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 static void dynamic_irq_init_x(unsigned int irq, bool keep_chip_data)
  22 {
  23         struct irq_desc *desc;
  24         unsigned long flags;
  25
  26         desc = irq_to_desc(irq);
  27         if (!desc) {
  28                 WARN(1, KERN_ERR "Trying to initialize invalid IRQ%d\n", irq);
  29                 return;
  30         }
  31
  32         /* Ensure we don't have left over values from a previous use of this irq */
  33         raw_spin_lock_irqsave(&desc->lock, flags);
  34         desc->status = IRQ_DISABLED;
  35         desc->irq_data.chip = &no_irq_chip;
  36         desc->handle_irq = handle_bad_irq;
  37         desc->depth = 1;
  38         desc->irq_data.msi_desc = NULL;
  39         desc->irq_data.handler_data = NULL;
  40         if (!keep_chip_data)
  41                 desc->irq_data.chip_data = NULL;
  42         desc->action = NULL;
  43         desc->irq_count = 0;
  44         desc->irqs_unhandled = 0;
  45 #ifdef CONFIG_SMP
  46         cpumask_setall(desc->irq_data.affinity);
  47 #ifdef CONFIG_GENERIC_PENDING_IRQ
  48         cpumask_clear(desc->pending_mask);
  49 #endif
  50 #endif
  51         raw_spin_unlock_irqrestore(&desc->lock, flags);
  52 }
  53
  54 /**
  55  *      dynamic_irq_init - initialize a dynamically allocated irq
  56  *      @irq:   irq number to initialize
  57  */
  58 void dynamic_irq_init(unsigned int irq)
  59 {
  60         dynamic_irq_init_x(irq, false);
  61 }
  62
  63 /**
  64  *      dynamic_irq_init_keep_chip_data - initialize a dynamically allocated irq
  65  *      @irq:   irq number to initialize
  66  *
  67  *      does not set irq_to_desc(irq)->irq_data.chip_data to NULL
  68  */
  69 void dynamic_irq_init_keep_chip_data(unsigned int irq)
  70 {
  71         dynamic_irq_init_x(irq, true);
  72 }
  73
  74 static void dynamic_irq_cleanup_x(unsigned int irq, bool keep_chip_data)
  75 {
  76         struct irq_desc *desc = irq_to_desc(irq);
  77         unsigned long flags;
  78
  79         if (!desc) {
  80                 WARN(1, KERN_ERR "Trying to cleanup invalid IRQ%d\n", irq);
  81                 return;
  82         }
  83
  84         raw_spin_lock_irqsave(&desc->lock, flags);
  85         if (desc->action) {
  86                 raw_spin_unlock_irqrestore(&desc->lock, flags);
  87                 WARN(1, KERN_ERR "Destroying IRQ%d without calling free_irq\n",
  88                         irq);
  89                 return;
  90         }
  91         desc->irq_data.msi_desc = NULL;
  92         desc->irq_data.handler_data = NULL;
  93         if (!keep_chip_data)
  94                 desc->irq_data.chip_data = NULL;
  95         desc->handle_irq = handle_bad_irq;
  96         desc->irq_data.chip = &no_irq_chip;
  97         desc->name = NULL;
  98         clear_kstat_irqs(desc);
  99         raw_spin_unlock_irqrestore(&desc->lock, flags);
 100 }
 101
 102 /**
 103  *      dynamic_irq_cleanup - cleanup a dynamically allocated irq
 104  *      @irq:   irq number to initialize
 105  */
 106 void dynamic_irq_cleanup(unsigned int irq)
 107 {
 108         dynamic_irq_cleanup_x(irq, false);
 109 }
 110
 111 /**
 112  *      dynamic_irq_cleanup_keep_chip_data - cleanup a dynamically allocated irq
 113  *      @irq:   irq number to initialize
 114  *
 115  *      does not set irq_to_desc(irq)->irq_data.chip_data to NULL
 116  */
 117 void dynamic_irq_cleanup_keep_chip_data(unsigned int irq)
 118 {
 119         dynamic_irq_cleanup_x(irq, true);
 120 }
 121
 122
 123 /**
 124  *      set_irq_chip - set the irq chip for an irq
 125  *      @irq:   irq number
 126  *      @chip:  pointer to irq chip description structure
 127  */
 128 int set_irq_chip(unsigned int irq, struct irq_chip *chip)
 129 {
 130         struct irq_desc *desc = irq_to_desc(irq);
 131         unsigned long flags;
 132
 133         if (!desc) {
 134                 WARN(1, KERN_ERR "Trying to install chip for IRQ%d\n", irq);
 135                 return -EINVAL;
 136         }
 137
 138         if (!chip)
 139                 chip = &no_irq_chip;
 140
 141         raw_spin_lock_irqsave(&desc->lock, flags);
 142         irq_chip_set_defaults(chip);
 143         desc->irq_data.chip = chip;
 144         raw_spin_unlock_irqrestore(&desc->lock, flags);
 145
 146         return 0;
 147 }
 148 EXPORT_SYMBOL(set_irq_chip);
 149
 150 /**
 151  *      set_irq_type - set the irq trigger type for an irq
 152  *      @irq:   irq number
 153  *      @type:  IRQ_TYPE_{LEVEL,EDGE}_* value - see include/linux/irq.h
 154  */
 155 int set_irq_type(unsigned int irq, unsigned int type)
 156 {
 157         struct irq_desc *desc = irq_to_desc(irq);
 158         unsigned long flags;
 159         int ret = -ENXIO;
 160
 161         if (!desc) {
 162                 printk(KERN_ERR "Trying to set irq type for IRQ%d\n", irq);
 163                 return -ENODEV;
 164         }
 165
 166         type &= IRQ_TYPE_SENSE_MASK;
 167         if (type == IRQ_TYPE_NONE)
 168                 return 0;
 169
 170         raw_spin_lock_irqsave(&desc->lock, flags);
 171         ret = __irq_set_trigger(desc, irq, type);
 172         raw_spin_unlock_irqrestore(&desc->lock, flags);
 173         return ret;
 174 }
 175 EXPORT_SYMBOL(set_irq_type);
 176
 177 /**
 178  *      set_irq_data - set irq type data for an irq
 179  *      @irq:   Interrupt number
 180  *      @data:  Pointer to interrupt specific data
 181  *
 182  *      Set the hardware irq controller data for an irq
 183  */
 184 int set_irq_data(unsigned int irq, void *data)
 185 {
 186         struct irq_desc *desc = irq_to_desc(irq);
 187         unsigned long flags;
 188
 189         if (!desc) {
 190                 printk(KERN_ERR
 191                        "Trying to install controller data for IRQ%d\n", irq);
 192                 return -EINVAL;
 193         }
 194
 195         raw_spin_lock_irqsave(&desc->lock, flags);
 196         desc->irq_data.handler_data = data;
 197         raw_spin_unlock_irqrestore(&desc->lock, flags);
 198         return 0;
 199 }
 200 EXPORT_SYMBOL(set_irq_data);
 201
 202 /**
 203  *      set_irq_msi - set MSI descriptor data for an irq
 204  *      @irq:   Interrupt number
 205  *      @entry: Pointer to MSI descriptor data
 206  *
 207  *      Set the MSI descriptor entry for an irq
 208  */
 209 int set_irq_msi(unsigned int irq, struct msi_desc *entry)
 210 {
 211         struct irq_desc *desc = irq_to_desc(irq);
 212         unsigned long flags;
 213
 214         if (!desc) {
 215                 printk(KERN_ERR
 216                        "Trying to install msi data for IRQ%d\n", irq);
 217                 return -EINVAL;
 218         }
 219
 220         raw_spin_lock_irqsave(&desc->lock, flags);
 221         desc->irq_data.msi_desc = entry;
 222         if (entry)
 223                 entry->irq = irq;
 224         raw_spin_unlock_irqrestore(&desc->lock, flags);
 225         return 0;
 226 }
 227
 228 /**
 229  *      set_irq_chip_data - set irq chip data for an irq
 230  *      @irq:   Interrupt number
 231  *      @data:  Pointer to chip specific data
 232  *
 233  *      Set the hardware irq chip data for an irq
 234  */
 235 int set_irq_chip_data(unsigned int irq, void *data)
 236 {
 237         struct irq_desc *desc = irq_to_desc(irq);
 238         unsigned long flags;
 239
 240         if (!desc) {
 241                 printk(KERN_ERR
 242                        "Trying to install chip data for IRQ%d\n", irq);
 243                 return -EINVAL;
 244         }
 245
 246         if (!desc->irq_data.chip) {
 247                 printk(KERN_ERR "BUG: bad set_irq_chip_data(IRQ#%d)\n", irq);
 248                 return -EINVAL;
 249         }
 250
 251         raw_spin_lock_irqsave(&desc->lock, flags);
 252         desc->irq_data.chip_data = data;
 253         raw_spin_unlock_irqrestore(&desc->lock, flags);
 254
 255         return 0;
 256 }
 257 EXPORT_SYMBOL(set_irq_chip_data);
 258
 259 /**
 260  *      set_irq_nested_thread - Set/Reset the IRQ_NESTED_THREAD flag of an irq
 261  *
 262  *      @irq:   Interrupt number
 263  *      @nest:  0 to clear / 1 to set the IRQ_NESTED_THREAD flag
 264  *
 265  *      The IRQ_NESTED_THREAD flag indicates that on
 266  *      request_threaded_irq() no separate interrupt thread should be
 267  *      created for the irq as the handler are called nested in the
 268  *      context of a demultiplexing interrupt handler thread.
 269  */
 270 void set_irq_nested_thread(unsigned int irq, int nest)
 271 {
 272         struct irq_desc *desc = irq_to_desc(irq);
 273         unsigned long flags;
 274
 275         if (!desc)
 276                 return;
 277
 278         raw_spin_lock_irqsave(&desc->lock, flags);
 279         if (nest)
 280                 desc->status |= IRQ_NESTED_THREAD;
 281         else
 282                 desc->status &= ~IRQ_NESTED_THREAD;
 283         raw_spin_unlock_irqrestore(&desc->lock, flags);
 284 }
 285 EXPORT_SYMBOL_GPL(set_irq_nested_thread);
 286
 287 /*
 288  * default enable function
 289  */
 290 static void default_enable(unsigned int irq)
 291 {
 292         struct irq_desc *desc = irq_to_desc(irq);
 293
 294         desc->irq_data.chip->unmask(irq);
 295         desc->status &= ~IRQ_MASKED;
 296 }
 297
 298 /*
 299  * default disable function
 300  */
 301 static void default_disable(unsigned int irq)
 302 {
 303 }
 304
 305 /*
 306  * default startup function
 307  */
 308 static unsigned int default_startup(unsigned int irq)
 309 {
 310         struct irq_desc *desc = irq_to_desc(irq);
 311
 312         desc->irq_data.chip->enable(irq);
 313         return 0;
 314 }
 315
 316 /*
 317  * default shutdown function
 318  */
 319 static void default_shutdown(unsigned int irq)
 320 {
 321         struct irq_desc *desc = irq_to_desc(irq);
 322
 323         desc->irq_data.chip->irq_mask(&desc->irq_data);
 324         desc->status |= IRQ_MASKED;
 325 }
 326
 327 /* Temporary migration helpers */
 328 static void compat_irq_mask(struct irq_data *data)
 329 {
 330         data->chip->mask(data->irq);
 331 }
 332
 333 static void compat_bus_lock(struct irq_data *data)
 334 {
 335         data->chip->bus_lock(data->irq);
 336 }
 337
 338 static void compat_bus_sync_unlock(struct irq_data *data)
 339 {
 340         data->chip->bus_sync_unlock(data->irq);
 341 }
 342
 343 /*
 344  * Fixup enable/disable function pointers
 345  */
 346 void irq_chip_set_defaults(struct irq_chip *chip)
 347 {
 348         if (!chip->enable)
 349                 chip->enable = default_enable;
 350         if (!chip->disable)
 351                 chip->disable = default_disable;
 352         if (!chip->startup)
 353                 chip->startup = default_startup;
 354         /*
 355          * We use chip->disable, when the user provided its own. When
 356          * we have default_disable set for chip->disable, then we need
 357          * to use default_shutdown, otherwise the irq line is not
 358          * disabled on free_irq():
 359          */
 360         if (!chip->shutdown)
 361                 chip->shutdown = chip->disable != default_disable ?
 362                         chip->disable : default_shutdown;
 363         if (!chip->end)
 364                 chip->end = dummy_irq_chip.end;
 365
 366         if (chip->bus_lock)
 367                 chip->irq_bus_lock = compat_bus_lock;
 368         if (chip->bus_sync_unlock)
 369                 chip->irq_bus_sync_unlock = compat_bus_sync_unlock;
 370
 371         if (chip->mask)
 372                 chip->irq_mask = compat_irq_mask;
 373 }
 374
 375 static inline void mask_ack_irq(struct irq_desc *desc, int irq)
 376 {
 377         if (desc->irq_data.chip->mask_ack)
 378                 desc->irq_data.chip->mask_ack(irq);
 379         else {
 380                 desc->irq_data.chip->irq_mask(&desc->irq_data);
 381                 if (desc->irq_data.chip->ack)
 382                         desc->irq_data.chip->ack(irq);
 383         }
 384         desc->status |= IRQ_MASKED;
 385 }
 386
 387 static inline void mask_irq(struct irq_desc *desc)
 388 {
 389         if (desc->irq_data.chip->irq_mask) {
 390                 desc->irq_data.chip->irq_mask(&desc->irq_data);
 391                 desc->status |= IRQ_MASKED;
 392         }
 393 }
 394
 395 static inline void unmask_irq(struct irq_desc *desc, int irq)
 396 {
 397         if (desc->irq_data.chip->unmask) {
 398                 desc->irq_data.chip->unmask(irq);
 399                 desc->status &= ~IRQ_MASKED;
 400         }
 401 }
 402
 403 /*
 404  *      handle_nested_irq - Handle a nested irq from a irq thread
 405  *      @irq:   the interrupt number
 406  *
 407  *      Handle interrupts which are nested into a threaded interrupt
 408  *      handler. The handler function is called inside the calling
 409  *      threads context.
 410  */
 411 void handle_nested_irq(unsigned int irq)
 412 {
 413         struct irq_desc *desc = irq_to_desc(irq);
 414         struct irqaction *action;
 415         irqreturn_t action_ret;
 416
 417         might_sleep();
 418
 419         raw_spin_lock_irq(&desc->lock);
 420
 421         kstat_incr_irqs_this_cpu(irq, desc);
 422
 423         action = desc->action;
 424         if (unlikely(!action || (desc->status & IRQ_DISABLED)))
 425                 goto out_unlock;
 426
 427         desc->status |= IRQ_INPROGRESS;
 428         raw_spin_unlock_irq(&desc->lock);
 429
 430         action_ret = action->thread_fn(action->irq, action->dev_id);
 431         if (!noirqdebug)
 432                 note_interrupt(irq, desc, action_ret);
 433
 434         raw_spin_lock_irq(&desc->lock);
 435         desc->status &= ~IRQ_INPROGRESS;
 436
 437 out_unlock:
 438         raw_spin_unlock_irq(&desc->lock);
 439 }
 440 EXPORT_SYMBOL_GPL(handle_nested_irq);
 441
 442 /**
 443  *      handle_simple_irq - Simple and software-decoded IRQs.
 444  *      @irq:   the interrupt number
 445  *      @desc:  the interrupt description structure for this irq
 446  *
 447  *      Simple interrupts are either sent from a demultiplexing interrupt
 448  *      handler or come from hardware, where no interrupt hardware control
 449  *      is necessary.
 450  *
 451  *      Note: The caller is expected to handle the ack, clear, mask and
 452  *      unmask issues if necessary.
 453  */
 454 void
 455 handle_simple_irq(unsigned int irq, struct irq_desc *desc)
 456 {
 457         struct irqaction *action;
 458         irqreturn_t action_ret;
 459
 460         raw_spin_lock(&desc->lock);
 461
 462         if (unlikely(desc->status & IRQ_INPROGRESS))
 463                 goto out_unlock;
 464         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
 465         kstat_incr_irqs_this_cpu(irq, desc);
 466
 467         action = desc->action;
 468         if (unlikely(!action || (desc->status & IRQ_DISABLED)))
 469                 goto out_unlock;
 470
 471         desc->status |= IRQ_INPROGRESS;
 472         raw_spin_unlock(&desc->lock);
 473
 474         action_ret = handle_IRQ_event(irq, action);
 475         if (!noirqdebug)
 476                 note_interrupt(irq, desc, action_ret);
 477
 478         raw_spin_lock(&desc->lock);
 479         desc->status &= ~IRQ_INPROGRESS;
 480 out_unlock:
 481         raw_spin_unlock(&desc->lock);
 482 }
 483
 484 /**
 485  *      handle_level_irq - Level type irq handler
 486  *      @irq:   the interrupt number
 487  *      @desc:  the interrupt description structure for this irq
 488  *
 489  *      Level type interrupts are active as long as the hardware line has
 490  *      the active level. This may require to mask the interrupt and unmask
 491  *      it after the associated handler has acknowledged the device, so the
 492  *      interrupt line is back to inactive.
 493  */
 494 void
 495 handle_level_irq(unsigned int irq, struct irq_desc *desc)
 496 {
 497         struct irqaction *action;
 498         irqreturn_t action_ret;
 499
 500         raw_spin_lock(&desc->lock);
 501         mask_ack_irq(desc, irq);
 502
 503         if (unlikely(desc->status & IRQ_INPROGRESS))
 504                 goto out_unlock;
 505         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
 506         kstat_incr_irqs_this_cpu(irq, desc);
 507
 508         /*
 509          * If its disabled or no action available
 510          * keep it masked and get out of here
 511          */
 512         action = desc->action;
 513         if (unlikely(!action || (desc->status & IRQ_DISABLED)))
 514                 goto out_unlock;
 515
 516         desc->status |= IRQ_INPROGRESS;
 517         raw_spin_unlock(&desc->lock);
 518
 519         action_ret = handle_IRQ_event(irq, action);
 520         if (!noirqdebug)
 521                 note_interrupt(irq, desc, action_ret);
 522
 523         raw_spin_lock(&desc->lock);
 524         desc->status &= ~IRQ_INPROGRESS;
 525
 526         if (!(desc->status & (IRQ_DISABLED | IRQ_ONESHOT)))
 527                 unmask_irq(desc, irq);
 528 out_unlock:
 529         raw_spin_unlock(&desc->lock);
 530 }
 531 EXPORT_SYMBOL_GPL(handle_level_irq);
 532
 533 /**
 534  *      handle_fasteoi_irq - irq handler for transparent controllers
 535  *      @irq:   the interrupt number
 536  *      @desc:  the interrupt description structure for this irq
 537  *
 538  *      Only a single callback will be issued to the chip: an ->eoi()
 539  *      call when the interrupt has been serviced. This enables support
 540  *      for modern forms of interrupt handlers, which handle the flow
 541  *      details in hardware, transparently.
 542  */
 543 void
 544 handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc)
 545 {
 546         struct irqaction *action;
 547         irqreturn_t action_ret;
 548
 549         raw_spin_lock(&desc->lock);
 550
 551         if (unlikely(desc->status & IRQ_INPROGRESS))
 552                 goto out;
 553
 554         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
 555         kstat_incr_irqs_this_cpu(irq, desc);
 556
 557         /*
 558          * If its disabled or no action available
 559          * then mask it and get out of here:
 560          */
 561         action = desc->action;
 562         if (unlikely(!action || (desc->status & IRQ_DISABLED))) {
 563                 desc->status |= IRQ_PENDING;
 564                 mask_irq(desc);
 565                 goto out;
 566         }
 567
 568         desc->status |= IRQ_INPROGRESS;
 569         desc->status &= ~IRQ_PENDING;
 570         raw_spin_unlock(&desc->lock);
 571
 572         action_ret = handle_IRQ_event(irq, action);
 573         if (!noirqdebug)
 574                 note_interrupt(irq, desc, action_ret);
 575
 576         raw_spin_lock(&desc->lock);
 577         desc->status &= ~IRQ_INPROGRESS;
 578 out:
 579         desc->irq_data.chip->eoi(irq);
 580
 581         raw_spin_unlock(&desc->lock);
 582 }
 583
 584 /**
 585  *      handle_edge_irq - edge type IRQ handler
 586  *      @irq:   the interrupt number
 587  *      @desc:  the interrupt description structure for this irq
 588  *
 589  *      Interrupt occures on the falling and/or rising edge of a hardware
 590  *      signal. The occurence is latched into the irq controller hardware
 591  *      and must be acked in order to be reenabled. After the ack another
 592  *      interrupt can happen on the same source even before the first one
 593  *      is handled by the associated event handler. If this happens it
 594  *      might be necessary to disable (mask) the interrupt depending on the
 595  *      controller hardware. This requires to reenable the interrupt inside
 596  *      of the loop which handles the interrupts which have arrived while
 597  *      the handler was running. If all pending interrupts are handled, the
 598  *      loop is left.
 599  */
 600 void
 601 handle_edge_irq(unsigned int irq, struct irq_desc *desc)
 602 {
 603         raw_spin_lock(&desc->lock);
 604
 605         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
 606
 607         /*
 608          * If we're currently running this IRQ, or its disabled,
 609          * we shouldn't process the IRQ. Mark it pending, handle
 610          * the necessary masking and go out
 611          */
 612         if (unlikely((desc->status & (IRQ_INPROGRESS | IRQ_DISABLED)) ||
 613                     !desc->action)) {
 614                 desc->status |= (IRQ_PENDING | IRQ_MASKED);
 615                 mask_ack_irq(desc, irq);
 616                 goto out_unlock;
 617         }
 618         kstat_incr_irqs_this_cpu(irq, desc);
 619
 620         /* Start handling the irq */
 621         if (desc->irq_data.chip->ack)
 622                 desc->irq_data.chip->ack(irq);
 623
 624         /* Mark the IRQ currently in progress.*/
 625         desc->status |= IRQ_INPROGRESS;
 626
 627         do {
 628                 struct irqaction *action = desc->action;
 629                 irqreturn_t action_ret;
 630
 631                 if (unlikely(!action)) {
 632                         mask_irq(desc);
 633                         goto out_unlock;
 634                 }
 635
 636                 /*
 637                  * When another irq arrived while we were handling
 638                  * one, we could have masked the irq.
 639                  * Renable it, if it was not disabled in meantime.
 640                  */
 641                 if (unlikely((desc->status &
 642                                (IRQ_PENDING | IRQ_MASKED | IRQ_DISABLED)) ==
 643                               (IRQ_PENDING | IRQ_MASKED))) {
 644                         unmask_irq(desc, irq);
 645                 }
 646
 647                 desc->status &= ~IRQ_PENDING;
 648                 raw_spin_unlock(&desc->lock);
 649                 action_ret = handle_IRQ_event(irq, action);
 650                 if (!noirqdebug)
 651                         note_interrupt(irq, desc, action_ret);
 652                 raw_spin_lock(&desc->lock);
 653
 654         } while ((desc->status & (IRQ_PENDING | IRQ_DISABLED)) == IRQ_PENDING);
 655
 656         desc->status &= ~IRQ_INPROGRESS;
 657 out_unlock:
 658         raw_spin_unlock(&desc->lock);
 659 }
 660
 661 /**
 662  *      handle_percpu_irq - Per CPU local irq handler
 663  *      @irq:   the interrupt number
 664  *      @desc:  the interrupt description structure for this irq
 665  *
 666  *      Per CPU interrupts on SMP machines without locking requirements
 667  */
 668 void
 669 handle_percpu_irq(unsigned int irq, struct irq_desc *desc)
 670 {
 671         irqreturn_t action_ret;
 672
 673         kstat_incr_irqs_this_cpu(irq, desc);
 674
 675         if (desc->irq_data.chip->ack)
 676                 desc->irq_data.chip->ack(irq);
 677
 678         action_ret = handle_IRQ_event(irq, desc->action);
 679         if (!noirqdebug)
 680                 note_interrupt(irq, desc, action_ret);
 681
 682         if (desc->irq_data.chip->eoi)
 683                 desc->irq_data.chip->eoi(irq);
 684 }
 685
 686 void
 687 __set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
 688                   const char *name)
 689 {
 690         struct irq_desc *desc = irq_to_desc(irq);
 691         unsigned long flags;
 692
 693         if (!desc) {
 694                 printk(KERN_ERR
 695                        "Trying to install type control for IRQ%d\n", irq);
 696                 return;
 697         }
 698
 699         if (!handle)
 700                 handle = handle_bad_irq;
 701         else if (desc->irq_data.chip == &no_irq_chip) {
 702                 printk(KERN_WARNING "Trying to install %sinterrupt handler "
 703                        "for IRQ%d\n", is_chained ? "chained " : "", irq);
 704                 /*
 705                  * Some ARM implementations install a handler for really dumb
 706                  * interrupt hardware without setting an irq_chip. This worked
 707                  * with the ARM no_irq_chip but the check in setup_irq would
 708                  * prevent us to setup the interrupt at all. Switch it to
 709                  * dummy_irq_chip for easy transition.
 710                  */
 711                 desc->irq_data.chip = &dummy_irq_chip;
 712         }
 713
 714         chip_bus_lock(desc);
 715         raw_spin_lock_irqsave(&desc->lock, flags);
 716
 717         /* Uninstall? */
 718         if (handle == handle_bad_irq) {
 719                 if (desc->irq_data.chip != &no_irq_chip)
 720                         mask_ack_irq(desc, irq);
 721                 desc->status |= IRQ_DISABLED;
 722                 desc->depth = 1;
 723         }
 724         desc->handle_irq = handle;
 725         desc->name = name;
 726
 727         if (handle != handle_bad_irq && is_chained) {
 728                 desc->status &= ~IRQ_DISABLED;
 729                 desc->status |= IRQ_NOREQUEST | IRQ_NOPROBE;
 730                 desc->depth = 0;
 731                 desc->irq_data.chip->startup(irq);
 732         }
 733         raw_spin_unlock_irqrestore(&desc->lock, flags);
 734         chip_bus_sync_unlock(desc);
 735 }
 736 EXPORT_SYMBOL_GPL(__set_irq_handler);
 737
 738 void
 739 set_irq_chip_and_handler(unsigned int irq, struct irq_chip *chip,
 740                          irq_flow_handler_t handle)
 741 {
 742         set_irq_chip(irq, chip);
 743         __set_irq_handler(irq, handle, 0, NULL);
 744 }
 745
 746 void
 747 set_irq_chip_and_handler_name(unsigned int irq, struct irq_chip *chip,
 748                               irq_flow_handler_t handle, const char *name)
 749 {
 750         set_irq_chip(irq, chip);
 751         __set_irq_handler(irq, handle, 0, name);
 752 }
 753
 754 void set_irq_noprobe(unsigned int irq)
 755 {
 756         struct irq_desc *desc = irq_to_desc(irq);
 757         unsigned long flags;
 758
 759         if (!desc) {
 760                 printk(KERN_ERR "Trying to mark IRQ%d non-probeable\n", irq);
 761                 return;
 762         }
 763
 764         raw_spin_lock_irqsave(&desc->lock, flags);
 765         desc->status |= IRQ_NOPROBE;
 766         raw_spin_unlock_irqrestore(&desc->lock, flags);
 767 }
 768
 769 void set_irq_probe(unsigned int irq)
 770 {
 771         struct irq_desc *desc = irq_to_desc(irq);
 772         unsigned long flags;
 773
 774         if (!desc) {
 775                 printk(KERN_ERR "Trying to mark IRQ%d probeable\n", irq);
 776                 return;
 777         }
 778
 779         raw_spin_lock_irqsave(&desc->lock, flags);
 780         desc->status &= ~IRQ_NOPROBE;
 781         raw_spin_unlock_irqrestore(&desc->lock, flags);
 782 }