arch/sparc64/kernel/setup.c

   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/segment.h>
  37 #include <asm/system.h>
  38 #include <asm/io.h>
  39 #include <asm/processor.h>
  40 #include <asm/oplib.h>
  41 #include <asm/page.h>
  42 #include <asm/pgtable.h>
  43 #include <asm/idprom.h>
  44 #include <asm/head.h>
  45 #include <asm/starfire.h>
  46 #include <asm/mmu_context.h>
  47 #include <asm/timer.h>
  48 #include <asm/sections.h>
  49 #include <asm/setup.h>
  50 #include <asm/mmu.h>
  51
  52 #ifdef CONFIG_IP_PNP
  53 #include <net/ipconfig.h>
  54 #endif
  55
  56 struct screen_info screen_info = {
  57         0, 0,                   /* orig-x, orig-y */
  58         0,                      /* unused */
  59         0,                      /* orig-video-page */
  60         0,                      /* orig-video-mode */
  61         128,                    /* orig-video-cols */
  62         0, 0, 0,                /* unused, ega_bx, unused */
  63         54,                     /* orig-video-lines */
  64         0,                      /* orig-video-isVGA */
  65         16                      /* orig-video-points */
  66 };
  67
  68 /* Typing sync at the prom prompt calls the function pointed to by
  69  * the sync callback which I set to the following function.
  70  * This should sync all filesystems and return, for now it just
  71  * prints out pretty messages and returns.
  72  */
  73
  74 void (*prom_palette)(int);
  75 void (*prom_keyboard)(void);
  76
  77 static void
  78 prom_console_write(struct console *con, const char *s, unsigned n)
  79 {
  80         prom_write(s, n);
  81 }
  82
  83 static struct console prom_console = {
  84         .name =         "prom",
  85         .write =        prom_console_write,
  86         .flags =        CON_CONSDEV | CON_ENABLED,
  87         .index =        -1,
  88 };
  89
  90 #define PROM_TRUE       -1
  91 #define PROM_FALSE      0
  92
  93 /* Pretty sick eh? */
  94 int prom_callback(long *args)
  95 {
  96         struct console *cons, *saved_console = NULL;
  97         unsigned long flags;
  98         char *cmd;
  99         extern spinlock_t prom_entry_lock;
 100
 101         if (!args)
 102                 return -1;
 103         if (!(cmd = (char *)args[0]))
 104                 return -1;
 105
 106         /*
 107          * The callback can be invoked on the cpu that first dropped
 108          * into prom_cmdline after taking the serial interrupt, or on
 109          * a slave processor that was smp_captured() if the
 110          * administrator has done a switch-cpu inside obp. In either
 111          * case, the cpu is marked as in-interrupt. Drop IRQ locks.
 112          */
 113         irq_exit();
 114
 115         /* XXX Revisit the locking here someday.  This is a debugging
 116          * XXX feature so it isnt all that critical.  -DaveM
 117          */
 118         local_irq_save(flags);
 119
 120         spin_unlock(&prom_entry_lock);
 121         cons = console_drivers;
 122         while (cons) {
 123                 unregister_console(cons);
 124                 cons->flags &= ~(CON_PRINTBUFFER);
 125                 cons->next = saved_console;
 126                 saved_console = cons;
 127                 cons = console_drivers;
 128         }
 129         register_console(&prom_console);
 130         if (!strcmp(cmd, "sync")) {
 131                 prom_printf("PROM `%s' command...\n", cmd);
 132                 show_free_areas();
 133                 if (current->pid != 0) {
 134                         local_irq_enable();
 135                         sys_sync();
 136                         local_irq_disable();
 137                 }
 138                 args[2] = 0;
 139                 args[args[1] + 3] = -1;
 140                 prom_printf("Returning to PROM\n");
 141         } else if (!strcmp(cmd, "va>tte-data")) {
 142                 unsigned long ctx, va;
 143                 unsigned long tte = 0;
 144                 long res = PROM_FALSE;
 145
 146                 ctx = args[3];
 147                 va = args[4];
 148                 if (ctx) {
 149                         /*
 150                          * Find process owning ctx, lookup mapping.
 151                          */
 152                         struct task_struct *p;
 153                         struct mm_struct *mm = NULL;
 154                         pgd_t *pgdp;
 155                         pud_t *pudp;
 156                         pmd_t *pmdp;
 157                         pte_t *ptep;
 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                         if (pte_present(*ptep)) {
 183                                 tte = pte_val(*ptep);
 184                                 res = PROM_TRUE;
 185                         }
 186                         pte_unmap(ptep);
 187                         goto done;
 188                 }
 189
 190                 if ((va >= KERNBASE) && (va < (KERNBASE + (4 * 1024 * 1024)))) {
 191                         unsigned long kernel_pctx = 0;
 192
 193                         if (tlb_type == cheetah_plus)
 194                                 kernel_pctx |= (CTX_CHEETAH_PLUS_NUC |
 195                                                 CTX_CHEETAH_PLUS_CTX0);
 196
 197                         /* Spitfire Errata #32 workaround */
 198                         __asm__ __volatile__("stxa      %0, [%1] %2\n\t"
 199                                              "flush     %%g6"
 200                                              : /* No outputs */
 201                                              : "r" (kernel_pctx),
 202                                                "r" (PRIMARY_CONTEXT),
 203                                                "i" (ASI_DMMU));
 204
 205                         /*
 206                          * Locked down tlb entry.
 207                          */
 208
 209                         if (tlb_type == spitfire)
 210                                 tte = spitfire_get_dtlb_data(SPITFIRE_HIGHEST_LOCKED_TLBENT);
 211                         else if (tlb_type == cheetah || tlb_type == cheetah_plus)
 212                                 tte = cheetah_get_ldtlb_data(CHEETAH_HIGHEST_LOCKED_TLBENT);
 213
 214                         res = PROM_TRUE;
 215                         goto done;
 216                 }
 217
 218                 if (va < PGDIR_SIZE) {
 219                         /*
 220                          * vmalloc or prom_inherited mapping.
 221                          */
 222                         pgd_t *pgdp;
 223                         pud_t *pudp;
 224                         pmd_t *pmdp;
 225                         pte_t *ptep;
 226                         int error;
 227
 228                         if ((va >= LOW_OBP_ADDRESS) && (va < HI_OBP_ADDRESS)) {
 229                                 tte = prom_virt_to_phys(va, &error);
 230                                 if (!error)
 231                                         res = PROM_TRUE;
 232                                 goto done;
 233                         }
 234                         pgdp = pgd_offset_k(va);
 235                         if (pgd_none(*pgdp))
 236                                 goto done;
 237                         pudp = pud_offset(pgdp, va);
 238                         if (pud_none(*pudp))
 239                                 goto done;
 240                         pmdp = pmd_offset(pudp, va);
 241                         if (pmd_none(*pmdp))
 242                                 goto done;
 243
 244                         /* Preemption implicitly disabled by virtue of
 245                          * being called from inside OBP.
 246                          */
 247                         ptep = pte_offset_kernel(pmdp, va);
 248                         if (pte_present(*ptep)) {
 249                                 tte = pte_val(*ptep);
 250                                 res = PROM_TRUE;
 251                         }
 252                         goto done;
 253                 }
 254
 255                 if (va < PAGE_OFFSET) {
 256                         /*
 257                          * No mappings here.
 258                          */
 259                         goto done;
 260                 }
 261
 262                 if (va & (1UL << 40)) {
 263                         /*
 264                          * I/O page.
 265                          */
 266
 267                         tte = (__pa(va) & _PAGE_PADDR) |
 268                               _PAGE_VALID | _PAGE_SZ4MB |
 269                               _PAGE_E | _PAGE_P | _PAGE_W;
 270                         res = PROM_TRUE;
 271                         goto done;
 272                 }
 273
 274                 /*
 275                  * Normal page.
 276                  */
 277                 tte = (__pa(va) & _PAGE_PADDR) |
 278                       _PAGE_VALID | _PAGE_SZ4MB |
 279                       _PAGE_CP | _PAGE_CV | _PAGE_P | _PAGE_W;
 280                 res = PROM_TRUE;
 281
 282         done:
 283                 if (res == PROM_TRUE) {
 284                         args[2] = 3;
 285                         args[args[1] + 3] = 0;
 286                         args[args[1] + 4] = res;
 287                         args[args[1] + 5] = tte;
 288                 } else {
 289                         args[2] = 2;
 290                         args[args[1] + 3] = 0;
 291                         args[args[1] + 4] = res;
 292                 }
 293         } else if (!strcmp(cmd, ".soft1")) {
 294                 unsigned long tte;
 295
 296                 tte = args[3];
 297                 prom_printf("%lx:\"%s%s%s%s%s\" ",
 298                             (tte & _PAGE_SOFT) >> 7,
 299                             tte & _PAGE_MODIFIED ? "M" : "-",
 300                             tte & _PAGE_ACCESSED ? "A" : "-",
 301                             tte & _PAGE_READ     ? "W" : "-",
 302                             tte & _PAGE_WRITE    ? "R" : "-",
 303                             tte & _PAGE_PRESENT  ? "P" : "-");
 304
 305                 args[2] = 2;
 306                 args[args[1] + 3] = 0;
 307                 args[args[1] + 4] = PROM_TRUE;
 308         } else if (!strcmp(cmd, ".soft2")) {
 309                 unsigned long tte;
 310
 311                 tte = args[3];
 312                 prom_printf("%lx ", (tte & 0x07FC000000000000UL) >> 50);
 313
 314                 args[2] = 2;
 315                 args[args[1] + 3] = 0;
 316                 args[args[1] + 4] = PROM_TRUE;
 317         } else {
 318                 prom_printf("unknown PROM `%s' command...\n", cmd);
 319         }
 320         unregister_console(&prom_console);
 321         while (saved_console) {
 322                 cons = saved_console;
 323                 saved_console = cons->next;
 324                 register_console(cons);
 325         }
 326         spin_lock(&prom_entry_lock);
 327         local_irq_restore(flags);
 328
 329         /*
 330          * Restore in-interrupt status for a resume from obp.
 331          */
 332         irq_enter();
 333         return 0;
 334 }
 335
 336 unsigned int boot_flags = 0;
 337 #define BOOTME_DEBUG  0x1
 338 #define BOOTME_SINGLE 0x2
 339
 340 /* Exported for mm/init.c:paging_init. */
 341 unsigned long cmdline_memory_size = 0;
 342
 343 static struct console prom_debug_console = {
 344         .name =         "debug",
 345         .write =        prom_console_write,
 346         .flags =        CON_PRINTBUFFER,
 347         .index =        -1,
 348 };
 349
 350 /* XXX Implement this at some point... */
 351 void kernel_enter_debugger(void)
 352 {
 353 }
 354
 355 int obp_system_intr(void)
 356 {
 357         if (boot_flags & BOOTME_DEBUG) {
 358                 printk("OBP: system interrupted\n");
 359                 prom_halt();
 360                 return 1;
 361         }
 362         return 0;
 363 }
 364
 365 /*
 366  * Process kernel command line switches that are specific to the
 367  * SPARC or that require special low-level processing.
 368  */
 369 static void __init process_switch(char c)
 370 {
 371         switch (c) {
 372         case 'd':
 373                 boot_flags |= BOOTME_DEBUG;
 374                 break;
 375         case 's':
 376                 boot_flags |= BOOTME_SINGLE;
 377                 break;
 378         case 'h':
 379                 prom_printf("boot_flags_init: Halt!\n");
 380                 prom_halt();
 381                 break;
 382         case 'p':
 383                 /* Use PROM debug console. */
 384                 register_console(&prom_debug_console);
 385                 break;
 386         default:
 387                 printk("Unknown boot switch (-%c)\n", c);
 388                 break;
 389         }
 390 }
 391
 392 static void __init process_console(char *commands)
 393 {
 394         serial_console = 0;
 395         commands += 8;
 396         /* Linux-style serial */
 397         if (!strncmp(commands, "ttyS", 4))
 398                 serial_console = simple_strtoul(commands + 4, NULL, 10) + 1;
 399         else if (!strncmp(commands, "tty", 3)) {
 400                 char c = *(commands + 3);
 401                 /* Solaris-style serial */
 402                 if (c == 'a' || c == 'b') {
 403                         serial_console = c - 'a' + 1;
 404                         prom_printf ("Using /dev/tty%c as console.\n", c);
 405                 }
 406                 /* else Linux-style fbcon, not serial */
 407         }
 408 #if defined(CONFIG_PROM_CONSOLE)
 409         if (!strncmp(commands, "prom", 4)) {
 410                 char *p;
 411
 412                 for (p = commands - 8; *p && *p != ' '; p++)
 413                         *p = ' ';
 414                 conswitchp = &prom_con;
 415         }
 416 #endif
 417 }
 418
 419 static void __init boot_flags_init(char *commands)
 420 {
 421         while (*commands) {
 422                 /* Move to the start of the next "argument". */
 423                 while (*commands && *commands == ' ')
 424                         commands++;
 425
 426                 /* Process any command switches, otherwise skip it. */
 427                 if (*commands == '\0')
 428                         break;
 429                 if (*commands == '-') {
 430                         commands++;
 431                         while (*commands && *commands != ' ')
 432                                 process_switch(*commands++);
 433                         continue;
 434                 }
 435                 if (!strncmp(commands, "console=", 8)) {
 436                         process_console(commands);
 437                 } else if (!strncmp(commands, "mem=", 4)) {
 438                         /*
 439                          * "mem=XXX[kKmM]" overrides the PROM-reported
 440                          * memory size.
 441                          */
 442                         cmdline_memory_size = simple_strtoul(commands + 4,
 443                                                              &commands, 0);
 444                         if (*commands == 'K' || *commands == 'k') {
 445                                 cmdline_memory_size <<= 10;
 446                                 commands++;
 447                         } else if (*commands=='M' || *commands=='m') {
 448                                 cmdline_memory_size <<= 20;
 449                                 commands++;
 450                         }
 451                 }
 452                 while (*commands && *commands != ' ')
 453                         commands++;
 454         }
 455 }
 456
 457 extern int prom_probe_memory(void);
 458 extern unsigned long start, end;
 459 extern void panic_setup(char *, int *);
 460
 461 extern unsigned short root_flags;
 462 extern unsigned short root_dev;
 463 extern unsigned short ram_flags;
 464 #define RAMDISK_IMAGE_START_MASK        0x07FF
 465 #define RAMDISK_PROMPT_FLAG             0x8000
 466 #define RAMDISK_LOAD_FLAG               0x4000
 467
 468 extern int root_mountflags;
 469
 470 char reboot_command[COMMAND_LINE_SIZE];
 471
 472 static struct pt_regs fake_swapper_regs = { { 0, }, 0, 0, 0, 0 };
 473
 474 void register_prom_callbacks(void)
 475 {
 476         prom_setcallback(prom_callback);
 477         prom_feval(": linux-va>tte-data 2 \" va>tte-data\" $callback drop ; "
 478                    "' linux-va>tte-data to va>tte-data");
 479         prom_feval(": linux-.soft1 1 \" .soft1\" $callback 2drop ; "
 480                    "' linux-.soft1 to .soft1");
 481         prom_feval(": linux-.soft2 1 \" .soft2\" $callback 2drop ; "
 482                    "' linux-.soft2 to .soft2");
 483 }
 484
 485 extern void paging_init(void);
 486
 487 void __init setup_arch(char **cmdline_p)
 488 {
 489         unsigned long highest_paddr;
 490         int i;
 491
 492         /* Initialize PROM console and command line. */
 493         *cmdline_p = prom_getbootargs();
 494         strcpy(saved_command_line, *cmdline_p);
 495
 496         printk("ARCH: SUN4U\n");
 497
 498 #ifdef CONFIG_DUMMY_CONSOLE
 499         conswitchp = &dummy_con;
 500 #elif defined(CONFIG_PROM_CONSOLE)
 501         conswitchp = &prom_con;
 502 #endif
 503
 504 #ifdef CONFIG_SMP
 505         i = (unsigned long)&irq_stat[1] - (unsigned long)&irq_stat[0];
 506         if ((i == SMP_CACHE_BYTES) || (i == (2 * SMP_CACHE_BYTES))) {
 507                 extern unsigned int irqsz_patchme[1];
 508                 irqsz_patchme[0] |= ((i == SMP_CACHE_BYTES) ? SMP_CACHE_BYTES_SHIFT : \
 509                                                         SMP_CACHE_BYTES_SHIFT + 1);
 510                 flushi((long)&irqsz_patchme[0]);
 511         } else {
 512                 prom_printf("Unexpected size of irq_stat[] elements\n");
 513                 prom_halt();
 514         }
 515 #endif
 516         /* Work out if we are starfire early on */
 517         check_if_starfire();
 518
 519         boot_flags_init(*cmdline_p);
 520
 521         idprom_init();
 522         (void) prom_probe_memory();
 523
 524         /* In paging_init() we tip off this value to see if we need
 525          * to change init_mm.pgd to point to the real alias mapping.
 526          */
 527         phys_base = 0xffffffffffffffffUL;
 528         highest_paddr = 0UL;
 529         for (i = 0; sp_banks[i].num_bytes != 0; i++) {
 530                 unsigned long top;
 531
 532                 if (sp_banks[i].base_addr < phys_base)
 533                         phys_base = sp_banks[i].base_addr;
 534                 top = sp_banks[i].base_addr +
 535                         sp_banks[i].num_bytes;
 536                 if (highest_paddr < top)
 537                         highest_paddr = top;
 538         }
 539         pfn_base = phys_base >> PAGE_SHIFT;
 540
 541         switch (tlb_type) {
 542         default:
 543         case spitfire:
 544                 kern_base = spitfire_get_itlb_data(sparc64_highest_locked_tlbent());
 545                 kern_base &= _PAGE_PADDR_SF;
 546                 break;
 547
 548         case cheetah:
 549         case cheetah_plus:
 550                 kern_base = cheetah_get_litlb_data(sparc64_highest_locked_tlbent());
 551                 kern_base &= _PAGE_PADDR;
 552                 break;
 553         };
 554
 555         kern_size = (unsigned long)&_end - (unsigned long)KERNBASE;
 556
 557         if (!root_flags)
 558                 root_mountflags &= ~MS_RDONLY;
 559         ROOT_DEV = old_decode_dev(root_dev);
 560 #ifdef CONFIG_BLK_DEV_INITRD
 561         rd_image_start = ram_flags & RAMDISK_IMAGE_START_MASK;
 562         rd_prompt = ((ram_flags & RAMDISK_PROMPT_FLAG) != 0);
 563         rd_doload = ((ram_flags & RAMDISK_LOAD_FLAG) != 0);
 564 #endif
 565
 566         init_task.thread_info->kregs = &fake_swapper_regs;
 567
 568 #ifdef CONFIG_IP_PNP
 569         if (!ic_set_manually) {
 570                 int chosen = prom_finddevice ("/chosen");
 571                 u32 cl, sv, gw;
 572
 573                 cl = prom_getintdefault (chosen, "client-ip", 0);
 574                 sv = prom_getintdefault (chosen, "server-ip", 0);
 575                 gw = prom_getintdefault (chosen, "gateway-ip", 0);
 576                 if (cl && sv) {
 577                         ic_myaddr = cl;
 578                         ic_servaddr = sv;
 579                         if (gw)
 580                                 ic_gateway = gw;
 581 #if defined(CONFIG_IP_PNP_BOOTP) || defined(CONFIG_IP_PNP_RARP)
 582                         ic_proto_enabled = 0;
 583 #endif
 584                 }
 585         }
 586 #endif
 587
 588         paging_init();
 589 }
 590
 591 static int __init set_preferred_console(void)
 592 {
 593         int idev, odev;
 594
 595         /* The user has requested a console so this is already set up. */
 596         if (serial_console >= 0)
 597                 return -EBUSY;
 598
 599         idev = prom_query_input_device();
 600         odev = prom_query_output_device();
 601         if (idev == PROMDEV_IKBD && odev == PROMDEV_OSCREEN) {
 602                 serial_console = 0;
 603         } else if (idev == PROMDEV_ITTYA && odev == PROMDEV_OTTYA) {
 604                 serial_console = 1;
 605         } else if (idev == PROMDEV_ITTYB && odev == PROMDEV_OTTYB) {
 606                 serial_console = 2;
 607         } else {
 608                 prom_printf("Inconsistent console: "
 609                             "input %d, output %d\n",
 610                             idev, odev);
 611                 prom_halt();
 612         }
 613
 614         if (serial_console)
 615                 return add_preferred_console("ttyS", serial_console - 1, NULL);
 616
 617         return -ENODEV;
 618 }
 619 console_initcall(set_preferred_console);
 620
 621 /* BUFFER is PAGE_SIZE bytes long. */
 622
 623 extern char *sparc_cpu_type;
 624 extern char *sparc_fpu_type;
 625
 626 extern void smp_info(struct seq_file *);
 627 extern void smp_bogo(struct seq_file *);
 628 extern void mmu_info(struct seq_file *);
 629
 630 static int show_cpuinfo(struct seq_file *m, void *__unused)
 631 {
 632         seq_printf(m,
 633                    "cpu\t\t: %s\n"
 634                    "fpu\t\t: %s\n"
 635                    "promlib\t\t: Version 3 Revision %d\n"
 636                    "prom\t\t: %d.%d.%d\n"
 637                    "type\t\t: sun4u\n"
 638                    "ncpus probed\t: %ld\n"
 639                    "ncpus active\t: %ld\n"
 640 #ifndef CONFIG_SMP
 641                    "Cpu0Bogo\t: %lu.%02lu\n"
 642                    "Cpu0ClkTck\t: %016lx\n"
 643 #endif
 644                    ,
 645                    sparc_cpu_type,
 646                    sparc_fpu_type,
 647                    prom_rev,
 648                    prom_prev >> 16,
 649                    (prom_prev >> 8) & 0xff,
 650                    prom_prev & 0xff,
 651                    (long)num_possible_cpus(),
 652                    (long)num_online_cpus()
 653 #ifndef CONFIG_SMP
 654                    , cpu_data(0).udelay_val/(500000/HZ),
 655                    (cpu_data(0).udelay_val/(5000/HZ)) % 100,
 656                    cpu_data(0).clock_tick
 657 #endif
 658                 );
 659 #ifdef CONFIG_SMP
 660         smp_bogo(m);
 661 #endif
 662         mmu_info(m);
 663 #ifdef CONFIG_SMP
 664         smp_info(m);
 665 #endif
 666         return 0;
 667 }
 668
 669 static void *c_start(struct seq_file *m, loff_t *pos)
 670 {
 671         /* The pointer we are returning is arbitrary,
 672          * it just has to be non-NULL and not IS_ERR
 673          * in the success case.
 674          */
 675         return *pos == 0 ? &c_start : NULL;
 676 }
 677
 678 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
 679 {
 680         ++*pos;
 681         return c_start(m, pos);
 682 }
 683
 684 static void c_stop(struct seq_file *m, void *v)
 685 {
 686 }
 687
 688 struct seq_operations cpuinfo_op = {
 689         .start =c_start,
 690         .next = c_next,
 691         .stop = c_stop,
 692         .show = show_cpuinfo,
 693 };
 694
 695 extern int stop_a_enabled;
 696
 697 void sun_do_break(void)
 698 {
 699         if (!stop_a_enabled)
 700                 return;
 701
 702         prom_printf("\n");
 703         flush_user_windows();
 704
 705         prom_cmdline();
 706 }
 707
 708 int serial_console = -1;
 709 int stop_a_enabled = 1;
 710
 711 static int __init topology_init(void)
 712 {
 713         int i, err;
 714
 715         err = -ENOMEM;
 716         for (i = 0; i < NR_CPUS; i++) {
 717                 if (cpu_possible(i)) {
 718                         struct cpu *p = kmalloc(sizeof(*p), GFP_KERNEL);
 719
 720                         if (p) {
 721                                 memset(p, 0, sizeof(*p));
 722                                 register_cpu(p, i, NULL);
 723                                 err = 0;
 724                         }
 725                 }
 726         }
 727
 728         return err;
 729 }
 730
 731 subsys_initcall(topology_init);