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 static bool irq_check_poll(struct irq_desc *desc)
 452 {
 453         if (!(desc->status & IRQ_POLL_INPROGRESS))
 454                 return false;
 455         return irq_wait_for_poll(desc);
 456 }
 457
 458 /**
 459  *      handle_simple_irq - Simple and software-decoded IRQs.
 460  *      @irq:   the interrupt number
 461  *      @desc:  the interrupt description structure for this irq
 462  *
 463  *      Simple interrupts are either sent from a demultiplexing interrupt
 464  *      handler or come from hardware, where no interrupt hardware control
 465  *      is necessary.
 466  *
 467  *      Note: The caller is expected to handle the ack, clear, mask and
 468  *      unmask issues if necessary.
 469  */
 470 void
 471 handle_simple_irq(unsigned int irq, struct irq_desc *desc)
 472 {
 473         struct irqaction *action;
 474         irqreturn_t action_ret;
 475
 476         raw_spin_lock(&desc->lock);
 477
 478         if (unlikely(desc->status & IRQ_INPROGRESS))
 479                 if (!irq_check_poll(desc))
 480                         goto out_unlock;
 481
 482         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
 483         kstat_incr_irqs_this_cpu(irq, desc);
 484
 485         action = desc->action;
 486         if (unlikely(!action || (desc->status & IRQ_DISABLED)))
 487                 goto out_unlock;
 488
 489         desc->status |= IRQ_INPROGRESS;
 490         raw_spin_unlock(&desc->lock);
 491
 492         action_ret = handle_IRQ_event(irq, action);
 493         if (!noirqdebug)
 494                 note_interrupt(irq, desc, action_ret);
 495
 496         raw_spin_lock(&desc->lock);
 497         desc->status &= ~IRQ_INPROGRESS;
 498 out_unlock:
 499         raw_spin_unlock(&desc->lock);
 500 }
 501
 502 /**
 503  *      handle_level_irq - Level type irq handler
 504  *      @irq:   the interrupt number
 505  *      @desc:  the interrupt description structure for this irq
 506  *
 507  *      Level type interrupts are active as long as the hardware line has
 508  *      the active level. This may require to mask the interrupt and unmask
 509  *      it after the associated handler has acknowledged the device, so the
 510  *      interrupt line is back to inactive.
 511  */
 512 void
 513 handle_level_irq(unsigned int irq, struct irq_desc *desc)
 514 {
 515         struct irqaction *action;
 516         irqreturn_t action_ret;
 517
 518         raw_spin_lock(&desc->lock);
 519         mask_ack_irq(desc);
 520
 521         if (unlikely(desc->status & IRQ_INPROGRESS))
 522                 if (!irq_check_poll(desc))
 523                         goto out_unlock;
 524
 525         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
 526         kstat_incr_irqs_this_cpu(irq, desc);
 527
 528         /*
 529          * If its disabled or no action available
 530          * keep it masked and get out of here
 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(&desc->lock);
 538
 539         action_ret = handle_IRQ_event(irq, action);
 540         if (!noirqdebug)
 541                 note_interrupt(irq, desc, action_ret);
 542
 543         raw_spin_lock(&desc->lock);
 544         desc->status &= ~IRQ_INPROGRESS;
 545
 546         if (!(desc->status & (IRQ_DISABLED | IRQ_ONESHOT)))
 547                 unmask_irq(desc);
 548 out_unlock:
 549         raw_spin_unlock(&desc->lock);
 550 }
 551 EXPORT_SYMBOL_GPL(handle_level_irq);
 552
 553 /**
 554  *      handle_fasteoi_irq - irq handler for transparent controllers
 555  *      @irq:   the interrupt number
 556  *      @desc:  the interrupt description structure for this irq
 557  *
 558  *      Only a single callback will be issued to the chip: an ->eoi()
 559  *      call when the interrupt has been serviced. This enables support
 560  *      for modern forms of interrupt handlers, which handle the flow
 561  *      details in hardware, transparently.
 562  */
 563 void
 564 handle_fasteoi_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                 if (!irq_check_poll(desc))
 573                         goto out;
 574
 575         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
 576         kstat_incr_irqs_this_cpu(irq, desc);
 577
 578         /*
 579          * If its disabled or no action available
 580          * then mask it and get out of here:
 581          */
 582         action = desc->action;
 583         if (unlikely(!action || (desc->status & IRQ_DISABLED))) {
 584                 desc->status |= IRQ_PENDING;
 585                 mask_irq(desc);
 586                 goto out;
 587         }
 588
 589         desc->status |= IRQ_INPROGRESS;
 590         desc->status &= ~IRQ_PENDING;
 591         raw_spin_unlock(&desc->lock);
 592
 593         action_ret = handle_IRQ_event(irq, action);
 594         if (!noirqdebug)
 595                 note_interrupt(irq, desc, action_ret);
 596
 597         raw_spin_lock(&desc->lock);
 598         desc->status &= ~IRQ_INPROGRESS;
 599 out:
 600         desc->irq_data.chip->irq_eoi(&desc->irq_data);
 601
 602         raw_spin_unlock(&desc->lock);
 603 }
 604
 605 /**
 606  *      handle_edge_irq - edge type IRQ handler
 607  *      @irq:   the interrupt number
 608  *      @desc:  the interrupt description structure for this irq
 609  *
 610  *      Interrupt occures on the falling and/or rising edge of a hardware
 611  *      signal. The occurence is latched into the irq controller hardware
 612  *      and must be acked in order to be reenabled. After the ack another
 613  *      interrupt can happen on the same source even before the first one
 614  *      is handled by the associated event handler. If this happens it
 615  *      might be necessary to disable (mask) the interrupt depending on the
 616  *      controller hardware. This requires to reenable the interrupt inside
 617  *      of the loop which handles the interrupts which have arrived while
 618  *      the handler was running. If all pending interrupts are handled, the
 619  *      loop is left.
 620  */
 621 void
 622 handle_edge_irq(unsigned int irq, struct irq_desc *desc)
 623 {
 624         raw_spin_lock(&desc->lock);
 625
 626         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
 627
 628         /*
 629          * If we're currently running this IRQ, or its disabled,
 630          * we shouldn't process the IRQ. Mark it pending, handle
 631          * the necessary masking and go out
 632          */
 633         if (unlikely((desc->status & (IRQ_INPROGRESS | IRQ_DISABLED)) ||
 634                     !desc->action)) {
 635                 if (!irq_check_poll(desc)) {
 636                         desc->status |= (IRQ_PENDING | IRQ_MASKED);
 637                         mask_ack_irq(desc);
 638                         goto out_unlock;
 639                 }
 640         }
 641         kstat_incr_irqs_this_cpu(irq, desc);
 642
 643         /* Start handling the irq */
 644         desc->irq_data.chip->irq_ack(&desc->irq_data);
 645
 646         /* Mark the IRQ currently in progress.*/
 647         desc->status |= IRQ_INPROGRESS;
 648
 649         do {
 650                 struct irqaction *action = desc->action;
 651                 irqreturn_t action_ret;
 652
 653                 if (unlikely(!action)) {
 654                         mask_irq(desc);
 655                         goto out_unlock;
 656                 }
 657
 658                 /*
 659                  * When another irq arrived while we were handling
 660                  * one, we could have masked the irq.
 661                  * Renable it, if it was not disabled in meantime.
 662                  */
 663                 if (unlikely((desc->status &
 664                                (IRQ_PENDING | IRQ_MASKED | IRQ_DISABLED)) ==
 665                               (IRQ_PENDING | IRQ_MASKED))) {
 666                         unmask_irq(desc);
 667                 }
 668
 669                 desc->status &= ~IRQ_PENDING;
 670                 raw_spin_unlock(&desc->lock);
 671                 action_ret = handle_IRQ_event(irq, action);
 672                 if (!noirqdebug)
 673                         note_interrupt(irq, desc, action_ret);
 674                 raw_spin_lock(&desc->lock);
 675
 676         } while ((desc->status & (IRQ_PENDING | IRQ_DISABLED)) == IRQ_PENDING);
 677
 678         desc->status &= ~IRQ_INPROGRESS;
 679 out_unlock:
 680         raw_spin_unlock(&desc->lock);
 681 }
 682
 683 /**
 684  *      handle_percpu_irq - Per CPU local irq handler
 685  *      @irq:   the interrupt number
 686  *      @desc:  the interrupt description structure for this irq
 687  *
 688  *      Per CPU interrupts on SMP machines without locking requirements
 689  */
 690 void
 691 handle_percpu_irq(unsigned int irq, struct irq_desc *desc)
 692 {
 693         irqreturn_t action_ret;
 694
 695         kstat_incr_irqs_this_cpu(irq, desc);
 696
 697         if (desc->irq_data.chip->irq_ack)
 698                 desc->irq_data.chip->irq_ack(&desc->irq_data);
 699
 700         action_ret = handle_IRQ_event(irq, desc->action);
 701         if (!noirqdebug)
 702                 note_interrupt(irq, desc, action_ret);
 703
 704         if (desc->irq_data.chip->irq_eoi)
 705                 desc->irq_data.chip->irq_eoi(&desc->irq_data);
 706 }
 707
 708 void
 709 __set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
 710                   const char *name)
 711 {
 712         struct irq_desc *desc = irq_to_desc(irq);
 713         unsigned long flags;
 714
 715         if (!desc) {
 716                 printk(KERN_ERR
 717                        "Trying to install type control for IRQ%d\n", irq);
 718                 return;
 719         }
 720
 721         if (!handle)
 722                 handle = handle_bad_irq;
 723         else if (desc->irq_data.chip == &no_irq_chip) {
 724                 printk(KERN_WARNING "Trying to install %sinterrupt handler "
 725                        "for IRQ%d\n", is_chained ? "chained " : "", irq);
 726                 /*
 727                  * Some ARM implementations install a handler for really dumb
 728                  * interrupt hardware without setting an irq_chip. This worked
 729                  * with the ARM no_irq_chip but the check in setup_irq would
 730                  * prevent us to setup the interrupt at all. Switch it to
 731                  * dummy_irq_chip for easy transition.
 732                  */
 733                 desc->irq_data.chip = &dummy_irq_chip;
 734         }
 735
 736         chip_bus_lock(desc);
 737         raw_spin_lock_irqsave(&desc->lock, flags);
 738
 739         /* Uninstall? */
 740         if (handle == handle_bad_irq) {
 741                 if (desc->irq_data.chip != &no_irq_chip)
 742                         mask_ack_irq(desc);
 743                 desc->status |= IRQ_DISABLED;
 744                 desc->depth = 1;
 745         }
 746         desc->handle_irq = handle;
 747         desc->name = name;
 748
 749         if (handle != handle_bad_irq && is_chained) {
 750                 desc->status &= ~IRQ_DISABLED;
 751                 desc->status |= IRQ_NOREQUEST | IRQ_NOPROBE;
 752                 desc->depth = 0;
 753                 desc->irq_data.chip->irq_startup(&desc->irq_data);
 754         }
 755         raw_spin_unlock_irqrestore(&desc->lock, flags);
 756         chip_bus_sync_unlock(desc);
 757 }
 758 EXPORT_SYMBOL_GPL(__set_irq_handler);
 759
 760 void
 761 set_irq_chip_and_handler(unsigned int irq, struct irq_chip *chip,
 762                          irq_flow_handler_t handle)
 763 {
 764         set_irq_chip(irq, chip);
 765         __set_irq_handler(irq, handle, 0, NULL);
 766 }
 767
 768 void
 769 set_irq_chip_and_handler_name(unsigned int irq, struct irq_chip *chip,
 770                               irq_flow_handler_t handle, const char *name)
 771 {
 772         set_irq_chip(irq, chip);
 773         __set_irq_handler(irq, handle, 0, name);
 774 }
 775
 776 void irq_modify_status(unsigned int irq, unsigned long clr, unsigned long set)
 777 {
 778         struct irq_desc *desc = irq_to_desc(irq);
 779         unsigned long flags;
 780
 781         if (!desc)
 782                 return;
 783
 784         /* Sanitize flags */
 785         set &= IRQF_MODIFY_MASK;
 786         clr &= IRQF_MODIFY_MASK;
 787
 788         raw_spin_lock_irqsave(&desc->lock, flags);
 789         desc->status &= ~clr;
 790         desc->status |= set;
 791         raw_spin_unlock_irqrestore(&desc->lock, flags);
 792 }