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