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/ftrace.h>
  20 #include <linux/mm.h>
  21 #include <linux/err.h>
  22 #include <linux/cpu.h>
  23 #include <linux/smp.h>
  24 #include <linux/seq_file.h>
  25 #include <linux/irq.h>
  26 #include <linux/percpu.h>
  27 #include <linux/clockchips.h>
  28
  29 #include <asm/atomic.h>
  30 #include <asm/cacheflush.h>
  31 #include <asm/cpu.h>
  32 #include <asm/cputype.h>
  33 #include <asm/mmu_context.h>
  34 #include <asm/pgtable.h>
  35 #include <asm/pgalloc.h>
  36 #include <asm/processor.h>
  37 #include <asm/sections.h>
  38 #include <asm/tlbflush.h>
  39 #include <asm/ptrace.h>
  40 #include <asm/localtimer.h>
  41 #include <asm/smp_plat.h>
  42
  43 /*
  44  * as from 2.5, kernels no longer have an init_tasks structure
  45  * so we need some other way of telling a new secondary core
  46  * where to place its SVC stack
  47  */
  48 struct secondary_data secondary_data;
  49
  50 /*
  51  * structures for inter-processor calls
  52  * - A collection of single bit ipi messages.
  53  */
  54 struct ipi_data {
  55         spinlock_t lock;
  56         unsigned long ipi_count;
  57         unsigned long bits;
  58 };
  59
  60 static DEFINE_PER_CPU(struct ipi_data, ipi_data) = {
  61         .lock   = SPIN_LOCK_UNLOCKED,
  62 };
  63
  64 enum ipi_msg_type {
  65         IPI_TIMER,
  66         IPI_RESCHEDULE,
  67         IPI_CALL_FUNC,
  68         IPI_CALL_FUNC_SINGLE,
  69         IPI_CPU_STOP,
  70 };
  71
  72 static inline void identity_mapping_add(pgd_t *pgd, unsigned long start,
  73         unsigned long end)
  74 {
  75         unsigned long addr, prot;
  76         pmd_t *pmd;
  77
  78         prot = PMD_TYPE_SECT | PMD_SECT_AP_WRITE;
  79         if (cpu_architecture() <= CPU_ARCH_ARMv5TEJ && !cpu_is_xscale())
  80                 prot |= PMD_BIT4;
  81
  82         for (addr = start & PGDIR_MASK; addr < end;) {
  83                 pmd = pmd_offset(pgd + pgd_index(addr), addr);
  84                 pmd[0] = __pmd(addr | prot);
  85                 addr += SECTION_SIZE;
  86                 pmd[1] = __pmd(addr | prot);
  87                 addr += SECTION_SIZE;
  88                 flush_pmd_entry(pmd);
  89                 outer_clean_range(__pa(pmd), __pa(pmd + 1));
  90         }
  91 }
  92
  93 static inline void identity_mapping_del(pgd_t *pgd, unsigned long start,
  94         unsigned long end)
  95 {
  96         unsigned long addr;
  97         pmd_t *pmd;
  98
  99         for (addr = start & PGDIR_MASK; addr < end; addr += PGDIR_SIZE) {
 100                 pmd = pmd_offset(pgd + pgd_index(addr), addr);
 101                 pmd[0] = __pmd(0);
 102                 pmd[1] = __pmd(0);
 103                 clean_pmd_entry(pmd);
 104                 outer_clean_range(__pa(pmd), __pa(pmd + 1));
 105         }
 106 }
 107
 108 int __cpuinit __cpu_up(unsigned int cpu)
 109 {
 110         struct cpuinfo_arm *ci = &per_cpu(cpu_data, cpu);
 111         struct task_struct *idle = ci->idle;
 112         pgd_t *pgd;
 113         int ret;
 114
 115         /*
 116          * Spawn a new process manually, if not already done.
 117          * Grab a pointer to its task struct so we can mess with it
 118          */
 119         if (!idle) {
 120                 idle = fork_idle(cpu);
 121                 if (IS_ERR(idle)) {
 122                         printk(KERN_ERR "CPU%u: fork() failed\n", cpu);
 123                         return PTR_ERR(idle);
 124                 }
 125                 ci->idle = idle;
 126         } else {
 127                 /*
 128                  * Since this idle thread is being re-used, call
 129                  * init_idle() to reinitialize the thread structure.
 130                  */
 131                 init_idle(idle, cpu);
 132         }
 133
 134         /*
 135          * Allocate initial page tables to allow the new CPU to
 136          * enable the MMU safely.  This essentially means a set
 137          * of our "standard" page tables, with the addition of
 138          * a 1:1 mapping for the physical address of the kernel.
 139          */
 140         pgd = pgd_alloc(&init_mm);
 141         if (!pgd)
 142                 return -ENOMEM;
 143
 144         if (PHYS_OFFSET != PAGE_OFFSET) {
 145 #ifndef CONFIG_HOTPLUG_CPU
 146                 identity_mapping_add(pgd, __pa(__init_begin), __pa(__init_end));
 147 #endif
 148                 identity_mapping_add(pgd, __pa(_stext), __pa(_etext));
 149                 identity_mapping_add(pgd, __pa(_sdata), __pa(_edata));
 150         }
 151
 152         /*
 153          * We need to tell the secondary core where to find
 154          * its stack and the page tables.
 155          */
 156         secondary_data.stack = task_stack_page(idle) + THREAD_START_SP;
 157         secondary_data.pgdir = virt_to_phys(pgd);
 158         __cpuc_flush_dcache_area(&secondary_data, sizeof(secondary_data));
 159         outer_clean_range(__pa(&secondary_data), __pa(&secondary_data + 1));
 160
 161         /*
 162          * Now bring the CPU into our world.
 163          */
 164         ret = boot_secondary(cpu, idle);
 165         if (ret == 0) {
 166                 unsigned long timeout;
 167
 168                 /*
 169                  * CPU was successfully started, wait for it
 170                  * to come online or time out.
 171                  */
 172                 timeout = jiffies + HZ;
 173                 while (time_before(jiffies, timeout)) {
 174                         if (cpu_online(cpu))
 175                                 break;
 176
 177                         udelay(10);
 178                         barrier();
 179                 }
 180
 181                 if (!cpu_online(cpu))
 182                         ret = -EIO;
 183         }
 184
 185         secondary_data.stack = NULL;
 186         secondary_data.pgdir = 0;
 187
 188         if (PHYS_OFFSET != PAGE_OFFSET) {
 189 #ifndef CONFIG_HOTPLUG_CPU
 190                 identity_mapping_del(pgd, __pa(__init_begin), __pa(__init_end));
 191 #endif
 192                 identity_mapping_del(pgd, __pa(_stext), __pa(_etext));
 193                 identity_mapping_del(pgd, __pa(_sdata), __pa(_edata));
 194         }
 195
 196         pgd_free(&init_mm, pgd);
 197
 198         if (ret) {
 199                 printk(KERN_CRIT "CPU%u: processor failed to boot\n", cpu);
 200
 201                 /*
 202                  * FIXME: We need to clean up the new idle thread. --rmk
 203                  */
 204         }
 205
 206         return ret;
 207 }
 208
 209 #ifdef CONFIG_HOTPLUG_CPU
 210 /*
 211  * __cpu_disable runs on the processor to be shutdown.
 212  */
 213 int __cpu_disable(void)
 214 {
 215         unsigned int cpu = smp_processor_id();
 216         struct task_struct *p;
 217         int ret;
 218
 219         ret = platform_cpu_disable(cpu);
 220         if (ret)
 221                 return ret;
 222
 223         /*
 224          * Take this CPU offline.  Once we clear this, we can't return,
 225          * and we must not schedule until we're ready to give up the cpu.
 226          */
 227         set_cpu_online(cpu, false);
 228
 229         /*
 230          * OK - migrate IRQs away from this CPU
 231          */
 232         migrate_irqs();
 233
 234         /*
 235          * Stop the local timer for this CPU.
 236          */
 237         local_timer_stop();
 238
 239         /*
 240          * Flush user cache and TLB mappings, and then remove this CPU
 241          * from the vm mask set of all processes.
 242          */
 243         flush_cache_all();
 244         local_flush_tlb_all();
 245
 246         read_lock(&tasklist_lock);
 247         for_each_process(p) {
 248                 if (p->mm)
 249                         cpumask_clear_cpu(cpu, mm_cpumask(p->mm));
 250         }
 251         read_unlock(&tasklist_lock);
 252
 253         return 0;
 254 }
 255
 256 /*
 257  * called on the thread which is asking for a CPU to be shutdown -
 258  * waits until shutdown has completed, or it is timed out.
 259  */
 260 void __cpu_die(unsigned int cpu)
 261 {
 262         if (!platform_cpu_kill(cpu))
 263                 printk("CPU%u: unable to kill\n", cpu);
 264 }
 265
 266 /*
 267  * Called from the idle thread for the CPU which has been shutdown.
 268  *
 269  * Note that we disable IRQs here, but do not re-enable them
 270  * before returning to the caller. This is also the behaviour
 271  * of the other hotplug-cpu capable cores, so presumably coming
 272  * out of idle fixes this.
 273  */
 274 void __ref cpu_die(void)
 275 {
 276         unsigned int cpu = smp_processor_id();
 277
 278         local_irq_disable();
 279         idle_task_exit();
 280
 281         /*
 282          * actual CPU shutdown procedure is at least platform (if not
 283          * CPU) specific
 284          */
 285         platform_cpu_die(cpu);
 286
 287         /*
 288          * Do not return to the idle loop - jump back to the secondary
 289          * cpu initialisation.  There's some initialisation which needs
 290          * to be repeated to undo the effects of taking the CPU offline.
 291          */
 292         __asm__("mov    sp, %0\n"
 293         "       b       secondary_start_kernel"
 294                 :
 295                 : "r" (task_stack_page(current) + THREAD_SIZE - 8));
 296 }
 297 #endif /* CONFIG_HOTPLUG_CPU */
 298
 299 /*
 300  * This is the secondary CPU boot entry.  We're using this CPUs
 301  * idle thread stack, but a set of temporary page tables.
 302  */
 303 asmlinkage void __cpuinit secondary_start_kernel(void)
 304 {
 305         struct mm_struct *mm = &init_mm;
 306         unsigned int cpu = smp_processor_id();
 307
 308         printk("CPU%u: Booted secondary processor\n", cpu);
 309
 310         /*
 311          * All kernel threads share the same mm context; grab a
 312          * reference and switch to it.
 313          */
 314         atomic_inc(&mm->mm_count);
 315         current->active_mm = mm;
 316         cpumask_set_cpu(cpu, mm_cpumask(mm));
 317         cpu_switch_mm(mm->pgd, mm);
 318         enter_lazy_tlb(mm, current);
 319         local_flush_tlb_all();
 320
 321         cpu_init();
 322         preempt_disable();
 323
 324         /*
 325          * Give the platform a chance to do its own initialisation.
 326          */
 327         platform_secondary_init(cpu);
 328
 329         /*
 330          * Enable local interrupts.
 331          */
 332         notify_cpu_starting(cpu);
 333         local_irq_enable();
 334         local_fiq_enable();
 335
 336         /*
 337          * Setup the percpu timer for this CPU.
 338          */
 339         percpu_timer_setup();
 340
 341         calibrate_delay();
 342
 343         smp_store_cpu_info(cpu);
 344
 345         /*
 346          * OK, now it's safe to let the boot CPU continue
 347          */
 348         set_cpu_online(cpu, true);
 349
 350         /*
 351          * OK, it's off to the idle thread for us
 352          */
 353         cpu_idle();
 354 }
 355
 356 /*
 357  * Called by both boot and secondaries to move global data into
 358  * per-processor storage.
 359  */
 360 void __cpuinit smp_store_cpu_info(unsigned int cpuid)
 361 {
 362         struct cpuinfo_arm *cpu_info = &per_cpu(cpu_data, cpuid);
 363
 364         cpu_info->loops_per_jiffy = loops_per_jiffy;
 365 }
 366
 367 void __init smp_cpus_done(unsigned int max_cpus)
 368 {
 369         int cpu;
 370         unsigned long bogosum = 0;
 371
 372         for_each_online_cpu(cpu)
 373                 bogosum += per_cpu(cpu_data, cpu).loops_per_jiffy;
 374
 375         printk(KERN_INFO "SMP: Total of %d processors activated "
 376                "(%lu.%02lu BogoMIPS).\n",
 377                num_online_cpus(),
 378                bogosum / (500000/HZ),
 379                (bogosum / (5000/HZ)) % 100);
 380 }
 381
 382 void __init smp_prepare_boot_cpu(void)
 383 {
 384         unsigned int cpu = smp_processor_id();
 385
 386         per_cpu(cpu_data, cpu).idle = current;
 387 }
 388
 389 static void send_ipi_message(const struct cpumask *mask, enum ipi_msg_type msg)
 390 {
 391         unsigned long flags;
 392         unsigned int cpu;
 393
 394         local_irq_save(flags);
 395
 396         for_each_cpu(cpu, mask) {
 397                 struct ipi_data *ipi = &per_cpu(ipi_data, cpu);
 398
 399                 spin_lock(&ipi->lock);
 400                 ipi->bits |= 1 << msg;
 401                 spin_unlock(&ipi->lock);
 402         }
 403
 404         /*
 405          * Call the platform specific cross-CPU call function.
 406          */
 407         smp_cross_call(mask);
 408
 409         local_irq_restore(flags);
 410 }
 411
 412 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
 413 {
 414         send_ipi_message(mask, IPI_CALL_FUNC);
 415 }
 416
 417 void arch_send_call_function_single_ipi(int cpu)
 418 {
 419         send_ipi_message(cpumask_of(cpu), IPI_CALL_FUNC_SINGLE);
 420 }
 421
 422 void show_ipi_list(struct seq_file *p)
 423 {
 424         unsigned int cpu;
 425
 426         seq_puts(p, "IPI:");
 427
 428         for_each_present_cpu(cpu)
 429                 seq_printf(p, " %10lu", per_cpu(ipi_data, cpu).ipi_count);
 430
 431         seq_putc(p, '\n');
 432 }
 433
 434 void show_local_irqs(struct seq_file *p)
 435 {
 436         unsigned int cpu;
 437
 438         seq_printf(p, "LOC: ");
 439
 440         for_each_present_cpu(cpu)
 441                 seq_printf(p, "%10u ", irq_stat[cpu].local_timer_irqs);
 442
 443         seq_putc(p, '\n');
 444 }
 445
 446 /*
 447  * Timer (local or broadcast) support
 448  */
 449 static DEFINE_PER_CPU(struct clock_event_device, percpu_clockevent);
 450
 451 static void ipi_timer(void)
 452 {
 453         struct clock_event_device *evt = &__get_cpu_var(percpu_clockevent);
 454         irq_enter();
 455         evt->event_handler(evt);
 456         irq_exit();
 457 }
 458
 459 #ifdef CONFIG_LOCAL_TIMERS
 460 asmlinkage void __exception_irq_entry do_local_timer(struct pt_regs *regs)
 461 {
 462         struct pt_regs *old_regs = set_irq_regs(regs);
 463         int cpu = smp_processor_id();
 464
 465         if (local_timer_ack()) {
 466                 irq_stat[cpu].local_timer_irqs++;
 467                 ipi_timer();
 468         }
 469
 470         set_irq_regs(old_regs);
 471 }
 472 #endif
 473
 474 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
 475 static void smp_timer_broadcast(const struct cpumask *mask)
 476 {
 477         send_ipi_message(mask, IPI_TIMER);
 478 }
 479 #else
 480 #define smp_timer_broadcast     NULL
 481 #endif
 482
 483 #ifndef CONFIG_LOCAL_TIMERS
 484 static void broadcast_timer_set_mode(enum clock_event_mode mode,
 485         struct clock_event_device *evt)
 486 {
 487 }
 488
 489 static void local_timer_setup(struct clock_event_device *evt)
 490 {
 491         evt->name       = "dummy_timer";
 492         evt->features   = CLOCK_EVT_FEAT_ONESHOT |
 493                           CLOCK_EVT_FEAT_PERIODIC |
 494                           CLOCK_EVT_FEAT_DUMMY;
 495         evt->rating     = 400;
 496         evt->mult       = 1;
 497         evt->set_mode   = broadcast_timer_set_mode;
 498
 499         clockevents_register_device(evt);
 500 }
 501 #endif
 502
 503 void __cpuinit percpu_timer_setup(void)
 504 {
 505         unsigned int cpu = smp_processor_id();
 506         struct clock_event_device *evt = &per_cpu(percpu_clockevent, cpu);
 507
 508         evt->cpumask = cpumask_of(cpu);
 509         evt->broadcast = smp_timer_broadcast;
 510
 511         local_timer_setup(evt);
 512 }
 513
 514 static DEFINE_SPINLOCK(stop_lock);
 515
 516 /*
 517  * ipi_cpu_stop - handle IPI from smp_send_stop()
 518  */
 519 static void ipi_cpu_stop(unsigned int cpu)
 520 {
 521         if (system_state == SYSTEM_BOOTING ||
 522             system_state == SYSTEM_RUNNING) {
 523                 spin_lock(&stop_lock);
 524                 printk(KERN_CRIT "CPU%u: stopping\n", cpu);
 525                 dump_stack();
 526                 spin_unlock(&stop_lock);
 527         }
 528
 529         set_cpu_online(cpu, false);
 530
 531         local_fiq_disable();
 532         local_irq_disable();
 533
 534         while (1)
 535                 cpu_relax();
 536 }
 537
 538 /*
 539  * Main handler for inter-processor interrupts
 540  *
 541  * For ARM, the ipimask now only identifies a single
 542  * category of IPI (Bit 1 IPIs have been replaced by a
 543  * different mechanism):
 544  *
 545  *  Bit 0 - Inter-processor function call
 546  */
 547 asmlinkage void __exception_irq_entry do_IPI(struct pt_regs *regs)
 548 {
 549         unsigned int cpu = smp_processor_id();
 550         struct ipi_data *ipi = &per_cpu(ipi_data, cpu);
 551         struct pt_regs *old_regs = set_irq_regs(regs);
 552
 553         ipi->ipi_count++;
 554
 555         for (;;) {
 556                 unsigned long msgs;
 557
 558                 spin_lock(&ipi->lock);
 559                 msgs = ipi->bits;
 560                 ipi->bits = 0;
 561                 spin_unlock(&ipi->lock);
 562
 563                 if (!msgs)
 564                         break;
 565
 566                 do {
 567                         unsigned nextmsg;
 568
 569                         nextmsg = msgs & -msgs;
 570                         msgs &= ~nextmsg;
 571                         nextmsg = ffz(~nextmsg);
 572
 573                         switch (nextmsg) {
 574                         case IPI_TIMER:
 575                                 ipi_timer();
 576                                 break;
 577
 578                         case IPI_RESCHEDULE:
 579                                 /*
 580                                  * nothing more to do - eveything is
 581                                  * done on the interrupt return path
 582                                  */
 583                                 break;
 584
 585                         case IPI_CALL_FUNC:
 586                                 generic_smp_call_function_interrupt();
 587                                 break;
 588
 589                         case IPI_CALL_FUNC_SINGLE:
 590                                 generic_smp_call_function_single_interrupt();
 591                                 break;
 592
 593                         case IPI_CPU_STOP:
 594                                 ipi_cpu_stop(cpu);
 595                                 break;
 596
 597                         default:
 598                                 printk(KERN_CRIT "CPU%u: Unknown IPI message 0x%x\n",
 599                                        cpu, nextmsg);
 600                                 break;
 601                         }
 602                 } while (msgs);
 603         }
 604
 605         set_irq_regs(old_regs);
 606 }
 607
 608 void smp_send_reschedule(int cpu)
 609 {
 610         send_ipi_message(cpumask_of(cpu), IPI_RESCHEDULE);
 611 }
 612
 613 void smp_send_stop(void)
 614 {
 615         cpumask_t mask = cpu_online_map;
 616         cpu_clear(smp_processor_id(), mask);
 617         if (!cpus_empty(mask))
 618                 send_ipi_message(&mask, IPI_CPU_STOP);
 619 }
 620
 621 /*
 622  * not supported here
 623  */
 624 int setup_profiling_timer(unsigned int multiplier)
 625 {
 626         return -EINVAL;
 627 }
 628
 629 static void
 630 on_each_cpu_mask(void (*func)(void *), void *info, int wait,
 631                 const struct cpumask *mask)
 632 {
 633         preempt_disable();
 634
 635         smp_call_function_many(mask, func, info, wait);
 636         if (cpumask_test_cpu(smp_processor_id(), mask))
 637                 func(info);
 638
 639         preempt_enable();
 640 }
 641
 642 /**********************************************************************/
 643
 644 /*
 645  * TLB operations
 646  */
 647 struct tlb_args {
 648         struct vm_area_struct *ta_vma;
 649         unsigned long ta_start;
 650         unsigned long ta_end;
 651 };
 652
 653 static inline void ipi_flush_tlb_all(void *ignored)
 654 {
 655         local_flush_tlb_all();
 656 }
 657
 658 static inline void ipi_flush_tlb_mm(void *arg)
 659 {
 660         struct mm_struct *mm = (struct mm_struct *)arg;
 661
 662         local_flush_tlb_mm(mm);
 663 }
 664
 665 static inline void ipi_flush_tlb_page(void *arg)
 666 {
 667         struct tlb_args *ta = (struct tlb_args *)arg;
 668
 669         local_flush_tlb_page(ta->ta_vma, ta->ta_start);
 670 }
 671
 672 static inline void ipi_flush_tlb_kernel_page(void *arg)
 673 {
 674         struct tlb_args *ta = (struct tlb_args *)arg;
 675
 676         local_flush_tlb_kernel_page(ta->ta_start);
 677 }
 678
 679 static inline void ipi_flush_tlb_range(void *arg)
 680 {
 681         struct tlb_args *ta = (struct tlb_args *)arg;
 682
 683         local_flush_tlb_range(ta->ta_vma, ta->ta_start, ta->ta_end);
 684 }
 685
 686 static inline void ipi_flush_tlb_kernel_range(void *arg)
 687 {
 688         struct tlb_args *ta = (struct tlb_args *)arg;
 689
 690         local_flush_tlb_kernel_range(ta->ta_start, ta->ta_end);
 691 }
 692
 693 void flush_tlb_all(void)
 694 {
 695         if (tlb_ops_need_broadcast())
 696                 on_each_cpu(ipi_flush_tlb_all, NULL, 1);
 697         else
 698                 local_flush_tlb_all();
 699 }
 700
 701 void flush_tlb_mm(struct mm_struct *mm)
 702 {
 703         if (tlb_ops_need_broadcast())
 704                 on_each_cpu_mask(ipi_flush_tlb_mm, mm, 1, mm_cpumask(mm));
 705         else
 706                 local_flush_tlb_mm(mm);
 707 }
 708
 709 void flush_tlb_page(struct vm_area_struct *vma, unsigned long uaddr)
 710 {
 711         if (tlb_ops_need_broadcast()) {
 712                 struct tlb_args ta;
 713                 ta.ta_vma = vma;
 714                 ta.ta_start = uaddr;
 715                 on_each_cpu_mask(ipi_flush_tlb_page, &ta, 1, mm_cpumask(vma->vm_mm));
 716         } else
 717                 local_flush_tlb_page(vma, uaddr);
 718 }
 719
 720 void flush_tlb_kernel_page(unsigned long kaddr)
 721 {
 722         if (tlb_ops_need_broadcast()) {
 723                 struct tlb_args ta;
 724                 ta.ta_start = kaddr;
 725                 on_each_cpu(ipi_flush_tlb_kernel_page, &ta, 1);
 726         } else
 727                 local_flush_tlb_kernel_page(kaddr);
 728 }
 729
 730 void flush_tlb_range(struct vm_area_struct *vma,
 731                      unsigned long start, unsigned long end)
 732 {
 733         if (tlb_ops_need_broadcast()) {
 734                 struct tlb_args ta;
 735                 ta.ta_vma = vma;
 736                 ta.ta_start = start;
 737                 ta.ta_end = end;
 738                 on_each_cpu_mask(ipi_flush_tlb_range, &ta, 1, mm_cpumask(vma->vm_mm));
 739         } else
 740                 local_flush_tlb_range(vma, start, end);
 741 }
 742
 743 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
 744 {
 745         if (tlb_ops_need_broadcast()) {
 746                 struct tlb_args ta;
 747                 ta.ta_start = start;
 748                 ta.ta_end = end;
 749                 on_each_cpu(ipi_flush_tlb_kernel_range, &ta, 1);
 750         } else
 751                 local_flush_tlb_kernel_range(start, end);
 752 }