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/smp.h>
  15#include <linux/percpu.h>
  16#include <linux/hrtimer.h>
  17#include <linux/kref.h>
  18#include <linux/workqueue.h>
  19
  20#include <linux/atomic.h>
  21#include <asm/ptrace.h>
  22
  23/*
  24 * These correspond to the IORESOURCE_IRQ_* defines in
  25 * linux/ioport.h to select the interrupt line behaviour.  When
  26 * requesting an interrupt without specifying a IRQF_TRIGGER, the
  27 * setting should be assumed to be "as already configured", which
  28 * may be as per machine or firmware initialisation.
  29 */
  30#define IRQF_TRIGGER_NONE       0x00000000
  31#define IRQF_TRIGGER_RISING     0x00000001
  32#define IRQF_TRIGGER_FALLING    0x00000002
  33#define IRQF_TRIGGER_HIGH       0x00000004
  34#define IRQF_TRIGGER_LOW        0x00000008
  35#define IRQF_TRIGGER_MASK       (IRQF_TRIGGER_HIGH | IRQF_TRIGGER_LOW | \
  36                                 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING)
  37#define IRQF_TRIGGER_PROBE      0x00000010
  38
  39/*
  40 * These flags used only by the kernel as part of the
  41 * irq handling routines.
  42 *
  43 * IRQF_DISABLED - keep irqs disabled when calling the action handler.
  44 *                 DEPRECATED. This flag is a NOOP and scheduled to be removed
  45 * IRQF_SHARED - allow sharing the irq among several devices
  46 * IRQF_PROBE_SHARED - set by callers when they expect sharing mismatches to occur
  47 * IRQF_TIMER - Flag to mark this interrupt as timer interrupt
  48 * IRQF_PERCPU - Interrupt is per cpu
  49 * IRQF_NOBALANCING - Flag to exclude this interrupt from irq balancing
  50 * IRQF_IRQPOLL - Interrupt is used for polling (only the interrupt that is
  51 *                registered first in an shared interrupt is considered for
  52 *                performance reasons)
  53 * IRQF_ONESHOT - Interrupt is not reenabled after the hardirq handler finished.
  54 *                Used by threaded interrupts which need to keep the
  55 *                irq line disabled until the threaded handler has been run.
  56 * IRQF_NO_SUSPEND - Do not disable this IRQ during suspend
  57 * IRQF_FORCE_RESUME - Force enable it on resume even if IRQF_NO_SUSPEND is set
  58 * IRQF_NO_THREAD - Interrupt cannot be threaded
  59 * IRQF_EARLY_RESUME - Resume IRQ early during syscore instead of at device
  60 *                resume time.
  61 */
  62#define IRQF_DISABLED           0x00000020
  63#define IRQF_SHARED             0x00000080
  64#define IRQF_PROBE_SHARED       0x00000100
  65#define __IRQF_TIMER            0x00000200
  66#define IRQF_PERCPU             0x00000400
  67#define IRQF_NOBALANCING        0x00000800
  68#define IRQF_IRQPOLL            0x00001000
  69#define IRQF_ONESHOT            0x00002000
  70#define IRQF_NO_SUSPEND         0x00004000
  71#define IRQF_FORCE_RESUME       0x00008000
  72#define IRQF_NO_THREAD          0x00010000
  73#define IRQF_EARLY_RESUME       0x00020000
  74
  75#define IRQF_TIMER              (__IRQF_TIMER | IRQF_NO_SUSPEND | IRQF_NO_THREAD)
  76
  77/*
  78 * These values can be returned by request_any_context_irq() and
  79 * describe the context the interrupt will be run in.
  80 *
  81 * IRQC_IS_HARDIRQ - interrupt runs in hardirq context
  82 * IRQC_IS_NESTED - interrupt runs in a nested threaded context
  83 */
  84enum {
  85        IRQC_IS_HARDIRQ = 0,
  86        IRQC_IS_NESTED,
  87};
  88
  89typedef irqreturn_t (*irq_handler_t)(int, void *);
  90
  91/**
  92 * struct irqaction - per interrupt action descriptor
  93 * @handler:    interrupt handler function
  94 * @name:       name of the device
  95 * @dev_id:     cookie to identify the device
  96 * @percpu_dev_id:      cookie to identify the device
  97 * @next:       pointer to the next irqaction for shared interrupts
  98 * @irq:        interrupt number
  99 * @flags:      flags (see IRQF_* above)
 100 * @thread_fn:  interrupt handler function for threaded interrupts
 101 * @thread:     thread pointer for threaded interrupts
 102 * @thread_flags:       flags related to @thread
 103 * @thread_mask:        bitmask for keeping track of @thread activity
 104 * @dir:        pointer to the proc/irq/NN/name entry
 105 */
 106struct irqaction {
 107        irq_handler_t           handler;
 108        void                    *dev_id;
 109        void __percpu           *percpu_dev_id;
 110        struct irqaction        *next;
 111        irq_handler_t           thread_fn;
 112        struct task_struct      *thread;
 113        unsigned int            irq;
 114        unsigned int            flags;
 115        unsigned long           thread_flags;
 116        unsigned long           thread_mask;
 117        const char              *name;
 118        struct proc_dir_entry   *dir;
 119} ____cacheline_internodealigned_in_smp;
 120
 121extern irqreturn_t no_action(int cpl, void *dev_id);
 122
 123#ifdef CONFIG_GENERIC_HARDIRQS
 124extern int __must_check
 125request_threaded_irq(unsigned int irq, irq_handler_t handler,
 126                     irq_handler_t thread_fn,
 127                     unsigned long flags, const char *name, void *dev);
 128
 129static inline int __must_check
 130request_irq(unsigned int irq, irq_handler_t handler, unsigned long flags,
 131            const char *name, void *dev)
 132{
 133        return request_threaded_irq(irq, handler, NULL, flags, name, dev);
 134}
 135
 136extern int __must_check
 137request_any_context_irq(unsigned int irq, irq_handler_t handler,
 138                        unsigned long flags, const char *name, void *dev_id);
 139
 140extern int __must_check
 141request_percpu_irq(unsigned int irq, irq_handler_t handler,
 142                   const char *devname, void __percpu *percpu_dev_id);
 143#else
 144
 145extern int __must_check
 146request_irq(unsigned int irq, irq_handler_t handler, unsigned long flags,
 147            const char *name, void *dev);
 148
 149/*
 150 * Special function to avoid ifdeffery in kernel/irq/devres.c which
 151 * gets magically built by GENERIC_HARDIRQS=n architectures (sparc,
 152 * m68k). I really love these $@%#!* obvious Makefile references:
 153 * ../../../kernel/irq/devres.o
 154 */
 155static inline int __must_check
 156request_threaded_irq(unsigned int irq, irq_handler_t handler,
 157                     irq_handler_t thread_fn,
 158                     unsigned long flags, const char *name, void *dev)
 159{
 160        return request_irq(irq, handler, flags, name, dev);
 161}
 162
 163static inline int __must_check
 164request_any_context_irq(unsigned int irq, irq_handler_t handler,
 165                        unsigned long flags, const char *name, void *dev_id)
 166{
 167        return request_irq(irq, handler, flags, name, dev_id);
 168}
 169
 170static inline int __must_check
 171request_percpu_irq(unsigned int irq, irq_handler_t handler,
 172                   const char *devname, void __percpu *percpu_dev_id)
 173{
 174        return request_irq(irq, handler, 0, devname, percpu_dev_id);
 175}
 176#endif
 177
 178extern void free_irq(unsigned int, void *);
 179extern void free_percpu_irq(unsigned int, void __percpu *);
 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 void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id);
 198
 199/*
 200 * On lockdep we dont want to enable hardirqs in hardirq
 201 * context. Use local_irq_enable_in_hardirq() to annotate
 202 * kernel code that has to do this nevertheless (pretty much
 203 * the only valid case is for old/broken hardware that is
 204 * insanely slow).
 205 *
 206 * NOTE: in theory this might break fragile code that relies
 207 * on hardirq delivery - in practice we dont seem to have such
 208 * places left. So the only effect should be slightly increased
 209 * irqs-off latencies.
 210 */
 211#ifdef CONFIG_LOCKDEP
 212# define local_irq_enable_in_hardirq()  do { } while (0)
 213#else
 214# define local_irq_enable_in_hardirq()  local_irq_enable()
 215#endif
 216
 217extern void disable_irq_nosync(unsigned int irq);
 218extern void disable_irq(unsigned int irq);
 219extern void disable_percpu_irq(unsigned int irq);
 220extern void enable_irq(unsigned int irq);
 221extern void enable_percpu_irq(unsigned int irq, unsigned int type);
 222
 223/* The following three functions are for the core kernel use only. */
 224#ifdef CONFIG_GENERIC_HARDIRQS
 225extern void suspend_device_irqs(void);
 226extern void resume_device_irqs(void);
 227#ifdef CONFIG_PM_SLEEP
 228extern int check_wakeup_irqs(void);
 229#else
 230static inline int check_wakeup_irqs(void) { return 0; }
 231#endif
 232#else
 233static inline void suspend_device_irqs(void) { };
 234static inline void resume_device_irqs(void) { };
 235static inline int check_wakeup_irqs(void) { return 0; }
 236#endif
 237
 238#if defined(CONFIG_SMP) && defined(CONFIG_GENERIC_HARDIRQS)
 239
 240extern cpumask_var_t irq_default_affinity;
 241
 242extern int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask);
 243extern int irq_can_set_affinity(unsigned int irq);
 244extern int irq_select_affinity(unsigned int irq);
 245
 246extern int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m);
 247
 248/**
 249 * struct irq_affinity_notify - context for notification of IRQ affinity changes
 250 * @irq:                Interrupt to which notification applies
 251 * @kref:               Reference count, for internal use
 252 * @work:               Work item, for internal use
 253 * @notify:             Function to be called on change.  This will be
 254 *                      called in process context.
 255 * @release:            Function to be called on release.  This will be
 256 *                      called in process context.  Once registered, the
 257 *                      structure must only be freed when this function is
 258 *                      called or later.
 259 */
 260struct irq_affinity_notify {
 261        unsigned int irq;
 262        struct kref kref;
 263        struct work_struct work;
 264        void (*notify)(struct irq_affinity_notify *, const cpumask_t *mask);
 265        void (*release)(struct kref *ref);
 266};
 267
 268extern int
 269irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify);
 270
 271static inline void irq_run_affinity_notifiers(void)
 272{
 273        flush_scheduled_work();
 274}
 275
 276#else /* CONFIG_SMP */
 277
 278static inline int irq_set_affinity(unsigned int irq, const struct cpumask *m)
 279{
 280        return -EINVAL;
 281}
 282
 283static inline int irq_can_set_affinity(unsigned int irq)
 284{
 285        return 0;
 286}
 287
 288static inline int irq_select_affinity(unsigned int irq)  { return 0; }
 289
 290static inline int irq_set_affinity_hint(unsigned int irq,
 291                                        const struct cpumask *m)
 292{
 293        return -EINVAL;
 294}
 295#endif /* CONFIG_SMP && CONFIG_GENERIC_HARDIRQS */
 296
 297#ifdef CONFIG_GENERIC_HARDIRQS
 298/*
 299 * Special lockdep variants of irq disabling/enabling.
 300 * These should be used for locking constructs that
 301 * know that a particular irq context which is disabled,
 302 * and which is the only irq-context user of a lock,
 303 * that it's safe to take the lock in the irq-disabled
 304 * section without disabling hardirqs.
 305 *
 306 * On !CONFIG_LOCKDEP they are equivalent to the normal
 307 * irq disable/enable methods.
 308 */
 309static inline void disable_irq_nosync_lockdep(unsigned int irq)
 310{
 311        disable_irq_nosync(irq);
 312#ifdef CONFIG_LOCKDEP
 313        local_irq_disable();
 314#endif
 315}
 316
 317static inline void disable_irq_nosync_lockdep_irqsave(unsigned int irq, unsigned long *flags)
 318{
 319        disable_irq_nosync(irq);
 320#ifdef CONFIG_LOCKDEP
 321        local_irq_save(*flags);
 322#endif
 323}
 324
 325static inline void disable_irq_lockdep(unsigned int irq)
 326{
 327        disable_irq(irq);
 328#ifdef CONFIG_LOCKDEP
 329        local_irq_disable();
 330#endif
 331}
 332
 333static inline void enable_irq_lockdep(unsigned int irq)
 334{
 335#ifdef CONFIG_LOCKDEP
 336        local_irq_enable();
 337#endif
 338        enable_irq(irq);
 339}
 340
 341static inline void enable_irq_lockdep_irqrestore(unsigned int irq, unsigned long *flags)
 342{
 343#ifdef CONFIG_LOCKDEP
 344        local_irq_restore(*flags);
 345#endif
 346        enable_irq(irq);
 347}
 348
 349/* IRQ wakeup (PM) control: */
 350extern int irq_set_irq_wake(unsigned int irq, unsigned int on);
 351
 352static inline int enable_irq_wake(unsigned int irq)
 353{
 354        return irq_set_irq_wake(irq, 1);
 355}
 356
 357static inline int disable_irq_wake(unsigned int irq)
 358{
 359        return irq_set_irq_wake(irq, 0);
 360}
 361
 362#else /* !CONFIG_GENERIC_HARDIRQS */
 363/*
 364 * NOTE: non-genirq architectures, if they want to support the lock
 365 * validator need to define the methods below in their asm/irq.h
 366 * files, under an #ifdef CONFIG_LOCKDEP section.
 367 */
 368#ifndef CONFIG_LOCKDEP
 369#  define disable_irq_nosync_lockdep(irq)       disable_irq_nosync(irq)
 370#  define disable_irq_nosync_lockdep_irqsave(irq, flags) \
 371                                                disable_irq_nosync(irq)
 372#  define disable_irq_lockdep(irq)              disable_irq(irq)
 373#  define enable_irq_lockdep(irq)               enable_irq(irq)
 374#  define enable_irq_lockdep_irqrestore(irq, flags) \
 375                                                enable_irq(irq)
 376# endif
 377
 378static inline int enable_irq_wake(unsigned int irq)
 379{
 380        return 0;
 381}
 382
 383static inline int disable_irq_wake(unsigned int irq)
 384{
 385        return 0;
 386}
 387#endif /* CONFIG_GENERIC_HARDIRQS */
 388
 389
 390#ifdef CONFIG_IRQ_FORCED_THREADING
 391extern bool force_irqthreads;
 392#else
 393#define force_irqthreads        (0)
 394#endif
 395
 396#ifndef __ARCH_SET_SOFTIRQ_PENDING
 397#define set_softirq_pending(x) (local_softirq_pending() = (x))
 398#define or_softirq_pending(x)  (local_softirq_pending() |= (x))
 399#endif
 400
 401/* Some architectures might implement lazy enabling/disabling of
 402 * interrupts. In some cases, such as stop_machine, we might want
 403 * to ensure that after a local_irq_disable(), interrupts have
 404 * really been disabled in hardware. Such architectures need to
 405 * implement the following hook.
 406 */
 407#ifndef hard_irq_disable
 408#define hard_irq_disable()      do { } while(0)
 409#endif
 410
 411/* PLEASE, avoid to allocate new softirqs, if you need not _really_ high
 412   frequency threaded job scheduling. For almost all the purposes
 413   tasklets are more than enough. F.e. all serial device BHs et
 414   al. should be converted to tasklets, not to softirqs.
 415 */
 416
 417enum
 418{
 419        HI_SOFTIRQ=0,
 420        TIMER_SOFTIRQ,
 421        NET_TX_SOFTIRQ,
 422        NET_RX_SOFTIRQ,
 423        BLOCK_SOFTIRQ,
 424        BLOCK_IOPOLL_SOFTIRQ,
 425        TASKLET_SOFTIRQ,
 426        SCHED_SOFTIRQ,
 427        HRTIMER_SOFTIRQ,
 428        RCU_SOFTIRQ,    /* Preferable RCU should always be the last softirq */
 429
 430        NR_SOFTIRQS
 431};
 432
 433#define SOFTIRQ_STOP_IDLE_MASK (~(1 << RCU_SOFTIRQ))
 434
 435/* map softirq index to softirq name. update 'softirq_to_name' in
 436 * kernel/softirq.c when adding a new softirq.
 437 */
 438extern char *softirq_to_name[NR_SOFTIRQS];
 439
 440/* softirq mask and active fields moved to irq_cpustat_t in
 441 * asm/hardirq.h to get better cache usage.  KAO
 442 */
 443
 444struct softirq_action
 445{
 446        void    (*action)(struct softirq_action *);
 447};
 448
 449asmlinkage void do_softirq(void);
 450asmlinkage void __do_softirq(void);
 451extern void open_softirq(int nr, void (*action)(struct softirq_action *));
 452extern void softirq_init(void);
 453extern void __raise_softirq_irqoff(unsigned int nr);
 454
 455extern void raise_softirq_irqoff(unsigned int nr);
 456extern void raise_softirq(unsigned int nr);
 457
 458/* This is the worklist that queues up per-cpu softirq work.
 459 *
 460 * send_remote_sendirq() adds work to these lists, and
 461 * the softirq handler itself dequeues from them.  The queues
 462 * are protected by disabling local cpu interrupts and they must
 463 * only be accessed by the local cpu that they are for.
 464 */
 465DECLARE_PER_CPU(struct list_head [NR_SOFTIRQS], softirq_work_list);
 466
 467DECLARE_PER_CPU(struct task_struct *, ksoftirqd);
 468
 469static inline struct task_struct *this_cpu_ksoftirqd(void)
 470{
 471        return this_cpu_read(ksoftirqd);
 472}
 473
 474/* Try to send a softirq to a remote cpu.  If this cannot be done, the
 475 * work will be queued to the local cpu.
 476 */
 477extern void send_remote_softirq(struct call_single_data *cp, int cpu, int softirq);
 478
 479/* Like send_remote_softirq(), but the caller must disable local cpu interrupts
 480 * and compute the current cpu, passed in as 'this_cpu'.
 481 */
 482extern void __send_remote_softirq(struct call_single_data *cp, int cpu,
 483                                  int this_cpu, int softirq);
 484
 485/* Tasklets --- multithreaded analogue of BHs.
 486
 487   Main feature differing them of generic softirqs: tasklet
 488   is running only on one CPU simultaneously.
 489
 490   Main feature differing them of BHs: different tasklets
 491   may be run simultaneously on different CPUs.
 492
 493   Properties:
 494   * If tasklet_schedule() is called, then tasklet is guaranteed
 495     to be executed on some cpu at least once after this.
 496   * If the tasklet is already scheduled, but its execution is still not
 497     started, it will be executed only once.
 498   * If this tasklet is already running on another CPU (or schedule is called
 499     from tasklet itself), it is rescheduled for later.
 500   * Tasklet is strictly serialized wrt itself, but not
 501     wrt another tasklets. If client needs some intertask synchronization,
 502     he makes it with spinlocks.
 503 */
 504
 505struct tasklet_struct
 506{
 507        struct tasklet_struct *next;
 508        unsigned long state;
 509        atomic_t count;
 510        void (*func)(unsigned long);
 511        unsigned long data;
 512};
 513
 514#define DECLARE_TASKLET(name, func, data) \
 515struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(0), func, data }
 516
 517#define DECLARE_TASKLET_DISABLED(name, func, data) \
 518struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(1), func, data }
 519
 520
 521enum
 522{
 523        TASKLET_STATE_SCHED,    /* Tasklet is scheduled for execution */
 524        TASKLET_STATE_RUN       /* Tasklet is running (SMP only) */
 525};
 526
 527#ifdef CONFIG_SMP
 528static inline int tasklet_trylock(struct tasklet_struct *t)
 529{
 530        return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state);
 531}
 532
 533static inline void tasklet_unlock(struct tasklet_struct *t)
 534{
 535        smp_mb__before_clear_bit(); 
 536        clear_bit(TASKLET_STATE_RUN, &(t)->state);
 537}
 538
 539static inline void tasklet_unlock_wait(struct tasklet_struct *t)
 540{
 541        while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); }
 542}
 543#else
 544#define tasklet_trylock(t) 1
 545#define tasklet_unlock_wait(t) do { } while (0)
 546#define tasklet_unlock(t) do { } while (0)
 547#endif
 548
 549extern void __tasklet_schedule(struct tasklet_struct *t);
 550
 551static inline void tasklet_schedule(struct tasklet_struct *t)
 552{
 553        if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
 554                __tasklet_schedule(t);
 555}
 556
 557extern void __tasklet_hi_schedule(struct tasklet_struct *t);
 558
 559static inline void tasklet_hi_schedule(struct tasklet_struct *t)
 560{
 561        if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
 562                __tasklet_hi_schedule(t);
 563}
 564
 565extern void __tasklet_hi_schedule_first(struct tasklet_struct *t);
 566
 567/*
 568 * This version avoids touching any other tasklets. Needed for kmemcheck
 569 * in order not to take any page faults while enqueueing this tasklet;
 570 * consider VERY carefully whether you really need this or
 571 * tasklet_hi_schedule()...
 572 */
 573static inline void tasklet_hi_schedule_first(struct tasklet_struct *t)
 574{
 575        if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
 576                __tasklet_hi_schedule_first(t);
 577}
 578
 579
 580static inline void tasklet_disable_nosync(struct tasklet_struct *t)
 581{
 582        atomic_inc(&t->count);
 583        smp_mb__after_atomic_inc();
 584}
 585
 586static inline void tasklet_disable(struct tasklet_struct *t)
 587{
 588        tasklet_disable_nosync(t);
 589        tasklet_unlock_wait(t);
 590        smp_mb();
 591}
 592
 593static inline void tasklet_enable(struct tasklet_struct *t)
 594{
 595        smp_mb__before_atomic_dec();
 596        atomic_dec(&t->count);
 597}
 598
 599static inline void tasklet_hi_enable(struct tasklet_struct *t)
 600{
 601        smp_mb__before_atomic_dec();
 602        atomic_dec(&t->count);
 603}
 604
 605extern void tasklet_kill(struct tasklet_struct *t);
 606extern void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu);
 607extern void tasklet_init(struct tasklet_struct *t,
 608                         void (*func)(unsigned long), unsigned long data);
 609
 610struct tasklet_hrtimer {
 611        struct hrtimer          timer;
 612        struct tasklet_struct   tasklet;
 613        enum hrtimer_restart    (*function)(struct hrtimer *);
 614};
 615
 616extern void
 617tasklet_hrtimer_init(struct tasklet_hrtimer *ttimer,
 618                     enum hrtimer_restart (*function)(struct hrtimer *),
 619                     clockid_t which_clock, enum hrtimer_mode mode);
 620
 621static inline
 622int tasklet_hrtimer_start(struct tasklet_hrtimer *ttimer, ktime_t time,
 623                          const enum hrtimer_mode mode)
 624{
 625        return hrtimer_start(&ttimer->timer, time, mode);
 626}
 627
 628static inline
 629void tasklet_hrtimer_cancel(struct tasklet_hrtimer *ttimer)
 630{
 631        hrtimer_cancel(&ttimer->timer);
 632        tasklet_kill(&ttimer->tasklet);
 633}
 634
 635/*
 636 * Autoprobing for irqs:
 637 *
 638 * probe_irq_on() and probe_irq_off() provide robust primitives
 639 * for accurate IRQ probing during kernel initialization.  They are
 640 * reasonably simple to use, are not "fooled" by spurious interrupts,
 641 * and, unlike other attempts at IRQ probing, they do not get hung on
 642 * stuck interrupts (such as unused PS2 mouse interfaces on ASUS boards).
 643 *
 644 * For reasonably foolproof probing, use them as follows:
 645 *
 646 * 1. clear and/or mask the device's internal interrupt.
 647 * 2. sti();
 648 * 3. irqs = probe_irq_on();      // "take over" all unassigned idle IRQs
 649 * 4. enable the device and cause it to trigger an interrupt.
 650 * 5. wait for the device to interrupt, using non-intrusive polling or a delay.
 651 * 6. irq = probe_irq_off(irqs);  // get IRQ number, 0=none, negative=multiple
 652 * 7. service the device to clear its pending interrupt.
 653 * 8. loop again if paranoia is required.
 654 *
 655 * probe_irq_on() returns a mask of allocated irq's.
 656 *
 657 * probe_irq_off() takes the mask as a parameter,
 658 * and returns the irq number which occurred,
 659 * or zero if none occurred, or a negative irq number
 660 * if more than one irq occurred.
 661 */
 662
 663#if defined(CONFIG_GENERIC_HARDIRQS) && !defined(CONFIG_GENERIC_IRQ_PROBE) 
 664static inline unsigned long probe_irq_on(void)
 665{
 666        return 0;
 667}
 668static inline int probe_irq_off(unsigned long val)
 669{
 670        return 0;
 671}
 672static inline unsigned int probe_irq_mask(unsigned long val)
 673{
 674        return 0;
 675}
 676#else
 677extern unsigned long probe_irq_on(void);        /* returns 0 on failure */
 678extern int probe_irq_off(unsigned long);        /* returns 0 or negative on failure */
 679extern unsigned int probe_irq_mask(unsigned long);      /* returns mask of ISA interrupts */
 680#endif
 681
 682#ifdef CONFIG_PROC_FS
 683/* Initialize /proc/irq/ */
 684extern void init_irq_proc(void);
 685#else
 686static inline void init_irq_proc(void)
 687{
 688}
 689#endif
 690
 691struct seq_file;
 692int show_interrupts(struct seq_file *p, void *v);
 693int arch_show_interrupts(struct seq_file *p, int prec);
 694
 695extern int early_irq_init(void);
 696extern int arch_probe_nr_irqs(void);
 697extern int arch_early_irq_init(void);
 698
 699#endif
 700
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