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