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 = &__get_cpu_var(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                 set_cpu_numa_node(cpu, numa_cpu_lookup_table[cpu]);
 384                 set_cpu_numa_mem(cpu, local_memory_node(numa_cpu_lookup_table[cpu]));
 385         }
 386
 387         cpumask_set_cpu(boot_cpuid, cpu_sibling_mask(boot_cpuid));
 388         cpumask_set_cpu(boot_cpuid, cpu_core_mask(boot_cpuid));
 389
 390         if (smp_ops && smp_ops->probe)
 391                 smp_ops->probe();
 392 }
 393
 394 void smp_prepare_boot_cpu(void)
 395 {
 396         BUG_ON(smp_processor_id() != boot_cpuid);
 397 #ifdef CONFIG_PPC64
 398         paca[boot_cpuid].__current = current;
 399 #endif
 400         set_numa_node(numa_cpu_lookup_table[boot_cpuid]);
 401         current_set[boot_cpuid] = task_thread_info(current);
 402 }
 403
 404 #ifdef CONFIG_HOTPLUG_CPU
 405
 406 int generic_cpu_disable(void)
 407 {
 408         unsigned int cpu = smp_processor_id();
 409
 410         if (cpu == boot_cpuid)
 411                 return -EBUSY;
 412
 413         set_cpu_online(cpu, false);
 414 #ifdef CONFIG_PPC64
 415         vdso_data->processorCount--;
 416 #endif
 417         migrate_irqs();
 418         return 0;
 419 }
 420
 421 void generic_cpu_die(unsigned int cpu)
 422 {
 423         int i;
 424
 425         for (i = 0; i < 100; i++) {
 426                 smp_rmb();
 427                 if (per_cpu(cpu_state, cpu) == CPU_DEAD)
 428                         return;
 429                 msleep(100);
 430         }
 431         printk(KERN_ERR "CPU%d didn't die...\n", cpu);
 432 }
 433
 434 void generic_mach_cpu_die(void)
 435 {
 436         unsigned int cpu;
 437
 438         local_irq_disable();
 439         idle_task_exit();
 440         cpu = smp_processor_id();
 441         printk(KERN_DEBUG "CPU%d offline\n", cpu);
 442         __get_cpu_var(cpu_state) = CPU_DEAD;
 443         smp_wmb();
 444         while (__get_cpu_var(cpu_state) != CPU_UP_PREPARE)
 445                 cpu_relax();
 446 }
 447
 448 void generic_set_cpu_dead(unsigned int cpu)
 449 {
 450         per_cpu(cpu_state, cpu) = CPU_DEAD;
 451 }
 452
 453 /*
 454  * The cpu_state should be set to CPU_UP_PREPARE in kick_cpu(), otherwise
 455  * the cpu_state is always CPU_DEAD after calling generic_set_cpu_dead(),
 456  * which makes the delay in generic_cpu_die() not happen.
 457  */
 458 void generic_set_cpu_up(unsigned int cpu)
 459 {
 460         per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
 461 }
 462
 463 int generic_check_cpu_restart(unsigned int cpu)
 464 {
 465         return per_cpu(cpu_state, cpu) == CPU_UP_PREPARE;
 466 }
 467
 468 static bool secondaries_inhibited(void)
 469 {
 470         return kvm_hv_mode_active();
 471 }
 472
 473 #else /* HOTPLUG_CPU */
 474
 475 #define secondaries_inhibited()         0
 476
 477 #endif
 478
 479 static void cpu_idle_thread_init(unsigned int cpu, struct task_struct *idle)
 480 {
 481         struct thread_info *ti = task_thread_info(idle);
 482
 483 #ifdef CONFIG_PPC64
 484         paca[cpu].__current = idle;
 485         paca[cpu].kstack = (unsigned long)ti + THREAD_SIZE - STACK_FRAME_OVERHEAD;
 486 #endif
 487         ti->cpu = cpu;
 488         secondary_ti = current_set[cpu] = ti;
 489 }
 490
 491 int __cpu_up(unsigned int cpu, struct task_struct *tidle)
 492 {
 493         int rc, c;
 494
 495         /*
 496          * Don't allow secondary threads to come online if inhibited
 497          */
 498         if (threads_per_core > 1 && secondaries_inhibited() &&
 499             cpu_thread_in_subcore(cpu))
 500                 return -EBUSY;
 501
 502         if (smp_ops == NULL ||
 503             (smp_ops->cpu_bootable && !smp_ops->cpu_bootable(cpu)))
 504                 return -EINVAL;
 505
 506         cpu_idle_thread_init(cpu, tidle);
 507
 508         /* Make sure callin-map entry is 0 (can be leftover a CPU
 509          * hotplug
 510          */
 511         cpu_callin_map[cpu] = 0;
 512
 513         /* The information for processor bringup must
 514          * be written out to main store before we release
 515          * the processor.
 516          */
 517         smp_mb();
 518
 519         /* wake up cpus */
 520         DBG("smp: kicking cpu %d\n", cpu);
 521         rc = smp_ops->kick_cpu(cpu);
 522         if (rc) {
 523                 pr_err("smp: failed starting cpu %d (rc %d)\n", cpu, rc);
 524                 return rc;
 525         }
 526
 527         /*
 528          * wait to see if the cpu made a callin (is actually up).
 529          * use this value that I found through experimentation.
 530          * -- Cort
 531          */
 532         if (system_state < SYSTEM_RUNNING)
 533                 for (c = 50000; c && !cpu_callin_map[cpu]; c--)
 534                         udelay(100);
 535 #ifdef CONFIG_HOTPLUG_CPU
 536         else
 537                 /*
 538                  * CPUs can take much longer to come up in the
 539                  * hotplug case.  Wait five seconds.
 540                  */
 541                 for (c = 5000; c && !cpu_callin_map[cpu]; c--)
 542                         msleep(1);
 543 #endif
 544
 545         if (!cpu_callin_map[cpu]) {
 546                 printk(KERN_ERR "Processor %u is stuck.\n", cpu);
 547                 return -ENOENT;
 548         }
 549
 550         DBG("Processor %u found.\n", cpu);
 551
 552         if (smp_ops->give_timebase)
 553                 smp_ops->give_timebase();
 554
 555         /* Wait until cpu puts itself in the online map */
 556         while (!cpu_online(cpu))
 557                 cpu_relax();
 558
 559         return 0;
 560 }
 561
 562 /* Return the value of the reg property corresponding to the given
 563  * logical cpu.
 564  */
 565 int cpu_to_core_id(int cpu)
 566 {
 567         struct device_node *np;
 568         const __be32 *reg;
 569         int id = -1;
 570
 571         np = of_get_cpu_node(cpu, NULL);
 572         if (!np)
 573                 goto out;
 574
 575         reg = of_get_property(np, "reg", NULL);
 576         if (!reg)
 577                 goto out;
 578
 579         id = be32_to_cpup(reg);
 580 out:
 581         of_node_put(np);
 582         return id;
 583 }
 584
 585 /* Helper routines for cpu to core mapping */
 586 int cpu_core_index_of_thread(int cpu)
 587 {
 588         return cpu >> threads_shift;
 589 }
 590 EXPORT_SYMBOL_GPL(cpu_core_index_of_thread);
 591
 592 int cpu_first_thread_of_core(int core)
 593 {
 594         return core << threads_shift;
 595 }
 596 EXPORT_SYMBOL_GPL(cpu_first_thread_of_core);
 597
 598 static void traverse_siblings_chip_id(int cpu, bool add, int chipid)
 599 {
 600         const struct cpumask *mask;
 601         struct device_node *np;
 602         int i, plen;
 603         const __be32 *prop;
 604
 605         mask = add ? cpu_online_mask : cpu_present_mask;
 606         for_each_cpu(i, mask) {
 607                 np = of_get_cpu_node(i, NULL);
 608                 if (!np)
 609                         continue;
 610                 prop = of_get_property(np, "ibm,chip-id", &plen);
 611                 if (prop && plen == sizeof(int) &&
 612                     of_read_number(prop, 1) == chipid) {
 613                         if (add) {
 614                                 cpumask_set_cpu(cpu, cpu_core_mask(i));
 615                                 cpumask_set_cpu(i, cpu_core_mask(cpu));
 616                         } else {
 617                                 cpumask_clear_cpu(cpu, cpu_core_mask(i));
 618                                 cpumask_clear_cpu(i, cpu_core_mask(cpu));
 619                         }
 620                 }
 621                 of_node_put(np);
 622         }
 623 }
 624
 625 /* Must be called when no change can occur to cpu_present_mask,
 626  * i.e. during cpu online or offline.
 627  */
 628 static struct device_node *cpu_to_l2cache(int cpu)
 629 {
 630         struct device_node *np;
 631         struct device_node *cache;
 632
 633         if (!cpu_present(cpu))
 634                 return NULL;
 635
 636         np = of_get_cpu_node(cpu, NULL);
 637         if (np == NULL)
 638                 return NULL;
 639
 640         cache = of_find_next_cache_node(np);
 641
 642         of_node_put(np);
 643
 644         return cache;
 645 }
 646
 647 static void traverse_core_siblings(int cpu, bool add)
 648 {
 649         struct device_node *l2_cache, *np;
 650         const struct cpumask *mask;
 651         int i, chip, plen;
 652         const __be32 *prop;
 653
 654         /* First see if we have ibm,chip-id properties in cpu nodes */
 655         np = of_get_cpu_node(cpu, NULL);
 656         if (np) {
 657                 chip = -1;
 658                 prop = of_get_property(np, "ibm,chip-id", &plen);
 659                 if (prop && plen == sizeof(int))
 660                         chip = of_read_number(prop, 1);
 661                 of_node_put(np);
 662                 if (chip >= 0) {
 663                         traverse_siblings_chip_id(cpu, add, chip);
 664                         return;
 665                 }
 666         }
 667
 668         l2_cache = cpu_to_l2cache(cpu);
 669         mask = add ? cpu_online_mask : cpu_present_mask;
 670         for_each_cpu(i, mask) {
 671                 np = cpu_to_l2cache(i);
 672                 if (!np)
 673                         continue;
 674                 if (np == l2_cache) {
 675                         if (add) {
 676                                 cpumask_set_cpu(cpu, cpu_core_mask(i));
 677                                 cpumask_set_cpu(i, cpu_core_mask(cpu));
 678                         } else {
 679                                 cpumask_clear_cpu(cpu, cpu_core_mask(i));
 680                                 cpumask_clear_cpu(i, cpu_core_mask(cpu));
 681                         }
 682                 }
 683                 of_node_put(np);
 684         }
 685         of_node_put(l2_cache);
 686 }
 687
 688 /* Activate a secondary processor. */
 689 void start_secondary(void *unused)
 690 {
 691         unsigned int cpu = smp_processor_id();
 692         int i, base;
 693
 694         atomic_inc(&init_mm.mm_count);
 695         current->active_mm = &init_mm;
 696
 697         smp_store_cpu_info(cpu);
 698         set_dec(tb_ticks_per_jiffy);
 699         preempt_disable();
 700         cpu_callin_map[cpu] = 1;
 701
 702         if (smp_ops->setup_cpu)
 703                 smp_ops->setup_cpu(cpu);
 704         if (smp_ops->take_timebase)
 705                 smp_ops->take_timebase();
 706
 707         secondary_cpu_time_init();
 708
 709 #ifdef CONFIG_PPC64
 710         if (system_state == SYSTEM_RUNNING)
 711                 vdso_data->processorCount++;
 712
 713         vdso_getcpu_init();
 714 #endif
 715         /* Update sibling maps */
 716         base = cpu_first_thread_sibling(cpu);
 717         for (i = 0; i < threads_per_core; i++) {
 718                 if (cpu_is_offline(base + i) && (cpu != base + i))
 719                         continue;
 720                 cpumask_set_cpu(cpu, cpu_sibling_mask(base + i));
 721                 cpumask_set_cpu(base + i, cpu_sibling_mask(cpu));
 722
 723                 /* cpu_core_map should be a superset of
 724                  * cpu_sibling_map even if we don't have cache
 725                  * information, so update the former here, too.
 726                  */
 727                 cpumask_set_cpu(cpu, cpu_core_mask(base + i));
 728                 cpumask_set_cpu(base + i, cpu_core_mask(cpu));
 729         }
 730         traverse_core_siblings(cpu, true);
 731
 732         smp_wmb();
 733         notify_cpu_starting(cpu);
 734         set_cpu_online(cpu, true);
 735
 736         local_irq_enable();
 737
 738         cpu_startup_entry(CPUHP_ONLINE);
 739
 740         BUG();
 741 }
 742
 743 int setup_profiling_timer(unsigned int multiplier)
 744 {
 745         return 0;
 746 }
 747
 748 #ifdef CONFIG_SCHED_SMT
 749 /* cpumask of CPUs with asymetric SMT dependancy */
 750 static int powerpc_smt_flags(void)
 751 {
 752         int flags = SD_SHARE_CPUCAPACITY | SD_SHARE_PKG_RESOURCES;
 753
 754         if (cpu_has_feature(CPU_FTR_ASYM_SMT)) {
 755                 printk_once(KERN_INFO "Enabling Asymmetric SMT scheduling\n");
 756                 flags |= SD_ASYM_PACKING;
 757         }
 758         return flags;
 759 }
 760 #endif
 761
 762 static struct sched_domain_topology_level powerpc_topology[] = {
 763 #ifdef CONFIG_SCHED_SMT
 764         { cpu_smt_mask, powerpc_smt_flags, SD_INIT_NAME(SMT) },
 765 #endif
 766         { cpu_cpu_mask, SD_INIT_NAME(DIE) },
 767         { NULL, },
 768 };
 769
 770 void __init smp_cpus_done(unsigned int max_cpus)
 771 {
 772         cpumask_var_t old_mask;
 773
 774         /* We want the setup_cpu() here to be called from CPU 0, but our
 775          * init thread may have been "borrowed" by another CPU in the meantime
 776          * se we pin us down to CPU 0 for a short while
 777          */
 778         alloc_cpumask_var(&old_mask, GFP_NOWAIT);
 779         cpumask_copy(old_mask, tsk_cpus_allowed(current));
 780         set_cpus_allowed_ptr(current, cpumask_of(boot_cpuid));
 781
 782         if (smp_ops && smp_ops->setup_cpu)
 783                 smp_ops->setup_cpu(boot_cpuid);
 784
 785         set_cpus_allowed_ptr(current, old_mask);
 786
 787         free_cpumask_var(old_mask);
 788
 789         if (smp_ops && smp_ops->bringup_done)
 790                 smp_ops->bringup_done();
 791
 792         dump_numa_cpu_topology();
 793
 794         set_sched_topology(powerpc_topology);
 795
 796 }
 797
 798 #ifdef CONFIG_HOTPLUG_CPU
 799 int __cpu_disable(void)
 800 {
 801         int cpu = smp_processor_id();
 802         int base, i;
 803         int err;
 804
 805         if (!smp_ops->cpu_disable)
 806                 return -ENOSYS;
 807
 808         err = smp_ops->cpu_disable();
 809         if (err)
 810                 return err;
 811
 812         /* Update sibling maps */
 813         base = cpu_first_thread_sibling(cpu);
 814         for (i = 0; i < threads_per_core; i++) {
 815                 cpumask_clear_cpu(cpu, cpu_sibling_mask(base + i));
 816                 cpumask_clear_cpu(base + i, cpu_sibling_mask(cpu));
 817                 cpumask_clear_cpu(cpu, cpu_core_mask(base + i));
 818                 cpumask_clear_cpu(base + i, cpu_core_mask(cpu));
 819         }
 820         traverse_core_siblings(cpu, false);
 821
 822         return 0;
 823 }
 824
 825 void __cpu_die(unsigned int cpu)
 826 {
 827         if (smp_ops->cpu_die)
 828                 smp_ops->cpu_die(cpu);
 829 }
 830
 831 void cpu_die(void)
 832 {
 833         if (ppc_md.cpu_die)
 834                 ppc_md.cpu_die();
 835
 836         /* If we return, we re-enter start_secondary */
 837         start_secondary_resume();
 838 }
 839
 840 #endif