arch/mips/kernel/smp.c

   1 /*
   2  * This program is free software; you can redistribute it and/or
   3  * modify it under the terms of the GNU General Public License
   4  * as published by the Free Software Foundation; either version 2
   5  * of the License, or (at your option) any later version.
   6  *
   7  * This program is distributed in the hope that it will be useful,
   8  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  10  * GNU General Public License for more details.
  11  *
  12  * You should have received a copy of the GNU General Public License
  13  * along with this program; if not, write to the Free Software
  14  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  15  *
  16  * Copyright (C) 2000, 2001 Kanoj Sarcar
  17  * Copyright (C) 2000, 2001 Ralf Baechle
  18  * Copyright (C) 2000, 2001 Silicon Graphics, Inc.
  19  * Copyright (C) 2000, 2001, 2003 Broadcom Corporation
  20  */
  21 #include <linux/cache.h>
  22 #include <linux/delay.h>
  23 #include <linux/init.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/smp.h>
  26 #include <linux/spinlock.h>
  27 #include <linux/threads.h>
  28 #include <linux/export.h>
  29 #include <linux/time.h>
  30 #include <linux/timex.h>
  31 #include <linux/sched.h>
  32 #include <linux/cpumask.h>
  33 #include <linux/cpu.h>
  34 #include <linux/err.h>
  35 #include <linux/ftrace.h>
  36 #include <linux/irqdomain.h>
  37 #include <linux/of.h>
  38 #include <linux/of_irq.h>
  39
  40 #include <linux/atomic.h>
  41 #include <asm/cpu.h>
  42 #include <asm/processor.h>
  43 #include <asm/idle.h>
  44 #include <asm/r4k-timer.h>
  45 #include <asm/mips-cpc.h>
  46 #include <asm/mmu_context.h>
  47 #include <asm/time.h>
  48 #include <asm/setup.h>
  49 #include <asm/maar.h>
  50
  51 cpumask_t cpu_callin_map;               /* Bitmask of started secondaries */
  52
  53 int __cpu_number_map[NR_CPUS];          /* Map physical to logical */
  54 EXPORT_SYMBOL(__cpu_number_map);
  55
  56 int __cpu_logical_map[NR_CPUS];         /* Map logical to physical */
  57 EXPORT_SYMBOL(__cpu_logical_map);
  58
  59 /* Number of TCs (or siblings in Intel speak) per CPU core */
  60 int smp_num_siblings = 1;
  61 EXPORT_SYMBOL(smp_num_siblings);
  62
  63 /* representing the TCs (or siblings in Intel speak) of each logical CPU */
  64 cpumask_t cpu_sibling_map[NR_CPUS] __read_mostly;
  65 EXPORT_SYMBOL(cpu_sibling_map);
  66
  67 /* representing the core map of multi-core chips of each logical CPU */
  68 cpumask_t cpu_core_map[NR_CPUS] __read_mostly;
  69 EXPORT_SYMBOL(cpu_core_map);
  70
  71 static DECLARE_COMPLETION(cpu_starting);
  72 static DECLARE_COMPLETION(cpu_running);
  73
  74 /*
  75  * A logcal cpu mask containing only one VPE per core to
  76  * reduce the number of IPIs on large MT systems.
  77  */
  78 cpumask_t cpu_foreign_map[NR_CPUS] __read_mostly;
  79 EXPORT_SYMBOL(cpu_foreign_map);
  80
  81 /* representing cpus for which sibling maps can be computed */
  82 static cpumask_t cpu_sibling_setup_map;
  83
  84 /* representing cpus for which core maps can be computed */
  85 static cpumask_t cpu_core_setup_map;
  86
  87 cpumask_t cpu_coherent_mask;
  88
  89 #ifdef CONFIG_GENERIC_IRQ_IPI
  90 static struct irq_desc *call_desc;
  91 static struct irq_desc *sched_desc;
  92 #endif
  93
  94 static inline void set_cpu_sibling_map(int cpu)
  95 {
  96         int i;
  97
  98         cpumask_set_cpu(cpu, &cpu_sibling_setup_map);
  99
 100         if (smp_num_siblings > 1) {
 101                 for_each_cpu(i, &cpu_sibling_setup_map) {
 102                         if (cpu_data[cpu].package == cpu_data[i].package &&
 103                                     cpu_data[cpu].core == cpu_data[i].core) {
 104                                 cpumask_set_cpu(i, &cpu_sibling_map[cpu]);
 105                                 cpumask_set_cpu(cpu, &cpu_sibling_map[i]);
 106                         }
 107                 }
 108         } else
 109                 cpumask_set_cpu(cpu, &cpu_sibling_map[cpu]);
 110 }
 111
 112 static inline void set_cpu_core_map(int cpu)
 113 {
 114         int i;
 115
 116         cpumask_set_cpu(cpu, &cpu_core_setup_map);
 117
 118         for_each_cpu(i, &cpu_core_setup_map) {
 119                 if (cpu_data[cpu].package == cpu_data[i].package) {
 120                         cpumask_set_cpu(i, &cpu_core_map[cpu]);
 121                         cpumask_set_cpu(cpu, &cpu_core_map[i]);
 122                 }
 123         }
 124 }
 125
 126 /*
 127  * Calculate a new cpu_foreign_map mask whenever a
 128  * new cpu appears or disappears.
 129  */
 130 void calculate_cpu_foreign_map(void)
 131 {
 132         int i, k, core_present;
 133         cpumask_t temp_foreign_map;
 134
 135         /* Re-calculate the mask */
 136         cpumask_clear(&temp_foreign_map);
 137         for_each_online_cpu(i) {
 138                 core_present = 0;
 139                 for_each_cpu(k, &temp_foreign_map)
 140                         if (cpu_data[i].package == cpu_data[k].package &&
 141                             cpu_data[i].core == cpu_data[k].core)
 142                                 core_present = 1;
 143                 if (!core_present)
 144                         cpumask_set_cpu(i, &temp_foreign_map);
 145         }
 146
 147         for_each_online_cpu(i)
 148                 cpumask_andnot(&cpu_foreign_map[i],
 149                                &temp_foreign_map, &cpu_sibling_map[i]);
 150 }
 151
 152 struct plat_smp_ops *mp_ops;
 153 EXPORT_SYMBOL(mp_ops);
 154
 155 void register_smp_ops(struct plat_smp_ops *ops)
 156 {
 157         if (mp_ops)
 158                 printk(KERN_WARNING "Overriding previously set SMP ops\n");
 159
 160         mp_ops = ops;
 161 }
 162
 163 #ifdef CONFIG_GENERIC_IRQ_IPI
 164 void mips_smp_send_ipi_single(int cpu, unsigned int action)
 165 {
 166         mips_smp_send_ipi_mask(cpumask_of(cpu), action);
 167 }
 168
 169 void mips_smp_send_ipi_mask(const struct cpumask *mask, unsigned int action)
 170 {
 171         unsigned long flags;
 172         unsigned int core;
 173         int cpu;
 174
 175         local_irq_save(flags);
 176
 177         switch (action) {
 178         case SMP_CALL_FUNCTION:
 179                 __ipi_send_mask(call_desc, mask);
 180                 break;
 181
 182         case SMP_RESCHEDULE_YOURSELF:
 183                 __ipi_send_mask(sched_desc, mask);
 184                 break;
 185
 186         default:
 187                 BUG();
 188         }
 189
 190         if (mips_cpc_present()) {
 191                 for_each_cpu(cpu, mask) {
 192                         core = cpu_data[cpu].core;
 193
 194                         if (core == current_cpu_data.core)
 195                                 continue;
 196
 197                         while (!cpumask_test_cpu(cpu, &cpu_coherent_mask)) {
 198                                 mips_cm_lock_other(core, 0);
 199                                 mips_cpc_lock_other(core);
 200                                 write_cpc_co_cmd(CPC_Cx_CMD_PWRUP);
 201                                 mips_cpc_unlock_other();
 202                                 mips_cm_unlock_other();
 203                         }
 204                 }
 205         }
 206
 207         local_irq_restore(flags);
 208 }
 209
 210
 211 static irqreturn_t ipi_resched_interrupt(int irq, void *dev_id)
 212 {
 213         scheduler_ipi();
 214
 215         return IRQ_HANDLED;
 216 }
 217
 218 static irqreturn_t ipi_call_interrupt(int irq, void *dev_id)
 219 {
 220         generic_smp_call_function_interrupt();
 221
 222         return IRQ_HANDLED;
 223 }
 224
 225 static struct irqaction irq_resched = {
 226         .handler        = ipi_resched_interrupt,
 227         .flags          = IRQF_PERCPU,
 228         .name           = "IPI resched"
 229 };
 230
 231 static struct irqaction irq_call = {
 232         .handler        = ipi_call_interrupt,
 233         .flags          = IRQF_PERCPU,
 234         .name           = "IPI call"
 235 };
 236
 237 static void smp_ipi_init_one(unsigned int virq,
 238                                     struct irqaction *action)
 239 {
 240         int ret;
 241
 242         irq_set_handler(virq, handle_percpu_irq);
 243         ret = setup_irq(virq, action);
 244         BUG_ON(ret);
 245 }
 246
 247 static unsigned int call_virq, sched_virq;
 248
 249 int mips_smp_ipi_allocate(const struct cpumask *mask)
 250 {
 251         int virq;
 252         struct irq_domain *ipidomain;
 253         struct device_node *node;
 254
 255         node = of_irq_find_parent(of_root);
 256         ipidomain = irq_find_matching_host(node, DOMAIN_BUS_IPI);
 257
 258         /*
 259          * Some platforms have half DT setup. So if we found irq node but
 260          * didn't find an ipidomain, try to search for one that is not in the
 261          * DT.
 262          */
 263         if (node && !ipidomain)
 264                 ipidomain = irq_find_matching_host(NULL, DOMAIN_BUS_IPI);
 265
 266         /*
 267          * There are systems which only use IPI domains some of the time,
 268          * depending upon configuration we don't know until runtime. An
 269          * example is Malta where we may compile in support for GIC & the
 270          * MT ASE, but run on a system which has multiple VPEs in a single
 271          * core and doesn't include a GIC. Until all IPI implementations
 272          * have been converted to use IPI domains the best we can do here
 273          * is to return & hope some other code sets up the IPIs.
 274          */
 275         if (!ipidomain)
 276                 return 0;
 277
 278         virq = irq_reserve_ipi(ipidomain, mask);
 279         BUG_ON(!virq);
 280         if (!call_virq)
 281                 call_virq = virq;
 282
 283         virq = irq_reserve_ipi(ipidomain, mask);
 284         BUG_ON(!virq);
 285         if (!sched_virq)
 286                 sched_virq = virq;
 287
 288         if (irq_domain_is_ipi_per_cpu(ipidomain)) {
 289                 int cpu;
 290
 291                 for_each_cpu(cpu, mask) {
 292                         smp_ipi_init_one(call_virq + cpu, &irq_call);
 293                         smp_ipi_init_one(sched_virq + cpu, &irq_resched);
 294                 }
 295         } else {
 296                 smp_ipi_init_one(call_virq, &irq_call);
 297                 smp_ipi_init_one(sched_virq, &irq_resched);
 298         }
 299
 300         return 0;
 301 }
 302
 303 int mips_smp_ipi_free(const struct cpumask *mask)
 304 {
 305         struct irq_domain *ipidomain;
 306         struct device_node *node;
 307
 308         node = of_irq_find_parent(of_root);
 309         ipidomain = irq_find_matching_host(node, DOMAIN_BUS_IPI);
 310
 311         /*
 312          * Some platforms have half DT setup. So if we found irq node but
 313          * didn't find an ipidomain, try to search for one that is not in the
 314          * DT.
 315          */
 316         if (node && !ipidomain)
 317                 ipidomain = irq_find_matching_host(NULL, DOMAIN_BUS_IPI);
 318
 319         BUG_ON(!ipidomain);
 320
 321         if (irq_domain_is_ipi_per_cpu(ipidomain)) {
 322                 int cpu;
 323
 324                 for_each_cpu(cpu, mask) {
 325                         remove_irq(call_virq + cpu, &irq_call);
 326                         remove_irq(sched_virq + cpu, &irq_resched);
 327                 }
 328         }
 329         irq_destroy_ipi(call_virq, mask);
 330         irq_destroy_ipi(sched_virq, mask);
 331         return 0;
 332 }
 333
 334
 335 static int __init mips_smp_ipi_init(void)
 336 {
 337         mips_smp_ipi_allocate(cpu_possible_mask);
 338
 339         call_desc = irq_to_desc(call_virq);
 340         sched_desc = irq_to_desc(sched_virq);
 341
 342         return 0;
 343 }
 344 early_initcall(mips_smp_ipi_init);
 345 #endif
 346
 347 /*
 348  * First C code run on the secondary CPUs after being started up by
 349  * the master.
 350  */
 351 asmlinkage void start_secondary(void)
 352 {
 353         unsigned int cpu;
 354
 355         cpu_probe();
 356         per_cpu_trap_init(false);
 357         mips_clockevent_init();
 358         mp_ops->init_secondary();
 359         cpu_report();
 360         maar_init();
 361
 362         /*
 363          * XXX parity protection should be folded in here when it's converted
 364          * to an option instead of something based on .cputype
 365          */
 366
 367         calibrate_delay();
 368         preempt_disable();
 369         cpu = smp_processor_id();
 370         cpu_data[cpu].udelay_val = loops_per_jiffy;
 371
 372         set_cpu_sibling_map(cpu);
 373         set_cpu_core_map(cpu);
 374
 375         cpumask_set_cpu(cpu, &cpu_coherent_mask);
 376         notify_cpu_starting(cpu);
 377
 378         /* Notify boot CPU that we're starting & ready to sync counters */
 379         complete(&cpu_starting);
 380
 381         synchronise_count_slave(cpu);
 382
 383         /* The CPU is running and counters synchronised, now mark it online */
 384         set_cpu_online(cpu, true);
 385
 386         calculate_cpu_foreign_map();
 387
 388         /*
 389          * Notify boot CPU that we're up & online and it can safely return
 390          * from __cpu_up
 391          */
 392         complete(&cpu_running);
 393
 394         /*
 395          * irq will be enabled in ->smp_finish(), enabling it too early
 396          * is dangerous.
 397          */
 398         WARN_ON_ONCE(!irqs_disabled());
 399         mp_ops->smp_finish();
 400
 401         cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
 402 }
 403
 404 static void stop_this_cpu(void *dummy)
 405 {
 406         /*
 407          * Remove this CPU:
 408          */
 409
 410         set_cpu_online(smp_processor_id(), false);
 411         calculate_cpu_foreign_map();
 412         local_irq_disable();
 413         while (1);
 414 }
 415
 416 void smp_send_stop(void)
 417 {
 418         smp_call_function(stop_this_cpu, NULL, 0);
 419 }
 420
 421 void __init smp_cpus_done(unsigned int max_cpus)
 422 {
 423 }
 424
 425 /* called from main before smp_init() */
 426 void __init smp_prepare_cpus(unsigned int max_cpus)
 427 {
 428         init_new_context(current, &init_mm);
 429         current_thread_info()->cpu = 0;
 430         mp_ops->prepare_cpus(max_cpus);
 431         set_cpu_sibling_map(0);
 432         set_cpu_core_map(0);
 433         calculate_cpu_foreign_map();
 434 #ifndef CONFIG_HOTPLUG_CPU
 435         init_cpu_present(cpu_possible_mask);
 436 #endif
 437         cpumask_copy(&cpu_coherent_mask, cpu_possible_mask);
 438 }
 439
 440 /* preload SMP state for boot cpu */
 441 void smp_prepare_boot_cpu(void)
 442 {
 443         set_cpu_possible(0, true);
 444         set_cpu_online(0, true);
 445 }
 446
 447 int __cpu_up(unsigned int cpu, struct task_struct *tidle)
 448 {
 449         mp_ops->boot_secondary(cpu, tidle);
 450
 451         /* Wait for CPU to start and be ready to sync counters */
 452         if (!wait_for_completion_timeout(&cpu_starting,
 453                                          msecs_to_jiffies(1000))) {
 454                 pr_crit("CPU%u: failed to start\n", cpu);
 455                 return -EIO;
 456         }
 457
 458         synchronise_count_master(cpu);
 459
 460         /* Wait for CPU to finish startup & mark itself online before return */
 461         wait_for_completion(&cpu_running);
 462         return 0;
 463 }
 464
 465 /* Not really SMP stuff ... */
 466 int setup_profiling_timer(unsigned int multiplier)
 467 {
 468         return 0;
 469 }
 470
 471 static void flush_tlb_all_ipi(void *info)
 472 {
 473         local_flush_tlb_all();
 474 }
 475
 476 void flush_tlb_all(void)
 477 {
 478         on_each_cpu(flush_tlb_all_ipi, NULL, 1);
 479 }
 480
 481 static void flush_tlb_mm_ipi(void *mm)
 482 {
 483         local_flush_tlb_mm((struct mm_struct *)mm);
 484 }
 485
 486 /*
 487  * Special Variant of smp_call_function for use by TLB functions:
 488  *
 489  *  o No return value
 490  *  o collapses to normal function call on UP kernels
 491  *  o collapses to normal function call on systems with a single shared
 492  *    primary cache.
 493  */
 494 static inline void smp_on_other_tlbs(void (*func) (void *info), void *info)
 495 {
 496         smp_call_function(func, info, 1);
 497 }
 498
 499 static inline void smp_on_each_tlb(void (*func) (void *info), void *info)
 500 {
 501         preempt_disable();
 502
 503         smp_on_other_tlbs(func, info);
 504         func(info);
 505
 506         preempt_enable();
 507 }
 508
 509 /*
 510  * The following tlb flush calls are invoked when old translations are
 511  * being torn down, or pte attributes are changing. For single threaded
 512  * address spaces, a new context is obtained on the current cpu, and tlb
 513  * context on other cpus are invalidated to force a new context allocation
 514  * at switch_mm time, should the mm ever be used on other cpus. For
 515  * multithreaded address spaces, intercpu interrupts have to be sent.
 516  * Another case where intercpu interrupts are required is when the target
 517  * mm might be active on another cpu (eg debuggers doing the flushes on
 518  * behalf of debugees, kswapd stealing pages from another process etc).
 519  * Kanoj 07/00.
 520  */
 521
 522 void flush_tlb_mm(struct mm_struct *mm)
 523 {
 524         preempt_disable();
 525
 526         if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
 527                 smp_on_other_tlbs(flush_tlb_mm_ipi, mm);
 528         } else {
 529                 unsigned int cpu;
 530
 531                 for_each_online_cpu(cpu) {
 532                         if (cpu != smp_processor_id() && cpu_context(cpu, mm))
 533                                 cpu_context(cpu, mm) = 0;
 534                 }
 535         }
 536         local_flush_tlb_mm(mm);
 537
 538         preempt_enable();
 539 }
 540
 541 struct flush_tlb_data {
 542         struct vm_area_struct *vma;
 543         unsigned long addr1;
 544         unsigned long addr2;
 545 };
 546
 547 static void flush_tlb_range_ipi(void *info)
 548 {
 549         struct flush_tlb_data *fd = info;
 550
 551         local_flush_tlb_range(fd->vma, fd->addr1, fd->addr2);
 552 }
 553
 554 void flush_tlb_range(struct vm_area_struct *vma, unsigned long start, unsigned long end)
 555 {
 556         struct mm_struct *mm = vma->vm_mm;
 557
 558         preempt_disable();
 559         if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
 560                 struct flush_tlb_data fd = {
 561                         .vma = vma,
 562                         .addr1 = start,
 563                         .addr2 = end,
 564                 };
 565
 566                 smp_on_other_tlbs(flush_tlb_range_ipi, &fd);
 567         } else {
 568                 unsigned int cpu;
 569                 int exec = vma->vm_flags & VM_EXEC;
 570
 571                 for_each_online_cpu(cpu) {
 572                         /*
 573                          * flush_cache_range() will only fully flush icache if
 574                          * the VMA is executable, otherwise we must invalidate
 575                          * ASID without it appearing to has_valid_asid() as if
 576                          * mm has been completely unused by that CPU.
 577                          */
 578                         if (cpu != smp_processor_id() && cpu_context(cpu, mm))
 579                                 cpu_context(cpu, mm) = !exec;
 580                 }
 581         }
 582         local_flush_tlb_range(vma, start, end);
 583         preempt_enable();
 584 }
 585
 586 static void flush_tlb_kernel_range_ipi(void *info)
 587 {
 588         struct flush_tlb_data *fd = info;
 589
 590         local_flush_tlb_kernel_range(fd->addr1, fd->addr2);
 591 }
 592
 593 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
 594 {
 595         struct flush_tlb_data fd = {
 596                 .addr1 = start,
 597                 .addr2 = end,
 598         };
 599
 600         on_each_cpu(flush_tlb_kernel_range_ipi, &fd, 1);
 601 }
 602
 603 static void flush_tlb_page_ipi(void *info)
 604 {
 605         struct flush_tlb_data *fd = info;
 606
 607         local_flush_tlb_page(fd->vma, fd->addr1);
 608 }
 609
 610 void flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
 611 {
 612         preempt_disable();
 613         if ((atomic_read(&vma->vm_mm->mm_users) != 1) || (current->mm != vma->vm_mm)) {
 614                 struct flush_tlb_data fd = {
 615                         .vma = vma,
 616                         .addr1 = page,
 617                 };
 618
 619                 smp_on_other_tlbs(flush_tlb_page_ipi, &fd);
 620         } else {
 621                 unsigned int cpu;
 622
 623                 for_each_online_cpu(cpu) {
 624                         /*
 625                          * flush_cache_page() only does partial flushes, so
 626                          * invalidate ASID without it appearing to
 627                          * has_valid_asid() as if mm has been completely unused
 628                          * by that CPU.
 629                          */
 630                         if (cpu != smp_processor_id() && cpu_context(cpu, vma->vm_mm))
 631                                 cpu_context(cpu, vma->vm_mm) = 1;
 632                 }
 633         }
 634         local_flush_tlb_page(vma, page);
 635         preempt_enable();
 636 }
 637
 638 static void flush_tlb_one_ipi(void *info)
 639 {
 640         unsigned long vaddr = (unsigned long) info;
 641
 642         local_flush_tlb_one(vaddr);
 643 }
 644
 645 void flush_tlb_one(unsigned long vaddr)
 646 {
 647         smp_on_each_tlb(flush_tlb_one_ipi, (void *) vaddr);
 648 }
 649
 650 EXPORT_SYMBOL(flush_tlb_page);
 651 EXPORT_SYMBOL(flush_tlb_one);
 652
 653 #if defined(CONFIG_KEXEC)
 654 void (*dump_ipi_function_ptr)(void *) = NULL;
 655 void dump_send_ipi(void (*dump_ipi_callback)(void *))
 656 {
 657         int i;
 658         int cpu = smp_processor_id();
 659
 660         dump_ipi_function_ptr = dump_ipi_callback;
 661         smp_mb();
 662         for_each_online_cpu(i)
 663                 if (i != cpu)
 664                         mp_ops->send_ipi_single(i, SMP_DUMP);
 665
 666 }
 667 EXPORT_SYMBOL(dump_send_ipi);
 668 #endif
 669
 670 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
 671
 672 static DEFINE_PER_CPU(atomic_t, tick_broadcast_count);
 673 static DEFINE_PER_CPU(struct call_single_data, tick_broadcast_csd);
 674
 675 void tick_broadcast(const struct cpumask *mask)
 676 {
 677         atomic_t *count;
 678         struct call_single_data *csd;
 679         int cpu;
 680
 681         for_each_cpu(cpu, mask) {
 682                 count = &per_cpu(tick_broadcast_count, cpu);
 683                 csd = &per_cpu(tick_broadcast_csd, cpu);
 684
 685                 if (atomic_inc_return(count) == 1)
 686                         smp_call_function_single_async(cpu, csd);
 687         }
 688 }
 689
 690 static void tick_broadcast_callee(void *info)
 691 {
 692         int cpu = smp_processor_id();
 693         tick_receive_broadcast();
 694         atomic_set(&per_cpu(tick_broadcast_count, cpu), 0);
 695 }
 696
 697 static int __init tick_broadcast_init(void)
 698 {
 699         struct call_single_data *csd;
 700         int cpu;
 701
 702         for (cpu = 0; cpu < NR_CPUS; cpu++) {
 703                 csd = &per_cpu(tick_broadcast_csd, cpu);
 704                 csd->func = tick_broadcast_callee;
 705         }
 706
 707         return 0;
 708 }
 709 early_initcall(tick_broadcast_init);
 710
 711 #endif /* CONFIG_GENERIC_CLOCKEVENTS_BROADCAST */