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 struct irq_data *irq_get_irq_data(unsigned int irq)
 260 {
 261         struct irq_desc *desc = irq_to_desc(irq);
 262
 263         return desc ? &desc->irq_data : NULL;
 264 }
 265 EXPORT_SYMBOL_GPL(irq_get_irq_data);
 266
 267 /**
 268  *      set_irq_nested_thread - Set/Reset the IRQ_NESTED_THREAD flag of an irq
 269  *
 270  *      @irq:   Interrupt number
 271  *      @nest:  0 to clear / 1 to set the IRQ_NESTED_THREAD flag
 272  *
 273  *      The IRQ_NESTED_THREAD flag indicates that on
 274  *      request_threaded_irq() no separate interrupt thread should be
 275  *      created for the irq as the handler are called nested in the
 276  *      context of a demultiplexing interrupt handler thread.
 277  */
 278 void set_irq_nested_thread(unsigned int irq, int nest)
 279 {
 280         struct irq_desc *desc = irq_to_desc(irq);
 281         unsigned long flags;
 282
 283         if (!desc)
 284                 return;
 285
 286         raw_spin_lock_irqsave(&desc->lock, flags);
 287         if (nest)
 288                 desc->status |= IRQ_NESTED_THREAD;
 289         else
 290                 desc->status &= ~IRQ_NESTED_THREAD;
 291         raw_spin_unlock_irqrestore(&desc->lock, flags);
 292 }
 293 EXPORT_SYMBOL_GPL(set_irq_nested_thread);
 294
 295 /*
 296  * default enable function
 297  */
 298 static void default_enable(struct irq_data *data)
 299 {
 300         struct irq_desc *desc = irq_data_to_desc(data);
 301
 302         desc->irq_data.chip->irq_unmask(&desc->irq_data);
 303         desc->status &= ~IRQ_MASKED;
 304 }
 305
 306 /*
 307  * default disable function
 308  */
 309 static void default_disable(struct irq_data *data)
 310 {
 311 }
 312
 313 /*
 314  * default startup function
 315  */
 316 static unsigned int default_startup(struct irq_data *data)
 317 {
 318         struct irq_desc *desc = irq_data_to_desc(data);
 319
 320         desc->irq_data.chip->irq_enable(data);
 321         return 0;
 322 }
 323
 324 /*
 325  * default shutdown function
 326  */
 327 static void default_shutdown(struct irq_data *data)
 328 {
 329         struct irq_desc *desc = irq_data_to_desc(data);
 330
 331         desc->irq_data.chip->irq_mask(&desc->irq_data);
 332         desc->status |= IRQ_MASKED;
 333 }
 334
 335 #ifndef CONFIG_GENERIC_HARDIRQS_NO_DEPRECATED
 336 /* Temporary migration helpers */
 337 static void compat_irq_mask(struct irq_data *data)
 338 {
 339         data->chip->mask(data->irq);
 340 }
 341
 342 static void compat_irq_unmask(struct irq_data *data)
 343 {
 344         data->chip->unmask(data->irq);
 345 }
 346
 347 static void compat_irq_ack(struct irq_data *data)
 348 {
 349         data->chip->ack(data->irq);
 350 }
 351
 352 static void compat_irq_mask_ack(struct irq_data *data)
 353 {
 354         data->chip->mask_ack(data->irq);
 355 }
 356
 357 static void compat_irq_eoi(struct irq_data *data)
 358 {
 359         data->chip->eoi(data->irq);
 360 }
 361
 362 static void compat_irq_enable(struct irq_data *data)
 363 {
 364         data->chip->enable(data->irq);
 365 }
 366
 367 static void compat_irq_disable(struct irq_data *data)
 368 {
 369         data->chip->disable(data->irq);
 370 }
 371
 372 static void compat_irq_shutdown(struct irq_data *data)
 373 {
 374         data->chip->shutdown(data->irq);
 375 }
 376
 377 static unsigned int compat_irq_startup(struct irq_data *data)
 378 {
 379         return data->chip->startup(data->irq);
 380 }
 381
 382 static int compat_irq_set_affinity(struct irq_data *data,
 383                                    const struct cpumask *dest, bool force)
 384 {
 385         return data->chip->set_affinity(data->irq, dest);
 386 }
 387
 388 static int compat_irq_set_type(struct irq_data *data, unsigned int type)
 389 {
 390         return data->chip->set_type(data->irq, type);
 391 }
 392
 393 static int compat_irq_set_wake(struct irq_data *data, unsigned int on)
 394 {
 395         return data->chip->set_wake(data->irq, on);
 396 }
 397
 398 static int compat_irq_retrigger(struct irq_data *data)
 399 {
 400         return data->chip->retrigger(data->irq);
 401 }
 402
 403 static void compat_bus_lock(struct irq_data *data)
 404 {
 405         data->chip->bus_lock(data->irq);
 406 }
 407
 408 static void compat_bus_sync_unlock(struct irq_data *data)
 409 {
 410         data->chip->bus_sync_unlock(data->irq);
 411 }
 412 #endif
 413
 414 /*
 415  * Fixup enable/disable function pointers
 416  */
 417 void irq_chip_set_defaults(struct irq_chip *chip)
 418 {
 419 #ifndef CONFIG_GENERIC_HARDIRQS_NO_DEPRECATED
 420         /*
 421          * Compat fixup functions need to be before we set the
 422          * defaults for enable/disable/startup/shutdown
 423          */
 424         if (chip->enable)
 425                 chip->irq_enable = compat_irq_enable;
 426         if (chip->disable)
 427                 chip->irq_disable = compat_irq_disable;
 428         if (chip->shutdown)
 429                 chip->irq_shutdown = compat_irq_shutdown;
 430         if (chip->startup)
 431                 chip->irq_startup = compat_irq_startup;
 432 #endif
 433         /*
 434          * The real defaults
 435          */
 436         if (!chip->irq_enable)
 437                 chip->irq_enable = default_enable;
 438         if (!chip->irq_disable)
 439                 chip->irq_disable = default_disable;
 440         if (!chip->irq_startup)
 441                 chip->irq_startup = default_startup;
 442         /*
 443          * We use chip->irq_disable, when the user provided its own. When
 444          * we have default_disable set for chip->irq_disable, then we need
 445          * to use default_shutdown, otherwise the irq line is not
 446          * disabled on free_irq():
 447          */
 448         if (!chip->irq_shutdown)
 449                 chip->irq_shutdown = chip->irq_disable != default_disable ?
 450                         chip->irq_disable : default_shutdown;
 451
 452 #ifndef CONFIG_GENERIC_HARDIRQS_NO_DEPRECATED
 453         if (!chip->end)
 454                 chip->end = dummy_irq_chip.end;
 455
 456         /*
 457          * Now fix up the remaining compat handlers
 458          */
 459         if (chip->bus_lock)
 460                 chip->irq_bus_lock = compat_bus_lock;
 461         if (chip->bus_sync_unlock)
 462                 chip->irq_bus_sync_unlock = compat_bus_sync_unlock;
 463         if (chip->mask)
 464                 chip->irq_mask = compat_irq_mask;
 465         if (chip->unmask)
 466                 chip->irq_unmask = compat_irq_unmask;
 467         if (chip->ack)
 468                 chip->irq_ack = compat_irq_ack;
 469         if (chip->mask_ack)
 470                 chip->irq_mask_ack = compat_irq_mask_ack;
 471         if (chip->eoi)
 472                 chip->irq_eoi = compat_irq_eoi;
 473         if (chip->set_affinity)
 474                 chip->irq_set_affinity = compat_irq_set_affinity;
 475         if (chip->set_type)
 476                 chip->irq_set_type = compat_irq_set_type;
 477         if (chip->set_wake)
 478                 chip->irq_set_wake = compat_irq_set_wake;
 479         if (chip->retrigger)
 480                 chip->irq_retrigger = compat_irq_retrigger;
 481 #endif
 482 }
 483
 484 static inline void mask_ack_irq(struct irq_desc *desc)
 485 {
 486         if (desc->irq_data.chip->irq_mask_ack)
 487                 desc->irq_data.chip->irq_mask_ack(&desc->irq_data);
 488         else {
 489                 desc->irq_data.chip->irq_mask(&desc->irq_data);
 490                 if (desc->irq_data.chip->irq_ack)
 491                         desc->irq_data.chip->irq_ack(&desc->irq_data);
 492         }
 493         desc->status |= IRQ_MASKED;
 494 }
 495
 496 static inline void mask_irq(struct irq_desc *desc)
 497 {
 498         if (desc->irq_data.chip->irq_mask) {
 499                 desc->irq_data.chip->irq_mask(&desc->irq_data);
 500                 desc->status |= IRQ_MASKED;
 501         }
 502 }
 503
 504 static inline void unmask_irq(struct irq_desc *desc)
 505 {
 506         if (desc->irq_data.chip->irq_unmask) {
 507                 desc->irq_data.chip->irq_unmask(&desc->irq_data);
 508                 desc->status &= ~IRQ_MASKED;
 509         }
 510 }
 511
 512 /*
 513  *      handle_nested_irq - Handle a nested irq from a irq thread
 514  *      @irq:   the interrupt number
 515  *
 516  *      Handle interrupts which are nested into a threaded interrupt
 517  *      handler. The handler function is called inside the calling
 518  *      threads context.
 519  */
 520 void handle_nested_irq(unsigned int irq)
 521 {
 522         struct irq_desc *desc = irq_to_desc(irq);
 523         struct irqaction *action;
 524         irqreturn_t action_ret;
 525
 526         might_sleep();
 527
 528         raw_spin_lock_irq(&desc->lock);
 529
 530         kstat_incr_irqs_this_cpu(irq, desc);
 531
 532         action = desc->action;
 533         if (unlikely(!action || (desc->status & IRQ_DISABLED)))
 534                 goto out_unlock;
 535
 536         desc->status |= IRQ_INPROGRESS;
 537         raw_spin_unlock_irq(&desc->lock);
 538
 539         action_ret = action->thread_fn(action->irq, action->dev_id);
 540         if (!noirqdebug)
 541                 note_interrupt(irq, desc, action_ret);
 542
 543         raw_spin_lock_irq(&desc->lock);
 544         desc->status &= ~IRQ_INPROGRESS;
 545
 546 out_unlock:
 547         raw_spin_unlock_irq(&desc->lock);
 548 }
 549 EXPORT_SYMBOL_GPL(handle_nested_irq);
 550
 551 /**
 552  *      handle_simple_irq - Simple and software-decoded IRQs.
 553  *      @irq:   the interrupt number
 554  *      @desc:  the interrupt description structure for this irq
 555  *
 556  *      Simple interrupts are either sent from a demultiplexing interrupt
 557  *      handler or come from hardware, where no interrupt hardware control
 558  *      is necessary.
 559  *
 560  *      Note: The caller is expected to handle the ack, clear, mask and
 561  *      unmask issues if necessary.
 562  */
 563 void
 564 handle_simple_irq(unsigned int irq, struct irq_desc *desc)
 565 {
 566         struct irqaction *action;
 567         irqreturn_t action_ret;
 568
 569         raw_spin_lock(&desc->lock);
 570
 571         if (unlikely(desc->status & IRQ_INPROGRESS))
 572                 goto out_unlock;
 573         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
 574         kstat_incr_irqs_this_cpu(irq, desc);
 575
 576         action = desc->action;
 577         if (unlikely(!action || (desc->status & IRQ_DISABLED)))
 578                 goto out_unlock;
 579
 580         desc->status |= IRQ_INPROGRESS;
 581         raw_spin_unlock(&desc->lock);
 582
 583         action_ret = handle_IRQ_event(irq, action);
 584         if (!noirqdebug)
 585                 note_interrupt(irq, desc, action_ret);
 586
 587         raw_spin_lock(&desc->lock);
 588         desc->status &= ~IRQ_INPROGRESS;
 589 out_unlock:
 590         raw_spin_unlock(&desc->lock);
 591 }
 592
 593 /**
 594  *      handle_level_irq - Level type irq handler
 595  *      @irq:   the interrupt number
 596  *      @desc:  the interrupt description structure for this irq
 597  *
 598  *      Level type interrupts are active as long as the hardware line has
 599  *      the active level. This may require to mask the interrupt and unmask
 600  *      it after the associated handler has acknowledged the device, so the
 601  *      interrupt line is back to inactive.
 602  */
 603 void
 604 handle_level_irq(unsigned int irq, struct irq_desc *desc)
 605 {
 606         struct irqaction *action;
 607         irqreturn_t action_ret;
 608
 609         raw_spin_lock(&desc->lock);
 610         mask_ack_irq(desc);
 611
 612         if (unlikely(desc->status & IRQ_INPROGRESS))
 613                 goto out_unlock;
 614         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
 615         kstat_incr_irqs_this_cpu(irq, desc);
 616
 617         /*
 618          * If its disabled or no action available
 619          * keep it masked and get out of here
 620          */
 621         action = desc->action;
 622         if (unlikely(!action || (desc->status & IRQ_DISABLED)))
 623                 goto out_unlock;
 624
 625         desc->status |= IRQ_INPROGRESS;
 626         raw_spin_unlock(&desc->lock);
 627
 628         action_ret = handle_IRQ_event(irq, action);
 629         if (!noirqdebug)
 630                 note_interrupt(irq, desc, action_ret);
 631
 632         raw_spin_lock(&desc->lock);
 633         desc->status &= ~IRQ_INPROGRESS;
 634
 635         if (!(desc->status & (IRQ_DISABLED | IRQ_ONESHOT)))
 636                 unmask_irq(desc);
 637 out_unlock:
 638         raw_spin_unlock(&desc->lock);
 639 }
 640 EXPORT_SYMBOL_GPL(handle_level_irq);
 641
 642 /**
 643  *      handle_fasteoi_irq - irq handler for transparent controllers
 644  *      @irq:   the interrupt number
 645  *      @desc:  the interrupt description structure for this irq
 646  *
 647  *      Only a single callback will be issued to the chip: an ->eoi()
 648  *      call when the interrupt has been serviced. This enables support
 649  *      for modern forms of interrupt handlers, which handle the flow
 650  *      details in hardware, transparently.
 651  */
 652 void
 653 handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc)
 654 {
 655         struct irqaction *action;
 656         irqreturn_t action_ret;
 657
 658         raw_spin_lock(&desc->lock);
 659
 660         if (unlikely(desc->status & IRQ_INPROGRESS))
 661                 goto out;
 662
 663         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
 664         kstat_incr_irqs_this_cpu(irq, desc);
 665
 666         /*
 667          * If its disabled or no action available
 668          * then mask it and get out of here:
 669          */
 670         action = desc->action;
 671         if (unlikely(!action || (desc->status & IRQ_DISABLED))) {
 672                 desc->status |= IRQ_PENDING;
 673                 mask_irq(desc);
 674                 goto out;
 675         }
 676
 677         desc->status |= IRQ_INPROGRESS;
 678         desc->status &= ~IRQ_PENDING;
 679         raw_spin_unlock(&desc->lock);
 680
 681         action_ret = handle_IRQ_event(irq, action);
 682         if (!noirqdebug)
 683                 note_interrupt(irq, desc, action_ret);
 684
 685         raw_spin_lock(&desc->lock);
 686         desc->status &= ~IRQ_INPROGRESS;
 687 out:
 688         desc->irq_data.chip->irq_eoi(&desc->irq_data);
 689
 690         raw_spin_unlock(&desc->lock);
 691 }
 692
 693 /**
 694  *      handle_edge_irq - edge type IRQ handler
 695  *      @irq:   the interrupt number
 696  *      @desc:  the interrupt description structure for this irq
 697  *
 698  *      Interrupt occures on the falling and/or rising edge of a hardware
 699  *      signal. The occurence is latched into the irq controller hardware
 700  *      and must be acked in order to be reenabled. After the ack another
 701  *      interrupt can happen on the same source even before the first one
 702  *      is handled by the associated event handler. If this happens it
 703  *      might be necessary to disable (mask) the interrupt depending on the
 704  *      controller hardware. This requires to reenable the interrupt inside
 705  *      of the loop which handles the interrupts which have arrived while
 706  *      the handler was running. If all pending interrupts are handled, the
 707  *      loop is left.
 708  */
 709 void
 710 handle_edge_irq(unsigned int irq, struct irq_desc *desc)
 711 {
 712         raw_spin_lock(&desc->lock);
 713
 714         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
 715
 716         /*
 717          * If we're currently running this IRQ, or its disabled,
 718          * we shouldn't process the IRQ. Mark it pending, handle
 719          * the necessary masking and go out
 720          */
 721         if (unlikely((desc->status & (IRQ_INPROGRESS | IRQ_DISABLED)) ||
 722                     !desc->action)) {
 723                 desc->status |= (IRQ_PENDING | IRQ_MASKED);
 724                 mask_ack_irq(desc);
 725                 goto out_unlock;
 726         }
 727         kstat_incr_irqs_this_cpu(irq, desc);
 728
 729         /* Start handling the irq */
 730         desc->irq_data.chip->irq_ack(&desc->irq_data);
 731
 732         /* Mark the IRQ currently in progress.*/
 733         desc->status |= IRQ_INPROGRESS;
 734
 735         do {
 736                 struct irqaction *action = desc->action;
 737                 irqreturn_t action_ret;
 738
 739                 if (unlikely(!action)) {
 740                         mask_irq(desc);
 741                         goto out_unlock;
 742                 }
 743
 744                 /*
 745                  * When another irq arrived while we were handling
 746                  * one, we could have masked the irq.
 747                  * Renable it, if it was not disabled in meantime.
 748                  */
 749                 if (unlikely((desc->status &
 750                                (IRQ_PENDING | IRQ_MASKED | IRQ_DISABLED)) ==
 751                               (IRQ_PENDING | IRQ_MASKED))) {
 752                         unmask_irq(desc);
 753                 }
 754
 755                 desc->status &= ~IRQ_PENDING;
 756                 raw_spin_unlock(&desc->lock);
 757                 action_ret = handle_IRQ_event(irq, action);
 758                 if (!noirqdebug)
 759                         note_interrupt(irq, desc, action_ret);
 760                 raw_spin_lock(&desc->lock);
 761
 762         } while ((desc->status & (IRQ_PENDING | IRQ_DISABLED)) == IRQ_PENDING);
 763
 764         desc->status &= ~IRQ_INPROGRESS;
 765 out_unlock:
 766         raw_spin_unlock(&desc->lock);
 767 }
 768
 769 /**
 770  *      handle_percpu_irq - Per CPU local irq handler
 771  *      @irq:   the interrupt number
 772  *      @desc:  the interrupt description structure for this irq
 773  *
 774  *      Per CPU interrupts on SMP machines without locking requirements
 775  */
 776 void
 777 handle_percpu_irq(unsigned int irq, struct irq_desc *desc)
 778 {
 779         irqreturn_t action_ret;
 780
 781         kstat_incr_irqs_this_cpu(irq, desc);
 782
 783         if (desc->irq_data.chip->irq_ack)
 784                 desc->irq_data.chip->irq_ack(&desc->irq_data);
 785
 786         action_ret = handle_IRQ_event(irq, desc->action);
 787         if (!noirqdebug)
 788                 note_interrupt(irq, desc, action_ret);
 789
 790         if (desc->irq_data.chip->irq_eoi)
 791                 desc->irq_data.chip->irq_eoi(&desc->irq_data);
 792 }
 793
 794 void
 795 __set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
 796                   const char *name)
 797 {
 798         struct irq_desc *desc = irq_to_desc(irq);
 799         unsigned long flags;
 800
 801         if (!desc) {
 802                 printk(KERN_ERR
 803                        "Trying to install type control for IRQ%d\n", irq);
 804                 return;
 805         }
 806
 807         if (!handle)
 808                 handle = handle_bad_irq;
 809         else if (desc->irq_data.chip == &no_irq_chip) {
 810                 printk(KERN_WARNING "Trying to install %sinterrupt handler "
 811                        "for IRQ%d\n", is_chained ? "chained " : "", irq);
 812                 /*
 813                  * Some ARM implementations install a handler for really dumb
 814                  * interrupt hardware without setting an irq_chip. This worked
 815                  * with the ARM no_irq_chip but the check in setup_irq would
 816                  * prevent us to setup the interrupt at all. Switch it to
 817                  * dummy_irq_chip for easy transition.
 818                  */
 819                 desc->irq_data.chip = &dummy_irq_chip;
 820         }
 821
 822         chip_bus_lock(desc);
 823         raw_spin_lock_irqsave(&desc->lock, flags);
 824
 825         /* Uninstall? */
 826         if (handle == handle_bad_irq) {
 827                 if (desc->irq_data.chip != &no_irq_chip)
 828                         mask_ack_irq(desc);
 829                 desc->status |= IRQ_DISABLED;
 830                 desc->depth = 1;
 831         }
 832         desc->handle_irq = handle;
 833         desc->name = name;
 834
 835         if (handle != handle_bad_irq && is_chained) {
 836                 desc->status &= ~IRQ_DISABLED;
 837                 desc->status |= IRQ_NOREQUEST | IRQ_NOPROBE;
 838                 desc->depth = 0;
 839                 desc->irq_data.chip->irq_startup(&desc->irq_data);
 840         }
 841         raw_spin_unlock_irqrestore(&desc->lock, flags);
 842         chip_bus_sync_unlock(desc);
 843 }
 844 EXPORT_SYMBOL_GPL(__set_irq_handler);
 845
 846 void
 847 set_irq_chip_and_handler(unsigned int irq, struct irq_chip *chip,
 848                          irq_flow_handler_t handle)
 849 {
 850         set_irq_chip(irq, chip);
 851         __set_irq_handler(irq, handle, 0, NULL);
 852 }
 853
 854 void
 855 set_irq_chip_and_handler_name(unsigned int irq, struct irq_chip *chip,
 856                               irq_flow_handler_t handle, const char *name)
 857 {
 858         set_irq_chip(irq, chip);
 859         __set_irq_handler(irq, handle, 0, name);
 860 }
 861
 862 void irq_modify_status(unsigned int irq, unsigned long clr, unsigned long set)
 863 {
 864         struct irq_desc *desc = irq_to_desc(irq);
 865         unsigned long flags;
 866
 867         if (!desc)
 868                 return;
 869
 870         /* Sanitize flags */
 871         set &= IRQF_MODIFY_MASK;
 872         clr &= IRQF_MODIFY_MASK;
 873
 874         raw_spin_lock_irqsave(&desc->lock, flags);
 875         desc->status &= ~clr;
 876         desc->status |= set;
 877         raw_spin_unlock_irqrestore(&desc->lock, flags);
 878 }