arch/powerpc/kernel/smp.c

   1 /*
   2  * SMP support for ppc.
   3  *
   4  * Written by Cort Dougan (cort@cs.nmt.edu) borrowing a great
   5  * deal of code from the sparc and intel versions.
   6  *
   7  * Copyright (C) 1999 Cort Dougan <cort@cs.nmt.edu>
   8  *
   9  * PowerPC-64 Support added by Dave Engebretsen, Peter Bergner, and
  10  * Mike Corrigan {engebret|bergner|mikec}@us.ibm.com
  11  *
  12  *      This program is free software; you can redistribute it and/or
  13  *      modify it under the terms of the GNU General Public License
  14  *      as published by the Free Software Foundation; either version
  15  *      2 of the License, or (at your option) any later version.
  16  */
  17
  18 #undef DEBUG
  19
  20 #include <linux/kernel.h>
  21 #include <linux/export.h>
  22 #include <linux/sched.h>
  23 #include <linux/smp.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/delay.h>
  26 #include <linux/init.h>
  27 #include <linux/spinlock.h>
  28 #include <linux/cache.h>
  29 #include <linux/err.h>
  30 #include <linux/device.h>
  31 #include <linux/cpu.h>
  32 #include <linux/notifier.h>
  33 #include <linux/topology.h>
  34
  35 #include <asm/ptrace.h>
  36 #include <linux/atomic.h>
  37 #include <asm/irq.h>
  38 #include <asm/hw_irq.h>
  39 #include <asm/kvm_ppc.h>
  40 #include <asm/page.h>
  41 #include <asm/pgtable.h>
  42 #include <asm/prom.h>
  43 #include <asm/smp.h>
  44 #include <asm/time.h>
  45 #include <asm/machdep.h>
  46 #include <asm/cputhreads.h>
  47 #include <asm/cputable.h>
  48 #include <asm/mpic.h>
  49 #include <asm/vdso_datapage.h>
  50 #ifdef CONFIG_PPC64
  51 #include <asm/paca.h>
  52 #endif
  53 #include <asm/vdso.h>
  54 #include <asm/debug.h>
  55 #include <asm/kexec.h>
  56
  57 #ifdef DEBUG
  58 #include <asm/udbg.h>
  59 #define DBG(fmt...) udbg_printf(fmt)
  60 #else
  61 #define DBG(fmt...)
  62 #endif
  63
  64 #ifdef CONFIG_HOTPLUG_CPU
  65 /* State of each CPU during hotplug phases */
  66 static DEFINE_PER_CPU(int, cpu_state) = { 0 };
  67 #endif
  68
  69 struct thread_info *secondary_ti;
  70
  71 DEFINE_PER_CPU(cpumask_var_t, cpu_sibling_map);
  72 DEFINE_PER_CPU(cpumask_var_t, cpu_core_map);
  73
  74 EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
  75 EXPORT_PER_CPU_SYMBOL(cpu_core_map);
  76
  77 /* SMP operations for this machine */
  78 struct smp_ops_t *smp_ops;
  79
  80 /* Can't be static due to PowerMac hackery */
  81 volatile unsigned int cpu_callin_map[NR_CPUS];
  82
  83 int smt_enabled_at_boot = 1;
  84
  85 static void (*crash_ipi_function_ptr)(struct pt_regs *) = NULL;
  86
  87 /*
  88  * Returns 1 if the specified cpu should be brought up during boot.
  89  * Used to inhibit booting threads if they've been disabled or
  90  * limited on the command line
  91  */
  92 int smp_generic_cpu_bootable(unsigned int nr)
  93 {
  94         /* Special case - we inhibit secondary thread startup
  95          * during boot if the user requests it.
  96          */
  97         if (system_state == SYSTEM_BOOTING && cpu_has_feature(CPU_FTR_SMT)) {
  98                 if (!smt_enabled_at_boot && cpu_thread_in_core(nr) != 0)
  99                         return 0;
 100                 if (smt_enabled_at_boot
 101                     && cpu_thread_in_core(nr) >= smt_enabled_at_boot)
 102                         return 0;
 103         }
 104
 105         return 1;
 106 }
 107
 108
 109 #ifdef CONFIG_PPC64
 110 int smp_generic_kick_cpu(int nr)
 111 {
 112         BUG_ON(nr < 0 || nr >= NR_CPUS);
 113
 114         /*
 115          * The processor is currently spinning, waiting for the
 116          * cpu_start field to become non-zero After we set cpu_start,
 117          * the processor will continue on to secondary_start
 118          */
 119         if (!paca[nr].cpu_start) {
 120                 paca[nr].cpu_start = 1;
 121                 smp_mb();
 122                 return 0;
 123         }
 124
 125 #ifdef CONFIG_HOTPLUG_CPU
 126         /*
 127          * Ok it's not there, so it might be soft-unplugged, let's
 128          * try to bring it back
 129          */
 130         generic_set_cpu_up(nr);
 131         smp_wmb();
 132         smp_send_reschedule(nr);
 133 #endif /* CONFIG_HOTPLUG_CPU */
 134
 135         return 0;
 136 }
 137 #endif /* CONFIG_PPC64 */
 138
 139 static irqreturn_t call_function_action(int irq, void *data)
 140 {
 141         generic_smp_call_function_interrupt();
 142         return IRQ_HANDLED;
 143 }
 144
 145 static irqreturn_t reschedule_action(int irq, void *data)
 146 {
 147         scheduler_ipi();
 148         return IRQ_HANDLED;
 149 }
 150
 151 static irqreturn_t tick_broadcast_ipi_action(int irq, void *data)
 152 {
 153         tick_broadcast_ipi_handler();
 154         return IRQ_HANDLED;
 155 }
 156
 157 static irqreturn_t debug_ipi_action(int irq, void *data)
 158 {
 159         if (crash_ipi_function_ptr) {
 160                 crash_ipi_function_ptr(get_irq_regs());
 161                 return IRQ_HANDLED;
 162         }
 163
 164 #ifdef CONFIG_DEBUGGER
 165         debugger_ipi(get_irq_regs());
 166 #endif /* CONFIG_DEBUGGER */
 167
 168         return IRQ_HANDLED;
 169 }
 170
 171 static irq_handler_t smp_ipi_action[] = {
 172         [PPC_MSG_CALL_FUNCTION] =  call_function_action,
 173         [PPC_MSG_RESCHEDULE] = reschedule_action,
 174         [PPC_MSG_TICK_BROADCAST] = tick_broadcast_ipi_action,
 175         [PPC_MSG_DEBUGGER_BREAK] = debug_ipi_action,
 176 };
 177
 178 const char *smp_ipi_name[] = {
 179         [PPC_MSG_CALL_FUNCTION] =  "ipi call function",
 180         [PPC_MSG_RESCHEDULE] = "ipi reschedule",
 181         [PPC_MSG_TICK_BROADCAST] = "ipi tick-broadcast",
 182         [PPC_MSG_DEBUGGER_BREAK] = "ipi debugger",
 183 };
 184
 185 /* optional function to request ipi, for controllers with >= 4 ipis */
 186 int smp_request_message_ipi(int virq, int msg)
 187 {
 188         int err;
 189
 190         if (msg < 0 || msg > PPC_MSG_DEBUGGER_BREAK) {
 191                 return -EINVAL;
 192         }
 193 #if !defined(CONFIG_DEBUGGER) && !defined(CONFIG_KEXEC)
 194         if (msg == PPC_MSG_DEBUGGER_BREAK) {
 195                 return 1;
 196         }
 197 #endif
 198         err = request_irq(virq, smp_ipi_action[msg],
 199                           IRQF_PERCPU | IRQF_NO_THREAD | IRQF_NO_SUSPEND,
 200                           smp_ipi_name[msg], NULL);
 201         WARN(err < 0, "unable to request_irq %d for %s (rc %d)\n",
 202                 virq, smp_ipi_name[msg], err);
 203
 204         return err;
 205 }
 206
 207 #ifdef CONFIG_PPC_SMP_MUXED_IPI
 208 struct cpu_messages {
 209         int messages;                   /* current messages */
 210         unsigned long data;             /* data for cause ipi */
 211 };
 212 static DEFINE_PER_CPU_SHARED_ALIGNED(struct cpu_messages, ipi_message);
 213
 214 void smp_muxed_ipi_set_data(int cpu, unsigned long data)
 215 {
 216         struct cpu_messages *info = &per_cpu(ipi_message, cpu);
 217
 218         info->data = data;
 219 }
 220
 221 void smp_muxed_ipi_message_pass(int cpu, int msg)
 222 {
 223         struct cpu_messages *info = &per_cpu(ipi_message, cpu);
 224         char *message = (char *)&info->messages;
 225
 226         /*
 227          * Order previous accesses before accesses in the IPI handler.
 228          */
 229         smp_mb();
 230         message[msg] = 1;
 231         /*
 232          * cause_ipi functions are required to include a full barrier
 233          * before doing whatever causes the IPI.
 234          */
 235         smp_ops->cause_ipi(cpu, info->data);
 236 }
 237
 238 #ifdef __BIG_ENDIAN__
 239 #define IPI_MESSAGE(A) (1 << (24 - 8 * (A)))
 240 #else
 241 #define IPI_MESSAGE(A) (1 << (8 * (A)))
 242 #endif
 243
 244 irqreturn_t smp_ipi_demux(void)
 245 {
 246         struct cpu_messages *info = this_cpu_ptr(&ipi_message);
 247         unsigned int all;
 248
 249         mb();   /* order any irq clear */
 250
 251         do {
 252                 all = xchg(&info->messages, 0);
 253                 if (all & IPI_MESSAGE(PPC_MSG_CALL_FUNCTION))
 254                         generic_smp_call_function_interrupt();
 255                 if (all & IPI_MESSAGE(PPC_MSG_RESCHEDULE))
 256                         scheduler_ipi();
 257                 if (all & IPI_MESSAGE(PPC_MSG_TICK_BROADCAST))
 258                         tick_broadcast_ipi_handler();
 259                 if (all & IPI_MESSAGE(PPC_MSG_DEBUGGER_BREAK))
 260                         debug_ipi_action(0, NULL);
 261         } while (info->messages);
 262
 263         return IRQ_HANDLED;
 264 }
 265 #endif /* CONFIG_PPC_SMP_MUXED_IPI */
 266
 267 static inline void do_message_pass(int cpu, int msg)
 268 {
 269         if (smp_ops->message_pass)
 270                 smp_ops->message_pass(cpu, msg);
 271 #ifdef CONFIG_PPC_SMP_MUXED_IPI
 272         else
 273                 smp_muxed_ipi_message_pass(cpu, msg);
 274 #endif
 275 }
 276
 277 void smp_send_reschedule(int cpu)
 278 {
 279         if (likely(smp_ops))
 280                 do_message_pass(cpu, PPC_MSG_RESCHEDULE);
 281 }
 282 EXPORT_SYMBOL_GPL(smp_send_reschedule);
 283
 284 void arch_send_call_function_single_ipi(int cpu)
 285 {
 286         do_message_pass(cpu, PPC_MSG_CALL_FUNCTION);
 287 }
 288
 289 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
 290 {
 291         unsigned int cpu;
 292
 293         for_each_cpu(cpu, mask)
 294                 do_message_pass(cpu, PPC_MSG_CALL_FUNCTION);
 295 }
 296
 297 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
 298 void tick_broadcast(const struct cpumask *mask)
 299 {
 300         unsigned int cpu;
 301
 302         for_each_cpu(cpu, mask)
 303                 do_message_pass(cpu, PPC_MSG_TICK_BROADCAST);
 304 }
 305 #endif
 306
 307 #if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC)
 308 void smp_send_debugger_break(void)
 309 {
 310         int cpu;
 311         int me = raw_smp_processor_id();
 312
 313         if (unlikely(!smp_ops))
 314                 return;
 315
 316         for_each_online_cpu(cpu)
 317                 if (cpu != me)
 318                         do_message_pass(cpu, PPC_MSG_DEBUGGER_BREAK);
 319 }
 320 #endif
 321
 322 #ifdef CONFIG_KEXEC
 323 void crash_send_ipi(void (*crash_ipi_callback)(struct pt_regs *))
 324 {
 325         crash_ipi_function_ptr = crash_ipi_callback;
 326         if (crash_ipi_callback) {
 327                 mb();
 328                 smp_send_debugger_break();
 329         }
 330 }
 331 #endif
 332
 333 static void stop_this_cpu(void *dummy)
 334 {
 335         /* Remove this CPU */
 336         set_cpu_online(smp_processor_id(), false);
 337
 338         local_irq_disable();
 339         while (1)
 340                 ;
 341 }
 342
 343 void smp_send_stop(void)
 344 {
 345         smp_call_function(stop_this_cpu, NULL, 0);
 346 }
 347
 348 struct thread_info *current_set[NR_CPUS];
 349
 350 static void smp_store_cpu_info(int id)
 351 {
 352         per_cpu(cpu_pvr, id) = mfspr(SPRN_PVR);
 353 #ifdef CONFIG_PPC_FSL_BOOK3E
 354         per_cpu(next_tlbcam_idx, id)
 355                 = (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) - 1;
 356 #endif
 357 }
 358
 359 void __init smp_prepare_cpus(unsigned int max_cpus)
 360 {
 361         unsigned int cpu;
 362
 363         DBG("smp_prepare_cpus\n");
 364
 365         /*
 366          * setup_cpu may need to be called on the boot cpu. We havent
 367          * spun any cpus up but lets be paranoid.
 368          */
 369         BUG_ON(boot_cpuid != smp_processor_id());
 370
 371         /* Fixup boot cpu */
 372         smp_store_cpu_info(boot_cpuid);
 373         cpu_callin_map[boot_cpuid] = 1;
 374
 375         for_each_possible_cpu(cpu) {
 376                 zalloc_cpumask_var_node(&per_cpu(cpu_sibling_map, cpu),
 377                                         GFP_KERNEL, cpu_to_node(cpu));
 378                 zalloc_cpumask_var_node(&per_cpu(cpu_core_map, cpu),
 379                                         GFP_KERNEL, cpu_to_node(cpu));
 380                 /*
 381                  * numa_node_id() works after this.
 382                  */
 383                 if (cpu_present(cpu)) {
 384                         set_cpu_numa_node(cpu, numa_cpu_lookup_table[cpu]);
 385                         set_cpu_numa_mem(cpu,
 386                                 local_memory_node(numa_cpu_lookup_table[cpu]));
 387                 }
 388         }
 389
 390         cpumask_set_cpu(boot_cpuid, cpu_sibling_mask(boot_cpuid));
 391         cpumask_set_cpu(boot_cpuid, cpu_core_mask(boot_cpuid));
 392
 393         if (smp_ops && smp_ops->probe)
 394                 smp_ops->probe();
 395 }
 396
 397 void smp_prepare_boot_cpu(void)
 398 {
 399         BUG_ON(smp_processor_id() != boot_cpuid);
 400 #ifdef CONFIG_PPC64
 401         paca[boot_cpuid].__current = current;
 402 #endif
 403         set_numa_node(numa_cpu_lookup_table[boot_cpuid]);
 404         current_set[boot_cpuid] = task_thread_info(current);
 405 }
 406
 407 #ifdef CONFIG_HOTPLUG_CPU
 408
 409 int generic_cpu_disable(void)
 410 {
 411         unsigned int cpu = smp_processor_id();
 412
 413         if (cpu == boot_cpuid)
 414                 return -EBUSY;
 415
 416         set_cpu_online(cpu, false);
 417 #ifdef CONFIG_PPC64
 418         vdso_data->processorCount--;
 419 #endif
 420         migrate_irqs();
 421         return 0;
 422 }
 423
 424 void generic_cpu_die(unsigned int cpu)
 425 {
 426         int i;
 427
 428         for (i = 0; i < 100; i++) {
 429                 smp_rmb();
 430                 if (per_cpu(cpu_state, cpu) == CPU_DEAD)
 431                         return;
 432                 msleep(100);
 433         }
 434         printk(KERN_ERR "CPU%d didn't die...\n", cpu);
 435 }
 436
 437 void generic_set_cpu_dead(unsigned int cpu)
 438 {
 439         per_cpu(cpu_state, cpu) = CPU_DEAD;
 440 }
 441
 442 /*
 443  * The cpu_state should be set to CPU_UP_PREPARE in kick_cpu(), otherwise
 444  * the cpu_state is always CPU_DEAD after calling generic_set_cpu_dead(),
 445  * which makes the delay in generic_cpu_die() not happen.
 446  */
 447 void generic_set_cpu_up(unsigned int cpu)
 448 {
 449         per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
 450 }
 451
 452 int generic_check_cpu_restart(unsigned int cpu)
 453 {
 454         return per_cpu(cpu_state, cpu) == CPU_UP_PREPARE;
 455 }
 456
 457 static bool secondaries_inhibited(void)
 458 {
 459         return kvm_hv_mode_active();
 460 }
 461
 462 #else /* HOTPLUG_CPU */
 463
 464 #define secondaries_inhibited()         0
 465
 466 #endif
 467
 468 static void cpu_idle_thread_init(unsigned int cpu, struct task_struct *idle)
 469 {
 470         struct thread_info *ti = task_thread_info(idle);
 471
 472 #ifdef CONFIG_PPC64
 473         paca[cpu].__current = idle;
 474         paca[cpu].kstack = (unsigned long)ti + THREAD_SIZE - STACK_FRAME_OVERHEAD;
 475 #endif
 476         ti->cpu = cpu;
 477         secondary_ti = current_set[cpu] = ti;
 478 }
 479
 480 int __cpu_up(unsigned int cpu, struct task_struct *tidle)
 481 {
 482         int rc, c;
 483
 484         /*
 485          * Don't allow secondary threads to come online if inhibited
 486          */
 487         if (threads_per_core > 1 && secondaries_inhibited() &&
 488             cpu_thread_in_subcore(cpu))
 489                 return -EBUSY;
 490
 491         if (smp_ops == NULL ||
 492             (smp_ops->cpu_bootable && !smp_ops->cpu_bootable(cpu)))
 493                 return -EINVAL;
 494
 495         cpu_idle_thread_init(cpu, tidle);
 496
 497         /* Make sure callin-map entry is 0 (can be leftover a CPU
 498          * hotplug
 499          */
 500         cpu_callin_map[cpu] = 0;
 501
 502         /* The information for processor bringup must
 503          * be written out to main store before we release
 504          * the processor.
 505          */
 506         smp_mb();
 507
 508         /* wake up cpus */
 509         DBG("smp: kicking cpu %d\n", cpu);
 510         rc = smp_ops->kick_cpu(cpu);
 511         if (rc) {
 512                 pr_err("smp: failed starting cpu %d (rc %d)\n", cpu, rc);
 513                 return rc;
 514         }
 515
 516         /*
 517          * wait to see if the cpu made a callin (is actually up).
 518          * use this value that I found through experimentation.
 519          * -- Cort
 520          */
 521         if (system_state < SYSTEM_RUNNING)
 522                 for (c = 50000; c && !cpu_callin_map[cpu]; c--)
 523                         udelay(100);
 524 #ifdef CONFIG_HOTPLUG_CPU
 525         else
 526                 /*
 527                  * CPUs can take much longer to come up in the
 528                  * hotplug case.  Wait five seconds.
 529                  */
 530                 for (c = 5000; c && !cpu_callin_map[cpu]; c--)
 531                         msleep(1);
 532 #endif
 533
 534         if (!cpu_callin_map[cpu]) {
 535                 printk(KERN_ERR "Processor %u is stuck.\n", cpu);
 536                 return -ENOENT;
 537         }
 538
 539         DBG("Processor %u found.\n", cpu);
 540
 541         if (smp_ops->give_timebase)
 542                 smp_ops->give_timebase();
 543
 544         /* Wait until cpu puts itself in the online & active maps */
 545         while (!cpu_online(cpu) || !cpu_active(cpu))
 546                 cpu_relax();
 547
 548         return 0;
 549 }
 550
 551 /* Return the value of the reg property corresponding to the given
 552  * logical cpu.
 553  */
 554 int cpu_to_core_id(int cpu)
 555 {
 556         struct device_node *np;
 557         const __be32 *reg;
 558         int id = -1;
 559
 560         np = of_get_cpu_node(cpu, NULL);
 561         if (!np)
 562                 goto out;
 563
 564         reg = of_get_property(np, "reg", NULL);
 565         if (!reg)
 566                 goto out;
 567
 568         id = be32_to_cpup(reg);
 569 out:
 570         of_node_put(np);
 571         return id;
 572 }
 573
 574 /* Helper routines for cpu to core mapping */
 575 int cpu_core_index_of_thread(int cpu)
 576 {
 577         return cpu >> threads_shift;
 578 }
 579 EXPORT_SYMBOL_GPL(cpu_core_index_of_thread);
 580
 581 int cpu_first_thread_of_core(int core)
 582 {
 583         return core << threads_shift;
 584 }
 585 EXPORT_SYMBOL_GPL(cpu_first_thread_of_core);
 586
 587 static void traverse_siblings_chip_id(int cpu, bool add, int chipid)
 588 {
 589         const struct cpumask *mask;
 590         struct device_node *np;
 591         int i, plen;
 592         const __be32 *prop;
 593
 594         mask = add ? cpu_online_mask : cpu_present_mask;
 595         for_each_cpu(i, mask) {
 596                 np = of_get_cpu_node(i, NULL);
 597                 if (!np)
 598                         continue;
 599                 prop = of_get_property(np, "ibm,chip-id", &plen);
 600                 if (prop && plen == sizeof(int) &&
 601                     of_read_number(prop, 1) == chipid) {
 602                         if (add) {
 603                                 cpumask_set_cpu(cpu, cpu_core_mask(i));
 604                                 cpumask_set_cpu(i, cpu_core_mask(cpu));
 605                         } else {
 606                                 cpumask_clear_cpu(cpu, cpu_core_mask(i));
 607                                 cpumask_clear_cpu(i, cpu_core_mask(cpu));
 608                         }
 609                 }
 610                 of_node_put(np);
 611         }
 612 }
 613
 614 /* Must be called when no change can occur to cpu_present_mask,
 615  * i.e. during cpu online or offline.
 616  */
 617 static struct device_node *cpu_to_l2cache(int cpu)
 618 {
 619         struct device_node *np;
 620         struct device_node *cache;
 621
 622         if (!cpu_present(cpu))
 623                 return NULL;
 624
 625         np = of_get_cpu_node(cpu, NULL);
 626         if (np == NULL)
 627                 return NULL;
 628
 629         cache = of_find_next_cache_node(np);
 630
 631         of_node_put(np);
 632
 633         return cache;
 634 }
 635
 636 static void traverse_core_siblings(int cpu, bool add)
 637 {
 638         struct device_node *l2_cache, *np;
 639         const struct cpumask *mask;
 640         int i, chip, plen;
 641         const __be32 *prop;
 642
 643         /* First see if we have ibm,chip-id properties in cpu nodes */
 644         np = of_get_cpu_node(cpu, NULL);
 645         if (np) {
 646                 chip = -1;
 647                 prop = of_get_property(np, "ibm,chip-id", &plen);
 648                 if (prop && plen == sizeof(int))
 649                         chip = of_read_number(prop, 1);
 650                 of_node_put(np);
 651                 if (chip >= 0) {
 652                         traverse_siblings_chip_id(cpu, add, chip);
 653                         return;
 654                 }
 655         }
 656
 657         l2_cache = cpu_to_l2cache(cpu);
 658         mask = add ? cpu_online_mask : cpu_present_mask;
 659         for_each_cpu(i, mask) {
 660                 np = cpu_to_l2cache(i);
 661                 if (!np)
 662                         continue;
 663                 if (np == l2_cache) {
 664                         if (add) {
 665                                 cpumask_set_cpu(cpu, cpu_core_mask(i));
 666                                 cpumask_set_cpu(i, cpu_core_mask(cpu));
 667                         } else {
 668                                 cpumask_clear_cpu(cpu, cpu_core_mask(i));
 669                                 cpumask_clear_cpu(i, cpu_core_mask(cpu));
 670                         }
 671                 }
 672                 of_node_put(np);
 673         }
 674         of_node_put(l2_cache);
 675 }
 676
 677 /* Activate a secondary processor. */
 678 void start_secondary(void *unused)
 679 {
 680         unsigned int cpu = smp_processor_id();
 681         int i, base;
 682
 683         atomic_inc(&init_mm.mm_count);
 684         current->active_mm = &init_mm;
 685
 686         smp_store_cpu_info(cpu);
 687         set_dec(tb_ticks_per_jiffy);
 688         preempt_disable();
 689         cpu_callin_map[cpu] = 1;
 690
 691         if (smp_ops->setup_cpu)
 692                 smp_ops->setup_cpu(cpu);
 693         if (smp_ops->take_timebase)
 694                 smp_ops->take_timebase();
 695
 696         secondary_cpu_time_init();
 697
 698 #ifdef CONFIG_PPC64
 699         if (system_state == SYSTEM_RUNNING)
 700                 vdso_data->processorCount++;
 701
 702         vdso_getcpu_init();
 703 #endif
 704         /* Update sibling maps */
 705         base = cpu_first_thread_sibling(cpu);
 706         for (i = 0; i < threads_per_core; i++) {
 707                 if (cpu_is_offline(base + i) && (cpu != base + i))
 708                         continue;
 709                 cpumask_set_cpu(cpu, cpu_sibling_mask(base + i));
 710                 cpumask_set_cpu(base + i, cpu_sibling_mask(cpu));
 711
 712                 /* cpu_core_map should be a superset of
 713                  * cpu_sibling_map even if we don't have cache
 714                  * information, so update the former here, too.
 715                  */
 716                 cpumask_set_cpu(cpu, cpu_core_mask(base + i));
 717                 cpumask_set_cpu(base + i, cpu_core_mask(cpu));
 718         }
 719         traverse_core_siblings(cpu, true);
 720
 721         set_numa_node(numa_cpu_lookup_table[cpu]);
 722         set_numa_mem(local_memory_node(numa_cpu_lookup_table[cpu]));
 723
 724         smp_wmb();
 725         notify_cpu_starting(cpu);
 726         set_cpu_online(cpu, true);
 727
 728         local_irq_enable();
 729
 730         cpu_startup_entry(CPUHP_ONLINE);
 731
 732         BUG();
 733 }
 734
 735 int setup_profiling_timer(unsigned int multiplier)
 736 {
 737         return 0;
 738 }
 739
 740 #ifdef CONFIG_SCHED_SMT
 741 /* cpumask of CPUs with asymetric SMT dependancy */
 742 static int powerpc_smt_flags(void)
 743 {
 744         int flags = SD_SHARE_CPUCAPACITY | SD_SHARE_PKG_RESOURCES;
 745
 746         if (cpu_has_feature(CPU_FTR_ASYM_SMT)) {
 747                 printk_once(KERN_INFO "Enabling Asymmetric SMT scheduling\n");
 748                 flags |= SD_ASYM_PACKING;
 749         }
 750         return flags;
 751 }
 752 #endif
 753
 754 static struct sched_domain_topology_level powerpc_topology[] = {
 755 #ifdef CONFIG_SCHED_SMT
 756         { cpu_smt_mask, powerpc_smt_flags, SD_INIT_NAME(SMT) },
 757 #endif
 758         { cpu_cpu_mask, SD_INIT_NAME(DIE) },
 759         { NULL, },
 760 };
 761
 762 void __init smp_cpus_done(unsigned int max_cpus)
 763 {
 764         cpumask_var_t old_mask;
 765
 766         /* We want the setup_cpu() here to be called from CPU 0, but our
 767          * init thread may have been "borrowed" by another CPU in the meantime
 768          * se we pin us down to CPU 0 for a short while
 769          */
 770         alloc_cpumask_var(&old_mask, GFP_NOWAIT);
 771         cpumask_copy(old_mask, tsk_cpus_allowed(current));
 772         set_cpus_allowed_ptr(current, cpumask_of(boot_cpuid));
 773
 774         if (smp_ops && smp_ops->setup_cpu)
 775                 smp_ops->setup_cpu(boot_cpuid);
 776
 777         set_cpus_allowed_ptr(current, old_mask);
 778
 779         free_cpumask_var(old_mask);
 780
 781         if (smp_ops && smp_ops->bringup_done)
 782                 smp_ops->bringup_done();
 783
 784         dump_numa_cpu_topology();
 785
 786         set_sched_topology(powerpc_topology);
 787
 788 }
 789
 790 #ifdef CONFIG_HOTPLUG_CPU
 791 int __cpu_disable(void)
 792 {
 793         int cpu = smp_processor_id();
 794         int base, i;
 795         int err;
 796
 797         if (!smp_ops->cpu_disable)
 798                 return -ENOSYS;
 799
 800         err = smp_ops->cpu_disable();
 801         if (err)
 802                 return err;
 803
 804         /* Update sibling maps */
 805         base = cpu_first_thread_sibling(cpu);
 806         for (i = 0; i < threads_per_core; i++) {
 807                 cpumask_clear_cpu(cpu, cpu_sibling_mask(base + i));
 808                 cpumask_clear_cpu(base + i, cpu_sibling_mask(cpu));
 809                 cpumask_clear_cpu(cpu, cpu_core_mask(base + i));
 810                 cpumask_clear_cpu(base + i, cpu_core_mask(cpu));
 811         }
 812         traverse_core_siblings(cpu, false);
 813
 814         return 0;
 815 }
 816
 817 void __cpu_die(unsigned int cpu)
 818 {
 819         if (smp_ops->cpu_die)
 820                 smp_ops->cpu_die(cpu);
 821 }
 822
 823 void cpu_die(void)
 824 {
 825         if (ppc_md.cpu_die)
 826                 ppc_md.cpu_die();
 827
 828         /* If we return, we re-enter start_secondary */
 829         start_secondary_resume();
 830 }
 831
 832 #endif