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 #include <linux/profile.h>
  35
  36 #include <asm/ptrace.h>
  37 #include <linux/atomic.h>
  38 #include <asm/irq.h>
  39 #include <asm/hw_irq.h>
  40 #include <asm/kvm_ppc.h>
  41 #include <asm/page.h>
  42 #include <asm/pgtable.h>
  43 #include <asm/prom.h>
  44 #include <asm/smp.h>
  45 #include <asm/time.h>
  46 #include <asm/machdep.h>
  47 #include <asm/cputhreads.h>
  48 #include <asm/cputable.h>
  49 #include <asm/mpic.h>
  50 #include <asm/vdso_datapage.h>
  51 #ifdef CONFIG_PPC64
  52 #include <asm/paca.h>
  53 #endif
  54 #include <asm/vdso.h>
  55 #include <asm/debug.h>
  56 #include <asm/kexec.h>
  57 #include <asm/asm-prototypes.h>
  58
  59 #ifdef DEBUG
  60 #include <asm/udbg.h>
  61 #define DBG(fmt...) udbg_printf(fmt)
  62 #else
  63 #define DBG(fmt...)
  64 #endif
  65
  66 #ifdef CONFIG_HOTPLUG_CPU
  67 /* State of each CPU during hotplug phases */
  68 static DEFINE_PER_CPU(int, cpu_state) = { 0 };
  69 #endif
  70
  71 struct thread_info *secondary_ti;
  72
  73 DEFINE_PER_CPU(cpumask_var_t, cpu_sibling_map);
  74 DEFINE_PER_CPU(cpumask_var_t, cpu_core_map);
  75
  76 EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
  77 EXPORT_PER_CPU_SYMBOL(cpu_core_map);
  78
  79 /* SMP operations for this machine */
  80 struct smp_ops_t *smp_ops;
  81
  82 /* Can't be static due to PowerMac hackery */
  83 volatile unsigned int cpu_callin_map[NR_CPUS];
  84
  85 int smt_enabled_at_boot = 1;
  86
  87 static void (*crash_ipi_function_ptr)(struct pt_regs *) = NULL;
  88
  89 /*
  90  * Returns 1 if the specified cpu should be brought up during boot.
  91  * Used to inhibit booting threads if they've been disabled or
  92  * limited on the command line
  93  */
  94 int smp_generic_cpu_bootable(unsigned int nr)
  95 {
  96         /* Special case - we inhibit secondary thread startup
  97          * during boot if the user requests it.
  98          */
  99         if (system_state == SYSTEM_BOOTING && cpu_has_feature(CPU_FTR_SMT)) {
 100                 if (!smt_enabled_at_boot && cpu_thread_in_core(nr) != 0)
 101                         return 0;
 102                 if (smt_enabled_at_boot
 103                     && cpu_thread_in_core(nr) >= smt_enabled_at_boot)
 104                         return 0;
 105         }
 106
 107         return 1;
 108 }
 109
 110
 111 #ifdef CONFIG_PPC64
 112 int smp_generic_kick_cpu(int nr)
 113 {
 114         BUG_ON(nr < 0 || nr >= NR_CPUS);
 115
 116         /*
 117          * The processor is currently spinning, waiting for the
 118          * cpu_start field to become non-zero After we set cpu_start,
 119          * the processor will continue on to secondary_start
 120          */
 121         if (!paca[nr].cpu_start) {
 122                 paca[nr].cpu_start = 1;
 123                 smp_mb();
 124                 return 0;
 125         }
 126
 127 #ifdef CONFIG_HOTPLUG_CPU
 128         /*
 129          * Ok it's not there, so it might be soft-unplugged, let's
 130          * try to bring it back
 131          */
 132         generic_set_cpu_up(nr);
 133         smp_wmb();
 134         smp_send_reschedule(nr);
 135 #endif /* CONFIG_HOTPLUG_CPU */
 136
 137         return 0;
 138 }
 139 #endif /* CONFIG_PPC64 */
 140
 141 static irqreturn_t call_function_action(int irq, void *data)
 142 {
 143         generic_smp_call_function_interrupt();
 144         return IRQ_HANDLED;
 145 }
 146
 147 static irqreturn_t reschedule_action(int irq, void *data)
 148 {
 149         scheduler_ipi();
 150         return IRQ_HANDLED;
 151 }
 152
 153 static irqreturn_t tick_broadcast_ipi_action(int irq, void *data)
 154 {
 155         tick_broadcast_ipi_handler();
 156         return IRQ_HANDLED;
 157 }
 158
 159 static irqreturn_t debug_ipi_action(int irq, void *data)
 160 {
 161         if (crash_ipi_function_ptr) {
 162                 crash_ipi_function_ptr(get_irq_regs());
 163                 return IRQ_HANDLED;
 164         }
 165
 166 #ifdef CONFIG_DEBUGGER
 167         debugger_ipi(get_irq_regs());
 168 #endif /* CONFIG_DEBUGGER */
 169
 170         return IRQ_HANDLED;
 171 }
 172
 173 static irq_handler_t smp_ipi_action[] = {
 174         [PPC_MSG_CALL_FUNCTION] =  call_function_action,
 175         [PPC_MSG_RESCHEDULE] = reschedule_action,
 176         [PPC_MSG_TICK_BROADCAST] = tick_broadcast_ipi_action,
 177         [PPC_MSG_DEBUGGER_BREAK] = debug_ipi_action,
 178 };
 179
 180 const char *smp_ipi_name[] = {
 181         [PPC_MSG_CALL_FUNCTION] =  "ipi call function",
 182         [PPC_MSG_RESCHEDULE] = "ipi reschedule",
 183         [PPC_MSG_TICK_BROADCAST] = "ipi tick-broadcast",
 184         [PPC_MSG_DEBUGGER_BREAK] = "ipi debugger",
 185 };
 186
 187 /* optional function to request ipi, for controllers with >= 4 ipis */
 188 int smp_request_message_ipi(int virq, int msg)
 189 {
 190         int err;
 191
 192         if (msg < 0 || msg > PPC_MSG_DEBUGGER_BREAK) {
 193                 return -EINVAL;
 194         }
 195 #if !defined(CONFIG_DEBUGGER) && !defined(CONFIG_KEXEC)
 196         if (msg == PPC_MSG_DEBUGGER_BREAK) {
 197                 return 1;
 198         }
 199 #endif
 200         err = request_irq(virq, smp_ipi_action[msg],
 201                           IRQF_PERCPU | IRQF_NO_THREAD | IRQF_NO_SUSPEND,
 202                           smp_ipi_name[msg], NULL);
 203         WARN(err < 0, "unable to request_irq %d for %s (rc %d)\n",
 204                 virq, smp_ipi_name[msg], err);
 205
 206         return err;
 207 }
 208
 209 #ifdef CONFIG_PPC_SMP_MUXED_IPI
 210 struct cpu_messages {
 211         long messages;                  /* current messages */
 212         unsigned long data;             /* data for cause ipi */
 213 };
 214 static DEFINE_PER_CPU_SHARED_ALIGNED(struct cpu_messages, ipi_message);
 215
 216 void smp_muxed_ipi_set_data(int cpu, unsigned long data)
 217 {
 218         struct cpu_messages *info = &per_cpu(ipi_message, cpu);
 219
 220         info->data = data;
 221 }
 222
 223 void smp_muxed_ipi_set_message(int cpu, int msg)
 224 {
 225         struct cpu_messages *info = &per_cpu(ipi_message, cpu);
 226         char *message = (char *)&info->messages;
 227
 228         /*
 229          * Order previous accesses before accesses in the IPI handler.
 230          */
 231         smp_mb();
 232         message[msg] = 1;
 233 }
 234
 235 void smp_muxed_ipi_message_pass(int cpu, int msg)
 236 {
 237         struct cpu_messages *info = &per_cpu(ipi_message, cpu);
 238
 239         smp_muxed_ipi_set_message(cpu, msg);
 240         /*
 241          * cause_ipi functions are required to include a full barrier
 242          * before doing whatever causes the IPI.
 243          */
 244         smp_ops->cause_ipi(cpu, info->data);
 245 }
 246
 247 #ifdef __BIG_ENDIAN__
 248 #define IPI_MESSAGE(A) (1uL << ((BITS_PER_LONG - 8) - 8 * (A)))
 249 #else
 250 #define IPI_MESSAGE(A) (1uL << (8 * (A)))
 251 #endif
 252
 253 irqreturn_t smp_ipi_demux(void)
 254 {
 255         struct cpu_messages *info = this_cpu_ptr(&ipi_message);
 256         unsigned long all;
 257
 258         mb();   /* order any irq clear */
 259
 260         do {
 261                 all = xchg(&info->messages, 0);
 262 #if defined(CONFIG_KVM_XICS) && defined(CONFIG_KVM_BOOK3S_HV_POSSIBLE)
 263                 /*
 264                  * Must check for PPC_MSG_RM_HOST_ACTION messages
 265                  * before PPC_MSG_CALL_FUNCTION messages because when
 266                  * a VM is destroyed, we call kick_all_cpus_sync()
 267                  * to ensure that any pending PPC_MSG_RM_HOST_ACTION
 268                  * messages have completed before we free any VCPUs.
 269                  */
 270                 if (all & IPI_MESSAGE(PPC_MSG_RM_HOST_ACTION))
 271                         kvmppc_xics_ipi_action();
 272 #endif
 273                 if (all & IPI_MESSAGE(PPC_MSG_CALL_FUNCTION))
 274                         generic_smp_call_function_interrupt();
 275                 if (all & IPI_MESSAGE(PPC_MSG_RESCHEDULE))
 276                         scheduler_ipi();
 277                 if (all & IPI_MESSAGE(PPC_MSG_TICK_BROADCAST))
 278                         tick_broadcast_ipi_handler();
 279                 if (all & IPI_MESSAGE(PPC_MSG_DEBUGGER_BREAK))
 280                         debug_ipi_action(0, NULL);
 281         } while (info->messages);
 282
 283         return IRQ_HANDLED;
 284 }
 285 #endif /* CONFIG_PPC_SMP_MUXED_IPI */
 286
 287 static inline void do_message_pass(int cpu, int msg)
 288 {
 289         if (smp_ops->message_pass)
 290                 smp_ops->message_pass(cpu, msg);
 291 #ifdef CONFIG_PPC_SMP_MUXED_IPI
 292         else
 293                 smp_muxed_ipi_message_pass(cpu, msg);
 294 #endif
 295 }
 296
 297 void smp_send_reschedule(int cpu)
 298 {
 299         if (likely(smp_ops))
 300                 do_message_pass(cpu, PPC_MSG_RESCHEDULE);
 301 }
 302 EXPORT_SYMBOL_GPL(smp_send_reschedule);
 303
 304 void arch_send_call_function_single_ipi(int cpu)
 305 {
 306         do_message_pass(cpu, PPC_MSG_CALL_FUNCTION);
 307 }
 308
 309 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
 310 {
 311         unsigned int cpu;
 312
 313         for_each_cpu(cpu, mask)
 314                 do_message_pass(cpu, PPC_MSG_CALL_FUNCTION);
 315 }
 316
 317 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
 318 void tick_broadcast(const struct cpumask *mask)
 319 {
 320         unsigned int cpu;
 321
 322         for_each_cpu(cpu, mask)
 323                 do_message_pass(cpu, PPC_MSG_TICK_BROADCAST);
 324 }
 325 #endif
 326
 327 #if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC)
 328 void smp_send_debugger_break(void)
 329 {
 330         int cpu;
 331         int me = raw_smp_processor_id();
 332
 333         if (unlikely(!smp_ops))
 334                 return;
 335
 336         for_each_online_cpu(cpu)
 337                 if (cpu != me)
 338                         do_message_pass(cpu, PPC_MSG_DEBUGGER_BREAK);
 339 }
 340 #endif
 341
 342 #ifdef CONFIG_KEXEC
 343 void crash_send_ipi(void (*crash_ipi_callback)(struct pt_regs *))
 344 {
 345         crash_ipi_function_ptr = crash_ipi_callback;
 346         if (crash_ipi_callback) {
 347                 mb();
 348                 smp_send_debugger_break();
 349         }
 350 }
 351 #endif
 352
 353 static void stop_this_cpu(void *dummy)
 354 {
 355         /* Remove this CPU */
 356         set_cpu_online(smp_processor_id(), false);
 357
 358         local_irq_disable();
 359         while (1)
 360                 ;
 361 }
 362
 363 void smp_send_stop(void)
 364 {
 365         smp_call_function(stop_this_cpu, NULL, 0);
 366 }
 367
 368 struct thread_info *current_set[NR_CPUS];
 369
 370 static void smp_store_cpu_info(int id)
 371 {
 372         per_cpu(cpu_pvr, id) = mfspr(SPRN_PVR);
 373 #ifdef CONFIG_PPC_FSL_BOOK3E
 374         per_cpu(next_tlbcam_idx, id)
 375                 = (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) - 1;
 376 #endif
 377 }
 378
 379 void __init smp_prepare_cpus(unsigned int max_cpus)
 380 {
 381         unsigned int cpu;
 382
 383         DBG("smp_prepare_cpus\n");
 384
 385         /*
 386          * setup_cpu may need to be called on the boot cpu. We havent
 387          * spun any cpus up but lets be paranoid.
 388          */
 389         BUG_ON(boot_cpuid != smp_processor_id());
 390
 391         /* Fixup boot cpu */
 392         smp_store_cpu_info(boot_cpuid);
 393         cpu_callin_map[boot_cpuid] = 1;
 394
 395         for_each_possible_cpu(cpu) {
 396                 zalloc_cpumask_var_node(&per_cpu(cpu_sibling_map, cpu),
 397                                         GFP_KERNEL, cpu_to_node(cpu));
 398                 zalloc_cpumask_var_node(&per_cpu(cpu_core_map, cpu),
 399                                         GFP_KERNEL, cpu_to_node(cpu));
 400                 /*
 401                  * numa_node_id() works after this.
 402                  */
 403                 if (cpu_present(cpu)) {
 404                         set_cpu_numa_node(cpu, numa_cpu_lookup_table[cpu]);
 405                         set_cpu_numa_mem(cpu,
 406                                 local_memory_node(numa_cpu_lookup_table[cpu]));
 407                 }
 408         }
 409
 410         cpumask_set_cpu(boot_cpuid, cpu_sibling_mask(boot_cpuid));
 411         cpumask_set_cpu(boot_cpuid, cpu_core_mask(boot_cpuid));
 412
 413         if (smp_ops && smp_ops->probe)
 414                 smp_ops->probe();
 415 }
 416
 417 void smp_prepare_boot_cpu(void)
 418 {
 419         BUG_ON(smp_processor_id() != boot_cpuid);
 420 #ifdef CONFIG_PPC64
 421         paca[boot_cpuid].__current = current;
 422 #endif
 423         set_numa_node(numa_cpu_lookup_table[boot_cpuid]);
 424         current_set[boot_cpuid] = task_thread_info(current);
 425 }
 426
 427 #ifdef CONFIG_HOTPLUG_CPU
 428
 429 int generic_cpu_disable(void)
 430 {
 431         unsigned int cpu = smp_processor_id();
 432
 433         if (cpu == boot_cpuid)
 434                 return -EBUSY;
 435
 436         set_cpu_online(cpu, false);
 437 #ifdef CONFIG_PPC64
 438         vdso_data->processorCount--;
 439 #endif
 440         migrate_irqs();
 441         return 0;
 442 }
 443
 444 void generic_cpu_die(unsigned int cpu)
 445 {
 446         int i;
 447
 448         for (i = 0; i < 100; i++) {
 449                 smp_rmb();
 450                 if (is_cpu_dead(cpu))
 451                         return;
 452                 msleep(100);
 453         }
 454         printk(KERN_ERR "CPU%d didn't die...\n", cpu);
 455 }
 456
 457 void generic_set_cpu_dead(unsigned int cpu)
 458 {
 459         per_cpu(cpu_state, cpu) = CPU_DEAD;
 460 }
 461
 462 /*
 463  * The cpu_state should be set to CPU_UP_PREPARE in kick_cpu(), otherwise
 464  * the cpu_state is always CPU_DEAD after calling generic_set_cpu_dead(),
 465  * which makes the delay in generic_cpu_die() not happen.
 466  */
 467 void generic_set_cpu_up(unsigned int cpu)
 468 {
 469         per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
 470 }
 471
 472 int generic_check_cpu_restart(unsigned int cpu)
 473 {
 474         return per_cpu(cpu_state, cpu) == CPU_UP_PREPARE;
 475 }
 476
 477 int is_cpu_dead(unsigned int cpu)
 478 {
 479         return per_cpu(cpu_state, cpu) == CPU_DEAD;
 480 }
 481
 482 static bool secondaries_inhibited(void)
 483 {
 484         return kvm_hv_mode_active();
 485 }
 486
 487 #else /* HOTPLUG_CPU */
 488
 489 #define secondaries_inhibited()         0
 490
 491 #endif
 492
 493 static void cpu_idle_thread_init(unsigned int cpu, struct task_struct *idle)
 494 {
 495         struct thread_info *ti = task_thread_info(idle);
 496
 497 #ifdef CONFIG_PPC64
 498         paca[cpu].__current = idle;
 499         paca[cpu].kstack = (unsigned long)ti + THREAD_SIZE - STACK_FRAME_OVERHEAD;
 500 #endif
 501         ti->cpu = cpu;
 502         secondary_ti = current_set[cpu] = ti;
 503 }
 504
 505 int __cpu_up(unsigned int cpu, struct task_struct *tidle)
 506 {
 507         int rc, c;
 508
 509         /*
 510          * Don't allow secondary threads to come online if inhibited
 511          */
 512         if (threads_per_core > 1 && secondaries_inhibited() &&
 513             cpu_thread_in_subcore(cpu))
 514                 return -EBUSY;
 515
 516         if (smp_ops == NULL ||
 517             (smp_ops->cpu_bootable && !smp_ops->cpu_bootable(cpu)))
 518                 return -EINVAL;
 519
 520         cpu_idle_thread_init(cpu, tidle);
 521
 522         /* Make sure callin-map entry is 0 (can be leftover a CPU
 523          * hotplug
 524          */
 525         cpu_callin_map[cpu] = 0;
 526
 527         /* The information for processor bringup must
 528          * be written out to main store before we release
 529          * the processor.
 530          */
 531         smp_mb();
 532
 533         /* wake up cpus */
 534         DBG("smp: kicking cpu %d\n", cpu);
 535         rc = smp_ops->kick_cpu(cpu);
 536         if (rc) {
 537                 pr_err("smp: failed starting cpu %d (rc %d)\n", cpu, rc);
 538                 return rc;
 539         }
 540
 541         /*
 542          * wait to see if the cpu made a callin (is actually up).
 543          * use this value that I found through experimentation.
 544          * -- Cort
 545          */
 546         if (system_state < SYSTEM_RUNNING)
 547                 for (c = 50000; c && !cpu_callin_map[cpu]; c--)
 548                         udelay(100);
 549 #ifdef CONFIG_HOTPLUG_CPU
 550         else
 551                 /*
 552                  * CPUs can take much longer to come up in the
 553                  * hotplug case.  Wait five seconds.
 554                  */
 555                 for (c = 5000; c && !cpu_callin_map[cpu]; c--)
 556                         msleep(1);
 557 #endif
 558
 559         if (!cpu_callin_map[cpu]) {
 560                 printk(KERN_ERR "Processor %u is stuck.\n", cpu);
 561                 return -ENOENT;
 562         }
 563
 564         DBG("Processor %u found.\n", cpu);
 565
 566         if (smp_ops->give_timebase)
 567                 smp_ops->give_timebase();
 568
 569         /* Wait until cpu puts itself in the online & active maps */
 570         while (!cpu_online(cpu))
 571                 cpu_relax();
 572
 573         return 0;
 574 }
 575
 576 /* Return the value of the reg property corresponding to the given
 577  * logical cpu.
 578  */
 579 int cpu_to_core_id(int cpu)
 580 {
 581         struct device_node *np;
 582         const __be32 *reg;
 583         int id = -1;
 584
 585         np = of_get_cpu_node(cpu, NULL);
 586         if (!np)
 587                 goto out;
 588
 589         reg = of_get_property(np, "reg", NULL);
 590         if (!reg)
 591                 goto out;
 592
 593         id = be32_to_cpup(reg);
 594 out:
 595         of_node_put(np);
 596         return id;
 597 }
 598 EXPORT_SYMBOL_GPL(cpu_to_core_id);
 599
 600 /* Helper routines for cpu to core mapping */
 601 int cpu_core_index_of_thread(int cpu)
 602 {
 603         return cpu >> threads_shift;
 604 }
 605 EXPORT_SYMBOL_GPL(cpu_core_index_of_thread);
 606
 607 int cpu_first_thread_of_core(int core)
 608 {
 609         return core << threads_shift;
 610 }
 611 EXPORT_SYMBOL_GPL(cpu_first_thread_of_core);
 612
 613 static void traverse_siblings_chip_id(int cpu, bool add, int chipid)
 614 {
 615         const struct cpumask *mask;
 616         struct device_node *np;
 617         int i, plen;
 618         const __be32 *prop;
 619
 620         mask = add ? cpu_online_mask : cpu_present_mask;
 621         for_each_cpu(i, mask) {
 622                 np = of_get_cpu_node(i, NULL);
 623                 if (!np)
 624                         continue;
 625                 prop = of_get_property(np, "ibm,chip-id", &plen);
 626                 if (prop && plen == sizeof(int) &&
 627                     of_read_number(prop, 1) == chipid) {
 628                         if (add) {
 629                                 cpumask_set_cpu(cpu, cpu_core_mask(i));
 630                                 cpumask_set_cpu(i, cpu_core_mask(cpu));
 631                         } else {
 632                                 cpumask_clear_cpu(cpu, cpu_core_mask(i));
 633                                 cpumask_clear_cpu(i, cpu_core_mask(cpu));
 634                         }
 635                 }
 636                 of_node_put(np);
 637         }
 638 }
 639
 640 /* Must be called when no change can occur to cpu_present_mask,
 641  * i.e. during cpu online or offline.
 642  */
 643 static struct device_node *cpu_to_l2cache(int cpu)
 644 {
 645         struct device_node *np;
 646         struct device_node *cache;
 647
 648         if (!cpu_present(cpu))
 649                 return NULL;
 650
 651         np = of_get_cpu_node(cpu, NULL);
 652         if (np == NULL)
 653                 return NULL;
 654
 655         cache = of_find_next_cache_node(np);
 656
 657         of_node_put(np);
 658
 659         return cache;
 660 }
 661
 662 static void traverse_core_siblings(int cpu, bool add)
 663 {
 664         struct device_node *l2_cache, *np;
 665         const struct cpumask *mask;
 666         int i, chip, plen;
 667         const __be32 *prop;
 668
 669         /* First see if we have ibm,chip-id properties in cpu nodes */
 670         np = of_get_cpu_node(cpu, NULL);
 671         if (np) {
 672                 chip = -1;
 673                 prop = of_get_property(np, "ibm,chip-id", &plen);
 674                 if (prop && plen == sizeof(int))
 675                         chip = of_read_number(prop, 1);
 676                 of_node_put(np);
 677                 if (chip >= 0) {
 678                         traverse_siblings_chip_id(cpu, add, chip);
 679                         return;
 680                 }
 681         }
 682
 683         l2_cache = cpu_to_l2cache(cpu);
 684         mask = add ? cpu_online_mask : cpu_present_mask;
 685         for_each_cpu(i, mask) {
 686                 np = cpu_to_l2cache(i);
 687                 if (!np)
 688                         continue;
 689                 if (np == l2_cache) {
 690                         if (add) {
 691                                 cpumask_set_cpu(cpu, cpu_core_mask(i));
 692                                 cpumask_set_cpu(i, cpu_core_mask(cpu));
 693                         } else {
 694                                 cpumask_clear_cpu(cpu, cpu_core_mask(i));
 695                                 cpumask_clear_cpu(i, cpu_core_mask(cpu));
 696                         }
 697                 }
 698                 of_node_put(np);
 699         }
 700         of_node_put(l2_cache);
 701 }
 702
 703 /* Activate a secondary processor. */
 704 void start_secondary(void *unused)
 705 {
 706         unsigned int cpu = smp_processor_id();
 707         int i, base;
 708
 709         atomic_inc(&init_mm.mm_count);
 710         current->active_mm = &init_mm;
 711
 712         smp_store_cpu_info(cpu);
 713         set_dec(tb_ticks_per_jiffy);
 714         preempt_disable();
 715         cpu_callin_map[cpu] = 1;
 716
 717         if (smp_ops->setup_cpu)
 718                 smp_ops->setup_cpu(cpu);
 719         if (smp_ops->take_timebase)
 720                 smp_ops->take_timebase();
 721
 722         secondary_cpu_time_init();
 723
 724 #ifdef CONFIG_PPC64
 725         if (system_state == SYSTEM_RUNNING)
 726                 vdso_data->processorCount++;
 727
 728         vdso_getcpu_init();
 729 #endif
 730         /* Update sibling maps */
 731         base = cpu_first_thread_sibling(cpu);
 732         for (i = 0; i < threads_per_core; i++) {
 733                 if (cpu_is_offline(base + i) && (cpu != base + i))
 734                         continue;
 735                 cpumask_set_cpu(cpu, cpu_sibling_mask(base + i));
 736                 cpumask_set_cpu(base + i, cpu_sibling_mask(cpu));
 737
 738                 /* cpu_core_map should be a superset of
 739                  * cpu_sibling_map even if we don't have cache
 740                  * information, so update the former here, too.
 741                  */
 742                 cpumask_set_cpu(cpu, cpu_core_mask(base + i));
 743                 cpumask_set_cpu(base + i, cpu_core_mask(cpu));
 744         }
 745         traverse_core_siblings(cpu, true);
 746
 747         set_numa_node(numa_cpu_lookup_table[cpu]);
 748         set_numa_mem(local_memory_node(numa_cpu_lookup_table[cpu]));
 749
 750         smp_wmb();
 751         notify_cpu_starting(cpu);
 752         set_cpu_online(cpu, true);
 753
 754         local_irq_enable();
 755
 756         cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
 757
 758         BUG();
 759 }
 760
 761 int setup_profiling_timer(unsigned int multiplier)
 762 {
 763         return 0;
 764 }
 765
 766 #ifdef CONFIG_SCHED_SMT
 767 /* cpumask of CPUs with asymetric SMT dependancy */
 768 static int powerpc_smt_flags(void)
 769 {
 770         int flags = SD_SHARE_CPUCAPACITY | SD_SHARE_PKG_RESOURCES;
 771
 772         if (cpu_has_feature(CPU_FTR_ASYM_SMT)) {
 773                 printk_once(KERN_INFO "Enabling Asymmetric SMT scheduling\n");
 774                 flags |= SD_ASYM_PACKING;
 775         }
 776         return flags;
 777 }
 778 #endif
 779
 780 static struct sched_domain_topology_level powerpc_topology[] = {
 781 #ifdef CONFIG_SCHED_SMT
 782         { cpu_smt_mask, powerpc_smt_flags, SD_INIT_NAME(SMT) },
 783 #endif
 784         { cpu_cpu_mask, SD_INIT_NAME(DIE) },
 785         { NULL, },
 786 };
 787
 788 void __init smp_cpus_done(unsigned int max_cpus)
 789 {
 790         cpumask_var_t old_mask;
 791
 792         /* We want the setup_cpu() here to be called from CPU 0, but our
 793          * init thread may have been "borrowed" by another CPU in the meantime
 794          * se we pin us down to CPU 0 for a short while
 795          */
 796         alloc_cpumask_var(&old_mask, GFP_NOWAIT);
 797         cpumask_copy(old_mask, tsk_cpus_allowed(current));
 798         set_cpus_allowed_ptr(current, cpumask_of(boot_cpuid));
 799
 800         if (smp_ops && smp_ops->setup_cpu)
 801                 smp_ops->setup_cpu(boot_cpuid);
 802
 803         set_cpus_allowed_ptr(current, old_mask);
 804
 805         free_cpumask_var(old_mask);
 806
 807         if (smp_ops && smp_ops->bringup_done)
 808                 smp_ops->bringup_done();
 809
 810         dump_numa_cpu_topology();
 811
 812         set_sched_topology(powerpc_topology);
 813
 814 }
 815
 816 #ifdef CONFIG_HOTPLUG_CPU
 817 int __cpu_disable(void)
 818 {
 819         int cpu = smp_processor_id();
 820         int base, i;
 821         int err;
 822
 823         if (!smp_ops->cpu_disable)
 824                 return -ENOSYS;
 825
 826         err = smp_ops->cpu_disable();
 827         if (err)
 828                 return err;
 829
 830         /* Update sibling maps */
 831         base = cpu_first_thread_sibling(cpu);
 832         for (i = 0; i < threads_per_core; i++) {
 833                 cpumask_clear_cpu(cpu, cpu_sibling_mask(base + i));
 834                 cpumask_clear_cpu(base + i, cpu_sibling_mask(cpu));
 835                 cpumask_clear_cpu(cpu, cpu_core_mask(base + i));
 836                 cpumask_clear_cpu(base + i, cpu_core_mask(cpu));
 837         }
 838         traverse_core_siblings(cpu, false);
 839
 840         return 0;
 841 }
 842
 843 void __cpu_die(unsigned int cpu)
 844 {
 845         if (smp_ops->cpu_die)
 846                 smp_ops->cpu_die(cpu);
 847 }
 848
 849 void cpu_die(void)
 850 {
 851         if (ppc_md.cpu_die)
 852                 ppc_md.cpu_die();
 853
 854         /* If we return, we re-enter start_secondary */
 855         start_secondary_resume();
 856 }
 857
 858 #endif