linux/include/linux/interrupt.h
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   1/* SPDX-License-Identifier: GPL-2.0 */
   2/* interrupt.h */
   3#ifndef _LINUX_INTERRUPT_H
   4#define _LINUX_INTERRUPT_H
   5
   6#include <linux/kernel.h>
   7#include <linux/bitops.h>
   8#include <linux/cpumask.h>
   9#include <linux/irqreturn.h>
  10#include <linux/irqnr.h>
  11#include <linux/hardirq.h>
  12#include <linux/irqflags.h>
  13#include <linux/hrtimer.h>
  14#include <linux/kref.h>
  15#include <linux/workqueue.h>
  16
  17#include <linux/atomic.h>
  18#include <asm/ptrace.h>
  19#include <asm/irq.h>
  20#include <asm/sections.h>
  21
  22/*
  23 * These correspond to the IORESOURCE_IRQ_* defines in
  24 * linux/ioport.h to select the interrupt line behaviour.  When
  25 * requesting an interrupt without specifying a IRQF_TRIGGER, the
  26 * setting should be assumed to be "as already configured", which
  27 * may be as per machine or firmware initialisation.
  28 */
  29#define IRQF_TRIGGER_NONE       0x00000000
  30#define IRQF_TRIGGER_RISING     0x00000001
  31#define IRQF_TRIGGER_FALLING    0x00000002
  32#define IRQF_TRIGGER_HIGH       0x00000004
  33#define IRQF_TRIGGER_LOW        0x00000008
  34#define IRQF_TRIGGER_MASK       (IRQF_TRIGGER_HIGH | IRQF_TRIGGER_LOW | \
  35                                 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING)
  36#define IRQF_TRIGGER_PROBE      0x00000010
  37
  38/*
  39 * These flags used only by the kernel as part of the
  40 * irq handling routines.
  41 *
  42 * IRQF_SHARED - allow sharing the irq among several devices
  43 * IRQF_PROBE_SHARED - set by callers when they expect sharing mismatches to occur
  44 * IRQF_TIMER - Flag to mark this interrupt as timer interrupt
  45 * IRQF_PERCPU - Interrupt is per cpu
  46 * IRQF_NOBALANCING - Flag to exclude this interrupt from irq balancing
  47 * IRQF_IRQPOLL - Interrupt is used for polling (only the interrupt that is
  48 *                registered first in a shared interrupt is considered for
  49 *                performance reasons)
  50 * IRQF_ONESHOT - Interrupt is not reenabled after the hardirq handler finished.
  51 *                Used by threaded interrupts which need to keep the
  52 *                irq line disabled until the threaded handler has been run.
  53 * IRQF_NO_SUSPEND - Do not disable this IRQ during suspend.  Does not guarantee
  54 *                   that this interrupt will wake the system from a suspended
  55 *                   state.  See Documentation/power/suspend-and-interrupts.rst
  56 * IRQF_FORCE_RESUME - Force enable it on resume even if IRQF_NO_SUSPEND is set
  57 * IRQF_NO_THREAD - Interrupt cannot be threaded
  58 * IRQF_EARLY_RESUME - Resume IRQ early during syscore instead of at device
  59 *                resume time.
  60 * IRQF_COND_SUSPEND - If the IRQ is shared with a NO_SUSPEND user, execute this
  61 *                interrupt handler after suspending interrupts. For system
  62 *                wakeup devices users need to implement wakeup detection in
  63 *                their interrupt handlers.
  64 */
  65#define IRQF_SHARED             0x00000080
  66#define IRQF_PROBE_SHARED       0x00000100
  67#define __IRQF_TIMER            0x00000200
  68#define IRQF_PERCPU             0x00000400
  69#define IRQF_NOBALANCING        0x00000800
  70#define IRQF_IRQPOLL            0x00001000
  71#define IRQF_ONESHOT            0x00002000
  72#define IRQF_NO_SUSPEND         0x00004000
  73#define IRQF_FORCE_RESUME       0x00008000
  74#define IRQF_NO_THREAD          0x00010000
  75#define IRQF_EARLY_RESUME       0x00020000
  76#define IRQF_COND_SUSPEND       0x00040000
  77
  78#define IRQF_TIMER              (__IRQF_TIMER | IRQF_NO_SUSPEND | IRQF_NO_THREAD)
  79
  80/*
  81 * These values can be returned by request_any_context_irq() and
  82 * describe the context the interrupt will be run in.
  83 *
  84 * IRQC_IS_HARDIRQ - interrupt runs in hardirq context
  85 * IRQC_IS_NESTED - interrupt runs in a nested threaded context
  86 */
  87enum {
  88        IRQC_IS_HARDIRQ = 0,
  89        IRQC_IS_NESTED,
  90};
  91
  92typedef irqreturn_t (*irq_handler_t)(int, void *);
  93
  94/**
  95 * struct irqaction - per interrupt action descriptor
  96 * @handler:    interrupt handler function
  97 * @name:       name of the device
  98 * @dev_id:     cookie to identify the device
  99 * @percpu_dev_id:      cookie to identify the device
 100 * @next:       pointer to the next irqaction for shared interrupts
 101 * @irq:        interrupt number
 102 * @flags:      flags (see IRQF_* above)
 103 * @thread_fn:  interrupt handler function for threaded interrupts
 104 * @thread:     thread pointer for threaded interrupts
 105 * @secondary:  pointer to secondary irqaction (force threading)
 106 * @thread_flags:       flags related to @thread
 107 * @thread_mask:        bitmask for keeping track of @thread activity
 108 * @dir:        pointer to the proc/irq/NN/name entry
 109 */
 110struct irqaction {
 111        irq_handler_t           handler;
 112        void                    *dev_id;
 113        void __percpu           *percpu_dev_id;
 114        struct irqaction        *next;
 115        irq_handler_t           thread_fn;
 116        struct task_struct      *thread;
 117        struct irqaction        *secondary;
 118        unsigned int            irq;
 119        unsigned int            flags;
 120        unsigned long           thread_flags;
 121        unsigned long           thread_mask;
 122        const char              *name;
 123        struct proc_dir_entry   *dir;
 124} ____cacheline_internodealigned_in_smp;
 125
 126extern irqreturn_t no_action(int cpl, void *dev_id);
 127
 128/*
 129 * If a (PCI) device interrupt is not connected we set dev->irq to
 130 * IRQ_NOTCONNECTED. This causes request_irq() to fail with -ENOTCONN, so we
 131 * can distingiush that case from other error returns.
 132 *
 133 * 0x80000000 is guaranteed to be outside the available range of interrupts
 134 * and easy to distinguish from other possible incorrect values.
 135 */
 136#define IRQ_NOTCONNECTED        (1U << 31)
 137
 138extern int __must_check
 139request_threaded_irq(unsigned int irq, irq_handler_t handler,
 140                     irq_handler_t thread_fn,
 141                     unsigned long flags, const char *name, void *dev);
 142
 143static inline int __must_check
 144request_irq(unsigned int irq, irq_handler_t handler, unsigned long flags,
 145            const char *name, void *dev)
 146{
 147        return request_threaded_irq(irq, handler, NULL, flags, name, dev);
 148}
 149
 150extern int __must_check
 151request_any_context_irq(unsigned int irq, irq_handler_t handler,
 152                        unsigned long flags, const char *name, void *dev_id);
 153
 154extern int __must_check
 155__request_percpu_irq(unsigned int irq, irq_handler_t handler,
 156                     unsigned long flags, const char *devname,
 157                     void __percpu *percpu_dev_id);
 158
 159extern int __must_check
 160request_nmi(unsigned int irq, irq_handler_t handler, unsigned long flags,
 161            const char *name, void *dev);
 162
 163static inline int __must_check
 164request_percpu_irq(unsigned int irq, irq_handler_t handler,
 165                   const char *devname, void __percpu *percpu_dev_id)
 166{
 167        return __request_percpu_irq(irq, handler, 0,
 168                                    devname, percpu_dev_id);
 169}
 170
 171extern int __must_check
 172request_percpu_nmi(unsigned int irq, irq_handler_t handler,
 173                   const char *devname, void __percpu *dev);
 174
 175extern const void *free_irq(unsigned int, void *);
 176extern void free_percpu_irq(unsigned int, void __percpu *);
 177
 178extern const void *free_nmi(unsigned int irq, void *dev_id);
 179extern void free_percpu_nmi(unsigned int irq, void __percpu *percpu_dev_id);
 180
 181struct device;
 182
 183extern int __must_check
 184devm_request_threaded_irq(struct device *dev, unsigned int irq,
 185                          irq_handler_t handler, irq_handler_t thread_fn,
 186                          unsigned long irqflags, const char *devname,
 187                          void *dev_id);
 188
 189static inline int __must_check
 190devm_request_irq(struct device *dev, unsigned int irq, irq_handler_t handler,
 191                 unsigned long irqflags, const char *devname, void *dev_id)
 192{
 193        return devm_request_threaded_irq(dev, irq, handler, NULL, irqflags,
 194                                         devname, dev_id);
 195}
 196
 197extern int __must_check
 198devm_request_any_context_irq(struct device *dev, unsigned int irq,
 199                 irq_handler_t handler, unsigned long irqflags,
 200                 const char *devname, void *dev_id);
 201
 202extern void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id);
 203
 204/*
 205 * On lockdep we dont want to enable hardirqs in hardirq
 206 * context. Use local_irq_enable_in_hardirq() to annotate
 207 * kernel code that has to do this nevertheless (pretty much
 208 * the only valid case is for old/broken hardware that is
 209 * insanely slow).
 210 *
 211 * NOTE: in theory this might break fragile code that relies
 212 * on hardirq delivery - in practice we dont seem to have such
 213 * places left. So the only effect should be slightly increased
 214 * irqs-off latencies.
 215 */
 216#ifdef CONFIG_LOCKDEP
 217# define local_irq_enable_in_hardirq()  do { } while (0)
 218#else
 219# define local_irq_enable_in_hardirq()  local_irq_enable()
 220#endif
 221
 222extern void disable_irq_nosync(unsigned int irq);
 223extern bool disable_hardirq(unsigned int irq);
 224extern void disable_irq(unsigned int irq);
 225extern void disable_percpu_irq(unsigned int irq);
 226extern void enable_irq(unsigned int irq);
 227extern void enable_percpu_irq(unsigned int irq, unsigned int type);
 228extern bool irq_percpu_is_enabled(unsigned int irq);
 229extern void irq_wake_thread(unsigned int irq, void *dev_id);
 230
 231extern void disable_nmi_nosync(unsigned int irq);
 232extern void disable_percpu_nmi(unsigned int irq);
 233extern void enable_nmi(unsigned int irq);
 234extern void enable_percpu_nmi(unsigned int irq, unsigned int type);
 235extern int prepare_percpu_nmi(unsigned int irq);
 236extern void teardown_percpu_nmi(unsigned int irq);
 237
 238/* The following three functions are for the core kernel use only. */
 239extern void suspend_device_irqs(void);
 240extern void resume_device_irqs(void);
 241extern void rearm_wake_irq(unsigned int irq);
 242
 243/**
 244 * struct irq_affinity_notify - context for notification of IRQ affinity changes
 245 * @irq:                Interrupt to which notification applies
 246 * @kref:               Reference count, for internal use
 247 * @work:               Work item, for internal use
 248 * @notify:             Function to be called on change.  This will be
 249 *                      called in process context.
 250 * @release:            Function to be called on release.  This will be
 251 *                      called in process context.  Once registered, the
 252 *                      structure must only be freed when this function is
 253 *                      called or later.
 254 */
 255struct irq_affinity_notify {
 256        unsigned int irq;
 257        struct kref kref;
 258        struct work_struct work;
 259        void (*notify)(struct irq_affinity_notify *, const cpumask_t *mask);
 260        void (*release)(struct kref *ref);
 261};
 262
 263#define IRQ_AFFINITY_MAX_SETS  4
 264
 265/**
 266 * struct irq_affinity - Description for automatic irq affinity assignements
 267 * @pre_vectors:        Don't apply affinity to @pre_vectors at beginning of
 268 *                      the MSI(-X) vector space
 269 * @post_vectors:       Don't apply affinity to @post_vectors at end of
 270 *                      the MSI(-X) vector space
 271 * @nr_sets:            The number of interrupt sets for which affinity
 272 *                      spreading is required
 273 * @set_size:           Array holding the size of each interrupt set
 274 * @calc_sets:          Callback for calculating the number and size
 275 *                      of interrupt sets
 276 * @priv:               Private data for usage by @calc_sets, usually a
 277 *                      pointer to driver/device specific data.
 278 */
 279struct irq_affinity {
 280        unsigned int    pre_vectors;
 281        unsigned int    post_vectors;
 282        unsigned int    nr_sets;
 283        unsigned int    set_size[IRQ_AFFINITY_MAX_SETS];
 284        void            (*calc_sets)(struct irq_affinity *, unsigned int nvecs);
 285        void            *priv;
 286};
 287
 288/**
 289 * struct irq_affinity_desc - Interrupt affinity descriptor
 290 * @mask:       cpumask to hold the affinity assignment
 291 * @is_managed: 1 if the interrupt is managed internally
 292 */
 293struct irq_affinity_desc {
 294        struct cpumask  mask;
 295        unsigned int    is_managed : 1;
 296};
 297
 298#if defined(CONFIG_SMP)
 299
 300extern cpumask_var_t irq_default_affinity;
 301
 302/* Internal implementation. Use the helpers below */
 303extern int __irq_set_affinity(unsigned int irq, const struct cpumask *cpumask,
 304                              bool force);
 305
 306/**
 307 * irq_set_affinity - Set the irq affinity of a given irq
 308 * @irq:        Interrupt to set affinity
 309 * @cpumask:    cpumask
 310 *
 311 * Fails if cpumask does not contain an online CPU
 312 */
 313static inline int
 314irq_set_affinity(unsigned int irq, const struct cpumask *cpumask)
 315{
 316        return __irq_set_affinity(irq, cpumask, false);
 317}
 318
 319/**
 320 * irq_force_affinity - Force the irq affinity of a given irq
 321 * @irq:        Interrupt to set affinity
 322 * @cpumask:    cpumask
 323 *
 324 * Same as irq_set_affinity, but without checking the mask against
 325 * online cpus.
 326 *
 327 * Solely for low level cpu hotplug code, where we need to make per
 328 * cpu interrupts affine before the cpu becomes online.
 329 */
 330static inline int
 331irq_force_affinity(unsigned int irq, const struct cpumask *cpumask)
 332{
 333        return __irq_set_affinity(irq, cpumask, true);
 334}
 335
 336extern int irq_can_set_affinity(unsigned int irq);
 337extern int irq_select_affinity(unsigned int irq);
 338
 339extern int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m);
 340
 341extern int
 342irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify);
 343
 344struct irq_affinity_desc *
 345irq_create_affinity_masks(unsigned int nvec, struct irq_affinity *affd);
 346
 347unsigned int irq_calc_affinity_vectors(unsigned int minvec, unsigned int maxvec,
 348                                       const struct irq_affinity *affd);
 349
 350#else /* CONFIG_SMP */
 351
 352static inline int irq_set_affinity(unsigned int irq, const struct cpumask *m)
 353{
 354        return -EINVAL;
 355}
 356
 357static inline int irq_force_affinity(unsigned int irq, const struct cpumask *cpumask)
 358{
 359        return 0;
 360}
 361
 362static inline int irq_can_set_affinity(unsigned int irq)
 363{
 364        return 0;
 365}
 366
 367static inline int irq_select_affinity(unsigned int irq)  { return 0; }
 368
 369static inline int irq_set_affinity_hint(unsigned int irq,
 370                                        const struct cpumask *m)
 371{
 372        return -EINVAL;
 373}
 374
 375static inline int
 376irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
 377{
 378        return 0;
 379}
 380
 381static inline struct irq_affinity_desc *
 382irq_create_affinity_masks(unsigned int nvec, struct irq_affinity *affd)
 383{
 384        return NULL;
 385}
 386
 387static inline unsigned int
 388irq_calc_affinity_vectors(unsigned int minvec, unsigned int maxvec,
 389                          const struct irq_affinity *affd)
 390{
 391        return maxvec;
 392}
 393
 394#endif /* CONFIG_SMP */
 395
 396/*
 397 * Special lockdep variants of irq disabling/enabling.
 398 * These should be used for locking constructs that
 399 * know that a particular irq context which is disabled,
 400 * and which is the only irq-context user of a lock,
 401 * that it's safe to take the lock in the irq-disabled
 402 * section without disabling hardirqs.
 403 *
 404 * On !CONFIG_LOCKDEP they are equivalent to the normal
 405 * irq disable/enable methods.
 406 */
 407static inline void disable_irq_nosync_lockdep(unsigned int irq)
 408{
 409        disable_irq_nosync(irq);
 410#ifdef CONFIG_LOCKDEP
 411        local_irq_disable();
 412#endif
 413}
 414
 415static inline void disable_irq_nosync_lockdep_irqsave(unsigned int irq, unsigned long *flags)
 416{
 417        disable_irq_nosync(irq);
 418#ifdef CONFIG_LOCKDEP
 419        local_irq_save(*flags);
 420#endif
 421}
 422
 423static inline void disable_irq_lockdep(unsigned int irq)
 424{
 425        disable_irq(irq);
 426#ifdef CONFIG_LOCKDEP
 427        local_irq_disable();
 428#endif
 429}
 430
 431static inline void enable_irq_lockdep(unsigned int irq)
 432{
 433#ifdef CONFIG_LOCKDEP
 434        local_irq_enable();
 435#endif
 436        enable_irq(irq);
 437}
 438
 439static inline void enable_irq_lockdep_irqrestore(unsigned int irq, unsigned long *flags)
 440{
 441#ifdef CONFIG_LOCKDEP
 442        local_irq_restore(*flags);
 443#endif
 444        enable_irq(irq);
 445}
 446
 447/* IRQ wakeup (PM) control: */
 448extern int irq_set_irq_wake(unsigned int irq, unsigned int on);
 449
 450static inline int enable_irq_wake(unsigned int irq)
 451{
 452        return irq_set_irq_wake(irq, 1);
 453}
 454
 455static inline int disable_irq_wake(unsigned int irq)
 456{
 457        return irq_set_irq_wake(irq, 0);
 458}
 459
 460/*
 461 * irq_get_irqchip_state/irq_set_irqchip_state specific flags
 462 */
 463enum irqchip_irq_state {
 464        IRQCHIP_STATE_PENDING,          /* Is interrupt pending? */
 465        IRQCHIP_STATE_ACTIVE,           /* Is interrupt in progress? */
 466        IRQCHIP_STATE_MASKED,           /* Is interrupt masked? */
 467        IRQCHIP_STATE_LINE_LEVEL,       /* Is IRQ line high? */
 468};
 469
 470extern int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
 471                                 bool *state);
 472extern int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
 473                                 bool state);
 474
 475#ifdef CONFIG_IRQ_FORCED_THREADING
 476# ifdef CONFIG_PREEMPT_RT
 477#  define force_irqthreads      (true)
 478# else
 479extern bool force_irqthreads;
 480# endif
 481#else
 482#define force_irqthreads        (0)
 483#endif
 484
 485#ifndef local_softirq_pending
 486
 487#ifndef local_softirq_pending_ref
 488#define local_softirq_pending_ref irq_stat.__softirq_pending
 489#endif
 490
 491#define local_softirq_pending() (__this_cpu_read(local_softirq_pending_ref))
 492#define set_softirq_pending(x)  (__this_cpu_write(local_softirq_pending_ref, (x)))
 493#define or_softirq_pending(x)   (__this_cpu_or(local_softirq_pending_ref, (x)))
 494
 495#endif /* local_softirq_pending */
 496
 497/* Some architectures might implement lazy enabling/disabling of
 498 * interrupts. In some cases, such as stop_machine, we might want
 499 * to ensure that after a local_irq_disable(), interrupts have
 500 * really been disabled in hardware. Such architectures need to
 501 * implement the following hook.
 502 */
 503#ifndef hard_irq_disable
 504#define hard_irq_disable()      do { } while(0)
 505#endif
 506
 507/* PLEASE, avoid to allocate new softirqs, if you need not _really_ high
 508   frequency threaded job scheduling. For almost all the purposes
 509   tasklets are more than enough. F.e. all serial device BHs et
 510   al. should be converted to tasklets, not to softirqs.
 511 */
 512
 513enum
 514{
 515        HI_SOFTIRQ=0,
 516        TIMER_SOFTIRQ,
 517        NET_TX_SOFTIRQ,
 518        NET_RX_SOFTIRQ,
 519        BLOCK_SOFTIRQ,
 520        IRQ_POLL_SOFTIRQ,
 521        TASKLET_SOFTIRQ,
 522        SCHED_SOFTIRQ,
 523        HRTIMER_SOFTIRQ, /* Unused, but kept as tools rely on the
 524                            numbering. Sigh! */
 525        RCU_SOFTIRQ,    /* Preferable RCU should always be the last softirq */
 526
 527        NR_SOFTIRQS
 528};
 529
 530#define SOFTIRQ_STOP_IDLE_MASK (~(1 << RCU_SOFTIRQ))
 531
 532/* map softirq index to softirq name. update 'softirq_to_name' in
 533 * kernel/softirq.c when adding a new softirq.
 534 */
 535extern const char * const softirq_to_name[NR_SOFTIRQS];
 536
 537/* softirq mask and active fields moved to irq_cpustat_t in
 538 * asm/hardirq.h to get better cache usage.  KAO
 539 */
 540
 541struct softirq_action
 542{
 543        void    (*action)(struct softirq_action *);
 544};
 545
 546asmlinkage void do_softirq(void);
 547asmlinkage void __do_softirq(void);
 548
 549#ifdef __ARCH_HAS_DO_SOFTIRQ
 550void do_softirq_own_stack(void);
 551#else
 552static inline void do_softirq_own_stack(void)
 553{
 554        __do_softirq();
 555}
 556#endif
 557
 558extern void open_softirq(int nr, void (*action)(struct softirq_action *));
 559extern void softirq_init(void);
 560extern void __raise_softirq_irqoff(unsigned int nr);
 561
 562extern void raise_softirq_irqoff(unsigned int nr);
 563extern void raise_softirq(unsigned int nr);
 564
 565DECLARE_PER_CPU(struct task_struct *, ksoftirqd);
 566
 567static inline struct task_struct *this_cpu_ksoftirqd(void)
 568{
 569        return this_cpu_read(ksoftirqd);
 570}
 571
 572/* Tasklets --- multithreaded analogue of BHs.
 573
 574   Main feature differing them of generic softirqs: tasklet
 575   is running only on one CPU simultaneously.
 576
 577   Main feature differing them of BHs: different tasklets
 578   may be run simultaneously on different CPUs.
 579
 580   Properties:
 581   * If tasklet_schedule() is called, then tasklet is guaranteed
 582     to be executed on some cpu at least once after this.
 583   * If the tasklet is already scheduled, but its execution is still not
 584     started, it will be executed only once.
 585   * If this tasklet is already running on another CPU (or schedule is called
 586     from tasklet itself), it is rescheduled for later.
 587   * Tasklet is strictly serialized wrt itself, but not
 588     wrt another tasklets. If client needs some intertask synchronization,
 589     he makes it with spinlocks.
 590 */
 591
 592struct tasklet_struct
 593{
 594        struct tasklet_struct *next;
 595        unsigned long state;
 596        atomic_t count;
 597        void (*func)(unsigned long);
 598        unsigned long data;
 599};
 600
 601#define DECLARE_TASKLET(name, func, data) \
 602struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(0), func, data }
 603
 604#define DECLARE_TASKLET_DISABLED(name, func, data) \
 605struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(1), func, data }
 606
 607
 608enum
 609{
 610        TASKLET_STATE_SCHED,    /* Tasklet is scheduled for execution */
 611        TASKLET_STATE_RUN       /* Tasklet is running (SMP only) */
 612};
 613
 614#ifdef CONFIG_SMP
 615static inline int tasklet_trylock(struct tasklet_struct *t)
 616{
 617        return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state);
 618}
 619
 620static inline void tasklet_unlock(struct tasklet_struct *t)
 621{
 622        smp_mb__before_atomic();
 623        clear_bit(TASKLET_STATE_RUN, &(t)->state);
 624}
 625
 626static inline void tasklet_unlock_wait(struct tasklet_struct *t)
 627{
 628        while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); }
 629}
 630#else
 631#define tasklet_trylock(t) 1
 632#define tasklet_unlock_wait(t) do { } while (0)
 633#define tasklet_unlock(t) do { } while (0)
 634#endif
 635
 636extern void __tasklet_schedule(struct tasklet_struct *t);
 637
 638static inline void tasklet_schedule(struct tasklet_struct *t)
 639{
 640        if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
 641                __tasklet_schedule(t);
 642}
 643
 644extern void __tasklet_hi_schedule(struct tasklet_struct *t);
 645
 646static inline void tasklet_hi_schedule(struct tasklet_struct *t)
 647{
 648        if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
 649                __tasklet_hi_schedule(t);
 650}
 651
 652static inline void tasklet_disable_nosync(struct tasklet_struct *t)
 653{
 654        atomic_inc(&t->count);
 655        smp_mb__after_atomic();
 656}
 657
 658static inline void tasklet_disable(struct tasklet_struct *t)
 659{
 660        tasklet_disable_nosync(t);
 661        tasklet_unlock_wait(t);
 662        smp_mb();
 663}
 664
 665static inline void tasklet_enable(struct tasklet_struct *t)
 666{
 667        smp_mb__before_atomic();
 668        atomic_dec(&t->count);
 669}
 670
 671extern void tasklet_kill(struct tasklet_struct *t);
 672extern void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu);
 673extern void tasklet_init(struct tasklet_struct *t,
 674                         void (*func)(unsigned long), unsigned long data);
 675
 676/*
 677 * Autoprobing for irqs:
 678 *
 679 * probe_irq_on() and probe_irq_off() provide robust primitives
 680 * for accurate IRQ probing during kernel initialization.  They are
 681 * reasonably simple to use, are not "fooled" by spurious interrupts,
 682 * and, unlike other attempts at IRQ probing, they do not get hung on
 683 * stuck interrupts (such as unused PS2 mouse interfaces on ASUS boards).
 684 *
 685 * For reasonably foolproof probing, use them as follows:
 686 *
 687 * 1. clear and/or mask the device's internal interrupt.
 688 * 2. sti();
 689 * 3. irqs = probe_irq_on();      // "take over" all unassigned idle IRQs
 690 * 4. enable the device and cause it to trigger an interrupt.
 691 * 5. wait for the device to interrupt, using non-intrusive polling or a delay.
 692 * 6. irq = probe_irq_off(irqs);  // get IRQ number, 0=none, negative=multiple
 693 * 7. service the device to clear its pending interrupt.
 694 * 8. loop again if paranoia is required.
 695 *
 696 * probe_irq_on() returns a mask of allocated irq's.
 697 *
 698 * probe_irq_off() takes the mask as a parameter,
 699 * and returns the irq number which occurred,
 700 * or zero if none occurred, or a negative irq number
 701 * if more than one irq occurred.
 702 */
 703
 704#if !defined(CONFIG_GENERIC_IRQ_PROBE) 
 705static inline unsigned long probe_irq_on(void)
 706{
 707        return 0;
 708}
 709static inline int probe_irq_off(unsigned long val)
 710{
 711        return 0;
 712}
 713static inline unsigned int probe_irq_mask(unsigned long val)
 714{
 715        return 0;
 716}
 717#else
 718extern unsigned long probe_irq_on(void);        /* returns 0 on failure */
 719extern int probe_irq_off(unsigned long);        /* returns 0 or negative on failure */
 720extern unsigned int probe_irq_mask(unsigned long);      /* returns mask of ISA interrupts */
 721#endif
 722
 723#ifdef CONFIG_PROC_FS
 724/* Initialize /proc/irq/ */
 725extern void init_irq_proc(void);
 726#else
 727static inline void init_irq_proc(void)
 728{
 729}
 730#endif
 731
 732#ifdef CONFIG_IRQ_TIMINGS
 733void irq_timings_enable(void);
 734void irq_timings_disable(void);
 735u64 irq_timings_next_event(u64 now);
 736#endif
 737
 738struct seq_file;
 739int show_interrupts(struct seq_file *p, void *v);
 740int arch_show_interrupts(struct seq_file *p, int prec);
 741
 742extern int early_irq_init(void);
 743extern int arch_probe_nr_irqs(void);
 744extern int arch_early_irq_init(void);
 745
 746/*
 747 * We want to know which function is an entrypoint of a hardirq or a softirq.
 748 */
 749#define __irq_entry              __attribute__((__section__(".irqentry.text")))
 750#define __softirq_entry  \
 751        __attribute__((__section__(".softirqentry.text")))
 752
 753#endif
 754