kernel/irq/manage.c

   1 /*
   2  * linux/kernel/irq/manage.c
   3  *
   4  * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
   5  * Copyright (C) 2005-2006 Thomas Gleixner
   6  *
   7  * This file contains driver APIs to the irq subsystem.
   8  */
   9
  10 #include <linux/irq.h>
  11 #include <linux/kthread.h>
  12 #include <linux/module.h>
  13 #include <linux/random.h>
  14 #include <linux/interrupt.h>
  15 #include <linux/slab.h>
  16 #include <linux/sched.h>
  17
  18 #include "internals.h"
  19
  20 #ifdef CONFIG_IRQ_FORCED_THREADING
  21 __read_mostly bool force_irqthreads;
  22
  23 static int __init setup_forced_irqthreads(char *arg)
  24 {
  25         force_irqthreads = true;
  26         return 0;
  27 }
  28 early_param("threadirqs", setup_forced_irqthreads);
  29 #endif
  30
  31 /**
  32  *      synchronize_irq - wait for pending IRQ handlers (on other CPUs)
  33  *      @irq: interrupt number to wait for
  34  *
  35  *      This function waits for any pending IRQ handlers for this interrupt
  36  *      to complete before returning. If you use this function while
  37  *      holding a resource the IRQ handler may need you will deadlock.
  38  *
  39  *      This function may be called - with care - from IRQ context.
  40  */
  41 void synchronize_irq(unsigned int irq)
  42 {
  43         struct irq_desc *desc = irq_to_desc(irq);
  44         unsigned int state;
  45
  46         if (!desc)
  47                 return;
  48
  49         do {
  50                 unsigned long flags;
  51
  52                 /*
  53                  * Wait until we're out of the critical section.  This might
  54                  * give the wrong answer due to the lack of memory barriers.
  55                  */
  56                 while (desc->istate & IRQS_INPROGRESS)
  57                         cpu_relax();
  58
  59                 /* Ok, that indicated we're done: double-check carefully. */
  60                 raw_spin_lock_irqsave(&desc->lock, flags);
  61                 state = desc->istate;
  62                 raw_spin_unlock_irqrestore(&desc->lock, flags);
  63
  64                 /* Oops, that failed? */
  65         } while (state & IRQS_INPROGRESS);
  66
  67         /*
  68          * We made sure that no hardirq handler is running. Now verify
  69          * that no threaded handlers are active.
  70          */
  71         wait_event(desc->wait_for_threads, !atomic_read(&desc->threads_active));
  72 }
  73 EXPORT_SYMBOL(synchronize_irq);
  74
  75 #ifdef CONFIG_SMP
  76 cpumask_var_t irq_default_affinity;
  77
  78 /**
  79  *      irq_can_set_affinity - Check if the affinity of a given irq can be set
  80  *      @irq:           Interrupt to check
  81  *
  82  */
  83 int irq_can_set_affinity(unsigned int irq)
  84 {
  85         struct irq_desc *desc = irq_to_desc(irq);
  86
  87         if (!desc || !irqd_can_balance(&desc->irq_data) ||
  88             !desc->irq_data.chip || !desc->irq_data.chip->irq_set_affinity)
  89                 return 0;
  90
  91         return 1;
  92 }
  93
  94 /**
  95  *      irq_set_thread_affinity - Notify irq threads to adjust affinity
  96  *      @desc:          irq descriptor which has affitnity changed
  97  *
  98  *      We just set IRQTF_AFFINITY and delegate the affinity setting
  99  *      to the interrupt thread itself. We can not call
 100  *      set_cpus_allowed_ptr() here as we hold desc->lock and this
 101  *      code can be called from hard interrupt context.
 102  */
 103 void irq_set_thread_affinity(struct irq_desc *desc)
 104 {
 105         struct irqaction *action = desc->action;
 106
 107         while (action) {
 108                 if (action->thread)
 109                         set_bit(IRQTF_AFFINITY, &action->thread_flags);
 110                 action = action->next;
 111         }
 112 }
 113
 114 #ifdef CONFIG_GENERIC_PENDING_IRQ
 115 static inline bool irq_can_move_pcntxt(struct irq_desc *desc)
 116 {
 117         return irq_settings_can_move_pcntxt(desc);
 118 }
 119 static inline bool irq_move_pending(struct irq_desc *desc)
 120 {
 121         return irqd_is_setaffinity_pending(&desc->irq_data);
 122 }
 123 static inline void
 124 irq_copy_pending(struct irq_desc *desc, const struct cpumask *mask)
 125 {
 126         cpumask_copy(desc->pending_mask, mask);
 127 }
 128 static inline void
 129 irq_get_pending(struct cpumask *mask, struct irq_desc *desc)
 130 {
 131         cpumask_copy(mask, desc->pending_mask);
 132 }
 133 #else
 134 static inline bool irq_can_move_pcntxt(struct irq_desc *desc) { return true; }
 135 static inline bool irq_move_pending(struct irq_desc *desc) { return false; }
 136 static inline void
 137 irq_copy_pending(struct irq_desc *desc, const struct cpumask *mask) { }
 138 static inline void
 139 irq_get_pending(struct cpumask *mask, struct irq_desc *desc) { }
 140 #endif
 141
 142 /**
 143  *      irq_set_affinity - Set the irq affinity of a given irq
 144  *      @irq:           Interrupt to set affinity
 145  *      @cpumask:       cpumask
 146  *
 147  */
 148 int irq_set_affinity(unsigned int irq, const struct cpumask *mask)
 149 {
 150         struct irq_desc *desc = irq_to_desc(irq);
 151         struct irq_chip *chip = desc->irq_data.chip;
 152         unsigned long flags;
 153         int ret = 0;
 154
 155         if (!chip->irq_set_affinity)
 156                 return -EINVAL;
 157
 158         raw_spin_lock_irqsave(&desc->lock, flags);
 159
 160         if (irq_can_move_pcntxt(desc)) {
 161                 ret = chip->irq_set_affinity(&desc->irq_data, mask, false);
 162                 switch (ret) {
 163                 case IRQ_SET_MASK_OK:
 164                         cpumask_copy(desc->irq_data.affinity, mask);
 165                 case IRQ_SET_MASK_OK_NOCOPY:
 166                         irq_set_thread_affinity(desc);
 167                         ret = 0;
 168                 }
 169         } else {
 170                 irqd_set_move_pending(&desc->irq_data);
 171                 irq_copy_pending(desc, mask);
 172         }
 173
 174         if (desc->affinity_notify) {
 175                 kref_get(&desc->affinity_notify->kref);
 176                 schedule_work(&desc->affinity_notify->work);
 177         }
 178         irq_compat_set_affinity(desc);
 179         irqd_set(&desc->irq_data, IRQD_AFFINITY_SET);
 180         raw_spin_unlock_irqrestore(&desc->lock, flags);
 181         return ret;
 182 }
 183
 184 int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
 185 {
 186         unsigned long flags;
 187         struct irq_desc *desc = irq_get_desc_lock(irq, &flags);
 188
 189         if (!desc)
 190                 return -EINVAL;
 191         desc->affinity_hint = m;
 192         irq_put_desc_unlock(desc, flags);
 193         return 0;
 194 }
 195 EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
 196
 197 static void irq_affinity_notify(struct work_struct *work)
 198 {
 199         struct irq_affinity_notify *notify =
 200                 container_of(work, struct irq_affinity_notify, work);
 201         struct irq_desc *desc = irq_to_desc(notify->irq);
 202         cpumask_var_t cpumask;
 203         unsigned long flags;
 204
 205         if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL))
 206                 goto out;
 207
 208         raw_spin_lock_irqsave(&desc->lock, flags);
 209         if (irq_move_pending(desc))
 210                 irq_get_pending(cpumask, desc);
 211         else
 212                 cpumask_copy(cpumask, desc->irq_data.affinity);
 213         raw_spin_unlock_irqrestore(&desc->lock, flags);
 214
 215         notify->notify(notify, cpumask);
 216
 217         free_cpumask_var(cpumask);
 218 out:
 219         kref_put(&notify->kref, notify->release);
 220 }
 221
 222 /**
 223  *      irq_set_affinity_notifier - control notification of IRQ affinity changes
 224  *      @irq:           Interrupt for which to enable/disable notification
 225  *      @notify:        Context for notification, or %NULL to disable
 226  *                      notification.  Function pointers must be initialised;
 227  *                      the other fields will be initialised by this function.
 228  *
 229  *      Must be called in process context.  Notification may only be enabled
 230  *      after the IRQ is allocated and must be disabled before the IRQ is
 231  *      freed using free_irq().
 232  */
 233 int
 234 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
 235 {
 236         struct irq_desc *desc = irq_to_desc(irq);
 237         struct irq_affinity_notify *old_notify;
 238         unsigned long flags;
 239
 240         /* The release function is promised process context */
 241         might_sleep();
 242
 243         if (!desc)
 244                 return -EINVAL;
 245
 246         /* Complete initialisation of *notify */
 247         if (notify) {
 248                 notify->irq = irq;
 249                 kref_init(&notify->kref);
 250                 INIT_WORK(&notify->work, irq_affinity_notify);
 251         }
 252
 253         raw_spin_lock_irqsave(&desc->lock, flags);
 254         old_notify = desc->affinity_notify;
 255         desc->affinity_notify = notify;
 256         raw_spin_unlock_irqrestore(&desc->lock, flags);
 257
 258         if (old_notify)
 259                 kref_put(&old_notify->kref, old_notify->release);
 260
 261         return 0;
 262 }
 263 EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
 264
 265 #ifndef CONFIG_AUTO_IRQ_AFFINITY
 266 /*
 267  * Generic version of the affinity autoselector.
 268  */
 269 static int
 270 setup_affinity(unsigned int irq, struct irq_desc *desc, struct cpumask *mask)
 271 {
 272         struct irq_chip *chip = irq_desc_get_chip(desc);
 273         struct cpumask *set = irq_default_affinity;
 274         int ret;
 275
 276         /* Excludes PER_CPU and NO_BALANCE interrupts */
 277         if (!irq_can_set_affinity(irq))
 278                 return 0;
 279
 280         /*
 281          * Preserve an userspace affinity setup, but make sure that
 282          * one of the targets is online.
 283          */
 284         if (irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
 285                 if (cpumask_intersects(desc->irq_data.affinity,
 286                                        cpu_online_mask))
 287                         set = desc->irq_data.affinity;
 288                 else {
 289                         irq_compat_clr_affinity(desc);
 290                         irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
 291                 }
 292         }
 293
 294         cpumask_and(mask, cpu_online_mask, set);
 295         ret = chip->irq_set_affinity(&desc->irq_data, mask, false);
 296         switch (ret) {
 297         case IRQ_SET_MASK_OK:
 298                 cpumask_copy(desc->irq_data.affinity, mask);
 299         case IRQ_SET_MASK_OK_NOCOPY:
 300                 irq_set_thread_affinity(desc);
 301         }
 302         return 0;
 303 }
 304 #else
 305 static inline int
 306 setup_affinity(unsigned int irq, struct irq_desc *d, struct cpumask *mask)
 307 {
 308         return irq_select_affinity(irq);
 309 }
 310 #endif
 311
 312 /*
 313  * Called when affinity is set via /proc/irq
 314  */
 315 int irq_select_affinity_usr(unsigned int irq, struct cpumask *mask)
 316 {
 317         struct irq_desc *desc = irq_to_desc(irq);
 318         unsigned long flags;
 319         int ret;
 320
 321         raw_spin_lock_irqsave(&desc->lock, flags);
 322         ret = setup_affinity(irq, desc, mask);
 323         raw_spin_unlock_irqrestore(&desc->lock, flags);
 324         return ret;
 325 }
 326
 327 #else
 328 static inline int
 329 setup_affinity(unsigned int irq, struct irq_desc *desc, struct cpumask *mask)
 330 {
 331         return 0;
 332 }
 333 #endif
 334
 335 void __disable_irq(struct irq_desc *desc, unsigned int irq, bool suspend)
 336 {
 337         if (suspend) {
 338                 if (!desc->action || (desc->action->flags & IRQF_NO_SUSPEND))
 339                         return;
 340                 desc->istate |= IRQS_SUSPENDED;
 341         }
 342
 343         if (!desc->depth++)
 344                 irq_disable(desc);
 345 }
 346
 347 static int __disable_irq_nosync(unsigned int irq)
 348 {
 349         unsigned long flags;
 350         struct irq_desc *desc = irq_get_desc_buslock(irq, &flags);
 351
 352         if (!desc)
 353                 return -EINVAL;
 354         __disable_irq(desc, irq, false);
 355         irq_put_desc_busunlock(desc, flags);
 356         return 0;
 357 }
 358
 359 /**
 360  *      disable_irq_nosync - disable an irq without waiting
 361  *      @irq: Interrupt to disable
 362  *
 363  *      Disable the selected interrupt line.  Disables and Enables are
 364  *      nested.
 365  *      Unlike disable_irq(), this function does not ensure existing
 366  *      instances of the IRQ handler have completed before returning.
 367  *
 368  *      This function may be called from IRQ context.
 369  */
 370 void disable_irq_nosync(unsigned int irq)
 371 {
 372         __disable_irq_nosync(irq);
 373 }
 374 EXPORT_SYMBOL(disable_irq_nosync);
 375
 376 /**
 377  *      disable_irq - disable an irq and wait for completion
 378  *      @irq: Interrupt to disable
 379  *
 380  *      Disable the selected interrupt line.  Enables and Disables are
 381  *      nested.
 382  *      This function waits for any pending IRQ handlers for this interrupt
 383  *      to complete before returning. If you use this function while
 384  *      holding a resource the IRQ handler may need you will deadlock.
 385  *
 386  *      This function may be called - with care - from IRQ context.
 387  */
 388 void disable_irq(unsigned int irq)
 389 {
 390         if (!__disable_irq_nosync(irq))
 391                 synchronize_irq(irq);
 392 }
 393 EXPORT_SYMBOL(disable_irq);
 394
 395 void __enable_irq(struct irq_desc *desc, unsigned int irq, bool resume)
 396 {
 397         if (resume) {
 398                 if (!(desc->istate & IRQS_SUSPENDED)) {
 399                         if (!desc->action)
 400                                 return;
 401                         if (!(desc->action->flags & IRQF_FORCE_RESUME))
 402                                 return;
 403                         /* Pretend that it got disabled ! */
 404                         desc->depth++;
 405                 }
 406                 desc->istate &= ~IRQS_SUSPENDED;
 407         }
 408
 409         switch (desc->depth) {
 410         case 0:
 411  err_out:
 412                 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n", irq);
 413                 break;
 414         case 1: {
 415                 if (desc->istate & IRQS_SUSPENDED)
 416                         goto err_out;
 417                 /* Prevent probing on this irq: */
 418                 irq_settings_set_noprobe(desc);
 419                 irq_enable(desc);
 420                 check_irq_resend(desc, irq);
 421                 /* fall-through */
 422         }
 423         default:
 424                 desc->depth--;
 425         }
 426 }
 427
 428 /**
 429  *      enable_irq - enable handling of an irq
 430  *      @irq: Interrupt to enable
 431  *
 432  *      Undoes the effect of one call to disable_irq().  If this
 433  *      matches the last disable, processing of interrupts on this
 434  *      IRQ line is re-enabled.
 435  *
 436  *      This function may be called from IRQ context only when
 437  *      desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
 438  */
 439 void enable_irq(unsigned int irq)
 440 {
 441         unsigned long flags;
 442         struct irq_desc *desc = irq_get_desc_buslock(irq, &flags);
 443
 444         if (!desc)
 445                 return;
 446         if (WARN(!desc->irq_data.chip,
 447                  KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
 448                 goto out;
 449
 450         __enable_irq(desc, irq, false);
 451 out:
 452         irq_put_desc_busunlock(desc, flags);
 453 }
 454 EXPORT_SYMBOL(enable_irq);
 455
 456 static int set_irq_wake_real(unsigned int irq, unsigned int on)
 457 {
 458         struct irq_desc *desc = irq_to_desc(irq);
 459         int ret = -ENXIO;
 460
 461         if (desc->irq_data.chip->irq_set_wake)
 462                 ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
 463
 464         return ret;
 465 }
 466
 467 /**
 468  *      irq_set_irq_wake - control irq power management wakeup
 469  *      @irq:   interrupt to control
 470  *      @on:    enable/disable power management wakeup
 471  *
 472  *      Enable/disable power management wakeup mode, which is
 473  *      disabled by default.  Enables and disables must match,
 474  *      just as they match for non-wakeup mode support.
 475  *
 476  *      Wakeup mode lets this IRQ wake the system from sleep
 477  *      states like "suspend to RAM".
 478  */
 479 int irq_set_irq_wake(unsigned int irq, unsigned int on)
 480 {
 481         unsigned long flags;
 482         struct irq_desc *desc = irq_get_desc_buslock(irq, &flags);
 483         int ret = 0;
 484
 485         /* wakeup-capable irqs can be shared between drivers that
 486          * don't need to have the same sleep mode behaviors.
 487          */
 488         if (on) {
 489                 if (desc->wake_depth++ == 0) {
 490                         ret = set_irq_wake_real(irq, on);
 491                         if (ret)
 492                                 desc->wake_depth = 0;
 493                         else
 494                                 irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
 495                 }
 496         } else {
 497                 if (desc->wake_depth == 0) {
 498                         WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
 499                 } else if (--desc->wake_depth == 0) {
 500                         ret = set_irq_wake_real(irq, on);
 501                         if (ret)
 502                                 desc->wake_depth = 1;
 503                         else
 504                                 irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
 505                 }
 506         }
 507         irq_put_desc_busunlock(desc, flags);
 508         return ret;
 509 }
 510 EXPORT_SYMBOL(irq_set_irq_wake);
 511
 512 /*
 513  * Internal function that tells the architecture code whether a
 514  * particular irq has been exclusively allocated or is available
 515  * for driver use.
 516  */
 517 int can_request_irq(unsigned int irq, unsigned long irqflags)
 518 {
 519         unsigned long flags;
 520         struct irq_desc *desc = irq_get_desc_lock(irq, &flags);
 521         int canrequest = 0;
 522
 523         if (!desc)
 524                 return 0;
 525
 526         if (irq_settings_can_request(desc)) {
 527                 if (desc->action)
 528                         if (irqflags & desc->action->flags & IRQF_SHARED)
 529                                 canrequest =1;
 530         }
 531         irq_put_desc_unlock(desc, flags);
 532         return canrequest;
 533 }
 534
 535 int __irq_set_trigger(struct irq_desc *desc, unsigned int irq,
 536                       unsigned long flags)
 537 {
 538         struct irq_chip *chip = desc->irq_data.chip;
 539         int ret, unmask = 0;
 540
 541         if (!chip || !chip->irq_set_type) {
 542                 /*
 543                  * IRQF_TRIGGER_* but the PIC does not support multiple
 544                  * flow-types?
 545                  */
 546                 pr_debug("No set_type function for IRQ %d (%s)\n", irq,
 547                                 chip ? (chip->name ? : "unknown") : "unknown");
 548                 return 0;
 549         }
 550
 551         flags &= IRQ_TYPE_SENSE_MASK;
 552
 553         if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
 554                 if (!(desc->istate & IRQS_MASKED))
 555                         mask_irq(desc);
 556                 if (!(desc->istate & IRQS_DISABLED))
 557                         unmask = 1;
 558         }
 559
 560         /* caller masked out all except trigger mode flags */
 561         ret = chip->irq_set_type(&desc->irq_data, flags);
 562
 563         switch (ret) {
 564         case IRQ_SET_MASK_OK:
 565                 irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
 566                 irqd_set(&desc->irq_data, flags);
 567
 568         case IRQ_SET_MASK_OK_NOCOPY:
 569                 flags = irqd_get_trigger_type(&desc->irq_data);
 570                 irq_settings_set_trigger_mask(desc, flags);
 571                 irqd_clear(&desc->irq_data, IRQD_LEVEL);
 572                 irq_settings_clr_level(desc);
 573                 if (flags & IRQ_TYPE_LEVEL_MASK) {
 574                         irq_settings_set_level(desc);
 575                         irqd_set(&desc->irq_data, IRQD_LEVEL);
 576                 }
 577
 578                 if (chip != desc->irq_data.chip)
 579                         irq_chip_set_defaults(desc->irq_data.chip);
 580                 ret = 0;
 581                 break;
 582         default:
 583                 pr_err("setting trigger mode %lu for irq %u failed (%pF)\n",
 584                        flags, irq, chip->irq_set_type);
 585         }
 586         if (unmask)
 587                 unmask_irq(desc);
 588         return ret;
 589 }
 590
 591 /*
 592  * Default primary interrupt handler for threaded interrupts. Is
 593  * assigned as primary handler when request_threaded_irq is called
 594  * with handler == NULL. Useful for oneshot interrupts.
 595  */
 596 static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
 597 {
 598         return IRQ_WAKE_THREAD;
 599 }
 600
 601 /*
 602  * Primary handler for nested threaded interrupts. Should never be
 603  * called.
 604  */
 605 static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
 606 {
 607         WARN(1, "Primary handler called for nested irq %d\n", irq);
 608         return IRQ_NONE;
 609 }
 610
 611 static int irq_wait_for_interrupt(struct irqaction *action)
 612 {
 613         while (!kthread_should_stop()) {
 614                 set_current_state(TASK_INTERRUPTIBLE);
 615
 616                 if (test_and_clear_bit(IRQTF_RUNTHREAD,
 617                                        &action->thread_flags)) {
 618                         __set_current_state(TASK_RUNNING);
 619                         return 0;
 620                 }
 621                 schedule();
 622         }
 623         return -1;
 624 }
 625
 626 /*
 627  * Oneshot interrupts keep the irq line masked until the threaded
 628  * handler finished. unmask if the interrupt has not been disabled and
 629  * is marked MASKED.
 630  */
 631 static void irq_finalize_oneshot(struct irq_desc *desc,
 632                                  struct irqaction *action, bool force)
 633 {
 634         if (!(desc->istate & IRQS_ONESHOT))
 635                 return;
 636 again:
 637         chip_bus_lock(desc);
 638         raw_spin_lock_irq(&desc->lock);
 639
 640         /*
 641          * Implausible though it may be we need to protect us against
 642          * the following scenario:
 643          *
 644          * The thread is faster done than the hard interrupt handler
 645          * on the other CPU. If we unmask the irq line then the
 646          * interrupt can come in again and masks the line, leaves due
 647          * to IRQS_INPROGRESS and the irq line is masked forever.
 648          *
 649          * This also serializes the state of shared oneshot handlers
 650          * versus "desc->threads_onehsot |= action->thread_mask;" in
 651          * irq_wake_thread(). See the comment there which explains the
 652          * serialization.
 653          */
 654         if (unlikely(desc->istate & IRQS_INPROGRESS)) {
 655                 raw_spin_unlock_irq(&desc->lock);
 656                 chip_bus_sync_unlock(desc);
 657                 cpu_relax();
 658                 goto again;
 659         }
 660
 661         /*
 662          * Now check again, whether the thread should run. Otherwise
 663          * we would clear the threads_oneshot bit of this thread which
 664          * was just set.
 665          */
 666         if (!force && test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
 667                 goto out_unlock;
 668
 669         desc->threads_oneshot &= ~action->thread_mask;
 670
 671         if (!desc->threads_oneshot && !(desc->istate & IRQS_DISABLED) &&
 672             (desc->istate & IRQS_MASKED)) {
 673                 irq_compat_clr_masked(desc);
 674                 desc->istate &= ~IRQS_MASKED;
 675                 desc->irq_data.chip->irq_unmask(&desc->irq_data);
 676         }
 677 out_unlock:
 678         raw_spin_unlock_irq(&desc->lock);
 679         chip_bus_sync_unlock(desc);
 680 }
 681
 682 #ifdef CONFIG_SMP
 683 /*
 684  * Check whether we need to chasnge the affinity of the interrupt thread.
 685  */
 686 static void
 687 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
 688 {
 689         cpumask_var_t mask;
 690
 691         if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
 692                 return;
 693
 694         /*
 695          * In case we are out of memory we set IRQTF_AFFINITY again and
 696          * try again next time
 697          */
 698         if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
 699                 set_bit(IRQTF_AFFINITY, &action->thread_flags);
 700                 return;
 701         }
 702
 703         raw_spin_lock_irq(&desc->lock);
 704         cpumask_copy(mask, desc->irq_data.affinity);
 705         raw_spin_unlock_irq(&desc->lock);
 706
 707         set_cpus_allowed_ptr(current, mask);
 708         free_cpumask_var(mask);
 709 }
 710 #else
 711 static inline void
 712 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
 713 #endif
 714
 715 /*
 716  * Interrupts which are not explicitely requested as threaded
 717  * interrupts rely on the implicit bh/preempt disable of the hard irq
 718  * context. So we need to disable bh here to avoid deadlocks and other
 719  * side effects.
 720  */
 721 static void
 722 irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
 723 {
 724         local_bh_disable();
 725         action->thread_fn(action->irq, action->dev_id);
 726         irq_finalize_oneshot(desc, action, false);
 727         local_bh_enable();
 728 }
 729
 730 /*
 731  * Interrupts explicitely requested as threaded interupts want to be
 732  * preemtible - many of them need to sleep and wait for slow busses to
 733  * complete.
 734  */
 735 static void irq_thread_fn(struct irq_desc *desc, struct irqaction *action)
 736 {
 737         action->thread_fn(action->irq, action->dev_id);
 738         irq_finalize_oneshot(desc, action, false);
 739 }
 740
 741 /*
 742  * Interrupt handler thread
 743  */
 744 static int irq_thread(void *data)
 745 {
 746         static const struct sched_param param = {
 747                 .sched_priority = MAX_USER_RT_PRIO/2,
 748         };
 749         struct irqaction *action = data;
 750         struct irq_desc *desc = irq_to_desc(action->irq);
 751         void (*handler_fn)(struct irq_desc *desc, struct irqaction *action);
 752         int wake;
 753
 754         if (force_irqthreads & test_bit(IRQTF_FORCED_THREAD,
 755                                         &action->thread_flags))
 756                 handler_fn = irq_forced_thread_fn;
 757         else
 758                 handler_fn = irq_thread_fn;
 759
 760         sched_setscheduler(current, SCHED_FIFO, &param);
 761         current->irqaction = action;
 762
 763         while (!irq_wait_for_interrupt(action)) {
 764
 765                 irq_thread_check_affinity(desc, action);
 766
 767                 atomic_inc(&desc->threads_active);
 768
 769                 raw_spin_lock_irq(&desc->lock);
 770                 if (unlikely(desc->istate & IRQS_DISABLED)) {
 771                         /*
 772                          * CHECKME: We might need a dedicated
 773                          * IRQ_THREAD_PENDING flag here, which
 774                          * retriggers the thread in check_irq_resend()
 775                          * but AFAICT IRQS_PENDING should be fine as it
 776                          * retriggers the interrupt itself --- tglx
 777                          */
 778                         irq_compat_set_pending(desc);
 779                         desc->istate |= IRQS_PENDING;
 780                         raw_spin_unlock_irq(&desc->lock);
 781                 } else {
 782                         raw_spin_unlock_irq(&desc->lock);
 783                         handler_fn(desc, action);
 784                 }
 785
 786                 wake = atomic_dec_and_test(&desc->threads_active);
 787
 788                 if (wake && waitqueue_active(&desc->wait_for_threads))
 789                         wake_up(&desc->wait_for_threads);
 790         }
 791
 792         /* Prevent a stale desc->threads_oneshot */
 793         irq_finalize_oneshot(desc, action, true);
 794
 795         /*
 796          * Clear irqaction. Otherwise exit_irq_thread() would make
 797          * fuzz about an active irq thread going into nirvana.
 798          */
 799         current->irqaction = NULL;
 800         return 0;
 801 }
 802
 803 /*
 804  * Called from do_exit()
 805  */
 806 void exit_irq_thread(void)
 807 {
 808         struct task_struct *tsk = current;
 809         struct irq_desc *desc;
 810
 811         if (!tsk->irqaction)
 812                 return;
 813
 814         printk(KERN_ERR
 815                "exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
 816                tsk->comm ? tsk->comm : "", tsk->pid, tsk->irqaction->irq);
 817
 818         desc = irq_to_desc(tsk->irqaction->irq);
 819
 820         /*
 821          * Prevent a stale desc->threads_oneshot. Must be called
 822          * before setting the IRQTF_DIED flag.
 823          */
 824         irq_finalize_oneshot(desc, tsk->irqaction, true);
 825
 826         /*
 827          * Set the THREAD DIED flag to prevent further wakeups of the
 828          * soon to be gone threaded handler.
 829          */
 830         set_bit(IRQTF_DIED, &tsk->irqaction->flags);
 831 }
 832
 833 static void irq_setup_forced_threading(struct irqaction *new)
 834 {
 835         if (!force_irqthreads)
 836                 return;
 837         if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
 838                 return;
 839
 840         new->flags |= IRQF_ONESHOT;
 841
 842         if (!new->thread_fn) {
 843                 set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
 844                 new->thread_fn = new->handler;
 845                 new->handler = irq_default_primary_handler;
 846         }
 847 }
 848
 849 /*
 850  * Internal function to register an irqaction - typically used to
 851  * allocate special interrupts that are part of the architecture.
 852  */
 853 static int
 854 __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
 855 {
 856         struct irqaction *old, **old_ptr;
 857         const char *old_name = NULL;
 858         unsigned long flags, thread_mask = 0;
 859         int ret, nested, shared = 0;
 860         cpumask_var_t mask;
 861
 862         if (!desc)
 863                 return -EINVAL;
 864
 865         if (desc->irq_data.chip == &no_irq_chip)
 866                 return -ENOSYS;
 867         /*
 868          * Some drivers like serial.c use request_irq() heavily,
 869          * so we have to be careful not to interfere with a
 870          * running system.
 871          */
 872         if (new->flags & IRQF_SAMPLE_RANDOM) {
 873                 /*
 874                  * This function might sleep, we want to call it first,
 875                  * outside of the atomic block.
 876                  * Yes, this might clear the entropy pool if the wrong
 877                  * driver is attempted to be loaded, without actually
 878                  * installing a new handler, but is this really a problem,
 879                  * only the sysadmin is able to do this.
 880                  */
 881                 rand_initialize_irq(irq);
 882         }
 883
 884         /*
 885          * Check whether the interrupt nests into another interrupt
 886          * thread.
 887          */
 888         nested = irq_settings_is_nested_thread(desc);
 889         if (nested) {
 890                 if (!new->thread_fn)
 891                         return -EINVAL;
 892                 /*
 893                  * Replace the primary handler which was provided from
 894                  * the driver for non nested interrupt handling by the
 895                  * dummy function which warns when called.
 896                  */
 897                 new->handler = irq_nested_primary_handler;
 898         } else {
 899                 irq_setup_forced_threading(new);
 900         }
 901
 902         /*
 903          * Create a handler thread when a thread function is supplied
 904          * and the interrupt does not nest into another interrupt
 905          * thread.
 906          */
 907         if (new->thread_fn && !nested) {
 908                 struct task_struct *t;
 909
 910                 t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
 911                                    new->name);
 912                 if (IS_ERR(t))
 913                         return PTR_ERR(t);
 914                 /*
 915                  * We keep the reference to the task struct even if
 916                  * the thread dies to avoid that the interrupt code
 917                  * references an already freed task_struct.
 918                  */
 919                 get_task_struct(t);
 920                 new->thread = t;
 921         }
 922
 923         if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
 924                 ret = -ENOMEM;
 925                 goto out_thread;
 926         }
 927
 928         /*
 929          * The following block of code has to be executed atomically
 930          */
 931         raw_spin_lock_irqsave(&desc->lock, flags);
 932         old_ptr = &desc->action;
 933         old = *old_ptr;
 934         if (old) {
 935                 /*
 936                  * Can't share interrupts unless both agree to and are
 937                  * the same type (level, edge, polarity). So both flag
 938                  * fields must have IRQF_SHARED set and the bits which
 939                  * set the trigger type must match. Also all must
 940                  * agree on ONESHOT.
 941                  */
 942                 if (!((old->flags & new->flags) & IRQF_SHARED) ||
 943                     ((old->flags ^ new->flags) & IRQF_TRIGGER_MASK) ||
 944                     ((old->flags ^ new->flags) & IRQF_ONESHOT)) {
 945                         old_name = old->name;
 946                         goto mismatch;
 947                 }
 948
 949                 /* All handlers must agree on per-cpuness */
 950                 if ((old->flags & IRQF_PERCPU) !=
 951                     (new->flags & IRQF_PERCPU))
 952                         goto mismatch;
 953
 954                 /* add new interrupt at end of irq queue */
 955                 do {
 956                         thread_mask |= old->thread_mask;
 957                         old_ptr = &old->next;
 958                         old = *old_ptr;
 959                 } while (old);
 960                 shared = 1;
 961         }
 962
 963         /*
 964          * Setup the thread mask for this irqaction. Unlikely to have
 965          * 32 resp 64 irqs sharing one line, but who knows.
 966          */
 967         if (new->flags & IRQF_ONESHOT && thread_mask == ~0UL) {
 968                 ret = -EBUSY;
 969                 goto out_mask;
 970         }
 971         new->thread_mask = 1 << ffz(thread_mask);
 972
 973         if (!shared) {
 974                 irq_chip_set_defaults(desc->irq_data.chip);
 975
 976                 init_waitqueue_head(&desc->wait_for_threads);
 977
 978                 /* Setup the type (level, edge polarity) if configured: */
 979                 if (new->flags & IRQF_TRIGGER_MASK) {
 980                         ret = __irq_set_trigger(desc, irq,
 981                                         new->flags & IRQF_TRIGGER_MASK);
 982
 983                         if (ret)
 984                                 goto out_mask;
 985                 }
 986
 987                 desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
 988                                   IRQS_INPROGRESS | IRQS_ONESHOT | \
 989                                   IRQS_WAITING);
 990
 991                 if (new->flags & IRQF_PERCPU) {
 992                         irqd_set(&desc->irq_data, IRQD_PER_CPU);
 993                         irq_settings_set_per_cpu(desc);
 994                 }
 995
 996                 if (new->flags & IRQF_ONESHOT)
 997                         desc->istate |= IRQS_ONESHOT;
 998
 999                 if (irq_settings_can_autoenable(desc))
1000                         irq_startup(desc);
1001                 else
1002                         /* Undo nested disables: */
1003                         desc->depth = 1;
1004
1005                 /* Exclude IRQ from balancing if requested */
1006                 if (new->flags & IRQF_NOBALANCING) {
1007                         irq_settings_set_no_balancing(desc);
1008                         irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
1009                 }
1010
1011                 /* Set default affinity mask once everything is setup */
1012                 setup_affinity(irq, desc, mask);
1013
1014         } else if (new->flags & IRQF_TRIGGER_MASK) {
1015                 unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
1016                 unsigned int omsk = irq_settings_get_trigger_mask(desc);
1017
1018                 if (nmsk != omsk)
1019                         /* hope the handler works with current  trigger mode */
1020                         pr_warning("IRQ %d uses trigger mode %u; requested %u\n",
1021                                    irq, nmsk, omsk);
1022         }
1023
1024         new->irq = irq;
1025         *old_ptr = new;
1026
1027         /* Reset broken irq detection when installing new handler */
1028         desc->irq_count = 0;
1029         desc->irqs_unhandled = 0;
1030
1031         /*
1032          * Check whether we disabled the irq via the spurious handler
1033          * before. Reenable it and give it another chance.
1034          */
1035         if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
1036                 desc->istate &= ~IRQS_SPURIOUS_DISABLED;
1037                 __enable_irq(desc, irq, false);
1038         }
1039
1040         raw_spin_unlock_irqrestore(&desc->lock, flags);
1041
1042         /*
1043          * Strictly no need to wake it up, but hung_task complains
1044          * when no hard interrupt wakes the thread up.
1045          */
1046         if (new->thread)
1047                 wake_up_process(new->thread);
1048
1049         register_irq_proc(irq, desc);
1050         new->dir = NULL;
1051         register_handler_proc(irq, new);
1052
1053         return 0;
1054
1055 mismatch:
1056 #ifdef CONFIG_DEBUG_SHIRQ
1057         if (!(new->flags & IRQF_PROBE_SHARED)) {
1058                 printk(KERN_ERR "IRQ handler type mismatch for IRQ %d\n", irq);
1059                 if (old_name)
1060                         printk(KERN_ERR "current handler: %s\n", old_name);
1061                 dump_stack();
1062         }
1063 #endif
1064         ret = -EBUSY;
1065
1066 out_mask:
1067         raw_spin_unlock_irqrestore(&desc->lock, flags);
1068         free_cpumask_var(mask);
1069
1070 out_thread:
1071         if (new->thread) {
1072                 struct task_struct *t = new->thread;
1073
1074                 new->thread = NULL;
1075                 if (likely(!test_bit(IRQTF_DIED, &new->thread_flags)))
1076                         kthread_stop(t);
1077                 put_task_struct(t);
1078         }
1079         return ret;
1080 }
1081
1082 /**
1083  *      setup_irq - setup an interrupt
1084  *      @irq: Interrupt line to setup
1085  *      @act: irqaction for the interrupt
1086  *
1087  * Used to statically setup interrupts in the early boot process.
1088  */
1089 int setup_irq(unsigned int irq, struct irqaction *act)
1090 {
1091         int retval;
1092         struct irq_desc *desc = irq_to_desc(irq);
1093
1094         chip_bus_lock(desc);
1095         retval = __setup_irq(irq, desc, act);
1096         chip_bus_sync_unlock(desc);
1097
1098         return retval;
1099 }
1100 EXPORT_SYMBOL_GPL(setup_irq);
1101
1102  /*
1103  * Internal function to unregister an irqaction - used to free
1104  * regular and special interrupts that are part of the architecture.
1105  */
1106 static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
1107 {
1108         struct irq_desc *desc = irq_to_desc(irq);
1109         struct irqaction *action, **action_ptr;
1110         unsigned long flags;
1111
1112         WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1113
1114         if (!desc)
1115                 return NULL;
1116
1117         raw_spin_lock_irqsave(&desc->lock, flags);
1118
1119         /*
1120          * There can be multiple actions per IRQ descriptor, find the right
1121          * one based on the dev_id:
1122          */
1123         action_ptr = &desc->action;
1124         for (;;) {
1125                 action = *action_ptr;
1126
1127                 if (!action) {
1128                         WARN(1, "Trying to free already-free IRQ %d\n", irq);
1129                         raw_spin_unlock_irqrestore(&desc->lock, flags);
1130
1131                         return NULL;
1132                 }
1133
1134                 if (action->dev_id == dev_id)
1135                         break;
1136                 action_ptr = &action->next;
1137         }
1138
1139         /* Found it - now remove it from the list of entries: */
1140         *action_ptr = action->next;
1141
1142         /* Currently used only by UML, might disappear one day: */
1143 #ifdef CONFIG_IRQ_RELEASE_METHOD
1144         if (desc->irq_data.chip->release)
1145                 desc->irq_data.chip->release(irq, dev_id);
1146 #endif
1147
1148         /* If this was the last handler, shut down the IRQ line: */
1149         if (!desc->action)
1150                 irq_shutdown(desc);
1151
1152 #ifdef CONFIG_SMP
1153         /* make sure affinity_hint is cleaned up */
1154         if (WARN_ON_ONCE(desc->affinity_hint))
1155                 desc->affinity_hint = NULL;
1156 #endif
1157
1158         raw_spin_unlock_irqrestore(&desc->lock, flags);
1159
1160         unregister_handler_proc(irq, action);
1161
1162         /* Make sure it's not being used on another CPU: */
1163         synchronize_irq(irq);
1164
1165 #ifdef CONFIG_DEBUG_SHIRQ
1166         /*
1167          * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1168          * event to happen even now it's being freed, so let's make sure that
1169          * is so by doing an extra call to the handler ....
1170          *
1171          * ( We do this after actually deregistering it, to make sure that a
1172          *   'real' IRQ doesn't run in * parallel with our fake. )
1173          */
1174         if (action->flags & IRQF_SHARED) {
1175                 local_irq_save(flags);
1176                 action->handler(irq, dev_id);
1177                 local_irq_restore(flags);
1178         }
1179 #endif
1180
1181         if (action->thread) {
1182                 if (!test_bit(IRQTF_DIED, &action->thread_flags))
1183                         kthread_stop(action->thread);
1184                 put_task_struct(action->thread);
1185         }
1186
1187         return action;
1188 }
1189
1190 /**
1191  *      remove_irq - free an interrupt
1192  *      @irq: Interrupt line to free
1193  *      @act: irqaction for the interrupt
1194  *
1195  * Used to remove interrupts statically setup by the early boot process.
1196  */
1197 void remove_irq(unsigned int irq, struct irqaction *act)
1198 {
1199         __free_irq(irq, act->dev_id);
1200 }
1201 EXPORT_SYMBOL_GPL(remove_irq);
1202
1203 /**
1204  *      free_irq - free an interrupt allocated with request_irq
1205  *      @irq: Interrupt line to free
1206  *      @dev_id: Device identity to free
1207  *
1208  *      Remove an interrupt handler. The handler is removed and if the
1209  *      interrupt line is no longer in use by any driver it is disabled.
1210  *      On a shared IRQ the caller must ensure the interrupt is disabled
1211  *      on the card it drives before calling this function. The function
1212  *      does not return until any executing interrupts for this IRQ
1213  *      have completed.
1214  *
1215  *      This function must not be called from interrupt context.
1216  */
1217 void free_irq(unsigned int irq, void *dev_id)
1218 {
1219         struct irq_desc *desc = irq_to_desc(irq);
1220
1221         if (!desc)
1222                 return;
1223
1224 #ifdef CONFIG_SMP
1225         if (WARN_ON(desc->affinity_notify))
1226                 desc->affinity_notify = NULL;
1227 #endif
1228
1229         chip_bus_lock(desc);
1230         kfree(__free_irq(irq, dev_id));
1231         chip_bus_sync_unlock(desc);
1232 }
1233 EXPORT_SYMBOL(free_irq);
1234
1235 /**
1236  *      request_threaded_irq - allocate an interrupt line
1237  *      @irq: Interrupt line to allocate
1238  *      @handler: Function to be called when the IRQ occurs.
1239  *                Primary handler for threaded interrupts
1240  *                If NULL and thread_fn != NULL the default
1241  *                primary handler is installed
1242  *      @thread_fn: Function called from the irq handler thread
1243  *                  If NULL, no irq thread is created
1244  *      @irqflags: Interrupt type flags
1245  *      @devname: An ascii name for the claiming device
1246  *      @dev_id: A cookie passed back to the handler function
1247  *
1248  *      This call allocates interrupt resources and enables the
1249  *      interrupt line and IRQ handling. From the point this
1250  *      call is made your handler function may be invoked. Since
1251  *      your handler function must clear any interrupt the board
1252  *      raises, you must take care both to initialise your hardware
1253  *      and to set up the interrupt handler in the right order.
1254  *
1255  *      If you want to set up a threaded irq handler for your device
1256  *      then you need to supply @handler and @thread_fn. @handler ist
1257  *      still called in hard interrupt context and has to check
1258  *      whether the interrupt originates from the device. If yes it
1259  *      needs to disable the interrupt on the device and return
1260  *      IRQ_WAKE_THREAD which will wake up the handler thread and run
1261  *      @thread_fn. This split handler design is necessary to support
1262  *      shared interrupts.
1263  *
1264  *      Dev_id must be globally unique. Normally the address of the
1265  *      device data structure is used as the cookie. Since the handler
1266  *      receives this value it makes sense to use it.
1267  *
1268  *      If your interrupt is shared you must pass a non NULL dev_id
1269  *      as this is required when freeing the interrupt.
1270  *
1271  *      Flags:
1272  *
1273  *      IRQF_SHARED             Interrupt is shared
1274  *      IRQF_SAMPLE_RANDOM      The interrupt can be used for entropy
1275  *      IRQF_TRIGGER_*          Specify active edge(s) or level
1276  *
1277  */
1278 int request_threaded_irq(unsigned int irq, irq_handler_t handler,
1279                          irq_handler_t thread_fn, unsigned long irqflags,
1280                          const char *devname, void *dev_id)
1281 {
1282         struct irqaction *action;
1283         struct irq_desc *desc;
1284         int retval;
1285
1286         /*
1287          * Sanity-check: shared interrupts must pass in a real dev-ID,
1288          * otherwise we'll have trouble later trying to figure out
1289          * which interrupt is which (messes up the interrupt freeing
1290          * logic etc).
1291          */
1292         if ((irqflags & IRQF_SHARED) && !dev_id)
1293                 return -EINVAL;
1294
1295         desc = irq_to_desc(irq);
1296         if (!desc)
1297                 return -EINVAL;
1298
1299         if (!irq_settings_can_request(desc))
1300                 return -EINVAL;
1301
1302         if (!handler) {
1303                 if (!thread_fn)
1304                         return -EINVAL;
1305                 handler = irq_default_primary_handler;
1306         }
1307
1308         action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1309         if (!action)
1310                 return -ENOMEM;
1311
1312         action->handler = handler;
1313         action->thread_fn = thread_fn;
1314         action->flags = irqflags;
1315         action->name = devname;
1316         action->dev_id = dev_id;
1317
1318         chip_bus_lock(desc);
1319         retval = __setup_irq(irq, desc, action);
1320         chip_bus_sync_unlock(desc);
1321
1322         if (retval)
1323                 kfree(action);
1324
1325 #ifdef CONFIG_DEBUG_SHIRQ_FIXME
1326         if (!retval && (irqflags & IRQF_SHARED)) {
1327                 /*
1328                  * It's a shared IRQ -- the driver ought to be prepared for it
1329                  * to happen immediately, so let's make sure....
1330                  * We disable the irq to make sure that a 'real' IRQ doesn't
1331                  * run in parallel with our fake.
1332                  */
1333                 unsigned long flags;
1334
1335                 disable_irq(irq);
1336                 local_irq_save(flags);
1337
1338                 handler(irq, dev_id);
1339
1340                 local_irq_restore(flags);
1341                 enable_irq(irq);
1342         }
1343 #endif
1344         return retval;
1345 }
1346 EXPORT_SYMBOL(request_threaded_irq);
1347
1348 /**
1349  *      request_any_context_irq - allocate an interrupt line
1350  *      @irq: Interrupt line to allocate
1351  *      @handler: Function to be called when the IRQ occurs.
1352  *                Threaded handler for threaded interrupts.
1353  *      @flags: Interrupt type flags
1354  *      @name: An ascii name for the claiming device
1355  *      @dev_id: A cookie passed back to the handler function
1356  *
1357  *      This call allocates interrupt resources and enables the
1358  *      interrupt line and IRQ handling. It selects either a
1359  *      hardirq or threaded handling method depending on the
1360  *      context.
1361  *
1362  *      On failure, it returns a negative value. On success,
1363  *      it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
1364  */
1365 int request_any_context_irq(unsigned int irq, irq_handler_t handler,
1366                             unsigned long flags, const char *name, void *dev_id)
1367 {
1368         struct irq_desc *desc = irq_to_desc(irq);
1369         int ret;
1370
1371         if (!desc)
1372                 return -EINVAL;
1373
1374         if (irq_settings_is_nested_thread(desc)) {
1375                 ret = request_threaded_irq(irq, NULL, handler,
1376                                            flags, name, dev_id);
1377                 return !ret ? IRQC_IS_NESTED : ret;
1378         }
1379
1380         ret = request_irq(irq, handler, flags, name, dev_id);
1381         return !ret ? IRQC_IS_HARDIRQ : ret;
1382 }
1383 EXPORT_SYMBOL_GPL(request_any_context_irq);