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/page.h>
  40 #include <asm/pgtable.h>
  41 #include <asm/prom.h>
  42 #include <asm/smp.h>
  43 #include <asm/time.h>
  44 #include <asm/machdep.h>
  45 #include <asm/cputhreads.h>
  46 #include <asm/cputable.h>
  47 #include <asm/mpic.h>
  48 #include <asm/vdso_datapage.h>
  49 #ifdef CONFIG_PPC64
  50 #include <asm/paca.h>
  51 #endif
  52 #include <asm/vdso.h>
  53 #include <asm/debug.h>
  54
  55 #ifdef DEBUG
  56 #include <asm/udbg.h>
  57 #define DBG(fmt...) udbg_printf(fmt)
  58 #else
  59 #define DBG(fmt...)
  60 #endif
  61
  62 #ifdef CONFIG_HOTPLUG_CPU
  63 /* State of each CPU during hotplug phases */
  64 static DEFINE_PER_CPU(int, cpu_state) = { 0 };
  65 #endif
  66
  67 struct thread_info *secondary_ti;
  68
  69 DEFINE_PER_CPU(cpumask_var_t, cpu_sibling_map);
  70 DEFINE_PER_CPU(cpumask_var_t, cpu_core_map);
  71
  72 EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
  73 EXPORT_PER_CPU_SYMBOL(cpu_core_map);
  74
  75 /* SMP operations for this machine */
  76 struct smp_ops_t *smp_ops;
  77
  78 /* Can't be static due to PowerMac hackery */
  79 volatile unsigned int cpu_callin_map[NR_CPUS];
  80
  81 int smt_enabled_at_boot = 1;
  82
  83 static void (*crash_ipi_function_ptr)(struct pt_regs *) = NULL;
  84
  85 /*
  86  * Returns 1 if the specified cpu should be brought up during boot.
  87  * Used to inhibit booting threads if they've been disabled or
  88  * limited on the command line
  89  */
  90 int smp_generic_cpu_bootable(unsigned int nr)
  91 {
  92         /* Special case - we inhibit secondary thread startup
  93          * during boot if the user requests it.
  94          */
  95         if (system_state == SYSTEM_BOOTING && cpu_has_feature(CPU_FTR_SMT)) {
  96                 if (!smt_enabled_at_boot && cpu_thread_in_core(nr) != 0)
  97                         return 0;
  98                 if (smt_enabled_at_boot
  99                     && cpu_thread_in_core(nr) >= smt_enabled_at_boot)
 100                         return 0;
 101         }
 102
 103         return 1;
 104 }
 105
 106
 107 #ifdef CONFIG_PPC64
 108 int smp_generic_kick_cpu(int nr)
 109 {
 110         BUG_ON(nr < 0 || nr >= NR_CPUS);
 111
 112         /*
 113          * The processor is currently spinning, waiting for the
 114          * cpu_start field to become non-zero After we set cpu_start,
 115          * the processor will continue on to secondary_start
 116          */
 117         if (!paca[nr].cpu_start) {
 118                 paca[nr].cpu_start = 1;
 119                 smp_mb();
 120                 return 0;
 121         }
 122
 123 #ifdef CONFIG_HOTPLUG_CPU
 124         /*
 125          * Ok it's not there, so it might be soft-unplugged, let's
 126          * try to bring it back
 127          */
 128         generic_set_cpu_up(nr);
 129         smp_wmb();
 130         smp_send_reschedule(nr);
 131 #endif /* CONFIG_HOTPLUG_CPU */
 132
 133         return 0;
 134 }
 135 #endif /* CONFIG_PPC64 */
 136
 137 static irqreturn_t call_function_action(int irq, void *data)
 138 {
 139         generic_smp_call_function_interrupt();
 140         return IRQ_HANDLED;
 141 }
 142
 143 static irqreturn_t reschedule_action(int irq, void *data)
 144 {
 145         scheduler_ipi();
 146         return IRQ_HANDLED;
 147 }
 148
 149 static irqreturn_t tick_broadcast_ipi_action(int irq, void *data)
 150 {
 151         tick_broadcast_ipi_handler();
 152         return IRQ_HANDLED;
 153 }
 154
 155 static irqreturn_t debug_ipi_action(int irq, void *data)
 156 {
 157         if (crash_ipi_function_ptr) {
 158                 crash_ipi_function_ptr(get_irq_regs());
 159                 return IRQ_HANDLED;
 160         }
 161
 162 #ifdef CONFIG_DEBUGGER
 163         debugger_ipi(get_irq_regs());
 164 #endif /* CONFIG_DEBUGGER */
 165
 166         return IRQ_HANDLED;
 167 }
 168
 169 static irq_handler_t smp_ipi_action[] = {
 170         [PPC_MSG_CALL_FUNCTION] =  call_function_action,
 171         [PPC_MSG_RESCHEDULE] = reschedule_action,
 172         [PPC_MSG_TICK_BROADCAST] = tick_broadcast_ipi_action,
 173         [PPC_MSG_DEBUGGER_BREAK] = debug_ipi_action,
 174 };
 175
 176 const char *smp_ipi_name[] = {
 177         [PPC_MSG_CALL_FUNCTION] =  "ipi call function",
 178         [PPC_MSG_RESCHEDULE] = "ipi reschedule",
 179         [PPC_MSG_TICK_BROADCAST] = "ipi tick-broadcast",
 180         [PPC_MSG_DEBUGGER_BREAK] = "ipi debugger",
 181 };
 182
 183 /* optional function to request ipi, for controllers with >= 4 ipis */
 184 int smp_request_message_ipi(int virq, int msg)
 185 {
 186         int err;
 187
 188         if (msg < 0 || msg > PPC_MSG_DEBUGGER_BREAK) {
 189                 return -EINVAL;
 190         }
 191 #if !defined(CONFIG_DEBUGGER) && !defined(CONFIG_KEXEC)
 192         if (msg == PPC_MSG_DEBUGGER_BREAK) {
 193                 return 1;
 194         }
 195 #endif
 196         err = request_irq(virq, smp_ipi_action[msg],
 197                           IRQF_PERCPU | IRQF_NO_THREAD | IRQF_NO_SUSPEND,
 198                           smp_ipi_name[msg], NULL);
 199         WARN(err < 0, "unable to request_irq %d for %s (rc %d)\n",
 200                 virq, smp_ipi_name[msg], err);
 201
 202         return err;
 203 }
 204
 205 #ifdef CONFIG_PPC_SMP_MUXED_IPI
 206 struct cpu_messages {
 207         int messages;                   /* current messages */
 208         unsigned long data;             /* data for cause ipi */
 209 };
 210 static DEFINE_PER_CPU_SHARED_ALIGNED(struct cpu_messages, ipi_message);
 211
 212 void smp_muxed_ipi_set_data(int cpu, unsigned long data)
 213 {
 214         struct cpu_messages *info = &per_cpu(ipi_message, cpu);
 215
 216         info->data = data;
 217 }
 218
 219 void smp_muxed_ipi_message_pass(int cpu, int msg)
 220 {
 221         struct cpu_messages *info = &per_cpu(ipi_message, cpu);
 222         char *message = (char *)&info->messages;
 223
 224         /*
 225          * Order previous accesses before accesses in the IPI handler.
 226          */
 227         smp_mb();
 228         message[msg] = 1;
 229         /*
 230          * cause_ipi functions are required to include a full barrier
 231          * before doing whatever causes the IPI.
 232          */
 233         smp_ops->cause_ipi(cpu, info->data);
 234 }
 235
 236 #ifdef __BIG_ENDIAN__
 237 #define IPI_MESSAGE(A) (1 << (24 - 8 * (A)))
 238 #else
 239 #define IPI_MESSAGE(A) (1 << (8 * (A)))
 240 #endif
 241
 242 irqreturn_t smp_ipi_demux(void)
 243 {
 244         struct cpu_messages *info = &__get_cpu_var(ipi_message);
 245         unsigned int all;
 246
 247         mb();   /* order any irq clear */
 248
 249         do {
 250                 all = xchg(&info->messages, 0);
 251                 if (all & IPI_MESSAGE(PPC_MSG_CALL_FUNCTION))
 252                         generic_smp_call_function_interrupt();
 253                 if (all & IPI_MESSAGE(PPC_MSG_RESCHEDULE))
 254                         scheduler_ipi();
 255                 if (all & IPI_MESSAGE(PPC_MSG_TICK_BROADCAST))
 256                         tick_broadcast_ipi_handler();
 257                 if (all & IPI_MESSAGE(PPC_MSG_DEBUGGER_BREAK))
 258                         debug_ipi_action(0, NULL);
 259         } while (info->messages);
 260
 261         return IRQ_HANDLED;
 262 }
 263 #endif /* CONFIG_PPC_SMP_MUXED_IPI */
 264
 265 static inline void do_message_pass(int cpu, int msg)
 266 {
 267         if (smp_ops->message_pass)
 268                 smp_ops->message_pass(cpu, msg);
 269 #ifdef CONFIG_PPC_SMP_MUXED_IPI
 270         else
 271                 smp_muxed_ipi_message_pass(cpu, msg);
 272 #endif
 273 }
 274
 275 void smp_send_reschedule(int cpu)
 276 {
 277         if (likely(smp_ops))
 278                 do_message_pass(cpu, PPC_MSG_RESCHEDULE);
 279 }
 280 EXPORT_SYMBOL_GPL(smp_send_reschedule);
 281
 282 void arch_send_call_function_single_ipi(int cpu)
 283 {
 284         do_message_pass(cpu, PPC_MSG_CALL_FUNCTION);
 285 }
 286
 287 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
 288 {
 289         unsigned int cpu;
 290
 291         for_each_cpu(cpu, mask)
 292                 do_message_pass(cpu, PPC_MSG_CALL_FUNCTION);
 293 }
 294
 295 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
 296 void tick_broadcast(const struct cpumask *mask)
 297 {
 298         unsigned int cpu;
 299
 300         for_each_cpu(cpu, mask)
 301                 do_message_pass(cpu, PPC_MSG_TICK_BROADCAST);
 302 }
 303 #endif
 304
 305 #if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC)
 306 void smp_send_debugger_break(void)
 307 {
 308         int cpu;
 309         int me = raw_smp_processor_id();
 310
 311         if (unlikely(!smp_ops))
 312                 return;
 313
 314         for_each_online_cpu(cpu)
 315                 if (cpu != me)
 316                         do_message_pass(cpu, PPC_MSG_DEBUGGER_BREAK);
 317 }
 318 #endif
 319
 320 #ifdef CONFIG_KEXEC
 321 void crash_send_ipi(void (*crash_ipi_callback)(struct pt_regs *))
 322 {
 323         crash_ipi_function_ptr = crash_ipi_callback;
 324         if (crash_ipi_callback) {
 325                 mb();
 326                 smp_send_debugger_break();
 327         }
 328 }
 329 #endif
 330
 331 static void stop_this_cpu(void *dummy)
 332 {
 333         /* Remove this CPU */
 334         set_cpu_online(smp_processor_id(), false);
 335
 336         local_irq_disable();
 337         while (1)
 338                 ;
 339 }
 340
 341 void smp_send_stop(void)
 342 {
 343         smp_call_function(stop_this_cpu, NULL, 0);
 344 }
 345
 346 struct thread_info *current_set[NR_CPUS];
 347
 348 static void smp_store_cpu_info(int id)
 349 {
 350         per_cpu(cpu_pvr, id) = mfspr(SPRN_PVR);
 351 #ifdef CONFIG_PPC_FSL_BOOK3E
 352         per_cpu(next_tlbcam_idx, id)
 353                 = (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) - 1;
 354 #endif
 355 }
 356
 357 void __init smp_prepare_cpus(unsigned int max_cpus)
 358 {
 359         unsigned int cpu;
 360
 361         DBG("smp_prepare_cpus\n");
 362
 363         /*
 364          * setup_cpu may need to be called on the boot cpu. We havent
 365          * spun any cpus up but lets be paranoid.
 366          */
 367         BUG_ON(boot_cpuid != smp_processor_id());
 368
 369         /* Fixup boot cpu */
 370         smp_store_cpu_info(boot_cpuid);
 371         cpu_callin_map[boot_cpuid] = 1;
 372
 373         for_each_possible_cpu(cpu) {
 374                 zalloc_cpumask_var_node(&per_cpu(cpu_sibling_map, cpu),
 375                                         GFP_KERNEL, cpu_to_node(cpu));
 376                 zalloc_cpumask_var_node(&per_cpu(cpu_core_map, cpu),
 377                                         GFP_KERNEL, cpu_to_node(cpu));
 378         }
 379
 380         cpumask_set_cpu(boot_cpuid, cpu_sibling_mask(boot_cpuid));
 381         cpumask_set_cpu(boot_cpuid, cpu_core_mask(boot_cpuid));
 382
 383         if (smp_ops && smp_ops->probe)
 384                 smp_ops->probe();
 385 }
 386
 387 void smp_prepare_boot_cpu(void)
 388 {
 389         BUG_ON(smp_processor_id() != boot_cpuid);
 390 #ifdef CONFIG_PPC64
 391         paca[boot_cpuid].__current = current;
 392 #endif
 393         current_set[boot_cpuid] = task_thread_info(current);
 394 }
 395
 396 #ifdef CONFIG_HOTPLUG_CPU
 397
 398 int generic_cpu_disable(void)
 399 {
 400         unsigned int cpu = smp_processor_id();
 401
 402         if (cpu == boot_cpuid)
 403                 return -EBUSY;
 404
 405         set_cpu_online(cpu, false);
 406 #ifdef CONFIG_PPC64
 407         vdso_data->processorCount--;
 408 #endif
 409         migrate_irqs();
 410         return 0;
 411 }
 412
 413 void generic_cpu_die(unsigned int cpu)
 414 {
 415         int i;
 416
 417         for (i = 0; i < 100; i++) {
 418                 smp_rmb();
 419                 if (per_cpu(cpu_state, cpu) == CPU_DEAD)
 420                         return;
 421                 msleep(100);
 422         }
 423         printk(KERN_ERR "CPU%d didn't die...\n", cpu);
 424 }
 425
 426 void generic_mach_cpu_die(void)
 427 {
 428         unsigned int cpu;
 429
 430         local_irq_disable();
 431         idle_task_exit();
 432         cpu = smp_processor_id();
 433         printk(KERN_DEBUG "CPU%d offline\n", cpu);
 434         __get_cpu_var(cpu_state) = CPU_DEAD;
 435         smp_wmb();
 436         while (__get_cpu_var(cpu_state) != CPU_UP_PREPARE)
 437                 cpu_relax();
 438 }
 439
 440 void generic_set_cpu_dead(unsigned int cpu)
 441 {
 442         per_cpu(cpu_state, cpu) = CPU_DEAD;
 443 }
 444
 445 /*
 446  * The cpu_state should be set to CPU_UP_PREPARE in kick_cpu(), otherwise
 447  * the cpu_state is always CPU_DEAD after calling generic_set_cpu_dead(),
 448  * which makes the delay in generic_cpu_die() not happen.
 449  */
 450 void generic_set_cpu_up(unsigned int cpu)
 451 {
 452         per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
 453 }
 454
 455 int generic_check_cpu_restart(unsigned int cpu)
 456 {
 457         return per_cpu(cpu_state, cpu) == CPU_UP_PREPARE;
 458 }
 459
 460 static atomic_t secondary_inhibit_count;
 461
 462 /*
 463  * Don't allow secondary CPU threads to come online
 464  */
 465 void inhibit_secondary_onlining(void)
 466 {
 467         /*
 468          * This makes secondary_inhibit_count stable during cpu
 469          * online/offline operations.
 470          */
 471         get_online_cpus();
 472
 473         atomic_inc(&secondary_inhibit_count);
 474         put_online_cpus();
 475 }
 476 EXPORT_SYMBOL_GPL(inhibit_secondary_onlining);
 477
 478 /*
 479  * Allow secondary CPU threads to come online again
 480  */
 481 void uninhibit_secondary_onlining(void)
 482 {
 483         get_online_cpus();
 484         atomic_dec(&secondary_inhibit_count);
 485         put_online_cpus();
 486 }
 487 EXPORT_SYMBOL_GPL(uninhibit_secondary_onlining);
 488
 489 static int secondaries_inhibited(void)
 490 {
 491         return atomic_read(&secondary_inhibit_count);
 492 }
 493
 494 #else /* HOTPLUG_CPU */
 495
 496 #define secondaries_inhibited()         0
 497
 498 #endif
 499
 500 static void cpu_idle_thread_init(unsigned int cpu, struct task_struct *idle)
 501 {
 502         struct thread_info *ti = task_thread_info(idle);
 503
 504 #ifdef CONFIG_PPC64
 505         paca[cpu].__current = idle;
 506         paca[cpu].kstack = (unsigned long)ti + THREAD_SIZE - STACK_FRAME_OVERHEAD;
 507 #endif
 508         ti->cpu = cpu;
 509         secondary_ti = current_set[cpu] = ti;
 510 }
 511
 512 int __cpu_up(unsigned int cpu, struct task_struct *tidle)
 513 {
 514         int rc, c;
 515
 516         /*
 517          * Don't allow secondary threads to come online if inhibited
 518          */
 519         if (threads_per_core > 1 && secondaries_inhibited() &&
 520             cpu % threads_per_core != 0)
 521                 return -EBUSY;
 522
 523         if (smp_ops == NULL ||
 524             (smp_ops->cpu_bootable && !smp_ops->cpu_bootable(cpu)))
 525                 return -EINVAL;
 526
 527         cpu_idle_thread_init(cpu, tidle);
 528
 529         /* Make sure callin-map entry is 0 (can be leftover a CPU
 530          * hotplug
 531          */
 532         cpu_callin_map[cpu] = 0;
 533
 534         /* The information for processor bringup must
 535          * be written out to main store before we release
 536          * the processor.
 537          */
 538         smp_mb();
 539
 540         /* wake up cpus */
 541         DBG("smp: kicking cpu %d\n", cpu);
 542         rc = smp_ops->kick_cpu(cpu);
 543         if (rc) {
 544                 pr_err("smp: failed starting cpu %d (rc %d)\n", cpu, rc);
 545                 return rc;
 546         }
 547
 548         /*
 549          * wait to see if the cpu made a callin (is actually up).
 550          * use this value that I found through experimentation.
 551          * -- Cort
 552          */
 553         if (system_state < SYSTEM_RUNNING)
 554                 for (c = 50000; c && !cpu_callin_map[cpu]; c--)
 555                         udelay(100);
 556 #ifdef CONFIG_HOTPLUG_CPU
 557         else
 558                 /*
 559                  * CPUs can take much longer to come up in the
 560                  * hotplug case.  Wait five seconds.
 561                  */
 562                 for (c = 5000; c && !cpu_callin_map[cpu]; c--)
 563                         msleep(1);
 564 #endif
 565
 566         if (!cpu_callin_map[cpu]) {
 567                 printk(KERN_ERR "Processor %u is stuck.\n", cpu);
 568                 return -ENOENT;
 569         }
 570
 571         DBG("Processor %u found.\n", cpu);
 572
 573         if (smp_ops->give_timebase)
 574                 smp_ops->give_timebase();
 575
 576         /* Wait until cpu puts itself in the online map */
 577         while (!cpu_online(cpu))
 578                 cpu_relax();
 579
 580         return 0;
 581 }
 582
 583 /* Return the value of the reg property corresponding to the given
 584  * logical cpu.
 585  */
 586 int cpu_to_core_id(int cpu)
 587 {
 588         struct device_node *np;
 589         const __be32 *reg;
 590         int id = -1;
 591
 592         np = of_get_cpu_node(cpu, NULL);
 593         if (!np)
 594                 goto out;
 595
 596         reg = of_get_property(np, "reg", NULL);
 597         if (!reg)
 598                 goto out;
 599
 600         id = be32_to_cpup(reg);
 601 out:
 602         of_node_put(np);
 603         return id;
 604 }
 605
 606 /* Helper routines for cpu to core mapping */
 607 int cpu_core_index_of_thread(int cpu)
 608 {
 609         return cpu >> threads_shift;
 610 }
 611 EXPORT_SYMBOL_GPL(cpu_core_index_of_thread);
 612
 613 int cpu_first_thread_of_core(int core)
 614 {
 615         return core << threads_shift;
 616 }
 617 EXPORT_SYMBOL_GPL(cpu_first_thread_of_core);
 618
 619 static void traverse_siblings_chip_id(int cpu, bool add, int chipid)
 620 {
 621         const struct cpumask *mask;
 622         struct device_node *np;
 623         int i, plen;
 624         const __be32 *prop;
 625
 626         mask = add ? cpu_online_mask : cpu_present_mask;
 627         for_each_cpu(i, mask) {
 628                 np = of_get_cpu_node(i, NULL);
 629                 if (!np)
 630                         continue;
 631                 prop = of_get_property(np, "ibm,chip-id", &plen);
 632                 if (prop && plen == sizeof(int) &&
 633                     of_read_number(prop, 1) == chipid) {
 634                         if (add) {
 635                                 cpumask_set_cpu(cpu, cpu_core_mask(i));
 636                                 cpumask_set_cpu(i, cpu_core_mask(cpu));
 637                         } else {
 638                                 cpumask_clear_cpu(cpu, cpu_core_mask(i));
 639                                 cpumask_clear_cpu(i, cpu_core_mask(cpu));
 640                         }
 641                 }
 642                 of_node_put(np);
 643         }
 644 }
 645
 646 /* Must be called when no change can occur to cpu_present_mask,
 647  * i.e. during cpu online or offline.
 648  */
 649 static struct device_node *cpu_to_l2cache(int cpu)
 650 {
 651         struct device_node *np;
 652         struct device_node *cache;
 653
 654         if (!cpu_present(cpu))
 655                 return NULL;
 656
 657         np = of_get_cpu_node(cpu, NULL);
 658         if (np == NULL)
 659                 return NULL;
 660
 661         cache = of_find_next_cache_node(np);
 662
 663         of_node_put(np);
 664
 665         return cache;
 666 }
 667
 668 static void traverse_core_siblings(int cpu, bool add)
 669 {
 670         struct device_node *l2_cache, *np;
 671         const struct cpumask *mask;
 672         int i, chip, plen;
 673         const __be32 *prop;
 674
 675         /* First see if we have ibm,chip-id properties in cpu nodes */
 676         np = of_get_cpu_node(cpu, NULL);
 677         if (np) {
 678                 chip = -1;
 679                 prop = of_get_property(np, "ibm,chip-id", &plen);
 680                 if (prop && plen == sizeof(int))
 681                         chip = of_read_number(prop, 1);
 682                 of_node_put(np);
 683                 if (chip >= 0) {
 684                         traverse_siblings_chip_id(cpu, add, chip);
 685                         return;
 686                 }
 687         }
 688
 689         l2_cache = cpu_to_l2cache(cpu);
 690         mask = add ? cpu_online_mask : cpu_present_mask;
 691         for_each_cpu(i, mask) {
 692                 np = cpu_to_l2cache(i);
 693                 if (!np)
 694                         continue;
 695                 if (np == l2_cache) {
 696                         if (add) {
 697                                 cpumask_set_cpu(cpu, cpu_core_mask(i));
 698                                 cpumask_set_cpu(i, cpu_core_mask(cpu));
 699                         } else {
 700                                 cpumask_clear_cpu(cpu, cpu_core_mask(i));
 701                                 cpumask_clear_cpu(i, cpu_core_mask(cpu));
 702                         }
 703                 }
 704                 of_node_put(np);
 705         }
 706         of_node_put(l2_cache);
 707 }
 708
 709 /* Activate a secondary processor. */
 710 void start_secondary(void *unused)
 711 {
 712         unsigned int cpu = smp_processor_id();
 713         int i, base;
 714
 715         atomic_inc(&init_mm.mm_count);
 716         current->active_mm = &init_mm;
 717
 718         smp_store_cpu_info(cpu);
 719         set_dec(tb_ticks_per_jiffy);
 720         preempt_disable();
 721         cpu_callin_map[cpu] = 1;
 722
 723         if (smp_ops->setup_cpu)
 724                 smp_ops->setup_cpu(cpu);
 725         if (smp_ops->take_timebase)
 726                 smp_ops->take_timebase();
 727
 728         secondary_cpu_time_init();
 729
 730 #ifdef CONFIG_PPC64
 731         if (system_state == SYSTEM_RUNNING)
 732                 vdso_data->processorCount++;
 733
 734         vdso_getcpu_init();
 735 #endif
 736         /* Update sibling maps */
 737         base = cpu_first_thread_sibling(cpu);
 738         for (i = 0; i < threads_per_core; i++) {
 739                 if (cpu_is_offline(base + i) && (cpu != base + i))
 740                         continue;
 741                 cpumask_set_cpu(cpu, cpu_sibling_mask(base + i));
 742                 cpumask_set_cpu(base + i, cpu_sibling_mask(cpu));
 743
 744                 /* cpu_core_map should be a superset of
 745                  * cpu_sibling_map even if we don't have cache
 746                  * information, so update the former here, too.
 747                  */
 748                 cpumask_set_cpu(cpu, cpu_core_mask(base + i));
 749                 cpumask_set_cpu(base + i, cpu_core_mask(cpu));
 750         }
 751         traverse_core_siblings(cpu, true);
 752
 753         smp_wmb();
 754         notify_cpu_starting(cpu);
 755         set_cpu_online(cpu, true);
 756
 757         local_irq_enable();
 758
 759         cpu_startup_entry(CPUHP_ONLINE);
 760
 761         BUG();
 762 }
 763
 764 int setup_profiling_timer(unsigned int multiplier)
 765 {
 766         return 0;
 767 }
 768
 769 void __init smp_cpus_done(unsigned int max_cpus)
 770 {
 771         cpumask_var_t old_mask;
 772
 773         /* We want the setup_cpu() here to be called from CPU 0, but our
 774          * init thread may have been "borrowed" by another CPU in the meantime
 775          * se we pin us down to CPU 0 for a short while
 776          */
 777         alloc_cpumask_var(&old_mask, GFP_NOWAIT);
 778         cpumask_copy(old_mask, tsk_cpus_allowed(current));
 779         set_cpus_allowed_ptr(current, cpumask_of(boot_cpuid));
 780
 781         if (smp_ops && smp_ops->setup_cpu)
 782                 smp_ops->setup_cpu(boot_cpuid);
 783
 784         set_cpus_allowed_ptr(current, old_mask);
 785
 786         free_cpumask_var(old_mask);
 787
 788         if (smp_ops && smp_ops->bringup_done)
 789                 smp_ops->bringup_done();
 790
 791         dump_numa_cpu_topology();
 792
 793 }
 794
 795 int arch_sd_sibling_asym_packing(void)
 796 {
 797         if (cpu_has_feature(CPU_FTR_ASYM_SMT)) {
 798                 printk_once(KERN_INFO "Enabling Asymmetric SMT scheduling\n");
 799                 return SD_ASYM_PACKING;
 800         }
 801         return 0;
 802 }
 803
 804 #ifdef CONFIG_HOTPLUG_CPU
 805 int __cpu_disable(void)
 806 {
 807         int cpu = smp_processor_id();
 808         int base, i;
 809         int err;
 810
 811         if (!smp_ops->cpu_disable)
 812                 return -ENOSYS;
 813
 814         err = smp_ops->cpu_disable();
 815         if (err)
 816                 return err;
 817
 818         /* Update sibling maps */
 819         base = cpu_first_thread_sibling(cpu);
 820         for (i = 0; i < threads_per_core; i++) {
 821                 cpumask_clear_cpu(cpu, cpu_sibling_mask(base + i));
 822                 cpumask_clear_cpu(base + i, cpu_sibling_mask(cpu));
 823                 cpumask_clear_cpu(cpu, cpu_core_mask(base + i));
 824                 cpumask_clear_cpu(base + i, cpu_core_mask(cpu));
 825         }
 826         traverse_core_siblings(cpu, false);
 827
 828         return 0;
 829 }
 830
 831 void __cpu_die(unsigned int cpu)
 832 {
 833         if (smp_ops->cpu_die)
 834                 smp_ops->cpu_die(cpu);
 835 }
 836
 837 void cpu_die(void)
 838 {
 839         if (ppc_md.cpu_die)
 840                 ppc_md.cpu_die();
 841
 842         /* If we return, we re-enter start_secondary */
 843         start_secondary_resume();
 844 }
 845
 846 #endif