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