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         long 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_set_message(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
 233 void smp_muxed_ipi_message_pass(int cpu, int msg)
 234 {
 235         struct cpu_messages *info = &per_cpu(ipi_message, cpu);
 236
 237         smp_muxed_ipi_set_message(cpu, msg);
 238         /*
 239          * cause_ipi functions are required to include a full barrier
 240          * before doing whatever causes the IPI.
 241          */
 242         smp_ops->cause_ipi(cpu, info->data);
 243 }
 244
 245 #ifdef __BIG_ENDIAN__
 246 #define IPI_MESSAGE(A) (1uL << ((BITS_PER_LONG - 8) - 8 * (A)))
 247 #else
 248 #define IPI_MESSAGE(A) (1uL << (8 * (A)))
 249 #endif
 250
 251 irqreturn_t smp_ipi_demux(void)
 252 {
 253         struct cpu_messages *info = this_cpu_ptr(&ipi_message);
 254         unsigned long all;
 255
 256         mb();   /* order any irq clear */
 257
 258         do {
 259                 all = xchg(&info->messages, 0);
 260 #if defined(CONFIG_KVM_XICS) && defined(CONFIG_KVM_BOOK3S_HV_POSSIBLE)
 261                 /*
 262                  * Must check for PPC_MSG_RM_HOST_ACTION messages
 263                  * before PPC_MSG_CALL_FUNCTION messages because when
 264                  * a VM is destroyed, we call kick_all_cpus_sync()
 265                  * to ensure that any pending PPC_MSG_RM_HOST_ACTION
 266                  * messages have completed before we free any VCPUs.
 267                  */
 268                 if (all & IPI_MESSAGE(PPC_MSG_RM_HOST_ACTION))
 269                         kvmppc_xics_ipi_action();
 270 #endif
 271                 if (all & IPI_MESSAGE(PPC_MSG_CALL_FUNCTION))
 272                         generic_smp_call_function_interrupt();
 273                 if (all & IPI_MESSAGE(PPC_MSG_RESCHEDULE))
 274                         scheduler_ipi();
 275                 if (all & IPI_MESSAGE(PPC_MSG_TICK_BROADCAST))
 276                         tick_broadcast_ipi_handler();
 277                 if (all & IPI_MESSAGE(PPC_MSG_DEBUGGER_BREAK))
 278                         debug_ipi_action(0, NULL);
 279         } while (info->messages);
 280
 281         return IRQ_HANDLED;
 282 }
 283 #endif /* CONFIG_PPC_SMP_MUXED_IPI */
 284
 285 static inline void do_message_pass(int cpu, int msg)
 286 {
 287         if (smp_ops->message_pass)
 288                 smp_ops->message_pass(cpu, msg);
 289 #ifdef CONFIG_PPC_SMP_MUXED_IPI
 290         else
 291                 smp_muxed_ipi_message_pass(cpu, msg);
 292 #endif
 293 }
 294
 295 void smp_send_reschedule(int cpu)
 296 {
 297         if (likely(smp_ops))
 298                 do_message_pass(cpu, PPC_MSG_RESCHEDULE);
 299 }
 300 EXPORT_SYMBOL_GPL(smp_send_reschedule);
 301
 302 void arch_send_call_function_single_ipi(int cpu)
 303 {
 304         do_message_pass(cpu, PPC_MSG_CALL_FUNCTION);
 305 }
 306
 307 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
 308 {
 309         unsigned int cpu;
 310
 311         for_each_cpu(cpu, mask)
 312                 do_message_pass(cpu, PPC_MSG_CALL_FUNCTION);
 313 }
 314
 315 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
 316 void tick_broadcast(const struct cpumask *mask)
 317 {
 318         unsigned int cpu;
 319
 320         for_each_cpu(cpu, mask)
 321                 do_message_pass(cpu, PPC_MSG_TICK_BROADCAST);
 322 }
 323 #endif
 324
 325 #if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC)
 326 void smp_send_debugger_break(void)
 327 {
 328         int cpu;
 329         int me = raw_smp_processor_id();
 330
 331         if (unlikely(!smp_ops))
 332                 return;
 333
 334         for_each_online_cpu(cpu)
 335                 if (cpu != me)
 336                         do_message_pass(cpu, PPC_MSG_DEBUGGER_BREAK);
 337 }
 338 #endif
 339
 340 #ifdef CONFIG_KEXEC
 341 void crash_send_ipi(void (*crash_ipi_callback)(struct pt_regs *))
 342 {
 343         crash_ipi_function_ptr = crash_ipi_callback;
 344         if (crash_ipi_callback) {
 345                 mb();
 346                 smp_send_debugger_break();
 347         }
 348 }
 349 #endif
 350
 351 static void stop_this_cpu(void *dummy)
 352 {
 353         /* Remove this CPU */
 354         set_cpu_online(smp_processor_id(), false);
 355
 356         local_irq_disable();
 357         while (1)
 358                 ;
 359 }
 360
 361 void smp_send_stop(void)
 362 {
 363         smp_call_function(stop_this_cpu, NULL, 0);
 364 }
 365
 366 struct thread_info *current_set[NR_CPUS];
 367
 368 static void smp_store_cpu_info(int id)
 369 {
 370         per_cpu(cpu_pvr, id) = mfspr(SPRN_PVR);
 371 #ifdef CONFIG_PPC_FSL_BOOK3E
 372         per_cpu(next_tlbcam_idx, id)
 373                 = (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) - 1;
 374 #endif
 375 }
 376
 377 void __init smp_prepare_cpus(unsigned int max_cpus)
 378 {
 379         unsigned int cpu;
 380
 381         DBG("smp_prepare_cpus\n");
 382
 383         /*
 384          * setup_cpu may need to be called on the boot cpu. We havent
 385          * spun any cpus up but lets be paranoid.
 386          */
 387         BUG_ON(boot_cpuid != smp_processor_id());
 388
 389         /* Fixup boot cpu */
 390         smp_store_cpu_info(boot_cpuid);
 391         cpu_callin_map[boot_cpuid] = 1;
 392
 393         for_each_possible_cpu(cpu) {
 394                 zalloc_cpumask_var_node(&per_cpu(cpu_sibling_map, cpu),
 395                                         GFP_KERNEL, cpu_to_node(cpu));
 396                 zalloc_cpumask_var_node(&per_cpu(cpu_core_map, cpu),
 397                                         GFP_KERNEL, cpu_to_node(cpu));
 398                 /*
 399                  * numa_node_id() works after this.
 400                  */
 401                 if (cpu_present(cpu)) {
 402                         set_cpu_numa_node(cpu, numa_cpu_lookup_table[cpu]);
 403                         set_cpu_numa_mem(cpu,
 404                                 local_memory_node(numa_cpu_lookup_table[cpu]));
 405                 }
 406         }
 407
 408         cpumask_set_cpu(boot_cpuid, cpu_sibling_mask(boot_cpuid));
 409         cpumask_set_cpu(boot_cpuid, cpu_core_mask(boot_cpuid));
 410
 411         if (smp_ops && smp_ops->probe)
 412                 smp_ops->probe();
 413 }
 414
 415 void smp_prepare_boot_cpu(void)
 416 {
 417         BUG_ON(smp_processor_id() != boot_cpuid);
 418 #ifdef CONFIG_PPC64
 419         paca[boot_cpuid].__current = current;
 420 #endif
 421         set_numa_node(numa_cpu_lookup_table[boot_cpuid]);
 422         current_set[boot_cpuid] = task_thread_info(current);
 423 }
 424
 425 #ifdef CONFIG_HOTPLUG_CPU
 426
 427 int generic_cpu_disable(void)
 428 {
 429         unsigned int cpu = smp_processor_id();
 430
 431         if (cpu == boot_cpuid)
 432                 return -EBUSY;
 433
 434         set_cpu_online(cpu, false);
 435 #ifdef CONFIG_PPC64
 436         vdso_data->processorCount--;
 437 #endif
 438         migrate_irqs();
 439         return 0;
 440 }
 441
 442 void generic_cpu_die(unsigned int cpu)
 443 {
 444         int i;
 445
 446         for (i = 0; i < 100; i++) {
 447                 smp_rmb();
 448                 if (per_cpu(cpu_state, cpu) == CPU_DEAD)
 449                         return;
 450                 msleep(100);
 451         }
 452         printk(KERN_ERR "CPU%d didn't die...\n", cpu);
 453 }
 454
 455 void generic_set_cpu_dead(unsigned int cpu)
 456 {
 457         per_cpu(cpu_state, cpu) = CPU_DEAD;
 458 }
 459
 460 /*
 461  * The cpu_state should be set to CPU_UP_PREPARE in kick_cpu(), otherwise
 462  * the cpu_state is always CPU_DEAD after calling generic_set_cpu_dead(),
 463  * which makes the delay in generic_cpu_die() not happen.
 464  */
 465 void generic_set_cpu_up(unsigned int cpu)
 466 {
 467         per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
 468 }
 469
 470 int generic_check_cpu_restart(unsigned int cpu)
 471 {
 472         return per_cpu(cpu_state, cpu) == CPU_UP_PREPARE;
 473 }
 474
 475 static bool secondaries_inhibited(void)
 476 {
 477         return kvm_hv_mode_active();
 478 }
 479
 480 #else /* HOTPLUG_CPU */
 481
 482 #define secondaries_inhibited()         0
 483
 484 #endif
 485
 486 static void cpu_idle_thread_init(unsigned int cpu, struct task_struct *idle)
 487 {
 488         struct thread_info *ti = task_thread_info(idle);
 489
 490 #ifdef CONFIG_PPC64
 491         paca[cpu].__current = idle;
 492         paca[cpu].kstack = (unsigned long)ti + THREAD_SIZE - STACK_FRAME_OVERHEAD;
 493 #endif
 494         ti->cpu = cpu;
 495         secondary_ti = current_set[cpu] = ti;
 496 }
 497
 498 int __cpu_up(unsigned int cpu, struct task_struct *tidle)
 499 {
 500         int rc, c;
 501
 502         /*
 503          * Don't allow secondary threads to come online if inhibited
 504          */
 505         if (threads_per_core > 1 && secondaries_inhibited() &&
 506             cpu_thread_in_subcore(cpu))
 507                 return -EBUSY;
 508
 509         if (smp_ops == NULL ||
 510             (smp_ops->cpu_bootable && !smp_ops->cpu_bootable(cpu)))
 511                 return -EINVAL;
 512
 513         cpu_idle_thread_init(cpu, tidle);
 514
 515         /* Make sure callin-map entry is 0 (can be leftover a CPU
 516          * hotplug
 517          */
 518         cpu_callin_map[cpu] = 0;
 519
 520         /* The information for processor bringup must
 521          * be written out to main store before we release
 522          * the processor.
 523          */
 524         smp_mb();
 525
 526         /* wake up cpus */
 527         DBG("smp: kicking cpu %d\n", cpu);
 528         rc = smp_ops->kick_cpu(cpu);
 529         if (rc) {
 530                 pr_err("smp: failed starting cpu %d (rc %d)\n", cpu, rc);
 531                 return rc;
 532         }
 533
 534         /*
 535          * wait to see if the cpu made a callin (is actually up).
 536          * use this value that I found through experimentation.
 537          * -- Cort
 538          */
 539         if (system_state < SYSTEM_RUNNING)
 540                 for (c = 50000; c && !cpu_callin_map[cpu]; c--)
 541                         udelay(100);
 542 #ifdef CONFIG_HOTPLUG_CPU
 543         else
 544                 /*
 545                  * CPUs can take much longer to come up in the
 546                  * hotplug case.  Wait five seconds.
 547                  */
 548                 for (c = 5000; c && !cpu_callin_map[cpu]; c--)
 549                         msleep(1);
 550 #endif
 551
 552         if (!cpu_callin_map[cpu]) {
 553                 printk(KERN_ERR "Processor %u is stuck.\n", cpu);
 554                 return -ENOENT;
 555         }
 556
 557         DBG("Processor %u found.\n", cpu);
 558
 559         if (smp_ops->give_timebase)
 560                 smp_ops->give_timebase();
 561
 562         /* Wait until cpu puts itself in the online & active maps */
 563         while (!cpu_online(cpu) || !cpu_active(cpu))
 564                 cpu_relax();
 565
 566         return 0;
 567 }
 568
 569 /* Return the value of the reg property corresponding to the given
 570  * logical cpu.
 571  */
 572 int cpu_to_core_id(int cpu)
 573 {
 574         struct device_node *np;
 575         const __be32 *reg;
 576         int id = -1;
 577
 578         np = of_get_cpu_node(cpu, NULL);
 579         if (!np)
 580                 goto out;
 581
 582         reg = of_get_property(np, "reg", NULL);
 583         if (!reg)
 584                 goto out;
 585
 586         id = be32_to_cpup(reg);
 587 out:
 588         of_node_put(np);
 589         return id;
 590 }
 591
 592 /* Helper routines for cpu to core mapping */
 593 int cpu_core_index_of_thread(int cpu)
 594 {
 595         return cpu >> threads_shift;
 596 }
 597 EXPORT_SYMBOL_GPL(cpu_core_index_of_thread);
 598
 599 int cpu_first_thread_of_core(int core)
 600 {
 601         return core << threads_shift;
 602 }
 603 EXPORT_SYMBOL_GPL(cpu_first_thread_of_core);
 604
 605 static void traverse_siblings_chip_id(int cpu, bool add, int chipid)
 606 {
 607         const struct cpumask *mask;
 608         struct device_node *np;
 609         int i, plen;
 610         const __be32 *prop;
 611
 612         mask = add ? cpu_online_mask : cpu_present_mask;
 613         for_each_cpu(i, mask) {
 614                 np = of_get_cpu_node(i, NULL);
 615                 if (!np)
 616                         continue;
 617                 prop = of_get_property(np, "ibm,chip-id", &plen);
 618                 if (prop && plen == sizeof(int) &&
 619                     of_read_number(prop, 1) == chipid) {
 620                         if (add) {
 621                                 cpumask_set_cpu(cpu, cpu_core_mask(i));
 622                                 cpumask_set_cpu(i, cpu_core_mask(cpu));
 623                         } else {
 624                                 cpumask_clear_cpu(cpu, cpu_core_mask(i));
 625                                 cpumask_clear_cpu(i, cpu_core_mask(cpu));
 626                         }
 627                 }
 628                 of_node_put(np);
 629         }
 630 }
 631
 632 /* Must be called when no change can occur to cpu_present_mask,
 633  * i.e. during cpu online or offline.
 634  */
 635 static struct device_node *cpu_to_l2cache(int cpu)
 636 {
 637         struct device_node *np;
 638         struct device_node *cache;
 639
 640         if (!cpu_present(cpu))
 641                 return NULL;
 642
 643         np = of_get_cpu_node(cpu, NULL);
 644         if (np == NULL)
 645                 return NULL;
 646
 647         cache = of_find_next_cache_node(np);
 648
 649         of_node_put(np);
 650
 651         return cache;
 652 }
 653
 654 static void traverse_core_siblings(int cpu, bool add)
 655 {
 656         struct device_node *l2_cache, *np;
 657         const struct cpumask *mask;
 658         int i, chip, plen;
 659         const __be32 *prop;
 660
 661         /* First see if we have ibm,chip-id properties in cpu nodes */
 662         np = of_get_cpu_node(cpu, NULL);
 663         if (np) {
 664                 chip = -1;
 665                 prop = of_get_property(np, "ibm,chip-id", &plen);
 666                 if (prop && plen == sizeof(int))
 667                         chip = of_read_number(prop, 1);
 668                 of_node_put(np);
 669                 if (chip >= 0) {
 670                         traverse_siblings_chip_id(cpu, add, chip);
 671                         return;
 672                 }
 673         }
 674
 675         l2_cache = cpu_to_l2cache(cpu);
 676         mask = add ? cpu_online_mask : cpu_present_mask;
 677         for_each_cpu(i, mask) {
 678                 np = cpu_to_l2cache(i);
 679                 if (!np)
 680                         continue;
 681                 if (np == l2_cache) {
 682                         if (add) {
 683                                 cpumask_set_cpu(cpu, cpu_core_mask(i));
 684                                 cpumask_set_cpu(i, cpu_core_mask(cpu));
 685                         } else {
 686                                 cpumask_clear_cpu(cpu, cpu_core_mask(i));
 687                                 cpumask_clear_cpu(i, cpu_core_mask(cpu));
 688                         }
 689                 }
 690                 of_node_put(np);
 691         }
 692         of_node_put(l2_cache);
 693 }
 694
 695 /* Activate a secondary processor. */
 696 void start_secondary(void *unused)
 697 {
 698         unsigned int cpu = smp_processor_id();
 699         int i, base;
 700
 701         atomic_inc(&init_mm.mm_count);
 702         current->active_mm = &init_mm;
 703
 704         smp_store_cpu_info(cpu);
 705         set_dec(tb_ticks_per_jiffy);
 706         preempt_disable();
 707         cpu_callin_map[cpu] = 1;
 708
 709         if (smp_ops->setup_cpu)
 710                 smp_ops->setup_cpu(cpu);
 711         if (smp_ops->take_timebase)
 712                 smp_ops->take_timebase();
 713
 714         secondary_cpu_time_init();
 715
 716 #ifdef CONFIG_PPC64
 717         if (system_state == SYSTEM_RUNNING)
 718                 vdso_data->processorCount++;
 719
 720         vdso_getcpu_init();
 721 #endif
 722         /* Update sibling maps */
 723         base = cpu_first_thread_sibling(cpu);
 724         for (i = 0; i < threads_per_core; i++) {
 725                 if (cpu_is_offline(base + i) && (cpu != base + i))
 726                         continue;
 727                 cpumask_set_cpu(cpu, cpu_sibling_mask(base + i));
 728                 cpumask_set_cpu(base + i, cpu_sibling_mask(cpu));
 729
 730                 /* cpu_core_map should be a superset of
 731                  * cpu_sibling_map even if we don't have cache
 732                  * information, so update the former here, too.
 733                  */
 734                 cpumask_set_cpu(cpu, cpu_core_mask(base + i));
 735                 cpumask_set_cpu(base + i, cpu_core_mask(cpu));
 736         }
 737         traverse_core_siblings(cpu, true);
 738
 739         set_numa_node(numa_cpu_lookup_table[cpu]);
 740         set_numa_mem(local_memory_node(numa_cpu_lookup_table[cpu]));
 741
 742         smp_wmb();
 743         notify_cpu_starting(cpu);
 744         set_cpu_online(cpu, true);
 745
 746         local_irq_enable();
 747
 748         cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
 749
 750         BUG();
 751 }
 752
 753 int setup_profiling_timer(unsigned int multiplier)
 754 {
 755         return 0;
 756 }
 757
 758 #ifdef CONFIG_SCHED_SMT
 759 /* cpumask of CPUs with asymetric SMT dependancy */
 760 static int powerpc_smt_flags(void)
 761 {
 762         int flags = SD_SHARE_CPUCAPACITY | SD_SHARE_PKG_RESOURCES;
 763
 764         if (cpu_has_feature(CPU_FTR_ASYM_SMT)) {
 765                 printk_once(KERN_INFO "Enabling Asymmetric SMT scheduling\n");
 766                 flags |= SD_ASYM_PACKING;
 767         }
 768         return flags;
 769 }
 770 #endif
 771
 772 static struct sched_domain_topology_level powerpc_topology[] = {
 773 #ifdef CONFIG_SCHED_SMT
 774         { cpu_smt_mask, powerpc_smt_flags, SD_INIT_NAME(SMT) },
 775 #endif
 776         { cpu_cpu_mask, SD_INIT_NAME(DIE) },
 777         { NULL, },
 778 };
 779
 780 void __init smp_cpus_done(unsigned int max_cpus)
 781 {
 782         cpumask_var_t old_mask;
 783
 784         /* We want the setup_cpu() here to be called from CPU 0, but our
 785          * init thread may have been "borrowed" by another CPU in the meantime
 786          * se we pin us down to CPU 0 for a short while
 787          */
 788         alloc_cpumask_var(&old_mask, GFP_NOWAIT);
 789         cpumask_copy(old_mask, tsk_cpus_allowed(current));
 790         set_cpus_allowed_ptr(current, cpumask_of(boot_cpuid));
 791
 792         if (smp_ops && smp_ops->setup_cpu)
 793                 smp_ops->setup_cpu(boot_cpuid);
 794
 795         set_cpus_allowed_ptr(current, old_mask);
 796
 797         free_cpumask_var(old_mask);
 798
 799         if (smp_ops && smp_ops->bringup_done)
 800                 smp_ops->bringup_done();
 801
 802         dump_numa_cpu_topology();
 803
 804         set_sched_topology(powerpc_topology);
 805
 806 }
 807
 808 #ifdef CONFIG_HOTPLUG_CPU
 809 int __cpu_disable(void)
 810 {
 811         int cpu = smp_processor_id();
 812         int base, i;
 813         int err;
 814
 815         if (!smp_ops->cpu_disable)
 816                 return -ENOSYS;
 817
 818         err = smp_ops->cpu_disable();
 819         if (err)
 820                 return err;
 821
 822         /* Update sibling maps */
 823         base = cpu_first_thread_sibling(cpu);
 824         for (i = 0; i < threads_per_core; i++) {
 825                 cpumask_clear_cpu(cpu, cpu_sibling_mask(base + i));
 826                 cpumask_clear_cpu(base + i, cpu_sibling_mask(cpu));
 827                 cpumask_clear_cpu(cpu, cpu_core_mask(base + i));
 828                 cpumask_clear_cpu(base + i, cpu_core_mask(cpu));
 829         }
 830         traverse_core_siblings(cpu, false);
 831
 832         return 0;
 833 }
 834
 835 void __cpu_die(unsigned int cpu)
 836 {
 837         if (smp_ops->cpu_die)
 838                 smp_ops->cpu_die(cpu);
 839 }
 840
 841 void cpu_die(void)
 842 {
 843         if (ppc_md.cpu_die)
 844                 ppc_md.cpu_die();
 845
 846         /* If we return, we re-enter start_secondary */
 847         start_secondary_resume();
 848 }
 849
 850 #endif