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(struct irq_data *data)
 291 {
 292         struct irq_desc *desc = irq_data_to_desc(data);
 293
 294         desc->irq_data.chip->irq_unmask(&desc->irq_data);
 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->irq_enable(&desc->irq_data);
 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_irq_unmask(struct irq_data *data)
 334 {
 335         data->chip->unmask(data->irq);
 336 }
 337
 338 static void compat_irq_ack(struct irq_data *data)
 339 {
 340         data->chip->ack(data->irq);
 341 }
 342
 343 static void compat_irq_mask_ack(struct irq_data *data)
 344 {
 345         data->chip->mask_ack(data->irq);
 346 }
 347
 348 static void compat_irq_eoi(struct irq_data *data)
 349 {
 350         data->chip->eoi(data->irq);
 351 }
 352
 353 static void compat_irq_enable(struct irq_data *data)
 354 {
 355         data->chip->enable(data->irq);
 356 }
 357
 358 static void compat_bus_lock(struct irq_data *data)
 359 {
 360         data->chip->bus_lock(data->irq);
 361 }
 362
 363 static void compat_bus_sync_unlock(struct irq_data *data)
 364 {
 365         data->chip->bus_sync_unlock(data->irq);
 366 }
 367
 368 /*
 369  * Fixup enable/disable function pointers
 370  */
 371 void irq_chip_set_defaults(struct irq_chip *chip)
 372 {
 373         /*
 374          * Compat fixup functions need to be before we set the
 375          * defaults for enable/disable/startup/shutdown
 376          */
 377         if (chip->enable)
 378                 chip->irq_enable = compat_irq_enable;
 379
 380         /*
 381          * The real defaults
 382          */
 383         if (!chip->irq_enable)
 384                 chip->irq_enable = default_enable;
 385         if (!chip->disable)
 386                 chip->disable = default_disable;
 387         if (!chip->startup)
 388                 chip->startup = default_startup;
 389         /*
 390          * We use chip->disable, when the user provided its own. When
 391          * we have default_disable set for chip->disable, then we need
 392          * to use default_shutdown, otherwise the irq line is not
 393          * disabled on free_irq():
 394          */
 395         if (!chip->shutdown)
 396                 chip->shutdown = chip->disable != default_disable ?
 397                         chip->disable : default_shutdown;
 398         if (!chip->end)
 399                 chip->end = dummy_irq_chip.end;
 400
 401         if (chip->bus_lock)
 402                 chip->irq_bus_lock = compat_bus_lock;
 403         if (chip->bus_sync_unlock)
 404                 chip->irq_bus_sync_unlock = compat_bus_sync_unlock;
 405         if (chip->mask)
 406                 chip->irq_mask = compat_irq_mask;
 407         if (chip->unmask)
 408                 chip->irq_unmask = compat_irq_unmask;
 409         if (chip->ack)
 410                 chip->irq_ack = compat_irq_ack;
 411         if (chip->mask_ack)
 412                 chip->irq_mask_ack = compat_irq_mask_ack;
 413         if (chip->eoi)
 414                 chip->irq_eoi = compat_irq_eoi;
 415 }
 416
 417 static inline void mask_ack_irq(struct irq_desc *desc)
 418 {
 419         if (desc->irq_data.chip->irq_mask_ack)
 420                 desc->irq_data.chip->irq_mask_ack(&desc->irq_data);
 421         else {
 422                 desc->irq_data.chip->irq_mask(&desc->irq_data);
 423                 if (desc->irq_data.chip->irq_ack)
 424                         desc->irq_data.chip->irq_ack(&desc->irq_data);
 425         }
 426         desc->status |= IRQ_MASKED;
 427 }
 428
 429 static inline void mask_irq(struct irq_desc *desc)
 430 {
 431         if (desc->irq_data.chip->irq_mask) {
 432                 desc->irq_data.chip->irq_mask(&desc->irq_data);
 433                 desc->status |= IRQ_MASKED;
 434         }
 435 }
 436
 437 static inline void unmask_irq(struct irq_desc *desc)
 438 {
 439         if (desc->irq_data.chip->irq_unmask) {
 440                 desc->irq_data.chip->irq_unmask(&desc->irq_data);
 441                 desc->status &= ~IRQ_MASKED;
 442         }
 443 }
 444
 445 /*
 446  *      handle_nested_irq - Handle a nested irq from a irq thread
 447  *      @irq:   the interrupt number
 448  *
 449  *      Handle interrupts which are nested into a threaded interrupt
 450  *      handler. The handler function is called inside the calling
 451  *      threads context.
 452  */
 453 void handle_nested_irq(unsigned int irq)
 454 {
 455         struct irq_desc *desc = irq_to_desc(irq);
 456         struct irqaction *action;
 457         irqreturn_t action_ret;
 458
 459         might_sleep();
 460
 461         raw_spin_lock_irq(&desc->lock);
 462
 463         kstat_incr_irqs_this_cpu(irq, desc);
 464
 465         action = desc->action;
 466         if (unlikely(!action || (desc->status & IRQ_DISABLED)))
 467                 goto out_unlock;
 468
 469         desc->status |= IRQ_INPROGRESS;
 470         raw_spin_unlock_irq(&desc->lock);
 471
 472         action_ret = action->thread_fn(action->irq, action->dev_id);
 473         if (!noirqdebug)
 474                 note_interrupt(irq, desc, action_ret);
 475
 476         raw_spin_lock_irq(&desc->lock);
 477         desc->status &= ~IRQ_INPROGRESS;
 478
 479 out_unlock:
 480         raw_spin_unlock_irq(&desc->lock);
 481 }
 482 EXPORT_SYMBOL_GPL(handle_nested_irq);
 483
 484 /**
 485  *      handle_simple_irq - Simple and software-decoded IRQs.
 486  *      @irq:   the interrupt number
 487  *      @desc:  the interrupt description structure for this irq
 488  *
 489  *      Simple interrupts are either sent from a demultiplexing interrupt
 490  *      handler or come from hardware, where no interrupt hardware control
 491  *      is necessary.
 492  *
 493  *      Note: The caller is expected to handle the ack, clear, mask and
 494  *      unmask issues if necessary.
 495  */
 496 void
 497 handle_simple_irq(unsigned int irq, struct irq_desc *desc)
 498 {
 499         struct irqaction *action;
 500         irqreturn_t action_ret;
 501
 502         raw_spin_lock(&desc->lock);
 503
 504         if (unlikely(desc->status & IRQ_INPROGRESS))
 505                 goto out_unlock;
 506         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
 507         kstat_incr_irqs_this_cpu(irq, desc);
 508
 509         action = desc->action;
 510         if (unlikely(!action || (desc->status & IRQ_DISABLED)))
 511                 goto out_unlock;
 512
 513         desc->status |= IRQ_INPROGRESS;
 514         raw_spin_unlock(&desc->lock);
 515
 516         action_ret = handle_IRQ_event(irq, action);
 517         if (!noirqdebug)
 518                 note_interrupt(irq, desc, action_ret);
 519
 520         raw_spin_lock(&desc->lock);
 521         desc->status &= ~IRQ_INPROGRESS;
 522 out_unlock:
 523         raw_spin_unlock(&desc->lock);
 524 }
 525
 526 /**
 527  *      handle_level_irq - Level type irq handler
 528  *      @irq:   the interrupt number
 529  *      @desc:  the interrupt description structure for this irq
 530  *
 531  *      Level type interrupts are active as long as the hardware line has
 532  *      the active level. This may require to mask the interrupt and unmask
 533  *      it after the associated handler has acknowledged the device, so the
 534  *      interrupt line is back to inactive.
 535  */
 536 void
 537 handle_level_irq(unsigned int irq, struct irq_desc *desc)
 538 {
 539         struct irqaction *action;
 540         irqreturn_t action_ret;
 541
 542         raw_spin_lock(&desc->lock);
 543         mask_ack_irq(desc);
 544
 545         if (unlikely(desc->status & IRQ_INPROGRESS))
 546                 goto out_unlock;
 547         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
 548         kstat_incr_irqs_this_cpu(irq, desc);
 549
 550         /*
 551          * If its disabled or no action available
 552          * keep it masked and get out of here
 553          */
 554         action = desc->action;
 555         if (unlikely(!action || (desc->status & IRQ_DISABLED)))
 556                 goto out_unlock;
 557
 558         desc->status |= IRQ_INPROGRESS;
 559         raw_spin_unlock(&desc->lock);
 560
 561         action_ret = handle_IRQ_event(irq, action);
 562         if (!noirqdebug)
 563                 note_interrupt(irq, desc, action_ret);
 564
 565         raw_spin_lock(&desc->lock);
 566         desc->status &= ~IRQ_INPROGRESS;
 567
 568         if (!(desc->status & (IRQ_DISABLED | IRQ_ONESHOT)))
 569                 unmask_irq(desc);
 570 out_unlock:
 571         raw_spin_unlock(&desc->lock);
 572 }
 573 EXPORT_SYMBOL_GPL(handle_level_irq);
 574
 575 /**
 576  *      handle_fasteoi_irq - irq handler for transparent controllers
 577  *      @irq:   the interrupt number
 578  *      @desc:  the interrupt description structure for this irq
 579  *
 580  *      Only a single callback will be issued to the chip: an ->eoi()
 581  *      call when the interrupt has been serviced. This enables support
 582  *      for modern forms of interrupt handlers, which handle the flow
 583  *      details in hardware, transparently.
 584  */
 585 void
 586 handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc)
 587 {
 588         struct irqaction *action;
 589         irqreturn_t action_ret;
 590
 591         raw_spin_lock(&desc->lock);
 592
 593         if (unlikely(desc->status & IRQ_INPROGRESS))
 594                 goto out;
 595
 596         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
 597         kstat_incr_irqs_this_cpu(irq, desc);
 598
 599         /*
 600          * If its disabled or no action available
 601          * then mask it and get out of here:
 602          */
 603         action = desc->action;
 604         if (unlikely(!action || (desc->status & IRQ_DISABLED))) {
 605                 desc->status |= IRQ_PENDING;
 606                 mask_irq(desc);
 607                 goto out;
 608         }
 609
 610         desc->status |= IRQ_INPROGRESS;
 611         desc->status &= ~IRQ_PENDING;
 612         raw_spin_unlock(&desc->lock);
 613
 614         action_ret = handle_IRQ_event(irq, action);
 615         if (!noirqdebug)
 616                 note_interrupt(irq, desc, action_ret);
 617
 618         raw_spin_lock(&desc->lock);
 619         desc->status &= ~IRQ_INPROGRESS;
 620 out:
 621         desc->irq_data.chip->irq_eoi(&desc->irq_data);
 622
 623         raw_spin_unlock(&desc->lock);
 624 }
 625
 626 /**
 627  *      handle_edge_irq - edge type IRQ handler
 628  *      @irq:   the interrupt number
 629  *      @desc:  the interrupt description structure for this irq
 630  *
 631  *      Interrupt occures on the falling and/or rising edge of a hardware
 632  *      signal. The occurence is latched into the irq controller hardware
 633  *      and must be acked in order to be reenabled. After the ack another
 634  *      interrupt can happen on the same source even before the first one
 635  *      is handled by the associated event handler. If this happens it
 636  *      might be necessary to disable (mask) the interrupt depending on the
 637  *      controller hardware. This requires to reenable the interrupt inside
 638  *      of the loop which handles the interrupts which have arrived while
 639  *      the handler was running. If all pending interrupts are handled, the
 640  *      loop is left.
 641  */
 642 void
 643 handle_edge_irq(unsigned int irq, struct irq_desc *desc)
 644 {
 645         raw_spin_lock(&desc->lock);
 646
 647         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
 648
 649         /*
 650          * If we're currently running this IRQ, or its disabled,
 651          * we shouldn't process the IRQ. Mark it pending, handle
 652          * the necessary masking and go out
 653          */
 654         if (unlikely((desc->status & (IRQ_INPROGRESS | IRQ_DISABLED)) ||
 655                     !desc->action)) {
 656                 desc->status |= (IRQ_PENDING | IRQ_MASKED);
 657                 mask_ack_irq(desc);
 658                 goto out_unlock;
 659         }
 660         kstat_incr_irqs_this_cpu(irq, desc);
 661
 662         /* Start handling the irq */
 663         desc->irq_data.chip->irq_ack(&desc->irq_data);
 664
 665         /* Mark the IRQ currently in progress.*/
 666         desc->status |= IRQ_INPROGRESS;
 667
 668         do {
 669                 struct irqaction *action = desc->action;
 670                 irqreturn_t action_ret;
 671
 672                 if (unlikely(!action)) {
 673                         mask_irq(desc);
 674                         goto out_unlock;
 675                 }
 676
 677                 /*
 678                  * When another irq arrived while we were handling
 679                  * one, we could have masked the irq.
 680                  * Renable it, if it was not disabled in meantime.
 681                  */
 682                 if (unlikely((desc->status &
 683                                (IRQ_PENDING | IRQ_MASKED | IRQ_DISABLED)) ==
 684                               (IRQ_PENDING | IRQ_MASKED))) {
 685                         unmask_irq(desc);
 686                 }
 687
 688                 desc->status &= ~IRQ_PENDING;
 689                 raw_spin_unlock(&desc->lock);
 690                 action_ret = handle_IRQ_event(irq, action);
 691                 if (!noirqdebug)
 692                         note_interrupt(irq, desc, action_ret);
 693                 raw_spin_lock(&desc->lock);
 694
 695         } while ((desc->status & (IRQ_PENDING | IRQ_DISABLED)) == IRQ_PENDING);
 696
 697         desc->status &= ~IRQ_INPROGRESS;
 698 out_unlock:
 699         raw_spin_unlock(&desc->lock);
 700 }
 701
 702 /**
 703  *      handle_percpu_irq - Per CPU local irq handler
 704  *      @irq:   the interrupt number
 705  *      @desc:  the interrupt description structure for this irq
 706  *
 707  *      Per CPU interrupts on SMP machines without locking requirements
 708  */
 709 void
 710 handle_percpu_irq(unsigned int irq, struct irq_desc *desc)
 711 {
 712         irqreturn_t action_ret;
 713
 714         kstat_incr_irqs_this_cpu(irq, desc);
 715
 716         if (desc->irq_data.chip->irq_ack)
 717                 desc->irq_data.chip->irq_ack(&desc->irq_data);
 718
 719         action_ret = handle_IRQ_event(irq, desc->action);
 720         if (!noirqdebug)
 721                 note_interrupt(irq, desc, action_ret);
 722
 723         if (desc->irq_data.chip->irq_eoi)
 724                 desc->irq_data.chip->irq_eoi(&desc->irq_data);
 725 }
 726
 727 void
 728 __set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
 729                   const char *name)
 730 {
 731         struct irq_desc *desc = irq_to_desc(irq);
 732         unsigned long flags;
 733
 734         if (!desc) {
 735                 printk(KERN_ERR
 736                        "Trying to install type control for IRQ%d\n", irq);
 737                 return;
 738         }
 739
 740         if (!handle)
 741                 handle = handle_bad_irq;
 742         else if (desc->irq_data.chip == &no_irq_chip) {
 743                 printk(KERN_WARNING "Trying to install %sinterrupt handler "
 744                        "for IRQ%d\n", is_chained ? "chained " : "", irq);
 745                 /*
 746                  * Some ARM implementations install a handler for really dumb
 747                  * interrupt hardware without setting an irq_chip. This worked
 748                  * with the ARM no_irq_chip but the check in setup_irq would
 749                  * prevent us to setup the interrupt at all. Switch it to
 750                  * dummy_irq_chip for easy transition.
 751                  */
 752                 desc->irq_data.chip = &dummy_irq_chip;
 753         }
 754
 755         chip_bus_lock(desc);
 756         raw_spin_lock_irqsave(&desc->lock, flags);
 757
 758         /* Uninstall? */
 759         if (handle == handle_bad_irq) {
 760                 if (desc->irq_data.chip != &no_irq_chip)
 761                         mask_ack_irq(desc);
 762                 desc->status |= IRQ_DISABLED;
 763                 desc->depth = 1;
 764         }
 765         desc->handle_irq = handle;
 766         desc->name = name;
 767
 768         if (handle != handle_bad_irq && is_chained) {
 769                 desc->status &= ~IRQ_DISABLED;
 770                 desc->status |= IRQ_NOREQUEST | IRQ_NOPROBE;
 771                 desc->depth = 0;
 772                 desc->irq_data.chip->startup(irq);
 773         }
 774         raw_spin_unlock_irqrestore(&desc->lock, flags);
 775         chip_bus_sync_unlock(desc);
 776 }
 777 EXPORT_SYMBOL_GPL(__set_irq_handler);
 778
 779 void
 780 set_irq_chip_and_handler(unsigned int irq, struct irq_chip *chip,
 781                          irq_flow_handler_t handle)
 782 {
 783         set_irq_chip(irq, chip);
 784         __set_irq_handler(irq, handle, 0, NULL);
 785 }
 786
 787 void
 788 set_irq_chip_and_handler_name(unsigned int irq, struct irq_chip *chip,
 789                               irq_flow_handler_t handle, const char *name)
 790 {
 791         set_irq_chip(irq, chip);
 792         __set_irq_handler(irq, handle, 0, name);
 793 }
 794
 795 void set_irq_noprobe(unsigned int irq)
 796 {
 797         struct irq_desc *desc = irq_to_desc(irq);
 798         unsigned long flags;
 799
 800         if (!desc) {
 801                 printk(KERN_ERR "Trying to mark IRQ%d non-probeable\n", irq);
 802                 return;
 803         }
 804
 805         raw_spin_lock_irqsave(&desc->lock, flags);
 806         desc->status |= IRQ_NOPROBE;
 807         raw_spin_unlock_irqrestore(&desc->lock, flags);
 808 }
 809
 810 void set_irq_probe(unsigned int irq)
 811 {
 812         struct irq_desc *desc = irq_to_desc(irq);
 813         unsigned long flags;
 814
 815         if (!desc) {
 816                 printk(KERN_ERR "Trying to mark IRQ%d probeable\n", irq);
 817                 return;
 818         }
 819
 820         raw_spin_lock_irqsave(&desc->lock, flags);
 821         desc->status &= ~IRQ_NOPROBE;
 822         raw_spin_unlock_irqrestore(&desc->lock, flags);
 823 }