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