kernel/irq/chip.c

   1 /*
   2  * linux/kernel/irq/chip.c
   3  *
   4  * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
   5  * Copyright (C) 2005-2006, Thomas Gleixner, Russell King
   6  *
   7  * This file contains the core interrupt handling code, for irq-chip
   8  * based architectures.
   9  *
  10  * Detailed information is available in Documentation/DocBook/genericirq
  11  */
  12
  13 #include <linux/irq.h>
  14 #include <linux/msi.h>
  15 #include <linux/module.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/kernel_stat.h>
  18
  19 #include "internals.h"
  20
  21 /**
  22  *      dynamic_irq_init - initialize a dynamically allocated irq
  23  *      @irq:   irq number to initialize
  24  */
  25 void dynamic_irq_init(unsigned int irq)
  26 {
  27         struct irq_desc *desc;
  28         unsigned long flags;
  29
  30         desc = irq_to_desc(irq);
  31         if (!desc) {
  32                 WARN(1, KERN_ERR "Trying to initialize invalid IRQ%d\n", irq);
  33                 return;
  34         }
  35
  36         /* Ensure we don't have left over values from a previous use of this irq */
  37         spin_lock_irqsave(&desc->lock, flags);
  38         desc->status = IRQ_DISABLED;
  39         desc->chip = &no_irq_chip;
  40         desc->handle_irq = handle_bad_irq;
  41         desc->depth = 1;
  42         desc->msi_desc = NULL;
  43         desc->handler_data = NULL;
  44         desc->chip_data = NULL;
  45         desc->action = NULL;
  46         desc->irq_count = 0;
  47         desc->irqs_unhandled = 0;
  48 #ifdef CONFIG_SMP
  49         cpumask_setall(desc->affinity);
  50 #ifdef CONFIG_GENERIC_PENDING_IRQ
  51         cpumask_clear(desc->pending_mask);
  52 #endif
  53 #endif
  54         spin_unlock_irqrestore(&desc->lock, flags);
  55 }
  56
  57 /**
  58  *      dynamic_irq_cleanup - cleanup a dynamically allocated irq
  59  *      @irq:   irq number to initialize
  60  */
  61 void dynamic_irq_cleanup(unsigned int irq)
  62 {
  63         struct irq_desc *desc = irq_to_desc(irq);
  64         unsigned long flags;
  65
  66         if (!desc) {
  67                 WARN(1, KERN_ERR "Trying to cleanup invalid IRQ%d\n", irq);
  68                 return;
  69         }
  70
  71         spin_lock_irqsave(&desc->lock, flags);
  72         if (desc->action) {
  73                 spin_unlock_irqrestore(&desc->lock, flags);
  74                 WARN(1, KERN_ERR "Destroying IRQ%d without calling free_irq\n",
  75                         irq);
  76                 return;
  77         }
  78         desc->msi_desc = NULL;
  79         desc->handler_data = NULL;
  80         desc->chip_data = NULL;
  81         desc->handle_irq = handle_bad_irq;
  82         desc->chip = &no_irq_chip;
  83         desc->name = NULL;
  84         clear_kstat_irqs(desc);
  85         spin_unlock_irqrestore(&desc->lock, flags);
  86 }
  87
  88
  89 /**
  90  *      set_irq_chip - set the irq chip for an irq
  91  *      @irq:   irq number
  92  *      @chip:  pointer to irq chip description structure
  93  */
  94 int set_irq_chip(unsigned int irq, struct irq_chip *chip)
  95 {
  96         struct irq_desc *desc = irq_to_desc(irq);
  97         unsigned long flags;
  98
  99         if (!desc) {
 100                 WARN(1, KERN_ERR "Trying to install chip for IRQ%d\n", irq);
 101                 return -EINVAL;
 102         }
 103
 104         if (!chip)
 105                 chip = &no_irq_chip;
 106
 107         spin_lock_irqsave(&desc->lock, flags);
 108         irq_chip_set_defaults(chip);
 109         desc->chip = chip;
 110         spin_unlock_irqrestore(&desc->lock, flags);
 111
 112         return 0;
 113 }
 114 EXPORT_SYMBOL(set_irq_chip);
 115
 116 /**
 117  *      set_irq_type - set the irq trigger type for an irq
 118  *      @irq:   irq number
 119  *      @type:  IRQ_TYPE_{LEVEL,EDGE}_* value - see include/linux/irq.h
 120  */
 121 int set_irq_type(unsigned int irq, unsigned int type)
 122 {
 123         struct irq_desc *desc = irq_to_desc(irq);
 124         unsigned long flags;
 125         int ret = -ENXIO;
 126
 127         if (!desc) {
 128                 printk(KERN_ERR "Trying to set irq type for IRQ%d\n", irq);
 129                 return -ENODEV;
 130         }
 131
 132         type &= IRQ_TYPE_SENSE_MASK;
 133         if (type == IRQ_TYPE_NONE)
 134                 return 0;
 135
 136         spin_lock_irqsave(&desc->lock, flags);
 137         ret = __irq_set_trigger(desc, irq, type);
 138         spin_unlock_irqrestore(&desc->lock, flags);
 139         return ret;
 140 }
 141 EXPORT_SYMBOL(set_irq_type);
 142
 143 /**
 144  *      set_irq_data - set irq type data for an irq
 145  *      @irq:   Interrupt number
 146  *      @data:  Pointer to interrupt specific data
 147  *
 148  *      Set the hardware irq controller data for an irq
 149  */
 150 int set_irq_data(unsigned int irq, void *data)
 151 {
 152         struct irq_desc *desc = irq_to_desc(irq);
 153         unsigned long flags;
 154
 155         if (!desc) {
 156                 printk(KERN_ERR
 157                        "Trying to install controller data for IRQ%d\n", irq);
 158                 return -EINVAL;
 159         }
 160
 161         spin_lock_irqsave(&desc->lock, flags);
 162         desc->handler_data = data;
 163         spin_unlock_irqrestore(&desc->lock, flags);
 164         return 0;
 165 }
 166 EXPORT_SYMBOL(set_irq_data);
 167
 168 /**
 169  *      set_irq_msi - set MSI descriptor data for an irq
 170  *      @irq:   Interrupt number
 171  *      @entry: Pointer to MSI descriptor data
 172  *
 173  *      Set the MSI descriptor entry for an irq
 174  */
 175 int set_irq_msi(unsigned int irq, struct msi_desc *entry)
 176 {
 177         struct irq_desc *desc = irq_to_desc(irq);
 178         unsigned long flags;
 179
 180         if (!desc) {
 181                 printk(KERN_ERR
 182                        "Trying to install msi data for IRQ%d\n", irq);
 183                 return -EINVAL;
 184         }
 185
 186         spin_lock_irqsave(&desc->lock, flags);
 187         desc->msi_desc = entry;
 188         if (entry)
 189                 entry->irq = irq;
 190         spin_unlock_irqrestore(&desc->lock, flags);
 191         return 0;
 192 }
 193
 194 /**
 195  *      set_irq_chip_data - set irq chip data for an irq
 196  *      @irq:   Interrupt number
 197  *      @data:  Pointer to chip specific data
 198  *
 199  *      Set the hardware irq chip data for an irq
 200  */
 201 int set_irq_chip_data(unsigned int irq, void *data)
 202 {
 203         struct irq_desc *desc = irq_to_desc(irq);
 204         unsigned long flags;
 205
 206         if (!desc) {
 207                 printk(KERN_ERR
 208                        "Trying to install chip data for IRQ%d\n", irq);
 209                 return -EINVAL;
 210         }
 211
 212         if (!desc->chip) {
 213                 printk(KERN_ERR "BUG: bad set_irq_chip_data(IRQ#%d)\n", irq);
 214                 return -EINVAL;
 215         }
 216
 217         spin_lock_irqsave(&desc->lock, flags);
 218         desc->chip_data = data;
 219         spin_unlock_irqrestore(&desc->lock, flags);
 220
 221         return 0;
 222 }
 223 EXPORT_SYMBOL(set_irq_chip_data);
 224
 225 /**
 226  *      set_irq_nested_thread - Set/Reset the IRQ_NESTED_THREAD flag of an irq
 227  *
 228  *      @irq:   Interrupt number
 229  *      @nest:  0 to clear / 1 to set the IRQ_NESTED_THREAD flag
 230  *
 231  *      The IRQ_NESTED_THREAD flag indicates that on
 232  *      request_threaded_irq() no separate interrupt thread should be
 233  *      created for the irq as the handler are called nested in the
 234  *      context of a demultiplexing interrupt handler thread.
 235  */
 236 void set_irq_nested_thread(unsigned int irq, int nest)
 237 {
 238         struct irq_desc *desc = irq_to_desc(irq);
 239         unsigned long flags;
 240
 241         if (!desc)
 242                 return;
 243
 244         spin_lock_irqsave(&desc->lock, flags);
 245         if (nest)
 246                 desc->status |= IRQ_NESTED_THREAD;
 247         else
 248                 desc->status &= ~IRQ_NESTED_THREAD;
 249         spin_unlock_irqrestore(&desc->lock, flags);
 250 }
 251 EXPORT_SYMBOL_GPL(set_irq_nested_thread);
 252
 253 /*
 254  * default enable function
 255  */
 256 static void default_enable(unsigned int irq)
 257 {
 258         struct irq_desc *desc = irq_to_desc(irq);
 259
 260         desc->chip->unmask(irq);
 261         desc->status &= ~IRQ_MASKED;
 262 }
 263
 264 /*
 265  * default disable function
 266  */
 267 static void default_disable(unsigned int irq)
 268 {
 269 }
 270
 271 /*
 272  * default startup function
 273  */
 274 static unsigned int default_startup(unsigned int irq)
 275 {
 276         struct irq_desc *desc = irq_to_desc(irq);
 277
 278         desc->chip->enable(irq);
 279         return 0;
 280 }
 281
 282 /*
 283  * default shutdown function
 284  */
 285 static void default_shutdown(unsigned int irq)
 286 {
 287         struct irq_desc *desc = irq_to_desc(irq);
 288
 289         desc->chip->mask(irq);
 290         desc->status |= IRQ_MASKED;
 291 }
 292
 293 /*
 294  * Fixup enable/disable function pointers
 295  */
 296 void irq_chip_set_defaults(struct irq_chip *chip)
 297 {
 298         if (!chip->enable)
 299                 chip->enable = default_enable;
 300         if (!chip->disable)
 301                 chip->disable = default_disable;
 302         if (!chip->startup)
 303                 chip->startup = default_startup;
 304         /*
 305          * We use chip->disable, when the user provided its own. When
 306          * we have default_disable set for chip->disable, then we need
 307          * to use default_shutdown, otherwise the irq line is not
 308          * disabled on free_irq():
 309          */
 310         if (!chip->shutdown)
 311                 chip->shutdown = chip->disable != default_disable ?
 312                         chip->disable : default_shutdown;
 313         if (!chip->name)
 314                 chip->name = chip->typename;
 315         if (!chip->end)
 316                 chip->end = dummy_irq_chip.end;
 317 }
 318
 319 static inline void mask_ack_irq(struct irq_desc *desc, int irq)
 320 {
 321         if (desc->chip->mask_ack)
 322                 desc->chip->mask_ack(irq);
 323         else {
 324                 desc->chip->mask(irq);
 325                 if (desc->chip->ack)
 326                         desc->chip->ack(irq);
 327         }
 328 }
 329
 330 /*
 331  *      handle_nested_irq - Handle a nested irq from a irq thread
 332  *      @irq:   the interrupt number
 333  *
 334  *      Handle interrupts which are nested into a threaded interrupt
 335  *      handler. The handler function is called inside the calling
 336  *      threads context.
 337  */
 338 void handle_nested_irq(unsigned int irq)
 339 {
 340         struct irq_desc *desc = irq_to_desc(irq);
 341         struct irqaction *action;
 342         irqreturn_t action_ret;
 343
 344         might_sleep();
 345
 346         spin_lock_irq(&desc->lock);
 347
 348         kstat_incr_irqs_this_cpu(irq, desc);
 349
 350         action = desc->action;
 351         if (unlikely(!action || (desc->status & IRQ_DISABLED)))
 352                 goto out_unlock;
 353
 354         desc->status |= IRQ_INPROGRESS;
 355         spin_unlock_irq(&desc->lock);
 356
 357         action_ret = action->thread_fn(action->irq, action->dev_id);
 358         if (!noirqdebug)
 359                 note_interrupt(irq, desc, action_ret);
 360
 361         spin_lock_irq(&desc->lock);
 362         desc->status &= ~IRQ_INPROGRESS;
 363
 364 out_unlock:
 365         spin_unlock_irq(&desc->lock);
 366 }
 367 EXPORT_SYMBOL_GPL(handle_nested_irq);
 368
 369 /**
 370  *      handle_simple_irq - Simple and software-decoded IRQs.
 371  *      @irq:   the interrupt number
 372  *      @desc:  the interrupt description structure for this irq
 373  *
 374  *      Simple interrupts are either sent from a demultiplexing interrupt
 375  *      handler or come from hardware, where no interrupt hardware control
 376  *      is necessary.
 377  *
 378  *      Note: The caller is expected to handle the ack, clear, mask and
 379  *      unmask issues if necessary.
 380  */
 381 void
 382 handle_simple_irq(unsigned int irq, struct irq_desc *desc)
 383 {
 384         struct irqaction *action;
 385         irqreturn_t action_ret;
 386
 387         spin_lock(&desc->lock);
 388
 389         if (unlikely(desc->status & IRQ_INPROGRESS))
 390                 goto out_unlock;
 391         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
 392         kstat_incr_irqs_this_cpu(irq, desc);
 393
 394         action = desc->action;
 395         if (unlikely(!action || (desc->status & IRQ_DISABLED)))
 396                 goto out_unlock;
 397
 398         desc->status |= IRQ_INPROGRESS;
 399         spin_unlock(&desc->lock);
 400
 401         action_ret = handle_IRQ_event(irq, action);
 402         if (!noirqdebug)
 403                 note_interrupt(irq, desc, action_ret);
 404
 405         spin_lock(&desc->lock);
 406         desc->status &= ~IRQ_INPROGRESS;
 407 out_unlock:
 408         spin_unlock(&desc->lock);
 409 }
 410
 411 /**
 412  *      handle_level_irq - Level type irq handler
 413  *      @irq:   the interrupt number
 414  *      @desc:  the interrupt description structure for this irq
 415  *
 416  *      Level type interrupts are active as long as the hardware line has
 417  *      the active level. This may require to mask the interrupt and unmask
 418  *      it after the associated handler has acknowledged the device, so the
 419  *      interrupt line is back to inactive.
 420  */
 421 void
 422 handle_level_irq(unsigned int irq, struct irq_desc *desc)
 423 {
 424         struct irqaction *action;
 425         irqreturn_t action_ret;
 426
 427         spin_lock(&desc->lock);
 428         mask_ack_irq(desc, irq);
 429
 430         if (unlikely(desc->status & IRQ_INPROGRESS))
 431                 goto out_unlock;
 432         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
 433         kstat_incr_irqs_this_cpu(irq, desc);
 434
 435         /*
 436          * If its disabled or no action available
 437          * keep it masked and get out of here
 438          */
 439         action = desc->action;
 440         if (unlikely(!action || (desc->status & IRQ_DISABLED)))
 441                 goto out_unlock;
 442
 443         desc->status |= IRQ_INPROGRESS;
 444         spin_unlock(&desc->lock);
 445
 446         action_ret = handle_IRQ_event(irq, action);
 447         if (!noirqdebug)
 448                 note_interrupt(irq, desc, action_ret);
 449
 450         spin_lock(&desc->lock);
 451         desc->status &= ~IRQ_INPROGRESS;
 452
 453         if (unlikely(desc->status & IRQ_ONESHOT))
 454                 desc->status |= IRQ_MASKED;
 455         else if (!(desc->status & IRQ_DISABLED) && desc->chip->unmask)
 456                 desc->chip->unmask(irq);
 457 out_unlock:
 458         spin_unlock(&desc->lock);
 459 }
 460 EXPORT_SYMBOL_GPL(handle_level_irq);
 461
 462 /**
 463  *      handle_fasteoi_irq - irq handler for transparent controllers
 464  *      @irq:   the interrupt number
 465  *      @desc:  the interrupt description structure for this irq
 466  *
 467  *      Only a single callback will be issued to the chip: an ->eoi()
 468  *      call when the interrupt has been serviced. This enables support
 469  *      for modern forms of interrupt handlers, which handle the flow
 470  *      details in hardware, transparently.
 471  */
 472 void
 473 handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc)
 474 {
 475         struct irqaction *action;
 476         irqreturn_t action_ret;
 477
 478         spin_lock(&desc->lock);
 479
 480         if (unlikely(desc->status & IRQ_INPROGRESS))
 481                 goto out;
 482
 483         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
 484         kstat_incr_irqs_this_cpu(irq, desc);
 485
 486         /*
 487          * If its disabled or no action available
 488          * then mask it and get out of here:
 489          */
 490         action = desc->action;
 491         if (unlikely(!action || (desc->status & IRQ_DISABLED))) {
 492                 desc->status |= IRQ_PENDING;
 493                 if (desc->chip->mask)
 494                         desc->chip->mask(irq);
 495                 goto out;
 496         }
 497
 498         desc->status |= IRQ_INPROGRESS;
 499         desc->status &= ~IRQ_PENDING;
 500         spin_unlock(&desc->lock);
 501
 502         action_ret = handle_IRQ_event(irq, action);
 503         if (!noirqdebug)
 504                 note_interrupt(irq, desc, action_ret);
 505
 506         spin_lock(&desc->lock);
 507         desc->status &= ~IRQ_INPROGRESS;
 508 out:
 509         desc->chip->eoi(irq);
 510
 511         spin_unlock(&desc->lock);
 512 }
 513
 514 /**
 515  *      handle_edge_irq - edge type IRQ handler
 516  *      @irq:   the interrupt number
 517  *      @desc:  the interrupt description structure for this irq
 518  *
 519  *      Interrupt occures on the falling and/or rising edge of a hardware
 520  *      signal. The occurence is latched into the irq controller hardware
 521  *      and must be acked in order to be reenabled. After the ack another
 522  *      interrupt can happen on the same source even before the first one
 523  *      is handled by the assosiacted event handler. If this happens it
 524  *      might be necessary to disable (mask) the interrupt depending on the
 525  *      controller hardware. This requires to reenable the interrupt inside
 526  *      of the loop which handles the interrupts which have arrived while
 527  *      the handler was running. If all pending interrupts are handled, the
 528  *      loop is left.
 529  */
 530 void
 531 handle_edge_irq(unsigned int irq, struct irq_desc *desc)
 532 {
 533         spin_lock(&desc->lock);
 534
 535         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
 536
 537         /*
 538          * If we're currently running this IRQ, or its disabled,
 539          * we shouldn't process the IRQ. Mark it pending, handle
 540          * the necessary masking and go out
 541          */
 542         if (unlikely((desc->status & (IRQ_INPROGRESS | IRQ_DISABLED)) ||
 543                     !desc->action)) {
 544                 desc->status |= (IRQ_PENDING | IRQ_MASKED);
 545                 mask_ack_irq(desc, irq);
 546                 goto out_unlock;
 547         }
 548         kstat_incr_irqs_this_cpu(irq, desc);
 549
 550         /* Start handling the irq */
 551         if (desc->chip->ack)
 552                 desc->chip->ack(irq);
 553
 554         /* Mark the IRQ currently in progress.*/
 555         desc->status |= IRQ_INPROGRESS;
 556
 557         do {
 558                 struct irqaction *action = desc->action;
 559                 irqreturn_t action_ret;
 560
 561                 if (unlikely(!action)) {
 562                         desc->chip->mask(irq);
 563                         goto out_unlock;
 564                 }
 565
 566                 /*
 567                  * When another irq arrived while we were handling
 568                  * one, we could have masked the irq.
 569                  * Renable it, if it was not disabled in meantime.
 570                  */
 571                 if (unlikely((desc->status &
 572                                (IRQ_PENDING | IRQ_MASKED | IRQ_DISABLED)) ==
 573                               (IRQ_PENDING | IRQ_MASKED))) {
 574                         desc->chip->unmask(irq);
 575                         desc->status &= ~IRQ_MASKED;
 576                 }
 577
 578                 desc->status &= ~IRQ_PENDING;
 579                 spin_unlock(&desc->lock);
 580                 action_ret = handle_IRQ_event(irq, action);
 581                 if (!noirqdebug)
 582                         note_interrupt(irq, desc, action_ret);
 583                 spin_lock(&desc->lock);
 584
 585         } while ((desc->status & (IRQ_PENDING | IRQ_DISABLED)) == IRQ_PENDING);
 586
 587         desc->status &= ~IRQ_INPROGRESS;
 588 out_unlock:
 589         spin_unlock(&desc->lock);
 590 }
 591
 592 /**
 593  *      handle_percpu_irq - Per CPU local irq handler
 594  *      @irq:   the interrupt number
 595  *      @desc:  the interrupt description structure for this irq
 596  *
 597  *      Per CPU interrupts on SMP machines without locking requirements
 598  */
 599 void
 600 handle_percpu_irq(unsigned int irq, struct irq_desc *desc)
 601 {
 602         irqreturn_t action_ret;
 603
 604         kstat_incr_irqs_this_cpu(irq, desc);
 605
 606         if (desc->chip->ack)
 607                 desc->chip->ack(irq);
 608
 609         action_ret = handle_IRQ_event(irq, desc->action);
 610         if (!noirqdebug)
 611                 note_interrupt(irq, desc, action_ret);
 612
 613         if (desc->chip->eoi)
 614                 desc->chip->eoi(irq);
 615 }
 616
 617 void
 618 __set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
 619                   const char *name)
 620 {
 621         struct irq_desc *desc = irq_to_desc(irq);
 622         unsigned long flags;
 623
 624         if (!desc) {
 625                 printk(KERN_ERR
 626                        "Trying to install type control for IRQ%d\n", irq);
 627                 return;
 628         }
 629
 630         if (!handle)
 631                 handle = handle_bad_irq;
 632         else if (desc->chip == &no_irq_chip) {
 633                 printk(KERN_WARNING "Trying to install %sinterrupt handler "
 634                        "for IRQ%d\n", is_chained ? "chained " : "", irq);
 635                 /*
 636                  * Some ARM implementations install a handler for really dumb
 637                  * interrupt hardware without setting an irq_chip. This worked
 638                  * with the ARM no_irq_chip but the check in setup_irq would
 639                  * prevent us to setup the interrupt at all. Switch it to
 640                  * dummy_irq_chip for easy transition.
 641                  */
 642                 desc->chip = &dummy_irq_chip;
 643         }
 644
 645         chip_bus_lock(irq, desc);
 646         spin_lock_irqsave(&desc->lock, flags);
 647
 648         /* Uninstall? */
 649         if (handle == handle_bad_irq) {
 650                 if (desc->chip != &no_irq_chip)
 651                         mask_ack_irq(desc, irq);
 652                 desc->status |= IRQ_DISABLED;
 653                 desc->depth = 1;
 654         }
 655         desc->handle_irq = handle;
 656         desc->name = name;
 657
 658         if (handle != handle_bad_irq && is_chained) {
 659                 desc->status &= ~IRQ_DISABLED;
 660                 desc->status |= IRQ_NOREQUEST | IRQ_NOPROBE;
 661                 desc->depth = 0;
 662                 desc->chip->startup(irq);
 663         }
 664         spin_unlock_irqrestore(&desc->lock, flags);
 665         chip_bus_sync_unlock(irq, desc);
 666 }
 667 EXPORT_SYMBOL_GPL(__set_irq_handler);
 668
 669 void
 670 set_irq_chip_and_handler(unsigned int irq, struct irq_chip *chip,
 671                          irq_flow_handler_t handle)
 672 {
 673         set_irq_chip(irq, chip);
 674         __set_irq_handler(irq, handle, 0, NULL);
 675 }
 676
 677 void
 678 set_irq_chip_and_handler_name(unsigned int irq, struct irq_chip *chip,
 679                               irq_flow_handler_t handle, const char *name)
 680 {
 681         set_irq_chip(irq, chip);
 682         __set_irq_handler(irq, handle, 0, name);
 683 }
 684
 685 void __init set_irq_noprobe(unsigned int irq)
 686 {
 687         struct irq_desc *desc = irq_to_desc(irq);
 688         unsigned long flags;
 689
 690         if (!desc) {
 691                 printk(KERN_ERR "Trying to mark IRQ%d non-probeable\n", irq);
 692                 return;
 693         }
 694
 695         spin_lock_irqsave(&desc->lock, flags);
 696         desc->status |= IRQ_NOPROBE;
 697         spin_unlock_irqrestore(&desc->lock, flags);
 698 }
 699
 700 void __init set_irq_probe(unsigned int irq)
 701 {
 702         struct irq_desc *desc = irq_to_desc(irq);
 703         unsigned long flags;
 704
 705         if (!desc) {
 706                 printk(KERN_ERR "Trying to mark IRQ%d probeable\n", irq);
 707                 return;
 708         }
 709
 710         spin_lock_irqsave(&desc->lock, flags);
 711         desc->status &= ~IRQ_NOPROBE;
 712         spin_unlock_irqrestore(&desc->lock, flags);
 713 }