linux/kernel/irq/manage.c
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   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#define pr_fmt(fmt) "genirq: " fmt
  11
  12#include <linux/irq.h>
  13#include <linux/kthread.h>
  14#include <linux/module.h>
  15#include <linux/random.h>
  16#include <linux/interrupt.h>
  17#include <linux/slab.h>
  18#include <linux/sched.h>
  19#include <linux/sched/rt.h>
  20#include <linux/task_work.h>
  21
  22#include "internals.h"
  23
  24#ifdef CONFIG_IRQ_FORCED_THREADING
  25__read_mostly bool force_irqthreads;
  26
  27static int __init setup_forced_irqthreads(char *arg)
  28{
  29        force_irqthreads = true;
  30        return 0;
  31}
  32early_param("threadirqs", setup_forced_irqthreads);
  33#endif
  34
  35static void __synchronize_hardirq(struct irq_desc *desc)
  36{
  37        bool inprogress;
  38
  39        do {
  40                unsigned long flags;
  41
  42                /*
  43                 * Wait until we're out of the critical section.  This might
  44                 * give the wrong answer due to the lack of memory barriers.
  45                 */
  46                while (irqd_irq_inprogress(&desc->irq_data))
  47                        cpu_relax();
  48
  49                /* Ok, that indicated we're done: double-check carefully. */
  50                raw_spin_lock_irqsave(&desc->lock, flags);
  51                inprogress = irqd_irq_inprogress(&desc->irq_data);
  52                raw_spin_unlock_irqrestore(&desc->lock, flags);
  53
  54                /* Oops, that failed? */
  55        } while (inprogress);
  56}
  57
  58/**
  59 *      synchronize_hardirq - wait for pending hard IRQ handlers (on other CPUs)
  60 *      @irq: interrupt number to wait for
  61 *
  62 *      This function waits for any pending hard IRQ handlers for this
  63 *      interrupt to complete before returning. If you use this
  64 *      function while holding a resource the IRQ handler may need you
  65 *      will deadlock. It does not take associated threaded handlers
  66 *      into account.
  67 *
  68 *      Do not use this for shutdown scenarios where you must be sure
  69 *      that all parts (hardirq and threaded handler) have completed.
  70 *
  71 *      Returns: false if a threaded handler is active.
  72 *
  73 *      This function may be called - with care - from IRQ context.
  74 */
  75bool synchronize_hardirq(unsigned int irq)
  76{
  77        struct irq_desc *desc = irq_to_desc(irq);
  78
  79        if (desc) {
  80                __synchronize_hardirq(desc);
  81                return !atomic_read(&desc->threads_active);
  82        }
  83
  84        return true;
  85}
  86EXPORT_SYMBOL(synchronize_hardirq);
  87
  88/**
  89 *      synchronize_irq - wait for pending IRQ handlers (on other CPUs)
  90 *      @irq: interrupt number to wait for
  91 *
  92 *      This function waits for any pending IRQ handlers for this interrupt
  93 *      to complete before returning. If you use this function while
  94 *      holding a resource the IRQ handler may need you will deadlock.
  95 *
  96 *      This function may be called - with care - from IRQ context.
  97 */
  98void synchronize_irq(unsigned int irq)
  99{
 100        struct irq_desc *desc = irq_to_desc(irq);
 101
 102        if (desc) {
 103                __synchronize_hardirq(desc);
 104                /*
 105                 * We made sure that no hardirq handler is
 106                 * running. Now verify that no threaded handlers are
 107                 * active.
 108                 */
 109                wait_event(desc->wait_for_threads,
 110                           !atomic_read(&desc->threads_active));
 111        }
 112}
 113EXPORT_SYMBOL(synchronize_irq);
 114
 115#ifdef CONFIG_SMP
 116cpumask_var_t irq_default_affinity;
 117
 118static bool __irq_can_set_affinity(struct irq_desc *desc)
 119{
 120        if (!desc || !irqd_can_balance(&desc->irq_data) ||
 121            !desc->irq_data.chip || !desc->irq_data.chip->irq_set_affinity)
 122                return false;
 123        return true;
 124}
 125
 126/**
 127 *      irq_can_set_affinity - Check if the affinity of a given irq can be set
 128 *      @irq:           Interrupt to check
 129 *
 130 */
 131int irq_can_set_affinity(unsigned int irq)
 132{
 133        return __irq_can_set_affinity(irq_to_desc(irq));
 134}
 135
 136/**
 137 * irq_can_set_affinity_usr - Check if affinity of a irq can be set from user space
 138 * @irq:        Interrupt to check
 139 *
 140 * Like irq_can_set_affinity() above, but additionally checks for the
 141 * AFFINITY_MANAGED flag.
 142 */
 143bool irq_can_set_affinity_usr(unsigned int irq)
 144{
 145        struct irq_desc *desc = irq_to_desc(irq);
 146
 147        return __irq_can_set_affinity(desc) &&
 148                !irqd_affinity_is_managed(&desc->irq_data);
 149}
 150
 151/**
 152 *      irq_set_thread_affinity - Notify irq threads to adjust affinity
 153 *      @desc:          irq descriptor which has affitnity changed
 154 *
 155 *      We just set IRQTF_AFFINITY and delegate the affinity setting
 156 *      to the interrupt thread itself. We can not call
 157 *      set_cpus_allowed_ptr() here as we hold desc->lock and this
 158 *      code can be called from hard interrupt context.
 159 */
 160void irq_set_thread_affinity(struct irq_desc *desc)
 161{
 162        struct irqaction *action;
 163
 164        for_each_action_of_desc(desc, action)
 165                if (action->thread)
 166                        set_bit(IRQTF_AFFINITY, &action->thread_flags);
 167}
 168
 169#ifdef CONFIG_GENERIC_PENDING_IRQ
 170static inline bool irq_can_move_pcntxt(struct irq_data *data)
 171{
 172        return irqd_can_move_in_process_context(data);
 173}
 174static inline bool irq_move_pending(struct irq_data *data)
 175{
 176        return irqd_is_setaffinity_pending(data);
 177}
 178static inline void
 179irq_copy_pending(struct irq_desc *desc, const struct cpumask *mask)
 180{
 181        cpumask_copy(desc->pending_mask, mask);
 182}
 183static inline void
 184irq_get_pending(struct cpumask *mask, struct irq_desc *desc)
 185{
 186        cpumask_copy(mask, desc->pending_mask);
 187}
 188#else
 189static inline bool irq_can_move_pcntxt(struct irq_data *data) { return true; }
 190static inline bool irq_move_pending(struct irq_data *data) { return false; }
 191static inline void
 192irq_copy_pending(struct irq_desc *desc, const struct cpumask *mask) { }
 193static inline void
 194irq_get_pending(struct cpumask *mask, struct irq_desc *desc) { }
 195#endif
 196
 197int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
 198                        bool force)
 199{
 200        struct irq_desc *desc = irq_data_to_desc(data);
 201        struct irq_chip *chip = irq_data_get_irq_chip(data);
 202        int ret;
 203
 204        ret = chip->irq_set_affinity(data, mask, force);
 205        switch (ret) {
 206        case IRQ_SET_MASK_OK:
 207        case IRQ_SET_MASK_OK_DONE:
 208                cpumask_copy(desc->irq_common_data.affinity, mask);
 209        case IRQ_SET_MASK_OK_NOCOPY:
 210                irq_set_thread_affinity(desc);
 211                ret = 0;
 212        }
 213
 214        return ret;
 215}
 216
 217int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask,
 218                            bool force)
 219{
 220        struct irq_chip *chip = irq_data_get_irq_chip(data);
 221        struct irq_desc *desc = irq_data_to_desc(data);
 222        int ret = 0;
 223
 224        if (!chip || !chip->irq_set_affinity)
 225                return -EINVAL;
 226
 227        if (irq_can_move_pcntxt(data)) {
 228                ret = irq_do_set_affinity(data, mask, force);
 229        } else {
 230                irqd_set_move_pending(data);
 231                irq_copy_pending(desc, mask);
 232        }
 233
 234        if (desc->affinity_notify) {
 235                kref_get(&desc->affinity_notify->kref);
 236                schedule_work(&desc->affinity_notify->work);
 237        }
 238        irqd_set(data, IRQD_AFFINITY_SET);
 239
 240        return ret;
 241}
 242
 243int __irq_set_affinity(unsigned int irq, const struct cpumask *mask, bool force)
 244{
 245        struct irq_desc *desc = irq_to_desc(irq);
 246        unsigned long flags;
 247        int ret;
 248
 249        if (!desc)
 250                return -EINVAL;
 251
 252        raw_spin_lock_irqsave(&desc->lock, flags);
 253        ret = irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask, force);
 254        raw_spin_unlock_irqrestore(&desc->lock, flags);
 255        return ret;
 256}
 257
 258int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
 259{
 260        unsigned long flags;
 261        struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
 262
 263        if (!desc)
 264                return -EINVAL;
 265        desc->affinity_hint = m;
 266        irq_put_desc_unlock(desc, flags);
 267        /* set the initial affinity to prevent every interrupt being on CPU0 */
 268        if (m)
 269                __irq_set_affinity(irq, m, false);
 270        return 0;
 271}
 272EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
 273
 274static void irq_affinity_notify(struct work_struct *work)
 275{
 276        struct irq_affinity_notify *notify =
 277                container_of(work, struct irq_affinity_notify, work);
 278        struct irq_desc *desc = irq_to_desc(notify->irq);
 279        cpumask_var_t cpumask;
 280        unsigned long flags;
 281
 282        if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL))
 283                goto out;
 284
 285        raw_spin_lock_irqsave(&desc->lock, flags);
 286        if (irq_move_pending(&desc->irq_data))
 287                irq_get_pending(cpumask, desc);
 288        else
 289                cpumask_copy(cpumask, desc->irq_common_data.affinity);
 290        raw_spin_unlock_irqrestore(&desc->lock, flags);
 291
 292        notify->notify(notify, cpumask);
 293
 294        free_cpumask_var(cpumask);
 295out:
 296        kref_put(&notify->kref, notify->release);
 297}
 298
 299/**
 300 *      irq_set_affinity_notifier - control notification of IRQ affinity changes
 301 *      @irq:           Interrupt for which to enable/disable notification
 302 *      @notify:        Context for notification, or %NULL to disable
 303 *                      notification.  Function pointers must be initialised;
 304 *                      the other fields will be initialised by this function.
 305 *
 306 *      Must be called in process context.  Notification may only be enabled
 307 *      after the IRQ is allocated and must be disabled before the IRQ is
 308 *      freed using free_irq().
 309 */
 310int
 311irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
 312{
 313        struct irq_desc *desc = irq_to_desc(irq);
 314        struct irq_affinity_notify *old_notify;
 315        unsigned long flags;
 316
 317        /* The release function is promised process context */
 318        might_sleep();
 319
 320        if (!desc)
 321                return -EINVAL;
 322
 323        /* Complete initialisation of *notify */
 324        if (notify) {
 325                notify->irq = irq;
 326                kref_init(&notify->kref);
 327                INIT_WORK(&notify->work, irq_affinity_notify);
 328        }
 329
 330        raw_spin_lock_irqsave(&desc->lock, flags);
 331        old_notify = desc->affinity_notify;
 332        desc->affinity_notify = notify;
 333        raw_spin_unlock_irqrestore(&desc->lock, flags);
 334
 335        if (old_notify)
 336                kref_put(&old_notify->kref, old_notify->release);
 337
 338        return 0;
 339}
 340EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
 341
 342#ifndef CONFIG_AUTO_IRQ_AFFINITY
 343/*
 344 * Generic version of the affinity autoselector.
 345 */
 346static int setup_affinity(struct irq_desc *desc, struct cpumask *mask)
 347{
 348        struct cpumask *set = irq_default_affinity;
 349        int node = irq_desc_get_node(desc);
 350
 351        /* Excludes PER_CPU and NO_BALANCE interrupts */
 352        if (!__irq_can_set_affinity(desc))
 353                return 0;
 354
 355        /*
 356         * Preserve the managed affinity setting and an userspace affinity
 357         * setup, but make sure that one of the targets is online.
 358         */
 359        if (irqd_affinity_is_managed(&desc->irq_data) ||
 360            irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
 361                if (cpumask_intersects(desc->irq_common_data.affinity,
 362                                       cpu_online_mask))
 363                        set = desc->irq_common_data.affinity;
 364                else
 365                        irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
 366        }
 367
 368        cpumask_and(mask, cpu_online_mask, set);
 369        if (node != NUMA_NO_NODE) {
 370                const struct cpumask *nodemask = cpumask_of_node(node);
 371
 372                /* make sure at least one of the cpus in nodemask is online */
 373                if (cpumask_intersects(mask, nodemask))
 374                        cpumask_and(mask, mask, nodemask);
 375        }
 376        irq_do_set_affinity(&desc->irq_data, mask, false);
 377        return 0;
 378}
 379#else
 380/* Wrapper for ALPHA specific affinity selector magic */
 381static inline int setup_affinity(struct irq_desc *d, struct cpumask *mask)
 382{
 383        return irq_select_affinity(irq_desc_get_irq(d));
 384}
 385#endif
 386
 387/*
 388 * Called when affinity is set via /proc/irq
 389 */
 390int irq_select_affinity_usr(unsigned int irq, struct cpumask *mask)
 391{
 392        struct irq_desc *desc = irq_to_desc(irq);
 393        unsigned long flags;
 394        int ret;
 395
 396        raw_spin_lock_irqsave(&desc->lock, flags);
 397        ret = setup_affinity(desc, mask);
 398        raw_spin_unlock_irqrestore(&desc->lock, flags);
 399        return ret;
 400}
 401
 402#else
 403static inline int
 404setup_affinity(struct irq_desc *desc, struct cpumask *mask)
 405{
 406        return 0;
 407}
 408#endif
 409
 410/**
 411 *      irq_set_vcpu_affinity - Set vcpu affinity for the interrupt
 412 *      @irq: interrupt number to set affinity
 413 *      @vcpu_info: vCPU specific data
 414 *
 415 *      This function uses the vCPU specific data to set the vCPU
 416 *      affinity for an irq. The vCPU specific data is passed from
 417 *      outside, such as KVM. One example code path is as below:
 418 *      KVM -> IOMMU -> irq_set_vcpu_affinity().
 419 */
 420int irq_set_vcpu_affinity(unsigned int irq, void *vcpu_info)
 421{
 422        unsigned long flags;
 423        struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
 424        struct irq_data *data;
 425        struct irq_chip *chip;
 426        int ret = -ENOSYS;
 427
 428        if (!desc)
 429                return -EINVAL;
 430
 431        data = irq_desc_get_irq_data(desc);
 432        chip = irq_data_get_irq_chip(data);
 433        if (chip && chip->irq_set_vcpu_affinity)
 434                ret = chip->irq_set_vcpu_affinity(data, vcpu_info);
 435        irq_put_desc_unlock(desc, flags);
 436
 437        return ret;
 438}
 439EXPORT_SYMBOL_GPL(irq_set_vcpu_affinity);
 440
 441void __disable_irq(struct irq_desc *desc)
 442{
 443        if (!desc->depth++)
 444                irq_disable(desc);
 445}
 446
 447static int __disable_irq_nosync(unsigned int irq)
 448{
 449        unsigned long flags;
 450        struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
 451
 452        if (!desc)
 453                return -EINVAL;
 454        __disable_irq(desc);
 455        irq_put_desc_busunlock(desc, flags);
 456        return 0;
 457}
 458
 459/**
 460 *      disable_irq_nosync - disable an irq without waiting
 461 *      @irq: Interrupt to disable
 462 *
 463 *      Disable the selected interrupt line.  Disables and Enables are
 464 *      nested.
 465 *      Unlike disable_irq(), this function does not ensure existing
 466 *      instances of the IRQ handler have completed before returning.
 467 *
 468 *      This function may be called from IRQ context.
 469 */
 470void disable_irq_nosync(unsigned int irq)
 471{
 472        __disable_irq_nosync(irq);
 473}
 474EXPORT_SYMBOL(disable_irq_nosync);
 475
 476/**
 477 *      disable_irq - disable an irq and wait for completion
 478 *      @irq: Interrupt to disable
 479 *
 480 *      Disable the selected interrupt line.  Enables and Disables are
 481 *      nested.
 482 *      This function waits for any pending IRQ handlers for this interrupt
 483 *      to complete before returning. If you use this function while
 484 *      holding a resource the IRQ handler may need you will deadlock.
 485 *
 486 *      This function may be called - with care - from IRQ context.
 487 */
 488void disable_irq(unsigned int irq)
 489{
 490        if (!__disable_irq_nosync(irq))
 491                synchronize_irq(irq);
 492}
 493EXPORT_SYMBOL(disable_irq);
 494
 495/**
 496 *      disable_hardirq - disables an irq and waits for hardirq completion
 497 *      @irq: Interrupt to disable
 498 *
 499 *      Disable the selected interrupt line.  Enables and Disables are
 500 *      nested.
 501 *      This function waits for any pending hard IRQ handlers for this
 502 *      interrupt to complete before returning. If you use this function while
 503 *      holding a resource the hard IRQ handler may need you will deadlock.
 504 *
 505 *      When used to optimistically disable an interrupt from atomic context
 506 *      the return value must be checked.
 507 *
 508 *      Returns: false if a threaded handler is active.
 509 *
 510 *      This function may be called - with care - from IRQ context.
 511 */
 512bool disable_hardirq(unsigned int irq)
 513{
 514        if (!__disable_irq_nosync(irq))
 515                return synchronize_hardirq(irq);
 516
 517        return false;
 518}
 519EXPORT_SYMBOL_GPL(disable_hardirq);
 520
 521void __enable_irq(struct irq_desc *desc)
 522{
 523        switch (desc->depth) {
 524        case 0:
 525 err_out:
 526                WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n",
 527                     irq_desc_get_irq(desc));
 528                break;
 529        case 1: {
 530                if (desc->istate & IRQS_SUSPENDED)
 531                        goto err_out;
 532                /* Prevent probing on this irq: */
 533                irq_settings_set_noprobe(desc);
 534                irq_enable(desc);
 535                check_irq_resend(desc);
 536                /* fall-through */
 537        }
 538        default:
 539                desc->depth--;
 540        }
 541}
 542
 543/**
 544 *      enable_irq - enable handling of an irq
 545 *      @irq: Interrupt to enable
 546 *
 547 *      Undoes the effect of one call to disable_irq().  If this
 548 *      matches the last disable, processing of interrupts on this
 549 *      IRQ line is re-enabled.
 550 *
 551 *      This function may be called from IRQ context only when
 552 *      desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL !
 553 */
 554void enable_irq(unsigned int irq)
 555{
 556        unsigned long flags;
 557        struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
 558
 559        if (!desc)
 560                return;
 561        if (WARN(!desc->irq_data.chip,
 562                 KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq))
 563                goto out;
 564
 565        __enable_irq(desc);
 566out:
 567        irq_put_desc_busunlock(desc, flags);
 568}
 569EXPORT_SYMBOL(enable_irq);
 570
 571static int set_irq_wake_real(unsigned int irq, unsigned int on)
 572{
 573        struct irq_desc *desc = irq_to_desc(irq);
 574        int ret = -ENXIO;
 575
 576        if (irq_desc_get_chip(desc)->flags &  IRQCHIP_SKIP_SET_WAKE)
 577                return 0;
 578
 579        if (desc->irq_data.chip->irq_set_wake)
 580                ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
 581
 582        return ret;
 583}
 584
 585/**
 586 *      irq_set_irq_wake - control irq power management wakeup
 587 *      @irq:   interrupt to control
 588 *      @on:    enable/disable power management wakeup
 589 *
 590 *      Enable/disable power management wakeup mode, which is
 591 *      disabled by default.  Enables and disables must match,
 592 *      just as they match for non-wakeup mode support.
 593 *
 594 *      Wakeup mode lets this IRQ wake the system from sleep
 595 *      states like "suspend to RAM".
 596 */
 597int irq_set_irq_wake(unsigned int irq, unsigned int on)
 598{
 599        unsigned long flags;
 600        struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
 601        int ret = 0;
 602
 603        if (!desc)
 604                return -EINVAL;
 605
 606        /* wakeup-capable irqs can be shared between drivers that
 607         * don't need to have the same sleep mode behaviors.
 608         */
 609        if (on) {
 610                if (desc->wake_depth++ == 0) {
 611                        ret = set_irq_wake_real(irq, on);
 612                        if (ret)
 613                                desc->wake_depth = 0;
 614                        else
 615                                irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE);
 616                }
 617        } else {
 618                if (desc->wake_depth == 0) {
 619                        WARN(1, "Unbalanced IRQ %d wake disable\n", irq);
 620                } else if (--desc->wake_depth == 0) {
 621                        ret = set_irq_wake_real(irq, on);
 622                        if (ret)
 623                                desc->wake_depth = 1;
 624                        else
 625                                irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE);
 626                }
 627        }
 628        irq_put_desc_busunlock(desc, flags);
 629        return ret;
 630}
 631EXPORT_SYMBOL(irq_set_irq_wake);
 632
 633/*
 634 * Internal function that tells the architecture code whether a
 635 * particular irq has been exclusively allocated or is available
 636 * for driver use.
 637 */
 638int can_request_irq(unsigned int irq, unsigned long irqflags)
 639{
 640        unsigned long flags;
 641        struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
 642        int canrequest = 0;
 643
 644        if (!desc)
 645                return 0;
 646
 647        if (irq_settings_can_request(desc)) {
 648                if (!desc->action ||
 649                    irqflags & desc->action->flags & IRQF_SHARED)
 650                        canrequest = 1;
 651        }
 652        irq_put_desc_unlock(desc, flags);
 653        return canrequest;
 654}
 655
 656int __irq_set_trigger(struct irq_desc *desc, unsigned long flags)
 657{
 658        struct irq_chip *chip = desc->irq_data.chip;
 659        int ret, unmask = 0;
 660
 661        if (!chip || !chip->irq_set_type) {
 662                /*
 663                 * IRQF_TRIGGER_* but the PIC does not support multiple
 664                 * flow-types?
 665                 */
 666                pr_debug("No set_type function for IRQ %d (%s)\n",
 667                         irq_desc_get_irq(desc),
 668                         chip ? (chip->name ? : "unknown") : "unknown");
 669                return 0;
 670        }
 671
 672        flags &= IRQ_TYPE_SENSE_MASK;
 673
 674        if (chip->flags & IRQCHIP_SET_TYPE_MASKED) {
 675                if (!irqd_irq_masked(&desc->irq_data))
 676                        mask_irq(desc);
 677                if (!irqd_irq_disabled(&desc->irq_data))
 678                        unmask = 1;
 679        }
 680
 681        /* caller masked out all except trigger mode flags */
 682        ret = chip->irq_set_type(&desc->irq_data, flags);
 683
 684        switch (ret) {
 685        case IRQ_SET_MASK_OK:
 686        case IRQ_SET_MASK_OK_DONE:
 687                irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK);
 688                irqd_set(&desc->irq_data, flags);
 689
 690        case IRQ_SET_MASK_OK_NOCOPY:
 691                flags = irqd_get_trigger_type(&desc->irq_data);
 692                irq_settings_set_trigger_mask(desc, flags);
 693                irqd_clear(&desc->irq_data, IRQD_LEVEL);
 694                irq_settings_clr_level(desc);
 695                if (flags & IRQ_TYPE_LEVEL_MASK) {
 696                        irq_settings_set_level(desc);
 697                        irqd_set(&desc->irq_data, IRQD_LEVEL);
 698                }
 699
 700                ret = 0;
 701                break;
 702        default:
 703                pr_err("Setting trigger mode %lu for irq %u failed (%pF)\n",
 704                       flags, irq_desc_get_irq(desc), chip->irq_set_type);
 705        }
 706        if (unmask)
 707                unmask_irq(desc);
 708        return ret;
 709}
 710
 711#ifdef CONFIG_HARDIRQS_SW_RESEND
 712int irq_set_parent(int irq, int parent_irq)
 713{
 714        unsigned long flags;
 715        struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0);
 716
 717        if (!desc)
 718                return -EINVAL;
 719
 720        desc->parent_irq = parent_irq;
 721
 722        irq_put_desc_unlock(desc, flags);
 723        return 0;
 724}
 725#endif
 726
 727/*
 728 * Default primary interrupt handler for threaded interrupts. Is
 729 * assigned as primary handler when request_threaded_irq is called
 730 * with handler == NULL. Useful for oneshot interrupts.
 731 */
 732static irqreturn_t irq_default_primary_handler(int irq, void *dev_id)
 733{
 734        return IRQ_WAKE_THREAD;
 735}
 736
 737/*
 738 * Primary handler for nested threaded interrupts. Should never be
 739 * called.
 740 */
 741static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id)
 742{
 743        WARN(1, "Primary handler called for nested irq %d\n", irq);
 744        return IRQ_NONE;
 745}
 746
 747static irqreturn_t irq_forced_secondary_handler(int irq, void *dev_id)
 748{
 749        WARN(1, "Secondary action handler called for irq %d\n", irq);
 750        return IRQ_NONE;
 751}
 752
 753static int irq_wait_for_interrupt(struct irqaction *action)
 754{
 755        set_current_state(TASK_INTERRUPTIBLE);
 756
 757        while (!kthread_should_stop()) {
 758
 759                if (test_and_clear_bit(IRQTF_RUNTHREAD,
 760                                       &action->thread_flags)) {
 761                        __set_current_state(TASK_RUNNING);
 762                        return 0;
 763                }
 764                schedule();
 765                set_current_state(TASK_INTERRUPTIBLE);
 766        }
 767        __set_current_state(TASK_RUNNING);
 768        return -1;
 769}
 770
 771/*
 772 * Oneshot interrupts keep the irq line masked until the threaded
 773 * handler finished. unmask if the interrupt has not been disabled and
 774 * is marked MASKED.
 775 */
 776static void irq_finalize_oneshot(struct irq_desc *desc,
 777                                 struct irqaction *action)
 778{
 779        if (!(desc->istate & IRQS_ONESHOT) ||
 780            action->handler == irq_forced_secondary_handler)
 781                return;
 782again:
 783        chip_bus_lock(desc);
 784        raw_spin_lock_irq(&desc->lock);
 785
 786        /*
 787         * Implausible though it may be we need to protect us against
 788         * the following scenario:
 789         *
 790         * The thread is faster done than the hard interrupt handler
 791         * on the other CPU. If we unmask the irq line then the
 792         * interrupt can come in again and masks the line, leaves due
 793         * to IRQS_INPROGRESS and the irq line is masked forever.
 794         *
 795         * This also serializes the state of shared oneshot handlers
 796         * versus "desc->threads_onehsot |= action->thread_mask;" in
 797         * irq_wake_thread(). See the comment there which explains the
 798         * serialization.
 799         */
 800        if (unlikely(irqd_irq_inprogress(&desc->irq_data))) {
 801                raw_spin_unlock_irq(&desc->lock);
 802                chip_bus_sync_unlock(desc);
 803                cpu_relax();
 804                goto again;
 805        }
 806
 807        /*
 808         * Now check again, whether the thread should run. Otherwise
 809         * we would clear the threads_oneshot bit of this thread which
 810         * was just set.
 811         */
 812        if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags))
 813                goto out_unlock;
 814
 815        desc->threads_oneshot &= ~action->thread_mask;
 816
 817        if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
 818            irqd_irq_masked(&desc->irq_data))
 819                unmask_threaded_irq(desc);
 820
 821out_unlock:
 822        raw_spin_unlock_irq(&desc->lock);
 823        chip_bus_sync_unlock(desc);
 824}
 825
 826#ifdef CONFIG_SMP
 827/*
 828 * Check whether we need to change the affinity of the interrupt thread.
 829 */
 830static void
 831irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
 832{
 833        cpumask_var_t mask;
 834        bool valid = true;
 835
 836        if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags))
 837                return;
 838
 839        /*
 840         * In case we are out of memory we set IRQTF_AFFINITY again and
 841         * try again next time
 842         */
 843        if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
 844                set_bit(IRQTF_AFFINITY, &action->thread_flags);
 845                return;
 846        }
 847
 848        raw_spin_lock_irq(&desc->lock);
 849        /*
 850         * This code is triggered unconditionally. Check the affinity
 851         * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
 852         */
 853        if (desc->irq_common_data.affinity)
 854                cpumask_copy(mask, desc->irq_common_data.affinity);
 855        else
 856                valid = false;
 857        raw_spin_unlock_irq(&desc->lock);
 858
 859        if (valid)
 860                set_cpus_allowed_ptr(current, mask);
 861        free_cpumask_var(mask);
 862}
 863#else
 864static inline void
 865irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
 866#endif
 867
 868/*
 869 * Interrupts which are not explicitely requested as threaded
 870 * interrupts rely on the implicit bh/preempt disable of the hard irq
 871 * context. So we need to disable bh here to avoid deadlocks and other
 872 * side effects.
 873 */
 874static irqreturn_t
 875irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
 876{
 877        irqreturn_t ret;
 878
 879        local_bh_disable();
 880        ret = action->thread_fn(action->irq, action->dev_id);
 881        irq_finalize_oneshot(desc, action);
 882        local_bh_enable();
 883        return ret;
 884}
 885
 886/*
 887 * Interrupts explicitly requested as threaded interrupts want to be
 888 * preemtible - many of them need to sleep and wait for slow busses to
 889 * complete.
 890 */
 891static irqreturn_t irq_thread_fn(struct irq_desc *desc,
 892                struct irqaction *action)
 893{
 894        irqreturn_t ret;
 895
 896        ret = action->thread_fn(action->irq, action->dev_id);
 897        irq_finalize_oneshot(desc, action);
 898        return ret;
 899}
 900
 901static void wake_threads_waitq(struct irq_desc *desc)
 902{
 903        if (atomic_dec_and_test(&desc->threads_active))
 904                wake_up(&desc->wait_for_threads);
 905}
 906
 907static void irq_thread_dtor(struct callback_head *unused)
 908{
 909        struct task_struct *tsk = current;
 910        struct irq_desc *desc;
 911        struct irqaction *action;
 912
 913        if (WARN_ON_ONCE(!(current->flags & PF_EXITING)))
 914                return;
 915
 916        action = kthread_data(tsk);
 917
 918        pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
 919               tsk->comm, tsk->pid, action->irq);
 920
 921
 922        desc = irq_to_desc(action->irq);
 923        /*
 924         * If IRQTF_RUNTHREAD is set, we need to decrement
 925         * desc->threads_active and wake possible waiters.
 926         */
 927        if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags))
 928                wake_threads_waitq(desc);
 929
 930        /* Prevent a stale desc->threads_oneshot */
 931        irq_finalize_oneshot(desc, action);
 932}
 933
 934static void irq_wake_secondary(struct irq_desc *desc, struct irqaction *action)
 935{
 936        struct irqaction *secondary = action->secondary;
 937
 938        if (WARN_ON_ONCE(!secondary))
 939                return;
 940
 941        raw_spin_lock_irq(&desc->lock);
 942        __irq_wake_thread(desc, secondary);
 943        raw_spin_unlock_irq(&desc->lock);
 944}
 945
 946/*
 947 * Interrupt handler thread
 948 */
 949static int irq_thread(void *data)
 950{
 951        struct callback_head on_exit_work;
 952        struct irqaction *action = data;
 953        struct irq_desc *desc = irq_to_desc(action->irq);
 954        irqreturn_t (*handler_fn)(struct irq_desc *desc,
 955                        struct irqaction *action);
 956
 957        if (force_irqthreads && test_bit(IRQTF_FORCED_THREAD,
 958                                        &action->thread_flags))
 959                handler_fn = irq_forced_thread_fn;
 960        else
 961                handler_fn = irq_thread_fn;
 962
 963        init_task_work(&on_exit_work, irq_thread_dtor);
 964        task_work_add(current, &on_exit_work, false);
 965
 966        irq_thread_check_affinity(desc, action);
 967
 968        while (!irq_wait_for_interrupt(action)) {
 969                irqreturn_t action_ret;
 970
 971                irq_thread_check_affinity(desc, action);
 972
 973                action_ret = handler_fn(desc, action);
 974                if (action_ret == IRQ_HANDLED)
 975                        atomic_inc(&desc->threads_handled);
 976                if (action_ret == IRQ_WAKE_THREAD)
 977                        irq_wake_secondary(desc, action);
 978
 979                wake_threads_waitq(desc);
 980        }
 981
 982        /*
 983         * This is the regular exit path. __free_irq() is stopping the
 984         * thread via kthread_stop() after calling
 985         * synchronize_irq(). So neither IRQTF_RUNTHREAD nor the
 986         * oneshot mask bit can be set. We cannot verify that as we
 987         * cannot touch the oneshot mask at this point anymore as
 988         * __setup_irq() might have given out currents thread_mask
 989         * again.
 990         */
 991        task_work_cancel(current, irq_thread_dtor);
 992        return 0;
 993}
 994
 995/**
 996 *      irq_wake_thread - wake the irq thread for the action identified by dev_id
 997 *      @irq:           Interrupt line
 998 *      @dev_id:        Device identity for which the thread should be woken
 999 *
1000 */
1001void irq_wake_thread(unsigned int irq, void *dev_id)
1002{
1003        struct irq_desc *desc = irq_to_desc(irq);
1004        struct irqaction *action;
1005        unsigned long flags;
1006
1007        if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1008                return;
1009
1010        raw_spin_lock_irqsave(&desc->lock, flags);
1011        for_each_action_of_desc(desc, action) {
1012                if (action->dev_id == dev_id) {
1013                        if (action->thread)
1014                                __irq_wake_thread(desc, action);
1015                        break;
1016                }
1017        }
1018        raw_spin_unlock_irqrestore(&desc->lock, flags);
1019}
1020EXPORT_SYMBOL_GPL(irq_wake_thread);
1021
1022static int irq_setup_forced_threading(struct irqaction *new)
1023{
1024        if (!force_irqthreads)
1025                return 0;
1026        if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT))
1027                return 0;
1028
1029        new->flags |= IRQF_ONESHOT;
1030
1031        /*
1032         * Handle the case where we have a real primary handler and a
1033         * thread handler. We force thread them as well by creating a
1034         * secondary action.
1035         */
1036        if (new->handler != irq_default_primary_handler && new->thread_fn) {
1037                /* Allocate the secondary action */
1038                new->secondary = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1039                if (!new->secondary)
1040                        return -ENOMEM;
1041                new->secondary->handler = irq_forced_secondary_handler;
1042                new->secondary->thread_fn = new->thread_fn;
1043                new->secondary->dev_id = new->dev_id;
1044                new->secondary->irq = new->irq;
1045                new->secondary->name = new->name;
1046        }
1047        /* Deal with the primary handler */
1048        set_bit(IRQTF_FORCED_THREAD, &new->thread_flags);
1049        new->thread_fn = new->handler;
1050        new->handler = irq_default_primary_handler;
1051        return 0;
1052}
1053
1054static int irq_request_resources(struct irq_desc *desc)
1055{
1056        struct irq_data *d = &desc->irq_data;
1057        struct irq_chip *c = d->chip;
1058
1059        return c->irq_request_resources ? c->irq_request_resources(d) : 0;
1060}
1061
1062static void irq_release_resources(struct irq_desc *desc)
1063{
1064        struct irq_data *d = &desc->irq_data;
1065        struct irq_chip *c = d->chip;
1066
1067        if (c->irq_release_resources)
1068                c->irq_release_resources(d);
1069}
1070
1071static int
1072setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary)
1073{
1074        struct task_struct *t;
1075        struct sched_param param = {
1076                .sched_priority = MAX_USER_RT_PRIO/2,
1077        };
1078
1079        if (!secondary) {
1080                t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
1081                                   new->name);
1082        } else {
1083                t = kthread_create(irq_thread, new, "irq/%d-s-%s", irq,
1084                                   new->name);
1085                param.sched_priority -= 1;
1086        }
1087
1088        if (IS_ERR(t))
1089                return PTR_ERR(t);
1090
1091        sched_setscheduler_nocheck(t, SCHED_FIFO, &param);
1092
1093        /*
1094         * We keep the reference to the task struct even if
1095         * the thread dies to avoid that the interrupt code
1096         * references an already freed task_struct.
1097         */
1098        get_task_struct(t);
1099        new->thread = t;
1100        /*
1101         * Tell the thread to set its affinity. This is
1102         * important for shared interrupt handlers as we do
1103         * not invoke setup_affinity() for the secondary
1104         * handlers as everything is already set up. Even for
1105         * interrupts marked with IRQF_NO_BALANCE this is
1106         * correct as we want the thread to move to the cpu(s)
1107         * on which the requesting code placed the interrupt.
1108         */
1109        set_bit(IRQTF_AFFINITY, &new->thread_flags);
1110        return 0;
1111}
1112
1113/*
1114 * Internal function to register an irqaction - typically used to
1115 * allocate special interrupts that are part of the architecture.
1116 */
1117static int
1118__setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
1119{
1120        struct irqaction *old, **old_ptr;
1121        unsigned long flags, thread_mask = 0;
1122        int ret, nested, shared = 0;
1123        cpumask_var_t mask;
1124
1125        if (!desc)
1126                return -EINVAL;
1127
1128        if (desc->irq_data.chip == &no_irq_chip)
1129                return -ENOSYS;
1130        if (!try_module_get(desc->owner))
1131                return -ENODEV;
1132
1133        new->irq = irq;
1134
1135        /*
1136         * If the trigger type is not specified by the caller,
1137         * then use the default for this interrupt.
1138         */
1139        if (!(new->flags & IRQF_TRIGGER_MASK))
1140                new->flags |= irqd_get_trigger_type(&desc->irq_data);
1141
1142        /*
1143         * Check whether the interrupt nests into another interrupt
1144         * thread.
1145         */
1146        nested = irq_settings_is_nested_thread(desc);
1147        if (nested) {
1148                if (!new->thread_fn) {
1149                        ret = -EINVAL;
1150                        goto out_mput;
1151                }
1152                /*
1153                 * Replace the primary handler which was provided from
1154                 * the driver for non nested interrupt handling by the
1155                 * dummy function which warns when called.
1156                 */
1157                new->handler = irq_nested_primary_handler;
1158        } else {
1159                if (irq_settings_can_thread(desc)) {
1160                        ret = irq_setup_forced_threading(new);
1161                        if (ret)
1162                                goto out_mput;
1163                }
1164        }
1165
1166        /*
1167         * Create a handler thread when a thread function is supplied
1168         * and the interrupt does not nest into another interrupt
1169         * thread.
1170         */
1171        if (new->thread_fn && !nested) {
1172                ret = setup_irq_thread(new, irq, false);
1173                if (ret)
1174                        goto out_mput;
1175                if (new->secondary) {
1176                        ret = setup_irq_thread(new->secondary, irq, true);
1177                        if (ret)
1178                                goto out_thread;
1179                }
1180        }
1181
1182        if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
1183                ret = -ENOMEM;
1184                goto out_thread;
1185        }
1186
1187        /*
1188         * Drivers are often written to work w/o knowledge about the
1189         * underlying irq chip implementation, so a request for a
1190         * threaded irq without a primary hard irq context handler
1191         * requires the ONESHOT flag to be set. Some irq chips like
1192         * MSI based interrupts are per se one shot safe. Check the
1193         * chip flags, so we can avoid the unmask dance at the end of
1194         * the threaded handler for those.
1195         */
1196        if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)
1197                new->flags &= ~IRQF_ONESHOT;
1198
1199        /*
1200         * The following block of code has to be executed atomically
1201         */
1202        raw_spin_lock_irqsave(&desc->lock, flags);
1203        old_ptr = &desc->action;
1204        old = *old_ptr;
1205        if (old) {
1206                /*
1207                 * Can't share interrupts unless both agree to and are
1208                 * the same type (level, edge, polarity). So both flag
1209                 * fields must have IRQF_SHARED set and the bits which
1210                 * set the trigger type must match. Also all must
1211                 * agree on ONESHOT.
1212                 */
1213                if (!((old->flags & new->flags) & IRQF_SHARED) ||
1214                    ((old->flags ^ new->flags) & IRQF_TRIGGER_MASK) ||
1215                    ((old->flags ^ new->flags) & IRQF_ONESHOT))
1216                        goto mismatch;
1217
1218                /* All handlers must agree on per-cpuness */
1219                if ((old->flags & IRQF_PERCPU) !=
1220                    (new->flags & IRQF_PERCPU))
1221                        goto mismatch;
1222
1223                /* add new interrupt at end of irq queue */
1224                do {
1225                        /*
1226                         * Or all existing action->thread_mask bits,
1227                         * so we can find the next zero bit for this
1228                         * new action.
1229                         */
1230                        thread_mask |= old->thread_mask;
1231                        old_ptr = &old->next;
1232                        old = *old_ptr;
1233                } while (old);
1234                shared = 1;
1235        }
1236
1237        /*
1238         * Setup the thread mask for this irqaction for ONESHOT. For
1239         * !ONESHOT irqs the thread mask is 0 so we can avoid a
1240         * conditional in irq_wake_thread().
1241         */
1242        if (new->flags & IRQF_ONESHOT) {
1243                /*
1244                 * Unlikely to have 32 resp 64 irqs sharing one line,
1245                 * but who knows.
1246                 */
1247                if (thread_mask == ~0UL) {
1248                        ret = -EBUSY;
1249                        goto out_mask;
1250                }
1251                /*
1252                 * The thread_mask for the action is or'ed to
1253                 * desc->thread_active to indicate that the
1254                 * IRQF_ONESHOT thread handler has been woken, but not
1255                 * yet finished. The bit is cleared when a thread
1256                 * completes. When all threads of a shared interrupt
1257                 * line have completed desc->threads_active becomes
1258                 * zero and the interrupt line is unmasked. See
1259                 * handle.c:irq_wake_thread() for further information.
1260                 *
1261                 * If no thread is woken by primary (hard irq context)
1262                 * interrupt handlers, then desc->threads_active is
1263                 * also checked for zero to unmask the irq line in the
1264                 * affected hard irq flow handlers
1265                 * (handle_[fasteoi|level]_irq).
1266                 *
1267                 * The new action gets the first zero bit of
1268                 * thread_mask assigned. See the loop above which or's
1269                 * all existing action->thread_mask bits.
1270                 */
1271                new->thread_mask = 1 << ffz(thread_mask);
1272
1273        } else if (new->handler == irq_default_primary_handler &&
1274                   !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) {
1275                /*
1276                 * The interrupt was requested with handler = NULL, so
1277                 * we use the default primary handler for it. But it
1278                 * does not have the oneshot flag set. In combination
1279                 * with level interrupts this is deadly, because the
1280                 * default primary handler just wakes the thread, then
1281                 * the irq lines is reenabled, but the device still
1282                 * has the level irq asserted. Rinse and repeat....
1283                 *
1284                 * While this works for edge type interrupts, we play
1285                 * it safe and reject unconditionally because we can't
1286                 * say for sure which type this interrupt really
1287                 * has. The type flags are unreliable as the
1288                 * underlying chip implementation can override them.
1289                 */
1290                pr_err("Threaded irq requested with handler=NULL and !ONESHOT for irq %d\n",
1291                       irq);
1292                ret = -EINVAL;
1293                goto out_mask;
1294        }
1295
1296        if (!shared) {
1297                ret = irq_request_resources(desc);
1298                if (ret) {
1299                        pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
1300                               new->name, irq, desc->irq_data.chip->name);
1301                        goto out_mask;
1302                }
1303
1304                init_waitqueue_head(&desc->wait_for_threads);
1305
1306                /* Setup the type (level, edge polarity) if configured: */
1307                if (new->flags & IRQF_TRIGGER_MASK) {
1308                        ret = __irq_set_trigger(desc,
1309                                                new->flags & IRQF_TRIGGER_MASK);
1310
1311                        if (ret)
1312                                goto out_mask;
1313                }
1314
1315                desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
1316                                  IRQS_ONESHOT | IRQS_WAITING);
1317                irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
1318
1319                if (new->flags & IRQF_PERCPU) {
1320                        irqd_set(&desc->irq_data, IRQD_PER_CPU);
1321                        irq_settings_set_per_cpu(desc);
1322                }
1323
1324                if (new->flags & IRQF_ONESHOT)
1325                        desc->istate |= IRQS_ONESHOT;
1326
1327                if (irq_settings_can_autoenable(desc))
1328                        irq_startup(desc, true);
1329                else
1330                        /* Undo nested disables: */
1331                        desc->depth = 1;
1332
1333                /* Exclude IRQ from balancing if requested */
1334                if (new->flags & IRQF_NOBALANCING) {
1335                        irq_settings_set_no_balancing(desc);
1336                        irqd_set(&desc->irq_data, IRQD_NO_BALANCING);
1337                }
1338
1339                /* Set default affinity mask once everything is setup */
1340                setup_affinity(desc, mask);
1341
1342        } else if (new->flags & IRQF_TRIGGER_MASK) {
1343                unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
1344                unsigned int omsk = irq_settings_get_trigger_mask(desc);
1345
1346                if (nmsk != omsk)
1347                        /* hope the handler works with current  trigger mode */
1348                        pr_warn("irq %d uses trigger mode %u; requested %u\n",
1349                                irq, nmsk, omsk);
1350        }
1351
1352        *old_ptr = new;
1353
1354        irq_pm_install_action(desc, new);
1355
1356        /* Reset broken irq detection when installing new handler */
1357        desc->irq_count = 0;
1358        desc->irqs_unhandled = 0;
1359
1360        /*
1361         * Check whether we disabled the irq via the spurious handler
1362         * before. Reenable it and give it another chance.
1363         */
1364        if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) {
1365                desc->istate &= ~IRQS_SPURIOUS_DISABLED;
1366                __enable_irq(desc);
1367        }
1368
1369        raw_spin_unlock_irqrestore(&desc->lock, flags);
1370
1371        /*
1372         * Strictly no need to wake it up, but hung_task complains
1373         * when no hard interrupt wakes the thread up.
1374         */
1375        if (new->thread)
1376                wake_up_process(new->thread);
1377        if (new->secondary)
1378                wake_up_process(new->secondary->thread);
1379
1380        register_irq_proc(irq, desc);
1381        new->dir = NULL;
1382        register_handler_proc(irq, new);
1383        free_cpumask_var(mask);
1384
1385        return 0;
1386
1387mismatch:
1388        if (!(new->flags & IRQF_PROBE_SHARED)) {
1389                pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
1390                       irq, new->flags, new->name, old->flags, old->name);
1391#ifdef CONFIG_DEBUG_SHIRQ
1392                dump_stack();
1393#endif
1394        }
1395        ret = -EBUSY;
1396
1397out_mask:
1398        raw_spin_unlock_irqrestore(&desc->lock, flags);
1399        free_cpumask_var(mask);
1400
1401out_thread:
1402        if (new->thread) {
1403                struct task_struct *t = new->thread;
1404
1405                new->thread = NULL;
1406                kthread_stop(t);
1407                put_task_struct(t);
1408        }
1409        if (new->secondary && new->secondary->thread) {
1410                struct task_struct *t = new->secondary->thread;
1411
1412                new->secondary->thread = NULL;
1413                kthread_stop(t);
1414                put_task_struct(t);
1415        }
1416out_mput:
1417        module_put(desc->owner);
1418        return ret;
1419}
1420
1421/**
1422 *      setup_irq - setup an interrupt
1423 *      @irq: Interrupt line to setup
1424 *      @act: irqaction for the interrupt
1425 *
1426 * Used to statically setup interrupts in the early boot process.
1427 */
1428int setup_irq(unsigned int irq, struct irqaction *act)
1429{
1430        int retval;
1431        struct irq_desc *desc = irq_to_desc(irq);
1432
1433        if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1434                return -EINVAL;
1435
1436        retval = irq_chip_pm_get(&desc->irq_data);
1437        if (retval < 0)
1438                return retval;
1439
1440        chip_bus_lock(desc);
1441        retval = __setup_irq(irq, desc, act);
1442        chip_bus_sync_unlock(desc);
1443
1444        if (retval)
1445                irq_chip_pm_put(&desc->irq_data);
1446
1447        return retval;
1448}
1449EXPORT_SYMBOL_GPL(setup_irq);
1450
1451/*
1452 * Internal function to unregister an irqaction - used to free
1453 * regular and special interrupts that are part of the architecture.
1454 */
1455static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
1456{
1457        struct irq_desc *desc = irq_to_desc(irq);
1458        struct irqaction *action, **action_ptr;
1459        unsigned long flags;
1460
1461        WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1462
1463        if (!desc)
1464                return NULL;
1465
1466        chip_bus_lock(desc);
1467        raw_spin_lock_irqsave(&desc->lock, flags);
1468
1469        /*
1470         * There can be multiple actions per IRQ descriptor, find the right
1471         * one based on the dev_id:
1472         */
1473        action_ptr = &desc->action;
1474        for (;;) {
1475                action = *action_ptr;
1476
1477                if (!action) {
1478                        WARN(1, "Trying to free already-free IRQ %d\n", irq);
1479                        raw_spin_unlock_irqrestore(&desc->lock, flags);
1480                        chip_bus_sync_unlock(desc);
1481                        return NULL;
1482                }
1483
1484                if (action->dev_id == dev_id)
1485                        break;
1486                action_ptr = &action->next;
1487        }
1488
1489        /* Found it - now remove it from the list of entries: */
1490        *action_ptr = action->next;
1491
1492        irq_pm_remove_action(desc, action);
1493
1494        /* If this was the last handler, shut down the IRQ line: */
1495        if (!desc->action) {
1496                irq_settings_clr_disable_unlazy(desc);
1497                irq_shutdown(desc);
1498                irq_release_resources(desc);
1499        }
1500
1501#ifdef CONFIG_SMP
1502        /* make sure affinity_hint is cleaned up */
1503        if (WARN_ON_ONCE(desc->affinity_hint))
1504                desc->affinity_hint = NULL;
1505#endif
1506
1507        raw_spin_unlock_irqrestore(&desc->lock, flags);
1508        chip_bus_sync_unlock(desc);
1509
1510        unregister_handler_proc(irq, action);
1511
1512        /* Make sure it's not being used on another CPU: */
1513        synchronize_irq(irq);
1514
1515#ifdef CONFIG_DEBUG_SHIRQ
1516        /*
1517         * It's a shared IRQ -- the driver ought to be prepared for an IRQ
1518         * event to happen even now it's being freed, so let's make sure that
1519         * is so by doing an extra call to the handler ....
1520         *
1521         * ( We do this after actually deregistering it, to make sure that a
1522         *   'real' IRQ doesn't run in * parallel with our fake. )
1523         */
1524        if (action->flags & IRQF_SHARED) {
1525                local_irq_save(flags);
1526                action->handler(irq, dev_id);
1527                local_irq_restore(flags);
1528        }
1529#endif
1530
1531        if (action->thread) {
1532                kthread_stop(action->thread);
1533                put_task_struct(action->thread);
1534                if (action->secondary && action->secondary->thread) {
1535                        kthread_stop(action->secondary->thread);
1536                        put_task_struct(action->secondary->thread);
1537                }
1538        }
1539
1540        irq_chip_pm_put(&desc->irq_data);
1541        module_put(desc->owner);
1542        kfree(action->secondary);
1543        return action;
1544}
1545
1546/**
1547 *      remove_irq - free an interrupt
1548 *      @irq: Interrupt line to free
1549 *      @act: irqaction for the interrupt
1550 *
1551 * Used to remove interrupts statically setup by the early boot process.
1552 */
1553void remove_irq(unsigned int irq, struct irqaction *act)
1554{
1555        struct irq_desc *desc = irq_to_desc(irq);
1556
1557        if (desc && !WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1558            __free_irq(irq, act->dev_id);
1559}
1560EXPORT_SYMBOL_GPL(remove_irq);
1561
1562/**
1563 *      free_irq - free an interrupt allocated with request_irq
1564 *      @irq: Interrupt line to free
1565 *      @dev_id: Device identity to free
1566 *
1567 *      Remove an interrupt handler. The handler is removed and if the
1568 *      interrupt line is no longer in use by any driver it is disabled.
1569 *      On a shared IRQ the caller must ensure the interrupt is disabled
1570 *      on the card it drives before calling this function. The function
1571 *      does not return until any executing interrupts for this IRQ
1572 *      have completed.
1573 *
1574 *      This function must not be called from interrupt context.
1575 */
1576void free_irq(unsigned int irq, void *dev_id)
1577{
1578        struct irq_desc *desc = irq_to_desc(irq);
1579
1580        if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1581                return;
1582
1583#ifdef CONFIG_SMP
1584        if (WARN_ON(desc->affinity_notify))
1585                desc->affinity_notify = NULL;
1586#endif
1587
1588        kfree(__free_irq(irq, dev_id));
1589}
1590EXPORT_SYMBOL(free_irq);
1591
1592/**
1593 *      request_threaded_irq - allocate an interrupt line
1594 *      @irq: Interrupt line to allocate
1595 *      @handler: Function to be called when the IRQ occurs.
1596 *                Primary handler for threaded interrupts
1597 *                If NULL and thread_fn != NULL the default
1598 *                primary handler is installed
1599 *      @thread_fn: Function called from the irq handler thread
1600 *                  If NULL, no irq thread is created
1601 *      @irqflags: Interrupt type flags
1602 *      @devname: An ascii name for the claiming device
1603 *      @dev_id: A cookie passed back to the handler function
1604 *
1605 *      This call allocates interrupt resources and enables the
1606 *      interrupt line and IRQ handling. From the point this
1607 *      call is made your handler function may be invoked. Since
1608 *      your handler function must clear any interrupt the board
1609 *      raises, you must take care both to initialise your hardware
1610 *      and to set up the interrupt handler in the right order.
1611 *
1612 *      If you want to set up a threaded irq handler for your device
1613 *      then you need to supply @handler and @thread_fn. @handler is
1614 *      still called in hard interrupt context and has to check
1615 *      whether the interrupt originates from the device. If yes it
1616 *      needs to disable the interrupt on the device and return
1617 *      IRQ_WAKE_THREAD which will wake up the handler thread and run
1618 *      @thread_fn. This split handler design is necessary to support
1619 *      shared interrupts.
1620 *
1621 *      Dev_id must be globally unique. Normally the address of the
1622 *      device data structure is used as the cookie. Since the handler
1623 *      receives this value it makes sense to use it.
1624 *
1625 *      If your interrupt is shared you must pass a non NULL dev_id
1626 *      as this is required when freeing the interrupt.
1627 *
1628 *      Flags:
1629 *
1630 *      IRQF_SHARED             Interrupt is shared
1631 *      IRQF_TRIGGER_*          Specify active edge(s) or level
1632 *
1633 */
1634int request_threaded_irq(unsigned int irq, irq_handler_t handler,
1635                         irq_handler_t thread_fn, unsigned long irqflags,
1636                         const char *devname, void *dev_id)
1637{
1638        struct irqaction *action;
1639        struct irq_desc *desc;
1640        int retval;
1641
1642        if (irq == IRQ_NOTCONNECTED)
1643                return -ENOTCONN;
1644
1645        /*
1646         * Sanity-check: shared interrupts must pass in a real dev-ID,
1647         * otherwise we'll have trouble later trying to figure out
1648         * which interrupt is which (messes up the interrupt freeing
1649         * logic etc).
1650         *
1651         * Also IRQF_COND_SUSPEND only makes sense for shared interrupts and
1652         * it cannot be set along with IRQF_NO_SUSPEND.
1653         */
1654        if (((irqflags & IRQF_SHARED) && !dev_id) ||
1655            (!(irqflags & IRQF_SHARED) && (irqflags & IRQF_COND_SUSPEND)) ||
1656            ((irqflags & IRQF_NO_SUSPEND) && (irqflags & IRQF_COND_SUSPEND)))
1657                return -EINVAL;
1658
1659        desc = irq_to_desc(irq);
1660        if (!desc)
1661                return -EINVAL;
1662
1663        if (!irq_settings_can_request(desc) ||
1664            WARN_ON(irq_settings_is_per_cpu_devid(desc)))
1665                return -EINVAL;
1666
1667        if (!handler) {
1668                if (!thread_fn)
1669                        return -EINVAL;
1670                handler = irq_default_primary_handler;
1671        }
1672
1673        action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1674        if (!action)
1675                return -ENOMEM;
1676
1677        action->handler = handler;
1678        action->thread_fn = thread_fn;
1679        action->flags = irqflags;
1680        action->name = devname;
1681        action->dev_id = dev_id;
1682
1683        retval = irq_chip_pm_get(&desc->irq_data);
1684        if (retval < 0) {
1685                kfree(action);
1686                return retval;
1687        }
1688
1689        chip_bus_lock(desc);
1690        retval = __setup_irq(irq, desc, action);
1691        chip_bus_sync_unlock(desc);
1692
1693        if (retval) {
1694                irq_chip_pm_put(&desc->irq_data);
1695                kfree(action->secondary);
1696                kfree(action);
1697        }
1698
1699#ifdef CONFIG_DEBUG_SHIRQ_FIXME
1700        if (!retval && (irqflags & IRQF_SHARED)) {
1701                /*
1702                 * It's a shared IRQ -- the driver ought to be prepared for it
1703                 * to happen immediately, so let's make sure....
1704                 * We disable the irq to make sure that a 'real' IRQ doesn't
1705                 * run in parallel with our fake.
1706                 */
1707                unsigned long flags;
1708
1709                disable_irq(irq);
1710                local_irq_save(flags);
1711
1712                handler(irq, dev_id);
1713
1714                local_irq_restore(flags);
1715                enable_irq(irq);
1716        }
1717#endif
1718        return retval;
1719}
1720EXPORT_SYMBOL(request_threaded_irq);
1721
1722/**
1723 *      request_any_context_irq - allocate an interrupt line
1724 *      @irq: Interrupt line to allocate
1725 *      @handler: Function to be called when the IRQ occurs.
1726 *                Threaded handler for threaded interrupts.
1727 *      @flags: Interrupt type flags
1728 *      @name: An ascii name for the claiming device
1729 *      @dev_id: A cookie passed back to the handler function
1730 *
1731 *      This call allocates interrupt resources and enables the
1732 *      interrupt line and IRQ handling. It selects either a
1733 *      hardirq or threaded handling method depending on the
1734 *      context.
1735 *
1736 *      On failure, it returns a negative value. On success,
1737 *      it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED.
1738 */
1739int request_any_context_irq(unsigned int irq, irq_handler_t handler,
1740                            unsigned long flags, const char *name, void *dev_id)
1741{
1742        struct irq_desc *desc;
1743        int ret;
1744
1745        if (irq == IRQ_NOTCONNECTED)
1746                return -ENOTCONN;
1747
1748        desc = irq_to_desc(irq);
1749        if (!desc)
1750                return -EINVAL;
1751
1752        if (irq_settings_is_nested_thread(desc)) {
1753                ret = request_threaded_irq(irq, NULL, handler,
1754                                           flags, name, dev_id);
1755                return !ret ? IRQC_IS_NESTED : ret;
1756        }
1757
1758        ret = request_irq(irq, handler, flags, name, dev_id);
1759        return !ret ? IRQC_IS_HARDIRQ : ret;
1760}
1761EXPORT_SYMBOL_GPL(request_any_context_irq);
1762
1763void enable_percpu_irq(unsigned int irq, unsigned int type)
1764{
1765        unsigned int cpu = smp_processor_id();
1766        unsigned long flags;
1767        struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1768
1769        if (!desc)
1770                return;
1771
1772        /*
1773         * If the trigger type is not specified by the caller, then
1774         * use the default for this interrupt.
1775         */
1776        type &= IRQ_TYPE_SENSE_MASK;
1777        if (type == IRQ_TYPE_NONE)
1778                type = irqd_get_trigger_type(&desc->irq_data);
1779
1780        if (type != IRQ_TYPE_NONE) {
1781                int ret;
1782
1783                ret = __irq_set_trigger(desc, type);
1784
1785                if (ret) {
1786                        WARN(1, "failed to set type for IRQ%d\n", irq);
1787                        goto out;
1788                }
1789        }
1790
1791        irq_percpu_enable(desc, cpu);
1792out:
1793        irq_put_desc_unlock(desc, flags);
1794}
1795EXPORT_SYMBOL_GPL(enable_percpu_irq);
1796
1797/**
1798 * irq_percpu_is_enabled - Check whether the per cpu irq is enabled
1799 * @irq:        Linux irq number to check for
1800 *
1801 * Must be called from a non migratable context. Returns the enable
1802 * state of a per cpu interrupt on the current cpu.
1803 */
1804bool irq_percpu_is_enabled(unsigned int irq)
1805{
1806        unsigned int cpu = smp_processor_id();
1807        struct irq_desc *desc;
1808        unsigned long flags;
1809        bool is_enabled;
1810
1811        desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1812        if (!desc)
1813                return false;
1814
1815        is_enabled = cpumask_test_cpu(cpu, desc->percpu_enabled);
1816        irq_put_desc_unlock(desc, flags);
1817
1818        return is_enabled;
1819}
1820EXPORT_SYMBOL_GPL(irq_percpu_is_enabled);
1821
1822void disable_percpu_irq(unsigned int irq)
1823{
1824        unsigned int cpu = smp_processor_id();
1825        unsigned long flags;
1826        struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
1827
1828        if (!desc)
1829                return;
1830
1831        irq_percpu_disable(desc, cpu);
1832        irq_put_desc_unlock(desc, flags);
1833}
1834EXPORT_SYMBOL_GPL(disable_percpu_irq);
1835
1836/*
1837 * Internal function to unregister a percpu irqaction.
1838 */
1839static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id)
1840{
1841        struct irq_desc *desc = irq_to_desc(irq);
1842        struct irqaction *action;
1843        unsigned long flags;
1844
1845        WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
1846
1847        if (!desc)
1848                return NULL;
1849
1850        raw_spin_lock_irqsave(&desc->lock, flags);
1851
1852        action = desc->action;
1853        if (!action || action->percpu_dev_id != dev_id) {
1854                WARN(1, "Trying to free already-free IRQ %d\n", irq);
1855                goto bad;
1856        }
1857
1858        if (!cpumask_empty(desc->percpu_enabled)) {
1859                WARN(1, "percpu IRQ %d still enabled on CPU%d!\n",
1860                     irq, cpumask_first(desc->percpu_enabled));
1861                goto bad;
1862        }
1863
1864        /* Found it - now remove it from the list of entries: */
1865        desc->action = NULL;
1866
1867        raw_spin_unlock_irqrestore(&desc->lock, flags);
1868
1869        unregister_handler_proc(irq, action);
1870
1871        irq_chip_pm_put(&desc->irq_data);
1872        module_put(desc->owner);
1873        return action;
1874
1875bad:
1876        raw_spin_unlock_irqrestore(&desc->lock, flags);
1877        return NULL;
1878}
1879
1880/**
1881 *      remove_percpu_irq - free a per-cpu interrupt
1882 *      @irq: Interrupt line to free
1883 *      @act: irqaction for the interrupt
1884 *
1885 * Used to remove interrupts statically setup by the early boot process.
1886 */
1887void remove_percpu_irq(unsigned int irq, struct irqaction *act)
1888{
1889        struct irq_desc *desc = irq_to_desc(irq);
1890
1891        if (desc && irq_settings_is_per_cpu_devid(desc))
1892            __free_percpu_irq(irq, act->percpu_dev_id);
1893}
1894
1895/**
1896 *      free_percpu_irq - free an interrupt allocated with request_percpu_irq
1897 *      @irq: Interrupt line to free
1898 *      @dev_id: Device identity to free
1899 *
1900 *      Remove a percpu interrupt handler. The handler is removed, but
1901 *      the interrupt line is not disabled. This must be done on each
1902 *      CPU before calling this function. The function does not return
1903 *      until any executing interrupts for this IRQ have completed.
1904 *
1905 *      This function must not be called from interrupt context.
1906 */
1907void free_percpu_irq(unsigned int irq, void __percpu *dev_id)
1908{
1909        struct irq_desc *desc = irq_to_desc(irq);
1910
1911        if (!desc || !irq_settings_is_per_cpu_devid(desc))
1912                return;
1913
1914        chip_bus_lock(desc);
1915        kfree(__free_percpu_irq(irq, dev_id));
1916        chip_bus_sync_unlock(desc);
1917}
1918EXPORT_SYMBOL_GPL(free_percpu_irq);
1919
1920/**
1921 *      setup_percpu_irq - setup a per-cpu interrupt
1922 *      @irq: Interrupt line to setup
1923 *      @act: irqaction for the interrupt
1924 *
1925 * Used to statically setup per-cpu interrupts in the early boot process.
1926 */
1927int setup_percpu_irq(unsigned int irq, struct irqaction *act)
1928{
1929        struct irq_desc *desc = irq_to_desc(irq);
1930        int retval;
1931
1932        if (!desc || !irq_settings_is_per_cpu_devid(desc))
1933                return -EINVAL;
1934
1935        retval = irq_chip_pm_get(&desc->irq_data);
1936        if (retval < 0)
1937                return retval;
1938
1939        chip_bus_lock(desc);
1940        retval = __setup_irq(irq, desc, act);
1941        chip_bus_sync_unlock(desc);
1942
1943        if (retval)
1944                irq_chip_pm_put(&desc->irq_data);
1945
1946        return retval;
1947}
1948
1949/**
1950 *      request_percpu_irq - allocate a percpu interrupt line
1951 *      @irq: Interrupt line to allocate
1952 *      @handler: Function to be called when the IRQ occurs.
1953 *      @devname: An ascii name for the claiming device
1954 *      @dev_id: A percpu cookie passed back to the handler function
1955 *
1956 *      This call allocates interrupt resources and enables the
1957 *      interrupt on the local CPU. If the interrupt is supposed to be
1958 *      enabled on other CPUs, it has to be done on each CPU using
1959 *      enable_percpu_irq().
1960 *
1961 *      Dev_id must be globally unique. It is a per-cpu variable, and
1962 *      the handler gets called with the interrupted CPU's instance of
1963 *      that variable.
1964 */
1965int request_percpu_irq(unsigned int irq, irq_handler_t handler,
1966                       const char *devname, void __percpu *dev_id)
1967{
1968        struct irqaction *action;
1969        struct irq_desc *desc;
1970        int retval;
1971
1972        if (!dev_id)
1973                return -EINVAL;
1974
1975        desc = irq_to_desc(irq);
1976        if (!desc || !irq_settings_can_request(desc) ||
1977            !irq_settings_is_per_cpu_devid(desc))
1978                return -EINVAL;
1979
1980        action = kzalloc(sizeof(struct irqaction), GFP_KERNEL);
1981        if (!action)
1982                return -ENOMEM;
1983
1984        action->handler = handler;
1985        action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND;
1986        action->name = devname;
1987        action->percpu_dev_id = dev_id;
1988
1989        retval = irq_chip_pm_get(&desc->irq_data);
1990        if (retval < 0) {
1991                kfree(action);
1992                return retval;
1993        }
1994
1995        chip_bus_lock(desc);
1996        retval = __setup_irq(irq, desc, action);
1997        chip_bus_sync_unlock(desc);
1998
1999        if (retval) {
2000                irq_chip_pm_put(&desc->irq_data);
2001                kfree(action);
2002        }
2003
2004        return retval;
2005}
2006EXPORT_SYMBOL_GPL(request_percpu_irq);
2007
2008/**
2009 *      irq_get_irqchip_state - returns the irqchip state of a interrupt.
2010 *      @irq: Interrupt line that is forwarded to a VM
2011 *      @which: One of IRQCHIP_STATE_* the caller wants to know about
2012 *      @state: a pointer to a boolean where the state is to be storeed
2013 *
2014 *      This call snapshots the internal irqchip state of an
2015 *      interrupt, returning into @state the bit corresponding to
2016 *      stage @which
2017 *
2018 *      This function should be called with preemption disabled if the
2019 *      interrupt controller has per-cpu registers.
2020 */
2021int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2022                          bool *state)
2023{
2024        struct irq_desc *desc;
2025        struct irq_data *data;
2026        struct irq_chip *chip;
2027        unsigned long flags;
2028        int err = -EINVAL;
2029
2030        desc = irq_get_desc_buslock(irq, &flags, 0);
2031        if (!desc)
2032                return err;
2033
2034        data = irq_desc_get_irq_data(desc);
2035
2036        do {
2037                chip = irq_data_get_irq_chip(data);
2038                if (chip->irq_get_irqchip_state)
2039                        break;
2040#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2041                data = data->parent_data;
2042#else
2043                data = NULL;
2044#endif
2045        } while (data);
2046
2047        if (data)
2048                err = chip->irq_get_irqchip_state(data, which, state);
2049
2050        irq_put_desc_busunlock(desc, flags);
2051        return err;
2052}
2053EXPORT_SYMBOL_GPL(irq_get_irqchip_state);
2054
2055/**
2056 *      irq_set_irqchip_state - set the state of a forwarded interrupt.
2057 *      @irq: Interrupt line that is forwarded to a VM
2058 *      @which: State to be restored (one of IRQCHIP_STATE_*)
2059 *      @val: Value corresponding to @which
2060 *
2061 *      This call sets the internal irqchip state of an interrupt,
2062 *      depending on the value of @which.
2063 *
2064 *      This function should be called with preemption disabled if the
2065 *      interrupt controller has per-cpu registers.
2066 */
2067int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
2068                          bool val)
2069{
2070        struct irq_desc *desc;
2071        struct irq_data *data;
2072        struct irq_chip *chip;
2073        unsigned long flags;
2074        int err = -EINVAL;
2075
2076        desc = irq_get_desc_buslock(irq, &flags, 0);
2077        if (!desc)
2078                return err;
2079
2080        data = irq_desc_get_irq_data(desc);
2081
2082        do {
2083                chip = irq_data_get_irq_chip(data);
2084                if (chip->irq_set_irqchip_state)
2085                        break;
2086#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2087                data = data->parent_data;
2088#else
2089                data = NULL;
2090#endif
2091        } while (data);
2092
2093        if (data)
2094                err = chip->irq_set_irqchip_state(data, which, val);
2095
2096        irq_put_desc_busunlock(desc, flags);
2097        return err;
2098}
2099EXPORT_SYMBOL_GPL(irq_set_irqchip_state);
2100