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