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  *      irq_set_chip - set the irq chip for an irq
  23  *      @irq:   irq number
  24  *      @chip:  pointer to irq chip description structure
  25  */
  26 int irq_set_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(irq_set_chip);
  47
  48 /**
  49  *      irq_set_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 irq_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         chip_bus_lock(desc);
  69         raw_spin_lock_irqsave(&desc->lock, flags);
  70         ret = __irq_set_trigger(desc, irq, type);
  71         raw_spin_unlock_irqrestore(&desc->lock, flags);
  72         chip_bus_sync_unlock(desc);
  73         return ret;
  74 }
  75 EXPORT_SYMBOL(irq_set_irq_type);
  76
  77 /**
  78  *      irq_set_handler_data - set irq handler data for an irq
  79  *      @irq:   Interrupt number
  80  *      @data:  Pointer to interrupt specific data
  81  *
  82  *      Set the hardware irq controller data for an irq
  83  */
  84 int irq_set_handler_data(unsigned int irq, void *data)
  85 {
  86         struct irq_desc *desc = irq_to_desc(irq);
  87         unsigned long flags;
  88
  89         if (!desc) {
  90                 printk(KERN_ERR
  91                        "Trying to install controller data for IRQ%d\n", irq);
  92                 return -EINVAL;
  93         }
  94
  95         raw_spin_lock_irqsave(&desc->lock, flags);
  96         desc->irq_data.handler_data = data;
  97         raw_spin_unlock_irqrestore(&desc->lock, flags);
  98         return 0;
  99 }
 100 EXPORT_SYMBOL(irq_set_handler_data);
 101
 102 /**
 103  *      irq_set_msi_desc - set MSI descriptor data for an irq
 104  *      @irq:   Interrupt number
 105  *      @entry: Pointer to MSI descriptor data
 106  *
 107  *      Set the MSI descriptor entry for an irq
 108  */
 109 int irq_set_msi_desc(unsigned int irq, struct msi_desc *entry)
 110 {
 111         struct irq_desc *desc = irq_to_desc(irq);
 112         unsigned long flags;
 113
 114         if (!desc) {
 115                 printk(KERN_ERR
 116                        "Trying to install msi data for IRQ%d\n", irq);
 117                 return -EINVAL;
 118         }
 119
 120         raw_spin_lock_irqsave(&desc->lock, flags);
 121         desc->irq_data.msi_desc = entry;
 122         if (entry)
 123                 entry->irq = irq;
 124         raw_spin_unlock_irqrestore(&desc->lock, flags);
 125         return 0;
 126 }
 127
 128 /**
 129  *      irq_set_chip_data - set irq chip data for an irq
 130  *      @irq:   Interrupt number
 131  *      @data:  Pointer to chip specific data
 132  *
 133  *      Set the hardware irq chip data for an irq
 134  */
 135 int irq_set_chip_data(unsigned int irq, void *data)
 136 {
 137         struct irq_desc *desc = irq_to_desc(irq);
 138         unsigned long flags;
 139
 140         if (!desc) {
 141                 printk(KERN_ERR
 142                        "Trying to install chip data for IRQ%d\n", irq);
 143                 return -EINVAL;
 144         }
 145
 146         if (!desc->irq_data.chip) {
 147                 printk(KERN_ERR "BUG: bad set_irq_chip_data(IRQ#%d)\n", irq);
 148                 return -EINVAL;
 149         }
 150
 151         raw_spin_lock_irqsave(&desc->lock, flags);
 152         desc->irq_data.chip_data = data;
 153         raw_spin_unlock_irqrestore(&desc->lock, flags);
 154
 155         return 0;
 156 }
 157 EXPORT_SYMBOL(irq_set_chip_data);
 158
 159 struct irq_data *irq_get_irq_data(unsigned int irq)
 160 {
 161         struct irq_desc *desc = irq_to_desc(irq);
 162
 163         return desc ? &desc->irq_data : NULL;
 164 }
 165 EXPORT_SYMBOL_GPL(irq_get_irq_data);
 166
 167 /**
 168  *      set_irq_nested_thread - Set/Reset the IRQ_NESTED_THREAD flag of an irq
 169  *
 170  *      @irq:   Interrupt number
 171  *      @nest:  0 to clear / 1 to set the IRQ_NESTED_THREAD flag
 172  *
 173  *      The IRQ_NESTED_THREAD flag indicates that on
 174  *      request_threaded_irq() no separate interrupt thread should be
 175  *      created for the irq as the handler are called nested in the
 176  *      context of a demultiplexing interrupt handler thread.
 177  */
 178 void set_irq_nested_thread(unsigned int irq, int nest)
 179 {
 180         struct irq_desc *desc = irq_to_desc(irq);
 181         unsigned long flags;
 182
 183         if (!desc)
 184                 return;
 185
 186         raw_spin_lock_irqsave(&desc->lock, flags);
 187         if (nest)
 188                 desc->status |= IRQ_NESTED_THREAD;
 189         else
 190                 desc->status &= ~IRQ_NESTED_THREAD;
 191         raw_spin_unlock_irqrestore(&desc->lock, flags);
 192 }
 193 EXPORT_SYMBOL_GPL(set_irq_nested_thread);
 194
 195 int irq_startup(struct irq_desc *desc)
 196 {
 197         desc->status &= ~(IRQ_MASKED | IRQ_DISABLED);
 198         desc->depth = 0;
 199
 200         if (desc->irq_data.chip->irq_startup)
 201                 return desc->irq_data.chip->irq_startup(&desc->irq_data);
 202
 203         irq_enable(desc);
 204         return 0;
 205 }
 206
 207 void irq_shutdown(struct irq_desc *desc)
 208 {
 209         desc->status |= IRQ_MASKED | IRQ_DISABLED;
 210         desc->depth = 1;
 211         desc->irq_data.chip->irq_shutdown(&desc->irq_data);
 212 }
 213
 214 void irq_enable(struct irq_desc *desc)
 215 {
 216         desc->irq_data.chip->irq_enable(&desc->irq_data);
 217 }
 218
 219 void irq_disable(struct irq_desc *desc)
 220 {
 221         desc->irq_data.chip->irq_disable(&desc->irq_data);
 222 }
 223
 224 /*
 225  * default enable function
 226  */
 227 static void default_enable(struct irq_data *data)
 228 {
 229         struct irq_desc *desc = irq_data_to_desc(data);
 230
 231         desc->irq_data.chip->irq_unmask(&desc->irq_data);
 232         desc->status &= ~IRQ_MASKED;
 233 }
 234
 235 /*
 236  * default disable function
 237  */
 238 static void default_disable(struct irq_data *data)
 239 {
 240 }
 241
 242 /*
 243  * default shutdown function
 244  */
 245 static void default_shutdown(struct irq_data *data)
 246 {
 247         struct irq_desc *desc = irq_data_to_desc(data);
 248
 249         desc->irq_data.chip->irq_mask(&desc->irq_data);
 250 }
 251
 252 #ifndef CONFIG_GENERIC_HARDIRQS_NO_DEPRECATED
 253 /* Temporary migration helpers */
 254 static void compat_irq_mask(struct irq_data *data)
 255 {
 256         data->chip->mask(data->irq);
 257 }
 258
 259 static void compat_irq_unmask(struct irq_data *data)
 260 {
 261         data->chip->unmask(data->irq);
 262 }
 263
 264 static void compat_irq_ack(struct irq_data *data)
 265 {
 266         data->chip->ack(data->irq);
 267 }
 268
 269 static void compat_irq_mask_ack(struct irq_data *data)
 270 {
 271         data->chip->mask_ack(data->irq);
 272 }
 273
 274 static void compat_irq_eoi(struct irq_data *data)
 275 {
 276         data->chip->eoi(data->irq);
 277 }
 278
 279 static void compat_irq_enable(struct irq_data *data)
 280 {
 281         data->chip->enable(data->irq);
 282 }
 283
 284 static void compat_irq_disable(struct irq_data *data)
 285 {
 286         data->chip->disable(data->irq);
 287 }
 288
 289 static void compat_irq_shutdown(struct irq_data *data)
 290 {
 291         data->chip->shutdown(data->irq);
 292 }
 293
 294 static unsigned int compat_irq_startup(struct irq_data *data)
 295 {
 296         return data->chip->startup(data->irq);
 297 }
 298
 299 static int compat_irq_set_affinity(struct irq_data *data,
 300                                    const struct cpumask *dest, bool force)
 301 {
 302         return data->chip->set_affinity(data->irq, dest);
 303 }
 304
 305 static int compat_irq_set_type(struct irq_data *data, unsigned int type)
 306 {
 307         return data->chip->set_type(data->irq, type);
 308 }
 309
 310 static int compat_irq_set_wake(struct irq_data *data, unsigned int on)
 311 {
 312         return data->chip->set_wake(data->irq, on);
 313 }
 314
 315 static int compat_irq_retrigger(struct irq_data *data)
 316 {
 317         return data->chip->retrigger(data->irq);
 318 }
 319
 320 static void compat_bus_lock(struct irq_data *data)
 321 {
 322         data->chip->bus_lock(data->irq);
 323 }
 324
 325 static void compat_bus_sync_unlock(struct irq_data *data)
 326 {
 327         data->chip->bus_sync_unlock(data->irq);
 328 }
 329 #endif
 330
 331 /*
 332  * Fixup enable/disable function pointers
 333  */
 334 void irq_chip_set_defaults(struct irq_chip *chip)
 335 {
 336 #ifndef CONFIG_GENERIC_HARDIRQS_NO_DEPRECATED
 337         /*
 338          * Compat fixup functions need to be before we set the
 339          * defaults for enable/disable/startup/shutdown
 340          */
 341         if (chip->enable)
 342                 chip->irq_enable = compat_irq_enable;
 343         if (chip->disable)
 344                 chip->irq_disable = compat_irq_disable;
 345         if (chip->shutdown)
 346                 chip->irq_shutdown = compat_irq_shutdown;
 347         if (chip->startup)
 348                 chip->irq_startup = compat_irq_startup;
 349 #endif
 350         /*
 351          * The real defaults
 352          */
 353         if (!chip->irq_enable)
 354                 chip->irq_enable = default_enable;
 355         if (!chip->irq_disable)
 356                 chip->irq_disable = default_disable;
 357         /*
 358          * We use chip->irq_disable, when the user provided its own. When
 359          * we have default_disable set for chip->irq_disable, then we need
 360          * to use default_shutdown, otherwise the irq line is not
 361          * disabled on free_irq():
 362          */
 363         if (!chip->irq_shutdown)
 364                 chip->irq_shutdown = chip->irq_disable != default_disable ?
 365                         chip->irq_disable : default_shutdown;
 366
 367 #ifndef CONFIG_GENERIC_HARDIRQS_NO_DEPRECATED
 368         if (!chip->end)
 369                 chip->end = dummy_irq_chip.end;
 370
 371         /*
 372          * Now fix up the remaining compat handlers
 373          */
 374         if (chip->bus_lock)
 375                 chip->irq_bus_lock = compat_bus_lock;
 376         if (chip->bus_sync_unlock)
 377                 chip->irq_bus_sync_unlock = compat_bus_sync_unlock;
 378         if (chip->mask)
 379                 chip->irq_mask = compat_irq_mask;
 380         if (chip->unmask)
 381                 chip->irq_unmask = compat_irq_unmask;
 382         if (chip->ack)
 383                 chip->irq_ack = compat_irq_ack;
 384         if (chip->mask_ack)
 385                 chip->irq_mask_ack = compat_irq_mask_ack;
 386         if (chip->eoi)
 387                 chip->irq_eoi = compat_irq_eoi;
 388         if (chip->set_affinity)
 389                 chip->irq_set_affinity = compat_irq_set_affinity;
 390         if (chip->set_type)
 391                 chip->irq_set_type = compat_irq_set_type;
 392         if (chip->set_wake)
 393                 chip->irq_set_wake = compat_irq_set_wake;
 394         if (chip->retrigger)
 395                 chip->irq_retrigger = compat_irq_retrigger;
 396 #endif
 397 }
 398
 399 static inline void mask_ack_irq(struct irq_desc *desc)
 400 {
 401         if (desc->irq_data.chip->irq_mask_ack)
 402                 desc->irq_data.chip->irq_mask_ack(&desc->irq_data);
 403         else {
 404                 desc->irq_data.chip->irq_mask(&desc->irq_data);
 405                 if (desc->irq_data.chip->irq_ack)
 406                         desc->irq_data.chip->irq_ack(&desc->irq_data);
 407         }
 408         desc->status |= IRQ_MASKED;
 409 }
 410
 411 static inline void mask_irq(struct irq_desc *desc)
 412 {
 413         if (desc->irq_data.chip->irq_mask) {
 414                 desc->irq_data.chip->irq_mask(&desc->irq_data);
 415                 desc->status |= IRQ_MASKED;
 416         }
 417 }
 418
 419 static inline void unmask_irq(struct irq_desc *desc)
 420 {
 421         if (desc->irq_data.chip->irq_unmask) {
 422                 desc->irq_data.chip->irq_unmask(&desc->irq_data);
 423                 desc->status &= ~IRQ_MASKED;
 424         }
 425 }
 426
 427 /*
 428  *      handle_nested_irq - Handle a nested irq from a irq thread
 429  *      @irq:   the interrupt number
 430  *
 431  *      Handle interrupts which are nested into a threaded interrupt
 432  *      handler. The handler function is called inside the calling
 433  *      threads context.
 434  */
 435 void handle_nested_irq(unsigned int irq)
 436 {
 437         struct irq_desc *desc = irq_to_desc(irq);
 438         struct irqaction *action;
 439         irqreturn_t action_ret;
 440
 441         might_sleep();
 442
 443         raw_spin_lock_irq(&desc->lock);
 444
 445         kstat_incr_irqs_this_cpu(irq, desc);
 446
 447         action = desc->action;
 448         if (unlikely(!action || (desc->status & IRQ_DISABLED)))
 449                 goto out_unlock;
 450
 451         desc->status |= IRQ_INPROGRESS;
 452         raw_spin_unlock_irq(&desc->lock);
 453
 454         action_ret = action->thread_fn(action->irq, action->dev_id);
 455         if (!noirqdebug)
 456                 note_interrupt(irq, desc, action_ret);
 457
 458         raw_spin_lock_irq(&desc->lock);
 459         desc->status &= ~IRQ_INPROGRESS;
 460
 461 out_unlock:
 462         raw_spin_unlock_irq(&desc->lock);
 463 }
 464 EXPORT_SYMBOL_GPL(handle_nested_irq);
 465
 466 static bool irq_check_poll(struct irq_desc *desc)
 467 {
 468         if (!(desc->status & IRQ_POLL_INPROGRESS))
 469                 return false;
 470         return irq_wait_for_poll(desc);
 471 }
 472
 473 /**
 474  *      handle_simple_irq - Simple and software-decoded IRQs.
 475  *      @irq:   the interrupt number
 476  *      @desc:  the interrupt description structure for this irq
 477  *
 478  *      Simple interrupts are either sent from a demultiplexing interrupt
 479  *      handler or come from hardware, where no interrupt hardware control
 480  *      is necessary.
 481  *
 482  *      Note: The caller is expected to handle the ack, clear, mask and
 483  *      unmask issues if necessary.
 484  */
 485 void
 486 handle_simple_irq(unsigned int irq, struct irq_desc *desc)
 487 {
 488         struct irqaction *action;
 489         irqreturn_t action_ret;
 490
 491         raw_spin_lock(&desc->lock);
 492
 493         if (unlikely(desc->status & IRQ_INPROGRESS))
 494                 if (!irq_check_poll(desc))
 495                         goto out_unlock;
 496
 497         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
 498         kstat_incr_irqs_this_cpu(irq, desc);
 499
 500         action = desc->action;
 501         if (unlikely(!action || (desc->status & IRQ_DISABLED)))
 502                 goto out_unlock;
 503
 504         desc->status |= IRQ_INPROGRESS;
 505         raw_spin_unlock(&desc->lock);
 506
 507         action_ret = handle_IRQ_event(irq, action);
 508         if (!noirqdebug)
 509                 note_interrupt(irq, desc, action_ret);
 510
 511         raw_spin_lock(&desc->lock);
 512         desc->status &= ~IRQ_INPROGRESS;
 513 out_unlock:
 514         raw_spin_unlock(&desc->lock);
 515 }
 516
 517 /**
 518  *      handle_level_irq - Level type irq handler
 519  *      @irq:   the interrupt number
 520  *      @desc:  the interrupt description structure for this irq
 521  *
 522  *      Level type interrupts are active as long as the hardware line has
 523  *      the active level. This may require to mask the interrupt and unmask
 524  *      it after the associated handler has acknowledged the device, so the
 525  *      interrupt line is back to inactive.
 526  */
 527 void
 528 handle_level_irq(unsigned int irq, struct irq_desc *desc)
 529 {
 530         struct irqaction *action;
 531         irqreturn_t action_ret;
 532
 533         raw_spin_lock(&desc->lock);
 534         mask_ack_irq(desc);
 535
 536         if (unlikely(desc->status & IRQ_INPROGRESS))
 537                 if (!irq_check_poll(desc))
 538                         goto out_unlock;
 539
 540         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
 541         kstat_incr_irqs_this_cpu(irq, desc);
 542
 543         /*
 544          * If its disabled or no action available
 545          * keep it masked and get out of here
 546          */
 547         action = desc->action;
 548         if (unlikely(!action || (desc->status & IRQ_DISABLED)))
 549                 goto out_unlock;
 550
 551         desc->status |= IRQ_INPROGRESS;
 552         raw_spin_unlock(&desc->lock);
 553
 554         action_ret = handle_IRQ_event(irq, action);
 555         if (!noirqdebug)
 556                 note_interrupt(irq, desc, action_ret);
 557
 558         raw_spin_lock(&desc->lock);
 559         desc->status &= ~IRQ_INPROGRESS;
 560
 561         if (!(desc->status & (IRQ_DISABLED | IRQ_ONESHOT)))
 562                 unmask_irq(desc);
 563 out_unlock:
 564         raw_spin_unlock(&desc->lock);
 565 }
 566 EXPORT_SYMBOL_GPL(handle_level_irq);
 567
 568 /**
 569  *      handle_fasteoi_irq - irq handler for transparent controllers
 570  *      @irq:   the interrupt number
 571  *      @desc:  the interrupt description structure for this irq
 572  *
 573  *      Only a single callback will be issued to the chip: an ->eoi()
 574  *      call when the interrupt has been serviced. This enables support
 575  *      for modern forms of interrupt handlers, which handle the flow
 576  *      details in hardware, transparently.
 577  */
 578 void
 579 handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc)
 580 {
 581         struct irqaction *action;
 582         irqreturn_t action_ret;
 583
 584         raw_spin_lock(&desc->lock);
 585
 586         if (unlikely(desc->status & IRQ_INPROGRESS))
 587                 if (!irq_check_poll(desc))
 588                         goto out;
 589
 590         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
 591         kstat_incr_irqs_this_cpu(irq, desc);
 592
 593         /*
 594          * If its disabled or no action available
 595          * then mask it and get out of here:
 596          */
 597         action = desc->action;
 598         if (unlikely(!action || (desc->status & IRQ_DISABLED))) {
 599                 desc->status |= IRQ_PENDING;
 600                 mask_irq(desc);
 601                 goto out;
 602         }
 603
 604         desc->status |= IRQ_INPROGRESS;
 605         desc->status &= ~IRQ_PENDING;
 606         raw_spin_unlock(&desc->lock);
 607
 608         action_ret = handle_IRQ_event(irq, action);
 609         if (!noirqdebug)
 610                 note_interrupt(irq, desc, action_ret);
 611
 612         raw_spin_lock(&desc->lock);
 613         desc->status &= ~IRQ_INPROGRESS;
 614 out:
 615         desc->irq_data.chip->irq_eoi(&desc->irq_data);
 616
 617         raw_spin_unlock(&desc->lock);
 618 }
 619
 620 /**
 621  *      handle_edge_irq - edge type IRQ handler
 622  *      @irq:   the interrupt number
 623  *      @desc:  the interrupt description structure for this irq
 624  *
 625  *      Interrupt occures on the falling and/or rising edge of a hardware
 626  *      signal. The occurence is latched into the irq controller hardware
 627  *      and must be acked in order to be reenabled. After the ack another
 628  *      interrupt can happen on the same source even before the first one
 629  *      is handled by the associated event handler. If this happens it
 630  *      might be necessary to disable (mask) the interrupt depending on the
 631  *      controller hardware. This requires to reenable the interrupt inside
 632  *      of the loop which handles the interrupts which have arrived while
 633  *      the handler was running. If all pending interrupts are handled, the
 634  *      loop is left.
 635  */
 636 void
 637 handle_edge_irq(unsigned int irq, struct irq_desc *desc)
 638 {
 639         raw_spin_lock(&desc->lock);
 640
 641         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
 642
 643         /*
 644          * If we're currently running this IRQ, or its disabled,
 645          * we shouldn't process the IRQ. Mark it pending, handle
 646          * the necessary masking and go out
 647          */
 648         if (unlikely((desc->status & (IRQ_INPROGRESS | IRQ_DISABLED)) ||
 649                     !desc->action)) {
 650                 if (!irq_check_poll(desc)) {
 651                         desc->status |= (IRQ_PENDING | IRQ_MASKED);
 652                         mask_ack_irq(desc);
 653                         goto out_unlock;
 654                 }
 655         }
 656         kstat_incr_irqs_this_cpu(irq, desc);
 657
 658         /* Start handling the irq */
 659         desc->irq_data.chip->irq_ack(&desc->irq_data);
 660
 661         /* Mark the IRQ currently in progress.*/
 662         desc->status |= IRQ_INPROGRESS;
 663
 664         do {
 665                 struct irqaction *action = desc->action;
 666                 irqreturn_t action_ret;
 667
 668                 if (unlikely(!action)) {
 669                         mask_irq(desc);
 670                         goto out_unlock;
 671                 }
 672
 673                 /*
 674                  * When another irq arrived while we were handling
 675                  * one, we could have masked the irq.
 676                  * Renable it, if it was not disabled in meantime.
 677                  */
 678                 if (unlikely((desc->status &
 679                                (IRQ_PENDING | IRQ_MASKED | IRQ_DISABLED)) ==
 680                               (IRQ_PENDING | IRQ_MASKED))) {
 681                         unmask_irq(desc);
 682                 }
 683
 684                 desc->status &= ~IRQ_PENDING;
 685                 raw_spin_unlock(&desc->lock);
 686                 action_ret = handle_IRQ_event(irq, action);
 687                 if (!noirqdebug)
 688                         note_interrupt(irq, desc, action_ret);
 689                 raw_spin_lock(&desc->lock);
 690
 691         } while ((desc->status & (IRQ_PENDING | IRQ_DISABLED)) == IRQ_PENDING);
 692
 693         desc->status &= ~IRQ_INPROGRESS;
 694 out_unlock:
 695         raw_spin_unlock(&desc->lock);
 696 }
 697
 698 /**
 699  *      handle_percpu_irq - Per CPU local irq handler
 700  *      @irq:   the interrupt number
 701  *      @desc:  the interrupt description structure for this irq
 702  *
 703  *      Per CPU interrupts on SMP machines without locking requirements
 704  */
 705 void
 706 handle_percpu_irq(unsigned int irq, struct irq_desc *desc)
 707 {
 708         irqreturn_t action_ret;
 709
 710         kstat_incr_irqs_this_cpu(irq, desc);
 711
 712         if (desc->irq_data.chip->irq_ack)
 713                 desc->irq_data.chip->irq_ack(&desc->irq_data);
 714
 715         action_ret = handle_IRQ_event(irq, desc->action);
 716         if (!noirqdebug)
 717                 note_interrupt(irq, desc, action_ret);
 718
 719         if (desc->irq_data.chip->irq_eoi)
 720                 desc->irq_data.chip->irq_eoi(&desc->irq_data);
 721 }
 722
 723 void
 724 __set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
 725                   const char *name)
 726 {
 727         struct irq_desc *desc = irq_to_desc(irq);
 728         unsigned long flags;
 729
 730         if (!desc) {
 731                 printk(KERN_ERR
 732                        "Trying to install type control for IRQ%d\n", irq);
 733                 return;
 734         }
 735
 736         if (!handle)
 737                 handle = handle_bad_irq;
 738         else if (desc->irq_data.chip == &no_irq_chip) {
 739                 printk(KERN_WARNING "Trying to install %sinterrupt handler "
 740                        "for IRQ%d\n", is_chained ? "chained " : "", irq);
 741                 /*
 742                  * Some ARM implementations install a handler for really dumb
 743                  * interrupt hardware without setting an irq_chip. This worked
 744                  * with the ARM no_irq_chip but the check in setup_irq would
 745                  * prevent us to setup the interrupt at all. Switch it to
 746                  * dummy_irq_chip for easy transition.
 747                  */
 748                 desc->irq_data.chip = &dummy_irq_chip;
 749         }
 750
 751         chip_bus_lock(desc);
 752         raw_spin_lock_irqsave(&desc->lock, flags);
 753
 754         /* Uninstall? */
 755         if (handle == handle_bad_irq) {
 756                 if (desc->irq_data.chip != &no_irq_chip)
 757                         mask_ack_irq(desc);
 758                 desc->status |= IRQ_DISABLED;
 759                 desc->depth = 1;
 760         }
 761         desc->handle_irq = handle;
 762         desc->name = name;
 763
 764         if (handle != handle_bad_irq && is_chained) {
 765                 desc->status |= IRQ_NOREQUEST | IRQ_NOPROBE;
 766                 irq_startup(desc);
 767         }
 768         raw_spin_unlock_irqrestore(&desc->lock, flags);
 769         chip_bus_sync_unlock(desc);
 770 }
 771 EXPORT_SYMBOL_GPL(__set_irq_handler);
 772
 773 void
 774 set_irq_chip_and_handler(unsigned int irq, struct irq_chip *chip,
 775                          irq_flow_handler_t handle)
 776 {
 777         set_irq_chip(irq, chip);
 778         __set_irq_handler(irq, handle, 0, NULL);
 779 }
 780
 781 void
 782 set_irq_chip_and_handler_name(unsigned int irq, struct irq_chip *chip,
 783                               irq_flow_handler_t handle, const char *name)
 784 {
 785         set_irq_chip(irq, chip);
 786         __set_irq_handler(irq, handle, 0, name);
 787 }
 788
 789 void irq_modify_status(unsigned int irq, unsigned long clr, unsigned long set)
 790 {
 791         struct irq_desc *desc = irq_to_desc(irq);
 792         unsigned long flags;
 793
 794         if (!desc)
 795                 return;
 796
 797         /* Sanitize flags */
 798         set &= IRQF_MODIFY_MASK;
 799         clr &= IRQF_MODIFY_MASK;
 800
 801         raw_spin_lock_irqsave(&desc->lock, flags);
 802         desc->status &= ~clr;
 803         desc->status |= set;
 804         raw_spin_unlock_irqrestore(&desc->lock, flags);
 805 }