linux/include/linux/interrupt.h
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   1/* interrupt.h */
   2#ifndef _LINUX_INTERRUPT_H
   3#define _LINUX_INTERRUPT_H
   4
   5#include <linux/kernel.h>
   6#include <linux/linkage.h>
   7#include <linux/bitops.h>
   8#include <linux/preempt.h>
   9#include <linux/cpumask.h>
  10#include <linux/irqreturn.h>
  11#include <linux/irqnr.h>
  12#include <linux/hardirq.h>
  13#include <linux/irqflags.h>
  14#include <linux/hrtimer.h>
  15#include <linux/kref.h>
  16#include <linux/workqueue.h>
  17
  18#include <linux/atomic.h>
  19#include <asm/ptrace.h>
  20#include <asm/irq.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 an 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.txt
  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 * @thread_flags:       flags related to @thread
 106 * @thread_mask:        bitmask for keeping track of @thread activity
 107 * @dir:        pointer to the proc/irq/NN/name entry
 108 */
 109struct irqaction {
 110        irq_handler_t           handler;
 111        void                    *dev_id;
 112        void __percpu           *percpu_dev_id;
 113        struct irqaction        *next;
 114        irq_handler_t           thread_fn;
 115        struct task_struct      *thread;
 116        unsigned int            irq;
 117        unsigned int            flags;
 118        unsigned long           thread_flags;
 119        unsigned long           thread_mask;
 120        const char              *name;
 121        struct proc_dir_entry   *dir;
 122} ____cacheline_internodealigned_in_smp;
 123
 124extern irqreturn_t no_action(int cpl, void *dev_id);
 125
 126extern int __must_check
 127request_threaded_irq(unsigned int irq, irq_handler_t handler,
 128                     irq_handler_t thread_fn,
 129                     unsigned long flags, const char *name, void *dev);
 130
 131static inline int __must_check
 132request_irq(unsigned int irq, irq_handler_t handler, unsigned long flags,
 133            const char *name, void *dev)
 134{
 135        return request_threaded_irq(irq, handler, NULL, flags, name, dev);
 136}
 137
 138extern int __must_check
 139request_any_context_irq(unsigned int irq, irq_handler_t handler,
 140                        unsigned long flags, const char *name, void *dev_id);
 141
 142extern int __must_check
 143request_percpu_irq(unsigned int irq, irq_handler_t handler,
 144                   const char *devname, void __percpu *percpu_dev_id);
 145
 146extern void free_irq(unsigned int, void *);
 147extern void free_percpu_irq(unsigned int, void __percpu *);
 148
 149struct device;
 150
 151extern int __must_check
 152devm_request_threaded_irq(struct device *dev, unsigned int irq,
 153                          irq_handler_t handler, irq_handler_t thread_fn,
 154                          unsigned long irqflags, const char *devname,
 155                          void *dev_id);
 156
 157static inline int __must_check
 158devm_request_irq(struct device *dev, unsigned int irq, irq_handler_t handler,
 159                 unsigned long irqflags, const char *devname, void *dev_id)
 160{
 161        return devm_request_threaded_irq(dev, irq, handler, NULL, irqflags,
 162                                         devname, dev_id);
 163}
 164
 165extern int __must_check
 166devm_request_any_context_irq(struct device *dev, unsigned int irq,
 167                 irq_handler_t handler, unsigned long irqflags,
 168                 const char *devname, void *dev_id);
 169
 170extern void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id);
 171
 172/*
 173 * On lockdep we dont want to enable hardirqs in hardirq
 174 * context. Use local_irq_enable_in_hardirq() to annotate
 175 * kernel code that has to do this nevertheless (pretty much
 176 * the only valid case is for old/broken hardware that is
 177 * insanely slow).
 178 *
 179 * NOTE: in theory this might break fragile code that relies
 180 * on hardirq delivery - in practice we dont seem to have such
 181 * places left. So the only effect should be slightly increased
 182 * irqs-off latencies.
 183 */
 184#ifdef CONFIG_LOCKDEP
 185# define local_irq_enable_in_hardirq()  do { } while (0)
 186#else
 187# define local_irq_enable_in_hardirq()  local_irq_enable()
 188#endif
 189
 190extern void disable_irq_nosync(unsigned int irq);
 191extern bool disable_hardirq(unsigned int irq);
 192extern void disable_irq(unsigned int irq);
 193extern void disable_percpu_irq(unsigned int irq);
 194extern void enable_irq(unsigned int irq);
 195extern void enable_percpu_irq(unsigned int irq, unsigned int type);
 196extern void irq_wake_thread(unsigned int irq, void *dev_id);
 197
 198/* The following three functions are for the core kernel use only. */
 199extern void suspend_device_irqs(void);
 200extern void resume_device_irqs(void);
 201
 202/**
 203 * struct irq_affinity_notify - context for notification of IRQ affinity changes
 204 * @irq:                Interrupt to which notification applies
 205 * @kref:               Reference count, for internal use
 206 * @work:               Work item, for internal use
 207 * @notify:             Function to be called on change.  This will be
 208 *                      called in process context.
 209 * @release:            Function to be called on release.  This will be
 210 *                      called in process context.  Once registered, the
 211 *                      structure must only be freed when this function is
 212 *                      called or later.
 213 */
 214struct irq_affinity_notify {
 215        unsigned int irq;
 216        struct kref kref;
 217        struct work_struct work;
 218        void (*notify)(struct irq_affinity_notify *, const cpumask_t *mask);
 219        void (*release)(struct kref *ref);
 220};
 221
 222#if defined(CONFIG_SMP)
 223
 224extern cpumask_var_t irq_default_affinity;
 225
 226/* Internal implementation. Use the helpers below */
 227extern int __irq_set_affinity(unsigned int irq, const struct cpumask *cpumask,
 228                              bool force);
 229
 230/**
 231 * irq_set_affinity - Set the irq affinity of a given irq
 232 * @irq:        Interrupt to set affinity
 233 * @cpumask:    cpumask
 234 *
 235 * Fails if cpumask does not contain an online CPU
 236 */
 237static inline int
 238irq_set_affinity(unsigned int irq, const struct cpumask *cpumask)
 239{
 240        return __irq_set_affinity(irq, cpumask, false);
 241}
 242
 243/**
 244 * irq_force_affinity - Force the irq affinity of a given irq
 245 * @irq:        Interrupt to set affinity
 246 * @cpumask:    cpumask
 247 *
 248 * Same as irq_set_affinity, but without checking the mask against
 249 * online cpus.
 250 *
 251 * Solely for low level cpu hotplug code, where we need to make per
 252 * cpu interrupts affine before the cpu becomes online.
 253 */
 254static inline int
 255irq_force_affinity(unsigned int irq, const struct cpumask *cpumask)
 256{
 257        return __irq_set_affinity(irq, cpumask, true);
 258}
 259
 260extern int irq_can_set_affinity(unsigned int irq);
 261extern int irq_select_affinity(unsigned int irq);
 262
 263extern int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m);
 264
 265extern int
 266irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify);
 267
 268#else /* CONFIG_SMP */
 269
 270static inline int irq_set_affinity(unsigned int irq, const struct cpumask *m)
 271{
 272        return -EINVAL;
 273}
 274
 275static inline int irq_force_affinity(unsigned int irq, const struct cpumask *cpumask)
 276{
 277        return 0;
 278}
 279
 280static inline int irq_can_set_affinity(unsigned int irq)
 281{
 282        return 0;
 283}
 284
 285static inline int irq_select_affinity(unsigned int irq)  { return 0; }
 286
 287static inline int irq_set_affinity_hint(unsigned int irq,
 288                                        const struct cpumask *m)
 289{
 290        return -EINVAL;
 291}
 292
 293static inline int
 294irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
 295{
 296        return 0;
 297}
 298#endif /* CONFIG_SMP */
 299
 300/*
 301 * Special lockdep variants of irq disabling/enabling.
 302 * These should be used for locking constructs that
 303 * know that a particular irq context which is disabled,
 304 * and which is the only irq-context user of a lock,
 305 * that it's safe to take the lock in the irq-disabled
 306 * section without disabling hardirqs.
 307 *
 308 * On !CONFIG_LOCKDEP they are equivalent to the normal
 309 * irq disable/enable methods.
 310 */
 311static inline void disable_irq_nosync_lockdep(unsigned int irq)
 312{
 313        disable_irq_nosync(irq);
 314#ifdef CONFIG_LOCKDEP
 315        local_irq_disable();
 316#endif
 317}
 318
 319static inline void disable_irq_nosync_lockdep_irqsave(unsigned int irq, unsigned long *flags)
 320{
 321        disable_irq_nosync(irq);
 322#ifdef CONFIG_LOCKDEP
 323        local_irq_save(*flags);
 324#endif
 325}
 326
 327static inline void disable_irq_lockdep(unsigned int irq)
 328{
 329        disable_irq(irq);
 330#ifdef CONFIG_LOCKDEP
 331        local_irq_disable();
 332#endif
 333}
 334
 335static inline void enable_irq_lockdep(unsigned int irq)
 336{
 337#ifdef CONFIG_LOCKDEP
 338        local_irq_enable();
 339#endif
 340        enable_irq(irq);
 341}
 342
 343static inline void enable_irq_lockdep_irqrestore(unsigned int irq, unsigned long *flags)
 344{
 345#ifdef CONFIG_LOCKDEP
 346        local_irq_restore(*flags);
 347#endif
 348        enable_irq(irq);
 349}
 350
 351/* IRQ wakeup (PM) control: */
 352extern int irq_set_irq_wake(unsigned int irq, unsigned int on);
 353
 354static inline int enable_irq_wake(unsigned int irq)
 355{
 356        return irq_set_irq_wake(irq, 1);
 357}
 358
 359static inline int disable_irq_wake(unsigned int irq)
 360{
 361        return irq_set_irq_wake(irq, 0);
 362}
 363
 364/*
 365 * irq_get_irqchip_state/irq_set_irqchip_state specific flags
 366 */
 367enum irqchip_irq_state {
 368        IRQCHIP_STATE_PENDING,          /* Is interrupt pending? */
 369        IRQCHIP_STATE_ACTIVE,           /* Is interrupt in progress? */
 370        IRQCHIP_STATE_MASKED,           /* Is interrupt masked? */
 371        IRQCHIP_STATE_LINE_LEVEL,       /* Is IRQ line high? */
 372};
 373
 374extern int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
 375                                 bool *state);
 376extern int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
 377                                 bool state);
 378
 379#ifdef CONFIG_IRQ_FORCED_THREADING
 380extern bool force_irqthreads;
 381#else
 382#define force_irqthreads        (0)
 383#endif
 384
 385#ifndef __ARCH_SET_SOFTIRQ_PENDING
 386#define set_softirq_pending(x) (local_softirq_pending() = (x))
 387#define or_softirq_pending(x)  (local_softirq_pending() |= (x))
 388#endif
 389
 390/* Some architectures might implement lazy enabling/disabling of
 391 * interrupts. In some cases, such as stop_machine, we might want
 392 * to ensure that after a local_irq_disable(), interrupts have
 393 * really been disabled in hardware. Such architectures need to
 394 * implement the following hook.
 395 */
 396#ifndef hard_irq_disable
 397#define hard_irq_disable()      do { } while(0)
 398#endif
 399
 400/* PLEASE, avoid to allocate new softirqs, if you need not _really_ high
 401   frequency threaded job scheduling. For almost all the purposes
 402   tasklets are more than enough. F.e. all serial device BHs et
 403   al. should be converted to tasklets, not to softirqs.
 404 */
 405
 406enum
 407{
 408        HI_SOFTIRQ=0,
 409        TIMER_SOFTIRQ,
 410        NET_TX_SOFTIRQ,
 411        NET_RX_SOFTIRQ,
 412        BLOCK_SOFTIRQ,
 413        BLOCK_IOPOLL_SOFTIRQ,
 414        TASKLET_SOFTIRQ,
 415        SCHED_SOFTIRQ,
 416        HRTIMER_SOFTIRQ,
 417        RCU_SOFTIRQ,    /* Preferable RCU should always be the last softirq */
 418
 419        NR_SOFTIRQS
 420};
 421
 422#define SOFTIRQ_STOP_IDLE_MASK (~(1 << RCU_SOFTIRQ))
 423
 424/* map softirq index to softirq name. update 'softirq_to_name' in
 425 * kernel/softirq.c when adding a new softirq.
 426 */
 427extern const char * const softirq_to_name[NR_SOFTIRQS];
 428
 429/* softirq mask and active fields moved to irq_cpustat_t in
 430 * asm/hardirq.h to get better cache usage.  KAO
 431 */
 432
 433struct softirq_action
 434{
 435        void    (*action)(struct softirq_action *);
 436};
 437
 438asmlinkage void do_softirq(void);
 439asmlinkage void __do_softirq(void);
 440
 441#ifdef __ARCH_HAS_DO_SOFTIRQ
 442void do_softirq_own_stack(void);
 443#else
 444static inline void do_softirq_own_stack(void)
 445{
 446        __do_softirq();
 447}
 448#endif
 449
 450extern void open_softirq(int nr, void (*action)(struct softirq_action *));
 451extern void softirq_init(void);
 452extern void __raise_softirq_irqoff(unsigned int nr);
 453
 454extern void raise_softirq_irqoff(unsigned int nr);
 455extern void raise_softirq(unsigned int nr);
 456
 457DECLARE_PER_CPU(struct task_struct *, ksoftirqd);
 458
 459static inline struct task_struct *this_cpu_ksoftirqd(void)
 460{
 461        return this_cpu_read(ksoftirqd);
 462}
 463
 464/* Tasklets --- multithreaded analogue of BHs.
 465
 466   Main feature differing them of generic softirqs: tasklet
 467   is running only on one CPU simultaneously.
 468
 469   Main feature differing them of BHs: different tasklets
 470   may be run simultaneously on different CPUs.
 471
 472   Properties:
 473   * If tasklet_schedule() is called, then tasklet is guaranteed
 474     to be executed on some cpu at least once after this.
 475   * If the tasklet is already scheduled, but its execution is still not
 476     started, it will be executed only once.
 477   * If this tasklet is already running on another CPU (or schedule is called
 478     from tasklet itself), it is rescheduled for later.
 479   * Tasklet is strictly serialized wrt itself, but not
 480     wrt another tasklets. If client needs some intertask synchronization,
 481     he makes it with spinlocks.
 482 */
 483
 484struct tasklet_struct
 485{
 486        struct tasklet_struct *next;
 487        unsigned long state;
 488        atomic_t count;
 489        void (*func)(unsigned long);
 490        unsigned long data;
 491};
 492
 493#define DECLARE_TASKLET(name, func, data) \
 494struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(0), func, data }
 495
 496#define DECLARE_TASKLET_DISABLED(name, func, data) \
 497struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(1), func, data }
 498
 499
 500enum
 501{
 502        TASKLET_STATE_SCHED,    /* Tasklet is scheduled for execution */
 503        TASKLET_STATE_RUN       /* Tasklet is running (SMP only) */
 504};
 505
 506#ifdef CONFIG_SMP
 507static inline int tasklet_trylock(struct tasklet_struct *t)
 508{
 509        return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state);
 510}
 511
 512static inline void tasklet_unlock(struct tasklet_struct *t)
 513{
 514        smp_mb__before_atomic();
 515        clear_bit(TASKLET_STATE_RUN, &(t)->state);
 516}
 517
 518static inline void tasklet_unlock_wait(struct tasklet_struct *t)
 519{
 520        while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); }
 521}
 522#else
 523#define tasklet_trylock(t) 1
 524#define tasklet_unlock_wait(t) do { } while (0)
 525#define tasklet_unlock(t) do { } while (0)
 526#endif
 527
 528extern void __tasklet_schedule(struct tasklet_struct *t);
 529
 530static inline void tasklet_schedule(struct tasklet_struct *t)
 531{
 532        if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
 533                __tasklet_schedule(t);
 534}
 535
 536extern void __tasklet_hi_schedule(struct tasklet_struct *t);
 537
 538static inline void tasklet_hi_schedule(struct tasklet_struct *t)
 539{
 540        if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
 541                __tasklet_hi_schedule(t);
 542}
 543
 544extern void __tasklet_hi_schedule_first(struct tasklet_struct *t);
 545
 546/*
 547 * This version avoids touching any other tasklets. Needed for kmemcheck
 548 * in order not to take any page faults while enqueueing this tasklet;
 549 * consider VERY carefully whether you really need this or
 550 * tasklet_hi_schedule()...
 551 */
 552static inline void tasklet_hi_schedule_first(struct tasklet_struct *t)
 553{
 554        if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
 555                __tasklet_hi_schedule_first(t);
 556}
 557
 558
 559static inline void tasklet_disable_nosync(struct tasklet_struct *t)
 560{
 561        atomic_inc(&t->count);
 562        smp_mb__after_atomic();
 563}
 564
 565static inline void tasklet_disable(struct tasklet_struct *t)
 566{
 567        tasklet_disable_nosync(t);
 568        tasklet_unlock_wait(t);
 569        smp_mb();
 570}
 571
 572static inline void tasklet_enable(struct tasklet_struct *t)
 573{
 574        smp_mb__before_atomic();
 575        atomic_dec(&t->count);
 576}
 577
 578extern void tasklet_kill(struct tasklet_struct *t);
 579extern void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu);
 580extern void tasklet_init(struct tasklet_struct *t,
 581                         void (*func)(unsigned long), unsigned long data);
 582
 583struct tasklet_hrtimer {
 584        struct hrtimer          timer;
 585        struct tasklet_struct   tasklet;
 586        enum hrtimer_restart    (*function)(struct hrtimer *);
 587};
 588
 589extern void
 590tasklet_hrtimer_init(struct tasklet_hrtimer *ttimer,
 591                     enum hrtimer_restart (*function)(struct hrtimer *),
 592                     clockid_t which_clock, enum hrtimer_mode mode);
 593
 594static inline
 595int tasklet_hrtimer_start(struct tasklet_hrtimer *ttimer, ktime_t time,
 596                          const enum hrtimer_mode mode)
 597{
 598        return hrtimer_start(&ttimer->timer, time, mode);
 599}
 600
 601static inline
 602void tasklet_hrtimer_cancel(struct tasklet_hrtimer *ttimer)
 603{
 604        hrtimer_cancel(&ttimer->timer);
 605        tasklet_kill(&ttimer->tasklet);
 606}
 607
 608/*
 609 * Autoprobing for irqs:
 610 *
 611 * probe_irq_on() and probe_irq_off() provide robust primitives
 612 * for accurate IRQ probing during kernel initialization.  They are
 613 * reasonably simple to use, are not "fooled" by spurious interrupts,
 614 * and, unlike other attempts at IRQ probing, they do not get hung on
 615 * stuck interrupts (such as unused PS2 mouse interfaces on ASUS boards).
 616 *
 617 * For reasonably foolproof probing, use them as follows:
 618 *
 619 * 1. clear and/or mask the device's internal interrupt.
 620 * 2. sti();
 621 * 3. irqs = probe_irq_on();      // "take over" all unassigned idle IRQs
 622 * 4. enable the device and cause it to trigger an interrupt.
 623 * 5. wait for the device to interrupt, using non-intrusive polling or a delay.
 624 * 6. irq = probe_irq_off(irqs);  // get IRQ number, 0=none, negative=multiple
 625 * 7. service the device to clear its pending interrupt.
 626 * 8. loop again if paranoia is required.
 627 *
 628 * probe_irq_on() returns a mask of allocated irq's.
 629 *
 630 * probe_irq_off() takes the mask as a parameter,
 631 * and returns the irq number which occurred,
 632 * or zero if none occurred, or a negative irq number
 633 * if more than one irq occurred.
 634 */
 635
 636#if !defined(CONFIG_GENERIC_IRQ_PROBE) 
 637static inline unsigned long probe_irq_on(void)
 638{
 639        return 0;
 640}
 641static inline int probe_irq_off(unsigned long val)
 642{
 643        return 0;
 644}
 645static inline unsigned int probe_irq_mask(unsigned long val)
 646{
 647        return 0;
 648}
 649#else
 650extern unsigned long probe_irq_on(void);        /* returns 0 on failure */
 651extern int probe_irq_off(unsigned long);        /* returns 0 or negative on failure */
 652extern unsigned int probe_irq_mask(unsigned long);      /* returns mask of ISA interrupts */
 653#endif
 654
 655#ifdef CONFIG_PROC_FS
 656/* Initialize /proc/irq/ */
 657extern void init_irq_proc(void);
 658#else
 659static inline void init_irq_proc(void)
 660{
 661}
 662#endif
 663
 664struct seq_file;
 665int show_interrupts(struct seq_file *p, void *v);
 666int arch_show_interrupts(struct seq_file *p, int prec);
 667
 668extern int early_irq_init(void);
 669extern int arch_probe_nr_irqs(void);
 670extern int arch_early_irq_init(void);
 671
 672#endif
 673