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/page.h>
  39 #include <asm/pgtable.h>
  40 #include <asm/prom.h>
  41 #include <asm/smp.h>
  42 #include <asm/time.h>
  43 #include <asm/machdep.h>
  44 #include <asm/cputhreads.h>
  45 #include <asm/cputable.h>
  46 #include <asm/mpic.h>
  47 #include <asm/vdso_datapage.h>
  48 #ifdef CONFIG_PPC64
  49 #include <asm/paca.h>
  50 #endif
  51 #include <asm/vdso.h>
  52 #include <asm/debug.h>
  53
  54 #ifdef DEBUG
  55 #include <asm/udbg.h>
  56 #define DBG(fmt...) udbg_printf(fmt)
  57 #else
  58 #define DBG(fmt...)
  59 #endif
  60
  61 #ifdef CONFIG_HOTPLUG_CPU
  62 /* State of each CPU during hotplug phases */
  63 static DEFINE_PER_CPU(int, cpu_state) = { 0 };
  64 #endif
  65
  66 struct thread_info *secondary_ti;
  67
  68 DEFINE_PER_CPU(cpumask_var_t, cpu_sibling_map);
  69 DEFINE_PER_CPU(cpumask_var_t, cpu_core_map);
  70
  71 EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
  72 EXPORT_PER_CPU_SYMBOL(cpu_core_map);
  73
  74 /* SMP operations for this machine */
  75 struct smp_ops_t *smp_ops;
  76
  77 /* Can't be static due to PowerMac hackery */
  78 volatile unsigned int cpu_callin_map[NR_CPUS];
  79
  80 int smt_enabled_at_boot = 1;
  81
  82 static void (*crash_ipi_function_ptr)(struct pt_regs *) = NULL;
  83
  84 /*
  85  * Returns 1 if the specified cpu should be brought up during boot.
  86  * Used to inhibit booting threads if they've been disabled or
  87  * limited on the command line
  88  */
  89 int smp_generic_cpu_bootable(unsigned int nr)
  90 {
  91         /* Special case - we inhibit secondary thread startup
  92          * during boot if the user requests it.
  93          */
  94         if (system_state == SYSTEM_BOOTING && cpu_has_feature(CPU_FTR_SMT)) {
  95                 if (!smt_enabled_at_boot && cpu_thread_in_core(nr) != 0)
  96                         return 0;
  97                 if (smt_enabled_at_boot
  98                     && cpu_thread_in_core(nr) >= smt_enabled_at_boot)
  99                         return 0;
 100         }
 101
 102         return 1;
 103 }
 104
 105
 106 #ifdef CONFIG_PPC64
 107 int smp_generic_kick_cpu(int nr)
 108 {
 109         BUG_ON(nr < 0 || nr >= NR_CPUS);
 110
 111         /*
 112          * The processor is currently spinning, waiting for the
 113          * cpu_start field to become non-zero After we set cpu_start,
 114          * the processor will continue on to secondary_start
 115          */
 116         if (!paca[nr].cpu_start) {
 117                 paca[nr].cpu_start = 1;
 118                 smp_mb();
 119                 return 0;
 120         }
 121
 122 #ifdef CONFIG_HOTPLUG_CPU
 123         /*
 124          * Ok it's not there, so it might be soft-unplugged, let's
 125          * try to bring it back
 126          */
 127         generic_set_cpu_up(nr);
 128         smp_wmb();
 129         smp_send_reschedule(nr);
 130 #endif /* CONFIG_HOTPLUG_CPU */
 131
 132         return 0;
 133 }
 134 #endif /* CONFIG_PPC64 */
 135
 136 static irqreturn_t call_function_action(int irq, void *data)
 137 {
 138         generic_smp_call_function_interrupt();
 139         return IRQ_HANDLED;
 140 }
 141
 142 static irqreturn_t reschedule_action(int irq, void *data)
 143 {
 144         scheduler_ipi();
 145         return IRQ_HANDLED;
 146 }
 147
 148 static irqreturn_t call_function_single_action(int irq, void *data)
 149 {
 150         generic_smp_call_function_single_interrupt();
 151         return IRQ_HANDLED;
 152 }
 153
 154 static irqreturn_t debug_ipi_action(int irq, void *data)
 155 {
 156         if (crash_ipi_function_ptr) {
 157                 crash_ipi_function_ptr(get_irq_regs());
 158                 return IRQ_HANDLED;
 159         }
 160
 161 #ifdef CONFIG_DEBUGGER
 162         debugger_ipi(get_irq_regs());
 163 #endif /* CONFIG_DEBUGGER */
 164
 165         return IRQ_HANDLED;
 166 }
 167
 168 static irq_handler_t smp_ipi_action[] = {
 169         [PPC_MSG_CALL_FUNCTION] =  call_function_action,
 170         [PPC_MSG_RESCHEDULE] = reschedule_action,
 171         [PPC_MSG_CALL_FUNC_SINGLE] = call_function_single_action,
 172         [PPC_MSG_DEBUGGER_BREAK] = debug_ipi_action,
 173 };
 174
 175 const char *smp_ipi_name[] = {
 176         [PPC_MSG_CALL_FUNCTION] =  "ipi call function",
 177         [PPC_MSG_RESCHEDULE] = "ipi reschedule",
 178         [PPC_MSG_CALL_FUNC_SINGLE] = "ipi call function single",
 179         [PPC_MSG_DEBUGGER_BREAK] = "ipi debugger",
 180 };
 181
 182 /* optional function to request ipi, for controllers with >= 4 ipis */
 183 int smp_request_message_ipi(int virq, int msg)
 184 {
 185         int err;
 186
 187         if (msg < 0 || msg > PPC_MSG_DEBUGGER_BREAK) {
 188                 return -EINVAL;
 189         }
 190 #if !defined(CONFIG_DEBUGGER) && !defined(CONFIG_KEXEC)
 191         if (msg == PPC_MSG_DEBUGGER_BREAK) {
 192                 return 1;
 193         }
 194 #endif
 195         err = request_irq(virq, smp_ipi_action[msg],
 196                           IRQF_PERCPU | IRQF_NO_THREAD | IRQF_NO_SUSPEND,
 197                           smp_ipi_name[msg], NULL);
 198         WARN(err < 0, "unable to request_irq %d for %s (rc %d)\n",
 199                 virq, smp_ipi_name[msg], err);
 200
 201         return err;
 202 }
 203
 204 #ifdef CONFIG_PPC_SMP_MUXED_IPI
 205 struct cpu_messages {
 206         int messages;                   /* current messages */
 207         unsigned long data;             /* data for cause ipi */
 208 };
 209 static DEFINE_PER_CPU_SHARED_ALIGNED(struct cpu_messages, ipi_message);
 210
 211 void smp_muxed_ipi_set_data(int cpu, unsigned long data)
 212 {
 213         struct cpu_messages *info = &per_cpu(ipi_message, cpu);
 214
 215         info->data = data;
 216 }
 217
 218 void smp_muxed_ipi_message_pass(int cpu, int msg)
 219 {
 220         struct cpu_messages *info = &per_cpu(ipi_message, cpu);
 221         char *message = (char *)&info->messages;
 222
 223         /*
 224          * Order previous accesses before accesses in the IPI handler.
 225          */
 226         smp_mb();
 227         message[msg] = 1;
 228         /*
 229          * cause_ipi functions are required to include a full barrier
 230          * before doing whatever causes the IPI.
 231          */
 232         smp_ops->cause_ipi(cpu, info->data);
 233 }
 234
 235 #ifdef __BIG_ENDIAN__
 236 #define IPI_MESSAGE(A) (1 << (24 - 8 * (A)))
 237 #else
 238 #define IPI_MESSAGE(A) (1 << (8 * (A)))
 239 #endif
 240
 241 irqreturn_t smp_ipi_demux(void)
 242 {
 243         struct cpu_messages *info = &__get_cpu_var(ipi_message);
 244         unsigned int all;
 245
 246         mb();   /* order any irq clear */
 247
 248         do {
 249                 all = xchg(&info->messages, 0);
 250                 if (all & IPI_MESSAGE(PPC_MSG_CALL_FUNCTION))
 251                         generic_smp_call_function_interrupt();
 252                 if (all & IPI_MESSAGE(PPC_MSG_RESCHEDULE))
 253                         scheduler_ipi();
 254                 if (all & IPI_MESSAGE(PPC_MSG_CALL_FUNC_SINGLE))
 255                         generic_smp_call_function_single_interrupt();
 256                 if (all & IPI_MESSAGE(PPC_MSG_DEBUGGER_BREAK))
 257                         debug_ipi_action(0, NULL);
 258         } while (info->messages);
 259
 260         return IRQ_HANDLED;
 261 }
 262 #endif /* CONFIG_PPC_SMP_MUXED_IPI */
 263
 264 static inline void do_message_pass(int cpu, int msg)
 265 {
 266         if (smp_ops->message_pass)
 267                 smp_ops->message_pass(cpu, msg);
 268 #ifdef CONFIG_PPC_SMP_MUXED_IPI
 269         else
 270                 smp_muxed_ipi_message_pass(cpu, msg);
 271 #endif
 272 }
 273
 274 void smp_send_reschedule(int cpu)
 275 {
 276         if (likely(smp_ops))
 277                 do_message_pass(cpu, PPC_MSG_RESCHEDULE);
 278 }
 279 EXPORT_SYMBOL_GPL(smp_send_reschedule);
 280
 281 void arch_send_call_function_single_ipi(int cpu)
 282 {
 283         do_message_pass(cpu, PPC_MSG_CALL_FUNC_SINGLE);
 284 }
 285
 286 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
 287 {
 288         unsigned int cpu;
 289
 290         for_each_cpu(cpu, mask)
 291                 do_message_pass(cpu, PPC_MSG_CALL_FUNCTION);
 292 }
 293
 294 #if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC)
 295 void smp_send_debugger_break(void)
 296 {
 297         int cpu;
 298         int me = raw_smp_processor_id();
 299
 300         if (unlikely(!smp_ops))
 301                 return;
 302
 303         for_each_online_cpu(cpu)
 304                 if (cpu != me)
 305                         do_message_pass(cpu, PPC_MSG_DEBUGGER_BREAK);
 306 }
 307 #endif
 308
 309 #ifdef CONFIG_KEXEC
 310 void crash_send_ipi(void (*crash_ipi_callback)(struct pt_regs *))
 311 {
 312         crash_ipi_function_ptr = crash_ipi_callback;
 313         if (crash_ipi_callback) {
 314                 mb();
 315                 smp_send_debugger_break();
 316         }
 317 }
 318 #endif
 319
 320 static void stop_this_cpu(void *dummy)
 321 {
 322         /* Remove this CPU */
 323         set_cpu_online(smp_processor_id(), false);
 324
 325         local_irq_disable();
 326         while (1)
 327                 ;
 328 }
 329
 330 void smp_send_stop(void)
 331 {
 332         smp_call_function(stop_this_cpu, NULL, 0);
 333 }
 334
 335 struct thread_info *current_set[NR_CPUS];
 336
 337 static void smp_store_cpu_info(int id)
 338 {
 339         per_cpu(cpu_pvr, id) = mfspr(SPRN_PVR);
 340 #ifdef CONFIG_PPC_FSL_BOOK3E
 341         per_cpu(next_tlbcam_idx, id)
 342                 = (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) - 1;
 343 #endif
 344 }
 345
 346 void __init smp_prepare_cpus(unsigned int max_cpus)
 347 {
 348         unsigned int cpu;
 349
 350         DBG("smp_prepare_cpus\n");
 351
 352         /*
 353          * setup_cpu may need to be called on the boot cpu. We havent
 354          * spun any cpus up but lets be paranoid.
 355          */
 356         BUG_ON(boot_cpuid != smp_processor_id());
 357
 358         /* Fixup boot cpu */
 359         smp_store_cpu_info(boot_cpuid);
 360         cpu_callin_map[boot_cpuid] = 1;
 361
 362         for_each_possible_cpu(cpu) {
 363                 zalloc_cpumask_var_node(&per_cpu(cpu_sibling_map, cpu),
 364                                         GFP_KERNEL, cpu_to_node(cpu));
 365                 zalloc_cpumask_var_node(&per_cpu(cpu_core_map, cpu),
 366                                         GFP_KERNEL, cpu_to_node(cpu));
 367         }
 368
 369         cpumask_set_cpu(boot_cpuid, cpu_sibling_mask(boot_cpuid));
 370         cpumask_set_cpu(boot_cpuid, cpu_core_mask(boot_cpuid));
 371
 372         if (smp_ops)
 373                 if (smp_ops->probe)
 374                         max_cpus = smp_ops->probe();
 375                 else
 376                         max_cpus = NR_CPUS;
 377         else
 378                 max_cpus = 1;
 379 }
 380
 381 void smp_prepare_boot_cpu(void)
 382 {
 383         BUG_ON(smp_processor_id() != boot_cpuid);
 384 #ifdef CONFIG_PPC64
 385         paca[boot_cpuid].__current = current;
 386 #endif
 387         current_set[boot_cpuid] = task_thread_info(current);
 388 }
 389
 390 #ifdef CONFIG_HOTPLUG_CPU
 391
 392 int generic_cpu_disable(void)
 393 {
 394         unsigned int cpu = smp_processor_id();
 395
 396         if (cpu == boot_cpuid)
 397                 return -EBUSY;
 398
 399         set_cpu_online(cpu, false);
 400 #ifdef CONFIG_PPC64
 401         vdso_data->processorCount--;
 402 #endif
 403         migrate_irqs();
 404         return 0;
 405 }
 406
 407 void generic_cpu_die(unsigned int cpu)
 408 {
 409         int i;
 410
 411         for (i = 0; i < 100; i++) {
 412                 smp_rmb();
 413                 if (per_cpu(cpu_state, cpu) == CPU_DEAD)
 414                         return;
 415                 msleep(100);
 416         }
 417         printk(KERN_ERR "CPU%d didn't die...\n", cpu);
 418 }
 419
 420 void generic_mach_cpu_die(void)
 421 {
 422         unsigned int cpu;
 423
 424         local_irq_disable();
 425         idle_task_exit();
 426         cpu = smp_processor_id();
 427         printk(KERN_DEBUG "CPU%d offline\n", cpu);
 428         __get_cpu_var(cpu_state) = CPU_DEAD;
 429         smp_wmb();
 430         while (__get_cpu_var(cpu_state) != CPU_UP_PREPARE)
 431                 cpu_relax();
 432 }
 433
 434 void generic_set_cpu_dead(unsigned int cpu)
 435 {
 436         per_cpu(cpu_state, cpu) = CPU_DEAD;
 437 }
 438
 439 /*
 440  * The cpu_state should be set to CPU_UP_PREPARE in kick_cpu(), otherwise
 441  * the cpu_state is always CPU_DEAD after calling generic_set_cpu_dead(),
 442  * which makes the delay in generic_cpu_die() not happen.
 443  */
 444 void generic_set_cpu_up(unsigned int cpu)
 445 {
 446         per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
 447 }
 448
 449 int generic_check_cpu_restart(unsigned int cpu)
 450 {
 451         return per_cpu(cpu_state, cpu) == CPU_UP_PREPARE;
 452 }
 453
 454 static atomic_t secondary_inhibit_count;
 455
 456 /*
 457  * Don't allow secondary CPU threads to come online
 458  */
 459 void inhibit_secondary_onlining(void)
 460 {
 461         /*
 462          * This makes secondary_inhibit_count stable during cpu
 463          * online/offline operations.
 464          */
 465         get_online_cpus();
 466
 467         atomic_inc(&secondary_inhibit_count);
 468         put_online_cpus();
 469 }
 470 EXPORT_SYMBOL_GPL(inhibit_secondary_onlining);
 471
 472 /*
 473  * Allow secondary CPU threads to come online again
 474  */
 475 void uninhibit_secondary_onlining(void)
 476 {
 477         get_online_cpus();
 478         atomic_dec(&secondary_inhibit_count);
 479         put_online_cpus();
 480 }
 481 EXPORT_SYMBOL_GPL(uninhibit_secondary_onlining);
 482
 483 static int secondaries_inhibited(void)
 484 {
 485         return atomic_read(&secondary_inhibit_count);
 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 % threads_per_core != 0)
 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 map */
 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 int *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 = *reg;
 595 out:
 596         of_node_put(np);
 597         return id;
 598 }
 599
 600 /* Return the value of the chip-id property corresponding
 601  * to the given logical cpu.
 602  */
 603 int cpu_to_chip_id(int cpu)
 604 {
 605         struct device_node *np;
 606
 607         np = of_get_cpu_node(cpu, NULL);
 608         if (!np)
 609                 return -1;
 610
 611         of_node_put(np);
 612         return of_get_ibm_chip_id(np);
 613 }
 614 EXPORT_SYMBOL(cpu_to_chip_id);
 615
 616 /* Helper routines for cpu to core mapping */
 617 int cpu_core_index_of_thread(int cpu)
 618 {
 619         return cpu >> threads_shift;
 620 }
 621 EXPORT_SYMBOL_GPL(cpu_core_index_of_thread);
 622
 623 int cpu_first_thread_of_core(int core)
 624 {
 625         return core << threads_shift;
 626 }
 627 EXPORT_SYMBOL_GPL(cpu_first_thread_of_core);
 628
 629 static void traverse_siblings_chip_id(int cpu, bool add, int chipid)
 630 {
 631         const struct cpumask *mask;
 632         struct device_node *np;
 633         int i, plen;
 634         const __be32 *prop;
 635
 636         mask = add ? cpu_online_mask : cpu_present_mask;
 637         for_each_cpu(i, mask) {
 638                 np = of_get_cpu_node(i, NULL);
 639                 if (!np)
 640                         continue;
 641                 prop = of_get_property(np, "ibm,chip-id", &plen);
 642                 if (prop && plen == sizeof(int) &&
 643                     of_read_number(prop, 1) == chipid) {
 644                         if (add) {
 645                                 cpumask_set_cpu(cpu, cpu_core_mask(i));
 646                                 cpumask_set_cpu(i, cpu_core_mask(cpu));
 647                         } else {
 648                                 cpumask_clear_cpu(cpu, cpu_core_mask(i));
 649                                 cpumask_clear_cpu(i, cpu_core_mask(cpu));
 650                         }
 651                 }
 652                 of_node_put(np);
 653         }
 654 }
 655
 656 /* Must be called when no change can occur to cpu_present_mask,
 657  * i.e. during cpu online or offline.
 658  */
 659 static struct device_node *cpu_to_l2cache(int cpu)
 660 {
 661         struct device_node *np;
 662         struct device_node *cache;
 663
 664         if (!cpu_present(cpu))
 665                 return NULL;
 666
 667         np = of_get_cpu_node(cpu, NULL);
 668         if (np == NULL)
 669                 return NULL;
 670
 671         cache = of_find_next_cache_node(np);
 672
 673         of_node_put(np);
 674
 675         return cache;
 676 }
 677
 678 static void traverse_core_siblings(int cpu, bool add)
 679 {
 680         struct device_node *l2_cache, *np;
 681         const struct cpumask *mask;
 682         int i, chip, plen;
 683         const __be32 *prop;
 684
 685         /* First see if we have ibm,chip-id properties in cpu nodes */
 686         np = of_get_cpu_node(cpu, NULL);
 687         if (np) {
 688                 chip = -1;
 689                 prop = of_get_property(np, "ibm,chip-id", &plen);
 690                 if (prop && plen == sizeof(int))
 691                         chip = of_read_number(prop, 1);
 692                 of_node_put(np);
 693                 if (chip >= 0) {
 694                         traverse_siblings_chip_id(cpu, add, chip);
 695                         return;
 696                 }
 697         }
 698
 699         l2_cache = cpu_to_l2cache(cpu);
 700         mask = add ? cpu_online_mask : cpu_present_mask;
 701         for_each_cpu(i, mask) {
 702                 np = cpu_to_l2cache(i);
 703                 if (!np)
 704                         continue;
 705                 if (np == l2_cache) {
 706                         if (add) {
 707                                 cpumask_set_cpu(cpu, cpu_core_mask(i));
 708                                 cpumask_set_cpu(i, cpu_core_mask(cpu));
 709                         } else {
 710                                 cpumask_clear_cpu(cpu, cpu_core_mask(i));
 711                                 cpumask_clear_cpu(i, cpu_core_mask(cpu));
 712                         }
 713                 }
 714                 of_node_put(np);
 715         }
 716         of_node_put(l2_cache);
 717 }
 718
 719 /* Activate a secondary processor. */
 720 void start_secondary(void *unused)
 721 {
 722         unsigned int cpu = smp_processor_id();
 723         int i, base;
 724
 725         atomic_inc(&init_mm.mm_count);
 726         current->active_mm = &init_mm;
 727
 728         smp_store_cpu_info(cpu);
 729         set_dec(tb_ticks_per_jiffy);
 730         preempt_disable();
 731         cpu_callin_map[cpu] = 1;
 732
 733         if (smp_ops->setup_cpu)
 734                 smp_ops->setup_cpu(cpu);
 735         if (smp_ops->take_timebase)
 736                 smp_ops->take_timebase();
 737
 738         secondary_cpu_time_init();
 739
 740 #ifdef CONFIG_PPC64
 741         if (system_state == SYSTEM_RUNNING)
 742                 vdso_data->processorCount++;
 743
 744         vdso_getcpu_init();
 745 #endif
 746         /* Update sibling maps */
 747         base = cpu_first_thread_sibling(cpu);
 748         for (i = 0; i < threads_per_core; i++) {
 749                 if (cpu_is_offline(base + i) && (cpu != base + i))
 750                         continue;
 751                 cpumask_set_cpu(cpu, cpu_sibling_mask(base + i));
 752                 cpumask_set_cpu(base + i, cpu_sibling_mask(cpu));
 753
 754                 /* cpu_core_map should be a superset of
 755                  * cpu_sibling_map even if we don't have cache
 756                  * information, so update the former here, too.
 757                  */
 758                 cpumask_set_cpu(cpu, cpu_core_mask(base + i));
 759                 cpumask_set_cpu(base + i, cpu_core_mask(cpu));
 760         }
 761         traverse_core_siblings(cpu, true);
 762
 763         smp_wmb();
 764         notify_cpu_starting(cpu);
 765         set_cpu_online(cpu, true);
 766
 767         local_irq_enable();
 768
 769         cpu_startup_entry(CPUHP_ONLINE);
 770
 771         BUG();
 772 }
 773
 774 int setup_profiling_timer(unsigned int multiplier)
 775 {
 776         return 0;
 777 }
 778
 779 void __init smp_cpus_done(unsigned int max_cpus)
 780 {
 781         cpumask_var_t old_mask;
 782
 783         /* We want the setup_cpu() here to be called from CPU 0, but our
 784          * init thread may have been "borrowed" by another CPU in the meantime
 785          * se we pin us down to CPU 0 for a short while
 786          */
 787         alloc_cpumask_var(&old_mask, GFP_NOWAIT);
 788         cpumask_copy(old_mask, tsk_cpus_allowed(current));
 789         set_cpus_allowed_ptr(current, cpumask_of(boot_cpuid));
 790
 791         if (smp_ops && smp_ops->setup_cpu)
 792                 smp_ops->setup_cpu(boot_cpuid);
 793
 794         set_cpus_allowed_ptr(current, old_mask);
 795
 796         free_cpumask_var(old_mask);
 797
 798         if (smp_ops && smp_ops->bringup_done)
 799                 smp_ops->bringup_done();
 800
 801         dump_numa_cpu_topology();
 802
 803 }
 804
 805 int arch_sd_sibling_asym_packing(void)
 806 {
 807         if (cpu_has_feature(CPU_FTR_ASYM_SMT)) {
 808                 printk_once(KERN_INFO "Enabling Asymmetric SMT scheduling\n");
 809                 return SD_ASYM_PACKING;
 810         }
 811         return 0;
 812 }
 813
 814 #ifdef CONFIG_HOTPLUG_CPU
 815 int __cpu_disable(void)
 816 {
 817         int cpu = smp_processor_id();
 818         int base, i;
 819         int err;
 820
 821         if (!smp_ops->cpu_disable)
 822                 return -ENOSYS;
 823
 824         err = smp_ops->cpu_disable();
 825         if (err)
 826                 return err;
 827
 828         /* Update sibling maps */
 829         base = cpu_first_thread_sibling(cpu);
 830         for (i = 0; i < threads_per_core; i++) {
 831                 cpumask_clear_cpu(cpu, cpu_sibling_mask(base + i));
 832                 cpumask_clear_cpu(base + i, cpu_sibling_mask(cpu));
 833                 cpumask_clear_cpu(cpu, cpu_core_mask(base + i));
 834                 cpumask_clear_cpu(base + i, cpu_core_mask(cpu));
 835         }
 836         traverse_core_siblings(cpu, false);
 837
 838         return 0;
 839 }
 840
 841 void __cpu_die(unsigned int cpu)
 842 {
 843         if (smp_ops->cpu_die)
 844                 smp_ops->cpu_die(cpu);
 845 }
 846
 847 void cpu_die(void)
 848 {
 849         if (ppc_md.cpu_die)
 850                 ppc_md.cpu_die();
 851
 852         /* If we return, we re-enter start_secondary */
 853         start_secondary_resume();
 854 }
 855
 856 #endif