arch/x86/mm/numa_64.c

   1 /*
   2  * Generic VM initialization for x86-64 NUMA setups.
   3  * Copyright 2002,2003 Andi Kleen, SuSE Labs.
   4  */
   5 #include <linux/kernel.h>
   6 #include <linux/mm.h>
   7 #include <linux/string.h>
   8 #include <linux/init.h>
   9 #include <linux/bootmem.h>
  10 #include <linux/mmzone.h>
  11 #include <linux/ctype.h>
  12 #include <linux/module.h>
  13 #include <linux/nodemask.h>
  14 #include <linux/sched.h>
  15
  16 #include <asm/e820.h>
  17 #include <asm/proto.h>
  18 #include <asm/dma.h>
  19 #include <asm/numa.h>
  20 #include <asm/acpi.h>
  21 #include <asm/k8.h>
  22
  23 #ifdef CONFIG_DEBUG_PER_CPU_MAPS
  24 # define DBG(x...) printk(KERN_DEBUG x)
  25 #else
  26 # define DBG(x...)
  27 #endif
  28
  29 struct pglist_data *node_data[MAX_NUMNODES] __read_mostly;
  30 EXPORT_SYMBOL(node_data);
  31
  32 struct memnode memnode;
  33
  34 s16 apicid_to_node[MAX_LOCAL_APIC] __cpuinitdata = {
  35         [0 ... MAX_LOCAL_APIC-1] = NUMA_NO_NODE
  36 };
  37
  38 int numa_off __initdata;
  39 static unsigned long __initdata nodemap_addr;
  40 static unsigned long __initdata nodemap_size;
  41
  42 DEFINE_PER_CPU(int, node_number) = 0;
  43 EXPORT_PER_CPU_SYMBOL(node_number);
  44
  45 /*
  46  * Map cpu index to node index
  47  */
  48 DEFINE_EARLY_PER_CPU(int, x86_cpu_to_node_map, NUMA_NO_NODE);
  49 EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_node_map);
  50
  51 /*
  52  * Which logical CPUs are on which nodes
  53  */
  54 cpumask_t *node_to_cpumask_map;
  55 EXPORT_SYMBOL(node_to_cpumask_map);
  56
  57 /*
  58  * Given a shift value, try to populate memnodemap[]
  59  * Returns :
  60  * 1 if OK
  61  * 0 if memnodmap[] too small (of shift too small)
  62  * -1 if node overlap or lost ram (shift too big)
  63  */
  64 static int __init populate_memnodemap(const struct bootnode *nodes,
  65                                       int numnodes, int shift, int *nodeids)
  66 {
  67         unsigned long addr, end;
  68         int i, res = -1;
  69
  70         memset(memnodemap, 0xff, sizeof(s16)*memnodemapsize);
  71         for (i = 0; i < numnodes; i++) {
  72                 addr = nodes[i].start;
  73                 end = nodes[i].end;
  74                 if (addr >= end)
  75                         continue;
  76                 if ((end >> shift) >= memnodemapsize)
  77                         return 0;
  78                 do {
  79                         if (memnodemap[addr >> shift] != NUMA_NO_NODE)
  80                                 return -1;
  81
  82                         if (!nodeids)
  83                                 memnodemap[addr >> shift] = i;
  84                         else
  85                                 memnodemap[addr >> shift] = nodeids[i];
  86
  87                         addr += (1UL << shift);
  88                 } while (addr < end);
  89                 res = 1;
  90         }
  91         return res;
  92 }
  93
  94 static int __init allocate_cachealigned_memnodemap(void)
  95 {
  96         unsigned long addr;
  97
  98         memnodemap = memnode.embedded_map;
  99         if (memnodemapsize <= ARRAY_SIZE(memnode.embedded_map))
 100                 return 0;
 101
 102         addr = 0x8000;
 103         nodemap_size = roundup(sizeof(s16) * memnodemapsize, L1_CACHE_BYTES);
 104         nodemap_addr = find_e820_area(addr, max_pfn<<PAGE_SHIFT,
 105                                       nodemap_size, L1_CACHE_BYTES);
 106         if (nodemap_addr == -1UL) {
 107                 printk(KERN_ERR
 108                        "NUMA: Unable to allocate Memory to Node hash map\n");
 109                 nodemap_addr = nodemap_size = 0;
 110                 return -1;
 111         }
 112         memnodemap = phys_to_virt(nodemap_addr);
 113         reserve_early(nodemap_addr, nodemap_addr + nodemap_size, "MEMNODEMAP");
 114
 115         printk(KERN_DEBUG "NUMA: Allocated memnodemap from %lx - %lx\n",
 116                nodemap_addr, nodemap_addr + nodemap_size);
 117         return 0;
 118 }
 119
 120 /*
 121  * The LSB of all start and end addresses in the node map is the value of the
 122  * maximum possible shift.
 123  */
 124 static int __init extract_lsb_from_nodes(const struct bootnode *nodes,
 125                                          int numnodes)
 126 {
 127         int i, nodes_used = 0;
 128         unsigned long start, end;
 129         unsigned long bitfield = 0, memtop = 0;
 130
 131         for (i = 0; i < numnodes; i++) {
 132                 start = nodes[i].start;
 133                 end = nodes[i].end;
 134                 if (start >= end)
 135                         continue;
 136                 bitfield |= start;
 137                 nodes_used++;
 138                 if (end > memtop)
 139                         memtop = end;
 140         }
 141         if (nodes_used <= 1)
 142                 i = 63;
 143         else
 144                 i = find_first_bit(&bitfield, sizeof(unsigned long)*8);
 145         memnodemapsize = (memtop >> i)+1;
 146         return i;
 147 }
 148
 149 int __init compute_hash_shift(struct bootnode *nodes, int numnodes,
 150                               int *nodeids)
 151 {
 152         int shift;
 153
 154         shift = extract_lsb_from_nodes(nodes, numnodes);
 155         if (allocate_cachealigned_memnodemap())
 156                 return -1;
 157         printk(KERN_DEBUG "NUMA: Using %d for the hash shift.\n",
 158                 shift);
 159
 160         if (populate_memnodemap(nodes, numnodes, shift, nodeids) != 1) {
 161                 printk(KERN_INFO "Your memory is not aligned you need to "
 162                        "rebuild your kernel with a bigger NODEMAPSIZE "
 163                        "shift=%d\n", shift);
 164                 return -1;
 165         }
 166         return shift;
 167 }
 168
 169 int __meminit  __early_pfn_to_nid(unsigned long pfn)
 170 {
 171         return phys_to_nid(pfn << PAGE_SHIFT);
 172 }
 173
 174 static void * __init early_node_mem(int nodeid, unsigned long start,
 175                                     unsigned long end, unsigned long size,
 176                                     unsigned long align)
 177 {
 178         unsigned long mem = find_e820_area(start, end, size, align);
 179         void *ptr;
 180
 181         if (mem != -1L)
 182                 return __va(mem);
 183
 184         ptr = __alloc_bootmem_nopanic(size, align, __pa(MAX_DMA_ADDRESS));
 185         if (ptr == NULL) {
 186                 printk(KERN_ERR "Cannot find %lu bytes in node %d\n",
 187                        size, nodeid);
 188                 return NULL;
 189         }
 190         return ptr;
 191 }
 192
 193 /* Initialize bootmem allocator for a node */
 194 void __init setup_node_bootmem(int nodeid, unsigned long start,
 195                                unsigned long end)
 196 {
 197         unsigned long start_pfn, last_pfn, bootmap_pages, bootmap_size;
 198         unsigned long bootmap_start, nodedata_phys;
 199         void *bootmap;
 200         const int pgdat_size = roundup(sizeof(pg_data_t), PAGE_SIZE);
 201         int nid;
 202
 203         start = roundup(start, ZONE_ALIGN);
 204
 205         printk(KERN_INFO "Bootmem setup node %d %016lx-%016lx\n", nodeid,
 206                start, end);
 207
 208         start_pfn = start >> PAGE_SHIFT;
 209         last_pfn = end >> PAGE_SHIFT;
 210
 211         node_data[nodeid] = early_node_mem(nodeid, start, end, pgdat_size,
 212                                            SMP_CACHE_BYTES);
 213         if (node_data[nodeid] == NULL)
 214                 return;
 215         nodedata_phys = __pa(node_data[nodeid]);
 216         printk(KERN_INFO "  NODE_DATA [%016lx - %016lx]\n", nodedata_phys,
 217                 nodedata_phys + pgdat_size - 1);
 218
 219         memset(NODE_DATA(nodeid), 0, sizeof(pg_data_t));
 220         NODE_DATA(nodeid)->bdata = &bootmem_node_data[nodeid];
 221         NODE_DATA(nodeid)->node_start_pfn = start_pfn;
 222         NODE_DATA(nodeid)->node_spanned_pages = last_pfn - start_pfn;
 223
 224         /*
 225          * Find a place for the bootmem map
 226          * nodedata_phys could be on other nodes by alloc_bootmem,
 227          * so need to sure bootmap_start not to be small, otherwise
 228          * early_node_mem will get that with find_e820_area instead
 229          * of alloc_bootmem, that could clash with reserved range
 230          */
 231         bootmap_pages = bootmem_bootmap_pages(last_pfn - start_pfn);
 232         nid = phys_to_nid(nodedata_phys);
 233         if (nid == nodeid)
 234                 bootmap_start = roundup(nodedata_phys + pgdat_size, PAGE_SIZE);
 235         else
 236                 bootmap_start = roundup(start, PAGE_SIZE);
 237         /*
 238          * SMP_CACHE_BYTES could be enough, but init_bootmem_node like
 239          * to use that to align to PAGE_SIZE
 240          */
 241         bootmap = early_node_mem(nodeid, bootmap_start, end,
 242                                  bootmap_pages<<PAGE_SHIFT, PAGE_SIZE);
 243         if (bootmap == NULL)  {
 244                 if (nodedata_phys < start || nodedata_phys >= end)
 245                         free_bootmem(nodedata_phys, pgdat_size);
 246                 node_data[nodeid] = NULL;
 247                 return;
 248         }
 249         bootmap_start = __pa(bootmap);
 250
 251         bootmap_size = init_bootmem_node(NODE_DATA(nodeid),
 252                                          bootmap_start >> PAGE_SHIFT,
 253                                          start_pfn, last_pfn);
 254
 255         printk(KERN_INFO "  bootmap [%016lx -  %016lx] pages %lx\n",
 256                  bootmap_start, bootmap_start + bootmap_size - 1,
 257                  bootmap_pages);
 258
 259         free_bootmem_with_active_regions(nodeid, end);
 260
 261         /*
 262          * convert early reserve to bootmem reserve earlier
 263          * otherwise early_node_mem could use early reserved mem
 264          * on previous node
 265          */
 266         early_res_to_bootmem(start, end);
 267
 268         /*
 269          * in some case early_node_mem could use alloc_bootmem
 270          * to get range on other node, don't reserve that again
 271          */
 272         if (nid != nodeid)
 273                 printk(KERN_INFO "    NODE_DATA(%d) on node %d\n", nodeid, nid);
 274         else
 275                 reserve_bootmem_node(NODE_DATA(nodeid), nodedata_phys,
 276                                         pgdat_size, BOOTMEM_DEFAULT);
 277         nid = phys_to_nid(bootmap_start);
 278         if (nid != nodeid)
 279                 printk(KERN_INFO "    bootmap(%d) on node %d\n", nodeid, nid);
 280         else
 281                 reserve_bootmem_node(NODE_DATA(nodeid), bootmap_start,
 282                                  bootmap_pages<<PAGE_SHIFT, BOOTMEM_DEFAULT);
 283
 284 #ifdef CONFIG_ACPI_NUMA
 285         srat_reserve_add_area(nodeid);
 286 #endif
 287         node_set_online(nodeid);
 288 }
 289
 290 /*
 291  * There are unfortunately some poorly designed mainboards around that
 292  * only connect memory to a single CPU. This breaks the 1:1 cpu->node
 293  * mapping. To avoid this fill in the mapping for all possible CPUs,
 294  * as the number of CPUs is not known yet. We round robin the existing
 295  * nodes.
 296  */
 297 void __init numa_init_array(void)
 298 {
 299         int rr, i;
 300
 301         rr = first_node(node_online_map);
 302         for (i = 0; i < nr_cpu_ids; i++) {
 303                 if (early_cpu_to_node(i) != NUMA_NO_NODE)
 304                         continue;
 305                 numa_set_node(i, rr);
 306                 rr = next_node(rr, node_online_map);
 307                 if (rr == MAX_NUMNODES)
 308                         rr = first_node(node_online_map);
 309         }
 310 }
 311
 312 #ifdef CONFIG_NUMA_EMU
 313 /* Numa emulation */
 314 static char *cmdline __initdata;
 315
 316 /*
 317  * Setups up nid to range from addr to addr + size.  If the end
 318  * boundary is greater than max_addr, then max_addr is used instead.
 319  * The return value is 0 if there is additional memory left for
 320  * allocation past addr and -1 otherwise.  addr is adjusted to be at
 321  * the end of the node.
 322  */
 323 static int __init setup_node_range(int nid, struct bootnode *nodes, u64 *addr,
 324                                    u64 size, u64 max_addr)
 325 {
 326         int ret = 0;
 327
 328         nodes[nid].start = *addr;
 329         *addr += size;
 330         if (*addr >= max_addr) {
 331                 *addr = max_addr;
 332                 ret = -1;
 333         }
 334         nodes[nid].end = *addr;
 335         node_set(nid, node_possible_map);
 336         printk(KERN_INFO "Faking node %d at %016Lx-%016Lx (%LuMB)\n", nid,
 337                nodes[nid].start, nodes[nid].end,
 338                (nodes[nid].end - nodes[nid].start) >> 20);
 339         return ret;
 340 }
 341
 342 /*
 343  * Splits num_nodes nodes up equally starting at node_start.  The return value
 344  * is the number of nodes split up and addr is adjusted to be at the end of the
 345  * last node allocated.
 346  */
 347 static int __init split_nodes_equally(struct bootnode *nodes, u64 *addr,
 348                                       u64 max_addr, int node_start,
 349                                       int num_nodes)
 350 {
 351         unsigned int big;
 352         u64 size;
 353         int i;
 354
 355         if (num_nodes <= 0)
 356                 return -1;
 357         if (num_nodes > MAX_NUMNODES)
 358                 num_nodes = MAX_NUMNODES;
 359         size = (max_addr - *addr - e820_hole_size(*addr, max_addr)) /
 360                num_nodes;
 361         /*
 362          * Calculate the number of big nodes that can be allocated as a result
 363          * of consolidating the leftovers.
 364          */
 365         big = ((size & ~FAKE_NODE_MIN_HASH_MASK) * num_nodes) /
 366               FAKE_NODE_MIN_SIZE;
 367
 368         /* Round down to nearest FAKE_NODE_MIN_SIZE. */
 369         size &= FAKE_NODE_MIN_HASH_MASK;
 370         if (!size) {
 371                 printk(KERN_ERR "Not enough memory for each node.  "
 372                        "NUMA emulation disabled.\n");
 373                 return -1;
 374         }
 375
 376         for (i = node_start; i < num_nodes + node_start; i++) {
 377                 u64 end = *addr + size;
 378
 379                 if (i < big)
 380                         end += FAKE_NODE_MIN_SIZE;
 381                 /*
 382                  * The final node can have the remaining system RAM.  Other
 383                  * nodes receive roughly the same amount of available pages.
 384                  */
 385                 if (i == num_nodes + node_start - 1)
 386                         end = max_addr;
 387                 else
 388                         while (end - *addr - e820_hole_size(*addr, end) <
 389                                size) {
 390                                 end += FAKE_NODE_MIN_SIZE;
 391                                 if (end > max_addr) {
 392                                         end = max_addr;
 393                                         break;
 394                                 }
 395                         }
 396                 if (setup_node_range(i, nodes, addr, end - *addr, max_addr) < 0)
 397                         break;
 398         }
 399         return i - node_start + 1;
 400 }
 401
 402 /*
 403  * Splits the remaining system RAM into chunks of size.  The remaining memory is
 404  * always assigned to a final node and can be asymmetric.  Returns the number of
 405  * nodes split.
 406  */
 407 static int __init split_nodes_by_size(struct bootnode *nodes, u64 *addr,
 408                                       u64 max_addr, int node_start, u64 size)
 409 {
 410         int i = node_start;
 411         size = (size << 20) & FAKE_NODE_MIN_HASH_MASK;
 412         while (!setup_node_range(i++, nodes, addr, size, max_addr))
 413                 ;
 414         return i - node_start;
 415 }
 416
 417 /*
 418  * Sets up the system RAM area from start_pfn to last_pfn according to the
 419  * numa=fake command-line option.
 420  */
 421 static struct bootnode nodes[MAX_NUMNODES] __initdata;
 422
 423 static int __init numa_emulation(unsigned long start_pfn, unsigned long last_pfn)
 424 {
 425         u64 size, addr = start_pfn << PAGE_SHIFT;
 426         u64 max_addr = last_pfn << PAGE_SHIFT;
 427         int num_nodes = 0, num = 0, coeff_flag, coeff = -1, i;
 428
 429         memset(&nodes, 0, sizeof(nodes));
 430         /*
 431          * If the numa=fake command-line is just a single number N, split the
 432          * system RAM into N fake nodes.
 433          */
 434         if (!strchr(cmdline, '*') && !strchr(cmdline, ',')) {
 435                 long n = simple_strtol(cmdline, NULL, 0);
 436
 437                 num_nodes = split_nodes_equally(nodes, &addr, max_addr, 0, n);
 438                 if (num_nodes < 0)
 439                         return num_nodes;
 440                 goto out;
 441         }
 442
 443         /* Parse the command line. */
 444         for (coeff_flag = 0; ; cmdline++) {
 445                 if (*cmdline && isdigit(*cmdline)) {
 446                         num = num * 10 + *cmdline - '0';
 447                         continue;
 448                 }
 449                 if (*cmdline == '*') {
 450                         if (num > 0)
 451                                 coeff = num;
 452                         coeff_flag = 1;
 453                 }
 454                 if (!*cmdline || *cmdline == ',') {
 455                         if (!coeff_flag)
 456                                 coeff = 1;
 457                         /*
 458                          * Round down to the nearest FAKE_NODE_MIN_SIZE.
 459                          * Command-line coefficients are in megabytes.
 460                          */
 461                         size = ((u64)num << 20) & FAKE_NODE_MIN_HASH_MASK;
 462                         if (size)
 463                                 for (i = 0; i < coeff; i++, num_nodes++)
 464                                         if (setup_node_range(num_nodes, nodes,
 465                                                 &addr, size, max_addr) < 0)
 466                                                 goto done;
 467                         if (!*cmdline)
 468                                 break;
 469                         coeff_flag = 0;
 470                         coeff = -1;
 471                 }
 472                 num = 0;
 473         }
 474 done:
 475         if (!num_nodes)
 476                 return -1;
 477         /* Fill remainder of system RAM, if appropriate. */
 478         if (addr < max_addr) {
 479                 if (coeff_flag && coeff < 0) {
 480                         /* Split remaining nodes into num-sized chunks */
 481                         num_nodes += split_nodes_by_size(nodes, &addr, max_addr,
 482                                                          num_nodes, num);
 483                         goto out;
 484                 }
 485                 switch (*(cmdline - 1)) {
 486                 case '*':
 487                         /* Split remaining nodes into coeff chunks */
 488                         if (coeff <= 0)
 489                                 break;
 490                         num_nodes += split_nodes_equally(nodes, &addr, max_addr,
 491                                                          num_nodes, coeff);
 492                         break;
 493                 case ',':
 494                         /* Do not allocate remaining system RAM */
 495                         break;
 496                 default:
 497                         /* Give one final node */
 498                         setup_node_range(num_nodes, nodes, &addr,
 499                                          max_addr - addr, max_addr);
 500                         num_nodes++;
 501                 }
 502         }
 503 out:
 504         memnode_shift = compute_hash_shift(nodes, num_nodes, NULL);
 505         if (memnode_shift < 0) {
 506                 memnode_shift = 0;
 507                 printk(KERN_ERR "No NUMA hash function found.  NUMA emulation "
 508                        "disabled.\n");
 509                 return -1;
 510         }
 511
 512         /*
 513          * We need to vacate all active ranges that may have been registered by
 514          * SRAT and set acpi_numa to -1 so that srat_disabled() always returns
 515          * true.  NUMA emulation has succeeded so we will not scan ACPI nodes.
 516          */
 517         remove_all_active_ranges();
 518 #ifdef CONFIG_ACPI_NUMA
 519         acpi_numa = -1;
 520 #endif
 521         for_each_node_mask(i, node_possible_map) {
 522                 e820_register_active_regions(i, nodes[i].start >> PAGE_SHIFT,
 523                                                 nodes[i].end >> PAGE_SHIFT);
 524                 setup_node_bootmem(i, nodes[i].start, nodes[i].end);
 525         }
 526         acpi_fake_nodes(nodes, num_nodes);
 527         numa_init_array();
 528         return 0;
 529 }
 530 #endif /* CONFIG_NUMA_EMU */
 531
 532 void __init initmem_init(unsigned long start_pfn, unsigned long last_pfn)
 533 {
 534         int i;
 535
 536         nodes_clear(node_possible_map);
 537         nodes_clear(node_online_map);
 538
 539 #ifdef CONFIG_NUMA_EMU
 540         if (cmdline && !numa_emulation(start_pfn, last_pfn))
 541                 return;
 542         nodes_clear(node_possible_map);
 543         nodes_clear(node_online_map);
 544 #endif
 545
 546 #ifdef CONFIG_ACPI_NUMA
 547         if (!numa_off && !acpi_scan_nodes(start_pfn << PAGE_SHIFT,
 548                                           last_pfn << PAGE_SHIFT))
 549                 return;
 550         nodes_clear(node_possible_map);
 551         nodes_clear(node_online_map);
 552 #endif
 553
 554 #ifdef CONFIG_K8_NUMA
 555         if (!numa_off && !k8_scan_nodes(start_pfn<<PAGE_SHIFT,
 556                                         last_pfn<<PAGE_SHIFT))
 557                 return;
 558         nodes_clear(node_possible_map);
 559         nodes_clear(node_online_map);
 560 #endif
 561         printk(KERN_INFO "%s\n",
 562                numa_off ? "NUMA turned off" : "No NUMA configuration found");
 563
 564         printk(KERN_INFO "Faking a node at %016lx-%016lx\n",
 565                start_pfn << PAGE_SHIFT,
 566                last_pfn << PAGE_SHIFT);
 567         /* setup dummy node covering all memory */
 568         memnode_shift = 63;
 569         memnodemap = memnode.embedded_map;
 570         memnodemap[0] = 0;
 571         node_set_online(0);
 572         node_set(0, node_possible_map);
 573         for (i = 0; i < nr_cpu_ids; i++)
 574                 numa_set_node(i, 0);
 575         e820_register_active_regions(0, start_pfn, last_pfn);
 576         setup_node_bootmem(0, start_pfn << PAGE_SHIFT, last_pfn << PAGE_SHIFT);
 577 }
 578
 579 unsigned long __init numa_free_all_bootmem(void)
 580 {
 581         unsigned long pages = 0;
 582         int i;
 583
 584         for_each_online_node(i)
 585                 pages += free_all_bootmem_node(NODE_DATA(i));
 586
 587         return pages;
 588 }
 589
 590 void __init paging_init(void)
 591 {
 592         unsigned long max_zone_pfns[MAX_NR_ZONES];
 593
 594         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 595         max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
 596         max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
 597         max_zone_pfns[ZONE_NORMAL] = max_pfn;
 598
 599         sparse_memory_present_with_active_regions(MAX_NUMNODES);
 600         sparse_init();
 601
 602         free_area_init_nodes(max_zone_pfns);
 603 }
 604
 605 static __init int numa_setup(char *opt)
 606 {
 607         if (!opt)
 608                 return -EINVAL;
 609         if (!strncmp(opt, "off", 3))
 610                 numa_off = 1;
 611 #ifdef CONFIG_NUMA_EMU
 612         if (!strncmp(opt, "fake=", 5))
 613                 cmdline = opt + 5;
 614 #endif
 615 #ifdef CONFIG_ACPI_NUMA
 616         if (!strncmp(opt, "noacpi", 6))
 617                 acpi_numa = -1;
 618         if (!strncmp(opt, "hotadd=", 7))
 619                 hotadd_percent = simple_strtoul(opt+7, NULL, 10);
 620 #endif
 621         return 0;
 622 }
 623 early_param("numa", numa_setup);
 624
 625 #ifdef CONFIG_NUMA
 626 /*
 627  * Setup early cpu_to_node.
 628  *
 629  * Populate cpu_to_node[] only if x86_cpu_to_apicid[],
 630  * and apicid_to_node[] tables have valid entries for a CPU.
 631  * This means we skip cpu_to_node[] initialisation for NUMA
 632  * emulation and faking node case (when running a kernel compiled
 633  * for NUMA on a non NUMA box), which is OK as cpu_to_node[]
 634  * is already initialized in a round robin manner at numa_init_array,
 635  * prior to this call, and this initialization is good enough
 636  * for the fake NUMA cases.
 637  *
 638  * Called before the per_cpu areas are setup.
 639  */
 640 void __init init_cpu_to_node(void)
 641 {
 642         int cpu;
 643         u16 *cpu_to_apicid = early_per_cpu_ptr(x86_cpu_to_apicid);
 644
 645         BUG_ON(cpu_to_apicid == NULL);
 646
 647         for_each_possible_cpu(cpu) {
 648                 int node;
 649                 u16 apicid = cpu_to_apicid[cpu];
 650
 651                 if (apicid == BAD_APICID)
 652                         continue;
 653                 node = apicid_to_node[apicid];
 654                 if (node == NUMA_NO_NODE)
 655                         continue;
 656                 if (!node_online(node))
 657                         continue;
 658                 numa_set_node(cpu, node);
 659         }
 660 }
 661 #endif
 662
 663
 664 /*
 665  * Allocate node_to_cpumask_map based on number of available nodes
 666  * Requires node_possible_map to be valid.
 667  *
 668  * Note: node_to_cpumask() is not valid until after this is done.
 669  * (Use CONFIG_DEBUG_PER_CPU_MAPS to check this.)
 670  */
 671 void __init setup_node_to_cpumask_map(void)
 672 {
 673         unsigned int node, num = 0;
 674         cpumask_t *map;
 675
 676         /* setup nr_node_ids if not done yet */
 677         if (nr_node_ids == MAX_NUMNODES) {
 678                 for_each_node_mask(node, node_possible_map)
 679                         num = node;
 680                 nr_node_ids = num + 1;
 681         }
 682
 683         /* allocate the map */
 684         map = alloc_bootmem_low(nr_node_ids * sizeof(cpumask_t));
 685         DBG("node_to_cpumask_map at %p for %d nodes\n", map, nr_node_ids);
 686
 687         pr_debug("Node to cpumask map at %p for %d nodes\n",
 688                  map, nr_node_ids);
 689
 690         /* node_to_cpumask() will now work */
 691         node_to_cpumask_map = map;
 692 }
 693
 694 void __cpuinit numa_set_node(int cpu, int node)
 695 {
 696         int *cpu_to_node_map = early_per_cpu_ptr(x86_cpu_to_node_map);
 697
 698         /* early setting, no percpu area yet */
 699         if (cpu_to_node_map) {
 700                 cpu_to_node_map[cpu] = node;
 701                 return;
 702         }
 703
 704 #ifdef CONFIG_DEBUG_PER_CPU_MAPS
 705         if (cpu >= nr_cpu_ids || !cpu_possible(cpu)) {
 706                 printk(KERN_ERR "numa_set_node: invalid cpu# (%d)\n", cpu);
 707                 dump_stack();
 708                 return;
 709         }
 710 #endif
 711         per_cpu(x86_cpu_to_node_map, cpu) = node;
 712
 713         if (node != NUMA_NO_NODE)
 714                 per_cpu(node_number, cpu) = node;
 715 }
 716
 717 void __cpuinit numa_clear_node(int cpu)
 718 {
 719         numa_set_node(cpu, NUMA_NO_NODE);
 720 }
 721
 722 #ifndef CONFIG_DEBUG_PER_CPU_MAPS
 723
 724 void __cpuinit numa_add_cpu(int cpu)
 725 {
 726         cpu_set(cpu, node_to_cpumask_map[early_cpu_to_node(cpu)]);
 727 }
 728
 729 void __cpuinit numa_remove_cpu(int cpu)
 730 {
 731         cpu_clear(cpu, node_to_cpumask_map[early_cpu_to_node(cpu)]);
 732 }
 733
 734 #else /* CONFIG_DEBUG_PER_CPU_MAPS */
 735
 736 /*
 737  * --------- debug versions of the numa functions ---------
 738  */
 739 static void __cpuinit numa_set_cpumask(int cpu, int enable)
 740 {
 741         int node = early_cpu_to_node(cpu);
 742         cpumask_t *mask;
 743         char buf[64];
 744
 745         if (node_to_cpumask_map == NULL) {
 746                 printk(KERN_ERR "node_to_cpumask_map NULL\n");
 747                 dump_stack();
 748                 return;
 749         }
 750
 751         mask = &node_to_cpumask_map[node];
 752         if (enable)
 753                 cpu_set(cpu, *mask);
 754         else
 755                 cpu_clear(cpu, *mask);
 756
 757         cpulist_scnprintf(buf, sizeof(buf), mask);
 758         printk(KERN_DEBUG "%s cpu %d node %d: mask now %s\n",
 759                 enable ? "numa_add_cpu" : "numa_remove_cpu", cpu, node, buf);
 760 }
 761
 762 void __cpuinit numa_add_cpu(int cpu)
 763 {
 764         numa_set_cpumask(cpu, 1);
 765 }
 766
 767 void __cpuinit numa_remove_cpu(int cpu)
 768 {
 769         numa_set_cpumask(cpu, 0);
 770 }
 771
 772 int cpu_to_node(int cpu)
 773 {
 774         if (early_per_cpu_ptr(x86_cpu_to_node_map)) {
 775                 printk(KERN_WARNING
 776                         "cpu_to_node(%d): usage too early!\n", cpu);
 777                 dump_stack();
 778                 return early_per_cpu_ptr(x86_cpu_to_node_map)[cpu];
 779         }
 780         return per_cpu(x86_cpu_to_node_map, cpu);
 781 }
 782 EXPORT_SYMBOL(cpu_to_node);
 783
 784 /*
 785  * Same function as cpu_to_node() but used if called before the
 786  * per_cpu areas are setup.
 787  */
 788 int early_cpu_to_node(int cpu)
 789 {
 790         if (early_per_cpu_ptr(x86_cpu_to_node_map))
 791                 return early_per_cpu_ptr(x86_cpu_to_node_map)[cpu];
 792
 793         if (!cpu_possible(cpu)) {
 794                 printk(KERN_WARNING
 795                         "early_cpu_to_node(%d): no per_cpu area!\n", cpu);
 796                 dump_stack();
 797                 return NUMA_NO_NODE;
 798         }
 799         return per_cpu(x86_cpu_to_node_map, cpu);
 800 }
 801
 802
 803 /* empty cpumask */
 804 static const cpumask_t cpu_mask_none;
 805
 806 /*
 807  * Returns a pointer to the bitmask of CPUs on Node 'node'.
 808  */
 809 const cpumask_t *cpumask_of_node(int node)
 810 {
 811         if (node_to_cpumask_map == NULL) {
 812                 printk(KERN_WARNING
 813                         "cpumask_of_node(%d): no node_to_cpumask_map!\n",
 814                         node);
 815                 dump_stack();
 816                 return (const cpumask_t *)&cpu_online_map;
 817         }
 818         if (node >= nr_node_ids) {
 819                 printk(KERN_WARNING
 820                         "cpumask_of_node(%d): node > nr_node_ids(%d)\n",
 821                         node, nr_node_ids);
 822                 dump_stack();
 823                 return &cpu_mask_none;
 824         }
 825         return &node_to_cpumask_map[node];
 826 }
 827 EXPORT_SYMBOL(cpumask_of_node);
 828
 829 /*
 830  * Returns a bitmask of CPUs on Node 'node'.
 831  *
 832  * Side note: this function creates the returned cpumask on the stack
 833  * so with a high NR_CPUS count, excessive stack space is used.  The
 834  * node_to_cpumask_ptr function should be used whenever possible.
 835  */
 836 cpumask_t node_to_cpumask(int node)
 837 {
 838         if (node_to_cpumask_map == NULL) {
 839                 printk(KERN_WARNING
 840                         "node_to_cpumask(%d): no node_to_cpumask_map!\n", node);
 841                 dump_stack();
 842                 return cpu_online_map;
 843         }
 844         if (node >= nr_node_ids) {
 845                 printk(KERN_WARNING
 846                         "node_to_cpumask(%d): node > nr_node_ids(%d)\n",
 847                         node, nr_node_ids);
 848                 dump_stack();
 849                 return cpu_mask_none;
 850         }
 851         return node_to_cpumask_map[node];
 852 }
 853 EXPORT_SYMBOL(node_to_cpumask);
 854
 855 /*
 856  * --------- end of debug versions of the numa functions ---------
 857  */
 858
 859 #endif /* CONFIG_DEBUG_PER_CPU_MAPS */