arch/arm/kernel/smp.c

   1 /*
   2  *  linux/arch/arm/kernel/smp.c
   3  *
   4  *  Copyright (C) 2002 ARM Limited, All Rights Reserved.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  */
  10 #include <linux/module.h>
  11 #include <linux/delay.h>
  12 #include <linux/init.h>
  13 #include <linux/spinlock.h>
  14 #include <linux/sched.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/cache.h>
  17 #include <linux/profile.h>
  18 #include <linux/errno.h>
  19 #include <linux/mm.h>
  20 #include <linux/err.h>
  21 #include <linux/cpu.h>
  22 #include <linux/smp.h>
  23 #include <linux/seq_file.h>
  24 #include <linux/irq.h>
  25 #include <linux/percpu.h>
  26 #include <linux/clockchips.h>
  27
  28 #include <asm/atomic.h>
  29 #include <asm/cacheflush.h>
  30 #include <asm/cpu.h>
  31 #include <asm/cputype.h>
  32 #include <asm/mmu_context.h>
  33 #include <asm/pgtable.h>
  34 #include <asm/pgalloc.h>
  35 #include <asm/processor.h>
  36 #include <asm/sections.h>
  37 #include <asm/tlbflush.h>
  38 #include <asm/ptrace.h>
  39 #include <asm/localtimer.h>
  40 #include <asm/smp_plat.h>
  41
  42 /*
  43  * as from 2.5, kernels no longer have an init_tasks structure
  44  * so we need some other way of telling a new secondary core
  45  * where to place its SVC stack
  46  */
  47 struct secondary_data secondary_data;
  48
  49 /*
  50  * structures for inter-processor calls
  51  * - A collection of single bit ipi messages.
  52  */
  53 struct ipi_data {
  54         spinlock_t lock;
  55         unsigned long ipi_count;
  56         unsigned long bits;
  57 };
  58
  59 static DEFINE_PER_CPU(struct ipi_data, ipi_data) = {
  60         .lock   = SPIN_LOCK_UNLOCKED,
  61 };
  62
  63 enum ipi_msg_type {
  64         IPI_TIMER,
  65         IPI_RESCHEDULE,
  66         IPI_CALL_FUNC,
  67         IPI_CALL_FUNC_SINGLE,
  68         IPI_CPU_STOP,
  69 };
  70
  71 static inline void identity_mapping_add(pgd_t *pgd, unsigned long start,
  72         unsigned long end)
  73 {
  74         unsigned long addr, prot;
  75         pmd_t *pmd;
  76
  77         prot = PMD_TYPE_SECT | PMD_SECT_AP_WRITE;
  78         if (cpu_architecture() <= CPU_ARCH_ARMv5TEJ && !cpu_is_xscale())
  79                 prot |= PMD_BIT4;
  80
  81         for (addr = start & PGDIR_MASK; addr < end;) {
  82                 pmd = pmd_offset(pgd + pgd_index(addr), addr);
  83                 pmd[0] = __pmd(addr | prot);
  84                 addr += SECTION_SIZE;
  85                 pmd[1] = __pmd(addr | prot);
  86                 addr += SECTION_SIZE;
  87                 flush_pmd_entry(pmd);
  88         }
  89 }
  90
  91 static inline void identity_mapping_del(pgd_t *pgd, unsigned long start,
  92         unsigned long end)
  93 {
  94         unsigned long addr;
  95         pmd_t *pmd;
  96
  97         for (addr = start & PGDIR_MASK; addr < end; addr += PGDIR_SIZE) {
  98                 pmd = pmd_offset(pgd + pgd_index(addr), addr);
  99                 pmd[0] = __pmd(0);
 100                 pmd[1] = __pmd(0);
 101                 clean_pmd_entry(pmd);
 102         }
 103 }
 104
 105 int __cpuinit __cpu_up(unsigned int cpu)
 106 {
 107         struct cpuinfo_arm *ci = &per_cpu(cpu_data, cpu);
 108         struct task_struct *idle = ci->idle;
 109         pgd_t *pgd;
 110         int ret;
 111
 112         /*
 113          * Spawn a new process manually, if not already done.
 114          * Grab a pointer to its task struct so we can mess with it
 115          */
 116         if (!idle) {
 117                 idle = fork_idle(cpu);
 118                 if (IS_ERR(idle)) {
 119                         printk(KERN_ERR "CPU%u: fork() failed\n", cpu);
 120                         return PTR_ERR(idle);
 121                 }
 122                 ci->idle = idle;
 123         } else {
 124                 /*
 125                  * Since this idle thread is being re-used, call
 126                  * init_idle() to reinitialize the thread structure.
 127                  */
 128                 init_idle(idle, cpu);
 129         }
 130
 131         /*
 132          * Allocate initial page tables to allow the new CPU to
 133          * enable the MMU safely.  This essentially means a set
 134          * of our "standard" page tables, with the addition of
 135          * a 1:1 mapping for the physical address of the kernel.
 136          */
 137         pgd = pgd_alloc(&init_mm);
 138         if (!pgd)
 139                 return -ENOMEM;
 140
 141         if (PHYS_OFFSET != PAGE_OFFSET) {
 142 #ifndef CONFIG_HOTPLUG_CPU
 143                 identity_mapping_add(pgd, __pa(__init_begin), __pa(__init_end));
 144 #endif
 145                 identity_mapping_add(pgd, __pa(_stext), __pa(_etext));
 146                 identity_mapping_add(pgd, __pa(_sdata), __pa(_edata));
 147         }
 148
 149         /*
 150          * We need to tell the secondary core where to find
 151          * its stack and the page tables.
 152          */
 153         secondary_data.stack = task_stack_page(idle) + THREAD_START_SP;
 154         secondary_data.pgdir = virt_to_phys(pgd);
 155         __cpuc_flush_dcache_area(&secondary_data, sizeof(secondary_data));
 156         outer_clean_range(__pa(&secondary_data), __pa(&secondary_data + 1));
 157
 158         /*
 159          * Now bring the CPU into our world.
 160          */
 161         ret = boot_secondary(cpu, idle);
 162         if (ret == 0) {
 163                 unsigned long timeout;
 164
 165                 /*
 166                  * CPU was successfully started, wait for it
 167                  * to come online or time out.
 168                  */
 169                 timeout = jiffies + HZ;
 170                 while (time_before(jiffies, timeout)) {
 171                         if (cpu_online(cpu))
 172                                 break;
 173
 174                         udelay(10);
 175                         barrier();
 176                 }
 177
 178                 if (!cpu_online(cpu))
 179                         ret = -EIO;
 180         }
 181
 182         secondary_data.stack = NULL;
 183         secondary_data.pgdir = 0;
 184
 185         if (PHYS_OFFSET != PAGE_OFFSET) {
 186 #ifndef CONFIG_HOTPLUG_CPU
 187                 identity_mapping_del(pgd, __pa(__init_begin), __pa(__init_end));
 188 #endif
 189                 identity_mapping_del(pgd, __pa(_stext), __pa(_etext));
 190                 identity_mapping_del(pgd, __pa(_sdata), __pa(_edata));
 191         }
 192
 193         pgd_free(&init_mm, pgd);
 194
 195         if (ret) {
 196                 printk(KERN_CRIT "CPU%u: processor failed to boot\n", cpu);
 197
 198                 /*
 199                  * FIXME: We need to clean up the new idle thread. --rmk
 200                  */
 201         }
 202
 203         return ret;
 204 }
 205
 206 #ifdef CONFIG_HOTPLUG_CPU
 207 /*
 208  * __cpu_disable runs on the processor to be shutdown.
 209  */
 210 int __cpu_disable(void)
 211 {
 212         unsigned int cpu = smp_processor_id();
 213         struct task_struct *p;
 214         int ret;
 215
 216         ret = platform_cpu_disable(cpu);
 217         if (ret)
 218                 return ret;
 219
 220         /*
 221          * Take this CPU offline.  Once we clear this, we can't return,
 222          * and we must not schedule until we're ready to give up the cpu.
 223          */
 224         set_cpu_online(cpu, false);
 225
 226         /*
 227          * OK - migrate IRQs away from this CPU
 228          */
 229         migrate_irqs();
 230
 231         /*
 232          * Stop the local timer for this CPU.
 233          */
 234         local_timer_stop();
 235
 236         /*
 237          * Flush user cache and TLB mappings, and then remove this CPU
 238          * from the vm mask set of all processes.
 239          */
 240         flush_cache_all();
 241         local_flush_tlb_all();
 242
 243         read_lock(&tasklist_lock);
 244         for_each_process(p) {
 245                 if (p->mm)
 246                         cpumask_clear_cpu(cpu, mm_cpumask(p->mm));
 247         }
 248         read_unlock(&tasklist_lock);
 249
 250         return 0;
 251 }
 252
 253 /*
 254  * called on the thread which is asking for a CPU to be shutdown -
 255  * waits until shutdown has completed, or it is timed out.
 256  */
 257 void __cpu_die(unsigned int cpu)
 258 {
 259         if (!platform_cpu_kill(cpu))
 260                 printk("CPU%u: unable to kill\n", cpu);
 261 }
 262
 263 /*
 264  * Called from the idle thread for the CPU which has been shutdown.
 265  *
 266  * Note that we disable IRQs here, but do not re-enable them
 267  * before returning to the caller. This is also the behaviour
 268  * of the other hotplug-cpu capable cores, so presumably coming
 269  * out of idle fixes this.
 270  */
 271 void __ref cpu_die(void)
 272 {
 273         unsigned int cpu = smp_processor_id();
 274
 275         local_irq_disable();
 276         idle_task_exit();
 277
 278         /*
 279          * actual CPU shutdown procedure is at least platform (if not
 280          * CPU) specific
 281          */
 282         platform_cpu_die(cpu);
 283
 284         /*
 285          * Do not return to the idle loop - jump back to the secondary
 286          * cpu initialisation.  There's some initialisation which needs
 287          * to be repeated to undo the effects of taking the CPU offline.
 288          */
 289         __asm__("mov    sp, %0\n"
 290         "       b       secondary_start_kernel"
 291                 :
 292                 : "r" (task_stack_page(current) + THREAD_SIZE - 8));
 293 }
 294 #endif /* CONFIG_HOTPLUG_CPU */
 295
 296 /*
 297  * This is the secondary CPU boot entry.  We're using this CPUs
 298  * idle thread stack, but a set of temporary page tables.
 299  */
 300 asmlinkage void __cpuinit secondary_start_kernel(void)
 301 {
 302         struct mm_struct *mm = &init_mm;
 303         unsigned int cpu = smp_processor_id();
 304
 305         printk("CPU%u: Booted secondary processor\n", cpu);
 306
 307         /*
 308          * All kernel threads share the same mm context; grab a
 309          * reference and switch to it.
 310          */
 311         atomic_inc(&mm->mm_users);
 312         atomic_inc(&mm->mm_count);
 313         current->active_mm = mm;
 314         cpumask_set_cpu(cpu, mm_cpumask(mm));
 315         cpu_switch_mm(mm->pgd, mm);
 316         enter_lazy_tlb(mm, current);
 317         local_flush_tlb_all();
 318
 319         cpu_init();
 320         preempt_disable();
 321
 322         /*
 323          * Give the platform a chance to do its own initialisation.
 324          */
 325         platform_secondary_init(cpu);
 326
 327         /*
 328          * Enable local interrupts.
 329          */
 330         notify_cpu_starting(cpu);
 331         local_irq_enable();
 332         local_fiq_enable();
 333
 334         /*
 335          * Setup the percpu timer for this CPU.
 336          */
 337         percpu_timer_setup();
 338
 339         calibrate_delay();
 340
 341         smp_store_cpu_info(cpu);
 342
 343         /*
 344          * OK, now it's safe to let the boot CPU continue
 345          */
 346         set_cpu_online(cpu, true);
 347
 348         /*
 349          * OK, it's off to the idle thread for us
 350          */
 351         cpu_idle();
 352 }
 353
 354 /*
 355  * Called by both boot and secondaries to move global data into
 356  * per-processor storage.
 357  */
 358 void __cpuinit smp_store_cpu_info(unsigned int cpuid)
 359 {
 360         struct cpuinfo_arm *cpu_info = &per_cpu(cpu_data, cpuid);
 361
 362         cpu_info->loops_per_jiffy = loops_per_jiffy;
 363 }
 364
 365 void __init smp_cpus_done(unsigned int max_cpus)
 366 {
 367         int cpu;
 368         unsigned long bogosum = 0;
 369
 370         for_each_online_cpu(cpu)
 371                 bogosum += per_cpu(cpu_data, cpu).loops_per_jiffy;
 372
 373         printk(KERN_INFO "SMP: Total of %d processors activated "
 374                "(%lu.%02lu BogoMIPS).\n",
 375                num_online_cpus(),
 376                bogosum / (500000/HZ),
 377                (bogosum / (5000/HZ)) % 100);
 378 }
 379
 380 void __init smp_prepare_boot_cpu(void)
 381 {
 382         unsigned int cpu = smp_processor_id();
 383
 384         per_cpu(cpu_data, cpu).idle = current;
 385 }
 386
 387 static void send_ipi_message(const struct cpumask *mask, enum ipi_msg_type msg)
 388 {
 389         unsigned long flags;
 390         unsigned int cpu;
 391
 392         local_irq_save(flags);
 393
 394         for_each_cpu(cpu, mask) {
 395                 struct ipi_data *ipi = &per_cpu(ipi_data, cpu);
 396
 397                 spin_lock(&ipi->lock);
 398                 ipi->bits |= 1 << msg;
 399                 spin_unlock(&ipi->lock);
 400         }
 401
 402         /*
 403          * Call the platform specific cross-CPU call function.
 404          */
 405         smp_cross_call(mask);
 406
 407         local_irq_restore(flags);
 408 }
 409
 410 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
 411 {
 412         send_ipi_message(mask, IPI_CALL_FUNC);
 413 }
 414
 415 void arch_send_call_function_single_ipi(int cpu)
 416 {
 417         send_ipi_message(cpumask_of(cpu), IPI_CALL_FUNC_SINGLE);
 418 }
 419
 420 void show_ipi_list(struct seq_file *p)
 421 {
 422         unsigned int cpu;
 423
 424         seq_puts(p, "IPI:");
 425
 426         for_each_present_cpu(cpu)
 427                 seq_printf(p, " %10lu", per_cpu(ipi_data, cpu).ipi_count);
 428
 429         seq_putc(p, '\n');
 430 }
 431
 432 void show_local_irqs(struct seq_file *p)
 433 {
 434         unsigned int cpu;
 435
 436         seq_printf(p, "LOC: ");
 437
 438         for_each_present_cpu(cpu)
 439                 seq_printf(p, "%10u ", irq_stat[cpu].local_timer_irqs);
 440
 441         seq_putc(p, '\n');
 442 }
 443
 444 /*
 445  * Timer (local or broadcast) support
 446  */
 447 static DEFINE_PER_CPU(struct clock_event_device, percpu_clockevent);
 448
 449 static void ipi_timer(void)
 450 {
 451         struct clock_event_device *evt = &__get_cpu_var(percpu_clockevent);
 452         irq_enter();
 453         evt->event_handler(evt);
 454         irq_exit();
 455 }
 456
 457 #ifdef CONFIG_LOCAL_TIMERS
 458 asmlinkage void __exception do_local_timer(struct pt_regs *regs)
 459 {
 460         struct pt_regs *old_regs = set_irq_regs(regs);
 461         int cpu = smp_processor_id();
 462
 463         if (local_timer_ack()) {
 464                 irq_stat[cpu].local_timer_irqs++;
 465                 ipi_timer();
 466         }
 467
 468         set_irq_regs(old_regs);
 469 }
 470 #endif
 471
 472 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
 473 static void smp_timer_broadcast(const struct cpumask *mask)
 474 {
 475         send_ipi_message(mask, IPI_TIMER);
 476 }
 477 #else
 478 #define smp_timer_broadcast     NULL
 479 #endif
 480
 481 #ifndef CONFIG_LOCAL_TIMERS
 482 static void broadcast_timer_set_mode(enum clock_event_mode mode,
 483         struct clock_event_device *evt)
 484 {
 485 }
 486
 487 static void local_timer_setup(struct clock_event_device *evt)
 488 {
 489         evt->name       = "dummy_timer";
 490         evt->features   = CLOCK_EVT_FEAT_ONESHOT |
 491                           CLOCK_EVT_FEAT_PERIODIC |
 492                           CLOCK_EVT_FEAT_DUMMY;
 493         evt->rating     = 400;
 494         evt->mult       = 1;
 495         evt->set_mode   = broadcast_timer_set_mode;
 496
 497         clockevents_register_device(evt);
 498 }
 499 #endif
 500
 501 void __cpuinit percpu_timer_setup(void)
 502 {
 503         unsigned int cpu = smp_processor_id();
 504         struct clock_event_device *evt = &per_cpu(percpu_clockevent, cpu);
 505
 506         evt->cpumask = cpumask_of(cpu);
 507         evt->broadcast = smp_timer_broadcast;
 508
 509         local_timer_setup(evt);
 510 }
 511
 512 static DEFINE_SPINLOCK(stop_lock);
 513
 514 /*
 515  * ipi_cpu_stop - handle IPI from smp_send_stop()
 516  */
 517 static void ipi_cpu_stop(unsigned int cpu)
 518 {
 519         if (system_state == SYSTEM_BOOTING ||
 520             system_state == SYSTEM_RUNNING) {
 521                 spin_lock(&stop_lock);
 522                 printk(KERN_CRIT "CPU%u: stopping\n", cpu);
 523                 dump_stack();
 524                 spin_unlock(&stop_lock);
 525         }
 526
 527         set_cpu_online(cpu, false);
 528
 529         local_fiq_disable();
 530         local_irq_disable();
 531
 532         while (1)
 533                 cpu_relax();
 534 }
 535
 536 /*
 537  * Main handler for inter-processor interrupts
 538  *
 539  * For ARM, the ipimask now only identifies a single
 540  * category of IPI (Bit 1 IPIs have been replaced by a
 541  * different mechanism):
 542  *
 543  *  Bit 0 - Inter-processor function call
 544  */
 545 asmlinkage void __exception do_IPI(struct pt_regs *regs)
 546 {
 547         unsigned int cpu = smp_processor_id();
 548         struct ipi_data *ipi = &per_cpu(ipi_data, cpu);
 549         struct pt_regs *old_regs = set_irq_regs(regs);
 550
 551         ipi->ipi_count++;
 552
 553         for (;;) {
 554                 unsigned long msgs;
 555
 556                 spin_lock(&ipi->lock);
 557                 msgs = ipi->bits;
 558                 ipi->bits = 0;
 559                 spin_unlock(&ipi->lock);
 560
 561                 if (!msgs)
 562                         break;
 563
 564                 do {
 565                         unsigned nextmsg;
 566
 567                         nextmsg = msgs & -msgs;
 568                         msgs &= ~nextmsg;
 569                         nextmsg = ffz(~nextmsg);
 570
 571                         switch (nextmsg) {
 572                         case IPI_TIMER:
 573                                 ipi_timer();
 574                                 break;
 575
 576                         case IPI_RESCHEDULE:
 577                                 /*
 578                                  * nothing more to do - eveything is
 579                                  * done on the interrupt return path
 580                                  */
 581                                 break;
 582
 583                         case IPI_CALL_FUNC:
 584                                 generic_smp_call_function_interrupt();
 585                                 break;
 586
 587                         case IPI_CALL_FUNC_SINGLE:
 588                                 generic_smp_call_function_single_interrupt();
 589                                 break;
 590
 591                         case IPI_CPU_STOP:
 592                                 ipi_cpu_stop(cpu);
 593                                 break;
 594
 595                         default:
 596                                 printk(KERN_CRIT "CPU%u: Unknown IPI message 0x%x\n",
 597                                        cpu, nextmsg);
 598                                 break;
 599                         }
 600                 } while (msgs);
 601         }
 602
 603         set_irq_regs(old_regs);
 604 }
 605
 606 void smp_send_reschedule(int cpu)
 607 {
 608         send_ipi_message(cpumask_of(cpu), IPI_RESCHEDULE);
 609 }
 610
 611 void smp_send_stop(void)
 612 {
 613         cpumask_t mask = cpu_online_map;
 614         cpu_clear(smp_processor_id(), mask);
 615         if (!cpus_empty(mask))
 616                 send_ipi_message(&mask, IPI_CPU_STOP);
 617 }
 618
 619 /*
 620  * not supported here
 621  */
 622 int setup_profiling_timer(unsigned int multiplier)
 623 {
 624         return -EINVAL;
 625 }
 626
 627 static void
 628 on_each_cpu_mask(void (*func)(void *), void *info, int wait,
 629                 const struct cpumask *mask)
 630 {
 631         preempt_disable();
 632
 633         smp_call_function_many(mask, func, info, wait);
 634         if (cpumask_test_cpu(smp_processor_id(), mask))
 635                 func(info);
 636
 637         preempt_enable();
 638 }
 639
 640 /**********************************************************************/
 641
 642 /*
 643  * TLB operations
 644  */
 645 struct tlb_args {
 646         struct vm_area_struct *ta_vma;
 647         unsigned long ta_start;
 648         unsigned long ta_end;
 649 };
 650
 651 static inline void ipi_flush_tlb_all(void *ignored)
 652 {
 653         local_flush_tlb_all();
 654 }
 655
 656 static inline void ipi_flush_tlb_mm(void *arg)
 657 {
 658         struct mm_struct *mm = (struct mm_struct *)arg;
 659
 660         local_flush_tlb_mm(mm);
 661 }
 662
 663 static inline void ipi_flush_tlb_page(void *arg)
 664 {
 665         struct tlb_args *ta = (struct tlb_args *)arg;
 666
 667         local_flush_tlb_page(ta->ta_vma, ta->ta_start);
 668 }
 669
 670 static inline void ipi_flush_tlb_kernel_page(void *arg)
 671 {
 672         struct tlb_args *ta = (struct tlb_args *)arg;
 673
 674         local_flush_tlb_kernel_page(ta->ta_start);
 675 }
 676
 677 static inline void ipi_flush_tlb_range(void *arg)
 678 {
 679         struct tlb_args *ta = (struct tlb_args *)arg;
 680
 681         local_flush_tlb_range(ta->ta_vma, ta->ta_start, ta->ta_end);
 682 }
 683
 684 static inline void ipi_flush_tlb_kernel_range(void *arg)
 685 {
 686         struct tlb_args *ta = (struct tlb_args *)arg;
 687
 688         local_flush_tlb_kernel_range(ta->ta_start, ta->ta_end);
 689 }
 690
 691 void flush_tlb_all(void)
 692 {
 693         if (tlb_ops_need_broadcast())
 694                 on_each_cpu(ipi_flush_tlb_all, NULL, 1);
 695         else
 696                 local_flush_tlb_all();
 697 }
 698
 699 void flush_tlb_mm(struct mm_struct *mm)
 700 {
 701         if (tlb_ops_need_broadcast())
 702                 on_each_cpu_mask(ipi_flush_tlb_mm, mm, 1, mm_cpumask(mm));
 703         else
 704                 local_flush_tlb_mm(mm);
 705 }
 706
 707 void flush_tlb_page(struct vm_area_struct *vma, unsigned long uaddr)
 708 {
 709         if (tlb_ops_need_broadcast()) {
 710                 struct tlb_args ta;
 711                 ta.ta_vma = vma;
 712                 ta.ta_start = uaddr;
 713                 on_each_cpu_mask(ipi_flush_tlb_page, &ta, 1, mm_cpumask(vma->vm_mm));
 714         } else
 715                 local_flush_tlb_page(vma, uaddr);
 716 }
 717
 718 void flush_tlb_kernel_page(unsigned long kaddr)
 719 {
 720         if (tlb_ops_need_broadcast()) {
 721                 struct tlb_args ta;
 722                 ta.ta_start = kaddr;
 723                 on_each_cpu(ipi_flush_tlb_kernel_page, &ta, 1);
 724         } else
 725                 local_flush_tlb_kernel_page(kaddr);
 726 }
 727
 728 void flush_tlb_range(struct vm_area_struct *vma,
 729                      unsigned long start, unsigned long end)
 730 {
 731         if (tlb_ops_need_broadcast()) {
 732                 struct tlb_args ta;
 733                 ta.ta_vma = vma;
 734                 ta.ta_start = start;
 735                 ta.ta_end = end;
 736                 on_each_cpu_mask(ipi_flush_tlb_range, &ta, 1, mm_cpumask(vma->vm_mm));
 737         } else
 738                 local_flush_tlb_range(vma, start, end);
 739 }
 740
 741 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
 742 {
 743         if (tlb_ops_need_broadcast()) {
 744                 struct tlb_args ta;
 745                 ta.ta_start = start;
 746                 ta.ta_end = end;
 747                 on_each_cpu(ipi_flush_tlb_kernel_range, &ta, 1);
 748         } else
 749                 local_flush_tlb_kernel_range(start, end);
 750 }