arch/parisc/kernel/smp.c

   1 /*
   2 ** SMP Support
   3 **
   4 ** Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
   5 ** Copyright (C) 1999 David Mosberger-Tang <davidm@hpl.hp.com>
   6 ** Copyright (C) 2001,2004 Grant Grundler <grundler@parisc-linux.org>
   7 **
   8 ** Lots of stuff stolen from arch/alpha/kernel/smp.c
   9 ** ...and then parisc stole from arch/ia64/kernel/smp.c. Thanks David! :^)
  10 **
  11 ** Thanks to John Curry and Ullas Ponnadi. I learned alot from their work.
  12 ** -grant (1/12/2001)
  13 **
  14 **      This program is free software; you can redistribute it and/or modify
  15 **      it under the terms of the GNU General Public License as published by
  16 **      the Free Software Foundation; either version 2 of the License, or
  17 **      (at your option) any later version.
  18 */
  19 #undef ENTRY_SYS_CPUS   /* syscall support for iCOD-like functionality */
  20
  21
  22 #include <linux/types.h>
  23 #include <linux/spinlock.h>
  24 #include <linux/slab.h>
  25
  26 #include <linux/kernel.h>
  27 #include <linux/module.h>
  28 #include <linux/sched.h>
  29 #include <linux/init.h>
  30 #include <linux/interrupt.h>
  31 #include <linux/smp.h>
  32 #include <linux/kernel_stat.h>
  33 #include <linux/mm.h>
  34 #include <linux/delay.h>
  35 #include <linux/bitops.h>
  36
  37 #include <asm/system.h>
  38 #include <asm/atomic.h>
  39 #include <asm/current.h>
  40 #include <asm/delay.h>
  41 #include <asm/tlbflush.h>
  42
  43 #include <asm/io.h>
  44 #include <asm/irq.h>            /* for CPU_IRQ_REGION and friends */
  45 #include <asm/mmu_context.h>
  46 #include <asm/page.h>
  47 #include <asm/pgtable.h>
  48 #include <asm/pgalloc.h>
  49 #include <asm/processor.h>
  50 #include <asm/ptrace.h>
  51 #include <asm/unistd.h>
  52 #include <asm/cacheflush.h>
  53
  54 #define kDEBUG 0
  55
  56 DEFINE_SPINLOCK(smp_lock);
  57
  58 volatile struct task_struct *smp_init_current_idle_task;
  59
  60 static volatile int cpu_now_booting __read_mostly = 0;  /* track which CPU is booting */
  61
  62 static int parisc_max_cpus __read_mostly = 1;
  63
  64 /* online cpus are ones that we've managed to bring up completely
  65  * possible cpus are all valid cpu
  66  * present cpus are all detected cpu
  67  *
  68  * On startup we bring up the "possible" cpus. Since we discover
  69  * CPUs later, we add them as hotplug, so the possible cpu mask is
  70  * empty in the beginning.
  71  */
  72
  73 cpumask_t cpu_online_map   __read_mostly = CPU_MASK_NONE;       /* Bitmap of online CPUs */
  74 cpumask_t cpu_possible_map __read_mostly = CPU_MASK_ALL;        /* Bitmap of Present CPUs */
  75
  76 EXPORT_SYMBOL(cpu_online_map);
  77 EXPORT_SYMBOL(cpu_possible_map);
  78
  79
  80 struct smp_call_struct {
  81         void (*func) (void *info);
  82         void *info;
  83         long wait;
  84         atomic_t unstarted_count;
  85         atomic_t unfinished_count;
  86 };
  87 static volatile struct smp_call_struct *smp_call_function_data;
  88
  89 enum ipi_message_type {
  90         IPI_NOP=0,
  91         IPI_RESCHEDULE=1,
  92         IPI_CALL_FUNC,
  93         IPI_CPU_START,
  94         IPI_CPU_STOP,
  95         IPI_CPU_TEST
  96 };
  97
  98
  99 /********** SMP inter processor interrupt and communication routines */
 100
 101 #undef PER_CPU_IRQ_REGION
 102 #ifdef PER_CPU_IRQ_REGION
 103 /* XXX REVISIT Ignore for now.
 104 **    *May* need this "hook" to register IPI handler
 105 **    once we have perCPU ExtIntr switch tables.
 106 */
 107 static void
 108 ipi_init(int cpuid)
 109 {
 110
 111         /* If CPU is present ... */
 112 #ifdef ENTRY_SYS_CPUS
 113         /* *and* running (not stopped) ... */
 114 #error iCOD support wants state checked here.
 115 #endif
 116
 117 #error verify IRQ_OFFSET(IPI_IRQ) is ipi_interrupt() in new IRQ region
 118
 119         if(cpu_online(cpuid) )
 120         {
 121                 switch_to_idle_task(current);
 122         }
 123
 124         return;
 125 }
 126 #endif
 127
 128
 129 /*
 130 ** Yoink this CPU from the runnable list...
 131 **
 132 */
 133 static void
 134 halt_processor(void)
 135 {
 136 #ifdef ENTRY_SYS_CPUS
 137 #error halt_processor() needs rework
 138 /*
 139 ** o migrate I/O interrupts off this CPU.
 140 ** o leave IPI enabled - __cli() will disable IPI.
 141 ** o leave CPU in online map - just change the state
 142 */
 143         cpu_data[this_cpu].state = STATE_STOPPED;
 144         mark_bh(IPI_BH);
 145 #else
 146         /* REVISIT : redirect I/O Interrupts to another CPU? */
 147         /* REVISIT : does PM *know* this CPU isn't available? */
 148         cpu_clear(smp_processor_id(), cpu_online_map);
 149         local_irq_disable();
 150         for (;;)
 151                 ;
 152 #endif
 153 }
 154
 155
 156 irqreturn_t
 157 ipi_interrupt(int irq, void *dev_id)
 158 {
 159         int this_cpu = smp_processor_id();
 160         struct cpuinfo_parisc *p = &cpu_data[this_cpu];
 161         unsigned long ops;
 162         unsigned long flags;
 163
 164         /* Count this now; we may make a call that never returns. */
 165         p->ipi_count++;
 166
 167         mb();   /* Order interrupt and bit testing. */
 168
 169         for (;;) {
 170                 spin_lock_irqsave(&(p->lock),flags);
 171                 ops = p->pending_ipi;
 172                 p->pending_ipi = 0;
 173                 spin_unlock_irqrestore(&(p->lock),flags);
 174
 175                 mb(); /* Order bit clearing and data access. */
 176
 177                 if (!ops)
 178                     break;
 179
 180                 while (ops) {
 181                         unsigned long which = ffz(~ops);
 182
 183                         ops &= ~(1 << which);
 184
 185                         switch (which) {
 186                         case IPI_NOP:
 187 #if (kDEBUG>=100)
 188                                 printk(KERN_DEBUG "CPU%d IPI_NOP\n",this_cpu);
 189 #endif /* kDEBUG */
 190                                 break;
 191
 192                         case IPI_RESCHEDULE:
 193 #if (kDEBUG>=100)
 194                                 printk(KERN_DEBUG "CPU%d IPI_RESCHEDULE\n",this_cpu);
 195 #endif /* kDEBUG */
 196                                 /*
 197                                  * Reschedule callback.  Everything to be
 198                                  * done is done by the interrupt return path.
 199                                  */
 200                                 break;
 201
 202                         case IPI_CALL_FUNC:
 203 #if (kDEBUG>=100)
 204                                 printk(KERN_DEBUG "CPU%d IPI_CALL_FUNC\n",this_cpu);
 205 #endif /* kDEBUG */
 206                                 {
 207                                         volatile struct smp_call_struct *data;
 208                                         void (*func)(void *info);
 209                                         void *info;
 210                                         int wait;
 211
 212                                         data = smp_call_function_data;
 213                                         func = data->func;
 214                                         info = data->info;
 215                                         wait = data->wait;
 216
 217                                         mb();
 218                                         atomic_dec ((atomic_t *)&data->unstarted_count);
 219
 220                                         /* At this point, *data can't
 221                                          * be relied upon.
 222                                          */
 223
 224                                         (*func)(info);
 225
 226                                         /* Notify the sending CPU that the
 227                                          * task is done.
 228                                          */
 229                                         mb();
 230                                         if (wait)
 231                                                 atomic_dec ((atomic_t *)&data->unfinished_count);
 232                                 }
 233                                 break;
 234
 235                         case IPI_CPU_START:
 236 #if (kDEBUG>=100)
 237                                 printk(KERN_DEBUG "CPU%d IPI_CPU_START\n",this_cpu);
 238 #endif /* kDEBUG */
 239 #ifdef ENTRY_SYS_CPUS
 240                                 p->state = STATE_RUNNING;
 241 #endif
 242                                 break;
 243
 244                         case IPI_CPU_STOP:
 245 #if (kDEBUG>=100)
 246                                 printk(KERN_DEBUG "CPU%d IPI_CPU_STOP\n",this_cpu);
 247 #endif /* kDEBUG */
 248 #ifdef ENTRY_SYS_CPUS
 249 #else
 250                                 halt_processor();
 251 #endif
 252                                 break;
 253
 254                         case IPI_CPU_TEST:
 255 #if (kDEBUG>=100)
 256                                 printk(KERN_DEBUG "CPU%d is alive!\n",this_cpu);
 257 #endif /* kDEBUG */
 258                                 break;
 259
 260                         default:
 261                                 printk(KERN_CRIT "Unknown IPI num on CPU%d: %lu\n",
 262                                         this_cpu, which);
 263                                 return IRQ_NONE;
 264                         } /* Switch */
 265                 /* let in any pending interrupts */
 266                 local_irq_enable();
 267                 local_irq_disable();
 268                 } /* while (ops) */
 269         }
 270         return IRQ_HANDLED;
 271 }
 272
 273
 274 static inline void
 275 ipi_send(int cpu, enum ipi_message_type op)
 276 {
 277         struct cpuinfo_parisc *p = &cpu_data[cpu];
 278         unsigned long flags;
 279
 280         spin_lock_irqsave(&(p->lock),flags);
 281         p->pending_ipi |= 1 << op;
 282         gsc_writel(IPI_IRQ - CPU_IRQ_BASE, cpu_data[cpu].hpa);
 283         spin_unlock_irqrestore(&(p->lock),flags);
 284 }
 285
 286
 287 static inline void
 288 send_IPI_single(int dest_cpu, enum ipi_message_type op)
 289 {
 290         if (dest_cpu == NO_PROC_ID) {
 291                 BUG();
 292                 return;
 293         }
 294
 295         ipi_send(dest_cpu, op);
 296 }
 297
 298 static inline void
 299 send_IPI_allbutself(enum ipi_message_type op)
 300 {
 301         int i;
 302
 303         for_each_online_cpu(i) {
 304                 if (i != smp_processor_id())
 305                         send_IPI_single(i, op);
 306         }
 307 }
 308
 309
 310 inline void
 311 smp_send_stop(void)     { send_IPI_allbutself(IPI_CPU_STOP); }
 312
 313 static inline void
 314 smp_send_start(void)    { send_IPI_allbutself(IPI_CPU_START); }
 315
 316 void
 317 smp_send_reschedule(int cpu) { send_IPI_single(cpu, IPI_RESCHEDULE); }
 318
 319 void
 320 smp_send_all_nop(void)
 321 {
 322         send_IPI_allbutself(IPI_NOP);
 323 }
 324
 325
 326 /**
 327  * Run a function on all other CPUs.
 328  *  <func>      The function to run. This must be fast and non-blocking.
 329  *  <info>      An arbitrary pointer to pass to the function.
 330  *  <retry>     If true, keep retrying until ready.
 331  *  <wait>      If true, wait until function has completed on other CPUs.
 332  *  [RETURNS]   0 on success, else a negative status code.
 333  *
 334  * Does not return until remote CPUs are nearly ready to execute <func>
 335  * or have executed.
 336  */
 337
 338 int
 339 smp_call_function (void (*func) (void *info), void *info, int retry, int wait)
 340 {
 341         struct smp_call_struct data;
 342         unsigned long timeout;
 343         static DEFINE_SPINLOCK(lock);
 344         int retries = 0;
 345
 346         if (num_online_cpus() < 2)
 347                 return 0;
 348
 349         /* Can deadlock when called with interrupts disabled */
 350         WARN_ON(irqs_disabled());
 351
 352         /* can also deadlock if IPIs are disabled */
 353         WARN_ON((get_eiem() & (1UL<<(CPU_IRQ_MAX - IPI_IRQ))) == 0);
 354
 355
 356         data.func = func;
 357         data.info = info;
 358         data.wait = wait;
 359         atomic_set(&data.unstarted_count, num_online_cpus() - 1);
 360         atomic_set(&data.unfinished_count, num_online_cpus() - 1);
 361
 362         if (retry) {
 363                 spin_lock (&lock);
 364                 while (smp_call_function_data != 0)
 365                         barrier();
 366         }
 367         else {
 368                 spin_lock (&lock);
 369                 if (smp_call_function_data) {
 370                         spin_unlock (&lock);
 371                         return -EBUSY;
 372                 }
 373         }
 374
 375         smp_call_function_data = &data;
 376         spin_unlock (&lock);
 377
 378         /*  Send a message to all other CPUs and wait for them to respond  */
 379         send_IPI_allbutself(IPI_CALL_FUNC);
 380
 381  retry:
 382         /*  Wait for response  */
 383         timeout = jiffies + HZ;
 384         while ( (atomic_read (&data.unstarted_count) > 0) &&
 385                 time_before (jiffies, timeout) )
 386                 barrier ();
 387
 388         if (atomic_read (&data.unstarted_count) > 0) {
 389                 printk(KERN_CRIT "SMP CALL FUNCTION TIMED OUT! (cpu=%d), try %d\n",
 390                       smp_processor_id(), ++retries);
 391                 goto retry;
 392         }
 393         /* We either got one or timed out. Release the lock */
 394
 395         mb();
 396         smp_call_function_data = NULL;
 397
 398         while (wait && atomic_read (&data.unfinished_count) > 0)
 399                         barrier ();
 400
 401         return 0;
 402 }
 403
 404 EXPORT_SYMBOL(smp_call_function);
 405
 406 /*
 407  * Flush all other CPU's tlb and then mine.  Do this with on_each_cpu()
 408  * as we want to ensure all TLB's flushed before proceeding.
 409  */
 410
 411 void
 412 smp_flush_tlb_all(void)
 413 {
 414         on_each_cpu(flush_tlb_all_local, NULL, 1, 1);
 415 }
 416
 417 /*
 418  * Called by secondaries to update state and initialize CPU registers.
 419  */
 420 static void __init
 421 smp_cpu_init(int cpunum)
 422 {
 423         extern int init_per_cpu(int);  /* arch/parisc/kernel/processor.c */
 424         extern void init_IRQ(void);    /* arch/parisc/kernel/irq.c */
 425         extern void start_cpu_itimer(void); /* arch/parisc/kernel/time.c */
 426
 427         /* Set modes and Enable floating point coprocessor */
 428         (void) init_per_cpu(cpunum);
 429
 430         disable_sr_hashing();
 431
 432         mb();
 433
 434         /* Well, support 2.4 linux scheme as well. */
 435         if (cpu_test_and_set(cpunum, cpu_online_map))
 436         {
 437                 extern void machine_halt(void); /* arch/parisc.../process.c */
 438
 439                 printk(KERN_CRIT "CPU#%d already initialized!\n", cpunum);
 440                 machine_halt();
 441         }
 442
 443         /* Initialise the idle task for this CPU */
 444         atomic_inc(&init_mm.mm_count);
 445         current->active_mm = &init_mm;
 446         if(current->mm)
 447                 BUG();
 448         enter_lazy_tlb(&init_mm, current);
 449
 450         init_IRQ();   /* make sure no IRQ's are enabled or pending */
 451         start_cpu_itimer();
 452 }
 453
 454
 455 /*
 456  * Slaves start using C here. Indirectly called from smp_slave_stext.
 457  * Do what start_kernel() and main() do for boot strap processor (aka monarch)
 458  */
 459 void __init smp_callin(void)
 460 {
 461         int slave_id = cpu_now_booting;
 462 #if 0
 463         void *istack;
 464 #endif
 465
 466         smp_cpu_init(slave_id);
 467         preempt_disable();
 468
 469 #if 0   /* NOT WORKING YET - see entry.S */
 470         istack = (void *)__get_free_pages(GFP_KERNEL,ISTACK_ORDER);
 471         if (istack == NULL) {
 472             printk(KERN_CRIT "Failed to allocate interrupt stack for cpu %d\n",slave_id);
 473             BUG();
 474         }
 475         mtctl(istack,31);
 476 #endif
 477
 478         flush_cache_all_local(); /* start with known state */
 479         flush_tlb_all_local(NULL);
 480
 481         local_irq_enable();  /* Interrupts have been off until now */
 482
 483         cpu_idle();      /* Wait for timer to schedule some work */
 484
 485         /* NOTREACHED */
 486         panic("smp_callin() AAAAaaaaahhhh....\n");
 487 }
 488
 489 /*
 490  * Bring one cpu online.
 491  */
 492 int __init smp_boot_one_cpu(int cpuid)
 493 {
 494         struct task_struct *idle;
 495         long timeout;
 496
 497         /*
 498          * Create an idle task for this CPU.  Note the address wed* give
 499          * to kernel_thread is irrelevant -- it's going to start
 500          * where OS_BOOT_RENDEVZ vector in SAL says to start.  But
 501          * this gets all the other task-y sort of data structures set
 502          * up like we wish.   We need to pull the just created idle task
 503          * off the run queue and stuff it into the init_tasks[] array.
 504          * Sheesh . . .
 505          */
 506
 507         idle = fork_idle(cpuid);
 508         if (IS_ERR(idle))
 509                 panic("SMP: fork failed for CPU:%d", cpuid);
 510
 511         task_thread_info(idle)->cpu = cpuid;
 512
 513         /* Let _start know what logical CPU we're booting
 514         ** (offset into init_tasks[],cpu_data[])
 515         */
 516         cpu_now_booting = cpuid;
 517
 518         /*
 519         ** boot strap code needs to know the task address since
 520         ** it also contains the process stack.
 521         */
 522         smp_init_current_idle_task = idle ;
 523         mb();
 524
 525         printk("Releasing cpu %d now, hpa=%lx\n", cpuid, cpu_data[cpuid].hpa);
 526
 527         /*
 528         ** This gets PDC to release the CPU from a very tight loop.
 529         **
 530         ** From the PA-RISC 2.0 Firmware Architecture Reference Specification:
 531         ** "The MEM_RENDEZ vector specifies the location of OS_RENDEZ which
 532         ** is executed after receiving the rendezvous signal (an interrupt to
 533         ** EIR{0}). MEM_RENDEZ is valid only when it is nonzero and the
 534         ** contents of memory are valid."
 535         */
 536         gsc_writel(TIMER_IRQ - CPU_IRQ_BASE, cpu_data[cpuid].hpa);
 537         mb();
 538
 539         /*
 540          * OK, wait a bit for that CPU to finish staggering about.
 541          * Slave will set a bit when it reaches smp_cpu_init().
 542          * Once the "monarch CPU" sees the bit change, it can move on.
 543          */
 544         for (timeout = 0; timeout < 10000; timeout++) {
 545                 if(cpu_online(cpuid)) {
 546                         /* Which implies Slave has started up */
 547                         cpu_now_booting = 0;
 548                         smp_init_current_idle_task = NULL;
 549                         goto alive ;
 550                 }
 551                 udelay(100);
 552                 barrier();
 553         }
 554
 555         put_task_struct(idle);
 556         idle = NULL;
 557
 558         printk(KERN_CRIT "SMP: CPU:%d is stuck.\n", cpuid);
 559         return -1;
 560
 561 alive:
 562         /* Remember the Slave data */
 563 #if (kDEBUG>=100)
 564         printk(KERN_DEBUG "SMP: CPU:%d came alive after %ld _us\n",
 565                 cpuid, timeout * 100);
 566 #endif /* kDEBUG */
 567 #ifdef ENTRY_SYS_CPUS
 568         cpu_data[cpuid].state = STATE_RUNNING;
 569 #endif
 570         return 0;
 571 }
 572
 573 void __devinit smp_prepare_boot_cpu(void)
 574 {
 575         int bootstrap_processor=cpu_data[0].cpuid;      /* CPU ID of BSP */
 576
 577 #ifdef ENTRY_SYS_CPUS
 578         cpu_data[0].state = STATE_RUNNING;
 579 #endif
 580
 581         /* Setup BSP mappings */
 582         printk("SMP: bootstrap CPU ID is %d\n",bootstrap_processor);
 583
 584         cpu_set(bootstrap_processor, cpu_online_map);
 585         cpu_set(bootstrap_processor, cpu_present_map);
 586 }
 587
 588
 589
 590 /*
 591 ** inventory.c:do_inventory() hasn't yet been run and thus we
 592 ** don't 'discover' the additional CPU's until later.
 593 */
 594 void __init smp_prepare_cpus(unsigned int max_cpus)
 595 {
 596         cpus_clear(cpu_present_map);
 597         cpu_set(0, cpu_present_map);
 598
 599         parisc_max_cpus = max_cpus;
 600         if (!max_cpus)
 601                 printk(KERN_INFO "SMP mode deactivated.\n");
 602 }
 603
 604
 605 void smp_cpus_done(unsigned int cpu_max)
 606 {
 607         return;
 608 }
 609
 610
 611 int __devinit __cpu_up(unsigned int cpu)
 612 {
 613         if (cpu != 0 && cpu < parisc_max_cpus)
 614                 smp_boot_one_cpu(cpu);
 615
 616         return cpu_online(cpu) ? 0 : -ENOSYS;
 617 }
 618
 619
 620
 621 #ifdef ENTRY_SYS_CPUS
 622 /* Code goes along with:
 623 **    entry.s:        ENTRY_NAME(sys_cpus)   / * 215, for cpu stat * /
 624 */
 625 int sys_cpus(int argc, char **argv)
 626 {
 627         int i,j=0;
 628         extern int current_pid(int cpu);
 629
 630         if( argc > 2 ) {
 631                 printk("sys_cpus:Only one argument supported\n");
 632                 return (-1);
 633         }
 634         if ( argc == 1 ){
 635
 636 #ifdef DUMP_MORE_STATE
 637                 for_each_online_cpu(i) {
 638                         int cpus_per_line = 4;
 639
 640                         if (j++ % cpus_per_line)
 641                                 printk(" %3d",i);
 642                         else
 643                                 printk("\n %3d",i);
 644                 }
 645                 printk("\n");
 646 #else
 647                 printk("\n 0\n");
 648 #endif
 649         } else if((argc==2) && !(strcmp(argv[1],"-l"))) {
 650                 printk("\nCPUSTATE  TASK CPUNUM CPUID HARDCPU(HPA)\n");
 651 #ifdef DUMP_MORE_STATE
 652                 for_each_online_cpu(i) {
 653                         if (cpu_data[i].cpuid != NO_PROC_ID) {
 654                                 switch(cpu_data[i].state) {
 655                                         case STATE_RENDEZVOUS:
 656                                                 printk("RENDEZVS ");
 657                                                 break;
 658                                         case STATE_RUNNING:
 659                                                 printk((current_pid(i)!=0) ? "RUNNING  " : "IDLING   ");
 660                                                 break;
 661                                         case STATE_STOPPED:
 662                                                 printk("STOPPED  ");
 663                                                 break;
 664                                         case STATE_HALTED:
 665                                                 printk("HALTED   ");
 666                                                 break;
 667                                         default:
 668                                                 printk("%08x?", cpu_data[i].state);
 669                                                 break;
 670                                 }
 671                                 if(cpu_online(i)) {
 672                                         printk(" %4d",current_pid(i));
 673                                 }
 674                                 printk(" %6d",cpu_number_map(i));
 675                                 printk(" %5d",i);
 676                                 printk(" 0x%lx\n",cpu_data[i].hpa);
 677                         }
 678                 }
 679 #else
 680                 printk("\n%s  %4d      0     0 --------",
 681                         (current->pid)?"RUNNING ": "IDLING  ",current->pid);
 682 #endif
 683         } else if ((argc==2) && !(strcmp(argv[1],"-s"))) {
 684 #ifdef DUMP_MORE_STATE
 685                 printk("\nCPUSTATE   CPUID\n");
 686                 for_each_online_cpu(i) {
 687                         if (cpu_data[i].cpuid != NO_PROC_ID) {
 688                                 switch(cpu_data[i].state) {
 689                                         case STATE_RENDEZVOUS:
 690                                                 printk("RENDEZVS");break;
 691                                         case STATE_RUNNING:
 692                                                 printk((current_pid(i)!=0) ? "RUNNING " : "IDLING");
 693                                                 break;
 694                                         case STATE_STOPPED:
 695                                                 printk("STOPPED ");break;
 696                                         case STATE_HALTED:
 697                                                 printk("HALTED  ");break;
 698                                         default:
 699                                 }
 700                                 printk("  %5d\n",i);
 701                         }
 702                 }
 703 #else
 704                 printk("\n%s    CPU0",(current->pid==0)?"RUNNING ":"IDLING  ");
 705 #endif
 706         } else {
 707                 printk("sys_cpus:Unknown request\n");
 708                 return (-1);
 709         }
 710         return 0;
 711 }
 712 #endif /* ENTRY_SYS_CPUS */
 713
 714 #ifdef CONFIG_PROC_FS
 715 int __init
 716 setup_profiling_timer(unsigned int multiplier)
 717 {
 718         return -EINVAL;
 719 }
 720 #endif