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   1 /*  $Id: setup.c,v 1.72 2002/02/09 19:49:30 davem Exp $
   2  *  linux/arch/sparc64/kernel/setup.c
   3  *
   4  *  Copyright (C) 1995,1996  David S. Miller (davem@caip.rutgers.edu)
   5  *  Copyright (C) 1997       Jakub Jelinek (jj@sunsite.mff.cuni.cz)
   6  */
   7
   8 #include <linux/errno.h>
   9 #include <linux/sched.h>
  10 #include <linux/kernel.h>
  11 #include <linux/mm.h>
  12 #include <linux/stddef.h>
  13 #include <linux/unistd.h>
  14 #include <linux/ptrace.h>
  15 #include <linux/slab.h>
  16 #include <asm/smp.h>
  17 #include <linux/user.h>
  18 #include <linux/a.out.h>
  19 #include <linux/tty.h>
  20 #include <linux/delay.h>
  21 #include <linux/config.h>
  22 #include <linux/fs.h>
  23 #include <linux/seq_file.h>
  24 #include <linux/syscalls.h>
  25 #include <linux/kdev_t.h>
  26 #include <linux/major.h>
  27 #include <linux/string.h>
  28 #include <linux/init.h>
  29 #include <linux/inet.h>
  30 #include <linux/console.h>
  31 #include <linux/root_dev.h>
  32 #include <linux/interrupt.h>
  33 #include <linux/cpu.h>
  34 #include <linux/initrd.h>
  35
  36 #include <asm/system.h>
  37 #include <asm/io.h>
  38 #include <asm/processor.h>
  39 #include <asm/oplib.h>
  40 #include <asm/page.h>
  41 #include <asm/pgtable.h>
  42 #include <asm/idprom.h>
  43 #include <asm/head.h>
  44 #include <asm/starfire.h>
  45 #include <asm/mmu_context.h>
  46 #include <asm/timer.h>
  47 #include <asm/sections.h>
  48 #include <asm/setup.h>
  49 #include <asm/mmu.h>
  50
  51 #ifdef CONFIG_IP_PNP
  52 #include <net/ipconfig.h>
  53 #endif
  54
  55 struct screen_info screen_info = {
  56         0, 0,                   /* orig-x, orig-y */
  57         0,                      /* unused */
  58         0,                      /* orig-video-page */
  59         0,                      /* orig-video-mode */
  60         128,                    /* orig-video-cols */
  61         0, 0, 0,                /* unused, ega_bx, unused */
  62         54,                     /* orig-video-lines */
  63         0,                      /* orig-video-isVGA */
  64         16                      /* orig-video-points */
  65 };
  66
  67 /* Typing sync at the prom prompt calls the function pointed to by
  68  * the sync callback which I set to the following function.
  69  * This should sync all filesystems and return, for now it just
  70  * prints out pretty messages and returns.
  71  */
  72
  73 void (*prom_palette)(int);
  74 void (*prom_keyboard)(void);
  75
  76 static void
  77 prom_console_write(struct console *con, const char *s, unsigned n)
  78 {
  79         prom_write(s, n);
  80 }
  81
  82 static struct console prom_console = {
  83         .name =         "prom",
  84         .write =        prom_console_write,
  85         .flags =        CON_CONSDEV | CON_ENABLED,
  86         .index =        -1,
  87 };
  88
  89 #define PROM_TRUE       -1
  90 #define PROM_FALSE      0
  91
  92 /* Pretty sick eh? */
  93 int prom_callback(long *args)
  94 {
  95         struct console *cons, *saved_console = NULL;
  96         unsigned long flags;
  97         char *cmd;
  98         extern spinlock_t prom_entry_lock;
  99
 100         if (!args)
 101                 return -1;
 102         if (!(cmd = (char *)args[0]))
 103                 return -1;
 104
 105         /*
 106          * The callback can be invoked on the cpu that first dropped
 107          * into prom_cmdline after taking the serial interrupt, or on
 108          * a slave processor that was smp_captured() if the
 109          * administrator has done a switch-cpu inside obp. In either
 110          * case, the cpu is marked as in-interrupt. Drop IRQ locks.
 111          */
 112         irq_exit();
 113
 114         /* XXX Revisit the locking here someday.  This is a debugging
 115          * XXX feature so it isnt all that critical.  -DaveM
 116          */
 117         local_irq_save(flags);
 118
 119         spin_unlock(&prom_entry_lock);
 120         cons = console_drivers;
 121         while (cons) {
 122                 unregister_console(cons);
 123                 cons->flags &= ~(CON_PRINTBUFFER);
 124                 cons->next = saved_console;
 125                 saved_console = cons;
 126                 cons = console_drivers;
 127         }
 128         register_console(&prom_console);
 129         if (!strcmp(cmd, "sync")) {
 130                 prom_printf("PROM `%s' command...\n", cmd);
 131                 show_free_areas();
 132                 if (current->pid != 0) {
 133                         local_irq_enable();
 134                         sys_sync();
 135                         local_irq_disable();
 136                 }
 137                 args[2] = 0;
 138                 args[args[1] + 3] = -1;
 139                 prom_printf("Returning to PROM\n");
 140         } else if (!strcmp(cmd, "va>tte-data")) {
 141                 unsigned long ctx, va;
 142                 unsigned long tte = 0;
 143                 long res = PROM_FALSE;
 144
 145                 ctx = args[3];
 146                 va = args[4];
 147                 if (ctx) {
 148                         /*
 149                          * Find process owning ctx, lookup mapping.
 150                          */
 151                         struct task_struct *p;
 152                         struct mm_struct *mm = NULL;
 153                         pgd_t *pgdp;
 154                         pud_t *pudp;
 155                         pmd_t *pmdp;
 156                         pte_t *ptep;
 157                         pte_t pte;
 158
 159                         for_each_process(p) {
 160                                 mm = p->mm;
 161                                 if (CTX_NRBITS(mm->context) == ctx)
 162                                         break;
 163                         }
 164                         if (!mm ||
 165                             CTX_NRBITS(mm->context) != ctx)
 166                                 goto done;
 167
 168                         pgdp = pgd_offset(mm, va);
 169                         if (pgd_none(*pgdp))
 170                                 goto done;
 171                         pudp = pud_offset(pgdp, va);
 172                         if (pud_none(*pudp))
 173                                 goto done;
 174                         pmdp = pmd_offset(pudp, va);
 175                         if (pmd_none(*pmdp))
 176                                 goto done;
 177
 178                         /* Preemption implicitly disabled by virtue of
 179                          * being called from inside OBP.
 180                          */
 181                         ptep = pte_offset_map(pmdp, va);
 182                         pte = *ptep;
 183                         if (pte_present(pte)) {
 184                                 tte = pte_val(pte);
 185                                 res = PROM_TRUE;
 186                         }
 187                         pte_unmap(ptep);
 188                         goto done;
 189                 }
 190
 191                 if ((va >= KERNBASE) && (va < (KERNBASE + (4 * 1024 * 1024)))) {
 192                         extern unsigned long sparc64_kern_pri_context;
 193
 194                         /* Spitfire Errata #32 workaround */
 195                         __asm__ __volatile__("stxa      %0, [%1] %2\n\t"
 196                                              "flush     %%g6"
 197                                              : /* No outputs */
 198                                              : "r" (sparc64_kern_pri_context),
 199                                                "r" (PRIMARY_CONTEXT),
 200                                                "i" (ASI_DMMU));
 201
 202                         /*
 203                          * Locked down tlb entry.
 204                          */
 205
 206                         if (tlb_type == spitfire)
 207                                 tte = spitfire_get_dtlb_data(SPITFIRE_HIGHEST_LOCKED_TLBENT);
 208                         else if (tlb_type == cheetah || tlb_type == cheetah_plus)
 209                                 tte = cheetah_get_ldtlb_data(CHEETAH_HIGHEST_LOCKED_TLBENT);
 210
 211                         res = PROM_TRUE;
 212                         goto done;
 213                 }
 214
 215                 if (va < PGDIR_SIZE) {
 216                         /*
 217                          * vmalloc or prom_inherited mapping.
 218                          */
 219                         pgd_t *pgdp;
 220                         pud_t *pudp;
 221                         pmd_t *pmdp;
 222                         pte_t *ptep;
 223                         pte_t pte;
 224                         int error;
 225
 226                         if ((va >= LOW_OBP_ADDRESS) && (va < HI_OBP_ADDRESS)) {
 227                                 tte = prom_virt_to_phys(va, &error);
 228                                 if (!error)
 229                                         res = PROM_TRUE;
 230                                 goto done;
 231                         }
 232                         pgdp = pgd_offset_k(va);
 233                         if (pgd_none(*pgdp))
 234                                 goto done;
 235                         pudp = pud_offset(pgdp, va);
 236                         if (pud_none(*pudp))
 237                                 goto done;
 238                         pmdp = pmd_offset(pudp, va);
 239                         if (pmd_none(*pmdp))
 240                                 goto done;
 241
 242                         /* Preemption implicitly disabled by virtue of
 243                          * being called from inside OBP.
 244                          */
 245                         ptep = pte_offset_kernel(pmdp, va);
 246                         pte = *ptep;
 247                         if (pte_present(pte)) {
 248                                 tte = pte_val(pte);
 249                                 res = PROM_TRUE;
 250                         }
 251                         goto done;
 252                 }
 253
 254                 if (va < PAGE_OFFSET) {
 255                         /*
 256                          * No mappings here.
 257                          */
 258                         goto done;
 259                 }
 260
 261                 if (va & (1UL << 40)) {
 262                         /*
 263                          * I/O page.
 264                          */
 265
 266                         tte = (__pa(va) & _PAGE_PADDR) |
 267                               _PAGE_VALID | _PAGE_SZ4MB |
 268                               _PAGE_E | _PAGE_P | _PAGE_W;
 269                         res = PROM_TRUE;
 270                         goto done;
 271                 }
 272
 273                 /*
 274                  * Normal page.
 275                  */
 276                 tte = (__pa(va) & _PAGE_PADDR) |
 277                       _PAGE_VALID | _PAGE_SZ4MB |
 278                       _PAGE_CP | _PAGE_CV | _PAGE_P | _PAGE_W;
 279                 res = PROM_TRUE;
 280
 281         done:
 282                 if (res == PROM_TRUE) {
 283                         args[2] = 3;
 284                         args[args[1] + 3] = 0;
 285                         args[args[1] + 4] = res;
 286                         args[args[1] + 5] = tte;
 287                 } else {
 288                         args[2] = 2;
 289                         args[args[1] + 3] = 0;
 290                         args[args[1] + 4] = res;
 291                 }
 292         } else if (!strcmp(cmd, ".soft1")) {
 293                 unsigned long tte;
 294
 295                 tte = args[3];
 296                 prom_printf("%lx:\"%s%s%s%s%s\" ",
 297                             (tte & _PAGE_SOFT) >> 7,
 298                             tte & _PAGE_MODIFIED ? "M" : "-",
 299                             tte & _PAGE_ACCESSED ? "A" : "-",
 300                             tte & _PAGE_READ     ? "W" : "-",
 301                             tte & _PAGE_WRITE    ? "R" : "-",
 302                             tte & _PAGE_PRESENT  ? "P" : "-");
 303
 304                 args[2] = 2;
 305                 args[args[1] + 3] = 0;
 306                 args[args[1] + 4] = PROM_TRUE;
 307         } else if (!strcmp(cmd, ".soft2")) {
 308                 unsigned long tte;
 309
 310                 tte = args[3];
 311                 prom_printf("%lx ", (tte & 0x07FC000000000000UL) >> 50);
 312
 313                 args[2] = 2;
 314                 args[args[1] + 3] = 0;
 315                 args[args[1] + 4] = PROM_TRUE;
 316         } else {
 317                 prom_printf("unknown PROM `%s' command...\n", cmd);
 318         }
 319         unregister_console(&prom_console);
 320         while (saved_console) {
 321                 cons = saved_console;
 322                 saved_console = cons->next;
 323                 register_console(cons);
 324         }
 325         spin_lock(&prom_entry_lock);
 326         local_irq_restore(flags);
 327
 328         /*
 329          * Restore in-interrupt status for a resume from obp.
 330          */
 331         irq_enter();
 332         return 0;
 333 }
 334
 335 unsigned int boot_flags = 0;
 336 #define BOOTME_DEBUG  0x1
 337 #define BOOTME_SINGLE 0x2
 338
 339 /* Exported for mm/init.c:paging_init. */
 340 unsigned long cmdline_memory_size = 0;
 341
 342 static struct console prom_debug_console = {
 343         .name =         "debug",
 344         .write =        prom_console_write,
 345         .flags =        CON_PRINTBUFFER,
 346         .index =        -1,
 347 };
 348
 349 /* XXX Implement this at some point... */
 350 void kernel_enter_debugger(void)
 351 {
 352 }
 353
 354 int obp_system_intr(void)
 355 {
 356         if (boot_flags & BOOTME_DEBUG) {
 357                 printk("OBP: system interrupted\n");
 358                 prom_halt();
 359                 return 1;
 360         }
 361         return 0;
 362 }
 363
 364 /*
 365  * Process kernel command line switches that are specific to the
 366  * SPARC or that require special low-level processing.
 367  */
 368 static void __init process_switch(char c)
 369 {
 370         switch (c) {
 371         case 'd':
 372                 boot_flags |= BOOTME_DEBUG;
 373                 break;
 374         case 's':
 375                 boot_flags |= BOOTME_SINGLE;
 376                 break;
 377         case 'h':
 378                 prom_printf("boot_flags_init: Halt!\n");
 379                 prom_halt();
 380                 break;
 381         case 'p':
 382                 /* Use PROM debug console. */
 383                 register_console(&prom_debug_console);
 384                 break;
 385         case 'P':
 386                 /* Force UltraSPARC-III P-Cache on. */
 387                 if (tlb_type != cheetah) {
 388                         printk("BOOT: Ignoring P-Cache force option.\n");
 389                         break;
 390                 }
 391                 cheetah_pcache_forced_on = 1;
 392                 add_taint(TAINT_MACHINE_CHECK);
 393                 cheetah_enable_pcache();
 394                 break;
 395
 396         default:
 397                 printk("Unknown boot switch (-%c)\n", c);
 398                 break;
 399         }
 400 }
 401
 402 static void __init process_console(char *commands)
 403 {
 404         serial_console = 0;
 405         commands += 8;
 406         /* Linux-style serial */
 407         if (!strncmp(commands, "ttyS", 4))
 408                 serial_console = simple_strtoul(commands + 4, NULL, 10) + 1;
 409         else if (!strncmp(commands, "tty", 3)) {
 410                 char c = *(commands + 3);
 411                 /* Solaris-style serial */
 412                 if (c == 'a' || c == 'b') {
 413                         serial_console = c - 'a' + 1;
 414                         prom_printf ("Using /dev/tty%c as console.\n", c);
 415                 }
 416                 /* else Linux-style fbcon, not serial */
 417         }
 418 #if defined(CONFIG_PROM_CONSOLE)
 419         if (!strncmp(commands, "prom", 4)) {
 420                 char *p;
 421
 422                 for (p = commands - 8; *p && *p != ' '; p++)
 423                         *p = ' ';
 424                 conswitchp = &prom_con;
 425         }
 426 #endif
 427 }
 428
 429 static void __init boot_flags_init(char *commands)
 430 {
 431         while (*commands) {
 432                 /* Move to the start of the next "argument". */
 433                 while (*commands && *commands == ' ')
 434                         commands++;
 435
 436                 /* Process any command switches, otherwise skip it. */
 437                 if (*commands == '\0')
 438                         break;
 439                 if (*commands == '-') {
 440                         commands++;
 441                         while (*commands && *commands != ' ')
 442                                 process_switch(*commands++);
 443                         continue;
 444                 }
 445                 if (!strncmp(commands, "console=", 8)) {
 446                         process_console(commands);
 447                 } else if (!strncmp(commands, "mem=", 4)) {
 448                         /*
 449                          * "mem=XXX[kKmM]" overrides the PROM-reported
 450                          * memory size.
 451                          */
 452                         cmdline_memory_size = simple_strtoul(commands + 4,
 453                                                              &commands, 0);
 454                         if (*commands == 'K' || *commands == 'k') {
 455                                 cmdline_memory_size <<= 10;
 456                                 commands++;
 457                         } else if (*commands=='M' || *commands=='m') {
 458                                 cmdline_memory_size <<= 20;
 459                                 commands++;
 460                         }
 461                 }
 462                 while (*commands && *commands != ' ')
 463                         commands++;
 464         }
 465 }
 466
 467 extern void panic_setup(char *, int *);
 468
 469 extern unsigned short root_flags;
 470 extern unsigned short root_dev;
 471 extern unsigned short ram_flags;
 472 #define RAMDISK_IMAGE_START_MASK        0x07FF
 473 #define RAMDISK_PROMPT_FLAG             0x8000
 474 #define RAMDISK_LOAD_FLAG               0x4000
 475
 476 extern int root_mountflags;
 477
 478 char reboot_command[COMMAND_LINE_SIZE];
 479
 480 static struct pt_regs fake_swapper_regs = { { 0, }, 0, 0, 0, 0 };
 481
 482 void register_prom_callbacks(void)
 483 {
 484         prom_setcallback(prom_callback);
 485         prom_feval(": linux-va>tte-data 2 \" va>tte-data\" $callback drop ; "
 486                    "' linux-va>tte-data to va>tte-data");
 487         prom_feval(": linux-.soft1 1 \" .soft1\" $callback 2drop ; "
 488                    "' linux-.soft1 to .soft1");
 489         prom_feval(": linux-.soft2 1 \" .soft2\" $callback 2drop ; "
 490                    "' linux-.soft2 to .soft2");
 491 }
 492
 493 void __init setup_arch(char **cmdline_p)
 494 {
 495         /* Initialize PROM console and command line. */
 496         *cmdline_p = prom_getbootargs();
 497         strcpy(saved_command_line, *cmdline_p);
 498
 499         printk("ARCH: SUN4U\n");
 500
 501 #ifdef CONFIG_DUMMY_CONSOLE
 502         conswitchp = &dummy_con;
 503 #elif defined(CONFIG_PROM_CONSOLE)
 504         conswitchp = &prom_con;
 505 #endif
 506
 507         /* Work out if we are starfire early on */
 508         check_if_starfire();
 509
 510         boot_flags_init(*cmdline_p);
 511
 512         idprom_init();
 513
 514         if (!root_flags)
 515                 root_mountflags &= ~MS_RDONLY;
 516         ROOT_DEV = old_decode_dev(root_dev);
 517 #ifdef CONFIG_BLK_DEV_INITRD
 518         rd_image_start = ram_flags & RAMDISK_IMAGE_START_MASK;
 519         rd_prompt = ((ram_flags & RAMDISK_PROMPT_FLAG) != 0);
 520         rd_doload = ((ram_flags & RAMDISK_LOAD_FLAG) != 0);
 521 #endif
 522
 523         task_thread_info(&init_task)->kregs = &fake_swapper_regs;
 524
 525 #ifdef CONFIG_IP_PNP
 526         if (!ic_set_manually) {
 527                 int chosen = prom_finddevice ("/chosen");
 528                 u32 cl, sv, gw;
 529
 530                 cl = prom_getintdefault (chosen, "client-ip", 0);
 531                 sv = prom_getintdefault (chosen, "server-ip", 0);
 532                 gw = prom_getintdefault (chosen, "gateway-ip", 0);
 533                 if (cl && sv) {
 534                         ic_myaddr = cl;
 535                         ic_servaddr = sv;
 536                         if (gw)
 537                                 ic_gateway = gw;
 538 #if defined(CONFIG_IP_PNP_BOOTP) || defined(CONFIG_IP_PNP_RARP)
 539                         ic_proto_enabled = 0;
 540 #endif
 541                 }
 542         }
 543 #endif
 544
 545         smp_setup_cpu_possible_map();
 546
 547         paging_init();
 548 }
 549
 550 static int __init set_preferred_console(void)
 551 {
 552         int idev, odev;
 553
 554         /* The user has requested a console so this is already set up. */
 555         if (serial_console >= 0)
 556                 return -EBUSY;
 557
 558         idev = prom_query_input_device();
 559         odev = prom_query_output_device();
 560         if (idev == PROMDEV_IKBD && odev == PROMDEV_OSCREEN) {
 561                 serial_console = 0;
 562         } else if (idev == PROMDEV_ITTYA && odev == PROMDEV_OTTYA) {
 563                 serial_console = 1;
 564         } else if (idev == PROMDEV_ITTYB && odev == PROMDEV_OTTYB) {
 565                 serial_console = 2;
 566         } else if (idev == PROMDEV_IRSC && odev == PROMDEV_ORSC) {
 567                 serial_console = 3;
 568         } else {
 569                 prom_printf("Inconsistent console: "
 570                             "input %d, output %d\n",
 571                             idev, odev);
 572                 prom_halt();
 573         }
 574
 575         if (serial_console)
 576                 return add_preferred_console("ttyS", serial_console - 1, NULL);
 577
 578         return -ENODEV;
 579 }
 580 console_initcall(set_preferred_console);
 581
 582 /* BUFFER is PAGE_SIZE bytes long. */
 583
 584 extern char *sparc_cpu_type;
 585 extern char *sparc_fpu_type;
 586
 587 extern void smp_info(struct seq_file *);
 588 extern void smp_bogo(struct seq_file *);
 589 extern void mmu_info(struct seq_file *);
 590
 591 unsigned int dcache_parity_tl1_occurred;
 592 unsigned int icache_parity_tl1_occurred;
 593
 594 static int ncpus_probed;
 595
 596 static int show_cpuinfo(struct seq_file *m, void *__unused)
 597 {
 598         seq_printf(m,
 599                    "cpu\t\t: %s\n"
 600                    "fpu\t\t: %s\n"
 601                    "promlib\t\t: Version 3 Revision %d\n"
 602                    "prom\t\t: %d.%d.%d\n"
 603                    "type\t\t: sun4u\n"
 604                    "ncpus probed\t: %d\n"
 605                    "ncpus active\t: %d\n"
 606                    "D$ parity tl1\t: %u\n"
 607                    "I$ parity tl1\t: %u\n"
 608 #ifndef CONFIG_SMP
 609                    "Cpu0Bogo\t: %lu.%02lu\n"
 610                    "Cpu0ClkTck\t: %016lx\n"
 611 #endif
 612                    ,
 613                    sparc_cpu_type,
 614                    sparc_fpu_type,
 615                    prom_rev,
 616                    prom_prev >> 16,
 617                    (prom_prev >> 8) & 0xff,
 618                    prom_prev & 0xff,
 619                    ncpus_probed,
 620                    num_online_cpus(),
 621                    dcache_parity_tl1_occurred,
 622                    icache_parity_tl1_occurred
 623 #ifndef CONFIG_SMP
 624                    , cpu_data(0).udelay_val/(500000/HZ),
 625                    (cpu_data(0).udelay_val/(5000/HZ)) % 100,
 626                    cpu_data(0).clock_tick
 627 #endif
 628                 );
 629 #ifdef CONFIG_SMP
 630         smp_bogo(m);
 631 #endif
 632         mmu_info(m);
 633 #ifdef CONFIG_SMP
 634         smp_info(m);
 635 #endif
 636         return 0;
 637 }
 638
 639 static void *c_start(struct seq_file *m, loff_t *pos)
 640 {
 641         /* The pointer we are returning is arbitrary,
 642          * it just has to be non-NULL and not IS_ERR
 643          * in the success case.
 644          */
 645         return *pos == 0 ? &c_start : NULL;
 646 }
 647
 648 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
 649 {
 650         ++*pos;
 651         return c_start(m, pos);
 652 }
 653
 654 static void c_stop(struct seq_file *m, void *v)
 655 {
 656 }
 657
 658 struct seq_operations cpuinfo_op = {
 659         .start =c_start,
 660         .next = c_next,
 661         .stop = c_stop,
 662         .show = show_cpuinfo,
 663 };
 664
 665 extern int stop_a_enabled;
 666
 667 void sun_do_break(void)
 668 {
 669         if (!stop_a_enabled)
 670                 return;
 671
 672         prom_printf("\n");
 673         flush_user_windows();
 674
 675         prom_cmdline();
 676 }
 677
 678 int serial_console = -1;
 679 int stop_a_enabled = 1;
 680
 681 static int __init topology_init(void)
 682 {
 683         int i, err;
 684
 685         err = -ENOMEM;
 686
 687         /* Count the number of physically present processors in
 688          * the machine, even on uniprocessor, so that /proc/cpuinfo
 689          * output is consistent with 2.4.x
 690          */
 691         ncpus_probed = 0;
 692         while (!cpu_find_by_instance(ncpus_probed, NULL, NULL))
 693                 ncpus_probed++;
 694
 695         for (i = 0; i < NR_CPUS; i++) {
 696                 if (cpu_possible(i)) {
 697                         struct cpu *p = kmalloc(sizeof(*p), GFP_KERNEL);
 698
 699                         if (p) {
 700                                 memset(p, 0, sizeof(*p));
 701                                 register_cpu(p, i, NULL);
 702                                 err = 0;
 703                         }
 704                 }
 705         }
 706
 707         return err;
 708 }
 709
 710 subsys_initcall(topology_init);