODE;
 471         struct device_node *cpu;
 472 
 473         /*
 474          * If a valid cpu-to-node mapping is already available, use it
 475          * directly instead of querying the firmware, since it represents
 476          * the most recent mapping notified to us by the platform (eg: VPHN).
 477          */
 478         if ((nid = numa_cpu_lookup_table[lcpu]) >= 0) {
 479                 map_cpu_to_node(lcpu, nid);
 480                 return nid;
 481         }
 482 
 483         cpu = of_get_cpu_node(lcpu, NULL);
 484 
 485         if (!cpu) {
 486                 WARN_ON(1);
 487                 if (cpu_present(lcpu))
 488                         goto out_present;
 489                 else
 490                         goto out;
 491         }
 492 
 493         nid = of_node_to_nid_single(cpu);
 494 
 495 out_present:
 496         if (nid < 0 || !node_possible(nid))
 497                 nid = first_online_node;
 498 
 499         map_cpu_to_node(lcpu, nid);
 500         of_node_put(cpu);
 501 out:
 502         return nid;
 503 }
 504 
 505 static void verify_cpu_node_mapping(int cpu, int node)
 506 {
 507         int base, sibling, i;
 508 
 509         /* Verify that all the threads in the core belong to the same node */
 510         base = cpu_first_thread_sibling(cpu);
 511 
 512         for (i = 0; i < threads_per_core; i++) {
 513                 sibling = base + i;
 514 
 515                 if (sibling == cpu || cpu_is_offline(sibling))
 516                         continue;
 517 
 518                 if (cpu_to_node(sibling) != node) {
 519                         WARN(1, "CPU thread siblings %d and %d don't belong"
 520                                 " to the same node!\n", cpu, sibling);
 521                         break;
 522                 }
 523         }
 524 }
 525 
 526 /* Must run before sched domains notifier. */
 527 static int ppc_numa_cpu_prepare(unsigned int cpu)
 528 {
 529         int nid;
 530 
 531         nid = numa_setup_cpu(cpu);
 532         verify_cpu_node_mapping(cpu, nid);
 533         return 0;
 534 }
 535 
 536 static int ppc_numa_cpu_dead(unsigned int cpu)
 537 {
 538 #ifdef CONFIG_HOTPLUG_CPU
 539         unmap_cpu_from_node(cpu);
 540 #endif
 541         return 0;
 542 }
 543 
 544 /*
 545  * Check and possibly modify a memory region to enforce the memory limit.
 546  *
 547  * Returns the size the region should have to enforce the memory limit.
 548  * This will either be the original value of size, a truncated value,
 549  * or zero. If the returned value of size is 0 the region should be
 550  * discarded as it lies wholly above the memory limit.
 551  */
 552 static unsigned long __init numa_enforce_memory_limit(unsigned long start,
 553                                                       unsigned long size)
 554 {
 555         /*
 556          * We use memblock_end_of_DRAM() in here instead of memory_limit because
 557          * we've already adjusted it for the limit and it takes care of
 558          * having memory holes below the limit.  Also, in the case of
 559          * iommu_is_off, memory_limit is not set but is implicitly enforced.
 560          */
 561 
 562         if (start + size <= memblock_end_of_DRAM())
 563                 return size;
 564 
 565         if (start >= memblock_end_of_DRAM())
 566                 return 0;
 567 
 568         return memblock_end_of_DRAM() - start;
 569 }
 570 
 571 /*
 572  * Reads the counter for a given entry in
 573  * linux,drconf-usable-memory property
 574  */
 575 static inline int __init read_usm_ranges(const __be32 **usm)
 576 {
 577         /*
 578          * For each lmb in ibm,dynamic-memory a corresponding
 579          * entry in linux,drconf-usable-memory property contains
 580          * a counter followed by that many (base, size) duple.
 581          * read the counter from linux,drconf-usable-memory
 582          */
 583         return read_n_cells(n_mem_size_cells, usm);
 584 }
 585 
 586 /*
 587  * Extract NUMA information from the ibm,dynamic-reconfiguration-memory
 588  * node.  This assumes n_mem_{addr,size}_cells have been set.
 589  */
 590 static void __init numa_setup_drmem_lmb(struct drmem_lmb *lmb,
 591                                         const __be32 **usm)
 592 {
 593         unsigned int ranges, is_kexec_kdump = 0;
 594         unsigned long base, size, sz;
 595         int nid;
 596 
 597         /*
 598          * Skip this block if the reserved bit is set in flags (0x80)
 599          * or if the block is not assigned to this partition (0x8)
 600          */
 601         if ((lmb->flags & DRCONF_MEM_RESERVED)
 602             || !(lmb->flags & DRCONF_MEM_ASSIGNED))
 603                 return;
 604 
 605         if (*usm)
 606                 is_kexec_kdump = 1;
 607 
 608         base = lmb->base_addr;
 609         size = drmem_lmb_size();
 610         ranges = 1;
 611 
 612         if (is_kexec_kdump) {
 613                 ranges = read_usm_ranges(usm);
 614                 if (!ranges) /* there are no (base, size) duple */
 615                         return;
 616         }
 617 
 618         do {
 619                 if (is_kexec_kdump) {
 620                         base = read_n_cells(n_mem_addr_cells, usm);
 621                         size = read_n_cells(n_mem_size_cells, usm);
 622                 }
 623 
 624                 nid = of_drconf_to_nid_single(lmb);
 625                 fake_numa_create_new_node(((base + size) >> PAGE_SHIFT),
 626                                           &nid);
 627                 node_set_online(nid);
 628                 sz = numa_enforce_memory_limit(base, size);
 629                 if (sz)
 630                         memblock_set_node(base, sz, &memblock.memory, nid);
 631         } while (--ranges);
 632 }
 633 
 634 static int __init parse_numa_properties(void)
 635 {
 636         struct device_node *memory;
 637         int default_nid = 0;
 638         unsigned long i;
 639 
 640         if (numa_enabled == 0) {
 641                 printk(KERN_WARNING "NUMA disabled by user\n");
 642                 return -1;
 643         }
 644 
 645         min_common_depth = find_min_common_depth();
 646 
 647         if (min_common_depth < 0) {
 648                 /*
 649                  * if we fail to parse min_common_depth from device tree
 650                  * mark the numa disabled, boot with numa disabled.
 651                  */
 652                 numa_enabled = false;
 653                 return min_common_depth;
 654         }
 655 
 656         dbg("NUMA associativity depth for CPU/Memory: %d\n", min_common_depth);
 657 
 658         /*
 659          * Even though we connect cpus to numa domains later in SMP
 660          * init, we need to know the node ids now. This is because
 661          * each node to be onlined must have NODE_DATA etc backing it.
 662          */
 663         for_each_present_cpu(i) {
 664                 struct device_node *cpu;
 665                 int nid;
 666 
 667                 cpu = of_get_cpu_node(i, NULL);
 668                 BUG_ON(!cpu);
 669                 nid = of_node_to_nid_single(cpu);
 670                 of_node_put(cpu);
 671 
 672                 /*
 673                  * Don't fall back to default_nid yet -- we will plug
 674                  * cpus into nodes once the memory scan has discovered
 675                  * the topology.
 676                  */
 677                 if (nid < 0)
 678                         continue;
 679                 node_set_online(nid);
 680         }
 681 
 682         get_n_mem_cells(&n_mem_addr_cells, &n_mem_size_cells);
 683 
 684         for_each_node_by_type(memory, "memory") {
 685                 unsigned long start;
 686                 unsigned long size;
 687                 int nid;
 688                 int ranges;
 689                 const __be32 *memcell_buf;
 690                 unsigned int len;
 691 
 692                 memcell_buf = of_get_property(memory,
 693                         "linux,usable-memory", &len);
 694                 if (!memcell_buf || len <= 0)
 695                         memcell_buf = of_get_property(memory, "reg", &len);
 696                 if (!memcell_buf || len <= 0)
 697                         continue;
 698 
 699                 /* ranges in cell */
 700                 ranges = (len >> 2) / (n_mem_addr_cells + n_mem_size_cells);
 701 new_range:
 702                 /* these are order-sensitive, and modify the buffer pointer */
 703                 start = read_n_cells(n_mem_addr_cells, &memcell_buf);
 704                 size = read_n_cells(n_mem_size_cells, &memcell_buf);
 705 
 706                 /*
 707                  * Assumption: either all memory nodes or none will
 708                  * have associativity properties.  If none, then
 709                  * everything goes to default_nid.
 710                  */
 711                 nid = of_node_to_nid_single(memory);
 712                 if (nid < 0)
 713                         nid = default_nid;
 714 
 715                 fake_numa_create_new_node(((start + size) >> PAGE_SHIFT), &nid);
 716                 node_set_online(nid);
 717 
 718                 size = numa_enforce_memory_limit(start, size);
 719                 if (size)
 720                         memblock_set_node(start, size, &memblock.memory, nid);
 721 
 722                 if (--ranges)
 723                         goto new_range;
 724         }
 725 
 726         /*
 727          * Now do the same thing for each MEMBLOCK listed in the
 728          * ibm,dynamic-memory property in the
 729          * ibm,dynamic-reconfiguration-memory node.
 730          */
 731         memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
 732         if (memory) {
 733                 walk_drmem_lmbs(memory, numa_setup_drmem_lmb);
 734                 of_node_put(memory);
 735         }
 736 
 737         return 0;
 738 }
 739 
 740 static void __init setup_nonnuma(void)
 741 {
 742         unsigned long top_of_ram = memblock_end_of_DRAM();
 743         unsigned long total_ram = memblock_phys_mem_size();
 744         unsigned long start_pfn, end_pfn;
 745         unsigned int nid = 0;
 746         struct memblock_region *reg;
 747 
 748         printk(KERN_DEBUG "Top of RAM: 0x%lx, Total RAM: 0x%lx\n",
 749                top_of_ram, total_ram);
 750         printk(KERN_DEBUG "Memory hole size: %ldMB\n",
 751                (top_of_ram - total_ram) >> 20);
 752 
 753         for_each_memblock(memory, reg) {
 754                 start_pfn = memblock_region_memory_base_pfn(reg);
 755                 end_pfn = memblock_region_memory_end_pfn(reg);
 756 
 757                 fake_numa_create_new_node(end_pfn, &nid);
 758                 memblock_set_node(PFN_PHYS(start_pfn),
 759                                   PFN_PHYS(end_pfn - start_pfn),
 760                                   &memblock.memory, nid);
 761                 node_set_online(nid);
 762         }
 763 }
 764 
 765 void __init dump_numa_cpu_topology(void)
 766 {
 767         unsigned int node;
 768         unsigned int cpu, count;
 769 
 770         if (!numa_enabled)
 771                 return;
 772 
 773         for_each_online_node(node) {
 774                 pr_info("Node %d CPUs:", node);
 775 
 776                 count = 0;
 777                 /*
 778                  * If we used a CPU iterator here we would miss printing
 779                  * the holes in the cpumap.
 780                  */
 781                 for (cpu = 0; cpu < nr_cpu_ids; cpu++) {
 782                         if (cpumask_test_cpu(cpu,
 783                                         node_to_cpumask_map[node])) {
 784                                 if (count == 0)
 785                                         pr_cont(" %u", cpu);
 786                                 ++count;
 787                         } else {
 788                                 if (count > 1)
 789                                         pr_cont("-%u", cpu - 1);
 790                                 count = 0;
 791                         }
 792                 }
 793 
 794                 if (count > 1)
 795                         pr_cont("-%u", nr_cpu_ids - 1);
 796                 pr_cont("\n");
 797         }
 798 }
 799 
 800 /* Initialize NODE_DATA for a node on the local memory */
 801 static void __init setup_node_data(int nid, u64 start_pfn, u64 end_pfn)
 802 {
 803         u64 spanned_pages = end_pfn - start_pfn;
 804         const size_t nd_size = roundup(sizeof(pg_data_t), SMP_CACHE_BYTES);
 805         u64 nd_pa;
 806         void *nd;
 807         int tnid;
 808 
 809         nd_pa = memblock_phys_alloc_try_nid(nd_size, SMP_CACHE_BYTES, nid);
 810         if (!nd_pa)
 811                 panic("Cannot allocate %zu bytes for node %d data\n",
 812                       nd_size, nid);
 813 
 814         nd = __va(nd_pa);
 815 
 816         /* report and initialize */
 817         pr_info("  NODE_DATA [mem %#010Lx-%#010Lx]\n",
 818                 nd_pa, nd_pa + nd_size - 1);
 819         tnid = early_pfn_to_nid(nd_pa >> PAGE_SHIFT);
 820         if (tnid != nid)
 821                 pr_info("    NODE_DATA(%d) on node %d\n", nid, tnid);
 822 
 823         node_data[nid] = nd;
 824         memset(NODE_DATA(nid), 0, sizeof(pg_data_t));
 825         NODE_DATA(nid)->node_id = nid;
 826         NODE_DATA(nid)->node_start_pfn = start_pfn;
 827         NODE_DATA(nid)->node_spanned_pages = spanned_pages;
 828 }
 829 
 830 static void __init find_possible_nodes(void)
 831 {
 832         struct device_node *rtas;
 833         u32 numnodes, i;
 834 
 835         if (!numa_enabled)
 836                 return;
 837 
 838         rtas = of_find_node_by_path("/rtas");
 839         if (!rtas)
 840                 return;
 841 
 842         if (of_property_read_u32_index(rtas,
 843                                 "ibm,max-associativity-domains",
 844                                 min_common_depth, &numnodes))
 845                 goto out;
 846 
 847         for (i = 0; i < numnodes; i++) {
 848                 if (!node_possible(i))
 849                         node_set(i, node_possible_map);
 850         }
 851 
 852 out:
 853         of_node_put(rtas);
 854 }
 855 
 856 void __init mem_topology_setup(void)
 857 {
 858         int cpu;
 859 
 860         if (parse_numa_properties())
 861                 setup_nonnuma();
 862 
 863         /*
 864          * Modify the set of possible NUMA nodes to reflect information
 865          * available about the set of online nodes, and the set of nodes
 866          * that we expect to make use of for this platform's affinity
 867          * calculations.
 868          */
 869         nodes_and(node_possible_map, node_possible_map, node_online_map);
 870 
 871         find_possible_nodes();
 872 
 873         setup_node_to_cpumask_map();
 874 
 875         reset_numa_cpu_lookup_table();
 876 
 877         for_each_present_cpu(cpu)
 878                 numa_setup_cpu(cpu);
 879 }
 880 
 881 void __init initmem_init(void)
 882 {
 883         int nid;
 884 
 885         max_low_pfn = memblock_end_of_DRAM() >> PAGE_SHIFT;
 886         max_pfn = max_low_pfn;
 887 
 888         memblock_dump_all();
 889 
 890         for_each_online_node(nid) {
 891                 unsigned long start_pfn, end_pfn;
 892 
 893                 get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
 894                 setup_node_data(nid, start_pfn, end_pfn);
 895                 sparse_memory_present_with_active_regions(nid);
 896         }
 897 
 898         sparse_init();
 899 
 900         /*
 901          * We need the numa_cpu_lookup_table to be accurate for all CPUs,
 902          * even before we online them, so that we can use cpu_to_{node,mem}
 903          * early in boot, cf. smp_prepare_cpus().
 904          * _nocalls() + manual invocation is used because cpuhp is not yet
 905          * initialized for the boot CPU.
 906          */
 907         cpuhp_setup_state_nocalls(CPUHP_POWER_NUMA_PREPARE, "powerpc/numa:prepare",
 908                                   ppc_numa_cpu_prepare, ppc_numa_cpu_dead);
 909 }
 910 
 911 static int __init early_numa(char *p)
 912 {
 913         if (!p)
 914                 return 0;
 915 
 916         if (strstr(p, "off"))
 917                 numa_enabled = 0;
 918 
 919         if (strstr(p, "debug"))
 920                 numa_debug = 1;
 921 
 922         p = strstr(p, "fake=");
 923         if (p)
 924                 cmdline = p + strlen("fake=");
 925 
 926         return 0;
 927 }
 928 early_param("numa", early_numa);
 929 
 930 /*
 931  * The platform can inform us through one of several mechanisms
 932  * (post-migration device tree updates, PRRN or VPHN) that the NUMA
 933  * assignment of a resource has changed. This controls whether we act
 934  * on that. Disabled by default.
 935  */
 936 static bool topology_updates_enabled;
 937 
 938 static int __init early_topology_updates(char *p)
 939 {
 940         if (!p)
 941                 return 0;
 942 
 943         if (!strcmp(p, "on")) {
 944                 pr_warn("Caution: enabling topology updates\n");
 945                 topology_updates_enabled = true;
 946         }
 947 
 948         return 0;
 949 }
 950 early_param("topology_updates", early_topology_updates);
 951 
 952 #ifdef CONFIG_MEMORY_HOTPLUG
 953 /*
 954  * Find the node associated with a hot added memory section for
 955  * memory represented in the device tree by the property
 956  * ibm,dynamic-reconfiguration-memory/ibm,dynamic-memory.
 957  */
 958 static int hot_add_drconf_scn_to_nid(unsigned long scn_addr)
 959 {
 960         struct drmem_lmb *lmb;
 961         unsigned long lmb_size;
 962         int nid = NUMA_NO_NODE;
 963 
 964         lmb_size = drmem_lmb_size();
 965 
 966         for_each_drmem_lmb(lmb) {
 967                 /* skip this block if it is reserved or not assigned to
 968                  * this partition */
 969                 if ((lmb->flags & DRCONF_MEM_RESERVED)
 970                     || !(lmb->flags & DRCONF_MEM_ASSIGNED))
 971                         continue;
 972 
 973                 if ((scn_addr < lmb->base_addr)
 974                     || (scn_addr >= (lmb->base_addr + lmb_size)))
 975                         continue;
 976 
 977                 nid = of_drconf_to_nid_single(lmb);
 978                 break;
 979         }
 980 
 981         return nid;
 982 }
 983 
 984 /*
 985  * Find the node associated with a hot added memory section for memory
 986  * represented in the device tree as a node (i.e. memory@XXXX) for
 987  * each memblock.
 988  */
 989 static int hot_add_node_scn_to_nid(unsigned long scn_addr)
 990 {
 991         struct device_node *memory;
 992         int nid = NUMA_NO_NODE;
 993 
 994         for_each_node_by_type(memory, "memory") {
 995                 unsigned long start, size;
 996                 int ranges;
 997                 const __be32 *memcell_buf;
 998                 unsigned int len;
 999 
1000                 memcell_buf = of_get_property(memory, "reg", &len);
1001                 if (!memcell_buf || len <= 0)
1002                         continue;
1003 
1004                 /* ranges in cell */
1005                 ranges = (len >> 2) / (n_mem_addr_cells + n_mem_size_cells);
1006 
1007                 while (ranges--) {
1008                         start = read_n_cells(n_mem_addr_cells, &memcell_buf);
1009                         size = read_n_cells(n_mem_size_cells, &memcell_buf);
1010 
1011                         if ((scn_addr < start) || (scn_addr >= (start + size)))
1012                                 continue;
1013 
1014                         nid = of_node_to_nid_single(memory);
1015                         break;
1016                 }
1017 
1018                 if (nid >= 0)
1019                         break;
1020         }
1021 
1022         of_node_put(memory);
1023 
1024         return nid;
1025 }
1026 
1027 /*
1028  * Find the node associated with a hot added memory section.  Section
1029  * corresponds to a SPARSEMEM section, not an MEMBLOCK.  It is assumed that
1030  * sections are fully contained within a single MEMBLOCK.
1031  */
1032 int hot_add_scn_to_nid(unsigned long scn_addr)
1033 {
1034         struct device_node *memory = NULL;
1035         int nid;
1036 
1037         if (!numa_enabled)
1038                 return first_online_node;
1039 
1040         memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
1041         if (memory) {
1042                 nid = hot_add_drconf_scn_to_nid(scn_addr);
1043                 of_node_put(memory);
1044         } else {
1045                 nid = hot_add_node_scn_to_nid(scn_addr);
1046         }
1047 
1048         if (nid < 0 || !node_possible(nid))
1049                 nid = first_online_node;
1050 
1051         return nid;
1052 }
1053 
1054 static u64 hot_add_drconf_memory_max(void)
1055 {
1056         struct device_node *memory = NULL;
1057         struct device_node *dn = NULL;
1058         const __be64 *lrdr = NULL;
1059 
1060         dn = of_find_node_by_path("/rtas");
1061         if (dn) {
1062                 lrdr = of_get_property(dn, "ibm,lrdr-capacity", NULL);
1063                 of_node_put(dn);
1064                 if (lrdr)
1065                         return be64_to_cpup(lrdr);
1066         }
1067 
1068         memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
1069         if (memory) {
1070                 of_node_put(memory);
1071                 return drmem_lmb_memory_max();
1072         }
1073         return 0;
1074 }
1075 
1076 /*
1077  * memory_hotplug_max - return max address of memory that may be added
1078  *
1079  * This is currently only used on systems that support drconfig memory
1080  * hotplug.
1081  */
1082 u64 memory_hotplug_max(void)
1083 {
1084         return max(hot_add_drconf_memory_max(), memblock_end_of_DRAM());
1085 }
1086 #endif /* CONFIG_MEMORY_HOTPLUG */
1087 
1088 /* Virtual Processor Home Node (VPHN) support */
1089 #ifdef CONFIG_PPC_SPLPAR
1090 struct topology_update_data {
1091         struct topology_update_data *next;
1092         unsigned int cpu;
1093         int old_nid;
1094         int new_nid;
1095 };
1096 
1097 #define TOPOLOGY_DEF_TIMER_SECS 60
1098 
1099 static u8 vphn_cpu_change_counts[NR_CPUS][MAX_DISTANCE_REF_POINTS];
1100 static cpumask_t cpu_associativity_changes_mask;
1101 static int vphn_enabled;
1102 static int prrn_enabled;
1103 static void reset_topology_timer(void);
1104 static int topology_timer_secs = 1;
1105 static int topology_inited;
1106 
1107 /*
1108  * Change polling interval for associativity changes.
1109  */
1110 int timed_topology_update(int nsecs)
1111 {
1112         if (vphn_enabled) {
1113                 if (nsecs > 0)
1114                         topology_timer_secs = nsecs;
1115                 else
1116                         topology_timer_secs = TOPOLOGY_DEF_TIMER_SECS;
1117 
1118                 reset_topology_timer();
1119         }
1120 
1121         return 0;
1122 }
1123 
1124 /*
1125  * Store the current values of the associativity change counters in the
1126  * hypervisor.
1127  */
1128 static void setup_cpu_associativity_change_counters(void)
1129 {
1130         int cpu;
1131 
1132         /* The VPHN feature supports a maximum of 8 reference points */
1133         BUILD_BUG_ON(MAX_DISTANCE_REF_POINTS > 8);
1134 
1135         for_each_possible_cpu(cpu) {
1136                 int i;
1137                 u8 *counts = vphn_cpu_change_counts[cpu];
1138                 volatile u8 *hypervisor_counts = lppaca_of(cpu).vphn_assoc_counts;
1139 
1140                 for (i = 0; i < distance_ref_points_depth; i++)
1141                         counts[i] = hypervisor_counts[i];
1142         }
1143 }
1144 
1145 /*
1146  * The hypervisor maintains a set of 8 associativity change counters in
1147  * the VPA of each cpu that correspond to the associativity levels in the
1148  * ibm,associativity-reference-points property. When an associativity
1149  * level changes, the corresponding counter is incremented.
1150  *
1151  * Set a bit in cpu_associativity_changes_mask for each cpu whose home
1152  * node associativity levels have changed.
1153  *
1154  * Returns the number of cpus with unhandled associativity changes.
1155  */
1156 static int update_cpu_associativity_changes_mask(void)
1157 {
1158         int cpu;
1159         cpumask_t *changes = &cpu_associativity_changes_mask;
1160 
1161         for_each_possible_cpu(cpu) {
1162                 int i, changed = 0;
1163                 u8 *counts = vphn_cpu_change_counts[cpu];
1164                 volatile u8 *hypervisor_counts = lppaca_of(cpu).vphn_assoc_counts;
1165 
1166                 for (i = 0; i < distance_ref_points_depth; i++) {
1167                         if (hypervisor_counts[i] != counts[i]) {
1168                                 counts[i] = hypervisor_counts[i];
1169                                 changed = 1;
1170                         }
1171                 }
1172                 if (changed) {
1173                         cpumask_or(changes, changes, cpu_sibling_mask(cpu));
1174                         cpu = cpu_last_thread_sibling(cpu);
1175                 }
1176         }
1177 
1178         return cpumask_weight(changes);
1179 }
1180 
1181 /*
1182  * Retrieve the new associativity information for a virtual processor's
1183  * home node.
1184  */
1185 static long vphn_get_associativity(unsigned long cpu,
1186                                         __be32 *associativity)
1187 {
1188         long rc;
1189 
1190         rc = hcall_vphn(get_hard_smp_processor_id(cpu),
1191                                 VPHN_FLAG_VCPU, associativity);
1192 
1193         switch (rc) {
1194         case H_FUNCTION:
1195                 printk_once(KERN_INFO
1196                         "VPHN is not supported. Disabling polling...\n");
1197                 stop_topology_update();
1198                 break;
1199         case H_HARDWARE:
1200                 printk(KERN_ERR
1201                         "hcall_vphn() experienced a hardware fault "
1202                         "preventing VPHN. Disabling polling...\n");
1203                 stop_topology_update();
1204                 break;
1205         case H_SUCCESS:
1206                 dbg("VPHN hcall succeeded. Reset polling...\n");
1207                 timed_topology_update(0);
1208                 break;
1209         }
1210 
1211         return rc;
1212 }
1213 
1214 int find_and_online_cpu_nid(int cpu)
1215 {
1216         __be32 associativity[VPHN_ASSOC_BUFSIZE] = {0};
1217         int new_nid;
1218 
1219         /* Use associativity from first thread for all siblings */
1220         if (vphn_get_associativity(cpu, associativity))
1221                 return cpu_to_node(cpu);
1222 
1223         new_nid = associativity_to_nid(associativity);
1224         if (new_nid < 0 || !node_possible(new_nid))
1225                 new_nid = first_online_node;
1226 
1227         if (NODE_DATA(new_nid) == NULL) {
1228 #ifdef CONFIG_MEMORY_HOTPLUG
1229                 /*
1230                  * Need to ensure that NODE_DATA is initialized for a node from
1231                  * available memory (see memblock_alloc_try_nid). If unable to
1232                  * init the node, then default to nearest node that has memory
1233                  * installed. Skip onlining a node if the subsystems are not
1234                  * yet initialized.
1235                  */
1236                 if (!topology_inited || try_online_node(new_nid))
1237                         new_nid = first_online_node;
1238 #else
1239                 /*
1240                  * Default to using the nearest node that has memory installed.
1241                  * Otherwise, it would be necessary to patch the kernel MM code
1242                  * to deal with more memoryless-node error conditions.
1243                  */
1244                 new_nid = first_online_node;
1245 #endif
1246         }
1247 
1248         pr_debug("%s:%d cpu %d nid %d\n", __FUNCTION__, __LINE__,
1249                 cpu, new_nid);
1250         return new_nid;
1251 }
1252 
1253 /*
1254  * Update the CPU maps and sysfs entries for a single CPU when its NUMA
1255  * characteristics change. This function doesn't perform any locking and is
1256  * only safe to call from stop_machine().
1257  */
1258 static int update_cpu_topology(void *data)
1259 {
1260         struct topology_update_data *update;
1261         unsigned long cpu;
1262 
1263         if (!data)
1264                 return -EINVAL;
1265 
1266         cpu = smp_processor_id();
1267 
1268         for (update = data; update; update = update->next) {
1269                 int new_nid = update->new_nid;
1270                 if (cpu != update->cpu)
1271                         continue;
1272 
1273                 unmap_cpu_from_node(cpu);
1274                 map_cpu_to_node(cpu, new_nid);
1275                 set_cpu_numa_node(cpu, new_nid);
1276                 set_cpu_numa_mem(cpu, local_memory_node(new_nid));
1277                 vdso_getcpu_init();
1278         }
1279 
1280         return 0;
1281 }
1282 
1283 static int update_lookup_table(void *data)
1284 {
1285         struct topology_update_data *update;
1286 
1287         if (!data)
1288                 return -EINVAL;
1289 
1290         /*
1291          * Upon topology update, the numa-cpu lookup table needs to be updated
1292          * for all threads in the core, including offline CPUs, to ensure that
1293          * future hotplug operations respect the cpu-to-node associativity
1294          * properly.
1295          */
1296         for (update = data; update; update = update->next) {
1297                 int nid, base, j;
1298 
1299                 nid = update->new_nid;
1300                 base = cpu_first_thread_sibling(update->cpu);
1301 
1302                 for (j = 0; j < threads_per_core; j++) {
1303                         update_numa_cpu_lookup_table(base + j, nid);
1304                 }
1305         }
1306 
1307         return 0;
1308 }
1309 
1310 /*
1311  * Update the node maps and sysfs entries for each cpu whose home node
1312  * has changed. Returns 1 when the topology has changed, and 0 otherwise.
1313  *
1314  * cpus_locked says whether we already hold cpu_hotplug_lock.
1315  */
1316 int numa_update_cpu_topology(bool cpus_locked)
1317 {
1318         unsigned int cpu, sibling, changed = 0;
1319         struct topology_update_data *updates, *ud;
1320         cpumask_t updated_cpus;
1321         struct device *dev;
1322         int weight, new_nid, i = 0;
1323 
1324         if (!prrn_enabled && !vphn_enabled && topology_inited)
1325                 return 0;
1326 
1327         weight = cpumask_weight(&cpu_associativity_changes_mask);
1328         if (!weight)
1329                 return 0;
1330 
1331         updates = kcalloc(weight, sizeof(*updates), GFP_KERNEL);
1332         if (!updates)
1333                 return 0;
1334 
1335         cpumask_clear(&updated_cpus);
1336 
1337         for_each_cpu(cpu, &cpu_associativity_changes_mask) {
1338                 /*
1339                  * If siblings aren't flagged for changes, updates list
1340                  * will be too short. Skip on this update and set for next
1341                  * update.
1342                  */
1343                 if (!cpumask_subset(cpu_sibling_mask(cpu),
1344                                         &cpu_associativity_changes_mask)) {
1345                         pr_info("Sibling bits not set for associativity "
1346                                         "change, cpu%d\n", cpu);
1347                         cpumask_or(&cpu_associativity_changes_mask,
1348                                         &cpu_associativity_changes_mask,
1349                                         cpu_sibling_mask(cpu));
1350                         cpu = cpu_last_thread_sibling(cpu);
1351                         continue;
1352                 }
1353 
1354                 new_nid = find_and_online_cpu_nid(cpu);
1355 
1356                 if (new_nid == numa_cpu_lookup_table[cpu]) {
1357                         cpumask_andnot(&cpu_associativity_changes_mask,
1358                                         &cpu_associativity_changes_mask,
1359                                         cpu_sibling_mask(cpu));
1360                         dbg("Assoc chg gives same node %d for cpu%d\n",
1361                                         new_nid, cpu);
1362                         cpu = cpu_last_thread_sibling(cpu);
1363                         continue;
1364                 }
1365 
1366                 for_each_cpu(sibling, cpu_sibling_mask(cpu)) {
1367                         ud = &updates[i++];
1368                         ud->next = &updates[i];
1369                         ud->cpu = sibling;
1370                         ud->new_nid = new_nid;
1371                         ud->old_nid = numa_cpu_lookup_table[sibling];
1372                         cpumask_set_cpu(sibling, &updated_cpus);
1373                 }
1374                 cpu = cpu_last_thread_sibling(cpu);
1375         }
1376 
1377         /*
1378          * Prevent processing of 'updates' from overflowing array
1379          * where last entry filled in a 'next' pointer.
1380          */
1381         if (i)
1382                 updates[i-1].next = NULL;
1383 
1384         pr_debug("Topology update for the following CPUs:\n");
1385         if (cpumask_weight(&updated_cpus)) {
1386                 for (ud = &updates[0]; ud; ud = ud->next) {
1387                         pr_debug("cpu %d moving from node %d "
1388                                           "to %d\n", ud->cpu,
1389                                           ud->old_nid, ud->new_nid);
1390                 }
1391         }
1392 
1393         /*
1394          * In cases where we have nothing to update (because the updates list
1395          * is too short or because the new topology is same as the old one),
1396          * skip invoking update_cpu_topology() via stop-machine(). This is
1397          * necessary (and not just a fast-path optimization) since stop-machine
1398          * can end up electing a random CPU to run update_cpu_topology(), and
1399          * thus trick us into setting up incorrect cpu-node mappings (since
1400          * 'updates' is kzalloc()'ed).
1401          *
1402          * And for the similar reason, we will skip all the following updating.
1403          */
1404         if (!cpumask_weight(&updated_cpus))
1405                 goto out;
1406 
1407         if (cpus_locked)
1408                 stop_machine_cpuslocked(update_cpu_topology, &updates[0],
1409                                         &updated_cpus);
1410         else
1411                 stop_machine(update_cpu_topology, &updates[0], &updated_cpus);
1412 
1413         /*
1414          * Update the numa-cpu lookup table with the new mappings, even for
1415          * offline CPUs. It is best to perform this update from the stop-
1416          * machine context.
1417          */
1418         if (cpus_locked)
1419                 stop_machine_cpuslocked(update_lookup_table, &updates[0],
1420                                         cpumask_of(raw_smp_processor_id()));
1421         else
1422                 stop_machine(update_lookup_table, &updates[0],
1423                              cpumask_of(raw_smp_processor_id()));
1424 
1425         for (ud = &updates[0]; ud; ud = ud->next) {
1426                 unregister_cpu_under_node(ud->cpu, ud->old_nid);
1427                 register_cpu_under_node(ud->cpu, ud->new_nid);
1428 
1429                 dev = get_cpu_device(ud->cpu);
1430                 if (dev)
1431                         kobject_uevent(&dev->kobj, KOBJ_CHANGE);
1432                 cpumask_clear_cpu(ud->cpu, &cpu_associativity_changes_mask);
1433                 changed = 1;
1434         }
1435 
1436 out:
1437         kfree(updates);
1438         return changed;
1439 }
1440 
1441 int arch_update_cpu_topology(void)
1442 {
1443         return numa_update_cpu_topology(true);
1444 }
1445 
1446 static void topology_work_fn(struct work_struct *work)
1447 {
1448         rebuild_sched_domains();
1449 }
1450 static DECLARE_WORK(topology_work, topology_work_fn);
1451 
1452 static void topology_schedule_update(void)
1453 {
1454         schedule_work(&topology_work);
1455 }
1456 
1457 static void topology_timer_fn(struct timer_list *unused)
1458 {
1459         if (prrn_enabled && cpumask_weight(&cpu_associativity_changes_mask))
1460                 topology_schedule_update();
1461         else if (vphn_enabled) {
1462                 if (update_cpu_associativity_changes_mask() > 0)
1463                         topology_schedule_update();
1464                 reset_topology_timer();
1465         }
1466 }
1467 static struct timer_list topology_timer;
1468 
1469 static void reset_topology_timer(void)
1470 {
1471         if (vphn_enabled)
1472                 mod_timer(&topology_timer, jiffies + topology_timer_secs * HZ);
1473 }
1474 
1475 #ifdef CONFIG_SMP
1476 
1477 static int dt_update_callback(struct notifier_block *nb,
1478                                 unsigned long action, void *data)
1479 {
1480         struct of_reconfig_data *update = data;
1481         int rc = NOTIFY_DONE;
1482 
1483         switch (action) {
1484         case OF_RECONFIG_UPDATE_PROPERTY:
1485                 if (of_node_is_type(update->dn, "cpu") &&
1486                     !of_prop_cmp(update->prop->name, "ibm,associativity")) {
1487                         u32 core_id;
1488                         of_property_read_u32(update->dn, "reg", &core_id);
1489                         rc = dlpar_cpu_readd(core_id);
1490                         rc = NOTIFY_OK;
1491                 }
1492                 break;
1493         }
1494 
1495         return rc;
1496 }
1497 
1498 static struct notifier_block dt_update_nb = {
1499         .notifier_call = dt_update_callback,
1500 };
1501 
1502 #endif
1503 
1504 /*
1505  * Start polling for associativity changes.
1506  */
1507 int start_topology_update(void)
1508 {
1509         int rc = 0;
1510 
1511         if (!topology_updates_enabled)
1512                 return 0;
1513 
1514         if (firmware_has_feature(FW_FEATURE_PRRN)) {
1515                 if (!prrn_enabled) {
1516                         prrn_enabled = 1;
1517 #ifdef CONFIG_SMP
1518                         rc = of_reconfig_notifier_register(&dt_update_nb);
1519 #endif
1520                 }
1521         }
1522         if (firmware_has_feature(FW_FEATURE_VPHN) &&
1523                    lppaca_shared_proc(get_lppaca())) {
1524                 if (!vphn_enabled) {
1525                         vphn_enabled = 1;
1526                         setup_cpu_associativity_change_counters();
1527                         timer_setup(&topology_timer, topology_timer_fn,
1528                                     TIMER_DEFERRABLE);
1529                         reset_topology_timer();
1530                 }
1531         }
1532 
1533         pr_info("Starting topology update%s%s\n",
1534                 (prrn_enabled ? " prrn_enabled" : ""),
1535                 (vphn_enabled ? " vphn_enabled" : ""));
1536 
1537         return rc;
1538 }
1539 
1540 /*
1541  * Disable polling for VPHN associativity changes.
1542  */
1543 int stop_topology_update(void)
1544 {
1545         int rc = 0;
1546 
1547         if (!topology_updates_enabled)
1548                 return 0;
1549 
1550         if (prrn_enabled) {
1551                 prrn_enabled = 0;
1552 #ifdef CONFIG_SMP
1553                 rc = of_reconfig_notifier_unregister(&dt_update_nb);
1554 #endif
1555         }
1556         if (vphn_enabled) {
1557                 vphn_enabled = 0;
1558                 rc = del_timer_sync(&topology_timer);
1559         }
1560 
1561         pr_info("Stopping topology update\n");
1562 
1563         return rc;
1564 }
1565 
1566 int prrn_is_enabled(void)
1567 {
1568         return prrn_enabled;
1569 }
1570 
1571 void __init shared_proc_topology_init(void)
1572 {
1573         if (lppaca_shared_proc(get_lppaca())) {
1574                 bitmap_fill(cpumask_bits(&cpu_associativity_changes_mask),
1575                             nr_cpumask_bits);
1576                 numa_update_cpu_topology(false);
1577         }
1578 }
1579 
1580 static int topology_read(struct seq_file *file, void *v)
1581 {
1582         if (vphn_enabled || prrn_enabled)
1583                 seq_puts(file, "on\n");
1584         else
1585                 seq_puts(file, "off\n");
1586 
1587         return 0;
1588 }
1589 
1590 static int topology_open(struct inode *inode, struct file *file)
1591 {
1592         return single_open(file, topology_read, NULL);
1593 }
1594 
1595 static ssize_t topology_write(struct file *file, const char __user *buf,
1596                               size_t count, loff_t *off)
1597 {
1598         char kbuf[4]; /* "on" or "off" plus null. */
1599         int read_len;
1600 
1601         read_len = count < 3 ? count : 3;
1602         if (copy_from_user(kbuf, buf, read_len))
1603                 return -EINVAL;
1604 
1605         kbuf[read_len] = '\0';
1606 
1607         if (!strncmp(kbuf, "on", 2)) {
1608                 topology_updates_enabled = true;
1609                 start_topology_update();
1610         } else if (!strncmp(kbuf, "off", 3)) {
1611                 stop_topology_update();
1612                 topology_updates_enabled = false;
1613         } else
1614                 return -EINVAL;
1615 
1616         return count;
1617 }
1618 
1619 static const struct file_operations topology_ops = {
1620         .read = seq_read,
1621         .write = topology_write,
1622         .open = topology_open,
1623         .release = single_release
1624 };
1625 
1626 static int topology_update_init(void)
1627 {
1628         start_topology_update();
1629 
1630         if (vphn_enabled)
1631                 topology_schedule_update();
1632 
1633         if (!proc_create("powerpc/topology_updates", 0644, NULL, &topology_ops))
1634                 return -ENOMEM;
1635 
1636         topology_inited = 1;
1637         return 0;
1638 }
1639 device_initcall(topology_update_init);
1640 #endif /* CONFIG_PPC_SPLPAR */
/* [<][>][^][v][top][bottom][index][help] */
root/arch/powerpc/mm/numa.c

DEFINITIONS
