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         unsigned long flags;
  29         struct irq_desc *desc = irq_get_desc_lock(irq, &flags);
  30
  31         if (!desc)
  32                 return -EINVAL;
  33
  34         if (!chip)
  35                 chip = &no_irq_chip;
  36
  37         desc->irq_data.chip = chip;
  38         irq_put_desc_unlock(desc, flags);
  39         /*
  40          * For !CONFIG_SPARSE_IRQ make the irq show up in
  41          * allocated_irqs. For the CONFIG_SPARSE_IRQ case, it is
  42          * already marked, and this call is harmless.
  43          */
  44         irq_reserve_irq(irq);
  45         return 0;
  46 }
  47 EXPORT_SYMBOL(irq_set_chip);
  48
  49 /**
  50  *      irq_set_type - set the irq trigger type for an irq
  51  *      @irq:   irq number
  52  *      @type:  IRQ_TYPE_{LEVEL,EDGE}_* value - see include/linux/irq.h
  53  */
  54 int irq_set_irq_type(unsigned int irq, unsigned int type)
  55 {
  56         unsigned long flags;
  57         struct irq_desc *desc = irq_get_desc_buslock(irq, &flags);
  58         int ret = 0;
  59
  60         if (!desc)
  61                 return -EINVAL;
  62
  63         type &= IRQ_TYPE_SENSE_MASK;
  64         if (type != IRQ_TYPE_NONE)
  65                 ret = __irq_set_trigger(desc, irq, type);
  66         irq_put_desc_busunlock(desc, flags);
  67         return ret;
  68 }
  69 EXPORT_SYMBOL(irq_set_irq_type);
  70
  71 /**
  72  *      irq_set_handler_data - set irq handler data for an irq
  73  *      @irq:   Interrupt number
  74  *      @data:  Pointer to interrupt specific data
  75  *
  76  *      Set the hardware irq controller data for an irq
  77  */
  78 int irq_set_handler_data(unsigned int irq, void *data)
  79 {
  80         unsigned long flags;
  81         struct irq_desc *desc = irq_get_desc_lock(irq, &flags);
  82
  83         if (!desc)
  84                 return -EINVAL;
  85         desc->irq_data.handler_data = data;
  86         irq_put_desc_unlock(desc, flags);
  87         return 0;
  88 }
  89 EXPORT_SYMBOL(irq_set_handler_data);
  90
  91 /**
  92  *      irq_set_msi_desc - set MSI descriptor data for an irq
  93  *      @irq:   Interrupt number
  94  *      @entry: Pointer to MSI descriptor data
  95  *
  96  *      Set the MSI descriptor entry for an irq
  97  */
  98 int irq_set_msi_desc(unsigned int irq, struct msi_desc *entry)
  99 {
 100         unsigned long flags;
 101         struct irq_desc *desc = irq_get_desc_lock(irq, &flags);
 102
 103         if (!desc)
 104                 return -EINVAL;
 105         desc->irq_data.msi_desc = entry;
 106         if (entry)
 107                 entry->irq = irq;
 108         irq_put_desc_unlock(desc, flags);
 109         return 0;
 110 }
 111
 112 /**
 113  *      irq_set_chip_data - set irq chip data for an irq
 114  *      @irq:   Interrupt number
 115  *      @data:  Pointer to chip specific data
 116  *
 117  *      Set the hardware irq chip data for an irq
 118  */
 119 int irq_set_chip_data(unsigned int irq, void *data)
 120 {
 121         unsigned long flags;
 122         struct irq_desc *desc = irq_get_desc_lock(irq, &flags);
 123
 124         if (!desc)
 125                 return -EINVAL;
 126         desc->irq_data.chip_data = data;
 127         irq_put_desc_unlock(desc, flags);
 128         return 0;
 129 }
 130 EXPORT_SYMBOL(irq_set_chip_data);
 131
 132 struct irq_data *irq_get_irq_data(unsigned int irq)
 133 {
 134         struct irq_desc *desc = irq_to_desc(irq);
 135
 136         return desc ? &desc->irq_data : NULL;
 137 }
 138 EXPORT_SYMBOL_GPL(irq_get_irq_data);
 139
 140 static void irq_state_clr_disabled(struct irq_desc *desc)
 141 {
 142         irqd_clear(&desc->irq_data, IRQD_IRQ_DISABLED);
 143 }
 144
 145 static void irq_state_set_disabled(struct irq_desc *desc)
 146 {
 147         irqd_set(&desc->irq_data, IRQD_IRQ_DISABLED);
 148 }
 149
 150 static void irq_state_clr_masked(struct irq_desc *desc)
 151 {
 152         irqd_clear(&desc->irq_data, IRQD_IRQ_MASKED);
 153 }
 154
 155 static void irq_state_set_masked(struct irq_desc *desc)
 156 {
 157         irqd_set(&desc->irq_data, IRQD_IRQ_MASKED);
 158 }
 159
 160 int irq_startup(struct irq_desc *desc)
 161 {
 162         irq_state_clr_disabled(desc);
 163         desc->depth = 0;
 164
 165         if (desc->irq_data.chip->irq_startup) {
 166                 int ret = desc->irq_data.chip->irq_startup(&desc->irq_data);
 167                 irq_state_clr_masked(desc);
 168                 return ret;
 169         }
 170
 171         irq_enable(desc);
 172         return 0;
 173 }
 174
 175 void irq_shutdown(struct irq_desc *desc)
 176 {
 177         irq_state_set_disabled(desc);
 178         desc->depth = 1;
 179         if (desc->irq_data.chip->irq_shutdown)
 180                 desc->irq_data.chip->irq_shutdown(&desc->irq_data);
 181         else if (desc->irq_data.chip->irq_disable)
 182                 desc->irq_data.chip->irq_disable(&desc->irq_data);
 183         else
 184                 desc->irq_data.chip->irq_mask(&desc->irq_data);
 185         irq_state_set_masked(desc);
 186 }
 187
 188 void irq_enable(struct irq_desc *desc)
 189 {
 190         irq_state_clr_disabled(desc);
 191         if (desc->irq_data.chip->irq_enable)
 192                 desc->irq_data.chip->irq_enable(&desc->irq_data);
 193         else
 194                 desc->irq_data.chip->irq_unmask(&desc->irq_data);
 195         irq_state_clr_masked(desc);
 196 }
 197
 198 void irq_disable(struct irq_desc *desc)
 199 {
 200         irq_state_set_disabled(desc);
 201         if (desc->irq_data.chip->irq_disable) {
 202                 desc->irq_data.chip->irq_disable(&desc->irq_data);
 203                 irq_state_set_masked(desc);
 204         }
 205 }
 206
 207 static inline void mask_ack_irq(struct irq_desc *desc)
 208 {
 209         if (desc->irq_data.chip->irq_mask_ack)
 210                 desc->irq_data.chip->irq_mask_ack(&desc->irq_data);
 211         else {
 212                 desc->irq_data.chip->irq_mask(&desc->irq_data);
 213                 if (desc->irq_data.chip->irq_ack)
 214                         desc->irq_data.chip->irq_ack(&desc->irq_data);
 215         }
 216         irq_state_set_masked(desc);
 217 }
 218
 219 void mask_irq(struct irq_desc *desc)
 220 {
 221         if (desc->irq_data.chip->irq_mask) {
 222                 desc->irq_data.chip->irq_mask(&desc->irq_data);
 223                 irq_state_set_masked(desc);
 224         }
 225 }
 226
 227 void unmask_irq(struct irq_desc *desc)
 228 {
 229         if (desc->irq_data.chip->irq_unmask) {
 230                 desc->irq_data.chip->irq_unmask(&desc->irq_data);
 231                 irq_state_clr_masked(desc);
 232         }
 233 }
 234
 235 /*
 236  *      handle_nested_irq - Handle a nested irq from a irq thread
 237  *      @irq:   the interrupt number
 238  *
 239  *      Handle interrupts which are nested into a threaded interrupt
 240  *      handler. The handler function is called inside the calling
 241  *      threads context.
 242  */
 243 void handle_nested_irq(unsigned int irq)
 244 {
 245         struct irq_desc *desc = irq_to_desc(irq);
 246         struct irqaction *action;
 247         irqreturn_t action_ret;
 248
 249         might_sleep();
 250
 251         raw_spin_lock_irq(&desc->lock);
 252
 253         kstat_incr_irqs_this_cpu(irq, desc);
 254
 255         action = desc->action;
 256         if (unlikely(!action || irqd_irq_disabled(&desc->irq_data)))
 257                 goto out_unlock;
 258
 259         irqd_set(&desc->irq_data, IRQD_IRQ_INPROGRESS);
 260         raw_spin_unlock_irq(&desc->lock);
 261
 262         action_ret = action->thread_fn(action->irq, action->dev_id);
 263         if (!noirqdebug)
 264                 note_interrupt(irq, desc, action_ret);
 265
 266         raw_spin_lock_irq(&desc->lock);
 267         irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
 268
 269 out_unlock:
 270         raw_spin_unlock_irq(&desc->lock);
 271 }
 272 EXPORT_SYMBOL_GPL(handle_nested_irq);
 273
 274 static bool irq_check_poll(struct irq_desc *desc)
 275 {
 276         if (!(desc->istate & IRQS_POLL_INPROGRESS))
 277                 return false;
 278         return irq_wait_for_poll(desc);
 279 }
 280
 281 /**
 282  *      handle_simple_irq - Simple and software-decoded IRQs.
 283  *      @irq:   the interrupt number
 284  *      @desc:  the interrupt description structure for this irq
 285  *
 286  *      Simple interrupts are either sent from a demultiplexing interrupt
 287  *      handler or come from hardware, where no interrupt hardware control
 288  *      is necessary.
 289  *
 290  *      Note: The caller is expected to handle the ack, clear, mask and
 291  *      unmask issues if necessary.
 292  */
 293 void
 294 handle_simple_irq(unsigned int irq, struct irq_desc *desc)
 295 {
 296         raw_spin_lock(&desc->lock);
 297
 298         if (unlikely(irqd_irq_inprogress(&desc->irq_data)))
 299                 if (!irq_check_poll(desc))
 300                         goto out_unlock;
 301
 302         desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
 303         kstat_incr_irqs_this_cpu(irq, desc);
 304
 305         if (unlikely(!desc->action || irqd_irq_disabled(&desc->irq_data)))
 306                 goto out_unlock;
 307
 308         handle_irq_event(desc);
 309
 310 out_unlock:
 311         raw_spin_unlock(&desc->lock);
 312 }
 313 EXPORT_SYMBOL_GPL(handle_simple_irq);
 314
 315 /**
 316  *      handle_level_irq - Level type irq handler
 317  *      @irq:   the interrupt number
 318  *      @desc:  the interrupt description structure for this irq
 319  *
 320  *      Level type interrupts are active as long as the hardware line has
 321  *      the active level. This may require to mask the interrupt and unmask
 322  *      it after the associated handler has acknowledged the device, so the
 323  *      interrupt line is back to inactive.
 324  */
 325 void
 326 handle_level_irq(unsigned int irq, struct irq_desc *desc)
 327 {
 328         raw_spin_lock(&desc->lock);
 329         mask_ack_irq(desc);
 330
 331         if (unlikely(irqd_irq_inprogress(&desc->irq_data)))
 332                 if (!irq_check_poll(desc))
 333                         goto out_unlock;
 334
 335         desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
 336         kstat_incr_irqs_this_cpu(irq, desc);
 337
 338         /*
 339          * If its disabled or no action available
 340          * keep it masked and get out of here
 341          */
 342         if (unlikely(!desc->action || irqd_irq_disabled(&desc->irq_data)))
 343                 goto out_unlock;
 344
 345         handle_irq_event(desc);
 346
 347         if (!irqd_irq_disabled(&desc->irq_data) && !(desc->istate & IRQS_ONESHOT))
 348                 unmask_irq(desc);
 349 out_unlock:
 350         raw_spin_unlock(&desc->lock);
 351 }
 352 EXPORT_SYMBOL_GPL(handle_level_irq);
 353
 354 #ifdef CONFIG_IRQ_PREFLOW_FASTEOI
 355 static inline void preflow_handler(struct irq_desc *desc)
 356 {
 357         if (desc->preflow_handler)
 358                 desc->preflow_handler(&desc->irq_data);
 359 }
 360 #else
 361 static inline void preflow_handler(struct irq_desc *desc) { }
 362 #endif
 363
 364 /**
 365  *      handle_fasteoi_irq - irq handler for transparent controllers
 366  *      @irq:   the interrupt number
 367  *      @desc:  the interrupt description structure for this irq
 368  *
 369  *      Only a single callback will be issued to the chip: an ->eoi()
 370  *      call when the interrupt has been serviced. This enables support
 371  *      for modern forms of interrupt handlers, which handle the flow
 372  *      details in hardware, transparently.
 373  */
 374 void
 375 handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc)
 376 {
 377         raw_spin_lock(&desc->lock);
 378
 379         if (unlikely(irqd_irq_inprogress(&desc->irq_data)))
 380                 if (!irq_check_poll(desc))
 381                         goto out;
 382
 383         desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
 384         kstat_incr_irqs_this_cpu(irq, desc);
 385
 386         /*
 387          * If its disabled or no action available
 388          * then mask it and get out of here:
 389          */
 390         if (unlikely(!desc->action || irqd_irq_disabled(&desc->irq_data))) {
 391                 desc->istate |= IRQS_PENDING;
 392                 mask_irq(desc);
 393                 goto out;
 394         }
 395
 396         if (desc->istate & IRQS_ONESHOT)
 397                 mask_irq(desc);
 398
 399         preflow_handler(desc);
 400         handle_irq_event(desc);
 401
 402 out_eoi:
 403         desc->irq_data.chip->irq_eoi(&desc->irq_data);
 404 out_unlock:
 405         raw_spin_unlock(&desc->lock);
 406         return;
 407 out:
 408         if (!(desc->irq_data.chip->flags & IRQCHIP_EOI_IF_HANDLED))
 409                 goto out_eoi;
 410         goto out_unlock;
 411 }
 412
 413 /**
 414  *      handle_edge_irq - edge type IRQ handler
 415  *      @irq:   the interrupt number
 416  *      @desc:  the interrupt description structure for this irq
 417  *
 418  *      Interrupt occures on the falling and/or rising edge of a hardware
 419  *      signal. The occurrence is latched into the irq controller hardware
 420  *      and must be acked in order to be reenabled. After the ack another
 421  *      interrupt can happen on the same source even before the first one
 422  *      is handled by the associated event handler. If this happens it
 423  *      might be necessary to disable (mask) the interrupt depending on the
 424  *      controller hardware. This requires to reenable the interrupt inside
 425  *      of the loop which handles the interrupts which have arrived while
 426  *      the handler was running. If all pending interrupts are handled, the
 427  *      loop is left.
 428  */
 429 void
 430 handle_edge_irq(unsigned int irq, struct irq_desc *desc)
 431 {
 432         raw_spin_lock(&desc->lock);
 433
 434         desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
 435         /*
 436          * If we're currently running this IRQ, or its disabled,
 437          * we shouldn't process the IRQ. Mark it pending, handle
 438          * the necessary masking and go out
 439          */
 440         if (unlikely(irqd_irq_disabled(&desc->irq_data) ||
 441                      irqd_irq_inprogress(&desc->irq_data) || !desc->action)) {
 442                 if (!irq_check_poll(desc)) {
 443                         desc->istate |= IRQS_PENDING;
 444                         mask_ack_irq(desc);
 445                         goto out_unlock;
 446                 }
 447         }
 448         kstat_incr_irqs_this_cpu(irq, desc);
 449
 450         /* Start handling the irq */
 451         desc->irq_data.chip->irq_ack(&desc->irq_data);
 452
 453         do {
 454                 if (unlikely(!desc->action)) {
 455                         mask_irq(desc);
 456                         goto out_unlock;
 457                 }
 458
 459                 /*
 460                  * When another irq arrived while we were handling
 461                  * one, we could have masked the irq.
 462                  * Renable it, if it was not disabled in meantime.
 463                  */
 464                 if (unlikely(desc->istate & IRQS_PENDING)) {
 465                         if (!irqd_irq_disabled(&desc->irq_data) &&
 466                             irqd_irq_masked(&desc->irq_data))
 467                                 unmask_irq(desc);
 468                 }
 469
 470                 handle_irq_event(desc);
 471
 472         } while ((desc->istate & IRQS_PENDING) &&
 473                  !irqd_irq_disabled(&desc->irq_data));
 474
 475 out_unlock:
 476         raw_spin_unlock(&desc->lock);
 477 }
 478
 479 #ifdef CONFIG_IRQ_EDGE_EOI_HANDLER
 480 /**
 481  *      handle_edge_eoi_irq - edge eoi type IRQ handler
 482  *      @irq:   the interrupt number
 483  *      @desc:  the interrupt description structure for this irq
 484  *
 485  * Similar as the above handle_edge_irq, but using eoi and w/o the
 486  * mask/unmask logic.
 487  */
 488 void handle_edge_eoi_irq(unsigned int irq, struct irq_desc *desc)
 489 {
 490         struct irq_chip *chip = irq_desc_get_chip(desc);
 491
 492         raw_spin_lock(&desc->lock);
 493
 494         desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
 495         /*
 496          * If we're currently running this IRQ, or its disabled,
 497          * we shouldn't process the IRQ. Mark it pending, handle
 498          * the necessary masking and go out
 499          */
 500         if (unlikely(irqd_irq_disabled(&desc->irq_data) ||
 501                      irqd_irq_inprogress(&desc->irq_data) || !desc->action)) {
 502                 if (!irq_check_poll(desc)) {
 503                         desc->istate |= IRQS_PENDING;
 504                         goto out_eoi;
 505                 }
 506         }
 507         kstat_incr_irqs_this_cpu(irq, desc);
 508
 509         do {
 510                 if (unlikely(!desc->action))
 511                         goto out_eoi;
 512
 513                 handle_irq_event(desc);
 514
 515         } while ((desc->istate & IRQS_PENDING) &&
 516                  !irqd_irq_disabled(&desc->irq_data));
 517
 518 out_eoi:
 519         chip->irq_eoi(&desc->irq_data);
 520         raw_spin_unlock(&desc->lock);
 521 }
 522 #endif
 523
 524 /**
 525  *      handle_percpu_irq - Per CPU local irq handler
 526  *      @irq:   the interrupt number
 527  *      @desc:  the interrupt description structure for this irq
 528  *
 529  *      Per CPU interrupts on SMP machines without locking requirements
 530  */
 531 void
 532 handle_percpu_irq(unsigned int irq, struct irq_desc *desc)
 533 {
 534         struct irq_chip *chip = irq_desc_get_chip(desc);
 535
 536         kstat_incr_irqs_this_cpu(irq, desc);
 537
 538         if (chip->irq_ack)
 539                 chip->irq_ack(&desc->irq_data);
 540
 541         handle_irq_event_percpu(desc, desc->action);
 542
 543         if (chip->irq_eoi)
 544                 chip->irq_eoi(&desc->irq_data);
 545 }
 546
 547 void
 548 __irq_set_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
 549                   const char *name)
 550 {
 551         unsigned long flags;
 552         struct irq_desc *desc = irq_get_desc_buslock(irq, &flags);
 553
 554         if (!desc)
 555                 return;
 556
 557         if (!handle) {
 558                 handle = handle_bad_irq;
 559         } else {
 560                 if (WARN_ON(desc->irq_data.chip == &no_irq_chip))
 561                         goto out;
 562         }
 563
 564         /* Uninstall? */
 565         if (handle == handle_bad_irq) {
 566                 if (desc->irq_data.chip != &no_irq_chip)
 567                         mask_ack_irq(desc);
 568                 irq_state_set_disabled(desc);
 569                 desc->depth = 1;
 570         }
 571         desc->handle_irq = handle;
 572         desc->name = name;
 573
 574         if (handle != handle_bad_irq && is_chained) {
 575                 irq_settings_set_noprobe(desc);
 576                 irq_settings_set_norequest(desc);
 577                 irq_settings_set_nothread(desc);
 578                 irq_startup(desc);
 579         }
 580 out:
 581         irq_put_desc_busunlock(desc, flags);
 582 }
 583 EXPORT_SYMBOL_GPL(__irq_set_handler);
 584
 585 void
 586 irq_set_chip_and_handler_name(unsigned int irq, struct irq_chip *chip,
 587                               irq_flow_handler_t handle, const char *name)
 588 {
 589         irq_set_chip(irq, chip);
 590         __irq_set_handler(irq, handle, 0, name);
 591 }
 592
 593 void irq_modify_status(unsigned int irq, unsigned long clr, unsigned long set)
 594 {
 595         unsigned long flags;
 596         struct irq_desc *desc = irq_get_desc_lock(irq, &flags);
 597
 598         if (!desc)
 599                 return;
 600         irq_settings_clr_and_set(desc, clr, set);
 601
 602         irqd_clear(&desc->irq_data, IRQD_NO_BALANCING | IRQD_PER_CPU |
 603                    IRQD_TRIGGER_MASK | IRQD_LEVEL | IRQD_MOVE_PCNTXT);
 604         if (irq_settings_has_no_balance_set(desc))
 605                 irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
 606         if (irq_settings_is_per_cpu(desc))
 607                 irqd_set(&desc->irq_data, IRQD_PER_CPU);
 608         if (irq_settings_can_move_pcntxt(desc))
 609                 irqd_set(&desc->irq_data, IRQD_MOVE_PCNTXT);
 610         if (irq_settings_is_level(desc))
 611                 irqd_set(&desc->irq_data, IRQD_LEVEL);
 612
 613         irqd_set(&desc->irq_data, irq_settings_get_trigger_mask(desc));
 614
 615         irq_put_desc_unlock(desc, flags);
 616 }
 617 EXPORT_SYMBOL_GPL(irq_modify_status);
 618
 619 /**
 620  *      irq_cpu_online - Invoke all irq_cpu_online functions.
 621  *
 622  *      Iterate through all irqs and invoke the chip.irq_cpu_online()
 623  *      for each.
 624  */
 625 void irq_cpu_online(void)
 626 {
 627         struct irq_desc *desc;
 628         struct irq_chip *chip;
 629         unsigned long flags;
 630         unsigned int irq;
 631
 632         for_each_active_irq(irq) {
 633                 desc = irq_to_desc(irq);
 634                 if (!desc)
 635                         continue;
 636
 637                 raw_spin_lock_irqsave(&desc->lock, flags);
 638
 639                 chip = irq_data_get_irq_chip(&desc->irq_data);
 640                 if (chip && chip->irq_cpu_online &&
 641                     (!(chip->flags & IRQCHIP_ONOFFLINE_ENABLED) ||
 642                      !irqd_irq_disabled(&desc->irq_data)))
 643                         chip->irq_cpu_online(&desc->irq_data);
 644
 645                 raw_spin_unlock_irqrestore(&desc->lock, flags);
 646         }
 647 }
 648
 649 /**
 650  *      irq_cpu_offline - Invoke all irq_cpu_offline functions.
 651  *
 652  *      Iterate through all irqs and invoke the chip.irq_cpu_offline()
 653  *      for each.
 654  */
 655 void irq_cpu_offline(void)
 656 {
 657         struct irq_desc *desc;
 658         struct irq_chip *chip;
 659         unsigned long flags;
 660         unsigned int irq;
 661
 662         for_each_active_irq(irq) {
 663                 desc = irq_to_desc(irq);
 664                 if (!desc)
 665                         continue;
 666
 667                 raw_spin_lock_irqsave(&desc->lock, flags);
 668
 669                 chip = irq_data_get_irq_chip(&desc->irq_data);
 670                 if (chip && chip->irq_cpu_offline &&
 671                     (!(chip->flags & IRQCHIP_ONOFFLINE_ENABLED) ||
 672                      !irqd_irq_disabled(&desc->irq_data)))
 673                         chip->irq_cpu_offline(&desc->irq_data);
 674
 675                 raw_spin_unlock_irqrestore(&desc->lock, flags);
 676         }
 677 }