arch/m32r/kernel/smp.c

   1 /*
   2  *  linux/arch/m32r/kernel/smp.c
   3  *
   4  *  M32R SMP support routines.
   5  *
   6  *  Copyright (c) 2001, 2002  Hitoshi Yamamoto
   7  *
   8  *  Taken from i386 version.
   9  *    (c) 1995 Alan Cox, Building #3 <alan@redhat.com>
  10  *    (c) 1998-99, 2000 Ingo Molnar <mingo@redhat.com>
  11  *
  12  *  This code is released under the GNU General Public License version 2 or
  13  *  later.
  14  */
  15
  16 #undef DEBUG_SMP
  17
  18 #include <linux/irq.h>
  19 #include <linux/interrupt.h>
  20 #include <linux/spinlock.h>
  21 #include <linux/mm.h>
  22 #include <linux/smp.h>
  23 #include <linux/profile.h>
  24 #include <linux/cpu.h>
  25
  26 #include <asm/cacheflush.h>
  27 #include <asm/pgalloc.h>
  28 #include <asm/atomic.h>
  29 #include <asm/io.h>
  30 #include <asm/mmu_context.h>
  31 #include <asm/m32r.h>
  32
  33 /*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
  34 /* Data structures and variables                                             */
  35 /*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
  36
  37 /*
  38  * Structure and data for smp_call_function(). This is designed to minimise
  39  * static memory requirements. It also looks cleaner.
  40  */
  41 static DEFINE_SPINLOCK(call_lock);
  42
  43 struct call_data_struct {
  44         void (*func) (void *info);
  45         void *info;
  46         atomic_t started;
  47         atomic_t finished;
  48         int wait;
  49 } __attribute__ ((__aligned__(SMP_CACHE_BYTES)));
  50
  51 static struct call_data_struct *call_data;
  52
  53 /*
  54  * For flush_cache_all()
  55  */
  56 static DEFINE_SPINLOCK(flushcache_lock);
  57 static volatile unsigned long flushcache_cpumask = 0;
  58
  59 /*
  60  * For flush_tlb_others()
  61  */
  62 static volatile cpumask_t flush_cpumask;
  63 static struct mm_struct *flush_mm;
  64 static struct vm_area_struct *flush_vma;
  65 static volatile unsigned long flush_va;
  66 static DEFINE_SPINLOCK(tlbstate_lock);
  67 #define FLUSH_ALL 0xffffffff
  68
  69 DECLARE_PER_CPU(int, prof_multiplier);
  70 DECLARE_PER_CPU(int, prof_old_multiplier);
  71 DECLARE_PER_CPU(int, prof_counter);
  72
  73 extern spinlock_t ipi_lock[];
  74
  75 /*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
  76 /* Function Prototypes                                                       */
  77 /*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
  78
  79 void smp_send_reschedule(int);
  80 void smp_reschedule_interrupt(void);
  81
  82 void smp_flush_cache_all(void);
  83 void smp_flush_cache_all_interrupt(void);
  84
  85 void smp_flush_tlb_all(void);
  86 static void flush_tlb_all_ipi(void *);
  87
  88 void smp_flush_tlb_mm(struct mm_struct *);
  89 void smp_flush_tlb_range(struct vm_area_struct *, unsigned long, \
  90         unsigned long);
  91 void smp_flush_tlb_page(struct vm_area_struct *, unsigned long);
  92 static void flush_tlb_others(cpumask_t, struct mm_struct *,
  93         struct vm_area_struct *, unsigned long);
  94 void smp_invalidate_interrupt(void);
  95
  96 void smp_send_stop(void);
  97 static void stop_this_cpu(void *);
  98
  99 int smp_call_function(void (*) (void *), void *, int, int);
 100 void smp_call_function_interrupt(void);
 101
 102 void smp_send_timer(void);
 103 void smp_ipi_timer_interrupt(struct pt_regs *);
 104 void smp_local_timer_interrupt(void);
 105
 106 void send_IPI_allbutself(int, int);
 107 static void send_IPI_mask(cpumask_t, int, int);
 108 unsigned long send_IPI_mask_phys(cpumask_t, int, int);
 109
 110 /*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
 111 /* Rescheduling request Routines                                             */
 112 /*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
 113
 114 /*==========================================================================*
 115  * Name:         smp_send_reschedule
 116  *
 117  * Description:  This routine requests other CPU to execute rescheduling.
 118  *               1.Send 'RESCHEDULE_IPI' to other CPU.
 119  *                 Request other CPU to execute 'smp_reschedule_interrupt()'.
 120  *
 121  * Born on Date: 2002.02.05
 122  *
 123  * Arguments:    cpu_id - Target CPU ID
 124  *
 125  * Returns:      void (cannot fail)
 126  *
 127  * Modification log:
 128  * Date       Who Description
 129  * ---------- --- --------------------------------------------------------
 130  *
 131  *==========================================================================*/
 132 void smp_send_reschedule(int cpu_id)
 133 {
 134         WARN_ON(cpu_is_offline(cpu_id));
 135         send_IPI_mask(cpumask_of_cpu(cpu_id), RESCHEDULE_IPI, 1);
 136 }
 137
 138 /*==========================================================================*
 139  * Name:         smp_reschedule_interrupt
 140  *
 141  * Description:  This routine executes on CPU which received
 142  *               'RESCHEDULE_IPI'.
 143  *               Rescheduling is processed at the exit of interrupt
 144  *               operation.
 145  *
 146  * Born on Date: 2002.02.05
 147  *
 148  * Arguments:    NONE
 149  *
 150  * Returns:      void (cannot fail)
 151  *
 152  * Modification log:
 153  * Date       Who Description
 154  * ---------- --- --------------------------------------------------------
 155  *
 156  *==========================================================================*/
 157 void smp_reschedule_interrupt(void)
 158 {
 159         /* nothing to do */
 160 }
 161
 162 /*==========================================================================*
 163  * Name:         smp_flush_cache_all
 164  *
 165  * Description:  This routine sends a 'INVALIDATE_CACHE_IPI' to all other
 166  *               CPUs in the system.
 167  *
 168  * Born on Date: 2003-05-28
 169  *
 170  * Arguments:    NONE
 171  *
 172  * Returns:      void (cannot fail)
 173  *
 174  * Modification log:
 175  * Date       Who Description
 176  * ---------- --- --------------------------------------------------------
 177  *
 178  *==========================================================================*/
 179 void smp_flush_cache_all(void)
 180 {
 181         cpumask_t cpumask;
 182         unsigned long *mask;
 183
 184         preempt_disable();
 185         cpumask = cpu_online_map;
 186         cpu_clear(smp_processor_id(), cpumask);
 187         spin_lock(&flushcache_lock);
 188         mask=cpus_addr(cpumask);
 189         atomic_set_mask(*mask, (atomic_t *)&flushcache_cpumask);
 190         send_IPI_mask(cpumask, INVALIDATE_CACHE_IPI, 0);
 191         _flush_cache_copyback_all();
 192         while (flushcache_cpumask)
 193                 mb();
 194         spin_unlock(&flushcache_lock);
 195         preempt_enable();
 196 }
 197
 198 void smp_flush_cache_all_interrupt(void)
 199 {
 200         _flush_cache_copyback_all();
 201         clear_bit(smp_processor_id(), &flushcache_cpumask);
 202 }
 203
 204 /*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
 205 /* TLB flush request Routins                                                 */
 206 /*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
 207
 208 /*==========================================================================*
 209  * Name:         smp_flush_tlb_all
 210  *
 211  * Description:  This routine flushes all processes TLBs.
 212  *               1.Request other CPU to execute 'flush_tlb_all_ipi()'.
 213  *               2.Execute 'do_flush_tlb_all_local()'.
 214  *
 215  * Born on Date: 2002.02.05
 216  *
 217  * Arguments:    NONE
 218  *
 219  * Returns:      void (cannot fail)
 220  *
 221  * Modification log:
 222  * Date       Who Description
 223  * ---------- --- --------------------------------------------------------
 224  *
 225  *==========================================================================*/
 226 void smp_flush_tlb_all(void)
 227 {
 228         unsigned long flags;
 229
 230         preempt_disable();
 231         local_irq_save(flags);
 232         __flush_tlb_all();
 233         local_irq_restore(flags);
 234         smp_call_function(flush_tlb_all_ipi, NULL, 1, 1);
 235         preempt_enable();
 236 }
 237
 238 /*==========================================================================*
 239  * Name:         flush_tlb_all_ipi
 240  *
 241  * Description:  This routine flushes all local TLBs.
 242  *               1.Execute 'do_flush_tlb_all_local()'.
 243  *
 244  * Born on Date: 2002.02.05
 245  *
 246  * Arguments:    *info - not used
 247  *
 248  * Returns:      void (cannot fail)
 249  *
 250  * Modification log:
 251  * Date       Who Description
 252  * ---------- --- --------------------------------------------------------
 253  *
 254  *==========================================================================*/
 255 static void flush_tlb_all_ipi(void *info)
 256 {
 257         __flush_tlb_all();
 258 }
 259
 260 /*==========================================================================*
 261  * Name:         smp_flush_tlb_mm
 262  *
 263  * Description:  This routine flushes the specified mm context TLB's.
 264  *
 265  * Born on Date: 2002.02.05
 266  *
 267  * Arguments:    *mm - a pointer to the mm struct for flush TLB
 268  *
 269  * Returns:      void (cannot fail)
 270  *
 271  * Modification log:
 272  * Date       Who Description
 273  * ---------- --- --------------------------------------------------------
 274  *
 275  *==========================================================================*/
 276 void smp_flush_tlb_mm(struct mm_struct *mm)
 277 {
 278         int cpu_id;
 279         cpumask_t cpu_mask;
 280         unsigned long *mmc;
 281         unsigned long flags;
 282
 283         preempt_disable();
 284         cpu_id = smp_processor_id();
 285         mmc = &mm->context[cpu_id];
 286         cpu_mask = mm->cpu_vm_mask;
 287         cpu_clear(cpu_id, cpu_mask);
 288
 289         if (*mmc != NO_CONTEXT) {
 290                 local_irq_save(flags);
 291                 *mmc = NO_CONTEXT;
 292                 if (mm == current->mm)
 293                         activate_context(mm);
 294                 else
 295                         cpu_clear(cpu_id, mm->cpu_vm_mask);
 296                 local_irq_restore(flags);
 297         }
 298         if (!cpus_empty(cpu_mask))
 299                 flush_tlb_others(cpu_mask, mm, NULL, FLUSH_ALL);
 300
 301         preempt_enable();
 302 }
 303
 304 /*==========================================================================*
 305  * Name:         smp_flush_tlb_range
 306  *
 307  * Description:  This routine flushes a range of pages.
 308  *
 309  * Born on Date: 2002.02.05
 310  *
 311  * Arguments:    *mm - a pointer to the mm struct for flush TLB
 312  *               start - not used
 313  *               end - not used
 314  *
 315  * Returns:      void (cannot fail)
 316  *
 317  * Modification log:
 318  * Date       Who Description
 319  * ---------- --- --------------------------------------------------------
 320  *
 321  *==========================================================================*/
 322 void smp_flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
 323         unsigned long end)
 324 {
 325         smp_flush_tlb_mm(vma->vm_mm);
 326 }
 327
 328 /*==========================================================================*
 329  * Name:         smp_flush_tlb_page
 330  *
 331  * Description:  This routine flushes one page.
 332  *
 333  * Born on Date: 2002.02.05
 334  *
 335  * Arguments:    *vma - a pointer to the vma struct include va
 336  *               va - virtual address for flush TLB
 337  *
 338  * Returns:      void (cannot fail)
 339  *
 340  * Modification log:
 341  * Date       Who Description
 342  * ---------- --- --------------------------------------------------------
 343  *
 344  *==========================================================================*/
 345 void smp_flush_tlb_page(struct vm_area_struct *vma, unsigned long va)
 346 {
 347         struct mm_struct *mm = vma->vm_mm;
 348         int cpu_id;
 349         cpumask_t cpu_mask;
 350         unsigned long *mmc;
 351         unsigned long flags;
 352
 353         preempt_disable();
 354         cpu_id = smp_processor_id();
 355         mmc = &mm->context[cpu_id];
 356         cpu_mask = mm->cpu_vm_mask;
 357         cpu_clear(cpu_id, cpu_mask);
 358
 359 #ifdef DEBUG_SMP
 360         if (!mm)
 361                 BUG();
 362 #endif
 363
 364         if (*mmc != NO_CONTEXT) {
 365                 local_irq_save(flags);
 366                 va &= PAGE_MASK;
 367                 va |= (*mmc & MMU_CONTEXT_ASID_MASK);
 368                 __flush_tlb_page(va);
 369                 local_irq_restore(flags);
 370         }
 371         if (!cpus_empty(cpu_mask))
 372                 flush_tlb_others(cpu_mask, mm, vma, va);
 373
 374         preempt_enable();
 375 }
 376
 377 /*==========================================================================*
 378  * Name:         flush_tlb_others
 379  *
 380  * Description:  This routine requests other CPU to execute flush TLB.
 381  *               1.Setup parmeters.
 382  *               2.Send 'INVALIDATE_TLB_IPI' to other CPU.
 383  *                 Request other CPU to execute 'smp_invalidate_interrupt()'.
 384  *               3.Wait for other CPUs operation finished.
 385  *
 386  * Born on Date: 2002.02.05
 387  *
 388  * Arguments:    cpumask - bitmap of target CPUs
 389  *               *mm -  a pointer to the mm struct for flush TLB
 390  *               *vma -  a pointer to the vma struct include va
 391  *               va - virtual address for flush TLB
 392  *
 393  * Returns:      void (cannot fail)
 394  *
 395  * Modification log:
 396  * Date       Who Description
 397  * ---------- --- --------------------------------------------------------
 398  *
 399  *==========================================================================*/
 400 static void flush_tlb_others(cpumask_t cpumask, struct mm_struct *mm,
 401         struct vm_area_struct *vma, unsigned long va)
 402 {
 403         unsigned long *mask;
 404 #ifdef DEBUG_SMP
 405         unsigned long flags;
 406         __save_flags(flags);
 407         if (!(flags & 0x0040))  /* Interrupt Disable NONONO */
 408                 BUG();
 409 #endif /* DEBUG_SMP */
 410
 411         /*
 412          * A couple of (to be removed) sanity checks:
 413          *
 414          * - we do not send IPIs to not-yet booted CPUs.
 415          * - current CPU must not be in mask
 416          * - mask must exist :)
 417          */
 418         BUG_ON(cpus_empty(cpumask));
 419
 420         BUG_ON(cpu_isset(smp_processor_id(), cpumask));
 421         BUG_ON(!mm);
 422
 423         /* If a CPU which we ran on has gone down, OK. */
 424         cpus_and(cpumask, cpumask, cpu_online_map);
 425         if (cpus_empty(cpumask))
 426                 return;
 427
 428         /*
 429          * i'm not happy about this global shared spinlock in the
 430          * MM hot path, but we'll see how contended it is.
 431          * Temporarily this turns IRQs off, so that lockups are
 432          * detected by the NMI watchdog.
 433          */
 434         spin_lock(&tlbstate_lock);
 435
 436         flush_mm = mm;
 437         flush_vma = vma;
 438         flush_va = va;
 439         mask=cpus_addr(cpumask);
 440         atomic_set_mask(*mask, (atomic_t *)&flush_cpumask);
 441
 442         /*
 443          * We have to send the IPI only to
 444          * CPUs affected.
 445          */
 446         send_IPI_mask(cpumask, INVALIDATE_TLB_IPI, 0);
 447
 448         while (!cpus_empty(flush_cpumask)) {
 449                 /* nothing. lockup detection does not belong here */
 450                 mb();
 451         }
 452
 453         flush_mm = NULL;
 454         flush_vma = NULL;
 455         flush_va = 0;
 456         spin_unlock(&tlbstate_lock);
 457 }
 458
 459 /*==========================================================================*
 460  * Name:         smp_invalidate_interrupt
 461  *
 462  * Description:  This routine executes on CPU which received
 463  *               'INVALIDATE_TLB_IPI'.
 464  *               1.Flush local TLB.
 465  *               2.Report flush TLB process was finished.
 466  *
 467  * Born on Date: 2002.02.05
 468  *
 469  * Arguments:    NONE
 470  *
 471  * Returns:      void (cannot fail)
 472  *
 473  * Modification log:
 474  * Date       Who Description
 475  * ---------- --- --------------------------------------------------------
 476  *
 477  *==========================================================================*/
 478 void smp_invalidate_interrupt(void)
 479 {
 480         int cpu_id = smp_processor_id();
 481         unsigned long *mmc = &flush_mm->context[cpu_id];
 482
 483         if (!cpu_isset(cpu_id, flush_cpumask))
 484                 return;
 485
 486         if (flush_va == FLUSH_ALL) {
 487                 *mmc = NO_CONTEXT;
 488                 if (flush_mm == current->active_mm)
 489                         activate_context(flush_mm);
 490                 else
 491                         cpu_clear(cpu_id, flush_mm->cpu_vm_mask);
 492         } else {
 493                 unsigned long va = flush_va;
 494
 495                 if (*mmc != NO_CONTEXT) {
 496                         va &= PAGE_MASK;
 497                         va |= (*mmc & MMU_CONTEXT_ASID_MASK);
 498                         __flush_tlb_page(va);
 499                 }
 500         }
 501         cpu_clear(cpu_id, flush_cpumask);
 502 }
 503
 504 /*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
 505 /* Stop CPU request Routins                                                 */
 506 /*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
 507
 508 /*==========================================================================*
 509  * Name:         smp_send_stop
 510  *
 511  * Description:  This routine requests stop all CPUs.
 512  *               1.Request other CPU to execute 'stop_this_cpu()'.
 513  *
 514  * Born on Date: 2002.02.05
 515  *
 516  * Arguments:    NONE
 517  *
 518  * Returns:      void (cannot fail)
 519  *
 520  * Modification log:
 521  * Date       Who Description
 522  * ---------- --- --------------------------------------------------------
 523  *
 524  *==========================================================================*/
 525 void smp_send_stop(void)
 526 {
 527         smp_call_function(stop_this_cpu, NULL, 1, 0);
 528 }
 529
 530 /*==========================================================================*
 531  * Name:         stop_this_cpu
 532  *
 533  * Description:  This routine halt CPU.
 534  *
 535  * Born on Date: 2002.02.05
 536  *
 537  * Arguments:    NONE
 538  *
 539  * Returns:      void (cannot fail)
 540  *
 541  * Modification log:
 542  * Date       Who Description
 543  * ---------- --- --------------------------------------------------------
 544  *
 545  *==========================================================================*/
 546 static void stop_this_cpu(void *dummy)
 547 {
 548         int cpu_id = smp_processor_id();
 549
 550         /*
 551          * Remove this CPU:
 552          */
 553         cpu_clear(cpu_id, cpu_online_map);
 554
 555         /*
 556          * PSW IE = 1;
 557          * IMASK = 0;
 558          * goto SLEEP
 559          */
 560         local_irq_disable();
 561         outl(0, M32R_ICU_IMASK_PORTL);
 562         inl(M32R_ICU_IMASK_PORTL);      /* dummy read */
 563         local_irq_enable();
 564
 565         for ( ; ; );
 566 }
 567
 568 /*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
 569 /* Call function Routins                                                     */
 570 /*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
 571
 572 /*==========================================================================*
 573  * Name:         smp_call_function
 574  *
 575  * Description:  This routine sends a 'CALL_FUNCTION_IPI' to all other CPUs
 576  *               in the system.
 577  *
 578  * Born on Date: 2002.02.05
 579  *
 580  * Arguments:    *func - The function to run. This must be fast and
 581  *                       non-blocking.
 582  *               *info - An arbitrary pointer to pass to the function.
 583  *               nonatomic - currently unused.
 584  *               wait - If true, wait (atomically) until function has
 585  *                      completed on other CPUs.
 586  *
 587  * Returns:      0 on success, else a negative status code. Does not return
 588  *               until remote CPUs are nearly ready to execute <<func>> or
 589  *               are or have executed.
 590  *
 591  * Cautions:     You must not call this function with disabled interrupts or
 592  *               from a hardware interrupt handler, you may call it from a
 593  *               bottom half handler.
 594  *
 595  * Modification log:
 596  * Date       Who Description
 597  * ---------- --- --------------------------------------------------------
 598  *
 599  *==========================================================================*/
 600 int smp_call_function(void (*func) (void *info), void *info, int nonatomic,
 601         int wait)
 602 {
 603         struct call_data_struct data;
 604         int cpus;
 605
 606 #ifdef DEBUG_SMP
 607         unsigned long flags;
 608         __save_flags(flags);
 609         if (!(flags & 0x0040))  /* Interrupt Disable NONONO */
 610                 BUG();
 611 #endif /* DEBUG_SMP */
 612
 613         /* Holding any lock stops cpus from going down. */
 614         spin_lock(&call_lock);
 615         cpus = num_online_cpus() - 1;
 616
 617         if (!cpus) {
 618                 spin_unlock(&call_lock);
 619                 return 0;
 620         }
 621
 622         /* Can deadlock when called with interrupts disabled */
 623         WARN_ON(irqs_disabled());
 624
 625         data.func = func;
 626         data.info = info;
 627         atomic_set(&data.started, 0);
 628         data.wait = wait;
 629         if (wait)
 630                 atomic_set(&data.finished, 0);
 631
 632         call_data = &data;
 633         mb();
 634
 635         /* Send a message to all other CPUs and wait for them to respond */
 636         send_IPI_allbutself(CALL_FUNCTION_IPI, 0);
 637
 638         /* Wait for response */
 639         while (atomic_read(&data.started) != cpus)
 640                 barrier();
 641
 642         if (wait)
 643                 while (atomic_read(&data.finished) != cpus)
 644                         barrier();
 645         spin_unlock(&call_lock);
 646
 647         return 0;
 648 }
 649
 650 /*==========================================================================*
 651  * Name:         smp_call_function_interrupt
 652  *
 653  * Description:  This routine executes on CPU which received
 654  *               'CALL_FUNCTION_IPI'.
 655  *
 656  * Born on Date: 2002.02.05
 657  *
 658  * Arguments:    NONE
 659  *
 660  * Returns:      void (cannot fail)
 661  *
 662  * Modification log:
 663  * Date       Who Description
 664  * ---------- --- --------------------------------------------------------
 665  *
 666  *==========================================================================*/
 667 void smp_call_function_interrupt(void)
 668 {
 669         void (*func) (void *info) = call_data->func;
 670         void *info = call_data->info;
 671         int wait = call_data->wait;
 672
 673         /*
 674          * Notify initiating CPU that I've grabbed the data and am
 675          * about to execute the function
 676          */
 677         mb();
 678         atomic_inc(&call_data->started);
 679         /*
 680          * At this point the info structure may be out of scope unless wait==1
 681          */
 682         irq_enter();
 683         (*func)(info);
 684         irq_exit();
 685
 686         if (wait) {
 687                 mb();
 688                 atomic_inc(&call_data->finished);
 689         }
 690 }
 691
 692 /*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
 693 /* Timer Routins                                                             */
 694 /*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
 695
 696 /*==========================================================================*
 697  * Name:         smp_send_timer
 698  *
 699  * Description:  This routine sends a 'LOCAL_TIMER_IPI' to all other CPUs
 700  *               in the system.
 701  *
 702  * Born on Date: 2002.02.05
 703  *
 704  * Arguments:    NONE
 705  *
 706  * Returns:      void (cannot fail)
 707  *
 708  * Modification log:
 709  * Date       Who Description
 710  * ---------- --- --------------------------------------------------------
 711  *
 712  *==========================================================================*/
 713 void smp_send_timer(void)
 714 {
 715         send_IPI_allbutself(LOCAL_TIMER_IPI, 1);
 716 }
 717
 718 /*==========================================================================*
 719  * Name:         smp_send_timer
 720  *
 721  * Description:  This routine executes on CPU which received
 722  *               'LOCAL_TIMER_IPI'.
 723  *
 724  * Born on Date: 2002.02.05
 725  *
 726  * Arguments:    *regs - a pointer to the saved regster info
 727  *
 728  * Returns:      void (cannot fail)
 729  *
 730  * Modification log:
 731  * Date       Who Description
 732  * ---------- --- --------------------------------------------------------
 733  *
 734  *==========================================================================*/
 735 void smp_ipi_timer_interrupt(struct pt_regs *regs)
 736 {
 737         struct pt_regs *old_regs;
 738         old_regs = set_irq_regs(regs);
 739         irq_enter();
 740         smp_local_timer_interrupt();
 741         irq_exit();
 742         set_irq_regs(old_regs);
 743 }
 744
 745 /*==========================================================================*
 746  * Name:         smp_local_timer_interrupt
 747  *
 748  * Description:  Local timer interrupt handler. It does both profiling and
 749  *               process statistics/rescheduling.
 750  *               We do profiling in every local tick, statistics/rescheduling
 751  *               happen only every 'profiling multiplier' ticks. The default
 752  *               multiplier is 1 and it can be changed by writing the new
 753  *               multiplier value into /proc/profile.
 754  *
 755  * Born on Date: 2002.02.05
 756  *
 757  * Arguments:    *regs - a pointer to the saved regster info
 758  *
 759  * Returns:      void (cannot fail)
 760  *
 761  * Original:     arch/i386/kernel/apic.c
 762  *
 763  * Modification log:
 764  * Date       Who Description
 765  * ---------- --- --------------------------------------------------------
 766  * 2003-06-24 hy  use per_cpu structure.
 767  *==========================================================================*/
 768 void smp_local_timer_interrupt(void)
 769 {
 770         int user = user_mode(get_irq_regs());
 771         int cpu_id = smp_processor_id();
 772
 773         /*
 774          * The profiling function is SMP safe. (nothing can mess
 775          * around with "current", and the profiling counters are
 776          * updated with atomic operations). This is especially
 777          * useful with a profiling multiplier != 1
 778          */
 779
 780         profile_tick(CPU_PROFILING);
 781
 782         if (--per_cpu(prof_counter, cpu_id) <= 0) {
 783                 /*
 784                  * The multiplier may have changed since the last time we got
 785                  * to this point as a result of the user writing to
 786                  * /proc/profile. In this case we need to adjust the APIC
 787                  * timer accordingly.
 788                  *
 789                  * Interrupts are already masked off at this point.
 790                  */
 791                 per_cpu(prof_counter, cpu_id)
 792                         = per_cpu(prof_multiplier, cpu_id);
 793                 if (per_cpu(prof_counter, cpu_id)
 794                         != per_cpu(prof_old_multiplier, cpu_id))
 795                 {
 796                         per_cpu(prof_old_multiplier, cpu_id)
 797                                 = per_cpu(prof_counter, cpu_id);
 798                 }
 799
 800                 update_process_times(user);
 801         }
 802 }
 803
 804 /*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
 805 /* Send IPI Routins                                                          */
 806 /*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
 807
 808 /*==========================================================================*
 809  * Name:         send_IPI_allbutself
 810  *
 811  * Description:  This routine sends a IPI to all other CPUs in the system.
 812  *
 813  * Born on Date: 2002.02.05
 814  *
 815  * Arguments:    ipi_num - Number of IPI
 816  *               try -  0 : Send IPI certainly.
 817  *                     !0 : The following IPI is not sended when Target CPU
 818  *                          has not received the before IPI.
 819  *
 820  * Returns:      void (cannot fail)
 821  *
 822  * Modification log:
 823  * Date       Who Description
 824  * ---------- --- --------------------------------------------------------
 825  *
 826  *==========================================================================*/
 827 void send_IPI_allbutself(int ipi_num, int try)
 828 {
 829         cpumask_t cpumask;
 830
 831         cpumask = cpu_online_map;
 832         cpu_clear(smp_processor_id(), cpumask);
 833
 834         send_IPI_mask(cpumask, ipi_num, try);
 835 }
 836
 837 /*==========================================================================*
 838  * Name:         send_IPI_mask
 839  *
 840  * Description:  This routine sends a IPI to CPUs in the system.
 841  *
 842  * Born on Date: 2002.02.05
 843  *
 844  * Arguments:    cpu_mask - Bitmap of target CPUs logical ID
 845  *               ipi_num - Number of IPI
 846  *               try -  0 : Send IPI certainly.
 847  *                     !0 : The following IPI is not sended when Target CPU
 848  *                          has not received the before IPI.
 849  *
 850  * Returns:      void (cannot fail)
 851  *
 852  * Modification log:
 853  * Date       Who Description
 854  * ---------- --- --------------------------------------------------------
 855  *
 856  *==========================================================================*/
 857 static void send_IPI_mask(cpumask_t cpumask, int ipi_num, int try)
 858 {
 859         cpumask_t physid_mask, tmp;
 860         int cpu_id, phys_id;
 861         int num_cpus = num_online_cpus();
 862
 863         if (num_cpus <= 1)      /* NO MP */
 864                 return;
 865
 866         cpus_and(tmp, cpumask, cpu_online_map);
 867         BUG_ON(!cpus_equal(cpumask, tmp));
 868
 869         physid_mask = CPU_MASK_NONE;
 870         for_each_cpu_mask(cpu_id, cpumask){
 871                 if ((phys_id = cpu_to_physid(cpu_id)) != -1)
 872                         cpu_set(phys_id, physid_mask);
 873         }
 874
 875         send_IPI_mask_phys(physid_mask, ipi_num, try);
 876 }
 877
 878 /*==========================================================================*
 879  * Name:         send_IPI_mask_phys
 880  *
 881  * Description:  This routine sends a IPI to other CPUs in the system.
 882  *
 883  * Born on Date: 2002.02.05
 884  *
 885  * Arguments:    cpu_mask - Bitmap of target CPUs physical ID
 886  *               ipi_num - Number of IPI
 887  *               try -  0 : Send IPI certainly.
 888  *                     !0 : The following IPI is not sended when Target CPU
 889  *                          has not received the before IPI.
 890  *
 891  * Returns:      IPICRi regster value.
 892  *
 893  * Modification log:
 894  * Date       Who Description
 895  * ---------- --- --------------------------------------------------------
 896  *
 897  *==========================================================================*/
 898 unsigned long send_IPI_mask_phys(cpumask_t physid_mask, int ipi_num,
 899         int try)
 900 {
 901         spinlock_t *ipilock;
 902         volatile unsigned long *ipicr_addr;
 903         unsigned long ipicr_val;
 904         unsigned long my_physid_mask;
 905         unsigned long mask = cpus_addr(physid_mask)[0];
 906
 907
 908         if (mask & ~physids_coerce(phys_cpu_present_map))
 909                 BUG();
 910         if (ipi_num >= NR_IPIS)
 911                 BUG();
 912
 913         mask <<= IPI_SHIFT;
 914         ipilock = &ipi_lock[ipi_num];
 915         ipicr_addr = (volatile unsigned long *)(M32R_ICU_IPICR_ADDR
 916                 + (ipi_num << 2));
 917         my_physid_mask = ~(1 << smp_processor_id());
 918
 919         /*
 920          * lock ipi_lock[i]
 921          * check IPICRi == 0
 922          * write IPICRi (send IPIi)
 923          * unlock ipi_lock[i]
 924          */
 925         spin_lock(ipilock);
 926         __asm__ __volatile__ (
 927                 ";; CHECK IPICRi == 0           \n\t"
 928                 ".fillinsn                      \n"
 929                 "1:                             \n\t"
 930                 "ld     %0, @%1                 \n\t"
 931                 "and    %0, %4                  \n\t"
 932                 "beqz   %0, 2f                  \n\t"
 933                 "bnez   %3, 3f                  \n\t"
 934                 "bra    1b                      \n\t"
 935                 ";; WRITE IPICRi (send IPIi)    \n\t"
 936                 ".fillinsn                      \n"
 937                 "2:                             \n\t"
 938                 "st     %2, @%1                 \n\t"
 939                 ".fillinsn                      \n"
 940                 "3:                             \n\t"
 941                 : "=&r"(ipicr_val)
 942                 : "r"(ipicr_addr), "r"(mask), "r"(try), "r"(my_physid_mask)
 943                 : "memory"
 944         );
 945         spin_unlock(ipilock);
 946
 947         return ipicr_val;
 948 }